[Experience with 100 anesthetized patients ventilated with laryngeal mask]. We studied 100 adult patients who were anesthetized for different surgical procedures and were ventilated with laryngeal mask either with spontaneous or controlled ventilation. Despite of the inexperience we achieved an appropriate placement of the mask in 99% of cases; 74% at the first attempt, 22% at the second, and 4% at the third. In 87.8% of patients we had an adequate control of the air way. In 12.2% of cases there were problems in relation to the controlled ventilation. In one patient we were unable to correctly place the mask and another anesthetic technique had to be performed. Laryngeal mask is useful in the control of the air way in anesthetized patients with spontaneous ventilation. Some inconvenience may arise when controlled ventilation is used.


[Paradoxical bradycardia and hemorrhagic shock]. We report two cases of paradoxical bradycardia associated with acute hemorrhage and hypotension in conscious patients who had no antecedents of myocardial disease. In some cases of massive and rapid hypovolemia the occurrence of bradycardia may constitute a protective reflex directed to improve ventricular filling. This reflex is probably mediated by a vagal mechanism which acts on a previously increased sympathetic nerve tone and tends to maintain systemic vascular resistances and keep a cerebral blood flow high enough to preserve conscience level. We discuss the differential diagnosis with vasovagal syncope which can also occur during the initial phases of acute hemorrhage and during the preterminal bradycardia that develops during the so called "irreversible phase" of shock. Paradoxical bradycardia during hemorrhagic shock is always a sign of important bleeding that requires a rapid reposition of volemia. Administration of vagolytic agents is contraindicated since they can favour the occurrence of severe cardiac arrhythmias.


Choice of exercise: a predictor of behavioral risks? After controlling for differences in gender, educational achievement, and exercise duration among a sample of 7,248 Americans 18-34 years old, we found that runners-joggers-fast walkers (RJWs) and tennis players were less likely to be obese, smoke, consume large quantities of alcohol, and drive without seat belts than those who participate in team and an aggregate of other sports. These behavioral differences might be explained by imprecise data, intervening variables such as exercise intensity, or other variables that were not measured. But a more interesting explanation is that running-jogging-fast walking and playing tennis are integral components of healthy lifestyles, and team sports and some other exercise behaviors are part of riskier ways of living. No consistent association was found between duration of exercise and behavioral risk.


Physical activity levels of 5-11-year-old children in England as determined by continuous observation. Continuous observation of the physical activity of 56 preadolescent children was conducted in four regions of England from October 1988 to July 1989. Observations were undertaken during school break times, lunch times, and physical education lessons, as well as during the children's free time. Of total time observed, the children spent 32.4% of it engaged in moderate to vigorous physical activity (MVPA). Children were shown to be most active during school breaks and least active during free time at home. However, it is thought that cardiorespiratory benefits are best achieved by participation in sustained periods of MVPA. Only 8 (14%) of the 56 children were observed to participate in MVPA for sustained periods of 20 min or longer. A random sample of 55 physical education lessons was observed. Only 6 children engaged in MVPA for sustained periods of 5 min or more, and no children participated in MVPA for 10 min or longer. The implications of these results are that, although the children engaged in a reasonable amount of MVPA, it may not have been sustained for periods of sufficient length to produce a cardiovascular training response. Consideration is given to ways of promoting lifelong involvement in physical activity.


Transition play in team performance of volleyball: a log-linear analysis. The purpose of this study was to develop and test a method to analyze and evaluate sequential skill performances in a team sport. An on-line computerized system was developed to record and summarize the sequential skill performances in volleyball. Seventy-two sample games from the third Federation of International Volleyball Cup men's competition were videotaped and grouped into two categories according to the final team standing and game outcome. Log-linear procedures were used to investigate the nature and degree of the relationship in the first-order (pass-to-set, set-to-spike) and second-order (pass-to-spike) transition plays. Results showed that there was a significant dependency in both the first-order and second-order transition plays, indicating that the outcome of a skill performance is highly influenced by the quality of a preceding skill performance. In addition, the pattern of the transition plays was stable and consistent, regardless of the classification status: Game Outcome, Team Standing, or Transition Process. The methodology and subsequent results provide valuable aids for a thorough understanding of the characteristics of transition plays in volleyball. In addition, the concept of sequential performance analysis may serve as an example for sport scientists in investigating probabilistic patterns of motor performance.


The reliability of distance run tests for children in grades K-4. The purpose of this study was to determine test-retest reliability for the 1-mile, 3/4-mile, and 1/2-mile distance run/alk tests for children in Grades K-4. Fifty-one intact physical education classes were randomly assigned to one of the three distance run conditions. A total of 1,229 (621 boys, 608 girls) completed the test-retests in the fall (October), with 1,050 of these students (543 boys, 507 girls) repeating the tests in the spring (May). Results indicated that the 1-mile run/walk distance, as recommended for young children in most national test batteries, has acceptable intraclass reliability (.83 less than R less than .90) for both boys and girls in Grades 3 and 4, has minimal (fall) to acceptable (spring) reliability for Grade 2 students (.70 less than R less than .83), but is not reliable for children in Grades K and 1 (.34 less than R less than .56). The 1/2 mile was the only distance meeting minimal reliability standards for boys and girls in Grades K and 1 (.73 less than R less than .82). Results also indicated that reliability estimates remained fairly stable across gender and age groups from the fall to spring testing periods, with the exception of the noticeably improved values for Grade 2 students on the 1-mile run/walk test. Criterion-referenced reliability (P, percent agreement) was also estimated relative to Physical Best and Fitnessgram run/walk standards. Reliability coefficients for all age group standards were acceptable to high (.70 less than P less than .95), except for Fitnessgram standards for 5-year-old girls on the 1-mile test for both fall and spring and for 6-year-old boys and girls on the 1-mile test administered in the spring.


The difficulty of sit-ups tests: an empirical investigation. This study estimated the difficulty of various sit-ups tests using an item response theory (IRT) model, the Rasch Poisson Counts model. Scores were obtained on 18 sit-ups tests. All tests were thought to vary in difficulty based on clinical observations. Item difficulty was defined by the Poisson model as the difficulty of Step 1, where the difficulty of a step represented the difficulty of completing a sit-up. The difficulty values of the tests ranged from -4.02 to -3.57. The easiest test was executed with hands on thighs and feet anchored. Most tests had good fit values. The results demonstrated that a variety of sit-ups tests can provide a range of difficulties and variety in forming a sit-ups test bank.


EMG amplitude and spatial assimilation effects in rapid bimanual movement. To investigate whether spatial assimilation effects are due to premovement control processes or postinitiation feedback processes, surface EMG recordings were made from two agonists and one antagonist during both single and dual movements involving the upper limb(s). In the single condition, subjects (N = 7) made 25 Short (20 degrees) and 25 Long (60 degrees) reversal movements using levers in the sagittal plane, in 195 ms to reversal. In the dual condition, both Short and Long movements were performed simultaneously for 75 trials, the last 25 of which were without knowledge of results. Subjects overshot the Short target in the dual condition, showing spatial assimilation effects. Overshooting was associated with increased peak EMG in the initial (premovement) agonist burst, supporting the notion that spatial assimilation effects are modulated via premovement control processes.


"Show and tell" in the gymnasium revisited: developmental differences in modeling and verbal rehearsal effects on motor skill learning and performance. Little research has investigated the observational learning process from a developmental perspective. The purpose of this study was to extend previous research by considering two factors: performance versus learning and sequencing versus form scores. Children (N = 60) comprising two age groups (5-0 to 6-11 and 8-0 to 9-11 years) were randomly assigned to verbal rehearsal only, model only, or model plus verbal rehearsal conditions. The task was a 6-part motor skill sequence in which proper sequencing and quality of form were assessed. A 2 x 3 x 4 (age group by model type by trial blocks) repeated measures MANOVA revealed a significant three-way interaction. Older children performed equally well under any of the model type conditions during both performance and learning. For younger children, a model plus rehearsal was superior to rehearsal only on sequence and form at performance and learning and superior to model only on sequence scores during the first two performance trial blocks. Model only and model plus rehearsal conditions were equally effective on form scores. These results suggest that age differences exist in the modeling of motor skills under conditions varying in model type, sequence and form scores, and performance and learning phases.


Muscular strength and endurance as a function of age and activity level. Muscular strength, endurance, and rate of fatigue were studied in populations of various ages actively engaged in strength and endurance training, as compared with those not engaged in such activities. The strength and fatigability of the elbow flexor muscles were studied for 62 subjects at the ages of 20 (n = 11 active, 10 inactive), 35 (n = 11 active, 10 inactive), and 50 (n = 10 active, 10 inactive) years, tested within 2 years of the appropriate age. They performed a 6-min bout of maximal rhythmic contractions of the dominant arm at a rate of 30 contractions per min. Force applied to the transducer was converted into electrical activity and transmitted to a recorder, where differences in mean values for initial strength, final strength, absolute endurance, and relative endurance were examined for significance. Rates of fatigue and the fatigue curves were also obtained for each group. Results revealed significantly less muscular strength, absolute endurance, and relative endurance as the age of the subjects increased, but no significant difference for age was found in final strength at the conclusion of the exercise bout. Significant differences were found between active and inactive subjects in initial strength, final strength, and absolute endurance in favor of the active subjects. No significant interaction between activity level and age was found for any of the dependent variables. The rates of fatigue were similar for all ages except for the inactive 20-year-old subjects, whose rate of fatigue was markedly slower than that found for all other groups of subjects.(ABSTRACT TRUNCATED AT 250 WORDS)


The effects of cold application and modified PNF stretching techniques on hip joint flexibility in college males. The purpose of the study was to determine the effects of modified Proprioceptive Neuromuscular Facilitation (PNF) flexibility techniques on hip flexion in college males and to determine if local cold application enhances the effectiveness of these techniques. Male subjects (N = 120), with an average age of 21.5 +/- 2.7 years, were randomly assigned to one of four different kinds of stretching treatments with cold or no cold application (15 per group). Range of motion (ROM) in degrees was determined following four stretching techniques: three modified PNF (PCP, 3-PIECP, 3-PIFCP) and a passive stretch (P). Data were analyzed using a 2 (conditions) x 4 (treatments) ANOVA. There were no significant differences in ROM between cold and no cold conditions. Significant differences existed among ROM techniques (p less than .05). Post hoc analyses revealed that the three modified PNF techniques resulted in greater ROM than the passive stretch technique. However, we conclude that cold application does not influence the effectiveness of selected stretching techniques.


