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Biomedical subjects

K Okuda

Publications and source records attributed to K Okuda.

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

Effects of cardiac sympathetic nervous system on the stunned myocardium experimental study with 123I-metaiodobenzylguanidine.

123I-Metaiodobenzylguanidine (123I-MIBG) uptake in the stunned myocardium was investigated in open chest dogs. 123I-MIBG is a tracer taken up in presynaptic adrenergic vesicles and reflects the function of the myocardial sympathetic nervous system. This study revealed that in the stunned myocardium without infarct, 123I-MIBG uptake was normal up to 40 minutes of ischemia and that exogenous noradrenaline improved deteriorated regional wall motion with increased uptake of 123I-MIBG. However, uptake of 123I-MIBG per flow decreased with infarct in ischemic areas, and it showed a linear relation with regional wall motion. Thus, in the absence of infarction 123I-MIBG is a tracer to differentiate stunning from more severe ischemia with persistent wall motion abnormality. Normal uptake and storage of 123I-MIBG in the stunned condition suggests that catecholamine release or second effector mechanism may relate to the mechanism.

3-Iodobenzylguanidine↗
PubMed1991

delta 4-3-Oxosteroid 5 beta-reductase. Structure and function.

delta 4-3-Oxosteroid 5 beta-reductase catalysing reduction of delta 4-3-oxosteroids to give A/B cis-conformation was intraperitoneally injected into BALB/c strain mice with Ribi adjuvant. Monoclonal antibody specific for this enzyme was prepared from their spleen cells. Using this monoclonal antibody as a probe the enzyme was further purified using reversed phase liquid chromatography to determine amino-acid sequence protein-chemically. Attempts to determine the N-terminal amino acid failed, indicating that the N-terminal amino acid is blocked. The protein was therefore subjected to digestion with lysyl endopeptidase after alkylating with iodoacetate. The peptides thus formed were isolated and purified by reversed-phase high-performance liquid chromatography and their amino-acid sequences were determined. Using antibodies and oligonucleotides as probes a cDNA which contained a 978 bp long open reading frame encoding 326 amino-acid residues (Mr 37376) was isolated from rat liver cDNA libraries and the entire sequence of the protein was deciphered from its nucleotide sequence. The COS cells transfected with this cDNA revealed a versatile activity to reduce varied kinds of delta 4-3-oxosteroids, i.e. 7 alpha-hydroxy-4-cholesten-3-one, androstenedione and cortisone as postulated by Okuda and Okuda (1984, J. Biol. Chem. 259, 7519-7524) and Furuebisu et al. (1987, Biochim. Biophys. Acta 912, 110-114. With a newly established immunoblotting assay method several tissues and organs were surveyed and it was found that the enzyme exists only in the liver and there is an apparent difference between sexes as to the content of this enzyme. However, there was little if any difference in the amount of mRNAs between both sexes, which may indicates that the sexual difference of rat liver cytosol 5 beta-reductase is due to a posttranslational modification and/or degradation.

Amino Acid Sequence↗
PubMed1991

Penetration in vitro of bovine oocytes during maturation by frozen-thawed spermatozoa.

Bovine immature oocytes cultured for various times in TC-199 medium were inseminated with frozen-thawed spermatozoa in Medium BO with caffeine (5 mM) and heparin (10 micrograms/ml). Very high penetration rates (95-100%) were obtained in all oocytes which had been cultured for 0-20 h. When oocytes cultured for 0 and 4 h were inseminated, 100% of them were penetrated and had a decondensing sperm head and most of the oocytes remained at the stage of condensed germinal vesicle (GV) to telophase-I 20-22 h after insemination. The formation of male and female pronuclei was first observed in oocytes inseminated 8 h after culture. The proportions of polyspermy and average number of spermatozoa in penetrated oocytes gradually decreased as oocyte maturation proceeded. Penetration of at least one spermatozoon with a decondensing head into oocytes at the GV stage (without culture) was almost completed up to 8 h after insemination and at that time most of the penetrated oocytes were still at the stage of GV or condensed GV. These results indicate that maturation of bovine oocytes is not required for sperm penetration into the vitellus or for sperm nuclear decondensation under the in-vitro conditions used.

