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Biomedical subjects

J Yamanaka

Publications and source records attributed to J Yamanaka.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Usefulness of electroglottogram (EGG) and photoglottogram (PGG) for the analysis or vocal fold vibration--a high speed digital imaging study].

Simultaneous recordings of EGG, PGG and high-speed digital imaging (HSDI) of vocal fold vibration were made in 3 normal male subjects and the results were compared to evaluate the usefulness of EGG and PGG for the analysis of the vibratory pattern. Each subject was required to produce sounds of 3 different pitches at 3 different intensity levels in the recording sessions and the 27 sets of data samples were collected. For each data set, the glottal area waveform (GAW), glottal width waveform (GWW), EGG, differentiated EGG, PGG, differentiated PGG, and voice waveform were displayed in a graphic form on the same time axis and their patterns were compared. Based on the analysis of GAW and GWW, it was found that there were variations in the pattern of closing and opening of the vocal fold margin corresponding to the differences in the type of phonation. The EGG waveform appeared to correspond well to that of the movement of the vocal fold margin in the closing phase, while the correspondency was less apparent in the opening phase. It is considered that the EGG waveform is dependent on the mode of contact between the two vocal folds and that a careful observation of the EGG is useful and practical for predicting the pattern of vocal fold vibration. On the other hand, it was difficult to determine the onset of the closing and opening phases only from PGG waveform and there was a timing difference between the PGG and GAW. Although PGG seemed to be useful for judging the presence or absence of the opening phase and for the pitch measurement, it is considered to be unsuitable for a precise cycle-by-cycle analysis of the pattern of vocal fold vibration.

Adult↗
PubMed2000

[The management of infectious mediastinitis after the open heart surgery].

Between October of 1992 and September of 1998, we performed 604 open heart operations. Among them, 12 cases (1.9%) were complicated with postoperative infectious mediastinitis. Five patients (Group A) were treated by conservative therapy which consists of open drainage and intermittent closed irrigation with dilute povidone iodine solution. Seven patients (Group B) were treated surgically in addition to the above-mentioned conservative treatment. Among those patients, one patient developed fatal complication. We have realized that mental care of the patients was also very important when long term hospitalization was necessitated. The hyperbaric oxygen therapy seemed to be also effective for postoperative mediastinitis caused by MRSA.

Aged↗
PubMed2000

[The management of aortic root replacement using the Top-Hat/Gelweave composite graft].

Composite graft replacement of the aortic root has become a routine procedure for annuloaortic ectasia (AAE) and aortic valve insufficiency (AR) with aortic dissection and the results have improved. We treated six cases of aortic root reconstruction using the Carrel patch method in 1998. The Top-Hat/Gelweave Composite graft fit together well and the procedure is technically similar to standard valve replacement. Upon measuring the valve size a Gelweave graft 1 mm larger than the valve size should be selected. There were no incidence of hemorrhage or postoperative hemolysis. Further long-term follow-up is necessary.

Aged↗
PubMed2000

[Retrograde continuous cold blood cardioplegia for combined aortic valve replacement and coronary artery bypass grafting].

Efficacy of retrograde continuous cold blood cardioplegia (RCBC) during aortic valve replacement combined with coronary bypass grafting was studied. Forty patients underwent elective aortic valve replacement, either combined with coronary bypass grafting (7 patients: group I), or isolated (33 patients: group II) using RCBC between 1996 and 1999 were analyzed retrospectively. Aortic cross clamp time was significantly prolonged in group I (150 +/- 33 min) compared to group II (109 +/- 32 min). The postoperative peak creatine kinase-MB levels were similar in both groups (73.3 +/- 23.9 versus 97.6 +/- 88.7 ng/ml). The doses of dopamine and dobutamine administered during 24 hours after surgery did not differ between the two groups (7.5 +/- 3.9 versus 6.5 +/- 5.5 mg/kg). The early (< 30-day) mortality was 0 in group I, and 3.0% in group II. These results suggest that RCBC is a safe method of myocardial protection in patients undergoing aortic valve replacement combined with coronary artery bypass grafting.

Aged↗
PubMed1998

Additional techniques adopted for major vascular anastomoses during orthotopic liver transplantation.

