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Biomedical subjects

H Yokoi

Publications and source records attributed to H Yokoi.

At least 163 records · Page 9Linked to original sources
PubMed1991

[Multidisciplinary therapy after hepatectomy for hepatocellular carcinoma from the view point of tumor recurrence].

This study was performed to elucidate the risk factors of early recurrence after hepatectomy for the 112 patients with hepatocellular carcinoma, excluding absolute non-curative resections and operative deaths, and effects of early prophylactic management were evaluated. In Cox's multivariate analysis, 3 pathological factors of portal vein invasion, intrahepatic metastasis and capsule formation or capsule infiltration as well as the nuclear DNA ploidy pattern were significantly correlated to postoperative recurrence. The patients with 2 or more pathological factors or with DNA aneuploid tumors developed recurrence at early postoperative period. However, even in the DNA aneuploid tumors, the patients with high DNA index and low S-phase fraction showed relatively better prognosis. Argyrophilic proteins of nucleolar organizer regions (AgNOR) were also correlated well to nuclear DNA analysis, showing one of the good indicators for estimating biological malignant nature. Therefore, intra-arterial regional chemolipiodolization therapy should be performed for these high risk patients at early period after hepatectomy. With these managements we have been getting much lower incidence of early recurrence.

Carcinoma, Hepatocellular↗
PubMed1991

[Angiography of silent myocardial ischemia].

From March 1986 through October 1987, elective diagnostic coronary angiography was performed in 1,542 consecutive patients. Among them, silent myocardial ischemia was investigated based on the histories in their medical questionnaires, the results of exercise stress tests and the presence of significant coronary artery stenosis. Exercise-induced silent myocardial ischemia was documented only in 3% in the non-infarction group, and in 2.1% of those with significant coronary stenosis. However, asymptomatic post-infarction patients comprised 33%. With regard to the extent of coronary artery disease in the non-infarction group, one-, two- and three-vessel disease accounted for 42%, 29% and 29%, respectively (NS). However, one-vessel disease was predominant among the asymptomatic post-infarction patients (p < 0.01). Among the non-infarction group, those with asymptomatic coronary stenosis had a relatively high incidence of diabetes mellitus (p < 0.01), but such a difference was not significant among the asymptomatic post-infarction patients. Among the post-infarction group, many of those who had chest pain during exercise showed redistribution on exercise thallium scintigraphy. Angioplasty was performed in most of the patients in the asymptomatic group, but its long-term effects are yet unknown.

Adult↗
PubMed1990

Clinicopathological studies and operative results of hepatocellular carcinoma with liver cirrhosis, comparing HB-associated cirrhosis to alcoholic and post-transfusion cirrhosis.

The present study was undertaken to elucidate clinicopathological findings and operative results of HCC with HB-associated cirrhosis, compared with those in HCC patients with alcoholic and post-transfusion cirrhosis. The number of the HBV group was 26 cases, consisting of 17 in sAg(+), 4 in eAg(+) and 5 in eAb(+) subgroups. The number of the post-transfusion group was 7 and that of alcoholic group was 12. A high incidence of hypersplenism and esophageal varix in the eAg(+) subgroup was found. ICG R15 was the highest, KICG and ICG Rmax were the lowest in the eAg(+) subgroup. The mean diameter of tumors was the largest, 6.6 +/- 3.9 cm, in the sAg(+) subgroup and was the smallest, 2.2 +/- 1.7 cm, in the eAg(+) subgroup. The incidence of postoperative jaundice, hyperammoninemia and live dysfunction were the highest in the sAg(+) and eAg(+) subgroup. One and three-year survival rate were 76.9% and 48.1% in the sAg(+) subgroup, 60.0% and 30.0% in the eAb(+) subgroup, and the one-year survival rate in the eAg(+) subgroup was 50.0%. The three-year survival rate could not be calculated because 3 years had not passed since the operation. The prognosis was the poorest in the HBV group among all groups. This study suggests that in HBV-associated cirrhosis, hepatectomy might induce "acute on chronic" changes (acute hepatitis and fulminant hepatitis). Therefore we should select operative procedures by considering surgical risk and the etiology of liver cirrhosis in hepatectomy.

Adult↗
PubMed1990

[A case of giant thymolipoma in a child].

