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Biomedical subjects

N Nishimura

Publications and source records attributed to N Nishimura.

At least 127 records · Page 7Linked to original sources
PubMed1995

Effects of the dopamine-related drug bromocriptine on event-related potentials and its relation to the law of initial value.

Effects of the dopamine-related drug bromocriptine (BCT) on event-related potentials (ERP) were investigated in 18 healthy volunteers. Bromocriptine 2.5 mg or an inactive placebo was administered according to a completely randomized double-blind, cross-over design. The ERP were recorded 3 h after medication was given. Although BCT prolonged the P300 latency, it had no effect on the amplitudes of the ERP components as a whole. Bromocriptine increased the latencies of N100, P200 and P300 in the respective short-latency subject group, and decreased the latency of N200 in the long-latency subject group. It increased the amplitude of N200 in the low-amplitude subject group. It was concluded that the prolongation of P300 latency as a whole and the different responses that take place are dependent on the initial values and were recognized in the effect of a single administration of BCT 2.5 mg. The results of this study are discussed in relation to the law of initial value.

Adolescent↗
PubMed1995

[Effects of chronic losartan treatment on myocardial, vascular structure and reactivity with aging in spontaneously hypertensive rats (SHR): its effects compared with those of captopril].

To compare the effects of an angiotensin II (Ang II)-receptor antagonist and an angiotensin-converting enzyme (ACE) inhibitor on myocardial, vascular structure and reactivity, SHR (5-week-old) were treated with losartan of captoril for 16 weeks. Losartan (10 mg/kg/day, p.o.) and captopril (30 mg/kg/day, p.o.) significantly prevented the development of hypertension with aging, and the effects by these drugs were almost similar. Losartan and captopril significantly reduced the ventricular weight and the thickening of the coronary artery. Maximal coronary flow (MCF) induced by adenosine in the isolated heart was significantly higher in both the losartan and captopril groups. However, MCF in the captopril group was significantly lower than that in the losartan group. The pressor response to exogenous norepinephrine in the mesenteric arterial bed was significantly lower in the losartan group, whereas that in the captopril group was not. These findings suggest that the local Ang II produced by enzymes other than ACE also may play a role in vascular hypertrophy and hyperresponsiveness in SHR.

Aging↗
PubMed1995

Gastric myoelectrical activities in elderly human subjects--surface electrogastrographic observations.

To investigate the alteration of the gastric electrical activities by aging, we performed electrogastrography (EGG) on 13 asymptomatic young human subjects under 60 years old (the young group) and 12 subjects over 60 years (the elderly group). Surface EGG was recorded at fasting state for 30 minutes in each subject. We expressed the frequency distribution of surface EGG in each subject with the median value of frequency distribution (FMED) to represent the center of the electrical activities, and the interquartile range of frequency distribution (FIQR) as the indicator of regularity. FMED in the young group was 3.0: [2.9, 3.4] (median: [range]) cycles per minute (cpm), while it was 3.3: [3.0, 4.0] in the elderly group which showed statistically a significant difference between the groups (p = 0.01). FIQR in the young group was 0.5: [0.1, 1.8] and that in the elderly group was 0.55: [0.4, 1.7], which was not significantly different statistically. These data showed that aging increases the frequencies of the rhythm of surface EGG, without disturbing its regularity. This change may be a part of a spectrum of physiological changes accompanied with aging, and are unlikely to have clinico-pathological significance.

Adult↗
PubMed1995

Valine requirement of the finishing pig.

