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Biomedical subjects

M Nagata

Publications and source records attributed to M Nagata.

At least 379 records · Page 21Linked to original sources
PubMed1991

Argon-laser gonioplasty following goniosynechialysis.

We performed laser gonioplasty following goniosynechialysis on 12 eyes that exhibited a very narrow angle. In these cases, angle closure had recurred postoperatively, although gonioscopy carried out at the time of goniosynechialysis revealed opening of the trabecular meshwork. The use of laser gonioplasty following goniosynechialysis was most effective in flattening the configuration of the iris and opening the iridocorneal angle. The induced alteration of the structure of the iris remained unchanged in all cases throughout the follow-up period, and intraocular pressure remained below 20 mmHg in 9 of the 12 eyes. It thus appears that a combination of goniosynechialysis and laser gonioplasty may be effective in the management of refractory angle-closure glaucoma in the presence of an extremely narrow angle.

Acute Disease↗
PubMed1991

Detection of multidrug-resistant protein, P-glycoprotein in childhood leukaemia and lymphoma.

Flow cytometric detection of surface P-glycoprotein, a multidrug-resistant gene product, with a monoclonal antibody, MRK 16, was performed on cells obtained from 18 children with leukaemia and lymphoma. Of 18 patients examined, 1 with malignant lymphoma at relapse showed a significant increase in P-glycoprotein-positive cells and a strong resistance to chemotherapy. Overexpression of P-glycoprotein in a case with B-cell type malignant lymphoma was confirmed by immuno-precipitation and Northern hybridization analysis. The present study suggests that an increased expression of surface P-glycoprotein might be involved in multidrug resistance at least in a certain case of childhood leukaemia and lymphoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

Tilt and decentration of the implanted posterior chamber intraocular lens.

Management of surgically induced astigmatism is an important problem for surgeons implanting intraocular lenses. Besides corneal astigmatism, the fixation status of the intraocular lens (IOL) may contribute to total astigmatism. This study was undertaken to evaluate the effect of tilt and decentration of the implanted posterior chamber IOL on the total astigmatism. The tilting angle of the IOL was measured by a method using the 3rd and 4th Purkinje images, and the grade of the decentration was obtained photogrammetrically. The average tilt angle was 7.53 +/- 3.03 degrees (SD). The average decentration was 0.68 +/- 0.33 mm (SD) from the corneal center. Based on these data, the astigmatic error induced by the tilt or decentration of the implanted IOL was calculated as within 0.4 diopter. These data suggest that the fixation status of the IOL implanted in the bag does not cause a serious astigmatic error.

Aged↗
PubMed1991

Nonlinear interpolation of mandibular kinesiographic signals by applying sensitivity method to a GMDH correction model.

The purpose of the present paper was to propose an improved nonlinear interpolation method for estimating distorted kinesiographic recording of interlattice points in space, and to evaluate its correction accuracy. The group method of data handling (GMDH) correction method we have reported previously is essentially different from other geometric correction methods in the sense that the GMDH correction model can be adapted to the measurement environment in which kinesiographic signals are subject to ferromagnetic interferences. Due to its inherent structure, however, our previous GMDH correction model was restricted to kinesiographic signals representing lattice points in space. In this paper, we explored the sensitivity method for GMDH correction modeling. This provides for nonlinear interpolation of kinesiographic signals for interlattice points. Nominals, i.e., true values, of 3-D coordinates of the interlattice points were determined by means of a mandibular jaw movement simulator together with simultaneous recording of distorted kinesiographic signals which corresponded to the nominals. Distorted signals were corrected by the new method of correction modeling. A mean estimation error of 0.16 mm (SD 0.19 mm) was determined for 24 interlattice coordinates. Thus, nonlinear interpolation by the sensitivity method was confirmed to be effective.

Data Interpretation, Statistical↗
PubMed1991

A case of transient hyperphosphatasaemia of infancy associated with a probable allergic disorder.

Serum alkaline phosphatase (ALP) activity was found to be grossly elevated (8594 U/L) in a 2-year-old female child, returning towards normal during the subsequent 2 months. Electrophoresis revealed two bands of ALP activity; isoenzyme analysis identified the cathodic band as being of bone origin and the anodic band as sialylated liver ALP. Whilst the aetiology of transient hyperphosphataemia remains unclear a probable allergic disorder appears to be a contributory factor in this patient.

