Biomedical subjects

H Tokunaga

Publications and source records attributed to H Tokunaga.

At least 109 records · Page 6Linked to original sources

PubMed1995

[A case of minor strut fracture of Björk-Shiley Convexo-concave valve and a case of elective prophylactic reoperation].

We reported 2 cases of previous valve replacement with Björk-Shiley Convexo-concave (C-C) valve prosthesis. A 43-year-old male who had undergone mitral valve replacement with 27 mm C-C valve was admitted with severe dyspnea. Although intensive medical treatment was initiated, he died 18 hours after admission. An autopsy revealed minor strut fracture of C-C valve. An electron minor strut fracture of C-C valve. An electron microscopic examination of the explanted valve revealed destruction of minor strut. A 52-year-old female who had underwent aortic valve replacement with 21 mm C-C valve 10 years previously had elective prophylactic reoperation. The postoperative course was uneventful. An electron microscopic examination of the minor strut revealed small linear strain which may cause fatigue defects.

Adult↗

PubMed1995

[A huge idiopathic brain stone in the posterior fossa].

We report a case of idiopathic brain stone occurring in the posterior fossa. A 72-year-old woman with a huge calcified mass in the posterior fossa on plain craniogram was referred to us. She had suffered from intractable tinnitus and mild cerebellar ataxia for twenty years. CT scan revealed a dense bony mass in the posterior fossa. Angiogram only showed an avascular huge mass in the posterior fossa. MRI clearly revealed the shape, heterogenous composition and anatomical relation to the surrounding structure of the mass. The mass was totally removed uneventfully under ABR and SEP monitoring. The patient was discharged with improvement of subjective symptoms. The mass was histologically diagnosed as an idiopathic brain stone because its components were mainly calcified tissues and collagen fiber of unknown etiology; no viable cells were found in any of the specimens. Idiopathic brain stones are very rare and only eight cases have been reported in the literature. The etiology and clinical symptoms of this condition are briefly discussed.

Aged↗

PubMed1995

[Intrascrotal epidermal cyst: a case report].

A 37-year-old male visited our hospital complaining of right scrotal mass formation. An elastic hard, fist-size mass was found in the right scrotum. Under the diagnosis of an intrascrotal benign tumor, the mass was removed. The tumor had no relation to the testis or epididymis. The surgical specimen weighted 220 g and measured 13 x 8 x 8 cm in size. Histopathological diagnosis was epidermal cyst of the intrascrotum. Epidermal cyst of the intrascrotum is a rare disease and only 13 cases have been previously reported in Japan.

Adult↗

PubMed1995

[Effect of dexamethasone on intercellular adhesion molecule-1 expression on cultured bronchial epithelial cells stimulated by inflammatory cytokines].

Bronchial asthma is characterized as a chronic inflammation of the airway that causes an infiltration of lymphocytes and eosinophils. Cell to cell interaction or cell to tissue interaction is essential for infiltration of eosinophils to underlying tissues. These phenomena are closely related to the expression of intercellular adhesion molecule-1 (ICAM-1). Inhalation of steroids, such as beclomethasone dipropionate, is commonly used to cure airway inflammation. In this study, we investigated the effect of cytokines on ICAM-1 expression on human bronchial epithelial cell lines, NCI-H292. Moreover, the effect of dexamethasone on ICAM-1 expression stimulated by IL-1 beta, TNF-alpha and IFN-gamma was observed. Treatment with IL-1 beta, TNF-alpha and IFN-gamma dose-dependently increased ICAM-1 expression on NCI-H292 cells. Inhibitory effects were exerted by dexamethasone on ICAM-1 expression in cells stimulated by IL-1 beta and IFN-gamma in a dose-dependent manner, but not in cells stimulated by TNF-alpha. These results suggest that the inhibition of ICAM-1 expression could be related to the pharmacological action of steroid drugs.

Bronchi↗

PubMed1995

[Dural AVF of the posterior fossa associated with sinus occlusion presenting as intracerebral hemorrhage: case report].

