Canadian regulation of contraceptive devices

Widespread use and technical developments associated with oral contraceptives (OCs), IUDs, techniques involved with abortion, and laparoscopy have resulted in hazards which require governmental control. The objectives and regulatory aspects of contraceptive devices undertaken by the Bureau of Medical Devices is described. The development of quality standards, both voluntary and regulatory, and the importance of postmarket controls for contraceptive devices are recent developments designed to ensure improvement in the health of the Canadian public. New and developing contraceptive device technology may have profound effects on the health and wellbeing of the Canadian public. The challenge of ensuring the safety and efficacy of contraceptive devices must be better met by communication from those patients who are affected. Physician and other allied health professionals who interface with the patient must be sensitive to the concerns of the patients.

Psychosocial functioning, life change, and clinical status in adolescents with cystic fibrosis

Twenty-six adolescents with cystic fibrosis (CF) were administered the Tennessee Self Concept Scale. The mean overall scores placed the CF patients at the 30th percentile of a normative adolescent population. Eighty-five percent were at appropriate school grade level, 69% participated in physical education classes, and 81% had future plans for college and/or a career. Total Life Event scores of CF adolescents were not significantly different from the normal adolescent population. However, in 22 CF adolescents evaluated with a modified National Institute of Health Scoring System, negative Life Event scores were higher in 10 adolescents with moderate to severely impaired health status than in 12 with lesser impairment. This relationship was not modified by other psychosocial variables.

A system for the analysis of long-term electrocardiographic studies in clinical research and training

A computer system has been developed for the analysis of data from long-term electrocardiographic studies in the context of an institution committed to clinical research and training. The major characteristics required of such a system are intelligence, flexibility, friendliness, and maintainability. These attributes are achieved by a user interface which consists of menus and interactive graphics, and by the use of highly modular software developed in a high-level programming language. The system has been used in studies of the effects of drugs on cardiac arrhythmias and has been easy to learn and convenient to use.

Electrocardiographic monitoring in ambulatory patients with cardiac arrhythmias

The merits of Holter monitor recording, intermittent event recording, and transtelephonic recording are stated, the equipment used for each method is described, and the type of data obtained is analyzed.

Nitrous oxide production by Escherichia coli is correlated with nitrate reductase activity

Nitrous oxide production by Escherichia coli seems to result from the reduction of NO2- by NO3- reductase. This hypothesis is consistent with previous observations and with the observation that molybdenum was required for both NO3- reduction and N2O production. Several E. coli NO3- reductase mutants were assayed for both N2O-producing and NO3--reducing activity. The hypothesized role of NO3- reductase is supported by the correlation of these two activities. Nitrate reduction to NH4+ enhanced growth, but NO2- reduction to N2O apparently did not. Therefore, this process differs significantly from respiratory denitrification.

Pharmacokinetic and pharmacodynamic effects of diltiazem

The pharmacokinetic and pharmacodynamic effects of diltiazem were studied in 8 patients after a short intravenous infusion (20 mg over 10 minutes), a single oral dose (60 or 90 mg), and repeated oral administration (60 or 90 mg every 6 hours for 16 doses). Diltiazem levels decreased in a triexponential manner after intravenous infusion. Terminal half-lives after intravenous, single oral, and repeated oral administration were not significantly different (4.5 +/- 1.3, 3.7 +/- 0.6, and 4.9 +/- 0.4 hours, respectively). The kinetic effects of oral diltiazem were nonlinear. With repeated oral administration, there was accumulation of both diltiazem and its metabolite, deacetyldiltiazem. The diltiazem area under the time versus concentration curve increased by a factor of 2.39 +/- 0.42 (p = 0.00002). Most patients showed a double peaked time versus concentration curve after oral administration, indicating possible enterohepatic recirculation. After intravenous administration, there was a substantial increase in the P-R interval (14.3 +/- 5.4%). Although only small changes in P-R interval were seen with a single oral dose, with chronic administration there was persistent P-R interval prolongation, peaking at 17.3 +/- 5.6% over control. Counterclockwise hysteresis was present in the P-R interval versus plasma diltiazem concentration curve after intravenous administration. Only small changes were seen in heart rate and blood pressure.

Design considerations for a medical school hospital cancer patient data system

Tumor registries abound, but there are few that successfully incorporate information age data management resources. This article describes the evolutionary process of designing, implementing, and maintaining a computer-based cancer patient information system for a medical school hospital. The primary requirement was that accurate information about the cancer experience at University of Texas Medical Branch (UTMB) be readily available. Since the tumor registry staff were not data processing professionals, this system had to use commonly available, well documented, readily maintained, and easily used data management resources. The UTMB registry, as documented by the marked increase in frequency and scope of use, demonstrates that a quality information resource can have a significant impact on hospital cancer programs and could serve as a prototype for other institutions having similar needs.

