Alterations in cat cerebrocortical capillary morphometrical parameters following K+-induced cerebrocortical swelling. Histochemical, electron microscopic, and morphometrical techniques were employed in the determination of the effects attributed to K+-induced cerebrocortical swelling on cat cerebrocortical capillary diameter, length, surface area, volume, and minimal intercapillary distance. Bilaterally exposed and intact temporoparietal cerebral cortices of 4 conditioned adult cats were simultaneously superfused with isotonic, artificial CSF containing 3.5 mM K+ (control) and 54 mM K+ experimental), for 1h at 37 degrees C with monitoring of systemic vital function, hematocrit, arterial blood gases, and determination of cerebrocortical tissue water content. The mean values for cerebrocapillary diameter were 5% (P less than 0.05) greater in swollen tissues when compared with comparable mean values determined for controls. The values for minimal intercapillary distance determined from control and experimental animals plotted as relative frequency histograms represented two distinct populations (P less than 0.005). The significance of altered capillary morphometric parameters are discussed in relation to K+-induced cerebrocortical swelling.


[Visuo-constructive disorders in right and left brain-damaged patients (author's transl)]. There seems to be some lack of agreement between clinical and experimental findings pertaining to the neurodynamic mechanisms of visuo-constructive disabilities in right and left brain-damaged patients. Clinical studies have revealed qualitative differences between drawing disabilities of right and left hemispheric origin, while experimental data suggest that the same mechanism underlies both types of constructional disorder. In order to reconcile these conflicting findings, the existence of "nuclear" impairment and more "peripheral" disturbances in constructional apraxia is suggested. Nuclear impairment seems to consist of a visuo-perceptive disorder independent of the hemispheric locus of lesion; peripheral disturbance could be different in right and left brain-damaged patients, motor and symbolic disorders being typical of left-sided lesions while unilateral spatial neglect would be characteristic of right hemispheric injuries.


Normal and benzo(a)pyrene-transformed fetal mouse brain cell. I. Tumorigenicity and immunochemical detection of glial fibrillary acidic protein. Primary cultures of whole brain and cortex cells origination from 14-day-old A/Jax or C3H mouse fetuses were treated with benzo(a)pyrene (B(a)P) for 24 h. After 7 to 8 passages a malignant transformation was observed in the chemically treated whole brain and cortex cultures. Control cultures of cortex remained non-transplantable during the whole experiment (up to 14 passages) whereas in the control cultures originating from whole brain a spontaneous transformation appeared after 11 passages. With horseradish peroxidase-labelled antibody, the specific glial fibrillary acidic protein (GFAP) was detected in both control and transformed total brain and cortex cultures, and in the tumors initiated by the in vitro transformed cells. This finding shows that glialike cells persisted after a long in vitro maintanance and transformation.


Normal and benzo(a)pyrene-transformed fetal mouse brain cells. II. Ultrastructural study. An ultrastructural study was performed on normal and Benzo(a)-pyrene(B(a)P)-transformed fetal mouse brain cells. Early subcultures of a strain initiated from whole brain presented three cell types in vitro: astroglial, poorly differentiated glial, and spongioblastic types. After B(a)P-treatment, there was an exclusive transformation and the growth of neuroglia sometimes without gliofibrillary maturation, but with the presence of glial fibrillary acidic protein (GFAP) in the cytoplasm. Early subcultures of another strain initiated from cortex only presented poorly differentiated neuroglial cells. After transformation, cell maturation as evidenced by gliofibrillogenesis and GFAP production by these cells was observed. In both cases, the potentiality of glial differentiation after in vitro malignant transformation by a chemical carcinogen seemed preserved.


Amniotic fluid phosphatidylinositol and phosphatidylglycerol. I. Normal pregnancies. Phosphatidylinositol (PI) and phosphatidylglycerol (PG) appear normally in the amniotic fluid during the last weeks of pregnancy. The present study indicated as have previous studies (5, 6, 8, 10) that these phospholipids are linked to the surfactant system in the fetal lung. The concentrations of lecithin (L), PI, PG and sphingomyelin (S) were measured in 207 samples from 165 normal pregnancies. The augmentation in PI was found to parallel that in lecithin, and the PI/S ratios reached maximum values at about 30 weeks of gestation. The augmentation in PG appeared about two weeks later. Eleven premature infants who contracted respiratory distress syndrome (RDS) had significantly lower PG concentrations than 15 premature infants with no RDS (p less than 0.01). No correlation to the PI concentrations could be observed. All but one of the 11 affected infants had low L/S ratios.


Serum beta-human chorionic gonadotrophin levels in the early diagnosis of ectopic pregnancy. Beta-HCG in serum was analysed in 64 cases of ectopic tubal pregnancy who wree different groups; ruptured ectopic pregnancy, ectopic pregnancy accompanied by amenorrhea or adnexal mass and ectopic pregnancy without palpable adnexal mass and amenorrhea. The mean HCG levels for the three groups were 8 790 IU/l, 2 580 IU/l and 690 IU/l, respectively, which related more to the symptoms than to the estimated length of pregnancy. Eleven per cent of the women had an IUD and five per cent were taking low dose gestagens. Screening of cases with acute lower abdominal pain or irregular vaginal bleeding with beta-HCG in serum will facilitate an early diagnosis of ectopic pregnancy and be of special value in patients with less typical symptoms.


Effects of betamethasone on plasma levels of estriol, cortisol and HCS in late pregnancy. The effect of a single dose of betamethasone on the maternal plasma concentration of estriol and cortisol was studied. The concentration of estriol decreased rapidly. A maximal suppression of about 70 per cent was seen after 6-24 hours. A similar influence on the maternal plasma concentration of cortisol was observed. HCS (human chorionic somatomammotropin) was not influenced by betamethasone. These facts have to be taken into consideration after treatment with synthetic corticosteroids in high risk pregnancies.


Serum and amniotic fluid heat labile alkaline phosphatase and aminotransferases in association with meconium stained liquor. On their origin, distribution and clinical use. A method for detecting meconium in the amniotic fluid is described. Samples of maternal serum, cord serum and amniotic fluid were tested for alkaline phosphatase and transaminases activity in 32 healthy, term gravidas during labor in whom meconium stained amniotic fluid was found. The values obtained were compared to those of a control group consisting of 32 normal term pregnancies in whom the amniotic fluid was clear. Mean alkaline phosphatase activity was significantly higher in the study group in all three compartments - maternal, fetal and amniotic fluid. A significant and positive correlation between levels of alkaline phosphatase in the amniotic fluid and in maternal serum was found in the study group. Alkaline phosphatase value of 550 IU/L or more in maternal serum was diagnostic and levels between 350--500 IU/L were highly suggestive for the presence of menconium in the amniotic fluid. Mean levels of transaminases (SGOT and SGPT) were similar in the two groups and all were within normal range. The origin of alkaline phosphatase and the mode of transfer of the three enzymes are also discussed. It is suggested that this method can also be used during the third trimester of pregnancy.


Effect of induction of general anesthesia for cesarean section on intervillous blood flow. Intervillous blood flow was measured by a new intravenous 133Xe method before and during induction of general anesthesia for cesarean section in 10 healthy mothers. The flow values showed a highly significant decrease (p less than 0.001) (35 per cent on an average) at the time of anesthesia compared with the control values. The impairment was observed in all the cases. The role of the maternal changes in hemodynamic parameters and acid-base balance as a background of this decrease is discussed.


Pregnancy complications following conization of the uterine cervix (I). The literature on the course of pregnancies following conization of the uterine cervix has been studied. It is demonstrated that an evaluation of the possible effect of conization upon subsequent pregnancy should be based upon a comparison of either pregnancies before and after conization or upon a comparison between pregnancies in women with a previous conization and in a control group of women without conization. In both cases the possible influence of conization can be evaluated only if the patient material is described as regards age, parity, number of previous pregnancies, smoking habits, etc., factors which may all influence the course of pregnancy. None of the previous publications have described the patient material sufficiently, and most studies have not tried to set up control groups. Due to these deficiencies we do not find it justified that conization leads to reduced fertility, increased frequency of spontaneous abortion, nor to increased perinatal mortality. An increased prematurity rate may not be rejected, however, but this point has not been adequately evaluated in the previous papers.


Evaluation of smears obtained by cervical scraping and an endocervical swab in the diagnosis of neoplastic disease of the uterine cervix. A study of the supplementary value of an endocervical swab smear in addition to cervical scraping in the cytological diagnosis of cervical neoplasias is presented. The two sampling techniques were applied to a population with a high prevalence of neoplastic cervical disease. The endocervical swab smear was a useful adjunct in the detection of mild and moderate dysplasia, and a combination of the two sampling methods decreased the false negative rate in the diagnosis of intraepithelial, as well as invasive neoplasia. In the sphere of specific cytological diagnosis cervical scraping was found to be the more accurate method for diagnosing severe dysplasia and carcinoma in situ, while endocervical swab smears were more useful in diagnosing mild and moderate dysplasia. Differences between the results obtained in our study and comparable studies are discussed. It is concluded that the endocervical swab smear is a valuable adjunct to cervical scraping in the diagnosis of malignant cervical disease. It should not, however, be used as the only sampling method as it produces a higher proportion of unsatisfactory smears, and also because the severity of the epithelial lesion is more likely to be underestimated.


The cryosurgical treatment of intraepithelial neoplasia. At the Finseninstituttet and the Radium Centre in Copenhagen, from 1971-1975 inclusive, cryosurgery was carried out altogether 59 times on 57 patients. Only 8 patients showed histopathological changes in the biopsies sufficient to indicate conization. Hysterectomy was carried out on 8 patients. In 7 of these the removed uteri showed either no malignant changes or changpy. Invasive growth was discovered only in 1 patient, who later underwent a total hysterectomy by the Wertheim method. A biopsy on 1 patient with carcinoma in situ, suspected invasive growth, was treated with radium.


