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S Jacob

Publications and source records attributed to S Jacob.

At least 181 records · Page 10Linked to original sources
PubMed1987

Lipid droplet accumulation in the heart during fasting.

Lipid droplet accumulation (LDA) in the myocardium in the different regions of the mouse heart was studied after varying periods of starvation. LDA appeared as early as 6 h and remained even after 72 h of starvation. Higher grades of LDA were seen in the left atrium and right ventricle. Females showed a higher degree of infiltration than males. The possible causes for the distribution of lipid droplets are discussed and it is suggested that in long-term starvation reduced oxidation of fatty acids due to mitochondrial inhibition may be a factor in the production of LDA.

Animals↗
PubMed1987

[Intracellular amino acid concentrations in the musculature of 3 species of animals under physiologic, pathophysiologic and infusion therapy conditions].

In the first part of this paper methodological aspects of intracellular amino-acid analysis in three species of animals, i.e. in rats, rabbits, and cats are dealt with. The genetic homogeneity as well as the age of the animal groups, metabolic differences between carnivores and herbivores, the length of the intestine and, thus, the time elapsing before the postabsorptive state is reached, furthermore, the body size which, in studies with muscle biopsies, makes correlated samples either possible or impossible; all these factors are experimental variables potentially affecting the evidence of the results obtained. Amino acids being involved in ammonia detoxification or showing raised plasma levels in hepatic failure form the subject of the subsequent parts of this paper. In the muscle cells of the three above species investigated after an overnight fast, the concentration of glutamine was about 5.5 times and that of glutamate about 4.1 times higher than in human muscle. Regarding glutamine and glutamate, there were no marked differences between the three species. As to the other amino acids measured in the rats, rabbits, and cats, alanine, the branched-chain amino acid (BCAA) as well as methionine and phenylalanine had intracellular values similar to those observed in humans. To test the hypothesis that ammonia lowers the BCAA plasma levels by considerably increasing glutamine synthesis and decreasing the intracellular glutamate pool with consecutively intensified transamination of BCAA for partial replenishment of this pool, we infused ammonium salts and created portocaval shunts in animal experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1987

Ultrastructure of the ferret submandibular gland.

Submandibular glands of two male and two female adult ferrets were examined using electron microscopy. The secretory endpiece consisted of mucous acini and seromucous demilunes. The acinar cells were filled with mucous granules of moderate electron density. Each granule had a fine fibrillar substructure. Two types of demilune cells could be identified, based on the differing electron density of their secretion granules. In some cells the granules were more electron-dense than in others. These granules may contain the two types of mucosubstances identified in an earlier study. The demilunes probably drained into the intercellular canaliculi present in between them and eventually into the acinar lumen through a demilune projecting into it. The intercalated ducts were shorter compared to those of the parotid glands. Many of the striated duct cells contained electron-dense secretion granules. The basal plasmalemma of these cells was invaginated to form linear folds. Few agranular cells were interspersed among the granulated cells of the striated ducts.

Animals↗
PubMed1987

Ultrastructure of the ferret parotid gland.

Parotid glands of two male and two female adult ferrets were examined using electron microscopy. The acinar cells contained an abundance of rough endoplasmic reticulum, an extensive Golgi complex, and electron-dense granules with a denser spot in each. The acinar lumen and the intercellular canaliculi were lined by a large number of prominent microvilli. The intercalated ducts were long and in their proximal part the cells contained small electron-dense granules, whereas the distal portions were lined by agranular cells. The majority of cells in the intralobular striated ducts contained a large number of granules. These granules were of varying shapes and were moderately electron-dense. Each granule had a close fitting membranous envelope. The agranular cells had a prominent Golgi zone, free ribosomes and a few lysosomes. Both the granular and agranular duct cells had an abundance of mitochondria towards the basal regions of the cells. The excretory ducts resembled the intralobular striated ducts. No sexual dimorphism was observed in the ferret parotid.

