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Biomedical subjects

Y Sakamoto

Publications and source records attributed to Y Sakamoto.

At least 343 records · Page 19Linked to original sources
PubMed1994

Burkitt type leukaemia associated with multiple myeloma.

We describe a 77-year-old man with multiple myeloma (MM) who developed Burkitt type leukaemia (BTL) 16 months after the initial diagnosis of MM. MM was positive for CD10 with immunoglobulin (Ig) kappa, kappa Bence Jones protein (BJP) and a normal karyotype. BTL was positive for CD10, CD19, CD20 and HLA-DR with Ig mu and lambda, lambda BJP and a clonal abnormal karyotype of 46,XY,-13, t(8;14)(q24;q32),11q+,14q+, +mar. The patient died 9 d after diagnosis of BTL despite treatment with multiple agents. This is, to our knowledge, the first such case to be reported.

Aged↗
PubMed1994

Urinary excretion of acid-soluble peptides in children with Duchenne muscular dystrophy.

In order to investigate the validity of the hypothesis that acid-soluble peptides (ASP) in urinary excreta can be applied as an index of the protein catabolism of the whole body, we measured the urinary excretion of ASP in 46 normal children and in 18 children with Duchenne muscular dystrophy (DMD), in which continuous breakdown of skeletal muscle protein is presumed. The mean value of ASP in the children with DMD was significantly higher than that in normal controls. The concentration of ASP was correlated with that of 3-methylhistidine (3MH), which has been proposed as an index of muscle breakdown. This finding indicates that urinary ASP reflects the catabolism of body proteins. No correlation was observed between the concentration of ASP and that of 1-methylhistidine (1MH), which is used as an objective index of meat and fish ingestion. After the administration of bestatin, an inhibitor of leucine aminopeptidase, for 9 months, the urinary ASP concentration of children with DMD increased markedly. This increase is thought to have been directly caused by the bestatin itself. Urinary ASP is therefore apparently a more conveniently applied index of protein catabolism than is urinary 3MH, which requires the application of several restrictions. However, it should not be applied when the effect of bestatin administration is evident.

Adolescent↗
PubMed1994

[Long term observation on beta-hemolytic streptococci in institutions for handicapped preschool children. Streptococcal Diseases Study Group].

Studies on beta-hemolytic streptococci have been carried out in 2 institutions for handicapped preschool children during the last nine-year period from 1985 to 1993. These studies were based on continuous throat cultures, 4 to 12 times a year, from 244 children including Down's syndrome and mentally retarded children in K-institution (K), and from 134 including cerebral palsy and other cerebrospinal disorders in H-institution (H). A significant difference (p < 0.05) was demonstrated in the isolation rates between K (11.1%) and H (6.4%). In K, isolation rates of beta-hemolytic streptococci ranged from 0 to 43.5%, showing a higher rate in winter (16.5%) than in summer (6.6%), and elevated-isolation rates of homologous types were demonstrate four times during the study period; i.e., type T12 in '87, type T28 in '88, type T1 in '90 and '92. In H, on the other hand, no higher rates (as to group A) were observed in winter or summer. In relation to disorders of children, the rates were 12.6% in Down's syndrome (mean age 2.7y), 10.0% in mentally retarded children (3.9y) and 6.4% in cerebral palsy or others with cerebrospinal disorders (3.3y). Down's syndrome, the youngest group, revealed the highest isolation rate of beta-hemolytic streptococci. In only two cases isolated hemologous types detected were over two times continuously.

Child, Institutionalized↗
PubMed1994

Value of phase-shift gradient-echo MR imaging in the differentiation of pelvic lesions with high signal intensity at T1-weighted imaging.