Effect of including parents in a school-based exercise and nutrition program for children. The purpose of this study was to examine the effect of parental involvement in a school-based program about exercise and nutrition. One fifth grade and one sixth grade class were randomly assigned to each of the three different treatment conditions, a school-and-home condition (n = 45), a school-only condition (n = 43), and a control condition (n = 44). In the school-and-home condition, the children's parents were also asked to participate in nutritional and exercise activities at home as a family "home team." A multivariate analysis of variance on change scores was completed on the following variables: height, weight, skinfold, sit-and-reach, sit-ups, mile run, exercise knowledge, saturated fat, cholesterol, percent calories from fat, percent calories from carbohydrates, and nutrition knowledge. There was a significant difference among groups. The school-and-home and school-only groups showed significantly greater improvement than the control group but were not significantly different from each other. Univariate analyses on posttest scores indicated that the school-and-home children scored significantly higher than the control group on sit-and-reach flexibility and nutrition knowledge. The results indicate that including the family was primarily effective in facilitating children's improvements in flexibility and nutrition knowledge rather than in diet and exercise behaviors.


Benefit from long-term O2 therapy in chronic obstructive pulmonary disease patients. The Nocturnal Oxygen Therapy Trial (NOTT) and Medical Research Council (MRC) trial have clearly indicated that long-term oxygen therapy (LTO) improved survival in patients with hypoxemic chronic obstructive pulmonary disease (COPD), but the mechanisms accounting for this improved survival could not be established. In particular, there was no link between survival and changes in pulmonary hemodynamics. More recent studies have shown even better results of survival in patients under LTO after at least 5 years. LTO improves the quality of life in these patients by improving their neuropsychological condition, by increasing their walking distance, and by reducing the time spent in hospital. Whether LTO improves pulmonary hemodynamics and right ventricular function is still debated. No significant changes in mean pulmonary artery pressure (PAP) were observed in the MRC study in patients receiving O2 during greater than 15 h/day, whereas a modest but significant fall in PAP was noticed after 6 months in the NOTT patients receiving O2 during greater than 18 h/day. In our own study, confirmed by more recent data from our laboratory, a reversal in the progression of pulmonary hypertension was observed in patients receiving O2 during greater than 16 h/day, but it is not possible to say whether a rather small decrease in PAP and pulmonary vascular resistance will have favorable effects on life expectancy. Presently, we do not know whether LTO can reverse, at least partially, the structural changes in the pulmonary vessels possibly induced by chronic alveolar hypoxia, and we need to perform further studies in this field.


Exercise-limiting factors in respiratory distress. Exercise performance data, circulatory function and respiratory and leg muscle quality, expressed as muscle fiber composition, are reviewed and together with our own data discussed as possible limiting factors for physical performance in chronic obstructive pulmonary disease (COPD). COPD is regarded as synonymous with reduced physical performance, exaggerated breathlessness or dyspnea, muscle hypotrophy and/or wasting and, frequently, malnutrition. Impaired right ventricular circulatory function seems to be essential. The observed preponderance of fast twitch (FT), 'glycogenolytic' and capillary-poor muscle fiber type in the investigated muscles might reflect endowment, a 'hypoxic vasoconstriction'-related downregulation of the other main fiber type: the slow twitch (ST), capillary-rich, fatigue-resistant fiber, and/or selective muscle trauma to ST fibers. Ischemic heart disease (IHD) patients demonstrate a similar fiber type pattern in leg muscles. Both COPD and IHD patients have low leg muscle and plasma deposits of antioxidants such as coenzyme Q10 (CoQ10) and alpha-tocopherol. This could reflect a depressed resistance to radical induced cell trauma and/or malnutrition. The magnitude of the antioxidant reduction is less pronounced in patients rich in FT fibers indicating a ST fiber-related susceptibility to trauma. Treatment of other muscle disorders including heart muscle with, e.g., CoQ10 improves performance due to a causative enhanced antioxidant potential, reduced catabolism and/or an upregulated muscle anabolism, increased mitochondrial volume/function, etc. Such data are lacking in COPD.


Muscle energetics and ultrastructure in chronic hypoxia. High-altitude exposure impairs both maximal aerobic and anaerobic (lactic and alactic) performances. The maximal aerobic power (VO2max) decreases exponentially with increasing altitude. At 5,350 m, a sudden rise in inspired O2 pressure (PIO2) was found to raise the VO2max of acclimatized lowlanders from 70 to only 92% of the control sea-level value. Since the hemoglobin concentration was about 35% higher than that of the controls, hemoglobin O2 saturation was restored to about 100%, and maximal cardiac output was only 10-20% lower than at sea level, the above result can only be the consequence: (1) of a reduced muscle mass and/or of muscle deterioration, and (2) of impaired muscle perfusion. In muscle biopsies taken from the vastus lateralis muscles of mountaineers after a 6- to 8-week sojourn at high altitude, a reduction in the fiber cross-sectional area was found which was accompanied by a decrease in the volume density of the mitochondria and by a lower tissue oxidative capacity. In acclimatized lowlanders, the maximal blood lactate concentration after exhausting exercise was halved compared to sea-level conditions. On the other hand, the peak anaerobic power was not affected by severe hypoxia within the first 3 weeks of exposure; thereafter, it decreased by about 25%, probably as a consequence of muscle deterioration. It is concluded that, whereas in acute hypoxia VO2max is primarily reduced by a lack of O2, in chronic hypoxia muscle deterioration may become an important factor contributing to the limitation of the maximal aerobic performance.


Can long-term oxygen therapy improve exercise capacity and prognosis? The lack of studies as to whether the correction of desaturations during exercise can play a role in improving survival still leaves many problems usually met in the common practice open. (1) Why prescribe long-term oxygen therapy (LTOT) on exercise? Up to now, supplemental oxygen during exercise seems more an approach to the 'dyspnea symptom' than a pivotal component of a comprehensive strategy for long-term management of severe chronic airway obstruction. (2) Who needs LTOT on exercise? It seems reasonable to correct desaturations if this leads to a substantial improvement in exercise tolerance. As to the method of clinical assessment, pulse oximetry can be used for measuring desaturation between rest and exercise, although absolute values are not reliable. (3) How to prescribe LTOT on exercise? In practice, the O2 flow able to prevent desaturation on exercise, restoring an SaO2 greater than 90%, is the usual prescription criterion after an appropriate testing able to demonstrate a significant increase in exercise tolerance and conducted comparing the results breathing air with those on O2, the patient being unaware of the inhaled mixture. (4) How to administrate LTOT on exercise? A portable source is usually employed to allow the greatest possible independency. A reservoir nasal cannula can halve the oxygen wastage and is less expensive than a pulse demand valve. In patients needing 24-hour oxygen therapy the transtracheal catheter is being used more and more at present.(ABSTRACT TRUNCATED AT 250 WORDS)


Is loss of body weight in chronic obstructive pulmonary disease patients with emphysema secondary to low tissue oxygenation? The available clinical information to date does not support the hypothesis that tissue oxygen debt is the primary cause of the wasting process in the chronic obstructive pulmonary disease (COPD) patient population. However, this should not deter the 'believers' of the hypothesis from further investigation. The information outlined above supports the need for reconsideration of this clinical problem. Tissue oxygen requirements and utilization is a complex interplay of multiple variables. Likewise, the assessment of nutritional status in the setting of oxygen therapy is complicated by shifts in body fluid compartments independent of changes in the fat-free mass (FFM). Utilization of newer techniques will be required to resolve the contribution of low tissue oxygenation to the wasting process. The continued development of noninvasive methods for the assessment of tissue metabolism, cardiac function, and tissue energy requirements will allow investigators to further clarify the relationship between tissue oxygenation and metabolism in patients with COPD. Clinical trials designed to examine this issue must recognize the multiple effects of oxygen on all aspects of nutrient utilization, including caloric intake, needs, and tissue delivery. Failure to address all aspects of this system will lead to continued debate regarding the etiology of weight loss in the COPD patient population.


Effects of long-term oxygen therapy due to portable liquid oxygen tanks in disabled malnourished chronic obstructive pulmonary disease patients with borderline hypoxemia. Aim of the study and methods. Long-term oxygen therapy by light-weight portable liquid oxygen systems may improve the degree of functional handicap in patients with severe chronic obstructive pulmonary disease (COPD), borderline hypoxemia or exertional hypoxemia, limited walking distance and malnutrition who do not fulfill the Nocturnal Oxygen Therapy Trial criteria for long-term oxygen therapy. The paper will discuss a proposal for a study plan to test this hypothesis. After a period of stabilization, the methods of measurements include functional tests (walking tests, cycle exercise test [FiO2 21, 35%], baseline measurements of pulmonary function, arterial blood gases, lactate, right heart catheterization, radionuclide ventriculography). The study is designed as a multicentric, controlled, parallel and randomized test for oxygen treatment and no treatment by oxygen. The main outcome will be tested on the results of functional tests (walking tests, VO2max) to demonstrate the possible benefit of long-term oxygen therapy in borderline hypoxemic COPD patients.