Of 372 patients who underwent liver transplants between January 1985 and March 1995, 7 required variations in vascular anastomoses due to discrepancies in the size-match of the donor and recipient vessels, the presence of a thrombosed hepatic artery or portal vein, or complete absence of the portal vein. The techniques described herein enabled us to perform successful transplantation in all patients. Although rethrombosis of the portal vein developed in one patient after a third transplant, this patient remains clinically well. The use of an operating microscope and the harvesting of an extended length of donor superior mesenteric vein or vascular grafts of the donor iliac or saphenous vessels, for potentially difficult transplants, are invaluable techniques.

Adult↗
PubMed1998

Idiopathic benign biliary stricture.

A rare case of idiopathic benign biliary stricture is reported. A 50-year-old man with liver dysfunction underwent ultrasonography, which revealed dilation of the intrahepatic bile ducts, and endoscopic retrograde cholangiopancreatography, which revealed a short, ring-like stenosis at the junction of the left and right hepatic ducts. Although a benign stricture was suspected, radiologic tests alone were insufficient to make a firm diagnosis. Therefore, a cholecystectomy and resection of the extrahepatic biliary tract were performed. Microscopic examination of the resected specimen demonstrated no evidence of malignancy. The final diagnosis was mild, localized, chronic cholangitis. The patient had not had previous biliary tract surgery, choledocholithiasis, nor did he have a congenital abnormality of the biliary tract, bile duct carcinoma, or pancreatic disease. Since there was no evidence of primary sclerosing cholangitis, the stricture was considered to be idiopathic.

Anastomosis, Surgical↗
PubMed1997

Hepatoprotective effect of a nonselective endothelin receptor antagonist (TAK-044) in the transplanted liver.

This study was designed to investigate whether or not a novel nonselective endothelin A/B (ETA/ETB) receptor antagonist (TAK-044) provides hepatoprotection during porcine liver transplantation. The grafts were stored in chilled Euro-Collins solution and recirculated following reflush with lactated Ringer's with (TAK group) or without (control group) TAK-044 (10 mg/kg). Intracellular (cytoplasma, mitochondria, and nucleus) calcium (Ca) concentrations were measured in the hepatic biopsy materials obtained serially at varying time point from donor laparotomy to recipient closure using an electron probe X-ray microanalyzer. Liver function tests also were determined. The cold and warm ischemia times of the grafts were comparable between the two groups. The peak endothelin-1 T-1) concentration after recirculation was significantly higher in the TAK group than in the control group (129 +/- 30 pg/ml vs 26 +/- 6.5 pg/ml). However, release of liver enzymes, increases in total bile acid, and deterioration of indocyanine green retention rate were significantly suppressed in the TAK group. In the control group, the intracellular Ca concentrations, especially in the mitochondrial fraction, were elevated markedly following recirculation of the hepatic arterial flow. In the TAK group, this effect was suppressed. Thus, the supplementary use of the nonselective ETA/ETB receptor antagonist TAK-044 via a rinse route may alleviate an early postreperfusion microcirculatory disturbance of the liver grafts without adverse effects by the increased ET-1 on the systemic circulation.

Animals↗
PubMed1997

Correlation of hepatitis virus serologic status with clinicopathologic features in patients undergoing hepatectomy for hepatocellular carcinoma.

BACKGROUND: This study investigated the relationship between clinicopathologic features and various viral serologies in patients who underwent hepatectomy in the treatment of hepatocellular carcinoma (HCC). METHODS: Two hundred two patients were allocated to four groups, according to their positivity or negativity for hepatitis B surface antigen (HBsAg) and hepatitis C virus antibody (HCVAb): Group I (HBsAg[-], HCVAb[+], n = 151), Group II (HBsAg[+], HCVAb[-], n = 27), Group III (HBsAg[-], HCVAb[-], n = 20), or Group IV (HBsAg[+], HCVAb[-], n = 4). The mean age of the HBsAg positive patients (Groups II and IV) was 10 years younger than that of the HBsAg negative patients (Groups I and III). RESULTS: The male-to-female ratio was higher in HCVAb negative groups (II and III). The HCVAb positive groups (I and IV) had a significantly poorer hepatic reserve and smaller resections than the HCVAb negative groups. Because the tumors were more advanced (as determined by TNM staging) in Group II, the 3-year crude and disease free survival rates were lower in Group II than in Group I. However, HCVAb negative groups (II and III), when compared at 5 years with the limited subsets of patients who had tumors at earlier stages or a curative resection, had significantly better crude and disease free 5-year survival rates than the HCVAb positive group (I). CONCLUSIONS: Clinicopathologic features differ from one another in accordance with the viral seromarkers in HCC patients. Significantly better crude and disease free survival after complete resection were promising results for patients with non-HCV-related HCC. By comparison, for patients with HCV-related HCC, the risk of intrahepatic recurrences never subsided even in later years after complete resection. Therefore, posthepatectomy follow-up management should be individualized depending on the viral serologic status of HCC patients.

