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Biomedical subjects

M Nasu

Publications and source records attributed to M Nasu.

At least 37 records · Page 2Linked to original sources
PubMed2002

Value of plasma B type natriuretic peptide measurement for heart disease screening in a Japanese population.

BACKGROUND: Conflict exists regarding the usefulness of measuring plasma B type natriuretic peptide (BNP) concentrations for identifying impaired left ventricular (LV) systolic function during mass screening. Various cardiac abnormalities, regardless of degree of LV dysfunction, are prone to carry a high risk of cardiovascular events. OBJECTIVE: To examine the validity of plasma BNP measurement for detection of various cardiac abnormalities in a population with a low prevalence of coronary heart disease and LV systolic dysfunction. DESIGN AND SETTING: Participants in this cross sectional study attended a health screening programme in Iwate, northern Japan. Plasma BNP concentrations were determined in 1098 consecutive subjects (mean age 56 years) by direct radioimmunoassay. All subjects underwent multiphasic health checkups including physical examination, ECG, chest radiography, and transthoracic echocardiography. RESULTS: Conventional diagnostic methods showed 39 subjects to have a wide range of cardiac abnormalities: lone atrial fibrillation or flutter in 11; previous myocardial infarction in seven; valvar heart disease in seven; hypertensive heart disease in six; cardiomyopathy in six; atrial septal defect in one; and cor pulmonale in one. No subjects had a low LV ejection fraction (< 40%). To assess the utility of plasma BNP measurement for identification of such patients, receiver operating characteristic analysis was performed. The optimal threshold for identification was a BNP concentration of 50 pg/ml with sensitivity of 89.7% and specificity of 95.7%. The area under the receiver operating characteristic curve was 0.970. The positive and negative predictive values at the cutoff level were 44.3% and 99.6%, respectively. CONCLUSION: Measurement of plasma BNP concentration is a very efficient and cost effective mass screening technique for identifying patients with various cardiac abnormalities regardless of aetiology and degree of LV systolic dysfunction that can potentially develop into obvious heart failure and carry a high risk of a cardiovascular event.

Adult↗
PubMed2001

Optical imaging of neural activity in multiple auditory cortical fields of guinea pigs.

Neural activity of multiple fields in the auditory cortex of anesthetized guinea pigs in response to pure tones was visualized by optical recording using a voltage-sensitive dye (RH795). Ten auditory fields were identified based on the tonotopic organization and response latency: the core fields consisting of the primary (AI) and secondary (AII) fields and surrounding belt areas consisting of dorso-anterior (DA), dorsal (D), dorso-posterior (DP), posterior (P), ventro-posterior (VP), ventro-medial (VM), ventro-anterior (VA) and ventral (V) fields. Tonotopic organization was observed in all the fields apart from DA, D, DP and V. Spatio-temporal displays suggest that the auditory information spreads from the core fields of AI and AII to belt fields via three distinct (dorsocaudal, caudal and ventrorostral) pathways.

Acoustic Stimulation↗
PubMed2001

Discovery of novel mesangial cell proliferation inhibitors using a three-dimensional database searching method.

A three-dimensional pharmacophore model of mesangial cell (MC) proliferation inhibitors was generated from a training set of 4-(diethoxyphosphoryl)methyl-N-(3-phenyl-[1,2,4]thiadiazol-5-yl)benzamide, 2, and its derivatives using the Catalyst/HIPHOP software program. On the basis of the in vitro MC proliferation inhibitory activity, a pharmacophore model was generated as seven features consisting of two hydrophobic regions, two hydrophobic aromatic regions, and three hydrogen bond acceptors. Using this model as a three-dimensional query to search the Maybridge database, structurally novel 41 compounds were identified. The evaluation of MC proliferation inhibitory activity using available samples from the 41 identified compounds exhibited over 50% inhibitory activity at the 100 nM range. Interestingly, the newly identified compounds by the 3D database searching method exhibited the reduced inhibition of normal proximal tubular epithelial cell proliferation compared to a training set of compounds.

Benzamides↗
PubMed2001

Clinical and pathologic findings in 52 consecutively autopsied cases with multiple myeloma.

