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Biomedical subjects

R Matsuda

Publications and source records attributed to R Matsuda.

At least 37 records · Page 2Linked to original sources
PubMed1997

Measurement of uncertainty and discrimination limit in purity tests of drug quality.

Because of baseline fluctuation in an instrumental analysis, a purity test can overlook an illegitimate drug which contains an undesirable substance in more amount than a prescribed reference value. This paper proposes a probability theory to predict the lowest (average) signal, E[Y2], of the substance which can be discriminated from the (average) reference signal, E[Y1], with a high probability (here, 95%) in liquid chromatography (LC). The difference between the lowest signal and reference signal, E[Y2]-E[Y1] (> 0), is referred to here as a discrimination limit. The repetition of experiments to estimate the standard deviation of measurements is unnecessary for the probability theory, but a mathematical treatment of instrumental baselines (Fourier transform, etc.) is essential. The Monte Carlo simulation is carried out in which the reference signal and predicted signal for the discrimination limit are overlaid randomly 5000 times on real LC baselines. The result is satisfactory: the observed probability for the right answer is 94.3 or 94.8%; the theoretical one is 95%. The normality of the measurement distribution is examined for LC and capillary electrophoresis to verify the fundamental assumption of the proposed theory.

Chromatography, Liquid↗
PubMed1997

Unfused C2C12 mouse skeletal muscle cells express neurofilament 140K protein.

Expression of neurofilament 140K protein in C2C12 mouse skeletal muscle cells was studied. Immunofluorescence and immunoblot analyses revealed that NF140K was expressed at the proliferative stage and was colocalized with the muscle-specific intermediate protein desmin. As muscle cell differentiation proceeded, the number of NF140K-positive cells decreased whereas the number of cells expressing muscle-specific marker proteins such as sarcomeric myosin heavy chain and troponin-T increased. Down-regulation of NF140K and upregulation of a myogenic regulatory gene, the myogenin gene, started simultaneously. In differentiated muscle cell cultures, unfused cells residing between myotubes remained NF140K-positive. NF140K and desmin double-positive cells were also found in a primary culture of adult mouse skeletal muscle cells. The results suggest that NF140K may be a unique marker for uncommitted myoblasts.

Animals↗
PubMed1997

[A method for knowing the statistical reliability of instrumental measurements].

The precision of instrumental measurements, usually expressed by SD (standard deviation) or RSD (relative standard deviation) is of importance in a society as well as in a world of analytical chemistry. For example, the detection limit and confidence intervals of calibration lines which are based on the precision are inevitable for regulatory science. As is well-known in statistics, however, a small number of repetitive experiments (e.g., 5) lead to a poor reliability of the precision. This presentation shows a method (called FUMI theory) which can provide a precision from a single measurement of noise and signal without any repetitive measurements. The statistical reliability of the precision from the FUMI theory corresponds to that from the repetitive method of 50 experiments.

Statistics as Topic↗
PubMed1997

[Relationship between design of calibration and precision of measurement].

The method to estimate the confidence interval of calibration line was established. The method used the variance of measurement that can be predicted based on the background fluctuation. The validity of the estimated confidence interval was verified experimentally. The relationship between the calibration design and the analytical precision can be predicted with this method. The ill-designed calibration line deteriorates the trueness of the measurement as well as the precision.

Calibration↗
PubMed1996

Expression of neurofilament proteins in proliferating C2C12 mouse skeletal muscle cells.

Expression of neurofilament proteins, NF140K, NF68K, and NF200K, in C2C12 mouse skeletal muscle cells was studied. Immunofluorescence and immunoblot analyses revealed that NF140K was expressed in proliferating C2C12 cells and its localization was similar to desmin, a muscle-specific intermediate filament protein. NF140K became undetectable in C2C12 cells as muscle cell differentiation proceeded. Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analyses confirmed the expression of NF140K, NF68K, and NF200K in proliferating C2C12 cells. Sequences of the RT-PCR products of NF140K and NF68K were identical to that of authentic mouse NF140K and NF68K, respectively. The NF140K and NF68K mRNA were down-regulated during myogenesis in contrast to the up-regulation of mRNA encoding troponin-T. Furthermore, subcloned C2C12 cells, which express NF140K at a higher level, exhibited retarded myogenesis, i.e., delayed onset of myosin heavy chain synthesis and myoblast fusion. These results suggest that neurofilament proteins may play an inhibitory role in commitment of muscle cell differentiation. The presence of neurofilament proteins in skeletal muscle cells indicates that desmin, vimentin, and neurofilament proteins can be expressed in a single muscle cell.

