Postoperative adverse events of common surgical procedures in the Medicare population. Mortality rates are the most widely used measure in assessing patient outcome from hospitalization. However, they may be an insensitive measure of quality for surgical patients because death is a relatively rare outcome. A random sample of patient data (n = 8126) selected from the Medicare files of seven states was used to identify, through chart abstraction, clinical postoperative complications of surgery that could serve as measures of quality. Four surgical procedures were studied: 1) coronary artery bypass grafting; 2) coronary angioplasty; 3) cholecystectomy; and 4) prostatectomy. Severity at admission was controlled for using severity-of-illness models developed with chart-abstracted data to predict adverse events after these four procedures. 30-day mortality rates ranged from 1.0% to 6.6%, while the prevalence of postoperative adverse events identified from chart review was greater (6.9% to 33.3%). There were significant differences between patients with and without adverse events. For example, coronary artery bypass graft patients with adverse events had prolonged postsurgical lengths of stay (18.5 +/- 13.2 vs. 13.2 +/- 6.2, P less than 0.001) and higher mortality rates (15.2% vs. 2.6%, P less than 0.001). The R-square values using clinical indicators at admission to predict the occurrence of any adverse event ranged from 0.05 to 0.13. Clinically meaningful adverse events of surgery can be successfully identified through chart abstraction and appear to be valid measures of postoperative complications among surgical patients. Severity adjustment at admission only modestly predicts the occurrence of these adverse events.


Encouraging preventive services for low-income children. The effect of expanding Medicaid. Every year since 1984, Congress has expanded Medicaid to cover an increasing proportion of low-income children. In this study, a multivariate analysis of data from the 1987 National Medical Expenditure Survey was used to determine whether expanded Medicaid eligibility is likely to be effective in encouraging recommended preventive visits for low-income, preschool children. For low-income children who would otherwise be uninsured, a full year of Medicaid increased the probability of any well-child visits by 17 percentage points, and compliance with the guidelines of the American Academy of Pediatrics for well-child visits increased by 13 percentage points. The generosity of Medicaid fees did not alter the magnitude of these effects. However, even if all uninsured children under 200% of the poverty line were eligible for Medicaid, low-income children would continue to lag behind other children in their use of preventive services. Factors other than insurance and income, such as the lower educational attainment of low-income mothers, explain approximately 80% of the gap between children above and below 200% of poverty. The rate of compliance with the American Academy of Pediatrics guidelines was less than 50% for all preschool children. Departures from the recommended schedule of visits were particularly pronounced in the second year of life and may interfere with children receiving the recommended immunizations in a timely manner.


Ownership and organizational performance. A comparison of technical efficiency across hospital types. Using a national data base of urban hospitals, the effect of ownership (government, nonprofit, and for-profit) on the technical efficiency of hospitals was examined. Efficiency scores were computed using a method called data envelopment analysis. Controlling for environmental and hospital characteristics, for-profit hospitals were found somewhat less frequently and government hospitals consistently more frequently in the efficient category. When examining highly inefficient hospitals as a percentage of those receiving inefficient scores, for-profit hospitals appeared to be highly inefficient relative to the other ownership forms. Government and nonprofit hospitals were somewhat indistinguishable from one another regarding their percentages of highly inefficient scores. For-profit hospitals also tended to use supply and capital asset (hospital size) inputs less efficiently, and service and labor inputs more efficiently than hospitals in the other ownership categories.


An analysis of short-term alcoholism treatment cost functions. A number of alcohol treatment studies have documented variations in the average cost of treating alcoholics. However, these studies have provided little explanation for these variations. In this study, three major issues in the measurement of alcoholism treatment costs are investigated: 1) choice of treatment location, i.e., inpatient versus outpatient; 2) interaction of treatment locations in the estimation of costs; 3) impact of type of alcohol problem and comorbidities on treatment costs. The study includes an integrated framework that jointly estimates treatment location and treatment costs conditional on treatment location, concentrating on short-term alcoholism treatment and using insurance claims data to specify a 6-month period beginning with each individual's first treatment for alcoholism. The different treatment types subsumed in the categories alcohol abuse and alcohol dependence are also addressed. Results indicate that comorbidities are crucial in determining treatment location. Once treatment location is determined, however, their effects on treatment costs, while measurable, are statistically insignificant. Partial treatment effects, conditional on treatment location, differ substantially from full treatment effects, which are determined jointly with treatment location.


An analysis of panel data. The impact of a psychiatric consultation letter on the expenditures and outcomes of care for patients with somatization disorder. In this study, the cost and health outcomes of a psychiatric consultation letter to primary care physicians caring for a sample of patients diagnosed with somatization disorder, a psychiatric condition associated with multiple, unexplained medical complaints, was assessed. To accommodate the small sample size of 73 patients, outcome effects were calculated using panel analysis. Study patients were randomized to a consultation or noconsultation group, and were repeatedly assessed at equal time intervals. Data were analyzed using parsimonious regression models derived from economic theory. During the 1-year follow-up period, a psychiatric consultation letter was associated with a 12% reduction in health care costs ($455 per patient within first year), with no evidence of deterioration in physical, mental, or general health. Less powerful t-test comparisons between treated and control groups lead to different conclusions. Reasons for these differences are discussed.


Economies of scope and payment for physician services. Physician payment reform will base payment largely upon physician work. Current reforms assume that services are provided independently, yet physicians may often perform two or more services at one time. There is evidence from other industries that services provided jointly may not require the same total resources as identical services provided independently. This study evaluated whether physician-reported work and time were the same for some common services when provided jointly and when provided separately. Six case vignettes were constructed consisting of two services each. Forty-four general internists rated the total work and time required for each vignette performed as a whole, and for the two services performed separately. Total work was estimated using a magnitude estimation technique similar to that used in developing the resource-based relative value scale. For five of the six vignettes, the work rating for performing the services together was significantly less than the sum of the ratings for the separate services. The work savings associated with providing services together ranged from 4% to 30% of the total work of the separate services. A similar reduction was observed for the estimated time to perform services jointly in four of the six vignettes. In no case was work or time lower when services were provided separately. Physicians report lower work and time for at least some pairs of services, compared with providing the same services separately. Reimbursement mechanisms that fail to account for these reductions may provide incentives to combine or add services.


The impact of the Texas 1989 motorcycle helmet law on total and head-related fatalities, severe injuries, and overall injuries. The State of Texas implemented a mandatory total motorcycle helmet law for all operators and passengers, effective September 1, 1989. In this study the impact of this intervention on frequency of both total and head-related fatalities, severe injuries, and overall injuries for operators during the subsequent year was quantified. This quantification is important because 26 states in the United States fail to have strict, mandatory helmet laws. The Box-Tiao time-series intervention methodology is used to estimate secular trends before and changes after the implementation of the law, analyzing Department of Public Safety monthly injury accident data for a period of 6 years collected from traffic accident reports filed for each motorcycle injury accident. Trends in fatalities and injuries (except for head-related deaths) estimated before implementation of the law approximated the 9.4% average annual decline in motorcycle registrations. Additional declines of 12.6% and 57.0%, respectively, were estimated for total and head-related fatalities during the year after the law was implemented. Declines of 13.1% and 54.6% were estimated for severe injuries for total and head-related accidents. Declines of 12.3% and 52.9% were found for total and head-related injuries overall.


General practitioners' uncertainty, risk preference, and use of laboratory tests. In this effort to explore the relationships between risk-taking attitude and laboratory test use, three different measures of risk-taking attitudes were obtained in a cross-sectional study of 75 Dutch general practitioners. The measures used were based on a Dutch scale by Grol et al. (dealing with risks and self-reproach in missing serious and in self-limiting diseases), measures from the prospect theory (risk preference in face of gain and in face of loss), and the responses to a direct question regarding the relationship between the use of laboratory tests and the fear of missing diagnoses. Mutual correlation between all the scales was low. The laboratory test use of the general practitioner was measured and divided into two categories: 1 "top ten" tests; and 2) the remaining other tests. Two risk-taking attitude measures explain 28% of the "top ten" test variance and three risk-taking variables account for 38% of the variance in the 'other' test usage.


Home blood pressure monitoring. Effect on use of medical services and medical care costs. The objective of this study was to determine whether a hypertension management program in which patients monitor their own blood pressure (BP) at home can reduce costs without compromising BP control. The prospective, randomized, controlled 1-year clinical trial was conducted at four medical centers of the Kaiser Permanente Medical Care Program in the San Francisco Bay Area. Of 467 patients with uncomplicated hypertension who were referred by their physicians, 37 declined to participate in the study; 215 were randomly assigned to a Usual Care (UC) group and 215 to a Home BP group. Twenty-five UC patients and 15 Home BP patients did not return for year-end BP measurements. Patients in the UC group were referred back to their physicians. Patients in the Home BP group were trained to measure their own BP and return the readings by mail. Patients were given a standard procedure to follow in case of unusually high or low BP readings at home. The number and type of outpatient medical services used were obtained from patient medical records for the study year and the prior year. Costs of care for hypertension were calculated by assigning relative value units to each outpatient service. Trained technicians measured each patient's BP at entry into the study and 1 year later. Home BP patients made 1.2 fewer hypertension-related office visits than UC patients during the study year (95% confidence interval (CI): 0.8, 1.7). Mean adjusted cost for physician visits, telephone calls, and laboratory tests associated with hypertension care was $88.76 per patient per year in the Home BP group, 29% less than in the UC group (95% CI: $16.11, $54.74). The annualized cost of implementing the home BP system was approximately $28 per patient during the study year and would currently be approximately $15. After 1 year, BP control in men in the Home BP group was better than in men in the UC group; BP control was equally good in women in both groups. Management of uncomplicated hypertension based on periodic home BP reports can achieve BP control with fewer physician visits, resulting in substantial cost savings.


Physician volume and obstetric outcome.

Physician volume and obstetric outcome. Although much has been written regarding regionalization of obstetric services and inferences made about centralization of labor and delivery, little data exist that specifically address the volume-outcome relationship for obstetrics. The purpose of this study was to determine the relationship between physician volume and perinatal outcome as measured by neonatal and perinatal mortality. A sample of 210,547 births to Missouri residents from 1984 to 1987 was studied using multivariate logistic regression with perinatal death and neonatal death as outcomes. No relationship was found between physician volume and outcome.


