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Biomedical subjects

H Yoshimoto

Publications and source records attributed to H Yoshimoto.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Acute and subacute toxicity studies of Bis(2,3-dibromopropyl) phosphate magnesium in rat].

Acute and subacute oral toxicity tests of Bis(2,3-dibromopropyl) phosphate magnesium (Bis-BP.Mg) were carried out in Wistar rats. In the acute toxicity test, Bis-BP.Mg suspended in arabic gum was administered orally to a group consisting of 10 male and 10 female rats, and they were observed for 14 days. LD50 values of male and female rats were 283 (253 approximately 314) mg/kg and 261 (219 approximately 310) mg/kg, respectively. As toxic symptoms, eyelid closure, crouching, shivering and staggering gait were observed in the treated groups of both sexes. In gross findings, hypertrophy, discoloration and necrotic change of the liver, and hypertrophy and discoloration of the kidney were observed in the treated groups. In histopathological examination, necrosis, desquamation, large nuclei formation of the tubular epithelium, and tubular dilatation of the kidney and necrosis of the liver cells were observed in the treated groups. In the subacute toxicity test, groups of rats consisting of 5 males and 5 females were fed a commercial diet containing 0, 30, 100, 300 and 1000 ppm Bis-BP.Mg for 45 days. In body weight and food consumption, there were no significant difference between the control and treated groups. Significant increases were observed in the liver and kidney weights of male rats fed 1000 ppm Bis-BP.Mg. Histopathologically, desquamation, swelling, and large nuclei formation of the tubular epithelium and tubular dilatation of the kidney were observed, but they were much less frequent than those in the acute toxicity test. It was concluded that Bis-BP.Mg has apparent renal toxicity.

Administration, Oral↗
PubMed1991

[The effect of bile duct pressure on cholangiovenous reflux. A clinical study].

The measurement of the filling pressure of the bile duct during the process of endoscopic retrograde catheter cholangiography, and the determination of blood culture and blood iodine before and after cholangiography were carried out to probe into the effect of bile duct pressure on cholangiovenous reflux. In 32 cases, 2 had positive blood culture after cholangiography, with a bile duct pressure being 2.98 kPa and 3.72 kPa respectively. Nineteen cases with a pressure below 2.94 kPa showed negative blood culture. In 10 cases with a bile duct filling pressure below 2.16 kPa, no increase in blood iodine was noted whereas, blood iodine level was increased in 5 out of 9 cases (55.6%) with a bile duct filling pressure between 2.16-2.94 kPa, and in 9 out of 13 cases 69.2% with the pressure greater than 2.94 kPa. We believed that during direct cholangiography, the bile duct pressure should be lower than 2.94 kPa in order to prevent the complication of bacteremia. For patients hypersensitive to iodine, the bile duct pressure should be lower than 2.16 kPa.

Bile Duct Diseases↗
PubMed1991

Sphincter of Oddi motor activity in patients with anomalous pancreaticobiliary junction.

Sphincter of Oddi motor activity was investigated in seven patients with an anomalous pancreaticobiliary junction and in six controls by endoscopic manometry under fluoroscopy. Characteristic phasic wave activity was observed in the sphincter segment in both groups. Amplitude of the phasic contractions was significantly higher in the disease group than in controls (100.8 +/- 14.1 mm Hg vs. 55.2 +/- 4.3 mm Hg, p less than 0.02). Although those with the anomalous pancreaticobiliary junction had a longer common channel (15-30 mm), the length of the sphincter segment with the phasic wave activity was not different. The phasic activity was not seen at the junction of the pancreatic and bile ducts in disease groups. Bile obtained from within the bile duct showed a very high concentration of amylase. Morphine given to cause spasm of the sphincter increased basal pressure and frequency of the phasic waves in all controls. The response to morphine was similar in two patients in whom the anomalous junction was studied, but the procedure was complicated by acute pancreatitis in one of them. These findings suggest that contractions of the sphincter of Oddi in patients with the anomalous junction may contribute to reflux between the pancreatic and bile ducts, leading to various pathologic conditions associated with this anomaly.