We studied clinical features and pathologic findings in 52 consecutively autopsied patients with multiple myeloma in our center between 1979 and 1998. Distant extraosseous involvement was found in 33 patients (63.5%). Thirty-one patients (59.6%) were proven to have infection at autopsy, among which pneumonia was most common site of infection. Amyloidosis was shown in 8 patients. Second malignancies were observed in 4 cases. The three major causes of death were hemorrhage, infection, and renal failure, which accounted for death in approximately 70% of the patients. Advances in the anticancer and antimicrobial chemotherapies might have decreased deaths due to myeloma itself or infection.

Aged↗
PubMed2001

Safety and efficacy of granulocyte and monocyte adsorption apheresis in patients with active ulcerative colitis: a multicenter study.

Active ulcerative colitis (UC) is characterized by activation and infiltration of granulocytes and monocytes/macrophages into the colonic mucosa. The infiltrated leukocytes can cause mucosal damage by releasing degradative proteases, reactive oxygen derivatives, and proinflammatory cytokines. The aim of this trial (conducted in 14 specialist centers) was to assess safety and efficacy of granulocyte and monocyte adsorption apheresis in patients with active UC most of whom were refractory to conventional drug therapy. We used a new adsorptive type extracorporeal column (G-1 Adacolumn) filled with cellulose acetate beads (carriers) of 2 mm in diameter, which selectively adsorb granulocytes and monocytes/macrophages. Patients (n = 53) received five apheresis sessions, each of 60 minutes duration, flow rate 30 ml per minute for 5 consecutive weeks in combination with 24.4 +/- 3.60 mg prednisolone (mean +/- SE per patient per day, baseline dose). During 60 minutes apheresis, 26% of granulocytes, 19.5% of monocytes and 2% of lymphocytes adsorbed to the carriers. At week 7, 58.5% of patients had remission or improved, the dose of prednisolone was reduced to 14.2 +/- 2.25 mg (n = 37). The apheresis treatment was fairly safe, only eight non-severe side effects (in 5 patients) were reported. Based on our results, we believe that in patients with active severe UC, patients who are refractory to conventional drugs, granulocyte and monocyte adsorption apheresis is a useful adjunct to conventional therapy. This procedure should have the potential to allow tapering the dose of corticosteroids, shorten the time to remission and delay relapse.

Adult↗
PubMed2001

Aortic valve repair in dominant aortic regurgitation.

OBJECTIVE: We studied immediate and mid-term results after aortic valve repair. METHODS: Immediate and mid-term results were studied in 63 patients undergoing aortic valve repair, calculating survival and reoperation free rates. RESULTS: Subjects were 49 men and 14 women aged 15 to 76 years (mean: 53 +/- 17 years). Mean preoperative aortic regurgitation grading of 1 to 4 was 3.2 +/- 0.7. Mean preoperative New York Heart Association functional class was 1.9 +/- 0.8. Two in-hospital deaths occurred. (3.2%) Mean aortic regurgitation grade at discharge was 1.3 +/- 0.8 (p < 0.0001; vs preoperative grade) and functional class was 1.1 +/- 0.2 (p < 0.0001; vs preoperative class),--significantly improved. Overall follow-up was 98.4%, and mean follow-up continued 41.4 +/- 22.1 months. Mean functional class at follow-up was 1.2 +/- 0.4 (n = 49), improved from preoperative class (p < 0.0001). Mean aortic regurgitation grading at follow-up was 1.8 +/- 0.8 (n = 41), improved from preoperative grading (p < 0.0001). Five-year survival was 95.1 +/- 2.8%. One-year reoperation freedom was 96.6 +/- 2.4% and 5-year 77.9 +/- 6.9%. CONCLUSIONS: Survival after surgery was good, while reoperation was comparable to other reports but less satisfactory compared to reoperation freedom after aortic valve replacement. Based on reoperative findings, a change in indication was made. We believe technical refinements could improve postoperative results.

Adolescent↗
PubMed2001

Evaluation of prostate-specific antigen (PSA) membrane test for forensic examination of semen.

