Search PubMed⌕ Search

Biomedical subjects

T Yoshimura

Publications and source records attributed to T Yoshimura.

At least 325 records · Page 18Linked to original sources
PubMed1996

Occupational health.

Epidemiological studies on several selected topics in occupational health in Japan is introduced in the present paper. Karoushi or sudden death due to overwork was proposed in 1978. Hypertension was suggested to be one of the risk factors for Karoushi, although the risk factors related only to work conditions have not been clarified yet. Epidemiological studies on occupational stress and stress-related diseases have been developed, even with the difficulties of definition or measurement of occupational stress. The depression state and mental state were influenced by occupational stress and personality. A large scale cohort study on 180 thousand radiation workers in Japan has been conducted since 1990 in order to obtain scientific information on the health effects due to low dose protracted radiation exposure. In order to assess occupational cancer risk due to hazardous working environment in Japan, several epidemiological studies were carried out. One cohort study on Japanese forest workers for vibration syndrome showed that the latent interval for the development of vibration induced white finger was 6.2 years. Finally, evaluation studies of mass cancer screening programs in Japan were introduced. It was stressed that the epidemiological approach should be strengthened more in order to obtain more information for prevention of occupational diseases or work-related diseases and for the promotion of workers' health.

Humans↗
PubMed1996

Incidence of methicillin-resistant Staphylococcus aureus (MRSA) isolation in a skilled nursing home: a third report on the risk factors for the occurrence of MRSA infection in the elderly.

A case control study was carried out in order to evaluate the various factors which may influence the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) infections in a skilled nursing home. From April 1991 to March 1994, bacterial cultures were performed in 55 out of 102 residents in a nursing home based on various clinical aspects. We divided 102 residents into following three groups; (1) the MRSA group (n = 10), residents whose materials for bacterial culture were positive for MRSA, (2) the non-MRSA group (n = 45), residents whose specimens were negative for MRSA but positive for other bacteria, (3) the control group (n = 47), residents who did not have to undergo a bacterial culture because they were free from moderate and severe infectious diseases. Compared with the control group, the activities of daily living score and the serum albumin level were significantly lower in the MRSA group and the non-MRSA group at the beginning of the study. In contrast, the number of antibiotics used prior to the bacterial culture and the proportion of hospitalization within 6 months prior to the bacterial culture were significantly larger in the MRSA group than in either the non-MRSA group, or the control group. These results thus suggest that a low activities of daily living score, the use of many kinds of antibiotics and a recent previous hospitalization may be risk factors of MRSA infection in a nursing home environment.

Aged↗
PubMed1996

Effects of estrogen and progesterone on plasma platelet-activating factor-acetylhydrolase activity and low-density lipoprotein cholesterol concentration in men.

OBJECTIVE: We examined the effects of estrogen and progesterone on the plasma platelet-activating factor (PAF)-acetylhydrolase activity and lipoprotein concentrations in men. METHOD: Ten healthy men received 6 days of oral mestranol (0.24 mg/day) followed by 6 days of oral norethisterone (20 mg/day). The PAF-acetylhydrolase activity and lipoprotein profiles were determined in each subject prior to and following mestranol loading and following norethisterone administration. RESULT: The mestranol caused a significant decrease in both the plasma PAF-acetylhydrolase activity and the low-density lipoprotein (LDL) cholesterol concentrations of 26.4% and 26.9%, respectively; norethisterone appeared to revert the PAF-acetylhydrolase activity and LDL cholesterol concentrations to the levels observed prior to mestranol loading. In addition, the plasma PAF-acetylhydrolase activity was positive correlated with the LDL cholesterol concentration (r = 0.58, P < 0.001). CONCLUSION: The results of this study indicate that mestranol and norethisterone exert an effect on the plasma PAF-acetylhydrolase activity in men, possibly by influencing plasma LDL cholesterol concentrations.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1996

Effects of parathyroidectomy and calcium supplementation on the pressor response to angiotensin II in conscious rats.

OBJECTIVE: We evaluated the effect of parathyroidectomy (PTx) and of calcium supplementation on the pressor response to angiotensin II (Ang II) in conscious rats. STUDY DESIGN: PTx and sham surgery were performed on 10-week-old male Wistar rats. The mean arterial pressure (MAP), heart rate, and the effective pressor dose of Ang II (EPD) which defined as the dose of Ang II required to elicit a rise of 20 mmHg in MAP, were evaluated in PTx and sham operated rats. Intracellular free calcium in platelets was assessed with the fluorescent dye, fura-2 acetoxymethyl ester. In addition, after administering a dose of supplemental calcium chloride, a 10, 20, or 40 mg/rat, we determined the changes in the MAP, EPD, and serum calcium level. RESULTS: The EPD in the PTx rats was significantly lower than the sham operated rats. The serum concentration of calcium in PTx was also significantly lower than the sham operated rats. A statistically significant negative relationship was observed between the EPD and intracellular free calcium in PTx rats. Following administration of 20 mg of calcium chloride (7.4 mg of elemental calcium) to the PTx rats, the EPD returned to the level seen in sham operated rats. CONCLUSION: Results suggest that a depletion of parathyroid hormone is associated with the pressor response to Ang II, and is involved in the regulation of intracellular free calcium.