PURPOSE: To assess the value of phase-shift gradient-echo magnetic resonance (MR) imaging with the fast low-angle shot (FLASH) technique in the differentiation of hemorrhagic tumors and teratomas. MATERIALS AND METHODS: T1- and T2-weighted spin-echo imaging and phase-shift MR imaging were performed in 60 patients. On T1-weighted images, the signal intensity of lesions was compared with that of intraperitoneal fat. Findings at MR imaging were compared with the surgical findings. The diagnostic performance of each pulse sequence was analyzed with receiver operating characteristic curves. RESULTS: Sixty high-signal-intensity lesions were identified in 45 patients at T1-weighted imaging. Hemorrhagic lesions and teratomas had similar signal intensities on both T1- and T2-weighted images. Lesions were detected more decisively with FLASH imaging than with T1- and T2-weighted imaging. CONCLUSIONS: Phase-shift gradient-echo imaging is a readily available method for the differential diagnosis of lesions with high signal intensity at T1-weighted MR imaging.

Adolescent↗
PubMed1994

Hypertrophic olivary degeneration: MR imaging and pathologic findings.

PURPOSE: To assess magnetic resonance (MR) imaging findings of hypertrophic olivary degeneration (HOD) due to hemorrhage and correlate them with pathologic findings. MATERIALS AND METHODS: MR imaging was performed in 11 patients--eight with pontine tegmental hemorrhages (THs) and three with cerebellar hemorrhages in the dentate nuclei. The interval from hemorrhagic ictus to the MR studies was 3 weeks to 49 months. Pathologic specimens came from a woman who died of brain stem hemorrhage. RESULTS: Involvement of the central tegmental tract produced ipsilateral HOD; that of the dentate nucleus or superior cerebellar peduncle produced contralateral HOD. Bilateral olivary changes occurred only when the TH also involved the superior cerebellar peduncle. In bilateral THs, HOD was limited to the dominant bleeding side because of the lateral position of the central tegmental tract. Hyperintense areas of the oliva appeared 3 weeks after ictus. Hypertrophy appeared after 5-15 months. Microscopically, vacuolar degeneration of neurons and hypertrophy of astrocytes with gliosis were seen. CONCLUSION: MR images may depict very early neuronal changes in the oliva and are well correlated with pathologic staging.

Adult↗
PubMed1994

Species difference in cholesteryl ester cycle and HDL-induced cholesterol efflux from macrophage foam cells.

The species difference in the turnover rates of the cholesteryl ester (CE) cycle in macrophage foam cells (MFC) was examined in mice and rats. MFC were induced by acetyl-LDL and pulsed with [3H]oleate, followed by a chase with [14C]oleate. The replacement of the initial amount of cholesteryl [3H]oleate by cholesteryl [14C]oleate within 24 hours was 63% in mouse MFC, whereas it was 33% in rat MFC. The corresponding replacement in rabbit MFC was < 10%. In addition, HDL removed 41% of the CE mass from mouse MFC but only 22% from rat MFC. HDL-induced CE reduction from mouse MFC was enhanced by 40% by the inhibitor for acyl-coenzyme A:cholesterol acyltransferase (58-035), whereas the enhancing effect was not observed with rat MFC. These results indicate that the rate of CE turnover may serve as a critical factor to determine the capacity of MFC to respond to HDL-induced CE reduction, suggesting the possibility that the species difference in the turnover rates of the CE cycle in MFC might explain, in part, the species difference in susceptibility to experimental atherosclerosis.

Acyl Coenzyme A↗
PubMed1994

Inhibition of analgesic-induced asthma by leukotriene receptor antagonist ONO-1078.