Academic pursuits in the multispecialty clinic. Although usually viewed as institutions that provide excellence in health care delivery, the larger multispecialty clinics must also be considered as major national academic resources. The professional staffs at multispecialty clinics not only have provided important contributions scientifically but have also made a major clinical impact on overall health care delivery. This issue is dedicated to the founding physicians of Alton Ochsner Medical Foundation and, in particular, to Alton Ochsner who provided the guiding inspiration in a continuing quest to achieve these academic goals.


Alton Ochsner. The man and his contributions. Alton Ochsner, the senior founding partner of the Ochsner Clinic and the Alton Ochsner Medical Foundation, is a giant among twentieth century medical figures. He was the first to propose that cigarette smoking is the primary cause of lung cancer, and he and four colleagues founded one of the nation's largest group practices and academic centers. A man of great personal charm, energy, and vision, he wished to be remembered foremost as a teacher. His two-generation polemic concerning the adverse effects of tobacco use provided a rich legacy for the amelioration and prevention of disease.


The role of the multispecialty clinic in health care delivery in the twenty-first century. The major multispecialty clinics have established their niche as centers of excellence in coordinated patient care and patient-centered teaching and research. They will be increasingly dependent on local practice and participation in health care plans in future years. Their status as referral centers will hinge on their documentation of cost-effective care of high quality for the ultratertiary patient and on their ability to be recognized for this care by employers, insurers, and national health plans.


Graduate education in the multispecialty group. Graduate education traditionally has had different reasons for being in the multispecialty clinic. Practitioners in the multispecialty clinics have learned that the best way to ensure high quality patient care is with a graduate education program. This article reviews the components of graduate education in a multispecialty setting.


Development of innovative therapies in the large multispecialty clinic setting. Innovation is intrinsic to medicine and to medical progress. As American medicine enters the twenty-first century, it is confronted with enormous opportunities to innovate both in the science and practice of medicine. Indeed, medicine is challenged to do so by society. Cellular and molecular medicine, along with new insights derived from health care research, offer the opportunity to improve the health of the American people without unduly taxing the economy. Research and innovation in these areas are within the grasp of many clinics, and it would seem important that, because they are major providers of health care, as many clinics as possible aggressively enter these fields in preparation for delivering health care in the next century.


The multispecialty clinic in a changing environment. The Ochsner Clinic, faced with a health care delivery environment undergoing dramatic changes, developed a strategy that included the addition of primary care specialists, satellite neighborhood clinics, a distant (regional) multispecialty clinic, and a health maintenance organization. The fundamental changes necessary for a group practice to internalize such a strategy are discussed. The opportunities for graduate medical education and research in the new environment are described.


Myocardial revascularization. Coronary angioplasty and bypass surgery indications. Coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) have been performed increasingly over the last 20 and 10 years, respectively. The growth in PTCA is both complementary and threatening to CABG. The controversy between cardiologists and cardiac surgeons over the role of each procedure will no doubt continue as new devices are developed for coronary interventions. This article reviews the controversy and provides information to internists so that they will be fully prepared to advise patients about their treatment options.


Options for percutaneous coronary and peripheral revascularization. Angioplasty has become an established treatment for both coronary and peripheral atherosclerosis, and a number of new techniques and devices promise to improve the results of percutaneous intervention during the coming decades. It is likely that balloon angioplasty will remain the percutaneous treatment of choice for both coronary and peripheral intervention; however, we look with hope toward the development of new devices that will expand the role of percutaneous angioplasty and improve the long-term success of these procedures. As technical expertise grows with the new procedures, prospective randomized trials comparing them with standard PTCA will be required to enable physicians to judge their clinical utility.


Infections in orthotopic heart transplant patients at the Ochsner Medical Institutions. Ninety-five orthotopic heart transplants were performed at the Ochsner Foundation Hospital. Twenty-nine of 62 patients followed for 1 year had 48 major infections, including 20 bacterial, 15 viral, 7 fungal, and 6 parasitic. Eighty-six percent of all patients survived 1 year, but infections caused five of the nine deaths. Improved diagnosis and therapy of disseminated aspergillosis could have prevented two deaths.


Infections in the compromised host.

Infections in the compromised host. The normal defense mechanisms against infection include (1) normal skin and mucous membranes, (2) humoral immunity, (3) phagocytic system, and (4) cellular immunity. The compromised (immunocompromised) host is an individual who has one or more deficiencies in these defense mechanisms. This article reviews potential infections in the compromised host as well as an approach to evaluation of these patients.


Gallstone disease. Pathophysiology, epidemiology, natural history, and treatment options. In 1991, only symptomatic gallstones should be treated. The treatment of choice for all gallstones continues to be surgical removal. Except for stones in the common bile duct, which are amenable to removal by endoscopic papillotomy, nonsurgical treatment of gallstones should be investigated further before it can have widespread applicability. The major challenge in the future may be medical prevention of gallstone formation in susceptible individuals. Laparoscopic cholecystectomy seems to have moved to the forefront of surgical therapy in patients who are candidates for the procedure.


Selection of patients for peripheral revascularization surgery. The recognition of the extent of vascular disease has introduced several medical subspecialties, radiology and vascular surgery, to a multidisciplinary approach to these problems. Of particular importance is the primary care physician, who often is the first to see these patients and should be familiar with common vascular problems. Only then will initial care and disposition be appropriate.


Innovative therapies in hematology and oncology. As one can see, there are a number of new and exciting advances in the prevention, detection, and treatment of various malignancies. We anxiously await the future to see the exact integration of the tremendous advances taking place in the cellular and molecular biopsy of disease and its application to the therapy of patients.


Selection of patients for kidney organ transplantation. Renal transplantation is a viable alternative for most patients with end-stage renal disease, either before or after the institution of dialysis. Evaluation of potential recipients is necessary before transplantation and is mandatory to exclude patients who are likely to have a poor outcome. Such evaluation also may identify special problems and conditions in patients with end-stage renal disease who will require intervention before transplantation. Identification and evaluation of each transplant donor is also very important. Although organs from related living donors usually have better long-term function, survival, and fewer complications, most efforts in the transplantation community are spent attempting to extend the survival of cadaver kidney transplants. This goal could be accomplished by increasing availability of cadaver organs, improving histocompatibility of donor-recipient pairs, and improving available immunosuppressive therapy.


Cardiac transplantation: clinical aspects of recipient selection. The improved outcome following cardiac transplantation has produced changes in the traditional criteria for potential candidates. We have analyzed these changes and the clinical aspects involved in the selection process, which are of critical importance to assure an excellent result of cardiac transplantation in patients with advanced heart failure.


Selection of patients for lung transplantation. The number of lung and heart-lung transplantations is growing rapidly, and hundreds of combined heart-lung, single-lung, and double-lung transplantations have been performed to date, resulting in increased survival and improved quality of life for patients with end-stage pulmonary disorders. Improved surgical technique, immunosuppression, and optimal patient selection are largely responsible for this success. Although the indications for transplantation continue to expand, the number of potential recipients far exceeds the number of available donors, making the evaluation and selection process vital to the success of any transplantation program. A multidisciplinary approach is presented that can be expected to eliminate a large number of prospective candidates and thus enhance matching limited donor organs with transplantation candidates.


Patient selection for pancreas transplantation. Pancreas transplantation is the only currently available potential cure for type I diabetes. Because of the complications of the procedure and the toxicity of immunosuppression, patients must be carefully selected. The procedure can be justified in patients who already require immunosuppression for a renal allograft. The benefits of improved quality of life and protection from the development of nephropathy in the kidney allograft are significant. Pancreas transplantation alone is harder to justify; the risks of immunosuppression would seem to outweigh the known benefits of normalization of blood glucose. Before pancreas transplantation gains wide acceptance, the graft survival rates must improve. Currently, pancreas graft survival rates are greater than 80% at 1 year, but less than 50% 5 years after the transplantation. Improvement in these rates may occur with the development of more effective and less toxic immunosuppressive agents. Continued improvement in surgical technique should also contribute to overall pancreas transplantation success. Until then, however, pancreas transplantation should be viewed as a therapy for only selected patients in whom the benefits clearly outweigh the risks.


Total joint replacement of the hip and knee. Total hip and knee replacements are among the most common orthopedic surgical procedures performed on patients with arthritis. The procedures are highly successful in appropriately selected patients. The authors approach total joint replacement from a medical perspective, emphasizing indications, contraindications, preoperative evaluation, clinical outcome, and potential complications.


Auditory performance of children with cochlear ossification and partial implant insertion. The management of the profoundly deaf child with a cochlear implant poses a special challenge, particularly when total ossification of the cochlea is present. In this setting, insertion of an electrode array into a child's cochlea is often difficult. Our experience supports the feasibility of partial insertion of a multichannel implant into the basal turn of an ossified cochlea. Five children with ossified cochleae who had undergone partial implantation of a multichannel electrode were compared with the performance of matched controls who had full insertion of multichannel implants. No dramatic differences were detected during a 6- to 18-month follow-up period on selected test measures. These preliminary results suggest that active electrode number may exert a limited effect on performance with a cochlear implant. Drilling out the basal turn of an ossified cochlea in conjunction with partial insertion of a multichannel implant appears to be an acceptable surgical and rehabilitational alternative for placement of a cochlear implant prosthesis in children with complete cochlear ossification.


Preliminary results with the Clarion cochlear implant. A new cochlear implant has become available. This device, called the Clarion Multichannel Cochlear Implant, is the result of collaborative efforts between the University of California, San Francisco (UCSF), the Research Triangle Institute (RTI), Research Triangle Park, North Carolina, and the device manufacturer and sponsor, MiniMed Technologies of Sylmar, California. The Clarion represents a new generation of multi-programmable cochlear implant systems. Options in waveform, the stimulation mode, and the temporal distribution of the signal permit the device to be optimally customized for each individual patient. The speech coding scheme offering the greatest opportunity for speech recognition can be selected. The first Clarion recipient has recently been implanted at UCSF, initiating the Clarion's investigational clinical trials. A description of the device and preliminary patient results are presented.


