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Biomedical subjects

H Yokoi

Publications and source records attributed to H Yokoi.

At least 145 records · Page 8Linked to original sources
PubMed1993

Acute myocardial infarction induced by ergonovine administration for artificially induced abortion.

Acute myocardial infarction after artificially induced abortion is an uncommon event because such patients are usually young females and are not usually subject to atherosclerosis. This report describes two premenopausal females who developed acute myocardial infarction after administration of ergot derivatives which were used following abortion. Coronary arteries in both cases were angiographically normal. Both patients were smokers. We concluded that the ischemic event was caused by coronary vasospasm which was precipitated by the acute administration of ergot derivatives.

Abortion, Induced↗
PubMed1992

Significance of multidisciplinary therapy for hepatocellular carcinoma.

The effect of multidisciplinary therapy for hepatocellular carcinoma (HCC) was evaluated in 121 resected cases. The 5-year survival was 100% for absolute curative resection (12 cases), 59.1% for relative curative resection (n = 37) and 10.9% for relative non-curative resection (n = 59). However, none of the patients survived for more than 3 years after absolute non-curative resection (n = 13). The non-recurrence in the preoperative TAE groups was different from that in non-TAE groups undergoing absolute and relative curative resection. The 1- and 3-year non-recurrence rates for relative non-curative resection were 92.3% and 53.8%, respectively, for the preoperative TAE group and 56.1% and 28.1%, respectively for the non-TAE group. These data show that preoperative TAE is effective in relative non-curative resection. Functional disturbances of the coagulation-fibrinolysis system in cirrhotic patients were improved after PSE. All patients undergoing hepatectomy after PSE had an uneventful postoperative course, including well-maintained function of the coagulation-fibrinolysis system and a decrease in splenic volume. At 1 year after hepatectomy, cirrhotic patients with critical liver function and poor coagulation-fibrinolysis showed appreciable hepatic regeneration. One patient died of hepatic failure 1 year after the operation. In recurrent HCC, the 1-, 2- and 3-year survival values after reresection were 100%, 75.0% and 25.0%, respectively. The respective values following TAE were 79.0%, 42.0% and 9.0%. Three cases of recurrent HCC were effectively treated, i.e., two patients achieved a partial response and one showed no change, by continuous intra-arterial infusion of 5-FU and lentinan with intermittent one-shot injections of epirubicin using a subcutaneous infusion pump. These three patients are alive at 1 year and 7 months, 1 year and 4 months and 6 months after the treatment, respectively.

Adult↗
PubMed1992

Statistical analysis of clinical risk factors for coronary artery spasm: identification of the most important determinant.

Coronary artery spasm plays an important role in acute ischemic events, and it has a close relationship with coronary atherosclerosis. Thus we attempted to determine the most significant risk factor for coronary artery spasm. Among 3000 consecutive patients who underwent coronary cineangiography with ergonovine maleate testing, 330 with typical angina pectoris (group 1) and 294 with old myocardial infarction (group 2) were studied. We divided each group into three or four subgroups according to the presence of fixed organic stenosis (FOS+) or a positive reaction to ergonovine maleate (coronary artery spasm [CAS]+). We examined the relationship between coronary artery spasm and eight coronary risk factors: age, sex, hypertension, diabetes mellitus, smoking, and serum cholesterol, uric acid, and high-density lipoprotein cholesterol levels. The proportion of smokers in the subgroups with CAS(+) was significantly higher than in the subgroups with CAS(-)(p less than 0.01). There was no correlation between smoking and fixed organic stenosis. According to the results of multiple regression analysis, there was a positive correlation between smoking and CAS(+) and between serum high-density lipoprotein cholesterol levels and CAS(+)(p less than 0.01). Thus we concluded that smoking is the most significant risk factor in discriminating between patients with and without coronary artery spasm.

Cholesterol, HDL↗
PubMed1992

Primary esophageal non-Hodgkin's lymphoma.

A 77-year-old woman with primary esophageal non-Hodgkin's lymphoma in clinical stage IEA (Ann Arbor Classification) developed pain and difficulty in swallowing. An upper gastrointestinal examination revealed a submucosal tumor from the upper to the middle portion of the esophagus. Histopathological examination at endoscopic biopsy with endoscopic partial incision showed non-Hodgkin's lymphoma (diffuse type--large cell). Immunohistological examination of tumor cells disclosed LCA (+), CD3(DAKO) (+), MT1 (+), UCHL1 (+), MB1 (+), MxPanB (-) and EMA (-) reactivity and showed T cell lymphoma. The clinical stage was determined to be IEA after further work-up. Improvement of swallowing difficulty and esophageal findings on upper gastrointestinal series were noted after modified CHOP therapy and radiotherapy (total 50 Gy).

