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Biomedical subjects

A Koizumi

Publications and source records attributed to A Koizumi.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Clinical analysis of patients with sepsis--comparison between underlying diseases].

We evaluated the clinical data in 83 patients with sepsis, which was diagnosed by both Bone's definition of sepsis and positive isolates from blood culture, according to their underlying diseases. This study enrolled a total of 117 septic episodes in 83 patients (57 males and 26 females, mean age: 52.0 years). We classified 3 groups, including hematological malignancies (46 patients, 72 episodes), solid malignant tumors (23 patients, 25 episodes) and non-malignancies (14 patients, 20 episodes), by the underlying diseases. Of the total number of isolates from blood culture, 53.0% were single gram-positive bacteria, 33.3% were single gram-negative bacteria, 7.7% were single fungus and 6.0% were polymicrobial organisms. In addition, coagulase negative staphylococci was isolated most often in patients with hematological malignancies. Sepsis was often caused by infectious focuses of hemorrhoid, stomatitis or intravenous catheter in patients with hematological malignancies, by pneumonia in patients with solid malignant tumors and by urinary tract infection in patients with non-malignancies. Mortality of sepsis in patients with solid malignant tumors (48%) was highest in 3 groups. Septic patients, who were complicated with shock and/or DIC, has poor prognosis in all groups. Serum albumin level was significantly lower in dead patients than patients who survived. These results suggest that clinical features may be different according to the underlying diseases of patients with sepsis.

Aged↗
PubMed1998

[An epidemiological investigation for MRSA and PRSP in Kinki area. Kinki Infection Working Group].

Recent trends in the development of resistance of the Staphylococcus aureus and Streptococcus pneumoniae to antibiotics were investigated, using a questionnaire delivered to participants at a meeting of the Kinki District Society of Infections. Methicillin-resistant Staphylococcus aureus (MRSA) accounted for 55.4% of all isolated S. aureus, and more than 80% of MRSA was detected within hospitals. In outpatients, MRSA was often detected in pus, while in hospitalized patients, MRSA was often detected in sputum. Further, MRSA was accompanied by some other organisms (most frequently Pseudomonas aeruginosa) in 64.7% of MRSA positive patients. The sensitivity of MRSA to vancomycin (VCM) was 100%, to sulfamethoxazole-trimethoprim (ST) 99.2%, and to arbekacin, 98.6%. In contrast, Penicillin-resistant Streptococcus pneumoniae (PRSP) accounted for 42.4% of all isolates of Streptococcus pneumoniae. About 50% of PRSP was detected in out-patients. For both hospitalized patients and outpatients, PRSP was most frequently detected in sputum. PRSP was accompanied by some other organisms (most frequently Haemophilus influenzae) in 49.3% of PRSP positive patients, PRSP had high sensitivity to cephems, carbapenems and VCM.

Aminoglycosides↗
PubMed1998

A cross-sectional observation of the health effects of hydrazine hydrate and differences of its metabolism by NAT2 polymorphism.

OBJECTIVES: To summarize the results of two studies that attempted to clarify: (1) the health effects of hydrazine hydrate (HH) (N2H4 x H2O: CAS No. 7803-57-8); and (2) the influence of allelic polymorphism of N-acetyltransferase (NAT2) on the metabolism of HH. METHODS: A cross-sectional survey was carried out on 172 male HH-exposed workers and 125 male referent workers at five factories in Japan. The biological half-lives of HH after 1 h of exposure were determined in 12 workers, four workers in each of three NAT2 phenotypes. Clinical examinations were performed and acute and chronic subjective symptoms related to HH were examined by self-administered questionnaires. NAT2 phenotypes were assessed. RESULTS: No hydrazine was detected in either the breathing zones or the urine of the referent workers. The mean hydrazine concentration in the breathing zones, hydrazine and acetylhydrazine in urine, and the cumulative exposure level were 0.0109 ppm, 0.8660 micromol/g x Cr, and 2.80 ppm-years, respectively. There was no difference and no dose-dependent change in the health examination items between HH-exposed and referent workers after adjusting confounding factors, nor in terms of the differences of NAT2 phenotypes. Of 90 subjective symptoms, complaints of nightmares were significantly related to HH exposure. The half-life of urinary hydrazine and acetylhydrazine on rapid, intermediate, and slow phenotypes was 1.68, 3.01, and 4.46 h, respectively. CONCLUSION: This study suggested that current and cumulative exposure to HH did not affect the workers' health, and the half-life of the slow phenotype was longer than those of the rapid and intermediate phenotypes.