Animals↗
PubMed1991

In-vitro penetration of pig oocytes matured in culture by frozen-thawed ejaculated spermatozoa.

Pig oocytes matured in culture were inseminated with frozen-thawed ejaculated spermatozoa without preincubation in modified tissue culture medium (TCM) 199. High penetration rates (85-89%) and increased incidence of polyspermy were obtained at 25-100 x 10(6) spermatozoa/ml. Wide variation in penetration rates (16-89%) was observed in oocytes inseminated in medium containing 5mM caffeine and at 25-50 x 10(6) spermatozoa/ml obtained from 6 boars, regardless of sperm motility. At 25-50 x 10(6) spermatozoa/ml, penetration rates of oocytes were dependent upon the concentration of caffeine in the medium: there was no penetration without caffeine, but penetration was highest (89%) with 5mM caffeine. None of the oocytes was penetrated in the medium supplemented with heparin at 5-40 micrograms/ml. When heparin was included in the medium with 5mM caffeine, it inhibited the efficacy of caffeine to promote sperm penetration of oocytes.

Animals↗
PubMed1991

Duplex pulsed Doppler sonography of portal vein thrombosis in hepatocellular carcinoma.

Sixteen patients with hepatocellular carcinoma had duplex pulsed Doppler scanning of the portal thrombus and comparative angiography. Fifteen patients demonstrated detectable Doppler signals from the thrombus. The Doppler signals were corroborated by the "thread-and-streaks" sign on angiography in eight patients. This suggests that signals come from tumor vessels within the thrombus. Therefore, the presence of Doppler signals in the thrombotic portal venous system is not only due to partial obstruction of the lumen. Tumor thrombus from hepatocellular carcinoma must be considered, especially when the detectable signals are pulsatile waves.

Adult↗
PubMed1991

[Comparison of two hours' biofiltration and four hours' bicarbonate hemodialysis by multiple clinical parameters].

Ten uremic patients maintained stable on regular dialysis treatment participated in a comparison study of 2 hours' biofiltration and 4 hours' bicarbonate hemodialysis with informed consents. In biofiltration, ultrafiltrate was replaced by a solution consisting of Na 145 mEq/l, HCO3- 100 and Cl 45 at the infusion rate 2.51/hour. Dialysate composition was Na 130-149 mEq/l, K 1.0, Cl 119, Ca 2.5, Mg 0.5, CH3COO- 15 and glucose 200 mg/dl. Hemodiafilter was F80, polysulphone, 1.9 m2, manufactured by Fresenius Co. Ltd. Blood flow rate was 5 ml/min/kg.body.weight to keep urea index (Kt/V) over 1.0. B-A-B' comparison was designed in which B and B' stand for 4 hours' bicarbonate hemodialysis while A for 2 hours' biofiltration, 3 times per week for 2 months, respectively. It was intended to find out if there are aggravations of clinical parameters in A after B and/or improvements in B' after A in view of evaluation of optimum for 2 hours' biofiltration. One patient was withdrawn from biofiltration at 15th treatment in A because of frequent muscular twitchings. Others finished the whole program, thus making drop-out rate 10%. No significant differences were observed in the following parameters between B and A and between A and B': cardiothoratic ratio, pre-treatment blood pressure, human atrial natriuretic hormone, cardiovascular dynamics, total protein, BUN, serum creatinine, uric acid, beta 2 microglobulin, blood counts, blood gas analysis, electrolytes, alkaline-phosphatase, PTH-C, protein catabolic rate (PCR), lipids and liver functions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

The inhibitory effect of plant extracts on the collagenolytic activity and cytotoxicity of human gingival fibroblasts by Porphyromonas gingivalis crude enzyme.

