Biomedical subjects
Publications and source records attributed to F Sakuma.
We measured the invariant mass spectra of electron-positron pairs in the target rapidity region of 12-GeV p+A reactions. We have observed a significant difference in the mass spectra below the omega meson between p+C and p+Cu interactions. This difference indicates that the spectral shape of mesons is modified at normal nuclear-matter density.
The initial presentation of a patient with Wegener's granulomatosis was indistinguishable from that of Henoch-Schönlein purpura. The patient presented with skin purpura and pulmonary hemorrhage followed by purpura in the colon. The diagnosis of this patient at that time was Henoch-Schönlein purpura. With time, massive lesions in the sinus and those with cavities in the lung became apparent, and a specimen obtained from the sinus massive lesion was disclosed to be granulomatous inflammation. Retrospectively, the proteinase 3 antineutrophil cytoplasmic antibody turned out to be strongly positive in her stored serum from the time of the initial presentation.
OBJECTIVE: To investigate the significance of the presence or absence of the thymus in the development of pulmonary hypertension (PH) following monocrotaline (MCT) administration, the degree of MCT-induced PH (MCT-PH) in athymic nude (F344/N Jcl-rnu) rats was compared with that in their euthymic (rnu/+) littermates. METHODS: Histopathological studies of the lung in terms of interstitial edema, congestion, thickening of the alveolar wall, inflammatory cell infiltration and degeneration of arteries were performed by staining with hematoxylin-eosin (HE), elastin van Gieson and Masson's trichrome. The medial wall thickness of the small pulmonary arteries and the weight ratio of the right ventricular free wall (RV) to that of the left ventricle plus septum [RV/(LV + S) weight ratio] were used as indices of the degree of PH. Toluidine blue staining was performed to estimate the number of the mast cells in the lung interstitium. RESULTS: Interstitial edema was significantly severer in MCT- injected euthymic rats than in MCT-injected athymic nude rats (p < 0.01); in contrast, the thickening of the alveolar wall was severer in MCT-injected athymic nude rats than in MCT-injected euthymic rats (p < 0.05). The degree of MCT-PH, as determined by the medial wall thickness of the small pulmonary arteries and RV/(LV + S) weight ratio in MCT-injected athymic nude rats, was significantly severer than in MCT-injected euthymic rats (p < 0.05 and p < 0.01, respectively). The number of mast cells was significantly greater in MCT-injected athymic nude rats than in MCT-injected euthymic rats (p < 0.01). The degree of the medial wall thickness of the small pulmonary arteries was significantly correlated with RV/(LV + S) weight ratio (p < 0.05) as well as with the number of mast cells in MCT-injected rats. CONCLUSIONS: Athymic nude rats developed severer PH than euthymic rats along with a greater number of mast cells and severer histopathological changes, such as thickening of the alveolar wall. Mast cell proliferation was considered to play a pivotal role in the development of PH in MCT-PH.
A method is presented to determine simultaneously the temperature distribution and the intrinsic emissivities of a cavity surface when radiance distributions along the cavity wall for two wavelengths are given. The intrinsic emissivity and reflection characteristics are assumed not to depend on position on the cavity wall. The intrinsic emissivity and reflection characteristics giving the smallest difference between calculated temperature distributions for the two wavelengths are found. The values found and thus the temperature distributions are verified to be close to the true ones. The method is examined on a cylindrocone by a simulation and applied to radiance temperature distributions measured on a commercially available double cone.
Gicerin is a cell adhesion molecule in the immunoglobulin (Ig) superfamily and is expressed abundantly during development in the nervous system. It has homophilic cell adhesion activity and also has heterophilic binding activity with NOF (neurite outgrowth factor) and mediates neurite extension. There are two isoforms of gicerin, one with a short (s-gicerin) and the other with a longer cytoplasmic domain (l-gicerin). We have reported that s-gicerin possesses stronger activities than l-gicerin during cell aggregation, in NOF-binding, and in neurite extension. In this study, we established cell lines which expressed a mutant-gicerin whose cytoplasmic domain was deleted and we compared the above three biological activities of the mutant-gicerin with those of s- and l-gicerin. We found that the mutant-gicerin retained all these activities, but the activities were weaker than those of s-gicerin and almost the same as those of l-gicerin. We concluded that the cytoplasmic domain of gicerin is not essential for optimal adhesive activities of gicerin, but might be involved in the regulation of its activities.
