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Biomedical subjects

I Kobayashi

Publications and source records attributed to I Kobayashi.

At least 55 records · Page 3Linked to original sources
PubMed2001

Optimal atrioventricular delay setting determined by evoked QT interval in patients with implanted stimulus-T-driven DDDR pacemakers.

Cardiac function is improved by optimizing the atrioventricular (AV) delay. An automatic optimizing function of AV delay may be necessary to achieve the most favourable haemodynamic state in paced patients. The QT interval may change when cardiac function is improved by optimizing the AV delay. The QT or stimulus-T interval is used as a sensor for rate-responsive pacemakers. Evoked (e) QT interval is measured as the time duration from the ventricular pace pulse (stimulus) and the T-sense point that is the steepest point of the intracardiac T wave (stimulus-T interval). The relationship between AV delay, eQT interval and cardiac function was studied in 10 patients (73 +/- 10 (SD) years old) with an implanted stimulus-T-driven DDDR pacemaker. Cardiac output (CO) and pulmonary capillary wedge pressure (PCWP) were measured by Swan-Ganz catheter. The AV delay was prolonged stepwise by 30 ms. Electrocardiogram event markers which indicated ventricular spike and sensed T wave were recorded, and the interval between two event markers was measured as eQT interval. When AV delay was changed from 240 ms to the AV delay at which CO was maximal (172 +/- 33 ms), eQT interval prolonged from 346 +/- 60 to 353 +/- 62 ms (P < 0.01). There was a significant positive correlation between the optimal AV delay at which CO was maximal (172 +/- 33 ms) and the optimal AV delay which was predicted from the maximum eQT interval (179 +/- 37 ms, r = 0.92, P < 0.001). When AV delay was changed from 240 ms to the predicted optimal AV delay, CO increased from 4.2 +/- 0.7 to 4.5 +/- 0.81.min-1 (P < 0.001) and PCWP was decreased from 7.1 +/- 4.0 to 5.7 +/- 3.1 mmHg (P < 0.05). In conclusion, the optimal AV delay can be predicted from the eQT interval which is sensed by an implanted pacemaker. Automatic setting of the optimal AV delay may be achieved by the QT sensor of an implanted pacemaker.

Aged↗
PubMed2001

Optically stimulated luminescence from Al2O3:C irradiated with relativistic heavy ions.

Optically stimulated luminescence (OSL) from Al2O3:C (ALOC) irradiated with selected heavy ions (4He, 12C, 40Ar, and 56Fe) was examined for discussion on the effectiveness of ALOC for space radiation protection dosimetry. The OSL efficiency on the absorbed dose basis was almost unity for He (LETinfinity x H2O: 2.2 keV x microm(-1)) and decreased with increasing LET for C (14 keV x microm(-1)), Ar (91 keV x microm(-1)), and Fe (198 keV x microm(-1)); a notable reduction greater than 60%, was observed for Fe ions. The linearity in dose response and the angular independence for the heavy ions were fairly good (+/- <15%) Although further experimental studies are clearly necessary, these results suggest that small ALOC chips can be a part of an integrating dosimetry system in future space missions.

Aluminum Oxide↗
PubMed2001

[Direct identification of mycobacteria from the positive cultures in mycobacteria growth indicator tube (MGIT)].