Methods for evaluating the intrauterine location of carcinoma. The intrauterine location of endometrial carcinoma was investigated with curettage, hysterography and hysteroscopy in 83 patients. These three methods are complementary. Curettage provides important information about the differentiation of the tumor. Hysterography is suitable especially for elucidating the anatomy of the cervical canal and uterine cavity. Direct examination by hysteroscopy gives a reliable picture when defining the boundary between stages I and II.


Menorrhagia, diffuse myometrial hypertrophy and the intrauterine contraceptive device: a report of fourteen cases. Fourteen uteri, removed for IUD-associated menorrhagia, were studied. Twelve of these IUD-bearing uteri showed pure diffuse myometrial hypertrophy; the other two uteri were enlarged as a result of multiple leiomyomas in one case and extensive deep adenomyosis in the other. The incidence of pure myometrial hypertrophy in the IUD group was far in excess of that observed in a control non-IUD-bearing menorrhagia series, where leiomyomas and/or deep adenomyosis were mostly responsible for the uterine enlargement.


Biological fate of methenamine in man. Absorption, renal excretion and passage to umbilical cord blood, amniotic fluid and breast milk. Methenamine hippurate was administered orally as tablets or granules to healthy volunteers. Plasma concentrations of methenamine reached a maximum 1--2 hours after a single dose and then declined with a half-life of about 4 hours. The apparent distribution volume was similar to that of total body water. Renal clearance of methenamine was somewhat lower than that of creatinine. In cross-over experiments over six days, methenamine recovered in the urine corresponded to about 80 per cent of the dose given per 12 hours, slightly lower values being obtained from granules than from tablets. The efficient renal elimination of methenamine was confirmed in similar studies on patients post-operatively. Methenamine hippurate was also given to healthy pregnant women during labor, a few hours before expected delivery. Methenamine was found to pass the placental barrier. The concentration of methenamine in umbilical cord plasma was low but reached the level in maternal plasma after about 4 hours. In amniotic fluid the methenamine con centration was low and varying. No correlation was obtained to the maternal or umbilical cord plasma levels. The methenamine concentration in breast milk was of the same magnitude as in maternal plasma. It is concluded that methenamine may be safely given to pregnant and lactating women with respect to the ellbeing of the child.


Minimal brain dysfunction in children born in breech presentation. The influence of delivery in breech presentation on the occurrence of minimal brain dysfunction (MBD) has been studied. Parents of 8--15 year old children were asked to account for behavioral and educational deficits and needs of their children from birth until the date of investigation. It was found that among prematurely delivered children, the frequency of MBD, defined as hyperkinesia and learning disability, amounted to about 20 per cent and was similarly distributed between children , however, the average frequency of hyperkinesia and learning disability amounted to 8 per cent; in children born in breech presentation it was 14 per cent, while in those born in vertex presentation the corresponding figure was 2 per cent. MBD was more common in boys (16 per cent) than in girls (12 per cent).


Infertility and cervical Chlamydia trachomatis infections. Of the 51 women examined for infertility, 19.6 per cent were found Chl. trachomatis culture-positive. This differs, although not significantly, from the 9 per cent isolation rate among our general gynecological outpatients. The results suggest that Chl. trachomatis should be considered in women with unexplained infertility.


X/X translocation and Turner's syndrome in a woman with climacterium praecox. A woman with X/X translocation is presented, and the association between the different types of X/X translocation and Turner's syndrome as well as the question of menstruations and fertility in women with Turner's syndrome are discussed. It is concluded that streak gonads should most probably not be included in the definition of Turner's syndrome.


Maternal sepsis, uterine rupture and coagulopathy complicating cervical cerclage. A previously healthy woman with a Shirodkar cerclage for cervical incompetence had a spontaneous rupture of the membranes at the 37th week of pregnancy. Three days later after a short period of weak labor pains, she developed a severe sepsis, uterine rupture and coagulopathy leading to renal failure, beta-hemolytic streptococcus group B and peptostreptococcous could be cultured from the amniotic fluid immediately after rupture of the membranes and from the uterus and placenta.


Vestibular neuronitis; a follow-up study. Forty-three patients suffering from vestibular neuronitis were examinated during the acute attack and on an average 3.2 years afterwards. In the follow-up examination there was no caloric reactions in 7 patients, lowered in 15 patients and normal symmetric reactions in 21 persons. In the first examination all had normal symmetric hearing, in the follow-up examination there was 5 to 10 db hearing loss in 4.6 and 8 kHz on the diseased side in 24 patients.


On pathogenesis of symptoms in Ménière's disease. A conception of the mechanism for initiating symptoms in Ménière's disease has been forwarded. According to this conception production of endolymph may vary also in normals. The hydrops in Ménière cases is brought about by a relative insufficiency in endolymphatic draining routes and the hydrops presents itself only at peak endolymph production periods. The attacks of vertigo are brought about at the distension of the sacs as well as of the regaining of normal shape of the sacs. The mechanism causing the vertigo could be an effect of mechanical push-and-pull effect on the sensory epithelium of the cristae. The early low-tone hearing loss and the persistant normal caloric reactivity also in advanced Méière cases may be due to simple physical laws : distensions of sacs with equal walls will more easily be brought about in wider than narrow compartments.


Activation of human monocytes by mediators from lymphocytes stimulated with Corynebacterium parvum. Human monocytes activated in vitro by lymphokine-containing supernatants of autologous or allogeneic lymphocytes stimulated in vitro by Corynebacterium parvum (CP) expressed increased ability to suppress DNA-synthesis in a human tumour cell line. Monocyte activation was not dependent on in vitro differentiation of monocytes, enhanced cytostatic ability being observed at all stages of in vitro differentiation. The lymphokine-induced cytostatic ability was not affected by intensive washing and trypsin treatment of the activated monocytes, but disappeared during 48 hours of in vitro culture of the activated cells. The increased cytostatic ability of lymphokine-activated monocytes did not seem to be due to stable supernatant factors released from monocytes. CP stimulated DNA-synthesis in peripheral blood lymphocytes of 28 normal donors, thus confirming the mitogenic effect of CP on human lymphocytes. Lymphokine production in response to CP correlated with the magnitude of DNA-synthesis, but appeared before DNA-synthesis could be detected in the lymphocytes.


The binding of protein A of immunoglobulin G and of Fab and Fc fragments. Results are presented to show that protein A (pA) may fix to the Fab region of IgG outside the antigen binding site. Thus, pA-reactive Fab fragments were isolated both from specific anti-egg albumin and specific anti-measles virus antibodies. A probable significance of this Fab reactivity in the precipitation reaction between IgG and pA is discussed. Reactive IgG from human, guinea pig, rabbit, and porcine normal sera all showed similar avidity towards pA. Slight differences between IgG subclasses were, however, observed. The avidity of pA-reactive Fab and Fc fragments, isolated from normal porcine IgG, was highest in the latter.


The effects of a beta 1-blocking agent, atenolol, on blood pressure, plasma renin activity and prostaglandin F2 alpha excretion in patients with essential hypertension. The antihypertensive action of beta-blocking agents has been suggested to be associated with the decrease in plasma renin activity (PRA) and can be antagonized by indomethacin, a prostaglandin (PG) synthesis inhibitor. We studied the acute and long-term effects of a beta 1-blocking agent, atenolol (50 mg b.i.d.), on blood pressure (BP), PRA and urinary PGF2 alpha excretion in 12 male patients (40 years old) with essential hypertension. BP was measured by means of a brachial cuff. PRA and PGF2 alpha were estimated radioimmunologically. One day after the initiation of atenolol treatment, BP fell significantly, the supine values from 159/114 to 143/104 mmHg and the erect from 158/118 to 140/106 mmHg. In six weeks BP decreased further to 135/94 and 134/96 mmHg, respectively. After the cessation of atenolol for three weeks BP rose to the pre-atenolol level. When the dose was readjusted (25-150 mg daily for 26 weeks), diastolic BP remained at 100 mmHg or higher in only two patients. During the atenolol treatment PRA declined to one-third of the pre-atenolol level in one day and to one-half in six weeks. The urinary excretion of PGF2 alpha was not affected by atenolol. Our results suggest that 1) the antihypertensive action of atenolol and the reduction of PRA are substantial already in one day, and 2) the decrease in BP or PRA is not associated with PGF2 alpha production.


The diagnostic challenge of left atrial myxoma. Importance of echocardiographic screening. Left atrial myxomas are extremely difficult to diagnose since their variable manifestations mimic a host of clinical entities more commonly seen, e.g. mitral stenosis, endocarditis, rheumatic fever, cardiomyopathy or mesenchymosis. At the same time, early diagnosis followed by prompt surgical removal are mandatory to prevent mutilating or lethal complications of the tumor. Six cases of left atrial myxoma were diagnosed in our hospital during 2 1/2 years. We present the case histories, diagnostic procedures and surgical findings, consolidating the unique role of echocardiography in detecting left atrial myxomas. We propose the use of echocardiography as a screening examination for atrial myxomas in the following settings: suspected mitral obstructive disease, suspected endocarditis with negative blood cultures, peripheral embolism or thrombosis in young patients, unexplained cardiac failure and mesenchymosis with uncharacteristic presentation.


Massive embolization of cardiac myxoma. A case report. A case of left atrial myxoma with massive embolization in a 20-year-old woman is described. The initial clinical picture was confusing, but repeated examinations, including enzyme determinations and arteriographies, disclosed the presence of multiple arterial emboli. At embolectomy, histological investigation of embolic masses showed a picture indicating cardiac myxoma. This diagnosis was confirmed by pulmonary angiography and the tumour was removed. Postischaemic oedema of the legs necessitated decompression operations. The peripheral circulation was restored and the final result was excellent. Some aspects of the clinical presentation of this uncommon disease are discussed.


Diastolic wave initiating ventricular tachyarrhythmias and suppressible by lignocaine and isoprenaline. A patient is described with ventricular tachycardia and premature beats (VPB) probably initiated by a diastolic wave, which--like the VPBs--could be eliminated by lignocaine and isoprenaline.