A 69-year-old man was admitted because of sudden onset of consciousness disturbance. Neurological examination on admission revealed slightly disturbed consciousness, sensory aphasia and right hemiparesis. CT scan disclosed a hematoma in the left posterior temporal lobe. Left carotid angiograms showed dural AVF of the transverse/sigmoid sinus fed mainly by the left occipital and posterior auricular arteries. On the angiograms the left sigmoid sinus was completely occluded. This was associated with retrograde venous flow into the cortical veins, the superior petrosal sinus and the contralateral traverse sinus. After stabilizing the condition, we totally resected the dural AVF including the left transverse sinus. The postoperative course was uneventful. Histopathological examination of the surgically resected specimen revealed that the dural A-V fistula per se existed in the sinus wall.

Aged↗

PubMed1995

[A case report of surgical treatment for aortic regurgitation and coronary ostial stenosis associated with aortitis syndrome].

A 52-year-old female was presented to our hospital complaining of chest oppression and dyspnea on exercise. Preoperative angiography and catheterization revealed aortic regurgitation and ostial stenosis of the right coronary artery. Aortic valve replacement (AVR) with SJM 19 A and aortocoronary bypass (CABG) with saphenous vein graft were performed successfully. Histopathological examination of the aortic wall revealed healed phase aortitis syndrome. Post operative course was uneventful. For healed phase aortitis syndrome perioperative steroid administration was not necessary. However careful observation was recommended for long term complication such as recurrence of aortitis, valve detachment, perivalvular leakage and graft occlusion. This is the 16th case successfully treated with AVR and CABG for Aortitis syndrome.

Aortic Arch Syndromes↗

PubMed1995

[A case of food-dependent exercise-induced anaphylaxis induced by shrimp].

The clinical study and in vitro study used with leukocytes were made of a case of food-dependent exercise-induced anaphylaxis induced by shrimp. A 26-year-old man experienced anaphylactic reaction of nasal obstruction, face edema and dyspnea while running 90 minutes after eating shrimp. He experienced similar episodes two years ago in his past history. IgE-RAST was positive for shrimp. Anaphylactic reaction and elevation of plasma histamine levels were verified by exercise challenge test after eating 100 g shrimp. At the same time, we verified the dedine of plasma cAMP levels after eating shrimp. In leukocyte stimulating test used with shrimp antigen, histamine level elevations, which were lower compared with calcium ionophore A23187 (Ca I 10(-6) M) stimulation, were recognized in dose dependent manner in this patient. But in normal subject, histamine level elevations were not recognized. We diagnosed him food-dependent exercise-induced anaphylaxis. It was suggested that there was relation between histamine release and decline of cAMP levels of plasma after eating shrimp in this case.

Adult↗

PubMed1994

Twelve years' experience with the St. Jude Medical valve prosthesis.

Since July 1978, 1,284 patients have received the St. Jude Medical prosthesis (425 aortic, 636 mitral, and 223 double aortic-mitral), and the results in these patients were reviewed according to guidelines of the Society of Thoracic Surgeons. Follow-up was complete in 98%. Of 80 late deaths, 29% were valve related. The actuarial survival rate, including operative deaths, at 12 years was 81.7% and 87.1%, respectively, for aortic and mitral valve replacement, and it was 82.6% at 11 years after double valve replacement. All patients were anticoagulated with warfarin to maintain the thrombotest value between 10% and 25%, which is equivalent to between 2.8 and 1.6 times the control according to the international normalized ratio of the prothrombin time. The linearized rate of complication for aortic, mitral, and double valve replacement, respectively (expressed as the percent per patient-year), was as follows: structural deterioration, 0; non-structural dysfunction, 0.16, 0.30, and 0.20; valve thrombosis, 0.05, 0.09, and 0; thromboembolism, 1.35, 1.63, and 0.79; anticoagulant-related hemorrhage, 0.10, 0.18, and 0.10; and prosthetic valve endocarditis, 0.21, 0.06, and 0.20. Reoperation was performed in 16 patients. The freedom from reoperation rate at 12 years was 99.5% and 98.0% for aortic and mitral valve replacement, respectively, and it was 99.1% at 11 years for double valve replacement. Thus, during the 12-year follow-up in patient who received the St. Jude Medical prosthesis, the valve performed satisfactorily and with an acceptable risk of late complication even though patients were anticoagulated using a lower dose of warfarin.