A case report of a giant thymolipoma in 6-year-old boy is reported. Following school screening, an abnormal shadow in the left chest was found on the chest X-ray. CT scan and MRI suggested the mediastinal tumor containing a fatty mass. The tumor was resected on bloc through the median sternotomy and left antero-lateral thoracotomy. The tumor was 85 X 210 X 140 mm in size and 1380 g in weight. The postoperative histological examination revealed the thymolipoma. We were able to find only 19 other reported cases of thymolipoma in Japanese literature. Of 19 cases, this thymolipoma is the largest one in proportion to the patient's body weight.

Child↗
PubMed1990

[A case of mediastinal cavernous hemangioma].

A 6-year-old boy had an abnormal shadow on the chest X-ray film. It showed a tumor shadow with calcification on the right hilum. The plain CT scan showed an anterior mediastinal mass and its density was similar to that of large vessels. On the angio CT scan the lesion displayed a much lower enhancement than large vessels. The tumor was resected completely by median sternotomy. It was 5.6 X 3.6 X 3.0 cm in size and contained a phlebolith 5 mm in diameter. The histological diagnosis was cavernous hemangioma.

Child↗
PubMed1989

Indications, complications, and short-term clinical outcome of percutaneous transvenous mitral commissurotomy.

Percutaneous transvenous mitral commissurotomy was performed in 106 consecutive patients. Significant symptomatic improvement was achieved in 97 patients (92%). Mean left atrial pressure decreased (from 18 +/- 8 to 11 +/- 8 mm Hg, p less than 0.00001), mean mitral diastolic pressure gradient decreased (from 12 +/- 7 to 7 +/- 6 mm Hg, p less than 0.00001), and mitral valve area increased (from 1.40 +/- 0.40 to 2.00 +/- 0.50 cm2, p less than 0.00001). Based on echocardiographic characteristics of the mitral apparatus, patients were grouped retrospectively in three categories: pliable (group 1, n = 37), semipliable (group 2, n = 59), and rigid (group 3, n = 10). Clinical success was achieved in 36 patients of group 1 (97%) and in 55 patients of group 2 (93%). Only six patients in group 3 (60%) improved symptomatically (p less than 0.001 vs. group 1, p less than 0.001 vs. group 2). The severity of mitral regurgitation increased in five patients of group 1 (14%), in 12 of group 2 (20%), and in three of group 3 (33%). Six patients had recurrent symptoms at 9 months after commissurotomy. Recurrence of symptoms was significantly more frequent in group 3 compared with the other two groups (group 1, 3%; group 2, 4%; and group 3, 50%; p less than 0.0001 vs. groups 1 and 2). Multiple regression analysis identified the previously mentioned echocardiographic characteristics of the mitral apparatus as the significant predictor for clinical outcome. Thus, percutaneous transvenous mitral commissurotomy can be considered a safe and effective treatment for patients with pliable valves. Patients with semipliable or with rigid valves should be selected for operation very carefully.

Adult↗
PubMed1989

[Clinical evaluation of surgical treatment of lung cancer involving the chest wall].

Twenty-four patients with primary lung cancer involving chest wall underwent pulmonary and chest wall resections. All patients were males ranging from 38 to 74 years of age. Pain was the most frequent symptom. Twenty-three lobectomies and one pneumonectomy were performed. Resections of parietal pleura were performed in 4 patients and en block resections of chest wall were performed in 20 patients. After operation, postsurgical stage was pT3N0M0 in 16 patients, pT3N1M0 in 4 patients and pT3N2M0 in four. Operative mortality was 4.2%. Actuarial survival of 23 patients surviving operation was 45.7% at 1 year, 28.7% at 2 year and 17.2% at 3 and 5 year. Three patients who had no lymphnode metastases and no rib invasion survived more than 5 years. We concluded that long term survival can be expected in pN0 patients without invasion to the ribs.

Adenocarcinoma↗
PubMed1989

[Progression of a new lesion after percutaneous transluminal coronary angioplasty--report of a case].

A-62-years-old man was admitted our hospital because of angina at rest and during effort. Coronary angiography revealed 25% fixed stenosis in Seg. 6, 90% in Seg. 7, 75% in Seg. 10, and 50% in Seg. 12. Percutaneous transluminal angioplasty was performed for segment 7 and complete revascularization was obtained finally. Two and a half months later, progressive lesion occurred in the segment proximal to the angioplasty site (Seg. 6). The manipulation of the guiding catheter in the coronary artery proximal to the PTCA site might have developed atherogenesis in this area. So we must consider the possibilities of both restenosis and new lesions when one has the recurrence of ischemic symptoms after coronary angioplasty.

