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Biomedical subjects

N Katoh

Publications and source records attributed to N Katoh.

At least 145 records · Page 8Linked to original sources
PubMed1991

Increased nuclear type II estradiol receptor concentrations in rat spleen during the course of pregnancy.

Estradiol receptors are classified into type I and type II receptors by their affinity and capacity for estradiol binding. The type II receptors are thought to be significant in the suppression of immune response, such as in the pregnancy-associated immunosuppression. The present study was undertaken to show the presence of type II receptors in rat spleen and to examine the change of receptor distribution after estradiol administration and during pregnancy. Scatchard analysis revealed that the type II receptors were present in rat spleen, and dissociation constants were estimated to be 3.23 x 10(-9) M for cytosol and 4.29 x 10(-9) M for nuclei. The receptors possessed specificity for estradiol and diethylstilbestrol, but not for promegestone, methyltrienolone and dexamethasone. Administration of estradiol to rats resulted in the increase of nuclear receptor concentrations with concomitant decrease of cytosolic concentrations. During pregnancy, the receptor concentrations were increased in the nuclear fraction, but were not significantly changed in the cytosolic fraction. The dissociation constants of the receptors in pregnant rat spleen (4.77 x 10(-9) M for cytosol and 7.20 x 10(-9) M for nuclei) were similar to those in the non-pregnant control, suggesting the quantitative change of the receptors during pregnancy.

Animals↗
PubMed1991

[A population based epidemiological study of senile cataracts].

A population based study on senile cataracts was conducted on 295 participants in an ophthalmologic examination in a rural area of Ishikawa prefecture. Subjects were above 40 years of age and received an ophthalmologic examination and were personally interviewed. The following results were obtained. 1) Prevalence of senile cataracts increased with age. 2) For eyes with lens opacity grade III 66.3% showed a visual acuity below 0.7, while about 45% with lens opacity grade I or II was a visual acuity below 0.7. 3) Among those determined to have senile cataracts by this study the proportion with a prior diagnosis of senile cataracts was low, i.e., 36% even in advanced cataracts with lens opacity grade III. The proportion improved with worsened visual acuity and having a personal ophthalmologist. 4) Of those already diagnosed with senile cataracts, 56.7% failed to visit an eye specialist after than. This proportion tended to be lower in persons with worsened visual acuity. 5) About a half of those who continued to visit an eye doctor utilized anti-cataract medication. 6) The level of knowledge regarding senile cataracts was statistically lower with age.

Adult↗
PubMed1991

[Role of neutrophils-derived oxygen radicals for the formation of rat gastric mucosal injury by ischemia-reinfusion].

The implication of neutrophils-derived oxygen radicals in the formation of ischemia-reinfusion (I-R) injury in the rat stomach was evaluated. Male SD rats were subjected to 20 min hypotension and 20 min reinfusion of shed blood as we described previously (Gastroenterology 88: 1162, 1985). The area of gross gastric lesions was measured and scores of histologic damage assessed by our criteria as reported previously (Gastroenterology 94:1135, 1988). Luminol-dependent chemiluminescence (CL) was assessed in blood samples withdrawn from the portal vein and abdominal aorta immediately before killing rats. In a study prior to the I-R experiment, 3 ml of anti-neutrophils monoclonal antibody (ANA) given i.p. was confirmed to significantly reduce the number of neutrophils in blood from the carotid artery with the reduction rate being constant by 6 to 18 hr after. On the basis of this results, rats were administered ANA i.p. at the same dose 12 hr before I-R. Controls received normal rat serum. The area of gross gastric lesions in the corpus (69 vs. 191 mm2), but not in the antrum (13 vs. 20 mm3), was significantly reduced in the ANA group compared to that in control. The scores of histologic damage was significantly smaller in both the corpus (1.2 vs. 2.0) and antrum (0.8 vs. 1.5) in the ANA group than in the control. ANA significantly reduced the number of neutrophils and the CL levels in blood from both the portal vein (number, 107 vs. 915; CL, 26 vs. 235 RLU) and abdominal aorta (number, 52 vs. 368; CL, 24 vs. 268 RLU) in the ANA groups as compared to controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Cysteine protease in bovine milk capable of hydrolyzing casein as the substrate and elevation of the activity during the course of mastitis.

