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Biomedical subjects

A Kawashima

Publications and source records attributed to A Kawashima.

At least 163 records · Page 9Linked to original sources
PubMed1992

Hypoxia-induced ANP secretion in subjects susceptible to high-altitude pulmonary edema.

We investigated the effects of acute hypoxia (10% O2) on plasma level of atrial natriuretic peptide (ANP) and pulmonary hemodynamics in five subjects with a history of high-altitude pulmonary edema (HAPE). Plasma renin activity and plasma levels of aldosterone, epinephrine and norepinephrine were also measured. The plasma ANP levels in HAPE-susceptible subjects rose significantly in response to 10% O2 (from 34.8 +/- 5.4 to 51.4 +/- 7.3 pg.ml-1; P less than 0.05), not associated with any increase in either atrial pressure. Compared with six control subjects, the rise of ANP level was greater in HAPE-susceptible subjects (16.6 +/- 4.4 vs 3.9 +/- 1.2 pg.ml-1; P less than 0.05). There was a significant positive correlation between the rise of ANP level and the increase of pulmonary arterial pressure. No significant difference was observed in any of other hormonal responses to acute hypoxia between the two groups. We interpret these results as indicating that the ANP secretory response to acute hypoxia in HAPE-susceptible subjects, which is not mediated by an increase in atrial pressure, may be greater than that in nonsusceptible subjects in association with a greater pressor response of pulmonary circulation.

Adult↗
PubMed1992

Collagenous and basement membrane proteins of chordoma: immunohistochemical analysis.

Tissue localization of collagenous and basement membrane proteins in the extracellular matrix of five sacro-coccygeal chordomas and human fetal notochords was examined immunohistochemically to assess the implications for the histogenesis and histological diagnosis of chordoma. Human fetal notochords and conventional chordomas both exhibited basement membrane proteins (such as type IV collagen and laminin) and type VI collagen on the surfaces of cellular cords. Type II collagen, a main structural protein of cartilage, was also present in both tissues. In the chordomas, however, type II collagen was not so widespread as it was in the notochords, and the predominant collagenous protein was type I. In contrast, an altered deposition of these proteins was noticed in a recurrent tumour which, histologically, showed considerable atypia and eventually metastasized to the liver. The characteristic cartilage-type and basement membrane proteins disappeared and unusual collagen types, such as types III and V, appeared in the stroma. The results further support the notochordal origin of chordoma and suggest that the immunohistochemistry of collagenous and basement membrane proteins may be a helpful criterion for the histological diagnosis and prediction of the biological aggressiveness of chordomas.

Adult↗
PubMed1992

Comparison of helical and serial CT with regard to three-dimensional imaging of musculoskeletal anatomy.

To test the hypothesis that helical computed tomographic (CT) scans provide three-dimensional images as good as or better than those provided by serial CT, two objects were used to study the effects of helical CT: an angled cylindrical bone phantom and a human cadaveric femur specimen with a simulated fracture 1 mm wide. Both objects were immersed in a water bath, and a series of helical and serial CT scans were obtained with various parameters. Volumetric rendering was applied to the resultant data sets to create three-dimensional images, which three radiologists reviewed in a blinded manner to rate their fidelity, accuracy, and diagnostic usefulness. As expected, the images obtained with thin collimation and small intersection spacing or slow table movement were considered superior. Helical and serial CT data acquired with similar parameters were similar in quality, but helical CT is approximately five times faster than serial CT; hence, it is possible to use thinner collimation and obtain more sectional data with helical CT.

Femur↗
PubMed1991

Pulmonary Aspergillus chest wall involvement in chronic granulomatous disease: CT and MRI findings.

Pulmonary Aspergillus infection in patients with chronic granulomatous disease tends to involve the chest wall and consequently carries a high mortality rate. We report the findings of computed tomography (CT) and magnetic resonance imaging (MRI) in three such cases. One patient underwent both CT and MRI, one, CT only, and one, MRI only. In all three, both CT and MRI demonstrated pulmonary consolidations with direct extension to the adjacent chest wall. In both patients who were examined by CT, scans revealed permeative osteolytic changes of adjacent rib or spine compatible with osteomyelitis. In both patients who were examined by MRI, adjacent chest wall involvement was depicted on T1-weighted images and showed increased signal intensity on T2-weighted images. In one of these patients, the chest wall lesion was well defined on T2-weighted images, an appearance compatible with abscess. Epidural extension was demonstrated on MRI in the other patient, who later developed paraparesis. We suggest that CT and MRI have a complementary role in evaluating chest wall invasion by pulmonary Aspergillus infection in chronic granulomatous disease.

