Biomedical subjects

J Hirota

Publications and source records attributed to J Hirota.

At least 37 records · Page 2Linked to original sources

PubMed1998

T-cell-receptor signalling in inositol 1,4,5-trisphosphate receptor (IP3R) type-1-deficient mice: is IP3R type 1 essential for T-cell-receptor signalling?

Stimulation of T-cells via the T-cell receptor (TCR) complex is accompanied by an increase in intracellular Ca2+ concentration ([Ca2+]i). Recently, it was reported that a stable transformant of the human T-cell line, Jurkat, expressing an antisense cDNA construct of inositol 1,4,5-trisphosphate receptor (IP3R) type 1 (IP3R1), failed to demonstrate increased [Ca2+]i or interleukin-2 production after TCR stimulation and was also resistant to apoptotic stimuli. This cell line lacked IP3R1 expression, but expressed the type-2 and -3 receptors, IP3R2 and IP3R3 respectively [Jayaraman, Ondriasova, Ondrias, Harnick and Marks (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 6007-6011, and Jayaraman and Marks (1997) Mol. Cell. Biol. 17, 3005-3012]. The authors concluded that IP3R1 is essential for TCR signalling and suggested that Ca2+ release via IP3R1 is a critical mediator of apoptosis. To establish whether a loss of IP3R1 function in T-cells occurred in vivo and in vitro, we investigated Ca2+ signalling after TCR stimulation and the properties of T-cells using IP3R1-deficient (IP3R1-/-) mice. As IP3R1-/- mice die at weaning, we transplanted bone marrow cells of IP3R1-/- mice into irradiated wild-type mice. Western blot analysis showed that the recipient IP3R1-containing (IP3R1+/+) lymphocytes were replaced by the donor IP3R1-/- lymphocytes after transplantation and that expression of IP3R2 and IP3R3 was unaltered. In contrast with the previous reports, T-cells lacking IP3R1 were able to mobilize Ca2+ from intracellular Ca2+ stores after stimulation via the TCR. We observed no significant differences between IP3R1+/+ and IP3R1-/- T-cells in terms of the number of thymocytes and splenocytes, the proportion of the T-cell phenotype, proliferative response to anti-CD3 monoclonal antibody (mAb) stimulation and cell viability. Therefore IP3R1 is not essential for T-cell development and function.

Animals↗

PubMed1998

Cardiopulmonary bypass established via a sutured vascular graft in the presence of extraanatomic bypass.

Cardiopulmonary bypass (CPB) was established via a sutured collagen sealed knitted Dacron graft in two patients who had undergone extraanatomic bypasses for lower limb ischemia, whose ascending aorta was not suitable for cannulation. One patient, with a history of femorofemoral bypass, underwent surgery for a ruptured aortic arch aneurysm (AAA) and the other patient, with a history of axillobifemoral bypass for chronic dissection involving the aortic arch and descending aorta, had unstable angina and underwent coronary artery bypass grafting. This technique of perfusion was found to be safe and effective for patients with an impaired ascending aorta who have undergone an extraanatomic bypass for the lower limb.

Aged↗

PubMed1998

[A successful repair of infective endocarditis accompanied by a pseudoaneurysm of the left ventricle].

The present paper reports a successful surgical treatment of a 47-year-old male with a pseudoaneurysm of the left ventricle. The patient has also been administered Penicillin G for 5 months to treat endocarditis. Cardiac catheterization showed severe aortic stenosis and a pseudoaneurysm of the left ventricle which was dilating in systole. The patient underwent patch closure of the pseudoaneurysm whose ostium was situated at the miral-aortic inter valvular fibrosa followed by aortic valve replacement and direct closure of a right Valsalva sinus aneurysm. His postoperative course was uneventful. The patient had no recurrence of endocarditis nor malfunction of the prosthetic valve for one year postsurgery. This is the first report in Japan of successful surgical treatment of a pseudoaneurysm of the left ventricle due to perforation of the miral-aortic intervalvular fibrosa after endocarditis.

Aneurysm, False↗

PubMed1998

Primary aortoenteric fistula with a chronic isolated abdominal aortic dissection: report of a case.