Angina Pectoris↗
PubMed1989

[Gastroesophageal reflux after esophageal surgery--evaluations based on esophageal transit scintigram].

By means of esophageal transit scintigram using 99mTc-DTPA, 15 patients (13 esophageal carcinomas and 2 cardia carcinomas) were studied, in whom esophagogastric anastomosis was done according to the posterior invagination anastomosis technique we had devised. In all 8 patients with anastomosis at cervical region, gastroesophageal reflux was not seen on both scintigrams before and after meals, and the average pressure gradient of high pressure zone at anastomosis was 39.8 cmH2O. In 2 of 7 patients with intrathoracic anastomosis, the scintigram before meals showed severe reflex, and the endoscopic findings showed diffuse and moderate erosion in the esophageal mucosa. The average pressure gradient across the anastomosis was 6.5 cmH2O. In these 2 patients, the new fornix with a sharp angle of His was not formed. In the remaining 5 patients with intrathoracic anastomosis, reflux was not seen on the scintigram before meals. However, in 2 of them, the scintigram after meal and endoscopic examination revealed mild reflux and mild esophagitis respectively. Furthermore in one patient very mild reflux was observed only on the scintigram after meals but the endoscopic findings showed the normal esophageal mucosa. In these 5 patients, the average pressure gradient across the anastomosis was 17.0 cmH2O, which was significantly higher (p less than 0.01) than that in 2 patients with severe reflux and was significantly lower (p less than 0.01) than the mean value of high pressure zone in 8 patients with cervical anastomosis. In conclusion, it is presumed that the formation of a large fornix enough to store food and a sharp angle of His are important factors in maintaining an anti-reflux mechanism. The esophageal transit scintigram was proved to be an excellent technique in detecting and evaluating quantitatively gastroesophageal reflux.

Aged↗
PubMed1989

[An approach of in vivo measurement for ultrasonic myocardial tissue characterization].

The purpose of this study is to characterize regional myocardial alternations of reflected ultrasound throughout a cardiac cycle in normal and ischemic myocardium. Integrated ultrasonic backscatter (2-5 MHz) gated R wave of ECG was measured at the base, middle and apex in 4 dogs, and the apex before and after ischemia in other 4 dogs. Quantitative ultrasonic backscatter (IB) was reflected to a steel reflector. At the apex and middle, where a cyclic pattern of IB was discernible, maximum values were recorded near end diastole and minimum near end systole. The amplitude of the variation of IB throughout a cardiac cycle for each region increase progressively from base to middle to apex. Time-averaged IB over a cardiac cycle (averaged IB) was similar for each area of the heart (base = -50.6 +/- 0.5 dB (mean +/- SE), middle -49.4 +/- 0.5 dB, apex -49.7 +/- 0.6 dB. p = NS for comparison of any two regions). After occluding left anterior descending coronary artery for 30 minutes, the variation of IB was markedly blunted and averaged IB increased significantly (-47.5 +/- 0.5 dB. p less than 0.01 compared with preocclusion (-50.8 +/- 0.5 dB]. These results suggested that IB and averaged IB may permit assessment of intrinsic geometrical changes throughout a cardiac cycle (contractile properties) and histological changes respectively.

Animals↗
PubMed1988

Restenosis after successful percutaneous transluminal coronary angioplasty: serial angiographic follow-up of 229 patients.

To further understand the temporal mode and mechanisms of coronary restenosis, 229 patients were studied by prospective angiographic follow-up on day 1 and at 1, 3 and 6 months and 1 year after successful percutaneous transluminal coronary angioplasty. Quantitative measurement of coronary stenosis was achieved by cinevideodensitometric analysis. Actuarial restenosis rate was 12.7% at 1 month, 43.0% at 3 months, 49.4% at 6 months and 52.5% at 1 year. In 219 patients followed up for greater than or equal to 3 months, mean stenosis diameter was 1.91 +/- 0.53 mm immediately after coronary angioplasty, 1.72 +/- 0.52 mm on day 1, 1.86 +/- 0.58 mm at 1 month and 1.43 +/- 0.67 mm at 3 months. In 149 patients followed up for greater than or equal to 6 months, mean stenosis diameter was 1.66 +/- 0.58 mm at 3 months and 1.66 +/- 0.62 mm at 6 months. In 73 patients followed up for 1 year, mean stenosis diameter was 1.65 +/- 0.56 mm at 6 months and 1.66 +/- 0.57 mm at 1 year. Thus, stenosis diameter decreased markedly between 1 month and 3 months after coronary angioplasty and reached a plateau thereafter. In conclusion, restenosis is most prevalent between 1 and 3 months and rarely occurs beyond 3 months after coronary angioplasty.

