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Biomedical subjects

M Nasu

Publications and source records attributed to M Nasu.

At least 271 records · Page 15Linked to original sources
PubMed1993

[Experimental study in Japanese monkeys with Helicobacter pylori infection].

Japanese monkeys were studied for one month from 6 months (short-term) after inoculation of Helicobacter pylori, and two years (long-term). In the short-term study, macroscopic and histological gastritis were observed for 5 infected monkeys. The gastritis score, the ammonia concentration in the gastric secretion and the level of serum antibody (IgG) were higher for the infected group than for the control. In the long term study, H. pylori was always recovered for 2 years in the infected group, and the gastritis score was higher than the control. The intracellular periodic acid-Schiff (PAS) positive substances in the infected group decreased than that of the control. The tall of pyloric gland in the infected group was significantly decreased on 6 months from 1.5 years. These results suggest that the Japanese monkey can be used as experimental model of H. pylori infection and that H. pylori can induce chronic active gastritis similar to human.

Animals↗
PubMed1993

[In vitro anti-microbial activity against H. pylori and clinical efficacy of various drugs].

The in vitro antimicrobial activity against H. pylori and clinical efficacy of various antibiotics and antiulcer drugs are summarized in this study. H. pylori highly sensitive to most of the beta-lactams and macrolides. Especially, amoxicillin and clarithromycin have satisfactory in vitro activity against H. pylori. The anti-ulcer drugs, sofalcon and plaunotol, used in Japan as mucosal protective agents, also have a weak activity against H. pylori with MIC50 12.5 micrograms/ml and MIC90, 50-100 micrograms/ml, while H2-receptor antagonists do not have in vitro activity. Efficacy of antibiotics as monotherapy for eradicating H. pylori is rather poor. The best results with monotherapy are obtained with clarithromycin and amoxicillin. Omeprazole monotherapy suppresses H. pylori infection but does not eradicate H. pylori. Combined therapy with omeprazole and amoxicillin have strong synergistic effects on the eradication of H. pylori (68.8%). Newly developed proton pump inhibitors, such as lansoprazole, E-3810 and their derivatives, showed strong in vitro activity against H. pylori suggesting that these drugs may be useful for the treatment of H. pylori infection.

Anti-Bacterial Agents↗
PubMed1993

A case report of allergic granulomatosis and angiitis (Churg-Strauss syndrome) with a review of the literature.

We report the case of a 67-year-old man with allergic granulomatosis and angiitis (AGA; Churg-Strauss syndrome) who developed nephrotic syndrome during his clinical course and demonstrated membranous nephropathy on renal necropsy by electron microscopy. Following the development of symptoms of bronchial asthma accompanied by eosinophilia and mononeuritis multiplex, transbronchial lung biopsy confirmed a diagnosis of AGA. The patient died of pneumonia and disseminated intravascular coagulopathy, but necropsy revealed severe tubulo-interstitial damage with neutrophilic infiltration and, in half of the glomeruli, mesangial proliferation with subepithelial dense deposits. This paper thus describes a rare case of AGA complicated by a secondary type of stage I membranous nephropathy.

Aged↗
PubMed1993

[Significance of urinary fibrin/fibrinogen degradation products (FDP) measured by highly sensitive ELISA method in various renal diseases].

In order to clarify the abnormalities of intra-glomerular coagulation and fibrinolysis in patients with various renal diseases, urinary fibrin/fibrinogen degradation products (FDP) have been examined by several methods. We established a highly sensitive new method of enzyme-linked immunosorbent assay for urinary FDP. The results were as follow: 1) The mean +/- SD of urinary FDP in normal subjects was 10.30 +/- 9.08ng/ml. 2) The urinary FDP levels in chronic glomerulonephritis, nephrotic syndrome and chronic renal failure patients were significantly higher than normal subjects, and the levels in SLE, Alport's syndrome patients were higher than normal subjects. 3) The urinary FDP levels were a little bit higher in the patients with proliferative glomerulonephritis than in chronic glomerulonephritis patients with minor lesion or membranous nephropathy. 4) There was significant correlation between urinary FDP and urinary protein in chronic glomerulonephritis, while there was no correlation in nephrotic syndrome. 5) There was no correlation between urinary FDP and intra-glomerular fibrin deposits examined by immunofluorescent study in chronic glomerulonephritis, while in nephrotic syndrome, there were high levels of urinary FDP in the positive fibrin deposits cases. These results suggested that the most of the part of excretion of the urinary FDP in chronic glomerulonephritis is associated with the filtration of blood FDP to urine through the glomerular basement membrane, while in the nephrotic syndrome cases the origin of urinary FDP is related to the filtration and/or the intra-glomerular coagulation abnormalities.