A 47-year-old woman on long-term hemodialysis due to a chronic isolated abdominal aortic dissection was admitted to our department with severe abdominal pain. She had not suffered any hematemesis or melena. An emergency laparotomy revealed an abdominal aortic aneurysm with a diameter of 60mm, densely adhered to the ileum. An aortoenteric fistula manifesting as intramural rupture into the ileum was found after infrarenal abdominal aortic and bilateral common iliac cross-clamping. The fistula on the ileac side was nontransmural, but that on the aortic side communicated with the pseudolumen of the abdominal aorta, and contained mural thrombus. The infrarenal abdominal aorta and bilateral common iliac arteries were replaced with a collagen-sealed woven Dacron bifurcated graft. Histological examination of the ileum in this portion showed intramural bleeding and xanthomatous granulation with foam cell infiltration in the thickened subserosa. While it is difficult to diagnose nonpenetrating aortoenteric fistula preoperatively, such a fistula must be considered in a patient with severe abdominal pain, for whom previous abdominal aortic surgery has been performed or when an abdominal aneurysm is observed. To our knowledge, no other case of an aortoenteric fistula presenting as an intramural rupture into the ileum in an isolated abdominal aortic dissection has ever been reported.

Adult↗

PubMed1998

Minimally invasive cardiac surgery in the adult: surgical instruments, equipment, and techniques.

To clarify the special instruments and equipment used for minimally invasive cardiac surgery (MICS), we examined the initial experiences with MICS operations with ministernotomy or minithoracotomy at our institution. Fifty adult patients with congenital, valvular, and/or ischemic heart diseases underwent MICS operations, and all surgical procedures were completed without conversion to full sternotomy. The length of the skin incision was about 10 cm or less in all patients. Postoperative recovery was favorable, and the majority of the patients were discharged from the hospital around the end of the second postoperative week. In this series of patients, an oscillating bone saw, lifting type retractor, 2 blade spreader, cannula with a balloon, and right-angled aortic clamp among other items, were very useful for successfully performing various operations with MICS approaches and techniques. The associated results suggest that MICS with ministernotomy or minithoracotomy was feasible using special instruments and equipment and could be encouraged for adult patients with various cardiovascular diseases.

Adult↗

PubMed1998

[Coronary artery bypass grafting to the left circumflex artery in the atrioventricular groove].

Coronary artery bypass graftings were performed to the left circumflex artery (LCX) system in the atrioventricular groove (#11 or #13) in addition to revascularization to the left anterior descending artery system using conventional technique in 10 patients with left main trunk lesion. Distal anastomosis was done at #11 of LCX in 6 patients using saphenous vein graft, and at #13 of LCX in 4 patients using 2 saphenous vein grafts and using 2 internal thoracic artery grafts. The mean flow rate of SVG operated by this technique showed larger values than that of SVGs by sequential bypass or individual bypass technique to #12 and/or #14 of LCX. Postoperative angiographies showed excellent graft patencies and symptomatic improvements were achieved. This technique of coronary artery revascularization is recommended and useful in patients whose #12 and #14 of LCX system is too small to make distal anastomosis.

Aged↗

PubMed1998

Multivarious clinical manifestations of multiple pseudoaneurysms in Behçet's disease.

In Behçet's disease, an aneurysm is prone to progress rapidly to a pseudoaneurysm. Acute limb ischemia due to acute thrombosis of a femoral pseudoaneurysm and subsequent Horner's syndrome due to another subclavian pseudoaneurysm are very rare but acceptable complications in Behçet's disease. We present a case of Behçet's disease with multiple pseudoaneurysms, which also showed these other clinical manifestations. Over a short time span, the patient rapidly developed left femoral and right subclavian pseudoaneurysms, which were successfully resected with graft replacements.

Adult↗

PubMed1998

Massive aortic regurgitation by spontaneous rupture of a fibrous strand in a fenestrated aortic valve.

A very rare case of Marfan syndrome associated with acute aortic regurgitation due to rupture of a fibrous strand of a fenestrated aortic valve is presented. Although an aortic valve fenestration usually has no pathologic significance, its association with aortic annular dilatation plays an important role. Rupture of a myxomatously degenerated fibrous strand loaded with high tension from annular dilatation reducing the coaptation area of each cusp during diastole was the suspected cause of acute massive regurgitation by complete retroversion of the right coronary cusp. Rupture of a fibrous strand of a fenestrated aortic valve with a dilated annulus could result in acute massive aortic regurgitation, for which prompt surgical repair is mandatory.

Adult↗

PubMed1998

A case of ruptured descending thoracic aortic aneurysm into the right pleural cavity: importance of preoperative drainage of the right pleural cavity.

We present an unusual case of a ruptured descending thoracic aortic aneurysm into the right pleural cavity of a patient with pectus carinatum. The presence of pectus carinatum played an important role in the development of the aneurysm at the atypical site and the rupture into the right pleural cavity. A small amount of right pleural bleeding on admission can increase and develop to massive hemothorax until emergency operation. Massive bleeding in the right pleural cavity where the dependent lung is located causes atelectasis and increased shunt fraction under one lung ventilation. Therefore, continuous drainage of the right pleural cavity is essential to prevent serious hypoxia during graft replacement in a case of ruptured descending thoracic aneurysm into the right hemithorax.

