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Biomedical subjects

H Hata

Publications and source records attributed to H Hata.

At least 109 records · Page 6Linked to original sources
PubMed1996

The evaluation of masticatory function with low adhesive colour-developing chewing gum.

Many objective methods have been described to evaluate masticatory function. Recently, a new chewing gum system has been reported that utilizes a phloxine-sodium bicarbonate reaction and measures a chromatic coordinate as a functional indicator. A low-adhesive colour-developing chewing gum has been developed by selecting an appropriate gum base. This study examined the applicability of the system and reproducibility of results in subjects with different dental states. Tests were performed on 15 natural dentate subjects and 15 complete denture wearers after determination of germane test conditions through a pilot study. The colour was measured by a*, one of the coordinates in the L*a*b* colour system. All subjects could perform the test. The coefficient of variation ranged from 1.87% to 7.90%, averaging 5.15% in the natural dentate subjects and from 1.5% to 17.9%, averaging 9.75% in the complete denture wearers. The 95% confidence interval of a* was 28.76 +/- 1.76 in the natural dentate subjects and 10.05 +/- 2.58 in the complete denture wearers. The results indicated that this material can be useful for both complete denture wearers and subjects with a natural dentition with adequate reproducibility.

Adhesives↗
PubMed1996

Fas/Apo-1 (CD95)-mediated and CD95-independent apoptosis of malignant plasma cells.

CD95 (Fas/Apo-1) mediates apoptosis in cells of various types. Expression of CD95 and its function were investigated in myeloma cells and most plasma cell lines have been found to be CD95-positive. Anti-CD95 antibody induced apoptosis in these cell lines in a manner dependent on intensity of CD95 expression. Bel-2 expression levels in these cell lines were not correlated with sensitivity to CD95-induced apoptosis. Myeloma cells from approximately 70% of cases analyzed expressed CD95, suggesting a high frequency of CD95 expression of myeloma cells. The incidence of CD95 expression in samples from extramedullary lesions were higher than those of bone marrow myeloma cells. Anti-CD95 antibody did not induce apoptosis in some freshly isolated myeloma cells despite the expression of CD95 induced apoptosis in myeloma cell lines in a manner dependent on intensity of CD95 expression. In fresh samples, intensity of CD95 expression was not correlated with apoptosis evoked by anti-CD95 antibody. Interestingly, isolated myeloma cells with an high-level expression of CD95 showed spontaneous apoptosis during in vitro incubation. This was observed in samples from cases with high serum levels of lactate dehydrogenase (LDH), suggesting that the LDH was derived from cells undergoing spontaneous apoptosis in vivo. Taken together, CD95 is expressed in most myeloma cell lines and in many freshly isolated myeloma cells. However, some of the latter escape from CD95-dependent apoptosis despite the expression of CD95. Moreover, some myeloma cells from cases with aggressive disease may undergo apoptosis in a CD95-independent manner. In this review, the significance of CD95 and apoptosis of myeloma cells are discussed.

Animals↗
PubMed1996

Experiences of postcardiotomy assist: pneumatic ventricular assist device or venoarterial bypass with percutaneous cardiopulmonary support.

From October 1982 to the present, 16 patients have been supported by a pneumatic ventricular assist device (VAD). Since April 1990, we have introduced a venoarterial bypass (VAB) with percutaneous cardiopulmonary support (PCPS) system. This PCPS system was used in 12 patients. The long-term survival rate of PCPS cases (41%) was much better than that of VAD cases (19%). The main cause of death in VAD cases was multiple organ failure (MOF). Although VAB was initiated more recently than VAD, the duration on support was longer in the VAD group than in the VAB group. Because of the longer support duration and the presence of many patients with MOF, coagulopathy deteriorated more readily in the VAD group than in the VAB group. In the case of postcardiotomy cardiopulmonary bypass weaning or low-output syndrome (LOS), the VAB with PCPS system should be applied first under intraaortic balloon pumping assist because of its simplicity and low cost. Thereafter, VAD should be applied in cases refractory to VAB support.

Adult↗
PubMed1996

[Establishment of a new human ovarian serous cystadenocarcinoma cell line (IM), and influence on cell proliferations by cisplatin with or without hyperthermia].

A new cell line, designated IM has been established from operation material derived from a woman with ovarian serous cystadenocarcinoma. The population doubling time of the 35th passage IM cell was 28.8 hours. And it was successively subcultured 165 times in over 7 years, moreover still kept CA125 production. The nuclear DNA and cell surface CA125 antigen were double stained by propidium iodide and anti CA125 monoclonal antibody-FITC. Then the two color cytogram obtained by flow cytometry was drawn up. For the most part of CA125 positive cell retained G0 + G1 of cell cycle, the lesser part was in G2 + M phase. The S phase rate of IM cell incubated with cisplatin at 37 degrees C or 41 degrees C for 1 hour that estimated by BrdU-propidium iodide double stain method of flow cytometry, it was suggested that the inhibition of DNA synthesis by cisplatin was increased with 41 degrees C low hyperthermia.

