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Biomedical subjects

H Murakami

Publications and source records attributed to H Murakami.

At least 541 records · Page 30Linked to original sources
PubMed1991

Regional differences in the sweating responses of older and younger men.

Ten older (60-71 yr) and nine younger (20-25 yr) active healthy men were exposed to passive heating [by placing the lower legs and feet in a 43 degrees C water bath for 60 min while sitting in a warm (35 degrees C, 45% relative humidity) chamber] in summer and winter. The increase in rectal temperature (Tre) was significantly (P less than 0.05) greater, and mean skin temperature and forearm blood flow were lower, for the older men in both seasons. Total sweating rate was lower in the older men, but significantly (P less than 0.05) so only in the summer. The Tre threshold for sweating was unaffected by either age or site (back vs. thigh). The local sweating rate (msw) on the thigh was significantly lower (P less than 0.05) for the older men throughout the exposure, whereas there were no significant age-related differences for the average or peak values of back msw, although lesser sweating on the back occurred during the first 30 min of exposure. The decreased msw on the thigh was due to a lower sweat output per heat-activated sweat gland rather than from recruitment of fewer glands. It was concluded that regional differences exist in the age-related decrement in sweat gland function. Furthermore, these findings suggest that aging leads to a decreased ability to maintain body temperature with passive heating of the extremities, which may be attributed in part to decreased regional sweat gland function.

Adult↗
PubMed1991

Identification and characterization of basic fibroblast growth factor in porcine thyroids.

Fibroblast growth factor (FGF) is one of the most potent endothelial cell growth factors and has been found in almost all tissues in the body. However, there is no definitive report showing that FGF exists in the thyroid. In this report, we describe heparin binding endothelial cell growth factor activity in porcine thyroids. The extract from normal adult porcine thyroids was loaded onto a heparin-sepharose affinity column. The mitogenic activity on endothelial cells was found to elute from the column with 0.9 M-2.0 M NaCl. Polyacrylamide gel electrophoresis and an immunoblotting of bioactive fractions showed the basic FGF immunoreactivity in a double band with a molecular weight of 18K and 20K. These results strongly imply that the adult porcine thyroid-derived heparin binding endothelial cell growth factor may be authentic basic FGF and one of its high molecular weight forms. In support of this conclusion, basic FGF mRNA was detected in poly A+ RNA isolated from cultured porcine thyroid cells. On the other hand, recombinant human basic FGF at the concentration of 0.1-10 ng/ml increased the incorporation of 3H-thymidine into FRTL-5 cells and porcine thyroid follicular cells in culture. The stimulatory effects were also observed when the biologically active fractions of heparin-sepharose column of the thyroid extract were added to the culture. In addition, both recombinant human basic FGF at 10 ng/ml and heparin binding fractions from porcine thyroids inhibited TSH-induced iodide uptake by porcine thyroid cells in culture. These results suggest that basic FGF may be one of the important local modulators of thyroid function, cell growth, and angiogenesis.

Animals↗
PubMed1991

[A simple multiple maze test to estimate learning and memory in mice: application to the effect of scopolamine on learning and memory].

The apparatus consists of a home cage, a maze cage and a starting box. A maze with four right-middle-left decisions was placed in the maze cage. The starting box was attached and a water tap was placed at an area corresponding to the entrance of the maze. The exit of the maze and the home cage are connected with a tunnel. Food was placed in the home cage. 1) Mice were housed for 10 hr a day in the apparatus and then removed to another cage for fasting. One trial a day was carried out after fasting for more than 12 hr. In each trial, a mouse was put at the starting box, and then the number of errors (entering a blind alley) and the time until the mouse reached the home cage were counted. The mouse passed through the maze with a small number of errors and time. 2) Administration of scopolamine (0.125-0.5 mg/kg, i.p.) to a mouse that had mastered the maze transiently disturbed the maze performance dose-dependently. 3) Mice were housed for 4 hr a day. Scopolamine (0.25 mg/kg, i.p.) was administered either before or after the housing. Scopolamine disturbed the maze performance in the case of both procedures. These results suggest that the method is useful for estimating the memory in mice.

Animals↗
PubMed1991

Withdrawal like responses of rat hippocampal slices following brief exposure to morphine.

An acutely acquired dependence was investigated in rat hippocampal slices after brief exposure to morphine. Morphine augmented the population spike amplitude. Naloxone not only reversed the augmentation but decreased the amplitude to a level below that of the control. The inhibitory effect of naloxone correlated with the period of preincubation with morphine. These results suggested that the decreased response may indicate the withdrawal state acquired in vitro.

Animals↗
PubMed1991

Clinical analysis of reexpansion pulmonary edema.

