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Biomedical subjects

J Kawai

Publications and source records attributed to J Kawai.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Transthoracic digital color Doppler assessment of the left anterior descending coronary artery and intramyocardial blood flow].

Noninvasive assessment of the distal left anterior descending coronary artery and intramyocardial blood flow were attempted in 50 consecutive patients (28 males and 22 females, mean age [+/-SD] 58 +/- 12 years) using a 7.5 MHz transducer (Doppler frequency: 5 MHz) and a SSA-380A ultrasound digital system with special optimal settings for the color Doppler examination. Modified apical acoustic windows were used to visualize the blood flow in the distal left anterior descending coronary artery and the intramyocardial artery. By selecting a sample volume (2 mm wide) on the color trace of these blood flows, Doppler spectral tracing of the distal left anterior descending coronary artery and intramyocardial blood flows could be recorded using pulsed-wave Doppler system. Blood flow in the distal left anterior descending coronary artery was detected in 43 (86%, Vmax = 22 +/- 8.7 cm/sec, Vmean = 16 +/- 5.1 cm/sec) of 50 patients, and intramyocardial blood flow in 40 (80%, Vmax = 26 +/- 11.0 cm/sec, Vmean = 19 +/- 8.5 cm/sec) of 50 patients. Distal left anterior descending coronary artery and the intramyocardial blood flows can be imaged by transthoracic digital color Doppler echocardiography in the clinical setting.

Coronary Circulation↗
PubMed1996

Stac, a novel neuron-specific protein with cysteine-rich and SH3 domains.

In RLGS-M (restriction landmark genomic scanning using methylation-sensitive endonuclease) displays of mouse brains, spot #91 is one of tissue-specific gel spots whose intensity changes developmentally. We have now cloned the corresponding cDNA from this spot and analyzed its structure and expression. The deduced amino acid sequence revealed that the #91 cDNA encodes a novel protein of 403 amino acids which consists of a cysteine-rich domain and a SH3 domain. We designated this gene as Stac. Northern blotting and in situ hybridization analyses demonstrated that 2.7 kb of Stac mRNA is expressed predominantly in brain and neurons, especially in hippocampus, cerebellum and inferior olive. Further, the gene product of 47 kDa was found by western blotting analysis in the soluble fractions of brain as well as Stac-expression vector-transfected NIH3T3 cells. Although the function of Stac is unknown so far, it is likely involved in a neuron-specific signal transduction.

Amino Acid Sequence↗
PubMed1996

Restriction landmark cDNA scanning (RLCS): a novel cDNA display system using two-dimensional gel electrophoresis.

We have developed a new method, designated restriction landmark cDNA scanning (RLCS), which displays many cDNA species quantitatively and simultaneously as two-dimensional gel spots. In this method cDNA species of uniform length were prepared for each mRNA species using restriction enzymes. After the restriction enzyme sites were radiolabeled as landmarks, the labeled fragments were subjected to high resolution two-dimensional gel electrophoresis. In analyses of cDNA samples from adult mouse liver and brain (cerebral cortex, cerebellum and brain stem) we detected approximately 500 and >1000 discrete gel spots respectively of various intensities at a time. The spot patterns of the three brain regions were very similar, although not identical, but were quite different from the pattern for the liver. RNA blot hybridization analysis using several cloned spot DNAs as probes showed that differences in intensity of the spots among RLCS profiles correlated well with expression levels of the corresponding mRNA species in the brain regions. Because the spots and their intensities reflect distinct mRNA species and their expression level respectively, the RLCS is a novel cDNA display system which provides a great deal of information and should be useful for systematic documentation of differentially expressed genes.

Animals↗
PubMed1996

Measurement of intratumor pH by pH indicator used in 19F-magnetic resonance spectroscopy. Measurement of extracellular pH decrease caused by hyperthermia combined with hydralazine.

RATIONALE AND OBJECTIVES: Without affect of metabolic changes, the authors measured intratumor pH by using 19F-magnetic resonance spectroscopy (MRS) with a fluorine compound (ZK-150471) on the basis of a calibration curve by pH electrode. METHODS: Using the 4.7-tesla magnetic resonance apparatus, a fluorine compound that had acid-base equilibrial change and was impermeable within cell membranes was used. The fluorine compound was injected intravenously. The signal was obtained from mouse mammary cancer by creating an experimental tumor on the leg of mice. And the tumors, which were heated with and without hydralazine. The pH evaluated from chemical shift of the fluorine compound. The pH data was obtained from an electrode for reference. RESULTS: The pH of nontreated tumors (n = 25) were 6.94 + 0.091. The pH decreased to 6.772 + 0.169 at 20 minutes even after 20 minutes of heating, and decreased to < 6.71 at 40 minutes after every heating time. The pH decreased to 6.456 at 20 minutes after 15 minutes of heating combined with hydralazine, and to 6.416 at 40 minutes after same treatment. CONCLUSIONS: It is possible to measure the extracellular pH by 19F-MRS with the fluorine compound noninvasively in vivo, even after heating.