Cochleovestibular nerve compression syndrome. I. Clinical features and audiovestibular findings. Cochleovestibular nerve compression syndrome (CNCS) is the term used to describe a group of audiovestibular symptoms thought to be due to a vessel compressing the cochleovestibular nerve. These symptoms include recurrent vertigo, continuous disequilibrium and acquired motion intolerance. Recently, Moller reported that CNCS can be diagnosed based on abnormalities in the auditory brainstem response (ABR). After specifically excluding all other vestibular disorders, 63 patients with symptoms suggestive of CNCS were identified. These patients were systematically evaluated with a standard neurotologic test battery, and the results were reviewed retrospectively. Hearing loss was found in 51 (81%) of 63 cases, including 33 cases of unilateral high-frequency loss and 14 cases of middle-frequency loss. ABR data were interpreted with respect to Moller's criteria, and abnormal studies were found in 42 (75%) of 56 cases. Abnormal electronystagmograms were found in 57 (93%) of 61 cases. Thirteen of the patients subsequently underwent a posterior fossa procedure for vertigo and, vessels were found in contact with the cochleovestibular nerve in 11 of 13 cases. The results of this study suggest that the majority of CNCS patients have neurotologic test findings that suggest an abnormality of the cochleovestibular nerve. The results and their implications are discussed.


Cochleovestibular nerve compression syndrome. II. Vestibular nerve histopathology and theory of pathophysiology. The present study was undertaken to systematically examine and characterize pathological changes in vestibular nerve specimens obtained at surgery in patients with symptomatic cochleovestibular nerve compression syndrome (CNCS). Vestibular nerves were obtained in six cases of CNCS and were intermingled with vestibular nerves obtained in cases of Meniere's disease. All of the nerve specimens were coded and reviewed microscopically in a blind-study fashion by the neuropathologist. The vestibular nerves obtained from CNCS cases showed significant endoneurial fibrosis, compared to controls (specimens from patients with Meniere's disease). Based on observations in this study, as well as the clinical symptoms and audiovestibular test findings in these patients, a theory of pathophysiology in CNCS of the cochleovestibular nerve is proposed. The implications of this theory are discussed with respect to the diagnosis of CNCS.


Experimental otitis media with effusion induced by middle ear effusion. Experimental otitis media with effusion was induced in chinchillas by middle ear effusion, which was induced by an injection of immune complex into the tympanic cavity. To elucidate the pathogenesis of otitis media with effusion, cytologic and biochemical findings of the effusion and histopathology of the middle ear mucosa of effusion-induced chinchillas were compared with those of experimental otitis media with effusion induced by different procedures; eustachian tube obstruction, intratympanic inoculation of endotoxin, and immune reaction. No significant differences were seen in cytology, biochemistry, and histopathology among OMEs induced by these procedures. However, middle ear effusions, when compared with the corresponding sera, were proven to contain higher amounts of histamine and prostaglandin E2. These findings seem to demonstrate that middle ear effusion containing a large number of inflammatory mediators is essential for induction and prolongation of inflammatory reaction in the middle ear.


Hypoplastic endolymphatic sac, hydrops, and Mondini deformity: a case report. The Mondini deformity of the inner ear is usually associated with a large vestibular aqueduct and endolymphatic sac. The authors present a case with a hypoplastic sac and endolymphatic hydrops, which are presumed to be the cause of the Meniere's syndrome symptoms that occurred in mid-life.


Presence of urokinase-type plasminogen activator (u-PA) in tissue extracts of antrochoanal polyp. Using a biochemical technique, the authors characterized and identified a plasminogen activator (PA) derived from tissue extracts of antrochoanal polyp (AP) and paranasal mucous membrane (PMM) with chronic sinusitis. The results of fibrin zymography indicated that the tissue extracts of AP revealed two lytic zones and that those of PMM revealed a single lytic zone on fibrin-agarose plates. One of the AP zones exhibited the same relative mobility as the PMM zone (molecular weight: 65 kd), while the other AP zone had a smaller molecular weight (about 54 kd). Goat immunoglobulin G (IgG) fraction of antihuman uterine tissue-type plasminogen activator (t-PA) inhibited the 65-kd lytic zones of AP and PMM. Antihuman low-molecular-weight urokinase inhibited only the 54-kd lytic zone of AP, and nonspecific goat IgG failed to inhibit any of the lytic zones. On the other hand, 10(-2) mol trans 4-(aminomethyl)cyclohexane-carboxylic acid (t-AMCHA) inhibited all of the lytic zones. No lytic zones could be observed on plasminogen-free fibrin-agarose plates. These findings confirmed that the tissue extracts of PMM contained t-PA, and that those of AP contained both t-PA and urokinase-type plasminogen activator (u-PA). In addition, it appeared that u-PA in inflammatory tissue was related to proliferative changes of the mucous membrane.


Nasal airway dilation and obstructed breathing in sleep. Nasal respiratory airflow resistances of awake snorers averaged 0.188 +/- 0.165 Pa/cm3/s (N = 306) and were not elevated beyond the normal range (less than 0.25 Pa/cm3/s). Resistances were decreased substantially from a mean of 0.164 +/- 0.128 to 0.065 +/- 0.037 Pa/cm3/s (N = 72) by a nasal vestibular dilator (Nozovent). Effects of the dilator on breathing disorders in sleep were determined by polysomnographic recordings that included frequency, duration and intensity of snoring, apneas, hypopneas, and oxygen saturation in 10 heavy snorers while asleep with and without the dilator in situ over periods of several hours. No significant changes were detected in these parameters in any stage of sleep.


Three-dimensional anatomy of human Scarpa's ganglion. Using a computer-aided three-dimensional reconstruction and measurement method, the authors studied the shape and dimensions of Scarpa's ganglion and interrelations of the ganglion to nearby important anatomical structures in 10 normal human temporal bones obtained from 10 individuals of different ages (12 gestational weeks to 72 years). In the postnatal cases, Scarpa's ganglion was shaped like a distorted hourglass. Although the shape of the ganglion varied somewhat among specimens, a superior division, inferior division, and isthmus ganglionaris were distinguishable in each case. Volume of the ganglion was relatively consistent after birth, so that width and height of the ganglion were inversely correlated with each other (linear regression analysis, P less than .05). There seemed to be, however, a possible postnatal increase in the distances from the ganglion to neighboring structures and in the length of the internal auditory canal; these increases were probably the result of postnatal growth of the temporal bone. Moreover, the width of the ganglion in any single specimen was found to correlate significantly positively with the distances from the ganglion to the vestibular end-organs and the length of the internal auditory canal in that specimen (linear regression analysis, P less than .01). This finding suggests that Scarpa's ganglion may be elongated secondary to the elongation of the vestibular nerve due to the growth of the temporal bone. In fetuses, each portion of the ganglion was less clearly identifiable than that portion in postnatal cases. The dimensions of Scarpa's ganglion were found to have reached maturity around the time of birth.


Malignant parotid tumors in 110 consecutive patients: treatment results and prognosis. The UICC 1987 classification system was used to retrospectively analyze the treatment results and prognostic factors in 110 consecutive patients. All of the patients had malignant parotid tumors which had been diagnosed and treated during the period from 1970 to 1986. Treatment consisted of surgery, radiotherapy, or a combination. Malignant mixed tumors were seen in 28% of the patients, mucoepidermoid tumors in 18%, adenoid cystic tumors in 15%, acinic tumors in 13%, undifferentiated tumors in 11%, adenocarcinomas in 10%, and other types in 5%. Ten-year corrected survival rate was 52%, and significant differences of survival were found between: 1. patients with disease stages I through IV (I: 85%; II: 69%; III: 43%; IV: 14%); 2. those with local tumor extension (34%) and without local tumor extension (79%); 3. patients with facial nerve palsy (0%) and without facial nerve palsy (57%); and 4. those with low- or intermediate-grade malignant tumors (69% combined) and those with high-grade malignant tumors (30%). After primary treatment, 45% of the patients were cured, and, additionally, 22% were salvaged after local or neck node recurrences. It is concluded that there is a good correlation between TNM classification of UICC 1987 (stage and local extension of tumor) and prognosis, and that facial nerve palsy and grade of malignancy are important prognostic factors.


Refinement of the transpalatine exposure of the nasopharynx. The intrasulcular incision provides excellent transpalatine exposure of the nasopharynx with a viable palatal flap. There is less chance for naso-oral fistula formation since the resulting suture line is always over underlying bone. This safely allows extensive removal of the hard palate. Additionally, the continuous sling suture allows excellent flap reapproximation using the teeth as anchors for the replaced palatal flap. Patients tolerate oral feedings within 24 hours of their operations and require minimal postoperative analgesics. The extended intrasulcular incision offers many advantages over other methods for transpalatine exposures to the nasopharynx.


The sensitivity of auditory brainstem response testing in small acoustic neuromas. Auditory brainstem response (ABR) testing is a reliable and sensitive test for retrocochlear pathology in neurotologic diagnosis. Several investigators have reported the sensitivity of ABR testing as 95% or greater. Fifty-one consecutive patients with surgically confirmed acoustic neuromas were examined. Forty patients had sufficient hearing preoperatively for assessment with ABR. In addition, all had been evaluated with gadolinium-enhanced magnetic resonance imaging and conventional electronystagmography. Overall, 34 of 40 patients (85%) had abnormal ABRs. One of 25 patients with extracanalicular tumors had a normal ABR for a false-negative rate of 4%; however, 5 of 15 patients with intracanalicular tumors had normal ABRs for a false-negative rate of 33%. Tumor size and nerve of origin were important factors affecting the ABR sensitivity. The ABR was less sensitive in detecting intracanalicular tumors than in detecting extracanalicular tumors.


Nasopharyngeal carcinoma: treatment results with primary radiation therapy. One hundred three patients with nasopharyngeal carcinoma were treated with radiotherapy at UCLA Medical Center from January 1955 to December 1990. Overall survival, disease-free survival, and local control rates were analyzed. In addition, survival from 1955 to 1978 and from 1979 to 1990 were evaluated. Overall 5- and 10-year actuarial survival rates for all patients were 58% and 47%, respectively. Disease-free survival rates at 3 and 5 years were 45% and 30%, respectively. Local, persistent, or recurrent disease in the nasopharynx was the primary cause of failure, occurring in 32% of patients and correlating with the initial tumor size (T stage). Twenty-four percent of patients developed distant metastases, which correlated with nodal status but not with T stage. Seventy-nine percent of patients failed either locally or distally by 4 years. Sex, race, age, and T and N stage categories were evaluated as prognostic variables in terms of survival. Control of primary disease is important in determining long-term outcome. Modern imaging techniques have greatly assisted in the evaluation of disease extent and treatment options.


