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Biomedical subjects

K Nakano

Publications and source records attributed to K Nakano.

At least 325 records · Page 18Linked to original sources
PubMed1996

Calcific degeneration of bioprosthetic aortic valves in patients receiving steroid therapy.

BACKGROUND AND AIMS OF THE STUDY: Calcification of glutaraldehyde-preserved bioprosthetic valves is a frequent long-term complication of valve replacement, although the mechanism responsible for such degeneration is not clearly understood. In the current study, we investigated the calcific degeneration of bioprosthetic aortic valves in patients who had been given steroid treatment for aortitis in order to evaluate the immune response to glutaraldehyde-preserved bioprostheses. METHODS: Ten patients who had undergone aortic valve replacement with bioprosthetic valves were studied. Their mean age was 48.4 years (range: 27 to 64 years). Aortitis was due to Takayasu disease in eight patients and to Behcet aortitis in two. The bioprosthetic valves used included bovine pericardial xenografts (n = 8) and porcine aortic valves (n = 2). The mean daily dosage of prednisone was 10.1 mg (range: 2.5 to 60 mg); mean duration of therapy was 8.0 years. The mean patient follow up, using echocardiography, was 11.5 years (range: 8.5 to 16 years). The total follow up period was 115 patient-years. RESULTS: During follow up, three reoperations were required because of valve detachment, aortic insufficiency due to perforation of the aortic cusp, and aortic insufficiency with coronary orifice stenosis, respectively. No reoperations were required for stenotic degeneration of the bioprosthetic valves. Seven bioprosthetic valves were still functioning between 8.5 and 16 years after implantation. Calcific degeneration in two of three bovine pericardial valves that required replacing was surprisingly minimal; separation of collagen fibers in the valves by infiltration with plasma proteins was also minimal. CONCLUSIONS: These results suggest that the calcific degeneration of bioprosthetic valves may be decreased by concomitant steroid therapy for aortitis, though further research will be required to confirm this effect and to determine the mechanism(s) involved.

Adult↗
PubMed1996

Radioimmunoprecipitation assay for glutamic acid decarboxylase antibodies evaluated clinically with sera from patients with insulin-dependent diabetes mellitus.

We evaluated a new, commercially developed radioimmunoprecipitation assay for measuring glutamic acid decarboxylase (GAD) antibodies by using recombinant human GAD65. The intra- and interassay CVs were 8.0% (n = 20) and 8.6% (n = 15), respectively. We found GAD antibodies in 74% (23 of 31; 95% confidence interval 55-88%), 70% (14 of 20; 46-88%), and 65% (28 of 43; 49-79%) of patients at, respectively, < or = 1 year, 1-2 years, and 2-4 years after the onset of insulin-dependent diabetes mellitus (IDDM) and in 30% (30 of 99; 21-40%) of patients with long-term diabetes (4-22 years). We also detected GAD antibodies in 8% (9 of 106; 4-16%) of patients with non-insulin-dependent diabetes mellitus (NIDDM). The frequency of GAD antibodies in the NIDDM group was markedly higher in the insulin-deficient patients [67% (6 of 9; 30-93%)], who initially were nonketotic and non-insulin-dependent for > or = 6 months but later became insulin dependent, than in the non-insulin-deficient patients [3% (3 of 97; 1-9%)]. This new commercial assay is easy to use and provides a specific and sensitive method for evaluating GAD antibodies in IDDM.

Adolescent↗
PubMed1995

The vestibular nuclei of the rat project to the lateral part of the thalamic parafascicular nucleus (centromedian nucleus in primates).

To clarify the vestibular projections to the centromedian-parafascicular nuclear complex, the Phaseolus vulgaris leucoagglutinin (PHA-L) and horseradish peroxidase conjugated to wheat germ agglutinin (WGA-HRP), tracing studies have been done in rats. The data demonstrated that the lateral parafasicular nucleus received vestibular afferents mainly from the ventral part of medial vestibular nucleus, and the superior and inferior vestibular nuclei, with an ipsilateral predominance. These findings suggest the vestibular influence to the motor loop of the basal ganglia thalamocortical projections.

Afferent Pathways↗
PubMed1995

Modified maze procedure for patients with atrial fibrillation undergoing simultaneous open heart surgery.