Adolescent↗
PubMed1997

Electrophysiological evidence of an increase in cold tolerance of cardiac muscles in mice after energy restriction.

Life-prolonging energy restriction (ER) has been known to extend longevity. The heart was selected as the target organ of ER and the electrophysiological properties of ER on the heart were investigated. Action potential parameters were measured on ventricular papillary muscles of C57BL/6 mice (2-6 months of age). Resting membrane potential (Rm) did not change even when the temperature was lowered to 20 degrees C in ER mice (-67.5 +/- 0.8 mV), however, the membrane was depolarized in the control (-61.1 +/- 1.1 mV). Action potential duration measured at 30 and 50% repolarization was significantly prolonged in ER mice at 20-35 degrees C. Ouabain (10 microM) decreased Rm in ER mice at 20 degrees C (-68.6 +/- 1.0 to -63.6 +/- 0.8 mV), but failed to decrease Rm in the control (-60.6 +/- 1.8 to -62.1 +/- 1.2 mV). There were no significant differences in extracted Na, K-ATPase activity or affinity and binding capacity of ouabain between ER and control hearts. These results indicate that in ER mice the lack of effect of temperature on Rm was not due to a change in the physicochemical properties of Na, K-ATPase. The present study collectively suggests that ER increases cold tolerance in the heart of mice.

Acclimatization↗
PubMed1997

[Campylobacter jejuni enteritis in three patients with HIV infection].

Gatrointestinal symptoms, which include diarrhea, are as common as respiratory symptoms in patients with HIV infection. Gastrointestinal symptoms may result from infections, neoplasma, HIV enteropathy or drug toxicity. Three HIV-infected patients admitted to our hospital complaining of diarrhea and fever. We confirmed their diagnosis as Campylobacter jejuni enteritis by bacteriological examination of their feces. All of them had eaten inadequately cooked meat in restaurants before the onset of their enteritis. Their symptoms immediately improved after the administration of antimicrobial agents. One strain of C. jejuni isolated in our cases, however, was resistant to ofloxacin. This case report suggests that we must counsel HIV-infected patients to avoid inadequately cooked food and observe resistant patterns of C. jejuni to antimicrobial agents in Japan in the future.

AIDS-Related Opportunistic Infections↗
PubMed1997

Electrophysiological characterization of cultured hepatic stellate cells in rats.

This study aimed to examine electrophysiological properties of cultured rat hepatic stellate cells (HSCs) using the whole cell configuration of patch-clamp technique. At least three different current components were identified. First, when the membrane was depolarized to voltages more positive than -40 mV, a transient outward K+ current was evoked. Second, membrane hyperpolarization below -60 mV evoked a sustained and inward-rectifying K+ current. The third component was a current flowing outward, which was activated when the cell was depolarized more positively than 0 mV. The channel for this current allowed Na+, K+, and Cl- to pass nonspecifically, suggesting the presence of hemi gap-junctional channel. Furthermore, a laser photobleaching technique revealed the presence of gap junctions between adjacent HSCs. A voltage-gated Ca2+ current, which is known to occur in smooth muscle cells, was searched for but was not detectable. These results suggest that membrane potential of HSCs is determined specifically by the two distinct K+ channels and by an intercellular mechanism involving gap-junctional communication.

Animals↗
PubMed1997

A novel locus, Mody4, distal to D7Mit189 on chromosome 7 determines early-onset NIDDM in nonobese C57BL/6 (Akita) mutant mice.

In this article, we report on a nonobese C57BL/6 (B6) mouse model of NIDDM named Akita mouse, characterized by early age onset and autosomal dominant mode of inheritance. At 7 weeks of age, the mean morning blood glucose levels (mmol/l) under ad libitum feeding conditions were significantly higher (P < 0.01, analysis of variance [ANOVA]) in diabetic mice than in unaffected mice: 27.3 +/- 5.3 for diabetic males (n = 50) and 9.3 +/- 1.2 for unaffected males (n = 50); 13.6 +/- 3.8 for diabetic females (n = 50) and 8.7 +/- 1.1 for unaffected females (n = 50), while corresponding immunoreactive insulin levels in plasma were significantly lower in diabetic mice than in unaffected mice. In vitro insulin secretion was also impaired, even at 4 weeks of age. The 50% survival time for male diabetic mice (305 days) was significantly shorter than that of unaffected counterpart mice but not for diabetic females. Obesity did not occur in diabetic mice. Histological examinations of the pancreas in diabetic mice, from 4 to 35 weeks of age, revealed decreases in the numbers of active beta-cells without insulitis. Morphometry demonstrated specific decreases in immunologically detectable insulin density in islets in diabetic mice, even at 4 weeks of age, without changes of relative islet areas. By linkage analysis, a single locus was identified on the basis of 178 N2 mice [(B6 x C3H/He)F1 x B6 and (B6 x C3H/He)F1 x C3H/He]. This locus, which we named Mody4, was mapped to chromosome 7 in a region 2-8 cM distal to D7Mit189 (logarithm of odds [LOD] score = 15.6 and 10.3).