CA-125 Antigen↗
PubMed1995

Expression of Fas/Apo-1 (CD95) and apoptosis in tumor cells from patients with plasma cell disorders.

Fas/Apo-1 antigen (CD95) is a cell surface molecule that directly mediates apoptosis. Fas expression was studied in five plasma cell lines, 11 multiple myeloma cases, and three plasma cell leukemia (PCL) cases. Induction of apoptosis by anti-Fas antibody was studied in five plasma cell lines and fresh plasma cells from eight patients. Apoptosis was confirmed by morphologic analysis alone or in combination with DNA electrophoresis analysis. Four of the five cell lines showed Fas expression, three of which showed induction of apoptosis by anti-Fas antibody. One cell line, RPMI 8226, showed the highest sensitivity for Fas-mediated apoptosis. High bcl-2 expression was found in KMS12PE, which showed resistance to Fas-mediated apoptosis despite its Fas expression. Plasma cells from seven fresh cases, including all five cases with high serum lactate dehydrogenase (LDH), showed expression of Fas antigen. Fas-induced apoptosis was found in five cases at various levels, although significant induction of apoptosis was found in only one case. Interestingly, Fas-independent apoptosis was induced during culture without anti-Fas antibody in cases with high serum LDH. These results indicate that plasma cells from aggressive myeloma with high LDH express Fas antigen and undergo apoptosis through either Fas-mediated or Fas-independent pathways. An understanding of the mechanism of apoptosis in malignant plasma cells should contribute to investigations of the pathophysiology of and therapy for myeloma/PCL.

Adult↗
PubMed1995

Studies on the tumor-promoting activity of biomaterials: inhibition of metabolic cooperation by polyetherurethane and silicone.

When V79 metabolic cooperation (MC) assay was performed to detect tumor-promoting activities, inhibitory activities on the gap-junctional intercellular communication were first detected in both extracts prepared from polyetherurethane (PEU) and silicone. The former inhibited more strongly than the latter. Furthermore, the lowest effective concentrations in MC assay correlated well with the values of the total active incidences obtained by histologic evaluation of the 2-year implantation test in rats. Poly(tetramethylene oxide) (PTMO) showed the highest inhibitory activities among the constituents of PU. Thus, the shorter the chain length of PTMO, the stronger the inhibitory activities of PTMO in MC assay. PTMO moiety may play an important role in the tumor-promotion stage during tumorigenesis induced by PU.

Animals↗
PubMed1995

Studies on the tumor-promoting activity of additives in biomaterials: inhibition of metabolic cooperation by phenolic antioxidants involved in rubber materials.

For the detection of tumor-promoting activities of phenolic antioxidants, the inhibitory activities on the intercellular gap-junctional communication were investigated using the V79 metabolic cooperation (MC) assay. Among eight antioxidants, 4,4'-butylidene-bis(3-methyl-6-tert-butyl-phenol), 2,2'-methylene-bis(4-methyl-6-tert-butylphenol) (MBMBP), and styrenated phenol (SP) showed stronger inhibitory activities than lithocholic acid, which is known to be a tumor promotor. However, 4,4'-thio-bis(3-methyl-6-tert-butylphenol), Irganox 1010, and 1330 did not inhibit at any concentrations. When the single-electron oxidation potentials were compared among antioxidants, the electrochemical ease estimated with the first oxidation potential was correlated with the cytotoxic potentials (r = 0.88), but not with the inhibitory activities in an MC assay. The tumor-promoting activity of MBMBP was also investigated using an in vitro, two-stage Balb/c 3T3 transformation assay. MBMBP did not show initiating activity, but significant promoting activity at concentrations of both 1 and 2.5 micrograms/ml were noted. These concentrations were close to the lowest effective inhibitory concentration (1.3 micrograms/ml) of MBMBP in an MC assay. In conclusion, there is a possibility that the phenolic antioxidants that show inhibitory activities in an MC assay contribute to the enhancement of tumor incidence induced by biomaterials.

Animals↗
PubMed1995

Mechanisms of coronary hyperconstriction in response to serotonin induced by X-irradiation in miniature pigs: increased constrictive response of medial smooth muscle.