Predictors of survival in patients treated with long-term oxygen therapy. Long-term oxygen therapy (LTOT) has been shown in two controlled trials to improve survival in patients with hypoxic chronic obstructive pulmonary disease. The cause of this improved survival is unknown and was best correlated in the Medical Research Council (MRC) trial with the sum of the PaCO2 and the red cell mass. However, the survival curves of treated and untreated patients in the MRC trial for males were not significant until greater than 500 days of treatment. This suggests that some patients derive little benefit from LTOT. Follow-up data from the National Institutes of Health (NIH) trial indicate that pulmonary haemodynamics, including pulmonary vascular resistance, predict survival in such patients. In a previous study in 115 randomly selected patients with chronic obstructive pulmonary disease (COPD) who were not treated with LTOT, we found that PaO2 and PaCO2, measured when breathing air, were more significant predictors of survival than the presence of cor pulmonale or right ventricular function. We have also compared a group of 154 patients treated with LTOT in two centres, in Warsaw and Edinburgh, where criteria for patient selection for LTOT and subsequent survival curves were very similar in both centres. A pulmonary arterial pressure of greater than 29 mm Hg and a PaO2 when breathing air of less than 7.0 kPa produced a significant decrease in survival using a Cox survival model. These results suggest that patients with more severe COPD may not benefit from LTOT. Other factors such as poor compliance with treatment, lack of adequate oxygenation and increasing age of patients prescribed LTOT may also contribute to the reduced benefit from this treatment.(ABSTRACT TRUNCATED AT 250 WORDS)


Indications for long-term oxygen therapy. The Medical Research Council and the Nocturnal Oxygen Therapy Trial studies clearly demonstrated that long-term oxygen therapy (LTOT) for more than 15 h/day improved mortality and morbidity in a well-defined group of patients with chronic obstructive pulmonary disease. There are no similar randomised control studies in patients with other hypoxaemic lung diseases such as pulmonary fibrosis and pneumoconiosis. The prescription of oxygen for other restrictive lung disorders is complicated by hypoventilation requiring mechanical support as well as oxygen and should be restricted to special centres. The clearest indications for LTOT are for patients with cor pulmonale, hypoxic chronic bronchitis and emphysema, and in terminally ill patients who require palliation. Before LTOT is considered, the patient must be clinically stable and on appropriate optimum therapy such as antibiotics, bronchodilators, physiotherapy and having stopped smoking tobacco. Many patients first present for LTOT with profound hypoxaemia and hypercapnia during an infective, often oedematous exacerbation of their lung disease. Assessments should occur during convalescence when the patient is clinically stable. They should be shown to have a PaO2 less than 7.3 kPa and/or a PaCO2 greater than 6 kPa on two occasions at least 3 weeks apart. FEV1 should be less than 1.5 litres, and there should be a less than 15% improvement in FEV1 after bronchodilators. All patients should be assessed by an experienced chest physician. Patients with a PaO2 between 7.3 and 8 kPa who have polycythaemia, right heart failure or pulmonary hypertension may gain benefit from LTOT but this is still to be clearly proven.(ABSTRACT TRUNCATED AT 250 WORDS)


Immunoassay for the determination of surfactant apoprotein (SP-A) in human amniotic fluid: comparison with other indices of assessing foetal lung maturity. The concentration of the major surfactant-associated protein SP-A (28-36 kDa) was determined in 73 amniotic fluid samples obtained from normal (n = 40) and complicated (n = 33) pregnancies. Lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol (PG) levels were also determined in all the samples by one-dimensional step-wise thin-layer chromatography. An enzyme-linked immunosorbent assay was used to determine human lung surfactant apoprotein SP-A. The amount of SP-A in human amniotic fluid increased as a function of gestational age from 8 mg l-1 at 36 weeks to 11.75 mg l-1 at 40-41 weeks of gestation. There was a significant difference (p less than 0.01) in amniotic fluid SP-A concentration from female (9.93 +/- 0.60 micrograms ml-1) compared to male (9.10 +/- 0.52 micrograms ml-1) foetuses. In amniotic fluid samples obtained from a group of complicated pregnancies, SP-A levels were significantly lower than in the normal group when adjusted for gestational age and sex of the foetus (p less than 0.05).


[Chronic urticaria. Characteristics, diagnosis and treatment]. Urticaria and angioedema are skins disorders more frequently in allergy sections of clinics. They are a serious health problem because in 90% of the cases, the causes are not determined and in a similar percentage, the results of treatment are not satisfactory either to the patient or the consulting physician. To find out some characteristics of chronic urticaria in our area, we studied 45 patients who sought consultation at the General Regional and Zone Hospital No. 6 of the IMSS in Ciudad Madero, Tamps., in a given time span. Persons of both sexes and all ages were included. All were given a complete allergy medical history and a complete series of laboratory exams to try to determine the diagnosis. Etiology the treatment was done separating the patients into two groups with four types of antihistaminics considered within the basic medicinal chart of the IMSS. The study shows that the skin rash and angioedema together had a frequency rate of 81.25% with a greater frequency in females (81.25%) between the ages of 20 and 40. The etiology could be determined in only 37.77% of the cases with a high emphasis on parasite. It is notable that in 56.25% of the cases there was an earlier history of some type of respiratory allergy not diagnosed. We observed that there were better results if two antihistamines H1 were combined to provide specific treatment of immunotherapy with good results.


[Epidemiology of allergic diseases in the Tampico-Ciudad Madero- Altamira metropolitan area]. There is a need to know the epidemiology behavior of health problem, with the purpose of creating the supporting basis for all action to its concern. In the cities Tampico, Madero and Altamira, a systematic exploration of the prevalent situation of allergic disorders did not exist: now, there is a study of 730 people selected at random, by means of questionnaire including 55 items applied to the population as a whole that live in the different zones of this area. It has been found that 54% show an allergic illness, it must be observed that in 66% of them a familial allergic history existed, whereas 45% has seasoning crisis environmental-related.


Effects of pivalic acid-containing prodrugs on carnitine homeostasis and on response to fasting in children. Treatment of 17 children aged 2-9.5 years with a combination of pivmecillinam and pivampicillin (250-500 mumol 24 h-1) for more than 1 year resulted in a reduction of the free carnitine concentration in serum and muscle to less than 10% of the mean reference value. The decline in serum was slow, with an estimated half-life of about 5 months. Spontaneous replenishment occurred at about the same slow rate. Thus, there is no increase in endogenous carnitine synthesis as a response to increased demand of carnitine for detoxification. Supplementation with carnitine during treatment required at least a four-fold molar excess over pivalic acid to achieve and sustain a normal carnitine concentration. The replenishment of carnitine occurred with a half-life of 1.1-3.0 months. From determination of muscle-carnitine concentration in patients treated with pivaloyl-containing antibiotics and in patients with organic aciduris, we conclude that serum carnitine is a good predictor of carnitine stores in the body. Six non-supplemented patients with a serum free-carnitine concentration of 0.7-2.6 mumol l-1 had an inadequate ketone-body increase during a 24-h fast. Vomiting, nausea and tiredness occurred in three cases following the fasting period. After normalization of the serum-carnitine concentration, a normal response to fasting was observed. Thus, in some organic acidurias, for example medium-chain acyl-CoA dehydrogenase deficiency, a low liver concentration of carnitine may be an important contributing factor to hypoglycaemic and Reye-like attacks. We believe that prodrugs which contain pivalic acid should be avoided if acceptable alternatives exist. If used, supplementation with at least four-fold molar excess of carnitine is advisable.


Are ethane and pentane evolution and thiobarbituric acid reactivity specific for lipid peroxidation in erythrocyte membranes? Peroxidation of human erythrocyte membranes was followed in vitro with head space analysis of ethane and pentane and a thiobarbituric acid assay in a standardized system liberating free oxygen radicals. Simultaneously, the decrease of the membrane palmitic, linoleic, arachidonic and docosahexaenoic acid was monitored. The recoveries of the peroxidation products of the red cell ghost preparations were compared with those obtained by peroxidation of pure fatty acids. Experiments using purified fatty acids revealed that ethane was preferentially produced from docosahexaenoic and linolenic, and pentane from linoleic and arachidonic acids. Thiobarbituric acid-reactive material (TBAR) was produced from each unsaturated fatty acid tested, but the amount was dependent on the number of carbon chain double bonds. During peroxidation of the erythrocyte ghosts, 72% of ethane and 51% pentane were produced during the first 12 h of incubation, whereas TBAR was produced at a constant rate throughout the 36-h test period. Hydrocarbon and TBAR production were similarly inhibited by desferoxamine (at p less than 0.005 and p less than 0.0001, respectively). The total recoveries of ethane, pentane and TBAR exceeded the amount expected by 7.8-, 1.4- and 5.5-fold, respectively. It was concluded that measurement of pentane is a reliable method to monitor lipid peroxidation during oxidative damage of the erythrocyte membrane.


Glomerular filtration rate in pregnancy: a study in normal subjects and in patients with hypertension, preeclampsia and diabetes. We have studied renal function during pregnancy using plasma clearance of iohexol to determine the glomerular filtration rate (GFR). In normal pregnancy, GFR was elevated by 40% throughout pregnancy and during the first week post partum, and fell to levels similar to those in non-pregnant women within 1 month. The development of GFR in diabetic pregnant women and in women with gestational hypertension was similar to that recorded in normal pregnancy. In subjects with preeclampsia the rise in GFR observed in normal pregnancy was absent, and no change in GFR was recorded after delivery. We conclude that the development of proteinuria and fluid retention typical of preeclampsia is paralleled by a deterioration of GFR.


Proton magnetic resonance spectroscopy of fractionated plasma lipoproteins and reconstituted plasma from healthy subjects and patients with cancer. Proton nuclear magnetic resonance spectra at 500 MHz of plasma and the very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL) fractions isolated by KBr gradient ultracentrifugation were analysed in 16 cancer patients, six pregnant and nine non-pregnant healthy subjects. In spectra with narrow plasma composite aliphatic peaks (methylene at 1.2-1.4 p.p.m. and methyl at 0.8-0.9 p.p.m., respectively), a relative increase in either VLDL, LDL, or both, or a decrease in HDL signals was observed. The mechanism for line-width narrowing seemed different in cancer patients (less signals from HDL relative to VLDL) compared with pregnant women (more signals from LDL). By reconstitution of plasma samples from both healthy subjects and patients with malignant disease, decreased concentration of VLDL or HDL resulted in broadening or narrowing of the composite peaks, respectively. The effects of VLDL and HDL on the plasma line width were moderated by the signals from LDL. Within lipoprotein fractions, the methylene and methyl resonances were shifted to a higher field with increased observation temperature, the change in shift being greatest for HDL. The line width of composite peaks in plasma varied with the observation temperature, depending on the relative concentrations of individual lipoproteins. The correlation coefficient (r) for the relation between total plasma triglyceride level and the average of the line-width of the composite methylene and methyl peaks was -0.78 (p less than 0.001). For spectra of individual lipoproteins, statistical significant relationships were found between line-widths and triglyceride content of the LDL fraction (methyl line-width, r = -0.63) (p less than 0.001) and between methylene line-width and cholesterol of HDL (r = 0.54) (p = 0.003). In summary, the shape and width of the composite aliphatic peaks of plasma were affected by the relative concentration, chemical shift and transition temperature of both VLDL, LDL, and HDL, and by the total triglyceride level. Comparing pregnancy and malignant disease, the lipoprotein resonances contributed differently in giving narrow composite signals.


