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H Suda

Publications and source records attributed to H Suda.

At least 145 records · Page 8Linked to original sources
PubMed1995

Direct measurement for elasticity of myosin head.

During muscle contraction, chemical energy from ATP hydrolysis is converted to the relative sliding movement of actin and myosin filaments. In order to elucidate the molecular mechanism of sliding-force generation, it is a crucial clue to know an elastic modulus of myosin. Here, we report direct measurements of Young's modulus of myosin head (myosin subfragment-1) isolated from rabbit skeletal muscle, using a surface forces apparatus. Our results show that the elasticity of myosin subfragment-1 has direction and is about 0.3 GPa along the long axis during ATP hydrolysis. When the bow-shaped subfragment-1 is modelled as an elastic rod, the stiffness and the bending fluctuations of subfragment-1 are calculated to be 3-7 pN/nm and about 1 nm, respectively. These results strongly support a model of multiple power strokes rather than the conventional tilting-crossbridge model.

Adenosine Triphosphate↗
PubMed1995

Novel antitumor indolocarbazole compound 6-N-formylamino-12,13-dihydro-1,11- dihydroxy-13-(beta-D-glucopyranosyl)-5H-indolo[2,3-a]pyrrolo[3,4- c]carbazole-5,7(6H)-dione (NB-506): induction of topoisomerase I-mediated DNA cleavage and mechanisms of cell line-selective cytotoxicity.

A new indolocarbazole antitumor agent, NB-506 [6-N-formylamino-12,13-dihydro-1,11-dihydroxy-13-(beta-D-glucopyranosyl) -5H- indolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7(6H)-dione], enhanced the DNA cleavage catalyzed by HeLa S3 topoisomerase I at 0.01 microM but not the cleavage by topoisomerase II at 300 microM. It also caused single-strand DNA breakage in intact cells at 0.08 microM and more. Unlike the known topoisomerase I inhibitor camptothecin, NB-506 intercalated with DNA. However, the binding affinity to DNA and the inhibition against DNA polymerase alpha and RNA polymerase II were marginal compared with those of Adriamycin or actinomycin D. NB-506 inhibited the growth of various tumor cell lines at two micromoles or less, and its cytotoxicity was found to be cell line selective. This selective cytotoxicity of NB-506 was not fully explained by the differences in topoisomerase I activity in these cell lines, but there was some relationship between the amount of NB-506 accumulated in these cell lines and its cytotoxicity toward them. In conclusion, NB-506 is a potent topoisomerase I poison, acting selectively on tumor cell lines accumulating NB-506.

Animals↗
PubMed1995

Novel indolocarbazole compound 6-N-formylamino-12,13-dihydro-1,11-dihydroxy- 13-(beta-D-glucopyranosyl)-5H-indolo[2,3-a]pyrrolo-[3,4-c]carbazole- 5,7(6H)-dione (NB-506): its potent antitumor activities in mice.

NB-506 [6-N-formylamino-12,13-dihydro-1,11-dihydroxy-13-(beta-D- glucopyranosyl)-5H-indolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7(6H)-di one d is a new antitumor indolocarbazole compound. The growths of murine M5076 and Ehrlich solid tumors were inhibited 76 and 96%, respectively, by i.v. injection at doses of 300 mg/m2. Furthermore, NB-506 caused regression of nodules of human PC-13 lung cancer and MKN-45 stomach cancer cells at i.v. doses of 90 mg/m2. Human HCT 116 and LS 180 colon cancers also regressed with injections of NB-506. Repeated injections of NB-506 had a stronger antitumor effect than intermittent injections in mice with MKN-45. The cumulative toxicity of NB-506 was low in terms of lethality in mice, i.e., the LD50s on single and 10 repeated i.v. injections into CDF1 mice were 990 and 810 mg/m2/injection, respectively. In conclusion, NB-506 is considered to be an interesting possible candidate as an anticancer drug for treatment of solid tumors in humans.

Animals↗
PubMed1995

Three groups of afferent pulpal feline nerve fibres show different electrophysiological response properties.