Prostate-specific antigen (PSA) is a glycoprotein produced by the prostatic gland and functions to liquefy the seminal fluid. Recently several PSA membrane test kits utilizing an immunochromatographic assay are commercially available for clinical screening of PSA concentration in serum. In this study, we applied the three PSA test kits to forensic examination of semen, and evaluated the sensitivity and specificity of the PSA test kits. The specificity were the same, but SMITEST PSA Card had the highest sensitivity among the three kits. Furthermore we certified that the SMITEST PSA Card was little affected by heat or contaminants such as other body fluids, reagent of preliminary test for semen stain and spermicides, and the PSA kit was applied to 30 casework samples.

Journal Article↗
PubMed2001

Promoting effects of xylazine on development of thyroid tumors in rats initiated with N-bis(2-hydroxypropyl)nitrosamine and the mechanism of action.

To cast light on whether xylazine hydrochloride (XZ), a veterinary medicine commonly used as a sedative agent for food-producing animals, has any promoting potential for thyroid carcinogenesis, the following studies were performed. In Experiment I, male F344 rats received a diet containing 1000 or 0 p.p.m. XZ for 52 weeks with or without initiation with 2400 mg/kg N:-bis(2-hydroxypropyl)nitrosamine (DHPN). Focal follicular cell hyperplasias, adenomas and/or carcinomas were induced in the DHPN alone, XZ alone and DHPN+XZ groups, and the incidences and multiplicities of these lesions in the DHPN+XZ group were significantly increased as compared with the DHPN alone case. In Experiment II, male F344 rats received a diet containing 1000 or 0 p.p.m. XZ and were examined for serum levels of triiodothyronine (T(3)), thyroxine (T(4)) and thyroid-stimulating hormone (TSH) at weeks 1, 2 and 4. In the XZ group, significant increase in thyroid weight and decrease in serum T(4) levels were observed at all time points. Serum T(3) and TSH levels were significantly decreased and increased, respectively, at week 1, but returned to within the control range thereafter. In Experiment III, male F344 rats received a diet containing 1000 or 0 p.p.m. XZ, they were examined for thyroid iodine uptake and organification of XZ after 1 and 2 weeks. The thyroidal iodine uptake per milligram of thyroid and the amount of iodine bound to 1 mg protein showed a tendency for decrease at week 1 and significant decrease at week 2. These results indicate that XZ has tumor-promoting effects on thyroid follicular cells, and suggest an involvement of alterations in thyroid-related hormone levels due to inhibition of thyroid iodine uptake and organification, resulting, provably, in serum TSH stimulation depending on continuous reduction of serum T(4) level through the feedback system in the pituitary-thyroid axis.

Adenoma↗
PubMed2001

[Clinical characterization of blaIMP positive gram-negative rods isolated cases].

We detected the metallo-beta-lactamase gene blaIMP positive strains of the gram-negative rods (GNR) isolated in Oita Medical University Hospital between 1993 and 1999 and studied the clinical characteristics of patients infected or colonized with blaIMP positive GNR. 25 strains (20 Pseudomonas aeruginosa and 5 Serratia marcescens) were detected and most of them were isolated from urinary samples after 1997. In the studies of antimicrobial susceptibility, some strains had sensitivity to aztreonum or imipenem although most of the strains showed multidrug resistance. When blaIMP positive GNR were isolated from patients, these strains were thought to have caused infection in 88% of the patients. About half of the patients were over 65 years old and had malignant diseases. Most of the patients had inserted urinary tract catheters, intratracheal tube or intravernous catheters. It was suggested that the insertion of the catheters were related to infection of blaIMP positive GNRs. Two patients were not treated with any antibiotics before the isolation of blaIMP positive GNRs although more than half of the patients were administered carbapenems and cephems. Most of strains were isolated in the same department and showed the same genotype by pulsed field gel electrophoresis.

Bacterial Proteins↗
PubMed2001

Pretreatment of mice with clindamycin improves survival of endotoxic shock by modulating the release of inflammatory cytokines.

