Biomedical subjects

K Oishi

Publications and source records attributed to K Oishi.

At least 145 records · Page 8Linked to original sources

PubMed1995

Expression of hepatic calcium-binding protein regucalcin mRNA is elevated by refeeding of fasted rats: involvement of glucose, insulin and calcium as stimulating factors.

The effect of refeeding on the expression of Ca(2+)-binding protein regucalcin mRNA in the liver of fasted rats was investigated. When rats were fasted overnight, the hepatic regucalcin mRNA level was reduced about 70% of that in feeding rats. Refeeding produced a remarkable elevation of hepatic regucalcin mRNA level (about 150-170% of fasted rats). Liver regucalcin concentration was appreciably increased by refeeding, although it was not altered by fasting. The oral administration of glucose (2 g/kg body weight) to fasted rats caused a significant increase in hepatic regucalcin mRNA level. Moreover, hepatic regucalcin mRNA level was clearly elevated by a single subcutaneous administration of insulin (10 and 100 U/kg) to fasted rats. The hormonal effect was not further enhanced by the simultaneous administration of calcium chloride (250 mg Ca/kg) to fasted rats, although calcium administration stimulated regucalcin mRNA expression in the liver. The present study suggests that the expression of hepatic regucalcin mRNA stimulated by refeeding is significantly involved in the action of insulin and/or calcium as stimulating factors.

Animals↗

PubMed1995

Contribution of brain injury to hypertension following intravenously-administered pancuronium in rats.

Abnormal hypertension sometimes occurs following intravenous administration (i.v.) of pancuronium in patients with brain injury. The present experiment was designed to determine whether brain injury contributes to the hypertensive response of i.v. pancuronium. Forty-six Wister strain rats were studied, of which 39 had induced brain injury at (a) upper pons (b) midbrain (c) thalamus region (excluding hypothalamus) and (d) cerebellum or a combination of these sites. The injury was made by single insertion of a 22 Gauge needle through the skull surface. The quantity of pancuronium solution administered i.v. in each case was 1.0 ml containing either 0.8 mg/kg or 8 mg/kg of pancuronium. Group A (n = 7) had no brain injury and the mean arterial pressure (MAP) did not change following i.v. administration of pancuronium. In Group B (n = 9) (a+b+c, 8.0 mg/kg) MAP rose from 90.9 +/- 15.4 to 102 +/- 22.0 mmHg and in Group C (n = 7) (a+b+c, 0.8 mg/kg) MAP rose from 148.4 +/- 13.3 to 160 +/- 14.4 mmHg. In Group D (n = 5) (b+c, 8.0 mg/kg) MAP remained unchanged. In Group E (n = 5) (a, 8.0 mg/kg) MAP rose from 130.3 +/- 18.7 to 146 +/- 27.6 mmHg and in Group F (n = 6) (a, 0.8 mg/kg) MAP rose from 129.7 +/- 15.6 to 135.8 +/- 13.8 mmHg. In Group G (n = 7) (d, 8.0 mg/kg) MAP remained unchanged. Since the MAP was elevated in only those groups that received injury in the upper pons, we concluded that injury in the upper pons can lead to hypertension following i.v. administration of pancuronium.

Animals↗

PubMed1995

Carbachol-induced desensitization of rat basophilic leukemia (RBL-2H3) cells transfected with human m3 muscarinic acetylcholine receptors.

1. Carbachol-induced homologous desensitization of the secretory response was investigated by transfecting RBL-2H3 cells with cDNA encoding the human m3 muscarinic acetylcholine receptor (RBL-m3). 2. Exposure of RBL-m3 cells to 100 microM carbachol for 30 min in Ca2+-free medium inhibited the secretion induced by the subsequent addition of 10 microM carbachol plus Ca2+. 3. Desensitized cells bound [3H]quinuclidinyl benzilate with a similar Bmax and Kd to those of control cells. 4. The carbachol-induced transient increase in levels of inositol 1,4,5-trisphosphate was not changed by desensitization. 5. Homologous desensitization persisted when desensitized cells were permeabilized with Staphylococcal alpha-toxin.

Animals↗

PubMed1995

Regulation of exocytosis by the small GTP-binding protein Rho in rat basophilic leukemia (RBL-2H3) cells.

