Supplementation with isoflavonoid phytoestrogens does not alter serum lipid concentrations: a randomized controlled trial in humans

Isoflavonoids are a class of flavonoids that are derived in the human diet mainly from soybean-based foods. The major dietary isoflavonoids, genistein and daidzein, have estrogen-like activity and are classed as phytoestrogens. Because estrogens can lower serum LDL cholesterol and raise HDL cholesterol, the objective of this study was to determine if isoflavonoids could improve serum lipids in healthy subjects. Forty-six men and 13 postmenopausal women not receiving hormone replacement therapy completed a randomized, double-blind, placebo-controlled trial of two-way parallel design and 8 wk duration. One tablet containing 55 mg of isoflavonoids (predominantly in the form of genistein) or one placebo tablet was taken daily with the evening meal. Subjects maintained their usual diet and physical activity, which were unchanged throughout the intervention. Measurement of isoflavonoids and their metabolites in 24-h urine samples provided an assessment of compliance and of isoflavonoid metabolism. Serum total, LDL, HDL and HDL subclass cholesterol, triglycerides and lipoprotein (a) were assessed at baseline and during the last week of intervention. After adjustment for baseline values, no significant differences in postintervention serum lipid and lipoprotein (a) concentrations between groups were identified. Further adjustment for age, gender and weight change did not alter the results. In addition, changes in urinary isoflavonoids were not significantly correlated with changes in serum lipids and lipoprotein (a). Therefore, this study does not support the hypothesis that isoflavonoid phytoestrogens can improve the serum lipids, at least in subjects with average serum cholesterol concentrations.     

Collateral blood supply through the ophthalmic artery: a steal phenomenon analyzed by color Doppler imaging

OBJECTIVE: This study aimed to evaluate the retrobulbar circulatory effects of reversed ophthalmic artery flow (ROAF) on the ophthalmic artery branches by means of color Doppler imaging. DESIGN: The design was a case-controlled study. PARTICIPANTS: Among 56 consecutive patients with severe (>70% stenosis) occlusive carotid artery disease, 15 patients (26.8%) with ROAF were identified. The control group consisted of 15 patients with similar degrees of carotid artery stenosis and forward ophthalmic artery flow. INTERVENTION: Arteriography and measurement of the retrobulbar hemodynamic parameters with color Doppler imaging were performed. MAIN OUTCOME MEASURES: Blood flow velocities and resistive index in the ophthalmic, central retinal, and temporal short posterior ciliary arteries were measured. RESULTS: Arteriography confirmed the diagnosis of ROAF in all 15 patients. There was no patient with ROAF diagnosed by arteriography and not diagnosed by color Doppler imaging. The frequency of bilateral severe occlusive carotid artery disease was significantly higher in the ROAF group (40%) compared to the control group (6.6%) (P = 0.04). Patients with ROAF showed significantly reduced vascular resistance in the ophthalmic artery (P = 0.03), higher vascular resistance, and lower blood flow velocities in the central retinal and temporal short posterior ciliary arteries (P < 0.05). CONCLUSION: This study suggests that patients with ROAF show a steal phenomenon, characterized by a shunt to the low-resistance intracranial circuit and reduction of retrobulbar blood flow.     

Family planning knowledge, attitudes and practices in women with schizophrenic spectrum disorders

This study set out to test three hypotheses about family planning in women with schizophrenic spectrum disorders, as compared to demographically comparable non-mentally ill control women: that they (1) report at least as much unprotected intercourse while not desiring pregnancy; (2) have less knowledge about contraception; and (3) perceive more, and different, obstacles to obtaining or using birth control. A semistructured Family Planning Interview was administered to subjects (n = 44) with Research Diagnostic Criteria diagnoses of schizophrenia and schizoaffective disorder, and to non-mentally ill control subjects (n = 50). The participants had high rates of unprotected intercourse, as did non-mentally ill controls. They had significantly less reproductive and contraceptive knowledge than the control subjects, and were more likely to perceive birth control as difficult to obtain. The most common reason women with schizophrenic spectrum disorders gave for failing to use birth control was that they did not expect to have sex, while that given by non-mentally ill subjects related to side-effects of birth control. Important obstacles to family planning in women with schizophrenic spectrum disorders include relative lack of knowledge and difficulty planning ahead. Although many women with schizophrenia could benefit from long-acting, reversible contraception, many may be unaware of those options and/or may find them difficult to obtain. Integrating family planning with mental health care might better address the unique needs of this population.     

Cognitive ability and cerebral lateralisation in transsexuals

INTRODUCTION: The application of high-frequency current to the AV junctional area results in a temperature rise in the myocardium and may cause accelerated junctional rhythm (AJR). The aim of the study was to characterize heat-induced AJR in an in vitro animal model. METHODS AND RESULTS: Studies were performed in isolated perfused pig and rabbit hearts. Using a small heating probe, we could induce AJR from a discrete area located in the middle of the triangle of Koch, which was smaller than the area from which RF energy application could elicit AJR. Histology showed that the heat-sensitive area was located over, or close to, the compact AV node. It did not correspond with the areas where double potentials were found or with the site(s) of earliest atrial activation during VA conduction. Microelectrode recordings revealed that AJR arose in nodal-type cells. Heat increased the slope of the phase 4 depolarization and shortened the action potential duration. Two types of AJR were observed: the first one was regular and the second one showed irregularity in the intervals. Interaction of multiple foci and the presence of conduction block between the foci and the His bundle caused the irregularity of the His-His intervals during the second type of AJR. CONCLUSION: AJR observed during heat and RF application in the AV nodal area results from the effect of heat on AV nodal cells with underlying pacemaker activity. The heat-sensitive area is located over, or very close to, the compact AV node.     