Effects on muscle electrolytes of potassium and magnesium infusions, spironolactone medication and operation in a case of primary aldosteronism. Serum and muscle electrolytes were determined in a case of primary aldosteronism before and after potassium and magnesium infusions as well as spironolactone treatment and following surgery. Repeated potassium infusions resulted in a transient normalization of the muscle potassium (K/m), followed within 3-4 days by a return to the previously low K/m. Magnesium infusions did not give any increase in muscle magnesium (Mg/m). On the contrary, there was a decrease in Mg/m concomitant with a decrease in K/m. Treatment with spironolactone for one month was followed by a normalization of both serum and muscle electrolytes. Following surgery the serum potassium and K/m remained normal, but the serum magnesium (Mg/s) and Mg/m showed a decrease to subnormal values. Despite the initial findings of normal Mg/s and Mg/m as well as excretion of more than 80% of the i.v. magnesium dose, this may indicate that there was a magnesium deficiency in the skeletal pool.


Non-selective and selective beta-1-adrenoceptor blocking agents in the treatment of hyperthyroidism. Treatment for one month with propranolol or atenolol, a selective beta-1-adrenoceptor blocking agent, was evaluated in 20 hyperthyroid patients. The patients improved to the same extent on either drug, as shown by a clinical diagnostic index. Basal metabolic rate decreased by 11% during both treatments, while it was unchanged in seven untreated hyperthyroid controls. Thyroxine concentration did not change during any treatment. During propranolol treatment T3 decreased from 4.6 to 3.9 nmol/l, while no changes were observed during atenolol treatment or in the control group. No significant changes were seen in free T4, free T3 or rT3 concentrations on any treatment, although free T3 was observed to decrease slightly during propranolol treatment. Thus, the improvement of the clinical symptoms of hyperthyroidism cannot be explained by diminished thyroid hormone concentrations in serum, since the reduction was small during propranolol and absent during atenolol treatment.


Self-poisoning treated in the ICU.

Self-poisoning treated in the ICU. This retrospective study compares number and type of self-poisonings admitted to the intensive care units (ICU) at Sahlgren's Hospital, Gothenburg, during 1972 and 1976. The total number of patients requiring intensive care was unchanged, but a change in the pattern of self-poisoning was seen. In 1976 the number of patients requiring intensive care following acute alcohol intoxication had increased, whereas the number of barbiturate and methaqualone poisonings decreased. Tricyclic antidepressants formed the largest group in both years. Fewer patients needed endotracheal intubation and IPPV in 1976 than in 1972. Also, fewer complications were seen, and the death rate among ICU-treated patients decreased. In the Gothenburg area barbiturates accounted for one half of all deaths due to self-poisoning and tricyclic antidepressants for one fifth. Any expected decrease in intensive care as a result of fewer barbiturate and methaqualone poisonings was obscured by an increase in severe alcohol intoxication.


Emergency room resuscitation of patients with cardiac arrest outside hospital. Outcome and immediate prognosis in 319 patients. Resuscitation was attempted in 319 patients brought to hospital with cardiac arrest during a 5-year period. Primary successful results were achieved in 50 patients (15.7%). Twelve patients were long-term survivors (3.4%), 10 of whom had normal brain function, whereas 2 had mild cerebral dysfunction. To improve prognostication in patients with initially successful resuscitation, Bayes' theorem was applied using 4 clinical findings after 24 hours' treatment: reactions to painful stimuli, pupillary size, light reactions and BP, Bayes' theorem as well as coma depth after 24 hours gave valuable information regarding individual prognosis.


Mortality, arrhythmias and pump failure in acute myocardial infarction in relation to estimated infarct size. Serial estimations of total serum creatine kinase (S-CK) were made in 194 consecutive patients with acute myocardial infarction (AMI). By itself, the maximum CK value could not separate patients in terms of high and low mortality but when the maximum CK value was related to age for patients with and without a history of previous AMI, two subgroups became apparent, one with 46% mortality (high-risk group) and another with 6% (low-risk group) during the hospital stay plus the next 90 days. In 114 of the patients, infarct size could be calculated. A good correlation was found between maximum CK and calculated infarct size (r = 0.93). Calculated infarct size alone could not distinguish between high and low mortality but when it was related to age for patients with and without a history of previous AMI, two subgroups emerged, one with 43% mortality and another with 3% during the hospital stay plus the next 90 days. The incidence of ventricular tachycardia during the stay in the Coronary Care Unit did not differ between the two risk groups separated either by maximum CK value or calculated infarct size. However, the incidence of shock and severe left heart failure during the acute phase was higher in the high-risk groups.


The Q-T syndrome--a family description.

The Q-T syndrome--a family description. This paper describes a family of nine siblings of whom five suffer from the surdocardiac syndrome. All five are deaf-mute and have medical histories typical of the syndrome, with frequent syncopal attacks during the childhood, often caused by stress. Two of these five siblings have not suffered more than single attacks since puberty and are still alive. The other three had had continuous frequent attacks into adult years and died in connection with syncopes at 20, 27 and 37 years of age. The diagnosis, pathogenesis, treatment and genetics of the syndrome are discussed.


A controlled study of early discharge after uncomplicated myocardial infarction. Out of 383 myocardial infarction (MI) patients aged below 70 years, 252 (66%) were judged after the third day in hospital to have had uncomplicated infarctions. These patients were allocated at random to two groups, one of which was given treatment for 8 days and the other for 15 days. No significant differences in mortality, morbidity or incapacity for work could be detected during the three-month period of follow-up. The findings thus support previous conclusions that early discharge from hospital after uncomplicated MI is not associated with greater risk for the patient than later discharge.


Comparison of streptokinase with heparin: late results in the treatment of deep venous thrombosis. Nineteen cases were reinvestigated 8-14 years after treatment with SK or heparin. Judging from personal interviews, foot volumometry and phlebography, treatment with SK appears to be more preferable since it was less often followed by late severe postthrombotic changes.


Blood pressure in 60-year-old men. Findings in a health survey and some comparisons with 50-year-old men in the same community. A population survey of 60-year-old men (n=331) was performed in Uppsala. tthe prevalence of hypertension defined as established hypertension and those having an unknown diastolic blood pressure (DBP) of greater than or equal to 105 mmHg was 19.3%. Of the hypertensive population, 35.9% had not been detected previously. In the treated group, 43.9% were poorly controlled regarding the BP level. Thus 64.1% of the total hypertensive population at the age of 60 years were either undetected or inadequately controlled. Excretion of urinary electrolytes was also evaluated in this work. All participants of the health survey except four performed a 24-hour collection of urine following the health examination. Care was taken with endogenous creatinine clearance. Negative and significant correlations were noted between excretion of sodium and potassium in urine and DBP levels in the group (n=23) of untreated hypertensives. In a population sample (n=135) of healthy subjects devoid of medical treatment in the same population survey, a positive and significant correlation was noted between the systolic BP and the urinary excretion of sodium. Thus up to a certain BP level there is a pressure diuresis and at higher BP levels the kidney retains electrolytes.


Two- and three-dimensional hexon crystals. Soluble hexon of type 1 adenovirus was highly purified with different techniques and dialysed against 0.5 M acetate buffer. With this procedure tetrahedral crystals were produced from the soluble hexon capsomers of the virus capsid. Electron microscopic observation of the crystallization process, revealed the development of dense two-dimensional "crystal sheets" following dialysis, in homogeneous hexon preparations containing single hexons. No such formations were observed so far with other types. The occurrence of two-dimensional crystals decreased proportionally to the appearance of three-dimensional crystals, which refers to their possible role in the mechanism of three-dimensional crystal formation.


Toxoplasma antibodies in ophthalmological patients. Sera of 532 patients suffering from different ophthalmological diseases were studied for the presence of toxoplasma antibodies. Complement fixation test was positive in 44.9% of the patients. As compared with the 26.8% positivity rate determined earlier in the normal population the seropositivity in eye-patients was significantly higher. The highest incidence, 50%, was found in the age group of 21--30 years. In diseases with a confirmed aetiological role of toxoplasmosis, the incidence of seropositivity was higher than in the total material. This suggests that Toxoplasma gondii may have had a role in part of the diseases of the patients studied.


Dianhydrodulcitol treatment of lymphocytic choriomeningitis virus infection in suckling mice. Mice 2--4 days of age were pretreated with a single 5 mg/kg dose of dianhydrodulcitol (DAD) and later infected intracerebrally with lymphocytic choriomeningitis (LCM) virus. These animals had a lower mortality rate and died later than the untreated control animals. Thus DAD pretreatment prevented in part of the animals the development of lethal meningitis, the consequence of LCM virus infection, reducing the cellular immune response. This effect of DAD could equally be observed in animals infected at the age of 16--18 days and of 4 weeks.


Adaptation of the influenza neuraminidase and neuraminidase-inhibition assays to the microtitrator system. A micro-method based on Warren's colour reaction has been developed for influenza neuraminidase and neuraminidase-inhibition assays. Extraction with butanol is omitted and the assay is performed in wells of special plexiglass trays, where the reaction mixon and compared to controls in the same tray. The micro-assay, being inexpensive, time-saving and easy to perform even in poorly equipped laboratories, is suitable for large-scale serological screening and identification of the neuraminidase antigen of isolates.


Incidence of non-cholera vibrios in Hungary. In the period 1971 to 1976, 200 non-cholera vibrio (NCV) strains were isolated in Hungary; 18 of the cultures were derived from 34 729 faecal and 182 from 237 surface water samples. Ninety-two strains belonged to the Heiberg-Smith group I and 108 to group II. Two strains failed to give the string test and 3 were pteridine resistant. The strains were classified into 48 serotypes according to Smith's system. Faecal NCV strains belonged to serotypes 46 and 328; these serotypes did not occur in water. Of the 18 faecal strains 13 were isolated from 18 048 persons who had travelled in cholera-infected areas, and 5 strains from persons who had never left Hungary (2 from 4559 patients with diarrhoea and 3 from 6061 healthy individuals). These data indicate that although NCV are present in the environment, they play an insignificant role in enteric infections in Hungary.


