The fine structure of nerve fibers and endings in the lateral cerebral ventricles of the rat

The brains of adult rats were fixed by vascular perfusion with glutaraldehyde. Tissue blocks were cut from the walls in the anterior horn of the lateral ventricles. The blocks were impregnated with uranyl magnesium acetate and embedded in Vestopal. Numerous nerve fibers lay supraependymally, singly or in groups, between the microvilli and cilia of the ependymal cells. Varicosities occurred along the fiber, often in close succession. The intraventricular nerve endings were flask-shaped. Vesicles were present in the cytoplasm of the nerve processes, varying considerably in shape, size and content. They were round or flattened. Some contained a dense core, whilst others were more or less empty. A zonula adhaerens was sometimes observed between a nerve ending and the luminal plasma membrane of an ependymal cell. The present study and other studies are compatible with the concept that the intraventricular nerve processes are receptors, possibly registering the composition of the cerebrospinal fluid. A further possibility is that the nerve processes give off a secretion to the cerebrospinal fluid.     

Sibship characteristics and risk of multiple sclerosis: a nationwide cohort study in Denmark

It has been hypothesized that age at infection with a common microbial agent may be associated with the risk of multiple sclerosis (MS). The authors addressed this hypothesis by using number of older siblings and other sibship characteristics as an approximation of age at exposure to common infections. Data on family characteristics and vital status from the Danish Civil Registration System were used to establish a cohort of all Danes whose mothers had been born in Denmark since 1935. Persons diagnosed with MS during the period 1968-1998 were identified through linkage with the Danish Multiple Sclerosis Register. The cohort of 1.9 million Danes was followed for 28.1 million person-years; during that time, 1,036 persons developed MS. Overall, there was no association between number of older siblings, number of younger siblings, total number of siblings, age distance from the nearest younger sibling, or exposure to younger siblings under 2 years of age and risk of MS later in life. There was no association of MS risk with multiple birth (vs. singleton birth) or with the age of the mother or father at birth. These results do not lend support to the hypothesis that number of older siblings or any of the other sibship characteristics studied is associated with risk of MS.     

The state of pediatric interfacility transport: consensus of the second National Pediatric and Neonatal Interfacility Transport Medicine Leadership Conference

Interfacility transport of pediatric and neonatal patients for advanced or specialty medical care is an integral part of our medical delivery system. Assessment of current services and planning for the future are imperative. As part of this process, the American Academy of Pediatrics and the Section on Transport Medicine held the second National Pediatric and Neonatal Transport Leadership Conference in Chicago in June 2000. Ninety-nine total participants, representing 25 states and 5 international locations, debated and discussed issues relevant to the developing specialty of pediatric transport medicine. These topics included: 1) the role of the medical director, 2) benchmarking of neonatal and pediatric transport programs, 3) clinical research, 4) accreditation, 5) team configuration, 6) economics of transport medicine in health care delivery, 7) justification of transport teams in institutions, and 8) international transport/extracurricular transport opportunities. Insights and conclusions from this meeting of transport leaders are presented in the consensus statement.     

Occupational exposure to airborne proteolytic enzymes and lifestyle risk factors for dental erosion--a cross-sectional study

This study examined the hypothesis that occupational exposure to airborne proteolytic enzymes is associated with dental erosions on the facial surfaces of exposed teeth. Individuals (n = 425) working at a pharmaceutical and biotechnological enterprise (Novozymes A/S) were examined; their mean age was 35 years (range = 18-67 years) and 143 (34%) were women. Two hundred and two of these individuals were newly employed by the company. Occupational exposure was assessed from questionnaire and workplace information. For practical analytical purposes, individuals were categorized as either previously exposed to proteolytic enzymes or not. Information on relevant lifestyle factors and medical history was obtained from a questionnaire. The main effect measure was facial erosion, but lingual erosion indices and the presence of Class V restorations were also considered. The validity of these measures was shown to be very high. Adjusted for potential confounders, there was no association between history of occupational exposure to proteolytic enzymes and prevalent facial or lingual erosion. With respect to prevalence of Class V restorations, the association was significant. The present study did not support directly our primary hypothesis that occupational exposure to airborne proteolytic enzymes is associated with dental erosions on the facial surfaces of exposed teeth. However, the results indicate that exposure to proteolytic enzymes may lead to pronounced tooth substance loss, demanding treatment.     

Pharmacological approaches to inhibit endogenous glucose production as a means of anti-diabetic therapy

The inappropriate overproduction of glucose by the liver is one of the key contributors to the hyperglycaemia of the diabetic state, and thus is a logical site of intervention for novel anti-diabetic approaches. Metformin is the only currently marketed anti-hyperglycaemic drug whose action is attributed largely to its having inhibitory effects on hepatic glucose production, but its molecular site and mechanism(s) of action remain unknown, whereas the liver acting PPAR alpha agonists have their effects primarily on lipid metabolism. This review therefore rather focuses on candidate molecular targets within the liver for anti-hyperglycaemic therapy, and describes potential rate-controlling receptors and enzymes within the glucose producing pathways (glycogenolysis and gluconeogenesis). Most focus is directed towards inhibitors of the enzymes glucose-6-phosphatase, fructose-1,6-bisphosphatase and glycogen phosphorylase, and towards glucagon receptor antagonists, as these appear to be the most advanced in preclinical and clinical development, although progress with other potential targets is also described. Evidence of the anti-diabetic potential of such agents from animal studies is presented, and the relative merits of each approach are reviewed and compared. It is likely that such agents will become important additions to the therapeutic approaches to combat diabetes.     