Animals↗
PubMed1996

Efficacy and side effects of intermittent recombinant interferon-alpha 2a in chronic aggressive hepatitis C: with or without initial daily administration.

To investigate the therapeutic effect and incidence of side effects of recombinant interferon-alpha 2a (IFN-alpha) in chronic aggressive hepatitis C under stratification by administration mode, a study was conducted by assigning patients to either group A (daily consecutive administration of 9 million units (MU) IFN-alpha for 2 weeks and, thereafter, 3 MU intermittently 3 times weekly for 22 weeks) or group B (exclusively intermittent administration; 9 MU IFN-alpha twice weekly or 6 MU IFN-alpha thrice weekly for 24 weeks). The 28 patients in group A received IFN-alpha for 24 weeks up to a total dose of 324 MU and the 53 patients in group B received the same for 24 weeks up to a total dose of 432 MU. When recovery was defined as the absence of hepatitis C virus (HCV)-RNA 6 months after the completion of treatment, the rate of recovery for group A was 32.1% and that for group B was 37.7%, the latter being higher but without significance. Side effects in groups A and B consisted of leucopenia occupying 14.3 and 7.5%, respectively, and thrombocytopenia occupying 42.9 and 11.3%, respectively; group B exhibited lower values for both side effects. No difference was detected between these groups in other side effects, including pyrexia, generalized malaise, arthralgia or psilosis. Intermittent administration from the outset permitted shortened duration of hospitalization and earlier rehabilitation. Intermittent administration of INF-alpha is required when treating patients with chronic hepatitis C showing lower leucocyte or platelet counts.

Chronic Disease↗
PubMed1996

Evaluation of human skin irritation by carboxylic acids, alcohols, esters and aldehydes, with nitrocellulose-replica method and closed patch testing.

Closed patch testing and the nitrocellulose-replica method are performed as useful clinical methods for the evaluation of human skin irritation by cosmetics and topical medicaments. Comparison of the sensitivity between microscopic scoring by nitrocellulose-replica method and visual scoring by closed patch test in the detection of skin irritation, however, has not been well studied with statistical analysis. Here, we evaluated human skin irritation by carboxylic acids, alcohols, esters and aldehydes, with different chain length (C8-C18), using both methods. The results of closed patch testing showed that, although the score of skin irritation for carboxylic acids (C8, C12), alcohols (C8) and aldehydes (C8), tested at a concentration of 0.5 m-2.0 m, significantly increased with increasing concentration of the test compounds, ester compounds scarcely caused any irritation on the surface of the skin occluded. In addition, an increase of carbon chain length in the test compounds made it impossible to detect skin irritation. In contrast, the nitrocellulose-replica method could evaluate skin reactions against very weak irritants that gave no macroscopic alterations on the skin surface in the closed patch test. However, the scoring system is somewhat subjective and should be improved to make the analysis more objective.

Adult↗
PubMed1996

Heterogeneity in the appearance and distribution of macrophage subsets and their possible involvement in hypertensive vascular lesions in rats.

In hypertensive vascular lesions, various pathologic changes are exhibited. To clarify the mechanisms responsible for this diversity of vascular lesions, we immunohistochemically examined hypertensive vascular lesions in stroke-prone spontaneously hypertensive rats with reference to the distribution of macrophage subsets. The brain, kidney, heart, and aorta were dissected from stroke-prone spontaneously hypertensive rats and Wistar-Kyoto rats at 8, 12, 16, and 20 weeks of age. Immunohistochemistry was performed with antibodies against the macrophage markers ED1, ED2, and OX42, the MHC class II antigen marker OX6, the T-lymphocyte markers CD4, CD5, and CD8, and other markers, such as alpha-smooth muscle actin, proliferating cell nuclear antigen, and von Willebrand factor. Fibrinoid necrosis was dominant in the brain, and fibrocellular proliferative lesions were dominant in the kidney. Immunohistochemically, the decreased intensity of alpha-smooth muscle actin immunostaining preceded the formation of vascular lesions. Although preexisting ED2-positive perivascular resident macrophages completely disappeared in fibrinoid necrosis, MHC class II-negative and ED1-positive macrophages were scattered around the lesion and showed phagocytosis in the brain, which indicates that macrophages in fibrinoid necrosis had extravasated and acted only as scavengers. In the kidney, there was extensive accumulation of MHC class II-positive and ED1-positive macrophages with T lymphocytes along the affected arteries. These inflammatory cells seemed to be supplied through the perivascular interstitial space, not through the endothelium, and the accumulation of these cells preceded the development of fibrocellular proliferative lesions. In the heart and aorta, macrophage accumulation was either absent or slight, and vascular lesions were rarely observed. These findings suggest that heterogeneity in the time course of macrophage infiltration and in the distribution of macrophage subsets among the vascular trees of various organs seems to be correlated with the diversity of hypertensive vascular lesions. Differences in the routes that supply macrophages and their functions may determine the pathologic changes in the vascular lesions.