Responses were recorded, after the application of four types of stimuli (slow or rapid elevation of temperature, hydrostatic negative pressure through thin dentine, and bradykinin directly applied to exposed pulp), from functional single fibres innervating the cat lower canine tooth pulp, dissected from the inferior alveolar nerve. A total of 278 single pulpal fibres were isolated. A fibres (n = 220) were divided into two groups: one (FA; fast A fibre, n = 160) consisting of those whose conduction velocities (CVs) were more than 2 m/s both inside and outside the tooth pulp, and the other (SA delta; slow A delta fibre, n = 60) consisting of those whose intrapulpal CVs were less than 2 m/s and extrapulpal CVs greater than 2 m/s. Fifty eight C fibres (C) were also found. None of FA, 40% of SA delta and 52% of C responded to continuous heat. None of C, 47% of FA and 45% of SA delta responded to rapid elevation of temperature. None of C, 20% of FA and 20% of SA delta responded to hydrostatic pressure. None of FA, 83% of SA delta and all of C responded to bradykinin. It was found that 21 of 60 SA delta responded to both types of stimuli that reportedly activate only A (rapid heat and hydrostatic negative pressure) or C (continuous slow heat and bradykinin) nerve fibres and that 29 SA delta responded to slow heating and/or bradykinin, similar to C fibres.

Animals↗
PubMed1995

Interferon-gamma inductive effect of liposomes as an immunoadjuvant.

Adjuvant effect of liposomes was compared to that of aluminium hydroxide (Alum) using ovalbumin (OVA) as a model antigen, and the difference in adjuvanticity of liposomes from Alum has been evaluated on the basis of cytokine production. Both adjuvants enhanced the IgG levels, but a remarkable difference was observed in the production of IgG subclass; Alum enhanced IgG1 levels, and liposomes enhanced IgG2a, IG2b, and IG3 levels. Further, Alum enhanced antigen-specific IgE levels, whereas liposomes did not. To clarify the difference in adjuvant effect of these adjuvants, secretion of cytokines, especially interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) which regulate IgE production, was estimated ex vivo. Overnight culture of splenic cells obtained from mice immunized with liposomes encapsulating OVA elicits IFN-gamma secretion, but not IL-4 secretion. On the other hand, the production of both cytokines was elevated by the immunization with OVA-Alum complex. The results indicate that the difference of adjuvant activity between liposomes and Alum may come from the difference in the secretion of IL-4 and that, consequently, a different class of antibody response is developed. More importantly, negatively charged liposomes containing phosphatidylserine remarkably promoted IFN-gamma secretion compared to neutral liposomes.

Adjuvants, Immunologic↗
PubMed1995

Importance of clinical examination and diagnosis. A case of dens invaginatus.

A case report is presented that shows a radiolucent lesion between the maxillary left lateral incisor and canine tooth, both of which were vital. The cause of the lesion was initially unclear. The patient was to be treated surgically, however, precise examination made it clear that the cause of the radiolucent lesion was due to the exposure of a second canal because of attrition of the lateral incisor crown. The final diagnosis of the tooth was dens invaginatus. This case highlights the importance of careful examination and correct diagnosis.

Child↗
PubMed1995

Erythematous papules in a patient with cardiac myxoma: a case report and review of the literature.

A 35-year-old woman was followed up by a physician for one and a half years as a case of transient ischemic attach (TIA) due to thrombosis. She had a few erythematous papules on the dorsal side of her right forearm and on the right side of her neck. From the history of TIA and the transient erythematous papules, we suggested the possibility of cardiac myxoma. Echocardiogram demonstrated a large mass in her left atrium. An immediate operation was carried out, and the cardiac myxoma was excised surgically. Histological examination of the erythematous papule revealed myxoma emboli.

Adult↗
PubMed1995

Neonatal alloimmune thrombocytopenia involving HPA-5b (Br(a)): a rare Japanese case.

Neonatal alloimmune thrombocytopenia (NAIT) is caused by platelet antigen incompatibility between the mother and fetus. The frequency of NAIT varies among ethnic groups. In Caucasians, HPA-5b (Br(a)) is the antigen that is second most frequently implicated. In Japan, NAIT due to anti-HPA-5b antibody is quite rare. The present case is the second case of Br(a)-NAIT in Japanese and the first case serologically confirmed by monoclonal antibody-specific immobilization of platelet antigens.

