Biomedical subjects

H Nohara

Publications and source records attributed to H Nohara.

At least 19 recordsLinked to original sources

PubMed2004

[Radiofrequency modified maze operation for chronic atrial fibrillation with ASD; report of a case].

A 61-year-old man with congestive heart failure was referred to our hospital and diagnosed as atrial septal defect (ASD) [Qp/Qs = 1.6] with chronic atrial fibrillation. Occurrence of atrial fibrillation was supposed to be the cause of heart failure rather than L-R shunt of ASD. The patient was successfully operated on with the use of routine cardiopulmonary bypass. Radiofrequency modified maze procedure was done, and then small ASD (1 cm of diameter) was closed with patch. Postoperative transthoracic Doppler echocardiography confirmed clear A wave for transmitral and transtricuspid flow. The patient recovered uneventfully and was discharged in stable sinus rhythm and has been drug free since then.

Atrial Fibrillation↗

PubMed2003

Long-term follow-up of large flat colorectal tumors resected endoscopically.

BACKGROUND AND STUDY AIM: When a large flat colorectal tumor is excised by piecemeal endoscopic resection, it is not possible to obtain suitable specimens for histopathological examination to assess whether the resection has been complete. We prospectively analysed follow-up colonoscopy examinations of endoscopic polypectomy resection sites for residual lesions. PATIENTS AND METHODS: A total of 24 patients with large flat colorectal tumors were treated using an endoscopic submucosal saline injection technique. The resection site was prospectively examined for residual lesions using a magnifying colonoscope, at 3, 6, 12 and 24 months postoperatively. RESULTS: None of the 5 patients who underwent en bloc resection exhibited residual lesions postoperatively. Of the 19 patients who underwent piecemeal resection, one died of an asthma attack and 18 were followed up. Residual lesions were detected in four of these 18 patients (three adenomas and one cancer), which were resected endoscopically. When the tumor was resected endoscopically en bloc and was judged histologically to be completely resected, residual lesions were not detected at follow-up. However, residual lesions were detected in 22.2 % of patients 3 months after initial resection when polyps were resected piecemeal. After treatment, residual lesions were detected in two patients (11.1 %) at 24 months. CONCLUSION: After piecemeal endoscopic resection for large flat colorectal tumors, it is necessary to follow-up and remove residual lesions endoscopically every 3 months until they all are removed.

Adenocarcinoma↗

PubMed2002

Increased rectal wall thickness may predict relapse in ulcerative colitis: a pilot follow-up study by ultrasonographic colonoscopy.

BACKGROUND AND STUDY AIMS: Ulcerative colitis is a chronic inflammatory bowel disease with repeated remission and relapse, although the occurrence of relapse is difficult to predict. We performed a prospective study to determine whether there is a relationship in ulcerative colitis between the inflammatory changes identified by endoscopic ultrasonography (EUS) and relapse. PATIENTS AND METHODS: Participants were 23 ulcerative colitis patients who had not suffered a relapse for 1 month, with a Seo activity index less-than-or-equal 150 and Baron grade 1 at colonoscopy. The thickness of the first to the third layer of the rectal wall in these patients was measured by EUS at the start of the study. They were subsequently followed up for 1 year to record any relapses, defined as having a Seo activity index > 150 and Baron grade greater-than-or-equal 2 at colonoscopy. RESULTS: Relapse occurred in eight patients. The mean activity index of the relapsed patients was 187.3 (95 % confidence interval (CI), 166.4 - 208.2) at the end of the study. The thickness of the first to the third layer of the rectal wall, as evaluated by EUS at the beginning of the study, was significantly larger in the relapse group (mean 2.73 mm, 95 % CI 2.13 - 3.33 mm) than in the non-relapse group (1.79 mm; 1.56 - 1.99 mm; P = 0.0001). CONCLUSIONS: Catheter probe-assisted endoluminal ultrasonography may predict the occurrence of relapse of ulcerative colitis.

Adult↗

PubMed2001

Early results of coronary grafting using ultrasonically skeletonized internal thoracic arteries.

