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Biomedical subjects

T Hadama

Publications and source records attributed to T Hadama.

At least 37 records · Page 2Linked to original sources
PubMed1998

Laparoscopic cholecystectomy in patients undergoing anticoagulant therapy.

We recently performed a laparoscopic cholecystectomy on three patients receiving preoperative oral anticoagulant therapy. The patients requiring anticoagulants for pre-existing cardiac conditions have the following risks at surgery: thromboembolism, hemorrhage, endocarditis, and cardiopulmonary dysfunction. In patients receiving anticoagulant therapy, one must thus maintain a balanced international normalized ratio of the prothrombin time to prevent thromboembolism or hemorrhage. Warfarin sodium was discontinued preoperatively in all patients. Heparin sodium was individualized according to each patient's risk of thromboembolism. As a result, these patients all underwent a laparoscopic cholecystectomy without complications. Attention was paid to achieve hemostasis in the operative field and the trocar inserted sites during the procedure. The administration of warfarin sodium was resumed on the first postoperative day in all patients. Restarting warfarin sodium early also helps to simplify postoperative management. A broad spectrum of antibiotic therapy was also used to reduce the risk of endocarditis. Each patient's cardiopulmonary function was carefully monitored. The minimal invasion experienced during a laparoscopic cholecystectomy may thus facilitate the management of gallstones in patients receiving systemic anticoagulation treatment based on the findings of this limited series.

Adult↗
PubMed1998

Mechanism of preservation of myocardial calcium channel function by pyruvate cardioplegic solution.

We evaluated the effects of adding pyruvate to a cardioplegic solution on the preservation of the dihydropyridine-sensitive calcium (Ca2+) current responses to beta-adrenergic stimulation in rabbit cardiac myocytes by measurement of single-channel open probability. Single ventricular myocytes were isolated and stored in St. Thomas' solution with or without pyruvate at 4 degrees C for 2, 6, 12, or 24 hours, and cell-attached single Ca2+ channel currents recordings were made at 20 degrees to 22 degrees C after each storage period. When 0.1 micromol/L isoproterenol (ISO) was applied to the cells, the percent mean open probability of the Ca2+ channels tested in freshly isolated cells was 181% +/- 27% (n = 12) of control values. These responses decreased with an increasing duration of the hypothermic storage and were only 112% +/- 22% (n = 5) of control values after 24 hours of storage in the absence of pyruvate. Conversely, the responses were significantly preserved, to as much as 143% +/- 17% (n = 7), in the presence of 10 mmol/L pyruvate in the storage solution. The application of forskolin to stimulate adenylate cyclase or a membrane-permeable cyclic adenosine monophosphate mimicked the effects of ISO when the myocytes were stored with pyruvate. Pyruvate did not alter the open-channel kinetics or single-channel conductance and lacked any apparent direct effect on the Ca2+ channel activity. We suggest that pyruvate added to the hypothermic storage solution preserves the high-energy phosphates in myocytes that are responsible for Ca2+ channel phosphorylation via beta-adrenergic stimulation. (J Lab

Animals↗
PubMed1998

Mutations of p53 and K-ras genes as prognostic factors for non-small cell lung cancer.

To evaluate the importance of mutations of p53 and K-ras genes in the prognosis of patients with non-small cell lung cancer, one hundred and forty-four patients who underwent surgery were studied. DNA was extracted from frozen specimens. Polymerase chain reaction-single strand conformation polymorphism and sequencing were performed to investigate mutations of p53 from exon 5 to 8, and mutations of exon 1 of K-ras. Mutations of p53 gene occurred in 35. 4% of patients, and mutations of the K-ras gene in 8.3%. The overall survival rate of non-small cell lung cancer patients with wild-type K-ras was better than that of patients whose tumors had mutations of K-ras (P=0.0330). Among patients with adenocarcinoma of the lung, the overall survival rate of patients with wild-type p53 was strikingly better than that of patients whose tumors had mutations of p53 (P=0.0234). Multivariate analysis with the Cox regression model of all patients with non-small cell lung cancer and those with adenocarcinoma indicated that mutations of K-ras best correlated with the overall survival rate (P=0.0005 and P=0.0361, respectively). In conclusion, evaluation of mutations of both the p53 and K-ras genes in the lung tumors might be useful for assessing the prognosis, especially in patients with adenocarcinoma.

Adenocarcinoma↗
PubMed1997

Quasispecies nature of hepatitis C virus and response to alpha interferon: significance as a predictor of direct response to interferon.