[Skin reactivity in allergic conjunctivitis]. Allergic conjunctivitis is a very common disease in our country. We intend to determine the most frequent ocular involvement and the specific sensitivity to common aeroallergens. A longitudinal prospective study was performed on 20 patients from the allergy/immunology and ophthalmology outpatient service, Hospital Infantil de Mexico Federico Gomez, from May to July 1990. All of them had allergic conjunctivitis and were evaluated for ocular involvement and reactivity to common aeroallergens by skin prick test.


Enhanced urinary albumin excretion after 35 weeks of gestation and during labour in normal pregnancy. This study reports on the urinary albumin to creatinine ratio during normal pregnancy, with special emphasis on the pre-delivery and labour periods. Albumin was determined in single voided urine specimens obtained from healthy non-pregnant women (n = 16) and healthy pregnant women (n = 203; Groups A and B, 133 females examined during clinic visits and presentation at obstetric department; Group C, 70 females examined during labour) by radioimmunoassay (RIA). The mean ratio (+/- SD) for albumin/creatinine (A/Cr) in non-pregnant women was 1.46 +/- 0.32 mg mmol-1 Cr. Thus, 2.10 mg mmol-1 Cr (mean+2 SD) was considered to be the upper limit of normo-albuminuria. During pregnancy, 73% of the women (97 out of 133, Groups A and B) excreted less than or equal to 2.10 mg mmol-1 Cr. During the first 35 weeks of gestation, 30 of 34 pregnant women (88%) excreted less than or equal to 2.10 mg mmol-1 Cr, the mean being 0.93 +/- 0.64 mg mmol-1 Cr (median 1.0 mg mmol-1). During 36-42 weeks of gestation, the median A/Cr was 1.93 mg mmol-1 Cr (range 0.43-12.16) and 32 of 99 (32%) had values greater than 2.10 mg mmol-1 Cr, an increase of more than two-fold (p less than 0.031) compared with the first 35 weeks. During labour, 61% of non-haematuric urines (33 of 54, Group C) were greater than 2.10 mg mmol-1 Cr, being 125% greater (p less than 0.006) than that observed during pregnancy. Thus in normal pregnancy, A/Cr is increased during the late period of pregnancy and during labour.


Comparison of the proportion of unconjugated to total serum cholic acid and the [14C]-xylose breath test in patients with suspected small intestinal bacterial overgrowth. The proportion of unconjugated to total cholic acid in fasting serum and the 1-gram [14C]-xylose breath test were determined in 36 patients with suspected bacterial overgrowth of the small intestine. Twenty-two patients had an abnormal [14C]-xylose breath test, indicating bacterial overgrowth. The proportion of unconjugated to total cholic acid was significantly higher in the patients with an abnormal breath test compared with those displaying a normal breath test (47 +/- 5% vs 16 +/- 3%). A good correlation was obtained between the proportion of unconjugated to total cholic acid and the breath test (r = 0.63, n = 36). Provided the [14C]-xylose breath test is reliable as a test of bacterial overgrowth, determination of the proportion of unconjugated to total cholic acid in fasting serum had a sensitivity of 73% and a specificity of 94%. It is suggested that determination of the proportion of unconjugated to total cholic acid in peripheral venous blood may be useful as a simple screening test for detection of bacterial contamination of the upper small intestine provided the patients do not have bile acid malabsorption.


Proposal of a new method to avoid misinterpretations in the evaluation of the leukergy test. The leukergy test has been widely used in recent years to detect the phenomenon of leucocyte aggregation in various clinical conditions. It is performed by processing some drops of blood on a slide. According to the authors proposing this test, the leucocyte aggregation is expressed as the mean of the number of aggregates detected among 300 cells of a randomly chosen tract of two slides. We noted, however, that significant differences in the percentage of leucocyte aggregates were sometimes detected between two different slides prepared from the same patient, and hypothesized that an unequal distribution of aggregates along the slide could explain this finding. To test this hypothesis we analysed separately the leucocyte aggregates of three tracts of equal size of blood smears taken from 20 patients. Three slides, numbered 1, 2 and 3, were prepared from each patient. The first tract run by the drops when placing them in the slide showed a significantly lower percentage of aggregates than the remaining tracts (p less than 0.01 post hoc Tukey test). We conclude that the distribution of aggregated leucocytes is unequal along the slide and that the evaluation of the phenomenon of leukergy should always include the count of aggregates of the proximal, intermediate and distal tract of each slide.


Anaplasmosis in Uganda. I. Use of dried blood on filter paper and serum samples for serodiagnosis of anaplasmosis--a comparative study. The suitability of blood collected on filter papers in comparison with corresponding conventional serum samples in the diagnosis of bovine anaplasmosis was studied using the Complement Fixation Test (CFT), DOT-ELISA, Western immunoblot and Rapid Card Agglutination Test (RCAT). Dried blood on Whatman filter paper no. 1 was eluted in 1.8 ml of PBS 0.05% Tween 20 given an initial dilution of 1:100. The reactivity in both DOT-ELISA and Western immunoblotting was similar to that obtained with the sera diluted 1:100. Filter paper samples gave lower reactivity in all the tests as compared with corresponding serum samples. There was no significant difference in the reactivity between the eluates from filter papers stored at room temperature and those stored at 4 degrees C. Storage at room temperature did not significantly affect reactivity for up to 6 months. Eluates from filter papers stored for 6 months at room temperature continued to give similar reactivity to those from freshly prepared filter papers in both DOT-ELISA and Western blot, and in the Rapid Card Agglutination Test. It is concluded that collecting blood on filter papers is a suitable technique for large-scale screening and for seroepidemiological studies on anaplasmosis, and offers many advantages especially in developing countries where transport and cold chain facilities are a major constraint.


Anaplasmosis in Uganda. II. Prevalence of bovine anaplasmosis. The prevalence of bovine anaplasmosis was studied in 320 Zebu cattle randomly selected from three regions of Uganda (central, south-western and north-western) using DOT-ELISA, Western immunoblotting, Rapid Card Agglutination Test (RCAT), Capillary Tube Agglutination Test (CAT), Complement Fixation Test (CFT), and parasitological techniques. Dried blood on Whatman filter paper no. 1 was eluated in PBS 0.05% Tween 20 prior to testing at an initial dilution of 1:25. The incidence of parasitaemia ranged from 25% in the central region to 35% in the north-western region and the serological prevalence was lower in the central region and highest in the north-west. Prevalence rates assayed by DOT-ELISA and Western immunoblotting were 1.5-fold greater than those tested with RCAT and 3-fold greater than in CAT. The overall prevalence rates by DOT-ELISA and Western immunoblotting compared favourably with CFT data. The present data utilizing dried blood on filter papers indicate that there is a high prevalence of anaplasmosis in those regions of Uganda surveyed and it confirms our observations and those of others that collecting blood on filter papers is a suitable technique for large-scale screening and for seroepidemiological studies.


Options for immunocontraception and issues to be addressed in the development of birth control vaccines. Although the number of family planning methods currently available to couples has never been greater, the range and type of options are still not adequate to meet the widely varying personal needs and demands of individuals worldwide. Birth control vaccines offer a number of theoretical attractions although the development, preclinical and clinical testing of such vaccines pose a number of unique problems requiring novel solutions. If the on-going studies in this area are successful, a valuable new family planning method may be available by the end of the current decade.


Anti-sperm and anti-ovum vaccines: the selection of candidate antigens and the outcome of preclinical studies. A clear conceptual basis for anti-sperm and other modes of immunological birth control exists in spite of the limited basic research done on surface antigens of sperm or egg. In the normal physiological condition, the immune system does not respond to sperm, egg or fetus. Compared with anti-egg or anti-fetus immunocontraception, an anti-sperm vaccine has two theoretical advantages. First it would work in both males and females; second, it would not raise problems of autoimmunity in the female if a sperm-specific protein is used. However, for the development of such contraceptive vaccines the following scientific questions need to be resolved: (1) what surface protein to use as an antigen; (2) what adjuvant to use in humans for an anti-fertility vaccine; (3) how to maintain a high titre; (4) how the contraceptive effect will be terminated; and (5) what are the potential side-effects.


Anti-hCG vaccines are in clinical trials. Two vaccines inducing antibodies against human chorionic gonadotropin (hCG) have completed Phase I clinical trials, indicating the reversibility and safety of these vaccines. One is currently in Phase II efficacy trials in women in three major centres in India. The available data suggest that the vaccine prevents pregnancy above antibody titres of 50 ng/ml hCG bioneutralization capacity.


Anti-LHRH and anti-pituitary gonadotropin vaccines: their development and clinical applications. Active immunization against hormones involved in the regulation of reproduction is a promising approach to immunocontraception. The hypothalamic peptide, LHRH, controls the synthesis and release of the pituitary gonadotropins, LH and FSH, which regulate gonadal steroidogenesis, sperm production, follicular development and ovulation. Immunizing female primates against LHRH or LH induces infertility, but also disrupts the menstrual cycle. Immunization against the beta subunit of the placental hormone, chorionic gonadotropin (hCG), or its fragment prevents pregnancy without interfering with menstrual cycles or ovulation. hCG vaccines have reached the stage of clinical trials. FSH and LHRH have been tested for immunocontraception in male primates. While active as well as passive immunization against FSH reduced spermatogenesis severely, azoospermia could not be achieved consistently. Immunization against LHRH effectively suppressed spermatogenesis in rats and rabbits. Normal sexual behaviour was maintained by concomitant androgen administration. Fertility was restored when antibody titres declined and no adverse effects were observed. A number of LHRH vaccine preparations are being tested in men in several countries, including the United States. Since the LHRH vaccine reduces serum testosterone levels the first clinical studies involve men with prostate cancer. These trials will be followed by immunization of normal men if the antibody response is sufficient and no adverse effects are observed.