High-performance liquid chromatographic analysis of diltiazem and its metabolite in plasma

A rapid, selective and reproducible high-performance liquid chromatographic method for the analysis in plasma of the calcium channel blocking agent, diltiazem, and one of its metabolites, deacetyldiltiazem is described. The method involves extraction with the methyl tert.-butyl ether of the drugs and the internal standard (verapamil), back-extraction into sulphuric acid and reversed-phase chromatography with UV detection. Over a concentration range of 10-1000 ng/ml the average coefficient of variation for diltiazem was 5.4% and for deacetyldiltiazem was 8.3%.

Mothers of adolesent mothers

The attitude of forty-four mothers of adolescent mothers (MAM) were assessed by interview and questionnaire. Most adolescent mothers (AM) and their infants lived with MAM. Thirty-two percent of MAM and sisters of AM had themselves experienced a pregnancy prior to seventeen years of age. The majority of MAM expressed positive feelings about AM and their infants. MAM reported little change in their own life style as a result of their daughter's pregnancy. Most MAM's provided child care and financial assistance for AM, but reported that the AM had primary child care responsibility for the infant.

Pontine hemorrhage causing Fisher one-and-a-half syndrome with facial paralysis

The case of a 58-year-old white man with a history of high blood pressure and chronic obstructive pulmonary disease who developed double vision followed by right-sided facial paralysis is reported. A computerized axial tomogram (CT) scan showed an enhancing lesion in the pontine tegmentum, and the diagnoses of pontine glioma or hemorrhage were considered. Physical findings were limited to the cranial nerves. Conservative management with Decadron for 3 weeks resulted in a prompt clinical improvement, and a CT scan 1 month later showed resolution of the lesion, effectively ruling out a glioma. Total clinical recovery occurred at the end of 6 months. To our knowledge this is the first report of a case of Fisher one-and-a-half syndrome with facial paralysis correlated with computed tomography.

Replication of lactate dehydrogenase-elevating virus in macrophages. 1. Evidence for cytocidal replication

Cultures of starch-elicited peritoneal mouse macrophages in medium containing macrophage growth factor (MGF) were infected with lactate dehydrogenase-elevating virus (LDV) and, after various times in culture, LDV production was monitored as a function of time by infectivity titrations in mice, by measuring [3H]uridine incorporation into LDV RNA and extracellular LDV, by autoradiographic analysis of the proportion of productively infected cells and by electron microscopy. Regardless of the age of the cultures when infected with LDV, only a small proportion of the macrophages (generally between 3 and 20% of the total) became productively infected after a primary infection; maximum virus RNA synthesis and virus production occurred during the first 24 h after infection and then decreased precipitously. Productively infected macrophages could be readily recognized in electron micrographs of 24-h infected macrophage cultures and in sections of spleens from 24-h infected mice by characteristic morphological alterations. These consisted of formation of clusters of double-membrane vesicles with a diameter of 100 to 300 mumol, budding of nucleocapsids into vesicles with single membranes and accumulation of mature virions in these vesicles. One to 4 days later, however, such cells were no longer found in infected cultures or spleens of infected mice and superinfection did not restimulate LDV replication. Cultures established with macrophages from 1-day LDV-infected mice also did not support LDV replication. We conclude that LDV replication in cultures or mice is limited to a single cycle in a subpopulation of macrophages and that infection leads to cell death and rapid phagocytosis of the dead cells by the resistant, uninfected macrophages.

Effect of pulsatile gonadotropin-releasing hormone on the release of luteinizing hormone and follicle-stimulating hormone in vitro by anterior pituitaries from lactating and cycling rats

The ability of pituitaries from lactating animals to secrete LH and FSH in response to gonadotropin-releasing hormone (GnRH) was studied in vitro using a pituitary incubation system. Hemipituitaries were exposed to GnRH for 6 min during each hour of incubation. LH release by anterior pituitaries (APs) from day 5 postpartum rats nursing eight pups, in response to pulsatile exposure to GnRH, was significantly less than that released by APs from diestrous cycling females. Even though the amount of LH released by APs increased as lactation progressed, LH release by APs from day 15 postpartum rats nursing eight pups was still less than LH release by APs from diestrous females. In contrast pituitaries from lactating females nursing two pups released amounts of LH similar to that released by pituitaries from diestrous females, whereas females deprived of their litters for 48 h showed a greater response than diestrous females. Generally, there was a good quantitative relationship between the amount of LH released in vitro and plasma LH concentrations for all the intact groups studied. The ability of lactation to suppress the postcastration rise in serum LH also was demonstrated in vitro as pituitaries from ovariectomized or intact females nursing eight pups released similar amounts of LH on days 5 and 10 postpartum. However, by day 15 postpartum, even though serum LH concentrations were still very low, pituitaries from ovariectomized lactating females released LH in vitro at a rate similar to pituitaries from nonlactating rats. Serum FSH concentrations were not suppressed but similar in intact and cycling females. Also, the total amount of FSH released in vitro in response to GnRH by pituitaries from lactating and cycling females did not differ significantly, even though LH release differed greatly among these groups of animals. However, the patterns of GnRH-stimulating FSH secretion differed among intact lactating, ovariectomized lactating, and nonlactating females. Pituitary LH concentrations were similar on day 5 postpartum and diestrus and on day 15 postpartum and proestrus. Pituitary FSH concentrations on day 5 postpartum were similar to those during diestrus and proestrus and had increased 2-3 times by day 15 postpartum. Generally, there was no correlation between the amount of LH or FSH released by pituitaries in response to GnRH and pituitary gonadotropin content. In summary, the inability of pituitaries from lactating rats to respond adequately to large doses of GnRH in vitro suggests that the suckling stimulus indirectly suppresses pituitary responsiveness to GnRH. This suppression differentially affects basal LH secretion, but not basal FSH secretion, and may be the direct result of inadequate GnRH stimulation in vivo.