Actuarial Analysis↗

PubMed1994

A case of Sipple's syndrome with malignant pheochromocytoma treated with 131I-metaiodobenzyl guanidine and a combined chemotherapy with cyclophosphamide, vincristine and dacarbazine.

A 39-year-old woman with Sipple's syndrome and a malignant pheochromocytoma (PHE) is presented. She is a member of a big family with this syndrome and had undergone bilateral, subtotal adrenalectomy because of bilateral PHE six years prior to the present admission. In 1989, a small nodule was identified in her right thyroid lobe by ultrasonography and was suspected to be a medullary thyroid carcinoma (MTC). Further examinations revealed the coexistence of multiple lung and liver masses. These tumors were considered to be metastases of PHE because of the increased urinary excretion of catecholamines as well as extremely high catecholamines both in the hepatic venous blood and in the cystic fluid of the liver tumor even though there was no apparent recurrences of PHE in the adrenal region. After surgical removal of the MTC in August, 1989, she was given 3.7 GBq of 131I-metaiodobenzyl guanidine (131I-MIBG) infusions twice--in October, 1989 and in August, 1990. 131I-MIBG showed a strong accumulation in the lung and liver masses on both occasions. Periodic increases in blood pressure and tachycardia with an excessive catecholamine secretion were observed over two weeks after the first treatment. However, this treatment was not effective in reducing urinary catecholamines nor the size of the metastatic tumors. She, therefore, underwent chemotherapy with cyclophosphamide, vincristine and decarbazine in 1991, which slightly but significantly reduced urinary excretion of catecholamines and the size of the lung tumors. She had clinically stable period for one year after the treatment but rapid growth of these metastatic tumors occurred afterwards and she died in August, 1992.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Iodobenzylguanidine↗

PubMed1994

[Transcranial Doppler measurement of middle cerebral artery blood flow during continuous retrograde cerebral perfusion].

This is the first report of cerebral blood flow measurement with transcranial Doppler (TCD) during aortic arch reconstruction using continuous retrograde cerebral perfusion (CRCP) with deep hypothermia. Cerebral blood flow velocity was measured in 6 patients. CRCP was performed via the superior vena cava (SVC) at 30 cmH2O of internal juglar vein pressure and at 18 degrees C or lower of minimum bladder temperature. During the operation, the flow velocity of the middle cerebral artery (MCA) was continuously measured with TCD fixed on the temple. The cerebral blood flow during CRCP was different in each of the 6 patient. The retrograde MCA flow could be measured during CRCP in 3 patients, and the flow velocity was 11-60% of the MCA flow velocity before cardiopulmonary bypass. In the other 3 patients, retrograde MCA flow could not be detected during CRCP, but antegrade MCA flow could be found after antegrade perfusion was resumed. The antegrade flow velocity right after CRCP became more than the MCA flow before CRCP, which was regarded as a reaction due to cerebral ischemia. All the patients awoke within several (2-9) hours after operations and had no permanent neurological complications. But 2 patients developed drowsiness for several days after the operations; their CRCP times were 127 and 131 minutes. It is concluded that CRCP is a simple technique for brain protection, but the cerebral blood flow during CRCP is a simple technique for brain protection, but the cerebral blood flow during CRCP is different in each patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

[Cyclosporin A inhibits interleukin 5 (IL-5) production from human peripheral lymphocytes].

Inflammation of mucosa and epithelial damage the of bronchi are characteristic pathological features of asthma. Infiltration of T lymphocytes and eosinophils followed by their activation and release of cytokines seems to be a contributing process. We studied the interaction of interleukin 2 (IL-2) and interleukin 5 (IL-5), cytokines which act on eosinophils, using human peripheral lymphocytes. We found that cyclosporin A (CyA) inhibited the IL-5 production from human peripheral lymphocytes induced by IL-2 stimulation. Human peripheral lymphocytes were isolated from healthy volunteers and bronchial asthma patients with mild eosinophilia. Lymphocyte cultures stimulated with IL-2 were cultured at 37 degrees C in a humidified atmosphere of 5% CO2 in air. After 72 hours' incubation, the proliferative response of the lymphocytes was examined by [3H]thymidine uptake, and at the same time IL-5 in the supernatant of the culture medium was assayed by ELISA. The lymphocytes proliferated on IL-2 stimulation in all cases; IL-5 was detected in 3 out of 9 healthy volunteer cases and 7 out of 11 asthma patient cases. CyA added at the beginning of incubation inhibited both of these responses in a dose-dependent manner.