Animals↗
PubMed1996

Measurement of plasma annexin V by ELISA in the early detection of acute myocardial infarction.

Annexin V is a calcium binding protein which is widely present in various cells and tissues. Using annexin V which we isolated and purified from human cardiac muscle, we prepared an anti-human cardiac annexin V monoclonal antibody. Identification of annexin V was made by means of partial amino acid sequences. An enzyme-linked immunosorbent assay (ELISA) was developed using this monoclonal antibody and anti-canine cardiac annexin V polyclonal antibody. With this ELISA, plasma annexin V concentration was measured in 196 normal healthy individuals, 23 acute myocardial infarction (AMI) patients who were hospitalized within 6 h after the onset of chest pain, and 130 patients with other diseases, including lung, liver and kidney disease. The plasma annexin V concentration in normal healthy individuals was 1.7 +/- 0.6 ng/ml (mean +/- S.D.), while that in AMI patients was elevated to 13.2 +/- 6.8 ng/ml (P < 0.0001) at the time of initial blood drawing, 3.2 +/- 1.5 h after onset of pain, and these values were higher than normal in 21 out of 23 cases (91.3%) of AMI. In all cases excepting 3, annexin V concentration immediately decreased after the onset of pain. The annexin V concentration in patients with old myocardial infarction, chest pain syndrome, valvular heart disease, lung disease and kidney disease was 1.8 +/- 0.8, 2.0 +/- 0.7, 1.7 +/- 1.1, 2.3 +/- 1.4 and 2.1 +/- 1.2 ng/ml, respectively, being within normal limits. The values in liver disease patients and trauma patients were 3.7 +/- 2.7 (P < 0.05) and 3.3 +/- 2.4 (P < 0.05) ng/ml, respectively, being slightly higher than that in normal healthy individuals.

Adult↗
PubMed1996

[Costal chondritis treated by resection of the entire costal arch].

A 68-year-old man had chronic pleural empyema, an alveolar fistula, and purulent perichondritis. The pericostal abscess extended beneath both sides of the costal arch and had a cutaneous sinus in the right hypochondrium, but it did not communicate with the cavity of the pleural empyema. In separated operations, the entire costal arch was resected and the alveolar fistula was closed with the pedunculate latissimus dorsal muscle. Neither tuberculosis bacilli nor tubercular granulomas were seen in resected specimens. The postoperative course was uneventful and the pericostal abscess healed, but the alveolar fistula recurred and the patient died of pneumonia 3 years and 6 months after the first surgery.

Aged↗
PubMed1995

Visualization of dystrophic muscle fibers in mdx mouse by vital staining with Evans blue: evidence of apoptosis in dystrophin-deficient muscle.

Degenerating muscle fibers in the skeletal muscle of mdx mice were visualized by vital staining with Evans blue. Evans blue injected intravenously stained only degenerating muscle fibers which were visible as blue fibers macroscopically and could also be seen as red fluorescent fibers microscopically. Evans blue-stained muscle fibers were either hypercontracted or degrading. Intact or regenerating muscle fibers in mdx mice and muscle fibers in B10 control mice were not stained with the dye. DNA isolated from Evans blue-stained fibers exhibited fragmentation to approximately 180 base pairs on agarose gel electrophoresis. Such DNA fragmentation was not found in DNA from unstained muscle fibers in mdx or B10 mice. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL)-positive myonuclei were also found in Evans blue-stained muscle fibers but not in unstained ones. These results indicate that degenerating muscle fibers in the mdx mouse show an increase in membrane permeability and undergo apoptosis. Vital staining with Evans blue is useful not only for distinguishing degenerating muscle fibers, but also for studying the degeneration process biochemically in dystrophin-deficient muscle. This method may also be useful for evaluating the therapeutic effects of drug administration, gene transfer, and myoblast transfer in the mdx mouse.

