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Biomedical subjects

A Matsuda

Publications and source records attributed to A Matsuda.

At least 343 records · Page 19Linked to original sources
PubMed1990

[Quantitative assessment of mineral content in metacarpal bone with Fuji computed radiography].

A new microdensitometry method for quantitative assessment of bone mineral content using Fuji computed radiography (FCR) was developed and the results were compared with those obtained by the conventional film-screen method. Using both methods, X-ray pictures of the 2nd metacarpal bone were taken with a reference aluminum step wedge in nine normal subjects and nine parameters representing the width and density of bone marrow and cortex were calculated in the middle of the bone shaft. Interobserver reproducibility assessed for three parameters was significantly higher in the FCR method than the conventional one. The value of sigma GS computed by the FCR method, that is equivalent to the net bone density of the transverse section of the shaft, showed higher correlation with the one obtained by computed tomography in comparison with the conventional method. In our FCR method, moreover, interobserver reproducibility and accuracy was improved by employing automatic manipulation as much as possible in the process of calculation. The exposure dose in the FCR method could be reduced to half of the one in the conventional method without deteriorating the accuracy. In conclusion, our new microdensitometry method with FCR provides high accuracy and good reproducibility for the measurement of bone mineral content with small exposure dose and is likely to be useful for the long-term follow-up of the osteoporotic patients from the variety of causes.

Adult↗
PubMed1990

2-(p-Nitrophenyl)-2'-deoxyadenosine, a new type of mutagenic nucleoside.

A crude preparation of 2-phenyladenosine was found to be mutagenic in the Ames Salmonella assay. In the purification of this preparation, it was revealed that 2-phenyladenosine itself was nonmutagenic but that 2-(m- and p-nitrophenyl)-adenosines (5m,p) contaminating the sample were the mutagenic principles. A structure-activity relationship study was carried out, and it was found that 5p, 2-(p-nitrophenyl)-adenine (7p), and 2-(p-nitrophenyl)-2'-deoxyadenosine (15p) were strongly mutagenic toward S. typhimurium TA98 and TA100 without metabolic activation, the potency being in the order 15p greater than 7p greater than 5p. The potency of 15p in TA98 was one order of magnitude greater than that of 4-nitroquinoline N-oxide. 15p also showed mutagenicity in the mouse cell line FM3A in culture.

Adenosine↗
PubMed1990

Free-radical reactions induced by OH-radical attack on cytosine-related compounds: a study by a method combining ESR, spin trapping and HPLC.

Free-radical reactions induced by OH-radical attack on cytosine-related compounds were investigated by a method combining ESR, spin trapping with 2-methyl-2-nitrosopropane and high-performance liquid chromatography (HPLC). Cytidine, 2'-deoxycytidine, cytidine 3'-monophosphate, cytidine 5'-monophosphate, 2'-deoxycytidine 5'-monophosphate and their derivatives, of which 5,6-protons at the base moiety were replaced by deuterons, and polycytidylic acid (poly(C] were employed as samples. OH radicals were generated by X-irradiating an N2O-saturated aqueous solution. Five spin adducts were separated by HPLC. Examination of them by ESR spectroscopy and UV photospectrometry showed that spin adducts assigned to C5 and C6 radicals due to OH addition to the 5,6 double-bond, a deaminated form of the spin adduct derived from a C5 radical due to the cyclization reaction between C5' of the sugar and C6 of the base, and a spin adduct assigned to the C4' radical due to H abstraction by OH radicals were produced. From these results the sites of OH-radical attack and the subsequent radical reactions in cytosine-related compounds were clarified.

Chemical Phenomena↗
PubMed1990

Improvement of anemia by recombinant erythropoietin in patients with myelodysplastic syndromes and aplastic anemia.

Eight patients with myelodysplastic syndromes (MDS) and four patients with aplastic anemia (AA) were treated with recombinant erythropoietin (rEpo) to investigate its effect on the anemia of these patients. rEpo was administered by i.v. injection three times a week for at least four weeks. The doses were 3,000, 6,000, or 12,000 U/day. Despite an elevated "endogenous" Epo level, a greater than 1.5 g/dl increase in hemoglobin (Hb) concentration was observed in one patient with refractory anemia (RA), one patient with refractory anemia with excess of blasts (RAEB), and one patient with AA. A greater than 50% decrease in red cell transfusion requirement was observed in one patient with RA and one patient with AA. One RA patient and one AA patient have received rEpo as maintenance therapy for more than 64 and 100 weeks, respectively. They no longer need red cell transfusions and have had a normal Hb concentration and normal ferrokinetics. No side effect was seen. These results indicate that rEpo may benefit some patients with MDS and AA who are dependent on red cell transfusions while further studies will be necessary to elucidate the mechanism by which rEpo stimulates erythropoiesis and improves anemia in patients with these diseases.

Adult↗
PubMed1990

Effects of bestatin on myelopoietic stem cells in normal and cyclophosphamide-treated mice.