Suppression of endotoxin release and subsequent production of inflammatory cytokines is crucial in the treatment of septic shock. We investigated the effect of clindamycin (CLI) on endotoxic shock induced in mice by Escherichia coli lipopolysaccharide (LPS). Mice were treated with CLI (160 to 600 mg/kg) or saline and then injected with E. coli LPS and D-(+)-galactosamine intraperitoneally 0.5 h after CLI administration. Pretreatment with CLI significantly improved survival in a dose-dependent manner (CLI, at 160, 300, and 440 mg/kg) and significantly lowered the peak concentrations of tumor necrosis factor alpha and interleukin-1beta (IL-1beta) in serum. However, the peak concentrations of IL-6 in the sera of CLI-treated mice were higher than in control mice. Our findings suggest that CLI alters LPS-induced inflammatory cytokine production and suppresses endotoxin-induced mortality in this murine model.

Animals↗
PubMed2001

Comparison of genomic structures and antigenic reactivities of orthologous 29-kilodalton outer membrane proteins of Helicobacter pylori.

We purified a 29-kDa Helicobacter pylori outer membrane protein (Omp29 protein) and cloned the gene encoding the protein from H. pylori strain ATCC 43504. The Omp29 gene corresponded to the reported JHP73 and the HP78-79 genes of H. pylori strains. A corresponding nucleotide fragment was detected in all 150 tested H. pylori clinical isolates by PCR or Southern blotting. The amplified Omp29-corresponding fragments were categorized into a ca. 770-bp-long group and a larger-fragment group. Sequence analysis indicated that the larger fragments were likely synthesized from the 770-bp fragments by insertion of an irrelevant fragment via 17-bp-long repeat sequences. Immunoblot analysis implies that the ca. 770-bp fragment is responsible for the protein homologous to Omp29, whereas the larger fragments are not responsible for those proteins or encoding antigenically distinct proteins. We postulate that the H. pylori outer membrane protein Omp29 can alter its antigenicity through gene modifications mediated by nucleotide transfer.

Antibodies, Bacterial↗
PubMed2001

Antimicrobial susceptibilities of Helicobacter pylori isolates under microaerophilic atmospheres established by two different methods.

The MICs of clarithromycin, amoxicillin, and metronidazole for 150 Helicobacter pylori isolates were determined using the AnaeroPack system and were compared with those determined using a microaerophilic incubator. The MICs of clarithromycin, amoxicillin, and metronidazole determined under both microaerophilic atmospheres were mostly within one twofold dilution for 146 (97.3%), 150 (100%), and 149 (99.3%) of the isolates, respectively.

Anaerobiosis↗
PubMed2001

Spontaneous normalization of negative T waves in infarct-related leads reflects improvement in left ventricular wall motion even in patients with persistent abnormal Q waves after anterior wall acute myocardial infarction.

This study aimed to clarify whether spontaneous T-wave normalization (TWN) in infarct-related leads reflects improvement in left ventricular (LV) wall motion even in patients with persistent abnormal Q waves after acute myocardial infarction (AMI). Eighty-five patients were classified into the following 3 groups: patients with Q-wave regression (group A, n = 21), those with persistent abnormal Q waves and TWN (group B, n = 36), and those with persistent abnormal Q waves and absence of TWN (group C, n = 28). Groups A and B had greater improvement in LV ejection fraction and regional wall motion between 1 and 6 months after AMI than group C. In conclusion, spontaneous TWN in the healing stage of anterior AMI reflects functional recovery of viable myocardium in the infarct region even in patients with persistent abnormal Q waves.

Aged↗
PubMed2001

Relationship between terminal QRS distortion on the admission electrocardiogram and the time course of left ventricular wall motion in anterior wall acute myocardial infarction.