Asthma↗

PubMed1993

Endogenous erythropoietin and salt sensitivity of blood pressure in patients with essential hypertension.

To investigate a possible involvement of endogenous erythropoietin (EPO) in the salt sensitivity of blood pressure in essential hypertensive (EHT) patients, plasma EPO concentrations were measured during different salt intakes in 14 patients with EHT. All patients were given low salt (34 mmol NaCl/day) and high salt (342 mmol NaCl/day) diet of 7 days each. The plasma EPO concentrations were significantly higher on the high salt diet than those of low salt diet (23.5 +/- 1.9 v 18.7 +/- 1.8 mIU/ml, mean +/- SD, P < .05). The percentage change of plasma EPO concentration with salt loading correlated positively with hematocrit (Ht) at high salt diet (r = -0.62, P < .02) and tended to be correlated with plasma hemoglobin at high salt diet (r = 0.52, P < .10). These results suggest that the secretion of EPO is increased in response to hemodilution caused by the salt loading and the increased EPO concentration in plasma which may contribute to the increase in blood pressure through an expansion of total blood volume due to an enhanced red cell generation in combination with salt and water retentions.

Adult↗

PubMed1993

[Aortic regurgitation developed seven years after mediastinal radiation therapy: report of a case].

We report on radiation-induced valvular dysfunction in a 41-year-old woman who developed aortic regurgitation with clinical symptoms, requiring aortic valve replacement seven years after mediastinal radiation therapy for carcinoma of the breast. She was treated with cobalt radiation therapy of 4000 rads to her left mediastinum. The excised three-cuspid aortic valve was edematous and densely fibrotic without commissural fusion. Histological examination strongly suggested that the aortic valve with diffuse fibrosis, destruction of elastic fibers and bizarre nucleus in fibroblasts had been induced by mediastinal radiation therapy. To our knowledge, symptomatic radiation-induced valvular dysfunction in the aortic position has been reported infrequently, with only eleven reported cases. In this case, symptomatic aortic regurgitation was diagnosed seven years after mediastinal radiation therapy. It is emphasized that long-term follow-up is important for patients receiving mediastinal radiation therapy.

Adult↗

PubMed1993

Change in responsiveness of airway and beta-adrenoceptor in guinea pigs.

Allergen inhalation challenge resulted in significant (p < 0.05) increase in airway responsiveness to methacholine soon after immediate airway response (IAR) in guinea pigs actively sensitized with inhaled ovalbumin (OA) in vivo. We have investigated the involvement of thromboxane (Tx) A2 and platelet activating factor (PAF) in this airway hyperresponsiveness (AH). Pretreatment with CS-518, a selective thromboxane synthetase inhibitor, significantly inhibited both IAR (p < 0.07) and AH (p < 0.01), while pretreatment with WEB 2086, a PAF receptor antagonist, significantly inhibited only IAR (p < 0.05), but not AH after IAR. Propranolol, when inhaled before OA exposure, had no effect on bronchomotor tone, but if inhaled after IAR, it caused immediate death of guinea pigs. This result suggests that hyperresponsiveness of beta-adrenoceptor to propranolol may be induced by IAR. Examination of bronchoalveolar lavage (BAL) fluid revealed that no changes in cellular content were observed 60 min after OA exposure. In vitro, responsiveness of tracheal smooth muscle to carbachol was not changed by sensitization. Furthermore, anaphylactic reaction in vitro had no effect on the responsiveness. We conclude that airway responsiveness increases soon after IAR when infiltration of inflammatory cells is not yet found in vivo. It is also suggested that TxA2 but not PAF is involved in AH. Hyperresponsiveness to propranolol after IAR in OA sensitized guinea pigs illustrates the possibility of changes in function of beta-adrenoceptor after IAR.

Animals↗

PubMed1993

[A case report of left ventricular-right atrial communication due to infective endocarditis].