Animals↗
PubMed1995

Central diabetes insipidus caused by pituitary metastasis of lung cancer.

Tumor metastasis to the hypophyseal system has rarely been reported with either clinical or radiographic evidence. A 52-year-old woman presented with polydipsia, polyuria, and loss of appetite. She was diagnosed as having diabetes insipidus caused by pituitary micrometatasis of lung adenocarcinoma. After she had been treated with radiation therapy to the pituitary gland, the gland size was reduced as confirmed by magnetic resonance imaging, and her urine volume decreased. However, meningitis carcinomatosa appeared later. This was a rare case of secondary diabetes insipidus due to pituitary metastasis of lung cancer.

Adenocarcinoma↗
PubMed1995

[A case of bilateral multiple lung metastases from breast cancer successfully treated with carboplatin].

A 57-year-old female was admitted for right breast tumor. Modified radical mastectomy (Kodama method) was carried out. A prophylactic postoperative radiation was undertaken because of large tumor (T4b) and histologic metastasis to a Rotter's lymph node. At the end of irradiation, bilateral lung metastases were found on chest CT gram. The combination endocrine chemotherapy using MPA 600 mg and UFT 3 capsules p.o. daily and ADM 10 or 20 mg i.v. every two weeks was performed on an outpatient basis. As the lung metastases were increased four months later, carboplatin 150 mg i.v. was replaced with ADM. Four months later, the metastases almost disappeared on CT gram. These results suggested the possibility of one of the therapeutic options for metastatic breast cancer.

Adenocarcinoma↗
PubMed1994

Ectopic expression of c-kit in small-cell lung cancer.

Accumulating evidence suggests that c-kit plays an important role in the regulation of growth of at least 3 lineages of stem cells, while only very limited data are available on the development of human solid tumors. Our recent studies have shown that c-kit transcripts are expressed in a very restricted sub-set of human solid tumors such as small-cell lung cancer (SCLC). We have also conducted an immunohistological study on in situ localization of the c-kit protein in various human solid tumors as well as in corresponding fetal and adult normal tissues. No c-kit expression was detected in normal bronchial epithelial cells or pneumocytes in lung parenchyma of human fetal and adult specimens, indicating that the c-kit protein is aberrantly expressed in lung-cancer cells. We also found that significant chemotactic response as well as moderate in vitro cell growth occurred in SCLC cell lines upon addition of recombinant human stem-cell factor.

Adenocarcinoma↗
PubMed1994

Purification of cardiac annexin V from the beagle dog heart and changes in its localization in the ischemic rat heart.

We isolated and purified 35 kDa protein from the myocardium of the beagle dog and identified it to be annexin V from partial amino acid sequence determination. It was confirmed that anticanine cardiac annexin V rabbit polyclonal antibody, which was produced using the 35 kDa protein, cross-reacts with annexin V of the myocardium, lung, liver, kidney, and brain of the rat. The localization of cardiac annexin V and the effect of ischemia for 30-180 min in the rat were immunohistochemically studied with the use of the Langendorff perfusion heart. In the normal myocardium, annexin V, accompanied by cross-striation, was observed throughout the cell. In ischemia of 30 min, extracellular leakage of annexin V was observed with uneven staining in the cytoplasm. When the ischemic time exceeded 60 min, annexin V was observed in the cell membrane with a decrease of annexin V in the cytoplasm. Also, extracellular leakage of annexin V was observed prominently. In ischemia for 180 min, almost all the annexin V in the cytoplasm disappeared. These results suggest that the level of ischemia can be estimated from the changes in localization of annexin V.

Animals↗
PubMed1994

[Determination of organochlorine and organophosphorus pesticide levels in imported beef].

A simple and efficient cleanup method was established for capillary gas chromatographic determination of 12 organochlorine and 11 organophosphorus pesticides in beef. Extracted fat was subjected to silica gel dry column chromatography and further cleaned up by Florisil minicolumn chromatography for organochlorine pesticide analysis, while partitioning between n-hexane and acetonitrile of the extract and silica gel minicolumn chromatography were employed for the analysis of organophosphorus pesticides. Several samples (imported Australian beef) were analyzed by the proposed method. DDT was detected in 14 (0.01-0.10 ppm). BHC was found in 11 (0.003-0.031 ppm) and dieldrin was demonstrated in 2 (0.004 and 0.008 ppm). Heptachlors and the 11 organophosphorus pesticides investigated were not detected in any of the meat samples.

