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Biomedical subjects

S Murano

Publications and source records attributed to S Murano.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Improvement of respiratory function with weight reduction in obese elderly].

The patient was a 74-year-old woman who had been obese since age 18. Her obesity was refractory to dietary manipulation. She had been suffering from increasing dyspnea for several months and eventually could not even move. She was admitted to a hospital and diagnosed as having heart failure. Although her cardiac function recovered with medical treatment, her symptoms did not improve. The patient was then sent to our hospital. On admission, her height and weight were 149 cm and 81.9 kg, respectively, yielding a body mass index (BMI) of 36.6 kg/m2. Arterial blood gas analysis in room air revealed hypoxemia and an apnea index of 27 per hour. She was given a daily 500-1000 kcal diet. After four months of treatment, her weight decreased to 65 kg with a BMI of 29.3 kg/m2. Weight reduction together with the usage of progesterone-derivatives resulted in marked improvement of sleep apnea. The apnea index decreased to 3/h and arterial blood gas values normalized. This patient seemed to have suffered from both obesity hypoventilation syndrome and sleep apnea syndrome. Improvement of respiratory function was achieved through relief of airway obstruction and weight reduction, with activation of the respiratory center due to progesterone treatment.

Aged↗
PubMed1991

Diverse gene sequences are overexpressed in werner syndrome fibroblasts undergoing premature replicative senescence.

Genes that play a role in the senescent arrest of cellular replication are likely to be overexpressed in human diploid fibroblasts (HDF) derived from subjects with Werner syndrome (WS) because these cells have a severely curtailed replicative life span. To identify some of these genes, a cDNA library was constructed from WS HDF after they had been serum depleted and repleted (5 days in medium containing 1% serum followed by 24 h in medium containing 20% serum). Differential screening of 7,500 colonies revealed 102 clones that hybridized preferentially with [32P]cDNA derived from RNA of WS cells compared with [32P]cDNA derived from normal HDF. Cross-hybridization and partial DNA sequence determination identified 18 independent gene sequences, 9 of them known and 9 unknown. The known genes included alpha 1(I) procollagen, alpha 2(I) procollagen, fibronectin, ferritin heavy chain, insulinlike growth factor-binding protein-3 (IGFBP-3), osteonectin, human tissue plasminogen activator inhibitor type I, thrombospondin, and alpha B-crystallin. The nine unknown clones included two novel gene sequences and seven additional sequences that contained both novel segments and the Alu class of repetitive short interspersed nuclear elements; five of these seven Alu+ clones also contained the long interpersed nuclear element I (KpnI) family of repetitive elements. Northern (RNA) analysis, using the 18 sequences as probes, showed higher levels of these mRNAs in WS HDF than in normal HDF. Five selected mRNAs studied in greater detail [alpha 1(I) procollagen, fibronectin, insulinlike growth factor-binding protein-3, WS3-10, and WS9-14] showed higher mRNA levels in both WS and late-passage normal HDF than in early-passage normal HDF at various intervals following serum depletion/repletion and after subculture and growth from sparse to high-density confluent arrest. These results indicate that senescence of both WS and normal HDF is accompanied by overexpression of similar sets of diverse genes which may play a role in the senescent arrest of cellular replication and in the genesis of WS, normal biological aging, and attendant diseases.

Base Sequence↗
PubMed1990

Werner syndrome: a molecular genetic hypothesis.

On the basis of clinical and experimental observations, we postulate that the primary genetic abnormality in Werner syndrome (WS) is mutation in a gene encoding a trans-acting factor that normally represses a second genetic locus or its product, an inhibitor of DNA synthesis elaborated when cells reach the end of their replicative life span. The result is early derepression of this second locus, leading to reduced initiation of DNA synthesis and premature replicative senescence. This hypothesis and its corollaries provide a heuristic model for decisive experiments.

DNA↗
PubMed1989

Studies on the molecular-genetic basis of replicative senescence in Werner syndrome and normal fibroblasts.