Clinical impact of mild carbohydrate intolerance in pregnancy: a study of 2904 nondiabetic Danish women with risk factors for gestational diabetes mellitus

OBJECTIVE: The objective was to study the clinical impact of mild carbohydrate intolerance in pregnant women with risk factors for gestational diabetes mellitus. STUDY DESIGN: This was a historical cohort study of 2904 pregnant women examined for gestational diabetes on the basis of risk factors. Information on oral glucose tolerance test results and clinical outcomes was collected from laboratory charts and medical records. RESULTS: The following outcomes increased significantly with increasing glucose values during the oral glucose tolerance test: shoulder dystocia, macrosomia, emergency cesarean section, assisted delivery, hypertension, and induction of labor. However, when corrections were made for other risk factors, hypertension and induction of labor were only marginally associated with glucose levels. CONCLUSION: In a group of nondiabetic pregnant women with risk factors for gestational diabetes, there was a graded increase in the frequency of shoulder dystocia and other maternal-fetal complications with increasing glucose levels during an oral glucose tolerance test.     

Human menopausal gonadotropin versus recombinant follicle-stimulating hormone in normogonadotropic women down-regulated with a gonadotropin-releasing hormone agonist who were undergoing in vitro fertilization and intracytoplasmic sperm injection: a prospective randomized study

OBJECTIVE: To evaluate clinical and endocrinological effects of intranasal (IN) vs. subcutaneous (SC) GnRH-a for pituitary down-regulation combined with hMG vs. rFSH. DESIGN: Prospective, randomized study. SETTING: University hospital, IVF unit. PATIENT(S): Three hundred seventy-nine normogonadotropic women eligible for IVF or ICSI. INTERVENTION(S): Randomization to intranasal (IN) or SC GnRH-a and to hMG or rFSH. MAIN OUTCOME MEASURE(S): Oocytes retrieved, embryos developed, clinical pregnancy, and delivery rates. Serum hormone concentrations on stimulation days 1 (S1) and 8 (S8), and oocyte pick-up (OPU) day. RESULT(S): After randomization, four groups were formed: IN/hMG (n = 100), IN/FSH (n = 98), SC/hMG (n = 89), and SC/FSH (n = 92). Mean number of oocytes retrieved and of transferable and transferred embryos were similar in the four groups. Clinical pregnancy rate per started cycle was significantly higher in the IN/HMG group than in the SC/FSH group (P<.05) and was intermediate in the two remaining groups. Se-LH on S8 in the two SC groups was significantly lower than in the two IN groups. Se-E2 on S8 in the SC/FSH group was significantly lower than in the other three groups. CONCLUSION(S): The clinical and endocrinological outcome in IVF and ICSI-treated normogonadotropic women is significantly influenced by mode of down-regulation as well as gonadotropin formulation.     

Managed care experiences of clinical neuropsychologists

Abstract

Although the eventual outcomes of what has become known as ‘health care reform’ are still far from clear, it is essential that clinical neuropsychologists begin to evaluate and respond, individually and as a discipline, to the evolving changes in national health care. With timely information regarding the impact of these changes in health care management, neuropsychologists can proactively develop, distribute, and implement expectations regarding appropriate standards of care among policy makers and reimbursement sources. Within this context, the results of a brief national survey of beliefs, experiences, and concerns of 259 clinical neuropsychologists are discussed. In sum, the majority of clinical neuropsychologists believe that health care ‘reform’, will have a negative effect on their practice, and many report serious difficulties already experienced under managed care systems. At least one third of clinical neuropsychologists sampled have experienced reductions in income levels, hourly reimbursement, referral sources, and overall number of referrals secondary to working within a managed care system, and more than half report having been excluded as providers from managed care systems. Additional concerns include increased paperwork and administrative time, loss of control over decisions essential to designing appropriate neuropsychological batteries, lack of appropriate representation, and diminished patient care. Proactive recommendations for dealing with these health care economic changes are presented.     

Racial/Ethnic Differences in Trust in Health Care: HIV Conspiracy Beliefs and Vaccine Research Participation

BACKGROUND

Prior research has documented a high prevalence of conspiracy beliefs about the origin of the human immunodeficiency virus (HIV) and the role of the government in the acquired immunodeficiency syndrome (AIDS) epidemic, particularly among racial and ethnic minorities in the United States. Whether such beliefs are a barrier to participation in HIV prevention research is not known.

OBJECTIVE

To understand the prevalence of HIV conspiracy beliefs and their relationship to willingness to participate in HIV vaccine research among three racial/ethnic groups.

DESIGN

Cross-sectional survey.

PARTICIPANTS

Six hundred and one community-recruited volunteers (33.0 % White, 32.5 % Mexican American, and 34.5 % African American).

MAIN MEASURES

We evaluated the level of agreement with six previously described HIV conspiracy beliefs, trust in medical research, and willingness to participate in HIV vaccine research. Multivariate models were used to compare these parameters among the three racial/ethnic groups while controlling for the potential confounding effects of socioeconomic status, access to health care, and other demographic factors.

RESULTS

African Americans, Mexican Americans, and whites had similar levels of distrust in medical research. African and Mexican Americans were more likely to endorse one or more of six HIV conspiracy beliefs than whites (59.0 % and 58.6 % versus 38.9 %, respectively, P?<?0.001), but were significantly more willing to participate in HIV vaccine research (ORs 1.58, CI 1.10–2.25 and 2.53, CI 1.75–3.66, respectively). Among respondents of all racial/ethnic groups, endorsing HIV conspiracy beliefs was not associated with willingness to participate in research.

CONCLUSIONS

HIV conspiracy beliefs, while common among all racial and ethnic groups in the United States, do not preclude willingness to participate in HIV prevention research.