Aged↗

PubMed1997

The release of nitroglycerin absorbed into the central venous catheter.

This study was conducted to evaluate the release of nitroglycerin (NG) that has been absorbed into the central venous catheter. A 0.05% NG solution was infused through a central venous catheter and the flow rates were set at 1, 5, or 10 ml/h, given over 12, 24, or 48 h. The catheter was flushed with lactate Ringer solution after completion of the NG infusion. The elution of the lactate Ringer solution from the tip of the catheter was then collected and assayed for its NG concentration by high performance liquid chromatography (HPLC). A higher concentration of NG was released with a faster flow rate and a longer infusion. The high level of NG release continued during the first 20 min, and ranged from a minimum of 0.07 mg/ml to a maximum that exceeded 0.15 mg/ml. Subsequently, the NG concentration gradually declined, but low concentrations of 0.006-0.02 mg/ml were still maintained 360 min later. Thus, it is suggested that if a catheter such as the Swan-Ganz continues to be used after the completion of a NG infusion, certain pharmacological effects due to the absorption of NG into the catheter body should be expected for at least 60 min.

Absorption↗

PubMed1997

[Reconstructive surgery for head and neck cancers under multiple facility cooperation system].

The problems with the system for reconstructive surgery for head and neck cancers in our department where plastic surgeons are regularly invited from distant facilities were discussed. Especially, the importance of preoperative discussion between the plastic surgeons and ENT doctors was stressed. The computer system with Internet will play an important role in exchanging information such as CT scans and MRI scans between the plastic surgeons and ENT doctors. Moreover, the establishment of a system to prevent postoperative troubles such as closure of anastomosed vessels was stressed. Twenty-seven re-vascularized free flaps had been transferred with a 96.3% success rate (26 of 27 cases). We concluded that the system for reconstructive surgery under the multiple facility cooperation system worked well.

Adult↗

PubMed1997

[The leaflet fracture of a 19 mm SJM (HP) valve during valve insertion to the calcified small aortic annulus].

Aortic valve replacement was undergone in a 70-year-old woman with calcified aortic stenosis. Calcified and fused tricuspid aortic valve was excised and a 21 mm sizer passed with some difficulty through the annulus. A 19 mm SJM HP serious was selected and the horizontal mattress suturing technique was used. The valve was held at the cuff near the hinge guard and seated into the annulus by the usual amount of pressure, however, one leaflet fracture was retrieved and the valve was removed. A 19 mm standard SJM valve was then successfully implanted. The potential factors of leaflet fracture suggested that the leaflet thickness of smaller sized SJM valves showed smaller values than other bileaflet valves in the same sized-valves. In addition, the SJM valve does not have an orifice stiffening ring like other bileaflet valves. So, needless to say direct pressure to the leaflet, indirect pressure might cause valve destruction during insertion. The abnormal pressure applied to the direction from one hinge guard to the other can introduce deforming of the orifice ring resulting in leaflet fracture like this case. The pressure directed to the perpendicular direction may introduce leaflet escape due to the deforming of the valve orifice.

Aged↗

PubMed1997

[One stage operation for sternal turnover with preserved rectus muscle pedicles and aortic root replacement associated with Marfan's syndrome].

A 40-year-old man with Marfan's syndrome had annulo aortic ectasia with Sellers grade 4 aortic valve regurgitation and Wada grade 3 pectus excavatum. Simultaneous operation was successfully performed by aortic valve composite graft insertion and sternal turnover with the rectus muscle pedicles. Following a midline skin incision, the cost-sterno complex (plastron) was dissected together with the bilateral rectus muscle pedicles, and the sternum was divided transversely through the second intercostal space. The plastron with muscle pedicles was retracted away from the anterior chest toward the abdomen and was covered by the moistened sternal bag made of polyethylene to prevent dryness and contamination during the composite graft insertion. The aortic root was replaced with a composite graft consisting of a 25 mm SJM valve and a 26 mm Hemashield graft. A short interposed 10 mm Hemashield graft was inserted between the ostia of the left coronary artery and the composite graft. The right coronary artery was reimplanted in the aortic conduit using the button technique with a doughnut pledget. This one stage method offered excellent operative exposure and enabled us to prevent possible necrosis of the sternum, infection of the mediastinal sinus, and postoperative cardiac failure resulting from chest wall compression. In this procedure, active usage of the rapid autologous transfusion system effectively reduced the total amount of blood transfusion.

Adult↗

PubMed1997

[A successful surgical treatment for huge left circumflex artery-right ventricle fistula using the fistula occlusion test].