Middle ear infection due to vibrio alginolyticus. Bacteriological characterization. A 47-year-old male suffering from chronic purulent ear discharge was investigated bacteriologically in autumn 1977. The isolated strain was identified as Vibrio alginolyticus. The fact that the patient spent his vacation at a Black-Sea resort every year strongly pleads for a direct inoculation of the halophilic Vibrio.


Proprioceptive influences on directional hearing: dependence on the movement type. Proprioceptive effects (PE) on directional hearing, i.e., sound image shifts relatively to the sound source, produced by changes in head position, were studied in their dependence on head movement type in two groups of listeners. The first group included subjects in whom horizontal head deviation to the right or to the left, performed on instruction before the presentation of clicks, caused sound image displacement of 10-15 degrees. When the same sounds were made signals of movement direction, i.e., of pointing with the head at the sound source, PE became fully inhibited in all subjects. The second group included listeners in whom PE was either absent or only very small; substitution of passive head deviations for active turns resulted (in 63 percent of cases) in PEs which presumably had been previously inhibited. Thus identical muscle activities play different roles in auditory spatial perception depending on the type of movement and on the significance of the acoustic signal for the motor act.


Avoidance acquisition in cats as a function of temporal and intensity factors. Acquisition of an active bar-pressing avoidance response was investigated in a factorial design with 3, 5 or 9 s CS-US intervals and CSs of 70- or 50-dB of white noise. As the CS-US interval increased the required time to meet the avoidance criterion decreased. The shorter the CS-US interval and the more intense the CS, the shorter the median response latencies observed at the end of the training. The latency data were analyzed in Vincentized fifths of acquisition trials. At the beginning of training, when the highest proportion of responses occurred soon after the US onset, escape latencies were shorter in groups trained with shorter CS-US intervals and the more intense CS. During the 1st and 2nd fifths of training, avoidances occurred with the same probability in each part the CS-US interval. By the middle of the training, after a performance level of 50 percent avoidance responses was reached, a rapid increase in the number of short-latency avoidance was observed, which was more pronounced in groups trained with the 70 dB CS. While the general shape of the latency distributions was preserved during the remaining two fifths of the training, a further increase in the intensity effect was noted, which occurred along with a decrease in the CS-US interval effect. The data are in favour of Two-factor Theory of Avoidance learning and suggest that at various stages of training, different variables emerge for acquisition and consolidation of the avoidance reflex. Data supported the hypothesis that two different mechanisms are involved in performance of short- and long-latency avoidance responses.


A system of command neurons in snail's escape behavior. Intracellular stimulation of each of the nine identified neurons released a specific withdrawal reactions. These cells fire in response to strong tactile, light and thermal stimuli releasing escape behavior, and are assumed to be command neurons.


Optic nerve gliomas. II. Cytological characteristics. Observations on cell and tissue cultures. Cytological characteristics of optic nerve gliomas were studied parallel with histological structures in cell and tissue cultures. Histologically the tumours consisted of four different cell types: spindle-shaped elongated cells, round cells, stellate forms, and multinucleated cells. Dynamic properties of cultured optic glioma cells showed that stable cellular elements of the parent tissue arise from two fundamental populations, viz from elongated (piloid), and from round cells. Cells of both populations displayed a series of changes in the course of their cultures. A certain part of the slender elongated cells enlarged and became plump piloid cells of various shapes, or big stellate astrocytes. Giant multinucleated variants of these forms also emerged by fusion of the mononucleate forms. The round cells gradually turned into immature Astrocytes, and by a subsequent cell fusion they gave birth to big stellate cells. With the ageing of the cultures a polymorphous cellular picture developed which was mainly due to the active migratory and intracellular movement of the elongated and round cellular elements. Mitoses played a negligible role in this process. Several characteristics suggest that the round shapes are immature glia cells, and represent the least differentiated elements among all the cell components. The stellate and giant multinucleated forms might be considered as end-products of glia cell differentiation and they could originate both from the elongated and the round cells.


Schwannoma of the sellar region.

Schwannoma of the sellar region. A 25-year-old woman who had experienced brief periods of loss of consciousness and grand mal seizures was found to have a midline mass in the sellar region as evidenced by computer tomography and angiography. Preoperatively, it was thought to be a meningioma but histologically and ultrastructurally it turned out to be a Schwannoma. Since cranial nerves were not involved, clinically or morphologically, this nerve sheath tumour could have originated from Schwann cells of sensory, possibly trigeminal, nerves, vasomotor nerves, or ectopic Schwann cells.


Persistent embryonic veins in the arteriovenous malformations of the dura. The basic anatomy of the arteriovenous malformations of the dura is similar to that of the internal carotid (pial) malformations, as the arterial feeders in both these lesions arise from the internal carotid artery in the embryo. The venous drainage occurs through definite channels into the major venous sinuses. Therefore, the dural and the pial malformations should be classified together. The scalp malformations have no features similar to these groups. The prominent occipital artery is not necessarily the primary feeder. Whenever a prominent occipital artery is seen, special efforts must be made to locate the primary dural feeders arising from the internal carotid artery.


Subarachnoid haemorrhage of unknown aetiology. One hundred and forty consecutive subarachnoid haemorrhages (SAH) which presented either an intracranial vascular malformation (102 cases: aneurysm 80 cases, AVH 22 cases) or remained of "unknown aetiology" (38 cases) were studied. SAH caused by other factors (neoplasms, thrombo-embolisms, systemic diseases etc.) were excluded. The 38 cases with bleeding of "unknown aetiology" have been studied by complete cerebral angiography, pneumoencephalogram or CT scan, and have been followed for two years. The most important clinical factors in the three groups have been compared by a statistical method to verify the hypothesis that SAH of "unknown aetiology" is caused by vascular micromalformations which are angiographically not evident either because of their small size or because of their "spontaneous" recovery after bleeding due to thrombosis and disappearance of the malformation. From the data collected it may be concluded that SAH of "unknown aetiology" is a benign lesion, typically occurring in middle age, but with no clear characteristics that enable identification of the anatomical substratum from it originates.


Chronic bilateral subdural haematoma in adults. Twenty-nine patients with chronic bilateral subdural haematomas were surgically treated during 1966 to 1977. Twenty-four of them (83%) had a history of head injury, which caused unconsciousness in eight cases. The mean interval from trauma to operation was eleven weeks. The mean age of the patients was 60 years. The prevalence of the most commonly encountered symptoms and signs was: headache 72%, mental symptoms 48%, papilloedema 41%, vertigo 31%, nausea 28%, reduced consciousness 28%, walking difficulties 24%, hemiparesis 24%, and paraparesis 14%. The aggregate thickness of haematomas was 34 mm, 36 mm, and 40 mm in age groups of 20--39, 40--59, and over 60 years, respectively. All patients were operated on, four of them only unilaterally. Three patients in the whole series died. Two of them had been operated upon only on one side in the first session, the haematoma of the other side being evacuated 8 1/2 hours and four days later, respectively. Unilateral operation is likely to cause severe distortion of the midline structures and the brain stem and thus aggravates the cerebral situation. Therefore the necessity of simultaneous evacuation of the haematomas on both sides is stressed. The reason for the death of the third patient was delay in diagnosis. All three patients who died belonged to the group of eight patients with a reduced level of consciousness before surgery. Twenty-three of the survivors were fully independent in their daily lives, and three needed some help after operative treatment.


Examination of the metabolism of oedematous brain tissue. V. The metabolism of oedematous white matter from rabbit brain. Glucose and gas metabolism as well as water, sodium, and potassium content of normal and oedematous white matter slices of rabbit brain have been determined. A cutting technique for the preparation of the slices is described. Although the increase of the relative water content in oedematous white matter is much more pronounced than in oedema of the grey matter, we observed only one significant change: the pyruvate production in vitro is about 20% higher in slices prepared from oedematous brain.


Acquired hydrocephalus. V. Determination of the formation rate of albumin in the ventricular system. By quantitative isotope ventriculography (QIV), the formation rate of albumin in the ventricular system (FRalb) was determined in 14 hydrocephalic and 14 nonhydrocephalic patients. The FRalb was significantly reduced in the patients with acquired hydrocephalus. By a comparison of the mean formation rate of albumin (MFRalb) and the mean absorption rate of albumin (MARalb), a significant biological difference in the two groups of patients was demonstrated.


Sexual experimentation by adolescents while babysitting. This paper deals with the sexual experiences an adolescent might have as a result of babysitting. The impact of babysitters in our culture has been ignored in the literature, and yet we find it practiced widely by teenagers in the United States. Parents and society in general have few guidelines in sitter selection and in recognizing the potential impact of the sitter on their children.


Encopresis in adolescence: two case studies. Encopresis is an underreported psychopathological symptom of adolescence, not necessarily defining a specific diagnostic entity. The two cases presented offer an opportunity to evaluate encopresis occurring in markedly different adolescent pathological entities and developmental backgrounds. The first patient presented a longitudinal life course wherein toilet training and fecal considerations were prominent throughout his development. Indeed, this young man had such areas of cohesive functioning, as to be appropriately considered within the range of characterological pathology, severe, though it may be. In marked contrast, the second patient's encopresis represented but a small part of a totally encompassing psychotic disintegration.


Self-injury behavior, economic status and the family anomie syndrome among adolescents. Only recently has there been a focus upon the psychosocial environment of the family that surrounds the suicide-prone individual. The purpose of this research was to learn more about the association of economic status and family anomie, operationationalized by family normlessness and powerlessness scales, to the differential vulnerability of adolescents to suicide potential. The research design called for a detailed interview with the persons attempting suicide and members of their families. The study samples consisted of 30 low economic and 25 high economic status families. It was predicted that social anomie could be translated into behavioral (attempted suicide) and attitudinal (normlessness and powerlessness) determinants when viewed with regard to its impact upon the family. Significant differences in the degree of normlessness and powerlessness were found for suicidal and nonsuicidal adolescents and their families. These differences appear to be part of a family anomie syndrome.