Alanine Transaminase↗
PubMed1997

[Necrotizing sarcoid granulomatosis diagnosed by video thoracoscopic lung biopsy].

A 28-year-old woman was admitted to our hospital because of chest pain. A chest roentgenogram and a chest computed tomogram revealed many nodular shadows on both sides. Examinations of specimens obtained by and by transbronchial lung biopsy during fiberoptic bronchoscopy were not diagnostic, and therefore video thoracoscopic lung biopsy was done. The lung lesion was characterized by aggregates of epithelioid cell granulomas, along with granulomatous and necrotizing angitis. We therefore diagnosed necrotizing sarcoid granulomatosis, and began to administer prednisolone. The nodular shadows disappeared within four weeks. In this case video thoracoscopic lung biopsy was useful in the diagnosis of necrotizing sarcoid granulomatosis in the lung.

Adult↗
PubMed1996

A tumor preventive effect of dietary restriction is antagonized by a high housing temperature through deprivation of torpor.

Energy restriction (ER) has proven to be the only effective means of retarding aging in mice. The mechanisms of multiplicity of effects of ER on aging remain, however, fragmentary. ER induces daily torpor, the induction of which is reduced by increasing the ambient temperature to 30 degrees C. The effects of preventing hypothermia in ER animals were studied in terms of the expected consequences of ER on survival, disease pattern and a number of physiological parameters in autoimmune prone MRL/lpr mice and lymphoma prone C57BL, 6 mice. The results demonstrate that torpor plays a crucial role in the prevention of lymphoma development but does not have an affect on other aspects of ER, such as prevention of autoimmune diseases.

Aging↗
PubMed1996

Elevation of serum soluble tumour necrosis factor (TNF) receptor and IL-1 receptor antagonist levels in bronchial asthma.

The specific inhibitor for TNF-alpha activity, soluble form of the 55-kD TNF receptor (sTNF-RI) and soluble form of the 75-kD receptor (sTNF-RII), and the specific inhibitor for IL-1 activity, IL-1 receptor antagonist (IL-1Ra), have been identified. It has been shown that the levels of these inhibitors are elevated in plasma/serum and biological fluids in several diseases, and the protective and inhibitory effect of these inhibitors exist in several inflammatory diseases. In the present study, we measured serum levels of sTNF-RI, STNF-RII and IL-1Ra by ELISA in 36 patients with bronchial asthma (16 atopic and 20 non-atopic) during asthma attacks and in stable conditions in order to assess the state of these inhibitors in allergic inflammation. The levels of sTNF-RI, sTNF-RII and IL-1Ra in sera obtained during bronchial asthma attacks were higher than those in sera obtained in stable conditions. These findings were obtained regardless of atopic status. These results suggest that higher levels of serum sTNF-RI, sTNF-RII and IL-1Ra may reflect up-regulation of TNF-R expression and IL-1Ra production in allergic inflammation, and sTNF-RI, sTNF-RII and IL-1Ra may contribute to regulating TNF-alpha- and IL-1-mediated production and development of allergic inflammation.

Adult↗
PubMed1996

[Effect of prolonged administration of erythromycin on the drug sensitivity and the biological properties of Streptococcus pneumoniae].

