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Biomedical subjects

M Nishimura

Publications and source records attributed to M Nishimura.

At least 703 records · Page 39Linked to original sources

Diagnostic significance of dopamine estimation using plasma and urine in patients with adrenal and renal insufficiency, renal transplantation and hypertension.

Although free and conjugated dopamine (DA) constitute most of the plasma and urine catecholamine pool, the diagnostic significance of DA estimation for the evaluation of illness is not clear. We evaluated the clinical utility of DA estimation by measuring free and conjugated DA in patients with various illness. Patients with adrenal insufficiency did not show decreases in DA concentrations but did demonstrate reductions in free and conjugated plasma adrenaline (Ad). Patients with established stage of essential hypertension exhibited decreased plasma concentrations of free and conjugated DA, although they were hyperadrenergic. In patients with chronic renal insufficiency and failure, the free DA concentration in the urine decreased depending on the severity of renal impairment. Conversely, plasma concentrations of conjugated DA are higher in patients with chronic renal failure than in normal subjects. The high plasma concentrations of conjugated DA decreased dramatically following hemodialysis and renal transplantation. Urinary free DA excretion increased markedly following renal transplantation. In conclusion, the estimation of the free and conjugated DA in plasma and urine is clinically useful for the diagnosis of adrenal insufficiency, essential hypertension, and renal insufficiency and failure. It also can be used to monitor the effectiveness of hemodialysis and renal transplantation.

Adrenal Insufficiency↗

Experimental infection of SPF piglets with porcine reproductive and respiratory syndrome (PRRS) viruses isolated from two farms.

Porcine reproductive and respiratory syndrome (PRRS) viruses were isolated from pig samples obtained from two farms characterized by an increased number of stillbirth and high mortality in new-born piglets (farm A), and respiratory distress with high mortality in weaning and growing pigs (farm B) in 1993, respectively. When primary specific pathogen-free piglets, 5-day-old or 13-day-old, were experimentally inoculated with the isolates, they showed clinical signs of depress, anorexia, pyrexia, diarrhea, sitting posture and periocular edema. Rate of the weight gain was reduced in the inoculated piglets compared with the non-inoculated pig. There were no apparent differences in clinical signs between the piglets inoculated with the virus samples derived from farms A and B. Microscopically, the most prominent changes observed in experimentally inoculated piglets were interstitial pneumonia, nonpurulent myocarditis and catarrhal lymphnoditis post inoculation day (PID) 28. Viruses were recovered from tissues collected from the inoculated piglets on PID 7 or 28. Furthermore, the viruses were continuously recovered from the sera from PID 7 to PID 28. Antibodies measured by indirect immunofluorescence assay to PRRS virus were first detected in sera on PID 14, and the antibody titer rose to 1:1280 on PID 28.

Animals↗

The effects of applied vs auto-PEEP on local lung unit pressure and volume in a four-unit lung model.

BACKGROUND: The application of positive end-expiratory pressure (PEEP) and maintenance of increased mean airway pressure (MAP) has been associated with improved oxygenation in adult respiratory distress syndrome. Recently, attention has been directed toward elevating MAP by establishing auto-PEEP when ventilating with an inverse inspiratory to expiratory ratio in opposition to applied PEEP. We theorized that FRC distribution and local lung unit end-expiratory pressure (EEP) would be different when equal levels of PEEP were established by applying PEEP or by producing auto-PEEP. METHODS: Using a four-chamber lung model with each chamber having a different time constant (TC), we applied equal levels of applied PEEP (I:E ratio 1:3) and auto-PEEP (I:E ratio 3:1) and evaluated local lung unit EEP and end expiratory lung volume (EELV). RESULTS: During all trials with applied PEEP, local lung unit EEP was equal to applied PEEP, whereas during auto-PEEP local EEP differed (p < 0.01). At a tracheal auto-PEEP level of 12.7 cm H2O, the lung unit with the longest TC (slow lung unit) had an EEP of 15.8 cm H2O, while the shortest TC unit (fast lung unit) had an EEP of 10.1 cm H2O (p < 0.01). Similarly, local EELVs were more maldistributed with auto-PEEP than with applied PEEP. At a tracheal PEEP level of 12.7 cm H2O, the EELV increase in the slow lung unit with auto-PEEP was 1,054 mL vs 918 with applied PEEP (p < 0.01), whereas the fast lung unit's EELV increase with auto-PEEP was 142 mL compared with 212 mL with applied PEEP (p < 0.01). CONCLUSION: Comparing equal levels of the auto-PEEP with applied PEEP, a greater maldistribution of local lung unit EEP and EELV was established with the auto-PEEP. During auto-PEEP, the greatest EEP and EELV occurred in the slow lung unit, and the lowest EEP and EELV developed in the fast lung unit.