Cysteine protease was found to be present in bovine milk that catalyzed casein as the substrate. The protease was activated by reducing agents such as 2-mercaptoethanol and inhibited by monoiodoacetic acid, but not affected by the addition of phenylmethylsulfonyl fluoride, calcium or ethylene glycol bis (beta-aminoethyl)-N,N,N',N'-tetraacetic acid. The protease activity was linear as a function of protein amount and incubation time, and showed maximum at pH 6.0. By Sephacryl S-200 chromatography, at least two types of cysteine proteases having molecular weights of 45 kDa and more than 150 kDa were detected. The activity was increased in mastitic milk, and well correlated with the stages of mastitis, as indicated by the California mastitis test, somatic cell count and protein concentration. These results suggested that cysteine protease(s) is involved in the pathogenesis of mastitis.

Animals↗
PubMed1990

Protein kinase C and its endogenous substrate proteins in bovine mammary gland.

Protein kinase C activity was evaluated and its endogenous substrate proteins were explored in bovine mammary gland. Activity was detected in both cytosolic and particulate fractions. However, the activity was more abundant in particulate than in cytosolic fractions. By gradient elution (0 to .5 M NaCl) of the enzyme from a DEAE-cellulose column, cytosolic enzyme was eluted at about .2 M NaCl, and particulate enzyme was eluted at .3 to .5 M NaCl, suggesting that the particulate enzyme was different from the cytosolic enzyme. At least four proteins (52, 43, 41, and 35 kdal) were demonstrated for the substrates of the enzyme in the gland. Two (52 and 43 kdal) of the four proteins were mainly detected in particulate fraction, whereas the 35-kdal protein was in cytosolic fraction and the 41-kdal protein was equally distributed in both fractions.

Animals↗
PubMed1990

R-plasmid mediated transfer of beta-lactam resistance in Bacteroides fragilis.

We described plasmid mediated transfer of resistance to beta-lactam antibiotics between Bacteroides fragilis strains. Ampicillin-resistance was transferred from B. fragilis strain GAI-10150 to a B. fragilis strain JC-101 with a frequency of 10(-6)/input donor by a filter mating technique. A common plasmid band, named pBFKW1, was found in both the donor and the transconjugants. The plasmid was purified by an ethidium bromide-CsCl ultracentrifugation. The molecular size of the plasmid pBFKW1 which seemed to encode the beta-lactam resistance and beta-lactamase production was estimated ca. 40 kb by the analysis of endonuclease digest. Substrate profile of the enzymes derived from the donor and a transconjugant were of cephalosporinase character.

Ampicillin Resistance↗
PubMed1990

[Role of PAF for the formation of gastric mucosal injury induced by ischemia-reinfusion in the rat].

Oxyradicals of neutrophils are supposed to play a role in the formation of gastric mucosal injury induced by ischemia-reinfusion (I-R). Recently, platelet-activating factor (PAF) is suggested to be involved in the I-R injury as one of chemical mediators since this substance may be produced in hypoxic tissue, stimulating oxyradical generation of neutrophils. In the present study, using CV-3988, a PAF antagonist, the severity of gastric mucosal damage and chemiluminescence (CL) activity of neutrophils of circulating blood were measured to evaluate the role of PAF in the I-R injury. SD rats fasted overnight were anesthetized and instilled 0.1N HCl into the stomach. Rats were then subjected to reduction of blood pressure to 20-30 mmHg for 20 min by bleeding followed by reinfusion of shed blood for 20 min. Two groups of rats each received 10 mg/kg CV-3988 (PAF-A grup) or saline (I-R group) i.v. 5 min prior to bleeding. After killing rats, the area of gross gastric lesions and the index of histologic damage were assessed. In separate PAF-A and I-R groups of rats, and control rats received saline i.v. and no hypotension, blood samples were collected from the portal vein and the abdominal aorta 45 min after acid instillation. Luminol-dependent CL stimulated by PMA of blood samples was measured using the photometer Monolight 401. CL activity was expressed as [peak CL/neutrophils number].(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Evaluation of SOD activity in gastric mucosa of hemorrhagic shock rats].