Experimental and clinical studies suggest that X-irradiation to the coronary artery may enhance vasoconstrictive response. This study aimed to clarify the effect of X-irradiation on the vasomotor response of porcine coronary artery. X-ray (15 Gy) was selectively irradiated to the left anterior descending coronary artery (LAD) in 14 Göttingen miniature pigs. The coronary vasomotor responses to serotonin at the irradiated site (LAD) and the control site (the left circumflex artery; LCX) were assessed by quantitative arteriography before and 1 h and 1, 2, and 4 weeks after X-irradiation. At 2 weeks, endothelium-dependent vasodilation in response to substance P was also evaluated arteriographically in vivo. At 2 weeks, isometric tension studies were performed to evaluate the constrictive responses of medial muscle strips and endothelium-dependent relaxation. Coronary vasoconstriction in response to serotonin was enhanced 1 week after, and further augmentation was noted 2 and 4 weeks after X-irradiation. Endothelium-dependent vasodilation in response to substance P in vivo was preserved 2 weeks after X-irradiation. Coronary arteriography showed no organic stenosis at the irradiated site. In vitro studies demonstrated that medial muscle strips of the irradiated site showed hypercontraction in response to serotonin and that endothelium-dependent relaxation in response to serotonin and substance P was preserved at the irradiated site. A histological study revealed no appreciable changes of the endothelial cells or intimal thickening.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Serum amino acid disturbance in multiple myeloma with hyperammonemia.

From October 1987 to November 1993 we evaluated the serum levels of ammonia and amino acids in 85 patients with multiple myeloma. Six of the 85 cases of multiple myeloma demonstrated hyperammonemia and none of the known causes of hyperammonemia, such as liver failure, could be identified in these patients. All six patients also showed serum amino acid disturbances and conscious disorders in various degrees. In this study we compared these abnormalities in multiple myeloma with those in chronic liver failure (n = 14), the basic diseases of which were liver cirrhosis in six cases and liver cirrhosis complicated hepatocellular carcinoma in eight cases. There was a marked difference in the levels of individual serum amino acids between these two groups. The level of glycine was significantly higher in the multiple myeloma group (P < 0.001); on the other hand, that of tyrosine was significantly higher in the liver failure group (P < 0.005). The histidine (P < 0.005) and arginine (P < 0.005) levels were lower in the myeloma group. The ratio of glycine to tyrosine (Gly/Tyr) was 16.7 +/- 4.85 in the myeloma group and 1.7 +/- 0.12 in the liver failure group. The ratio of glycine to tyrosine was an important criterion for differential diagnosis.

Adult↗
PubMed1995

Resected early gastric cancer--clinicopathological studies on 610 cases.

A total of 610 cases of early gastric cancer were studied, retrospectively. Of these, 541 (88.7%) cases were single and 62 (10.1%) cases were multiple cancers. Lymph node metastasis occurred in 11.2% of the elevated, in 8.2% of the depressed and in 15.1% of the mixed type. There was no lymph node metastasis when a mucosal or submucosal cancer was less than 10 mm in diameter. By contrast, in the cases in which the preoperative diagnosis was suspected advanced cancer, the incidence of lymph node metastasis was high, at 33%. Therefore, when the preoperative diagnosis is advanced cancer, standard radical gastrectomy and/or extended radical gastrectomy should be selected even though they are found to be early gastric cancer. The age-corrected 5-year survival rate was 98.5% in the cases with no lymph node metastasis and 93.0% in the cases with lymph node metastasis (p > 0.05). The 5-year survival rate was 100% in mucosal cancer and 95.5% in submucosal cancer (p > 0.05).

Adult↗
PubMed1995

Vasoreactivity and restenosis after coronary angioplasty in the atherosclerotic pig model.

BACKGROUND: The effect of coronary angioplasty on coronary spasm remains unknown. We examined the effects of balloon angioplasty, using an oversized balloon, on coronary hypercontraction and eventual restenosis in a pig model of coronary spasm. METHODS: We performed balloon angioplasty, using an oversized balloon at the site of coronary spasm superimposed on atherosclerosis with 6 (group A, n = 14) or 1 (group B, n = 14) atmospheres of inflation pressure in miniature pigs. Using coronary angiography we assessed the coronary basal diameter and diameter change in response to histamine and serotonin before, immediately after, and 4 weeks after angioplasty. Histological examinations were performed immediately after and 4 weeks after the angioplasty. RESULTS: Before angioplasty, histamine- and serotonin-induced hypercontraction was reproducibly noted at the atherosclerotic site. Immediately after angioplasty, the coronary diameter became larger (P < 0.01) than before angioplasty in group A, but there was no significant difference in group B. The hypercontraction in group A was abolished immediately after and 4 weeks after angioplasty, whereas the hypercontraction in group B was unchanged. Histological examination revealed medial necrosis immediately after and medial fibrosis 4 weeks after angioplasty, which were more prominent in group A. Four weeks after angioplasty, the magnitude of restenosis was greater in group A than in group B. CONCLUSIONS: Angioplasty using an oversized balloon with the higher atmosphere of inflation pressure abolished coronary hypercontraction immediately after and 4 weeks after angioplasty, which probably resulted from the irreversible damage to medial smooth muscles; however, this did not prevent restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1995

Endothelin-1 is not involved in serotonin-induced coronary spasm in a swine model.

