Biomedical subjects

M Nakano

Publications and source records attributed to M Nakano.

At least 397 records · Page 22Linked to original sources

PubMed1997

Renal stones in patients with rheumatoid arthritis.

OBJECTIVE: Renal stones are reported to be one of the causes of hematuria in patients with juvenile rheumatoid arthritis (RA). We performed abdominal ultrasonography on patients with RA to investigate the frequency of renal stones and whether renal stones are related to hematuria. METHODS: We conducted abdominal ultrasonography in 224 patients with RA (42 men, 182 women). Mean age was 61.4 years, and the mean duration of disease was 13.5 years. RESULTS: Renal stones were defined as hyperechoic spots with acoustic shadows, and they were observed in 37 patients. We also noticed hyperechoic spots without acoustic shadows in 50 patients. Five of these 50 patients also had renal stones. Twenty-one patients showing hyperechoic spots without acoustic shadows underwent computed tomographic scans, and apparent calcifications were observed in 10 patients. Age and sex matched controls had a significantly lower incidence of renal stones and hyperechoic spots without acoustic shadows than did patients with RA. Hematuria was more frequently observed in patients with RA with renal stones than in those without renal stones or hyperechoic spots without acoustic shadows. Urinary calcium/creatinine (Ca/Cr) ratios were elevated in patients compared to controls. Urinary Ca/Cr ratios in patients taking vitamin D3 were higher than those of patients not receiving the vitamin. Administration of vitamin D3 also was associated with increased incidence of renal stones. CONCLUSION: We observed a high incidence of renal stones in patients with RA. Hematuria was more prevalent in patients with RA with renal stones than in those without. These results suggest the importance of performing abdominal ultrasonography on patients with RA.

Aged↗

PubMed1997

[Assessment of left ventricular function by pressure-volume loop in VSD and TOF before and after operation].

This study estimates the perioperative left ventricular function of VSD and TOF by using Pressure-Volume (PV) loop. The most characteristic hemodynamic change of VSD is a decreased volume load. Although ejection fraction significantly decreased after the operation, this change did not mean a deteriorated left ventricular contractility. Emax, which is an index of left ventricular contractility on PV loop, improved and pressure-volume area (PVA) which is correlated with 02 consumption of left ventricule was reduced. Mechanical efficiency of left ventricular energetic state did not significantly change. Left ventricular volume and ejection fraction in TOF slightly increased after the operation. Increased ejection fraction reflected a compensation to volume overload after surgery. Emax slightly decreased and PVA increased. Meanwhile mechanical efficiency increased after the operation indicating well preserved ventricular contractility. In particular, the shape of PV loop of both VSD and TOF eventually became usual square after operation due to recover of the isovolumic contraction and relaxation phase. These characteristics had better to be concerned for improvement of surgical techniques as in conotruncal repair, particularly in TOF in the setting of better quality of life with low atrial pressure.

Child↗

PubMed1997

[Mitral valve plasty and LV patch reconstruction for a left ventricular aneurysm with mitral regurgitation].

Three years after myocardial infarction, a 60-year-old man had congestive heart failure caused by left ventricular aneurysm with mitral regurgitation. He underwent the following concomitant operations: (1) patch reconstruction for a left ventricular aneurysm and (2) mitral plasty for a torn chordate and mitral regurgitation by using valvuloplasty, a shortening chordae and a prosthetic ring. A postoperative examination indicated that his cardiac function had markedly improved.

Heart Aneurysm↗

PubMed1996

Structural requirements of taxoids for nitric oxide and tumor necrosis factor production by murine macrophages.