Adult↗

Strain difference of the adrenal cortex between A/J and SM/J mice, progenitors of SMXA recombinant inbred group.

The recombinant inbred (RI) mouse group is useful for genetic analysis of a phenotype which is regulated by multiple loci. The female adrenal cortex was compared histologically to detect the strain differences between A/J and SM/J for the purpose of genetic analysis of adrenocortical morphogenesis using the SMXA RI group constructed between A/J and SM/J. Clear morphological differences were found in the zona reticularis and X zone in addition to the significantly small body and adrenal weights in SM/J. The z. reticularis was markedly thicker in SM/J than in A/J and the X zone was constituted of vacuolated cells in A/J and non-vacuolated cells in SM/J. The genetic control of these morphological traits was analyzed using SMXA RI strains. The results suggest that the thickness of the z. reticularis may be controlled by single locus and that vacuolation of the X zone by 3 different loci between A/J and SM/J.

Adrenal Cortex↗

Identification and minisatellite linkage analysis of SMXA recombinant inbred strains of mice by DNA fingerprinting.

SMXA recombinant inbred (RI) strains of mice were produced by systematic inbreeding from the F2 generation of a cross between two progenitor inbred strains, A/J and SM/J, which differ considerably with respect to many characteristics, and consists of 28 inbred strains. In this study, we investigated the applicability of DNA fingerprinting with M13 phage DNA to the identification of these closely related strains. DNA fingerprints of the SMXA RI strains and their progenitors, SM/J and A/J, showed strain-specific patterns, with the same banding patterns within each strain. Linkage analysis by using strain distribution patterns of minisatellite loci with 108 genetic markers containing microsatellites, biochemical and immunological marker genes allowed 23 minisatellite loci to be assigned to 11 chromosomes. The results suggested that DNA fingerprinting with M13 phage DNA is applicable not only for strain identification but also for genetic monitoring of RI strains on almost all chromosomes.

Animals↗

Effect of repeated administrations of neomycin on the neuromuscular functions and the enhancement of d-tubocurarine action in mice.

Effects of repeated s.c. treatments with 50 mumol (approx. 31 mg)/kg/day of neomycin for 10 or 15 days were examined in mice. There were no significant differences between saline and neomycin treatment groups in the motor coordination assessed by rota-rod test and traction test. On tension recordings, an in vitro addition of d-tubocurarine inhibited the twitch tensions evoked by the nerve stimulations in both cases of saline or neomycin treatment. Neomycin treatments shifted the concentration-response curve between twitch tension and d-tubocurarine to the left, dependently on its injection days. These results suggest that repeated treatments with neomycin enhance the inhibitory effect of d-tubocurarine on the neuromuscular transmission in mice without eliciting motor incoordination and muscle relaxation.

Animals↗

Refractory anemia with an excess of blasts developed into overt leukemia with leukothrombocytosis.

A 72-year-old man with refractory anemia with an excess of blasts developed overt leukemia with leukothrombocytosis. Hematological and physical findings closely resembled those of an accelerated or blastic phase of chronic myelocytic leukemia. The cytogenetic anomaly of i(17q) was observed during the course. The present case is suggestive of the diversities of myelodysplastic syndromes (MDS), including relationships between MDS and myeloproliferative disorders (MPD) and acute leukemia.

Aged↗

Effect of octreotide on ventilation and dyspnea sensation in a patient with cirrhotic hypoxemia.

We examined the long-term effects of octreotide, a somatostatin analogue, on ventilation in a case of cirrhotic hypoxemia. After daily administration of octreotide for one month, the dyspnea on exertion was notably ameliorated, although pulmonary gas exchange was only slightly improved. The octreotide therapy reduced the hypoxic ventilatory drive, which may be one reason for the relief of the dyspnea sensation.

Chronic Disease↗

A questionnaire survey on the use of dust respirators among lead workers in small scale companies.

In order to find out whether dust respirators are properly used among lead workers in small scale manufacturing companies of lead pigments and stabilizers, a questionnaire survey was carried out for 141 lead workers. The questionnaire consisting of 7 items of questions including selection, use, maintenance, storage and instruction of respirators was distributed to all 141 workers. This survey revealed that 22% of the total workers wore unauthorized dust respirators, and that 73% used a knitcover. Instruction by health supervisors of how to use and where to store the respirators was found to be effective for inspection of valve and a proper place to store dust respirator. However, the result that significantly large percentage of workers used the knitcover following the health supervisors' instruction can be taken to indicate that health supervisors should be given more precise information on deteriorated face-sealing of the respirator facepiece with the knitcover.

