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Biomedical subjects

K Matsubara

Publications and source records attributed to K Matsubara.

At least 361 records · Page 20Linked to original sources
PubMed1990

[Changes in the ECG and myocardial blood flow of the right and left ventricular walls under acute pulmonary arterial stenosis].

For studying the effect of regional myocardial blood flow changes on the epicardial ECG of right and left ventricular walls under acute right ventricular pressure overload, we mapped the epicardial using 64-channel shock electrodes, and estimated the myocardial blood flow with radioactive microspheres. In 9 anesthetized open-chest dogs, the main pulmonary artery was gradedly constricted to the level of mild (peak RV pressure: PRVP, 50-70 mmHg), moderate (PRVP, 70-80 mmHg) and severe stenosis (PRVP, over 80 mmHg). Labeled microspheres were injected into the left atrium before and after the PA constriction, and the epicardial ECGs were recorded continuously. After the completion of the experiment, 9 areas of each right and left ventricular wall were excised. The myocardium was divided into three layers and the flow data were compared to the changes of ECG parameters. In the cases where there was severe PA stenosis, the right ventricular myocardial blood flow decreased to a significantly greater degree (63% reduction from the control), especially in the subepicardial layer, than the flow in the left ventricle (37% reduction from the control). ST potential, STT and QRST Area Map increased in the right ventricle but decreased in the left ventricle. Activation Recovery Time of the right ventricle decreased due to the severe ischemia of the right ventricle. The value of QRS Area Map of the left ventricle decreased significantly in parallel with the decrease in cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

[A case of type C Niemann-Pick disease].

We diagnosed a 3-year-old boy as type C Niemann-Pick disease by studies on cultured fibroblasts; sphingomyelinase activity was almost normal, but esterification of exogenously administered cholesterol was deficient. Also sparse cultures of his fibroblasts developed a relatively intense fluorescence with filipin that was not observed either in normal or type B Niemann-Pick fibroblasts. We tried to treat him with dimethylsulfoxide (DMSO), 100 mg-120 mg/day for a year, but it had clinically insufficient effect on our case.

Child, Preschool↗
PubMed1990

[Evaluation of endobronchial foreign bodies by 99mTc-MAA pulmonary perfusion scintigraphy].

We evaluated the lung perfusion scintigraphic findings of endobronchial foreign bodies in four children. We could detect the bronchial stenosis due to foreign bodies by lung perfusion scintigraphy more easily than plain chest radiograph and predict the location at lobar bronchi level according to the hypoperfusion area. We guessed that the scintigraphic abnormal finding after plain chest radiographic normalization reflect bronchial inflammatory change after foreign body removal and so it is very important to perform the follow up scintigraphic examination.

Bronchi↗
PubMed1990

[Measurements of reversibility of optic disc cupping in glaucoma using a computerized videographic image analyzer].

Optic disc changes were studied in young and elderly glaucoma patients who underwent reduction of intraocular pressure (IOP) by filtrating surgery. A computerized videographic image analysis system (Optic Nerve Head Analyzer, Rodenstock) was used to measure the cup/disc-ratio, the ratio of the rim area over the disc area (rim area/disc area-ratio), and the ratio of the cup volume over the disc area (cup volume/disc area-ratio) before and after filtrating surgery. Each parameter was assessed as total and quadrantal values. Materials consisted of 19 eyes of 15 patients (8 eyes of 5 patients with primary open angle glaucoma, 2 eyes of 2 patients with secondary glaucoma, and 9 eyes of 7 patients with developmental glaucoma). Sixteen eyes (84%) of 12 patients showed a decrease of the total cup/disc-ratio after operation. In this group, the patients had a decrease in IOP of 18.9 +/- 10. 6mmHg (mean +/- SD) after the operation. Among 16 eyes that had a decreased total cup/disc-ratio, statistically significant decrease of the cup/disc-ratio (p less than 0.01) and statistically significant increase of the rim area/disc area-ratio (p less than 0.01) were noted in total and for all quadrants except for the temporal. The greatest improvement of cupping was seen in the nasal quadrant. With regard to cup volume/disc area-ratio, a statistically significant decrease was observed in total and in all quadrants (p less than 0.01). The IOP change correlated linearly with that of the total cup volume/disc area-ratio (R = 0.51, p less than 0.05). No statistically significant linear correlation was noted between age and the change in any disc parameter.

Adolescent↗
PubMed1989

The conformation of mature human alpha-amylase conditions its secretion from yeast.