BACKGROUND/AIMS: We evaluated the significance of the quasispecies nature of HCV as a predictor of the response to alpha interferon therapy in patients with chronic hepatitis C. METHODS: Natural alpha interferon was administered in 62 patients for 24 weeks (daily for 2 weeks, then three times weekly for 22 weeks) and factors were analyzed that could affect the response. HCV subtype, HCV RNA concentrations and the number of HCV quasispecies were evaluated before treatment. HCV RNA concentrations were measured by branched DNA probe assay. The number of HCV quasispecies was measured by fluorescence single-strand conformation polymorphism analysis. RESULTS: The HCV RNA concentration (p < 0.0001), HCV subtype (p = 0.0076), and the number of HCV quasispecies (p = 0.0024) were significantly associated with a complete response. Multivariate analyses showed that the number of HCV quasispecies was an independent predictor of the disappearance of HCV RNA during the administration of alpha interferon, but did not predict a relapse after its completion. Pretreatment concentration of HCV RNA was the only factor that was related to a long-term disappearance of HCV RNA. CONCLUSIONS: The number of HCV quasispecies was significantly related to the response to alpha interferon early in its administration. The pretreatment concentration of HCV RNA was mainly related to a relapse following completion of treatment.

Adult↗
PubMed1996

Nucleotide sequence diversity of hypervariable region 1 of hepatitis C virus in Japanese hemophiliacs with chronic hepatitis C and patients with chronic posttransfusion hepatitis C.

Hemophiliac patients with chronic hepatitis C might be exposed to and become infected with multiple hepatitis C virus (HCV) strains by means of frequent use of blood products, even if they are infected with a single subtype of HCV. To test this hypothesis, we analyzed the genetic diversity of hypervariable region 1 (HVR1) of HCV in chronically infected hemophiliacs and in patients with chronic posttransfusion hepatitis with a single HCV inoculation. The diversity of nucleotide sequences in HVR1 of serum HCV RNA was compared between 21 hemophiliacs infected with a single HCV subtype and 16 patients with posttransfusion HCV infection. The number of HCV quasispecies was determined by fluorescence single-strand conformation polymorphism (SSCP) analysis. Direct sequencing was performed to determine the diversity in HVR1. The number of HCV quasispecies in the blood was 5.2 +/- 2.0 clones in hemophiliacs and 4.0 +/- 2.3 clones in posttransfusion patients, a nonsignificant difference (P = .0943). The number of sites at which the nucleotide was not homogenous in all quasispecies was significantly higher in hemophiliacs (13.0% +/- 7.4%) than in posttransfusion hepatitis patients (2.7% +/- 2.8%; P < .0001). In conclusion, there was a high degree of genetic variation in HVR1 of HCV specimens isolated from hemophiliacs compared with posttransfusion patients. These findings indicate the possibility that multiple infections of a single HCV subtype may occur among patients frequently exposed to blood products; single HCV subtypes may therefore derive from multiple origins.

Adult↗
PubMed1996

Repair of a ruptured aortic arch aneurysm complicated by postoperative paraplegia: report of a case.

We report herein the rare case of a 79-year-old man who suffered permanent paraplegia after undergoing an otherwise successful total arch replacement for a ruptured aortic arch aneurysm. During cardiopulmonary bypass, perfusion to the distal aorta was maintained from the femoral artery, and postoperative aortography showed intact tributaries from the aorta including the intercostal arteries. Postoperative paraplegia is an extremely rare complication of operations on the aortic arch; however, we speculate that the paraplegia in this patient could be attributed either to a steal phenomenon involving the radicular artery, or to the anatomical particularity of the spinal cord artery described by Cole and Gutelius as the "segmental system".

Aged↗
PubMed1996

[A case of pulmonary dirofilariasis diagnosed through thoracoscopic lung biopsy].

A fifty-year-old man was admitted to our hospital for evaluation of an abnormal shadow in a routine chest X-ray film. Thorax CT scan revealed a relatively well defined nodule with a diameter 15 mm and pleural thickness in the posterior segment of the right lower lobe. A diagnosis by broncoscopy was undefinite and suspected to be a lung cancer. So thoracoscopic lung biopsy was performed to remove it. In a cross section of the resected nodule two degenerated worm structures were revealed and we diagnosed pulmonary dirofilariasis. Pulmonary dirofilariasis has been an increasing reported disease. Most of cases revealed a peripheral lung lesion. Thoracoscopic lung resection was useful for the diagnosis, considering as minimally invasive examination.

