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Biomedical subjects

M Hata

Publications and source records attributed to M Hata.

At least 109 records · Page 6Linked to original sources
PubMed1998

Congenital coronary artery fistula treated surgically in the right atrium and the atrial septum.

Various surgical techniques have been employed according to the type of the coronary fistula. In this case, preoperative examinations by aortography and MRI revealed a coronary artery fistula which originated from a site just proximal of the RCA, ran through the interatrial septum and drained into the posterior wall of right atrium. The ratio of pulmonary to systemic blood flow (Qp/Qs) was 1. 95. During surgery, we were not able to ligate or divide the fistula on the cardiac surface because the fistulous vessel originated from the posterior aspect of the proximal RCA. After establishing a cardiopulmonary bypass, the opening of the fistula in the right atrium was closed with an autologous pericardium patch, the surface of the interatrial septum was incised and the fistula was identified. The conduit was then divided and closed in the atrial septum. The postoperative course was uneventful. This approach is able to interrupt the fistula safely without interfering with normal coronary flow. Closure of the outlet and division of the fistula itself is a recommendable method to insure interruption of fistulous communication.

Adult↗
PubMed1997

Stent angioplasty for renovascular disease associated with acute aortic dissection.

Aortic replacement was performed in a patient with acute type A aortic dissection originating from the descending thoracic aorta. Postoperatively, a persistent false lumen resulted in severe stenosis of the right renal artery. Percutaneous stent angioplasty improved renovascular hypertension and renal function. This procedure is useful for management of patients with branch complications of aortic dissection.

Aortic Dissection↗
PubMed1997

Dominant mutations of Drosophila MAP kinase kinase and their activities in Drosophila and yeast MAP kinase cascades.

Eight alleles of Dsor1 encoding a Drosophila homologue of mitogen-activated protein (MAP) kinase kinase were obtained as dominant suppressors of the MAP kinase kinase kinase D raf. These Dsor1 alleles themselves showed no obvious phenotypic consequences nor any effect on the viability of the flies, although they were highly sensitive to upstream signals and strongly interacted with gain-of-function mutations of upstream factors. They suppressed mutations for receptor tyrosine kinases (RTKs); torso (tor), sevenless (sev) and to a lesser extent Drosophila EGF receptor (DER). Furthermore, the Dsor1 alleles showed no significant interaction with gain-of-function mutations of DER. The observed difference in activity of the Dsor1 alleles among the RTK pathways suggests Dsor1 is one of the components of the pathway that regulates signal specificity. Expression of Dsor1 in budding yeast demonstrated that Dsor1 can activate yeast MAP kinase homologues if a proper activator of Dsor1 is coexpressed. Nucleotide sequencing of the Dsor1 mutant genes revealed that most of the mutations are associated with amino acid changes at highly conserved residues in the kinase domain. The results suggest that they function as suppressors due to increased reactivity to upstream factors.

Alleles↗
PubMed1997

Screening of H-ras gene point mutations in 50 cases of bladder carcinoma.

BACKGROUND: Mutation converts the H-ras gene into an activated oncogene in about 10% of human bladder cancers. Codons 12 and 61 are the major "hot spots" for activation. A simple and accurate method to detect point mutations in these codons may be clinically useful for early diagnosis of bladder cancer. METHODS: Bladder cancer samples from 50 patients, plus 10 samples of normal bladder mucosa, were analyzed for possible point mutation of the H-ras gene at either codon 12 or codon 61. The H-ras gene DNA segments that include these 2 codons were amplified by PCR methods, then the possible presence of a point mutation was evaluated at each codon by susceptibility of the respective DNA segments to digestion with the restriction enzyme and by dot blot hybridization assay. A bladder cancer patient who had an H-ras gene mutation was examined to see whether the mutation was also detectable in the cells released in the urine. RESULTS: Definite or possible point mutations were found in 6 (12%) out of 50 bladder cancer patients, while no mutation was detected in normal mucosa. A point mutation could also be detected in cells isolated from the patient's urine sample. CONCLUSION: The prevalence of point mutations at codon 12 or codon 61 of the H-ras gene found in this study was similar to that previously estimated for human bladder cancer by DNA transfection assay. The method we have used for detecting point mutations of the H-ras gene provides a simple and highly accurate way to detect mutated cancer cells even in the urine. It may be clinically usable for early diagnosis of bladder cancer.