The ability of the AccuProbe (Kyokuto) to identify mycobacteria directly from the positive cultures in an automatic detector for mycobacteria (BACTEC MGIT960, Becton Dickinson) was evaluated. Sputum samples were collected from patients with suspected mycobacteriosis between February and April 1999 and conventionally incubated in MGIT960 (37 degrees C for 42 days). The MGIT-positive cultures were successively incubated for several days and were directly identified with the AccuProbe. Monomycobacterial strains were detected from 93 (93.9%) of the 99 sputum samples and polymycobacterial strains were detected from 6 sputum samples (6.1%). Viable cell counts in the positive cultures in MGIT960 were determined using Middlebrook 7H10 agar. The cell counts of Mycobacterium tuberculosis and Mycobacterium avium-intracellulare complex (MAC) varied greatly among the individual samples; the former, 3.8 x 10(2)-2.5 x 10(6) cfu/ml and the latter 1.5 x 10(3)-1.9 x 10(8) cfu/ml. The great differences in the cell counts were observed among these samples. Although the cultures in MGIT were estimated as positive, the early stage of bacterial growth might be used as the samples for the cell counting. By this method, 96 of the total 101 cases were successfully identified as follows: M. tuberculosis 57 cases (56.4%) and MAC 39 cases (38.6%). In conclusion, the present results indicate that the direct identification of mycobacteria from the positive cultures in MGIT960 using AccuProbe is useful for a rapid diagnosis in microbiological testing for mycobacteriosis which has tended to increase in recent years.

Culture Media↗
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

Up-regulated TGF-beta mRNA expression in splenic T cells of high IgA-prone mice: a murine model of IgA nephropathy with glomerulosclerosis.

BACKGROUND/AIMS: Recently, we established a high serum IgA-prone inbred (HIGA) mouse strain as a murine model of spontaneous IgA nephropathy by selective mating of high serum IgA ddY mice, and found that they showed enhanced production of glomerular extracellular matrix components with increased expression of TGF-beta mRNA and protein in the kidneys. In this study, we examined the roles of lymphocytes in the development of high serum IgA in this strain. METHODS: We performed flow cytometric analyses of T and B cells in splenic mononuclear cells (SMNCs) from these mice using BALB/c mice as normal controls. We also compared serum TGF-beta1 concentrations and TGF-beta mRNA expression levels in the B-cell-depleted (T-cell-rich) fraction of SMNCs in these mice. RESULTS: HIGA mice showed significantly fewer CD3-positive cells compared with BALB/c mice when young, but not when aged. The CD4/CD8 ratio of HIGA mice was lower than that of BALB/c mice, but this difference was not significant. Although the number of B220-positive cells did not vary significantly, the ratio of surface IgA-positive B cells was significantly increased in both young and adult HIGA mice. The B-cell-depleted SMNCs from HIGA mice exhibited higher levels of expression of TGF-beta and TGF-beta1 mRNA than controls from a young age, which were maintained throughout life, but there were no differences in PDGF, MCP-1 or bFGF expression between these two strains. In contrast to local mRNA expression, serum TGF-beta1 concentration was decreased in HIGA mice compared with BALB/c controls. CONCLUSION: These findings suggest that the mating procedure performed to establish HIGA mice selected for a unique phenotype of local up-regulation of TGF-beta production in the kidneys, as well as T cells that may contribute to both the early and consistently high serum IgA expression and enhanced production of renal extracellular matrix components in HIGA mice. Additionally, TGF-beta1 may act locally, not systemically, in a paracrine or autocrine manner.

Animals↗
PubMed2001

Optimization of atrioventricular delay and follow-up in a patient with congestive heart failure with an implanted DDD pacemaker: case report.

It has been reported that cardiac function can be improved by implanting a DDD pacemaker (PM) and setting a short atrioventricular (AV) delay in patients with impaired cardiac function. A previous report found that the critical AV delay that induces diastolic mitral regurgitation (MR) may represent the upper limit of the optimal AV delay. The optimal AV delay can be predicted by a simple method: slightly prolonged AV delay minus the interval between the end of the atrial kick and complete closure of the mitral valve (duration of diastolic MR) at the AV delay setting. The patient was a 84-year-old man with an old myocardial infarction. He had repeated admissions to hospital for congestive heart failure. ECG showed prolongation of the PQ interval (0.28 s) and complete left bundle branch block. Cardiac function was improved by AV sequential pacing when the AV delay was set at 120ms. After DDD-PM implantation, the cardiothoracic ratio decreased from 57 to 45% and cardiac function was improved from New York Heart Association class III to I. The AV delay was optimized during follow-up. Four years after PM implantation, the patient was in good condition without further hospital admission.

