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Biomedical subjects

K Sakuma

Publications and source records attributed to K Sakuma.

At least 109 records · Page 6Linked to original sources
PubMed1987

Low protein--high energy diet induces repressed transcription of albumin mRNA in rat liver.

The effects of diet at the molecular level were investigated by feeding rats control or protein-deficient diets. Each of the control and the protein-deficient groups was further divided into three subgroups according to the level of energy intake. Liver DNA, RNA and total cellular protein concentrations and serum albumin and albumin mRNA concentrations were determined. Protein deficiency caused a marked inhibition of liver growth but the size of most cells remained normal. The low protein diet caused concurrent decreases in the levels of serum albumin and serum mRNA. However, this effect was observed only with the combination of a low protein diet and normal energy intake. The low protein-low energy diet failed to induce the low serum albumin level. Our findings suggest that the altered balance between at least two factors of protein and energy intake serves as a trigger for several metabolic changes which ultimately regulate specific genes.

Animals↗
PubMed1987

A long-term cortical blindness after head trauma.

Here is a case of long-term cortical blindness after a head trauma. Its etiology is ascribed to the cerebral vascular occlusion caused by the head trauma. From the findings of both a computerized tomography (CT) and magnetic resonance image (MRI), the lesions of our case are assumed to be in the bilateral areas 17 (Brodmann), some part of the bilateral areas 18, 19 (Brodmann) and bilateral optic radiations. On determination of the areas of these lesions, the location of the lesion in the bilateral areas 17 has been especially done by using the MRI. The MRI findings in our case have a full significance on this point.

Adult↗
PubMed1985

Cyclic guanidines. 17. Novel (N-substituted amino)imidazo[2,1-b]quinazolin-2 ones: water-soluble platelet aggregation inhibitors.

A series of novel 1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin-2-one derivatives substituted with a secondary amino group has been prepared and tested for the activities of inhibiting platelet aggregation in rats in vitro and ex vivo. Most of the compounds were found to be the potent inhibitors of platelet aggregation. Some of the active compounds were soluble in water and effective via iv infusion in rats. Structure-activity relationships have indicated that a lipophilic secondary amino group located at position 6 or 7 contributed to retention of potent activity. Among the compounds studied, 7-piperidino-1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin-2- one (13 g,DN-9693) was the most favorable compound.

Animals↗
PubMed1984

Formation of transcribing mononucleosome-eukaryotic RNA polymerase II complexes in vitro as a simple model of active chromatin.

Mononucleosomes obtained from cultured mouse hepatoma cells were incubated with RNA polymerase II from wheat germ. No free DNA was liberated as available templates under the experimental condition employed. Size analysis of the transcripts showed that the polymerase initiated transcription from either terminus and read through the DNA template of mononucleosomes. Sucrose density gradient centrifugation of the reaction mixture resolved mononucleosome-polymerase complexes from free materials. The complexes were characterized by the enrichment of DNA fragments containing the nucleosome linker region, the presence of H1 histone, and the increased susceptibility to DNase I. Both the complexes formed in the presence and absence of precursor nucleotides were susceptible. These suggest that RNA polymerase II prefers to bind to the linker region, and the polymerase-bound nucleosomes are structurally altered. The data were discussed in context with possible mechanisms of transcription of the nucleosome structure.

Animals↗
PubMed1984

A prospective cohort study of hepatitis B surface antigen carriers in a working population.

A 10-year prospective cohort study was made of 495 male hepatitis B surface antigen (HBsAg) carriers aged over 40 at entry. The observed/expected mortality rate ratio of primary liver cancer (PLC) was 10.40, based on the general population in Japan. The annual incidence rate of PLC (including 2 survivals) was 365/100,000 person-years. All histologically confirmed cases of PLC were hepatocellular carcinoma (HCC). The chronic HBsAg carrier state is suggested to be a risk factor of HCC.

Adult↗
PubMed1983

Follow-up study of children with cerebral coordination disturbance (CCD, Vojta).