Alanine Transaminase↗
PubMed1997

Sclerosing inflammatory pseudotumor arising from the carotid artery region.

We report a 42-year-old female patient with sclerosing inflammatory pseudotumor. She had found a mass in her left neck after she caught a cold. An elastic hard mass (25 x 15 mm), unaccompanied by any other symptoms, was palpated adjacent to the left carotid bifurcation. The mass extended vertically along the common carotid artery, partially adhering to the pulsating artery. Under ultrasonography, the mass was characterized by a homogenized low echoic shadow surrounding the left common carotid artery. Angiography revealed a slight narrowing of the common carotid artery with a surrounding hypovascular mass. Computerized tomography (CT) and magnetic resonance imaging (MRI) both showed a mass enclosing the carotid artery; a Ga scintigram also showed a highly concentrated mass. Surgical removal of the mass included removing part of the carotid artery, internal and external carotid arteries and sympathetic trunk. The left internal jugular vein was transplanted to connect the common carotid artery to the internal carotid artery. Although the hypoglossal and vagus nerves adhered to the mass, they were preserved by sharp dissection with the scalpel. Although hypoglossal and vagus nerve dysfunction were observed temporarily after the surgery, Horner's syndrome appeared and persisted. Histological examination revealed markedly fibrotic tissues surrounding the carotid artery with extensive lymphocyte and plasmacyte infiltration and a diagnosis of sclerosing inflammatory pseudotumor was made.

Adult↗
PubMed1997

[A case report of aorto-coronary artery bypass surgery in patient with essential thrombocythemia].

Essential thrombocytosis was detected by chance in a 55-year-old patient with angina pectoris when cardiac catheterization was performed. The diagnosis of thrombocytosis (platelet count > 1,000000/mm3) was established by detailed investigations. This patient had stenosis of the coronary arteries and the right common iliac artery. About one month after cardiac catheterization, the patient underwent coronary bypass surgery following normalization of the platelet count with interferon therapy, which was also used to control the platelet count perioperatively. The operation was completed without major problems, and the postoperative course was uneventful. This case is reported in detail.

Angina Pectoris↗
PubMed1997

Topical cooling-assisted hepatic segmentectomy for cirrhotic liver with hepatocellular carcinoma.

BACKGROUND: A safe limit for normothermic consecutive portal triad occlusion in hepatectomy for the cirrhotic liver was believed to be around 30 minutes. Possibly, the occlusion time can be prolonged by cooling the ischemic liver in vivo. We describe the technique of segmentectomy assisted by topical cooling and its usefulness in prolonging the hepatic inflow occlusion time for cirrhotic livers without causing further ischemic injury. STUDY DESIGN: Fifty patients with hepatocellular carcinoma and chronic hepatic disease who underwent right-sided segmentectomy under hemihepatic inflow occlusion were divided into two groups: normothermic (n = 27), and hypothermic with hemihepatic topical cooling using ice slush (n = 23). Segmentectomies were carried out in the same way in both groups, guided by initial enbloc ligation of the corresponding portal pedicles. RESULTS: The mean right hepatic inflow occlusion time was significantly longer in the hypothermic group than in the normothermic group (53 +/- 22 minutes compared with 17 +/- 9.3 minutes). Despite the significant difference in occlusion time, no differences were found in the recovery of hepatic functions and the incidence of postoperative complications between the groups. Intraoperative blood loss was significantly less in the hypothermic group. CONCLUSIONS: The hepatic right-sided partial inflow occlusion time can safely be prolonged to 60 to 90 minutes in the presence of cirrhosis without causing another injury from ischemia and intermittent reperfusion.

Aged↗
PubMed1997

Potential for bilateral nephrectomy to reduce oxalate release after combined liver and kidney transplantation for primary hyperoxaluria type 1.