Siblings as babysitters: responses of adolescents to younger siblings in problem situations. Adolescents (75 males, 150 females) assumed the role of parent surrogate and responded to nine problem situations involving younger siblings. Responses were coded into 21 categories--grouped as high, medium, low and non-power as well as "effective" or "ineffective"--and analyzed by sex, grade (10, 11, or 12) and birth order (first-, second-, or laterborn). Ninety-two percent of responses were categorized as "ineffective" (i.e., not communicating own or sibling's feelings). Seniors used less high and more medium and non-power responses than younger students. Most students, particularly females, expressed interest in joining a group to learn better ways of relating to younger siblings.


The Anti-Social Activities Attitude Scale. A scale was developed to measure attitudes toward anti-social activities for adolescents. Reliability coefficients were greater than .9. Validity was determined by comparing two known groups.


Meniere's disease: a neuropsychological study II. 23 Meniere patients were examined with an extensive battery of neuropsychological tests. In a previous investigation the authors had demonstrated that patients with a long duration of Meniere's disease had psychological disturbances, presumably localized in the nondominant hemisphere. In the present investigation the patients had a short duration of the disease, and we were unable to reproduce the psychological disturbances. It is concluded that the central changes in the nondominant hemisphere function develop over a long period of time. It is hoped for that further neuropsychological investigations of Meniere patients can give more information of what is primary in Meniere's disease: peripheral sensory or central neurological changes.


Epidemiological survey of definite cases of Meniere's disease collected by the seventeen members of the Meniere's Disease Research Committee of Japan in 1975--1976. Between Aril 1975 and December 1976, the second nationwide survey of Meniere's disease in Japan was made by the 17 members of the Meniere's Disease Research Committee of Japan. The epidemiological data from 520 patients with definite Meniere's disease were analyzed in comparison with those from the 126 patients in the non-Meniere vertiginous group (Control A) and the 228 patients in the rhinolaryngological group (Control B). The male:female ratio of definite cases of Meniere's disease was almost the same, and the age distribution peaked at the age group of 40--49 years for males, while the peak for females was at the age group of 30--39 years. 5.8% of the 520 patients had a close relative who also suffered from Meniere's disease. From the epidemiological features, it may appear that the occurrence of vertiginous attacks in Meniere's disease is influenced much more by individual than by environmental factors. However, this feature can be considered as another evidence of the psychosomatic disorders involved in Meniere's disease.


Bilateral Meniere's disease.

Bilateral Meniere's disease. A survey of 265 Japanese patients with Meniere's disease revealed bilateral involvement in approximately 29% of all these patients. Somatic and psychiatric aspects of bilateral Meniere's disease were as follows. (1) The duration of the disease in cases of bilateral involvement was significantly longer than cases of unilateral involvement. (2) An abnormal general condition, a more extensive degree of hearing loss and neurotic type were frequently diagnosed in cases of bilateral involvement. Based on these results, it was concluded that psychiatric management and prevention of aggravation of deafness should be part of the management of treatment in bilateral Meniere's disease.


Measurement of eye deviation under the nonfixative condition in patients with peripheral labyrinthine disorders, especially Meniere's disease. Among 232 Japanese patients with peripheral disorders, 98 had a unilateral Meniere's disease. In these patients and 20 healthy adults, recordings of eye deviation were made utilizing DC-ENG under two conditions, i.e. eyes closed (EC) and eyes open in the absolute darkness (AD). (1) 90 % tolerance interval of AD. was significantly smaller than that of EC in controls. (2) Appearance of nystagmus in 5 groups with labyrinthine lesions was compared with the direction of deviation toward and against the affected side in both conditions. (3) Concerning unilateral Meniere's, the relationship among deviation, nystagmus and caloric response was analyzed statistically and the clinical application discussed.


The ultrastructure of the endolymphatic sac in Meniere's disease. Biopsies of the endolymphatic sac were performed in 6 patients undergoing endolymphatic sac decompression and/or drainage procedures. Electron microscopy revealed extensive subendothelial fibrosis with loss of vascularity, heavy deposition of collagen and flattening of luminal cells. In patients with long-standing disease, complete obliteration of the endolymphatic sac lumen appeared to occur. There was poor correlation between the surgeon's ability to identify the lumen of the endolymphatic sac and its presence in the biopsy specimen.


Caloric nystagmus: ENG in comparison with observation by Frenzel's glasses. After caloric stimulation with water at 30 degrees C for 30 sec an electronystagmogram (ENG) was registered. Simultaneously with the ENG the test person's nystagmus was observed by Frenzel's glasses. If the evaluation is limited to the frequency of the nystagmus and if it is possible to neglect the velocity of the slow phase, the simple observation through Frenzel's glasses and its plotting on a time chart recorder is no less effective than an ENG for measuring the difference between the right and left labyrinth.


Dynamic evaluation of human vestibulo-ocular function using white noise rotation stimulus and linear system parameter estimation techniques. White noise acceleration inputs were used to determine the human VOR transfer function both for normal subjects and for patients falling into two pilot categories: unilateral labyrinthectomy and reduced bilateral responses. The systematic patterns shown in the transfer function of the pilot abnormal categories as compared to the normal data suggests one method of classifying test results (table I). Frequency domain linear systems parameter fits were also made using the same data. The changes in these fit parameters, when pilot abnormal data is compared to normal data, suggests the use of the parameter fits themselves as a second classification scheme (fig. 1). The second scheme is not appropriate in cases where the response is unrelated to the stimulus.


Some critical remarks on the interpretation of vestibular test results. In the scope of the evaluation of vestibular function, the attention is drawn to the fact that results of tests are to be considered in a relative way. They do not express the absolute functional capacity, but in half of the cases it can be shown that the functional state is intensity dependent. This can be observed in claoric tests as well as in rotation tests. In these latter even the type of stimulation may give a different result. The experiences obtained in a number of cases by both stimulation types confirm this assessment that the functional result is always to be considered in this relative way. This implies some reserves as to the comparability of results of various authors, using different stimulation schemes. On the other hand, and this especially in rotation tests, application of more stimulation intensities allows to separate cases with stable from those with labile results.


Accumulation of substances with melanin affinity to the internal ear. Therapeutic or ototoxic mechanism? The capacity of the melanin in the internal ear to accumulate and retain labelled lidocaine, bupivacaine and chlorpromazine after intravenous and intraperitoneal injection was examined by whole-body autoradiography. Both young pigmented hooded rats and albino rats were studied. In the pigmented rats chlorpromazine showed the greatest accumulation, which was more pronounced in the cochlea than in the vestibular portion. The other two substances were evenly distributed in the internal ear. After a single injection of chlorpromazine and of bupivacaine these substances were still bound to the melanin of the internal ear after 14 days, which was the longest survival time. Lidocaine, on the other hand, had disappeared after only 4 days. In albino animals there was very weak, transient uptake of chlorpromazine and bupivacaine, but not of lidocaine, in the internal ear. In studies in vitro on isolated bovine eye melanin there was considerably greater adsorption of chlorpromazine than of lidocaine and bupivacaine.


Vestibular neuronal function during ischemia. Response of vestibular neurons to vertebral and carotid artery occlusion in rabbits. The relation between ischemia experimentally produced by occlusion of arteries injecting to the brain and the changes in vestibular excitability was examined in 102 rabbit vestibular neurons responding to sinusoidal rotation. During occlusion of ipsilateral and/or contralateral vertebral and common carotid arteries, the neuronal activity took on three different patterns with respect to the frequency of neuronal discharge. The incidence of alteration of neuronal activities reflected vestibular excitability dependent on hemodynamic changes due to occlusion of the ipsilateral vertebral artery rather than due to occlusion of the contralateral artery. Occlusion of common carotid arteries caused no significant difference between the right and left vessels in the resultant change of the neuronal activity, and differed little, either, from occlusion of vertebral arteries in the incidence of the changes. A supplementary experiment, in which the four arteries were only partially occluded, clearly showed that the resultant changes in neuronal activity reflect the role of Willis' circle in the maintenance of blood flow to vestibular nuclei.


Low-frequency harmonic acceleration in the evaluation of surgical treatment of Meniere's disease. 23 patients with classical findings of Meniere's disease and so diagnosed by a neurotologist were tested with harmonic acceleration. 7 of these patients were selected to receive endolymphatic-mastoid shunts for intractable vertigo and/or highly progressive fluctuant hearing loss. All 7 patients showed an increase in the impairment in their phase relationships at the lowest frequency (0.01Hz) following surgery which was considered to be secondary to the procedure. Later this phase lag returned to a level approaching normal. They also showed a definite decrease in the asymmetry (labyrinthine preponderance) of their nystagmic responses to acceleration.


Optokinetic nystagmus in artificial hemianopsy. Optokinetic nystagmus in cases of artificial hemianopsy was studied. Hemianopsy was produced by using a combination of a projector, an erasing device and DC ENG. The effect of the condition of foveal vision in hemianopsy, whether reserved or involved, was discussed. When foveal vision was reserved, nystagmus during stimulation in cases of hemianopsy was essentially the same as in the normal eye. In cases of hemianopsy in which foveal vision was involved, there was a remarkable difference between the mystagmus induced by foveofugal stimulation and that induced by foveopetal stimulation. In the former case the nystagmus was very fine and irregular, in spite of the fact that the nystagmus was well induced (it was nearly the same as in the normal eye in the latter case). Foveal vision is very important for the formation of the slow component of optokinetic nystagmus. Foveopetal movement of the image on the peripheral retina is very important for the formation of the quick component. Foveofugal movement on the peripheral retinal has, on the contrary, only a small effect in attracting the eye.


The mechanism of inhibition of caloric nystagmus by eye closure. 24 normal adults and 324 clinical cases were examined, for the purpose of shedding light on the mechanism of inhibition of caloric nystagmus by eye closure. When the eyes were closed, an eye was suddenly adducted 13 +/- 5 degrees and elevated 55 +/- 11 degrees. These adductive and upward eye movements were normal responses caused by eye closure. Caloric nystagmus was inhibited by upward eye deviation. With the turning down of the vertical eye position, the caloric-nystagmus inhibition was released. During eye closure, there were four types of vertical eye-movement responses: (a) holding the eye position up, (b) fluctuation around an upward eye position, (c) gradual downward turning, (d) sudden downward turning, Types a, b and c were seen in normal subjects. However, type d was not seen in normal people.


