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Biomedical subjects

S Shimizu

Publications and source records attributed to S Shimizu.

At least 271 records · Page 15Linked to original sources
PubMed1999

Use of protein AG in an enzyme-linked immunosorbent assay for screening for antibodies against parapoxvirus in wild animals in Japan.

Using protein AG in an enzyme-linked immunosorbent assay (ELISA), we tried to detect antibodies against parapoxvirus in 9 species of wild animals in Japan: the Japanese badger (Meles meles anakuma), Japanese black bear (Ursus thibetanus japonicus), Japanese deer (Cervus nippon centralis), Japanese monkey (Macaca fuscata), Japanese raccoon dog (Nyctereutes procyonoides viverrinus), Japanese serow (Capricornis crispus), Japanese wild boar (Sus scrofa leucomystax), masked palm civet (Paguma larvata), and nutria (Myocastor coypus). A total of 272 serum samples were collected over the period from 1984 to 1995 and were tested by the protein AG-ELISA, the agar gel immunodiffusion test, and an indirect immunofluorescence assay. The protein AG-ELISA was effective in a serological survey for parapoxvirus in wild animals, and antibodies were detected only in Japanese serows. A total of 24 of 66 (36.4%) Japanese serows reacted positively, and they were found in almost all prefectures in all years tested. These results suggest that epizootic cycles of parapoxvirus exist widely in Japanese serows and that they could be reservoirs for the virus in the field in Japan. Moreover, it is probable that they might carry the virus to domestic animals such as cattle, sheep, and goats.

Animals↗
PubMed1999

[Ca2+]i homeostasis and cyclic nucleotide relaxation in aorta of phospholamban-deficient mice.

Phospholamban (PLB), a protein localized in the sarcoplasmic reticulum (SR), inhibits the SR Ca2+-ATPase; phosphorylation of PLB relieves this inhibition. We previously reported significant differences in contractility in aorta from mice in which the gene for PLB was ablated (PLB-). In this study, we measured intracellular Ca2+ concentration ([Ca2+]i) with fura 2 in the intact mouse aorta to more directly test the hypothesis that these changes are ascribable to altered SR function in vivo. Ten micromoles per liter of the alpha-agonist phenylephrine (PE) increased [Ca2+]i monotonically to a steady state in the wild-type aorta. In contrast, in PLB- aorta there was an initial rapid increase to a peak [Ca2+]i, which then decreased to a steady state that was lower than that in the wild type. Upon removal of the stimulus (either PE or KCl), the decrease in [Ca2+]i was two times as fast in the PLB- as in the wild-type aorta. There were no significant differences between PLB- and wild-type aortas in the concentration vs. force relations or the time courses of relaxation in response to forskolin or sodium nitroprusside. Interestingly, stimulation of the cAMP pathway before cGMP pathway activation resulted in a significant increase in sensitivity and a difference in relaxation parameters between PLB- and wild-type aortas. Western blot analysis indicated that the PLB-to-sarcoendoplasmic reticulum Ca2+ATPase ratio in the mouse aorta was similar to that in the heart; 20-fold more aortic than heart homogenate was required to achieve a similar level of immunoreactivity. Our data indicate that PLB can play a major role in modulating smooth muscle [Ca(2+)](i) but only a minor role, if any, in cyclic nucleotide-mediated relaxation.

Animals↗
PubMed1999

Bilirubin as an anti-oxidant for surgical stress: a preliminary report of bilirubin oxidative metabolites.

BACKGROUND: Bilirubin has been recognized as an anti-oxidant. The purpose of this study was to examine whether bilirubin would act as an antioxidant for surgical stress in humans. MATERIALS AND METHODS: Serum bilirubin and urinary bilirubin oxidative metabolites (BOM) were measured in 96 patients who underwent surgery. The antioxidant activity of bilirubin was assessed using BOM measured by enzyme-linked immunosorbent assay with an anti-bilirubin monoclonal antibody. RESULTS: Serum bilirubin levels increased after surgery in all 96 patients (p < 0.01), but did not correlate with operation time or blood loss (p = 0.53 and p = 0.28, respectively). BOM increased only in patients with major surgeries (p = 0.048). Significant correlations between BOM and operation time and blood loss were found (p < 0.01). CONCLUSIONS: Bilirubin appears to act as an antioxidant for invasive surgery in humans. Urinary BOM could be a reliable marker for the degree of surgical stress.

Adolescent↗
PubMed1999

[Receptor-activated Ca2+ influx: capacitative Ca2+ entry and TRP proteins].