Animals↗
PubMed1994

[Determination of total bromine in foods by ECD gas chromatograph].

A determination method for total bromine that presents in various chemical forms in foods by gas chromatograph with ECD was investigated. Food samples were ashed with KOH at 600 degrees C for 2h and the residue was dissolved in water and filtered. The filtrate was acidified with sulfuric acid, and potassium permanganate solution was added to the solution. The liberated bromine was reacted with cyclopentanone and the product was extracted with hexane and quantified by gas chromatograph with ECD. Recovery of bromine by this method was more than 80% and the detection limit was lower than that of the conventional method. The total bromide in the samples prepared for the total diet study program was quantified by this method and the total intake of bromine was estimated. The total intake of bromine was 8-12 mg and about 20% of ADI (1 mg/kg/day).

Bromine↗
PubMed1993

Autonomous migration of human fetal skin fibroblasts into a denuded area in a cell monolayer is mediated by basic fibroblast growth factor and collagen.

Human fetal skin fibroblasts (TIG-3S) were found to migrate into a denuded area in a cell monolayer when cultured in both serum-depleted and serum-supplemented media, unlike adult-donor skin fibroblasts which migrated well only when cultured in serum-supplemented medium. Therefore, a series of experiments was carried out to determine whether autocrine factors are involved in their migration. The migration of TIG-3S cells in serum-depleted medium was suppressed by the addition of suramin, a factor with growth factor antagonist properties, which suggests that growth factors are important for cell migration. The suramin-induced inhibition was reversed completely by adding excess basic fibroblast growth factor (bFGF) to the culture medium and partially by platelet-derived growth factor (PDGF). Treatment with neutralizing anti-PDGF antibody did not suppress TIG-3S cell migration, whereas neutralizing anti-bFGF antibody did, which indicates that bFGF is an autocrine and PDGF a paracrine factor involved in cell migration. Next, an experiment was performed to ascertain whether the extracellular matrix is involved in TIG-3S cell migration. Monensin, an inhibitor of extracellular matrix secretion, inhibited cell migration, which was reversed by adding excess type I collagen, but not excess plasma fibronectin. In addition, further evidence for the involvement of collagen was provided by the observation that ethyl-3,4-dihydroxybenzoate, a specific inhibitor of collagen synthesis, suppressed cell migration. These results suggest that the autonomous migration of TIG-3S human fetal skin fibroblasts is mediated by bFGF and type I collagen, which they produce and secrete.

Antioxidants↗
PubMed1993

Expression of the c-kit protein in human solid tumors and in corresponding fetal and adult normal tissues.

The proto-oncogene c-kit encodes a transmembrane tyrosine kinase receptor that is thought to play an important role in hematopoiesis, spermatogenesis, and melanogenesis. We previously showed that the c-kit messenger RNA is preferentially expressed in small cell lung cancer and that its ligand, stem cell factor, is expressed in a broad spectrum of human cancers. Using anti-c-kit antisera raised against synthetic peptides, in situ localization of the c-kit protein in various human solid tumors as well as in corresponding fetal and adult normal tissues was studied by the ABC method. The results suggest that the c-kit gene products may be involved in the pathogenesis of a very restricted subset of human solid tumors such as small cell lung cancer. Interestingly, nuclear protein immunologically related to c-kit was found in both normal and neoplastic medullary cells of the adrenal gland.

Adrenal Gland Neoplasms↗
PubMed1993

[Analytical validation in compendium methods].

Well validated analytical methods should be used in official tests in order to eliminate the type I and II errors. The analytical validation is the process to confirm that the performance characteristics of a proposed analytical method is adequate for its intended use. The performance characteristics of an analytical method are validated by evaluating that observed analytical performance parameters of the analytical method meet the criteria required by a test to which the analytical method is applied. Basic rules in analytical validation were described in this report. The more strict rules for determination of the limit of detection and the test of precision than usually applied were proposed.

Chemistry Techniques, Analytical↗