1. We investigated the effect of Clostridium botulinum C3 ADP-ribosyltransferase upon beta-hexosaminidase release induced by various stimuli from streptolysin-O (0.5-1 U/ml)-permeabilized rat basophilic leukemia (RBL-2H3) cells. 2. The C3 transferase inhibited beta-hexosaminidase release induced by Ca2+ or by guanosine-5'-(3-thiotriphosphate) (GTP gamma S) plus Ca2+. 3. The C3 transferase also inhibited beta-hexosaminidase release induced by stimulating high affinity IgE and m3 muscarinic acetylcholine receptors. 4. The substrate for the C3 transferase was present in cytosol of RBL-2H3 cells, indicating the presence of rho p21. About 60% of the total cellular substrate protein remained within the cells permeabilized by 1 U/ml of streptolysin-O. 5. The protein rho p21 appears to be regulated by several pathways and it may function as an integration point for exocytosis.

ADP Ribose Transferases↗

PubMed1995

Long-term results of mitral valve repair for non-rheumatic mitral regurgitation.

The durability of mitral valve repaired with reconstructive techniques is variable. If the durability continues to be good, mitral valve repair may be the procedure of choice in many patients with mitral regurgitation. Between December 1970 and June 1993, 54 patients had mitral valve repair for non-rheumatic mitral regurgitation. There were 38 men and 16 women with a mean age of 46.8 (range 19-68) years. The pathology which required surgical treatment was torn chordae in 38 patients, elongation of the chordae in five, valve prolapse without elongation or rupture of the chordae in six, infective endocarditis in three, and annular dilatation in two. Forty-four patients had triangular or quadrangular resection of the mitral leaflet, and seven had annuloplasty alone. Choral reconstruction was performed on three patients. There were no operative deaths. Five patients (9%) died late after operation. The actuarial survival rate and the valve-related death-free rate at 10 years were 83.9% and 90.0%, respectively. Seven patients (13%) required reoperation. Freedom from reoperation at 10 years was 84.5%. Improper evaluation of residual regurgitation during operation and suture dehiscence were the principal causes of reoperation. It was concluded that mitral valve repair for non-rheumatic mitral regurgitation showed low operative mortality and stable long-term results. It is suggested that intraoperative transoesophageal colour Doppler echocardiography provides accurate assessment of mitral valve competence and may be helpful in reducing the need for reoperation.

Adult↗

PubMed1995

Increasing the thermal dose in transurethral microwave thermotherapy produces no improvement in therapeutic efficacy.

BACKGROUND: Transurethral microwave thermotherapy (TUMT) is a minimally invasive treatment for benign prostatic hyperplasia (BPH). It has been reported that increased thermal dose and higher intraprostatic temperatures resulted in improved clinical response. Recently we treated BPH patients with the prostatron device using a new version of software (Prostasoft 2.5), which was intended to increase thermal delivery by allowing maximum power up to 70W. The safety and clinical results were compared between the patients treated with Prostasoft 2.5 and those treated with the currently available software (Prostasoft 2; maximum power up to 50W). METHODS: A total of 105 patients were treated successively with two treatment protocols. Sixty-three patients were treated with Prostasoft 2 between September 1992 and July 1993, while 42 were treated with Prostasoft 2.5 between August 1993 and April 1994. Therefore, this investigation was a retrospective nonrandomized study. There was no significant difference in the baseline patient characteristics between the two groups. RESULTS: Total thermal dose delivered to the prostate was significantly higher in the Prostasoft 2.5 group than that in the Prostasoft 2 group (137 kJ versus 116 kJ, P < 0.05). No serious complications were encountered in either group. Six months after TUMT, in both the Prostasoft 2.5 and Prostasoft 2 groups there was an improvement in patient condition as measured by the mean I-PSS, QOL, and peak flow rate values, as well as the overall therapeutic efficacy. The two groups differed in the amount of posttreatment improvement from between 8% and 22%, but this difference was not statistically significant. CONCLUSIONS: Our study suggests that higher thermal dose attained by Prostasoft 2.5 does not necessarily result in more pronounced clinical improvement, although clinical response to TUMT has often been reported to be dependent upon thermal dose.

Aged↗

PubMed1995

Transurethral microwave thermotherapy for benign prostatic hyperplasia: clinical results after a 1-year follow-up.

