Biomedical subjects

H Yoshihara

Publications and source records attributed to H Yoshihara.

At least 19 recordsLinked to original sources

PubMed1992

Synergistic stimulation of nitric oxide hemoglobin production in rats by recombinant interleukin 1 and tumor necrosis factor.

Nitric oxide (NO) is formed from arginine in Escherichia coli lipopolysaccharide (LPS) treated rat; however, none of specific cytokine inducing NO generation is yet determined. We studied the effect of interleukin 1 (IL-1) and tumor necrosis factor (TNF) on NO production in rats by detecting NO-hemoglobin in their blood, using electron spin resonance. Either IL-1 or TNF alone stimulated NO-hemoglobin formation. Combined administration of IL-1 and TNF markedly enhanced NO-hemoglobin generation, demonstrating the synergistic character of both stimuli on NO production. Further, LPS and TNF in combination were more potent stimulator of NO-hemoglobin production in rats than each alone.

Animals↗

PubMed1992

Cellulose acetate electrophoretic determination of bone alkaline phosphatase activity in healthy subjects and diabetic patients with and without osteopenia.

We adapted the electrophoretic method of bone alkaline phosphatase (ALP) determination using neuraminidase from Vibrio cholerae to separate bone and liver ALP on cellulose acetate membrane. Treatment of separator plus serum (1:8, neuraminidase 111 U/l in final) for 10 min at room temperature (25 +/- 1 degree C) and subsequent electrophoresis made it possible to quantify bone ALP activity simply and rapidly. The precision of the data was at the level of CV of 1.6% (within-day) and 4.7% (day-to-day), with recovery rates of 97-103%. The normal range of bone ALP activity depended on age and sex. Seventy-eight diabetes mellitus (DM) patients, excluding those with renal failure, were divided into two groups of those with and without osteopenia with matching of age (+/- 3 years) and sex. Bone ALP (P < 0.001) and total ALP (P < 0.05) activities and urine calcium/creatinine ratio (P < 0.05) were significantly higher in DM with osteopenia than in DM without osteopenia. Therefore, bone formation and absorption may be accelerated in DM with osteopenia in comparison with DM without osteopenia.

Adult↗

PubMed1992

Detection of nitric oxide production in lipopolysaccharide-treated rats by ESR using carbon monoxide hemoglobin.

Release of nitric oxide (NO), from macrophages activated with E. coli lipopolysaccharide (LPS) and endothelial cells, has been proposed using chemiluminescence and spectrophotometry. However these methods can not distinguish NO from NO2-. The present study was aimed to prove in vivo production of NO, by ESR using CO-hemoglobin (HbCO) as a trapping agent of NO in the peritoneal cavity of rats treated with LPS. We detected a broad signal in the recovered HbCO solution. Inositol hexaphosphate induced a three-line hyperfine structure, characteristic of NO-hemoglobin (HbNO). In the arterial blood, ESR signal of HbNO with faint hyperfine structure was detected. NG-Monomethyl-L-arginine inhibited the formation of HbNO. HbNO was not detected in the peritoneal cavity of the LPS-untreated rat given i.p. both NO2- and HbCO. HbNO was, therefore, derived from NO, not from NO2-. These results show that free NO is produced in vivo by the stimulation of LPS.

Animals↗

PubMed1992

Hepatic tissue oxygenation as a predictive indicator of ischemia-reperfusion liver injury.

The purpose of this study was to determine whether hepatic tissue oxygenation after ischemia-reperfusion procedures is an indicator for later liver injury. Partial ischemia in the liver was induced by ligating the left pedicles. Rats were divided into two groups according to duration of ischemia: group A (30-min ischemia) and group B (60-min ischemia). Indices of blood oxygenation and blood volume in regional hepatic tissue, serum ALT levels and histological appearance of livers were evaluated. Twenty-four hours after ischemia and reflow, all rats in group A were alive, whereas only 67% survived in group B. Blood-oxygenation index and blood-volume index in group A rats rebounded quickly after reperfusion. In group B, blood-oxygenation index and blood-volume index remained significantly lower than in group A after reperfusion. Serum ALT levels at 60 and 120 min after reperfusion in group B were significantly higher than those in group A. Blood-oxygenation index measured at 5 and 60 min of reperfusion showed significant correlation with serum ALT levels at 120 min of reperfusion. When the percentage recovery of blood-oxygenation index at 5 and 60 min after reperfusion was more than 75%, all rats survived. No obvious signs of hepatocellular degeneration were observed histologically 5 min after reperfusion; however, substantial hepatocellular degeneration had occurred at 120 min of reperfusion in groups A and B. These data indicate that a decline in hepatic tissue oxygenation during the early phase of reperfusion (even when no obvious hepatocellular degeneration has been observed) can be a predictor of subsequent liver injury and prognosis.