Animals↗
PubMed1996

Relationship between pump speed design and hemolysis in an axial flow blood pump.

In an attempt to reduce the hemolysis caused by axial flow blood pumps, we investigated whether the specific speed should be kept within the standard engineering range or whether pump speed should be minimized, thus making the specific speed beyond the standard range. Four pumps with 11.8 mm diameter impellers were designed to accommodate a flow of 5 L/min and a head of 100 mm Hg. The pumps were tested at 4 speeds: A, 14,000; B, 18,000; C, 22,000; and D, 26,000 rpm. Pump performance data were obtained, and the maximum point of total pump efficiency was found for each pump. The maximum efficiencies were A, 50%; B, 58%; C, 52%; and D, 53%. The specific speed of each pump recorded at the maximum efficiency point was calculated as A, 899; B, 954; C, 1,218; and D, 1,951 rpm. Hemolytic tests were performed with fresh goat blood in a closed, mock-loop circuit. Hemolytic indexes were A, 0.036; B, 0.22; C, 0.35; and D, 0.66. We have concluded that decreased hemolysis is correlated with a lower pump speed and that the specific speed for the lowest pump speed is less than the standard range. Having a specific speed outside the standard range was not correlated with reduced total pump efficiency.

Blood Flow Velocity↗
PubMed1996

[A detection for replication error (RER) and LOH by microsatellite analysis in human lung cancer].

Recently, it has been considered that the pleomorphic changes in the microsatellite areas, which are said to exist at 50 to 100 thousand places on the human chromosome, are the results of abnormality in the repairing mechanism in cancer cells, and active attempts are now being made to detect such changes using PCR. In the DNA of cancer tissue where the repairing function has decreased, sequence repeat different in length from that of the DNA of normal tissue is observed. Such abnormal repeat shows itself as replication error (RER). As method of detecting RER, PCR was hitherto performed using RI-labeled primer, and after electrophoresis, detection was made by autoradiography. In order to obtain a reproducible result in a simple way, we attempted to detect by RER with auto-sequencer in 60 patients with lung cancer. As a result, we obtained data with a high sensitivity and objectivity. Therefore, a report is made on this study of ours.

Base Sequence↗
PubMed1996

[A case of aortic dissection associated with congenital bicuspid aortic valve].

It is known that bicuspid aortic valve with dilatation of the ascending aorta is one of risk factors of the aortic dissection. A case of acute aortic dissection (DeBakey type-II) associated with bicuspid aortic valve who underwent successfully operation 8 hours after onset is reported. This patient went into cardiogenic shock because of cardiac tamponade and aortic valve regurgitation immediately after onset. Aortic valve and the ascending aorta were replaced using composite graft (#23 SJM prosthetic aortic valve and 26 mm woven Dacron vascular graft) combined with coronary artery reconstruction by Cabrol's technique. Aortic valve showed bicuspid and histological examination revealed cystic medionecrosis and loss of elastic fiber. Postoperative course was uneventful and this patients is doing well 3 years after the operation.

Acute Disease↗
PubMed1995

University of Wisconsin solution preserves myocardial calcium current response to isoproterenol in isolated canine ventricular myocytes.

BACKGROUND: University of Wisconsin (UW) solution has been shown to be an effective solution for cold storage of various organs. This study was designed to evaluate the subcellular protective mechanism of UW solution during cardiac myocyte storage using patch-clamp techniques for the first time as a tool for the detection of myocyte viability. METHODS AND RESULTS: The protective effects of UW solution on the preservation of dihydropyridine-sensitive Ca2+ channel current response to catecholamine were evaluated in canine cardiac ventricular cells by measurement of single channel open probability. Single ventricular myocytes were isolated and stored in UW solution, in Stanford (SF) solution, or in St Thomas' (ST) solution at 4 degrees C for 2, 6, 12, and 24 hours, and after each storage period, recordings were made of cell-attached single Ca2+ channel currents. When 0.1 mumol/L isoproterenol was applied, percent mean open probability of the Ca2+ channel tested in freshly isolated cells was 167 +/- 4% (n = 24) of controls (100%). The response was decrescent with increased duration of the hypothermic storage and was only 130 +/- 12% (n = 4) after 24 hours of storage in SF solution and 135 +/- 9% (n = 7) in ST solution. However, it was significantly highly preserved as much as 165 +/- 9% (n = 6) in UW solution. Ca2+ channel kinetics and channel conductance were not changed after up to 24 hours of hypothermic storage. CONCLUSIONS: Hypothermic storage of canine cardiac myocytes in UW solution preserved beta-adrenergic response, which suggests that UW solution during cold storage preserved high-energy phosphates in myocytes that are responsible for Ca2+ channel phosphorylations.