Since September 1992, 63 patients with symptomatic benign prostatic hyperplasia (BPH) have been treated with transurethral microwave thermotherapy (TUMT) using the Prostatron device. The International Prostate Symptom Score (I-PSS) and quality of life (QOL) score were used to evaluate subjective symptoms. The mean I-PSS (total, irritative and obstructive scores) and QOL scores had decreased by 40, 38, 45 and 40%, respectively, at 12 months (p < 0.0001). While the mean peak flow rate had increased by 72% (p < 0.001). The clinical efficacy at 12 months was 42%, using a modification of the response criteria proposed at the 2nd International Consultation on Benign Prostatic Hyperplasia. There were no significant differences in the baseline and treatment parameters between those who responded favorably to TUMT and those who did not. The total thermal dose delivered to the prostate did not predict clinical response. However, there was a positive correlation between I-PSS or QOL at baseline and % reduction at 3, 6 and 12 months, and a negative correlation between peak flow rate at baseline and % increase at 3 and 6 months. There were no major complications associated with TUMT during the follow-up period. In summary, our 1-year clinical results are compatible with previous reports, suggesting that TUMT is a safe, effective and lasting non-surgical treatment for BPH. However, evaluation of efficacy should be based on uniform criteria to facilitate comparisons of different clinical trials. The most suitable patient profiles for TUMT could not be identified by retrospective analysis.

Aged↗

PubMed1995

Total aortic replacement in a patient with mega aorta syndrome--a case report.

A 64-year-old woman without manifestations of Marfan syndrome was referred for the close investigation of a pulsatile abdominal mass. Computed tomographic scans and magnetic resonance images revealed aneurysmal dilatation of the entire aorta, including the ascending aorta and extending to the bifurcation of the aorta, as well as tortuousness of the thoracoabdominal and abdominal aorta. Digital subtraction angiography also showed aneurysmal dilatation of the entire aorta and trivial aortic regurgitation. However, aortic annular dilatation was not found by echocardiography or aortography. The entire aorta was replaced in two stages. First, graft replacement of the ascending aorta, except for the sinus segment, and the aortic arch was performed using an elephant trunk technique under hypothermic cardiopulmonary bypass with selective cerebral perfusion. Twelve weeks later, the remaining aorta, including the descending aorta and extending to the common iliac artery on the right side, and to the common femoral artery on the left side, was replaced with a partial cardiopulmonary bypass using femoral artery and vein cannulation. We believe that patients with mega aorta syndrome are best treated by total aortic replacement. The results in the present case indicate that the elephant trunk technique is useful for extensive aortic replacement in stages, and greatly facilitates the second stage operative procedures.

Aorta↗

PubMed1995

Clinical evaluation of polymerase chain reaction DNA amplification method for the diagnosis of pulmonary tuberculosis in patients with negative acid-fast bacilli smear.

We evaluated the sensitivity and specificity of polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis among 109 patients who were suspected to have active pulmonary tuberculosis (PTB) and showed negative acid-fast bacilli (AFB) smears in a total of 393 samples of sputum (169), gastric aspirate (134), and urine (90) which fulfilled different criteria for the positivity of PCR. The patients were subsequently divided into one group of active PTB composed of 15 patients with definite PTB and 43 patients with highly suspected PTB, and another group of 51 non-active PTB patients. The PCR assay using samples of sputum and gastric aspirate proved to be specific for active PTB. The PCR method for diagnosis of active PTB using sputum samples was sensitive (97.8%) but lacked specificity (27.0%) when regarded as PCR positive when at least one positive reaction was obtained among all samples examined. However, the PCR of gastric aspirate demonstrated a sensitivity of 63.4% and a specificity of 76.7%. Our data supports that the PCR method for detecting active PTB in AFB smear negative patients using gastric aspirate shows markedly improved sensitivity over the conventional method (25.9%), although it still lacks specificity. PCR assay for M. tuberculosis using multiple samples of gastric aspirate in conjunction with careful clinical observations for the presence of active infection is essential for the diagnosis of active PTB among patients with negative AFB smear.

Bacteriological Techniques↗

PubMed1995

Total body fat estimations by near-infrared interactance, A-mode ultrasound, and underwater weighing.

We studied 94 (41 men and 53 women) healthy 18 to 65 years old Caucasians for body composition utilizing 3 methods: 1) Underwater weighing (UWW) for body density, 2) A-mode ultrasound subcutaneous fat determination, and 3) Near-infrared (NIR) interactance spectral data. We then utilized the Wherry-Doolittle test selection method to predict percent of total body fat (%fat) from either ultrasound or NIR data with anthropometric measurements, optimizing for the fewest number of data points which correlated highly with UWW results. It was found that %fat could be estimated with a correlation of > 0.9 when measured at 4 sites (different between men and women) by ultrasound, age (women) and height (men). We also found a correlation of > 0.8 using 2 sites by NIR, weight, age, and height. It has been suggested that the ultrasound method would produce better estimates of both local and total body fat.

Adipose Tissue↗

PubMed1995

The geography of prostate cancer and its treatment in Japan.