BACKGROUND: Persistent atrial fibrillation (AF) leaves patients symptomatic and at increased risk of thromboembolism even after otherwise successful cardiac surgery. METHODS AND RESULTS: To treat AF secondary to cardiac lesions requiring surgery, we combined a modified maze procedure in 101 patients simultaneously undergoing valvular procedures (87), repair of congenital anomalies (12), and other procedures (2), including 24 repeat operations. Duration of AF varied from 0.1 to 30 years (average +/- SD, 8.8 +/- 7.0 years); the f-wave voltage ranged from 0 to 0.45 mV (0.15 +/- 0.09 mV); and cardiothoracic ratio varied from 40% to 99% (63 +/- 9%). Aortic cross-clamp time varied from 75 to 229 minutes (138 +/- 31 minutes), with bypass time ranging from 119 to 326 minutes (217 +/- 42 minutes). There were two early deaths (2%), no late deaths, and one episode of transient neurological ischemic attack in follow-up ranging from 1.0 to 3.1 years, for a total of 190 patient-years. Postoperative rhythms were sinus in 83 patients (82%), junctional in 4 (4%), and persistent AF in 14 (14%), each of whom had mitral valve disease. Patients with other underlying pathology had complete recovery of atrial rhythm. A normal-sized A wave was detected in 88% for transtricuspid flow and in 73% for transmitral flow, suggesting concomitant recovery of atrial contraction. Among 36 patients without mechanical valves, 30 (83%) with atrial rhythm and contraction have been taken off anticoagulation therapy, including 10 who are free of all medication. CONCLUSIONS: The results suggest that the combined approach is safe, effective, and indicated in patients who are judged capable of tolerating the procedure and likely to regain atrial rhythm.

Aged↗
PubMed1995

Expression of the MAGE gene family in human head-and-neck squamous-cell carcinomas.

The MAGE genes encode certain tumor-associated antigens recognized by cytotoxic T lymphocytes. We investigated the expression of the MAGE-1, -2, -3, -4, -41, and -6 genes in 88 head-and-neck squamous-cell carcinomas (83 fresh tumor samples and 5 cell lines), using a reverse-transcription-polymerase-chain-reaction assay, followed by dot-blot hybridization with sequence-specific oligonucleotides and/or restriction enzyme-pattern analysis. The MAGE-1, -2, -3, -4, -41 and -6 genes were expressed at the mRNA level in 27, 34, 36, 22, 16 and 35, respectively, of 83 fresh tumor samples. At least one of these genes was expressed in 59 of the 83 samples. Neither non-tumor inflammatory cells nor normal tissues were positive for these genes. The MAGE-1 gene was expressed relatively frequently in SCC of the oropharynx, hypopharynx and maxillary sinus, but at lower rates in SCC of the larynx and of the tongue and oral cavity. MAGE-1 was frequently expressed in poorly differentiated SCC, somewhat less frequently in moderately differentiated SCC, and only infrequently in well-differentiated SCC. The expression levels of the other MAGE genes also varied with the anatomic site as well as the degree of differentiation. Our results suggest that specific immunotherapy against MAGE gene products may be useful for patients with head-and-neck carcinomas.

Antigens, Neoplasm↗
PubMed1995

Motility related protein 1 (MRP-1/CD9) expression: inverse correlation with metastases in breast cancer.

In our previous studies we showed that motility related protein 1 (MRP-1) is a glycoprotein recognized by mAb M31-15, and that the sequence of MRP-1 is identical to that of CD9, a WBC differentiation antigen. Transfection of MRP-1/CD9 cDNA into cultured nonhematopoietic cells suppresses cell motility. The extent of suppression is directly related to the level of MRP-1/CD9 expression. In addition, the metastatic potential of MRP-1/CD9-transfected melanoma BL6 cells is lower than that of control BL6 cells. To determine whether these experimental results are of relevance with respect to actual human tumors, we investigated MRP-1/CD9 expression in 143 invasive ductal carcinomas of the breast. Of 97 patients with MRP-1/CD9-positive tumors, only 36 (37.1%) had lymph node involvement. In contrast, 21 of 39 (53.8%) patients whose tumors had reduced MRP-1/CD9 immunoreactivity and 5 of 7 patients whose primary carcinomas were not stained by the anti-MRP-1/CD9 MAb had lymph node metastases. The comparison of protein expression by 62 primary tumors and their respective metastatic lymph nodes revealed that in almost 50% of the cases, the latter had lower MRP-1/CD9 levels than the former. Moreover, reverse transcriptase-PCR-based analysis disclosed that MRP-1/CD9 gene expression in the metastatic lymph nodes of 17 of 32 patients was strikingly lower than in the primary invasive ductal carcinomas. Gene overexpression was not observed in any of the samples studied. Our data suggest that low MRP-1/CD9 expression may be associated with the metastatic potential of certain human tumors.

Adult↗
PubMed1995

Distinct immunohistochemical localization of IL-4 in human inflamed airway tissues. IL-4 is localized to eosinophils in vivo and is released by peripheral blood eosinophils.