Angiotensin II↗
PubMed1996

[Occupational and lifestyle factors related to musculoskeletal and fatigue symptoms among middle-aged female workers in a frozen food processing factory].

A survey was conducted on musculoskeletal and fatigue symptoms related to individual and work-related risk factors among middle-aged female workers in a frozen food processing factory by using a self-administered questionnaire. Proportions of workers who frequently experienced, during the last one month, stiff muscle or pain in the neck-shoulder, back and lower limbs were 32.9%, 26.8% and 15.9%, respectively. The proportion for fatigue symptom was 30.5%. Factors related to fatigue were: short duration of employment [odds ratio (OR) 1.8, 95% confidence interval (CI) 1.1-2.9], light body weight [OR 0.6, CI 0.3-1.1], long house work [OR 1.7, CI 0.9-3.3], short sleep hours [OR 1.6, CI 1.0-2.5], walking to and from work [OR 0.5, CI 0.2-1.0], those related to back pain were: high body height [OR 2.4, CI 0.8-7.4], light body weight [OR 0.4, CI 0.2-0.9], those related to lower limb symptom were: working height below hip height [OR 2.3, CI 1.2-4.4], working height above shoulder height [OR 3.0, CI 1.5-5.7], high body height [OR 3.4, CI 1.2-10.1] and low body height [OR 2.4, CI 0.8-7.4]. Workers' subjective evaluation of height of work table was significantly related to the body height. These results indicate that it would be necessary to improve ergonomic aspects of work considering individual characteristics as well as to advise workers on their lifestyle.

Body Height↗
PubMed1996

[A case of progressive multifocal leukoencephalopathy with methionine uptake demonstrated by PET].

We report here a 55-year-old man with progressive multifocal leukoencephalopathy (PML) associated with chronic adult T cell leukemia (ATL). Neurological examination revealed mild dementia, right homonymous hemianopsia and visual agnosia. Serologically anti-HTLV-I antibody was positive. Peripheral blood analysis showed ATL cells up to 23% in white blood cells. Because he did not have symptoms or signs directly related to ATL, it was considered that he had chronic ATL. T2-weighted cranial MRI demonstrated multiple hyperintensity lesions confined to the white matter from the bilateral occipital to parietal lobes, without enhancement after gadolinium administration or mass effect. We performed stereotactic biopsy of the left occipitoparietal white matter. Histological examination of the biopsied specimens showed demyelinated lesions, containing foamy macrophages and bizarre astrocytes. Oligodendrocytes contained nuclear inclusions which reacted with an antibody against the JC virus (JCV) antigen. These findings were consistent with those of PML. The genomic analysis of JCV from the biopsied brain revealed deletions in the regulatory region. We investigated cerebral blood flow, glucose and amino acid metabolism in this patient using positron emission tomography, and obtained the following three characteristic findings in the lesions: 1) luxury perfusion state, 2) decreased fluorodeoxyglucose (FDG) uptake, and 3) increased methionine (Met) uptake. These findings resembled those of low grade tumors.

Animals↗
PubMed1996

[A case of central homonymous hemianopsia due to cerebral infarction of the occipital tip].

A 54-year-old man was admitted to the hospital because of the restriction of the right visual field. Goldmann's visual field test revealed the right central hemianopsia. MRI showed the infarction of the left occipital lobe tip. Cerebral angiography showed the occlusion of the left calcarine artery but no abnormality in the branches of the middle cerebral artery (MCA). The occipital lobe tip receives the projection from the macular area and is supplied by both calcarine artery and a branch of MCA. Therefore, cases of central homonymous hemianopsia due to vascular disorders have been relatively rare and the macular vision is usually spared. In contrast to the above knowledge, only one artery occlusion resulted in the central hemianopsia in our case. Poor anastomosis between PCA and MCA in the occipital tip of our patient may explain occurrence of the infarction of that area.

Cerebral Infarction↗
PubMed1996

[A Japanese family with probably autosomal dominant adult-onset leukodystrophy].

We report here a family with leukodystrophy clinical features of which are characterized as adult onset, probably autosomal dominant inheritance, hyperreflexia, cerebellar ataxia, autonomic dysfunction and no peripheral nerve involvement. T2-weighted brain MRI revealed diffuse high signal areas in the cerebral white matter. The disorder in our subjects can be distinguished from most leukodystrophies in terms of genetic inheritance, clinical manifestations and laboratory data. Our family is quite similar to the kindred which Eldridge et al. described in 1984 as "hereditary adult-onset leukodystrophy simulating chronic progressive multiple sclerosis". Our family is the third report of this type of leukodystrophy and the first among non-Irish/Scottish family.