It is well known that plant extracts inhibit some enzymatic activities. The present study examined the inhibitory effects of natural plant extracts against the collagenolytic activity of Porphyromonas gingivalis. The enzyme was isolated from a culture supernatant of P. gingivalis 381. The aqueous and 50% ethanolic extracts of Ginkgo biloba, Mosla chinensis, Salvia officinalis, Cinnamomum cassia, and a catechin extract of Camellia sinensis exhibited strong inhibitory effects on collagenolytic activity. The activities of these plant extracts were higher than that of tetracycline-HCl. They also inhibited the cytotoxicity of P. gingivalis crude enzyme against human gingival fibroblasts. C. sinensis catechin was the most effective agent in neutralizing the cytotoxicity of P. gingivalis. The aqueous and 50% ethanolic extracts of C. cassia had relatively strong anti-cytotoxic activity. Although the other samples strongly inhibited the collagenolytic activity of P. gingivalis, they were not effectively anti-cytotoxic. The present findings suggest that C. sinensis and C. cassia extracts are effective in reducing the pathogenicity of periodontopathic bacteria.

Catechin↗
PubMed1991

Stroke-cirrhosis relationship: an autopsy study in a heavy drinking population.

A positive association between alcohol consumption and stroke incidence has been clearly established. The present study evaluated the frequency of stroke in a sample of 500 autopsied patients affected by liver cirrhosis mainly due to chronic alcohol abuse as confirmed by the histologic pattern mostly of mixed and micronodular types. Frequency of stroke was compared to that of 4,741 non-cirrhotic patients autopsied in the same period. Our findings demonstrate that stroke frequency, especially when due to thromboembolism, decreased significantly in cirrhotics. Therefore, hepatopathy is a crucial event in alcoholic patients. Nevertheless the concomitant presence of liver cirrhosis, in studies dealing with this subject, is not being currently evaluated.

Age Factors↗
PubMed1991

[Predictive factors of etiologic agents of community-acquired pneumonia presenting at a district general hospital].

Community-acquired pneumonia is one of the major respiratory diseases causing hospital admission in previously healthy patients. Prompt and appropriate antibiotic selection is essential for recovery. The authors tried to determine the distribution of the etiologic agents of community-acquired pneumonias and to analyze predictive factors. Out of 188 cases of community-acquired pneumonia presenting to our hospital, etiologic agents were determined in 106 cases (56%). Twenty-nine cases were due to Streptococcus pneumoniae, 27 cases due to Mycoplasma, 17 cases due to Haemophilus influenzae and 21 cases due to Mycobacterium tuberculosis. M. tuberculosis was the cause in 11% of all cases and the importance of pulmonary tuberculosis must be emphasized as a community-acquired pneumonia. Out of 58 cases under 50 years old, Mycoplasma pneumoniae was the etiologic agent in 23 cases (40%) and S. pneumoniae in 7 cases (12%). Out of 62 cases not less than 70 years old. M. tuberculosis was the most common etiologic agent (15 cases, 24%). S. pneumoniae followed, being causative in 13 cases (21%). M. tuberculosis was the cause in 10 cases out of 31 cases who did not complain of fever at presentation. In 86 cases who did not show leukocytosis on admission, 21 cases were due to Mycoplasma (24%) and 15 cases were due to M. tuberculosis (17%). In particular 17 cases were due to Mycoplasma among 28 cases under 50 years old without leukocytosis (61%), and 11 cases were due to M. tuberculosis in the 27 cases no less than 70 years old without leukocytosis (41%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Subgingival microflora in children of early childhood, school age and circumpuberty. The proportion and frequency of gram-negative bacteria in periodontally healthy and gingivitis groups].