Percutaneous endoscopic gastrostomy in the management of head and neck carcinoma. In patients undergoing resection of head and neck malignancies, structural and functional deficits commonly preclude adequate oral nutrition and prolong hospital stay. To address this issue, the benefit of routine preoperative placement of percutaneous endoscopic gastrostomy (PEG) was studied in a group of these patients. The postoperative course of 89 patients undergoing primary resection of advanced (stage III and IV) squamous cell carcinomas of the upper aerodigestive tract was examined. The hospital stay was reduced by up to 61% with PEG compared to hospital stay with standard nasogastric tube (NGT) alimentation. The difference was statistically significant for primary sites involving the larynx and pharynx, but not for lesions of the oral cavity. For tongue base tumors, there was a trend toward reduced hospitalization which did not reach statistical significance. The fistulization rate was unchanged. The complication rate for PEG was 5%, and morbidity was less with PEG than with NGT. The authors recommend the preoperative placement of PEGs for all patients with advanced carcinomas of the larynx, hypopharynx, and oropharynx.


Expression of the major mammalian stress protein in the rat cochlea following transient ischemia. The transient expression of stress proteins in cells exposed to adverse environmental conditions is thought to provide a survival advantage. In the present study, the expression of the major mammalian stress protein, Hsp72, was characterized in the rat peripheral auditory system following varying periods of unilateral cochlear ischemia and reperfusion. Western blot analysis of whole cochlear homogenates revealed Hsp72 expression after as little as 5 minutes of cochlear ischemia. Cochlear Hsp72 immunoreactivity following 10 minutes of ischemia was observed within 2 hours, remained evident through 6 hours, and decreased toward control levels by 12 hours. Preliminary immunocytochemical localization data revealed Hsp72 expression in the outer hair cells. The characterization of Hsp72 expression following transient ischemia represents the first step toward understanding the role that stress proteins have in the protection of the mammalian auditory system.


Free-floating endolymph particles: a new operative finding during posterior semicircular canal occlusion. Most clinicians accept cupulolithiasis as the pathophysiological mechanism underlying benign paroxysmal positional vertigo (BPPV.) According to this theory, a cupular deposit induces a gravitational effect on the posterior canal crista. Posterior semicircular canal occlusion is a new operative procedure for treating incapacitating BPPV. It is postulated that canal occlusion abolishes endolymph movement within the canal, effectively fixing the cupula and rendering it unresponsive to both angular and linear acceleration (gravity). During two recent canal occlusions, abundant "free-floating particles" were identified within the posterior canal endolymph. When changing the position of the canal in the earth vertical plane, these free-floating particles would move under the influence of gravity. The hydrodynamic drag of the particles would induce endolymph movement with cupular displacement leading to the typical response. This finding supports an alternate explanation to cupulolithiasis as the pathophysiological mechanism underlying BPPV.


Transtympanic endoscopy of the middle ear. Modern optical technology has made available fiberoptic and rigid endoscopes with diameters of 2 mm and less with acceptable resolution. Endoscopes of small caliber were introduced through a strategically placed myringotomy or an existing perforation to perform exploration of the middle ear as an in-the-office procedure. This technique is now routinely used as an adjunct in the diagnostic evaluation of patients with suspected middle ear conditions. Exploratory surgery of the middle ear may be avoided or definitive procedures may be planned better based on endoscopic findings.


Anterior cricoid split for subglottic stenosis: experience at the Children's Hospital of New Jersey. Twenty-five children with acquired and congenital subglottic stenosis (SGS) were managed with the anterior cricoid split (ACS) operation at the authors' institution from September 1987 to January 1990. Ages ranged from 2.5 months to 5.5 years. Twenty-one (84%) of the children were extubated after 5 to 14 days of nasotracheal intubation and have remained stable after an average follow-up of 10 months. Atelectasis was a common postoperative problem, encountered in 12 (48%) of the patients. Other complications included a tracheocutaneous fistula, prolapse of soft tissue into the tracheal lumen via the cricoid incision, a subglottic granuloma, and 2 cases of prolonged lower extremity paresis following reversal of vecuronium. The results of this retrospective study indicate that the ACS is a valuable first-line procedure for the management of SGS in a variety of pediatric patients.


Role of brain histamine H1- and H2-receptors in neostigmine-induced hyperglycemia in rats. We previously reported that when neostigmine, an inhibitor of acetylcholine esterase, was injected into the third cerebral ventricle, the concentration of hepatic venous plasma glucose was increased via central muscarinic receptors in anesthetized rats. To determine whether brain histamine receptors are involved in cholinergic system transmission with regard to central nervous system (CNS)-mediated glucoregulation, we examined the effects of the H1 receptor antagonist pyrilamine and the H2 receptor antagonist ranitidine on neostigmine-induced hyperglycemia in anesthetized rats. The injection of pyrilamine (5 x 10(-9)-5 x 10(-7) mol) into the third cerebral ventricle suppressed hyperglycemia induced by intraventricular injection of neostigmine (1 x 10(-9) mol) in a dose-dependent manner. Injection of ranitidine (5 x 10(-9)-5 x 10(-7) mol) into the third cerebral ventricle did not suppress the hyperglycemia induced by neostigmine, but enhanced it in a dose-dependent manner. These findings suggest that neostigmine-induced CNS-mediated hyperglycemia is transmitted by not only brain cholinergic muscarinic receptors but also in part by histamine H1 receptors.


Effect of naloxone and beta-casomorphin on the hypothalamic-pituitary-luteinizing hormone axis in vitro. The effect of naloxone and beta-casomorphin on luteinizing hormone (LH) release from pituitary cell aggregates, obtained by three-dimensional culture, with or without mediobasal hypothalamic fragments was studied in vitro. Short-term naloxone perifusion at a concentration of 10(-5)M did not modify either basal or LHRH-stimulated LH release from the pituitary cell aggregates. In contrast, a 12-min naloxone perifusion at the same concentration caused an increase in LH release in the mediobasal hypothalamic-pituitary cell aggregate axis. This increase was rapid (12-16 min after time pulse), marked [up to 10 times (p less than 0.004) the initial base line], short (return to the base line secretion 32-40 min after the beginning of the time pulse) and dose-dependent, with a rise greater than 1000% at a concentration of 10(-4) (p less than 0.006). The same effect was observed when a second pulse was applied 48 min after the first one. LH release induced by naloxone was antagonized 56 +/- 2% (p less than 0.03) by beta-casomorphin (an exogenous opiate) at a concentration of 10(-5) M. beta-casomorphin alone did not modify LH basal secretion, but inhibited 25.1 +/- 2.4% (p less than 0.008) LH release enhanced by LHRH. These results indicate that naloxone, an opiate antagonist, markedly increases LH release via a mu-type opioid receptor mechanism at the hypothalamic level only, during short-term exposure.


Protein B23 (M.W./pI = 37 kD/5.1) is the only major protein extracted from HeLa nucleoli with 3M urea. HeLa nucleoli were isolated using the NP-40 method and subsequently extracted with 3M urea. The extract was incubated at 60 degrees C for 30 min, and precipitated proteins were removed by centrifugation. The supernatant was analyzed by one- and two-dimensional SDS polyacrylamide gel electrophoresis (PAGE). Protein B23 was the only major protein extracted from HeLa nucleoli by this procedure. Using this procedure, 1 mg of protein B23 was obtained from 2 g of HeLa cells. The purity of the extracted protein B23 was 98%, as measured by one- and two-dimensional gel electrophoresis.


Effect of tryptophan administration on circulating melatonin levels in chicks and rats: evidence for stimulation of melatonin synthesis and release in the gastrointestinal tract. The administration of L-tryptophan (Trp, 150-300 mg/kg) to rats and chicks causes a rapid and dose-dependent elevation of circulating melatonin. The elevation of serum melatonin was greater after oral compared to the intraperitoneal route of administration of the same dose of Trp (150 mg/kg). The Trp-induced increase of circulating melatonin was unaffected by prior pinealectomy but was almost abolished by a partial ligature of the portal vein. The Trp-induced increase of melatonin in the portal blood preceded that in the systemic circulation. The gut contains considerable amounts of melatonin and the Trp-induced elevation of melatonin was greater in the duodenum compared to the pineal or the blood. The enterochromaffin cells of the gastrointestinal tract appear to be the major source of the Trp-induced increment of circulating melatonin. The possibility is discussed that the sedating, sleep inducing effects of Trp are mediated by the Trp-induced elevation of circulating melatonin.


Central interaction of dexamethasone and RU-38486 on morphine antinociception in mice. The central interference induced by dexamethasone and RU-38486, (a glucocorticoid receptor antagonist) on morphine antinociception were studied by using the tail flick test in mice. Dexamethasone, injected intracerebrally (i.c.v.) 10 minutes before morphine, dose-dependently reduced morphine antinociception, whereas RU-38486 which was injected with the same lag time, potentiated it. When dexamethasone and RU-38486 were administered together i.c.v., 10 minutes before morphine, an overall reduction of morphine antinociception was observed, similar to that observed with dexamethasone pretreatment only. The present results strongly suggest a central site of interaction for dexamethasone and RU-38486 on morphine antinociception; the short latency and the dose-related slope for this interaction may suggest a mechanism at least in part different from the glucocorticoid-induced genomic activation.


The physiological consequences of glutathione variations. The major low molecular weight thiol inside cells, the tripeptide glutathione (GSH), is of importance for protection of the cell against oxidative challenge, for thiol homeostasis required to guarantee basic functions, and for defence mechanisms against xenobiotics. Since the pathophysiological significance of a perturbed GSH status in human disease is less clear, this review evaluates the consequences of in vivo variations of GSH. Owing to intracellular GSH concentrations above 2 mM depletion of GSH as such has little metabolic consequences unless an additional stress is superimposed. The kinetic properties of GSH-dependent enzymes imply that loss of up to 90% of intracellular GSH may still be compatible with cellular integrity. Mitochondrial GSH, which accounts for about 10% of total cellular GSH, may define the threshold beyond that toxicity commences. Thus, in cases of severe GSH-depletion a substitution of GSH as a therapeutic measure seems justified. Such a severe depletion of GSH has been described for some diseases such as liver dysfunction, AIDS or pulmonary fibrosis.