Pigs weighing approximately 70 kg were used in two experiments to determine the valine requirement during the finishing period. In the first experiment, 10 gilts were allotted in two 5 x 5 Latin square designs to five semipurified diets that ranged in valine concentration from .35 to .55%. Urinary urea excretion was measured during each of the 3-d periods of the Latin square. Urea N excretion in relation to N intake and to creatinine N excretion was minimized (quadratic effect, P < .10) at valine concentrations of .45 to .50%. In Exp. 2, 36 barrows and 36 gilts were fed one of six diets containing .35 to .60% valine. The highest weight gains (not significant) and feed efficiencies (quadratic effect, P < .05) were achieved by the pigs that consumed .45% valine. Plasma urea concentration at the end of the experiment was lowest (quadratic effect, P < .05) in pigs that consumed .50% valine. Estimates of the valine requirement based on breakpoint and quadratic equation analyses ranged from .40 to .50% total valine (.33 to .43% ileal digestible valine). Pigs in Exp. 2 consumed approximately 2.5 kg/d (8,850 kcal/d of ME). Thus, the estimate of the valine requirement is approximately 11 g/d. These estimates of the valine requirements of finishing pigs are slightly higher than the National Research Council requirements when expressed as a percentage of the diet but are similar when expressed on a grams per day basis.

Animal Feed↗
PubMed1995

Personality deviation and gastric motility in patients with functional dyspepsia.

We studied gastric motor functions by scintigraphic gastric emptying analysis and surface electrogastrography (EGG), and personality trait deviation in patients with functional dyspepsia. Delayed gastric emptying was observed in 17/35 patients and reduced normal EGG activity in 22/35 functional dyspepsia patients. There was a highly significant negative correlation between the gastric retention rate (at 150 min) and the duration of normal EGG waves. Abnormally high T scores on the Minnesota Multiphasic Personality Inventory (MMPI) test (70 or above) were found in 14/21 patients. Hypochondriasis (Hs) and conversion hysteria (Hy) were the most common abnormal findings. Ninety percent of functional dyspepsia patients (19/21) had either gastric dysmotility and/or psychological deviation. Although there was no significant correlation between gastric dysmotility and deviation in personality traits in functional dyspepsia patients, these data suggest that brain-gut interactions may play an important role in the symptoms of functional dyspepsia.

Adolescent↗
PubMed1995

Clinical effect of etidronate disodium (EHDP) on heterotopic ossification following total hip arthroplasty.

We investigated the status of the development of heterotopic ossification and compared the frequency of heterotopic ossification in the EHDP group with that in the untreated (control) group to evaluate the efficacy and safety of EHDP. Seventy-seven patients who had undergone total hip arthroplasty or femoral head prosthesis for the treatment of osteoarthritis and femoral neck fracture were enrolled in the study. Heterotopic ossification surrounding the hip joint was evaluated according to the roentgenographic classification. In the control group, heterotopic ossification was found in 10 patients (20%) during the period, while in the EHDP group, it was found in one patient (3.7%) during the treatment period after the operation. Gastrointestinal disorder, in one case only was a side effect observed during EHDP treatment. It was revealed that EHDP inhibits heterotopic ossification following total hip replacement in patients with osteoarthritis.

Adult↗
PubMed1994

Molecular cloning and characterization of two rab GDI species from rat brain: brain-specific and ubiquitous types.

Rab GDP dissociation inhibitor (GDI) is a regulatory protein for Rab proteins that controls not only the GDP/GTP exchange reaction of Rab proteins but also their translocation between the cytosol and cell membranes. Recently, rab GDI cDNAs have been isolated from human, bovine, rat, and Drosophila, and these Rab GDI proteins indicated an important role in the regulation of intracellular vesicle traffic. In this study, we have isolated two different rab GDI cDNAs, designated rat rab GDI alpha and beta, from a rat brain cDNA library using bovine rab GDI cDNA as a probe. Rat rab GDI alpha and beta show 99 and 86% amino acid identity with bovine rab GDI, respectively, indicating that rat rab GDI alpha is a rat counterpart of bovine rab GDI. Both rat Rab GDI alpha and beta proteins expressed in Escherichia coli showed a similar degree of activity of regulating the GDP/GTP exchange reaction to that of bovine Rab GDI using Rab3A and Rab11 as substrates. Northern blot analysis revealed that rab GDI alpha mRNA was expressed abundantly in brain but much less in other tissues, whereas rat rab GDI beta mRNA was ubiquitously expressed. Reverse transcription-polymerase chain reaction analysis revealed that astrocytes expressed rat rab GDI beta gene but not rat rab GDI alpha gene. These results indicate that Rab GDI alpha is involved in sorting of highly specialized vesicles in brain such as neurosecretory vesicles, whereas Rab GDI beta plays a general role in vesicular trafficking in diverse types of cells.