Primary hyperoxaluria type 1 (PH-1) is frequently associated with end stage renal failure due to urinary calculi, obstructive uropathy and interstitial deposits of calcium oxalate. The currently accepted treatment for PH-1 is liver transplantation to replace the deficient enzyme peroxisomal alanine glycoxylate aminotransferase (AGT) and a simultaneous renal transplant to restore renal function. The transplanted kidney may become significantly impaired or fail when systemic calcium oxalate is eliminated by renal excretion. The native kidneys are a major source of this oxalate. This study was undertaken to determine whether there is a difference in oxalate clearance following combined liver-kidney transplant in patients with PH-1 by comparing the effect of native kidney nephrectomy at the time of transplantation against leaving the native kidneys in situ. Regression analysis was used to compare daily urinary oxalate excretion corrected for body surface area. There was a significant reduction in urinary oxalate excretion (P < 0.05) in the patient who had undergone bilateral nephrectomy compared to the patient whose native kidneys remained in situ for the first 100 d following combined liver and kidney transplantation. No difference was observed in the serum oxalate levels between patients over the same period or in the renal function assessed by creatinine clearance corrected for body surface area. Total body oxalate load was not determined in this study. A larger study should be undertaken to examine the benefits of nephrectomy in reducing oxalate deposition in recently inserted allografts for patients with PH-1.

Adult↗
PubMed1996

The management of difficult abdominal closure after pediatric liver transplantation.

Between January 1985 and December 1994, 164 liver transplantations were performed on 141 children. There were 100 reduced-size and 64 whole-liver grafts. Primary closure of the abdominal wound was not possible in 21 patients because of liver size, bowel edema, and distension. Temporary SILASTIC patch closure of the abdominal wound was used. For 16 of the 21 patients, removal of the SILASTIC patch and abdominal wall closure were completed by the seventh postoperative day; for the others, these were accomplished by the end of 2 weeks. The method is recommended when primary wound closure is not possible.

Child↗
PubMed1996

[The evaluation of the bio-compatibility and the clinical usefulness of heparin-coated cardiopulmonary bypass circuits].

We studied the biocompatibility and the clinical usefulness of heparin-coated cardiopulmonary bypass circuits (Duraflow-II) compared with non-coated circuits. First study was done to clarify the biocompatibility of heparin coated circuit. 33 cases of elective coronary artery bypass grafting were randomized into two grops. Both group had full dose heparin in this study and laboratory tests were done such as blood cell count, free hemoglobin, AT-III, fibrinogen, FDP, and complement system. The use of heparin-coated circuits resulted in a reduction of C3a generation, and a reduction of fibrinogen consumption. The decline of AT-III may be due to bonding of coated heparin to AT-III, leading to effective anticoagulation. Next study was carried out in 26 cases. In heparin coated group, the amount of heparin was reduced to 200 IU/kg compared to 350 IU/kg in control group. ACT was maintained above 300 sec. and 400 sec. respectively. The amount of post operative bleeding was identical in both groups. There was no case which required autologous blood transfusion, re-operation for bleeding in both groups. Myocardial infarction and hospital mortality were not seen in this study. Concerning the fear of graft occlusion in low dose heparin surgery, there was no statistical difference of graft patency in both groups. In conclusion, heparin coated CPB circuits (Duraflo-II) are favorable in the meaning of biocompatibility and sefely used with low dose heparin.

Biocompatible Materials↗
PubMed1996

[A case report of pseudo-false aneurysm of the left ventricle perforated into the right ventricle].

A 60-year-old diabetic women with acute inferior myocardial infarction was admitted to our hospital. An echocardiogram suggested a left ventricular false aneurysm. A left ventricular cineangiogram showed the communication between the left ventricle and the right ventricle through a false aneurysm. At operation one week after the infarction, the pericardial space was free from adhesions. A pseudo-false aneurysm communicating to both ventricle was revealed. The defects were closed with patches and pledgetted mattress sutures. The pseudo-false aneurysm was obliterated with pledgetted mattress and running sutures. The postoperative course was uneventful and the patient was discharged without complication. We emphasize the importance of preoperative morphological and hemodynamic evaluation using a left ventricular cineangiogram in the case of post-myocardial infarction ventricular septal perforation.

Aneurysm, False↗