Bioactivation of mushroom hydrazines to mutagenic products by mammalian and fungal enzymes.

Agaritine (N2-[L-(+)-glutamyl]-4-(hydroxymethylphenyl)hydrazine), the principal hydrazine found in the edible mushroom Agaricus bisporus, as well as the N'-acetyl derivative of 4-(hydroxymethyl)phenylhydrazine and 4-(hydroxymethyl)benzene diazonium ion, as the tetraborate salt, considered as the putative proximate and ultimate carcinogens of agaritine, were all synthesised chemically. The mutagenicity of these compounds and of 4-hydrazinobenzoic acid, a precursor of agaritine biosynthesis in mushroom, was investigated in the Ames test, using Salmonella typhimurium strain TA104, in the absence and in the presence of either mushroom tyrosinase or rat hepatic cytosol as activation systems. In the absence of an activation system the diazonium ion was clearly the most mutagenic of the four compounds studied.

Septal extension grafts: a method of controlling tip projection shape.

Failure to control the projection, shape, and rotation of the nasal tip is a common occurrence among patients with weak lower lateral cartilages. These patients' noses are characterized by a weak midvault, a plunging tip with "Polly beak," and drawn-up alae. The purpose of our study was to identify methods for controlling the position and shape of the nasal tip in these high-risk patients.

Bioactivation of the mushroom hydrazine, agaritine, to intermediates that bind covalently to proteins and induce mutations in the Ames test.

The present study was undertaken to establish whether liver and kidney enzyme systems, from rat and mouse, have the potential to metabolise and bioactivate agaritine, beta-N-(gamma-L(+)glutamyl)-4-(hydroxymethyl)phenylhydrazine, the most abundant hydrazine present in the edible mushroom Agaricus bisporus. Agaritine was weakly mutagenic, in the absence of an activation system, in Salmonella typhimurium strain TA104. Rat kidney homogenates, characterised by high gamma-glutamyl transpeptidase activity, enhanced the mutagenic response.

Changes in gravity influence rat postnatal motor system development: from simulation to space flight.

Our research examines the role of the environment in postnatal nervous system development. Recently we have been studying the effects of changes in gravity on the motor system of rats from postnatal day (P) 2 to 31 using kinematic analysis of swimming, walking, and righting reflexes. Using the tail suspension model of weightlessness we identified sensitive and critical periods of motor system development corresponding to the time during which a motor skill is first achieved.

Effects of the Transcendental Meditation program on adaptive mechanisms: changes in hormone levels and responses to stress after 4 months of practice.

Stress has been implicated in both somatic and mental disorders. The mechanisms by which stress leads to poor health are largely unknown. However, studies in animals suggest that chronic stress causes high basal cortisol and low cortisol response to acute stressors and that such changes may contribute to disease.

PTP NE-6: a brain-enriched receptor-type protein tyrosine phosphatase with a divergent catalytic domain.

A receptor-type protein tyrosine phosphatase, PTP NE-6, was identified from rat olfactory epithelial cDNA and cloned from a rat brain cDNA library. PTP NE-6 mRNA is abundant in brain and expressed at lower levels in olfactory tissue and adrenal gland. In situ hybridization demonstrates that PTP NE-6 mRNA is expressed throughout the brain, with highest levels in the medial habenula and at intermediate levels in layer IV of cortex, medial geniculate nucleus, inferior colliculus, hypothalamus, and thalamus.

Electrophysiological correlates of higher states of consciousness during sleep in long-term practitioners of the Transcendental Meditation program.

Standard ambulatory night sleep electroencephalograph (EEG) of 11 long-term practitioners of the Transcendental Meditation (TM) program reporting "higher states of consciousness" during sleep (the experimental group) was compared to that of nine short-term practitioners and 11 non-practitioners. EEG tracings during stages 3 and 4 sleep showed the experimental group to have: 1) theta-alpha activity simultaneously with delta activity and 2) decreased chin electromyograph (EMG) during deep sleep (p = 0.002) compared to short-term practitioners.

Anger expression correlates with platelet aggregation.

Potential relationships between increased platelet aggregability and such psychological characteristics as hostility and anger were investigated as part of a larger intervention study investigating the potential efficacy of stress-reduction treatments. Participants performed 6-minute mental arithmetic tests under time pressure. Blood was sampled during the first minute of the task and whole blood platelet aggregation was measured in an aggregometer, using collagen and ADP.

A controlled study of the effects of the Transcendental Meditation program on cardiovascular reactivity and ambulatory blood pressure.

Cardiovascular responses to stress reactivity has been proposed as a risk factor for hypertension. In this study, we evaluated the effects of stress reduction on both laboratory cardiovascular reactivity and ambulatory blood pressure in real life on 39 normotensive male subjects who were pretested for ambulatory blood pressure and cardiovascular reactivity to stress using a battery of laboratory stressors. Thereafter, subjects were randomly assigned to practice either the Transcendental Meditation (TM) technique or a cognitive-based stress education control (SEC) for four months.

Localization of the L-glutamine synthetase gene to chromosome 1q23.

Glutamine synthetase (E.C. 6.

Trial of stress reduction for hypertension in older African Americans. II. Sex and risk subgroup analysis.