Receptor-activated Ca2+ channels (RACC) are triggered in response to activation of G protein-coupled receptors or tyrosine kinase-coupled receptors. RACCs, together with voltage-dependent Ca2+ channels, form physiologically the most important Ca2+ influx pathways, being highly diverged in activation mechanisms and Ca2+ permeability. Characterization of mammalian homologues of Drosophila TRP proteins has been an important clue for understanding molecular mechanisms underlying receptor-activated Ca2+ influx in vertebrate cells. Recent issues have been whether any members of the TRP family form capacitative Ca2+ entry (CCE) channels activated by release of Ca2+ from internal stores and their depletion. We have isolated cDNAs that encode seven mouse TRP homologues, TRP1-7. TRP homologues are distributed differently among tissues, although they are all abundant in the brain. Functional characterization of TRP proteins recombinantly expressed in HEK cells indicate that TRP5 is highly permeable to Ca2+, while TRP3 and 7 are non-selective cation channels. The results demonstrate that TRP3,5,7 are capable of generating Ca2+ currents after desensitization of the stimulated G-protein-coupled receptors and replenishment of stores, suggesting that store depletion is not necessary to maintain activity of the TRP homologues. Ca2+ positively regulates TRP channels through Ca(2+)-calmodulin pathways, but via different Ca(2+)-calmodulin-dependent enzymes. Thus, activation of TRP channels is not tightly coupled with store depletion as CCE, suggesting that CCE (or CRAC) channels are molecular entities separate from TRP.

Animals↗
PubMed1999

Stimulation of in vitro angiogenesis by tetrahydrobiopterin in bovine aortic endothelial cells.

This study examined whether tetrahydrobiopterin (BH4) stimulates angiogenesis by measuring the formation of tube-like structures in vascular endothelial cells. Bovine aortic endothelial cells that were cultured between two layers of collagen type I gel formed tube-like networks. Addition of BH4 or sepiapterin, a precursor of BH4 synthesis, stimulated the formation of tube-like structures. The sepiapterin-stimulated tube formation was completely inhibited by co-treatment with N-acetylserotonin, an inhibitor of sepiapterin reductase. These findings show that BH4 stimulates in vitro angiogenesis in vascular endothelial cells.

Animals↗
PubMed1999

Effects of a probiotic on the lipid metabolism of cocks fed on a cholesterol-enriched diet.

The effects of a probiotic (a mixture of Bacillus, Lactobacillus, Streptococcus, Clostridium, Saccharomyces and Candida) on the lipid metabolism, and caecal flora and metabolites of cocks were studied. The cholesterol level of the liver and serum was significantly decreased in the cocks fed on the cholesterol-enriched diet containing the probiotic. The distribution and frequency of occurrence of flora, and the chemical characteristics of the metabolites in the caecal content of the cocks were also affected by the inclusion of the probiotic in the basal and cholesterol-enriched diets. The Enterobacteriaceae species were significantly decreased in number, while the Bacillus, Streptococcus, Bifidobacterium and Lactobacillus species were significantly increased. The presence of yeast was observed, and the ammonia level was significantly reduced. The pH value, however, was not affected. The concentration of short-chain fatty acids in the caecal content of the cocks fed on the cholesterol-enriched diet supplemented with the probiotic was increased. It is, therefore, suggested that the incorporation of a probiotic in the diet would improve the balance of the intestinal flora and metabolites. Furthermore, it would also suppress the serum and liver cholesterol levels of cocks fed on the cholesterol-enriched diet.

Animals↗
PubMed1999

NAD(+)-dependent (S)-specific secondary alcohol dehydrogenase involved in stereoinversion of 3-pentyn-2-ol catalyzed by Nocardia fusca AKU 2123.

An NAD(+)-dependent alcohol dehydrogenase was purified to homogeneity from Nocardia fusca AKU 2123. The enzyme catalyzed (S)-specific oxidation of 3-pentyn-2-ol (PYOH), i.e., part of the stereoinversion reaction for the production of (R)-PYOH, which is a valuable chiral building block for pharmaceuticals, from the racemate. The enzyme used a broad variety of secondary alcohols including alkyl alcohols, alkenyl alcohols, acetylenic alcohols, and aromatic alcohols as substrates. The oxidation was (S)-isomer specific in every case. The K(m) and Vmax for (S)-PYOH and (S)-2-hexanol oxidation were 1.6 mM and 53 mumol/min/mg, and 0.33 mM and 130 mumol/min/mg, respectively. The enzyme also catalyzed stereoselective reduction of carbonyl compounds. (S)-2-Hexanol and ethyl (R)-4-chloro-3-hydroxybutanoate in high optical purity were produced from 2-hexanone and ethyl 4-chloro-3-oxobutanoate by the purified enzyme, respectively. The K(m) and Vmax for 2-hexanone reduction were 2.5 mM and 260 mumol/min/mg. The enzyme has a relative molecular mass of 150,000 and consists of four identical subunits. The NH2-terminal amino acid sequence of the enzyme shows similarity with those of the carbonyl reductase from Rhodococcus erythropolis and phenylacetaldehyde reductase from Corynebacterium sp.