Aged↗
PubMed1992

Intraductal mucin-producing tumors of the pancreas.

Four cases of intraductal mucin-producing tumors of the pancreas are presented, with a literature review. These tumors have been reported with increasing frequency, especially in Japan, since it was advocated that they represented a new clinical entity in 1982. Despite the recent controversy, intraductal mucin-producing pancreatic tumor has been recognized as a distinct entity, i.e., mucinous ductal ectasia. In the present paper, clinical features of these tumors and their relation to our own classification of mucin-producing pancreatic tumors are discussed.

Adenocarcinoma, Mucinous↗
PubMed1992

Mucin-producing cystic adenocarcinoma of the pancreas, a case report, 7-year follow-up period.

Mucinous ductal ectasia is recognized as a premalignant disease. Recently, we have encountered a patient with a mucin-producing neoplasm of the pancreas, who had been under periodic observation for chronic pancreatitis for 7 years prior to diagnosis of carcinoma and surgery. A 54-year-old male who had been investigated with US, CT and ERCP for chronic pancreatitis developed a mucin-producing ductal carcinoma of the pancreas. In this case a series of US and ERCP images obtained during the 7-year period had demonstrated insidious growth of the tumor. Pancreaticoduodenectomy was carried out, and the histopathological diagnosis was mucin-producing adenocarcinoma of the pancreas. The patient has been well and has suffered no recurrence for 2 years after surgery.

Adenocarcinoma, Mucinous↗
PubMed1992

[Analysis of factors affecting anaerobic threshold in healthy subjects].

The anaerobic threshold (AT) is used to determine the exercise capacity in patients with heart failure and healthy subjects. To determine the factors affecting AT, we determined the AT in healthy subjects, and examined the factors that determine AT in healthy subjects. One hundred and sixteen healthy subjects (79 men and 37 women) performed on a bicycle a stepwise increasing submaximal exercise. During the work test the parameters usually used in the detection of AT (Vo2, Vco2, VE), blood pressure, heart rate and oxygen saturation were recorded by a computerized system every minute. AT was determined from changes in ventilation and gas-exchange. The fat index was calculated from height and body weight measured at the beginning of the ventilatory function test. A significant correlation was obtained between AT and age, AT and fat index, AT and %VC, AT and maximum heart rate during exercise, AT and recovery rate of heart rate after exercise, and AT and Vo2 at rest. In addition, we examined the relationship among the parameters in 4 groups according to sex and age (30-49; younger, 50-69; older), because sex and age affected most parameters. We found a significant correlation between AT and fat index (older men and women), AT and %VC (younger and older women), AT and Vo2 at rest (younger and older men). We considered that the main factors that determined AT in healthy subjects were age, sex, fat index, %VC and Vo2 at rest.

Adolescent↗
PubMed1991

Fibrolamellar carcinoma of the liver--a case report.

A 36-year-old woman was admitted to our hospital because of general fatigue. The physical and laboratory findings on admission revealed splenomegaly, pancytopenia, hypocoagulopathy, liver hypofunction with a hepaplastin test of 55% and ICG Rmax of 0.6 mg/kg/min. Diagnostic imaging showed a hypoechoic mass 1.5 in diameter a low density area on the CT scan and a faint tumor stain on the AAG in the posterior inferior area of the liver. On a diagnosis of hepatocellular carcinoma with liver cirrhosis and hypersplenism, partial hepatectomy and splenectomy were performed. The resected hepatic specimen revealed a small liver cancer of 1.9 x 1.5 x 1.3 cm with liver cirrhosis. The specimen consisted of a firm rubbery mass. Macroscopically, the tumor appeared oval and was lobulated with a thin capsule. A fibrous scar was observed in the central area. Microscopically, malignant hepatocytes showed various shapes, ranging from polygonal to spindle form, with eosinophilic granular cytoplasm and were surrounded by abundant fibrous stroma. Orcein stain, revealed that these malignant hepatocytes contained many black granules of copper-binding protein. Immunoperoxidase staining for alpha 1-antitrypsin was also positive in the malignant hepatocytes. However, within this lamellar fibrous regions, there were many cords of tumor cells in which nucleoli were absent and abortive biliary differentiation was suggested. Consequently this tumor was diagnosed as an atypical fibrolamellar hepatocellular carcinoma. We think that this case is the 3rd case reported in Japan and the 2nd case in a Japanese person.