Alkaline Phosphatase↗
PubMed1991

Involvement of nicotinic receptors in the dorsal motor nucleus of the vagus in regulation of gastric motility in rats.

Roles of nicotinic receptors in the dorsal motor nucleus of the vagus (DMV) in the regulation of gastric motility were investigated in urethane-anesthetized rats in which an intragastric balloon had been placed. Nicotine (0.1 nmole) microinjected into the DMV but not the nucleus ambiguus induced dual changes, a decrease followed by an increase in gastric motility. Administration of 0.1 nmole of hexamethonium into the DMV significantly inhibited the decrease in gastric motility induced by intravenously administered nicotine.

Animals↗
PubMed1991

A histochemical study of the development of premaxilla and maxilla during secondary palate formation in the mouse embryo.

The development of premaxilla and maxilla in the mouse fetus during secondary palate formation from the 12th to the 16th days of gestation was histochemically assessed. To determine the developmental stages, a classification based on the morphogenesis of the limbs, or the "limb score" (LS) was employed. The stage of LS coincided with the gestational age from the 13th to the 15th days. Early on the 12th day, alkaline phosphatase (ALPase) activity was intense in the mesenchyme lateral to the incisor tooth bud and latero-inferior to the inferior orbital nerve. Subsequently, osteoblasts differentiated at these two sites. The ALPase positive area grew concomitantly with the nasal capsule, the molar tooth germ, and the closure of the secondary palate. The area of bone differentiation contoured the orbital nerve and extended to the rostral part of the secondary palate. At the LS stage -6 (13.52 days), ALPase activity was observed in the mesenchyme medial to, and also surrounding the molar tooth germ. The area of osteogenesis of the secondary palate spread along the medial side of the molar tooth germ, where the formation of the medial alveolar process of the maxilla was completed by the LS stage 3 (15.35 days). The ALPase positive area extended to the horizontal palatal shelves. By late on the 16th day, the palatal process was fully developed. In parallel, bone resorption began on the molar side of the alveolar process. Acid phosphatase and tartrate-resistant acid phosphatase activities (ACPase and TRACPase activity, respectively) revealed ACPase and TRACPase positive mononuclear cells around the molar tooth germ long before ossification occurred. Our results thus suggest an involvement of the incisor tooth bud and the infra-orbital nerve in the initial osteogenesis of the premaxilla and maxilla. Enzyme activities lead to the consideration that osteoclast precursors initiate differentiation around the molar tooth germ. Ostensibly, the mechanical force from the growth of the molar tooth would promote differentiation and activation of osteoclasts located on the alveolar process. Also, the LS classification would improve and simplify future studies of the development of the secondary palate.

Acid Phosphatase↗
PubMed1991

Superinduction of cytotoxic interferon-beta in glioma cells.

The possibility for new interferon therapy was investigated using the effect of endogenous human interferon-beta (HuIFN-beta) on various culture cell lines. Cell lines were exposed to superinduction agents (poly I: poly C, cycloheximide, and actinomycin D) and the production of endogenous interferon analyzed. Quantitative determination of HuIFN-beta and messenger ribonucleic acid (mRNA) showed HuIFN-beta was induced in all of five glioma cell lines, one of two melanoma cell lines, and all of three lung carcinoma cell lines as well as fibroblasts. Northern blot analysis showed HuIFN-beta mRNA induced in glioma cells was identical to that from fibroblasts. Endogenous HuIFN-beta induced from glioma cells had a cytostatic or cytocidal effect against various human glioma cell lines, even those resistant to fibroblast-derived HuIFN-beta. These results show it may be possible to use the induction of excess endogenous cytotoxic HuIFN-beta in human glioma tissue itself.

Fibroblasts↗
PubMed1991

Prevention of cyclophosphamide-induced and spontaneous diabetes in NOD/Shi/Kbe mice by anti-MHC class I Kd monoclonal antibody.