Based on evidence that human diploid fibroblasts (HDF) from the Werner syndrome (WS) of premature aging might overexpress an inhibitor of DNA synthesis (IDS), we prepared a eukaryotic cDNA expression library from WS mRNA and tested it for IDS activity in a transient assay. Two of six WS cDNA pools tested gave IDS activity, then on plus/minus screening revealed several differentially expressed cDNA clones. By slot blot and Northern analysis, one cDNA clone was found to be overexpressed in WS and normal senescent HDF, but not in quiescent normal HDF, indicating that it is senescence-specific. Further studies are needed to clarify: a) whether this cDNA truly acts as an IDS; b) if so, whether it acts alone or in concert with other cDNAs; and c) whether it is involved in the degenerative and malignant sequelae of WS and normal aging.

Aging↗
PubMed1989

[Growth factors in the serum in patients with Werner's syndrome].

Premature development of atherosclerosis is a fatal complication together with cancer in patients with Werner' syndrome, a known syndrome of premature aging. Proliferation of arterial smooth muscle cells (SMC) is a key event in the formation of atherosclerosis. This paper studied the serum growth promoting activity of Werner's syndrome in cultured rabbit aortic SMC. Serum of cases of Werner's syndrome showed significantly higher growth-promoting activities than those of age-matched controls. The levels of serum growth hormone, plasma somatomedin C, and urine epidermal growth factor were not increased in Werner's syndrome. The level of serum insulin was generally increased in Werner's syndrome. However, there was no correlation between serum insulin level and growth promoting activity, and the effective dose of insulin for the promotion of SMC growth was ten thousand times higher than that contained in the serum. The above results suggest that elevated serum growth-promoting activity in Werner's syndrome is in part responsible for the premature atherosclerosis and that this elevated activity is derived from either platelet derived growth factor or an unknown growth factor(s) contained in the serum.

Adult↗
PubMed1987

The effects of mazindol on local cerebral glucose utilization in rats.

The effects of mazindol (1 mg or 10 mg/animal, p.o.) on local cerebral utilization of glucose were studied by the quantitative autoradiographic [14C]2-deoxyglucose method in conscious adult male rats. Significant increases in local cerebral utilization of glucose were observed 2 hr after administration of 10 mg of mazindol in 10 out of 37 anatomically discrete regions examined. These 10 areas included regions rich in dopaminergic receptors (substantia nigra, globus pallidus), and also regions with few dopaminergic receptors (cerebral cortex, thalamus, cerebellum). Only the habenular nucleus showed a significant decrease in utilization of glucose induced by the administration of 10 mg of mazindol. No significant changes in local cerebral utilization of glucose were observed following the administration of 1 mg of mazindol. The fact that the pattern of utilization of glucose observed in this study resembled that produced by apomorphine, a putative dopaminergic agonist, indicates that the pharmacological effects of mazindol are related to the dopaminergic system.

Animals↗
PubMed1987

Impaired intermediate-density lipoprotein triglyceride hydrolysis in familial lecithin:cholesterol acyltransferase (LCAT) deficiency.

A new lecithin:cholesterol acyltransferase (LCAT)-deficient family was found in Japan. In the proband, both LCAT activity and LCAT mass were deficient. The patient's parents, child, and sister, diagnosed as heterozygotes, had half-normal LCAT activity and LCAT mass. In the patient, an increase of intermediate-density lipoprotein (IDL, 1.006 less than d less than 1.019) fraction was observed. In postheparin plasma, both lipoprotein lipase and hepatic triglyceride lipase activities were low. Hydrolysis of [14C] triolein by human hepatic triglyceride lipase in patient IDL was decreased compared to that in IDL from normal postprandial serum. Preincubation of these IDL with normal plasma in the absence of 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) increased the rate of hydrolysis, in the presence of DTNB, this increment was not observed. These results suggest that one cause of IDL increase in the LCAT-deficient patient might be the difficulty of hydrolysis of these lipoprotein particles by hepatic triglyceride lipase.

Adult↗
PubMed1986

Nephropathy of familial lecithin-cholesterol acyltransferase deficiency: report of a case.

A ninth Japanese patient afflicted with lecithin-cholesterol acyltransferase (LCAT) deficiency is described with emphasis on renal pathology. The most striking feature is massive deposition of lipid material in the glomeruli, particularly in the glomerular basement membrane (GBM) and in the mesangial region. The glomerular changes appear to be similar to that seen in some cases with cirrhosis of the liver. Lipid material contains a large amount of apolipoprotein-B detected by immunohistology. In two renal biopsies, taken three years apart, renal pathology is essentially the same and glomerular pathology is most characteristic. It is suggested that lipid deposition in glomeruli in this patient is rather slow. Family study of the present case reveals consanguinous marriages in the previous two generations suggesting the exaggerated gene expression of LCAT deficiency in this family.