Adult↗
PubMed1991

The role of peripheral capacitance and resistance vessels in hypotension following hemodialysis.

The arterial pressure (AP) response to hemodialysis was studied with echocardiography and strain gauge plethysmography in 17 patients with end-stage renal disease; mean AP was unchanged in seven (group A) and was reduced by more than 10 mm Hg in 10 patients (group B). Following dialysis, body weight decreased and heart rate increased equally in both groups. Ejection fraction did not change in the two groups. Left ventricular end-diastolic volume fell by 13 +/- 10% in group A and by 24 +/- 16% in group B. Cardiac index (CI) fell in group B, but remained unchanged in group A. Systemic vascular resistance (SVR) did not change in both groups. The change in mean AP before and after dialysis was significantly correlated with that in Cl (r = 0.49, p less than 0.05), but not with that in SVR. Calf venous pressure-volume curves were not different between the two groups before dialysis. Hemodialysis shifted the curve toward the volume axis for group B but not for group A. These results suggest that hypotension following dialysis is mainly due to the fall in cardiac output, in which increases in venous distensibility play an important role.

Blood Volume↗
PubMed1991

Some taxonomical characteristics of encapsulated Lactobacillus sp. KPB-167B isolated from kefir grains and characterization of its extracellular polysaccharide.

A capsular polysaccharide-producing strain KPB-167B isolated from kefir grains was identified as a homofermentative Lactobacillus. The carbohydrate fermentation pattern and DNA base composition of the strain were different from those of other capsular Lactobacillus species previously isolated from kefir grains. The polysaccharide produced by Lactobacillus sp. KPB-167B was found similar to kefiran by 13C-NMR and methylation analysis. Lactobacillus sp. KPB-167B could grow and produce capsular polysaccharide in MRSL medium with better yield than L. kefiranofaciens, which suggested that it is suitable for kefiran production.

Animals↗
PubMed1991

Progression of coronary atherosclerosis: is coronary spasm related to progression?

A total of 239 patients undergoing serial coronary angiography with a concomitant ergonovine provocation test were studied between July 1974 and June 1987. The progression of coronary artery disease was evaluated in relation to risk factors, especially coronary artery spasm. Patients were classified into three groups: 1) new myocardial infarction group (39 patients); 2) progression without infarction group (90 patients); and 3) nonprogression group (110 patients). To assess how risk factors and coronary spasm are related to the occurrence of new myocardial infarction and progression without infarction, 11 variables in the three groups were examined: age, gender, the time interval between the studies, fasting blood sugar, systolic blood pressure, diastolic blood pressure, smoking, serum cholesterol, triglyceride, uric acid and a positive response to the ergonovine provocation test. Multiple regression analysis selected three independent predictors of progression without infarction: cholesterol (p less than 0.01), systolic blood pressure (p less than 0.05) and a positive response to the ergonovine provocation test (p less than 0.001). Multiple regression analysis also selected three independent predictors of the occurrence of new myocardial infarction: fasting blood sugar (p less than 0.01), systolic blood pressure (p less than 0.05) and a positive response to the ergonovine provocation test (p less than 0.001). A positive response to the ergonovine provocation test was the strongest factor for occurrence of both new myocardial infarction and progression without infarction. To evaluate segmental arterial changes, 3,275 coronary artery segments were analyzed in the 239 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗
PubMed1991

Laser microdissection and single unique primer PCR allow generation of regional chromosome DNA clones from a single human chromosome.

We have developed an argon laser chromosome microdissection technique in conjunction with a polymerase chain reaction (PCR) approach to directly amplify microdissected chromosomes. The single 22-mer primer used in PCR, although unique in sequence (5'-TAGATCTGA-TATCTGAATTCCC-3'), randomly primed and amplified any target DNA. These methods were applied to the distal half of the short arm of human chromosome 4 containing the Huntington disease (HD) locus. Forty-four percent of representative clones from this library identify single-copy DNA sequences. This calculation suggests that the resulting chromosome-specific DNA library contains approximately 600 nonoverlapping sequences with an average size 350 bp at an average spacing of 30 kbp along chromosome 4. This microdissection and PCR cloning procedure is a simple and general approach for constructing a chromosome region-specific DNA library from a single metaphase spread.

