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Biomedical subjects

N Nakaya

Publications and source records attributed to N Nakaya.

At least 37 records · Page 2Linked to original sources

[A case of Lemmel's syndrome with serious jaundice exacerbated by eating].

An 86-year old woman rapidly developed serious jaundice (T-Bil 18.3 mg/dl 12.3 mg/dl). Her jaundice was exacerbated by eating, and improved by fasting. Abdominal CT showed a giant diverticulum in the second part of the duodenum and dilation of the proximal common bile duct. Endoscopic findings confirmed juxtapapillary duodenal diverticulum in contact with the distal common bile duct. MRCP revealed extrinsic compression of the distal common bile duct by the diverticulum. Lemmel's syndrome was diagnosed. Jaundice did not recur after surgery. We speculated that in this case the diverticulum filled by duodenal contents easily compressed the distal common bile duct after eating.

Aged↗

Increase in histidine decarboxylase activity in tissues of mice bearing Colon-26 tumor cells.

The changes in histidine decarboxylase (HDC) activity, histamine and tele-methylhistamine contents were examined in tissues of mice after the inoculation of Colon-26 tumor cells subcutaneously into the lower back. The HDC activity in the spleen of mice increased significantly 14 days after the inoculation of Colon-26 and the increase in HDC activity continued for up to 28 days. However, the histamine content in the spleen of tumor-bearing mice was not changed significantly during the observation period. In the following experiments, two subclones of the Colon-26 cell line, cachexia-inducing clone-20 and non cachexia-inducing clone-5, were used and the induction of HDC activity in mice was examined in four tissues, spleen, lung, liver and kidney. Both clone-20 and clone-5 induced the increase in HDC activity to the same extent in the spleen and lung, but not in the liver and kidney. As observed using the Colon-26 original cell line, the histamine contents in the four tissues of tumor-bearing mice were not different from those in the control mice. In contrast, the levels of tele-methylhistamine, one of the major catabolites of histamine, in the tumor-bearing mice increased significantly compared with the control mice in all four tissues examined. There was a correlation between the increase in tele-methylhistamine level and the increase in HDC activity in the tissues. A histological study indicated that the tissue mast cells were not increased in spleen and lung of tumor-bearing mice. These findings indicated that the increase in HDC activity in the spleen and lung occurred in parallel with the growth of inoculated tumor cells in mice and suggested that the cells other than mast cells may be involved in the increase in HDC activity. The tumor-bearing state produced histamine with a high turnover rate in the mouse tissues, especially in the spleen and lung.

Adenocarcinoma↗

Analysis of serum lipid levels in Japanese men and women according to body mass index. Increase in risk of atherosclerosis in postmenopausal women. Research Group on Serum Lipid Survey 1990 in Japan.

Relatively low serum lipid levels are thought to be an important factor contributing to the low incidence of ischemic heart diseases (IHD) in Japanese. It has been proven that obesity or overweight constitutes a basal condition for several risk factors in atherosclerosis. The purpose of this study is to obtain data on serum lipids and lipoprotein profiles in relation to body mass index (BMI), which will enable us to compare the nature and weight of metabolic risk factors in atherosclerosis between Japanese and people in Western countries. Data of total serum cholesterol, triglyceride, and HDL-cholesterol levels of Japanese men and women obtained from a large-scale survey in 1990 were analysed according to BMI for different age groups. Apolipoprotein A-I and B and Lp(a) were also measured in randomly selected samples and their contribution as a risk factor was estimated especially in postmenopausal women. The subjects in two age groups of men (20-39 and 40 59 years) and women (20 39 and 50-69 years) were graded into quintiles according to the BMI. The middle grades of BMI were 21.9-23.3 and 22.4-23.6 for younger and older men, and 20.0-21.1 and 22.2-23.6 for younger and older women, respectively. These values are much lower than those in Western populations, the border between the IVth and the top quintile almost corresponding to the average for Americans. Total cholesterol showed a tendency to shift into higher ranges in all age groups in both men and women as BMI increased, with the highest distribution remaining in the range of 160-199 mg/dl (4.2-5.2 mmol/l). The average cholesterol levels for the top quintile of BMI were still lower than most of the average values in Western populations. The distribution of cholesterol in higher ranges was much greater and the difference according to BMI was smaller in older women than in men. In both men and women, whether younger or older, about 90% of the subjects in the lower quintiles of BMI had triglyceride levels lower than 150 mg/dl. The distribution in the higher range of triglyceride was small in women, not only at younger ages but also in postmenopausal women at the top quintile of BMI. About 85% of the younger women with a middle grade of BMI had an HDL-cholesterol level higher than 50 mg/dl. The values in postmenopausal women were still higher than in men aged 40-59 years. Shift of the distribution curves of HDL-cholesterol according to BMI was similar in all groups and more remarkable than the change in triglyceride. The average HDL-cholesterol levels at the top quintile were almost comparable to the average values in Western countries; the difference in HDL-cholesterol levels between the two populations can mostly be explained by the difference in BMI. Smokers showed a slightly lower total cholesterol and significantly (3-4 mg/dl) lower HDL-cholesterol levels, although there was no difference in distribution of BMI between smokers and non-smokers. Relatively low total cholesterol levels even in smokers has probably contributed to the low incidence of IHD in spite of the high frequency of smoking in Japanese population. Mean Lp(a) levels showed a tendency to increase after age 40 in women. BMI itself did not have a correlation with serum Lp(a) levels. The distribution curve of Lp(a) shifted to higher levels as total cholesterol increased and the tendency was most remarkable in women around or after the menopause. It was remarkable in older women that as the total cholesterol or apo B level increased there was also an increased prevalence of abnormal ECG with a pattern of myocardial ischemia. Postmenopausal women seem to have a great risk of atherosclerosis regarding the lipid and lipoprotein profile even in the Japanese population.