Taxol (paclitaxel), a microtubule stabilizer with antitumor activity, mimics the actions of lipopolysaccharide (LPS) on murine macrophages (M phi). In the present study, a variety of synthetic analogs of paclitaxel were examined for their potencies to induce nitric oxide (NO) and tumor necrosis factor (TNF) production by peritoneal M phi from LPS-responsive C3H/HeN, and LPS-hyporesponsive C3H/HeJ mice, and by M phi-like LPS-responsive J774.1 and its mutant LPS-hyporesponsive J7.DEF3 cells. In this structure-activity relationship study, we found that (i) the benzoyl group at the C-3' position of paclitaxel is the most important site to activate C3H/HeN M phi; (ii) the phenyl group at C-3' is not a requisite for the activity; (iii) there is good correlation between NO and TNF production by the M phi in response to compounds, except for the analogs having a tert-butoxycarbonyl (10-acetyldocetaxel) or a thiophene-2-carbonyl group at C-3'-N instead of a benzoyl group, which is more dominant in TNF than in NO production; (iv) the compounds tested induce neither NO nor TNF production by C3H/HeJ M phi; (v) active compounds to C3H/He M phi induce TNF production by J7.DEF3 cells as well as J774.1 cells; and (vi) there is no correlation between the NO/TNF inducibility to C3H/HeN M phi and growth inhibitory activity against M phi-like J774.1 and J7.DEF3 cells. These data also suggest that the binding of taxoid/LPS to tubulin is not essential for the M phi activation.

Animals↗

PubMed1996

Structural characterization of the N-linked carbohydrate chains of the zona pellucida glycoproteins from bovine ovarian and fertilized eggs.

The N-linked oligosaccharides that were released by hydrazinolysis from glycoproteins of zonae pellucidae of bovine ovarian eggs, were composed of neutral (23%) and acidic (77%) carbohydrate chains; almost all the acidic chains were neutralized by sialidase digestion. Sugar mapping analysis of pyridylaminated N-linked chains by reverse-phase and normal-phase HPLC and 500-MHz 1H-NMR spectroscopy revealed that the major neutral chain is a high-mannose-type oligosaccharide and the acidic chains are di-, tri-, and tetra-antennary, fucosylated complex-type chains that have N-acetyllactosamine repeats in the non-reducing regions. The structures of the neutral chain and the core regions of the acidic chains of N-linked oligosaccharides from the zona proteins of fertilized eggs, which were obtained by the in vitro fertilization method, were essentially the same as those of the ovarian egg zonae. The amount, however, of the acidic chains decreased to 32 mol/100 mol in the fertilized egg zonae, which suggests that a sialidase released from the oocyte during fertilization operates on the zona glycoproteins.

Animals↗

PubMed1996

Requirements for cytochrome b5 in the oxidation of 7-ethoxycoumarin, chlorzoxazone, aniline, and N-nitrosodimethylamine by recombinant cytochrome P450 2E1 and by human liver microsomes.

NADH-dependent 7-ethoxycoumarin O-deethylation activities could be reconstituted in systems containing cytochrome b5 (b5), NADH-b5 reductase, and bacterial recombinant P450 2E1 in 100 mM potassium phosphate buffer (pH 7.4) containing a synthetic phospholipid mixture and cholate. Replacement of NADH-b5 reductase with NADPH-P450 reductase yielded a 4-fold increase in 7-ethoxycoumarin O-deethylation activity, and further stimulation (approximately 1.5-fold) could be obtained when NADPH was used as an electron donor. Removal of b5 from the NADH- and NADPH-supported systems caused a 90% loss of 7-ethoxycoumarin O-deethylation activities in the presence of NADPH-P450 reductase, but resulted in complete loss of the activities in the absence of NADPH-P450 reductase. Km values were increased and Vmax values were decreased for 7-ethoxycoumarin O-deethylation when b5 was omitted from the NADPH-supported P450 2E1-reconstituted systems. Requirements for b5 in P450 2E1 systems were also observed in chlorzoxazone 6-hydroxylation, aniline p-hydroxylation, and N-nitrosodimethylamine N-demethylation. In human liver microsomes, NADH-dependent 7-ethoxycoumarin O-deethylation, chlorzoxazone 6-hydroxylation, aniline p-hydroxylation, and N-nitrosodimethylamine N-demethylation activities were found to be about 55, 41, 33, and 50%, respectively, of those catalyzed by NADPH-supported systems. Anti-rat NADPH-P450 reductase immunoglobulin G inhibited 7-ethoxycoumarin O-deethylation activity catalyzed by human liver microsomes more strongly in NADPH- than NADH-supported reactions, while anti-human b5 immunoglobulin G inhibited microsomal activities in both NADH- and NADPH-supported systems to similar extents. These results suggest that b5 is an essential component in P450 2E1-catalyzed oxidations of several substrates used, that about 10% of the activities occur via P450 2E1 reduction by NADPH-P450 reductase in the absence of b5, and that the NADH-supported system contributes, in part, to some reactions catalyzed by P450 2E1 in human liver microsomes.