BACKGROUND: We have developed an ultrasonic complete skeletonization technique for obtaining internal thoracic artery (ITA) grafts and have used this method clinically since January 1998. In this report, we discuss the early results of bilateral ITA grafts obtained with our method. METHODS: We studied 200 consecutive patients who underwent coronary artery bypass grafting using ITAs obtained by this technique. Angiography of the grafts was performed in 188 patients (94%) within 1 month after coronary artery bypass grafting. RESULTS: The ITA grafts were about 4 cm longer than pedicled ITA grafts. The free flow through the grafts was at least 30% higher than through pedicled ITAs. The early patency rate determined by postoperative angiography of the grafts was 99.7% for left ITAs and 100% for right ITAs. No patient required postoperative intervention or repeated surgery. CONCLUSIONS: Ultrasonic complete skeletonization increases the effective length of ITA bypasses, improves free flow through the bypasses, and it is less invasive than conventional pedicled harvesting. These excellent early results indicate that this technique is a straightforward, safe, less invasive, and optimal method for obtaining ITA bypass grafts.

Adult↗

PubMed2001

Dynamic localization and function of Bni1p at the sites of directed growth in Saccharomyces cerevisiae.

Formin homology (FH) proteins are implicated in cell polarization and cytokinesis through actin organization. There are two FH proteins in the yeast Saccharomyces cerevisiae, Bni1p and Bnr1p. Bni1p physically interacts with Rho family small G proteins (Rho1p and Cdc42p), actin, two actin-binding proteins (profilin and Bud6p), and a polarity protein (Spa2p). Here we analyzed the in vivo localization of Bni1p by using a time-lapse imaging system and investigated the regulatory mechanisms of Bni1p localization and function in relation to these interacting proteins. Bni1p fused with green fluorescent protein localized to the sites of cell growth throughout the cell cycle. In a small-budded cell, Bni1p moved along the bud cortex. This dynamic localization of Bni1p coincided with the apparent site of bud growth. A bni1-disrupted cell showed a defect in directed growth to the pre-bud site and to the bud tip (apical growth), causing its abnormally spherical cell shape and thick bud neck. Bni1p localization at the bud tips was absolutely dependent on Cdc42p, largely dependent on Spa2p and actin filaments, and partly dependent on Bud6p, but scarcely dependent on polarized cortical actin patches or Rho1p. These results indicate that Bni1p regulates polarized growth within the bud through its unique and dynamic pattern of localization, dependent on multiple factors, including Cdc42p, Spa2p, Bud6p, and the actin cytoskeleton.

Actins↗

PubMed2000

The Hecht vault performed at the 1995 World Gymnastics Championships: deterministic model and judges' scores.

The aim of this study was to determine the mechanical variables that govern success of the Hecht vault. The participants were 122 male gymnasts from 30 countries performing the vault at the 1995 World Gymnastics Championships. The vaults were filmed using a Photosonics 16-mm motion picture camera operating at 100 Hz. Approximately 80 frames were digitized for each vault analysed. The method of Hay and Reid was used to develop a theoretical model to identify the mechanical and physical variables that determine linear and angular motions of the vault. Correlational analysis was used to establish the strength of the relationship between the causal mechanical variables identified in the model and the judges' scores. Significant correlations (P < 0.005) indicated that the following were important determinants of success: large horizontal and vertical velocities at take-off from the board and the horse; large vertical and angular distances of pre-flight; large vertical impulses of high force and short duration exerted on the horse and the resulting large changes in vertical velocity on the horse; and large horizontal and vertical distances and long times of post-flight. Of the 18 significant variables identified in the present study, the angular distance of pre- and post-flights, the horizontal velocity and angular momentum at take-off from the horse, and the average moment of inertia and duration of post-flight collectively accounted for 57% of the variation in the judges' scores.

Biomechanical Phenomena↗

PubMed2000

Coronary artery bypass grafting using the "Super Pulse" dynamic pulsatile cardiopulmonary bypass device in patients with cerebrovascular occlusive disease.

