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Biomedical subjects

T Kohno

Publications and source records attributed to T Kohno.

At least 199 records · Page 11Linked to original sources
PubMed1997

A sandwich transfer enzyme immunoassay for salmon calcitonin: determination of the bioavailability of intranasal salmon calcitonin in human.

A sandwich transfer enzyme immunoassay for salmon calcitonin (SCT) and its usability for the pharmacokinetic study are described. The assay procedure consisted of the reaction of SCT with 2,4-dinitrophenyl biotinyl anti-SCT IgG and anti-SCT Fab'-beta-galactosidase conjugate, trapping onto (anti-2,4-dinitrophenyl bovine serum albumin) IgG-coated polystyrene balls, eluting with epsilon N-2,4-dinitrophenyl-L-lysine and transferring to streptavidin-coated polystyrene balls and fluorometric detection of beta-D-galactosidase activity. The practical detection limit of SCT was 0.05 pg (15 amol)/50 microliters of sample and 1 pg/ml as the concentration. The application of this method has enabled us to directly estimate the bioavailability of SCT dosed intranasally at the therapeutic level (160 IU, 31 micrograms) for its anti-osteoporotic effect as compared to an intramuscular dose (10 IU, 1.9 micrograms). The pharmacokinetic parameters of the intranasal SCT (n = 6) thus estimated were as follows: the area under the blood concentration-time curve (AUC) 9400 +/- 5400 (SD) pg.h/ml, and the mean residence time (MRT) = 42 +/- 14 (SD) min, when the AUC for the intramuscular SCT (n = 3) = 5600 +/- 2000 (SD) pg.h/ml and the MRT = 39 +/- 19 (SD) min.

2,4-Dinitrophenol↗
PubMed1997

Indocyanine green angiography in choroidal osteoma.

BACKGROUND: Choroidal osteoma is a rare choroidal tumor; knowledge of its indocyanine green characteristics is limited. METHODS: The fundus photographs and the fluorescein and indocyanine green angiograms of three patients were reviewed. Each patient was examined at least twice with a follow-up varying from 10 to 60 months. RESULTS: Late-phase fluorescein angiograms allow assessment of the extension of the osteoma as it is variably hyperfluorescent due to tumor staining combined with a variable degree of overlying retinal pigment epithelial changes. The hypofluorescent area observed in the early phase of the indocyanine green angiogram corresponds with the extent of the osteoma but the borders may be difficult to demarcate. In the late phase of the indocyanine green angiogram, hypofluorescence due to choriocapillaris loss and hyperfluorescence due to leakage from abnormal choroidal vessels are combined. Infrared angiography high-lights abnormal choroidal vessels and vascular spiders present on the tumor surface. It is difficult to differentiate these choroidal vascular anomalies from subretinal neovascularization. CONCLUSIONS: We find no homogeneous pattern either on fluorescein or on infrared angiography. The findings may change with follow-up, indicating changes within the tumor or the surrounding tissue that are still poorly understood.

Adult↗
PubMed1997

Thoracoscopic cardiomyoplasty: a canine feasibility study.

BACKGROUND: Thoracoscopy may be effective in reducing the surgical stress of cardiomyoplasty. The feasibility of thoracoscopy in cardiomyoplasty was investigated. METHODS: Cardiomyoplasty by thoracoscopy and by the open method through a thoracotomy was performed in dogs. After 8 to 10 weeks of preconditioning, the hemodynamic effect of burst stimulation was measured. RESULTS: Cardiomyoplasty by thoracoscopy took 90 +/- 21 minutes (mean +/- standard deviation), whereas cardiomyoplasty by the open method took 67 +/- 10 minutes (p < 0.05). As a result of burst stimulation, aortic pressure, descending aortic flow, and left atrial pressure increased by 15.1% +/- 6.5%, 8.6% +/- 6.3%, and 3.8% +/- 4.6%, respectively, in the dogs that received the cardiomyoplasty by thoracoscopy, whereas those indices increased by 16.5% +/- 6.9%, 9.8% +/- 5.9%, and 4.8% +/- 4.2%, respectively, in dogs that received cardiomyoplasty by the open method. No significant difference between the two groups was shown in any index. CONCLUSIONS: Cardiomyoplasty by thoracoscopy was technically practical, and its hemodynamic effect was similar to that of the open method. The feasibility of cardiomyoplasty by thoracoscopy was thereby suggested.

Animals↗
PubMed1997

BDNF and trkB mRNA expression in neurons of the neonatal mouse barrel field cortex: normal development and plasticity after cauterizing facial vibrissae.