Aniline Compounds↗

PubMed1996

Phospholipase A(2) activity in non-glycated and glycated low density lipoproteins.

The oxidation of low density lipoprotein (LDL) is believed to be an important risk factor for atherosclerosis. We have previously reported that glycation of LDL enhances LDL oxidation. Incubation of LDL in the presence of 200 mM glucose resulted in the enhanced formation of phosphatidylcholine hydroperoxide (PC-OOH) and cholesteryl ester hydroperoxide (CE-OOH). Fe(3+)-ADP accelerated the formation of hydroperoxides. The concentration of PC-OOH was much smaller than that of CE-OOH. In addition, we found a PC-OOH decomposing activity in LDL by following linoleic acid hydroperoxide (18:2-OOH) formation from 1-stearoyl-2-[13'-(S)-hydroperoxy-9', 11'-octadecadienoyl]-sn-glycero-3-phosphocholine (SLPC-OOH). Hydrolysis was similar between LDL and glycated LDL. Pretreatment by para-bromophenacylbromide, histidine modifier and phospholipase A(2) inhibitor, retarded the formation of 18:2-OOH only by 30%. The addition of equimolar platelet activating factor (PAF) reduced hydrolysis by 50%, indicating PAF acetylhydrolase may be responsible for the hydrolysis of PC-OOH.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

PubMed1996

Multiple primary esophageal and concurrent upper aerodigestive tract cancer and the aldehyde dehydrogenase-2 genotype of Japanese alcoholics.

BACKGROUND: Multiple intraesophageal primary cancer and upper aerodigestive tract (UADT) cancer associated with esophageal cancer are common diseases, especially in heavy drinkers. They are often explained by the concept of field cancerization, which suggests a similar etiology. However, little is known about the nature of the hypothesized etiology. METHODS: Among 901 Japanese male alcoholics systematically screened by upper gastrointestinal endoscopy (with esophageal iodine staining), 33 had squamous cell carcinoma of the esophagus. The multiplicity of their esophageal carcinoma and their concurrent UADT cancer was compared with their genotype for aldehyde dehydrogenase-2 (ALDH2), the major determinant of blood acetaldehyde concentration after drinking. RESULTS: Of 17 patients with inactive ALDH2, 13 (76.5%) had multiple primary carcinoma of the esophagus, whereas 5 of 16 (31.3%) with active ALDH2 had multiple carcinomas (P < 0.01). The prevalence of concurrent UADT cancer was 29.4% in those patients with inactive ALDH2, compared with 6.3% in those patients with active ALDH2. CONCLUSIONS: Inactive ALDH2 is a risk factor for multiple carcinoma of the esophagus in alcoholics. Acetaldehyde, a recognized animal carcinogen, appears to play a critical role in field cancerization.

Alcoholism↗

PubMed1996

Biological activities of lipopolysaccharide of Burkholderia (Pseudomonas) pseudomallei.

