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Biomedical subjects

N Aoki

Publications and source records attributed to N Aoki.

At least 73 records · Page 4Linked to original sources
PubMed2000

A novel mouse gene, Sh3yl1, is expressed in the anagen hair follicle.

In an attempt to investigate the genes expressed in the anagen hair follicle, we differentially screened a mouse anagen skin cDNA library, and identified a cDNA encoding a novel protein containing one Src homology 3 domain at the carboxyl terminus. The predicted amino acid sequence revealed a significant homology with YHRO 16c/Ysc 84, the yeast Src homology 3 domain-containing protein, for which transcripts are expressed at high levels during meiosis. The sequence identity was remarkable at the amino terminus as well as the carboxyl-terminal Src homology 3 domain, suggesting that the novel protein is a mouse homolog of the yeast protein, and we have termed this protein Sh3yl1. In northern blot study, the transcripts were detected not only in the skin but also in other tissues, especially the kidney, stomach, small intestine, and colon. Furthermore, in mouse skin, the expression of these transcripts basically followed the hair-growth cycle, increasing significantly during mid and late anagen phases, and decreasing during catagen, telogen, and early anagen phases. An in situ hybridization experiment showed that the Sh3yl1 transcripts are expressed predominantly in the hair bulb, the hair shaft, inner root sheath, and outer root sheath in the lower half of the follicle during mid and late anagen phases. These transcripts were not detected in catagen, telogen, and early anagen hair follicles, or in other skin components. Thus, these data suggest the possible involvement of Sh3yl1 in the development of hair follicles during the anagen phase.

Amino Acid Sequence↗
PubMed2000

Decision analysis of prophylactic treatment for patients with high-risk esophageal varices.

BACKGROUND: Clinical decision analyses were conducted to quantify the uncertainty and to identify important factors in selection of prophylactic therapy for patients with esophageal varices. METHODS: A Markov model compared variceal ligation, beta-blockers, and "watchful waiting" strategies in terms of bleeding-free life years. Transition probabilities were obtained from meta-analyses of published data. A hypothetical 50-year-old white man with high-risk esophageal varices and cirrhosis served as the prototypical baseline case. Traditional n-way sensitivity analyses were applied to clarify the influence of each factor, and Monte Carlo probabilistic sensitivity analyses were used to investigate clinical uncertainty. RESULTS: Probabilistic sensitivity analyses demonstrated that 77.0% of hypothetical cases had more bleeding-free life years after variceal ligation, whereas 23% had more when treated with beta-blockers. On the basis of one-way sensitivity analyses, only 2 factors (variceal bleeding rates after ligation and treatment with beta-blockers) influenced the strategy choice. CONCLUSIONS: Variceal ligation is an effective prophylactic therapy in many cases, but nearly one quarter of patients with high-risk esophageal varices and cirrhosis may benefit more from prophylactic treatment with beta-blockers. Additional clinical studies identifying key variceal bleeding risk factors may lead to more effective clinical decision making for these patients.

Adrenergic beta-Antagonists↗
PubMed2000

Prognostic value of C-reactive protein levels within six hours after the onset of acute myocardial infarction.

BACKGROUND: Inflammation is an important feature of atherosclerotic lesions, and the vulnerability of coronary lesions in acute myocardial infarction (AMI) at the time of onset may be related to blood levels of C-reactive protein (CRP) on admission, before CRP levels are affected by myocardial damage. METHODS: A total of 234 patients with AMI in whom plasma CRP was measured within 6 hours after onset were studied. They were divided into 2 groups: group 1 (n = 49) with elevated CRP (>/=0.3 mg/dL) on admission within 6 hours after onset and group 2 (n = 185) with normal CRP (<0.3 mg/dL) within 6 hours after onset. All were treated by primary percutaneous transluminal coronary angioplasty with provisional stenting. RESULTS: There were no significant differences in baseline characteristics between the 2 groups. In-hospital adverse coronary events, including coronary reocclusion, reinfarction, target vessel revascularization, and death, were significantly more frequent in group 1 (22.4%) than in group 2 (4.3%, P <.005), and bailout stenting was performed significantly more frequently in group 1 (61. 2%) than in group 2 (37.8%, P <.005). In contrast, there were no significant differences between the 2 groups in parameters that represent myocardial damage, including peak creatine kinase and left ventricular ejection fraction. CONCLUSION: CRP levels within 6 hours after the onset of AMI reflect the vulnerability of culprit coronary lesions and predict adverse coronary events after primary PTCA/stenting.

Aged↗
PubMed2000

Ser162-Dependent inactivation of overproduced sucrose-phosphate synthase protein of maize leaf in transgenic rice plants.