Amino Acid Sequence↗
PubMed1994

Metallothionein mRNA in the testis and prostate of the rat detected by digoxigenin-labeled riboprobe.

Metallothionein (MT), a cysteine-rich heavy metal-binding protein, has been considered to play a role in the homeostatic control and detoxification of heavy metals, such as zinc, copper, and cadmium. In the present study, we have utilized a digoxigenin-labeled riboprobe to localize MT mRNA only by bright-field optics in the testis and prostate of the rat. In the rat testis, MT mRNA was found predominantly in primary spermatocytes and also in secondary spermatocytes and spermatids, but not in the spermatogonia, Sertoli cells, and Leydig cells. On the other hand, MT protein was present in these spermatogenic cells as well as in spermatozoa and Sertoli cells. In the prostate, MT mRNA was found predominantly in the epithelium of the dorsolateral lobes, but not in the ventral lobe, which is in agreement with the observed localization of MT protein. The utilization of both in situ hybridization and immunohistochemical staining on the same tissue specimens show MT gene expression in specific cell types in the male genital organs.

Animals↗
PubMed1994

Correlation between serum levels of alanine aminotransferase and ferritin in male blood donors with antibody to hepatitis C virus.

Chronic hepatitis C has been demonstrated to be associated with hepatic iron overload, and the hypothesis that the disease activity of hepatitis C is associated with iron cytotoxicity was tested in male volunteer blood donors. Sera with either antibody to hepatitis C virus or hepatitis B surface antigen were selected for determination of ferritin concentration and alanine aminotransferase activity. A correlation between serum ferritin concentration (Y; microgram/l) and alanine aminotransferase activity (X; IU/l) was found in donors with antibody to hepatitis C (log Y = 0.65 x log X + 0.98, r = 0.53, and P < 0.01). The correlation was lower in donors with hepatitis B surface antigen (r = 0.37; P < 0.01). Hepatitis C virus infection probably induces time-dependent iron accumulation associated with the progression of disease activity, while hepatitis B virus infection results in a variety of iron loads with different clinical features. The high disease activity related to hyperferritinemia suggests the presence of iron-induced liver damage in donors with hepatitis C.

Adult↗
PubMed1994

Possible role of metallothionein in the cellular defense mechanism against UVB irradiation in neonatal human skin fibroblasts.

The role of metallothionein (MT) in protecting skin cells against UVB irradiation was investigated. Fibroblast strains from normal adult (HS-K) and neonatal (NB1RGB) human skins as well as keratinocyte strains from human skin (SV40-HSK) and newborn Balb/c mouse skin (Pam 212) were exposed to UVB irradiation. The sensitivity of HS-K and NB1RGB cells to UVB irradiation was similar; those of SV40-HSK and Pam 212 cells were two- and six-fold as sensitive to UVB irradiation as HS-K cells, respectively. The HS-K cells contained the greatest cellular reduced form of glutathione (GSH) levels compared to the three other skin cells: the levels were 13-, 7- and 6-fold of those in NB1RGB, SV40-HSK and Pam 212 cells, respectively. These results indicated that the sensitivity of skin cells to UVB irradiation was not always associated with their endogenous GSH levels. In particular, despite the fact that NB1RGB cells contained a relatively small amount of GSH, they were less sensitive to UVB irradiation. NB1RGB cells contained 4-30 times more MT than those in other skin cells examined. The sulfhydryl residues of MT molecules in the NB1RGB cells were estimated to be mostly unoccupied by metals, suggesting they act in a similar way to those of GSH. Moreover, NB1RGB cells in which the MT content was elevated by dexamethasone (1 microM) or Zn2+ (7 micrograms/mL) treatment were more resistant to UVB irradiation than nontreated ones. These results suggest that, at least in neonatal human skin fibroblasts, MT may play a role in protection against UVB irradiation.

