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Biomedical subjects

M Hayasaka

Publications and source records attributed to M Hayasaka.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Pulmonary malignant fibrous histiocytoma presenting as hemothorax].

A 39-year-old woman, who suffered from a sudden episode of severe left-sided back pain, was admitted to our hospital because of hemothorax. Chest CT scans revealed a mass extending from the left hilum to the posterior thoracic wall. The mass occluded the left pulmonary artery at the left main bronchus. Examination of a frozen section of a specimen obtained during a thoracotomy showed a sarcomatous tumor. A left pneumonectomy was then performed. Microscopic examination of a specimen revealed that the tumor was composed of spindle cells with cellular atypia and mitosis forming fascicles and storiform arrays. Malignant fibrous histiocytoma (storiform-pleomorphic pattern) was diagnosed. Chemotherapy was carried out six times during the year after surgery. No recurrence of the tumor has been seen during 20 months of follow-up.

Adult↗
PubMed1996

[Clinical usefulness of trans-brachial angiography for abdominal diseases].

Trans-brachial angiography for abdominal disease has several advantages for the patient. For example, the patient can walk immediately following angiography and can return home or eat in the sitting position after examination. We performed trans-brachial angiography on 451 cases of abdominal disease from June 1992 to March 1995. The purpose of performing angiography in 215 of these cases was examination only, while that in the remaining 236 cases was embolization of liver tumor. Four hundred and five cases were used for the study of safety and accuracy, and the remaining 46 cases as well as another 51 cases of trans-femoral angiography were used for the study of technical difficulty. Based on these experience, we have concluded that trans-brachial angiography for abdominal disease is highly useful, safe and accurate, and can provide significant advantages for patients requiring abdominal angiography.

Adult↗
PubMed1995

Invasive thymoma with hypogammaglobulinemia spreading within the bronchial lumen.

A case of invasive thymoma with hypogammaglobulinemia showing endobronchial growth is presented. A 63-year-old man was admitted for evaluation of a left hilar mass. A biopsy specimen obtained from the intraluminal mass, which occluded the left upper division bronchus, was highly suggestive of thymoma. The laboratory tests were almost normal except for hypogammaglobulinemia. The tumor was resected with the left upper lobe. Most of the tumor invaded the left upper lobe, and grew into the bronchi. The case was diagnosed histologically as invasive thymoma spreading within the bronchial lumen.

Agammaglobulinemia↗
PubMed1995

Salt-sensitive hypertension in transgenic mice overexpressing Na(+)-proton exchanger.

Essential hypertension is one of the most common diseases that exacerbate the risk of cardiovascular or cerebrovascular attacks. Although the etiology of essential hypertension remains unclear, recent investigations have revealed that an enhancement of Na(+)-proton (Na(+)-H+) exchange activity is a frequently observed ion transport abnormality in hypertensive patients and animal models. To test the hypothesis that increased Na(+)-H+ exchange causes hypertension, we produced transgenic mice overexpressing Na(+)-H+ exchanger and analyzed their Na+ metabolism and blood pressure. Urinary excretion of water and Na+ was significantly decreased in transgenic mice, and systolic blood pressure was elevated after salt loading. The impaired urinary excretion of Na+ suggested that the Na(+)-H+ exchanger overexpressed in the renal tubules increased reabsorption of Na+, which caused a blood pressure elevation by Na+ retention after excessive salt intake. Our results demonstrate that overexpression of Na(+)-H+ exchanger can be a genetic factor that interacts with excessive salt intake and causes salt-sensitive blood pressure elevation.

Animals↗
PubMed1994

Monoclonal antibody-based enzyme-linked immunosorbent assay for glycyrrhizin and its aglycon, glycyrrhetic acid.

Monoclonal antibodies (MoAbs) specific for glycyrrhetic acid (GA) were prepared and characterized. Obtained MoAbs (AGA-1, AGA-3, and AGA-6) reacted with GA dose-dependently, but not with glycyrrhizin (GL), carbenoxolone, and steroids. Next, an enzyme-linked immunosorbent assay (ELISA) system using AGA-1 was established. The standard curve showed good linearity between 0.01 and 1000 ng/ml of GA, and the detection limit was 5 pg/ml. Recovery, and intra- and interassay variations of this assay system was satisfactory. GL was also measurable quantitatively after acid-hydrolysis of the samples. The developed ELISA system would be useful to determine GL and GA in biological samples or drugs as an alternative method to high performance liquid chromatography (HPLC).

Antibodies, Monoclonal↗
PubMed1994

Phenthoate metabolites in human poisoning.