Adult↗

[Anti-hyperlipidemic drug].

Drug treatment of hyperlipidemia was reviewed. In the first part, mode of action, efficacy and safety of lipid-lowering agents were described and in the second part, strategies for treatment of hyperlipidemia was described. Treatment of hypercholesterolemia should be started with statin and if the reduction is not enough, cholestimide or nicotinic acid or probucol can be added. Mild hypertriglyceridemia can be treated with dextran sulfate sodium, but usually low dose of fenofibrate or bezafibrate will be necessary. For severe cases, combination therapy with fibrate and nicotinic acid or ethyl icosapentate is required. Treatment of combined hyperlipidemia should be started with fibrate, but when the increment of cholesterol is superior to triglyceride, statin can be chosen. If these drugs are not fully effective, combination therapy with statin and ethyl icosapentate is recommended.

Humans↗

[Effectiveness and practice of dietary therapy and exercise].

Dietary therapy and physical activity are cornerstones for lipid lowering and prevention of cardiovascular disease. The efficacy of dietary therapy has been established in several primary and secondary prevention studies. Exercise is believed to be useful to prevent atherosclerosis, but there has been no mega trial performed. The beneficial effect of physical activity may be mediated in several ways, such as reduction in VLDL, increase in HDL, reduction in body weight and reduction in blood pressure. According to the guideline of Japan Atherosclerosis Society, dietary modification is recommended to perform in three steps and practical use of the guideline was described. For exercise, aerobic activity, such as brisk walking, jogging, swimming and bicycling are recommended. Intensity, amount and frequency of exercise were described.

Exercise Therapy↗

Clinical efficacy and safety of cerivastatin: summary of pivotal phase IIb/III studies.

Cerivastatin is a new, third-generation 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor ("statin"), which is administered to hypercholesterolemic patients at doses equivalent to 1-3% of the doses of other statins. This report reviews the pivotal Phase IIb/III clinical trials in which the efficacy and safety of cerivastatin was compared with placebo and active comparator statins (lovastatin, simvastatin, and pravastatin) after both short- and long-term administration. Overall, the studies showed that at doses of 0.025-0.4 mg/day, cerivastatin produced dose-dependent reductions in low-density lipoprotein (LDL) cholesterol and total cholesterol, which were significantly greater than placebo. The greatest reductions were achieved with 0.4 mg/day cerivastatin. On this dose, >40% of patients achieved reductions in LDL cholesterol >40% and in a further 9% of patients, LDL cholesterol was decreased by >50%. At higher doses, cerivastatin also demonstrated potent triglyceride-lowering effects in a subgroup of patients with raised plasma triglycerides. Reductions in atherogenic lipids and lipoproteins were accompanied by significant increases in high-density lipoprotein (HDL) cholesterol, apolipoprotein A-I, and antiatherogenic lipoprotein A-I. Long-term administration of cerivastatin for periods of up to 2 years was associated with persistent reductions in LDL cholesterol, total cholesterol, triglycerides, and apolipoprotein B as well as increases in HDL cholesterol similar to those observed after initial administration. Long-term cerivastatin treatment was also well tolerated. There was no significant difference between the incidence of adverse effects with cerivastatin and comparator statins or between cerivastatin and other statins with respect to clinically significant increases in either hepatic enzymes or creatine phosphokinase. In conclusion, these studies indicate that cerivastatin is a safe and effective long-term treatment for patients with primary hypercholesterolemia and also suggest that higher doses should be investigated.