We evaluated the effect of ONO-1078, a selective leukotriene-C4, -D4, and -E4-receptor antagonist, on bronchoconstriction intensity during inhalation challenge with dipyrone (a pyrazolone derivative) in six aspirin-sensitive asthmatics. A double-blind, randomized, crossover design was used. After ingestion of 225 mg ONO-1078 or matching placebo, subjects underwent bronchial provocation with dipyrone on two occasions, separated by 4 wk. Aerosol inhalation of dipyrone was performed increasing the concentration stepwise from 0.08 to 10% (wt/vol). FEV1 was measured every 10 min up to 30 min after inhalation of each concentration. Threshold concentrations causing a fall in FEV1 > or = 20% of baseline value were 0.4% in four subjects and 2% in the other two on the placebo day. After pretreatment with ONO-1078, threshold concentration was 10% in two subjects, and no fall in FEV1 was observed in the other four, even after inhalation of 10% dipyrone. Values of PD20 were 21.9 +/- 8.2 units (mean +/- SEM) after placebo and 311.6 +/- 40.3 units after ONO-1078, respectively, and a statistically significant difference occurred (p < 0.001). Provocation of bronchoconstriction was completely inhibited in subjects whose plasma ONO-1078 levels were more than 0.5 microgram/ml. These results support the hypothesis that sulfidopeptide leukotriene-induced bronchoconstriction is one important component in the pathophysiology of aspirin-induced asthma.

Adult↗
PubMed1994

Meisenheimer rearrangement of azetopyridoindoles, VI. Synthesis of 12-carbaeudistomin and related compounds.

For structure-activity relationship investigation of eudistomins 1, 12-carbaeudistomin 3, its 1,10-trans isomer 4, and 11,12-didehydro-12-carbaeudistomin 5 have been synthesized. The [2,3]-Meisenheimer rearrangement of the corresponding N-oxide of the 2-vinylazetopyridoindole 12a bearing a benzenesulfonyl group as a protective group of the indole nitrogen atom afforded the oxazepino ester 14, which was easily isomerized to 20a. Compounds 3 and 4 were synthesized from 14 and 20a, respectively, according to the following reaction sequences [hydrogenation of the double bond (Pd-C/H2), desulfonylation (Mg in MeOH), hydrolysis (AlBr3-EtSH), and Curtius rearrangement (a mixed anhydride method using NaN3), followed by debenzylation (Pd-C/H2)]. The Curtius reaction of the carboxylic acid 27 using DPPA gave the carbamate 29, which was subjected to debenzylation (AlBr3-EtSH) followed by desulfonylation (LiAlH4) to afford 5. Evaluation of anti-influenza virus activities of the amino compounds 3, 4, and 5 revealed that 12-carbaeudistomin 3 possesses a specific activity against influenza virus B.

Antiviral Agents↗
PubMed1994

Statistical characterization of negative control data in the Ames Salmonella/microsome test.

A statistical characterization of negative control data in the Ames Salmonella/microsome reverse mutation test was performed using data obtained at Takeda Analytical Research Laboratories during January 1989 to April 1990. The lot-to-lot variability of bacterial stock cultures and day-to-day variability of experiments were small for Salmonella typhimurium strains TA1535 and TA1537 and Escherichia coli WP2uvrA, but they were larger for S. typhimurium TA100. The number of revertant colonies for all test strains studied here followed Poisson distributions within the same day. The two-fold rule that is an empirical method to evaluate the Ames Salmonella/microsome test results has been widely used in Japan. This two-fold rule was evaluated statistically. The comparison-wise type I error rate was less than 0.05 for TA98, TA100, TA1535, TA1537, and WP2uvrA. Moreover, this rule is particularly conservative for TA100, for which the type I error rate was nearly 0.

Analysis of Variance↗
PubMed1994

Statistical analysis of data in mutagenicity assays: rodent micronucleus assay.

To evaluate chemical safety, many kinds of short-term mutagenicity assays are performed together with long-term assays in animals. Rationales and methodology for these assays have been well discussed and documented. No statistical method, however, has been singled out as the method of choice for the evaluation of mutagenicity assay data, although a number of reports on statistical methods to evaluate such data have been published. Among the mutagenicity assays, the micronucleus assay using mouse bone marrow erythropoietic cells have been widely used to assess cytogenetic activities of test chemicals. A statistical evaluation procedure for this assay is proposed herein, combining the use of historical control data and dose-response relationships. The probability of type I errors and the power of this method are compared with those of some other conventional methods by Monte Carlo simulation.