Endotoxic activities of lipopolysaccharide (LPS) isolated from Burkholderia (Pseudomonas) pseudomallei, a causative agent of melioidosis, were investigated. Compared to an enterobacterial LPS (SAE-LPS), B. pseudomallei LPS (BP-LPS) exhibited weaker pyrogenic activity in rabbits, lethal toxicity in galactosamine-sensitized mice and murine macrophage activation, i.e. production of tumor necrosis factor, interleukin-6 and nitric oxide. BP-LPS, on the other hand, exhibited stronger mitogenic activity to murine splenocytes than SAE-LPS; moreover, it stimulated even the splenocytes of LPS-resistant C3H/HeJ mice. Unusual chemical structures in the acid-stable inner core region attached to the lipid A moiety of BP-LPS may be responsible for this strong mitogenic activity.

Animals↗

PubMed1996

Age-related changes in the metabolism of neurotransmitters in rat striatum: a microdialysis study.

Rats from one month to 22 months of age were subjected to in vivo brain microdialysis under a free-moving condition. The 3,4-dihydroxyphenylacetic acid level in the striatum reached a maximum at 3 months old. However, both basal and potassium-induced dopamine release were maximal at 1.5 months, which represents sexual maturation (puberty). The inhibitory effect of monoamine oxidase (MAO) activity by pargyline was maximal at 1.5 months. The delayed maximum level of the metabolites may be due to different age-related changes in MAO-A and MAO-B. From these results, it is suggested that in the rat striatum, the release of dopamine is maximal at the age of sexual maturation, and that the whole synaptic function of the dopaminergic neurons is at its highest during late adolescence.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1996

Roles of cytochrome b5 in the oxidation of testosterone and nifedipine by recombinant cytochrome P450 3A4 and by human liver microsomes.

NADH-dependent testosterone 6 beta-hydroxylation and nifedipine oxidation activities could be reconstituted in systems containing cytochrome b5 (b5), NADH-b5 reductase, and bacterial recombinant cytochrome P450 (P450) 3A4 with a synthetic phospholipid mixture, cholate, MgCl2, and reduced glutathione. Replacement of NADH-b5 reductase with NADPH-P450 reductase produced an eightfold increase in testosterone 6 beta-hydroxylation activity. Further stimulation could be obtained when NADPH was used as an electron donor instead of NADH. Removal of b5 from the NADH- and NADPH-supported systems caused a 90% loss of testosterone 6 beta-hydroxylation activities in the presence of NADPH-P450 reductase but resulted in complete loss of the activities in the absence of NADPH-P450 reductase. These results suggested that about 10% of the activities was due to electron flow from NADPH-P450 reductase to P450 3A4 in the absence of b5. In the presence of testosterone and MgCl2, P450 3A4 was reduced by b5 and NADH-b5 reductase, although the rate of P450 3A4 reduction was much slower than that by NADPH-P450 reductase. Anti-human b5 immunoglobulin G (IgG) (purified using rabbit b5 affinity chromatography) inhibited testosterone 6 beta-hydroxylation activity catalyzed by human liver microsomes more strongly in NADH- than in NADPH-supported reactions. However, anti-rat NADPH-P450 reductase IgG inhibited microsomal activities in both NADH- and NADPH-supported systems to similar extents. Addition of NADH enhanced NADPH-supported testosterone and nifedipine oxidations in human liver microsomes. MgCl2 stimulated rates of reduction of b5 by NADPH-P450 reductase, but not by NADH-b5 reductase, in reconstituted systems. These results suggest that b5 is an essential component in P450 3A4-catalyzed testosterone hydroxylation and nifedipine oxidation in human liver microsomes. Our previous observation that rates of reduction of ferric P450 3A4 by NADPH-P450 reductase are accelerated by complexation with substrates and b5 is supported in this study.

Animals↗

PubMed1996

Multiple myeloma-associated systemic vasculopathy due to crystalglobulin or polyarteritis nodosa.

Systemic vasculopathy is a rare complication of multiple myeloma (MM). We describe a patient diagnosed with MM who developed clinical features of systemic vasculopathy including gangrene, livedo reticularis, hypertension, renal failure, and perforation of the small intestine. Histopathologic examination of the small intestine revealed necrotizing vasculitis in the small arteries, along with crystalline deposits in the small vessels. To our knowledge, previously reported cases of systemic vasculopathy associated with MM include at least 9 cases due to crystalglobulin deposition in vessels and 2 due to polyarteritis nodosa. Deposits of crystalglobulin may have induced systemic necrotizing vasculitis in our patient.