Patients with coronary disease complicated by severe carotid or intracranial arterial stenosis underwent coronary artery bypass graft surgery (CABG) using a novel method of dynamic pulsatile cardiopulmonary bypass (Super Pulse CPB). The Super Pulse technique can maintain the systolic pressure and systolic-diastolic amplitude in such a way that they mimic the physiologic circulation. Forty-five patients (33 males and 12 females, mean age 65.1 years) with coronary disease who had a greater than 75% stenosis of the carotid or intracranial arteries were evaluated. Evaluation was performed for the following 3 groups: 8 patients with conventional pulsatile CPB (Group I), 8 patients with conventional pulsatile CPB plus intraaortic balloon pumping (Group II), and 29 patients with Super Pulse CPB. Maximum, minimum, and mean perfusion pressures during CPB were 112.7, 53.6, and 76.9 mmHg (integrated mean), respectively, in Group III. The systolic-diastolic amplitude was significantly better than for Group I and similar to baseline pressures. No patients in Group II or Group III developed perioperative cerebral disorders or myocardial infarction, while in Group I perioperative cerebral disorders developed in 3 patients, myocardial infarction occurred in 2 patients, and 2 patients died during hospitalization. The initial performance of the Super Pulse CPB indicates excellent safety, and is useful for patients with co-morbid cerebral arterial disease.

Aged↗

PubMed2000

[Management of coronary artery disease combined with aortic stenosis: how to do with mild aortic stenosis].

A total of fourteen patients with combined operation of coronary artery bypass grafting (CABG) and aortic valve replacement (AVR) for coronary artery disease (CAD) and aortic stenosis (AS) were reviewed to evaluate the indication of the combined operation. Preoperative pressure gradient across the valve and effective orifice area were 21-89 mmHg (mean 64 mmHg), 0.5-1.9 cm2 (mean 0.92 cm2), respectively. The extent of CAD was 1-3 (mean 2.0). Fractional shortening (%FS) ranged from 13% to 43% with mean value of 28%. All patients underwent CABG and AVR. The number of grafts was 1-4 (mean 2.3) with internal thoracic artery used in 7 cases. Mechanical valves were employed for all patients except 1 case with cerebral aneurysm. There was no operative death, although low output syndrome developed in 2 cases. One had poor left ventricular function preoperatively, and the other was emergency case. Fractional shortening improved postoperatively even in two cases with preoperative %FS less than 20%, and all grafts were patent on postoperative coronary angiography. The event-free survival was 100% during 32 months of mean follow-up. Combined AVR with CABG is recommended to avoid risky secondary operation in patients of CAD and AS, even if one of which is relatively mild, because of the fact that operative and late results of the combined surgery are satisfactory.

Adult↗

PubMed1999

Retrograde cerebral perfusion versus selective cerebral perfusion as evaluated by cerebral oxygen saturation during aortic arch reconstruction.

BACKGROUND: Time limits for neuroprotection by retrograde cerebral perfusion (RCP) and selective cerebral perfusion (SCP) in aortic arch aneurysm repair or dissection are undergoing definition. METHODS: Using near-infrared optical spectroscopy, changes in regional cerebrovascular oxygen saturation (rSO2) were compared between the two perfusion methods. RESULTS: Immediately before cardiopulmonary bypass, baseline rSO2 was 63.9%+/-6.9% for the RCP and 66.1%+/-5.3% for the SCP group (no significant difference). As patients were core-cooled to 20 degrees C, rSO2 increased to 73.1%+/-8.8% and 74.1%+/-7.9% in the RCP and SCP groups, respectively. With circulatory arrest, rSO2 suddenly decreased. After starting cerebral perfusion, rSO2 returned to prearrest values in the SCP group but continued decreasing steadily in the RCP group, to levels below baseline after about 25 minutes. At the end of perfusion, rSO2 was 57.4%+/-12.2% for the RCP group and 71.7%+/-6.9% for the SCP group, and the ratio of rSO2 to baseline value was 0.89 for RCP and 1.08 for SCP despite a shorter brain perfusion time for RCP (38.8+/-18.0 versus 103.3+/-43.3 minutes). Three of 5 patients whose ratios of rSO2 to baseline at the end of brain protection were 0.7 or less had neurologic deficits. CONCLUSIONS: Although SCP showed no clinically important time limitation, rSO2 continued to decrease with time during RCP. An rSO2 ratio less than 0.7 could represent a critical lower limit.