Effects of inorganic iodide, epidermal growth factor and phorbol ester on hormone synthesis by porcine thyroid follicles cultured in suspension. Porcine thyroid follicles cultured in suspension for 96 h synthesized and secreted thyroid hormones in the presence of thyrotropin (TSH). The secretion of newly synthesized hormones was assessed by determining the contents of thyroxine (T4) and triiodothyronine (T3) in the media and by paperchromatographic analysis of 125I-labelled hormones in the media where the follicles were cultured in the presence and absence of inhibitors of hormone synthesis. The hormone synthesis and secretion was modified by exogenously added NaI (0.1-100 microM). The maximal response was obtained at 1 microM. Thyroid peroxidase (TPO) activity in the cultured follicles with TSH for 96 h was dose-dependently inhibited by NaI. One hundred microM of NaI completely inhibited TSH-induced TPO activity. Moreover, both epidermal growth factor (EGF: 10(-9) and 10(-8) M) and phorbol 12-myristate 13-acetate (PMA: 10(-8) and 10(-7) M) inhibited de novo hormone synthesis. An induction of TPO activity by TSH was also inhibited by either agent. These data provide direct evidences that thyroid hormone synthesis is regulated by NaI as well as TSH at least in part via regulation of TPO activity and also that both EGF and PMA are inhibitory on thyroid hormone formation.


A synthetic analogue of vitamin D3, 22-oxa-1,25-dihydroxy-vitamin D3, stimulates the production of prostacyclin by vascular tissues. We investigated the effect of 22-oxa-1,25-dihydroxyvitamin D3, a synthetic analogue of vitamin D3, on the production of prostacyclin by vascular tissues using rat aortic rings and A7r5 cells derived from fetal rat aortic smooth muscle. Prostacyclin synthesis by aortic rings of rats treated with 22-oxa-1,25-dihydroxyvitamin D3 was much higher than that of non-treated controls, but did not cause any significant hypercalcemia. Treatment with 22-oxa-1,25-dihydroxyvitamin D3 significantly increased the production of prostacyclin by A7r5 cells for 48 hours in a dose-dependent manner. In time-course studies, cells incubated with 22-oxa-1,25-dihydroxyvitamin D3 or 1,25-dihydroxyvitamin D3 produced prostacyclin progressively over a period of 48 hours. The shortest period of incubation that produced a significant amount of prostacyclin compared with control cultures was 24 hours. We observed that treatment with 22-oxa-1,25-dihydroxyvitamin D3 induced cyclooxygenase mRNA in A7r5 cells. Our data suggest that 22-oxa-1,25-dihydroxyvitamin D3 may possibly be a protective substance against the development of atherosclerosis by modulating prostaglandin metabolism.


Suppressive effect of coenzyme Q10 on phospholipase A2 activation in cardiac cells after prolonged swimming. Phospholipase A2 (PLA2) activity is elevated in cardiac microsomal fractions and phospholipids (PL) are much reduced in both the cardiac mitochondria and microsomal fractions from rats subjected to prolonged swimming. Preadministration of coenzyme Q10 (CoQ10 i.v. 30 mg/kg) significantly suppressed these changes. Two groups of 8-week-old male Wistar rats were trained to swim, receiving 30 min of training for 4 days. On the fifth day they were given an intravenous injection of either 30 mg/kg CoQ10 in saline or 1 ml saline. Thirty minutes later they began to swim for 3 hours carrying a weight representing 3% of body weight. On completion of the swim they were sacrified by instantaneous decapitation, and cardiac mitochondria were isolated. Mitochondria were also prepared from saline injected, unexercised control rats. Phosphatidylethanolamine (PE) and phosphatidylcholine (PC) concentrations were measured with HPLC and PLA2 activity was assayed fluorometrically. The mitochondrial concentrations (means +/- SEM, n = 6) of PE and PC were respectively 126 +/- 22 and 140 +/- 22 nmol/mg protein in the exercise-CoQ10 group against 66 +/- 4 and 50 +/- 10 nmol/mg protein in the exercise-saline group. The specific PLA2 activities (expressed as nmol degraded dipyrene phosphorylethanolamine substrate/hr/mg protein) in the microsomes was 0.20 +/- 0.02 in the exercise-CoQ10 group against 0.30 +/- 0.02 in the exercise-saline group. These results suggest CoQ10 has a protective effect against an excessive reduction in mitochondrial membrane phospholipids during prolonged exercise.


Suppression of the development of uterine adenomyosis by danazol treatment in mice. Inhibitory effects of danazol, an isoxazol derivative of synthetic steroid 17 alpha-ethinyl-testosterone, on the development of uterine adenomyosis, a pathological disorder of endometrial tissue defined as the presence of endometrial glands and stroma in the myometrium, were investigated in mice of SHN strain. Mice treated with 0.5 microgram danazol for 5 weeks during 4-9 weeks of age and killed at 21 weeks of age showed significantly lower incidence of the spontaneous development of adenomyosis than the age-matched intact control mice. The inhibitory effects of danazol were also evident in mice bearing pituitary isografts which were effective in inducing an early and a high incidence of adenomyosis. Furthermore, the treatment with danazol resulted in the decrease of serum levels of luteinizing hormone (LH) and prolactin (PRL) associated with hypofunction of ovaries and persistent diestrus. These results support the usefulness of danazol for the clinical treatment of gynecological disorders except for hypofunction of ovaries.


Impairment by cyclosporin A of reperfusion-induced arrhythmias. This study introduces the immunosuppressor, cyclosporin A, as a cardioprotective drug. This effect was analyzed during development of reperfusion/induced arrhythmias after 5-min period of coronary ligation in hearts of rats under anesthesia. The results indicate that cyclosporin, when given before coronary occlusion, at a dose of 20 mg/kg, effectively protects against the high incidence of arrhythmias and the fall in blood pressure induced by reperfusion. In addition, in inhibits the delivery of lactic dehydrogenase and creatine kinase enzymes to the plasma. We propose that the protective effect could be related with its well documented action to restrain Ca(2+)-induced damage of mitochondrial functions.


BMY-14802 protects against ischemia-induced neuronal damage in the gerbil. BMY-14802, a selective sigma ligand currently under investigation as an atypical antipsychotic agent, was tested for potential anti-ischemic activity. BMY-14802 (10, 30 and 50 mg/kg) did not produce any stereotyped behavior, ataxia or seizures. When gerbils were pretreated with 10, 30 or 50 mg/kg of BMY-14802 30 min prior to bilateral occlusion of carotid arteries for 5 min, BMY-14802 significantly protected against ischemia-induced neuronal loss in the hippocampus. Thus, BMY-14802 may also be useful as an anti-ischemic agent that does not produce psychotomimetic effects.


Endothelin-3 like immunoreactivity in plasma of patients with cirrhosis of the liver. A highly specific and sensitive radioimmunoassay (RIA) has been established for determination of endothelin-3 like immunoreactivity in human plasma to investigate its possible role in hemodynamic alterations due to liver disease. Crossreactivity with other endothelin isoforms was always below 4 %, the lower detection limit following extraction on Sep-Pak C18 cartridges was 0.5 pg/ml. The concentration of endothelin-3 (mean +/- SEM) was 4.16 +/- 0.56 pg/ml (n = 13) in plasma of patients with cirrhosis of the liver, three fold higher than in age matched controls (1.35 +/- 0.27 pg/ml, n = 12, p less than 0.01). Plasma immunoreactivity was confirmed to be endothelin-3 related by reverse-phase HPLC. These data could suggest a role of plasma endothelin-3 in circulatory changes, as they occur in cirrhosis of the liver.


Regulation of prostaglandin secretion from epithelial and stromal cells of the bovine endometrium by interleukin-1 beta, interleukin-2, granulocyte-macrophage colony stimulating factor and tumor necrosis factor-alpha. Bovine endometrium was obtained on day 16 of pregnancy (estrus = 0) and separated into epithelial and stromal cell populations. When confluent, the two cell populations were treated for 24 h with cytokines at 1, 10 and 100 ng/ml. Prostaglandin (PG) E2 was the major prostaglandin produced by both cell types. For control cultures, more PGE2 was secreted into medium by stromal cells than by epithelial cells, whereas secretion of PGF was similar for epithelial and stromal cells. Interleukin-1 beta had no effect on prostaglandin production by stromal cell cultures but increased epithelial production of PGE2 and, to a lesser extent, PGF. Conversely, granulocyte-macrophage colony stimulating factor had no effect on epithelial cells but reduced secretion of PGE2 and PGF from stromal cells. There were no effects of interleukin-2 or tumor necrosis factor-alpha on prostaglandin secretion. Results indicate that certain cytokines can regulate endometrial prostaglandin secretion in a cell type-restricted manner.


Transfer of liposomes containing dolichol into isolated hepatocytes. Isolated rat hepatocytes were preincubated with egg lecithin liposomes containing [3H]dolichol and [3H]dolichyl ester, and the intracellular levels and distributions of these lipids were subsequently determined after incubation in a liposome-free medium. [3H]Dolichol was recovered initially mainly in microsomes, and no increase with time in the low level of this compound in the mitochondrial/lysosomal fraction could be observed. A small portion of the labeled dolichol was esterified in the endoplasmic reticulum and transferred to the lysosome-containing fraction. [3H]Dolichyl linoleate was initially localized in microsomes and supernatant, but later accumulated in the mitochondria/lysosomes. Dolichyl linoleate was found in the membrane of microsomes, in the membrane and lumen of lysosomes, and in the soluble cytoplasm. Exogenous dolichol recovered in microsomes was not phosphorylated to any significant extent. Liposomal phosphatidylcholine also showed preferential accumulation in microsomes after incubation with hepatocytes. These results indicate that exogenous or endogenously formed dolichyl esters are transferred from the endoplasmic reticulum to lysosomes, probably through the cytoplasm. It appears that fatty acids play a role in targeting these lipids to their intracellular locations.


Effect of ethanol on platelet phospholipase A2. Platelet aggregation is known to be inhibited by ethanol, and this has been suggested to be one of the attenuating effects of ethanol in cardiovascular disease. Recent studies have implicated an inhibition of phospholipase A2 induced arachidonic acid release, since the production of prostanoids that are formed from arachidonic acid and are involved in the aggregation process has been shown to be diminished by ethanol. Phospholipase A2 is found in platelets in both a cytosolic form, from where it may translocate to the plasma membrane to release arachidonic acid, and in a secretory form which is released extracellularly upon activation. In the present study, the effect of ethanol on the secretion of phospholipase A2 and on its activity was determined. It was found that ethanol inhibited phospholipase A2 secretion but not its activity. By contrast, the activity of the cytosolic form of phospholipase A2 was inhibited by ethanol.