The effect of administering prostaglandin E1 (PGE1) on the extent of monocrotaline (MCT)-induced pulmonary hypertension and cytokine production [interleukins (IL) 1 and 6 and tumor necrosis factor (TNF)] by macrophages during MCT induction of pulmonary hypertension was studied. Right ventricle/left ventricle plus septum weight ratios (RV/LV + S) were used as an index of the development of pulmonary hypertension. Administering PGE1 at a dose of 0.2 mg/kg/day for 4 weeks reduced significantly the RV/LV + S ratio from 0.428 +/- 0.070 to 0.243 +/- 0.059 (p < 0.01) and decreased the production of these cytokines: IL-1, from 4.675 +/- 3.558 to 1.800 +/- 0.722 units; IL-6, from 0.322 +/- 0.121 to 0.060 +/- 0.039 units; and TNF, from 0.578 +/- 0.369 to 0.004 +/- 0.004 units. In another series of experiments, a significant reduction of the RV/LV + S ratio was noted for only 1 week when we administered PGE1 immediately after the injection of MCT. We confirmed that histopathologic improvements of lungs were noted by administering 0. 2 mg/kg PGE1 for 4 weeks. In another experiment, PGE1 at a concentration of 2 microg/ml suppressed a rise in the cytosolic Ca2+ concentration of lipopolysaccharide-stimulated peritoneal macrophages of rats in vitro, suggesting that PGE1 suppressed cytokine production by macrophages through the suppression of the Ca2+ influx. These results suggest that administering PGE1 may be effective in the treatment of some forms of pulmonary hypertension in humans.
Clinical study has been conducted to evaluate the efficacy of chemotherapy with docetaxel and cisplatin in six patients with advanced non-small cell lung cancer. Treatment schedule consisted of docetaxel 60 mg/m2 and cisplatin 80 mg/m2 on day 1 and repeated every 4 weeks. Eligible patients had histologically proven locally advanced or metastatic non-small cell lung cancer, PS < or = 2, age < or = 74, normal hematological, hepatic and renal functions and informed consent in writing. Six patients have been included; all were males, median age 64 (range 47-74), histology; adenocarcinoma 4, squamous cell carcinoma 2, stage III B 4, stage IV 2. Among these 6 patients, 3 PR (50%) were observed. Neutropenia was the most common adverse event (83%). The lowest granulocyte counts were most frequently seen on day 9.4 (range: 6-14). Non hematologic adverse events included alopecia (6 cases), general fatigue (5 cases), anorexia (5 cases) and emesis (3 cases). These events were recovered rapidly with no therapy. The results suggest that combination chemotherapy of docetaxel and cisplatin will be effective and safe under careful observation.
Experimental pulmonary hypertension (PH) was induced by a single injection of monocrotaline (MCT), a pyrrolizidine alkaloid extracted from Crotalaria spectabilis. The effect of beraprost sodium, a stable prostacyclin analogue, on the development of MCT-induced PH in rats was studied. Chronic administration of beraprost sodium at a dose of 30 micrograms/kg/day initiated on the same day as MCT injection decreased the degree of PH determined by weight ratio of right ventricular free wall to that of left ventricle plus septum depending on the duration of administration. Although the injection of prostaglandin E1 (PGE1) at a dose of 200 micrograms/kg/day initiated 1 week after MCT injection did not decrease the degree of PH significantly, beraprost sodium administration at doses of 30 and 100 micrograms/kg/day decreased the degree of PH significantly. The cytoprotective effect of beraprost sodium against endothelial cell (EC) damage is believed to be involved in inhibiting development of PH in MCT-injected rats. The amounts of cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) produced by alveolar macrophages decreased in accordance with the inhibiting effect of beraprost sodium on development of PH, indicating that beraprost sodium inhibited the development of PH in MCT-injected rats not only through its effect of vasodilation and anti-platelet aggregation in pulmonary circulation but also through its antiinflammatory effects.
The role of activated cells determined by staining with bromodeoxyuridine (BrdU) and the role of alveolar macrophages as a source of cytokines were investigated in monocrotaline (MCT)-induced pulmonary hypertension (PH) in rats. BrdU was mainly incorporated by mononuclear cells; their number increased strikingly prior to the development of PH. Cytokines such as interleukin (IL)-1, IL-6 and tumor necrosis factor were produced during the development of PH. The amount of IL-6 showed significant correlation (p < 0.05) with the number of BrdU-positive cells, which, in turn, correlated with the extent of PH. These results indicate that BrdU-positive cells and cytokines produced by alveolar macrophages may play an important role in the pathogenesis of MCT-induced PH in rats.
