Search PubMed⌕ Search

Biomedical subjects

S Brody

Publications and source records attributed to S Brody.

At least 109 records · Page 6Linked to original sources

Adrenal steroids, bone mineral content and endometrial pathology in postmenopausal women.

In 19 postmenopausal women, basal serum levels of cortisol, unconjugated dehydroepiandrosterone (DHA), dehydroepiandrosterone sulphate (DHAS), testosterone and unconjugated and total estrone were measured both before and during an ACTH test. A positive correlation was found both between basal levels of DHAS and the DHA response to ACTH, respectively, and trabecular bone mineral content of the distal forearm. A significant correlation was also observed between bone mineral content and precancerous/cancerous states of the uterine epithelium.

Adrenal Cortex Hormones↗

Circadian rhythms in Neurospora crassa: oligomycin-resistant mutations affect periodicity.

Nuclear mutations conferring resistance to oligomycin, a mitochondrial inhibitor, shorten the period of the circadian conidiation rhythm of Neurospora crassa from the normal 21.5 hours to 18 to 19 hours and slow the linear growth rate by 30 percent. These olir mutations map very close to frq, a locus at which mutations affecting periodicity have been previously obtained. The possibilities are discussed that mitochondria are involved in circadian rhythm generation and that certain period-length mutations affect mitochondrial functions.

Biological Transport↗

Transitional objects: idealization of a phenomenon.

Winnicott's thesis about transitional objects and transitional phenomena indicates that Kleinian theory, as well as his own preference for imaginative play with ideas, influenced his interpretation of his discovery and led to misapplications of its meaning. An alternative interpretation of its meaning, one that may be aligned more easily with other clinical data, is submitted. A brief review of the literature is appended.

Child↗

Circadian rhythms in Neurospora crassa: effects of unsaturated fatty acids.

Employing a fatty acid-requiring strain (bd csp cel) of Neurospora crassa, the 21.5-h period of the circadian spore-forming rhythm was manipulated by fatty acid supplementation. The addition to the medium of an unsaturated fatty acid (oleic, linoleic, or linolenic acid) lengthened the period to 26, 40, or 33 h, respectively. Ther period-lengthening effect of linoleic acid was proportional to its concentration up to 1.3 X 10(-4) M, and also was reversed by the addition to the medium of a saturated fatty acid, palmitic acid. None of these period-lengthening effects was observed in the prototrophic strain (bd csp cel+).

Circadian Rhythm↗

Lipid and cell wall changes in an inositol-requiring mutant of Neurospora crassa.

An inositol deficiency in the inositol-requiring (inl) mutant of Neurospora crassa led to changes in the composition of the inositol-containing lipids and the cell wall. On deficient levels of inositol, phosphatidyl inositol decreased by 23-fold, di(inositolphosphoryl) ceramide decreased by 4-fold, and monoinositolphosphoryl ceramide increased slightly. The inositol deficiency also led to an aberrant hyphal morphology and changes in both the amount of cell wall and the amino sugar content of the cell wall. The glucosamine content of the cell wall decreased by 50%, the galactosamine increased by 50%, but no significant changes were found in the content of the cell wall amino sugar precursors, or in the amino acid, glucose, or total hexose content of the cell wall. Inositol-containing compounds were found associated with purified cell wall material. These compounds were bound tightly to the cell wall but could be removed by treatment with alkali, a treatment which disrupts the cell wall integrity. Possible mechanisms of how changes in lipid composition can affect cell wall biosynthesis are discussed.

Cell Wall↗

Circadian rhythms in Neurospora crassa: effects of saturated fatty acids.

To assess their effects on the conidiation rhythm in Neurospora, 14 saturated fatty acids from 6 to 24 carbons long were used to supplement the bd csp and bd csp cel strains. Both strains express a circadian spore-forming rhythm when grown on solid media; the cel mutation confers a partial fatty acid requirement. Fatty acid supplements from 8 to 13 carbons long lengthened the free-running period of bd csp cel compared with the control value of 21 h; the maximal effect (33 h) was obtained with nonanoic acid (9:0) at a concentration of 5 x 10(-4) M. In contrast, the period of bd csp remained unchanged under all experimental conditions. The short-chain fatty acids (<14 carbons) reduced the rate of advance of the growth front in both strains, compared with unsupplemented controls. However, this inhibition did not appear to be responsible for the lengthened periods in bd csp cel. Nor was direct incorporation of the short-chain (period-lengthening) fatty acids into mycelial total lipids responsible, since such incorporation was not observed. In fact, extensive metabolic conversion of these supplements by both strains was indicated by the disappearance of short-chain fatty acids from the agar media coupled with their absence in mycelial lipids, and by the liberation of (14)CO(2) from cultures supplemented with [1-(14)C]lauric acid (12:0).

Circadian Rhythm↗

[Perinatal care].

Explore the source record for details and available documents.

Child Health Services↗

Correlation of enzymatic activity and thermal resistance with hydration state in ungerminated Neurospora conidia.

Ungerminated Neurospora crassa conidia were incubated at 0, 50, and 100% relative humidity, giving rise to conidia in dry, quasi-dry, and wet hydration states, respectively. Metabolic activity was detected by monitoring levels of reduced glutathione (GSH), oxidized glutathione (GSSG), and the soluble-amino acid pools as a function of incubation time. Wet conidia (approximately 65% water content) exhibited significant metabolic activity as evidenced by: (i) reduction of GSSG to GSH, (ii) degradation of GSH, and (iii) changes in the pool sizes of certain amino acids. GSSG accumulated slowly in dry conidia (less than 5% water content) and more rapidly in quasi-dry conidia (approximately 13% water content), indicating that enzymatic reduction of GSSG is inactive in these states. Longevity and thermal resistance were high for dry conidia and low for wet conidia, but were not influenced by variation in GSSG content. The water content of conidia exhibited a hysteresis effect in that at a given relative humidity previously dried conidia attained a lower water content than freshly harvested conidia.

Glutathione↗

Biochemical and genetic studies on galactosamine metabolism in Neurospora crassa.

In Neurospora, galactosamine can be released from the cell wall and from an alcohol-soluble compound by acid hydrolysis. All of the detectable alcohol-soluble galactosamine was present as uridine diphospho-2-acetamido-2-deoxy-D-galactose (UDPGalNAc). The results of pulse-labeling studies and enzymatic assays indicated that UDPGalNAc was synthesized via the epimerization of uridine diphospho-2-acetamido-2-de+xy-D-glucose (UDPGlcNAc). A single-gene morphological mutant, doily (do), which grew at less than 4% the rate of the wild-type strain, had 3% of the wild-type UDPGalNAc content and 0.5% of the wild-type level of cell wall galactosamine but normal levels of UDPGlcNAc and cell wall glucosamine. Cell extracts of the doily cultures containing only 20% of the specific activity of UDPGlcNAc-4-epimerase found in the extracts of wild-type cultures. Two types of faster-growing partial revertants of the doily strain were isolated. One type had an intermediate level of both alcohol-soluble and cell wall galactosamine. A second type had an intermediate level of alcohol-soluble galactosamine but low levels of cell wass galactosamine. Genetic analyses indicated that the reverse mutations had occurred at the do locus in both types. This finding that cell wall glucosamine synthesis and growth rate can be separated genetically indicates that mutations at the do lucus lead to pleiotropic effects.

Carbohydrate Epimerases↗