Aged↗
PubMed1988

Production of 5' Nucleotide by Using Halophilic Nuclease H Preferentially Adsorbed on Flocculated Cells of the Halophile Micrococcus varians subsp. halophilus.

A bioreactor with a column of flocculated cells of the moderate halophile Micrococcus varians subsp. halophilus which adsorbed the halophilic nuclease H was designed to be used in the production of 5' nucleotides from RNA. A remarkable characteristic of the flocculated cells was that they preferentially adsorbed much exogenous nuclease, excluding adsorbed 5' nucleotidase. Furthermore, desalting treatment of the flocculated cells in the presence of 2% MgSO(4) . 7H(2)O gave rise to selective inactivation of 5' nucleotidase without the loss of nuclease H activity, and 5'-guanylic acid was produced with the bioreactor.

Journal Article↗
PubMed1988

Morphological changes in the cochlear aqueduct following herpes simplex virus inoculation into the subarachnoid space.

Type 1 herpes simplex virus (HSV-1) was inoculated into the subarachnoid space through the cisterna magna of guinea pigs to study morphological changes of the inner ear and the ability of the cochlear aqueduct to protect the inner ear. Although most of the animals developed clinical manifestations of meningoencephalitis within a few days after inoculation, Preyer's reflex remained intact. Scanning electron microscopy revealed some significant changes in the cochlear aqueduct. Lymphocytes and macrophages were predominant, with narrowing of reticular tissue spaces caused by the swelling of the periotic duct tissue. The cribriform structure of the internal orifice of the cochlear aqueduct appeared to be completely obstructed, whereas it was normal in the presence of bacterial infection as previously reported (1). The morphological changes were confined to the cochlear aqueduct.

Animals↗
PubMed1988

Amelioration of normothermic canine liver ischemia with prostacyclin.

A model of hepatic ischemia was developed in dogs using a pump-driven splanchnic-to-jugular vein bypass during crossclamping of the portal triad. An LD50 was established with three hours of ischemia. PGI2 given for one hour before the ischemic insult ameliorated the ischemic injury and increased survival.

Animals↗
PubMed1987

[Precordial ST-segment elevation caused by right coronary artery occlusion].

Among 57 consecutive patients undergoing percutaneous transluminal coronary angioplasty (PTCA) of the right coronary artery, eight patients showed precordial ST-segment elevation in leads V1-3 during the procedure. The mechanism of this ST elevation was investigated reviewing the coronary angiographic findings. All patients had angina pectoris, but none had evidence of myocardial infarction. The balloon inflation time was limited to 60 sec, and 12 lead electrocardiograms were recorded every 15 sec. In the eight patients who had precordial ST-segment elevation, six had the anatomically dominant right coronary artery, and two had proportioned (balanced) left and right coronary arteries. Six patients, however, had functionally dominant left coronary arteries because of good collaterals supplying the right coronary artery from the left coronary artery. Thus, functionally, six had the dominant left coronary artery, one had proportioned coronary supply, and only one had the dominant right coronary artery. In all eight patients, the most proximal portion of the right coronary artery was occluded during PTCA, obstructing both the conus branches and the right ventricular branches. This often induced precordial ST-segment elevation in cases with the functionally dominant left or proportioned coronary artery. This ST-segment elevation seemed to represent right ventricular ischemia, as the inferior wall was protected from ischemia by good collaterals. However, precordial ST-segment elevation was rare in the functionally dominant right coronary artery even when the most proximal portion of the right coronary artery was occluded. This fact seemed due to masking of electrocardiographic manifestations of right ventricular ischemia by the dominant electrical forces of inferior wall ischemia.

Adult↗