Development of the central somatosensory system is profoundly modulated by the sensory periphery. Cauterization of facial whiskers alters the segregation pattern of barrels in rodents only during a few days just after birth (critical period). Although a molecular basis of the segregation of barrel neurons and the critical period for the anatomical plasticity observed in layer IV barrel neuron is not clear yet, the accumulating evidence suggests that neurotrophins modulate synaptic connections including central nervous system. In this study, we showed by in situ hybridization that mouse barrel side neurons express brain-derived neurotrophic factor (BDNF) mRNA and both catalytic and non-catalytic forms of trkB mRNA. Cautery of row C vibrissae on the right side of the face within 24 h after birth (post natal day 0, PND0) reduced the expression of BDNF and trkB mRNA from the division region between the contralateral row C barrels at PND7. The vibrissae in row A, C, and E were cauterized at PND0 followed by quantitative RT-PCR for BDNF and trkB mRNA with total RNA isolated from the barrel region at PND7. The result showed that BDNF, but not trkB, mRNA was increased several-fold in the contralateral barrel region. These data suggest that the expression of BDNF mRNA is differentially regulated between injured barrels and actively innervated barrels. The differential expression of the mRNA encoding neurotrophins and their receptors may be important in regulating the injury-dependent re-segregation of barrels.

Animals↗
PubMed1997

Allelotype and replication error phenotype of small cell lung carcinoma.

Allelotype and replication error (RER) phenotype analyses were performed to clarify the pathogenetic significance of inactivation of tumor suppressor genes and genomic instability in the genesis and progression of small cell lung carcinoma (SCLC). We examined 37 cases of SCLC for loss of heterozygosity (LOH) and microsatellite instability at 49 loci on all 39 nonacrocentric chromosomal arms. LOH was frequently (>70%) detected on chromosomes 3p (29/32, 90.6%), 5q (15/21, 71.4%), 13q (25/26, 96.2%), 17p (22/25, 88.0%), and 22q (24/33, 72.7%). Frequent LOH (>70%) on these loci was observed even among seven cases of stage I tumors. The incidence of LOH on all 39 nonacrocentric chromosomal arms was not significantly different between primary tumors and metastases. These results suggest that inactivation of multiple tumor suppressor genes accumulates relatively early during progression of SCLC and it may be responsible for clinically and biologically aggressive phenotype of SCLC. RER was observed in 6/37 (16.2%) of SCLC, however, RER at multiple loci was observed only in two cases. Therefore, it was indicated that genomic instability is uncommon, but might play a role in the genesis of a small subset of SCLC.

Alleles↗
PubMed1997

Infrequent mutations of the transforming growth factor beta-type II receptor gene at chromosome 3p22 in human lung cancers with chromosome 3p deletions.

Mutations in the transforming growth factor beta-type II receptor (TGFbeta RII) gene have been detected in several types of human cancers that represent the phenotype of genomic instability. The TGFbeta RII gene has been mapped to chromosome 3p, on which loss of heterozygosity (LOH) was frequently detected in both small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC). To investigate whether the TGFbeta RII gene on 3p22 is inactivated in lung cancers, we examined 35 sporadic lung cancers (15 SCLC and 20 NSCLC) with LOH on 3p for mutations of the TGFbeta RII gene. We previously produced eight intron based primer pairs for mutational analysis of the entire coding region of the TGFbeta RII gene. Using these primers, we screened for mutations of the TGFbeta RII gene by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis. A mutation was detected in a case of SCLC: one base insertion in the polyadenine tract of exon 3. This tumor showed the replication error (RER) phenotype. There were no mutations in exons 1, 2, 4, 5, 6 and 7. These results indicate that the polyadenine tract is a mutational hot spot in the TGFbeta RII gene in RER positive tumors, and that TGFbeta RII mutations occur rarely in lung cancers with LOH on chromosome 3p.

Carcinoma, Non-Small-Cell Lung↗
PubMed1997

Hairpin structure of an RNA 28-mer, which contains a sequence of the enzyme component of a hammerhead ribozyme system: evidence for tandem G:A pairs that are not of side-by-side type.

An RNA 28-mer (Rz28) was obtained as a major product by in vitro transcription with T7 RNA polymerase of a promoter-template DNA, which contains a sequence for the enzyme component, RNA 24-mer (Rz24), of a mutant hammerhead ribozyme system. Sequence analysis and enzymatic probing study showed that Rz28 has 4 extra nucleotides at the 3'-terminus, the sequence of which is complementary to that of the 5'-terminal sequence of Rz24, and forms a stable hairpin structure. NMR studies using a 15N-guanine-labeled derivative suggested that Rz28 contains tandem G:A pairs that are not of the side-by-side type which is found in the crystal structure of hammerhead ribozyme complexes. Comparison of the HMQC spectra of 15N-guanine-labeled Rz28 and Rz24 suggested that Rz24 also contains the same type of tandem G:A pairs.