Adolescent↗
PubMed1993

Relative abundance and the relationships between aniline, phenol and catechol degraders in fresh water.

Relative abundance and relationships between aniline, phenol and catechol degraders were investigated in unpolluted and polluted fresh waters in Osaka prefecture, Japan. Phenol and catechol degraders were found more frequently compared to aniline degraders. The results indicate that these degraders were more abundant in polluted waters than in unpolluted waters. Aniline degraders isolated from the Ina River water showed a higher capability of degrading catechol than phenol. Analysis on sequence homology among these three kinds of degraders indicated a possible relationship between aniline degraders and certain strains of both catechol and phenol degraders.

Alcaligenes↗
PubMed1992

Spatio-temporal pattern of frequency representation in the auditory cortex of guinea pigs.

The spatio-temporal pattern of sound-evoked neural activity in the guinea pig auditory cortex was studied by optical recording with the aid of voltage-sensitive dye. Changes in light intensity induced by sounds at various frequencies and pressure levels were recorded with a 12 x 12 array of photodiodes. The amplitudes of the responses were displayed as sequential two-dimensional images. Tonotopical organization was found in two subdivisions of the auditory cortex, the anterior field (field A) and the dorsocaudal field (field DC). The frequency gradients in fields A and DC had a mirror-image relationship. This agrees with results obtained by the microelectrode technique. However, the tonotopic response observed in our study was transient. The focal activity that began in field A propagated in two directions; dorsally along the iso-frequency bands in field A, and caudally toward field DC. This suggests that the sound information processing initiates at field A, and its outputs are transferred to field DC, which is probably a hierarchically higher center.

Acoustic Stimulation↗
PubMed1992

Activation of human multidrug resistance-1 gene promoter in response to heat shock stress.

The multidrug resistance (MDR1) gene encodes a P-glycoprotein, which catalyzes the energy-dependent efflux of anticancer agents. Various environmental stresses including heat shock can induce the expression of endogenous MDR1 genes. In order to study the regulatory mechanisms of MDR1 gene expression, we have established human cancer KB cell lines which could stably integrate bacterial chloramphenicol acetyltransferase (CAT) gene driven by various lengths of the MDR1 promoter. Kst-6 has an integrated plasmid, pMDRCAT1, containing the human MDR1 promoter of -2 kilobases. The MDR1 gene promoter contains a typical heat shock element (HSE) motif located -152 bp to -178 bp from the initiation site. Heat shock at 45 degrees C for 90 min significantly induced CAT activity in Kst-6 cells. Northern blot analysis showed a 4-5 fold increase in CAT mRNA levels in Kst-6 cells. Deletion analysis of the MDR1 promoter demonstrated that the induction of CAT activity was observed in Kxh-14 cells containing a HSE-deleted MDR1 promoter construct, pMDRCAT7. However, further deletion analysis showed that heat shock could not induce CAT activity in Khp-1 cells containing -76 approximately +121 base sequence of the promoter, suggesting that a new heat shock responsible element was located at between -136 and -76. Gel shift assay showed that the heat shock factor (HSF) could bind to the HSE motif located at -152 bp to -178 bp in the MDR1 promoter. We also found that one distinct DNA-protein complex formed specifically within the MDR1 promoter region -99 to -66 was not significantly increased, but relatively more stabilized under mild denaturing condition in the nuclear extract of heat-shocked cells. In our present assay system, activation of the MDR1 promoter in response to heat shock appears to be mediated through both a new heat shock responsive element and MDR1 specific transcription factor.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Protein degradation by the phosphoinositide-specific phospholipase C-alpha family from rat liver endoplasmic reticulum.

