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Biomedical subjects

R Nakamura

Publications and source records attributed to R Nakamura.

At least 253 records · Page 14Linked to original sources
PubMed1991

Serological studies of Porphyromonas (Bacteroides) gingivalis and correlation with enzyme activity.

Porphyromonas gingivalis from the human oral cavity was serologically characterized using absorbed and unabsorbed rabbit antisera. The reference strains were ATCC 33277, W50, W83, 381 and hara 1. The 432 isolates were from periodontal pockets of 63 patients with adult periodontitis. Using sonicated antigens, four serotypes were identified by immunodiffusion tests and immunoelectrophoresis. Each patient harbored only one serotype of P. gingivalis, and serotypes I and IV predominated. The incidence of serotype I was four times higher than that of serotype II, and approximately seven times higher than that of serotype III. The collagenolytic and some proteolytic enzymes of representatives of each serotype were assessed. Although all strains produced these enzymes to some degree, some differences in their levels were observed. Serotype II strains were more collagenolytic than serotypes I or III, and serotype III exhibited lower activities of N-CBz-glycyl-glycyl-arginyl peptidase than other serotypes. Antibiotic sensitivity was also compared with antimicrobial disks, and serotype IV strains exhibited high sensitivity to the four antibiotics used.

Anti-Bacterial Agents↗
PubMed1991

Purification and characterization of three types of proteases from culture supernatants of Porphyromonas gingivalis.

Three types of caseinolytic proteases (Pase-A, Pase-B, and Pase-C) were isolated and purified from culture supernatants of Porphyromonas gingivalis 381 by the combined procedures of acetone precipitation, gel filtration, solubilization with octylthioglucoside followed by affinity chromatography on arginine-Sepharose 4B, high-performance liquid chromatography (HPLC) on Biofine IEC-DEAE, and HPLC on TSK-G4000SW. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Pase-A and -B showed diffuse protein bands of 105 to 110 and 72 to 80 kDa, respectively, and Pase-C showed a clear band of about 44 kDa. Pase-B and -C hydrolyzed some synthetic substrates for trypsin, but Pase-B did not act on the carboxyl side of lysine in insulin chain B or on a synthetic substrate which trypsin and Pase-C acted on. Pase-A did not act on the synthetic substrates but cleaved the peptide bonds Glu-Ala and Ala-Leu of insulin. Leupeptin inhibition of the caseinolytic activity of both Pase-A and -B was similar to its inhibition of Pase-C. Phenylmethylsulfonyl fluoride and diisopropyl fluorophosphate strongly inhibited Pase-A, but no significant effect on the other enzymes was observed, suggesting that only Pase-A is a serine protease. The inhibitory characteristics of Pase-B and -C were very similar. Pase-A was not thiol dependent for enzyme activity, but Pase-B was strongly dependent, i.e., even more so than Pase-C. Pase-A inactivated the inhibitory activity of plasma alpha-1-antitrypsin, but the other two did not. These results show that P. gingivalis produces different types of proteases other than the trypsinlike protease generally reported.

Amino Acid Sequence↗
PubMed1991

Experimental lethal infection of Leptospira interrogans in mice treated with cyclophosphamide.

After preadministration of cyclophosphamide (300 mg/kg), BALB/c mice were lethally infected with Leptospira interrogans serovar lai and a virulent strain of Leptospira interrogans serovar copenhageni, and leptospiral cells were detected in both kidneys of infected mice by indirect immunofluorescent assay. Nonpathogenic leptospirae, Leptospira biflexa serovar patoc, Leptonema illini, and an avirulent strain of L. interrogans serovar copenhageni, were not parasitic to the mice treated with cyclophosphamide. The cyclophosphamide-treated mice were protected from the homologous leptospiral infection by passive immunization with anti-leptospiral monoclonal antibody or with rabbit antiserum and by active immunization with lyophilized organisms or with protective antigen. The results of active immunization in mice treated with cyclophosphamide agreed well with those in nontreated hamsters, which were sensitive to the organisms. Furthermore, these experiments were reproducible with any lot of cyclophosphamide used. These results indicated that cyclophosphamide-treated mice can be used in the experimental infection of Leptospira in place of hamsters or guinea pigs.

Animals↗
PubMed1991

Initial pathophysiological changes in chronic pancreatitis induced by pancreatic ductular obstruction model.