Adult↗
PubMed1990

Islet cell tumors of the pancreas. The diagnostic value of endoscopic retrograde pancreatography.

Eleven cases of pancreatic islet cell tumors were reviewed to compare diagnostic ability of endoscopic retrograde pancreatography (ERP) with other imaging modalities. ERP localized three out of five tumors studied and showed a suspicious finding in an additional patient. All these tumors were located in the pancreatic head. Thus, the diagnostic ability of ERP was superior in the head portion, where recognition of a tumor is often difficult at the operation, and a more complicated procedure is required for removal. Nonfunctioning islet cell tumors were localized by hypervascularity on angiogram, but retroperitoneal leiomyosarcoma remained to be excluded in one patient. ERP with an indwelling balloon catheter revealed the pancreatic origin of the tumors and precisely determined the line of pancreatic resection by vividly visualizing pancreatic duct obstruction and intact distal branches. We conclude that ERP is helpful to localize functioning islet cell tumors of the pancreas especially in the head portion and plays an important role for planning resection of nonfunctioning islet cell tumors.

Adenoma↗
PubMed1990

Characterization and physical mapping of plasmids of black-pigmented Bacteroides.

Eight species of black-pigmented Bacteroides (BPB) were examined for plasmid content. Three classes of plasmids with molecular sizes of 16.0 kilobase (kb), 5.4 kb and 5.0 kb were found in 7 of 125 Bacteroides intermedius strains. One strain each of Porphyromonas (former Bacteroides) asaccharolyticus and of Bacteroides levii were also shown to have plasmids. However, no plasmids were detected in 90 strains of Porphyromonas (Bacteroides) gingivalis. The plasmids were purified and digested with restriction endonucleases for restriction mapping. The maps obtained in this study have given us information on the scheme of constructing recombinants which may be usable as shuttle vectors, by the recombination of BPB and Escherichia coli plasmids.

Bacteroides↗
PubMed1990

[Clinical utility of long-term administration of trapidil (MDR-1865) in the treatment of diabetic retinopathy].

In order to investigate the usefulness of prolonged administration of trapidil in the treatment of diabetic retinopathy, a follow-up study was carried out after the end of a placebo-controlled, double-blind study of the drug in case of the trapidil-treated group who continued to be treated with 300 mg/day of trapidil (Rocornal) (TT group) and those of the placebo group who were not given any treatment after the end of the study (PP group). The TT group was significantly superior or tended to be superior to the PP group in improvement of hard exudates, retinal hemorrhages and soft exudates, and also in improvement of capillary microaneurysms on fluorescein fundus angiography. In the course of diabetic retinopathy by the global evaluation of findings in individual cases, the TT group was significantly superior or tended to be superior to the PP group. Photocoagulation was performed on 20 (28%) of 72 eyes of the PP group and 13 (19%) of 68 eyes of the TT group, with the mean interval to photocoagulation being 7.2 months for the PP group and 14.0 months for the TT group. There was a significant difference between the 2 groups in terms of the interval to photocoagulation. Randomized fundus photographic evaluation of the findings by the central evaluation committee showed that the TT group was significantly superior or tended to be superior in improving retinal hemorrhages, soft exudates and leakage of fluorescein dye, and was also significantly superior or tended to be superior in relation to the course of the retinopathy, which was consistent with the evaluation by the attending ophthalmologists.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Intraretinal neovascularization in rats with experimental renovascular hypertension].

Newly formed intraretinal vessels caused by experimental renovascular hypertension were studied histopathologically in rats. In these rats, dystrophy of the outer retinal layer and disappearance of retinal small capillaries were found in correlation with the duration of hypertensive state. In particular, retina obtained from rats with severe hypertension maintained for 6 months or more showed marked tissue damage and intraretinal proliferation of pigment epithelial cell with numerous microvessels. Most of these vessels were characterized by endothelial cell with large nuclei and slit-like narrowed lumina. Similar microvessels were also frequently observed in neighboring pigment epithelial cell layer. Endothelial fenestrations were observed in these vessels, although no findings were observed suggesting vessels penetrating through Bruch's membrane from the choroid. Similar vessels were also found in the inner plexiform layer and rarely in the nerve fiber layer. They were surrounded by processes resembling basal infolding of pigment epithelial cell. However, no fenestration of endothelial cells was found in these vessels.