An in-house program of continuing education for perinatal nurses

The value of continuing education for nurses continues to be stressed by nursing educators and nursing administrators. An in-house program, similar to the one described above, could be useful for other acute-care health facilities. It seems highly probable that certification by a recognized credentials-granting agency, especially a specialty of nursing, such as obstetrics or neonatology, wil become an important evaluation tool for those who employ nurses. It seems logical and cost-effective for nurses to take advantage of this opportunity to learn from resources in their own institution.

Adolescents' use of mental health services in a comprehensive treatment facility: age, sex and mode of entry

Data are presented from the clinical records of 185 adolescents who were admitted to the mental health service of a youth health center serving a community of military dependents. Eight and one-half per cent of the population made a first visit to the center during an eight month period. Midadolescence (ages 15-16) was the age period when patients began to refer themselves to mental health services in significant numbers. The importance of parents as referral sources decreased with age, while medical and school sources were important in all ages. The psychological morbidity in the target population was greater in midadolescence than in early and late adolescence and higher in females than in males. Females presented with more somatic and family problems, males more often with aggressive behavior problems.

Trauma as an etiologic and aggravating factor in multiple sclerosis

We carried out a retrospective and prospective epidemiologic study designed to detect an association between trauma and multiple sclerosis in 130 patients and 82 age- and sex-matched controls. Electrical injury was followed by an increased frequency of exacerbation, which did not achieve statistical significance. There was no statistically significant association between other types of trauma and onset or deterioration of the disease. These findings do not prove that such an association cannot exist for any one individual patient; however, they do not provide evidence to support this idea.

Wernicke's disease complicating surgical therapy for morbid obesity

A case of Wernicke's disease complicating surgical therapy for morbid obesity is presented. Features emphasized include the occurrence of the condition in a nonalcoholic patient and the persistence of neurological signs and symptoms despite prompt therapy. Prophylactic treatment in situations of potential thiamine depletion is essential if iatrogenic Wernicke's disease is to be avoided.

Upward gaze paralysis following unilateral pretectal infarction. Computerized tomography correlation

Sudden paralysis of upward gaze developed in a 47-year-old diabetic woman. Computerized tomographic scan and subsequent studies were consistent with a unilateral pretectal infarction. The mechanisms of upward gaze are discussed.

Pelvic inflammatory disease. A review

Pelvic inflammatory disease (PID), a bacterial infection centered in the fallopian tubes, is increasingly encountered among adolescents seen by the pediatrician. This review describes two cases representative of gonococcal and nongonococcal PID and the pathophysiology, epidemiology, diagnosis and treatment of this disorder are discussed. Emphasis is placed on management by the primary care pediatrician and indications for gynecologic consultation.

Confusion, dysphasia, and asterixis following metrizamide myelography

A patient exhibited confusion, dysphasia, and striking asterixis 18 hours after metrizamide myelography. The symptoms lasted for a day and a half. While metrizamide is a useful contrast medium, side effects are not unusual and can, on occasion, be quite severe.

Role of prolactin in regulating gonadotropin secretion and gonad function in female rats

The role of prolactin in female reproduction has been studied extensively in two systems; in the regulation of corpus luteum function, and in the regulation of gonadotropin secretion. In the rat, prolactin is an essential component of the luteotropic complex since it is the hormone responsible for transforming a corpus luteum of the estrous cycle into a corpus luteum of pseudopregnancy or pregnancy, which allows progesterone secretion to be maintained. The biphasic surges of prolactin initiated by cervical stimulation at the time of ovulation continue to be important throughout pseudopregnancy to maintain elevated levels of progesterone. During pregnancy, the luteotropic requirements change so that prolactin is no longer required after midpregnancy. In addition to its luteotropic effects, prolactin also has antigonadotropic effects that contribute significantly to the suppression of gonadotropin secretion during lactation. Suckling-induced prolactin secretion contributes to the suppression of both basal gonadotropin secretion and the postcastration rise in gonadotropins during lactation. Prolactin may have some effect at the pituitary to suppress responsiveness to luteinizing hormone-releasing hormone (LHRH), but its primary site of action appears to be the hypothalamus. Prolactin may be acting at the hypothalamus either to cause a decrease in LHRH secretion or to cause the release of substances that inhibit pituitary gonadotropin secretion directly.