Antigens, Human Platelet↗
PubMed1995

Application of a new perchloric acid treatment method to measure endotoxin by an endotoxin-specific chromogenic Limulus test in neonatal septicemia.

The endotoxin in blood was measured to establish both the cut-off value and to detect Gram-negative septicemia. We employed a new perchloric acid treatment method using an endotoxin-specific chromogenic Limulus test (Endospecy test). The cut-off value of endotoxin in blood was 11.2 pg/mL. All cases of septicemia (n = 7) showed high values of endotoxin. Three cases were Group B streptococci, and two cases were Escherichia coli. The others were showed to be negative in blood cultures. The paired values of endotoxin titers during a 48 h interval were useful to evaluate the effectiveness of antibiotics.

Bacteremia↗
PubMed1995

[Effect of efonidipine hydrochloride, a calcium channel blocker, on the experimental cerebral ischemia/anoxia].

The anti-ischemic and anti-anoxic effects of efonidipine, a dihydropyridine calcium antagonist, were studied in several models for cerebral ischemia and anoxia in mice and rats, and the effects were compared with those of nicardipine and flunarizine. Both efonidipine and flunarizine showed protective effects in the models of KCN-induced anoxia and complete ischemia induced by decapitation in mice 6 hr after the treatment, while nicardipine did not show such a long-lasting effect. Efonidipine (1 mg/kg, i.p.), but not nicardipine and flunarizine, prolonged the tolerance times in the asphyxic anoxia model. In mice, efonidipine (4 mg/kg, i.p.) significantly reduced the cumulative mortality rate after bilateral carotid artery ligation. The survival rates at 20 hr after bilateral carotid artery ligation were 33% in the group treated with efonidipine, significantly higher than that in the control group, 0%. On the other hand, the treatment with nicardipine or flunarizine did not increase the rates at 20 hr after the ligation. Moreover, efonidipine attenuated the disturbance of cerebral energy metabolism induced by decapitation in rats. These effects of efonidipine observed in this study were on the whole superior to those of the reference drugs, strongly suggesting the improving effect of efonidipine on cerebral ischemia and anoxia.

Animals↗
PubMed1995

[Report of dental treatment for an island of Okinawa].

Dental treatment was performed on the the inhabitants of Iriomote Island, which is a non-dentist island at present, in Okinawa; two hundred forty-five patients received the treatment for 647 man-days during the period from July 6 through 28, 1994. Since completion of the treatment plan was considered to be necessary during that period, treatments for many teeth had to be done simultaneously because a large number of dental caries and periodontal disease were found. Dental hygienic education such as brushing instruction was made but the long-term educational program is considered to be important so as to prevent dental disease as well. It is to be desired that many dentists become interested in the treatment in non-dentist areas.

Adolescent↗
PubMed1995

Varus derotation osteotomy for persistent dysplasia in congenital dislocation of the hip. Proximal femoral growth and alignment changes in the leg.

We studied the morphological changes in the proximal femur in 42 patients (42 hips) who had had varus derotation osteotomy of the upper femur for residual acetabular dysplasia and congenital subluxation of the hip and who did not show deformity of the head of the femur. In 19 patients the alignment of the whole leg was examined. The femoral neck-shaft angle (FNSA) at the final examination was unrelated to that immediately after operation or to the state of the acetabulum at that time. The postoperative FNSA was not related to the final result but the CE angle obtained at surgery influenced the outcome. The femoral length did not differ significantly between the unaffected and affected sides. Significant differences were found in the femorotibial angle (176.6 degrees v 174.5 degrees) and in the point of intersection between the mechanical axis and knee (65.0% v 57.2%).

Acetabulum↗
PubMed1995

[Clinical study on the ideal temperature of blood cardioplegic solution in coronary artery bypass graft surgery].