The effect of bestatin on hematopoietic parameters and bone marrow progenitor activity (colony-forming unit - granulocyte/macrophage: CFU-GM) was examined in normal and myelosuppressed C57BL/6 mice. CFU-GM frequency and absolute number were determined with a limiting dilution analysis of bone marrow cells in soft agar using recombinant murine colony-stimulating factor - granulocyte/macrophage. We report that bestatin increased splenic, bone marrow, and peripheral blood cellularity and the number of CFU-GM over a dose range from 2.5 mg/kg through 100 mg/kg following i.p., i.v., or oral administration. The greatest myeloid stimulation was observed following multiple injections of bestatin. Bestatin also increased the recovery from cyclophosphamide-induced myelodepression as measured by these parameters. The hematopoietic properties of bestatin following oral administration is of potential importance for clinical application.

Administration, Oral↗
PubMed1990

Horseshoe lung without respiratory distress.

A case of horseshoe lung associated with scimitar syndrome is reported. The patient, a six year old boy, had no respiratory distress. Plain chest film showed hypoplasia of the right lung and scimitar vein. Angiography demonstrated that right inferior pulmonary arteries crossed the midline and reached to the left lung base.

Child↗
PubMed1990

Hypervariable region 5'-flanking [Leu A3]insulin gene of insulin Tochigi is different from those of insulin Wakayama I,II.

Three families with abnormal insulinemia have been reported in Japan and sequencing analysis revealed that they had the same point mutation in one allele of the insulin genes causing [Leu A3]insulin. To estimate whether or not this same mutation came from a common ancestor we determined the sequence of the hypervariable region 5'-flanking the third [Leu A3]insulin allele (insulin Tochigi). This region is composed of 42 tandem repeating oligonucleotides, is 599 base pairs long and the sequence is 5' cdi jfa faa aba baa aaa fab aaa caa aac aca cba aaf ccb 3' (abbreviated as a = ACAGGGGTGTGGGG; b = ACAGGGGTCTGGGG; c = ACAGGGGTCCTGGGG; d = ACAGGGGTCCGGGG; f = ACAGGGGTCCCGGGG; i = ACAGGGTCCTGGGG; j = ACAGGGGTGTGAGG). The length of this region is different from those of the first and second [Leu A3]insulin alleles (insulin Wakayama I,II). This difference suggests either that insulin Tochigi and insulin Wakayama I,II are not of the same origin, or that three cases of [Leu A3]insulin in Japan have the same ancestor but recombination has occurred in this region at some point in the past.

Base Sequence↗
PubMed1990

Early site of lymphatic involvement from right renal cell carcinoma: CT demonstration and method of lymphadenectomy.

The value of lymphadenectomy in the treatment of renal cell carcinoma remains controversial. The precise location of nodal metastasis and method of lymphadenectomy had seldom been mentioned. We report 2 patients with right renal cell carcinoma who had regional lymph node involvement without blood-borne metastasis. The involved lymph nodes were demonstrated by CT scan just behind the inferior vena cava at the level of renal hilus. These nodes seemed to be the first sites of nodal involvement from the right renal cell carcinoma. Elevation of the inferior vena cava by dividing its small branches, including a few lumbar veins, was necessary for complete removal of these nodes en bloc with the right kidney.

Aged↗
PubMed1990

High frequency of aspartic acid at position 57 of HLA-DQ beta-chain in Japanese IDDM patients and nondiabetic subjects.

The HLA-DQ beta-chain (DQB1) genes of 72 Japanese patients with insulin-dependent diabetes mellitus (IDDM) and 85 control subjects were studied with polymerase chain-reaction (PCR) amplification and allele-specific oligonucleotide hybridization. DQW4 (DQBBlank) and DQw9 (DQB3.3) were increased in IDDM patients compared with the control subjects, and DQB1.2, DQB1.9, and DQw7 (DQB3.1) were decreased. Thirty-five (48.6%) IDDM patients had both alleles carrying an aspartic acid at position 57 of the DQ beta-chain (Asp 57), 35 (48.6%) were Asp 57/non-Asp 57 heterozygous, and 2 (2.8%) had non-Asp 57 alleles only. Of 85 control subjects, the respective values for these three genotypes were 49 (57.6%), 29 (34.1%), and 7 (8.2%), respectively. The high frequency of Asp 57 alleles in both IDDM and control subjects contrasts with data for Whites. Therefore, the Asp 57 hypothesis that the presence of an aspartic acid at position 57 of DQ beta-chain provides protection against developing IDDM is not tenable for Japanese IDDM patients. The DRB1 gene, particularly position 57 of the DR beta-chain, may contribute to IDDM susceptibility in Japanese.

Adolescent↗
PubMed1990

Invention of anti-Leishmania drugs on the basis of the nucleoside structures.