Chi-Square Distribution↗

[Gene technology to overproduce the enzymes useful as diagnostic reagents].

We cloned the genes encoding the microbial enzymes described below and discussed the possibility as the diagnostic reagents: Creatinase(CR) and sarcosine oxidase(SOX) are useful for a diagnostic measurement of creatinine in combination with creatinase. Bacillus sp. B-0618 produces both CR and SOX enzymes when grown in the presence of an inducer, choline chloride. We cloned these two genes encoding CR and SOX by using recombinant DNA techniques. We found that the SOX-encoding gene is located upstream from the CR-encoding gene. When the CR- and SOX-encoding genes were independently inserted into the pUC-based vector and introduced into Escherichia coli, the transformants produced 15.5-fold more CR and 50-fold more SOX than Bacillus sp. B-0618, respectively, in the absence of the inducer. Although the Bacillus SOX is a flavoprotein, we created an FAD-free SOX by site-directed DNA mutagenesis. The mutant protein no longer expressed the SOX activity. Cholesterol esterase is useful for a diagnostic measurement of total cholesterol in combination with cholesterol oxidase. We cloned a gene encoding the cholesterol esterase enzyme. When the gene was introduced into the non-producing Streptomyces strain, the transformant produced the cholesterol esterase. Phospholipase A2 is a diverse family of enzymes that hydrolyze the sn-2 fatty acyl ester bond of phosphoglycerides producing free fatty acids and lysophospholipids. The enzymes are present in pancreatic juice and in the venoms of snakes and bees, where they serve digestive functions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Effect of supplemental oxygen on exercise performance in patients with chronic obstructive pulmonary disease and an arterial oxygen tension over 60 Torr].

The effects of supplemental oxygen on exercise tolerance and exercise-induced dyspnea in patients with chronic obstructive pulmonary disease (COPD) and an arterial oxygen tension (PaO2) over 60 Torr were studied. Twenty two men who met the criteria stated above underwent three 6-minute walk tests while breathing room air, compressed air, or supplemental oxygen, in a double-blind randomized crossover fashion. The distance walked in 6 minutes was recorded, and the degree of dyspnea during exercise was quantified on a visual analog scale with a questionnaire that had eight descriptors of dyspnea sensations. The distances walked were: 535 +/- 27 (SE) for room air, 545 +/- 27 for compressed air, and 563 +/- 23 m for O2. These data indicate a significant placebo effect and an effect of supplemental oxygen. The data regarding dyspnea also indicated both a significant placebo effect and an effect of supplemental oxygen, but the descriptors for the placebo effect differed from those for the effect of supplemental oxygen. Patients in whom arterial desaturation (below 88%) developed during exercise with compressed air benefited from supplemental oxygen: they walked significantly farther and their dyspnea scores for two of the eight descriptors were significantly lower. However, patients in whom arterial desaturation (below 88%) did not develop during exercise with compressed air did not benefit from supplemental oxygen. Nonetheless, the degree of dyspnea during exercise with compressed air could not be used to predict the beneficial effect of supplemental oxygen.

Aged↗

[Changes of tympanic temperature by stellate ganglion block].

The effects of stellate ganglion block (SGB) on the temperature of tympanic membrane were determined clinically. Thirty patients received SGB with 8 ml of 1 % mepivacaine. The tympanic temperature was measured using radiation non-contact tympanic membrane thermometer before and after administration of SGB for 30 min on the side where SGB was given. Before SGB the tympanic temperature was 37.29 +/- 0.08 degrees C, and there was no difference in the readings between the two sides. The tympanic temperature dropped significantly 5 min after SGB and reached its lowest value of 36.90 +/- 0.08 degrees C 15 min later. This drop persisted for more than 30 min after SGB. The fact that therapeutic effect of SGB is partly due to vasodilation and improvement in blood flow to the affected region was demonstrated, but these effects in internal carotid arterial system have not yet been studied in detail. Tympanic temperature has been proposed as a valid index of brain temperature in man. The mechanism of brain cooling has been suggested that countercurrent heat exchange takes place between carotid and jugular blood flow. Therefore the result of the study suggests that SGB could enhance an increase in the brain blood flow.