An experimental chronic pancreatitis model was made in five dogs with chronic pancreatic fistula by injection of microspheres into the peripheral pancreatic duct. Sequential changes of pancreatic exocrine and endocrine functions with morphology were studied. Significant decreases in volume bicarbonate output and amylase output were detected in each sample collected separately on secretin and secretin cerulean stimulation. While the viscosity of pancreatic juice was significantly increased with a concomitant increase in hexosamine concentration, chronic pancreatitis was demonstrated morphologically. These results suggest that concentrated pancreatic juice caused by a decrease in volume and an increase in viscosity of pancreatic juice with a concomitant increase in hexosamine concentration brings about the progression of chronic pancreatitis in this experimental model.

Amylases↗
PubMed1991

[Autologous blood transfusion aided with erythropoietin in transurethral resection of the prostate].

Erythropoietin (EPO) with an established clinical efficacy in renal anemia has in recent years become applied as an aid to autologous blood transfusion in surgical patients. This report describes our experience with autotransfusion along with the use of EPO in transurethral resection of the prostate (TUR-P), indicating its usefulness. Ten patients with benign prostatic hypertrophy aged 60 to 74 years received 3000 units of EPO, with an iron preparation, nine times beginning 3 weeks prior to operation. Autologous blood of 300 ml was collected from the patient each at 2 and 1 week before operation and was used at TUR-P. Five other patients who underwent TUR-P with the same volume of autotransfusion accompanied by preparative medication with the iron alone served as controls. In the EPO treated group (mean age, 68.3 years) the mean value for hemoglobin concentration (Hb) was 14.0 +/- 1.6 g/dl on the day of operation, which showed a recovery rate of 94.9 +/- 5.4% (Hb recovery rate) as against the pre-EPO treatment value (mean: 14.8 +/- 1.3 g/dl). This Hb recovery rate was significantly greater (p less than 0.001) when compared to 82.2 +/- 2.5% in the control group (mean age, 68.2 years). Of the EPO treated patients, those in their sixties (n = 6; mean age, 66.3 years) exhibited a significantly higher Hb recovery rate (98.3 +/- 3.5%) than the rate (89.9 +/- 3.0%) for patients in their seventies (N = 4; mean age, 71.3 years) (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Transfusion, Autologous↗
PubMed1991

[Clinical studies of bacteriuria in renal transplantation recipients. Correlation with pyuria and symptomatic genitourinary tract infection].

The clinical state of bacteriuria and its correlation with pyuria and symptomatic genitourinary tract infection (GUTI) were studied in 42 renal transplantation recipients who were followed up in the Kidney Center of Tokyo Women's Medical College over 6 months and who showed bacteriuria more than 3 times between January and December in 1987. The results were as follows. 1) Of the 42 recipients, bacteriuria was found less than 5 times in 19 patients, 6 to 10 times in 18 patients and more than 11 times in 5 patients. There was a tendency for the same bacteria to be isolated several times from the same patient. The most commonly isolated bacterias were Enterobacter, Enterococcus, Serratia and E. coli. 2) Bacteriuria was accompanied by pyuria in 33 patients (79%) and by symptomatic GUTI in 12 patients (29%). Bacteriuria without pyuria was shown in 9 patients (21%) without symptomatic GUTI and it was suggested that bacteriuria did not result in graft hypofunction after two years. 3) Of 16 patients with bacteriuria accompanied by pyuria, symptomatic GUTI occurred in 9 patients (56%). Of these, one patient was found to have VUR of the transplanted kidney, another was found to have VUR of the native kidney, and a third patient died due to interstitial pneumonitis presumably as a result of overimmunosuppression. Transplantation recipients with bacteriuria accompanied by pyuria develop symptomatic GUTIs frequently and should be treated with proper antibacterial agents. When bacteriuria continues, further examination should be performed for an organic disease of the urinary tract or an overimmunosuppressed state. When a patient shows bacteriuria without pyuria, chemotherapy is not needed and it is sufficient to observe the course carefully.

Adult↗
PubMed1991

[Prediction of severity of coronary artery disease by treadmill exercise testing].