Animals↗
PubMed1996

Pseudoaneurysm and ventricular septal rupture complicated with inferior myocardial infarction diagnosed by two-dimensional and Doppler echocardiography: case report.

A 72-year-old woman with inferior myocardial infarction presented with both a pseudoaneurysm and a ventricular septal rupture detected by two-dimensional and Doppler echocardiography. The pseudoaneurysm originated from the junctional area between the inferior portion of the ventricular septum and posterior left ventricular wall. The short-axis view of two-dimensional echocardiography revealed an abrupt discontinuity of the junctional area and an echo-free space behind the left ventricular cavity. The communication orifice was 5 mm wide. Color Doppler echocardiography showed a left-to-right shunt flow from the pseudoaneurysm to the right ventricle was visualized. Combined use of two-dimensional and color Doppler echocardiography was useful for detecting a pseudoaneurysm resulting in rupture of the ventricular septum.

Aged↗
PubMed1996

[Effect of heparin-supplemented iopamidol on the blood coagulation].

The purpose of the study was to determine the concentration of heparin to be added to iopamidol in order to assure adequate anticoagulant activity and tolerability. Iopamidol that contained heparin at a concentration of 3 U/ml showed the anticoagulant activity similar to ionic contrast agents, while maintaining excellent tolerability.

Animals↗
PubMed1996

[Automatic assessment of left ventricular cavity area by the automated contour tracking method].

Measurements of left ventricular cavity area by the manual tracing method from apical four-chamber views were compared with those using the automated contour tracking (ACT) method. Nine consecutive patients in whom clear images were obtained by two-dimensional echocardiography were studied, and left ventricular end-diastolic, end-systolic areas an fractional area changes were calculated using the ACT method. The ACT method slightly underestimated left ventricular cavity areas, but excellent correlations were obtained with left ventricular end-diastolic and end-systolic areas between the ACT and manual methods (r = 0.99, SEE = 1.5 cm2; r = 0.99, SEE = 1.2 cm2; respectively). Manual tracing fractional area change correlated well with that by the ACT method (r = 0.95, SEE = 3.4%). The ACT method provides accurate estimates of the area of the left ventricular cavity.

Cardiac Volume↗
PubMed1995

Correspondence of RLGS-M spot behavior with tissue expression on mouse homologue of DP1/TB2 gene.

RLGS-M is a novel method which enables visual and quantitative detection of many methylatable loci as two-dimensional gel spots. We isolated and characterized a mouse genomic clone corresponding to the RLGS-M gel spot #109v, which showed different intensities between two tissues: the spot was much more faint in liver than in brain. Southern and Northern blot analysis disclosed this spot behavior to be related to the methylation state of NotI site and also to be correlated with the differential expression in both tissues; the transcripts for #109v were observed in the brain but hardly any in the liver. Furthermore, in the base sequence analysis, this #109v gene was found to be the mouse homologue of human DP1/TB2 gene and had a CpG island adjacent to the NotI site. These results indicate that the mouse DP1/TB2 gene is expressed corresponding to its RLGS-M spot behavior which is related to its methylation condition.

Animals↗
PubMed1995

Direct detection and isolation of restriction landmark genomic scanning (RLGS) spot DNA markers tightly linked to a specific trait by using the RLGS spot-bombing method.

