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Biomedical subjects

M Sakai

Publications and source records attributed to M Sakai.

At least 451 records · Page 25Linked to original sources
PubMed1993

The conformational analysis and photoisomerization of retinochrome analogs with polyenals.

3,7-Dimethyl-2,4,6,8,10-dodecapentaenal was synthesized for reconstitution of the retinochrome analog. Its opsin shift was 1000 cm-1 smaller than that of native retinochrome, whose chromophore contains the same number of double bonds. The conformational change from 6-s-trans to 6-s-cis, as figured in a retinal molecule, plays an important role in the formation of the retinochrome analog, based on the estimation of opsin shifts for retinal analogs locked in the 6-s conformation. Thus the conformation of the 6-7 single bond in the native retinochrome was suggested to be 6-s-cis. Analysis of the circular dichroic spectra of retinochrome analogs revealed that the 6-s conformation is independent of the appearance of the beta-band. The stereoselectivity in the photoisomerization of the retinal analogs by a retinochrome template depends on the hydrophobic binding in the region of the beta-ionone ring.

Circular Dichroism↗
PubMed1993

Infection of human synovial cells by human T cell lymphotropic virus type I. Proliferation and granulocyte/macrophage colony-stimulating factor production by synovial cells.

The present study was performed to clarify the relationship between human T cell lymphotropic virus type I (HTLV-I) infection and chronic inflammatory arthropathy. To determine the ability of HTLV-I to infect synovial cells and the effect on synovial cell proliferation, synovial cells were cocultured with the HTLV-I-producing T cell lines (MT-2 or HCT-1). After coculture with HTLV-I-infected T cells, the synovial cells expressed HTLV-I-specific core antigens, and HTLV-I proviral DNA was detected from the synovial cells by polymerase chain reaction. These cocultured synovial cells with HTLV-I-infected T cells proliferated more actively than the synovial cells cocultured with uninfected T cells. This stimulatory effect of HTLV-I-infected T cells on synovial cell proliferation seems necessary to contact each other. After being cocultured with MT-2 cells, synovial cells proliferated more actively than control cells even after several passages. Furthermore, HTLV-I-infected synovial cells produced significant amounts of granulocyte/macrophage colony-stimulating factor. These results suggest that HTLV-I can infect synovial cells, resulting their active proliferation and may be involved in the pathogenesis of proliferative synovitis similar to that found in rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1993

Protein kinase activity associated with the IME2 gene product, a meiotic inducer in the yeast Saccharomyces cerevisiae.

The IME2 gene product (Ime2) is required for entry into meiosis and sporulation in S. cerevisiae. It has been predicted to be composed of two domains, an amino-terminal domain with homology to protein kinases and a carboxy-terminal acidic domain. The Ime2 was identified in extracts of meiotic cells carrying multi- but not low-copy IME2 in immunoblot analysis using an Ime2-specific antibody. Immune complexes were found to phosphorylate Ime2 and several exogenous proteins. Low-copy plasmids expressing truncated Ime2 proteins that lack part of or the entire carboxy-terminal domain enabled cells to undergo sporulation even under a certain repressive nutritional condition. These cells contained increased levels of protein kinase activity compared with control cells. These results suggest that the amino-terminal domain has a protein kinase activity and that the acidic tail is not essential for either the kinase activity or sporulation but serves in a negative role. An Ime2-beta-galactosidase fusion was shown by immunofluorescence microscopy to be localized predominantly to the nucleus, suggesting a nuclear function of Ime2.

Antigen-Antibody Complex↗
PubMed1993

Stimulation of mitogenesis in human thyroid epithelial cells by endothelin.

We investigated whether a potent vasoconstrictor, endothelin, stimulated the proliferation of human thyroid epithelial cells (thyrocytes). [3H]-thymidine incorporation into normal thyrocytes and thyrocytes from patients with Graves' disease was significantly increased at 10(-9) mol/l endothelin, reaching a plateau at 10(-8) mol/l. The proliferative responses of the thyrocytes obtained from patients with Graves' disease were similar to those of normal thyrocytes. Furthermore, the cell number of thyrocytes stimulated by endothelin was increased as compared with that of unstimulated thyrocytes. Neither indomethacin nor heparin affected this endothelin-stimulated thyrocyte proliferation. When thyrocytes were cultured with both endothelin and recombinant interleukin 1 beta, there was an additive effect on thyrocyte proliferation. The Ca2+ entry blocker, verapamil, inhibited both the proliferative responses of thyrocytes to endothelin and the additive effect of endothelin and recombinant interleukin 1 beta on thyrocyte proliferation. These results suggest that endothelin functions as a growth-promoting factor for human thyrocytes, presumably through intracellular calcium influx.