Anti-trophectoderm vaccines: rationale and methods used for antigen identification and selection. Trophoblast, forming a continuous interface at the maternal-fetal junction, is of considerable interest to biologists. An area of recent research is the search for trophoblast-specific antigens. It is believed that identification and characterization of these antigens may have many practical applications such as in development of contragestational vaccines. To be acceptable for humans such a vaccine will need to be effective before the completion of implantation and appearance of the primitive streak about 14 days after fertilization. This will not alter the menstrual cycle or the time of menses. Vaccines having a later effect resulting in termination of pregnancy after this time would be considered abortifacients. Although logistical and ethical considerations necessitated the use of post-implantation human trophoblast in WHO Birth Control Vaccine studies, the antigens isolated from such tissues would need to be expressed and be detectable on the surface of pre-implantation trophectoderm if they are to represent appropriate candidates for vaccine development. The criteria for identification and selection of these antigens will be reviewed.


Future perspectives for vaccine development. The successful development of an anti-fertility vaccine necessitates overcoming obstacles in eliciting an immune response to self species body constituents. The feasibility of accomplishing this task has been demonstrated for certain antigens described in this workshop; however, additional vaccine candidate antigens may yet be revealed from the application of recent advances in molecular biology. Improvements in vaccine design are likely to occur from discovery of more appropriate epitopes on targeting antigens, new carrier molecules for terminating immunological tolerance, expression of vaccine antigens in suitable live vectors, the co-immunization with more than one antigen, the use of safer and/or more effective adjuvants and vehicles, more efficient immunization by targeting antigens to specific lymphoid cells, and the development of superior vaccine delivery systems. Research directed to restricting the immune response to the genital tract and to intentionally reverse the effects of immunization will likely be pursued in the future. All of these areas need to be addressed if vaccines are to be developed that are not only safe and effective but also highly acceptable as birth control methods.


Immunoblot analysis of sera from Ethiopian cutaneous leishmaniasis by antibody class. We have determined the specificity of the classes of anti-leishmanial antibodies which are detectable in serum from patients with active cutaneous leishmaniasis. On immunoblots, differences exist in the patterns of antigen recognition by IgG, IgM, IgA and IgE antibodies present in localized cutaneous leishmaniasis (LCL) and diffuse cutaneous leishmaniasis (DCL) patient serum. Each class of antibody showed differing patterns of banding to the various molecular species of parasite antigens. There was significant variation in the specificities of the IgG antibody reactivities between individual patients. The patterns of IgM binding were generally homogeneous and restricted to antigens with M(r) greater than 40 kDa. The only class of anti-Leishmania antibodies which showed shared patterns of common antigen recognition by all of the patients studied were IgA antibodies. The reactivities of IgE antibodies encompassed two antigens of M(r) 36 and 46-48 kDa which were not recognized by any of the other isotypes. Such antibody class associated reactivity may be useful in the design of serodiagnostic assays for the detection of Leishmania infection or other infectious agents.


Determination by Widal agglutination of the baseline titre for the diagnosis of typhoid fever in two Nigerian states. This study was carried out in Borno and Plateau States of Nigeria to determine the baseline titre for the diagnosis of typhoid fever using a single Widal test. Of 172 patients with symptoms and signs of typhoid fever, 92.4% and 90.7% had reciprocal O and H antibody titres respectively of 160 or above. On the other hand, 95.3% and 66.3% of the 937 healthy control subjects had reciprocal O and H antibody titres respectively of 80 or less. The results of this study suggest that in Borno and Plateau States of Nigeria a reciprocal O antibody titre of 160 and above in persons with illness whose symptoms and signs are compatible with typhoid fever could be considered diagnostic using the single Widal test.


Cytokine responses to parasite antigens: in vitro cytokine production to promastigotes of L. aethiopica by cells from non-Leishmania exposed donors may influence disease establishment. The various cytokine responses associated with stimulation by parasites is discussed with emphasis on Leishmania parasites. Cells from normal individuals can respond to Leishmania antigens in vitro but the state of the antigen used for stimulation influences the outcome. We have used cells from non-Leishmania exposed donors and stimulated them in vitro with variously treated promastigotes of L. aethiopica. The levels of some cytokines released into the supernatant were measured. All the Leishmania preparations tested induced high levels of IL-6, whereas IFN-gamma production to the different stimuli was variable in the individual donors. The ability of these supernatants to inhibit intracellular forms of L. aethiopica was sometimes stronger in L. aethiopica-induced than in PHA-induced cultures. Such strong non-Leishmania specific responses, if they exist in vivo, may influence whether disease is established when the host encounters Leishmania parasites.


Reduced natural killer cell activity in multi-drug resistant pulmonary tuberculosis. Cellular immune status in five patients with multi-drug resistant pulmonary tuberculosis was investigated and compared with five matched controls with non-resistant tuberculosis. A significant reduction in fresh natural killer (NK)-cell activity was found in the resistant group (P less than 0.005). There were no significant differences between the two groups in lymphocyte phenotype, proliferation or PPD-specific cytotoxicity. Reduced NK-cell function may play a role in the pathogenesis of multi-drug resistant pulmonary tuberculosis.


Identification of anti-Plasmodium falciparum antibodies in human breast milk. Malarial infections are rarely observed in neonates. It has been postulated that some immunity may be passively transferred during nursing, but anti-malarial antibodies (Abs) have not been detected in human milk. In this study, milk samples, collected 2-14 days after parturition from women at the Central Maternity Hospital, Yaounde, were evaluated for total IgG and IgA antibody levels by radial diffusion, protein composition by SDS-PAGE, anti-malarial antibodies using an isotype-specific immunofluorescence assay, and the ability to immunoprecipitate Plasmodium falciparum antigens metabolically labelled with 35S-methionine. Results showed that anti-P. falciparum antibodies were present in breast milk, and that paired milk and serum samples from individual women contained Abs that recognized similar malarial antigens.


Serum interleukin (IL-1 beta) in patients with diffuse scleritis. Scleritis is a painful, destructive inflammatory eye disease. We measured serum IL-1 beta in ten patients with diffuse scleritis and in control subjects matched for age and sex. Patients with diffuse scleritis were found to have significantly elevated serum concentrations of IL-1 beta in comparison to normal subjects (P less than 0.02). The results suggest that IL-1 beta is associated with diffuse scleritis and may influence scleral breakdown in diffuse scleritis.


Ocular and systemic determination of IL-1 beta and tumour necrosis factor in a patient with ocular inflammation. Cytokines such as interleukin-1 beta (IL-1 beta) and tumour necrosis factor (TNF) may play an important role in ocular inflammation. We studied a patient with clinical features of sympathetic ophthalmia secondary to previous penetrating ocular injuries, and compared the ocular and systemic levels of IL-1 beta and TNF to control serum, and correlated these findings to histopathological sections of the patient's eye. Histology showed the presence of a diffuse chronic inflammatory infiltrate within the choroid and in a perivascular distribution in the retina. The significantly elevated ocular and systemic levels of IL-1 beta and TNF suggest that there is not only a localized ocular response but a systemic response as well. The presence of IL-1 beta TNF may play a role in the pathogenesis of ocular inflammation once the blood ocular barrier has been breached and ocular antigens have been exposed to the systemic immune system.


Cells from healthy non-exposed individuals produce cytokines to selected fractions of Leishmania promastigotes. We are interested in cellular responses to antigens of parasites to which the cell donor has not been previously exposed and how such responses may influence parasite establishment. In order to characterize such responses we have used cells from unexposed healthy donors and analysed the lymphoproliferative response to various Leishmania aethiopica antigen preparations and the cytokines produced in the process. Peripheral blood lymphocytes were stimulated with SDS-PAGE separated L. aethiopica antigen coupled to nitrocellulose particles. Fifteen of the 16 unexposed individuals tested had proliferative responses to either the whole or/and the antigen-bearing nitrocellulose fractions (NC fractions). Although the degree of response to the fractionated antigen varied in individuals, major stimulatory fractions were found in the high molecular weight region of 110-80 kDa (fractions 3-6) and low molecular weight region of 46-18 kDa (fractions 12-16). Substantial amounts of interferon gamma (IFN-gamma) and interleukin 2 (IL-2) were present in the supernatants of cells stimulated with the whole unfractionated antigen. The potential relevance of such responses in resistance to Leishmania infection is discussed.


Generation of lymphokine-activated killer cells by adherent LGL phenotype cells and non-adherent T lymphocytes. In this work we separated human blood lymphocytes (PBL) in two populations (A-LAK and NA-LAK cells) by the adherence plastic method. A maximum adherence of cells was obtained after 2 days of PBL incubation in LAK medium containing 500 U/ml rIL-2. The A-LAK cells had LGL phenotype but 40% of them had a macrophage phenotype marker and less than 20% weakly expressed a T-cell marker. This population, when reincubated in culture, produced an increasing titre of interferon. At the same time, a significant NK activity against K562 target cells was measured just after enrichment; these enriched adherent cells also developed an increased LAK activity against DAUDI cell lines, ninefold more at 6 days than when assayed just after enrichment. In contrast, 75% of the NA-LAK enriched cells expressed T-cell marker; these produced two- to threefold less interferon than A-LAK cells at all time-points. The NA-LAK lymphocytes enhanced principally LAK activity measured by 70% lysis against DAUDI target cells tested at 6 days of culture. Further studies are in progress to determine the nature of the effector cells that mediated LAK activity.


Post-mortem HLA tissue typing of retinal pigment epithelial cells. Retinal pigment epithelial cells (RPE) were derived from bulbi of cornea donors and maintained in culture. The time-span between donor's death and cell cultivation ranged from 2 to 122 h. The mean numbers of hours was 25.6 (n = 130). After IFN-gamma stimulation, cells were serologically typed for class I and class II antigens. Unclear class I allospecificities were verified by one-dimensional isoelectric focusing. Data from the serological typing of lymphocytes and those of the serological and biochemical typing of RPE from the same donors were compared in 22 cases. There was a discrepancy of less than 5%, whereby either the typing on lymphocytes could not identify some specificities declared as blanks or the RPE typing had failed to clearly define a specificity. Our data show that the strategy adopted here is very successful for tissue typing post mortem, thus increasing the number of available HLA-matched corneas and consequently reducing the number of corneal graft rejections.