The immune mechanisms directly responsible for beta-cell destruction in insulin-dependent diabetes are undefined. We studied the role of MHC class I-restricted T lymphocytes in the development of diabetes in cyclophosphamide (CY)-treated male and untreated female NOD mice (H-2Kd,Db). After administration of CY to 10-wk-old male NOD/Shi/Kbe mice, 37 of 64 (58%) phosphate-buffered saline-injected control mice and 13 of 22 (59%) anti-Kb and 12 of 27 (44%) anti-Db monoclonal antibody (MoAb)-injected mice became diabetic by 14 wk of age, whereas only 3 of 38 (8%) anti-Kd and 2 of 13 (15%) anti-Lyt-2 MoAb-injected mice did. In untreated female NOD/Shi/Kbe mice, 30 of 46 (65%) mice developed spontaneous diabetes by 30 wk of age, whereas none of 9 anti-Kd MoAb-injected mice became diabetic. Immunohistochemical studies showed that islet-infiltrating cells in CY-treated control mice were composed mainly of both L3T4+ and Lyt-2+ T lymphocytes, whereas many L3T4+ and very few Lyt-2+ lymphocytes infiltrated within the islets in anti-Kd MoAb-injected mice. Administration of anti-Lyt-2 MoAb induced the absence of Lyt-2+ T lymphocytes in the islet and spleen. However, anti-Kd MoAb did not change the number of spleen cells or the T-lymphocyte subset and response to concanavalin A. These results suggest that MHC class I Kd-restricted Lyt-2+ T lymphocytes play an important role as direct effector cells in destruction of beta-cells in NOD/Shi/Kbe mice.

Animals↗
PubMed1991

Morphological analysis of selective destruction of pancreatic beta-cells by cytotoxic T lymphocytes in NOD mice.

Interactions of pancreatic islets and islet-associated mononuclear cells (IAMCs) from the nonobese diabetic (NOD) mouse were morphologically investigated. To obtain IAMCs, pancreatic islets isolated from adult NOD mice were cultured for 7 days with interleukin 2. Noted by light microscopy, interactions between IAMCs and freshly isolated islets from young NOD mice began 30 min after the initiation of the coculture, and 6 h later, normal cellular array of the islets was lost. By electron microscopy, most IAMCs had low nucleus-cytoplasm ratio, the nucleus was notched and exhibited condensed chromatin along the nuclear membrane, and well-developed Golgi complexes and several mitochondria were distributed in the cytoplasm. These IAMCs adhered to beta-cells, but not to alpha- or delta-cells, with their pseudopods and caused cytolysis of beta-cells. Immunohistochemical study with antibodies specific for pancreatic hormones demonstrated that only cells reacting with anti-insulin antibody were selectively lost as the incubation time proceeded. Electron immunohistochemistry by immunogold technique showed that effector cells in IAMCs reacted with anti-CD8 (Lyt-2) antibody, but not anti-CD4 (L3T4) or anti-asialogangliosideM1 antibody. In addition, the concentration of pancreatic hormones in the culture medium, used as a marker of cytolysis, also demonstrated that insulin was significantly increased after 6 h of culture, whereas glucagon and somatostatin were not. These results suggest that CD8+ cytotoxic T lymphocytes are involved in the selective destruction of pancreatic beta-cells in the NOD mouse.

Animals↗
PubMed1991

High susceptibility of cataract Shionogi (CTS) mice to passive anaphylactic shock mediated by allogeneic IgE and IgG1 monoclonal antibodies.

The susceptibility of cataract Shionogi (CTS) mice as young as 8 to 10 weeks of age to passive anaphylactic shock mediated by anti-benzylpenicilloyl IgE and IgG1 monoclonal antibodies was compared with those of other strains of the same age including sister strains such as nonobese-diabetic (NOD) and nonobese-nondiabetic (NON). When the animals had been treated with killed Bordetella pertussis organisms, potent sensitization, enough to cause lethal shock, was produced by either monoclonal antibody preparation in CTS, NOD, C57BL/6J and DS/Shi strains, but not at all in C3H/He, DBA/2 and BALB/c strains. In the NON strain, lethal shock was elicited in the animals sensitized with the IgG1 antibody but not in those sensitized with the IgE antibody. Without the pertussis pretreatment, sensitization sufficient to cause lethal shock was produced at a high frequency by the IgG1 antibody in CTS and NOD mice but not in the other strains. When the IgE antibody was used, lethal shock was not observed in any of the mouse strains tested except for one CTS mouse. These results indicate that CTS as well as NOD are highly susceptible strains, and that IgG1 antibody is more effective than IgE antibody for producing systemic sensitization for anaphylactic shock. In addition to these findings, the results revealed an age-dependent potentiation of anaphylactic shock in CTS mice. The IgE antibody-mediated lethal shock was produced in all the aged animals of this mouse strain tested without the Bp treatment, but not in aged NOD and NON mice.

