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Biomedical subjects

A Nagata

Publications and source records attributed to A Nagata.

At least 199 records · Page 11Linked to original sources
PubMed1981

HLA antigens in chronic idiopathic pancreatitis compared with chronic alcoholic pancreatitis.

HLA A and B antigens in 46 patients with chronic pancreatitis were studied in Japan. Patients were divided into the two groups according to the etiology of the disease: one was chronic idiopathic pancreatitis (18 cases) and the other was chronic alcoholic pancreatitis (28 cases). One hundred twenty unrelated subjects were also examined as control. HLA B5 was detected in 14 of 18 cases of chronic idiopathic pancreatitis, which was significantly higher statistically than in control (P less than 0.001, corrected P less than 0.05). In contrast, no HLA antigens of locus A and B were found which had a relationship to chronic alcoholic pancreatitis. These results suggest that some genetic factors may be implicated in the development of chronic idiopathic pancreatitis and differing from that of alcoholic pancreatitis.

Adult↗
PubMed1981

Intranuclear virus-like particles in the hepatocytes of the patients with non-A, non-B hepatitis.

Liver specimens were obtained from 21 non-A, non-B hepatitis patients when their serum transaminase levels were still elevated. The specimens were investigated by transmission electron microscope in order to investigate the presence of the structure relating to this type of hepatitis. Intranuclear electron-dense aggregates of virus-like particles were observed in 2 out of 21 cases. One was an unresolved acute hepatitis case with short-incubation posttransfusion type, and the other was a chronic persistent hepatitis case without bloodtransfusion. The size of these particles varied from 22 to 28 nm in diameter. The incidence of hepatocytes with the particles was approximately 2 to 3% of the cells investigated. These particles may represent an intranuclear alteration in close association with one type of non-A, non-B hepatitis.

Adult↗
PubMed1981

In vivo correlation between DNA supercoiling and transcription.

The superhelical density of pMT plasmid DNA in Escherichia coli cells was measured as a function of the transcriptional activity, which was reduced by treatment with coumermycin or oxolinic acid. Superhelicity was assayed by agarose gel electrophoresis of DNA extracted from cells gently lysed by sarkosyl. Coumermycin treatment reduced the proportion of supercoiled plasmid DNA in concert with a decrease in the rate of plasmid-coded synthesis of trp mRNA, implying a correlation between supercoiling of DNA and its suitability for transcription. On the other hand, the oxolinic acid-induced loss of supercoiled plasmid DNA was relatively small, while concomitant inhibition of trp mRNA synthesis was very severe. Treatment of the cells with these two drugs never removed all of supertwists from the pMT plasmids carried.

Aminocoumarins↗
PubMed1981

Anaerobic threshold determination by blood lactate and myoelectric signals.

This study examined the potential use of myoelectric signal analysis for determination of anaerobic threshold (AT). Ten college students performed incremental exercise on a bicycle ergometer during which blood samples from either the brachial or radial artery were drawn and corresponding intergrated electromyogram (IEMG) and power spectra also were recorded. Blood AT was determined by observing the changes in arterial blood lactate, Po2 Pco2, HCO3-, and pH. EMG AT was determined by the non-linear increase in IEMG and abrupt increase in frequency band width at 70% of the peak frequency (FRQ70%) which could represent the most active frequency band. The results indicated that a significant increase in FRQ70% occurred immediately after the occurrence of blood AT (p less than 0.05). However, no significant increase could be found in peak frequency. Regression analyses revealed that EMG AT Vo2 correlated significantly with blood AT Vo2 (r = 0.921, p less than 0.001) and with gas exchange AT Vo2 (r = 0.921, p less than 0.001). It was concluded that analysis of myoelectric signals, which reflect motor unit recruitment and discharge frequency, could provide a non-invasive estimate of AT.

Adult↗
PubMed1981

A study of chronic pancreatitis by serial endoscopic pancreatography.

The pancreatic duct system was studied with repeated endoscopic retrograde pancreatography in 31 patients with chronic pancreatitis, 32 patients with suspected chronic pancreatitis, and 16 controls without pancreatic disease. In chronic alcoholic pancreatitis the pancreatograms showed marked changes during the initial examination with progression even after abstinence or reduction of drinking. In the alcoholics with suspected chronic pancreatitis, progressive lesions in branch ducts with almost intact main ducts were recognized. In contrast, no remarkable alterations on serial pancreatograms were observed in nonalcoholic cases with definite or suspected chronic pancreatitis. These results suggest that pancreatic duct lesions play an important role in the development and progression of chronic alcoholic pancreatitis in contrast to chronic nonalcoholic pancreatitis.

Adult↗
PubMed1980

[Methods of eliminating alkaloids from the seeds of Lupinus mutabilis Sweet].

The basic purpose of this work was to find a simple and economic method to control and eliminate the presence of alkaloids, as detected by organoleptic or toxicity tests, in Lupinus mutabilis, S. (tarhui) seeds. Taking advantage of the physical and chemical properties of the seeds, they were subjected to four methods of extraction; b) chemical treatment; c) extraction with two solvents, and d) treatment with a modified water-heat process. The results indicated that the most adequate method was the water-heat modified treatment, which showed a yield of 85% and a debittering efficiency of 98.6%, figures which were above those obtained with any of the other treatments studied. The final product had a bland taste without traces of bitterness and a 32% concentration of protein in the kayra line. Amino acid content showed this product to have an unusual high lysine content.

Alkaloids↗
PubMed1979

In vivo enhancement of general and specific transcription in Escherichia coli by DNA gyrase activity.

The effect of drugs which inhibit DNA gyrase, including nalidixic acid, oxolinic acid and coumerycin, on transcription of Escherichia coli bacteria, phage and plasmid genomes was studied. Quantitative estimates of the synthesis of RNA under drug-treatment conditions showed that synthesis of many RNA species, including trp mRNA, was subject to inhibiton by the drug. Transcription directed by the lambda promoter pR was selectively less sensitive to the drug action than transcription initiated at the lambda promoter pL. Evidence was obtained showing that diminished transcription resulted from less frequent RNA chain initiation rather than a premature arrest of the chain elongation. Inhibiton of transcription by these DNA gyrase inhibitors was observed even in the absence of DNA replication. The inhibition by oxolinic acid or coumerycin was not observed in an E. coli strain bearing a nalAr mutation or a cour mutation, respectively. The reduction of trp mRNA synthesis in oxolinic acid-treated cells cannot be attributed to the increase in the rate of nascent mRNA degradation. These results indicate that DNA gyrase is generally required for intracellular RNA synthesis, and suggest that the supercoiling of DNA by this winding enzyme enhances the initiation of transcription.

Bacteriophage lambda↗
PubMed1979

The metabolism of benzyclane [1-benzyl-1-(3-N,N-dimethylaminopropoxy)cycloheptane] in rat and man.

1. Two metabolites, isolated from the urine of rats dosed with bencyclane fumarate, were characterized as cis-1-benzyl-1-(3-N,N-dimethylaminopropoxy)-4-hydroxycycloheptane (metabolite I) and 1-benzyl-1-(3-N,N-dimethylaminopropoxy)-4-oxocycloheptane (metabolite II). 2. Bencyclane and the two metabolites were determined in the urine of rats and volunteers by g.l.c. Metabolite I was a major metabolite in men, being excreted in urine to the extent of 23.5% dose in the first 24 h.

Animals↗