In order to clarify the time course of left ventricular (LV) wall motion in patients with anterior acute myocardial infarction (AMI) showing terminal QRS distortion on the admission electrocardiogram (ECG), the present study examined 106 patients with their first anterior AMI (< or =6 h) who underwent emergency coronary arteriography and cardiac cathetherization at 1 and 6 months after the infarction. The patients were classified into 2 groups according to the presence (group A, n=23) or absence (group B, n=83) of terminal QRS distortion (emergence of the J point at > or =50% of the R-wave amplitude in leads with QR configuration and/or absence of S waves in leads with RS configuration) on the admission ECG. Group A had a lower LV ejection fraction and more reduced regional wall motion (RWM) in the infarct region at both 1 and 6 months after AMI than group B. The degree of improvement in RWM between 1 and 6 months after AMI was less in group A than in group B (-0.1+/-0.5 vs 0.4+/-0.6 SD/chord, p<0.01). This study indicates that patients with anterior AMI showing terminal QRS distortion on the admission ECG have more severely depressed LV wall motion and less improvement in RWM in the infarct region in the healing stage, suggesting that this sign is an indicator of severe myocardial damage.

Aged↗
PubMed2001

Current bioremediation practice and perspective.

The use of microbes to clean up polluted environments, bioremediation, is a rapidly changing and expanding area of environmental biotechnology. Although bioremediation is a promising approach to improve environmental conditions, our limited understanding of biological contribution to the effect of bioremediation and its impact on the ecosystem has been an obstacle to make the technology more reliable and safer. Providing fundamental data to resolve these issues, i.e., the behavior of the target bacteria directly related to the degradation of contaminants and the changes in microbial communities during bioremediation, has been a challenge for microbiologists since many environmental bacteria cannot yet be cultivated by conventional laboratory techniques. The application of culture-independent molecular biological techniques offers new opportunities to better understand the dynamics of microbial communities. Fluorescence in situ hybridization (FISH), in situ PCR, and quantitative PCR are expected to be powerful tools for bioremediation to detect and enumerate the target bacteria that are directly related to the degradation of contaminants. Nucleic acid based molecular techniques for fingerprinting the 16S ribosomal DNA (rDNA) of bacterial cells, i.e., denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP), enable us to monitor the changes in bacterial community in detail. Such advanced molecular microbiological techniques will provide new insights into bioremediation in terms of process optimization, validation, and the impact on the ecosystem, which are indispensable data to make the technology reliable and safe.

Journal Article↗
PubMed2001

Hypertrophic pulmonary osteoarthropathy associated with non-small cell lung cancer demonstrated growth hormone-releasing hormone by immunohistochemical analysis.

Hypertrophic pulmonary osteoarthropathy (HPO) associated with non-small cell lung cancer in a 58-year-old man was accompanied by an elevated serum level of growth hormone (GH). HPO rapidly disappeared after resection of the primary tumor and the elevation of serum GH was resolved. Immunohistochemically the tumor contained growth hormone-releasing hormone (GHRH) but not GH. These findings suggest that the high serum GH level due to ectopic GHRH production in the tumor, was a contributing factor in HPO. This is the second reported case of non-small cell lung cancer which was immunohistochemically positive for GHRH associated with HPO.

Carcinoma, Non-Small-Cell Lung↗
PubMed2001

[Clinical evaluation of metallo-beta-lactamase producing bacterium].

The metallo-beta-lactamase producing bacterium are increasing in recent years. We characterized cases infected or colonized with blaIMP, which is metallo-beta-lactamase IMP-1 gene, positive gram-negative rods(GNRs). About half of the cases had malignant diseases as underliningg disease. When blaIMP positive GNRs were isolated, most of cases shows clinical signs of infection such as fever and elevation of C-reactive protein in serum. Most of strains were isolated from urinary samples and all patients from whom blaIMP positive bacterium were isolated from urinary samples were inserted urinary tract catheter. It was suggested that the insertion of catheters related to infection of blaIMP positive GNRs. No antibiotics were administered to several patients before the isolation of blaIMP positive GNRs although broad spectrum antibiotics such as carbapenems were administered to more than half of the patients. It is very important to prevent their dissemination in hospitals because most of blaIMP positive GNRs were isolated in same departments and showed identical pattern by pulsed field gel electrophoresis. And it is also important for treatment of the infectious disease due to blaIMP positive GNR to remove the catheter and improve general conditions of patients.

Bacterial Proteins↗