OBJECTIVES: The role of endothelin-1 (ET-1) in the pathogenesis of coronary artery spasm is not well understood. We aimed to determine if ET-1 is involved in serotonin-induced coronary spasm in the swine model. METHODS: In 10 miniature pigs, a segment of the left anterior descending coronary artery was denuded and irradiated with X-ray. Three months after endothelial denudation, coronary vasomotion was assessed in vivo by quantitative arteriography. RESULTS: Intracoronary serotonin at 10 micrograms/kg provoked coronary spasm (augmented narrowing of the luminal diameter) at the denuded site (diameter reduction 93 +/- 4%) but not at the non-denuded control site (19 +/- 4%, P < 0.01) associated with ST segment elevation in the region perfused by the denuded artery. Intracoronary administration of ET-1 at 25 ng/kg caused mild vasoconstriction of the denuded (26 +/- 4) and non-denuded site (16 +/- 3%, n.s.), but provoked ST segment elevation in the regions perfused by both the denuded and non-denuded arteries. The treatment with an endothelin antagonist (BQ123 0.1 mg/kg) significantly attenuated coronary vasoconstriction and ST segment elevation evoked with ET-1, but did not alter serotonin-induced vasoconstriction either at the denuded or control site. CONCLUSIONS: The results of this study suggest that endogenous ET-1 may not be involved in the pathogenesis of serotonin-induced coronary spasm in our swine model.

Animals↗
PubMed1995

[Enlargement of the aortic and mitral double valve rings with double valve replacement using coupling valve method].

A 46-year-old woman was hospitalized with congestive heart failure. She had undergone a mitral valve replacement (23 mm) 17 years earlier and complicated a left ventricular rupture. Upon admission, she was diagnosed with aortic and mitral stenoinsufficiency with narrowed annuli on both valves, tricuspid insufficiency, and a left ventricular pseudoaneurysm. The operative procedure consisted of enlarging the aortic and mitral valve rings and replacing them by the coupling valve method. The orifice of the pseudoaneurysm was repaired with a patch closure applied from the endocardial side. A tricuspid annuloplasty was performed using the DeVega's method. Her postoperative course was uneventful. This is the first report of a successful operation to correct double narrowed annuli along with a ruptured left ventricule. The coupling valve procedure employed here should prove useful for similar cases requiring enlargement and replacement of the aortic and mitral valves simultaneously.

Aneurysm, False↗
PubMed1995

[Inhibitory effects of menogaril to the proliferation of HTLV-I infected T-cell lines and fresh tumor cells from adult T-cell leukemia patients].

Anti-cancer effect of anthracyclines are well established. In vitro inhibitory effects of a new anthracyclin-derivative drug, menogaril (TUT-7) which is developed for oral administration, on three human T-cell leukemia virus type-I (HTLV-I) infected T-cell lines, a HTLV-I non-infected T cell line, and fresh tumor cells from four adult T-cell leukemia (ATL) cases are evaluated and compared to those of doxorubicin. The inhibitory effects of TUT-7 is almost as much as those of doxorubicin. Both TUT-7 and doxorubicin induced apoptosis to a HTLV-I infected cell line and inhibited proliferation of fresh tumor cells from ATL of chronic, acute and lymphoma type in a dose dependent manner. We have already reported that skin eruption of ATL patient improved by oral administration of TUT-7. This new anthracyclin-derivative would be useful in treating ATL patients even in out-patients clinic keeping a good quality of life.

Apoptosis↗
PubMed1995

[Monoclonal antibodies against myeloma cells].

Tumor cells in multiple myeloma are considered to originate from terminally differentiated B-cells e. g. plasma cells. Although it is known that antigens on circulating B-cells, such as CD20, are lost during terminal B-cell differentiation, antigens which are acquired on plasma cells are not well known. Plasma cell specific antibodies would provide useful informations of B-cell differentiation and diagnosis of myeloma. Moreover, therapeutic applications of these antibodies are already reported, especially, in bone marrow transplantation. On the other hand, phenotypic heterogeneity of myeloma cells is investigated by analyzing various antigens on myeloma cells. Monoclonal antibodies against myeloma cells which have appeared in the literature and their clinical applications are summarized.

Antibodies, Monoclonal↗