Our objective was to test the short-term efficacy and feasibility of two stress-reduction approaches for the treatment of hypertension in older African Americans, focusing on subgroup analysis by sex and by high and low risk on six measures of hypertension risk: psychosocial stress, obesity, alcohol use, physical inactivity, dietary sodium-potassium ratio, and a composite measure. The study involved a follow-up subgroup analysis of a 3-month randomized, controlled, single-blind trial conducted in a primary care, inner-city health center. Subjects were 127 African American men and women, aged 55 to 85 years, with diastolic pressure of 90 to 104 mm Hg and systolic pressure less than or equal to 179 mm Hg.

Renal artery aneurysm: a report of 28 cases.

Renal artery aneurysms are being increasingly encountered due to the wider use of angiography. From 1972 to 1992, 28 patients with renal artery aneurysm were identified in the present study, including 18 women and 10 men, with a mean age of 58 years. The aneurysms were discovered incidentally in 39% of patients during evaluation for hypertension in 39%, and during investigation of abdominal pain in 22%.

The impact of the transcendental meditation program on government payments to physicians in Quebec.

Purpose: This study evaluated whether governmental medical payments in Quebec were affected by the Transcendental Meditation (TM) technique.

Design: This retrospective study used a pre- and postintervention design in which government payments for physicians' services were reviewed for 3 years before and up to 7 years after subjects started the technique. Payment data were adjusted for aging and year-specific variation (including inflation) using normative data.

Molecular analysis and breakpoint definition of a set of human chromosome 21 somatic cell hybrids.

Rodent-human somatic cell hybrids containing single human chromosomes or chromosome fragments are extremely valuable in physical mapping, marker analysis, and disease mapping. Chromosome 21 has been extensively studied in this fashion, and a single set of hybrids has been utilized in mapping the majority of chromosome 21 markers. The utility of a set of hybrids depends upon the definition of the human chromosome content.

Physical mapping of the holoprosencephaly critical region in 21q22.3, exclusion of SIM2 as a candidate gene for holoprosencephaly, and mapping of SIM2 to a region of chromosome 21 important for Down syndrome.

We set out to define the holoprosencephaly (HPE) critical region on chromosome 21 and also to determine whether there were human homologues of the Drosophila single-minded (sim) gene that might be involved in HPE. Analysis of somatic cell hybrid clones that contained rearranged chromosomes 21 from HPE patients defined the HPE minimal critical region in 21q22.3 as D21S113 to qter.

Stress reduction and preventing hypertension: preliminary support for a psychoneuroendocrine mechanism.

Our objective was to identify endocrine-related mechanisms capable of mediating preventive effects of stress reduction in hypertensive heart disease. Since beneficial effects of stress reduction accrue over time, this cross-sectional, descriptive study sought differences between healthy students not practicing a systematic technique for reducing stress (the average stress, or AS, group, n = 33) and a similar group who for 8.5 years had practiced the Transcendental Meditation (TM) technique, used widely to reduce stress (the low stress, or LS, group, n = 22).

Tyrosine phosphatase signalling in a lower plant: cell-cycle and oxidative stress-regulated expression of the Chlamydomonas eugametos VH-PTP13 gene.

The first evidence for tyrosine phosphatase signalling pathways in plants is presented by characterizing a putative protein tyrosine phosphatase gene from the unicellular green alga Chlamydomonas eugametos. This cDNA, referred to as VH-PTP13, contains an open reading frame specifying a protein with a molecular weight of 30.3 kDa, that has significant homology with a distinct group of dual-specificity phosphatases.

Stress, steroids, and "ojas": neuroendocrine mechanisms and current promise of ancient approaches to disease prevention.

Recent research on causes of disease and aging has increasingly supported the importance of stress. One theory of the relationship between stress and disease is based on the concept of homeostasis, a term coined by Cannon over 50 years ago to signify those states and mechanisms responsible for the "staying power of the body". Bernard, Cannon, Selye and other leading researchers held that full, normal function of the self-regulating or homeostatic power of the body maintains the balanced, integrated condition we recognize as health.

Evaluation of a new colorimetric assay for serum lithium.

Using patient samples (n = 175) collected in our clinical chemistry laboratory, we have undertaken an analysis of a new colorimetric dry slide-based serum lithium (Li+) assay from Eastman Kodak for its Ektachem instrumentation series. Analyzer imprecision was acceptable, and good correlation was seen between the Ektachem assay and an ion-selective electrode (ISE)-based assay currently in use in our laboratory (r = 0.99).

Purification of, generation of monoclonal antibodies to, and mapping of phosphoribosyl N-formylglycinamide amidotransferase.

5'-Phosphoribosyl N-formylglycinamide (FGAR) amidotransferase (EC 6.3.5.

A novel receptor-type protein tyrosine phosphatase is expressed during neurogenesis in the olfactory neuroepithelium.

Tyrosine phosphorylation plays a central role in the control of neuronal cell development and function. Yet, few neuronal protein tyrosine phosphatases (PTPs) have been identified. We examined rat olfactory neuroepithelium for expression of novel PTPs potentially important in neuronal development and regeneration.

The isolated and perfused brain of the guinea-pig in vitro.

We describe here an isolated and perfused in vitro adult guinea-pig whole brain preparation which is an extension of the previously described in vitro brainstem-cerebellum preparation. Viability was tested by the analysis of trans-synaptic responses along the visual pathways following the electrical stimulation of the optic nerve or the optic radiations. The evoked field potentials were recorded in the dorsal lateral geniculate, the superior colliculus and the visual cortex.