The dual effect of oxidation on lipid bilayer structure. Sphingomyelin membranes were prepared with different levels of oxidative damage caused by tert-butyl hydroperoxide (TBH). Temperature-induced changes in membrane hydrocarbon chain packing (phase transitions) were monitored using infrared spectroscopy. Lipid phase transition characteristics were evaluated from thermodynamic parameters fitted to the experimental transition curve data. At temperatures below the lipid phase transition Tc, hydrocarbon chains pack in an ordered state whereas above the Tc the hydrocarbon chains pack in a disordered state. Compared to the non-oxidized control, the packing of the hydrocarbon chains of mildly oxidized sphingomyelin (less than 10 nmol TBH/mg lipid) was no different at all temperatures below the Tc, and was more ordered above the Tc. The hydrocarbon chains of strongly oxidized sphingomyelin (greater than 10 nmol TBH/mg lipid) were more disordered at temperatures above and below the Tc compared to the control samples. These results suggest that lipid oxidation has a dual effect on lipid order. A more ordered or disordered state may result depending on the degree of oxidation and the state of lipid order prior to oxidation. These results could be important for explaining the structural changes in oxidized membranes high in sphingomyelin such as those found in the ocular lens and liver plasma membranes.


Decreased lecithin:cholesterol acyltransferase activity in the plasma of hypercholesterolemic pigs. Lecithin:cholesterol acyltransferase (LCAT) activity levels were determined, as function of plasma total cholesterol (TC) in 13 normocholesterolemic (TC less than 85 mg/dL) and in 28 hypercholesterolemic (TC greater than 98 mg/dL) pigs. The normocholesterolemic group consisted of pigs that carried apo-B allelic genes other than Lpb5 and or Lpb8. The hypercholesterolemic group consisted of Lpb5/x and Lpb5/8 heterozygous and Lpb5/5 homozygous animals. The data reported in this study show that the LCAT activity in the plasma of hypercholesterolemic (HC) pigs (79 +/- 43 units) was significantly lower (p less than 0.0005) compared to the normocholesterolemic controls (175 +/- 45 units). Furthermore, LCAT activity was positively correlated with TC in the normocholesterolemic group (r = +0.54; p less than 0.05), whereas it was negatively correlated with TC in the hypercholesterolemic group (r = -0.73; p less than 0.001). Additional data obtained from incubation experiments suggest that the lower LCAT activity in hypercholesterolemic pigs may be due, at least in part, to inhibition of LCAT activity by components found in the lipoprotein-deficient fractions of the plasma of hypercholesterolemic pigs.


Oxysterols in cultured bovine aortic smooth muscle cells and in the monocyte-like cell line U937. Oxysterols in cultured bovine aortic smooth muscle cells and in the monocyte-like cell line U937 were analyzed by gas-liquid chromatography. The following products were detected: 7 alpha- and 7 beta-hydroxycholesterol, 7-ketocholesterol, cholesterol-alpha-epoxide, cholesterol-beta-epoxide, cholestanetriol, and 20- and 25-hydroxycholesterol. The proportions of oxidized cholesterol varied from 1 to 3% of total cholesterol. The concentrations of oxysterols were lower when the smooth muscle cells were maintained in a vitamin E-enriched medium, and were higher in U937 cells when the cells were activated with phorbol myristate acetate. The cell oxysterol content appears to be regulated by factors that inhibit or enhance free radical generation. The concentrations of oxysterols found in cells may serve as an indicator of the extent of lipid peroxidation.


Effects of dietary n-3 fatty acid-enriched chicken eggs on plasma and tissue cholesterol and fatty acid composition of rats. The purpose of this study was to examine the effects of feeding n-3 polyunsaturated fatty acid (PUFA)-enriched chicken eggs on plasma and liver cholesterol levels and fatty acid composition in rats. Eggs were collected from laying hens fed diets containing 10% flax seed (Hn-3), 12% sunflower seed (Hn-6), or wheat and soybean meal control (CON). Yolk powders were prepared and fed at the 15% level to weanling female Sprague-Dawley rats for 28 days. Consumption of n-3 PUFA-enriched yolks significantly reduced both plasma and liver total cholesterol. Liver total lipids and phospholipids of rats fed Hn-3 diet were enriched with linolenic, eicosapentaenoic, and docosahexaenoic acids with a concomitant reduction of arachidonic acid in liver phospholipids. The plasma cholesterol of rats fed yolk powders enriched with n-6 PUFA (mainly linoleic acid) was reduced to the same extent as in those fed the n-3 enriched, but the liver cholesterol was significantly increased, indicating differential effects of dietary n-3 and n-6 PUFA. The results demonstrated that the cholesterolemic and tissue lipid modulating properties of chicken eggs could be modified in a favorable way by altering the fatty acid composition of yolk lipids through manipulation of laying hen diets.


Effects of bis homoallylic and homoallylic hydroxyl substitution on the olefinic 13C resonance shifts in fatty acid methyl esters. Substitution of a hydroxyl group at the bis homoallylic position (OH group located three carbons away from the olefinic carbon) in C18 unsaturated fatty acid esters (FAE) induces a 0.73 +/- 0.05 ppm upfield and a 0.73 +/- 0.06 ppm downfield shift on the delta and epsilon olefinic 13C resonances relative to the unsubstituted FAE, respectively. If the hydroxyl group is located on the carboxyl side of the double bond of the bis homoallylic hydroxy fatty acid esters (BHAHFA), the olefinic resonances are uniformly shifted apart by [formula: see text] where delta delta dbu represents the absolute value of the double bond resonance separation in the unsubstituted FAE and 1.46 ppm is the sum of the absolute values of the delta and epsilon shift parameters. With hydroxyl substitution on the terminal methyl side of the double bond, the olefinic shift separation is equal to [formula: see text] In homoallylic (OH group located two carbons away from the olefinic carbon) substituted FAE the gamma and delta induced hydroxyl shifts for the cis double bond resonances are +3.08 and -4.63 ppm, respectively while the trans double bond parameters are +4.06 and -4.18 ppm, respectively. The double bond resonance separation in homoallylic hydroxy fatty acid esters (HAHFA) can be calculated from the formula [formula: see text] for cis and [formula: see text] for the trans case when the OH substitution is on the carboxyl side of the double bond. Conversely, when the OH resides on the terminal methyl side, the double bond shift separations for cis and trans isomers are [formula: see text] and [formula: see text] respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


Chemiluminescence detection of 8a-hydroperoxy-tocopherone in photooxidized alpha-tocopherol. Photosensitized oxidation products of alpha-tocopherol were analyzed by reversed phase high-performance liquid chromatography (CL-HPLC) in combination with chemiluminescence detection, to measure hydroperoxide derivatives. An intense peak was observed on the chemiluminescence chromatogram, corresponding to 8a-hydroperoxy-alpha-tocopherone (alpha-tocopherol hydroperoxide), the identity of which was confirmed by 1H nuclear magnetic resonance and mass spectrometry. Observed peak intensities correlated with the peroxide value of oxidized alpha-tocopherol. As little as 50 pmol of 8a-hydroperoxy-alpha-tocopherone was detectable. The CL-HPLC method, which is specific for the detection of hydroperoxides, should prove useful in studies on tocopherol oxidation in foods and biological systems.


An extended method for separating and quantitating molecular species of phospholipids. An improved and extended method for separating and quantitating molecular species of four phospholipid classes is presented. Crude lipid extract is first separated into phospholipid classes on a silica column. Each phospholipid class is then separated into molecular species without derivatization using high-performance liquid chromatography on columns packed with octadecyl silica. Quantitation of individual species is achieved by measuring absorbance at 205 nm. Factors for converting absorbancies to mol fractions have been determined. Quantitation by absorbance at 205 nm agrees well with quantitation by gas chromatography which is preferred to quantitation by phosphate analysis. One hundred phospholipid species have been identified. A table of relative retention times of molecular species is provided. Examples of quantitative analyses of species composition are presented.


Alpha-helical requirements for free apolipoproteins to generate HDL and to induce cellular lipid efflux. The structural requirement has been studied for apolipoproteins in their free form to interact with cells, to generate high density lipoprotein (HDL), and to cause cellular lipid efflux (J. Biol. Chem. 266, 3080-3086, 1991). It is shown that human apolipoprotein (apo) A-IV and apolipophorin III of Manduca sexta cause cholesterol efflux from cholesterol-loaded mouse peritoneal macrophages and reduce intracellularly accumulated cholesteryl ester as a result of forming HDL-like particles with cellular lipids, as do apoA-I, A-II and E. On the other hand, similar to apoC-III, reduced-and-carboxymethylated human apoA-II had no such effect. Thus, apolipoproteins seem to require at least four amphiphilic helical segments per molecule to express this function.


Inhibition of myocardial lipoprotein lipase by U-57,908 (RHC 80267). U-57,908 (RHC 80267) was shown to inhibit lipoprotein lipase (LPL) activity in cardiac myocytes from rat hearts; the concentrations required for inhibition to 50% of control activity were 1.1 microM and 2.5 microM for myocyte homogenates and a post-heparin medium preparation, respectively. The inhibition of LPL activity by U-57,908 was not changed when the concentration of the triolein substrate and apolipoprotein CII activator in the assay was reduced. The availability of U-57,908 as a potent and selective LPL inhibitor may provide a useful experimental approach in studies on lipoprotein metabolism.


Liver lipid profiles of adults taking therapeutic doses of aspirin. The distributions of lipids of hepatic specimens obtained at autopsy from 7 adult patients who had been taking large amounts of aspirin for arthritis were compared to 7 control samples obtained from livers of autopsied adults without prior liver disease. The total neutral lipid levels of control livers were approximately one-third lower than those observed for livers of patients on aspirin. In addition, the phospholipid content of control specimens was significantly greater than that of livers from adult patients that had been on a high dose of aspirin for a long time. Examination of individual lipid classes showed that the concentrations of free fatty acids, triacylglycerols, and mono- and diacylglycerols were highest in livers of patients with aspirin exposure, and that all phospholipids were diminished. Phosphatidylcholines and phosphatidylethanolamines showed the greatest decrease. These results suggest that the livers of patients taking large amounts of aspirin may accumulate fatty acids and neutral lipids due to an impairment in the oxidation of fatty acids by hepatocytes. The data obtained also suggest that needle biopsy of the liver with measurement of distribution of hepatic lipids, perhaps together with histopathologic examination, may provide useful diagnostic information.