The present study characterized the microbial profiles of the gingival sulci in children. Subgingival samples from 36 gingivitis lesions of 18 patients and 36 sites in 18 healthy persons were examined. The tested individuals were divided into three stages according to physiological maturation i.e. early childhood, school age, circumpuberty. Puberty was confirmed through examination of wrist radiographs. Using continuous anaerobic techniques, samples were dispersed, diluted and then inoculated on selective and nonselective media and cultured under the condition appropriate gaseous phase respectively. Isolates were identified microbiologically and counted. All values were evaluated statistically. The samples were simultaneously examined by dark-field microscopy. Changes in the proportions and the frequency of periodontophathic bacteria were distinct in different stages of physiological maturation. Black-pigmented Bacteroides species were commonly found in gingivitis lesions. Bacteroides intermedius was frequently detected in the subgingival samples from children with gingivitis. In all stages, the proportion of black-pigmented Bacteroides and B. intermedius in the gingivitis groups were found to be significantly higher than that of the healthy groups. Statistical analysis revealed that levels of B. intermedius increased in circumpuberty stage compared with the 2 younger stages. Black-pigmented Bacteroides and B. intermedius were closely related to GI, PlI in 3 stages. Bacteroides gingivalis was found only in two gingivitis sites of a circumpubertal child with gingivitis. Actinobacillus actinomycetemcomitans was detected in 4 out of 12 sites in the school age group, and in 6 out of 12 sites in the circumpuberty group with gingivitis respectively. In the circumpuberty group, the proportion of A. actinomycetemcomitans in the gingivitis group was significantly higher than that of the healthy group, and A. actinomycetemcomitans was closely related to GI, PlI, CI, PPD. Eikenella corrodens was found to be associated with gingivitis in the school age and circumpuberty groups. No correlation was found in the detection of Fusobacterium nucleatum in 3 stages. Microscopic examination showed that the proportion of rods, fusiforms, filaments, motile rods, spirochetes in the gingivitis groups was significantly higher than that of the healthy groups, while the proportion of cocci in gingivitis groups was significantly lower than that of the healthy groups in 3 stages. Spirochetes were closely related to GI, PlI, PPD in all stages.

Adolescent↗
PubMed1991

A heat stable hemagglutinating activity of Eikenella corrodens.

Strains of Eikenella corrodens and Fusobacterium nucleatum were shown to possess lectinlike attachment factors. The present investigators found that E. corrodens has a heat stable factor which agglutinates sheep, mouse, and human erythrocytes. The activity is not abolished by additions of galactose or lactose. Lipopolysaccharide preparations from E. corrodens strains possessed strong hemagglutinating activity. LPSs of F. nucleatum did not agglutinate any erythrocytes tested. SDS-PAGE patterns stained with silver stain revealed that the LPSs of E. corrodens strains were rough type and those of F. nucleatum were wild type. The heat stable hemagglutinating activity of E. corrodens strains might be caused the rough type LPS of the cells.

Bacterial Adhesion↗
PubMed1991

Clinical and microbiological study of local minocycline delivery (Periocline) following scaling and root planing in recurrent periodontal pockets.

This study was designed to evaluate the clinical and microbiological effects of local administration of 2% minocycline-HCl ointment (Periocline) combined with scaling and root planing in recurrent periodontal pockets. Thirty-three sites were selected for this examination. The sites had probing depths greater than 5 mm and loss of attachment greater than 2 mm within the previous 3 months. They were assigned as test (22 sites) or control sites (11 sites). After meticulous scaling (SC) and root planing (RP), Periocline was delivered into the periodontal pockets of test sites: control sites were irrigated with biological saline following SC/RP. Administration of Periocline or irrigation with saline was performed once a week for 4 consecutive weeks. The effects on clinical conditions including probing pocket depth, clinical attachment level, and bleeding on probing were evaluated at baseline, 2, 4, 8, and 12 weeks. Microbiological examinations consisting of darkfield microscopic study and culture were performed at baseline, 4, and 12 weeks. Clinical conditions improved in both groups following treatment; significantly better improvements were obtained in the test group. Microbiological study revealed that Periocline effectively eliminated periodontopathic gram-negative bacteria. These results indicated that a combination of SC/RP with local administration of 2% minocycline for recurrent periodontal pockets brought about more satisfactory results than conventional SC/RP.

Administration, Topical↗
PubMed1991

Isolation and classification of anaerobic bacteria from pulp cavities of nonvital teeth in man.