Left ventricular-right atrial communication is a rare lesion and its etiology is almost exclusively congenital. A case of a 48-year-old woman with left ventricular right atrial communication due to infective endocarditis was presented. The communication was located at the atrioventricular portion of the membranous septum, i.e., supravalvular type, and was closed directly with mattress suture. Aortic valve replacement with 21 mm St. Jude Medical prosthesis was performed simultaneously. The postoperative course was uneventful. This complicated lesion should be surgically managed as soon as the diagnosis is confirmed.

Aortic Valve↗

PubMed1992

Calcium ion-mediated regulation of the alpha-toxin pore of Staphylococcus aureus.

The water-soluble alpha-toxin monomers of Staphylococcus aureus become hexamers forming the transmembrane pore when exposed to the membranes. This pore is freely permeable to small hydrophilic molecules, e.g. carboxyfluorescein, and becomes less permeable in the presence of calcium ions. Calcium ion-mediated decrease of the carboxyfluorescein leakage could not be eliminated by EDTA added in the medium, but the carboxyfluorescein could be freed by EDTA added in the intraliposomal space. This result suggests that the alpha-toxin pore changes its conformation as the calcium ion is bound and that the binding site is exposed to the intraliposomal side of the membrane. The interaction between the alpha-toxin hexamer and 8-anilino-1-naphthalene-sulfonic acid (ANS) was monitored by determining the fluorescence in the presence and absence of calcium chloride. The mean distances between the tryptophan residues of the alpha-toxin hexamer and the bound ANS were calculated to be 1.90 and 1.80 nm in the absence and presence, respectively, of calcium ions. The results showed the calcium ion mediated conformational change of the membrane-embedded alpha-toxin hexamer.

Anilino Naphthalenesulfonates↗

PubMed1992

[An assessment of the separation of mediastinal lymph nodes by preoperative mediastinoscopic examination as a dissecting measure in the surgical treatment of lung cancer].

The availability of the separation of mediastinal lymph nodes by preoperative mediastinoscopic examination as a dissecting measure was analyzed according to prognosis retrospectively because mediastinal lymph nodes dissection is made with ease and certainty after the examination. The separation by mediastinoscopic examination did not have an impact on the mediastinal lymph nodes dissection for carcinoma of the left lung and superior mediastinal lymph nodes metastases (# 1-4), but an influence on the dissection for carcinoma of the right lung and middle and lower mediastinal lymph nodes metastases (# 5-9). This result showed the existence of occult metastases and the good effects caused by the separation of mediastinal lymph nodes. In the histological type, the effects were present in squamous cell carcinoma and p-N0 adenocarcinoma, but it was concluded that the prognosis in adenocarcinoma was associated with other factors rather than lymph node metastasis. Therefore, it can be seen that the separation of mediastinal lymph nodes by preoperative mediastinoscopic examination is available as a dissecting measure.

Adult↗

PubMed1992

[Classification of congenitally bicuspid aortic valve and its angiographic and surgical significance].

From January, 1978 to December, 1990, 85 patients with congenital bicuspid aortic valve underwent aortic valve replacements (AVR) with St. Jude Medical valve prosthesis. We classified congenital bicuspid aortic valve into four types. Type I (44.7%): Two cusps are situated right and left, a coronary artery arises from each related sinus of valsalva. Type II (22.4%): Type I + raphe in the right cusp. Type III (3.5%): one cusp is located anteriorly, the other posteriorly and both coronary arteries arise from anterior cusp. Type IV (29.4%): Type III + raphe in the anterior cusp. Regarding to preoperative diagnosis, aortic stenosis dominated in Type I (78.8%) and aortic regurgitation dominated in Type IV (72.0%). Implanted valve sizes were 22.2 +/- 1.8 (Type I), 23.4 +/- 1.6 (Type II) and 24.0 +/- 2.2 (Type IV). There was a significant difference between Type I and Type II, same as Type I and Type IV. Babb's method and outflow measurement method were utilized to predict the aortic annular size. However, both of them were not reliable for estimating the size of the aortic annulus in cases of aortic stenosis undergoing AVR with a 21 mm prosthesis.

Adolescent↗