Centrofacial malignant granulomas. Clinicopathologic study of 40 cases and review of the literature. An important problem in the treatment of centrofacial ulcerations is to establish a precise diagnosis, since similar clinical and microscopic findings can result from many different causes (as in the centrofacial malignant granuloma syndrome [CFMG]). A comprehensive surgical biopsy protocol (known as SNFMI/GMCF), involving microbiology, parasitology, immunology and pathology laboratories, allowed us to evaluate and to treat 40 cases of CFMG, who form the basis of this report. In 13 of them, specific diagnoses were found and curative treatments could be given. In the remaining 27, the optical microscopy pattern met the criteria for CFMG without identifiable origin or the presence of so-called lethal midline granulomas; however, a more precise evaluation with the help of immunofluorescence studies led to the recognition of malignant lymphoma (ulcerative lymphoma of the midface [ULM]). Most of these lymphomas belonged to the T cell lineage; the others were of B lymphoid origin, or, more rarely, of histiocytic origin. Patients with ULM received radiotherapy and chemotherapy with a response rate of 70.3%; however, the toxicity was significant, with frequent occurrence of chemotherapy-induced neutropenia followed by severe infectious facial cellulitis. Six patients were enrolled in a preliminary open trial of treatment with recombinant alpha-2b interferon with little success. Three patients were treated with radiation therapy only, and survived. Thus, CFMG is a syndrome with specific causes and treatments, requiring multiple extensive biopsies to make the correct diagnosis. The recognition of ULM as the cause of the previously called "lethal midline granulomas" leads logically to the use of chemotherapy with growth factors in order to ameliorate its bad prognosis.


Parathyroid carcinoma: clinical and pathologic features in 43 patients. Parathyroid carcinoma accounts for 0.5 to 5% of all cases of hyperparathyroidism. We reviewed the clinical, surgical, and pathologic features observed in all patients with parathyroid carcinoma evaluated at the Mayo Clinic from 1920 through 1991. Forty-three patients (22 women, 21 men; mean age, 54 yrs, range 29-72) were identified, including 2 with familial hyperparathyroidism. Information on initial presentation was available in 40 patients: 15 (38%) presented with polydipsia or polyuria, 11 (27%) with myalgias or arthralgias, 7 (17%) with weight loss, and 4 (10%) with nephrolithiasis; 3 patients (7%) were asymptomatic at presentation. Of 31 patients in whom the initial neck examination was recorded, 14 (45%) had a palpable neck mass. The mean serum calcium and serum phosphorus levels were 14.6 mg/dl and 2.3 mg/dl, respectively. Parathyroid hormone levels were elevated in 21 of 21 patients (mean elevation, 10.2 times upper limit of normal). Complications included nephrolithiasis in 14 of 25 patients (56%), bone disease in 20 of 22 patients (91%) and both in 8 of 15 patients (53%). All patients underwent primary surgical resection of parathyroid carcinoma. Twenty-six of 43 patients (60%) required a second operation with 18 patients requiring multiple re-explorations. At the second operation, residual tumor was found in the neck (68%), mediastinum (16%), or both (12%). Six patients received radiation therapy to the neck (5 patients) or bones (1 patient) for recurrent or metastatic disease. Of these, 1 patient appeared cured of parathyroid carcinoma by radiation therapy 11 years after documented tumor invasion of his trachea. Repeated excision of tumor recurrences was an effective means of controlling hypercalcemia in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)


Hereditary and acquired C1-inhibitor deficiency: biological and clinical characteristics in 235 patients. Two hundred and twenty-six patients with inherited C1 inhibitor (C1-INH) deficiency, also known as hereditary angioedema (HAE), have been studied. They belonged to 80 unrelated families, and in 11 of them C1-INH was functionally deficient but antigenically normal (type II HAE). Genetic analysis of type 1 families demonstrated restriction fragment length polymorphisms in 11% and abnormal mRNAs in 25%. In type II families, the site of the mutation appeared to determine the rate of catabolism of the dysfunctional C1-INH and its antigenic plasma levels. Clinical symptoms (subcutaneous and mucous swellings) generally first appeared within the second decade of life. The frequency of symptoms was highly variable from patient to patient, but a few patients remained asymptomatic throughout their lives. Prophylactic treatment with attenuated androgens was administered to 59 patients and was totally effective in 57, without significant side effects. Sixty-seven laryngeal and 15 abdominal attacks were treated with C1-INH plasma concentrate, yielding initial regression of symptoms in 30 to 90 minutes. The acquired deficiency of C1-INH, also known as acquired angioedema, was diagnosed in 9 patients. Eight of them had an autoantibody against C1-INH; the only patient without the autoantibody had associated chronic lymphocytic leukemia. Prophylactic treatment with attenuated androgens was effective in this last patient, while those with the autoantibody against C1-INH benefited from prophylaxis with antifibrinolytic agents. Replacement therapy with C1-INH concentrate was necessary only for patients with autoantibodies and required doses 3 or 4 times higher than those used in HAE.


Cardiovascular disease in systemic lupus erythematosus. A study of 75 patients form a defined population. All patients with systemic lupus erythematosus in a prospective, epidemiologically based study within a defined area in southern Sweden were invited to participate in an investigation of cardiac function. From 1981 to 1988, 101 patients were included in the study, and 75 of them were investigated according to a fixed protocol by echocardiography, Doppler cardiography, electrocardiography (ECG) at rest and at exercise, and myocardial scintigraphy (in patients whose ECG became abnormal during exercise). IgG anticardiolipin antibodies (IgG aCL) were determined by ELISA. Twenty of the 75 patients (27%) had valvular disease and 12 of these (60%) had increased concentrations of IgG aCL, compared with 12 of 55 (22%) without valvular disease (p less than 0.01). Pericardial effusion was detected in 14 patients (19%) during the study period. Mild pulmonary hypertension was found in 11 patients (16%), who also had increased frequency of IgG aCL. Myocardial infarction had occurred in 7 patients, 3 of whom were women less than 40 years of age. Echocardiography revealed regional hypokinesis or akinesis in 5 of the patients with myocardial infarction. Exercise testing revealed low work capacity in 13 of 54 patients (24%), the limiting symptoms being mainly exhaustion or musculoskeletal pain. An abnormal resting ECG was found in 9 of the patients participating in the exercise test. During exercise, abnormal ST-depression was observed in 8 patients, 2 of whom developed angina. Myocardial scintigraphy was performed in 6 of these patients, revealing reversible uptake defects in all. Prolonged glucocorticoid treatment was associated with valvular abnormalities as well as myocardial infarction. Valvular abnormalities and IgG aCL appeared to be risk factors for cerebral infarction.


Reducing the risks in pregnant teens who are very young and those with mild mental retardation. A 3-year evaluation of The Children and Adolescent Pregnancy Project suggests that adolescents with mental retardation may be at increased risk for early pregnancy and dropping out of school. The Pregnancy Project is a school-based intervention that primarily serves black and Hispanic pregnant teens with mild to moderate mental retardation and elementary school-age pregnant teens in the same program. Outcome data were presented in terms of four common indicators of teen pregnancy programs: low birth weight, infant mortality, school drop out, and repeat pregnancy rates. Results indicate that serving pregnant adolescents with mild to moderate mental retardation (ages 11 to 19) in the same program with very young pregnant teens (ages 11 to 15) is an effective and developmentally appropriate means of reducing risks.


Quality assurance and impact measurement of university affiliated programs. Provisions in the Developmental Disabilities Bill of Rights and Assistance Act (PL 101-496) emphasize the need to measure the impact of federally supported services in promoting the independence and productivity of clients and their integration in community settings. As a part of this overall emphasis, the Administration on Developmental Disabilities (ADD) has initiated a Quality Enhancement System for use in the University Affiliated Programs (UAPs) encompassing both process (formative) and outcome or impact (summative) evaluation. Whereas formative measures and techniques have been used for many years and are well developed, measures and techniques to determine impact have received much less attention in the professional literature. Characteristics of successful UAPs were outlined as a basis for suggesting appropriate measures of impact of UAP programs on clients and their families, on host and affiliated universities, and on the service system. Some barriers to implementation of impact measures in UAPs were discussed.


Income allowance policies of state Medicaid agencies as work incentives or disincentives for ICF/MR residents. Results of a survey of six Midwestern states demonstrated that although some state Medicaid agencies have had work incentive policies for ICF/MR residents for some time, others continue to utilize policies that are a disincentive to work. Policy changes toward employment incentives in state Medicaid agencies should improve work opportunities for workers with mental retardation at little expense to the government.


Identification of developmental disabilities and health problems among individuals under child protective services. Although a relation between child abuse and developmental disabilities has been established, information about the health and developmental status of children referred to child protective services is not adequately obtained. Case records of 150 children identified to child protective services were reviewed in order to determine the availability of health and developmental information. A screening protocol was developed for the purpose of reviewing case records that has potential for use by child protective services workers.


Specialized treatment for behavior problems of institutionalized persons with mental retardation. The extent of use and effectiveness of special treatment options (in-house behavior shaping units, specialized outside referral agencies, and mobile intensive treatment teams) in dealing with behavior problems of persons with mental retardation was determined. A survey was completed by 144 institutions throughout the United States; 86% of all facilities recognized a need for special treatment options to deal with clients who had severe behavior problems. Sixty-eight percent of the institutions had presently or in the recent past used at least one of the three treatment options. Comparisons of these options in terms of perceived effectiveness, length of intervention, and type of problem addressed were reported.


Social support of mothers of children with mental retardation. Utilization of social support and perceptions of family stress of 80 mothers with a child who had mental retardation were examined. Measures of family stress and social support were administered to subjects with a child in one of three normative transition periods. There were no significant differences in family stress scores across the groups. Analysis of variance procedures revealed significant differences in the utilization of intimate support across the age groups. Implications for further research in this area were discussed.


Pinworm eradication in community residential settings for people with developmental disabilities. Pinworm, a common parasitic infestation, can be a chronic nuisance in community and institutional residences for people with developmental disabilities. Asymptomatic human carriage of the parasite and its eggs often prevents eradication from a communal residential setting. The elimination of pinworm from a system of community residential settings through a public health approach was described.