Animals↗
PubMed1986

Metabolism of amino acids by the atrophied soleus of tail-casted, suspended rats.

Amino acid metabolism was investigated in atrophied soleus muscle from rats subjected to six days of tail-cast, hindlimb suspension. The fresh-frozen unloaded muscle showed higher concentrations of tyrosine and glutamate but lower amounts of aspartate, glutamine, ammonia, and a lower ratio of glutamine to glutamate than normal muscle. The atrophied muscle also showed faster in vitro production of alanine and tyrosine, and slower utilization of glutamate and aspartate. Despite a greater activity of glutamine synthetase, synthesis of glutamine was slower in the soleus muscle of suspended rats than in control muscle. Provision of ammonium chloride and/or glutamate showed that this slower synthesis of glutamine in the atrophied soleus probably was due to limiting amounts of free ammonia and not of glutamate. Flux through AMP deaminase was probably slower as demonstrated by the maintenance of a greater pool of total adenine nucleotides and by the slower release of nucleosides by the incubated soleus muscle of suspended v control rats. The extensor digitorum longus muscles of suspended animals showed greater glutamine production, glutamine synthetase activity, and aspartate utilization than control muscles. Data from muscles of intact, adrenalectomized and adrenalectomized, cortisol-treated rats suggested that the greater glutamine synthetase activity was mediated possibly by higher circulating glucocorticoid hormones and a greater response of the soleus muscle to these hormones. Glutamine synthesis in skeletal muscle may be regulated primarily by the availability of ammonia, which is associated with the degradation of adenine nucleotides, and secondarily by the amount of glutamine synthetase and glutamate in the tissue.

Adenine Nucleotides↗
PubMed1986

Morphology and histochemistry of the ferret prostate.

The gross anatomy, histology and histochemistry of the ferret prostate is described. The structure and course of the prostatic urethra and the ductus deferentes are also described. The prostate is the only accessory reproductive gland present in the ferret. The prostate consists of tubuloalveolar glands surrounded by fibromuscular connective tissue. Histochemical studies showed that the glandular parenchyma contained large amounts of sialidase-labile sialomucin as well as acid phosphatase and small quantities of alkaline phosphatase and proteins. The findings in this study are discussed in relation to similar studies in other animals and man.

Animals↗
PubMed1985

Beware of breast fibroadenomas in middle-aged women.

On first examination of 8512 Quebec area women from 40 to 59 years of age who participated in the National Study of Breast Cancer Screening, the prevalence of fibroadenoma was 8.3 per 1000. In two women, a carcinoma was discovered within their fibroadenoma--intraductal carcinoma in one and an infiltrating ductal carcinoma in the other. Clinical and histopathologic findings are described and the prognosis and treatment discussed. The peak age of women at the time of diagnosis of a fibroadenoma is in their twenties while for those with a fibroadenoma containing a carcinoma, it is in the forties. For patients under 25 years, excision can be postponed for a few months since spontaneous regression may occur and the risk of breast cancer is small at that age. For older women, treatment should not be delayed.

Adenofibroma↗
PubMed1984

Cognitive, perceptual, and personal-social development of prematurely born preschoolers.

This study was designed to determine possible differences in the cognitive, perceptual, and personal-social development of prematurely and maturely born 3-yr.-olds which might foreshadow later learning problems. The subjects were 40 prematurely born graduates of a neonatal intensive care unit (birth weight less than 2,500 gm, less than 37 wk. gestation) matched on the pair-level with full-term controls on sex, race, post-conceptual age, and socioeconomic background. All subjects were singletons and parity was matched at the group level. No differences were found between the groups on tests of higher mental processes including the General Cognitive, Verbal, Quantitative, and Memory Scales of the McCarthy Scales of Children's Abilities, and researcher-devised measures of problem-solving competence. No differences in parental reports of personal-social development were noted. Prematures did not perform as well as controls on perceptual performance tasks, and this difference was interpreted as reflecting relatively impaired visual-motor coordination.

Child, Preschool↗