Animals↗
PubMed1994

Metabolism of 3,5,3',5'-tetrachlorobiphenyl by rat liver microsomes and purified P4501A1.

1. The metabolism of 3,5,3',5'-tetrachlorobiphenyl (TCB) was investigated with liver microsomes and purified P450 from the male Wistar rat. 2. One novel metabolite was produced after incubation with liver microsomes derived from the 3-methylcholanthrene (MC)- and 3,4,5,3',4'-pentachlorobiphenyl-pretreated rat, but not after incubation with those from the untreated or phenobarbital (PB)-pretreated rat. These results suggest that P450 isozyme(s) induced by MC-type inducers is involved in 3,5,3',5'-TCB metabolism. 3. The chemical structure of this metabolite was identified to be 4-hydroxy-3,5,3',5'-TCB by comparison of its retention time in glc and the ms with those of a synthetic sample. 4. Purified rat P4501A1, a major MC-inducible P450 isozyme, catalyzed the 4-hydroxylation of 3,5,3',5'-TCB, but P4502B1, a major PB-inducible isozyme, was inactive. 5. Reduced glutathione completely inhibited the formation of the hydroxylated metabolite, suggesting that 4-hydroxylation of 3,5,3',5'-TCB proceeded via the 3,4-epoxide.

Animals↗
PubMed1994

Improvement of serum aminotransferase levels after phlebotomy in patients with chronic active hepatitis C and excess hepatic iron.

OBJECTIVES: Iron metabolism may be altered in patients with chronic active hepatitis C. In an attempt to evaluate whether excess iron contributes to liver injury, we used phlebotomy for removal of iron from patients with chronic hepatitis C. METHODS: All 10 patients had histochemically detectable iron in the liver and underwent an initial period of weekly or monthly phlebotomy of 200 or 400 ml. A serum ferritin level of 10 ng/ml or less was chosen as the endpoint, and maintenance phlebotomy was performed if the level rebounded. RESULTS: The treatment reduced mean serum alanine aminotransferase activity from 152 +/- 49 to 55 +/- 32 IU/L; this level became normal in five of the 10 patients. Anti-HCV antibodies could be detected in all patients throughout the study. Histologic abnormalities of the liver were unchanged except for disappearance of iron deposits from seven of the patients studied. CONCLUSIONS: Our findings suggest that iron removal may be beneficial for patients with chronic active hepatitis C and histochemical iron in the liver.

Adult↗
PubMed1994

[The effect of the posture in the spread of the epidural anesthesia].

In 20 gynecological patients, the radionuclide was injected through the epidural catheter to determine the effect of the posture on the distribution of the radionuclide in the epidural space. Each 5 were placed on supine, right decubitus, left decubitus or sitting position and the posture was maintained for 30 min after the injection of the radionuclide. The distribution of the radionuclide in the epidural space was determined by measurement of gamma ray by a gamma camera. The data were stored and analyzed by a digital computer (SINTIPAC). In supine and right decubitus position, the radionuclide was distributed more on the right side and in the left decubitus position the radionuclide was distributed evenly. In the sitting position the radionuclide was distributed more caudad and the cephalad distribution was limited compared to the other postures. In summary the solution in the epidural space may move by the gravity but these effects were very slight and are of only minor clinical significance.

Adult↗
PubMed1993

Clinical usefulness of computer-assisted diagnosis using combination assay of tumor markers for pancreatic carcinoma.