Age of Onset↗
PubMed1996

[A family of autosomal dominant facio-limb-girdle muscular dystrophy].

A family of autosomal dominant facio-limb-girdle muscular dystrophy was reported. The proband was a 28-year-old male. His father and sister suffered from a similar disease. All patients developed weakness of lower limbs and atrophy of thigh at second to fourth decades. All showed mild facial and neck flexor weakness as well as proximal dominant weakness and atrophy of four limbs. Limb muscle involvement was more severe in lower limbs than in upper limbs in all cases. Interestingly, all showed limitation of ankle dorsiflexion (tight heel cord), although distal muscles of lower limbs were not involved or only mildly involved clinically. On laboratory examination, serum CK increased slightly. Needle EMG revealed low amplitude, polyphasic MUP in limb muscles in all cases. Biopsied muscles taken from the proband showed non-specific myogenic changes. Rimmed vacuoles were not observed. Our cases were different from Bethlem myopathy, because the age of onset was late and joint contractures were mild in our cases, as compared with Bethlem myopathy. Clinical manifestations of our family showed a strong resemblance to the family reported by Girchlist et al, but similar cases were not reported in Japan.

Adult↗
PubMed1995

cDNA cloning of mouse ferredoxin reductase from kidney.

A cDNA encoding ferredoxin reductase has been isolated from a mouse kidney cDNA library using human ferredoxin reductase cDNA as a probe. Mouse ferredoxin reductase coded for 494 amino acid residues. The mouse mature enzyme which comprises 460 amino acid residues shared 87.8-89.1% amino acid identities with the bovine and human enzyme. Northern blot analysis showed that ferredoxin reductase mRNA was expressed in the adrenal, testis and ovary and to a lesser extent in the liver and kidney. However, this mRNA in the adrenal cell line, Y-1 cell, was not induced by adenosine 3',5'-cyclic monophosphate (cAMP) in contrast with ferredoxin mRNA.

Amino Acid Sequence↗
PubMed1995

Asian hereditary neuropathy patients with peripheral myelin protein-22 gene aneuploidy.

Japanese hereditary neuropathy with liability to pressure palsy (HNPP) patients have a deletion of one peripheral myelin protein-22 (PMP22) gene region in distal chromosome band 17p11.2 as do Caucasian patients. Japanese and Asiatic Indian CMT1A patients have a PMP22 gene duplication that results in Charcot-Marie-Tooth disease type IA (CMT1A; HMSNIA) in patients of European and Middle Eastern ancestry. About 70% of Japanese CMT1 patients have a PMP22 duplication as do Caucasians, while Japanese CMT1B, CMT2 and Dejerine-Sottas patients to not have PMP22 gene region aneuploidy. Although HNPP and CMT1A genotypes are generated simultaneously by unequal recombination that results in PMP22 gene aneuploidy in each daughter cell, only 3 Japanese HNPP probands with PMP22 deletion from a large patient population were referred to a single center compared to 18 referred CMT1A probands with PMP22 duplication. This lower HNPP frequency more likely reflects lower HNPP reproductive fitness than patient ascertainment bias because disease severity and variation in severity is about the same in CMT1A and HNPP patients and because all patients of both types were referred regardless of disease severity. These results, along with an apparently high de novo CMT1A mutation rate, suggest that common ancestors of Japanese, Asian Indians, and Caucasians carried PMP22 geneflanking sequences that enhance unequal crossing over.

Aneuploidy↗
PubMed1995

Molecular cloning of 25-hydroxyvitamin D-3 24-hydroxylase (Cyp-24) from mouse kidney: its inducibility by vitamin D-3.

A cDNA encoding a 25-hydroxyvitamin D-3 24-hydroxylase, Cyp-24, has been isolated from mouse kidney cDNA library by hybridization screening. Mouse Cyp-24, coding for 514 amino acid residues, shared 82.1 and 94.7% amino acid identity with human and rat CYP24s, respectively. Among mouse organs examined, Cyp-24 mRNA could be detected in the kidney. When mice were treated with vitamin D-3, Cyp-24 mRNA was induced in the kidney.

Amino Acid Sequence↗
PubMed1995

Electron paramagnetic resonance studies of ferric cytochrome c' from photosynthetic bacteria.