Reactivity of some monoclonal antibodies specific for human lymphocytes with vervet monkey peripheral blood mononuclear cells. Reactivities of some monoclonal antibodies to human lymphocyte surface antigens were tested on vervet monkey peripheral blood mononuclear cells (PBMC), using flow cytometry and immunoperoxidase techniques. A number of antibodies were identified which reacted with similar populations of lymphocytes from vervet monkeys. These included antibodies that define T cells, suppressor/cytotoxic cell subset, pan B cells, monocytes and MHC class I and II. A number of anti-CD4 markers examined were unsuitable for use in the vervet system.


Immunological consequences from exposure to benzo(a)pyrene during pregnancy. Progeny and maternal immune status after benzo(a)pyrene (BP) exposure of mothers at mid-pregnancy is disrupted in fetal liver (FL), in spleen and in thymus during pregnancy and postnatally. Mice suffer deficiencies in splenic and thymic mixed lymphocyte responses (MLR), and disorientations of T antigen expressing cells, punctuated by exorbitant increases in Lyt2, especially in FL. FL Lyt2 do not suppress an MLR, while Lyt1 mediate suppression. Isolated Thy1 show a weak response to Concanavalin A; FL Thy1 weakly express an MLR. Maternal macrophages and progeny B cells are also functionally abnormal. Thus, BP induces generalized immune deficiency that may affect ontogeny and which is potentially deleterious to health.


Iron deficiency and immune responses.

Iron deficiency and immune responses. Iron deficiency is often associated with the impairment of the immune system, particularly the functioning of T-cell lymphocytes. Studies were therefore carried out in mice to investigate the involvement of iron in T-cell functions. Iron deficiency in mice was induced nutritionally by feeding diets differing in iron content for 4 weeks to produce normal, moderately low and severely low haematological indices. The proliferation of lymphocytes stimulated by Con A from these groups of mice was significantly affected by the degree of iron deficiency. Iron depletion also resulted in decreased production of interleukin 2 (IL-2) in the proliferating cells. The implications of these findings in the manifestation of iron deficiency anaemia are discussed.


IgG subclass values from normal children in Cape Town. Sensitive and reproducible enzyme-linked immunoabsorbent assays (ELISA) have been developed to quantitate IgG subclass levels using monoclonal antibodies. Normal values for serum IgG subclass levels were determined in 300 healthy children between 6 months and 14 years of age and in 80 adults. High levels of IgG1 and delayed maturational development of IgG2 in children from Cape Town are different to results reported from developed countries. Genetic differences may account for this.


Vaccination of the vervet monkey (Cercopithecus aethiops) against infection with Schistosoma mansoni. Pilot experiments were carried out to assess the immunizing potential of radiation-attenuated cercariae of S. mansoni. Groups of 4 monkeys each were vaccinated 4-5 times at 3-5-week intervals using cercariae which had received 10, 20, 40 or 60 krad of gamma radiation. Animals were vaccinated with 1000 or 2000 cercariae per kilogram of body weight. Overall the difference in worm burdens between the vaccinated and unvaccinated groups was highly significant (P greater than 0.01). The highest level of protection achieved was 44.4%. This was in monkeys which were immunized five times with 2000, 20-krad cercariae at 3-4-week intervals. Protection levels of 33.3%, 36.6% and 37.0% were achieved in groups which had received, respectively, 1000 20-krad cercariae, 1000 10-krad cercariae, 2000 40-krad cercariae and 2000 60-krad cercariae. Vaccination reduced faecal egg counts markedly and intestinal tissue egg counts by 20-40%. Antischistosomular antibody was detectable in vitro 3 weeks after the first vaccination. Schistosomule kill rates of up to 60% were observed in vitro.


Immune responses after treatment for Schistosoma mansoni infections. The changes in the immune responses of patients before and at 3 weeks after treatment with anti-schistosomal drugs were investigated. Lymphocyte responses to Concanavalin A and to worm antigens were inhibited after treatment, whereas responses to cercarial and egg antigens remained unchanged. Eosinophil levels were significantly elevated after treatment and were positively correlated with the increase in anti-worm antibodies (r = 0.587), and negatively associated with anti-egg antibodies (r = -0.727). Although the eosinophil-dependent cytotoxicity to schistosomula was not significantly enhanced after treatment, some increased killing was evident of half the patients (7/15). On the other hand, the ability of adherent mononuclear cells to stimulate eosinophil functions was markedly enhanced by treatment (P less than 0.001). These studies suggest that treatment may enhance some of the potentially protective host's immune mechanisms.


Isolation and properties of 600-kDa and 23-kDa haemolymph proteins from the tsetse fly, Glossina morsitans: their possible role as biological insecticides. The haemolymph of the tsetse fly, Glossina morsitans morsitans, contains a high (lipophorin) and a low molecular weight protein of high densities, 1.11 and 1.29 g/ml, respectively. The purification of the proteins was achieved by a combination of density gradient ultracentrifugation and reported gel permeation chromatography. The lipophorin is of high molecular weight (M(r) integral of 600,000) and consists of two apoproteins, apolipophorin I (M(r) integral of 250,000) and apolipophorin II (M(r) integral of 80,000) both of which are glycosylated. Lipophorin also has a pI of 6.1. However, electrophoresis under non-denaturing and denaturing conditions showed the low molecular weight protein to be a single polypeptide chain (M(r) integral of 23,000). Amino acid analysis revealed a relatively high content of the acidic amino acids as well as serine and glycine. The protein contained lipids as shown by Sudan Black staining but was unglycosylated. Using rabbit antiserum against the isolated protein in immunodiffusion and immunoblotting experiments, no cross-reactivity was detected with haemolymph samples from insects representing six orders. In conclusion, the finding of lipophorin suggests that, although flies primarily utilize proline for their energy needs, there is an active transport mechanism for the supply of lipid requirements. However, the results for the low molecular weight protein indicate that the protein is unique to Glossina, suggesting that it may have an important role in the physiology of this insect and is therefore a significant target for vector management.


IFN-gamma and delayed-type hypersensitivity are associated with cutaneous leishmaniasis in vervet monkeys following secondary rechallenge with Leishmania major. IFN-gamma levels and delayed-type hypersensitivity (DTH) responses were evaluated in vervet monkeys, following secondary infection with Leishmania major (L. major). The animals had previously been vaccinated with leishmanial antigen, exposed to a primary infection and allowed to self-cure. Supernatants of peripheral blood mononuclear cell (PBMC) cultures, stimulated with either L. major antigen or Concanavalin A (Con A), were examined for the presence of IFN-gamma in a double sandwich enzyme-linked immunosorbent assay (ELISA). Significant levels of IFN-gamma were detected during active disease and following self-cure in both antigen and Con A supernatants. Higher levels of IFN-gamma were, however, present during active disease as compared with after self-cure. Positive and strong DTH responses were elicited in all experimental animals, following intradermal injection of fixed promastigotes (5 x 10(7)/animal) before rechallenge, during active infection and following self-cure. Again, strongest DTH responses were obtained during active infection as compared with the other sampling points. There was a correlation between IFN-gamma levels and DTH responses. It was concluded that IFN-gamma secretion and positive DTH responses are associated with secondary L. major infection and represent specific immunological correlates of protection in this disease model.


Anti-Onchocerca volvulus immunoglobulin subclass response in children from Sierra Leone. The humoral immune responses of a paediatric population of 224 children, 2-15 years of age, residing in an onchocerciasis endemic area of Sierra Leone, were studied to gain information that may be useful in the serodiagnosis of prepatent and low-level infections with Onchocerca volvulus. The antigen-specific levels of IgG and IgG4 were determined and evaluated in the context of the parasitological status of the child. Over 87% of the microfilaria-negative children had significant levels of antigen-specific antibodies against O. volvulus, suggesting that a large percentage of this paediatric population were harbouring prepatent or low-level infections. Over 60% of the children in the group that had detectable numbers of microfilariae in skin snips had elevated levels of O. volvulus-specific IgG4. In contrast, only 23% of the microfilaria-negative children had detectable IgG4 responses. The results presented here indicate that measures of O. volvulus-specific IgG4 may be a useful indicator of the parasitological status of children during the very early stages of onchocerciasis.


Cell-mediated and monoclonal antibody-dependent killing of Onchocerca volvulus microfilariae. To identify the target antigens implicated in the adherence and killing of microfilariae (mf) by leucocytes, we incubated nodular mf and leucocytes in the presence of anti-cuticular monoclonal antibodies (MOVs) and fresh serum. Leucocyte donors were patients with a mean age of 37 years (with 0-1 mf/snip), who had lived in the endemic village studied for at least 10 years. After 16-20 h of incubation, up to 74% of the mf could be seen with 10 or more cells adhering to them. By 36-40 h up to 54% of the mf had been killed by the leucocytes in the presence of a cocktail of monoclonal antibodies termed MOV GIV. The degree of killing in control experiments with the monoclonal antibody MOV 1 remained lower (P less than 0.05), ranging from 0.0 to 4.5% of mf with initial viability of 90-95%. Western blotting revealed MOV GIV prominent target antigens of 10.5, 18.0, 23.5 and 27 kDa in crude surface extracts of female O. volvulus. The detected antigens may play a role in host protection.


Cloning and sequencing of hepatitis B virus pre-S and S gene regions. The polymerase chain reaction (PCR) was used to amplify the pre-S1, pre-S2 and S gene regions of hepatitis B virus (HBV). Sera from three different patients were used as the source of HBV DNA. The resulting 1.2-kb amplification product was cloned into the plasmid pIBI30. Restriction enzyme analysis revealed that there are two BamHI sites located about 300 bp apart within the S gene. DNA sequencing revealed a greatest homology to the HBVadw subtype.


Herpes zoster ophthalmicus: an early pointer to HIV-1 positivity in young African patients. We studied prospectively 30 patients, seen over 10 months, who had herpes zoster ophthalmicus (HZO) and who were classified by age, sex, ophthalmological observations and HIV-1 status. Of patients who presented with HZO, 40% were HIV positive, and the majority were less than 40 years of age. The clinical manifestation of HZO has a high positive predictive value for HIV positivity in young patients with this viral infection.