UNLABELLED: Superoxide dismutase (SOD) exogenously administered has been documented to protect gastric mucosa against ischemia-reinfusion injury by scavenging oxygen radicals. However, the changes in levels of endogenous SOD in ischemic gastric mucosa are not known. To evaluate this, the present study was designed. METHODS: Fasted and anesthetized SD rats were given 0.1 N HCl i.g. and received the following procedures. Study 1: (1) Ischemia group--25 min after acid instillation, blood pressure was reduced to 20-30 mmHg for 20 min. (2) Ischemia-Reinfusion group--5 min after acid administration, rats received the same hypotension as above followed by reinfusion of shed blood for 20 min. (3) Control group-Rats were killed 45 min later without hypotension and reinfusion. Study 2: Three groups of rats treated with the same procedures as in Study 1 were given allopurinol (50 mg/kg/day) i.g. once daily for 2 days prior to the experiment. All rats were killed by exsanguination from the carotid artery to avoid as much as possible contamination of gastric mucosal samples with red blood cells rich in SOD. The supernatants of the corpus and antral mucosa homogenized were prepared for measuring their SOD activity using the nitrite method modified by Oyanagui. RESULTS: SOD activity in the gastric mucosa significantly increased in both the Ischemia (Ische.) and Ischemia-Reinfusion (I-R) groups compared to the control (Ische. vs. I-R vs. Cont'l: corpus-123.4 +/- 4.8 vs. 127.4 +/- 3.6 vs. 96.9 +/- 4.4 NU/Mg protein; antrum-71.6 +/- 2.8 vs. 81.4 +/- 6.8 vs. 62.1 +/- 3.1 NU/mg protein). No increase in SOD activity was observed in rats pretreated with allopurinol. CONCLUSION: SOD activity increases with oxyradicals generation in the rat stomach subjected to either hemorrhagic ischemia alone or hemorrhagic ischemia plus reinfusion. This also suggests that oxyradicals are generated even in the ischemic period.

Animals↗
PubMed1990

[Diffusion of cefmenoxime into prostatic fluid in the patients with acute bacterial prostatitis].

Expressed prostatic fluid (EPS) levels and serum levels of cefmenoxime (CMX) after intravenous administration were examined in 16 patients with acute bacterial prostatitis and 23 patients without prostatic diseases. Blood was drawn at 30, 60, 120 minutes and EPS was taken by prostatic massage at 60 minutes after the intravenous administration of 2 g CMX to evaluate the concentration of CMX. The concentration of CMX was determined by the bioassay using the E. coli NIHJ JC strain. The relationships between the EPS/serum ratio and peripheral WBC counts, CRP value and ESR 1h value were also analyzed. The serum levels of CMX at 60 minutes ranged between 20.3 micrograms/ml and 73.5 micrograms/ml (mean +/- S.D.: 41.8 +/- 14.2 micrograms/ml) in 16 patients with acute prostatitis, and between 21.5 micrograms/ml and 89.5 micrograms/ml (mean +/- S.D.: 49.5 +/- 18.7 micrograms/ml) in 23 patients without prostatic diseases. The EPS levels ranged between 0.4 micrograms/ml and 30.8 micrograms/ml (mean +/- S.D.: 12.6 +/- 9.6 micrograms/ml) in 16 patients with acute prostatitis, and between 0 and 2.3 micrograms/ml (mean +/- S.D.: 0.7 +/- 0.8 microgram/ml) in 19 patients without prostatic diseases. In 4 patients without prostatic diseases, the EPS amount was not large enough to evaluate the concentration of CMX. The EPS/serum ratio ranged between 0.006 and 0.697 (mean +/- S.D.: 0.31 +/- 0.21) in patients with acute prostatitis and between 0 and 0.058 (mean +/- S.D.: 0.015 +/- 0.018) in patients without prostatic diseases. The diffusion of CMX into the prostatic fluid in patients with acute prostatitis was strikingly higher than that in patients without prostatic diseases (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

[The process of occlusion and re-construction of the choriocapillaries following dye laser photocoagulation].

In order to elucidate the histopathological changes in the choriocapillaries following laser photocoagulation, moderate laser burns were performed on monkey retinas by an orange dye laser beam (595nm). Immediately after photocoagulation, the choriocapillaries were occluded by the intraluminal thrombus, however, the basement membrane of the endothelial cells remained. The newly-formed immature endothelial cells began to migrate along the pre-existing basement membrane toward the center from the edge of the lesion after 3 days. They formed new vascular lumens by coupling of intercellular junctions at 5 days. At 7 days, newly-formed capillaries were formed beneath the Bruch's membrane. After more than 7 days, the choriocapillaries in the lesion were re-constructed and required an almost normal structure with wide patent lumens, basement membrane, pericytes and fenestrations. It was showed that choriocapillaries occluded by moderate laser photocoagulation were re-constructed by the process of re-endothelialization along the preexisting basement membrane.