Adenine↗
PubMed1997

Detection of Epstein-Barr virus DNA in virus-infected cells by electron microscopic in situ hybridization.

We describe a procedure for in situ hybridization using a biotinylated Epstein-Barr virus (EBV) sequence with detection at the light and electron microscopic levels. In situ hybridization using an immunogold-silver staining detection system was used to identify biotinylated DNA probes in cell smears and in Lowicryl K4M-embedded EBV-infected and -noninfected cell lines. At the light microscopic level, the reaction product of hybridized EBV DNA sequence seemed to be located mainly in the nuclei. The labelling was dependent on the cell strains. However, at the electron microscopic level, the reaction product was evident as spots or clusters distributed not only in the nuclei of EBV-infected cells but also in the cytoplasm and extracellular particles. These findings suggest that immature particles in the cytoplasm contain EBV DNA. This procedure can be applied to the observation and identification of virus infection.

Biotinylation↗
PubMed1997

Monoclonal antibody #5-2-26 recognizes the phosphatase-sensitive epitope of rabies virus nucleoprotein.

We prepared monoclonal antibodies (MAbs) against the rabies virus N protein, among which one antibody (MAb 5-2-26) was shown to lack reactivity with the phosphatase-treated N protein. The MAb was able to recognize the sodium dodecyl sulfate (SDS)-denatured N protein. The MAb did not recognize the N-protein analogues produced in Escherichia coli (E. coli), indicating that the N-gene products were not normally processed in E. coli after translation. On the other hand, the MAb reacted normally with N-gene products produced in COS-7 cells, but not with those produced in the presence of K-252a (a protein kinase inhibitor of a broad spectrum). The MAb displayed weak cross-reactivity with the Triton-insoluble network structures composed of several components, while another phosphoprotein (M1) of the virus was not recognized at all. These results suggest that MAb 5-2-26 preferentially recognizes a phosphatase-sensitive linear epitope of N protein, which may enable further investigations to be conducted on the mechanism of N-protein phosphorylation and its role(s) in virus replication.

Animals↗
PubMed1997

Identification of a phosphatase-sensitive epitope of rabies virus nucleoprotein which is recognized by a monoclonal antibody 5-2-26.

We have investigated a phosphatase-sensitive sequential epitope of the nucleoprotein (N), one of the phosphoproteins of rabies virus, which is recognized by the monoclonal antibody (MAb) #5-2-26. The epitope was shared in common by all of the rabies virus strains we tested, including the HEP, ERA, CVS and Japanese strains (Nishigahara and Komatsukawa). Thin layer chromatography of the acid hydrolyzates of 32P-labeled N protein showed that the protein contained phosphoserine and phosphothreonine at a molar ratio of about 4 to 1, while no phosphotyrosine was detected. Immunoprecipitation studies with several deletion mutants of the N protein showed that the epitope is located in a region spanning from amino acid 344 to 415. If the phosphatase-sensitive epitope is located at or near the phosphoamino acid, the location of the latter could be narrowed further to a region from amino acid 354 to 389 by comparing the amino-acid sequences among the viral strains. To examine this assumption, point mutation was introduced by amino-acid substitution with alanine at either of five potential phosphorylation sites (i.e., positions 354, 375, 377, 386 and 389) in the 354-389 region. Among those, only one substitution, at position 389, greatly affected the antigenicity. Substitution of serine-389 by threonine also reduced the antigenicity. These results strongly suggest that serine-389 is a phosphorylation site and essential for constructing or stabilizing the antigenic structure for MAb 5-2-26.

Amino Acid Sequence↗
PubMed1997

Fiber digestion and weight gain in guinea pigs fed diets containing different fiber sources.

The effects of different fiber sources on feed intake, weight gain and digestibility of fiber were examined in guinea-pigs fed pelleted diets containing alfalfa meal, oaten hay, beet pulp and commercial hay cubes mixed with a basal diet at ratios of 3:1 (75% in the diet), 1:1 (50%) and 1:3 (25%). The basal diet contained 50.0% corn, 4.1% wheat, 22.1% wheat flour and 17.7% corn gluten meal. Food intake increased as the amount of fiber source was increased, but not in the case of beet pulp. The most digestible fiber (ADF and NDF) was that of beet pulp. Apparent digestibility of dry matter decreased with increasing ratios of fiber source to the basal diet for all fiber sources, but fiber and crude protein digestibilities varied and depended not only on the ratio of fiber to the basal diet but also on the source of the fiber.