The effect of myocardial protection in coronary artery bypass graft surgery was evaluated from enzymatic examination and cardiac function to clarify the ideal temperature of blood cardioplegic perfusate (BCP). The surgical cases were divided into two groups from the temperature of BCP; 8 degrees C BCP in 64 cases (Group I) and 20 degrees C BCP in 64 cases (Group II). Peak total creatine-Kinase (CK) and CK-MB fraction were significantly elevated in Group I than in Group II. The value of CK-MB was 79 +/- 79 IU/L in Group I and 37 +/- 26 IU/L in Group II (p < 0.01). The parameters of cardiac function were measured from radio-isotope (RI) ventriculography in the 35 cases with depressed ejection fraction and elevated left ventricular end-diastolic pressure (17 cases in Group I and 18 cases in Group II). Postoperative parameters such as ejection fraction, first third ejection fraction, peak ejection rate and early diastolic peak filling rate improved more significantly than preoperative values in Group II, although these parameters did not improve in Group I. From these results, 20 degrees C BCP provided excellent myocardial protection to arrested heart during coronary artery bypass surgery probably because of decreased viscosity of BCP and adequate oxygen carrying capacity to myocardium.

Blood↗
PubMed1995

[A case report of Budd-Chiari syndrome treated with radical operation].

We report a case of Budd-Chiari syndrome in which, radical operation was successfully performed. A 60-year-old male was admitted to our hospital for evaluation of liver dysfunction. Caval venography demonstrated caval obstruction with an extensive collateral circulation passing through the azygos veins. At the operation, intraoperative Doppler echography revealed complete obstruction with thrombus of the IVC. We performed endovenectomy and patch dilatation under circulatory assist with femorofemoral bypass. After this procedures, doppler echography demonstrated excellent flow with no residual stenosis. AKBR was immediately recovered from the abnormal states compared with other laboratory data. The patient has been doing well after 3 years postoperatively.

Budd-Chiari Syndrome↗
PubMed1995

[A case of successful redo-operation for active prosthetic valve endocarditis after modified Bentall operation].

A redo-operation for active prosthetic valve endocarditis after modified Bentall operation is reported. A 42-year-old man associated with Marfan syndrome was transferred to our hospital with complaints of high fever and general fatigue. A modified Bentall operation for acute aortic dissection was done five years ago. The aortic arch and descending thoracic aorta were replaced with prosthetic graft because of aneurysmal dilatation four years ago. Transesophagial echogram revealed a developing vegetation below the prosthetic valve and at the left ventricular outflow. A redo-operation of translocation method with Pieler method for coronary reconstruction was performed using a prosthetic valve of SJM 21 mm in size. After operation, hemolysis suddenly appeared and hepatic dysfunction gradually progressed. Reoperation was necessary for the redo-operation and and a SJM 21 mm valve was replaced with a new 25 mm SJM valve interposed between the graft. Hemolysis was immediately improved. A redo operation of translocation method with Pieler method for coronary reconstruction showed a good results.

Adult↗
PubMed1995

[Surgical treatment for Stanford type A acute aortic dissection].

From March 1983 to September 1994, 53 consecutive patients underwent an emergency operation for type A acute aortic dissection. Eighteen patients before 1988 (Group I) underwent simple ascending aortic replacement (n = 13) and composite graft replacement (n = 5) by conventional method. Thirty-five patients after 1989 (Group II) underwent extended ascending aortic replacement (n = 17), hemiarch replacement (n = 6), total arch replacement (n = 8) and composite graft replacement (n = 4) using a brief period of circulatory arrest. The overall hospital mortality rate was 36.8% in Group I and 25.7% in Group II. The survivals after initial operation was 47% at 10 years (Kaplan-Meier) and the event free rate was 78% at ten years, respectively. Computed tomographic scanning and aortogram demonstrated the patent false lumen in 20 patients (64.5%) at the descending thoracic aorta. In conclusion, extended ascending aortic replacement is the useful operative technique to perform accurate resection of intimal disruption and clamp-site aorta because the replacement of the entry site could reduce the risk of operative mortality and reoperation. Total arch replacement is not necessarily required, if the entry is properly resected by extended ascending aortic replacement or hemiarch replacement. Close follow-up must be considered at the patients with patent false lumen, especially in patient with Marfan's syndrome.

Acute Disease↗