Alanine Transaminase↗

PubMed1992

Ethanol-induced vasoconstriction causes focal hepatocellular injury in the isolated perfused rat liver.

The role of microcirculation in the pathogenesis of alcoholic liver injury was investigated in isolated perfused livers from fed rats. Infusion of ethanol into the portal vein at concentrations ranging from 25 to 200 mmol/L increased portal pressure, which is an indicator of hepatic vasoconstriction, in a concentration-dependent fashion. Portal pressure started to rise immediately on initiation of ethanol load and remained at higher than basal levels throughout the period of ethanol infusion. Release of lactate dehydrogenase, an indicator of cell injury, into the effluent perfusate began to increase after 20 to 30 min of ethanol infusion and continued to increase until the end of the experiment (60 min after the initiation of ethanol infusion). The lactate dehydrogenase level in the effluent perfusate at 60 min was dependent on the ethanol concentration (0 mmol/L, 8 +/- 3 IU/L; 25 mmol/L, 22 +/- 3 IU/L; 50 mmol/L, 51 +/- 11 IU/L; 100 mmol/L, 60 +/- 7 IU/L; 200 mmol/L, 120 +/- 7 IU/L). Simultaneous infusion of sodium nitroprusside (100 mumol/L), a known vasodilator, inhibited significantly the ethanol-induced increases in portal pressure and lactate dehydrogenase release by abolishing hepatic vasoconstriction. In histological examinations focal hepatocellular necrosis, evidenced by trypan blue staining of cell nuclei, was detected predominantly in midzonal and pericentral areas of the liver lobule after 60 min of ethanol infusion. Change in portal pressure during 60 min of ethanol infusion correlated significantly with levels of lactate dehydrogenase after ethanol infusion (r = 0.82; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Hormones increase oxygen uptake in periportal and pericentral regions of the liver lobule.

The effect of several hormones known to alter intracellular free Ca2+ on rates of O2 uptake in periportal and pericentral regions of the liver lobule was studied in the perfused liver. Regional O2 uptake was measured by stopping the flow and monitoring the decrease in O2 concentration. When perfusion was in the anterograde direction, basal rates of O2 uptake were two to three times higher in periportal than in pericentral regions, and phosphorylase alpha activity, which increases as a function of intracellular free Ca2+ levels, was higher in periportal regions. In contrast, when perfusion was in the retrograde direction, rates of O2 uptake were two to three times greater in pericentral regions. Infusion of epinephrine (0.1 microM) or angiotensin II (5 nM) increased the rate of O2 uptake nearly exclusively in downstream areas of the lobule where O2 tension was low. When perfusions were in the anterograde direction, epinephrine increased phosphorylase alpha activity significantly only in pericentral regions. Stimulation of O2 uptake by epinephrine was blocked by the alpha-adrenergic receptor blocker phentolamine (1 microM) but not by the beta-receptor blocker propranolol. Thus hormones that increase intracellular calcium stimulate O2 uptake predominantly in regions of the liver lobule where O2 tension is lowest, supporting the hypothesis that oxygen tension regulates O2 uptake in the liver via mechanisms involving intracellular free Ca2+.

Adrenergic alpha-Antagonists↗

PubMed1992

[The use of a metallic stent in 32 patients with benign prostatic hypertrophy. Preliminary results and 3 months of follow-up].