Animals↗
PubMed1994

The potentiation of carbachol-induced transient contractions in guinea-pig stomach muscles by a low temperature.

A transient contraction in guinea-pig stomach muscles was induced by carbachol (CCh, 10(-6) M) in a Ca(2+)-free Krebs solution. This CCh-induced transient contraction (CITC) was remarkable from 22 to 26 degrees C, but not so at other temperatures in most preparations. When a second CCh (10(-6) M) was applied to the tissue with rinsing off CCh 5 min after an application of the first CCh for 10 min, no CITC was observed. The peak amplitude of the CITC increased with the CCh concentration dose-dependently, and that of CITC (by 10(-6) M CCh) declined exponentially over time after washing the tissue with a Ca(2+)-free Krebs solution. The decline time constant increased from 4.8 +/- 1.2 min (mean +/- SEM; n = 5) at 35 degrees C to 13.2 +/- 2.5 min (mean +/- SEM; n = 5) at 22 degrees C. Furthermore, the falling phase of CITC (by 10(-6) M CCh) also showed an exponential decay of 7.4 +/- 0.2 s (mean +/- SEM; n = 6) at 35 degrees C in the time constant. This time constant increased to 22.3 +/- 0.3 s (mean +/- SEM; n = 6) at 22 degrees C. From the above results, it is concluded that CITC may be due to the Ca(2+)-release from an intracellular store site while released Ca2+ may be immediately excluded to an extracellular space by the Ca2+ pump of the plasma membrane, but the Ca2+ pump activity may be reduced and in addition the stored Ca2+ is kept for long time by a low temperature, which thus results in an increase in the amplitude and a prolongation of the falling phase of CITC.

Animals↗
PubMed1994

Richter's syndrome showing pronounced lymphadenopathy in response to administration of granulocyte colony-stimulating factor.

A patient with Richter's syndrome developed rapid generalized lymph node enlargement with a decrease of peripheral blood lymphocytes after recombinant human granulocyte colony-stimulating factor (rhG-CSF) therapy for neutropenia induced by chemotherapy. The lymphadenopathy subsided spontaneously following discontinuation of rhG-CSF medication. Reinstitution of rhG-CSF therapy was followed by the same response as during initial therapy. Histopathologically, the lesions were characteristic of diffuse large cell lymphoma (DLL) with no evidence of myeloid cell involvement. No spontaneous contraction of enlarged lymph nodes followed withdrawal of the second course, but the enlargement subsided with chemotherapy. The patient died of myocardial infarction. All residual tumors examined post mortem presented microscopic features of small lymphocytic lymphoma (SLL), and G-CSF receptor was demonstrated on these neoplastic cells by Northern blot hybridization analysis. This observation indicates that some B cell malignancies may retain G-CSF receptor and respond to G-CSF.

Aged↗
PubMed1994

Suppressive effect of cyclosporin A on delayed-type hypersensitivity to syngeneic testicular cells.

We have investigated the immunosuppressive effect of cyclosporin A (CsA) on delayed-type hypersensitivity (DTH) to syngeneic testicular cells (TC). DTH to syngeneic TC was induced by subcutaneous (sc) immunization with viable syngeneic TC and was augmented by a high dose of cyclophosphamide (CY)-pretreatment. DTH was suppressed by administration of CsA in a dose-dependent manner. When the mice were immunized alone or with 100 mg/kg of CY-pretreatment, 30 mg/kg or more of CsA suppressed DTH to TC. In mice immunized with 200 mg/kg of CY-pretreatment, 50 mg/kg of CsA was needed to suppress DTH. DTH is thought to play a key role in the induction and/or maintenance of experimental autoimmune orchitis (EAO). Our data show that DTH to syngeneic TC induced by immunization is suppressed by administration of CsA. Pretreatment of mice with immunization and administration of CsA suppressed DTH significantly when the mice were challenged with immunization with CY-pretreatment. However, DTH was rather enhanced significantly in mice pretreated with administration of CsA alone without preimmunization. Therefore, even though administration of CsA with immunization suppresses DTH, administration of CsA alone might rather eliminate suppressive mechanism resulting in augmentation of DTH.