The yeast Saccharomyces cerevisiae expresses the cloned cDNA (Amy) encoding human salivary alpha-amylase (Amy) under control of the yeast PHO5 promoter, and secretes the active enzyme into the culture medium. Two approaches were utilized to define the moiety of Amy, which is required for proper secretion and glycosylation. In one approach, chimeras were constructed with a variety of secretion signal sequences (yeast mating factor precursor sequence, yeast acid phosphatase signal sequence and human gastrin signal sequence) fused to the secretion signal-deleted Amy cDNA. The other approach involved analysis of a set of deletion series and a set of point mutations in the Amy-encoding region. The results showed that heterologous signal sequences were sufficient for proper secretion in yeast, irrespective of the insertion of some extra amino acids. In most cases, enzymes with deletions and Cys-465 substitution were not secreted, even though they had complete secretion signal sequences. Instead, they accumulated in the cell in a glycosylated form. Thus, proper secretion seems to require an appropriate conformation in the polypeptide moiety to be secreted.

Amino Acid Sequence↗
PubMed1989

On the cDNA's for two types of rat pancreatic secretory trypsin inhibitor.

Two types of cDNA, which code for the two types of rat pancreatic secretory trypsin inhibitors (PSTIs), were cloned and sequenced. Both predicted amino acid sequences consisting of 79 amino acids, with the secretion signal peptide consisting of 18 and 23 amino acids for PSTI-I and PSTI-II, respectively. The nucleotide sequences were 91% homologous between the two cDNAs, but 68% and 65% homologous, respectively, when compared with human PSTI cDNA. Northern blot analyses showed that PSTI-I is expressed in the pancreas, whereas PSTI-II is expressed in the pancreas and the liver using the same promoter. Southern blot analyses suggested that both PSTI-I and PSTI-II genes are single copy genes per haploid genome. Duplication of rat PSTI gene seems to have occurred recently, after the divergence of humans and rats.

Amino Acid Sequence↗
PubMed1989

Improved gas chromatography with electron-capture detection using a reaction pre-column for the determination of blood cyanide: a higher content in the left ventricle of fire victims.

We developed a head-space method for the determination of blood cyanide by gas chromatography with electron-capture detection. In this technique, a reaction pre-column, packed with chloramine-T, was used for the conversion of hydrogen cyanide into cyanogen chloride. Since the reaction pre-column eliminated the necessity for trapping hydrogen cyanide from the biological samples, blood cyanide was quickly analysed by acidification only. The reaction pre-column was durable for at least several months. The calibration curve gave good linearity when dichloromethane was used as the internal standard, and the lower detection limit taken from this plot was ca. 0.05 micrograms/ml. The relative standard deviation of spiked blood samples was in the range 0.6-3.9%. We determined blood cyanide levels at autopsy in victims who had died from fire using this method. A significantly higher cyanide content was detected in the left ventricular blood than in the right. There was a positive correlation between blood cyanide and carboxylhaemoglobin contents. This simple and sensitive technique could be very useful for the determination of cyanide in various samples.

Autopsy↗
PubMed1989

Two erbA homologs encoding proteins with different T3 binding capacities are transcribed from opposite DNA strands of the same genetic locus.

Two erbA homologs, termed ear-1 and ear-7, are present in the human genome on chromosome 17. The two genes reside in the same genetic locus with overlapping exons and are transcribed from opposite DNA strands. In addition, the ear-7 mRNA is alternatively spliced to generate two protein isoforms, namely the ear71 and ear72 proteins. Nucleotide sequence analysis predicts that the ear71 protein is a human counterpart of the chicken c-erbA protein, a molecule closely related or identical to thyroid hormone receptor. Indeed, Scatchard analysis of proteins synthesized in vitro indicated very high affinity binding of T3 to the ear71 protein but not to the ear72 protein. Interestingly, the ear-1 gene product showed low, but appreciable, binding to T3, although its authentic ligand remains to be clarified.

Amino Acid Sequence↗
PubMed1989

A novel type of human alpha-amylase produced in lung carcinoid tumor.

A novel type of alpha-amylase was detected in a lung carcinoid tissue after surveying the cDNA library constructed from this tumor mRNA. Nucleotide sequence analysis showed that the amylase expressed in this carcinoid tumor has 13 and 6 amino acid substitutions when compared with salivary amylase (Amy1) and pancreatic amylase (Amy2), respectively. The nucleotide sequence homologies of cDNAs between this carcinoid amylase and amy1, amy2 are 97.5% and 98.2%, respectively. The nucleotide sequence comparison strongly suggests that this new amylase is the product of the amy3 gene that has been detected in human genome [Emi et al., Gene 62 (1988) 229-235]

Amino Acid Sequence↗
PubMed1989

Molecular cloning and nucleotide sequence of human pancreatic prechymotrypsinogen cDNA.

The cDNA clone encoding human prechymotrypsinogen was isolated from a human pancreas cDNA library and its nucleotide sequence was determined. The sequence consists of a 16 bp 5' non-coding region, a 789 bp amino acid coding region and a 60 bp 3' non-coding region. The predicted product consists of 263 amino acids, including 18 amino acids for a signal peptide and 15 amino acids possible for an activation peptide. Southern blot analyses using the cloned cDNA as a probe revealed that human genomic DNA carries at least two genes that are related to chymotrypsinogen.