Base Sequence↗
PubMed1991

Restenosis after percutaneous transluminal coronary angioplasty: pathologic observations in 20 patients.

Histopathologic examination was performed in 20 patients undergoing antemortem coronary angioplasty. Thirty-four lesions were dilated and the interval between coronary angioplasty and death ranged from several hours to 4 years. Intimal proliferation of smooth muscle cells, as a major cause of restenosis, was observed in 83% to 100% of 28 lesions examined 11 days to 2 years after coronary angioplasty. In 20 lesions examined within 6 months, proliferating smooth muscle cells were predominantly of the synthetic type and there was abundant extracellular matrix substance chiefly composed of proteoglycans. In eight lesions examined between 6 months and 2 years, contractile type smooth muscle cells were dominant and extracellular matrix was composed chiefly of collagen. In three lesions examined after 2 years, evidence of antemortem coronary angioplasty was hardly identifiable and these lesions were almost indistinguishable from conventional atherosclerotic plaque. These temporal changes in histologic pattern provide a pathologic background for clinical reports that restenosis is predominantly found within 6 months after coronary angioplasty. Morphometric analysis revealed that the extent of intimal proliferation was significantly greater in lesions with evidence of medial or adventitial tears than in lesions with no or only intimal tears.

Aged↗
PubMed1991

[Morphological study of cochlea in experimental chronic serum sickness].

Relationship of circulating immune complexes to some inner ear disorders has been suggested recently. Thus, bovine serum albumin (BSA) nephritis, a model of chronic serum sickness, was made and morphological, immunological studies of cochlea were performed using light microscopy, transmission electron microscopy and immunofluorescent antibody methods. Group 1 consisted of animal sensitized with daily BSA injections for 90 days; in group 2, BSA was administered for 70 days, daily, and after a three-weeks interval, injections were continued for another 21 days; group 3 consisted of animals sensitized with daily BSA injections for 100 days followed by BSA injection into the facial nerve via the stylo-mastoid foramen. The animals (group 3) were sacrificed on day 1 and 4 following facial nerve sensitization for examination of cochlear morphological changes. No morphological changes were observed (group 1). Protrusion of marginal cells into endolymphatic space was seen, because of swelling of endoplasmic reticulum of the cells of stria vascularis's (group 2). Slight hydrops was present mainly in the basal turn (group 3). No IgG deposits were found in all groups. It appears that the changes in group 2 were caused by rather chronic nephritis than immune reaction. We conclude that damage induced in the cochlea is negligible compared to the extensive lesions observed in the kidney in chronic serum sickness.

Animals↗
PubMed1991

[Electron microscopic study on inner ear barotrauma: with emphasis on the cochlear damage].

In order to investigate inner ear barotrauma, guinea pigs were subjected to rapid decompression between 2 absolute pressure (ATA) and 1 ATA in a chamber. After pressure loading and observation for absence of Preyer's reflex, they were sacrificed immediately, 1 day, 1 week and 1 month later, respectively. Then, morphological changes of the organ of Corti and stria vascularis were studied under TEM and SEM. The immediate features noted were fracture of stereocilia with minimal intracellular changes. One day later, there was marked degeneration of outer hair cells and expansion of supporting cells. The damage to stereocilia clearly preceded morphological alterations within hair cell bodies and cannot be interpreted as arising secondary to hair cell degeneration. Most of outer hair cells eventually disappeared and were replaced by supporting cells. Inner hair cells degenerated slowly; 1 month later, some of them remained almost intact, despite disappearance of stereocilia. The continuity of reticular lamina was maintained not only immediately but also through the period of hair cell degeneration, thus preventing any leakage of endolymph into the organ of Corti. There was reversible dendritic swelling of inner hair cells immediately following the trauma. No changes of stria vascularis were observed over passage of time. The mechanism of hair cell damage due to inner ear barotrauma is presumed to be a deformity of the organ of Corti caused by pressure discrepancy between perilymph and endolymph resulting in an injury to stereocilia.

Animals↗