Nasal polyposis and asthma are inflammatory conditions of the airways characterized by infiltration of activated inflammatory cells, particularly eosinophils. IL-4 is a multifunctional cytokine considered to play an important role in eosinophilic inflammation. We examined the cellular distribution of immunoreactive IL-4 in nasal polyps, as well as in the bronchial mucosa of both nonasthmatic control subjects (n = 6) and patients with well-characterized mild asthma (n = 6) subjected to a diluent or an allergen challenge. To determine eosinophilic contribution, tissue sections were counterstained with FITC after IL-4 immunostaining. No eosinophils were observed in the bronchial mucosa of nonasthmatic subjects. Nasal polyp tissues contained approximately 15 times more eosinophils per mm2 compared with bronchial tissues from asthmatics after a diluent challenge. Allergen challenge resulted in a marked increase in eosinophil density in bronchial tissues. A negligible number of cells immunostaining IL-4 was observed in bronchial tissues from nonasthmatic control subjects. The density of IL-4-positive cells in nasal polyp tissues was almost three times greater compared with asthmatics bronchial tissues after a diluent challenge. Approximately 90% of the IL-4-positive cells in bronchial tissues did not exhibit fluorescence after FITC counterstaining; in contrast, about 80% of the IL-4-positive cells in nasal polyp tissues did. We also show that peripheral blood eosinophils from allergic subjects express IL-4 mRNA by Northern blot analysis, particularly on stimulation with secretory IgA immune complexes. Finally, the supernatant of stimulated eosinophils contained approximately 50 pg/10(6) cells of IL-4 as determined by ELISA. These data demonstrate that eosinophils express the message and release IL-4 in vitro, and that these cells are the primary source of immunoreactive IL-4 in tissues undergoing chronic severe mucosal inflammation.

Adult↗
PubMed1995

Nonionic contrast agents produce thrombotic effect by inducing adhesion of leukocytes on human endothelium.

The expression of P-selectin was more upregulated following the exposure to nonionic low osmolar contrast agents than to ionic contrast agents. Exposure to nonionic contrast agents led to a marked adhesion of leukocytes to endothelial cells. Thrombomodulin activity of endothelial cells was decreased, and plasminogen activator inhibitor-1 (PAI-1) and tumor necrosis factor (TNF) alpha in the supernatant were increased when leukocyte adhesion occurred after exposure to nonionic contrast agents. Results suggest that the adhesion of leukocytes to the endothelium increases procoagulant activity.

Cell Adhesion↗
PubMed1995

Isolation and sequencing of two cDNA clones encoding Rho proteins from the fission yeast Schizosaccharomyces pombe.

The rho genes encode a group of low-molecular-weight GTP-binding proteins that show about 30% identity in the amino-acid sequence to the ras gene product. Two cDNA clones, both of which are similar to the rho genes, were isolated from a cDNA library of the fission yeast Schizosaccharomyces pombe, using the human rhoA cDNA as a probe. These genes were called rho1+ and rho2+. The encoded Rho1 protein showed 72.7% identity to the budding yeast RHO1 and 66.8% to human RhoA, and the encoded Rho2 protein showed 53.2% identity to the budding yeast RHO2 and RhoA.

Amino Acid Sequence↗
PubMed1995

Decrease in CRE binding activity by chronic morphine administration in mouse brain.

Recent studies have suggested that opiate addiction is associated with transcriptional changes. We developed a novel method, in situ DNA-protein binding (ISDB), for investigating the distribution and changes of DNA binding activity of transcription factors in the brain. Using this method, we found that cAMP response element (CRE) binding activity was decreased by chronic morphine treatment in specific regions including the amygdala complex, thalamus, cerebral cortex and hypothalamus in mouse brain. This effect persisted for at least 14 days after the cessation of morphine. These data suggest that chronic morphine treatment elicits a long-term change in cAMP-mediated gene expression in the brain.

Animals↗
PubMed1995

Assessment of self-control behavior: validity analyses on a Japanese version of the self-control schedule.

To investigate the validity of a Japanese translation of Rosenbaum's Self-Control Schedule (SCS), 338 Japanese undergraduates were administered the scale. Construct validity of the SCS subscales, Constructive Self-Control and Ineffective Self-Control, in this study was achieved by correlations with coping responses. In addition, multiple regression analyses showed that Constructive Self-Control contributed to a negative prediction of future depression and psychosomatic symptoms, and Ineffective Self-Control predicted future depression and psychosomatic symptoms. These findings indicated that the Japanese version of the SCS employed in this study appeared to be a valid and promising measure of self-control.

Adaptation, Psychological↗
PubMed1995

Low platelet mitochondrial complex I and complex II/III activity in early untreated Parkinson's disease.