A surgical case of rare coronary artery fistula between the left circumflex artery and right ventricle was reported. A 46-year-old woman had suffered from exertional dyspnea and palpitation for three years. Pan systolic heart murmur was heard through the left 4th inter costal space. The chest X-ray film demonstrated cardiac enlargement and lung congestion, and the electrocardiograms showed atrial fibrillation and left ventricular hypertrophy when she was admitted to our hospital. Preoperative catheterization revealed a huge coronary artery fistula originating from the left circumflex artery and opening into the right ventricle through the posterior wall of the heart. The left-to-right shunt ratio was 60% and Qp/Qs was 2.47. At operation, the dilated circumflex artery fistula was carefully dissected and the tape was passed around the fistula as a tourniquet under extra corporeal circulation on the beating heart. To estimate myocardial ischemia, the fistula occlusion test was performed by tightening the previously placed tourniquet. Monitoring of electrocardiograms, transesophageal echocardiography, and hemodynamics were useful to detect myocardial ischemia. The occlusion test was performed under ECC for 5 minutes. No ischemic changes were observed. The fistula was interrupted under cardiac arrest at the point of the occlusion test.

Arteriovenous Fistula↗

PubMed1996

Thrombotic obstruction of a reinforced ringed expanded polytetrafluoroethylene graft caused by formation of a pseudoaneurysm at a nonanastomotic site: report of a case.

We report herein the case of a 72-year-old man in whom a nonanastomotic pseudoaneurysm arose from a reinforced ringed expanded polytetrafluoroethylene (EPTFE) graft (Gore-Tex, Flagstaff, AZ, USA) following an axillobifemoral bypass. The pseudoaneurysm developed 2 years after graft insertion and induced graft thrombosis. The development of the pseudoaneurysm can be attributed to the fact that his axillobifemoral bypass graft was so short it deformed the proximal anastomosis, and the graft was subcutaneously tunneled onto the major pectoral muscle. These technical errors placed the graft under too much tension in the longitudinal direction, which resulted in graft disruption and pseudoaneurysmal formation, followed by thrombosis of the axillary artery. Moreover, the possibility of direct trauma at the time of insertion cannot be substantiated. Although the very poor compliance and design of the externally supported ring could not tolerate stretch deformity in the Gore-Tex graft, only one other case of a nonanastomotic pseudoaneurysm has ever been reported.

Aged↗

PubMed1996

Clinical and histopathologic characteristics of tongue and gingiva carcinomas with occult and clinically evident cervical lymph-node metastasis.

Factors predisposing to occult metastasis were investigated in 66 tongue and 72 gingiva squamous cell carcinomas (SCCs). Occult metastasis was most frequently seen in tumors with grade 3 and occasionally in those with grade 4 invasion, no relation being shown with T-stage. When lymph-node metastases were analyzed with regard to tumor cell invasion mode and T-stage, T2 tumors with grade 3 invasion were mostly seen to give rise to occult metastasis, while grade 4 invasion was highly associated with N(+) metastasis in all T-stages. These results support the view that neck dissection should be recommended for tongue and gingiva SCCs exhibiting grade 3 invasion.

Aged↗

PubMed1996

Telomere position on the cat chromosome.

The telomere in the cat chromosome was detected by the fluorescence in situ hybridization method using all human telomere as a probe. In the metaphase chromosomes of cultured peripheral lymphocytes, telomere spots were observed in the terminal portions of the chromosomes. Although telomeres were confirmed in all chromosomes, the fluorescence intensity varied between the two homologues in some chromosomes.

Animals↗

PubMed1996

[Preoperative autologous blood donation in patients with malignant tumors of the head and neck region].

Twelve instances of preoperative autologous blood donation were assessed in 10 patients with malignant tumors of the head and neck region. All patients received preoperative radiation therapy and chemotherapy and most of the cases were also given recombinant human erythropoietin (EPO) and iron sulfate. Hemoglobin concentrations immediately before starting the 800ml blood donations were higher than 13g/dl in 5 cases and less than 13g/dl in 6 cases. The mean hemoglobin concentration just prior to donation and one week after donation in these two groups changed from 14.4g/dl to 12.5g/dl and 11.7g/dl to 11.7g/dl, respectively. A 1000ml blood donation was carried out in only one patient, and the hemoglobin concentrations just before donation and one week after donation were 11.4g/dl and 10.5g/dl, respectively. Only half of the blood volume scheduled, 400ml, was achieved in 3 of the 12 cases attempted because of fever, diarrhea and a change of the day of surgery, respectively. The mean estimated blood loss in the 10 patients that underwent surgery as planned was 898ml, and allogenic blood transfusion was avoided in all cases. We concluded that 800-1000ml preoperative autologous blood donation can be performed safely in patients with advanced malignant tumors of the head and neck region who have undergone preoperative radiation therapy and chemotherapy by giving EPO and iron sulfate.

Aged↗