Aberrant regeneration in idiopathic oculomotor nerve palsy: case report

Aberrant regeneration of the oculomotor nerve usually follows injury to the nerve by posterior communicating arty aneurysms or trauma. A case of idiopathic third nerve palsy with pupillary involvement occurred in an otherwise healthy 38-year-old man. Follow-up examination 32 months later showed evidence of oculomotor function with aberrant regeneration.

The physiologic consequences of vas ligation

Although the number of studies involving vasectomized men has been limited there appears to be no significant long-term effects. Endocrine function continues virtually unaltered. With a small number of exceptions spermatogenesis in man, as judged by a return of normal seminiferous tubule morphology, remains unchanged. However, the quality of the sperm may vary. The immunologic consequences of vasectomy have not been investigated fully. Although it is attractive to postulate that cross-reactive antibodies may develop to sperm antigens no autoimmune diseases in man secondary to vasectomy have been demonstrated. The increased incidence of atherosclerosias not been established in man. Presently, vasectomy remains a simple and safe means of permanent contraception.

Effects of prolactin on testicular regression and recrudescence in the golden hamster

Transfer of adult male hamsters from a long to a short photoperiod causes testicular atrophy, which is accompanied by decreases in testicular LH receptors and in plasma PRL and testosterone levels. A decrease in plasma gonadotropin levels is also frequently observed. When the decline in peripheral PRL concentration is prevented by transplantation of homologous pituitary(ies) under the kidney capsule, testicular atrophy is delayed and incomplete. This appears to be due to the maintenance of testicular LH receptors by PRL secreted from the grafts and probably also to the stimulation of GSH release from the in situ pituitary. In hamsters maintained in a long photoperiod, ectopic pituitary homografts can increase testicular LH receptor levels, concentrations of testosterone and FSH in the plasma, and the weights of the testes and the seminal vesicles. In contrast to the findings obtained in rats and mice, chronic hyperprolactinemia in the male hamster does not inhibit gonadotropin release or interfere with copulatory behavior. These findings are consistent with our earlier suggestion that PRL plays an important part in the regulation of gonadal function in the male hamster but indicate that testicular atrophy in a short photoperiod cannot be explained solely by a reduction in PRL release.

Role of the pituitary and the adrenals in mediating the effects of alcohol on testicular steroidogenesis in mice

We have previously demonstrated that intragastric administration of alcohol (1.24 g/kg body wt) to adult male mice results in suppression of testosterone production. We now report that the decline in peripheral testosterone levels in alcohol-treated mice is not accompanied by changes in plasma levels of luteinizing hormone, follicle stimulating hormone or estradiol-17 beta, and that it is markedly attenuated in adrenalectomized or adrenalectomized-corticosterone treated males.

Unwinding-like activity associated with avian retrovirus RNA-directed DNA polymerase

The avian retrovirus RNA-directed DNA polymerase contains an activity that is capable of removing hydrogen bonds from duplex nucleic acid molecules. This "unwinding-like" activity appears to be specific in its action, affecting RNA.DNA and DNA.DNA duplex molecules but not RNA.RNA duplexes. Studies with defined RNA.DNA hybrid molecules (e.g., Rous sarcoma virus RNA and complementary DNAs representing specific regions of the Rous sarcoma virus genome) and DNA.DNA duplexes indicate that, although this activity can remove a portion of the hydrogen bonds from these double-stranded structures, complete separation of complementary strands is not accomplished. The unwinding-like activity exhibits sensitivities to temperature and monovalent and divalent cation concentrations. It can also remove a specific large oligonucleotide from the 5' end of the viral genome subsequent to RNase H hydrolysis of viral RNA complexed to DNA present at that terminus. This reverse transcriptase-associated unwinding-like activity is discussed with respect to recently proposed models of retrovirus proviral DNA synthesis.

Granulomatous ileocolitis preceded by three years of pauciarticular arthritis

The case of a 12-year old male is presented in whom pauciarticular arthritis preceded the clinical onset of granulomatous ileocolitis by three years. Before the onset of gastrointestinal symptoms, the patients' clinical diagnosis was juvenile rheumatoid arthritis. This case stresses the importance of including inflammatory bowel disease in the differential diagnosis of pauciarticular arthritis in children.