Amino Acid Sequence↗
PubMed1989

Thyroid-stimulating hormone (TSH) deficiency caused by a single base substitution in the CAGYC region of the beta-subunit.

Congenital isolated thyroid-stimulating hormone (TSH) deficiency is an autosomal recessive disease that manifests as hypothyroidism (cretinism), causing severe mental and growth retardations. Patients were found to have a single base substitution in the codon for the 29th amino acid of the TSH beta subunit gene. The alteration is in the center of the so-called CAGYC region, which consists of an amino acid sequence conserved among all of the known glycoprotein hormone beta subunits. No other nucleotide substitutions have been found in the gene thus far sequenced. Microinjection of the mutated beta mRNAs into Xenopus laevis oocytes led to the formation of conformationally altered beta polypeptides that could not associate with alpha subunits. The mutation created a new recognition site for the enzyme MaeI. Southern blot hybridization of genomic DNA digested with MaeI showed that the patients were homozygous and their parents were heterozygous for the mutation. This test was also used to examine other family members for the disease.

Amino Acid Sequence↗
PubMed1989

Radioimmunoassay for erythropoietin using anti-recombinant erythropoietin antibody with high affinity.

A sensitive radioimmunoassay (RIA) for the detection of erythropoietin (EPO) was developed using anti-recombinant EPO antibody with high affinity. The sensitivity was 100 amol/tube (5 mIU/ml) and it was possible to detect a serum EPO level between 5 and 200 mIU/ml. This method enabled us to measure native EPO as well as recombinant EPO. With this method we determined serum EPO levels in healthy individuals and patients with chronic renal disease, rheumatoid arthritis and iron deficiency anemia. Values in patients with chronic renal disease were lower than those in healthy individuals, while values in patients with rheumatoid arthritis, or iron deficiency anemia were significantly higher than those in healthy individuals.

Anemia, Hypochromic↗
PubMed1989

Detection of hepatitis B virus X gene protein and antibody in type B chronic liver disease.

The genome of the hepatitis B virus contains a sequence (X gene) whose role is unclear. The almost complete region of the hepatitis B virus X gene was expressed in Escherichia coli, with the resulting protein being approximately 17 kilodaltons in molecular weight. Sera from 139 subjects were analyzed by Western blot analysis. Of the hepatitis B surface antigen-positive patients, anti-X was not found in 4 patients with acute hepatitis and in 12 healthy carriers, but was present in 41% (21/51) of the patients with chronic hepatitis, 63% (15/24) of those with liver cirrhosis, and 46% (12/26) of those with hepatocellular carcinoma. The expression of the X product in the liver tissues (43 hepatitis B surface antigen-positive patients) was investigated using an indirect immunohistochemical method. The X protein was observed in 64% (21/33) of the patients with chronic hepatitis and 50% (5/10) of those with liver cirrhosis, and was found when the serum was negative for anti-X. Hepatitis B core antigen was frequently expressed together with the X protein in the liver. The conclusions reached were that the frequency of anti-X increases with the length of chronic hepatitis B virus infection, that anti-X may suppress the expression of the X protein in the liver, and that the X protein may be related to hepatitis B virus replication.

Blotting, Western↗
PubMed1989

Relationship between hypertriglyceridemia and uric acid production in primary gout.

The relationship between uric acid metabolism and lipid levels was analyzed in 148 male subjects with primary gout. The subjects were divided into three groups according to their alcohol consumption: heavy drinkers, moderate drinkers, and nondrinkers or mild drinkers. There was no correlation between urinary uric acid excretion and serum triglyceride (TG) levels in the heavy group, but a marginally significant correlation was shown in the moderate group (P less than .05), and a significant correlation was observed in the nondrinker or mild group (P less than .001). This relationship in the nondrinker or mild group was also found to be significant after adjustment for BMI and age by multiple regression analysis. Serum lipoproteins were analyzed by sequential preparative ultracentrifugation in 21 patients with primary gout who neither drank alcohol nor were obese; VLDL-TG level, but not the VLDL cholesterol level, was found to be significantly correlated with 24-hour urinary uric acid excretion. These results indicate that there is a close correlation between the degree of uric acid production, as judged by 24-hour urinary uric acid excretion, and lipoprotein TG metabolism when the influence of alcohol intake is excluded.

Alcohol Drinking↗
PubMed1989

An in vitro system for screening anti-hepatitis B virus drugs.

A human hepatoblastoma cell line (HB 611) that continuously synthesizes hepatitis B viral (HBV) DNA was grown in the presence of various inhibitors of DNA synthesis, and the DNA from the cells was analyzed by the Southern blotting method to examine selective inhibition of the viral DNA synthesis. Among those that showed selective inhibition, and interferons alpha and beta, acyclovir, and dideoxy cytidine were effective. This system should be useful for screening new antiviral agents against HBV.

Acyclovir↗