From April 1990 to February 1992 two hundred and ten strains of Streptococcus pneumoniae were isolated in the laboratory of Nara Medical University Hospital. Frequency of erythromycin resistant Streptococcus pneumoniae, prescription mode of macrolide antibiotics and biological properties were investigated. 1. Erythromycin resistant Streptococcus pneumoniae was predominantly isolated from the wards of the respiratory unit of Inter- nal Medicine and Pediatrics. 2. Patients with erythromycin resistant Streptococcis pneumoniae were treated with macrolide antibiotics frequently in the respiratory unit of Internal Medicine and Pediatrics. 3. MIC90 of EM, CLDM, MINO and ABPC for Streptococcus pneumoniae was 8.0, 8.0, 8.0 and 1.0 micrograms/ml, respectively, indicating moderate resistance to penicillin derivatives and high resistance to macrolides, particularly EM; some strains showed high levels of MIC over 400 micrograms/ml. 4. Investigations on biological properties using VITEK GPI cards revealed that some erythromycin resistant strains showed less responsiveness to DEX, LAC, PUL and MEL. 5. The survival rate of mice infected with erythromycin resistant strains was longer than that with erythromycin sensitive strains. These findings suggested that the prolonged administration of erythromycin causes a virulence reduction of the organism.

Adult↗
PubMed1996

Developmental expression of proprotein-processing endoprotease furin in rat pancreatic islets.

The expression of furin in pancreatic beta-cells induces faster cell growth and a decrease in differentiated beta-cell-specific characteristics. During the development of rat pancreatic islets, the prohormone convertases, PC2 and PC3, appear during late gestation and are expressed long after birth. We investigated the developmental change in another yeast Kex2 family endoprotease, furin, in rat islets in relation to islet cell growth. Furin had appeared by gestational day 18 and was distributed in islets as well as exocrine tissues. The expression of furin in islets increased toward the neonatal stage. Bromodeoxyuridine (BrdU) incorporation was also elevated in the perinatal period. On postnatal days 10 and 20, staining characteristics were attenuated. On day 25, immediately after weaning, furin staining began to localize in the beta-cell region, and staining in the alpha-cell region became fainter. On day 270, the staining in the alpha-cell region disappeared, and staining in the beta-cell region remained positive, but was weaker. We conclude that furin expression was greatest during the perinatal period, when BrdU incorporation into islets was maximal. Furin expression continued, however, even after the BrdU incorporation decreased. Thus, furin appears to control the proliferation as well as differentiation of islet cells.

Aging↗
PubMed1996

A novel endogenous mouse mammary tumor virus locus in Asian wild mice and its evolutionary divergency.

The divergency of endogenous mouse mammary tumor virus (MMTV) in European mouse strains indicates acquisition of exogenous MMTV into their genomes during evolution. In the present study, we selected two strains of Asian wild mice, Cas-Hmi (Mus musculus castaneus) and Sub-Kjr (M. m. subspecies) to investigate a possible divergency of endogenous MMTVs among Asian mouse strains. Southern blot analysis and polymerase chain reaction (PCR) demonstrated that Cas-Hmi and Sub-Kjr have the full structure of integrated endogenous MMTVs, suggesting that these mice were diverged during evolution after MMTV endemics.

Animals↗
PubMed1996

An endemic condition of biochemical hypoglycemia among male volunteers.

Biochemical hypoglycemia has attracted attention because it triggers accidents through errors in judgment by impairing cognitive function. Its prevalence and associated risk factors have remained unexplored in the area of occupational health. The present study was designed to investigate its epidemiological aspects in male volunteers. The study population of 76 male volunteers, 63 of whom were firefighters and 13 had other jobs, filled out questionnaires by interview covering 37 factors concerning age, physical parameters, past and current health problems, habits (smoking, drinking, and exercise), food preferences and life style. The participants were asked to measure their blood glucose levels 9 times over a representative workday and holiday and record any symptoms of hypoglycemia at the time of measurement. The body fat ratio of each participant was measured by the bioelectrical impedance analysis method. 22.4% of the participants (17/76) experienced biochemical hypoglycemia (less than 60 mg/dl) at the time of blood glucose monitoring. Those who experienced biochemical hypoglycemia had significantly lower peak, average and nadir blood glucose levels (p < 0.05; 115.1 +/- 18.7 mg/dl, 82.2 +/- 7.0 mg/dl, 52.2 +/- 5.6 mg/dl, respectively) than those who did not (129.9 +/- 26.7 mg/dl, 97.0 +/- 9.9 mg/dl, 75.9 +/- 9.7 mg/dl, respectively). No symptom other than sudden hunger (p < 0.05) was correlated with biochemical hypoglycemia. Lower lean body mass index (lean body mass/height2) was the only statistically significant contributory risk factor (p < 0.05, Odds ratio: 2.91, 95% confidence interval 1.29-6.65) by multiple logistic analysis. Mean blood glucose levels had a positive correlation with lean body mass index (P < 0.0001, r2 = 0.372). The present results suggest that biochemical hypoglycemia is a potential risk problem in occupational settings. Low L.B.M.I. males should be educated about the possibility of biochemical hypoglycemia whoever have experienced a feeling of sudden hunger. Such precautions should be highly recommended to workers under dangerous and/or tense conditions in order to prevent error accidents in occupational settings.

