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Biomedical subjects

H Murakami

Publications and source records attributed to H Murakami.

At least 883 records · Page 49Linked to original sources

Enhancement of interferon-beta production with sphingomyelin from fermented milk.

A fermented milk, Kefir, contains an active substance which enhances IFN-beta secretion of a human osteosarcoma line MG-63 treated with a chemical inducer, poly I: poly C. The active substance in the fermented milk was identified to be sphingomyelin (SpM) by a combined use of a fast atom bombardment mass spectrometry (FAB-MS) and a fast atom bombardment tandem mass spectrometry (FAB-MS/MS). SpM from fermented milk (F-SpM) was a mixture of four molecular species of SpMs having C21-, C22-, C23- and C24-fatty acids. F-SpM enhanced the IFN secretion 14 times, SpMs from other sources also enhanced moderately (2-3 times). Sphingosine and lysosphingomyelin also enhanced the activity but ceramide and cerebroside did not.

Animals↗

Studies on cerebrospinal fluid kynurenic acid concentrations in epileptic children.

Kynurenic acid (KYA), the only known endogenous antagonist of the excitatory amino acids, is a metabolite of kynurenine. In the present study the levels of KYA were measured in the cerebrospinal fluid (CSF) of epileptic children and age-matched controls to investigate the relationship between various forms of epilepsy and KYA levels. CSF samples from four patients with West syndrome (WS), four patients with epilepsy with grand mal seizures on awakening (EGSA), and four patients with childhood epilepsy with occipital paroxysms (CEOP) were collected by lumbar puncture before treatment. The concentration of CSF KYA was analyzed by HPLC with electrochemical detection and compared with those of age-matched controls. The levels of CSF KYA were significantly lower (P < 0.05) in patients with WS compared with controls. The levels of CSF KYA in patients with EGSA and with CEOP did not differ significantly from control levels. These results suggest that the presence of seizures in WS is associated with altered kynurenine metabolism. The possibility that seizures in WS may be related to decreased production of KYA is discussed.

Epilepsy↗

MRI of myositis ossificans circumscripta.

Myositis ossificans circumscripta (or pseudomalignant osseous tumor of soft tissue) may be confused with malignant neoplasms if there is no clear history of trauma. Two cases are presented in which magnetic resonance imaging (MRI) clearly demonstrates disproportionally extensive abnormal signal intensity along the course of muscle fibers. Although the specificity of this finding is uncertain, MRI enhances the level of confidence in diagnosing myositis ossificans.

Adolescent↗

Effects of a calcium channel blocker, manidipine, on insulin sensitivity in essential hypertensives.

This study was designed to investigate the effects of the calcium channel blocker manidipine on insulin-dependent glucose uptake (insulin sensitivity) and insulin action to renal sodium handling and pressor systems in essential hypertensive (EHT). Seven EHT were hospitalized and a 2-h euglycemic hyperinsulinemic glucose clamp was performed in a fasting condition before and after 2 weeks administration of manidipine (20 mg/day). Insulin sensitivity was evaluated as M-value calculated from the infusion rate of glucose. Manidipine administration decreased mean blood pressure and increased M-value significantly in EHT. Before the manidipine treatment, hyperinsulinemia during the clamp induced a decrease of urinary sodium excretion and increases of plasma norepinephrine and plasma renin activity in EHT. After manidipine treatment, however, hyperinsulinemia induced natriuresis and did not augment the pressor systems activity. Thus, the calcium channel blocker improved insulin resistance as assessed by glucose clamp technique in EHT. Suppression of augmented renal sodium reabsorption and pressor system activities of insulin may be connected with the hypotensive mechanisms and the natriuresis caused by calcium channel blockers.

Blood Glucose↗

Use of thermal photography to explore the age-dependent effect of monosodium glutamate, NaCl and glucose on brown adipose tissue thermogenesis.

Using a sensitive thermocamera and a hairless substrain of Sprague-Dawley rats, we developed a novel in vivo method for the evaluation of diet-induced thermogenesis. The technique enabled time-dependent monitoring of spatial heat dissipation emanating from brown adipose tissue (BAT) during diet intake. Drinking of monosodium glutamate (MSG) solution (0.12 M) enhanced standard protein (15%) diet-induced heat dissipation in young (9-12 weeks old) hairless male rats. No significant enhancement was found in 9- to 12-week-old rats that received sodium chloride (0.12 M) or glucose solution (0.6 M). The enhancing effect of MSG was age-dependent and it was not observed in 18- to 22-week-old rats due to an age-dependent decrease of thermogenic responses. No age-related changes in MSG preference or diet intake were recorded. Although it is unclear whether the effect of MSG was purely enhancing or whether the effect was independently superimposed on the diet-induced thermic activity, the results suggest that in 9- to 12-week-old rats, preference for umami taste might be associated with its enhancing effect on diet-induced thermogenesis.