Coronary angiography was performed in 250 patients with a significant ischemic ST segment change detected by symptom-limited maximum treadmill exercise testing, and relationship between anatomical severity of coronary artery disease and parameters in exercise testing was studied. The age of the patients ranged from 34 to 76 years (188 men, 62 women). One-vessel disease (1VD) was presented in 82 patients, two-vessel disease (2VD) in 42, three-vessel disease or left main coronary disease (3VD) in 26, and no significant stenosis was presented in 100 subjects (Normal). Functional aerobic impairement (FAI) was evaluated in each group as a parameter of exercise capacity, myocardial aerobic impairment (MAI) and heart rate impairment (HRI) were also evaluated as a parameter of maximum myocardial oxygen requirements and maximum heart rate, respectively. Using these parameters, discriminant analysis was performed to compare the group with significant coronary artery disease and the Normal group. Also, to compare the group with multi-vessel disease and the group with less than 2VD. Also, the 3VD group and the group with less than 3VD. FAI, MAI and HRI were significantly different (p less than 0.0001) in each group. The discriminant formula to separate the group of significant coronary artery disease from the Normal group was Z = -1.049 + 0.02 [FAI] +0.08 [MAI] +0.03 [HRI]. According to this formula, sensitivity was 92.5% and specificity was 71.5%. The discriminant formula to separate the group with multi-vessel disease from the group with less than 2VD was Z = -4.731 + 0.07 [FAI] +0.106 [MAI] +0.02 [HRI]. According to this formula, sensitivity was 96.3% and specificity was 78.8%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[A case of whole visual field visuomotor ataxia of bilateral hands associated with bilateral parietooccipital lesions in the white matter].

A 29-year-old male with visuomotor ataxia was reported. Visuomotor ataxia of bilateral upper extremities was noted in whole visual field including central visual field (optische Ataxie). Neither contraction nor depression of visual field was detected by the test using kinetic or static perimeter, respectively. Magnetic resonance imaging and computed tomography of the brain revealed bilateral parietooccipital lesions in the white matter, and pathological examination of brain biopsy specimen demonstrated demyelination. We considered that bilateral parietooccipital lesions in the white matter were responsible for visuomotor ataxia in this case.

Adult↗
PubMed1991

[The involvement of rice protein 16KD in cross-allergenicity between antigens in rice, wheat, corn, Japanese millet, Italian millet].

Cross-reactivity between rice, wheat, corn, Japanese millet and Italian millet in Poaceae family were studied by absorption test, radioallergosorbent test (RAST), and RAST inhibition assay. In absorption test using Phadebas RAST discs, more than 50% absorption of IgE antibodies was observed between rice, wheat and corn. There were significant correlations of RAST values for cereal grains including rice, wheat, corn, Japanese millet and Italian millet. RAST inhibition assay between every combinations of these cereals showed dose-dependent decrease in IgE-binding. These data indicated cross-reactivity with IgE antibodies between the five cereals in Poaceae family. RAST values for RP16KD significantly correlated with those for Italian millet as well as rice but not with those for corn and wheat. There was a trend of positive correlation between RAST values for RP16KD and Japanese millet. In RAST inhibition assay using sera with positive RAST for these five cereal grains and RP16KD, RP16KD inhibited IgE-binding to these all cereal discs in dose-dependent manner. Similarly, all of five cereal grain extracts showed an effective diminution in IgE-binding to RP16KD disc. These results indicated possible participation of IgE-binding structure on RP16KD in cross-reactivity between these cereal grains in Poaceae family.

Adolescent↗
PubMed1991

Radial wedge osteotomy for Kienböck disease.

A radial wedge osteotomy, with reduction of the inclination angle of the distal part of the radius, was performed in twenty-seven patients who had Kienböck disease. After two to five years of follow-up, all of the patients were free of pain or had only mild pain in the wrist with strenuous activity. Flexion-extension of the wrist improved by more than 10 degrees in about half of the patients, and in most of the patients the grip strength increased by five kilograms or more. All but two of the postoperative results were satisfactory, as evaluated by the criteria of Lichtman et al. The osteotomy was effective even in patients who had zero or positive ulnar variance.

Adolescent↗
PubMed1991

Sclerotherapy of bleeding esophageal varices using a thrombogenic cocktail.

The short- and long-term efficacy of a thrombogenic sclerosant (1% tetradecyl sulfate, thrombin, and cefazolin) was studied in 101 patients. The majority of patients had alcoholic cirrhosis with Child's C classification (84/101). Bleeding was controlled in 94 per cent of patients with the first sclerotherapy. In-hospital and early (within 6 weeks) mortality were 14 per cent and 19 per cent, respectively. There was a strong correlation with hospital mortality and the severity of hepatic disease. Long-term follow-up in 70 patients (mean of 16 months) showed that survival correlated with compliance to follow-up sclerotherapy and abstention from further alcohol intake. Mortality in patients compliant with follow-up was 5 per cent (1/19), as compared with 24 per cent (12/51) in patients who were not compliant with follow-up sclerotherapy. The mortality in alcoholic cirrhotic patients who abstained from further alcoholic intake was 6 per cent (1/17), as compared with 23 per cent (10/44) in those who continued to abuse alcohol. No systemic thrombotic or allergic events related to the use of bovine thrombin were noted during a total of 349 sclerotherapy sessions.