The tonic oculomotor function of the cervical joint and muscle receptors. Cases of peripheral labyrinthine lesions were examined by stimulation of the cervical joint and muscle receptors. Head-chin (HC) position to one side induced compensatory oculomotor tone (ipsilateral nystagmus), which depended on the function of the horizontal canal of that side. This compensatory tone increased the duration of the optokinetic after-nystagmus (OKAN), with stripes moving contralaterally to the HC position. Isometric contraction of the muscles which rotate the HC to one side induced ipsilateral oculomotor tone (contralateral nystagmus), which depended on the function of the utricle acting in the same direction. In one case, the muscle-induced tone increased the frequency of the OKN with the slow phase in the same direction; in another, it prolonged the slow-phase pursuit interval. In the absence of a vestibular component, distortion of the OKN was induced.


Calcium ion uptake and exchange in otoconia. Calcium ion uptake into otoconia and bone mineral of the young adult rat was studied by use of 45Ca and liquid scintillation spectrometry. Results showed that saccular and utricular otoconia take up 45Ca in a time course generally comparable to bone but on a much lower scale. Saccular otoconia showed greater uptake than utricular. The results are interpreted to indicate the dynamic nature of saccular and utricular otoconia and their possible importance in preserving ionic homeostasis of the inferior and superior parts of the labyrinth, respectively.


The cochlear blood flow in relation to noise and cervical sympathectomy. The effect of noise and unilateral transection of the cervical sympathetic trunk on cochlear blood flow was studied in anesthetized cats. The sound pressure level was 100 dB and the exposure time 6 min. Neither noise nor sympathectomy were found to affect the blood flow.


A critical evaluation of the glycerol test in Meniere's disease. From the literature it is apparent that the glycerol test is being used frequently to evaluate Meniere patients, with regard to the choice of treatment, and in particular to find those who are suitable for surgery with different decompressive procedures. In our previous investigations on such patients we found that they often are extremely good placebo responders and it was natural to evaluate how important such psychological factors would be for the outcome of the glycerol test. In a group of patients with typical objective and subjective symptoms of Meniere's disease, the glycerol test was applied twice to each patient. In one of the tests, the patient was told that we would expect hearing to improve. In the other test, where the actual amount of glycerol was the same, we had the solution prepared with a different taste, and the patient was informed that we now would expect the hearing to deteriorate. The sequence of the two tests was randomly chosen for each patient. Most frequently the patient would follow our instructions, i.e. obtained a poorer hearing threshold when instructed to, and vice versa. The results are discussed with a special view to the risk of selection of suggestion-sensitive patients by this test.


Hearing improvement in attacks of Meniere's disease treated with pressure chamber. A method to reduce endolymphatic pressure by exposing patients with Meniere's disease to underpressure has earlier been described. In this work the possible mechanisms are discussed. A material of 36 patients with acute attacks, treated in this way, is now presented. 15 out of these patients experienced a rapid hearing improvement. In 11 cases the remission has lasted for more than 1 year. The method seems to be of great value for those who improved, since at least an early permanent damage to the cochlea can be avoided.


Cat primary canal neurons: relation of conduction velocity to resting and dynamic firing characteristics. Spontaneous discharge patterns of first-order canal afferents were analyzed in cats anethetized with pentobarbital sodium with particular emphasis on the relationship of regularity of resting discharge, sensitivity to angular acceleration and adaptation to the time delay between electrical labyrinthine stimulation and recording from afferents near Scarpa's ganglion. Regular units were found to have a high resting rate, low sensitivity to angular acceleration, were mostly nonadapting during prolonged acceleration and showed relatively long latency to electrical stimulation. Irregular units tended to have a low resting rate, high sensitivity, frequently showed adaptation and had short latencies. Intermediate neurons had mixed characteristics of regular and irregular units. In medulated nerve fibers, a direct relation exists between conduction velocity and fiber diameter. As latency is due primarily to conduction in the first-order axon, we may speculate that regular neurons have thin fibers which innervate the slope of the crista, irregular neurons have thick fibers which innervate the summit, and intermediate units have medium caliber fibers which innervate both the slope and summit of the crista ampullaris.


Analysis of nonlinear afferent response properties from the guitarfish semicircular canal. Nonlinear afferent response properties from the isolated guitarfish semicircular canal were investigated using a nonlinear system identification technique of combined high and low frequency rotational acceleration stimuli. Linear system unit impulse responses obtained from the dual inputs were systematically different relative to those obtained from low frequency stimuli only, implying nonlinear interactions. These results were attributed to neurophysiological mechanisms of phase locking and increased afferent excitability. A hypothesis was proposed in which similar nonlinear interactions could result from efferent activity in intact animals, suggesting that the efferents could act as a regulator of afferent response dynamics.


Genesis and maturation of vestibular hair cells. The embryologic development in vivo and in vitro of mammalian hair cells in the crista ampullaris was continuously followed with regard to structural differentiation and maturation from the terminal mitosis to the morphological condition at partus or equivalent age in vitro. Otocysts were explanted both early and late during embryologic development: 13th and 16 gestation day, respectively. Both in fetal life and during in vitro conditions, the surface structures of the developing hair cell with regular arrangement of kinocilium/stereocilia were first differentiated, followed by a cytologic transformation intracellularly and subsequent development of nerve endings. Hair cells were able to develop without any morphologic contact with the nervous system. The afferent nerve system developed before the efferent nerve system (CBA/CBA mouse).


Height vertigo and human posture.

Height vertigo and human posture. A theory is presented supporting a geometrical explanation for physiological height vertigo being a distance vertigo through visual destabilization of postural balance when the distance between the eyes and visible stationary contrasts becomes critically large. Physiological and posturographic data obtained under natural height vertigo conditions are consistent with this hypothesis.


Human development through occupation: theoretical frameworks in contemporary occupational therapy practice, part 1. In 1968, the report of a conference sponsored by the American Occupational Therapy Association called for the development of an integrated theory of occupational therapy. A review of the practical problems faced by therapists today, contrasted with major developments in the art and science of the field during the past decade, suggests that this goal has not been attained. However, three major theoretical frameworks for therapy have evolved through the work of Fidler and Mosey, Wilbarger, and Llorens, who participated in the conference on theory. Reilly and associates developed a fourth framework of significance. Through analysis of theoretical constructs, generic concepts that characterize occupational therapy can be identified. Theoretical constructs and research validation of the four approaches to occupational therapy are discussed in this article. A second article to appear in a subsequent issue of AJOT illustrates the use of the four theoretical frameworks to derive a philosophical basis for practice and a model of the practice process called "human development through occupation."


Upper extremity edema control: rationale of the techniques. Edema of the upper extremity is a condition frequently encountered by those interested in hand rehabilitation. It frequently accompanies other problems associated with functional restrictions of the upper extremities. Its control and prevention are a part of the total rehabilitation of these extremities. Persistent edema becomes painful, disfiguring, and disabling. Fibrosis develops in the edematous tissue leading to contractures. The susceptibility for infection increases and the functional ability of the limb decreases. Treatment is based upon an understanding of the pathophysiology of edema. Edema occurs when there is an imbalance of effective pressures across the capillary membrane or when there is an obstruction to venous and lymphatic flow. The conservative treatment program consists of elevation, massage, use of external compression devices, exercises, and instructions to avoid contributing factors. This paper will discuss the physiologic rationale for the effectiveness of these treatment methods.


Human development through occupation: a philosophy and conceptual model for practice, part 2. The development of a philosophy of practice called "human development through occupation" is described in this paper. This philosophy was developed through study and identification of generic concepts in four major theoretical frameworks for occupational therapy described in a preceding article. The philosophy of practice proposes a view of Man, a view of human health, and a view of the profession. These theoretical and philosophical resources are then used to construct a conceptual model of the content and sequence of the occupational therapy practice process. It is believed that the four theoretical frameworks, philosophy of practice, and conceptual model detailed in these two papers can provide direction for general practitioners and specialists in service, education, and research. Examples of application are included, together with suggestions for further investigation.


The overtranquilized patient.

The overtranquilized patient. When first seen, the overtranquilized patient may already be in withdrawal, may have other medical problems or may be seeking psychiatric help. The patient may, however, be primarily interested in obtaining more medication. Abuse and withdrawal of sedatives, tranquilizers, narcotics or alcohol, or a combination of these, present diagnostic pitfalls. Toxicologic studies are helpful in identifying the abused drug. The pentobarbital tolerance test is valuable in determining the daily dosage, stabilization and tapering. Follow-up is essential to patient care.


Interpretation of the electroencephalogram. The background pattern is described in terms of frequency and amplitude. Waves of varying frequencies may be normal or abnormal, depending on the patient's age and state of wakefulness. Specific features sought in the EEG are slowing of frequency, asymmetry of frequency or amplitude, paroxysmal disturbances, and spikes and sharp waves. Certain abnormalities may be present only after provocation by hyperventilation, sleep deprivation or induction, photic stimulation or drugs.


Myoglobinuria.

Myoglobinuria. Myoglobinuria has a variety of causes, ranging from trauma to heavy exercise. Symptoms usually consist of myalgia and muscle weakness; dark, bloody-looking urine may be noted. Myoglobin can be identified by readily available laboratory techniques. Acute renal failure can be a dangerous consequence of myoglobinuria but, with rapid recognition and strict monitoring, the prognosis in most cases is good.


Childhood automotive safety.

Childhood automotive safety. Automobile accidents are the number one killer of children. Effective devices for protecting infants and older children are now available. Counseling the parents on the proper use of car seats should begin in the prenatal period and should continue during regular checkups. Knowledge of the excuses that parents give for not using these devices can help offset some of the existing apathy. Family physicians are in an ideal position to provide proper preventive health counseling on the use of car restraints for children.


Ornithopulmonary disease.