Animals↗
PubMed1989

Relationship of biliary pressure to cholangiovenous reflux during endoscopic retrograde balloon catheter cholangiography.

In 32 patients undergoing endoscopic retrograde cholangiography with a balloon catheter, culture of bile, biliary pressure at maximal visualization of the biliary tract with iodinated contrast medium, serum iodine concentrations, and blood cultures before and after the procedure were obtained. There was a significant increase in the serum iodine concentration in five of nine patients (55.6%) with pressure between 22 cm H2O and 30 cm H2O and in nine of 13 patients (69.2%) with pressure above 30 cm H2O, while it remained low in 10 patients with pressure below 22 cm H2O. Two patients showed positive blood culture after the procedure, which yielded the same organisms as found in the bile. The biliary pressures in these two patients were 30.4 cm H2O and 38.0 cm H2O. These data suggest that during retrograde balloon catheter cholangiography: (1) cholangiovenous reflux of contrast medium develops with biliary pressure higher than 22 cm H2O, (2) the indicence of the cholangiovenous reflux increases as the pressure is elevated, and (3) regurgitation of bacteria occurs with pressure greater than 30 cm H2O. These findings are noteworthy because the number of patients who need direct cholangiography is increasing.

Adult↗
PubMed1989

Choledochoscopic electrohydraulic lithotripsy and lithotomy for stones in the common bile duct, intrahepatic ducts, and gallbladder.

Choledochoscopic lithotomy with the aid of electrohydraulic lithotripsy was performed in 40 patients, including 16 patients with choledocholithiasis, 15 with hepatolithiasis, and 9 with cholecystolithiasis. As a route for the choledochoscopy, a T-tube tract, external cholecystostomy, or jejunal limb of hepaticojejunostomy was used in nine patients, while percutaneous transhepatic biliary drainage followed by dilatation of the track was established in 31 patients. The largest cholesterol stone measured 55 mm by 33 mm and the largest bilirubinate stone measured 52 mm by 37 mm. The stones were disintegrated in all but one patient in whom choledochoscopic access to a gallstone was difficult due to deformity of the gallbladder. Complete removal of the stones was achieved in 38 of 39 patients. In a patient with hepatolithiasis, small stones located deep in inaccessible branches of the intrahepatic duct remained unremovable. There were no serious complication. Minor complications occurred, including bleeding from the bile duct mucosa in four patients and postprocedure chills and fever in three. Choledochoscopic lithotomy with electrohydraulic lithotripsy is efficient and useful to remove biliary calculi in patients who are poor surgical risks.

Adult↗
PubMed1989

[Basilar bifurcation aneurysm associated with internal carotid artery occlusion. Report of two cases].

Two cases of subarachnoid hemorrhage caused by rupture of a basilar bifurcation aneurysm associated with occlusion of the internal carotid artery (ICA) at the neck are presented. Case 1, a 71-year-old female, was hospitalized in a coma. Angiography demonstrated occlusion of the bilateral ICA, collateral blood supply through the branches of the foramen rotundum or vidian artery from the maxillary arteries and right posterior communicating artery, and a saccular aneurysm at the basilar bifurcation. The patient died 1 month later following rerupture of the aneurysm. Case 2, a 64-year-old male, was hospitalized for drowsiness. Angiography showed occlusion of the right ICA, collateral blood supply through a tortuous artery (a vidian artery), and a large aneurysm at the basilar bifurcation. Posterior circulation supplied anteriorly through the right posterior communicating artery. The patient died 1 month later because of rerupture of the aneurysm. Laminar thrombosis of the right ICA and an anastomotic vessel, seemingly a branch of the foramen rotundum or a vidian artery, were demonstrated by autopsy. The combination of cerebral aneurysm and collateral circulation is extremely rare in cases of occlusion of the ICA. The two cases described here suggest that hemodynamic stress is an important factor in the formation of cerebral aneurysms.

Aged↗
PubMed1989

Coexistence of cerebral aneurysm and renal angiomyolipoma--case report.

