Search PubMed⌕ Search

Biomedical subjects

M Hirose

Publications and source records attributed to M Hirose.

At least 199 records · Page 11Linked to original sources
PubMed1999

Role of mast cells as a trigger of inflammation in Helicobacter pylori infection.

Helicobacter pylori (H. pylori) induces severe inflammation and plays a key role in gastric mucosal diseases. In general, mast cells have been believed to play an important role in inflammation. Although mast cells were detected in the gastric mucosa, the role of mast cells in the gastric mucosal inflammation caused by H. pylori is still unclear. Therefore, we examined the effects of H. pylori water extract on the degranulation of mast cells to clarify the role of these cells in gastric mucosal inflammation induced by H. pylori. Mast cells prepared from rat abdominal cavity were incubated with H. pylori for 30 min. The protein concentrations of H. pylori water extract used in this study were 0.5-3 mg/ml. The degranulation of mast cells were monitored morphologically by phase contrast microscopy equipped with time-lapse video recording system and biochemically by measuring histamine and beta-hexosaminidase. H. pylori water extract induced the degranulation of mast cells dose-dependently. The identical experiment was performed without extracellular calcium, and no significant degranulation was found. The data indicates that the degranulation of mast cells by H. pylori water extract depend on extracellular calcium. The present results indicate that H. pylori might be involved in the gastric mucosal inflammation as a trigger of mast cell degranulation for releasing chemical mediators.

Albinism↗
PubMed1999

[Application of continuous intra-arterial blood gas monitoring system "Paratrend 7" for pulmonary lavage of a patient with alveolar proteinosis].

We applied a continuous intra-arterial blood gas monitoring system (Paratrend 7) to a patient with pulmonary alveolar proteinosis during pulmonary lavage. Lavage was performed under general anesthesia with one lung ventilation. We inserted the sensor of Patatrend 7 through a 20 G catheter into the radial artery, and monitored pH, PaCO2 and PaO2 continuously throughout the procedure. SpO2 and EtCO2 were also monitored. Saline 1000-1500 ml was instilled and drained repeatedly by volume limited methods. PaO2 values by Paratrend 7 increased during instillation and decreased during drainage of the irrigating fluid. In contrast, PaCO2 value by Paratrend 7 decreased slightly during instillation and increased during drainage. The change of SpO2 was almost the same as that by Paratrend 7, but the response time of pulse oxymetry was a little quicker than Paratrend 7. During the lavage procedure, respiratory and circulatory condition changed very rapidly, and it is necessary to monitor blood gas change intensively. Paratrend 7 is useful as a perioperative monitoring system, but pulse oxymetry might be sufficient during pulmonary lavage considering its cost.

Adult↗
PubMed1999

Effects of verapamil, zatebradine, and E-4031 on the pacemaker location and rate in response to sympathetic stimulation in dog hearts.

To investigate whether slow inward Ca2+ current (ICa), hyperpolarization-activated inward current (If), and a rapid type of delayed rectifier K+ current (IKr) similarly act on the pacemaker location, sinoatrial node region, and subsidiary superior and inferior pacemaker regions, we studied the effects of verapamil, zatebradine, and E-4031 on the atrial rate and the 3-ms earliest activation region (EAR) determined from the isochronal activation sequence map in the autonomically decentralized heart of the anesthetized dog. Three blockers decreased atrial rate similarly. Verapamil shifted the EAR from the SA node region to the inferior pacemaker region. The EAR induced by zatebradine was variable, but the EAR induced by E-4031 tended to shift to the inferior pacemaker region. Sympathetic nerve stimulation increased atrial rate and shifted the EAR to the superior pacemaker region. Verapamil attenuated the increased atrial rate by 28%, and it shifted the EAR to the lower pacemaker regions consistently. Zatebradine also attenuated the increased rate by 53% and shifted the EAR from the anterior to the posterior-superior right atrium. On the other hand, E-4031 affected neither the rate nor the EAR in response to sympathetic stimulation. These results suggest that ICa, If, and IKr inhibitors differentially influence the pacemaker activity among three pacemaker regions when sympathetic tone is absent or present and that the role of ICa, If, and IKr of the pacemaker cells distributed in the atrial pacemaker complex is different in the dog heart in situ.

Animals↗
PubMed1999

Simple, rapid, quantitative, and sensitive detection of telomere repeats in cell lysate by a hybridization protection assay.

BACKGROUND: Detection of telomere repeats by Southern hybridization of genomic DNA is time consuming, and the reading of a mean terminal restriction fragment (TRF) length from a smear pattern of an autoradiogram can be inaccurate. We developed a hybridization protection assay (HPA) for telomere repeats. METHODS: We heated 5 microL of DNA solution or 10 microL of cell or tissue lysate at 95 degrees C for 5 min, mixed it with 100 microL of hybridization solution containing 3 x 10(6) relative light units of acridinium ester-labeled probe, and incubated the mixture for 20 min at 60 degrees C. We then added 300 microL of selection buffer and incubated the mixture for 10 min at 60 degrees C to differentially hydrolyze unhybridized probe. Chemiluminescence was measured for 2 s per tube. RESULTS: The amount of telomere repeats was assayed by HPA within linearity from 10 to 3000 ng of purified genomic DNA or from 1000 to 100 000 cell equivalents of lysate. To normalize the amount of DNA in lysate, the amount of Alu sequence was measured by HPA. A ratio of telomere to Alu (TA ratio) = 0.01 corresponded to approximately 2 kbp of mean TRF length determined by Southern blotting in cultured fibroblast and colorectal tissue samples. The TA ratio decreased from 0.06 to 0.02 with increasing division age from 30 to 90 population doubling levels of cultured human fetal fibroblasts. The assay required approximately 45 min from collection of cell or tissue samples. CONCLUSIONS: The amount of telomere repeats was quantitatively measured by HPA in 10 ng of sheared genomic DNA or in the lysate of 1000 cells. This method is simple, rapid, quantitative, sensitive, and applicable to the measurement of telomere repeats in clinical samples such as needle biopsy specimen or as few as 1000 cells in body fluid or washings.