Aged↗

PubMed1999

Mechanism of apoptosis induced by a lysosomotropic agent, L-Leucyl-L-Leucine methyl ester.

Lysosomes are fundamental for cell growth, and thus inhibition of the lysosomal function often leads to cell death. L-Leucyl-L-leucine methyl ester (LeuLeuOMe) is a lysosomotropic agent that induces apoptosis of certain immune cells. LeuLeuOMe is taken up through receptor-mediated endocytosis, and then converted into (LeuLeu)n-OMe (n>3) by dipeptidyl peptidase I (DPPI) in lysosomes, which reportedly causes rupture of the lysosomes and DNA fragmentation. In this study we examined how lysosomal damage causes DNA fragmentation in LeuLeuOMe-treated HL-60 cells. When acridine orange was employed to monitor lysosomal membrane integrity, orange or red granular fluorescence was seen in normal cells. In contrast, LeuLeuOMe-treated cells showed orange, yellow or green cellular fluorescence all over the cytoplasm, suggesting that LeuLeuOMe induced a loss of lysosomal membrane integrity. The loss was inhibited by a DPPI inhibitor, GlyPheCHN2 (GFCHN2), but not by a caspase-3 inhibitor, Ac-DEVD-CHO, indicating that a condensation product was responsible for the loss. LeuLeuOMe also induced the activation of caspase-3-like protease and DNA fragmentation, both of which were inhibited by either GFCHN2 or Ac-DEVD-CHO. Therefore, the activation of caspase-3-like protease links the loss of lysosomal membrane integrity to DNA fragmentation during apoptosis induced by LeuLeuOMe.

Journal Article↗

PubMed1999

The effect of direct lidocaine injection into the clamped aortic segment on the spinal evoked potential: early diagnosis for spinal cord ischemia.

PURPOSE: The aim of this study was to identify a method to determine whether segmental artery reconstruction was indicated during aortic clamping. METHOD: Spinal cord evoked potential (SCEP) and regional spinal blood flow were studied in 24 adult dogs. Using the left heart bypass technique, aortic clamping divided the aorta into thoracic, abdominal, and terminal segments. After the occlusion of the descending aorta and discontinuation of the perfusion to the abdominal segment, animals were assigned to four groups: no treatment with perfusion to the terminal aorta (group IA), no treatment with cessation of bypass (group IB), 5% lidocaine administration (5 mg/kg) into the abdominal segment with perfusion to the terminal aorta (group IIA), and lidocaine administration with cessation of bypass (group IIB). RESULTS: Cessation of bypass reduced spinal blood flow and SCEP amplitude. Lidocaine injection allowed for a significant rapid decrease in SCEP amplitude in group IIB compared with group IB (24.2% +/- 13.4% versus 92.3% +/- 33.2%; p = 0.0039). The degree of spinal blood supply was reflected immediately in the magnitude of SCEP amplitude change by the direct lidocaine injection. (group IB versus group IIB; p = 0.023). CONCLUSION: The direct injection of lidocaine into the clamped aorta results in a rapidly change in SCEP in the threat of ischemia and can be used to make an early detection of the segmental arteries perfusing to the spinal cord.

Analysis of Variance↗

PubMed1998

Emergency percutaneous cardiopulmonary bypass support for acute myocardial infarction.

We assessed the efficacy of emergency percutaneous cardiopulmonary bypass support (PCPS) in the treatment of patients with acute myocardial infarction complicated by cardiogenic shock. Emergency PCPS was instituted in 21 consecutive patients beginning in 1991. After the stabilization of the hemodynamics, coronary reperfusion was performed by means of coronary artery bypass grafting or percutaneous transluminal coronary angioplasty. Of the seven patients with acute myocardial infarction involving either the left main or two-vessel territories, five survived more than 1 month, but only one patient remained alive and well after 20 months. The main cause of death for this group was low output syndrome. Four of 12 patients with acute left main trunkal occlusion in the catheter laboratory survived and showed a preserved cardiac function (mean followup 28.5 months). The main cause of death for this group was brain damage. Two patients with single-vessel territory acute myocardial infarction underwent PCPS to treat refractory ventricular fibrillation. Both patients were still alive and well at a 12-month followup. Percutaneous cardiopulmonary bypass support successfully stabilized the hemodynamics, allowing time to perform revascularization for all three groups of patients with life-threatening acute myocardial infarction. Recanalization was nevertheless unable to salvage the damaged myocardium in cases of prolonged ischemic time.