The age adjusted death rate from prostate cancer in Japan is one of the lowest in the world but is rising steadily. The vast majority of cases of prostate cancer remain undetected during life, the prevalence of prostate cancer detected at autopsy being 2800 times that of lethal cancer in Japanese in Japan, 570 times in whites in the USA and 470 times in blacks in the USA. A case-control study of prostate cancer carried out in Japan and the Netherlands revealed a number of statistically significant risk factors, including rural residence, more brothers, colon neoplasms in relatives, no morning erections, frequent sexual intercourse in 30s, episodes of sexually transmitted disease, lower plasma testosterone and dihydrotestosterone concentrations and lower beta-carotene intake.

Humans↗

PubMed1995

Aortic regurgitation due to non-traumatic rupture of the aortic valve commissures: report of two cases.

Two cases of severe aortic regurgitation due to non-traumatic rupture of the aortic valve commissures are reported. The cause of rupture was hypertension in one patient, but it could not be identified in the other, where microscopic examinations of the aortic wall and the aortic cusps showed no particular pathologic changes. M-mode echocardiography revealed enlargement of the left ventricle, diastolic flutter of the anterior mitral leaflet and diastolic separation of the closure line of the aortic cusps in both patients. Two-dimensional echocardiography showed a downward displacement of the prolapsing motion of the aortic valve cusp during diastole toward the left ventricular outflow tract in one patient, and eccentricity of the coaptation point of the aortic valve without thickening of the cusps in the other. In addition to clinical features of progressive heart failure and characteristic cardiac murmur, echocardiographic studies provided correct diagnosis of aortic valve prolapse resulting from rupture of the aortic valve commissures. Both patients underwent aortic valve replacement successfully.

Aortic Valve↗

PubMed1994

Expression of hepatic calcium-binding protein regucalcin mRNA is decreased by phenobarbital administration in rats.

The effect of phenobarbital on the expression of calcium-binding protein regucalcin mRNA in rat liver was investigated. The change of regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin cDNA (0.9 kb of open reading frame). Phenobarbital (4, 8 and 12 mg/ 100 g body weight) was intraperitoneally administered to rats 3 times with 24 h intervals, and the animals were sacrificed by bleeding at 24 h after the last administration. The hepatic regucalcin mRNA levels were markedly reduced by phenobarbital administration. This decrease was about 50% of control level with the 12 mg/100 g dose. Moreover, the hepatic regucalcin concentration was significantly decreased by the administration of phenobarbital (12 mg/100 g), although the serum regucalcin concentration was not altered appreciably. Meanwhile, serum transaminases (GOT and GPT) activities were not increased by the administration of phenobarbital (4 and 12 mg/100 g). The present study demonstrates that the expression of hepatic regucalcin mRNA is decreased by phenobarbital administration in rats, suggesting that regucalcin does not have a role in drug metabolism related to phenobarbital.

Alanine Transaminase↗

PubMed1994

Serum release of hepatic calcium-binding protein regucalcin by liver injury with galactosamine administration in rats.

Whether calcium-binding protein regucalcin, which mainly localizes in liver, is released into the serum by liver injury was investigated in rats administered galactosamine. Galactosamine (25 mg/100 g body weight) was intraperitoneally administered 3 times at 2 h intervals in rats, and the animals were sacrificed at 10, 24 and 48 h after the first administration of galactosamine. Liver regucalcin mRNA levels were clearly reduced at 24 and 48 h after galactosamine administration with estimating for Northern blotting assay. When hepatic regucalcin concentration was estimated by enzyme-linked immunoadsorbent assay (ELISA) with rabbit-anti-regucalcin IgG, liver regucalcin concentration was not significantly altered by galactosamine administration. Serum regucalcin concentration was markedly elevated at 10 and 24 h after the first administration of galactosamine. Serum transaminases (GOT and GPT) activities were significantly increased by galactosamine administration, indicating that liver injury was induced. The present study demonstrates that liver regucalcin is released into the serum by liver injury with galactosamine administration in rats.

Alanine Transaminase↗

PubMed1994

Amplitude reduction of H-reflex during mental movement simulation in elite athletes.