Adult↗
PubMed1997

A newly developed silicone-coated membrane oxygenator for long-term cardiopulmonary bypass and cardiac support.

The surface of polypropylene hollow fiber was successfully coated with a very thin (0.2 micron) silicone layer. Experimental studies were performed in long-term (6 h) normothermic cardiopulmonary bypass (CPB) using 10 goats. A conventional membrane oxygenator (Mera Excelung HPO-15H, MERA, Tokyo, Japan) was used for 5 goats as a control (Group C) and a new silicone-coated membrane oxygenator, which is of the same construction as that of the one used for Group C, for 5 (Group S). The O2 transfer and CO2 removal functions showed the same ranges. In the other parameters, there were no differences between the 2 groups. As for hemolysis, however, the plasma free hemoglobin of Group S was lower than that of Group C. Currently, 3 chronic percutaneous cardiopulmonary support (PCPS) experimental models have been conducted, and there has been no evidence of thromboembolism or deterioration of the oxygenator. In conclusion, this new oxygenator is suitable not only for CPB, but also for long-term cardiac support.

Animals↗
PubMed1997

Renal circulation and cellular metabolism during left ventricular assisted circulation: comparison study of pulsatile and nonpulsatile assists.

We examined left ventricular assist during 6 h for an acute myocardial infarction model in pigs. The outflow cannula was placed in the ascending aorta and an inflow cannula in the left atrium. A pump (Pulsatile group: Zeon Medical and Nonpulsatile group: Nikkiso HPM-15) was connected to each cannula. Items measured were the regional blood flow of the cortex and the medulla in the kidney, renal arterial flow, arterial blood ketone body ratio (AKBR), lactate/pyruvic acid, BUN, creatinine and beta 2-microglobulin. After experimental study, the kidneys were removed, and a pathological study was performed. In the pulsatile assisted group, renal cortical blood flow increased but medulla blood flow decreased. On the other hand, in the nonpulsatile assisted group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved, rather than in the nonpulsatile assisted group. The results of our study indicated that pulsatile assist produced superior circulation in the kidney, and the microcirculation on the cell level was superior as well in early treatment of acute left heart failure.

Animals↗
PubMed1997

[En bloc resection of the temporal bone for middle ear carcinoma extending to the cranial base].

En bloc resection of the temporal bone for squamous cell carcinoma of the middle ear was performed by the postauricular transtemporal and retromastoid approaches. The patient was a 70-year-old woman whose tumor extended to the middle and posterior cranial fossae. Temporal and retromastoid craniotomies were carried out, then the temporal dura and the cerebellar dura, and the transverse and sigmoid sinuses were exposed. The temporal dura and the cerebellar dura were opened, and the transverse sinus was ligated at the junction with the sigmoid sinus. After that, the tentorial dura was incised, the incision extending anteriorly to the middle cranial fossa and transecting the superior petrosal sinus. Consequently, a wide view into the middle and the posterior cranial fossae was obtained. In the posterior fossa, cranial nerves VII and VIII were divided. On the other hand, nerves IX, X and XI were preserved at the dural incision on the posterior surface of the temporal bone. Subsequently, in the area of the carotid canal, the temporal bone was drilled toward the medial side of the internal auditory canal and also posteriorly down to the jugular bulb. At this stage, the temporal bone and the soft tissue attachments, such as the middle and posterior cranial fossa dura, and the sigmoid sinus, were separated from the pyramidal apex and the clivus. The dural defect was repaired with a free pericranial graft. A rectus abdominis muscle flap was transferred to reconstruct the defect of the skull base resulting from the temporal bone resection. Postoperative complications like CSF leakage, meningitis and lower cranial nerve damage, were not seen after the treatment. The patient has shown no evidence of recurrence for the 28 months since the surgical treatment, and has not complained of any problems with swallowing or conducting conversations in daily life. With the contribution of recent developments in skull base and reconstruction surgery, more aggressive en bloc resection of the temporal bone can be carried out on patients with advanced middle ear carcinoma. These developments will also make it possible for patients whose prognosis was previously thought to be poor to have a chance for a cure.

Aged↗
PubMed1997

[A trial of laparoscopic assisted radical nephrectomy].