A 60-kDa protein homologous to phosphoinositide-specific phospholipase C-alpha was purified to apparent homogeneity on sodium dodecyl sulfate-polyacrylamide gel electrophoresis from the rough endoplasmic reticulum of rat liver through three sequential chromatographies on DEAE Toyopearl 650, AF-heparin Toyopearl 650M, and TSK gel G3000SW. The purified protein was monomeric, with an M(r) of 60,000. Eight types of protein were further separated from the 60-kDa protein and named ER60A-ER60H according to the order of their elution from a TSK gel DEAE-5PW column. They were essentially identical in terms of immunochemical properties and the NH2-terminal amino acid sequence. The partial amino acid sequence of ER60F showed homology to that of phosphoinositide-specific phospholipase C-alpha. ER60A-ER60H showed no phosphoinositide-specific phospholipase C activity. However, ER60A-ER60H catalyzed cleavage of themselves and the endoplasmic reticulum proteins protein disulfide-isomerase and calreticulin. Proteolytic degradation was inhibited by p-chloromercuribenzoate. These results indicate that ER60A-ER60H comprise a group of endoplasmic reticulum resident proteins and show thiol group-related proteolytic activity.

Amino Acid Sequence↗
PubMed1992

Hematological problems during the use of cardiac assist devices: clinical experiences in Japan.

Hematological changes occurring during use of left ventricular assist devices (LVADs) were evaluated in 3 patients suffering from postcardiotomy cardiogenic shock. LVAD treatment ranged from 6 to 9 days. During the procedure, no anticoagulants were used in the first two cases, while in the third case, a protease-inhibiting agent, nafamostat mesilate (FUT-175), was used. In the first two cases without any anticoagulants, fibrinopeptide A (FPA) and thrombin-antithrombin III complex (TAT) increased markedly over the course of LVAD treatment, suggesting the excessive activation of the coagulatory system. The fibrinolytic system also became activated during LVAD treatment as was indicated by a marked increase in FDP-D-dimer and alpha 2 plasmin inhibitor-plasmin complex (PIC). Continual decreases observed in Factor XII and prekallikrein indicate that the coagulofibrinolytic activation occurring during LVAD treatment is presumably the result of contact activation of these factors due to interaction of blood with the internal surface of the LVAD. In the third case with FUT-175, both coagulation and fibrinolysis were successfully maintained at minimum levels as was demonstrated by the extremely low levels of these molecular markers. There was also no significant consumption of any contact factors. FUT-175 looks promising as an anticoagulant during the use of cardiac assist devices.

Aged↗
PubMed1992

[A case of tracho-bronchial aspergillosis complicated with acute myeloblastic leukemia].

A 59-year-old male was admitted to our hospital in Jan. 1991 with complaints of general malaise and palpitation. Laboratory findings on admission showed anemia, thrombocytopenia and leukopenia consisted of 2.0% myeloblasts with Auerbodies. The bone marrow study showed granuloid hyperplasia with 45.5% myeloblasts. The diagnosis of acute myeloblastic leukemia (M1) was made. After BHAC-AMP therapy, he obtained complete remission. However, he complained of fever and cough, and his chest X ray film showed a focal infiltrative shadow in the right upper lung field. Antibiotics for bacteria and fungus were administered and the abnormal shadow improved in a week. However, as he had hemosputum, the bronchoscopic examination was performed, and multiple ulcers covered by yellow-white tissue were revealed on the wall of the trachea and bilateral main bronchi. Biopsy specimens obtained by transbronchial biopsy showed bronchial aspergillosis. Though intravenous infusion and inhalation of amphotericin B were effective for aspergillosis, he had a relapse of the leukemia and died in autumn, 1991.

Aspergillosis↗
PubMed1992

[Cytomegalovirus pneumonia treated with ganciclovir and intravenous CMV-hyperimmune globulin: case report].