Adult↗

PubMed1996

High prevalence of serum apolipoprotein E4 isoprotein in rheumatoid arthritis patients with amyloidosis.

OBJECTIVE: To determine whether serum Apolipoprotein E (Apo E) type 4 isoprotein is a risk factor for the development of amyloidosis in patients with rheumatoid arthritis (RA). METHODS: Using isoelectric focusing, we studied Apo E phenotype expression and the corresponding allele frequencies (epsilon 2, epsilon 3, and epsilon 4) in 35 patients with RA and amyloidosis, 65 patients with RA and without amyloidosis, and 63 healthy controls. RESULTS: The Apo E3/4 phenotype was significantly more common in the group with amyloidosis (31.4%) than in the patients without amyloidosis (12.3%; P < 0.05) or in healthy controls (12.7%; P < 0.05). The frequency of the epsilon 4 allele was significantly greater in the group with amyloidosis (0.16) than in the patients without amyloidosis (0.07; P < 0.05) or in healthy controls (0.07; P < 0.05). CONCLUSION: The presence of Apo E4 isoprotein may be a risk factor for the development of amyloidosis in patients with RA.

Adult↗

PubMed1996

Involvement of platelet-activating factor in cytokine production and neutrophil activation after hepatic ischemia-reperfusion.

Although platelet-activating factor (PAF) is implicated as an important mediator in the pathogenesis of hepatic ischemia-reperfusion (IR) injury, the precise mechanism of its action has not been studied. We examined the hypothesis that PAF may influence neutrophils by promoting the production of tumor necrosis factor alpha (TNF-alpha) and cytokine-induced neutrophil chemoattractant (CINC), a member of the interleukin-8 (IL-8) family, and may be associated with liver and lung injury during the early phase of reperfusion after total hepatic ischemia. Rats pretreated with a specific PAF receptor antagonist exhibited suppression of the increase in plasma TNF-alpha and CINC levels, as well as the priming of peripheral neutrophils for superoxide production after reperfusion when compared with animals pretreated with physiological saline. These effects resulted in a reduction of plasma liver enzymes and of hepatic and pulmonary neutrophil sequestration, as well as an increased survival rate. There was a strong correlation between the time course of CINC release and hepatic or pulmonary neutrophil sequestration. We concluded that PAF activates neutrophils, either directly or by promoting the production of TNF-alpha and CINC, and is involved in hepatic IR injury.

Animals↗

PubMed1996

Nitric oxide production by peritoneal macrophages of Mycobacterium bovis BCG-infected or non-infected mice: regulatory role of T lymphocytes and cytokines.

Infection with Mycobacterium bovis bacillus Calmette-Guerin (BCG) confers mice with strong abilities to produce nitric oxide (NO) and cytokines. Because the peritoneal macrophages taken from the mice immunized with live or heat-killed BCG can produce NO without any accessory cells and stimulants, it is difficult to clarify the immune regulation on NO production by manipulating the macrophages. Therefore, we investigated the participation of immune T cells and cytokines in NO production by using in vitro co-cultures of macrophages from non-immune mice with T cells prepared from BCG-infected mice in the presence or absence of a mycobacterial antigen, purified protein derivative (PPD). Although the non-immune thioglycollate (TGB)-elicited macrophages could not produce any detectable NO in the presence of PPD, supplementation of the macrophage cultures with CD4+ T cells prepared from BCG-infected mice enabled the macrophages to produce NO. Immunocytostaining showed that the macrophages, hut not the immune T cells, expressed inducible NO synthase (iNOS), indicating that they were NO producers. PPD could only induce NO production if there was cell-cell contact of the CD4+ T cells in the immune cells and antigen-presenting macrophages were required for the NO production in response to PPD; this interaction led to the production of soluble mediators that induced NO production by the TGB macrophages. NO production by the co-cultured cells was abrogated by adding either anti-interferon-gamma(IFN-gamma) or anti-tumor necrosis factor alpha (TNF-alpha) antibody. Furthermore, the roles of immune T cells and PPD could be replaced by adding recombinant IFN-gamma together with TNF-alpha to the macrophage cultures, but neither alone was sufficient to induce NO production by the macrophages. Our present data indicate that TNF-alpha produced by PPD-stimulated macrophages and IFN-gamma produced by cell-cell interaction of BCG-immune T cells and antigen-engulfed macrophages together activate the macrophages to produce NO.