Ornithopulmonary disease. Severe pulmonary infections in man may be caused by exposure to infected birds or their droppings. Ornithosis, histoplasmosis and cryptococcosis develop as a result of inhalation of an infective agent. Pigeon-breeder's lung is an allergic alveolitis caused by a hypersensitivity reaction to avian droppings or feathers. This condition is recurrent and is best treated by avoidance of further exposure. Corticosteroids are useful in acute cases.


Temporary atrial standstill.

Temporary atrial standstill. Temporary atrial standstill is a relatively rare event requiring intraatrial electrogram recordings for its documentation. Previous reports have emphasized its relationship to drug intoxication, infarction, the immediate post open-heart surgery period, or the premorbid state; significant impairment of atrial excitability is usual. The occurrence of atrial standstill in the presence of intact atrial excitability suggests "electrical isolation" of the atria. The three patients we describe manifested temporary atrial standstill while maintaining atrial excitability. Diffuse conduction system disease and drug effects played a contributory role.


Surgical treatment of anomalous left coronary artery from pulmonary artery: follow-up in teenagers and adults. To determine which method of surgical therapy might be optimal for patients with anomalous left coronary artery from the pulmonary artery (ALCAPA), a follow-up study was performed. Twenty-nine teenagers and adults who had ALCAPA diagnosed during life at age 13 years or older were identified mainly by literature search. Recent follow-up was obtained on all. Thirteen treated by ALCAPA ligation alone (Group A), were followed a mean of 9.2 years postoperately (range 1 to 15 years). There was no operative mortality. Three Group A patients died suddenly; a mean of five years (range 2 to 7 years) postoperatively. Sixteen patients treated by simultaneous ALCAPA ligation and saphenous vein graft (SVG) from aorta to left coronary artery (Group B) were followed a mean of five years (range 0 to 11 years) with one intraoperative death and no late mortality. Using the generalized Wilcoxon test for single censored samples, there was no significant difference in survival at any postoperative year when comparing both Groups A and B. The late appearance of sudden death in three Group A patients and no late deaths in Group B patients suggests that ligation and SVG, or its equivalent, may be the therapy of choice.


Analysis of human atrial fibrillatory waves using monophasic action potential technique. In 29 patients with atrial fibrillation, using the monophasic action potential technique, the fibrillatory waves were recorded and analyzed by statistical methods. Concerning the characteristics of the fibrillatory waves there are no differences between patients with rheumatic heart disease and with coronary heart disease. The patients with paroxysmal forms and those without heart failure and with normal heart size, have similar statistical data with regard to their fibrillatory waves. From the data presented, it could be possible to predict the efficacy of conversion to sinus rhythm and also the sinus rhythm stability after conversion.


Use of oral prazosin hydrochloride in congestive failure following acute myocardial infarction. The hemodynamic effects of the new oral vasocilator prazosin were evaluated in 11 patients with congestive failure following myocardial infarction. Prazosin decreased pulmonary trunk, pulmonary capillary, and right atrial pressures, systemic blood pressure, systemic vascular and total pulmonary resistances, and the heart rate X systolic blood pressure product (P less than 0.001). Cardiac and stroke indexes increased (P less than 0.001 and P less than 0.02, respectively). Heart rate, myocardial perfusion gradient, and stroke work index remained unchanged (P less than 0.05). Prazosin effect began in most patients 30 minutes after an oral administration of 2.5 to 7 mg; the maximum effect occurred from one to three hours later. The action is sustained for at least 6 hours in most patients and sometimes is present even 12 hours after a single dose administration. We conclude that prazosin, with a nitroprusside-like effect, improves left ventricular performance and myocardial O2 supply-demand relationship in patients with acute myocardial infarction, but optimal doses vary significantly, and the hazard of severe and sustained hypotension, or decline in cardiac output in patients with normal blood pressure or slightly elevated filling pressure, is present.


Echocardiography and fetal heart sounds in the diagnosis of fetal heart block. A 32-week fetus was demonstrated phonocardiographically and echocardiographically to have a regular atrial rate of 150 per minute and a regular ventricular rate of 39 per minute, indicating complete heart block. The diagnosis was suspected when two groups of heart sounds at two distinct rates were heard on auscultation, and was confirmed by the postnatal ECG. The maternal history was significant for the presence of systemic lupus erythematosus. The basis for the echocardiographic diatnosis of complete heart block, the presence of atrial heart sounds in complete heart block, and the relationship of maternal SLE to congenital heart block are discussed.


Local exhaust ventilation principles.

Local exhaust ventilation principles. Many industrial local exhaust ventilation systems have inadequate performance. This occurs because systems were poorly designed. Frequently, the performance of the local exhaust ventilation systems is impaired because of modifications. Nine factors which should be considered when designing a local exhaust ventilation system include: 1. minimizing capture distance; 2. providing adequate capture velocity (or adequate exhaust rate); 3. using gravitational force; 4. providing adequate conveying velocity for particulates; 5. minimizing pressure drop; 6. incorporating "containment" whenever possible; 7. providing even airflow distribution at hood faces; 8. placing the fan as the last system element whenever possible; and 9. installing a static pressure gauge and testing the system.


A comprehensive program in asbestos hazard surveillance and education. The surveillance program of asbestos workers at the Long Beach Naval Shipyard consists of a variety of clinical examinations and consultations; educational efforts targeted toward individual patients and groups; environmental measurement; maintenance of pertinent monographic and periodic literature; and records and report maintenance.


Size-selective preparation of inorganic fibers for biological experiments. Size-selective procedures were developed for the preparation of fiber fractions of uniform size of chrysotile, crocidolite, amosite and glass. The raw material was first ground to a suitable fineness, then prescreened in a vibrating bed aerosol generator and finally suspended in liquids by ultrasonic agitation. Size-separation was then achieved by slow sedimentation. In addition, fiber fractions of exceedingly long-fibers were prepared by utilizing a vibrating sieve in the gas phase or in liquids.


Gas chromatography/mass spectrometry: its application to industrial hygiene analytical problems. The mass spectrometer (MS), when used as a detector for the gas chromatography yields a system (GC/MS) which is compatible, sensitive, and provides specific information, suitable for qualitative or quantitative analyses for industrial hygiene samples. Examples of the use of two GC/MS/Data Systems utilizing industrial hygiene samples as encountered during the health hazard evaluation efforts of NIOSH (National Institute for Occupational Safety and Health) are presented. A quadrupole unit has been used as a service tool to analyze industrial field samples and a high resolution double focussing unit has been used in the areas of method development research.


Workplace exposure zones for classification of employee exposures to physical and chemical agents. A method involving classification of employee job tasks into exposure zones is proposed to guide the industrial hygienist in assigning personal samples to employees in a facility. Workers are assigned to an exposure zone on the basis of similar profiles of chemical exposures, ventilation characteristics, and job tasks. Two facilities are used to illustrate the power of the exposure zone method to reduce the number of required samples while increasing the confidence of identifying workers at high risk. Details of the zoning and calculation procedures are described in detail.


Retrospective industrial hygiene surveys. The true test of the long-term response of workers exposed to a hazardous agent is usually the epidemiological studies performed on same. This necessitates the long-term knowledge of exposure levels. Usually, the extent to which the exposures measured during recent experiences are representative of past exposures is difficult to assess as only limited historic measurements are available, and oftentimes the limited data are difficult to relate to today's measurement techniques. It is fallacious to assume that the conditions were worse in the past as it is fallacious to assume that they were better. The methodology of estimating past exposures to an agent based on industry-wide survey techniques is discussed.


The clearance of cadmium aerosols after inhalation exposure. CdO and CdCl2 aerosols were inhaled by two groups of rats and their subsequent clearance behaviour was studied. The half-life of the long term lung clearance rates was identical for both compounds, namely 67 days. For CdO, an initial faster clearance was observed, whereas the initial clearance of CdCl2 did not differ from its long term clearance rate, resulting in a relatively higher Cd burden of the lung in the CdCl2 study. Cd liver and kidney concentrations were also higher in the CdCl2 study, originating from a high resorption rate duringthe time of the exposure.


Biomonitoring of industrial styrene exposures. Worker exposure to styrene in two fiberglass boat plants was evaluated using conventional sampling techniques. The use of expired air and urine metabolite concentrations as indicators of styrene exposure is evaluated. The concentration of mandelic acid, a styrene metabolite in urine, is quantitated for workers without and with intermittent personal respiratory protection. A urinary Biological Limit Value is determined for exposures to the Threshold Limit Value of styrene.


Benzene exposures during gasoline loading at bulk marketing terminals. A study was conducted at 20 gasoline bulk marketing terminals to determine benzene exposure levels to both Gulf and outside carrier personnel operating at these facilities. Emphasis was placed on breathing zone samples of short duration during loading of trucks at the rack. Racks utilizing various methods of product transfer were surveyed. From the results of the study, it can be seen that the largest employee exposure to benzene occurs at facilities utilizing top loading without vapor recovery. Exposures during loading can exceed 0.5 ppm for an eight-hour time-weighted average.


Comparison of the aerodynamic size distribution of chain-like aggregates measured with a cascade impactor and a spiral centrifuge. Several authors have suggested that chain-like aggregates fragment in the jets of cascade impactors and that the impactor consequently underestimates the median aerodynamic diameter and overestimates the geometric standard deviation (GSD). The aerodynamic size distribution of (Pu0.14U0.86)02.2 aggregates were measured simultaneously with two Mercer cascade impactors and a LAPS spiral centrifuge to investigate this problem. Although the median aerodynamic diameters were generally in good agreement, the impactor consistently measured higher values for the GSD than did the spiral centrifuge. Based on experiments in which losses in the centrifuge inlet were measured, it was concluded that the centrifuge had measured the aerodynamic size distribution more accurately than the impactor. Interception of chain-like aggregates on the first few impactor stages may have been the primary reason for the disparity between the impactor and centrifuge measurements.


Fire fighter noise exposure.