Following the discovery of inhibition of electron transport complex 1 by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which produces a parkinsonian syndrome in humans, monkeys, and mice, several laboratories have reported abnormalities of complex I and other electron transport complexes (ETCs) in various tissues from patients with Parkinson's disease (PD). Criticism of the significance of these findings in the etiology of PD has centered on whether drug treatments or the debilitation of the disease process itself produced the low ETC activities. We present results from a blinded study of platelet mitochondrial ETC activities in 18 early untreated PD patients and 18 age- and sex-matched controls and in 13 spousal controls. Lower complex I activity in platelet mitochondria of PD patients was seen in early untreated disease and thus cannot be due to debilitation or drug therapy. Home environmental factors seem an unlikely explanation for the reduced complex I activity in PD patients but have not been excluded. Complex II/III activity was also reduced by 20% in PD compared with age-/sex-matched controls. The low complex I and II/III activities in platelet mitochondria appear to be related to the etiology of PD.

Adult↗
PubMed1995

Deletion in the L1 open reading frame of human papillomavirus type 6a genomes associated with recurrent laryngeal papilloma.

Human papillomavirus (HPV) type 6a genomes with a large deletion in their L1 open reading frames (ORF) were found in two of five recurrent cases of laryngeal papilloma. One of these mutant HPVs had a 186 base pair (bp) deletion near the N-terminus end of the L1 ORF, which encodes a major capsid protein. The other had a 454 bp deletion at the C-terminus end of L1 at which is located a nuclear localising signal (NLS). No other large deletion or insertion was found in the remaining regions of all five HPV6a genomes. The laryngeal papillomas which harboured the mutant viruses showed typical hyperplasia and pathological changes as observed in tumours induced by the wild-type virus. The biological significance of the two large deletions in the late region of HPV6a associated with laryngeal papilloma is discussed.

Amino Acid Sequence↗
PubMed1995

Cucurbitacin glycosides from Cabeça-de-negro.

Five cucurbitacin glycosides named cabenosides D-L were isolated from 'Cabeça-de-negro', the roots of Caput nigri. Among them, the structures of cabenosides D-H were elucidated as 10 alpha-cucurbit-5-en-11-oxo-3 beta,24R,25-triol-3-O-beta-D-glucopyranoside, 10 alpha-cucurbit-5-en-24-oxo-3 beta, 11 alpha,25-triol-25-O-beta-D- glucopyranosyl, [3,O-beta-D-glucopyranoside, 3-O-beta-D-glucopyranosyl-(1-2)-beta-D-glucopyranoside, 3-O-beta-D-glucopyranosyl-(1-6)-beta-D-glucopyranoside] and 10 alpha-cucurbit-5-en-11,24-dioxo-3 beta,25-diol-25-O-beta-D- glucopyranosyl, 3-O-beta-D-glucopyranosyl-(1-6)-beta-D-glucopyranoside, respectively, on the basis of chemical and spectral evidence.

Carbohydrate Sequence↗
PubMed1995

Cucurbitacin glycosides from Caput nigri.

The chemical structures of cabenosides I-L were investigated. These are four of the 12 cucurbitacin glycosides isolated from 'Cabeça-de-negro', the roots of Caput nigri. By means of chemical analyses the structures of cabenosides I-L were elucidated as 10 alpha-cucurbit-5-ene-3 beta,11 alpha,20S,24 xi,25-pentaol [3, 25-di-O-beta-D-glucopyranoside, and 3-O-beta-D-glucopyranosyl-(1-2)-beta-D-glucopyranosyl (sophorosyl), 25-O-beta-D-glucopyranoside], and 10 alpha-cucurbit-5,20,24-triene-11-oxo-3 beta,26-diol [3-O-beta-D-glucopyranosyl-(1-6)-beta-D-glucopyranosyl (gentiobiosyl), 26-O-beta-D-glucopyranoside and 3,26-di-O-gentiobioside], respectively.

Glycosides↗
PubMed1995

Induction of hepatic drug-metabolizing enzymes by chlornitrofen (CNP) and CNP-amino in rats and mice.

The induction of hepatic drug-metabolizing enzymes by chlornitrofen (CNP) and CNP-amino was studied in the liver of male rats and mice. CNP-amino increased the activities of 7-pentoxyresorufin O-depentylase (PROD) and 7-benzyloxyresorufin O-debenzylase (BROD) as CYP2B1-dependent monooxygenase 3.6- and 4.1-fold in rats. On the contrary, these enzyme activities in mice were induced by CNP rather than by CNP-amino. Furthermore, immunoblotting showed that the protein levels of CYP2B subfamily cytochrome P450 (P450) in liver microsomes of rats and mice were increased by CNP or CNP-amino. Phase II drug-metabolizing enzymes, UDP-glucuronyltransferase (UGT) and glutathione S-transferase (GST) levels in mice were also significantly increased from 1.4 to 2.5-fold by CNP or CNP-amino. However, neither CNP nor CNP-amino affected UGT and GST in rats. These results suggest that CNP and or CNP-amino induce the P450 isoforms of CYP2B subfamily in the rat and mouse liver, and that the inducibility of drug-metabolizing enzyme by the compounds is different between rats and mice.

Animals↗