Animal Feed↗
PubMed1997

Eighteen cases exposed to sarin in Matsumoto, Japan.

Forty-six patients who were exposed to sarin consulted our hospital because of darkness of vision, and ocular pain, vomiting, dyspnea and headaches on June 27 and 28, 1994. Eighteen patients were admitted and 4 of them were in the critical state. There were 6 features: 1) depression of plasma cholinesterase activity (17 of 18 patients, 94%), 2) hypokalemia (4/18, 22%), 3) depression of triglyceride (12/18, 67%), 4) hypocapnia (5/17, 29%), 5) partial pressure of oxygen (PaO2) <80 mmHg, or requirement of O2 inhalation (15/18, 83%), 6) white blood cells (WBC) >9,000 per mm3 (13/18, 72%). Seventeen patients were discharged from hospital, but one patient is still suffering from akinetic mutism after two years.

Adult↗
PubMed1997

Tactile sensor method for thoracoscopic detection of intrapulmonary nodules.

We have developed a tactile sensor which can be used to quantify the hardness of objects and applied it to thoracoscopic surgery for the localization of small invisible nodules in the lung. The hardness properties of objects can be obtained as changes in the resonance frequency of the tactile sensor (delta f). When the sensor probe is moved over the lung surface, a delta f curve is depicted on the computer screen. When the sensor tip passes the area just above a target nodule, a spike is evoked in the delta f curve. In thoracoscopic surgery, tactile sensor was employed to detect a total or 42 nodules, 32 indeterminate and 10 metastatic, in 37 patients. All except two of these detected nodules, had been preoperatively demonstrated with computed tomography. Each nodule was detected successfully by recognizing the spot on the pleura, at which the spike of delta f curve was evoked, and resected thoracoscopically. All of the indeterminate nodules were diagnosed intraoperatively; 28 benign tumors and 4 primary carcinomas. In conclusion, our tactile sensor method can be a viable alternative for thoracoscopic detection of small and invisible pulmonary nodules.

Humans↗
PubMed1997

Thoracoscopic implantation of a pacemaker lead: experimental study.

We have performed five thoracoscopic pacemaker lead implantations into the porcine myocardium. A small opening, approximately 2 cm in diameter, was made thoracoscopically in the pericardium overlying the apex of the left ventricle, avoiding phrenic nerve injury. Three screw-in type or two stab-in type standard sutureless unipolar epicardial electrodes were introduced through a trocar, and then screwed or stabbed into the myocardium near the apex of the left ventricle, avoiding the coronary vessels. Hemorrhage and arrhythmia were negligible during the procedures. Electrical tests of the pacing threshold and lead impedance after implantation of the leads revealed acceptable values in each lead. We conclude that thoracoscopic implantation of pacemaker leads is feasible, and may be used as a minimally invasive option when conventional transvenous techniques are unavailable or contraindicated.

Animals↗
PubMed1997

[Interstitial pneumonia with Sjögren's syndrome: successful treatment with steroids and an immunosuppressant].

A 44-year-old woman was admitted to our hospital complaining of dyspnea. A chest X-ray film obtained on admission showed bilaterally shrunken lungs, and peripheral bundle-like and linear shadows. A chest CT scan revealed marked thickening of bronchovascular bundles and low lung volumes. Mild dryness of the mouth, and the results of a Rose-Bengal test, Schirmer test, and sialography led to the diagnosis of primary Sjögren's syndrome. Corticosteroid pulse therapy was followed by slight improvement. To determine the pathological diagnosis and to plan further therapy, video-assisted thoracoscopic lung biopsy was done. Examination of the biopsy specimen revealed alveolitis and infiltration of lymphocytes, which suggested active interstitial pneumonia. Therapy with corticosteroids and the immunosuppressant azathioprine was followed by marked improvement.

Adult↗
PubMed1997

[Thoracoscopic surgery for the giant bulla complicating pulmonary eosinophilic granuloma: a case report].

We report a case of pulmonary eosinophilic granuloma (PEG) accompanied with a giant bulla successfully operated with a thoracoscopy. A 24-year-old female had been suffering from recurrent bilateral pneumothoraces with multiple bullae since February 1993. She was diagnosed as PEG with an open lung biopsy in July 1994. Repetitive pleurodesis were efficacious against the pneumothoraces. However, a bulla in the left upper lobe were growing with her respiratory function having worsened to bed rest. In May 1995, thoracoscopic surgery were performed to extinguish the bulla. Trocars were directly introduced into the lumen of the bulla. Ligation of the three communicating bronchial branches and tube drainage made the bulla disappear immediately. The patient had been well for one and a half year postoperatively.

Adult↗