Aged↗

PubMed1998

Surgical results for thoraco-abdominal aneurysm by modified DeBakey method using centrifugal biopump and renal cryopreservation.

BACKGROUND: In this paper, we report the surgical results of our DeBakey and Crawford combined method. METHODS: From 1985 to 1995, 22 consecutive patients with thoraco-abdominal aneurysms underwent a modified DeBakey and Crawford combined procedure to minimize the ischemic time for the spinal cord and visceral organs. The extent of aneurysm as classified by Crawford was as follows: Group I, 12; Group II, 4, Group III, 3; Group IV, 3. The etiology of the aneurysm was atherosclerosis in 19, cystic medial necrosis in 2, and aortitis in 1. The aneurysm was approached through the spiral opening method. First, end-to-side distal anastomosis was performed above the bifurcation under partial aortic clamping, and this was followed by proximal anastomosis. During the end-to-end proximal anastomosis, a Gott shunt tube or heparinless left heart bypass was used. In two patients, left renal artery had been previously reconstructed by a saphenous vein graft extending from the left common iliac artery. Then aneurysm was opened, and the right renal artery and superiors mesenteric artery were perfused with cold blood. In two patients, partial cardiopulmonary bypass and selective perfusion were performed. In eight patients, renal artery, celiac artery, superior mesenteric artery, and intercostal artery were reconstructed with a branch graft. RESULTS: No patient died within 30 days of surgery, however, one patient died of acute myocardial infarction (POD 54) and another of ventricular fibrillation during hemodialysis (POD 60). Postoperative complications included paraplegia, and renal failure requiring dialysis each in two patients. Postoperative angiography revealed 18/19 (94.7%) of grafts were patent. CONCLUSIONS: In conclusion, by using different techniques for spinal cord and visceral protection, including the Gott shunt, Biomedicus pump, renal cryopreservation, and separate revascularization of viscera and intercostal arteries, good results could be obtained.

Adult↗

PubMed1997

Single lung transplantation for canine pulmonary hypertension.

BACKGROUND: In spite of recent reports of the clinical application of single lung transplantation for pulmonary hypertension, there is little underlying experimental data because of the lack of a reliable animal pulmonary hypertensive transplant model. We have established a pulmonary hypertensive model in beagles with dehydromonocrotaline and have been able to measure cardiopulmonary hemodynamics accurately and use circulatory assists during procedures. The purpose of this study was to determine whether single lung transplantation could be performed after the protocol of clinical procedure. METHODS AND RESULTS: In six control dogs, allografting was successfully completed without cardiopulmonary bypass. Because one pulmonary hypertensive recipient dog died of right ventricular failure during the procedure without cardiopulmonary bypass, we used bypass for allografting in five pulmonary hypertensive dogs. Cardiopulmonary bypass lowered pulmonary artery pressure, allowing pulmonary arterial clamping and avoiding right ventricular overload. All pulmonary hypertensive dogs undergoing bypass were successfully weaned from bypass, indicating a good hemodynamic response to transplantation. In pulmonary hypertensive dogs, transplantation resulted in significant decreases in systolic pulmonary artery pressure and pulmonary vascular resistance, and a significant increase in blood flow to the graft lung, whereas in controls the results were the reverse. CONCLUSIONS: Thus we were able to show that hemodynamics improved after single lung transplantation with cardiopulmonary bypass in a new pulmonary hypertensive animal model. These relatively larger animals are valuable for further studies of single, double, bilateral, and heart-lung transplantation for pulmonary hypertension.

Animals↗

PubMed1997

Rupture of a dissecting aneurysm into the superior vena cava in Marfan's syndrome.