Age Factors↗
PubMed1991

[The influence of repirinast, an anti-allergic drug, on theophylline pharmacokinetics in patients with bronchial asthma].

In order to clarify whether repirinast, an inhibitor of chemical mediator release, could influence the pharmacokinetics of theophylline, a loading test using intravenous injection of aminophylline was performed in 10 subjects with bronchial asthma before and after treatment with 300 mg/day of repirinast. There was no significant difference in theophylline half-life before treatment (7.25 +/- 2.43 hr) and after treatment (7.82 +/- 3.35 hr). There was no significant difference in theophylline clearance before treatment (0.047 +/- 0.018 L/kg/hr) and after treatment (0.047 +/- 0.020 L/kg/hr). These results demonstrated that repirinast does not modify theophylline pharmacokinetics significantly.

Adult↗
PubMed1991

[Retrospective clinical evaluation of prognosis factors in stage D2 prostatic cancer treated with endocrine therapy].

Of 91 patients with prostatic cancer treated at our Department of Urology, from January 1976 through December 1987, 42 cases of stage D2 cancer treated with endocrine therapy were evaluated retrospectively with regard to clinical parameters and prognoses. The patients with marked increase in the level of the prostatic acid phosphatase (PACP), and the lactate dehydrogenase (LDH) in serum, and marked decrease in volume of hemoglobin (Hb) had a poor prognosis. The patients who took a long time to obtain a favorable response to the therapy had a poor prognosis. The response grade in NPCP criteria at 3 months after the initiation of therapy reflected the prognosis, and showed good correlation to the grade of favorable response.

Acid Phosphatase↗
PubMed1991

[A new method for immunological detection of fecal blood, using colloidal gold labeled with anti-human hemoglobin monoclonal antibody].

Application of colloidal gold agglutination to detection of fecal blood was done. Colloidal gold labeled with monoclonal antibody recognized human hemoglobin was agglutinated with hemoglobin and changed the color from red to gray. The color that diminished rapidly with an antigen was unchangeable from 30 min to 4 hr. Reaction was single step, and positive tests were easily distinguished from negative tests. Detectable hemoglobin concentration was 0.5 micrograms/ml. Comparison of colloidal gold agglutination with other methods, as low as latex agglutination and RPHA, showed good agreements in 1409 fecal samples. Colloidal gold agglutination method is superior in easiness of judgement and unnecessity of keeping time, and will be suitable for mass screening for colorectal cancer using 96 well microplate.

Agglutination Tests↗
PubMed1991

[Intra-graft balloon pumping--a clinical case report].

A 29-year-old female underwent tube graft replacement of distal aortic arch and descending aorta for dissecting aneurysm. After 42 minutes of aortic cross-clamping the patient was initially weaned satisfactorily from cardiopulmonary bypass (CPB). However, cardiac arrhythmia and cardiac arrest necessitated reestablishment of CPB. Electro-cardiography showed inferior myocardial infarction. To wean CPB intraaortic balloon pumping (IABP) was mandatory. But because of dissecting aortic aneurysm IABP in conventional method was contra-indicated. Intra graft balloon pumping (IGBP) was initiated while the patient was on full CPB. A low-porosity woven Dacron tube graft (22 mm) was anastomosed end-to-side to ascending aorta. A balloon was inserted into the tube graft to establish IGBP. This IGBP provided effective circulatory assist. The patient was weaned from CPB 1 hours after reestablishment of IGBP. Postoperative course was stable. The patient was returned to the operating room for removal of the balloon 3 days postoperatively. We reported the case for whom IGBP was effective. IGBP was effective circulatory support for the patient when conventional use of IABP was contra-indicated.

Adult↗