BACKGROUND: There has been extensive use of serum tumor markers in diagnosing pancreatic adenocarcinoma. There is no tumor marker, however, that alone has sufficient diagnostic accuracy. It is necessary to know which combination of tumor markers should be used to detect pancreatic cancer, with respect to clinical usefulness and cost effectiveness. METHODS: Serum levels of 17 kinds of tumor markers were determined in 145 patients and 40 healthy volunteers. Thirty-five patients with proven pancreatic adenocarcinoma, and 32 with benign pancreatobiliary disease (14 chronic pancreatitis and 18 biliary stones) were selected. For analysis of the usefulness of each tumor marker to differentiate these two groups, scatterplot and relative operating characteristic (ROC) analyses were used. A multivariate discriminant system to differentiate these two groups was developed using stepwise discriminant analysis by backward elimination selection. RESULTS: The significance of each tumor marker varied according to the tumor volume. By ROC analysis, the markers were divided into four subgroups according to their usefulness in discriminating pancreatic adenocarcinoma from benign pancreatobiliary disease. A discriminant system consisting of two different discriminant functions using nine tumor markers (CA 19-9, DUPAN-2, TPA, elastase-1, lipase, amylase, gamma-glutamyl transpeptidase, alkaline phosphatase, and lactate dehydrogenase) was developed and designated CAMPAS-P; it could differentiate between all 35 cases of pancreatic adenocarcinoma and 32 cases of benign pancreatobiliary disease. On the other hand, CAMPAS-P showed a low positive rate in pancreatic tumors of unusual histologic type, and poor organ-specific diagnostic ability in various digestive organ malignancies. CONCLUSIONS: CAMPAS-P may be very useful for differential diagnosis between pancreatic adenocarcinoma and benign pancreatobiliary disease.

Adenocarcinoma↗
PubMed1993

A study of the bioactive bone cement--bone interface: quantitative and histological evaluation.

The interface between bone and a bioactive glass cement--a mixture of bioactive glass powder and ammonium phosphate solution, previously reported on by the authors--was evaluated quantitatively and histologically. The materials tested were (1) the original bioactive glass cement (BCI cement); (2) an improved type of bioactive glass cement (BCII cement); (3) polymethylmethacrylate (PMMA) bone cement; and (4) a bioactive, apatite-wollastonite-containing, glass ceramic (A-WGC). Hardened cylindrical specimens of each cement were inserted loosely into canine femora and the interfacial shear strengths were measured using a push-out test. The interfacial strength values of the bioactive glass cements increased with prolonged implantation time. At each postimplantation time studied (8, 12, and 24 weeks), the interfacial strength value of BCI cement did not differ significantly from that of A-WGC. BCII cement interfacial strength was greater than that of BCI cement, whereas the interfacial strength of PMMA bone cement remained at a very low level throughout the study. Histological examinations revealed that direct bonding of both bioactive glass cements to bone had occurred without pathologic degradation. After 24 weeks, the defects between the bone and the bioactive glass cements had been filled with mature lamellar bone. Because the bioactive glass cement system developed by the authors, especially BCII cement, shows excellent osteoconductivity and bonds to bone tightly, we consider it to be a promising material for fixing prostheses into bone.

Animals↗
PubMed1993

Antibody against the carboxyl terminus of the F2 subunit of Sendai virus fusion glycoprotein inhibits proteolytic activation.

Rabbit antibody, F2C12, was prepared against a synthetic peptide of 13 amino acids corresponding to the C-terminus of the F2 subunit of Sendai virus F protein. F2C12 was shown to bind specifically to the F2 subunit, irrespective of proteolytic cleavage of the F protein. F2C12 did not affect the infectivity, hemolytic, and cell fusion activities of activated virus, but F2C12 did inhibit proteolytic cleavage of the precursor F0 to subunits, F1 and F2, by trypsin, factor Xa from chick embryos and Tryptase Clara from rat lungs. When F2C12 was added to the chorioallantoic cavity of chick embryos, cleavage activation of Sendai virus was inhibited. Intranasal administration of F2C12 to Sendai virus-infected rats suppressed activation and multiplication of progeny virus in the lungs. These results indicate that proteolytic cleavage of the F protein, with a single arginine residue at the cleavage site, occurs extracellularly in the allantoic cavity of chick embryos and in the bronchial lumen of rats.

Allantois↗