A 60-year-old male with adult T-cell leukemia (ATL) complained of fever, cough and dyspnea, after anti-leukemic chemotherapy. Chest X-ray film showed a diffuse interstitial shadow, and cytomegalic inclusions and cytomegalovirus (CMV) antigen were detected in the bronchoalveolar lavage specimen and sputum. The diagnosis of CMV pneumonia was made, then ganciclovir and intravenous CMV-hyperimmune globin was administered. Although CMV pneumonia was improved with the treatment, the patient died of ATL. There was no cytomegalic inclusions in the lung but in the adrenal at autopsy. The combination therapy of ganciclovir and intravenous CMV-hyperimmune globulin is considered to be effective for CMV pneumonia.

Cytomegalovirus↗
PubMed1992

[A case of penicillin-resistant pneumococcal pneumonia and penicillin-binding proteins of the clinical isolates].

We experienced a case of a 68-year-old female with beta-lactam antibiotics including penicillin G (PCG) resistant pneumococcal pneumonia, leading to death during the treatment with ceftizoxime (CZX). We reported the clinical course and the mechanism of resistance of isolated bacteria. The present case is the first in Japan. Minimum inhibitory concentration (MIC) against Streptococcus pneumoniae 88031 isolated from the present case was 1.56 micrograms/ml in PCG and 6.25 micrograms/ml in CZX, showing PCG resistance. The isolate was no beta-lactamase production and serotype 23. The drug susceptibility in 34 strains of S. pneumoniae which were isolated as causative organism of respiratory infection in our department in 1988 was studied. PCG high resistant strain (PCG MIC greater than 1.56 micrograms/ml) was only observed in the isolated strain in the present case and PCG low sensitive strains (PCG MIC = 0.1-1.0 micrograms/ml) were observed in 3 strains (8.8%). The CZX resistance was observed only in the present case. The detection of penicillin-binding protein (PBP) and binding affinity of beta-lactam antibiotics were studied using PCG sensitive strain, S. pneumoniae type I (preserved strain PCG MIC = 0.05 micrograms/ml, CZX MIC = 0.1 micrograms/ml, CMX MIC = 0.025 micrograms/ml) and PCG resistant strain, S. pneumoniae 88031. The result obtained showed that PBP1a, detected in sensitive strain type I, was not detected in resistant strain 88031 and PBP1b was increased. The binding of 14C-PCG of PCG resistant strain to PBP1b showed lower affinity for CZX and CMX than PCG sensitive strain.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Examination of antithyroid effects of smoking products in cultured thyroid follicles: only thiocyanate is a potent antithyroid agent.

We studied the antithyroid action of cigarette smoking products (nicotine, cotinine, and thiocyanate) in the physiological culture system of porcine thyroid follicles. Iodide uptake, iodine organification, de novo thyroid hormone formation, and iodide efflux were measured in the presence of 0-200 mumol/l nicotine, cotinine, or potassium thiocyanate. Nicotine and cotinine did not inhibit iodide transport or thyroid hormone formation. Thiocyanate concentrations equivalent to serum levels of smokers showed three independent antithyroid actions: (i) inhibition of iodide transport, (ii) inhibition of iodine organification, and (iii) increased iodide efflux. Inhibition of iodide transport by thiocyanate was competitive with iodide and independent of TSH concentration. Thiocyanate did not inhibit TSH mediated cAMP production or Na+K+ ATPase activity, a sodium pump for iodide transport. When 50 mumol/l thiocyanate was added 2 h after incubation with iodide or when 1 mumol/l thiocyanate was added from the beginning of incubation, iodine organification was inhibited without changing iodide transport. De novo thyroid hormone formation was clearly inhibited by 50 mumol/l thiocyanate. Thiocyanate increased iodide efflux although the degrees of iodide efflux by 10 mumol/l and 100 mumol/l thiocyanate did not differ significantly. In summary, thiocyanate, a product of smoking, has three independent antithyroid activities. The data of iodide transport kinetics suggest that thiocyanate can be an antithyroid agent particularly in iodine deficiency.

Animals↗
PubMed1992

Immunological studies on opportunistic infection and the development of adult T-cell leukemia.