Adolescent↗
PubMed1990

Rat pancreastatin inhibits both pancreatic exocrine and endocrine secretions in rats.

Effects of synthetic rat pancreastatin C-terminal fragment on both exocrine and endocrine pancreatic functions were examined in rats, in vivo and in vitro. Pancreastatin (20, 100 pmol, 1 nmol/kg/h) significantly inhibited CCK-8-stimulated pancreatic juice flow and protein output in a dose-related manner, in vivo. The inhibitory effect on bicarbonate output was not statistically significant. Pancreastatin did not significantly inhibit basal pancreatic secretions in vivo, and did not inhibit amylase release from the dispersed acini, in vitro. Insulin release stimulated by intragastric administration of glucose (5 g/kg) was significantly inhibited by pancreastatin (1 nmol/kg/h), in vivo. Plasma glucose concentrations were increased by pancreastatin infusion, but the increase was not statistically significant. Furthermore, pancreastatin inhibited insulin release from isolated islets, in vitro. Synthetic rat C-terminal pancreastatin fragment has bioactivities on both exocrine and endocrine pancreatic functions in rats.

Amylases↗
PubMed1990

Luminal bile regulates cholecystokinin release in conscious rats.

The effects of intraluminal bile on cholecystokinin release and pancreatic exocrine secretion were studied in conscious rats. Since it has been suggested that bile acid may influence pancreatic secretion indirectly by interacting with luminal protease activities, intraduodenal protease activities were eliminated by pancreatic juice diversion accompanied with simultaneous intraduodenal infusion of aprotinin. This treatment resulted in gradual increases in pancreatic juice flow, bicarbonate and protein outputs, and an increase in plasma cholecystokinin levels, reaching plateau levels 2 hr after the start of the treatment. When endogenous bile was excluded from the intestine, the pancreatic secretion and plasma cholecystokinin concentrations further increased. The intraduodenal infusion of sodium taurocholate during bile pancreatic juice diversion inhibited cholecystokinin release, while pancreatic protein output was only transiently decreased. The results indicate that bile in the duodenum directly regulates cholecystokinin release, probably through its major components, bile salts.

Animals↗
PubMed1990

Treatment of trans-scaphoid perilunate dislocations by internal fixation with the Herbert screw.

Thirteen patients with 14 dorsal trans-scaphoid perilunate dislocations were treated by open reduction and internal fixation of the scaphoid using a Herbert screw. The follow-up evaluations took place after a mean of 18 months. These perilunate dislocations were only trans-scaphoid in ten wrists, trans-radial styloid and trans-scaphoid in three and trans-scaphoid and trans-capitate in one. Based on Cooney's clinical scoring system, the scores of our series were two excellent, six good, five fair and one poor. This suggests that the Herbert screw can offer satisfactory results in the management of trans-scaphoid perilunate dislocations, despite its technical difficulties.

Adult↗
PubMed1990

Radial shortening for Kienböck's disease: factors affecting the operative result.

The operative results of radial shortening in 23 patients with Kienböck's disease were analysed on the basis of age, stage of disease, ulnar variance and the amount of radial shortening. The patient's age was found to be the factor which affected the operative result most and unsatisfactory results were obtained in patients over 30 years old. However, neither the clinical stage nor ulnar variance affected the results significantly and the results in patients with ulnar zero or plus were no worse than in patients with ulnar minus. The risk of ulnar wrist pain was increased when the radius was shortened more than 4 mm in patients with positive or zero ulnar variance. This was an important cause of unsatisfactory operative results.

Adolescent↗
PubMed1990

Excessive radial shortening in Kienböck's disease.

Two patients with Kienböck's disease who had been treated by radial shortening developed ulnar wrist pain post-operatively due to excessive radial shortening. In both cases, ulnar shortening was required to improve symptoms and function. Excessive radial shortening can cause ulnar wrist pain and compromise the improvement of grip strength and range of motion of the wrist.

Adult↗