Calcium↗
PubMed1993

[Comparison of life style and health practices between the subjects of occupational health services and those of community health services].

A questionnaire was mailed to a total of 3,889 residents 40, 45, 50, 55, 60, and 65 years of age living in 11 municipalities of Hida district, Gifu Prefecture, Japan, to inquire about their life style and health practices. Of the 3,889 residents, 2,919 (75.1%) responded to the questionnaire. They were divided into two groups for comparison; the subjects of occupational health services and those of community health services. The subjects of occupational health services at ages 40-55 showed lighter daily physical activity level than those of community health services. However, the subjects at ages 60 and 65 showed equally heavy daily physical activity level in two groups, which indicates that the subjects of occupational health services aged 60 and 65 years are engaged in heavier job at worksite and home. The prevalence of self-rated stress tended to be higher in the subjects of occupational health services. The mean health practice scores tended to be higher for the subjects of occupational health services than for those of community health services at ages 40-55. The percentage of people who had examinations for circulatory diseases were higher among the subjects of occupational health services at ages 40-60 compared with those for the subjects of community health services. Many of the subjects of occupational health services receiving an examination for stomach cancer had obtained the examination service at municipalities provided by local governments. The subjects of occupational health services generally showed superior attitudes toward health care, which suggests that health management for the former is more easily approached than the latter.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1993

Induction of ornithine decarboxylase immunoreactivity in the male mouse kidney following testosterone treatment: an axial heterogeneity in the proximal tubule.

The effect of testosterone on the activity of ornithine decarboxylase (ODC), its protein level and immunocytochemical distribution were examined in the mouse kidney. Male BALB C mice at 8 weeks of age were used throughout. Fourteen hours before death, they received a subcutaneous injection of testosterone (1 mg/animal) or solvent to measure renal ODC activity or to detect the distribution of ODC immunoreactivity in the kidney. Renal ODC activity and the content of the enzyme were markedly increased after testosterone treatment. Histologically, few cells that were obviously immunoreactive to ODC were observed in the control animals and in the testosterone-treated animals a marked increase in ODC immunoreactivity was observed only in the cortex. ODC immunoreactive cells were located diffusely in the proximal tubule. In the pars recta, cells were stained weakly and homogeneously, while in the pars convoluta, the luminal surface of the cells showed stronger immunoreactivity. Moreover, many granule-like particles that were strongly ODC immunoreactive were observed inside the lumen of the pars convoluta. These results show that testosterone treatment induces an increase in ODC content in certain cells located in the proximal tubule of the cortex.

Animals↗
PubMed1993

Lung function in patients with collagen vascular diseases: a study of non-smokers with normal chest roentgenograms.

Lung function was assessed in 52 patients with collagen vascular diseases (CVD) who had neither a smoking history nor an abnormality in their chest x-ray films. Values of the maximum mid-expiratory flow and the maximum expiratory flow after 50% or 75% of the forced vital capacity had been exhaled were decreased and the ratio of closing capacity to total lung capacity was increased in 36-100% (varied among categories of CVD) of patients with CVD, and the carbon monoxide diffusing capacity was decreased in 27-56% of the patients. These findings indicate that small airway diseases and a decrease in diffusing capacity are not rare in CVD patients, even if they had neither a smoking history nor abnormal findings in their chest x-ray films. Regular and routine tests on lung functions are thought to be effective to detect early pulmonary involvement in patients with CVD.

Adult↗
PubMed1993

Immunohistochemical study of superoxide dismutase in the olfactory mucosa.