Adolescent↗

Localization of a serine proteinase inhibitor, B-43, in the bovine pancreas.

B-43, a serine proteinase inhibitor belonging to the ovalbumin branch of the serpin superfamily, was purified and cloned from bovine brain. Since [35S]-labeled B-43 forms SDS-stable complexes with pancreatic serine proteinases, trypsin, alpha-chymotrypsin, and kallikrein, it has been suggested that B-43 is capable of inhibiting these serine proteinases and that B-43 may be present in the pancreas. In the present study, we investigated the localization of B-43 in the bovine pancreas immunohistochemically and examined the effect of B-43 on the amidolytic activities of pancreatic serine proteinases. Strong B-43-like immunoreactivity was localized in acinar cells, especially in the basal sides of the cells where the rough endoplasmic reticulum is located. The nuclei of the subpopulation of acinar cells were also immunoreactive for B-43. The recombinant glutathione S-transferase-B-43 fusion protein inhibited the amidolytic activity of trypsin and, to a lesser extent, alpha-chymotrypsin and kallikrein, but not elastase. These results suggest a role of B-43 in regulating serine proteinases both in the cytoplasm and the nucleus.

Animals↗

The expression and localization of serine proteinase inhibitor PI-6 mRNA in developmental and ischemic mouse brain.

A serine proteinase inhibitor, PI-6, is a member of the serine proteinase inhibitor (serpin) superfamily. In the present study, we investigated the developmental expression of PI-6 in the mouse brain and the effect of experimental ischemia on the expression of PI-6 in the adult brain. Northern blot analysis showed a high level of expression of PI-6 mRNA in brain stem and diencephalon as compared with other regions in the adult brain. The expression of PI-6 mRNA in the whole brain was increased gradually until 11 days after birth and was decreased again in the adult brain. In situ hybridization analysis revealed that the mRNA was localized in pyramidal cell layer of the post-natal hippocampus, especially in CA3 region, and in layer V of the cerebral cortex. In the brain stem, two specific motor nuclei, the facial nucleus and the motor nucleus of trigeminal nerve, which are important to active feeding, were strongly positive for PI-6 mRNA. Brain ischemia induced by bilateral ligation of the common carotid artery led to an increase in PI-6 mRNA expression in the whole brain, accompanied by the degeneration of hippocampal pyramidal cells. These results indicate distinct temporal and spatial expression of PI-6 in the mouse brain and suggest the involvement of PI-6 in the maturation of neurons and degenerative and regenerative processes.

Age Factors↗

Changes in monoamine turnover in the brain of cachectic mice bearing colon-26 tumor cells.

Patients with cancer cachexia often suffer from psychiatric disorders. In the present study, we investigated the changes in monoaminergic activities in the brain in tumor-bearing mice with reference to the development of cachexia. Two clones, clone-5 (noncachectic clone) and clone-20 (cachectic clone), derived from the murine Colon-26 adenocarcinoma cell line (Nippon Roche Research Center), were inoculated subcutaneously at 1 x 10(6) cells/0.2 ml into the right lower back of BALB/c mice. In clone-20 mice, body weight and locomotor activity decreased significantly 10-15 days after tumor inoculation. The levels of noradrenaline, dopamine, and 3,4-dihydroxyphenylacetic acid showed no significant change among the three groups. The noradrenaline turnover rate in clone-20 mice was increased in cerebral cortex, hypothalamus, and midbrain. The 5-hydroxytryptamine turnover rate in clone-20 mice was increased in hippocampus, cerebral cortex, midbrain, and pons-medulla oblongata. In contrast, the dopamine turnover rate in clone-20 mice was decreased markedly in hippocampus, cerebral cortex, striatum, hypothalamus, and cerebellum. There was no significant change in amine turnover between control and clone-5 mice except for dopamine in hippocampus, cerebral cortex, and striatum and 5-hydroxytryptamine in striatum. No significant change in the levels of amino acids in the brain was observed among the three groups of mice. It is concluded that some of the psychiatric disorders from which cancer cachectic patients suffer might be ascribable to changes in monoaminergic activities in the brain.