To investigate the role of Ser162 in phosphorylation-dependent regulation of maize sucrose-phosphate synthase (SPS) activities in rice, transgenic rice plants expressing wild-type or mutagenized maize SPS were produced. Our results indicate that Ser162 was responsible for overproduction-induced inactivation of SPS protein and for light/ dark modulation of this protein in vivo.

Gene Expression Regulation, Enzymologic↗
PubMed2000

[Competitive binding of some alkyl p-hydroxybenzoates to human estrogen receptor alpha and beta].

Alkyl p-hydroxybenzoates such as isobutyl p-hydroxybenzoate (PHBA-iBu), butyl p-hydroxybenzoate (PHBA-nBu), isopropyl p-hydroxybenzoate (PHBA-iPr), propyl p-hydroxybenzoate (PHBA-nPr), ethyl p-hydroxybenzoate (PHBA-Et), and methyl p-hydroxybenzoate (PHBA-Me) are widely used as preservatives, stabilizers and antiseptics for medical supplies, cosmetics, foodstuffs etc. We determined the binding affinity of alkyl p-hydroxybenzoates to human estrogen receptor alpha (ER alpha) and beta (ER beta) by non-RI receptor binding assays. PHBA-iBu had a high binding affinity for ER alpha (IC50: 6.0 x 10(-6) M, the relative binding affinity (RBA): 0.267) and ER beta (IC50: 5.0 x 10(-6) M, RBA: 0.340). These IC50 values and RBA were almost the same as those of bisphenol A. The ranking of the estrogenic potency of alkyl p-hydroxybenzoates for both ERs is different; that is, PHBA-iBu > PHBA-nBu[symbol: see text]PHBA-iPr[symbol: see text]PHBA-nPr > PHBA-Et >> PHBA-Me. Alkyl p-hydroxybenzoates bound with equal relative affinity to both ER alpha and beta proteins. Alkyl p-hydroxybenzoate having a long alkyl side-chain showed a high affinity for ER alpha and beta. These findings suggest that p-hydroxybenzoates may be endocrine disruptors.

Binding, Competitive↗
PubMed2000

An ELISA-based assay for detergent-solubilized cellular beta 1,4-galactosyltransferase activity. Use of a polyacrylamide derivative with GlcNAc-beta side chains as a solid phase acceptor substrate.

In our previous paper [Oubihi et al. (1998) Anal. Biochem., 257, 169-175], we have shown that a polyacrylamide-derived synthetic glycopolymer with GlcNAcbeta side chains, termed PAP(GlcNAcbeta), is useful as a solid phase acceptor substrate for the ELISA-based analyses of soluble beta1,4(-)galactosyltransferase (GalT) activity in milk. This method is now used to assay detergent-solubilized cellular GalT. The glycopolymer coated on polystyrene plates was shown to be highly stable against the non-ionic and ionic detergents tested (0 approximately 5% solutions of Triton X-100 and SDS). Such stability made it possible to incubate the ELISA plate with detergent-solubilized GalT and to wash the ELISA plate with SDS solution after the GalT reaction, leading to high accuracy and sensitivity of this assay. The GalT activity was assayed using this method for 1% Triton X-100 extracts of various tissue samples of mice and several cultured cell lines. The results showed that the specific GalT activity of tissue extracts was low in brain and intestine, and high in ovary, muscle, and kidney. As for the cultured cell lines, COS7, COMMA-1D and C2C12 cells showed high specific activity, while CHO and MDCK cells showed low activity. The myoblast C2C12 had a slight increase in GalT activity during starvation-induced cell differentiation. On the other hand, GaIT-I transcript estimated by RT-PCR rather decreased during C2C12 cell differentiation, suggesting a differentiation-dependent switch in GalT isozymes. Taken all together, the ELISA-based assay using PAP(GlcNAcbeta) as a solid phase acceptor substrate was demonstrated to be a useful method for the assay of membrane-bound galactosyltransferases.

Acrylic Resins↗
PubMed2000

Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and adrenal insufficiency induced by rathke's cleft cyst: a case report.