Aneurysmal dilatation of the aorta with subsequent dissection or rupture occurs frequently in patients with Marfan's syndrome. These complications are among the major causes of death. We report the case of a 51-year-old man with annulo-aortic ectasia in Marfan's syndrome. Acute aortic dissection and rupture into the superior vena cava occurred 8 years after aortic valve replacement. The preoperative diagnosis was made by right heart catheterization and computed tomography. A markedly increased left-to-right shunt occurred with rapid enlargement of the fistula due to the fragility of the aortic wall characteristic of Marfan's syndrome. Postmortem examination demonstrated severe medial necrosis with rupture of the aortic wall into the superior vena cava which was adherent to the suture line of the aortotomy from the previous surgery. Type A aortic dissection with severe congestive heart failure strongly suggested rupture into the pulmonary circulation.

Aortic Dissection↗

PubMed1996

Counterproductive effects of sodium bicarbonate in diabetic ketoacidosis.

Although a growing body of evidence supports that alkali therapy in diabetic ketoacidosis (DKA) might be counterproductive, our knowledge about the consequences of this treatment on ketone metabolism is limited. Consequently, we performed clinical and animal studies to further examine this topic. The clinical studies assessed seven patients with DKA treated with continuous insulin infusion at a low dosage. Three of them also received sodium bicarbonate (NaHCO3), whereas the remaining four acted as controls. The group receiving NaHCO3 showed a 6-h delay in the improvement of ketosis as compared with controls. In addition, there was an increase in acetoacetate (AcAc) levels during alkali administration, followed by an increase in 3-hydroxybutyrate (3-OHB) level after its completion. Significant differences were not found between groups in the response of plasma glucose to the overall therapy. The animal study examined the effects of a NaHCO3-rich perfusate on the hepatic production of ketones with the in situ rat-liver preparation. Alkali loading resulted in an immediate increase in the AcAc level followed by increases in both the 3-OHB level and the 3-OHB/AcAc ratio after its completion. Hepatic ketogenesis increased even further, to about twice the basal level, after termination of the NaHCO3 loading. This investigation confirms that alkali administration augments ketone production and unravels an effect of bicarbonate infusion that promotes a selective build up of AcAc in body fluids. The data support that alkali therapy in DKA has nonsaltuary effects in the metabolism and plasma levels of ketones.

Adult↗

PubMed1996

[A case report of an infective endocarditis caused by methicillin-resistant Staphylococcus aureus with successful mitral valve replacement].

We report a case of successful mitral valve replacement performed on the patient who is an infective endocarditis due to MRSA. She was 27-year-old female and treated by antibiotics medication because of remittent fever two years ago. On August 1995, cerebral infarction occurred and she was pointed out endocarditis. After high fever continued, blood cultures demonstrated MRSA. Furthermore, echocardiography showed vegetation on posterior mitral valve leaflet and moderate mitral regurgitation so, mitral valve replacement with a S.J.M. 25 mm performed to control MRSA sepsis condition. During operation, we used VCM 2 g into the extracorporeal circulation and after operation 0.5 g intravenously every 6 hours. Two weeks later we changed antibiotics to FOM, Viccillin and ABK according to the result of minimum inhibitory concentration (MIC) obtained through blood culture. The patient was discharged on the 44 th postoperative day because of her uneventful postoperative course.

Adult↗

PubMed1996

[Rupture of the aneurysm of the sinus valsalva: thirteen years after the initial diagnosis].

We report a case of an unruptured aneurysm of the sinus Valsalva (URASV) which was followed thirteen years without surgery. A 47-year-old female had a heart murmur detected at age 34 during pregnancy. Though an URASV was diagnosed, because the aneurysm was less than 1 cm in size, no surgery was advised at that time. Thirteen years later, she gradually noticed of increased heart beats and also dyspnea on exertion. Echocardiogram showed an aneurysm of the sinus Valsalva ruptured to the RV cavity. In June 1994, resection of the aneurysm was performed. One year later, the patient was asymptomatic. This may be the second longest long-term follow-up report of the patient with an unruptured aneurysm of the sinus Valsalva.

Aneurysm, Ruptured↗