Adolescent↗

Cytosolic aconitase participates in the glyoxylate cycle in etiolated pumpkin cotyledons.

Two different aconitases are known to be expressed after the germination of oil-seed plants. One is a mitochondrial aconitase that is involved in the tricarboxylic acid cycle. The other participates in the glyoxylate cycle, playing a role in gluconeogenesis from stored oil. We isolated and characterized a cDNA for an aconitase from etiolated pumpkin cotyledons. The cDNA was 3,145 bp long and capable of encoding a protein of 98 kDa. N-terminal and C-terminal amino acid sequences deduced from the cDNA did not contain mitochondrial or glyoxysomal targeting signals. A search of protein databases suggested that the cDNA encoded a cytosolic aconitase. Immunoblotting analysis with a specific antibody against the aconitase expressed in Escherichia coli revealed that developmental changes in the amount of the aconitase were correlated with changes in levels of other enzymes of the glyoxylate cycle during growth of seedlings. Further analysis by subcellular fractionation and immunofluorescence microscopy revealed that aconitase was present only the cytosol and mitochondria. No glyoxysomal aconitase was found in etiolated cotyledons even though all the other enzymes of the glyoxylate cycle are known to be localized in glyoxysomes. Taken together, the data suggest that the cytosolic aconitase participates in the glyoxylate cycle with four glyoxysomal enzymes.

Aconitate Hydratase↗

[Somatosensory evoked potentials in severely handicapped patients].

Somatosensory evoked potentials (SSEPs) were investigated to evaluate the function of the central nervous system in 53 severely handicapped patients. P9-P13 interpeak latencies of these patients were within normal limits in comparison with those of normal controls. But P13-N20 interpeak latencies showed various abnormalities including prolongation or absence. On etiological study, prenatal onset cases, especially in migration disorders, had markedly prolonged P13-N20 and postnatal onset cases frequently showed the absence of N20. Most of the patients showing diffuse brain destruction on CT scan revealed the absence of N20.

Adolescent↗

[Effects of temperature and humidity on the stability of nitric oxide, and efficacy of soda lime as a selective absorber of nitrogen dioxide].

Although inhaled nitric oxide (NO) has attracted attention as a pulmonary vasodilator, little heed has been given to its potential toxicity. Nitric oxide is known to be rapidly oxidized to nitrogen dioxide (NO2), which may damage pulmonary tissue. We examined the effects of temperature and humidity on the production of NO2 from NO. We also evaluated the amount of NO2 absorbed by soda lime, which is usually placed in the inspiratory line. For this purpose, we measured changes over time in the concentrations of NO and NO2 in mixtures that included NO, oxygen, and nitrogen in various concentrations, and at different temperatures and humidities. We confirmed that the formation of NO2 from NO follows the equation: -d[NO]/dt = 2 k[NO]2 [O2], where k is the rate constant. We found that k was significantly smaller at 37 degrees C than at 25 degrees C but was not influenced by humidity (0%, 40% or 90%). Although soda lime was very effective in absorbing NO2 from the inspiratory line, NO was simultaneously absorbed at the same molar ratio when the two gases existed together in the line. We thus conclude that inhalation of NO at 37 degrees C is more desirable than inhalation at room temperature, to suppress the production of NO2. When soda lime is used in the inspiratory line, attention should be paid to the reduction in the concentration of NO in the line.

Absorption↗

Immunocytochemical characterization of glial fibrillary tangles in Alzheimer's disease brain.

Neurofibrillary tangle is a major cytoskeletal pathology in Alzheimer's disease brains, and has been considered to develop exclusively in neuronal cells. We examined brains with Alzheimer's disease and observed argyrophilic fibrillary tangles not only in cortical neurons but also in subcortical glial cells in the frontal and temporal white matter. The tangles in glial cells were immunolabeled by antibodies against tau and ubiquitin, and double immunocytochemistry analyzed by confocal laser scanning microscopy demonstrated that the cytoplasms of tangle-bearing glia were labeled by antibodies against transferrin and 2'3'-cyclic nucleotide 3'-phosphohydrolase. Ultrastructurally, they were made up of bundles of straight filaments 16 nm in diameter and constricted filaments. These results indicate that fibrillary tangles resembling neurofibrillary tangles may develop in oligodendrocytes in brains with Alzheimer's disease and are distinguishable from glial cytoplasmic inclusions observed in multiple system atrophy brains. We referred to them as glial fibrillary tangles. Glial fibrillary tangles commonly occurred in this disease condition, and glial cells might be involved under the pathological processes similar to neuronal cells.

Aged↗