Five metabolites were detected in the plasma and urine of a patient following ingestion of the organophosphate insecticide, phenthoate. Intact phenthoate was detected only in gastric lavage fluid. After methylation of acidic extracts of plasma and urine, phenthoate acid, demethyl phenthoate, demethyl phenthoate oxon acid, demethyl phenthoate S-isomer, and demethyl phenthoate acid S-isomer were identified with synthesized phenthoate analogues by gas chromatography and gas chromatograph-mass spectrometry. The main metabolites were phenthoate acid and demethyl phenthoate oxon acid. Although demethyl phenthoate oxon acid was a significant metabolite, no phenthoate oxon, phenthoate oxon acid or demethyl phenthoate oxon were detected. If the oxon was formed in the patient, it may have been rapidly degraded by carboxylesterase or glutathione transferase to demethyl phenthoate oxon acid.

Chromatography, Gas↗
PubMed1994

[Clinicopathological study of 4 patients with idiopathic BOOP, interstitial type on chest X-ray].

We studied four patients with idiopathic Bronchiolitis Obliterans Organizing Pneumonia (BOOP) diagnosed by open lung biopsy. All of four presented with acute onset and a rapid course with progressive dyspnea. Their chest X-ray films showed ground-glass opacities with reduced volumes in the bilateral lower lobes. Their chest CT revealed marked increases in lung density with air bronchograms. Radiologically, it was difficult to distinguish these cases from patients with acute interstitial pneumonia. Histologically, in the uninflated specimens, the collapse of alveoli and alveolar spaces filled with foamy macrophages and proteinous exudates were observed. The organizing tissues were present predominantly in the alveolar ducts, but varied in extent among cases. We considered the reduced lung volumes on chest X-ray films and the marked increases in lung density on chest CT to reflect alveolar collapse. Proliferation of type II pneumocytes was remarkable in all cases, but reactivity to antisurfactant protein-A antibody staining was decreased in the collapsed alveoli. It was suggested that the alveolar collapse was caused, in part, by decreased pulmonary surfactant in addition to obstruction of the alveolar ducts. The rapid responses to of these patients corticosteroid therapy may be due to improvement of the alveolar collapse.

Adult↗
PubMed1993

Myogenin gene disruption results in perinatal lethality because of severe muscle defect.

Myogenin is a member of the basic helix-loop-helix (bHLH) gene family and converts multipotential mesodermal cells to myoblasts. The four members of the myoD family show unique spatio-temporal expression patterns and therefore may have different functions during myogenesis. Here we inactivate the myogenin gene in order to understand its role in myogenesis. Homozygous mutations are lethal perinatally owing to the resulting major defects in skeletal muscle. The extent of disorganization of muscle tissue differs in three regions. In the latero-ventral body wall, most cells, including myogenic cells, disappear and there is rapid accretion of fluid. In the limbs, cells of the myogenic lineage exist, but they are severely disrupted, and some of them are mono-nucleate with properties of myoblasts. In contrast, there are many axial, intercostal and back muscle fibres to be seen, although fibres are mainly disorganized and Z-lines are not present in most myofibrils. These findings are evidence that myogenin is crucial for muscle development in utero and demonstrate that other members of the myogenic gene family cannot compensate for the defect.

Animals↗
PubMed1993

Upstream region of the myogenin gene confers transcriptional activation in muscle cell lineages during mouse embryogenesis.

Myogenin, one of the MyoD-related factors containing basic-helix-loop-helix motifs, is transcriptionally activated in skeletal muscle lineages in somites and limb buds during embryogenesis. In an attempt to understand regulatory mechanisms which govern transcriptional activation of the myogenin gene, transgenic mice bearing the lacZ gene driven by the upstream region of the myogenin gene were generated. Stereoscopic visualization of LacZ-positive cells of these transgenic mouse embryos revealed that the upstream region of the myogenin gene conferred its transcriptional activation in cells of the skeletal muscle lineages in somites, limb buds, and visceral arches. Moreover, transient LacZ expression in newly formed somites in addition to its strong activation in myotomal regions of mature somites with a rostro-caudal gradient raised the possibility that myogenin is transcriptionally activated in immature somites before myotome formation.

Animals↗
PubMed1993

[A case of rheumatoid arthritis with obstructive bronchiolitis appearing after D-penicillamine therapy].

A 56-year-old woman was diagnosed as having rheumatoid arthritis in 1983. She was treated with D-penicillamine in addition to non-steroid anti-inflammatory drugs from April 1990. In August she noticed shortness of breath on exertion. Chest X-ray films showed bilateral interstitial shadows, and chest CT revealed bilateral multiple wedge-shaped shadows extending distally. Blood gas analysis showed severe hypoxemia and pulmonary function tests demonstrated decreased %VC, FEV1.0% and diffusion capacity. Open lung biopsy specimens revealed infiltration of inflammatory cells and fibrotic change in the walls of bronchioles. She was diagnosed as having obstructive bronchiolitis. Corticosteroid therapy and discontinuation of D-penicillamine therapy stopped the progression of her symptoms, and she was discharged on corticosteroid maintenance treatment and home oxygen therapy.

Arthritis, Rheumatoid↗
PubMed1991

The stem cells of a primordial germ cell-derived teratocarcinoma have the ability to form viable mouse chimeras.