3'-Deoxy-3'-fluoroinosine is a potent inhibitor for the growth of the promastigote form of Leishmania tropica and Leishmania donovani. In culture, the EC50 values of 3'-deoxy-3'-fluoroinosine are 2.3 x 10(-7) and 1.0 x 10(-6) M for the promastigotes of L. tropica and L. donovani, respectively. It is less toxic towards mouse mammary tumor FM3A cells: the EC50 value is 2.0 x 10(-4) M. 3'-Deoxy-3'-fluoroinosine is metabolized by Leishmania promastigotes to give 3'-deoxy-3'-fluoroadenosine-5'-triphosphate. This metabolic conversion provides a mechanism for the parasite-selective toxicity of 3'-deoxy-3'-fluoroinosine.

Animals↗
PubMed1990

Effect of stripping thyroxin from thyroxin-binding globulin on the measurement of free thyroxin in serum by equilibrium dialysis and by radioimmunoassay.

In considering factors that might influence measurement of free thyroxin (T4), we evaluated the proportion (%) of T4 that could be stripped from thyroxin-binding globulin (TBG). The percentage of free T4 was measured in serially diluted sera from four normal subjects, four patients with hyperthyroidism or hypothyroidism, four pregnant women, and four malnourished subjects with low TBG. The critical percentage of stripping was determined by the product of the percentage free T4 and the critical dilution factor (the point where the percentage free T4 began to decrease). The mean values obtained for the respective patient groups--6.38%, 2.76%, 16.73%, 9.75%, and 4.28%--were proved to be related to the rate of saturation of TBG with T4. Values for percentage stripping determined with the "GammaCoat two-step RIA" and the "LiquiSol RIA" were well within the critical percentage stripping by equilibrium dialysis, except in the case of low-TBG serum as measured by LiquiSol RIA. Free T4 concentration as measured by LiquiSol RIA decreased as sample volume decreased. These findings were ascribed to the relatively high values for percentage stripping in the LiquiSol RIA, which led to erroneously low values for free T4.

Adult↗
PubMed1990

[A case report of endobronchial lipoma].

Endobronchial lipomas are rare benign tumors of the lung. Nineteen cases have been reported in Japan. We present a case of endobronchial lipoma obstructing the left B4b and chronic saccular bronchiectasis throughout the left upper lobe. A 42-year-old man, 174 cm tall and weighing 47 kg, was referred for investigation of an abnormal chest X-ray film. He had a history of pneumonia and pyothorax in infancy. The chest X-ray film showed linear densities and ill-defined, irregular opacities in the upper-middle lung field. CT scan and tomographic studies showed multiple cystic spaces in the left upper lobe in which the volume was diminished. An angiogram of the left bronchial artery showed peripheral hypervascularity in the left upper lobe and systemic-to-pulmonary artery shunt. Fiberoptic bronchoscopy revealed a smooth, pink mass obstructing B4b. Biopsy specimens were insufficient for histological diagnosis. Preoperatively, an inflammatory polyp in association with chronic saccular bronchiectasis was suspected. Left upper lobectomy was performed on January 13, 1989. Gross examination of the resected specimen showed a pedunculated polypoid mass, 1.5 X 1.2 X 0.6 cm, attached to the bronchial mucosa of B4bii and saccular ectatic changes of bronchi not only in the lingular division but also in upper division. Microscopically, the endobronchial tumor consisted of mature adipose tissue covered with columnar bronchial epithelium. The fat was fairly well localized in the submucosa, but was not encapsulated and did not enclose glands or smooth muscle fibers. The endobronchial lipoma was thought to originate in the bronchus of chronic saccular bronchiectasis.

Adult↗
PubMed1990

[Long-term evaluation after correction of tetralogy of Fallot].

The long-term survivors of the patients who underwent corrective surgery for tetralogy of Fallot between 1956 and 1988 were analyzed with respect to symptoms, late death, reoperation, and ventricular arrhythmias. For analysis, these 380 patients were separated into three periods, April 1956-December 1968 (Period 1), January 1968-May 1978 (Period 2), and June 1978-December 1988 (Period 3). In Period 3, the intracardiac procedures were performed with or without minimal right ventriculotomy. There were 24 late deaths (6.3%), and 10 of them were sudden. Nine patients (2.4%) required reoperation. Actuarial reoperation free survival rate was 93.8% at 10 years, 90.0% at 20 years, and 85.3% at 30 years. There were no differences in the actuarial curve between 3 periods though there was no late death in Period 3. NYHA functional class was I in 229 (80%) out of all 287 patients whose symptoms were clear to follow up, II in 50 (17), and III in 8 (3%). There was no patient in NYHA class IV. The incidence of NYHA class II and III was significantly higher in Period 1 (23%) and 2 (28%) than Period 3 (7%) (p less than 0.01, p less than 0.01). Ventricular arrhythmias were evaluated in 155 patients with ambulatory electrocardiography. Significant ventricular arrhythmias of Lown's grade 2 to 4 were detected in 52 patients (34%). The incidence of significant ventricular arrhythmias of Lown's grade 2 to 4 was significantly higher in Period 1 (50%) and 2 (53%) than Period 3 (15%) (p less than 0.01, p less than 0.01). Thus symptoms and ventricular arrhythmias increased when the follow-up interval exceeded 10 years or in patients with large ventriculotomy.

Actuarial Analysis↗