Alcohol Dehydrogenase↗
PubMed1999

An autopsy case of familial idiopathic dilatation of bilateral atria.

A 59-year-old male patient was followed up for congestive heart failure. Echo cardiogram showed no abnormal findings other than a remarkable dilatation of the bilateral atria. The coronary arteries and left ventricular contraction were normal. Left ventricular endomyocardial biopsy showed no significant abnormal findings. Further, we examined his siblings using dynamic magnetic resonance imaging (MRI) and found that they all also had dilated bilateral atria. After several hospitalizations, the proband died from cardiogenic shock. Pathological findings showed nonspecific change in bilateral atria and ventricles. This is a very rare case of familial idiopathic dilatation of bilateral atria.

Fatal Outcome↗
PubMed1999

Spontaneous hemothorax secondary to immature teratoma of the mediastinum.

Spontaneous hemothorax in a 20-year-old boy was caused by rupture of an immature teratoma of the mediastinum. The tumor bled spontaneously into the right pleural space. This life-threatening complication necessitated emergency surgery. The unusual cause and the interesting clinical course of spontaneous hemothorax are described.

Adult↗
PubMed1999

Hypoglycemic coma masquerading thyrotoxic storm.

A 59-year-old woman was hospitalized in hypoglycemic coma. Although hypoglycemia was promptly reversed, she was in a somnolent, restless state with tachycardia, tremor, profuse sweating, and high body temperature. Thyrotoxic storm was highly suspected and vigorous antithyroid regimens gradually brought her up to normal mental and cardiovascular states in several days. However, profound generalized myopathy necessitated the maintenance with a respirator. One month later, an episode of angina pectoris was followed by generalized convulsion, coma, and death in a few days. Neuroimaging study disclosed posterior leukoencephalopathy syndrome. This case is instructive in that hypoglycemic coma may masquerade the major symptomatology of thyrotoxic storm, and that profound myopathy and angiopathic or angiospastic processes of the brain and the heart may interfere with the outcome.

Brain↗
PubMed1999

Lumbar spinal subdural hematoma following craniotomy--case report.

A 52-year-old female complained of lumbago and weakness in the lower extremities 6 days after craniotomy for clipping an aneurysm. Neurological examination revealed symptoms consistent with lumbosacral cauda equina compression. The symptoms affecting the lower extremities spontaneously disappeared within 3 days. Magnetic resonance (MR) imaging 10 days after the operation demonstrated a lumbar spinal subdural hematoma (SSH). She had no risk factor for bleeding at this site, the symptoms appeared after she began to walk, and MR imaging suggested the SSH was subacute. Therefore, the SSH was probably due to downward movement of blood from the cranial subdural space under the influence of gravity. SSH as a complication of cranial surgery is rare, but should be considered if a patient develops symptoms consistent with a lumbar SSH after craniotomy.

Brain↗
PubMed1999

Bow hunter's stroke associated with an aberrant course of the vertebral artery--case report.

A 53-year-old male presented with repeated vertebrobasilar insufficiency on turning the head to the left. Angiography revealed severe stenosis of the dominant right vertebral artery at the atlantoaxial level in this position. Decompression surgery for the affected vertebral artery at the transverse foramen of the atlas was planned. However, surgery revealed an aberrant course of the artery, turning at the orifice of the transverse foramen of the atlas and perforating the dura at the occipitoatlantal level after passing through the bony canal of the atlas. Therefore, decompression was performed at the bony canal, which was the contributing site, and the symptoms improved. Bow hunter's stroke may be caused by atlantoaxial arterial anomalies, so accurate preoperative evaluation of the region is necessary to avoid anatomical confusion at surgery.

Atlanto-Axial Joint↗
PubMed1999

Formation of 8,11,14-octadecatrienoic acid (18:3 n-4) from naturally occurring unique fatty acid, 9,12-hexadecadienoic acid (16:2 n-4), in animal cell cultures.