713 children (from newborn to 12-month-old) with delayed motor development were carefully examined and classified into normal, very light cerebral coordination disturbance (CCD, Vojta), light CCD, moderate CCD, severe CCD, suspected cerebral palsy (CP) and other diseases at their first visit, and were followed up carefully. Finally, 89.0% of very light CCD, 71.4% of light CCD, 56.0% of moderate CCD and 30.0% of severe CCD developed into normal. 59.5% of moderate CCD and 45.5% of severe CCD among children who were given Vojta's physiotherapy developed into normal. The classification of cases with delayed motor development into very light, light, moderate and severe CCD based on the extent of abnormality in their postural reflexes is useful and well correlated with their prognosis. Treatment by Vojta's method seems to be efficient and helpful for young children with delayed motor development.

Female↗
PubMed1982

Hepatocellular carcinoma arising in noncirrhotic and highly cirrhotic livers: a comparative study of histopathology and frequency of hepatitis B markers.

Hepatocellular carcinoma (HCC) associated with cirrhosis and HCC developing in a noncirrhotic liver may have differing pathogeneses. To study this possibility, 425 autopsied cases of HCC were investigated. Of these, 45 livers were not cirrhotic, 50 were highly cirrhotic (liver weight less than 99 g), and the remaining 331 were cirrhotic but not so highly. The average age was significantly older in the highly cirrhotic group, suggesting a longer premalignant period of chronic liver disease. The liver weight in the noncirrhotic group was about 3.5 times that in the highly cirrhotic group. Hepatitis B surface antigen was positive in serum in only 9.3% and in liver tissue in 10% in the noncirrhotic cases, the positivity rate being much lower compared with other groups (P less than 0.005--0.01), yet antibody to HB core was positive in 90%. The antibody titers were low, however, indicating that these noncirrhotic patients had in the past had HB virus (HBV) infection with no residual chronic B hepatitis. Analysis of the grades of anaplasia of cancer tissue demonstrated an inverse correlation between the degree of fibrosis and grade of anaplasia, i.e., the more advanced the fibrosis, the less anaplastic the cancer. These data suggest that HCC arising in highly cirrhotic liver and in noncirrhotic livers have different pathogenetic backgrounds, and that HBV infection, even though transient, has a certain role in hepatocarcinogenesis. The generally held conjecture that HCC in a noncirrhotic liver is caused by nonviral carcinogens and HCC arising on the ground of cirrhosis is due to HBV seems untenable in such a simple concept.

Adult↗
PubMed1982

[Effect of dopamine intracerebrally injected by the Valzelli method on methamphetamine-stereotypy and hypermotility].

In this investigation, the effect of methamphetamine (MAPT) was examined on stereotyped licking and biting and locomotor activity in reserpinized rats which were administered dopamine (DA) intracerebrally. Twenty-four hours after the treatment of reserpine (RE, 1.25 mg/kg ip) or 0.9% saline solution. Wistar male rats received DA (300 micrograms/rat ic) or 0.9% saline solution (5 microliters/rat ic) by Valzelli's method and then 10 min later MAPT (3 mg/kg or 10 mg/kg ip) Stereotyped biting was induced by each dose of MAPT in reserpinized rats. This was suppressed, however, in reserpinized rats given DA. Stereotyped licking was induced by MAPT (10 mg/kg ip) in saline-treated rats. This score did not differ in comparison with the case given DA. Hypermotility was shown by each dose of MAPT in reserpinized and saline-treated rats. This was particularly potentiated in reserpinized rats given DA before the MAPT (10 mg/kg ip), but not any cases of saline-treated rats combined with DA. It is suggested that MAPT-induced stereotyped licking and biting are suppressed in reserpinized rats given DA in a high dose while MAPT-induced hypermotility is potentiated in rats treated as above.

Animals↗
PubMed1982

Prognosis of hepatitis B virus surface antigen carriers in relation to routine liver function tests: a prospective study.