Electronic ground nature of ferric cytochromes c' isolated from five photosynthetic bacteria. Chromatium vinosum ATCC 17899, Rhodobacter capsulatus ATCC 11166, Rhodopseudomonas palustris ATCC 17001, Rhodospirillum molischianum ATCC 14031, and Rhodospirillum rubrum ATCC 11170 has been investigated by electron paramagnetic resonance (EPR) spectroscopy. EPR spectra indicate that the electronic ground state of five ferric cytochromes c' is a quantum mechanical admixed-spin state of a high spin (S = 5/2) and an intermediate spin (S = 3/2) at pH 7.2 and is high-spin state at pH 11.0. At physiological pH, however, the content of an intermediate spin state differs with the bacterial source of the protein: approximately 50%, Chromatium vinosum; approximately 40%, Rhodobacter capsulatus and Rhodopseudomonas palustris; approximately 10%, Rhodospirillum molischianum and Rhodospirillum rubrum. Computer simulation of the spectra supports this diversity of the contribution of an intermediate spin state. Model studies of the ferric porphyrin complexes suggest that the correlation between content of an intermediate spin state and heme iron displacement from the mean heme plane. Therefore, the variation of the content of an intermediate spin state observed in the present study reflects the subtle difference in the degree of heme iron displacement among the proteins.

Chromatium↗
PubMed1995

Mouse cytochrome P-450 linked ferredoxin: its cDNA cloning and inducibility by dibutyryladenosine 3',5'-cyclic monophosphate and forskolin.

Two full-length cDNAs (F1-1 and F41-1) complementary to mouse kidney mRNA coding for cytochrome P-450 (P450) linked ferredoxin were isolated and completely sequenced. The coding sequences between F1-1 and F41-1 were identical. However, the 3' untranslated regions of F1-1 and F41-1 were 228 and 27 bases long due to the presence of alternative polyadenylation sites, respectively. The deduced amino acid sequence of mouse cytochrome P-450 linked ferredoxin showed 92.5, 75.0, 71.2 and 71.0% identities with those of rat, human, pig and bovine cytochrome P-450 linked ferredoxin, respectively. The cytochrome P-450 linked ferredoxin mRNA was detected in adrenal, kidney and ovary among the organs examined. The treatment of Y-1 cells with dibutyryladenosine 3',5'-cyclic monophosphate or forskolin induced the transcript of cytochrome P-450 linked ferredoxin mRNA.

Amino Acid Sequence↗
PubMed1995

Adrenoleukodystrophy: the restoration of peroxisomal beta-oxidation by transfection of normal cDNA.

In order to elucidate the function of ALDP [a protein encoded by the gene responsible for adrenoleukodystrophy (ALD)], normal ALDP cDNA, inserted in an expression vector driven by chicken beta-actin promotor, was transfected into ALD fibroblasts. In a transient expression system, the fatty acid composition did not change even though the ALDP was newly synthesized based on the findings of a western blot analysis. In a stable expression system, 3 cell lines were strongly positive for ALDP. In these cells the level of very long chain fatty acid (C26:0) turned out to be as low as those of the control, while the activities of C24 beta-oxidation, as checked by two different methods, became normal. From these results, it is concluded that ALDP is indispensable for the function of peroxisomal beta-oxidation, and thus the treatment of ALD may be possible by the supplementation of ALDP.

ATP Binding Cassette Transporter, Subfamily D, Mem↗
PubMed1995

Neutrophil accumulation and activation by homologous IL-8 in rabbits. IL-8 induces destruction of cartilage and production of IL-1 and IL-1 receptor antagonist in vivo.

Whether or not IL-8 attracts T lymphocytes and activates neutrophils in vivo remains unclear. Most studies on function of IL-8 in vivo have been done on human IL-8 in heterologous animals. To elucidate the role of IL-8 in vivo, we injected homologous IL-8 into rabbit knee joints and investigated the inflammatory response. Injection of 10 micrograms of rabbit IL-8 induced a massive accumulation of neutrophils. IL-8 attracts T lymphocytes in vitro; however, rabbit IL-8 induced no appreciable lymphocyte accumulation in rabbits. Although human IL-8 was reported not to induce cartilage destruction when injected into heterologous animals, we observed that rabbit IL-8 did provoke a release of neutrophil elastase, leading to cartilage destruction, when injected into rabbits. An inhibitor against neutrophil elastase (ONO-5046) prevented destruction of the cartilage. Injection of rabbit IL-8 induced bioactive and immunoreactive IL-1 beta and IL-1 receptor antagonist (IL-1Ra) in the joint cavity. Immunohistochemistry showed that IL-1 beta and IL-1Ra positive cells were infiltrating leukocytes. In neutrophil-depleted rabbits, rabbit IL-8 induced far lesser concentrations of IL-1 beta and IL-1Ra and no cartilage destruction compared with findings in normal rabbits. Thus, the infiltrating neutrophils are the main producers of these cytokines and are responsible for the cartilage destruction. In addition to neutrophil chemotactic activity, IL-8 proved to have a neutrophil-activating capability in vivo, with respect to release of neutrophil elastase and induction of IL-1 beta and IL-1Ra.

Animals↗