Adolescent↗
PubMed1991

Werner's syndrome combined with quintuplicate malignant tumors: a case report and review of literature data.

The authors report a case of Werner's syndrome complicated by quintuplicate malignancy, and review the literature data. Four malignancies occurred synchronously in the case: osteosarcoma of the left distal tibia, malignant melanoma of the left plantar region, gastric cancer, pulmonary coin lesion. The osteosarcoma and malignant melanoma were treated by below-knee amputation and the gastric cancer by palliative surgery; the pulmonary coin lesion did not respond to cisplatin chemotherapy. It was difficult to treat the multiple primary cancer curatively, and patient died of respiratory failure due to a brain tumor seven months after surgery. The postmortem examination revealed a papillary carcinoma of the thyroid gland and a leiomyosarcoma of the lung. In some cases of Werner's syndrome, attention should be paid to the concurrent occurrence of multiple primary malignant neoplasms.

Humans↗
PubMed1991

CT of posterior mediastinal masses.

This article presents an algorithmic approach to the evaluation of posterior mediastinal masses seen with computed tomography (CT). CT remains the study of choice, since it not only can be used to help confirm the presence of these masses, but it also helps define the (a) location and extent of the lesion, (b) adjacent organ involvement, or (c) vascular involvement. Causes of posterior mediastinal masses include esophageal lesions, congenital or acquired vascular lesions, foregut cysts, intrathoracic goiters, mediastinal pseudocysts, fat-containing tumors, adenopathy, neurogenic tumors, infectious spondylitis, and vertebral tumors. From the CT appearance of the lesion, one can often distinguish among the various masses and identify their origin and cause. This information enables patient triage and therapy to be expedited and, in most cases of posterior mediastinal masses, allows a correct diagnosis to be made solely on the basis of the CT examination.

Blood Vessels↗
PubMed1990

Malignant pleural mesothelioma: CT manifestations in 50 cases.

Malignant pleural mesothelioma, a rare and usually fatal neoplasm that is associated with asbestos exposure, is being encountered with increasing frequency. Pretreatment CT findings from 50 patients with malignant pleural mesothelioma are illustrated. Pleural thickening was found in 46 (92%) of the 50 patients, thickening of the pleural surfaces of the interlobar fissures in 43 (86%), pleural calcifications in 10 (20%), and pleural effusions in 37 (74%). The volume of the involved hemithorax varied appreciably. Contractions of the involved hemithorax was noted in 21 (42%) of 50 patients and contralateral mediastinal shift in seven (14%). Disease beyond the parietal pleura was found in the chest wall (nine patients), mediastinum, lymph nodes, and diaphragm.

Adult↗
PubMed1990

Immune status in two brothers with Omenn's syndrome: no discernible chimerism on FACS analysis using a monoclonal antibody specific for a maternally restricted HLA antigen.

Sequential immunologic examinations, including lymph node biopsies, in two brothers with clinical characteristics of Omenn's syndrome are presented in this study. Although the number of circulating T cells with mature phenotype (OKT3+, TCR1+) was within normal range, the lymphocyte proliferative response to mitogens was poor. Examinations of the lymph nodes revealed marked lymphoid depletion associated with eosinophilic infiltration and reticular cell proliferation. Over the clinical course of 5 months, circulating T cells also mostly disappeared. Thymic hypoplasia was noted at autopsy. Although intrauterine graft-versus host disease (GVHD) has been hypothesized as being the pathogenetic mechanism in this syndrome, maternal lymphocytes circulating in these patients were not identified either by karyotype and HLA typing or by highly sensitive FACS analysis and immunohistochemical studies using a monoclonal antibody, HLA-A9, specific for a maternally restricted HLA antigen, Aw24. In conclusion, the familial occurrence and the absence of maternal chimerism might be the essential features of Omenn's syndrome which should be differentiated from fetal GVHD.

Antibodies, Monoclonal↗
PubMed1990

Radiation-induced malignant pleural mesothelioma.

Malignant pleural mesothelioma is a rare and usually fatal disease. Its association with asbestosis is well recognized. The authors report a case of malignant pleural mesothelioma that developed 30 years after the patient underwent radiotherapy for breast cancer. This appears to be the first such case reported in the radiology literature.