A prospective noncontrolled study of the safety and potential efficacy of the metallic stent was performed on 32 patients with benign prostatic hypertrophy. Mean age was 76.6 years (range, 56-98 years), and mean prostatic volume was 24.2 cm3. The patients were selected on the basis of a quantitative symptom score (QSS), uroflowmetry measurements, and residual urine volume (RU). Nineteen patients had urinary retention and remaining 13 patients had moderate symptoms and signs of prostatism. Placing the stent was successfully done in 31 patients (97%). It took 15 minutes to place the stent using transabdominal and/or endorectal sonography. After 3 months, 27 patients (87%) showed improved QSS. In patients with dysuria, maximum flow rate (MFR) and RU before treatment were 6.9 +/- 1.7 ml/sec and 112.3 +/- 61.8 ml, respectively. After treatment, they improved to 12.3 +/- 2.7 ml/sec and 12.7 +/- 6.7 ml, respectively. On the other hand, all patients who had urinary retention were able to urinate just after treatment, and MFR and RU were 12.9 +/- 3.6 ml/sec and 24.4 +/- 43.3 ml, respectively. Evaluation on the basis of improvement in MFR and reduction in RU showed that the stent was effective in 71% of total patients (22 out of 31 patients), 94% of the patients with urinary retention (17 out of 18 patients). The overall clinical efficacy of this stent was 68% (21 patients). There were no major complications such as urge incontinence and urinary tract infection during follow-up. Although proximal migration of the stent was observed in 6 patients, the stent could be taken out and replaced in 4 patients. From the above results, we conclude that the metallic stent is useful for the treatment of prostatism and urinary retention.

Aged↗

PubMed1992

[Subcapsular orchiectomy using the ultrasonic surgical aspirator in patients with advanced prostatic cancer].

We report a technique for performing subcapsular orchiectomy using the ultrasonic surgical aspirator (USA). The procedure was simple and safe, and was completed within one hour in 2 patients on whom it was carried out. Operative complications such as bleeding, postoperative pain and wound swelling were minimal, and compression dressings were not necessary. Postoperatively, the serum testosterone value was lowered to the castrate level. We conclude that subcapsular orchiectomy using USA is superior to conventional bilateral scrotal orchiectomy, and will be a useful option.

Humans↗

PubMed1992

[A case of muellerian duct cyst treated with minocycline hydrochloride sclerotherapy under ultrasound control].

We present a case of a muellerian duct cyst in a 55 year-old man. A cystic lesion was incidentally found between the prostate and the bladder on transabdominal ultrasound examination. Computerized tomography revealed a low density area homogeneous and round with a clear margin. Both urethrocystgram and vesiculogram demonstrated no cystic lesion. On diagnosis of muellerian duct cyst percutaneous needle aspiration was performed under ultrasound control. The aspirated fluid was yellow, clear and negative for cytology. Microscopically no spermatozoa were found in it. Minocycline (100 mg) was injected into the cyst. No recurrence has occurred since the operation. The literature of the cyst was briefly reviewed.

Cysts↗

PubMed1992

[Clinical study of terodiline hydrochloride for the treatment of urinary frequency and urinary incontinence, and its cardiovascular adverse effects].

We evaluated the effectiveness and side effects of terodiline hydrochloride in 109 patients with urinary frequency and urinary incontinence. The drug was administered at a dose of 24 mg once a day or 12 mg twice a day for 4 weeks. Symptoms such as urinary frequency and urinary incontinence were alleviated in 101 out of 109 patients (92.7%). Mild side effects such as thirst, dysuria, sense of residual urine, orthostatic hypotension and arrhythmia were observed in 9 out of 109 patients (8.2%). Side effects such as orthostatic hypotension and arrhythmia were observed on the 28th day or the 20th day of the administration, but these symptoms disappeared with discontinued use of this medicine. The results obtained from this study suggest that terodiline hydrochloride may be greatly useful for the patients with urinary frequency and urinary incontinence. But we must take account of the side effects such as orthostatic hypotension and arrhythmia.

Aged↗

PubMed1991

Ethanol-induced disturbance of hepatic microcirculation and hepatic hypoxia.

The hypothesis was tested whether ingestion of ethanol might disturb the hepatic microcirculation with resulting hepatic hypoxia. Infusion of ethanol increased the portal pressure concentration-dependently in rat livers perfused with Krebs-Henseleit buffer at a constant flow rate (Emax = 11.5 cm H2O, EC50 = 90 mM). This increase in portal pressure was due to hepatic vasoconstriction, since it diminished in the presence of sodium nitroprusside, a direct acting vasodilator. The regional hepatic tissue hemoglobin concentration after perfusion with added erythrocyte suspension (hematocrit 1%), measured by tissue-reflectance spectrophotometry, was significantly diminished by the infusion of ethanol, indicating the impairment of the microcirculation of the superficial layer of the liver. When the absorption spectrum of the liver was examined by reflectance spectrophotometry, infusion of ethanol caused a parallel reduction of all the mitochondrial respiratory cytochromes in a concentration-dependent fashion, concomitant with the increase of portal pressure, indicating a marked reduction of oxygen concentration in superficial liver tissue. The reduction of the respiratory cytochromes was also associated with the decrease in oxygen consumption of the liver, indicating that the hepatic hypoxia was due to the reduction of oxygen delivery to hepatocytes rather than the increased oxygen consumption of the liver. The reduction of the respiratory cytochromes was correlated with the increase in portal pressure and was inhibited by sodium nitroprusside. These data indicate that the ethanol-induced hepatic vasoconstriction disturbs hepatic microcirculation, resulting in hepatic hypoxia and reduction of mitochondrial respiratory cytochromes.