Twenty-one of 146 cases of spontaneous pneumothorax that were treated by thoracentesis or continuous low negative pressure suction drainage (-12 cm H2O) of the pleural space developed REPE. The rate of REPE was higher in patients 20 to 39 years of age than in those over the age of 40, and the rate progressively increased in proportion to the extent of pneumothorax, as assessed by roentgenographic criteria. It is postulated that age-related changes in the lung may afford some degree of protection against developing REPE. It is also suggested that the treatment of pneumothorax with thoracentesis and/or suction drainage in young patients, or in the face of a large pneumothorax, requires careful consideration in view of a relatively high incidence of REPE in such individuals.

Adult↗
PubMed1991

Site-related difference in the prevalence of mitral valve prolapse. Relation to the prevalence and severity of mitral regurgitation.

In this study, 431 consecutive patients with mitral valve prolapse (MVP) diagnosed by two-dimensional echocardiography were employed to further investigate the site-related difference in the prevalence of MVP. Following echocardiographic determination of the site and severity of MVP, a pulsed-Doppler technique was further performed to assess the existence and severity of mitral regurgitation (MR) in all patients. These patients were then classified by age in 10-year groups with patients older than 60 years being enrolled in one group. The younger groups accounted for a large number of the patients with MVP in our study, with the number of patients being reduced with age. In addition, female patients tended to predominate up until the 50s, but not in the 50 and older groups. The prevalence of MVP at the centro-medial site of the anterior mitral leaflet (AML) predominated in all age groups, gradually decreasing with age, except for a peak in the 40s, before continuing to decline in the 50 and older groups. On the other hand, the prevalence of MVP at the lateral site of the AML and at the posterior mitral leaflet (PML) increased with age. In the 50 and older age groups, the prevalence of MVP at these sites increased steeply with age. However, the prevalence of MVP at both the lateral site of the AML and PML did not significantly increase with age. The trend shown above was not significantly different for gender. The number of patients with MR increased with age independent of the site of MVP. However, the prevalence and severity of MR associated with MVP at the lateral site of the AML and/or at the PML were significantly greater than at the other sites up until the 50s (p less than 0.05). When patients were older than 50 years, this significant site-related difference in the prevalence of MR was not observed because of the higher prevalence of MR in the older patients in this study. Forty-one patients could be followed for 2 to almost 5 years. Three of the 41 patients were observed to have MVP at the centro-medial site of the AML in the initial examination, but the site of MVP had extended to the lateral side of the AML in the final examination. Two patients with MVP at all 3 sites of the AML demonstrated an increase in the severity of MVP. However, there were no newly documented cases of MR among those patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1991

Increased MR signal intensity due to cervical myelopathy. Analysis of 29 surgical cases.

The cases of 29 patients with cervical myelopathy, who had been treated by anterior spine fusion, were reviewed. The relationship between pre- and postoperative magnetic resonance (MR) images was investigated with special reference to increased signal intensity in the spinal cord on the T2-weighted images and the relevance of this finding to clinical conditions. Preoperatively, there were areas of increased signal intensity in 12 patients whereas there were no areas of increased signal intensity in the other 17. The lesions were not clearly demonstrated on T1-weighted images. The pre- and postoperative clinical condition of the patients whose preoperative MR images showed areas of increased signal intensity in the spinal cord on T2-weighted images was worse than that of the patients who did not have areas of increased signal intensity. Of the 12 patients with regions of increased signal intensity preoperatively, five showed decreased signal intensity postoperatively compared to the preoperative levels and seven had no change. The postoperative recovery of the five patients who showed decreased signal intensity postoperatively was better than that of the seven patients who exhibited no change. The areas of increased MR signal in the spinal cord might be due to edema, cord gliosis, demyelination, or microcavities.

Adult↗
PubMed1991

Establishment and characterization of monoclonal antibodies against bovine ephemeral fever virus.

We established fourteen monoclonal antibodies (MAbs) reactive to bovine ephemeral fever virus YHL strain, and characterized six representatives including three IgG1s (YG3/4, YG5/8, and YG6/7) and three IgMs (YM4/9, YM2/6, and YM6/8). Among them, YG3/4 and YM4/9 gave especially strong reactivities to the virus. YM4/9 reacted specifically with a 43K antigen of the virus, corresponding to the matrix protein 1. The other MAbs reacted most strongly with the 43K antigen, but also reacted with unknown 23K and 21K antigens. By a simultaneous two-site method using YM4/9 and YG3/4, it was possible to detect 10(4.10)TCID50/ml of the virus, in the presence of serum.

Animals↗
PubMed1991

Stimulation and inhibition of interferon-beta production of human diploid fibroblasts by foodstuffs.

We screened for foodstuffs affecting interferon-beta (IFN-beta) production of human foreskin diploid fibroblasts, in the presence of poly I.poly C, cycloheximide, and actinomycin D. alpha- and beta-caseins stimulated IFN-beta production dose-dependently, but kappa-casein inhibited it. Of the two chymosin fragments of kappa-casein, glycomacropeptide was an inhibitor but p-kappa-casein was not. beta-lactoglobulin stimulated IFN-beta production weakly, but lactoferrin inhibited it strongly. It was also shown that serum contained some factors inhibiting IFN-beta induction and stimulating its production.

Blood↗