Drug-induced reinstatement of heroin- and cocaine-seeking behaviour following long-term extinction is associated with expression of behavioural sensitization

The present study was designed to evaluate the relationship between reinstatement of drug-seeking behaviour following long-term extinction of intravenous (i.v.) drug self-administration (an animal model for craving) and long-term behavioural sensitization. Rats were allowed to self-administer heroin (50 microg/kg per inj., 14 daily sessions), cocaine (500 microg/kg per inj., 10 daily sessions) or saline. Following a 3-week extinction period, reinstatement tests were performed to evaluate priming effects of amphetamine, cocaine and heroin on nonreinforced drug-seeking behaviour. In addition, the occurrence of long-term behavioural sensitization in rats with a history of heroin or cocaine self-administration was determined. Heroin-seeking behaviour was reinstated by heroin (0.25 mg/kg), amphetamine (1.0 mg/kg) and cocaine (10 mg/kg). In addition, animals with a history of heroin self-administration displayed locomotor sensitization to both heroin and amphetamine. Cocaine-seeking behaviour was reinstated by cocaine and amphetamine, but not by heroin. Interestingly, locomotor sensitization to amphetamine, but not heroin, was observed in animals with a history of cocaine self-administration. In other words, the induction of drug-seeking behaviour following a prolonged drug-free period was found to be associated with the expression of long-term behavioural sensitization. These data provide experimental evidence for a role of behavioural sensitization in the incentive motivation underlying drug-seeking behaviour. If drug hyperresponsiveness would indeed be a crucial factor in drug-induced craving in human addicts, pharmacological readjustment of the neuroadaptations underlying drug sensitization may prevent relapse to drug use long after detoxification.     

S-fluoxetine in the prophylaxis of migraine: a phase II double-blind randomized placebo-controlled study

A tubular bioassay was used to measure analytically the local production and concentration of the antifungal Trichoderma secondary metabolite 6-n-pentyl-2H-pyran-2-one (6PAP) at the Trichoderma antagonist/pathogen interface. 6PAP levels significantly increased in the presence of the pathogen Botrytis cinerea, typically 300-700%, and were highest near the pathogen source. The level of response for a particular Trichoderma isolate was found to vary with the test organism used. Two products produced by biotransformation of 6PAP by B. cinerea in response to the interaction were also detected.     

Effects of nitric oxide on neuroendocrine function and behavior

Nitric oxide (NO) is an unusual chemical messenger. NO mediates blood vessel relaxation when produced by endothelial cells. When produced by macrophages, NO contributes to the cytotoxic function of these immune cells. NO also functions as a neurotransmitter and neuromodulator in the central and peripheral nervous systems. The effects on blood vessel tone and neuronal function form the basis for an important role of NO on neuroendocrine function and behavior. NO mediates hypothalamic portal blood flow and, thus, affects oxytocin and vasopression secretion; furthermore, NO mediates neuroendocrine function in the hypothalamic-pituitary-gonadal and hypothalamic-pituitary-adrenal axes. NO influences several motivated behaviors including sexual, aggressive, and ingestive behaviors. Learning and memory are also influenced by NO. Taken together, NO is emerging as an important chemical mediator of neuroendocrine function and behavior.     

Structure and practice of institutional review boards in the United States

OBJECTIVE: The institutional review board (IRB) is a critical element in the protection of patients' and subjects' rights with regard to their participation in research protocols. The purpose of this study was to describe the structure and current practices of IRBs in the United States. METHODS: A self-administered questionnaire was mailed to the IRB chair of each U.S. hospital with a capacity of at least 400 beds (n = 907). The survey contained 21 questions outlining committee size and structure, review of research proposals, and policies concerning scientific misconduct. Chairs also were asked what advice they would offer a young investigator preparing a proposal for submission. RESULTS: A total of 488 surveys (54%) were returned; 447 of the responding institutions had an IRB committee. Committees had an average of 14 members, representing 27 medical specialties. Orthopedics had the least IRB representation (10% of committees), followed by emergency medicine (12%) and ophthalmology (15%). The majority of research proposals go through 5 specific steps once submitted for review. Common reasons for proposal rejection were improperly designed consent form (54%), poor study design (44%), unacceptable risk to subjects (34%), ethical or legal reasons (24%), and scientific merit (14%). When a research proposal is rejected, 86% of the responding IRBs assist the investigator in making appropriate revisions. Although a number of IRBs (17%) have dealt with scientific misconduct allegations, only 58% have a written policy regarding research integrity. CONCLUSION: Despite variations in committee structure and representation, IRBs have similar procedures for governing research. Investigators should be familiar with these procedures and are encouraged to discuss their proposal with an IRB representative prior to formal review.