Adenocarcinoma↗

Immunohistochemical localization of macrophage migration inhibitory factor (MIF) in tanycytes, subcommissural organ and choroid plexus in the rat brain.

We investigated the immunohistochemical localization of the macrophage migration inhibitory factor (MIF) in the rat brain. In addition to epithelial ependymal cells lining the ventricular wall, tanycytes in the basomedial hypothalamus were heavily immunostained. The immunoreactive processes of tanycytes made contacts to sinusoidal capillaries and reached the pial surface forming an immuno-positive structure at the floor of the hypothalamus. Other immunoreactive cells contained the subcommissural organ in the roof of the third ventricle and the epithelial lamina of the choroid plexus. The localization of MIF in cells which have contact with cerebrospinal fluid and blood vessels suggests that MIF might play a role as a humoral factor in the brain.

Animals↗

Pharmacokinetic properties of YM17E, an inhibitor of acyl coenzyme A: cholesterol acyl transferase, and serum cholesterol levels in healthy volunteers.

We conducted a single and repeat oral dose study of YM17E, a novel inhibitor of acyl coenzyme A (CoA): cholesterol acyltransferase, in healthy male volunteers to evaluate the pharmacokinetic profile, tolerability and effect of the drug on serum cholesterol. In the single administration study, YM17E was administered after a meal to two groups of subjects (each containing six subjects taking the drug and three taking placebo) receiving 3, 60 and 300 mg or 15, 60 and 450 mg YM17E, respectively. Plasma concentrations of unchanged drug following single oral administration at 3-300 mg after a meal increased with increasing dose. In contrast, plasma concentrations after administration of 450 mg were almost the same as after 300 mg. Unchanged YM17E was not detected in urine after single administration, suggesting that it was excreted via the bile or urine after metabolism. Five active metabolites (M1, M2-a, M2-b, M3 and M4) were observed in plasma at concentrations comparable to those of unchanged YM17E. Their plasma concentrations increased in a slightly greater than dose-dependent manner from 3 to 300 mg. The effect of food was studied in an open crossover design with a 1-week washout period. Twelve subjects received 150 mg YM17E in both the fasted and post-prandial states. The AUC and Cmax after fasting were closely similar to those after a meal, showing that bioavailability was not affected by food intake. In the repeated oral dose study, the subjects received test drug at 150 mg or 300 mg (n = 6 each) or placebo (n = 3) twice a day (after breakfast and after dinner) for 7 days. On days 1 and 7, the subjects received YM17E once a day (after breakfast) for evaluation of pharmacokinetic properties. After repeated oral administration of 150 mg b.d., plasma concentrations reached steady state by day 5 (mean Cmin 48.6 ng.ml-1). After repeated administration of 300 mg b.d., plasma concentrations prior to each daily morning dose increased up to the 5th day (mean Cmin 166.6 ng.ml-1) and then tended to decrease until the 7th day. No significant signs, symptoms or changes in serum cholesterol levels were observed during the single and repeated oral dose studies at 150 mg b.d. Although statistical analysis was not conducted because of the small number of subjects, all subjects receiving repeated oral administration of 300 mg twice daily showed a 25% decrease in serum cholesterol level on day 7, but also the simultaneous occurrence of diarrhoea.

Administration, Oral↗

Presence of macrophage migration inhibitory factor (MIF) in ependyma, astrocytes and neurons in the bovine brain.

We investigated the immunohistochemical localization of a cytokine macrophage migration inhibitory factor (MIF) in the bovine brain. MIF was present in the ependymal cell linings of the cerebral ventricles throughout. Double immunostaining of the section with anti-glial fibrillary acidic protein (GFAP) antibody and with anti-MIF antibody showed that the astrocytes present in subependymal layer were immunoreactive for MIF. In the hippocampus, the pyramidal cells in the CA3 and CA4 subfields and the granule cells of the dentate gyrus were immunoreactive. The bundles of mossy fibers were stained along their projections to CA3 and CA4 regions. The nuclei of the subpopulation of these MIF-immunoreactive cells were also immunostained. These results indicated the widespread distribution of a cytokine, MIF, in the bovine brain and suggested the possibility that MIF might play additional roles than a proinflammatory mediator role in the brain.