In order to investigate the changes of motoneuron excitability during mental simulation of a voluntary movement (motor imagery; MI), the soleus H-reflex and several activities of autonomic effectors were recorded simultaneously when MI of speed skate sprint was performed. The subjects were seven elite speed skate athletes ranging in age from 18 to 24 years old. They were all skilled in MI, and could imagine full vivid skating movement internally as if they were really exercising. The subjects were awake, relaxed and blindfolded. At first, rest (5 min), positive relaxation (4 min) and concentration periods (2.5 min) were set up. Then, after the previous announcement for the start, MI was initiated by the sound of a signal gun which was recorded by a tape recorder. MIs were continued for each subject from about 36 s to 38 s, and these imaging times were very close to the actual personal best records of each subject. The autonomic effectors represented by skin conductance response (SCR), heart rate (HR), and respiration rate (RSR) became remarkably active during MI in all trials. SCR was increased by 51% on the average. Furthermore, HR and RSR were increased by 57% and 76% respectively, compared with those during resting period. These changes in the autonomic effectors were all significant and were those which were activated in actual movements. The amplitudes of H-reflex were almost all constant before MI initiation. However, the reduction of the H-reflex amplitude arose just after the start and lasted to the end of MI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Involvement of Ca(2+)-stimulated adenosine 5'-triphosphatase in the Ca2+ releasing mechanism of rat liver nuclei.

The regulatory role of Ca(2+)-stimulated adenosine 5'-triphosphatase (Ca(2+)-ATPase) in Ca2+ transport system of rat liver nuclei was investigated. Ca2+ uptake and release were determined with a Ca2+ electrode. Ca(2+)-ATPase activity was calculated by subtracting Mg(2+)-ATPase activity from (Ca(2+)-Mg2+)-ATPase activity. The release of Ca2+ from the Ca(2+)-loaded nuclei was evoked progressively after Ca2+ uptake with 1.0 mM ATP addition, while it was only slightly in the case of 2.0 mM ATP addition, indicating that the consumption of ATP causes a leak of Ca2+ from the Ca(2+)-loaded nuclei. The presence of N-ethylmaleimide (NEM; 0.1 mM) caused an inhibition of nuclear Ca2+ uptake and induced a promotion of Ca2+ release from the Ca(2+)-loaded nuclei. NEM (0.1 and 0.2 mM) markedly inhibited nuclear Ca(2+)-ATPase activity. This inhibition was completely blocked by the presence of dithiothreitol (DTT; 0.1 and 0.5 mM). Also, DTT inhibited the effect of NEM (0.1 mM) on nuclear Ca2+ uptake and release. Meanwhile, verapamil and diltiazem (10 microM), a blocker of Ca2+ channels, did not prevent the NAD+ (1.0 and 2.0 mM), zinc sulfate (1.0 and 2.5 microM) and arachidonic acid (10 microM)-induced increase in nuclear Ca2+ release, suggesting that Ca2+ channels do not involve on Ca2+ release from the nuclei. These results indicates that an inhibition of nuclear Ca(2+)-ATPase activity causes the decrease in nuclear Ca2+ uptake and the release of Ca2+ from the Ca(2+)-loaded nuclei. The present finding suggests that Ca(2+)-ATPase plays a critical role in the regulatory mechanism of Ca2+ uptake and release in rat liver nuclei.

Adenosine Triphosphate↗

PubMed1994

Effect of phorbol 12-myristate 13-acetate on Ca2+-ATPase activity in rat liver nuclei.

The effect of phorbol 12-myristate 13-acetate (PMA) on Ca(2+)-ATPase activity in rat liver nuclei was investigated. Ca(2+)-ATPase activity was calculated by subtracting Mg(2+)-ATPase activity from (Ca(2+)-Mg(2+)-ATPase activity. The nuclear Ca(2+)-ATPase activity was significantly increased by the presence of PMA (2-20 microM) in the enzyme reaction mixture; the maximum effect was seen at 10 microM. The PMA (10 microM)-increased Ca(2+)-ATPase activity was not blocked by the presence of staurosporine (2 microM) or dibucaine (2 and 10 microM), an inhibitor of protein kinase. Meanwhile, vanadate (20 and 100 microM) caused a significant reduction in the nuclear Ca(2+)-ATPase activity increased by PMA (10 microM). The present finding suggests that PMA has an activating effect on liver nuclear Ca(2+)-ATPase independent of protein kinase.

Adenosine Triphosphate↗

PubMed1994

Nonsurgical correction for thrombosis of a St. Jude Medical tricuspid prosthesis: report of a case.

A 43-year-old woman with rheumatic heart disease underwent replacement of the aortic, mitral, and tricuspid valves using three SJM prostheses. Despite adequate warfarin therapy, routine cineradiography performed on the 40th postoperative day showed one of the leaflets of the tricuspid prosthesis to be "stuck" in the semiclosing position. A thrombosis of the tricuspid prosthesis was successfully treated with a urokinase infusion and mechanical thrombolysis using a pacemaker, following which normal valve function was restored.

Adult↗