We used an anti-copper, zinc-superoxide dismutase (Cu,Zn-SOD) antibody in an immunohistochemical investigation of the distribution of SOD in the mouse olfactory mucosa. We also investigated differential staining with this antibody in comparison with an antibody specific to carnosine, a marker of mature olfactory cells. Mouse olfactory mucosa were immunostained with the ABC method with anti-SOD and anti-carnosine antibodies. When anti-SOD antibody was used, the sustentacular cells were positive in the olfactory region, whereas the olfactory cells were negative. In the respiratory region, the columnar epithelial cells were positive, whereas goblet cells were negative. The olfactory cells, olfactory vesicles and axons showed positive staining with anti-carnosine antibody, whereas the sustentacular and basal cells were negative.

Animals↗
PubMed1993

[An elderly case of supernormal conduction in the posterior division of the left bundle branch].

An electrophysiologic study was performed in a 95-year-old man with bifascicular block (right bundle branch block and left anterior hemiblock). During sinus rhythm (AA interval = 980 ms), every sinus beat was conducted to the ventricle. The AH interval was 130 ms and HV interval was 50 ms. A programmed premature atrial stimulation was performed after 8 paced beats at a slightly shorter cycle length than the sinus cycle length (900 ms). As the atrial coupling interval was shortened, the H1H2 interval also shortened. At an H1H2 interval of 680 ms the premature atrial beat was blocked distal to the recording site of the His potential. The block persisted up to an H1H2 interval of 560 ms. AV conduction resumed paradoxically when the H1H2 interval was further shortened to intervals lasting 540-490 ms. During this period the H2V2 interval was 50 ms. At still shorter H1H2 intervals, H2 was again blocked. The H2V2 intervals during this phase of improved conduction were unchanged compared with those of other conducted beats. Therefore normalization due to the gap phenomenon could be ruled out, and the improved conduction could be explained by a phenomenon of supernormal conduction in the posterior division of left bundle branch.

Aged↗
PubMed1993

Results and prognostic factors in the radical sinus operation for chronic sinusitis.

Radical surgical procedures of the maxillary sinus with or without involvement of the ethmoid, sphenoid and frontal sinuses were performed in 382 adult patients in the Department of Otorhinolaryngology. Tokai University Hospital in the 8-year period from 1984 to 1991. Of 382 patients, the postoperative symptomatology was studied in 189 patients by mcans of questionnaires. The postoperative results were finally analyzed in 63 patients whose subjective symptoms and objective findings were completely recorded. The follow-up period was over 3 months and subjective postoperative improvement was achieved in 83% and objective postoperative improvement in 75%; the overall improvement rate was 73%. In an analysis of results of the radical surgical operation, it appeared that poor results were closely related to the following factors: (1) maxillary sinus mucosa with cellular infiltration or edematous changes; (2) multiplicity of bacterial species including Gram-negative rods isolated from maxillary sinus secretion; (3) poor mucociliary clearance function; and (4) unsatisfactory postoperative treatment.

Adolescent↗
PubMed1993

Purification and characterization of human macrophage migration inhibitory factor: evidence for specific binding to glutathione and formation of subunit structure.

We cloned cDNA of human macrophage migration inhibitory factor (MIF) from a T-cell line encoding 116 amino acid residues and expressed it in E. coli. MIF specifically bound glutathione (dissociation constant = 600 microM), and the protein was effectively purified by an S-hexylglutathione Sepharose affinity column. MIF was homogeneous on SDS-PAGE and the molecular weight was calculated as 12.5 kDa. The molecular weight was in excellent agreement with that of the primary structure assumed from the cDNA. On the other hand, the molecular weight in the native form calculated by Sephadex G-100 gel chromatography was 24.3 kDa, which suggested that MIF formed a dimeric structure. To further confirm the native molecular weight, we carried out analytical ultracentrifugation. This precise hydrodynamic analysis revealed that the native molecular weight was 24.8 kDa, which confirmed that MIF existed as a homodimeric form.

Base Sequence↗
PubMed1993

Tungsten modulates the toxicity of paraquat for epithelial cells.