We have developed a technique for isolating DNA markers tightly linked to a target region that is based on RLGS, named RLGS spot-bombing (RLGS-SB). RLGS-SB allows us to scan the genome of higher organisms quickly and efficiently to identify loci that are linked to either a target region or gene of interest. The method was initially tested by analyzing a C57BL/6-GusS mouse congenic strain. We identified 33 variant markers out of 10,565 total loci in a 4.2-centimorgan (cM) interval surrounding the Gus locus in 4 days of laboratory work. The validity of RLGS-SB to find DNA markers linked to a target locus was also tested on pooled DNA from segregating backcross progeny by analyzing the spot intensity of already mapped RLGS loci. Finally, we used RLGS-SB to identify DNA markers closely linked to the mouse reeler (rl) locus on chromosome 5 by phenotypic pooling. A total of 31 RLGS loci were identified and mapped to the target region after screening 8856 loci. These 31 loci were mapped within 11.7 cM surrounding rl. The average density of RLGS loci located in the rl region was 0.38 cM. Three loci were closely linked to rl showing a recombination frequency of 0/340, which is < 1 cM from rl. Thus, RLGS-SB provides an efficient and rapid method for the detection and isolation of polymorphic DNA markers linked to a trait or gene of interest.

Animals↗
PubMed1995

Accessibility to tissue-specific genes from methylation profiles of mouse brain genomic DNA.

The DNA methylation status of a large number of genomic loci is visualized simultaneously and quantitatively as two-dimensional gel spots in the newly developed restriction landmark genomic scanning with a methylation-sensitive restriction enzyme (RLGS-M). Here, we demonstrate that RLGS-M using NorI as a methylation-sensitive enzyme could also scan gene loci of mammalian genomes, since almost all of the NotI loci corresponding to randomly chosen RLGS-M spots were located near or in transcriptional units (6 out of 7 NotI-linking clones) when mouse brain genomic DNA was used. This supports the previous prediction that most NotI sites are located in CpG islands (Lindsay and Bird, Nature 1987, 327, 336-338). Furthermore, beginning with RLGS-M spots we examined how to approach their corresponding RNA messages, whose expression may be associated with methylation. We compared RLGS-M patterns among various developmental stages of the mouse brain from embryonic day 9.5 to postnatal 8 weeks or among in vitro cell lines, and detected alterations of RLGS-M spots which were due to methylation of NotI sites. Two experiments using NotI-linking clones or polymerase chain reaction (PCR) were carried out to approach to their corresponding RNA messages. Consequently, we isolated two PCR-amplified clones (# 15 and # 91) which corresponded to methylatable loci and gave positive signals to mRNA from the adult brain. Furthermore, we identified two NotI-linking clones (C211 and C198) whose corresponding NotI loci localized near or at transcriptional units and were methylated in cell lines.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Serum antibody against Helicobacter pylori assayed by a new capture ELISA.

We developed a highly specific detection technique for serum antibody, using a monoclonal antibody to a specific antigen of Helicobacter pylori. A monoclonal antibody preparation that reacted with the 54-kDa molecule of H. pylori antigens was obtained. Using this preparation, an antigen-capture enzyme-linked immunosorbent assay (ELISA) was established by fixation of the monoclonal antibody, followed by reaction with sonicated whole cell antigens. The serum antibody titers of patients with gastritis and peptic ulcers were significantly higher than control titers, and the antibody titer correlated with the histological severity of gastritis. Patients positive for H. pylori by bacterial culture had higher titers than H. pylori-negative patients. Our new ELISA may be useful for the diagnosis of H. pylori infections and for evaluation of the severity of gastric inflammation.

Antibodies, Bacterial↗
PubMed1995

Comparative analysis of mouse NotI linking clones with mouse and human genomic sequences and transcripts.

NotI cleavage sites are frequently associated with CpG islands that identify the 5' regulatory sites of functional genes in the genome. Therefore we analyzed a sample of 22 NotI linking clones prepared from mouse brain DNA, to determine whether these mouse NotI site associated clones could be used for comparative analysis of mouse and human genomes by cross-reaction with both mouse and human genomic DNA and RNA in Southern and Northern hybridization. We further examined whether we could establish the identity of these clones with known genes by comparing the nucleotide sequences surrounding the NotI site with the GenBank database. We observed that 70% of the clones cross-hybridized with human DNA and that 4 of 11 tested clones (36%) detected a transcript in human HeLa cells RNA whereas 73% clones (8/11) detected transcripts in mouse RNAs from one or more organs. Single pass sequence analysis was successful on 16 of 19 clones. The GC content in these sequence was very high (48.8% to 73.8%) suggesting that 12 of 16 sequenced clones contained a CpG island. Three out of 19 clones showed significant similarity with previously analyzed mouse gene sequences in GenBank, including the mouse rRNA gene family, cathepsin and the scip POU-domain genes. In addition, two sequences showed significant similarity to the human and rabbit protein phosphatase 2A-beta subunit and the human transforming growth factor-beta. Thus, 5 of 16 clones showed homology with identified genes. These results and the recent work of using RLGS methods for genetic mapping indicate that NotI linking clones can be used to efficiently cross reference a comparative analysis of the mouse and human genomic maps.

Animals↗