Adipose Tissue, Brown↗

Effect of doxazosin on the size of LDL particle in the type 2 diabetic patients with hypertension.

Hypertension is common in patients with type 2 diabetes mellitus (DM), and contributes to the progression of its complications in patients with diabetes. Doxazosin is a selective alpha1-adrenoceptor-blocking anti-hypertensive agent and has a favorable impact upon lipid metabolism. We investigated the effect of doxazosin on the lipid metabolism in hypertensive patients with type 2 diabetes, especially low-density lipoprotein (LDL) particle size that is associated with many elements of the insulin resistance syndrome. Cross-sectional study (n=19) was designed to determine whether doxazosin, administered with an angiotensin II-converting enzyme inhibitor (ACEI) and a Ca antagonist, affects LDL particle size. As a follow-up study (n=6), lipid and glucose metabolism and LDL particle size were followed for 12 weeks before and after the initiation of doxazosin administration (1-4 mg/day). The average size of LDL particle was significantly larger in the patients treated with doxazosin (LDL-migration index (LDL-MI): 0.348+/-0.027) than those in the patient treated without doxazosin (0.378+/-0.035), although LDL cholesterol levels did not differ between the two groups. The plasma glucose and HbA1c levels remained unchanged. Lipid profile showed normolipemia throughout the period of the study. However, LDL particle size was demonstrated to become larger during the following period. Small LDL fraction (LDL3-7) diminished remarkably and large LDL (LDL1-2) increased on the polyacrylamide gel electrophoresis (PAGE) LDL system (LipoPrint). From this pilot study, it was concluded that doxazosin is a useful anti-hypertensive agent for hypertensive type 2 diabetic patients in improving the size of LDL particle.

Angiotensin-Converting Enzyme Inhibitors↗

Detection of VP-16-treated HL-60 cell apoptosis by TUNEL electron microscopy.

Apoptosis is essential to many physiological processes, including maturation of cells and the immune system. Deficient regulation of apoptosis may play an important role in many pathological conditions, such as autoimmunity, AIDS, and myelodysplastic syndrome. Several methods have been described to identify apoptotic cells. DNA strand breaks can be identified by labeling free 3'-OH termini with modified nucleotides by enzymatic reaction (TUNEL method). In this study, apoptosis was introduced in cultured HL-60 cells treated with VP-16, and the TUNEL method was adapted for electromicroscopy, called the EM TUNEL method. The results of the EM TUNEL method were compared with those of light microscopy and flow cytometry. Apoptotic cells following VP-16 (10 micrograms/mL) treatment were detected after 3 h by all methods (light microscopy, Erythrocin B, electron microscopy, flow cytometry, TUNEL, and EM TUNEL). EM TUNEL was the most sensitive method of detection, with a detection rate of 32%. Furthermore, EM TUNEL was more suitable for distinguishing cell lineage than light microscopy TUNEL. The results indicate that EM TUNEL can be used to detect apoptosis in bone marrow species in vivo.

Apoptosis↗

Expression of bovine cytochrome P450c17 cDNA in Saccharomyces cerevisiae.

We constructed expression plasmids for bovine adrenal cytochrome P450c17 (P450c17) by inserting the corresponding cDNA between the yeast alcohol dehydrogenase I promoter and terminator of the expression vector pAAH5. Plasmids pA alpha 1 and pA alpha 2 contained the entire coding region for bovine P450c17, whereas pAC alpha 1 included the cDNA coding for chimeric P450c alpha consisting of the amino-terminal 45 amino acid residues of rat P450c and the carboxy-terminal 482 amino acid residues of bovine P450c17. The transformed Saccharomyces cerevisiae AH22/pA alpha 1, AH22/pA alpha 2, and AH22/pAC alpha 1 cells produced about 1 x 10(5), 1 x 10(5), and 2 x 10(4) molecules per cell of the corresponding P450 hemoproteins, respectively. On incubation with the cultures of each of the three strains, progesterone was specifically converted into 17 alpha-hydroxyprogesterone, which was not further converted into androstenedione, indicating that the three strains showed 17 alpha-hydroxylase activity, but almost no C17,20-lyase activity. The microsomal fraction prepared from the AH22/pA alpha 1 cells showed 17 alpha-hydroxylase activity toward progesterone and pregnenolone to higher extents, and exhibited C17,20-lyase activity toward 17 alpha-hydroxypregnenolone to a lesser extent and almost no C17,20-lyase activity toward 17 alpha-hydroxyprogesterone. These results indicated that bovine P450c17 synthesized in S. cerevisiae cells manifests the 17 alpha-hydroxylase activity, but not the C17,20-lyase activity.