Aged↗
PubMed2001

Detection of antipituitary antibodies in patients with autoimmune thyroid disease.

The aim of the present study was to investigate the prevalence of antipituitary antibodies (APA) in patients with autoimmune thyroid disease as determined by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). Results by Western blot analysis showed positivity for APA in serum of 22.4% of patients with Graves' disease (n=143, p<0.05) and 18.5% of patients with Hashimoto's thyroiditis (n=54, p<0.05), which were significantly higher than 6.2% in healthy controls (n=97). Similar results were obtained with ELISA. The titers of APA measured by ELISA (APA/ELISA) remained unchanged before and after therapy with antithyroid drug for Graves' disease, while thyrotropin-binding inhibitor immunoglobulins (TBII) decreased significantly. Similarly, no changes in APA by Western blot analysis were observed after therapy. In patients with Graves' disease, APA were not associated with thyroid status. There was no difference in APA between patients with positive and negative thyroid autoantibodies. A significant but weak positive correlation between APA/ELISA and anti-human GH measured by ELISA (anti-hGH/ELISA) was observed in patients with Graves' disease (r=0.601 p<0.001) and Hashimoto's thyroiditis (r=0.428 p<0.005). These findings have demonstrated the existence of APA detected by Western blot analysis and ELISA in some cases of autoimmune thyroid disease. The present results suggest that hGH and other antigens may be involved in APA in patients with Graves' disease and Hashimoto's thyroiditis.

Adolescent↗
PubMed2001

Evaluation of signal-averaged electrocardiography for clinical diagnosis in arrhythmogenic right ventricular dysplasia.

Arrhythmogenic right ventricular dysplasia (ARVD) is a heart muscle disorder of unknown etiology that is characterized pathologically by fibrofatty replacement of the right ventricular myocardium. We investigated the relationship between the electrocardiogram (ECG) appearances and signal-averaged ECG (SAECG) in 7 cases with ARVD, and evaluated the usefulness of SAECG as a screening test to detect patients with ARVD. Compared with the conventional 12-lead ECG, the SAECG detects abnormalities at a higher rate in ARVD patients (57% versus 86%). SAECG was more sensitive as a screening test to detect patients with ARVD than 12-lead ECG.

Adolescent↗
PubMed2001

Effects of topical administration of 0.005% latanoprost solution on eyes of clinically normal horses.

OBJECTIVE: To determine the effect of 0.005% latanoprost solution on intraocular pressure (IOP) of eyes of clinically normal horses and establish the frequency of adverse effects of drug administration. ANIMALS: 20 adult clinically normal horses. PROCEDURE: IOP was recorded (7, 9, and 11 AM; 3, 5, and 7 PM) on days 1 and 2 (baseline), days 3 to 7 (treatment), and days 8 to 9 (follow-up). Latanoprost was administered to 1 randomly assigned eye of each horse every 24 hours during the treatment period, following the 7 AM IOP recording. Pupil size and the presence or absence of conjunctival hyperemia, epiphora, blepharospasm, blepharedema, and aqueous flare were recorded prior to IOP measurement. RESULTS: IOP was reduced from baseline by a mean value of 1.03 mm Hg (5%) in males and 3.01 mm Hg (17%) in females during the treatment period. Miosis developed in all treated eyes and was moderate to marked in 77% of horses, with the peak effect observed 4 to 8 hours after drug administration. Conjunctival hyperemia, epiphora, blepharospasm, and blepharedema were present in 100, 57, 42, and 12% of treated eyes, respectively, 2 to 24 hours following drug administration. Aqueous flare was not observed at any time point. CONCLUSIONS AND CLINICAL RELEVANCE: Although IOP was reduced with every 24-hour dosing of latanoprost, the frequency of prostaglandin-induced adverse events was high. Because recurrent uveitis appears to be a risk factor for glaucoma in horses, topical administration of latanoprost may potentiate prostaglandin-mediated inflammatory disease in affected horses.