Evidence of immunosuppression by bovine respiratory syncytial virus. Respiratory syncytial virus (RSV) is a major respiratory pathogen in human infants and calves. Calves and lambs infected with bovine RSV show mild clinical signs but they are more susceptible to secondary infection with Pasteurella haemolytica. Lambs infected with P. haemolytica 6 days after experimental infection with bovine RSV had significantly greater magnitudes of fever, higher disease and lesion scores and higher mortality rates than those infected with P. haemolytica or bovine RSV alone (P less than 0.05). Experimental infection with bovine RSV is characterized by alterations in lymphocyte subpopulations and down-regulation of some of their functions. For example, the number of T helper cells is significantly reduced during the first week of infection and peripheral blood mononuclear cells obtained from bovine RSV-infected lambs were less responsive to the mitogen phytohaemagglutinin but more susceptible to P. haemolytica cytotoxin than those obtained from control lambs. Infection with bovine RSV does not significantly affect the humoral immune responses of lambs against P. haemolytica cytotoxin. Bovine RSV does not appear to affect the capacity of alveolar macrophages to present antigens in vitro.


'Silent' HIV infection among wives of seropositive HIV carriers in the Ethiopian community in Israel. We have previously described the phenomenon of 'silent HIV carriers', i.e. individuals with HIV specific immunity and a positive PCR for HIV-1, yet HIV seronegative. In the present study, we have looked for such 'silent' carriers among wives of individuals infected with HIV in Africa (Ethiopia). In addition to determining HIV serology, peripheral blood mononuclear cells (PBMC) were tested by PCR for HIV-1 and for their ability to generate specific antibodies to HIV upon polyclonal B-cell activation (P-BAT). Out of 16 wives so tested, three were HIV seropositive and among the 13 seronegatives, eight were P-BAT positive and five were both P-BAT and PCR positive. These findings suggest that (1) 'silent' HIV carriers may indeed be present in African populations; (2) interpretation of the 'silent' carrier phenomenon is not clear and will depend on clinical follow-up and the ability to culture virus from such carriers; and (3) results of HIV serology in this population and probably in other African populations should be viewed with caution.


Tuberculosis and leprosy: attempts to identify T-cell antigens of potential value for vaccine design. Tuberculosis and leprosy are chronic bacterial infectious diseases which represent major health problems worldwide. It is generally accepted that, on the one hand, effective vaccination strategies are required for satisfactory control of these diseases and, on the other hand, that currently available vaccination measures are insufficient for this purpose. Ideally, a subunit vaccine should be designed which is composed of one or a few protective antigens. In this brief treatise our approach towards the identification of antigens with potential value for vaccine design is described. It comprises high resolution fractionation by two-dimensional gel electrophoresis, transfer of separated fractions by electroelution and testing of separated fractions with viable T cells and accessory cells. Using this approach we find: (1) multiple antigens are recognized by T cells from leprosy and tuberculosis patients as well as healthy contacts; (2) apparently, suppressive antigens exist in leprosy; (3) an antigen cluster which is apparently indicative for immunity against M. tuberculosis is present among secreted proteins. We hope that further improvement of this methodology will help in the rational design of subunit vaccines against tuberculosis and leprosy.


Serodiagnosis of bacterial diseases: problems and developments. Serodiagnosis is useful when pathogens cannot be detected quickly or easily by conventional methods or have been eliminated by the patient. Taking the example of leptospirosis, the microscopic agglutination test to detect specific antibodies after leptospires have disappeared from the patient's bloodstream is of unsurpassed reliability. Unfortunately the test is used mainly in specialized laboratories that can culture leptospires to serve as live antigens. Freeze-dried leptospires may allow the application of the test on a wide scale. The ELISA is useful for the detection of IgM antibodies in humans as a sign of current or recent infection. ELISA results must be confirmed by the microscopic agglutination test. A simplified easy-to-read ELISA using broadly reactive antigen for the detection of all types of leptospires might be useful for a quick detection of acute human leptospirosis. Using an appropriate antigenic preparation the ELISA is useful for the detection of antibodies in animals, e.g. cattle. As for pathogen detection, DNA-based methods such as PCR are promising for an early, quick and specific diagnosis. Antigenic analysis by monoclonal antibodies and genetic analysis by restriction fragment length polymorphism are for the time being complementary methods for the characterization of leptospiral isolates.


Specific IgG subclass antibody levels and phagocytosis of serotype 14 pneumococcus following immunization. Complement and specific antibody directed against capsular polysaccharide are necessary for efficient phagocytosis of pneumococci. In normal adults, specific antibody to pneumococci is predominantly of the IgG2 subclass. However, the role of IgG2 in bacterial clearance is debatable. We therefore decided to investigate the relationship between specific IgG subclass antibody levels and phagocytosis of serotype 14 pneumococcus, before and after immunization with a pneumococcal capsular polysaccharide vaccine. Specific IgG subclass antibody was measured by an ELISA technique and the effect of serum on phagocytosis of radiolabelled pneumococci by normal polymorphs was determined. We found that in the presence of complement, phagocytosis correlated significantly with both specific IgG1 and IgG2 antibody titres (r = 0.547, P = 0.002 and r = 0.464, P = 0.009, respectively). However, in decomplemented sera, the correlation with IgG1 antibody was lost, whereas that with IgG2 antibody was strengthened (r = 0.641, P = less than 0.001). The possibility that IgG2 binds to receptors on polymorphs should be considered.


Humoral factors of natural resistance of Bos indicus cattle selected for antibody titre to Brucella abortus. The concentration of lysozyme, total immunoglobulin and bactericidal activity were measured in sera of Bos indicus cattle, retrospectively screened for specific antibodies to Brucella abortus and classified as being positive reactors or negative reactors. In addition, the effect of complement in the sera was studied to demonstrate complement dependence of antibody-mediated bacterial killing. It was observed that, under the test conditions, serum bactericidal activity and concentration of total immunoglobulin were associated with high specific antibody levels (P less than 0.001). Furthermore, there was a slight decrease in the lytic activity of lysozyme in the sera of animals with high antibody titres.


Ergonomic analysis to characterize task constraint and repetitiveness as risk factors for musculoskeletal disorders in telecommunication office work. A modified activity analysis procedure was devised to quantify the presence of two task attributes identified in previous research as contributing to an increase in work demands and ergonomic hazards. The purpose of this study was to develop an exposure index based on the presence of two task attributes. The utility of this job activity analysis will, of course, be determined by the extent to which workers with varying degrees of muscular pain and discomfort correspond to the risk exposure group we have described. The results of both the medical and psychological assessments of the workers--contained in the final HETA report--will be used to assess the utility of our method and determine whether the task attributes of constraint and repetitiveness contribute to the onset of cumulative trauma disorders among clerical workers.


Priority setting and evaluation as tools for planning research strategy. The growing role of research as a factor for socioeconomic development has also stimulated efforts for setting priorities and for evaluating research strategies. Priorities can be set for problems which are known for their consequences or their existing characteristics. The only way to ensure research on new problems is to allow more space for basic research aimed at revealing new data and at describing new phenomena. Evaluation methods for applied research are available, and they have been successfully used for making research units more effective and for improving the quality of the research in question.


Arctic contaminants: sources, occurrence and pathways. Potentially toxic organic compounds, acids, metals and radionuclides in the northern polar region are a matter of concern as it becomes evident that long-range transport of pollution on hemispheric to global scales is damaging this part of the world. In this review and assessment of sources, occurrence, history and pathways of these substances in the north, the state of knowledge of the transport media--the ocean and atmospheric circulation--is also examined. A five-compartment model of the northern region is developed with the intent of assessing the pathways of northern contaminants. It shows that we know most about pathways of acids, metals and radionuclides and least about those of complex synthetic organic compounds. Of the total annual inputs of anthropogenic acidic sulphur and the metals lead and cadmium to the Arctic via the atmosphere, an estimated 10-14% are deposited. A water mass budget for the surface layer of the Arctic Ocean, the most biologically active part of that sea, is constructed to examine the mass budget for one of the major persistent organochlorine compound groups found in remote regions, hexachlorocyclohexanes (HCH), one isomer of which is lindane. It is concluded that both the atmosphere and the ocean are important transport media. Even for the HCH substances which are relatively easily measured and simple in composition compared to other synthetic organics, we know little about the occurrence and environmental physical/chemical characteristics that determine pathways into the food chain. More environmental measurements, chemical characterization studies and environmental chemical transport modelling are needed, as is better knowledge of the circulation of the Arctic Ocean and the marine food web.


Presence and implications of chemical contaminants in the freshwaters of the Canadian Arctic. Hydrocarbons, stable organochlorines, metals and radionuclides are widespread in the freshwaters of the Canadian Arctic. Petroleum-associated hydrocarbon sources include natural seepage, wastes and effluents from exploration, production and refining at Norman Wells and spills. Hydrocarbons also originate from combustion of carbon-based fuels, generally at lower latitudes and then reach the Arctic with air movements. Organochlorine compounds also move throughout the hemisphere by aerial pathways and have become distributed widely in Arctic fish. The organochlorine at highest concentration in Arctic freshwater is alpha-HCH, while those generally at highest concentrations in the fish are toxaphene, PCBs and chlordane. Metals are ubiquitous in Arctic freshwaters, with inputs of several metals by precipitation superimposed on natural geologic backgrounds. Mercury is found in muscle of fish from Arctic freshwaters at concentrations up to about 0.5 ppm. Radionuclides are also widespread at levels below those acceptable in food, with some local elevations near former mines. The implications of these contaminants for the northern ecosystems and the people dependent upon them are still not clear. Preliminary studies of inducible enzymes in fish suggest that the thresholds for biological damage have not been reached.


Inuit foods and diet: a preliminary assessment of benefits and risks. Traditional Inuit foods are contaminated with chemical residues from industrial and other activities around the world. The intake of polychlorinated biphenyls (PCBs) and polychlorinated camphenes (PCCs) exceeds the 'tolerable daily intake' (TDI) for many consumers. The implications of long term contaminant intake, even for single contaminants, are not known and will be difficult or impossible to determine in the foreseeable future. Traditional foods form a substantial part of the Inuit diet and are a major source of energy and essential nutrients. Available alternative imported foods are nutritionally inferior and substitution may lead to nutritional deficiencies and associated risks to health and to the social and cultural life of Arctic communities.