BACKGROUND: We tried a new procedure of gas-less laparoscopy assisted radical nephrectomy. METHODS: Prior to insertion of laparoscope, pararectal incision approximately 7 cm in length was made to enter into the intraabdominal cavity. A 12 mm trocar was placed just below the umbilicus and a flexible electroscope was inserted through it. A 10 cm size disposable fan for lifting up the abdominal wall was indwelled through the under space of trocar port. After appropriately lifting up the abdominal wall, a 10 mm trocar for working channel was placed at mid-axillar line. Under laparoscopic and trans-laparotomic views, radical nephrectomy was performed using the combined technique of laparoscopic and open surgery. RESULTS: Seven patients have been successfully treated with this procedure. The mean operating time of this procedure was significantly shorter than that of totally laparoscopic nephrectomy. The recovery time from the operation was as short as usual laparoscopic nephrectomy. CONCLUSION: We thought that this procedure could open a new scope of laparoscopic surgery.

Adult↗
PubMed1997

[A simultaneous operation of aortic root, arch replacement, and sternal elevation for Marfan's syndrome--a case report].

A 42-year-old male was transferred to our institution by his family doctor because of suspected type A aortic dissection with cardiac tamponade. His physical constitution gave the appearance of Marfan's syndrome. Contrast CT revealed DeBaky type 1 aortic dissection. Angiography detected an Annulo-aortic ectasia complicated by an aortic regurgitation (AR) grade IV. He also suffered from a severe funnel chest. We performed simultaneous procedures of aortic root, arch replacement, and sternal elevation. Upon operation, a staged aortic clamp technique was employed to reduce the period of cardiac arrest. In the sternal elevation, the bilateral internal thoracic arteries were preserved. Post operative course was uneventful. We consider it effective to employ the staged aortic clamp technique in a reconstruction of the entire thoracic aorta in the case of poor cardiac function and to preserve the bilateral internal thoracic arteries in sternal elevation in order to prevent infection.

Adult↗
PubMed1997

[A reconstruction of the left ventricle for post infarction left ventricular aneurysm complicated by ventricular septal perforation--a case report].

A 68-year-old male with post myocardial infarction left ventricular aneurysm (LVA) complicated by ventricular septal perforation (VSP) was treated surgically. At first, he was admitted with acute myocardial infarction by a physician. Coronary angiography (CAG) revealed a total occlusion of the left anterior descending coronary artery. It was improved to 99% of stenosis by PTCR. Echo cardiography revealed the VSP. However, the patient was approached conservatively because of complications of severe pneuminitis and acute hepatitis. Cardiac catheterization was performed three months after admission. The data on the catheterization are as follows: Left ventricular (LV) wall dyskinesis is presented at segment 1-5. Global ejection fraction (EF) = 26%, Corrected EF = 40%, LVEDP = 36 mmHg, Qp/Qs = 1.8. Elective surgery was then performed with IABP, LVA was resected 90 x 50 mm in size under ventricular fibrillation. VSP, which was 9 mm in size, was closed directly with Teflon felt strips. LV plication was then made with 3.0 polypropylene under cardiac arrest. Reconstruction of the LV was then performed with a double patch, of which a cow pericardium was laid on top of a Gore-Tex patch. Post operative cardiac function was improved remarkably. We consider this procedure excellent because of the avoidance of thrombus and the maintenance of the LV form.

Aged↗
PubMed1997

[A case report: successful treatment of acute type B aortic dissection with renal and leg ischemia].

A 56-year-old patient of acute type B aortic dissection with renal and leg ischemia successfully underwent emergency replacement of the descending thoracic aorta. Prior to this operation, we reperfused the ischemic legs in a controlled manner using a cardiopulmonary bypass circuit. This controlled limb reperfusion method could reduce reperfusion injury. Postoperatively, the patient also suffered from renovascular hypertension due to stenosis of the right renal artery. Renal stent angioplasty, performed 10 days after the operation, stabilized his blood pressure. Controlled limb reperfusion and renal stent angioplasty may be useful for managing branch complications associated with aortic dissection.

Aortic Dissection↗
PubMed1997

[Outpatient chemotherapy with continuous intravenous infusion for patients with recurrent renal cell carcinoma or advanced prostate carcinoma].