Administration, Topical↗
PubMed2001

Anti-alpha-fodrin autoantibody is an early diagnostic marker for childhood primary Sjögren's syndrome.

OBJECTIVE: alpha-fodrin is a recently identified autoantigen associated with adult primary Sjögren's syndrome (SS). We tested whether anti-alpha-fodrin antibody could also be used as a diagnostic marker for childhood SS. METHODS: We performed immunoblot analysis of sera from 7 patients with childhood primary SS using glutathione-S-transferase alpha-fodrin fusion protein as an antigen. RESULTS: Anti-alpha-fodrin antibody was detected in sera from all 7 patients with childhood primary SS, 2 of 4 with secondary SS, and one of 7 with systemic lupus erythematosus, but in no other healthy controls. CONCLUSION: The anti-alpha-fodrin autoantibody was detected before anti-SSA or SSB antibody became positive; thus anti-alpha-fodrin antibody could be a useful marker for the early diagnosis of SS.

Adolescent↗
PubMed2001

[Classification and pathophysiology of symptomatic obesity].

Symptomatic obesity was classified by 1) endocrine obesity, 2) central nerve-related obesity, 3) genetic syndrome with obesity and 4) drug-induced obesity. Pathogenesis and pathophysiology of the diseases which induce symptomatic obesity, were briefly described. The origins of hyperphagia and obesity in these diseases have not yet clarified. Gene abnormalties of the genetic syndrome with obesity will be elucidated in near future by the rapidly progress of molecular biological techniques.

Female↗
PubMed2001

Curative resection of both primary and second primary lung cancer.

Curative resection of a second primary lung cancer in a patient who survived small-cell lung cancer is reported. Small-cell cancer had been treated with chemotherapy followed by surgical resection 12 years before. The patient developed squamous cell cancer as the second primary tumor and underwent lobectomy with mediastinal node dissection. Patients who undergo two curative pulmonary resections of both primary and second primary lung cancer are extremely rare. The patient is alive 176 months after the initial diagnosis of small-cell lung cancer and 28 months after resection for his second primary lung cancer. Careful follow-up at an interval of 3-6 months beyond 10 years is very important because adequate treatments could lead to longer survival of patients with primary small-cell lung cancer.

Carcinoma, Small Cell↗
PubMed2001

Detection of differentially expressed genes in the early developmental stage of the mouse mandible.

We previously examined the development of the mouse mandible, and demonstrated that odontogenesis occurs between embryonic day 10.5 (E10.5) and E12. Based on the histological findings, we performed cDNA subtraction between the E10.5 and E12 mandibles to detect any differentially expressed genes which might be involved in the initiation of odontogenesis. By sequencing, homology search and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), we thus found Pgk-1, Ccte, Hsp86, Nucleolin, Hsc73, Frg1, N-ras, Set alpha and Hsj2 from the E10.5 mandible, and E25, ATPase6, Mum2, Thymosin beta4 and L21 from the E12 mandible to be differentially expressed genes. These genes are functionally related to protein transport, signal transduction, transcription, translation and molecular chaperon activity. In situ hybridization analyses of Set alpha and E25 showed that Set alpha was detected in the tooth germ at E12 and E14.5, thus indicating a close relationship of this gene to odontogenesis. Meanwhile, the in situ signal of E25 was found in the muscular layer of the tongue, thus suggesting E25 to be related to the differentiation of muscular tissue. In conclusion, we found 15 differentially expressed genes in the course of the early developmental stage of the mouse mandible using a combination of the cDNA subtraction and semi-quantitative RT-PCR methods, while in addition, two genes were demonstrated to be related to the initiation and the development of both tooth germ and the tongue according to the in situ hybridization technique.

Animals↗