Three patients with opportunistic infection preceding adult T-cell leukemia (ATL) are presented: a 66-year-old woman with cryptococcosis and Pneumocystis carinii pneumonia, a 46-year-old man with Pneumocystis carinii pneumonia, and a 55-year-old woman with cryptococcosis. Although, at the first examination, the first two had smoldering type ATL and the third case was an HTLV-I carrier, all three developed overt ATL 14-16 months after the onset of opportunistic infection. It is considered that there is immune suppression already present in HTLV-I carriers and in patients with smoldering ATL, and opportunistic infection is predictive of the development of ATL.

Aged↗
PubMed1992

Increase in peripheral natural killer cell activity in patients with autoimmune thyroid disease.

Changes in the activity and number of natural killer (NK) cells in peripheral blood in patients with autoimmune thyroid disease were examined. NK activity was measured in a 4-hr 51Cr-release assay and the number of NK cells was analyzed with FITC-conjugated monoclonal antibodies by use of an automated flow cytometer. NK activity in patients with untreated Graves' disease (n = 25, 39.7 +/- 13.5%, P less than 0.05) and Hashimoto's thyroiditis (n = 18, 41.0 +/- 14.2%, P less than 0.05) was high compared to the activity in non-pregnant controls (n = 61, 32.6 +/- 15.0%). NK activity in patients with postpartum Graves' thyrotoxicosis (n = 11, 48.6 +/- 18.9%) was markedly increased compared to the activity in non-pregnant controls (P less than 0.01) and in postpartum controls (n = 29, 33.8 +/- 15.2%, P less than 0.05), although the mean ages of each group did not differ significantly. Moreover, NK activities in the thyrotoxic state were significantly higher than those in the euthyroid state in the same patients with postpartum Graves' thyrotoxicosis or with postpartum destructive thyrotoxicosis. The number of CD16 positive cells increased in patients with postpartum Graves' thyrotoxicosis. However the number of CD16 and CD57 positive cells were normal in all other groups of patients. These results indicate that an increase of NK activity is associated with exacerbation of autoimmune thyroid disease both in Hashimoto's thyroiditis and in Graves' disease and suggest that NK cells might have an important role for the control of disease activity in autoimmune thyroid disease.

Adult↗
PubMed1992

[Changes of differential leukocyte counts during pregnancy and in the postpartum period].

We examined differential leukocyte counts in peripheral blood from 177 pregnant and postpartum women with an automated leukocyte differential system, and compared them with those of 52 nonpregnant and non-postpartum women. The proportions and numbers of neutrophils and monocytes increased throughout pregnancy, returned to the non-pregnant levels within one month after delivery, and decreased transiently at 4 or 7 to 10 months postpartum. The proportions and numbers of lymphocytes and eosinophils decreased throughout pregnancy, and increased transiently at 4 to 10 months postpartum and one month postpartum, respectively. The proportion and number of basophils decreased during pregnancy and one month postpartum, and those of large unstained cells (LUC) decreased in the third trimester of pregnancy, and both returned to the non-pregnant levels at 4 months postpartum and within one month postpartum, respectively. These data indicate that differential leukocyte counts change dynamically during pregnancy and after delivery until 1 year postpartum.

Adult↗
PubMed1992

[A case of idiopathic interstitial pneumonia with cytomegalovirus infection].

A 67-year-old female was admitted to our hospital because of fever, dry cough, and exertional dyspnea. The findings of chest X-ray, transbronchial lung biopsy, and bronchoalveolar lavage were compatible with the diagnosis of idiopathic interstitial pneumonia. Prednisolone was administered and she felt better for a while. However, she developed severe dyspnea, and marked diffuse infiltrative shadows were observed on chest X-ray after 3 months of steroid therapy. In spite of pulse therapy with methylprednisolone, she died of severe respiratory failure. Complement fixation test and IgG antibody enzyme immunoassay for cytomegalovirus were positive, but there was no change the titers between admission and death. IgM antibody was negative. The lung findings at autopsy compatible with usual interstitial pneumonia and diffuse alveolar damage, moreover, cytomegalovirus infection was observed. We consider that recurrent cytomegalovirus pneumonia had been present due to secondary immunodeficiency caused by administration of steroid hormones.

Aged↗