Fire fighter noise exposure. Occupational noise exposure was evaluated for eight fire fighter positions on board three types of emergency vehicles. One hundred seventy code-3responses were monitored and sound pressure levels in excess of 115 dBA found. Futhermore, sound pressures exceeding the OSHA allowable level of 90 dBA for eight hours exposure were determined. Octave band analyses were performed for overall code-3 noise and for specific noise sources on each vehicle. An evaluation of eighty-nine audiograms of fire fighters was also carried out. The findings of this study suggest that under present operational conditions fire fighters experience excessive short-duration, high intensity noise exposure and a hearing conservation program for the fire service is therefore recommended.


Evaluation of dust exposure in asbestos cement manufacturing operations. Previous investigations of the health of workers of the asbestos cement industry have demonstrated dose-response relationships for the diffuse radiographic changes of asbestosis and pulmonary function impairment. Studies of the mortality experience of past employees have also identified levels of cumulative exposure above which an excess of respiratory cancer could be detected. These epidemiologic studies were based on particulate concentrations determined by the midget impinger. We attempted to develop information that might lead to conversion of particulate to fiber concentrations in the industry in order that the risk assessment could be related to the current membrane filter methods. Pairs of impinger and membrane filter samples were taken in the various areas of the plant. Personal samples were also taken to determine the current exposure of workers. The ratio of fiber concentration to particle count varied from 0.63 to 2.5. Por correlation (0.18) was obtained at low fiber and particle counts and good correlation (0.91) was demonstrated in dustry areas where asbestos and silica were handled in a dry form. The concentration of fibers in 80% of the personal samples was less than 2 fibers/cc, and 60% were less than 0.5 fibers/cc. The results also show that no one conversion factor can be used for all areas of this type of operation.


Correlation of fluorescence intensity and carcinogenic potency of synthetic and natural petroleums in mouse skin. After standardized topical exposure of mouse skin to synthetic and natural petroleums, the penetration and persistence of the fluorescent components have been quantitated. Carcinogenicity of the same materials was determined by repeated skin application following by a period without treatment ot allow expression of malignantly transformed epidermal cells. No simple correlation was found for the materials between total specific fluorescence in either tissue or the test tube and their observed capacity to elicit skin necrosis or malignancy. The number of test materials was insufficient to allow generalization; however, the results do suggest that before fluorescence can be effectively employed as a tool for assessing potential occupational exposure to complex hydrocarbon mixtures, considerable refinement of the methodology will be required.


Age effect hearing levels for a white nonindustrial noise exposed population (ninep) and their use in evaluating industrial hearing conservation programs. A nonindustrial noise exposed population (NINEP) describing age effects for white males and females has been established that can be used as a reference in evaluating an industrial noise exposed population (INEP) data base. In making this comparison, it is desirable to match the two populations properly with respect to sex, race and age characteristics. Since there presently does not exist an equivalent black NINEP, it is necessary to first isolate the data representing the black population from the industrial sample. A definite learning curve exists in industrial audiometric data bases, with the degree of learning dependent upon the effectiveness of the hearing conservation program. Therefore, this variation must be considered when attempting to compare the industrial audiometric test data with the white NINEP data base presented herein.


Monitoring personal exposure to ethylenediamine in the occupational environment. A method for monitoring exposure to ethylenediamine (EDA) in the occupational environment is described. The EDA is adsorbed on activated silica gel, desorbed with 0.5 percent aqueous cupric chloride, and analyzed by gas chromatography using a 2 percent KOH on a Chromosorb 103 column. The method is sensitive to 200 micrograms/mL EDA and can detect 1.0 ppmv EDA in samples collected for 4.5 hours at a 300 cc per minute flow. The method has been evaluated in the laboratory and under plant conditions. Other amines do not interfere with the determination of EDA.


Cotton dust sampling efficiency of the vertical elutriator. A theoretical model of the vertical elutriator air sampler based upon the phenomenon of flow separation at the inlet was developed at SRRC. The model's equations were simulated by a computer program (VELUT). The model was calibrated by comparison of available experimental results to isokinetic sampling efficiencies calculated by the model. The calibrated model was used to predict integral efficiencies for a systematic assortment of size distributions of cotton dust. Rather than cutting off cleanly at 15 micrometers, the computer model exhibited a 50% differential efficiency at approximately 20 micrometers. Furthermore, the model predicted substantial non-zero collection efficiencies in the aerodynamic size range of individual cotton fibers. Program VELUT represents an objective method whereby the isokinetic sampling efficiency of the vertical elutriator can be explicitly calculated for any known or postulated ambient dust distribution presented to the sampler at its inlet plane.


Potential hazard associated with scraping preparative thin layer chromatography plates. Scraping TLC plates in a hood leads to contamination of the hood, equipment, worker, and the environment. The magnitude of contamination is presented as a fraction of the chemical delivered, and the effects of plate thickness, dryness, and adsorbent material are examined. Frequent clean-up and decontamination are recommended.


Computerization of data from continuous and sequential air monitoring systems. Continuous and sequential area air monitoring systems are more frequently becoming a necessity in both new and existing chemical manufacturing and processing plants. While these systems have most frequently been installed to alert employees to conditions of possible acute overexposure, they generate a wealth of data valuable in documenting employee exposures over extended period of time. Within the Dow Chemical Company, use of a dedicated microcomputer with area air monitoring systems has proven helful in summarizing each days' data and in calculating month-to-date totals for use in employee exposure documentation over long time periods.


Formation of carbon monoxide in air compressors. Oil-lubricated compressors are said to contaminate the air they compress with carbon monixde from pyrolyzed and oxidized lubricants. Experiments were performed in an instrumented compressor to determine if synthetic oils as lubricants would results in less contamination. The results suggest that for all oils the contamination is actually not great. Published results from low-temperature oxidation of hydrocarbons support this estimate.


AIHA metrication update.

AIHA metrication update. One of the major advantages of the SI is its precise nomenclature and rules of use. Close compliance with the SI nomenclature and rules of use assures that the SI are universally understood without additional parenthetical explanations. In the english system where symbols, abbreviations and other modifications are continuously changing one can never be sure what CFM, cfm, scf, acf, etc. mean unless the author first defines these abbreviations. More detailed information regarding the use of the SI are contained in the references cited at the end of this article.


Computer handling of occupational exposure data. A system has been developed for the computer handling of industrial hygiene data in the Michigan Division of Dow Chemical U.S.A. With the implementation of this system, future epidemiological studies might be completed in a few weeks as opposed to months when done menually. The system is capable of providing lists, either current or historical, of the chemicals used in a particular building; and all the available exposure data for specific employees can be obtained throughout their entire periods of employment. The system is also capable of summarizing all available exposure information for a given chemical. The heart of the chemical exposure data system lies in the record content. Each record contains: 1. Chemical identification number; 2. Employee number; 3. Job classification number; 4. Department index number; 5. Data type code; 6. Exposure data; 7. Units code; 8. Date; 9. Building number and 10. Reference. A detailed discussion of each of these parameters is contained in the text.


Artificial cutting-fluid smoke generation: effect of pressure. Industrial smoke from cutting fluid poses a potential carcinogenic hazard to workers. For toxicity tests, an artificial smoke device needs to be designed. Such a device would be easy to construct if it were known that smoke is a function of heat during cutting processes and not the cutting pressures. Gas chromatograph response was the same for smoke generated with and without pressure. The implication is that smoke generated during a metal cutting process is due to high temperature and is not influenced by the cutting surface pressures.


A method for measuring respiratory volume parameters of large animals during exposure to aerosols. The respiratory volume monitor was specifically designed to aid in quantitative control of exposures of beagle dogs to aerosols without adversely affecting the quality of the aerosol. The system monitors and displays tidal volume, total inhaled volume, breath count and elapsed time of exposure. The error in the total inhaled volume measurement does not exceed 10%.


Personal sampler for NOx.

Personal sampler for NOx. A personal sampler system for NOx (NO + NO2) and NO2 has been developed for monitoring workplace air. The NO2 sampler previously reported from this laboratory uses triethanolamine to trap NO2 which diffuses through a tube of appropriate dimensions. The NOx sampler contains the same elements as the NO2 device, but it is also fitted with a chromic acid impregnated disc; this disc converts NO to NO2 which is then trapped by the triethanolamine along with preformed NO2. The trapped NO2 in all cases is determined as nitrite colorimetrically and NO is measured by difference between the NOx and NO2 values. The NOx sampler gives accurate and reproducible results if the chromic acid disc is in place for 24 hours or less; it is necessary, therefore, to insert and remove the disc within reasonably short times before and after sampling. We believe, however, that this operation will not be a serious problem for the user.


Acute toxicity of methyl fluorosulfonate (Magic Methyl). Methyl fluorosulfonate (Magic Methyl), an active methylating agent used by research chemists, was studied for acute oral toxicity, acute inhalation toxicity, ocular irritation, and dermal irritation. This compound is very hazardous and may have been responsible for at least one human death. The results of these studies confirmed that Magic Methyl is markedly toxic by all routes studied and particularly by the inhalation route since the LC50 value for rats was found to be between 5 and 6 ppm.


An effective hearing conservation program. In a major chemical producing complex, noise problems of all kinds are encountered. One complex of The Dow Chemical Company, the Michigan Division, has approached this problem by setting up a Hearing Conservation Committee consisting of various disciplines: Safety, Industrial Hygiene, Medical, Engineering, and Production. This committee reviews each plant's Hearing Conservation Program bi-annually until all equivalent exposure ratios are less than one. Audiometric data is entered on a computer for rapid evaluation of periodic audiograms.


Investigation of a dual filter sampling method for gaseous and particulate fluoride. A two stage filter method designed to separate gaseous and particulate fluoride utilizing an alkaline treated filter to trap gaseous fluoride and post sampling heat treatment of the filters to promote desorption of gaseous fluoride from particulate phase was compared to standard impinger methods for the collection of hydrogen fluoride. Results indicate a high degree of comparability between the two methods. Initial studies involving the recovery of HF from dusted filters by heat treatment suggest recovery rates may vary directly with the amount of HF sampled for a given dust load.