Adrenal Glands↗

Genetically engineered P450 monooxygenases: construction of bovine P450c17/yeast reductase fused enzymes.

Seven P450/reductase fused enzymes were produced in Saccharomyces cerevisiae by expressing fused cDNAs consisting of bovine cytochrome P450c17 (P450c17) and yeast NADPH-cytochrome P450 reductase (reductase). These fused enzymes differed in the length and amino acid sequence of the hinge region between the P450 and reductase moieties. Expression of the fused constructs under the control of the yeast alcohol dehydrogenase I promoter and terminator of expression vector pAAH5 in S. cerevisiae AH22 cells resulted in the production of about 2-8 X 10(4) molecules per cell of the seven corresponding fused enzymes. Six of the fused enzymes incorporated a protoheme, as confirmed by reduced CO-difference spectra. Recombinant yeast strains producing each of the fused hemoproteins showed P450c17-dependent 17 alpha-hydroxylase activity toward progesterone. The most active fused enzyme, delta N23FE, which lacked the amino-terminal 23 amino acids of the reductase, showed about 10 times higher 17 alpha-hydroxylase activity than bovine P450c17, although the fused enzyme (delta N23FE)' with an amino acid sequence in the hinge region different from delta N23FE was less active than delta N23FE. The fused enzyme delta N0FE, consisting of P450c17 and whole reductase, showed about 1.8 times higher activity than bovine P450c17. No activity was found with delta N84FE lacking the amino-terminal 84 amino acids of the reductase moiety. P450c17-dependent C17,(20)-lyase activity toward 17 alpha-hydroxyprogesterone was detected to lesser extents in the recombinant yeast. Fused bovine P450c17/yeast reductase enzymes show enhanced 17 alpha-hydroxylase activity, and the length and amino acid sequence in the hinge region between the P450c17 and yeast reductase moieties can be important for efficient intramolecular electron transfer in the fused enzymes.

Animals↗

Superior mesenteric varices and splenic renal shunt with portal hypertension: a case report of liver cirrhosis with complications.

The case of a 58-year old woman with cirrhosis complicated by hepatocellular carcinoma, hepatic encephalopathy and superior mesenteric varices is described. Angiography revealed large superior mesenteric varices and it was demonstrated that the portal venous blood was shunted into the right internal iliac vein via the right ovarian vein. Clinically, this patient had hepatic encephalopathy and hyperammonaemia, but no oesophageal varices were discovered on endoscopy. The hepatic encephalopathy suggested that the portal blood containing ammonium from the superior mesenteric vein entered the brain through the systemic vein without the ammonia being metabolized by the liver.

Carcinoma, Hepatocellular↗

Successful treatment of concomitant acute myeloblastic leukaemia and adenoid cystic carcinoma of the palate.

The case of a 55-year old man who was affected simultaneously by acute myeloblastic leukaemia (AML) and adenoid cystic carcinoma of the palate is reported. The carcinoma was removed after induction chemotherapy for AML and the patient subjected to consolidation therapy. No reports are evident of other cases in which acute leukaemia and other malignancies were treated simultaneously, and in which the patient was cured of both. It is suggested that this case may serve as a reference for future similar cases.

Antineoplastic Combined Chemotherapy Protocols↗

Pipe friction head loss in transportation of high-concentration sludge for centralized solids treatment.

The objective of this study was to develop a method of predicting pipe friction head loss, which is a key factor in pipeline transportation of high-concentration sludge, thereby optimizing design for pipeline systems. The study involved both experimentation and analysis of pipeline transportation. Moreover, the study led to the representation of pipe friction head loss as functions of average velocity, transportation distance, pipe diameter, pipe interior roughness, and solids viscosity and temperature.

Algorithms↗

Electron microscopic analysis of myeloma cells in relation to drug response and prognosis.

Myeloma cells obtained from 33 patients were analyzed by electron microscopy to determine whether there is any correlation among ultrastructural characteristics of myeloma cells, drug response, and prognosis. The median survival time after diagnosis of responders (18 cases) and nonresponders (15 cases) was more than 423 days and 139 days, respectively. Nuclear immaturity and three cytoplasmic abnormalities--scattered pattern of mitochondria, single-sac looplike structures, and numerous intramitochondrial granules--were found to be associated with poor outcome. Although the cytoplasm of almost all the myeloma cells examined was judged to be mature or intermediate, the degree of nuclear immaturity was considered to correspond closely to the grade of nuclear-cytoplasmic asynchrony. Thus the electron microscopic examination of myeloma cells is of use to assess accurately their immaturity and abnormality and might provide clues for the prediction of drug response and prognosis of individual patients.

Female↗