Animals↗

PubMed1996

Geographic population structure and sequence divergence in the mitochondrial DNA control region of the Japanese wild boar (Sus scrofa leucomystax), with reference to those of domestic pigs.

Mitochondrial DNA (mtDNA) control regions from 40 Japanese wild boars were examined by direct sequencing after amplification by PCR. From the DNA sequences obtained, we found eight haplotypes, whose differences arose via transitions. The geographical distribution of these different haplotypes indicated that wild boar populations inhabited limited areas and that there was some restricted gene flow between local populations. Eight mtDNA haplotypes from Eastern and Western domestic pigs and the Ryukyu wild boar were also analyzed as references to those from Japanese wild boars. The cluster analyses of the control-region sequences showed that those from Japanese wild boars belong to the Asian type as do those from Eastern domestic pigs and the Ryukyu wild boar, which differed from the European type (Western domestic pigs).

Animals↗

PubMed1996

Comparative hypocholesterolemic effects of six vegetable oils in cholesterol-fed rat.

The hypocholesterolemic efficacies of various polyunsaturated fatty acids were compared in rats given cholesterol-enriched diets. Oenothera biennis Linn oil (OBLO, linoleic + gamma-linolenic), sunflower oil (linoleic), palm oil (PLO, oleic + linoleic), soybean oil (linoleic + alpha-linolenic), high-oleic safflower oil (oleic + linoleic), or mixed oil (linoleic + alpha-linolenic) was added to the diet at 200 g/kg (20% groups). OBLO was also added at 100 g/kg diet (10% group). The serum total and very low density lipoprotein + intermediate lipoprotein + low density lipoprotein cholesterol concentrations of the 10 and 20% OBLO groups were consistently lower than those in the other groups. The liver cholesterol concentration in the PLO group was lower in all groups. The liver cholesterol concentrations in the 10 and 20% OBLO groups were also lower than in the other groups. There were no significant differences in the fecal neutral sterol and bile acid extraction among groups.

Animals↗

PubMed1996

Optimal schedule for administering granulocyte colony-stimulating factor in chemotherapy-induced neutropenia in non-small-cell lung cancer.

A prospective randomized study was conducted to determine the optimal schedule of rhG-CSF (recombinant human granulocyte colony-stimulating factor). A group of 33 lung cancer patients treated with MVP therapy (mitomycin, vindesine, and cisplatin) were randomly assigned to three groups: an early prophylaxis group in which rhG-CSF was initiated on day 2 of the MVP cycle; a late prophylaxis group in which rhG-CSF was initiated on day 8; and a therapeutic group in which rhG-CFS was initiated after the onset of neutropenia. Ten patients who had received MVP therapy without rhG-CSF were also analyzed as a no-support group. The incidence of neutropenia was 80% (16/20 courses) in the early prophylaxis group, 44% (8/18) in the late prophylaxis group, 94% (17/18) in the therapeutic group, and 94% (16/17) in the no-support group. The incidence of neutropenia in the late prophylaxis group was less than in the early prophylaxis group (P<0.05), the therapeutic group (P<0.01), and the no-support group (P<0.01). The late prophylactic rhG-CSF schedule was therefore more effective in countering neutropenia than either the early prophylactic or therapeutic schedule.

Aged↗