Arctic marine ecosystem contamination.

Arctic marine ecosystem contamination. The current state of knowledge of levels, spatial and temporal trends of contaminants in the Arctic marine ecosystem varies greatly among pollutants and among environmental compartments. Levels of polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and some heavy metals such as mercury and lead, in Arctic marine mammals and fish are relatively well documented because of the need for comparisons with biota in more polluted environments and interest in the contamination of native diets. Levels of heavy metals, alkanes, polyaromatic hydrocarbons (PAH) and OCs in the Arctic Ocean are comparable to uncontaminated ocean waters in the mid-latitudes. But concentrations of alpha- and gamma-hexachlorocyclohexane (HCHs) are higher in northern waters far removed from local sources, possibly because lower water temperature reduces transfer to the atmosphere. Bioaccumulation of OCs and heavy metals in Arctic marine food chains begins with epontic ice algae or phytoplankton in surface waters. Polychlorinated camphenes (PCC), PCBs, DDT- and chlordane-related compounds are the major OCs in marine fish, mammals and seabirds. Mean concentrations of most PCBs and OC pesticides in ringed seal (Phoca hispida) and polar bear (Ursus maritimus) populations in the Canadian Arctic are quite similar indicating a uniform geographic distribution of contamination, although alpha-HCH showed a distinct latitudinal gradient in bears due to higher levels in zones influenced by continental runoff. Ringed seals from Spitzbergen have higher levels of PCBs, total DDT and polychlorinated dioxins/furans (PCDD/PCDFs). In contrast to other OCs, PCDD/PCDFs in Canadian Arctic ringed seals and polar bears were higher in the east/central Arctic than at more southerly locations. Remarkably high cadmium levels are found in kidney and liver of narwhal (Monodons monoceros) from western Baffin Bay (mean of 63.5 micrograms g-1) and western Greenland waters (median of 39.5 micrograms g-1). Mercury concentrations in muscle of ringed seal and cetaceans frequently exceed 0.5 microgram g-1 especially in older animals. Cadmium concentrations in polar bear liver increased from west to east, while mercury levels were higher in ringed seals from the western Canadian Arctic, which suggests that natural sources of these metals predominate. Studies of temporal trends in OCs in ringed seals and seabirds in the Canadian Arctic indicate PCB and DDT levels declined significantly from the early 1970s to the 1980s. There is a lack of temporal trend data for other OC pesticides as well as for heavy metals and hydrocarbons.(ABSTRACT TRUNCATED AT 400 WORDS)


Fibronectin: role in respiratory distress syndrome and bronchopulmonary dysplasia. Further investigation is required to delineate the biochemical and cellular interactions that influence lung injury and fibrosis. The results from studies in adults, neonates, and animals suggest that fibronectin may play a key role in the development of pulmonary fibrosis following acute lung injury. Fibronectin as well as other pulmonary cytokines are essential participants in efficient and orderly wound repair; however, the excessive production of these mediators may result in an exaggeration of the normal healing process with the eventual outcome of pulmonary fibrosis. The potential role of fibronectin and other cytokines as mediators and markers of BPD may thus allow for earlier detection and identification of those infants with RDS who are at greatest risk to develop BPD, as well as aiding in the development and selection of therapeutic interventions that can more effectively treat and possibly prevent the deleterious consequences of bronchopulmonary dysplasia.


Retinol (vitamin A) and riboflavin (vitamin B2) administration and metabolism in very low birth weight infants. The combination of marginal hepatic retinol stores at delivery and the reduction of daily retinol dose due to complications with the delivery system places the VLBW infant receiving parenteral nutrition at high risk for retinol deficiency during the first month of life. This has serious health implications because retinol is essential during this period for normal growth and repair of the pulmonary tissue in VLBW infants. Enterally fed VLBW infants, on the other hand, receive relatively higher doses of retinol from vitamin-supplemented premature infant formula and fortified breast milk. Equally serious is the problem of monitoring vitamin A status in infants receiving supplemental doses of vitamin A. It seems clear that while plasma vitamin A levels are the most easily available method of monitoring vitamin A status, further studies are necessary to determine if these levels correlate with hepatic content. This is of particular concern since liver disease is common in VLBW infants and vitamin A hepatotoxicity has been described in a cohort of 41 patients receiving therapeutic doses of the vitamin. While further research of daily enteral and parenteral retinol requirements of VLBW infants should continue, formulation of a specific VLBW parenteral vitamin supplement should also be developed.


Female education, age, parity, and reproduction cessation in Ghana. Data from the 1988 Ghana Demographic and Health Survey is employed to determine the existence of a relationship between the amount of education a woman has and her intent to cease childbearing. The findings are that with increasing levels of education, a female's desire to cease reproduction also increases. However, this relationship is obscured if parity is not controlled.


Education and timing of parenthood among Canadian women: a cohort analysis. This research examines factors associated with the timing of first birth in Canada, focusing primarily on the role of women's educational attainment. Proportional hazards modelling techniques are applied to data from the 1984 Canadian Fertility Survey (CFS) in order to determine how educational attainment, estimated as close as possible to the date of first birth, influences the timing of first birth and whether the importance of this variable varies according to age cohorts. The results suggest that among a number of variables useful for distinguishing different levels of risk, educational attainment proves to be the most important predictor in the model. Education exerts a substantial positive influence on birth timing for women of all age groups. As expected, moreover, significant cohort differences are also evident, with the greatest to the smallest impact on the risk from the youngest to the oldest cohorts. These clear-cut cohort differences indicate a fundamental change in the effects of education over time, a trend most likely resulting from substantial changes in both the content and social significance of formal schooling during the past few decades.


Achievement of reproductive intentions in Sri Lanka, 1982-1985: a longitudinal study. The achievement or reproductive intentions of Sri Lankan women was examined by using longitudinal data for the period 1982-85. Aggregate consistency between reproductive intentions and behavior was almost perfect, but at the individual level there were inconsistencies. Among those who wanted to have no more children, 23 per cent reported a birth in the intersurvey period of 3 years and 2 months, while failures to have a wanted birth stood at 36 per cent. There was a clear declining trend in the former type of inconsistencies in Sri Lanka, but the latter type has increased, possibly due to a continuing decline in family size ideals or due to deferred childbearing. Even though inconsistencies existed, expressed fertility intentions in 1982 significantly influenced the fertility outcome. The study also has a methodological focus on whether to include sterilized women when fertility intentions and behavior are examined longitudinally, but no specific problems were found with their inclusion. Results indicate that, apart from the intention variable, age, marital duration, family size, and education of husband and wife variables all influenced fertility in the follow-up period.


Seasonality of first coitus in the United States. Recent attention to causes of seasonality of births leads to an interest in seasonality patterns in the antecedents to birth, including gestational length, conception, and coital activity. In this paper we study the beginning of the process: first intercourse among adolescents and young adults. Analysis of a small and local dataset is suggestive that loss of virginity is particularly likely during the summer. A test of this "Summer Vacation Theory" using a large national dataset supports the generality of the phenomenon. Further, a prediction that seasonality patterns will change during the transition from high school to work and college is tested and supported. The existence of both biological and psycho-social mechanisms is suggested. Policy implications are reviewed.


Reproductive and socioeconomic determinants of child survival: confounded, interactive, and age-dependent effects. Studies of infant and child mortality have evolved to distinguish between two sets of explanatory variables-factors related to reproductive or maternal characteristics and socioeconomic factors, generally described as characteristics of the family or household. Almost all multivariate analyses include variables from each of these two sets, but there has been little consideration of the relationship between them. We examine how these two sets of variables jointly affect mortality. We test first for confounded effects by examining socioeconomic effects while excluding and then including reproductive variables in nested multivariate models. Next, we look for age-dependent effects among the explanatory variables and find that reproductive and socioeconomic factors affect mortality at differing ages of children. Finally, we examine interactive effects of the two sets of variables. We conclude that the higher mortality observed among the low status groups is not a result of greater concentration of poor reproductive patterns in those groups. Instead, higher status groups probably have more resources available for combating the negative effects of the same high-risk reproductive patterns.


A note of the generalizability of assortative mating coefficients for personality. While numerous studies have reported differential assortative mating coefficients for personality traits, little research has centered on cross-sample comparisons to determine their degree of generalizability. The present investigation examines the assortative mating coefficients for scales of the Minnesota Multiphasic Personality Inventory (MMPI) from five separate studies. An examination of these patterns of significant coefficients offers little support for this cross-sample generalizability. No significant correlations resulted between these studies in their coefficients, even when the unreliability of the different measures was controlled. It is concluded that there is little evidence to support statements of differential importance in assortment for personality variables beyond the sample under investigation.


Determinants of fertility decline in China, 1981: analysis of intermediate variables. This study examines the proximate determinants of fertility in China by making use of the data collected by the One-per-Thousand Sample Fertility Survey of 1982. The results indicate that the most important inhibitor of potential fertility is deliberate control. Its contribution to fertility change has been far greater than all other proximate determinants. The marital structure of the population is also an important factor, while lactational infecundability and induced abortion are relatively unimportant. Comparative results by using data from the In-depth Fertility Survey conducted in Shanghai Municipality, Hebei and Shaanxi Provinces in April 1985 agree well in the ranking of the four intermediate factors. The findings point to successful family planning program and government population policies, which propelled the fertility transition to a substantial degree. Further research needs and policy implications of the results of the study are discussed.


The fitness of human sociobiology: the future utility of four concepts in four subdisciplines. Reported here are the results of a survey inquiring into the rate of acceptance of four sociobiological concepts in regard to their usefulness for future research. Included in the survey were members of four subdisciplines: animal behavior (biology), biological anthropology, cultural anthropology, and developmental psychology. Three types of institutions were included: universities, four- and five-year colleges, and community colleges. A total of 1,631 responses are reported with the degree of acceptance varying from highest to lowest as follows: biology, biological anthropology, developmental psychology, and cultural anthropology. These variations are related to the central concepts of each subdiscipline.