We administered human interleukin (IL)-6 to rats to examine whether it is implicated in the development of pulmonary hypertension (PH). The rats injected with IL-6 developed PH as determined by the weight ratio of the right ventricle to the left ventricle+septum. This ratio decreased with the appearance of IgG anti-human IL-6 antibody. Histologically we observed in the lungs, luminal occlusion of small muscular arteries, capillaries filled with fibrin thrombi, and localized hemorrhage. IL-6 increased the number of platelets, and the number of platelets correlated with the extent of PH. Thus, it seems likely that (IL-6) is involved in the formation of PH in this model.
Clinical and laboratory studies on a total of 211 of infants and young children admitted to the National Santa Cruz General Hospital for various types of diarrhoea during 1991-1992 are described. A peak cluster was observed in children aged 1 year of which 80 per cent were acute diarrhoea and the remaining 20 per cent were prolonged or chronic diarrhoea. The major bacterial pathogen was enteropathogenic Escherichia coli. Other bacterial pathogens such as Klebsiella, Shigella, Cholera, etc., were detected. Ascaris, E. histolytica, Giardia and Ankylostoma were also detected. Many of the patients infected with enteropathogenic E. coli showed elevated serum titre to these bacterial antigens. Most of the detected E. coli and Shigella revealed that they were resistant to ampicillin, trimethoprim/sulfamethoxazole, and erythromycin, and some were resistant to gentamycin and chloramphenicol in vitro tests. It was difficult to make a diagnosis by clinical diagnosis alone for cholera of the el Tor Ogawa type. The detection of faecal leukocytes seems to be an useful predictor for diagnosis of invasive diarrhoea with mucobloody stools. Faecal pH and erythrocytes did not seem to be reliable diagnostic predictors. Fourteen cases (7 per cent) died of diarrhoeal disease. Many of them had complications with marked dehydration, hypoelectrolytaemia, malnutrition and infections, and rapid deterioration within 10 days despite rehydration therapy. Timely rapid rehydration and restoration of electrolytes followed by suitable management of complications are necessary.
We experienced three patients who have collagen diseases with respiratory failure accompanied by hyponatremia. They were one systemic lupus erythematosus patient with interstitial pneumonia, one rheumatoid arthritis patient with acute pneumonitis, and one dermatomyositis patient with pulmonary fibrosis and organizing pneumonia. In all 3 patients, hyponatremia appeared along with a decrease in arterial O2 partial pressure (PaO2) and the hyponatremia tended to improve when the PaO2 increased after inhalation of oxygen, even though their respiratory failure were not improved. In dermatomyositis patient, serum Na levels were over-corrected after increase in PaO2. The serum and urine osmolality, serum antidiuretic hormone (ADH) levels and clinical pictures demonstrated a presence of inappropriate secretion of ADH (SIADH) in all 3 cases when hyponatremia and hypoxia appeared. A close association between hyponatremia and hypoxia observed in 3 patients strongly suggested that their SIADH were associated with hypoxia since SIADH could be demonstrated by hypoxia. Therefore, it is important to realize that hypoxia-induced hyponatremia will be promptly corrected to hypernatremia by an oxygen inhalation, which could cause a lethal central pontine myelinolysis.
The following points on polyarteritis nodosa (PN) were presented: definition, difference between PN and vascular lesions in other collagen disease, diagnostic criteria, clinical symptoms and laboratory findings, clinical type, histologic stage, therapy and three case reports with two active vasculitis and one scarred vasculitis.
A questionnaire survey of blood donors at Santa Cruz General Hospital, Bolivia, showed that while there were no seropositive cases of syphilis, HBsAg, and HIV, the prevalence of Chagas' disease was very high (23%) among the 225 blood donors who responded to this questionnaire. Actual cases of Chagasic seropositive blood being used for blood transfusion were seen, including the urgent need for a program for Chagas' disease in Bolivia. From the results of this study, it is recommended that for blood donors from South American countries, the presence/absence of Chagas' disease should be confirmed.
Anticardiolipin antibodies (aCL) were studied in relation to pulmonary hypertension (PH) in 22 patients with mixed connective tissue disease (MCTD) or systemic lupus erythematosus (SLE). The mean pulmonary arterial pressure (mPAP) values were similar in the 12 MCTD and 10 SLE patients: 26 +/- 11 and 25 +/- 11 mm Hg, respectively. However, the frequency of PH was higher in SLE (60%) than in MCTD patients (33%). The titers of aCL were significantly higher in SLE (38 +/- 27 IU/ml) than in MCTD (17 +/- 7 IU/ml; p < 0.02). Two SLE patients with high titers of aCL had multiple cerebral infarction and transverse myelitis, and deep vein thrombosis, respectively. A significant correlation between the titers of aCL and mPAP was observed in patients with MCTD (p < 0.05), but not in patients with SLE.
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