9,12-Hexadecadienoic acid (16:2 n-4), present in small amounts in fish oils as a naturally occurring unique fatty acid, was incorporated into the phospholipids in rat liver BRL-3A cells to a similar extent as linoleic acid (18:2 n-6). 11,14-Octadecadienoic acid (18:2 n-4) and 8,11,14-octadecatrienoic acid (18:3 n-4) were detected in the cellular lipids of BRL-3A cells when incubated in a medium supplemented with 16:2 n-4 methyl ester. The cellular levels of these acids increased in parallel with 16:2 n-4 methyl ester added to the medium. These compounds were probably formed through conversion from 16:2 n-4 to 16:3 n-4 by delta 6 desaturation, and then 18:3 n-4 was produced by elongation, and part of the surplus 16:2 n-4, not desaturated to 16:3 n-4, elongated to 18:2 n-4. These results suggested that 16:2 n-4 was desaturated by delta 6 desaturase in vitro. It was also shown that 16:2 n-4 inhibited arachidonic acid synthesis from exogenous linoleic acid in BRL-3A cells as efficiently as alpha-linolenic acid (18:3 n-3).

Animals↗
PubMed1999

Effect of meal timing after resistance exercise on hindlimb muscle mass and fat accumulation in trained rats.

To study the effect of meal timing after exercise on body composition, 20 male rats were assigned to either a group fed a meal right after exercise (R) or a group fed a meal 4 h after exercise (L). Resistance exercise (squatting) was conducted from 6:00 to 7:00, 3 d/wk for 10 wk. Meals were consumed from 7:00 to 8:00 and from 19:00 to 20:00 for R, and from 11:00 to 12:00 and from 19:00 to 20:00 for L. The room was lighted from 7:00 to 19:00. After 10 wk, the body weight was comparable between the groups. The hindlimb muscle weight was higher in R than in L by 6% (p < 0.05), whereas the sum of the weight of perirenal, epididymal, and mesenteric adipose tissues was lower in R than in L by 24% (p < 0.01). The soleus lipoprotein lipase (LPL) activity was higher in R than in L by 70% (p < 0.01), and the activity negatively correlated with the adipose tissue weight (r = -0.49, p < 0.05). These results suggest the possibility that ingesting a meal right after resistance exercise may contribute to an increase in the muscle mass and to a decrease in the adipose tissue compared to ingesting a meal several hours later.

Adipose Tissue↗
PubMed1999

Effect of timing of meal intake after squat exercise training on bone formation in the rat hindlimb.

We hypothesized that bone acquisition was affected by the timing of meal intake after resistance exercise training. This was based on the following previous results: 1) Nutrient intake right after exercise resulted in an increase in muscle mass and a decrease in abdominal fat mass as well as muscle protein synthesis when compared to the intake of a meal later after the exercise; and 2) body composition has been proposed to be a good predictor of bone mass. To substantiate our hypothesis, 20 male rats were assigned to either a group fed a meal right after squat exercise (R) or a group fed a meal 4 h after the exercise (L). The 10-wk training program consisted of approximately 70% of one repetition maximum for each animal, 15 repetitions per set, 10 sets per day, 3 d per week. As a result, hindlimb muscle mass in the R group was greater (p < 0.05) than that in the L group and abdominal fat mass was less (p < 0.01) in the R group as compared to the L group, regardless of there being no significant difference in body weight between the groups. Bone volume in the tibia (p < 0.01) and femur (p < 0.05) were both significantly greater in the R group than in the L group. Bone mineral content index (BMCI) and bone mineral density index (BMDI) in the tibia of the R group were significantly (p < 0.05) greater than the corresponding values of the L group. The greater BMCI and BMDI in the tibia were positively and significantly (p < 0.05) related with hindlimb muscle mass, but not with abdominal fat mass. There was no significant difference in BMCI and BMDI in the femur between the groups. These results suggest that the R regimen may contribute to increased bone acquisition in the tibia as compared to the L regimen, and this effect is partly due to the enlargement of muscle mass in the R group as compared to the L group.

Adipose Tissue↗
PubMed1999

[Seven cases of marked pulmonary fibrosis in the upper lobe].

We report on 7 patients with marked idiopathic pulmonary fibrosis in the upper lung lobes. The patients were generally characterized by the following pathological and clinical features: (1) marked subpleural pulmonary opacities and reticular shadows mainly in the upper lobes, with a progressive reduction in lung volume; (2) nonspecific fibrosis (subpleural, zonal, rather well-defined fibrosis with small cysts and honeycomb lesions) in 5 patients and interstitial pneumonia in 2, mainly in the upper lobes; and (3) a slender build, and a family history of recurrent spontaneous pneumothorax. Clinically, all 7 cases resembled idiopathic upper-lobe fibrosis as described by Amitani in 1992. Further clinical and experimental research will be required to delineate the characteristics of idiopathic fibrosis affecting primarily the upper lobes.

Adult↗