Adult↗
PubMed1996

Epidemiological study on hypoglycemia endemic to female nurses and other workers.

Hypoglycemia has been reported to occur frequently among individuals with health-related occupations, especially hospital nurses. In this study, we investigated the risk factors of hypoglycemia. Both female hospital nurses and other female workers participated in this study, which included questionnaires, and daily blood glucose monitoring. Responses from 3,415 workers were included for analysis. 2,489 workers reported that they had never had hypoglycemic episodes (symptom-free group), while 926 workers reported that they had experienced hypoglycemic symptoms more than once. Of these workers, 207 had had episodes within one year of the study and had experienced them more than once a month (symptomatic group). Thirty-one volunteers were recruited from the above two groups-21 from the latter group and 10 from the former group-and daily blood glucose levels were determined: 6 days for nurses to cover three shifts (dayshift, nightshift and midnightshift) and 2 days for other workers. Nine of 21 volunteers from the symptomatic group had biochemical hypoglycemic reading(s) (< 60 mg/dl) during the monitoring; however, none of 10 volunteers from the symptom-free group had such readings. These nine volunteers were found to have lower mean blood glucose levels (p < 0.05) and lower minimum blood glucose levels (p < 0.05) than other volunteers. Simple logistic analyses revealed multiple risk factors in the symptomatic group. By adjusting the confounding effects, these multiple risk factors were reduced into a small number of risk factors: occupation as a nurse, histories of hypotension and glucosuria, eating snacks, eating deserts, and insomnia. The present report clearly demonstrated that there are hypoglycemic-prone individuals among symptomatic female workers, who were shown to have multiple risk factors for hypoglycemic symptoms.

Adult↗
PubMed1996

[Swyer-James syndrome with bronchial asthma and recurrent spontaneous pneumothorax].

An 18-year-old woman was admitted to our hospital for treatment of the fifth episode of spontaneous pneumothorax. She had a history of repeated pneumonia in childhood and mycoplasma pneumonia at 12 years of age. A chest X-ray film revealed a left-sided pneumothorax, atelectasis of the left upper lobe, and hyperlucency of the left lung. A bronchogram showed poor filling of the peripheral bronchi by contrast medium and mild cylindrical bronchiectasis in the proximal bronchi. Pulmonary arteriography showed small left pulmonary arteries. From these findings, Swyer-James syndrome was diagnosed. This case was complicated by bronchial asthma, with eosinophilia, a high level of IgE, and airway hyperresponsiveness. Atelectasis, multiple bullae, and bronchial asthma had been caused by mycoplasma pneumonia in childhood. Recurrent pneumothorax had been caused by emphysematous changes in the bronchioli and by underdeveloped pulmonary arteries. Surgery to treat the recurrent spontaneous pneumothorax was considered, but was not done because of the risk of relapse and the ventilation-perfusion imbalance due to the Swyer-James syndrome.

Adolescent↗
PubMed1996

[Suppression of experimental autoimmune uveitis by energy restriction].

The effects of energy restriction on experimental autoimmune uveitis (EAU) were investigated. Seven-week-old, male Lewis rats were divided into three groups. Experiment A) A control group was fed ad libitum, a second group was given 50% calorie restricted food from the day of immunization, and a third group was given 50% calorie restricted food from 2 weeks before immunization. Experiment B) A control group was fed ad libitum, a second group was given 25% calorie restricted food from 4 weeks before immunization, and a third group was given 50% calorie restricted food 4 weeks before immunization. All rats were immunized with interphotoreceptor retinoid-binding protein (IRBP). In experiment A), in the group given 50% calorie restricted food from 2 weeks before immunization, and in experiment B), in the group given 50% calorie restricted food from 4 weeks before immunization, the onset of EAU was significantly delayed, the clinical symptoms were lessened, and delayed hypersensitivity against IRBP was suppressed. Clinically and histologically, the severity was also low. In the group given 50% calorie restricted food from 4 weeks before immunization, the titer of anti-IRBP antibody was also significantly lower than in the control group.

Animals↗