We report a case of a seventy-year-old woman with syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and adrenal insufficiency induced by Rathke's cleft cyst. She experienced nausea, vomiting, diarrhea, and headache and disturbance of consciousness induced by hyponatremia at a serum sodium level of 100 mEq/l. In spite of severe hyponatremia, urinary sodium excretion was not suppressed and serum osmolality (270 mOsm/kg) was lower than urine osmolality (304 mOsm/kg), and arginine vasopressin (AVP) remained within normal range. SIADH was diagnosed because she was free from other diseases known to cause hyponatremia such as dehydration, cardiac dysfunction, liver dysfunction, renal dysfunction, hypothyroidism, and adrenal insufficiency. Cranial computed tomographic (CT) scan and cranial magnetic resonance (MR) imaging showed a cystic lesion of approximately 2 cm in diameter in the pituitary gland. These images suggested that the cystic lesion was a Rathke's cleft cyst, which was the cause of SIADH. Water restriction therapy normalized her serum sodium concentration and improved her symptoms. After one year, she suffered from general fatigue, appetite loss, fever, and body weight loss (5 kg/2 months). She had neither hypotension nor hypoglycemia, but her serum sodium level was low and serum cortisol, ACTH, and urine free cortisol were very low. Therefore, secondary adrenal insufficiency was suspected and diagnosed by stimulation tests. After start of hydrocortisone replacement therapy (10 mg/day), her symptoms disappeared. In conclusion, Rathke's cleft cyst should be kept in mind as a potential cause in a patient with SIADH, hypopituitarism, and/or adrenal insufficiency.

Adrenal Insufficiency↗
PubMed2000

Anti-malarial activity of leaf-extract of hydrangea macrophylla, a common Japanese plant.

To find a new anti-malarial medicine derived from natural resources, we examined the leaves of 13 common Japanese plants in vitro. Among them, a leaf-extract of Hydrangea macrophylla, a common Japanese flower, inhibited the parasitic growth of Plasmodium falciparum. The IC50 of Hydrangea macrophylla leaf extract to Plasmodium falciparum was 0.18 microg/ml. The IC50 to NIH 3T3-3 cells, from a normal mouse cell line, was 7.2 microg/ml. Thus, selective toxicity was 40. For the in vivo test, we inoculated Plasmodium berghei, a rodent malaria parasite, to ddY mice and administered the leaf-extract of Hydrangea macrophylla (3.6 mg/0.2 ml) orally 3 times a day for 3 days. Malaria parasites did not appear in the blood of in the treated mice, but they did appear in the control group on day 3 or 4 after inoculation with the parasites. When leaf extract was administered to 5 mice 2 times a day for 3 days, malaria parasites did not appear in 4 of the mice but did appear in 1 mouse. In addition, the leaf-extract was administered orally 3 times a day for 3 days to Plasmodium berghei infected mice with a parasitemia of 2.7%. In the latter group, malaria parasites disappeared on day 3 after initiating the treatment, but they appeared again after day 5 or 6. Although we could not cure the mice entirely, we confirmed that the Hydrangea macrophylla leaf extract did contain an anti-malarial substance that can be administered orally.

Animals↗
PubMed2000

Sleep patterns and total mortality: a 12-year follow-up study in Japan.

A population-based cohort study was conducted to assess the relationship between total mortality and self-reported sleep patterns as regards not only to sleep duration but also subjective sleep quality. A total of 5,322 inhabitants in Gifu Prefecture, Japan, completed a self-administered questionnaire on health status and lifestyles including habitual sleep patterns, and were followed-up for an average of 11.9 years. Relative risks were computed by using Cox proportional hazards models. Both longer and shorter sleep, compared to 7-8 hour-sleep, was related to significantly increased risk of total mortality in males (relative risk [RR] for > or = 10 hours = 1.94, and RR for < 7 hour = 1.90), but not in females. Females complaining of poor awakening state experienced a higher mortality risk compared to those who woke up normally (RR: 1.97). Males who usually fell asleep easily showed a marginally lower mortality risk compared to those who fell asleep normally (RR: 0.70). Female users of sleeping pills were at an elevated risk (RR: 1.89). These findings were almost unchanged after adjustment for sleep duration and other confounders. Poor self-reported quality of sleep seemed to be associated with an increased risk of mortality independently of sleep duration.

Adult↗
PubMed2000

[Changes in the antibacterial activity of chemotherapeutic agents (especially carbapenems) for 10 species of clinical isolates between 1994 and 1996. Surveillance group of the sensitivities of clinical isolates to antibacterial agents].