Breast Neoplasms↗
PubMed1990

[A study of albumin degradation in kidney lysosomes in the nephrotic rat].

Majority of albumin, filtered through the glomerulus, is absorbed and degraded in the renal proximal tubule. Hypoalbuminemia in nephrotic syndrome may occur because of increased albumin loss into the urine and also the increased rate of albumin degradation in the tubule cells. The present study is carried out in an attempt to elucidate the role of kidney lysosomes on albumin degradation in nephrotic rat. Nephrotic rat was induced by intraperitoneal injection of puromycin aminonucleoside and lysosomes were prepared from rat kidney cortex by Percoll gradient centrifugation of Ca2(+)-treated postnuclear supernatant. In fact, immunoblot analysis of SDS polyacrylamide gel electrophoresis of kidney lysosomal proteins revealed the presence of immunoreactive protein bands, corresponding to the endogenous albumin as well as small-molecular degradative intermediates. Albumin content of kidney lysosomal proteins, which was 15.4 +/- 1.5 mg/g protein in control rat, was measured by densitometer to be increased more than tenfold in nephrotic rat. These results suggest that kidney lysosomes play an important role of albumin degradation especially in nephrotic syndrome.

Animals↗
PubMed1989

Plasma levels of atrial natriuretic peptide under acute hypoxia in normal subjects.

To investigate whether the acute hypoxia can be a stimulus for atrial natriuretic peptide (ANP) secretion, plasma levels of ANP were determined under three different hypoxic conditions in six normal subjects. During 15% O2 breathing for 10 min, no significant change in plasma ANP level was observed. Severe hypoxia induced by 10% O2 breathing increased the mean pulmonary arterial pressure (Ppa) by 11.6 mm Hg within 10 min (P less than 0.01), accompanying a slight but significant rise in plasma ANP level of pulmonary artery (PA) from 24.3 +/- 5.3 to 28.2 +/- 4.6 pg/ml (P less than 0.05). There was a tendency for the ANP level of PA to rise under hypoxic hypobaria at 515 Torr for 10 min, followed by a decrease of that level during 100% O2 breathing under hypobaric condition. These changes, however, still remained in the normal range. No significant changes were observed both in right atrial pressure and in pulmonary capillary wedge pressure under any of the three hypoxic conditions. From these results we conclude that ANP can be released in response to the elevation of Ppa caused by acute hypoxia in normal subjects, but the changes in plasma ANP level may be too small to play a significant physiological role in hemodynamic responses to acute hypoxia.

Acute Disease↗
PubMed1989

Hemodynamic responses to acute hypoxia, hypobaria, and exercise in subjects susceptible to high-altitude pulmonary edema.

To verify the presence of the constitutional abnormality implicated in the pathogenesis of high-altitude pulmonary edema (HAPE), we evaluated the hemodynamic responses to hypoxia, hypobaria, and exercise in HAPE-susceptible subjects (HAPE-S). HAPE-S were five males with a history of HAPE. Five healthy volunteers who had repeated experiences of mountain climbing without any history of altitude-related problems served as controls. HAPE-S showed much greater increase in pulmonary vascular resistance index (PVRI) than the control subjects, resulting in a much higher level of pulmonary arterial pressure (Ppa), under both acute hypoxia of 15% O2 (Ppa = 29.0 +/- 2.8 vs. 17.8 +/- 0.3 Torr, P less than 0.05) and acute hypobaria of 515 Torr (32.3 +/- 2.8 vs. 19.1 +/- 0.8 Torr, P less than 0.05). Also, PVRI in HAPE-S exhibited a tendency to increase even during light exercise with supine bicycle ergometer (50 W), whereas PVRI in the control subjects significantly decreased, so that HAPE-S showed a greater increase in Ppa (delta Ppa = 16.0 +/- 1.5 vs. 4.9 +/- 1.1 Torr, P less than 0.001) and a greater decrease in arterial oxygen tension (17.8 +/- 4.7 vs. 5.6 +/- 1.7 Torr, P less than 0.05). We thus conclude that HAPE-S have a constitutional abnormality, which can be evaluated at low altitude, in the pulmonary circulatory responses to possible causative factors of HAPE such as hypoxia, hypobaria, and exercise.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

New platelet aggregation inhibitors.

From a cultured broth of Streptomyces matensis A-6621, we isolated three new platelet aggregation inhibitors designated as PI-080, PI-085 and PI-087. The structures of these compounds were established by spectral and chemical methods.

Animals↗