Organ-specific distribution of genotoxic effects in mice exposed to cooked food mutagens. The induction of organ-specific genotoxic effects of five cooked food mutagens in Swiss albino mice was investigated in microbial animal-mediated assays. The indicator of the induction of DNA damage was a pair of Escherichia coli K12 strains, differing vastly in repair capacity (uvrB/recA versus uvr+/rec+). All compounds gave positive results in the tested dose range between 2.5 and 40 mg/kg body weight (i.p. administration, exposure time 120 min). 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) were slightly more genotoxic than 2-amino-3,8-dimethylimidazo[4,5-f]quinoline (MeIQx), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) which caused similar effects. When the compounds were administered orally, higher doses were required to induce repairable DNA damage. The pattern of organ-specific effects was essentially similar for all compounds; genotoxicity was most pronounced in livers and lungs, whereas in kidneys, spleen and testes comparatively lower effects were measured. The activity of PhIP, MeIQ and IQ in the blood was similar to that observed in the liver. The results obtained in vivo were compared with data gained in vitro with subcellular organ fractions. Our findings indicate the following. (i) The concentrations required to induce repairable DNA damage in microbial animal-mediated assays are substantially higher than might be expected on the basis of the liquid suspension tests. (ii) The ranking order of the genotoxicity of the various compounds in vitro is similar to that measured in vivo, but the differences in genotoxic potencies are less pronounced in the living animal.(ABSTRACT TRUNCATED AT 250 WORDS)


Genotoxic effectivity--comparison of 36 nitrated furan and arenofuran derivatives on a quantitative scale. Statistical comparison of T7 and other short-term tests. Thirty-six nitrated furan and arenofuran derivatives were measured and quantitatively characterized by the T7 inactivation test. A wide range of substances previously studied allowed us to compare the collected quantitative data with those obtained by other workers using different short-term tests. Based on comparative statistical evaluation of these data a borderline was determined for the genotoxic effect: compounds having in our short-term test mutagenicity index (MI) values smaller than 8.0 are positive while the higher values represent negative genotoxicity. Classification of 36 nitrofuran/nitroarenofuran derivatives is given both on the basis of the quantitative genotoxicity scale and in terms of +/- on the qualitative scale. All but one compound were found to be genotoxic and the genotoxic activities of these compounds were compared with the results of other carcinogenicity or mutagenicity tests.


Flow cytometric micronucleus test with mouse peripheral erythrocytes. Flow cytometric (FC) analysis was applied to micronucleus test with mouse peripheral blood erythrocytes. The method is based on the measurement of peak fluorescence (PFL) of sphered glutaraldehyde-fixed erythrocytes before and after staining with 4',6-diamidino-2-phenylindole (DAPI), in an EPICS V flow cytometer. The frequency of micronucleated erythrocytes (MNEs) is calculated by a computer program comparing PFL data obtained with and without DAPI. To evaluate the method, male ddY mice were treated with 6-mercaptopurine and benzene and blood was collected from tail vein at intervals of 4-7 days. Both microscopic and FC analysis showed a steady increase in the incidence of MNEs, reaching a plateau when about a month had passed from the start of the treatments. The effects of benzo[a]pyrene, mitomycin C,N-ethyl-N-nitrosourea, bromodichloromethane and potassium chromate (VI) were also studied with both the manual and FC assay in samples collected a week after five weekly treatments. The percentages of MNEs obtained manually and by the FC measurements showed good correlation, the former three chemicals being positive and the latter two negative or, in the FC analysis, difficult to classify. Because of the high number of cells examined (50,000/animal), the FC analysis was probably more sensitive than the manual method where only 2000 cells were scored per animal. This was further suggested by (i) steady time responses, also for individual animals, in the FC results on 6-mercaptopurine and benzene, (ii) overall reduced inter-individual variation in the FC measurements, and (iii) detection of MNE induction by mitomycin C at a lower dose level with the FC than the manual analysis.(ABSTRACT TRUNCATED AT 250 WORDS)


A Chinese hamster ovary cell mutant (EM-C11) with sensitivity to simple alkylating agents and a very high level of sister chromatid exchanges. We have isolated a Chinese hamster ovary cell mutant hypersensitive to monofunctional alkylating agents. The mutant, designed as EM-C11, showed hypersensitivity to ethyl methanesulfonate (EMS), methyl methanesulfonate and ethylnitrosourea (8-, 7- and 2-fold, respectively, based on D10 values). About 2-fold increased sensitivity towards 4-nitroquinoline-1-oxide and only slightly increased sensitivity to X-rays (1.4-fold) and mitomycin C treatment (1.6-fold) were found in this mutant. EM-C11 was not hypersensitive to UV irradiation nor to adriamycin. The EM-C11 cells showed approximately 10-fold higher level of spontaneous sister chromatid exchange. The level of spontaneous chromosomal aberrations was 2- to 3-fold higher, but the frequency of EMS-induced chromosomal aberrations was approximately 10-fold higher in the mutant cells, in agreement with the increased sensitivity to killing. As measured by alkaline elution, EM-C11 cells showed a defect in the rejoining of single-strand DNA breaks after exposure to X-rays and even more so after the EMS treatment. Genetic analysis revealed that the EM-C11 mutant belongs to the same complementation group as the EM9 mutant described earlier. The XRCC1 gene which complements the defect in EM9 also complements the defect in EM-C11, confirming that these two independently isolated mutants are defective in the same gene.


Absence of translocation induction in mouse stem cell spermatogonia by chemical mutagens probably due to selective elimination. In order to discriminate between different mechanisms put forward to explain the low observed yields of reciprocal translocation configurations at diakinesis-metaphase I spermatocytes following treatment of mouse stem cell spermatogonia with chemical clastogens, the physiological states of stem cells at the moment of treatment were modified. The cell cycle was shortened by pretreatment with 2 Gy of X-rays and/or the DNA repair capacity inhibited by pretreatment with 3-aminobenzamide. Using these conditions the induction of translocations by ethyl methanesulfonate, N-ethyl-N-nitrosourea, methyl methanesulfonate and Adriamycin was studied. The results indicate that selective elimination of aberration carrying cells is probably to a large extent responsible for the low induction rate of translocations in stem cells by chemical clastogens. The high ratio of simple chromosome breaks versus chromosome exchange type aberrations induced by chemical mutagens might be the main cause of the selective elimination.


Interaction of omeprazole with DNA in rat tissues. There has been concern recently over the possible genotoxicity of omeprazole, a potent inhibitor of gastric acid secretion in humans. In order to investigate its possible DNA binding activity in vivo, 14C-labelled omeprazole was administered to male PVG rats, 8-10 weeks old, orally by gavage at a dose of 30 mg/kg. At various times after treatment, animals were killed and DNA isolated from the fundic and antral regions of the glandular stomach, and from the duodenum, ileum and colon. Scintillation counting of the DNA samples revealed a reproducible association of 14C that was not extractable with organic solvents and could not be removed from the DNA by column cartridge chromatography. DNA samples were digested enzymically to deoxyribonucleosides and analysed by reversed-phase high performance liquid chromatography (HPLC). With DNA from each tissue, most of the radioactivity eluted in a peak that was chromatographically distinct from normal nucleosides and from omeprazole itself. Chromatography following partial digestion of DNA gave rise to the same radioactivity elution profiles, whilst chromatography on hydroxyapatite resulted in retention of most of the radioactivity on the column using conditions under which DNA was eluted. These findings suggest either the formation in rat tissues of chemically-labile covalent omeprazole-DNA adducts or, more likely, a strong non-covalent interaction. The apparent DNA binding occurs rapidly in vivo and is short-lived, the maximum levels of radioactive incorporation (equivalent of up to 36 pmol omeprazole/mg DNA) occurring at 0.5 h in fundus, 0.5-1 h in antrum, 1 h in duodenum, 2 h in ileum and at 4-8 h in colon.


Effects of adenine arabinoside and coformycin on the kinetics of G2 chromatid aberrations in X-irradiated human lymphocytes. The kinetics of chromatid aberrations have been studied in human lymphocytes exposed to X-rays in the G2 phase of the cell cycle and incubated with or without the nucleoside analogue 9-beta-D-arabinofuranosyladenine (ara A), known to inhibit the repair of DNA double-strand breaks. In the absence of ara A an exponential decrease in frequencies of chromatid breaks occurred which we interpret as repair. Few breaks were observed if samples were harvested immediately following irradiation. The frequency of chromatid breaks at 1 h after X-irradiation (442 per 100 cells/Gy) was similar to that previously observed in Chinese hamster ovary (CHO) K1 cells. However, the exponential decrease of chromatid breaks between X-irradiation and sampling occurred with a t1/2 of 0.87 h, a faster rate than we have previously observed in CHO K1 cells and was not inhibited by 200 microM ara A alone, in contrast with our previous findings in a human fibroblast line. However, in the presence of the ADA inhibitor coformycin, inhibition of break repair was already observed at an ara A concentration of 100 microM indicating that the apparent unresponsiveness to ara A of lymphocyte chromatid break rejoining results from the deamination of this nucleoside analogue. This deamination effect was confirmed by measurements of DNA synthesis which showed stable inhibition of synthesis by ara A only when coformycin was present. Frequencies of chromatid exchanges in irradiated cells remained constant except at the sampling time directly after irradiation, consistent with the view that chromosomal radiosensitivity remained constant throughout the G2 phase, except for the period immediately prior to mitosis.(ABSTRACT TRUNCATED AT 250 WORDS)


The restriction endonuclease AluI induces sister chromatid exchange in Chinese hamster ovary cells. Chinese hamster ovary (CHO) cells were exposed to the restriction endonuclease AluI in the presence of 1.1 M glycerol. Chromosomal aberrations and sister chromatid exchange (SCE) were scored in first post-treatment metaphases following recovery times of 6-18 h. At all recovery times chromosomal aberrations were induced by the enzyme. In AluI-treated damaged cells significant elevations of SCE frequencies were found after recovery times of 12-18 h. These results indicate that SCE, unlike chromosomal aberrations, are induced only in late G1 and early S phase of the cell cycle. The lesions producing SCE are postulated as DNA single-strand breaks and gaps induced by AluI in canonical structures of DNA and in DNA-RNA hybrids.