Adenosine↗
PubMed1995

The effect of body position on a free-floating ball thrombus as observed by transesophageal echocardiography.

Two cases of free-floating left atrial ball thrombi (FLABT) in association with mitral stenosis were observed by transesophageal echocardiography (TEE). Our report describes the relation between body position and thrombi kinetics. Both cases demonstrated similar kinetics. In the supine and right lateral decubitus positions, the thrombi recoiled from and sometimes became entrapped within the mitral valve. In the sitting and left lateral decubitus positions, the thrombi appeared to be nearly fixed and did not contact with the mitral valve. Our results indicate that the latter two positions prevent thrombi disintegration and incarceration into the mitral valve. Finally, TEE is an extremely useful tool for assessing the safest position for individuals with FLABT.

Aged↗
PubMed1995

Hemodynamic profiles during concurrent intraaortic balloon pumping and venoarterial bypass--a canine study comparing subclavian and femoral artery perfusion sites.

Concomitant use of venoarterial bypass (VAB) with centrifugal pump and intraaortic balloon pumping (IABP) is a common technique for cardiopulmonary resuscitation. This experimental study examines whether coronary perfusion and hemodynamics are affected by the site of the blood supply, comparing the subclavian artery and the femoral artery. VAB and IABP were performed in 11 mongrel dogs with cardiopulmonary failure induced by acute myocardial infarction and hypoventilation. Aortic root pressure (AP), left atrial pressure, central venous pressure and coronary sinus blood flow (CSF) were measured, and blood gas analysis was performed. Subclavian artery perfusion (SAP) and femoral artery perfusion (FAP) were compared at bypass ratios of 25, 50, 75, 85, 100%. At bypass ratios of 75% and 85% the mean systolic AP was higher with SAP than with FAP. The mean diastolic AP was higher with SAP than with FAP at a bypass ratio of 50% or higher. CSF was higher with SAP than with FAP at a bypass ratio of 50% or higher. The coronary arteriovenous O2 content difference was lower with SAP than with FAP at a bypass ratio of 85% or higher. In conclusion, at a high bypass ratio, SAP was more effective than FAP in achieving diastolic augmentation, thus enhancing myocardial oxygen balance, even though SAP had less of a systolic unloading effect. These data support the use of SAP over FAP in patients with severe cardiopulmonary dysfunction requiring high-flow bypass, and especially in patients with myocardial ischemia.

Animals↗
PubMed1995

[Factors affecting the occurrence of anastomotic leakage after graft replacement of type A aortic dissection].

Fifty-seven patients of type A aortic dissection were underwent operations from Jan. 1985 to Nov. 1994. The number of patients who underwent graft replacement of the aorta and received aortogram after the operation was twenty-nine. To investigate factors affecting the occurrence of anastomotic leakage after graft replacement of the aorta, the aortograms of the 29 patients were examined retrospectively. The aortograms revealed leakage at the distal anastomotic site on 11 of the 29 patients. Eight factors: the kind of graft, Marfan's syndrome, the use of felt at the anastomotic site, the clamping method, distal anastomotic site, acute or chronic, the state of the aortic wall at the anastomotic site and the blood pressure control after operation, were examined relating to the occurrence of anastomotic leakage. The results showed 3 factors; acute or chronic, the state of the aortic wall and the blood pressure control, affected the occurrence of anastomotic leakage. In short, the anastomotic leakage easily occurred in patients who underwent in the acute stage and whose blood pressure was uncontrolled after the operation. Therefore, strict control of the blood pressure after the operation is the most effective for preventing anastomotic leakage.

Anastomosis, Surgical↗
PubMed1995

[Surgical treatment of traumatic rupture of the aortic valve with dove-coo murmur--case report].

Aortic regurgitation due to traumatic rupture of the aortic valve with dove-coo murmur is rare. A 71-year-old man was admitted for cardiac failure due to aortic regurgitation with dove-coo murmur, 4 years after the traffic accident. The aortic valve replacement was performed and his postoperative course was good. The aortic valve was tricuspid valve with the tear in the left side of right coronary cusp, and the size of the tear was 7 mm. The aortic valve was not recognized the findings of inflammatory or rheumatic change in the pathological study.

Aged↗