Animals↗

Cloning of a serine proteinase inhibitor from bovine brain: expression in the brain and characterization of its target proteinases.

A cDNA encoding of the serine proteinase inhibitor (serpin), B-43, was cloned from the cDNA library of the bovine brain. It encoded 378 amino acids, and the MW of the protein was estimated to be 42.6 kDa, which is consistent with that of the native B-43 purified from the bovine brain. The homology search revealed that B-43 belongs to the ovalbumin branch of the serpin superfamily. Among them, B-43 was most homologous to human placental thrombin inhibitor (PI-6) and its murine counterpart, with the amino acid identity of 76% and 71%, respectively. Northern blot analysis showed that the size of the transcript was 1.4 kb, and that the expression of B-43 in the bovine brain varied depending on the brain regions, i.e. a lower level of expression was observed in the cerebral cortex and the hippocampus compared to the level of expression that was observed in the medulla oblongata. [35S]-labeled B-43 protein was synthesized in vitro by using a rabbit reticulocyte lysate system, which formed complexes with proteinases such as thrombin, trypsin, alpha-chymotrypsin, and 7S nerve growth factor (NGF), but not with urokinase or plasmin. These results, together with the immunohistochemical localization of B-43 in astrocytes and in some neurons which was observed in the previous study suggest that B-43 may be involved in the regulation of serine proteinases present in the brain or extravasated from the blood.

Animals↗

Affinity purification of macrophage migration inhibitory factor/glycosylation inhibiting factor (MIF/GIF) from bovine brain by using a peptide ligand derived from a novel serpin.

We purified macrophage migration inhibitory factor/glycosylation inhibiting factor (MIF/GIF) from bovine brain by using an affinity column with the C-terminal region peptide of a novel serpin as a ligand. The affinity purified preparation showing a single band on SDS-PAGE contained four peptides on RP-HPLC, which were converged into two peptides time-dependently. Sequence analysis and Western blotting revealed that one was identical to bovine MIF/GIF and the other was an N-terminally modified form of MIF/GIF. These results indicated that there exist at least two forms of MIF/GIF in the bovine brain and that they have an affinity for the C-terminal portion of the serpin.

Amino Acid Sequence↗

A novel serpin-like protein, B-43, exists in both neurons and astrocytes: an immunohistochemical study in the parietal region of the bovine brain.

The presence of a novel member of serine proteinase inhibitor, B-43, was immunohistochemically indicated in both neurons and astrocytes in the parietal region of the bovine brain. B-43-like immunoreactivity was detected in pyramidal cells in the cortex and GFAP-positive astroglial cells in the white matter. The processes of B-43 may play a cooperative role with glia-derived nexin/protease nexin-1 and alpha 1-antichymotrypsin in the brain.

Animals↗

Clinical efficacy of fluvastatin for hyperlipidemia in Japanese patients.

The objective of the study was to evaluate the efficacy and safety of fluvastatin in patients with hypercholesterolemia, including heterozygous familial hypercholesterolemia, in a 1-year study (a 12-week open assessment, followed by 40 weeks of active treatment). Of the 337 patients enrolled in the study, the effects of fluvastatin were analyzed in 296 patients at baseline and at 12 weeks. Of these, 265 were receiving 20 mg/day fluvastatin at week 12 and in 20 patients the dose had been increased to 30 mg/day; 11 patients violated the dosing protocol. A total of 229 patients continued into the 40-week, long-term phase, and 212 patients were analyzed at baseline and after 24 and 52 weeks. At the end of treatment, 153 evaluable patients were still taking 20 mg/day fluvastatin, 1 was taking 10 mg/day, and 48 patients were taking 30 mg/day, and 10 were taking 40 mg/day. In the 20 mg/day fluvastatin group, low density lipoprotein cholesterol (LDL-C) levels decreased by 24.1% at week 12 and by 29.3% at week 52. In those patients requiring the higher doses, the corresponding reductions in LDL-C were 20.2% (week 12) and 26.7% (week 52). Total cholesterol was also reduced at week 12 by 17.0% (20 mg/day) and 15.7% (20-30 mg/day), and at week 52 by 20.4% (< or = 20 mg/day) and 19.2% (> or = 30 mg/day). Throughout the study, fluvastatin was generally well tolerated and no serious clinical adverse events were observed. In conclusion, long-term treatment of hypercholesterolemia with fluvastatin at dosages of 20-40 mg daily can be considered both safe and effective.

Anticholesteremic Agents↗