Adult↗
PubMed1984

Effect of niceritrol on lipid metabolism of aorta in atherosclerotic rats.

Atherosclerotic lesions were formed in the aorta of rats given a high cholesterol diet containing propylthiouracil (PTU) and vitamin D2 (atherogenic diet) for 8 weeks. The effects of niceritrol (pentaerythritol tetranicotinate), which lower the plasma lipid level, on lipid metabolism in the arterial wall of the atherosclerotic rats were studied. Niceritrol significantly decreased the plasma cholesterol level of atherosclerotic rats, which was 823 mg/100 ml, or about ten times that of control rats. On treatment with niceritrol, the cholesterol level was reduced most in the very low density lipoprotein (VLDL) fraction (d less than 1.006). Heparin-releasable lipoprotein lipase activity in epididymal adipose tissue, lipoprotein lipase activity in post-heparin plasma, and VLDL-triolein hydrolyzing activity in adipose tissue stromal vessels were all higher in niceritrol-treated atherosclerotic rats. Of the enzymes in the arterial wall concerned with cholesterol ester metabolism, acid cholesterol esterase activity was decreased in atherosclerotic rats, while niceritrol treatment increased this activity. The ratio of acyl-CoA cholesterol acyltransferase activity (ACAT) to neutral cholesterol esterase activity was higher in atherosclerotic rats than in control rats, but was lower in niceritrol-treated rats than in atherosclerotic rats. From these results, it is concluded that niceritrol modifies enzyme activities in such a way as to reduce the cholesterol ester content of the arterial wall and lower plasma VLDL and LDL cholesterol levels.

Adipose Tissue↗
PubMed1984

Rapid increase of profilin-like proteins during liver development.

Extraction of the cytoplasm of rat liver with 5% PCA and subsequent TCA (20%) treatment resulted in the recovery of only a few proteins, the predominant one having an apparent molecular weight of 12K. This 12K protein increased sharply (9-fold) between 2 weeks and 10-20 weeks and then decreased until at least 2 years after birth. 12K protein was separated into two components, 12K-1 (larger) and 12K-2 (smaller), by gel chromatography which had similar amino acid compositions to those of profilin (from Acanthamoeba and hog thyroid). Like profilin, 12K-1 protein inhibited the rate of actin polymerization, while 12K-2 protein did not. These findings suggest that liver profilin-like proteins increase sharply during development.

Actins↗
PubMed1983

Effect of clinofibrate on lipid metabolism of aorta in atherosclerotic rats.

Atherosclerotic lesions formed in the aorta of rats given diet containing propylthiouracil (PTU), vitamin D2 and high cholesterol diet (atherogenic) for 8 weeks. The effect of clinofibrate, which lowers the plasma lipid level, on lipid metabolism in the arterial wall of the atherosclerotic rats was studied. Clinofibrate significantly decreased the high plasma cholesterol level of atherosclerotic rats, which was 823 +/- 256 (mean +/- SD) mg/dl, or about ten times that of control rats (85 +/- 11 mg/dl). On treatment with clinofibrate, the cholesterol level was reduced most in the very low density lipoprotein (VLDL) fraction (d less than 1.006). Heparin-releasable lipoprotein lipase activity in epididymal adipose tissue, lipoprotein lipase activity in post heparin plasma, and VLDL-triolein hydrolizing activity in adipose tissue stromal vessels were higher in clinofibrate-treated rats than in atherosclerotic rats. Of the enzymes in the arterial wall concerned with cholesterol ester metabolism, acid cholesterol esterase activity was decreased in atherosclerotic rats, and clinofibrate treatment increased this activity. The ratio of acyl-CoA cholesterol acyltransferase activity (ACAT) to neutral cholesterol esterase activity was higher in atherosclerotic rats than in control rats and was lower in clinofibrate-treated rats than in atherosclerotic rats. From these results, it is concluded that clinofibrate modifies enzyme activities in such a way as to cause a reduction of cholesterol accumulation in the arterial wall and lowers the plasma VLDL and LDL cholesterol levels.

Animals↗