The anaerobic microflora of infected pulp cavities and chronic periapical abscesses was studied. A total of 19 infected nonvital teeth were subjected to this study. The coronal surface was swabbed with 70% ethanol to remove debris and to disinfect. Material in root canal chamber was obtained by sterilized paper points and suspended in reduced transport fluid. The samples were dispersed, diluted, and inoculated on blood agar plates. Isolates were identified by colony characteristics and cellular morphology, fermentation, indole production, nitrate reduction, gelatin digestion, urease production, ability to grow aerobically, API 20A System, and API ZYM System. Anaerobic bacteria were found in 14 pulp cavities. Anaerobic gram-negative rods, Actinomyces species, and Propionibacterium species were predominant in the root canals. Mixed infection with anaerobes and facultative anaerobes were demonstrated in most of the pulpal cavities of nonvital teeth.

Bacteria, Anaerobic↗
PubMed1991

[Adult T-cell leukemia with CD3 (-), CD4 (-) and CD8 (-)].

A case of an adult T-cell leukemia (ATL) with double negative (CD4-, CD8-) phenotype is reported. A-57-year-old man was consulted by his home doctor with us because of leucocytosis, splenomegaly and systemic lymphadenopathy. On admission, white blood cell count was 87,500/microliters with 77% of convoluted atypical cells. Serum anti-HTLV-1 antibody was positive and monoclonal insertion of HTLV-1 provirus into the atypical cell-gene was proved with southern blotting hybridization technique. A diagnosis of an ATL was made. Immunophenotypic analysis of leukemic cells showed CD3 (-), CD4 (-), CD8 (-) and genes encoding both TCR alpha and beta chains were rearranged. Though the patient responded to some degree to the combination chemotherapies including VEPA, he died of infectious complications about 4 months after admission.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

[Definitive myocardial blood flow evaluated by contrast echocardiography: experimental and A-C bypass flow studies].

We evaluated the feasibility of a new method for calculating definitive myocardial flow using contrast echocardiography in canine experiments and in patients who had undergone ACBG surgery. The principle for calculating flow was based on Kety-Schmidt method using time-intensity curve analysis between the epicardial and endocardial aspect. Inlet and outlet flows were hypothesized at the epicardium and endocardium, respectively. Analysis of time-contrast-intensity curves between the epicardium and endocardium, the difference of the area to the saturated point between epicardium and pericardium (A), and the saturated value (H) theoretically lead to the equation: Flow = 100 x (H/A) (Kety-Schmidt) in a 100-gram myocardium. No factors of intensity and time were included. Using this equation, the flow in 7 experimental canine and the flow of 9 patients who had ACBG surgery were compared to the electromagnetic flow. In the canine experiments, the left circumflex coronary artery was dissected free and was connected with contrast injector, a magnetic flowmeter and pneumatic occluder, proximal to distal in this order. Flow was controlled either by the occluder or drugs (papaverin and dipyridamole). Manually-agitated contrast media were injected rapidly (1 ml/2.5 sec), and M-mode echocardiographic recordings were densitometrically translated into time-intensity curves. Thirty-eight trials in 7 dogs showed close correlations (r = 0.901) between the electromagnetic flow and contrast echo flow. For the patients with ACBG, M-mode contrast echo recordings were made using transesophageal echo during the operations with contrast injections via the bypass grafts. Analysis of time-intensity curves was made and recorded in the same way as during the experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Hepatocellular carcinoma presenting with pyrexia and leukocytosis: report of five cases.

In the past 26 years we have encountered five patients with primary liver malignancy clinically characterized by high remittent fever and leukocytosis mimicking liver abscess. Two patients underwent exploratory laparotomy, and drainage was carried out in another. The clinical courses went rapidly downhill. The liver was cirrhotic in two patients. The interior of the main mass was almost totally necrotic in four cases. Histologically, the malignant cells in the main portion resembled sarcoma, but in some areas cells appeared epithelial with eosinophilic cytoplasm and were in a trabecular arrangement, except for one case not subjected to autopsy in which histological study was inadequate because of extensive necrosis. It seems that these neoplasms were very poorly differentiated hepatocellular carcinomas rather than combinations of sarcoma and hepatocellular carcinoma. These patients, therefore, may represent a distinct clinicopathological type of hepatocellular carcinoma that is very rare in Japan but perhaps more common in South Africa, where similar cases have been clinically described in larger numbers.

Adult↗