During October and December of each year of from 1994 to 1996, 3,849 strains of 10 species of bacteria were isolated from clinical materials in 21 institutions nationwide. The minimum inhibitory concentrations (MICs) for these bacteria of four carbapenems (imipenem [IPM], panipenem [PAPM], meropenem [MEPM], and biapenem [BIPM]) and other representative antibacterial agents were measured to investigate annual changes in antibacterial activity. Carbapenems showed potent activity against methicillin-sensitive S. aureus (MSSA), S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, S. marcescens, and the B. fragilis group, with the activity being stable. However, these drugs showed weak activity against methicillin-resistant S. aureus (MRSA) and P. aeruginosa. The antibacterial activity (MIC90) against the tested organisms generally remained stable. Particularly, there was annual improvement of the MIC90 values of IPM and BIPM for S. pneumoniae, as well as the values of IPM and PAPM for H. influenzae, and those of IPM, PAPM, and BIPM for S. marcescens. On the other hand, the activity of carbapenems (including IPM) against MRSA was not necessarily strong, but there was annual improvement of MIC90 values.

Bacteria↗
PubMed2000

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1998)].

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and analyzed some characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In these 18 institutions around the entire Japan, 532 strains of presumably etiological bacteria were isolated mainly from the sputa of 438 patients with lower respiratory tract infections during the period from October in 1998 to September in 1999. MICs of various antibacterial agents and antibiotics were determined against 85 strains of Staphylococcus aureus, 100 strains of Streptococcus pneumoniae, 96 strains of Haemophilus influenzae, 75 strains of Pseudomonas aeruginosa (non-mucoid strains), 6 strains of Pseudomonas aeruginosa (mucoid strains), 38 strains of Moraxella subgenus Branhamella catarrhalis, 26 strains of Klebsiella pneumoniae etc., and the susceptibilities of 517 strains were assessed except for those strains that died during transportation. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus: MRSA) accounted for 60.0%. Vancomycin (VCM) and arbekacin (ABK) showed the most potent activities against MRSA. But one of MRSA showed resistance to ABK with the MIC of 64 micrograms/ml. The sensitive strains of MRSA to VCM have decreased. The frequency of penicillin (PC)-intermediate S. pneumoniae (PISP) + PC-resistant S. pneumoniae (PRSP) have increased in 46.0% for 1998 comparatively from 30.9% of 1997's. But PRSP decreased, and PISP increased into 39.0% of 1998 years from 19.8% of 1997's. Panipenem (PAPM), imipenem (IPM) and faropenem (FRPM) showed the most potent activities against S. pneumoniae with MIC80s of 0.125 microgram/ml or below. Against H. influenzae and M. (B.) catarrhalis, almost all the drugs showed good activities. The sensitive strains of them against ceftazidime (CAZ) decreased in 1997, but those have increased in 1998. Inversely, the susceptibility of them against cefotiam (CTM) had been higher in 1997, but those have been lower in 1998. Tobramycin (TOB) showed the most potent activity against P. aeruginosa (both mucoid and nonmucoid strains). All drugs except ampicillin (ABPC) were active against K. pneumoniae. A quite few of K. pneumoniae showed low susceptibilities. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. The examination of age distribution indicated that the proportion of patients with ages over 70 years was 48.6% of all the patients showing a slight increase in every year. About the proportion of diagnosed diseases as follows: Bacterial pneumonia was the most frequent with 40.2%. The ratio of it has increased slightly, and the increased rate was 10% in patients with ages over 70 years compared with the results in 1997. Chronic bronchitis have decreased slightly with 27.6% in 1998. Number of strains isolated from patients before administration of antibiotics were more than those after administration of them in chronic bronchitis, but these were almost same number in bacterial pneumonia. Administration of antibiotics has changed the results of the frequency of isolation of bacterial species. Bacterial isolations before administration of antibiotics were as follows: S. pneumoniae 26.7%, H. influenzae 23.8%, S. aureus 13.3% and M. (B.) catarrhalis 10.8%. The frequencies of S. aureus decreased after antibiotics administration over 15 days, but the frequencies of P. aeruginosa (both mucoid and non-mucoid) was not affected. The frequencies of P. aeruginosa was 45.5% after administration over 15 days. The frequencies of S. pneumoniae decreased upon administration of antibiotics, these were only 4.5% over 15 days. The frequencies of H. (

Anti-Bacterial Agents↗
PubMed2000

Changing features of stent-supported primary angioplasty for acute myocardial infarction: impact of new flexible stents.