We report a late middle-aged female in whom a renal angiomyolipoma was discovered by ultrasound after she developed hemorrhagic shock following surgery for a ruptured cerebral aneurysm. This appears to be the first reported case of the coexistence of a cerebral aneurysm and a renal angiomyolipoma. The associations between cerebral aneurysm and various other pathological conditions are discussed, and attention is directed to diagnostic techniques and characteristic findings.

Female↗
PubMed1989

[Anterior pituitary function in the vegetative state].

Anterior pituitary function tests were performed in 33 patients in the vegetative state, and the results were assessed for correlation with various clinical factors. Radioimmunoassays were employed to measure the secretion of growth hormone and cortisol during insulin tolerance testing (regular insulin, 0.15 to 0.20 U/kg), luteinizing hormone and follicle stimulating hormone under administration of luteinizing hormone-releasing hormone (100 micrograms), and thyroid stimulating hormone and prolactin under administration of thyroid-releasing hormone (500 micrograms). Impairment rate, defined as number of abnormal hormone secretions divided by number of hormones examined, was calculated for each patient. The data were statistically assessed by analysis of variance in terms of disease, sex, age, site of lesion, etiology of vegetative state, duration of illness, brain atrophy as demonstrated by computed tomography, and Hockaday's electroencephalographic (EEG) grade. The results were as follows. 1) The levels of growth hormone, luteinizing hormone, follicle stimulating hormone, cortisol, thyroid stimulating hormone, and prolactin were abnormal in 70%, 67%, 45%, 39%, 36%, and 15% of cases, respectively. 2) Anterior pituitary hormone secretion was impaired in all 33 patients, severely in 52%. 3) The impairement rate was significantly increased in patients with ruptured cerebral aneurysms, primary coma, severe brain atrophy, and abnormal EEGs. 4) The impairment rate tended to be higher in long-term vegetative patients. These results suggest that, in the vegetative state, impairment of anterior pituitary function frequently occurs at the onset of disease and worsens over time.

Adolescent↗
PubMed1989

[Clinical study of hypertensive cerebellar hemorrhage: surgical indication and measurement of volume of hematoma].

There have been a few reports available for determining surgical indications in hypertensive cerebellar hemorrhage based on volume of hematoma on computerized tomography (CT). The authors then studied the clinical results of hypertensive cerebellar hemorrhage, and the surgical indication based on clinical findings and volume of hematoma on CT scan was considered. Forty-five patients with hypertensive cerebellar hemorrhage diagnosed by CT scan who were hospitalized to Matsue Red Cross Hospital from January 1980 up to December 1986 were studied. The 25 male and 20 female patients ranged in age from 52 to 85 years, and 16 of them were operated on. The results were as follows: 1) The Kanaya's neurological grading tended to be high in the patients with cerebellar vermis hemorrhage or a large volume of hematoma (greater than or equal to 30 ml). 2) In patients with grade I or II and a moderate volume of hematoma (15-30 ml), the patient complicated with hydrocephalus should be treated with ventricular drainage. The patients with grade III and IVa should be treated with surgical therapy (suboccipital craniectomy and evacuation of the hematoma). The patients with cerebellar vermis hemorrhage should be treated with surgical therapy. The patients with a large volume of hematoma (greater than or equal to 30 ml) should be treated with surgical therapy. The patients with grade IVb and V should not be treated actively because the prognosis is bad.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Combined long-term toxicity/carcinogenicity test of alpha-bromocinnamic aldehyde (BCA) applied to female mouse skin].