Animals↗
PubMed1994

Visibility of epidermoid tumors on steady-state free precession images.

PURPOSE: To determine whether steady-state free precession sequences improve the MR visibility of epidermoid tumors in comparison with spin-echo images. METHODS: Patients were four women and three men with epidermoid tumors in the subarachnoid spaces. MR was performed with a 1.5-T superconductive unit. For steady-state free precession imaging, three-dimensional Fourier transform fast imaging with steady-state free precession (FISP) images were used (20-40/7 [repetition time/echo time], flip angle of 25 degrees). The visualization and contrast-to-noise ratio were compared in FISP images and spin-echo images. In one case, the images of FISP and fast low-angle shot were obtained with variable repetition times and flip angles to evaluate the best pulse sequences for the visualization of epidermoid tumors. RESULTS: The contrast-to-noise ratios between tumors and cerebrospinal fluid ranged from 7.9 to 17.5 (average was 12.9) on FISP images. The average of contrast-to-noise ratios on T1, T2, and proton density-weighted spin-echo images were 1.6, 2.0, and 4.2, respectively. Three-dimensional Fourier transform FISP images best showed central nervous system and demonstrated epidermoid tumors excellently. CONCLUSIONS: Epidermoid tumors in the subarachnoid spaces were better demonstrated on steady-state free precession (three-dimensional Fourier transform FISP) than on conventional spin-echo images.

Aged↗
PubMed1994

[A case of quadricuspid aortic valve associated with mitral insufficiency].

We report a case of a 70-year-old woman who had congenital quadricuspid aortic valve. She had undergone Manouguian's operation because of the narrow annulus associated with aortic steno-insufficiency and mitral insufficiency. The aortic valve was found to have 4 equal-sized cusps. The noncoronary cusp was divided into two equal parts. This congenital quadricuspid valve was extremely rare anomaly and we have nerve seen the case which had been corrected surgically by Manouguian's procedure. The aortic valve was replaced by a 23 mm St. Jude Medical prosthesis and the mitral valve was replaced by a 29 mm CarboMedics prosthesis. The postoperative course was uneventful and she is doing well six months after operation.

Aged↗
PubMed1994

[Antitumor activity of combination treatment combining gemcitabine with cisplatin or vindesine against human lung cancer xenografted in nude mice].

Gemcitabine is a new ara-C derivative and shows much more potent cytotoxic action than ara-C, which may be explained by the fact that its intracellular concentration can be maintained over a longer period. We investigated anti-tumor activity combining gemcitabine with cisplatin (CDDP) or vindesine (VDS) with a lung cancer line H-74 that was relatively insensitive to gemcitabine. Mice were observed for 8 weeks, including the 4 week treatment period and the subsequent 4 week drug-free period. The tumor growth inhibition rate, histological changes, and side effects were evaluated at 4 and 8 weeks after the initiation of therapy. The anti-tumor effects of treatment combining gemcitabine with CDDP or VDS were more potent and lasted longer than each drug separately. Statistical analysis shows that the treatment combining gemcitabine with CDDP was additive or synergistic at 4 and 8 weeks after initiation, whereas the treatment combining gemcitabine with VDS was only additive at 4 weeks after initiation and additive or synergistic at 8 weeks after initiation. The side effects of both combination groups were less than those observed in only CDDP or VDS-treated animals. These results suggest the usefulness of a combination therapy combining gemcitabine with CDDP or VDS in future clinical applications.

Adenocarcinoma, Papillary↗