The employees of the Japan National Railways Co. working in the Tokyo area, comprising 98% men over the age of 40 yr, were examined for hepatitis B virus seromarkers and routine liver function tests (serum glutamic oxaloacetic transaminase, alkaline phosphatase, and zinc turbidity test) and were followed for 5 yr. The examinees included 202 hepatitis B surface antigen carriers, 502 positive for hepatitis B surface antibody, and 2426 negative for both. We found that the frequency of continuously abnormal liver function test was higher in hepatitis B surface antigen carriers compared with noncarriers. Of the 202 carriers, 4 (1.98%) died from hepatocellular carcinoma with or without cirrhosis, whereas in 2928 noncarriers only 2 (0.07%) died from liver diseases unrelated to hepatitis B virus, the difference being 28.3-fold. Three of the 4 who died from hepatocellular carcinoma initially had normal liver function tests. Mortality in carriers with initially normal liver function tests was 44.5 times higher than that in noncarriers with normal tests. Thus, asymptomatic carriers carry a high risk of dying from chronic liver disease. Routine liver function tests appear of limited value in predicting prognosis.

Adult↗
PubMed1981

Response of ovine uterine blood flow to angiotensin II: effect on the fetus.

The effect of intravenous infusion of angiotensin II (2 to 200 ng/kg/min) on uterine blood flow and cardiovascular performance was studied in the normotensive, unanesthetized pregnant ewe. With low rates of infusion (2 to 4 ng/kg/min), only a transient increase in uterine blood flow, lasting 1 to 3 minutes, was observed. Higher rates (110 to 200 ng/kg/min) of infusion caused a decrease in uterine blood flow; this decrease was significantly correlated to the dose. Angiotensin II also caused a significant decrease in the maternal heart rate and an increase in mean maternal arterial blood pressure as the rate of infusion was increased. A high rate of infusion resulted in decreased fetal heart rate and PaO2, probably due to a marked reduction in uteroplacental blood flow.

Angiotensin II↗
PubMed1981

Cyclic guanidines. 14. Imidazo[1,2-a]thienopyrimidin-2-one derivatives as blood platelet aggregation inhibitors.

A series of novel 1,2,3,5-tetrahydroimidazo[1,2-a]thieno[2,3-d]-, -[3,2,-d]-, and -[3,4-d]pyrimidin-2-one derivatives has been prepared and tested for the activity of inhibiting platelet aggregation in rats in vitro and ex vivo. These compounds were synthesized through the following reactions: sodium borohydride reduction of 2,4-dichlorothienopyrimidines, followed by ethoxycarbonylmethylation and successive amination. Most of the compounds were found to be potent inhibitors of blood and platelet aggregation. Structure-activity relationships have indicated the essential contribution of the lactam structure and lipophilic substituents on the thiophene ring to the effective interaction of the compounds with a receptor site on the platelet. Among the compounds studied, 1,2,3,5,6,7,8,9-octahydro-[1]benzothieno[2,3-d]imidazo[1,2-a]pyrimidin-2-one (9m) exhibited the most favorable activity.

Animals↗
PubMed1981

Toxicity of lidocaine in adult, newborn, and fetal sheep.

The relative central nervous system and cardiovascular toxicity of lidocaine was compared in adult, newborn, and fetal sheep during continuous infusion of lidocaine into the jugular vein at the rate of 2 mg x kg-1 x min-1. An identical sequence of toxic manifestations occurred in the adult, newborn, and fetus: convulsions, hypotension, respiratory arrest, and circulatory collapse. Doses necessary to produce these manifestations were highest in fetuses and lowest in adults. For example, in order to elicit convulsions, 5.8 +/- 1.8 mg/kg of lidocaine was required in the adults, 18.4 +/- 2.2 in the newborns, and 41.9 +/- 6.0 in the fetuses. Measurements of lidocaine concentrations in blood demonstrated that these toxic symptoms occurred at levels which were not significantly different among the three groups. The results indicate that fetal and newborn lambs are no more sensitive to lidocaine toxicity than are adult sheep. The fact that the highest doses were required in the fetuses is probably related to the placental clearance of the drug into mothers and better fetal maintenance of arterial Po2 despite convulsions and respiratory arrest (cessation of breathing-like movements).

Animals↗