Animals↗

PubMed1991

[Hyperthermic treatment in patients with benign prostatic hypertrophy].

Hyperthermic treatment was performed in 31 patients with benign prostatic hypertrophy (BPH). Eight patients of them had a urethral catheter because of urinary retention. The prostate was heated trans-rectally to 43-45 degrees C. The treatment consisted of 10 sessions of 60 min. each. To evaluate this treatment, the following parameters were determined before, during and one week after the last hyperthermia session: subjective symptoms score, and residual urine volume, uroflowmetry and transrectal ultrasound of the prostate as objective data. Symptoms score improve in all patients. Of 8 patients with a catheter, the catheter could be removed from 4 patients. There was no significant change in prostate volume, but significant decreases of residual urine volume, and increases of maximum flow rate and mean flow rate were observed. No adverse reactions were seen. Judging from the above results, this treatment is considered to be useful for patients with BPH.

Aged↗

PubMed1991

[Results of Kock pouch construction fully utilizing an auto-suture instrument].

From March 1987 to the end of February 1991, we performed Koch pouch construction as a urinary diversion on 20 patients who had undergone radical cystectomy due to bladder cancer. The operation was done according to the method of Skinner et al. We fully utilized an auto-suture instrument to ensure safe and stable suturing of the ileum and to shorten the operating time. It was of great concern that the staples placed at several portions might cause stone formation or aggravate infection. However, stone formation was observed only in one patient (5%) at the tip of a nipple valve in which a staple became the nucleus of the stone. Staples are usually not regarded as an obstacle as they are usually covered by the mucous membrane. In all patients, the maximum capacity of the pouch was more than 500 ml, intra-pouch pressure was kept low even when the pouch was inflated up to the maximum capacity, and reflux of urine into the upper urinary tract was not observed. As for complications, there was a slight degree of obstructive uropathy in 4 patients (20%), difficulty in catheter insertion was noted in 3 patients (15%), and stress incontinence-like urinary leakage was present in one patient when the capacity exceeded 500 ml. However, there were no complications which necessitated reoperation. In terms of blood chemistry, although there was a tendency towards a slight increase in BUN or hyperchloremia, no specific treatment was necessary as far as the kidney function was normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[Application of new intraurethral stent for higher risk patients with benign prostatic hypertrophy].

We reviewed our experience of the application of a new urethral stent (PROSTAKATH) for 8 patients with prostatic outflow obstruction from December 1989 to March 1990. 6 patients had required the Foley catheter for several months because of chronic urinary retention. 2 were dys-uric patients having a higher bladder residual urine volume. All were in a high risk group for surgery. 7 out of the 8 patients were treated successfully. The stent was not placed in one. All 7 patients in whom the urethral stent was placed voided freely after placement of the stent. Bladder residual urine was not detected by the ultrasound sonography except in one patient. The urethral stent used in this study was a spring-like spiral with an outside diameter of 21 Fr, it is made of gold-plated stainless steel. Under local anesthesia, it can be easily inserted using a 6-7 Fr. ureteral catheter as a guide wire under ultrasonic scanning guidance. During the follow-up period of 5-8 months, 1 patient had an episode of migration of the stent to the bladder 2 months later, which was removed endoscopically, and a new stent was placed. Side effects were observed in 2 patients; one complained of strong discomfort and the other suffered from urge incontinence. Both symptoms were ameliorated during the follow-up period. We conclude that the urethral stent is an effective device as a non-invasive treatment of prostatic outflow obstruction.

Aged↗

PubMed1991

[Clinical study of a metallic prostatic stent].