Animals↗
PubMed1990

[New devices for non-vascular interventional radiology].

Interventional Radiology (IVR) is a field of medicine, which has made diagnosis or treatment previously performed only by surgery possible percutaneously. For safe and successful IVR, good devices are necessary. Therefore, development of new devices is essential for the progress of IVR. Various kinds of new devices for non-vascular IVR are introduced, including new biopsy needles, AccuStick, Cope Gastrointestinal Suture, Rösch-Thurmond Fallopian Tube Catheterization Set, ESP Glove and others. Most of them are now commercially available in Japan. However, all of them cost much higher than they cost in the USA.

Humans↗
PubMed1989

Macrolide accumulation by Bacteroides fragilis ATCC 25285.

The accumulation of macrolide antibiotics in Bacteroides fragilis ATCC 25285 was increased in the order erythromycin, josamycin, and rokitamycin, depending on hydrophobicity. The half-times of efflux were also prolonged in the same order. Furthermore, MICs of the antibiotics were correlated with the extent of hydrophobicity. These findings suggest that the macrolide antibiotics are accumulated in B. fragilis by means of their hydrophobic properties, and the efficient accumulation of the drugs may explain the susceptibility of this gram-negative bacterium to macrolides.

Anaerobiosis↗
PubMed1989

Relative importance of four pressoregulatory mechanisms after 10% bleeding in rabbits.

Four physiological mechanisms are known to be important for recovery of arterial pressure (AP) after acute hemorrhage. These are the sino-aortic baroreflex (SA), the vagally mediated cardiopulmonary baroreflex (CP), the renin-angiotensin system (RA), and the vasopressin system (VP). We evaluated in anesthetized rabbits the relative importance of these mechanisms by repeating rapid, 10% arterial hemorrhage (6.5 ml/kg) once before and once after eliminating one of them and comparing the posthemorrhage hypotension. The study was conducted in two series. In the first series, we randomly grouped 24 rabbits into four groups, i.e., a sinoaortic baroreceptor-denervated group (SA) a vagotomized group (CP), a renin-angiotensin-blocked group (RA), and a vasopressin-blocked group (VP). In control conditions, AP fell to 88% at 2 min and 92% at 6 min after completing the hemorrhage. Significantly greater hypotension (e.g., 74% at 6 min) occurred only in the SA group. In the second series, we randomly classified 18 rabbits into three groups, i.e., an autonomic ganglion-blocked group (AB) plus a RA group and a VP group as before. Hypotension significantly greater than control (68% opposed to 91% at 6 min) occurred only in the AB group. We submit that as far as restoration of arterial pressure after rapid, mild hemorrhage in the rabbit is concerned, the arterial baroreceptor reflex system plays a far more important role than the vagally mediated cardiopulmonary baroreflex, the vasopressin system, or the renin-angiotensin system triggered directly by a fall in renal arterial pressure.

Animals↗
PubMed1989

Value of vectorcardiography in predicting progress in dilated cardiomyopathy.

Sixteen of 75 patients with dilated cardiomyopathy (DCM) died during a mean follow-up period of 39.7 months. In non-survivors, the cardiothoracic ratio and the left ventricular end-diastolic dimensions were greater, the left ventricular end-diastolic pressures were more elevated, and the cardiac index was lower than in the survivors at the time of initial diagnosis. There were no significant differences between survivors and non-survivors in the magnitude of the maximum QRS and T vectors or in the maximum T angle. In the non-survivors, the maximum QRS vector was directed more posteriorly and the width/length ratio of the loop in the horizontal plane was smaller than in survivors. The QRS loop in the horizontal plane was often distorted in non-survivors or showed a bizarre figure-of-eight configuration. It appears that in DCM a marked posterior displacement of a QRS loop that is narrow and distorted or is in a bizarre figure-of-eight configuration in the horizontal plane indicates an unfavorable prognosis.

Adult↗