We tried outpatient chemotherapy with continuous intravenous infusion of 5-fluorouracil (5-FU) and cisplatin (CDDP) for patients with recurrent renal cell carcinoma or advanced prostate carcinoma. This study was designed to evaluate the efficacy of our drug delivery system using two disposable balloon pumps and subcutaneous port, subjective symptoms caused by chemotherapy, and quality of life (QOL). There were 12 patients, including 7 cases of recurrent renal cell carcinoma and 5 cases of advanced prostate carcinoma. Their performance status (PS) was grade 0 or 1. The protocol for renal cell carcinoma consisted of combined chemotherapy with continuous infusion of 5-FU 250 mg/m2/day and CDDP 3 mg/m2/day in 2 weeks for 1 cycles (4 weeks). 5-FU and CDDP were administered with the Baxter infuser pumps (Intermate LV 1.5) and after 1 week we changed the new pumps. In treating advanced prostate carcinoma, Honvan 100 mg/day was substituted for 5-FU. We experienced 2 cases of problems with the drug delivery system during 10 months, which needed a change of the subcutaneous port. QOL score and subjective symptoms showed that patients were not always free because of carrying pumps and the side effects of chemotherapy, but they can return to social life and family instead of spending much time in the hospital. In conclusion, our drug delivery system is safe for outpatient chemotherapy, and QOL of patients with home anti-cancer chemotherapy is higher than that of patients with chemotherapy in the hospital.

Adult↗
PubMed1997

[A correlation between atrial natriuretic peptide, brain natriuretic peptide, and perioperative cardiac and renal functions in open heart surgery].

Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are homeostatic hormones secreted from the human heart which protect both cardiac and the renal function. It is well known that these hormones increase in patients along with increases in the severity of congestive heart failure or acute myocardial infarction. However, as yet there are no reports in the literature on changes of the secreted level of ANP or BNP in surgical patients undergoing cardiopulmonary bypass (CPB). We evaluated the relationship between ANP, BNP, and perioperative cardiac and renal functions in patients with heart failure caused by CPB. We selected 45 patients of elective open heart surgery. We measured plasma level of ANP in all 45 cases, and BNP in 18 cases at preoperation, postoperation, and postoperatively three days after, respectively. At the same time, the cardiac index (CI) was measured. These cases were divided into the following groups. Group A1 (n = 23): cases in which the preoperative ANP was less than 40 pg/ ml. Group A2 (n = 22): cases in which the preoperative ANP was more than 40. Group B1 (n = 8): cases in which the preoperative BNP is increased to the level of 5 times as mach as the normal level. Group B2 (n = 8): cases in which the preoperative BNP is increased to the level of 5 times as much as the normal level. Group B2 (n = 10): cases in which the preoperative BNP was more than that of 10 times as mach as normal level. We then carried out a comparative study of the perioperative cardiac and renal functions in group A1 and A2, and group B1 and B2, respectively. In the terms of preoperative cardiac and renal function, there were no significant differences between groups A1 and A2, and there were no significant differences in urinary volume during CPB or post operative CI. However, the urinary volume during CPB of group B1 was significantly more than that of B2. Furthermore, the incidence of postoperative CI in group B1. Furthermore, the incidence of postoperative CI in group B1 was significantly higher than in B2. The preoperative and post operative third day BNP level had significant negative correlations with postoperative CI and postoperative third day CI, respectively (r = -0.641, -0.514, p = 0.008, 0.012). The postoperative ANP and BNP levels tend to a mean level roughly similar to one another because of the easing of cardiac stress by surgery and postoperative management. According to these results and several instances in the literature, a preoperative high BNP is considered to suggest a potential perioperative risk for cardiac and renal function. We conclude that determination of the plasma BNP level can be helpful for decisions related to CPB flow and measures taken to enhance cardiac and renal protection during surgery, and therefore is a useful reference for perioperative management.

Aged↗
PubMed1996

Genomic cloning of a human heat shock protein 40 (Hsp40) gene (HSPF1) and its chromosomal localization to 19p13.2.

The Hsp40 (heat shock protein with molecular size of approximately 40 kDa) is one of the mammalian homologues of bacterial DnaJ heat shock protein. We have isolated and characterized a genomic DNA clone encompassing the entire coding sequences of the human Hsp40 cDNA. The Hsp40 gene (HGMW-approved symbol HSPF1) is composed of three exons divided by two introns. The 5' region of the gene is highly GC rich, and there are multiple basal elements for transcription factors including typical heat shock elements. The Hsp40 gene has been assigned to chromosome 19 band p13.2 by in situ hybridization.

Binding Sites↗