Bromocinnamic aldehyde (BCA), an antibacterial/antifungal agent, was tested for its chronic toxicity/carcinogenicity in female Slc:ddY mice. The animals received 0.25%, 1.0% and 4.0% of BCA dissolved in olive oil applied to the shaved back skin area twice a week for 79 weeks. The control group received olive oil alone under similar conditions. In addition to these animals, 5 animals in each group were killed at 6 and 12 months for investigation of the time-related toxic effect of BCA. A slight inhibition of body weight increase and a slight decrease in the survival rate were seen in the 4.0% BCA-treated group. No significant changes were observed in hematological parameters at 6, 12 and 18 months. In chemical biochemistry determination in the blood at 6 and 12 months, a significant decrease in non-esterified fatty acid and phospholipid values was observed in the experimental groups. Histopathologically, necrosis, scabbing, cell infiltration and thickening of the epidermis were noted at the site of application in the 4.0% BCA group. Moreover, extramedullary hematopoiesis and amyloid degeneration were detected in the spleen, while the incidence of adenomas in the lung decreased with a dose-response. These changes seemed to be the result of a non-specific inflammatory reaction to the irritation effects of the agent on the skin. No significant differences in the incidence of tumors were found between the control and experimental groups, not only at the site of application but also in other organs, although lung adenomas decreased dose-dependently in all treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldehydes↗
PubMed1989

[Distribution of cone pedicle and superficial capillary. A morphological study on the macular region of normal human retina].

The distribution and arrangement of cone pedicle (CP) and peri-foveolar superficial capillary net works (SC) in the macular region was studied in two eyes obtained from a 24-year-old male and a 34-year-old female, light and electron microscopically. CP and SC were not seen in the central area of the macular region. Both the CP-free zone and SC-free area were ellipsoid in form and the horizontal dimensions were larger than 140 microns and 425 microns in one case and 360 microns and 630 microns in the other. The dimensions of the SC-free area measured 200 microns and 500 microns in the first case and 520 microns and 650 microns in the second. The para-foveolar circle formed by CP- and SC-free zones were concentric and the SC circle was about 50 microns larger in radius than that of CP.

Adult↗
PubMed1988

Nonoperative removal of giant common bile duct calculi.

Endoscopic sphincterotomy has allowed us to extract relatively large stones from the common bile duct as compared with other methods utilizing a T-tube tract or the percutaneous transhepatic route. Twenty-four patients with large stones over 20 mm in diameter were selected and reviewed from a series of 469 sphincterotomy patients. Eleven stones passed into the duodenum spontaneously, the maximal size of which was 30 by 43 mm. Passage occurred within 4 days after sphincterotomy in 27 percent, 5 to 7 days after the procedure in 55 percent, and 8 to 13 days after the procedure in 18 percent and was accompanied by cholangitis in 55 percent of the patients. The small diameter of the stone and common bile duct dilatation down to the distal end seemed to be the factors favoring stone delivery. Five stones were removed using ordinary basket catheters by duodenoscopy; however, the largest one required 28 attempts. More recently, four stones were efficiently extracted after destruction by electrohydraulic or mechanical lithotripsy. Failure of removal in five patients was mainly due to a lack of space around the stone for basket manipulation or occurrence of severe cholangitis. Further refinements in technique in this regard are needed.

Adult↗
PubMed1988

Endoscopic sphincterotomy: long-term results in 408 patients with complete follow-up.

Endoscopic sphincterotomy was performed in 469 patients for the treatment of biliary calculi, with procedure-related morbidity of 6.3% and mortality of 0.4%. Long-term follow-up to 10.5 years (mean 3.7 years) was completed in all of 408 patients at least six months postsphincterotomy. Recurrent stones developed in 21 patients (5.8%) after a mean of 2.4 years (range 4 months to 7 years); in 6 after 3 years. Eight patients reformed stones more than twice at a mean interval of 1.8 years (range, 5 months to 3.5 years). In the 122 patients with gallbladders in situ, acute cholecystitis occurred in 5 of 31 with gallstones (16%), but in none of the 91 without gallstones. In the 237 patients who had undergone cholecystectomy, 4 late deaths occurred secondary to recurrent choledocholithiasis and cholangitis. In the 49 patients with primary intrahepatic stones, 3 late deaths occurred secondary to hepatic abscess. These results suggest that (a) endoscopic sphincterotomy is a very effective procedure in long-term follow-up, (b) cholangiography should be done at the appearance of slight abdominal symptoms even after 3 years, (c) patients who have ever reformed stones should undergo cholangiography yearly for at least 4 years, and (d) cholecystectomy is recommended for patients with gallbladders after sphincterotomy, only if gallstones are present.

Adult↗