Treatment using a metallic spiral was attempted on 22 patients. They had urinary retention in 16 cases and dysuria in 6. In 21 of them, the spiral was successfully placed under transrectal ultrasound control. In all 21 patients, voiding was possible immediately after placement of the spiral. As for urodynamic study, urine volume was 100-230 ml (mean: 172 ml), maximum flow rate was 13-21 ml/sec (mean: 17.3 ml/sec), and average flow rate was 4-12 ml/sec (mean: 8.2 ml/sec). Residual urine volume was less than 30 ml in 20 patients and 200 ml in one. As for complications, proximal migration of the spiral was observed in 6 patients. In 4 of them, the new spiral was placed. Perineal discomfort was seen in 3 patients, in 2 the spiral was removed. Pyuria associated with bacterial infection did not continue after the treatment in patients having a catheter. Severe urge incontinence and encrustation were never seen. The above findings suggest that, though a longterm study has not done, this treatment could be an effective treatment particularly for the elderly patients with general complications and/or who require removal of an indwelling catheter for clinical or social reasons.

Aged↗

PubMed1991

[Evaluation of the results of extracorporeal shock-wave lithotripsy (ESWL) for solitary upper urinary tract stone].

We performed extracorporeal shock-wave lithotripsy (ESWL) on 1,701 patients in a total of 2,438 sessions using the Dornier kidney lithotriptor Model HM III from July 1985 to the end of June 1990. Among the patients with a solitary stone, 1,200 cases were available for the follow-up study in which the results of ESWL were analyzed according to the location and size of the stone. ESWL performed against stones at pelvis and calyces gave the best results. The results obtained on stones less than 20 mm in diameter were especially favorable with a success rate of 84%. ESWL performed against ureter stones showed poor results with a success rate of 62% for the stones smaller than 20 mm in diameter. We further studied the results of ESWL performed against ureter stones by dividing the patients into three groups: the patients treated in situ, the patients with ureteral stents and the patients with D-J stents. The results for stones larger than 10 mm in diameter were significantly better in the patients with D-J stents than in the patients treated in situ or the patients with ureteral stents. Among the patients treated in situ, the results were significantly worse for impacted stones than for non-impacted stones when the stone size was 10-20 mm in diameter.

Evaluation Studies as Topic↗

PubMed1991

Ethanol-induced focal cell necrosis via microcirculatory disturbance in the perfused rat liver.

In the perfused rat liver, infusion of ethanol induced an initial increase in portal pressure which is an indicator of vasoconstriction and a subsequent increase in lactic dehydrogenase (LDH) release, which is an indicator of cell damage in a dose-dependent fashion. Simultaneous infusion of sodium nitroprusside, a potent vasodilator, (100 microM) inhibited the increases in portal pressure and LDH release. Focal hepatocellular necrosis evidenced by trypan-blue stained cell nuclei were localized in midzonal and pericentral area of the liver lobules at 60 min after ethanol load. These ethanol-induced microcirculatory disturbance might be involved in the pathogenesis of alcoholic liver disease.

Animals↗

PubMed1991

[Intracellular calcium level, lipid peroxidation, and development of gastric mucosal injury in rat hemorrhagic shock].

Although acute gastric mucosal lesions (AGMLs) develop after the mucosal ischemia and reperfusion, precise intracellular mechanism for the development of AGMLs remains unclear. In the present paper, we investigated intracellular calcium level, lipid peroxidation, and gastric mucosal lesion in rat hemorrhagic shock model. We estimated intracellular calcium by measuring phosphorylase a activity in the gastric mucosa. The mucosal phosphorylase a increased during hemorrhagic shock, while it returned to be normal after the reinfusion of shed blood. Although mucosal lipid peroxide and area of AGMLs did not increase significantly during hemorrhagic shock, they increased significantly after the reinfusion. Diltiazem, a calcium antagonist, prohibited both of the increase in mucosal phosphorylase a activity during hemorrhagic shock and the increase in lipid peroxide content and area of AGMLs after the reinfusion of the shed blood. Organ reflectance spectrophotometry revealed that the gastric corpus suffered mucosal ischemia and hypoxia during the hemorrhagic shock. The are of AGMLs had a good correlation with a level of lipid peroxidation in the gastric mucosa. These results suggest 1) that intracellular free calcium in gastric mucosa increases during the mucosal ischemia; 2) that a calcium antagonist prohibits the increased intracellular free calcium during mucosal ischemia; and 3) that a calcium antagonist prohibits the increased mucosal lipid peroxide and the development of AGMLs after the mucosal reperfusion. Thus it is concluded that the increased intracellular free calcium during ischemia plays a key role in the mucosal tissue injury in the ischemia-reperfusion state.

Animals↗