A euploid testicular teratocarcinoma line, STT-3, has been established from a tumor spontaneously occurring in the testis of a 129/Sv-ter male. Developmental ability of the STT-3 stem cells was tested by injecting these cells into mouse blastocysts. The frequency and the extent of chimerism were examined in mid-gestational fetuses and in live-born mice. STT-3 stem cells form viable chimeras at a high rate and differentiate into normal tissues. This is the first reported testicular teratocarcinoma-derived stem line with a proven capacity to form viable chimeric mice upon injection into the blastocysts.

Animals↗
PubMed1991

A stable cellular marker for the analysis of mouse chimeras: the bacterial chloramphenicol acetyltransferase gene driven by the human elongation factor 1 alpha promoter.

We have developed a method of marking of mouse cells by means of transfection of a foreign gene. The transgene chosen here was the plasmid pEF321CAT which contains the bacterial chloramphenicol acetyl transferase (CAT) gene linked to the promoter region of the human polypeptide chain elongation factor 1 alpha (hEF1 alpha) gene. Evaluation of the plasmid pEF321CAT as a cellular marker for mouse cells involved intensive examination of a transgenic mouse carrying pEF321CAT. The CAT gene was expressed in all tissues examined, demonstrating that the hEF1 alpha promoter was active in a wide range of mouse cells. The plasmid itself did not exert any harmful effect on the normal development of mice, and the CAT activity was immunohistologically detectable on sectioned tissues by the use of anti-CAT serum. When the plasmid was transferred into embryonal carcinoma (EC) cells and embryonic stem (ES) cells, the CAT gene was also found to be expressed constantly irrespective of their differentiation. These results demonstrated that the plasmid pEF321CAT can be used as a reliable and feasible cellular marker that would distinguish unequivocally the cells of each of genotype in chimeric tissues.

Aging↗
PubMed1988

Embryonic stem cell-mediated transfer and correct regulation of the chicken delta-crystallin gene in developing mouse embryos.

To study regulation of delta-crystallin expression during ontogeny, we transferred the gene from chicken into developing mouse embryos by first transforming an embryonic stem (ES) cell line of mouse and then producing chimaeric embryos by combining them with normal mouse embryos. Using this technique, genes were transferred into a variety of developing mouse tissues with high efficiency. Two delta-crystallin gene constructs were used: the wild-type gene with 2200 bp of the 5' flanking sequence, shown to be lens-specific in an assay using cultured mouse cells, and a mutant gene with 51 bp of the 5' flanking sequence, lacking the sequence required for expression in lens cells. Five independent lines carrying the former and two lines carrying the latter were employed in producing chimaeras. In the chimaeric embryos having the wild-type gene, delta-crystallin was expressed in the lens and in specific regions of the primitive central nervous system (CNS) as is seen in embryonic expression in the chicken. In adult mouse chimaeras also, expression was restricted to the lens and the CNS, in the pyramidal neurones of the piriform cortex and the hippocampus. delta-crystallin expression in these tissues is due to proper transcriptional regulation, since no expression was observed when chimaeras were produced with the ES lines carrying the mutant gene. The experimental results reported here demonstrate the advantage of ES-cell-mediated gene transfer in the study of embryonic gene regulation, because a number of gene constructs and chromosomal sites can be analysed shortly after embryo manipulation without requiring gene transmission to the next generation.

Animals↗
PubMed1987

Segmental wall motion abnormalities in dilated cardiomyopathy: hemodynamic characteristics and comparison with thallium-201 myocardial scintigraphy.

This study assessed the hemodynamic characteristics of segmental wall motion abnormality of the left ventricle in patients with dilated cardiomyopathy (DCM) and its relation to the thallium-201 (TI-201) myocardial scintigraphy (MPI). Left ventriculograms and MPI in 23 patients were analyzed by the use of quantitative indexes of regional wall motion and TI-201 uptake based on a mean and a standard deviation of 13 normal subjects. Relative normokinesis in our definition was more frequently seen in the inferior wall than in the anterior wall (p less than 0.01). In contrast, severe asynergy was more often seen in the anterior wall than in the inferior wall (p less than 0.01). There were 11 patients who had relative normokinesis and asynergy together. By means of the index of wall motion, the DCM patients were divided into two groups, one with segmental wall motion abnormality (SWMA) and another with diffuse wall motion abnormality (DWMA). The DWMA group had higher left ventricular end-diastolic pressures (p less than 0.05) and the tendency of large left ventricular end-diastolic volumes than the SWMA group. There was a rough correlation (r = 0.58) between the quantitative indexes of TI-201 uptake and wall motion at the same region of the left ventricle. Thus, the nonuniformity of the left ventricular wall motion was recognized in the patients with DCM and more increased preload was shown in the patients with DWMA than in the group with SWMA. Further, the regional asynergy may be related to the localized fibrosis within the left ventricle in DCM, considering the result that the worse TI-201 uptake was roughly accompanied by the more severe asynergy.

Adult↗