The modulation of paraquat toxicity by tungsten was studied in vitro using cultured MDCK epithelial cells. MDCK cells were cultured in minimal essential medium with or without 1 ppm tungsten. Proliferation of cells cultured with tungsten was not inhibited after exposure to 0.25 mM or 0.5 mM paraquat. In addition, lactate dehydrogenase release into the culture medium was lower for tungsten-treated cells than for cells cultured without tungsten. Cells cultured in medium alone showed reduced viability compared with controls after exposure to 0.5 mM paraquat, but 0.25 mM paraquat did not decrease cell viability. Tungsten-treated cells showed no decrease viability in after exposure to either concentration of paraquat. Cells exposed to paraquat developed a honeycomb morphology with scanty cytoplasm and abnormal nucleoli. However, these major structural changes were not observed in cells cultured with tungsten. Our study showed that cell damage after paraquat exposure was modulated by addition of tungsten to the culture medium. It is suggested that cytosolic xanthine oxidase activity was reduced by tungsten, leading to less production of superoxide and other radicals and thus conferring resistance to paraquat toxicity.

Animals↗
PubMed1993

[A case of right phrenic nerve paralysis as a complication of internal jugular vein cannulation by anterior approach].

We report a case of right phrenic nerve paralysis caused accidentally by compression after internal carotid artery puncture. Postoperatively she received respiratory management and conservative treatment after extubation. Cases of phrenic nerve paralysis following cardiac surgery have been reported, but paralysis as a complication of internal jugular vein cannulation by anterior approach is rare.

Accidents↗
PubMed1993

Prevention and control of nosocomial infection caused by methicillin-resistant Staphylococcus aureus in a premature infant ward--preventive effect of a povidone-iodine wipe of neonatal skin.

In early 1983 we experienced a small scale epidemic of Staphylococcus aureus coagulase type IV in the premature infants unit. Children had bacteraemia or impetigo. The microorganism was resistant to methicillin, erythromycin and lincomycin and was susceptible to tetracycline, chloramphenicol and cefmetazole. The results of coagulase typing and antimicrobial sensitivities indicated that these cases represented nosocomial infection with MRSA. The source and route of the infection were investigated, and measures were taken to prevent bacterial spread from carriers and to keep instruments and environments clean. As the source of infection was not identified, we tried wiping the body surface of the premature infants with a diluted IsodineR solution (10% povidone-iodine; 1:100 dilution) in order to prevent colonization of the microorganism on the body surface. As a result, no additional MRSA infection occurred in the premature infant unit. During the subsequent 6 years of frequent surveys of carriers and wiping the appropriate body surface with diluted IsodineR solution we have had no recurrence of MRSA. None of the premature infants wiped with IsodineR solution showed any objective abnormalities, although laboratory testing disclosed an elevated blood iodine level and a transient mild reduction of T4 in some infants.

Administration, Topical↗
PubMed1993

[Percutaneous removal of foreign bodies from the cardiovascular system: two experienced cases in addition to a review of 35 cases reported over the past 9 years in Japan].

From 1984 to 1992 in Japan, 37 cases, including 2 cases of our own, have been reported to involve the percutaneous removal of foreign bodies from the cardiovascular system by catheter. We reviewed the cases of these foreign bodies and the locations, approaches and types of catheters used for removal. The reported foreign bodies were usually iatrogenic in origin and were approximately two times larger than those found in patients who had self-dislodged catheters. The most common catheter approaches were from either the right femoral or saphenous veins.

Aged↗
PubMed1993

[A case of status asthmaticus complicated by with pneumoperitoneum during mechanical ventilation therapy].

A 46-year-old woman was admitted to our hospital for a severe asthma attack. On admission, systemic cyanosis was observed, and her consciousness state was drowsy. Arterial blood gas showed severe respiratory acidosis, hypoxia, and hypercapnea, with pH, PaO2, and PaCO2 of 7.163, 29.9 torr and 81.3 torr, respectively. Immediately, mechanical ventilation was commerced but on the third hospital day pneumomediastinum and subcutaneous emphysema appeared, and on the sixth day pneumoperitoneum also appeared. The chest CT scan on the sixth day showed free air around bilateral internal mammary vessels. This indicated that air moved from the mediastinum into the peritoneal cavity through an anterior route, via the sternocostal triangle formed by the xiphoid origins of the diaphragm medially and the costal origins laterally.

Female↗