Although primary coronary stenting for acute myocardial infarction (AMI) has been reported to be superior to primary percutaneous transluminal coronary angioplasty (PTCA), cautious entry criteria resulted in low-risk populations in these studies. This study was undertaken to delineate factors that have not been clarified by randomized multicenter studies and is based on the results of stent-supported primary PTCA for AMI using second-generation new stents. In 1994-1998, 355 AMI patients were studied < 12 hours after onset. The patients were divided into two groups: group 1 (n = 175) was treated in 1994-1996 and group 2 (n = 180) in 1997-1998. In group 1, bailout stenting was performed in 17% of the patients for acute coronary dissection or occlusion with use of Palmaz-Schatz stents. In group 2, stenting was performed in 62% of the patients for suboptimal coronary dilatation and dissection or occlusion, using second-generation flexible stents with excellent radial force in 65% of them (Multilink, GFX, and NIR). In-hospital death and reinfarction occurred in 7.4% of group 1 and 5.0% of group 2 patients, and follow-up death and reinfarction in 4.0% of group 1 and 0.6% of group 2 patients (p < 0.05). In-hospital target vessel revascularization was performed in 8.6% of group 1 and 3.3% of group 2 patients (p < 0.05), and follow-up target vessel revascularization in 21.1% of group 1 and 11.7% of group 2 patients (p<0.02). Thus, the total adverse clinical event rates were 36.0% in group 1 and 18.3% in group 2 (p < 0.01). In conclusion, outcomes of stent-supported coronary intervention in nonselected AMI patients have improved along with the availability of second-generation flexible stents, approaching the outcomes of primary stent studies in highly selected patients.

Angioplasty, Balloon, Coronary↗
PubMed2000

Plasma concentration of von Willebrand factor in acute myocardial infarction.

Recent investigations have revealed the crucial role of von Willebrand factor (vWF) in platelet thrombus formation under flow conditions. The plasma concentrations of vWF were measured together with various hemodynamic and hemostatic parameters in 51 cases of acute myocardial infarction. In 10 randomly selected cases, the plasma concentrations and distribution of multimers vWF were serially determined after reperfusion therapy by percutaneous transluminal coronary angioplasty (PTCA). The vWF concentration at the onset of the acute myocardial infarction was significantly higher than in an age-matched control group (vWF AG: 18.7 +/- 1.2 microg/ml vs. 10.3 +/- 0.5 microg/ml, p = 8.43 x 10-(12), mean +/- SE). Simultaneous determination of hemodynamic and hemostatic parameters revealed that the only two parameters that were significantly correlated with the patients' plasma vWF concentrations were their pulmonary capillary wedge pressure (PCWP) and heart rate, suggesting a relationship between hemodynamic changes induced by the onset of myocardial infarction and the vWF plasma concentrations. Serial determinations revealed that the vWF concentrations had not changed 1 h after reperfusion therapy, but that they significantly increased by 24 to 72 h. The distribution of the larger multimers of vWF also increased in the acute and subacute phase. The vWF concentration and multimer distribution normalized 14 days after the onset of the myocardial infarction. Our findings suggest that the vWF concentration increased in acute myocardial infarction patients, possibly in association with the hemodynamic deterioration that occurs in acute myocardial infarction.

Adult↗
PubMed2000

A novel point mutation of the splicing donor site in the intron 2 of the plasmin inhibitor gene.

Plasmin inhibitor (PI) is a major physiological inhibitor of plasmin-mediated fibrinolysis; hence, its deficiency results in a severe haemorrhagic diathesis. We analyzed the PI gene of a French boy apparently homozygous for PI deficiency and his heterozygous parents. Both alleles of the homozygous patient had a novel G to A transition at the consensus splicing donor site in the intron 2 of the PI gene. In an expression assay using the heterologous cells transfected with the mutant PI expression vector, 3 types of aberrant transcripts using a cryptic splicing donor site within the intron 2 were detected. All of these mRNAs had a stop codon upstream of the cryptic splicing site and encode only 25 amino acids, comprising the first 21 amino acids of the signal peptide (27 amino acids) plus 4 new amino acids. This mutant was designated as PI-Paris-Trousseau.

Animals↗
PubMed2000

[Long-term follow up of chronic myelogenous leukemia patients treated with natural interferon alpha--multi-institutional cooperative study].

The effects on survival in patients with chronic myelogenous leukemia (CML) treated with natural interferon alpha (Sumiferon) were analyzed. The subjects were 131 patients with CML who underwent treatment with Sumiferon between August 1991 and December 1992. Sumiferon was administered more than 8 weeks, and patients were followed for 5 years. In the end, 101 patients were analyzed after 30 patients were dropped from the study because they had received bone marrow transplantation. Survivals from the start of Sumiferon administration were 63.4% at 3 years, 52.5% at 4 years, and 42.6% at 5 years, respectively. Survivals were compared between the 74 patients who received Sumiferon administration with 1 year of diagnosis, and the 27 patients who received Sumiferon administration after more than 1 year from diagnosis. The 50% survivals were 2,089 days and 868 days, respectively (p = 0.0011). It was concluded that early administration of interferon alpha results in a prolonged survival of CML patients.

Adult↗