DNA↗
PubMed1999

[Postoperative hoarseness and sore throat after tracheal intubation: effect of a low intracuff pressure of endotracheal tube and the usefulness of cuff pressure indicator].

Many clinical reports have described postoperative hoarseness and sore throat after general anesthesia. In most cases, these symptoms were attributed to high pressure of the endotracheal tube cuff. The recommended cuff pressure is less than 25 mmHg, as excessive pressure produces ischemia of the tracheal mucosa. However, within the safe pressure range, postoperative hoarseness and sore throat are still often observed. In this study, one hundred and ninety patients of ASA classes I or II were allocated randomly to two groups, low cuff pressure group (< 15 mmHg) or high cuff pressure group (15-25 mmHg), using continuous monitoring with a cuff pressure gauge. We investigated the incidence of postoperative hoarseness and sore throat at 24 hours after intubation and on the seventh postoperative day. The incidence of postoperative hoarseness and sore throat was significantly decreased in the low pressure group at 24 hours after intubation as compared with the high pressure group, but there was no significant difference between the two groups on the seventh postoperative day. These results suggest that keeping the cuff pressure under 15 mmHg can prevent postoperative hoarseness or sore throat at 24 hours after intubation, and that a cuff pressure gauge is thought to be one of the indispensable monitors during anesthesia.

Adult↗
PubMed1999

The role of Wilms' tumor genes.

The constitutional chromosomal deletion within the short arm of one copy of chromosome 11, at band p13, which often correlated with WAGR syndrome consisting of Wilms' tumor with aniridia, genitourinary malformation, and mental retardation, provided the first clue to the genetic events in the development of Wilms' tumor. WT1 gene is encoded by 10 exons, resulting in messenger RNA subject to a complex pattern of alternative splicing. WT1 gene encodes a zinc finger transcription factor, which binds to GC-rich sequences and functions as a transcriptional activator or repressor for many growth factor genes. WT 1 protein is mainly expressed in developing kidney, testis, and ovary, indicating that it is involved in the differentiation of genitourinary tissues, all thought to be the sites of origin of Wilms' tumor. The point mutation of WT1 results in Denys-Drash syndrome. The other Wilms' tumor gene, WT2 at 11p15.5, is linked to Beckwith-Wiedemann syndrome. The possibility that WT1 is involved in the etiology of rhabdoid tumor of the kidney was discussed. WT1 is expressed in immortalized hematologic cells such as EBV-LCL and hematologic malignancies, but not in PBL or IL-2L. High level WT1 expression in leukemia cells and a poor prognosis are linked in patients with leukemia, making the gene a novel marker for leukemia cells. A correlated expression between WT1 and mdr-1 in vincristine resistant cells indicates a close relation with multi-drug resistance and is a promising diagnostic marker for chemoresistance in hematologic malignancies.

Animals↗
PubMed1999

Virtual reality in a children's hospital.

We used virtual reality technology to improve the quality of life and amenity of in-patients in a children's hospital. Children in the hospital could enjoy a zoo, amusement park, and aquarium, in virtual. They played soccer, skiing and horse riding in virtual. They could communicate with persons who were out of the hospital and attend the school which they had gone to before entering hospital. They played music with children who had been admitted to other children's hospitals. By using this virtual technology, the quality of life of children who suffered from psychological and physiological stress in the hospital greatly improved. It is not only useful for their QOL but also for the healing of illness. However, these methods are very rare. Our systemic in our children's hospital is the first to be reported in Japan both software and hardware of virtual reality technology to increase the QOL of sick children need further development.

Child↗
PubMed1999

Virtual reality--current multimedia--the world of virtual reality for children.

Some people go as far to say that the invention of virtual technology is comparable to Columbus' discovery of the American continent. Nowadays, computers are regarded as essential tools for children to explore their new world. It will be interesting to observe and guide the growth of these children who have entered into such a world filled with many possibilities.

Child↗
PubMed1999

[A 13-week subchronic oral toxicity study of Perilla extracts in F344 rats].

A 13-week subchronic oral toxicity study of Perilla extracts in drinking water containing 0%, 2.5%, 5% and 10% extracts was performed in both sexes of F344 rats. Rats were randomly divided into 4 groups each consisting of 10 males and 10 females. No animals died during the period of administration. There were no treatment-related changes in body weight gain or in hematological or blood biochemistry values. Nor were any treatment-related histopathological changes observed in the highest dose group. These findings indicate that ingestion of 10% Perilla extracts in drinking water for 13-week does not cause any toxicological changes in rats.

Administration, Oral↗
PubMed1999

[13-week subchronic oral toxicity study of ammonium sulfate in rats].

A 13-week subchronic oral toxicity study of ammonium sulfate was performed in both sexes of F344 rats by feeding them a CRF-1 powder diet containing concentrations of 0%, 0.38%, 0.75%, 1.5%, and 3.0% of the substance. Rats were randomly divided into 5 groups each consisting of 10 males and 10 females. Male animals in the 3% group exhibited diarrhea during the administration period. No changes indicating obvious ammonium sulfate toxicity were observed in the body weights, organ weights, hematological, serum biochemical, or histopathological examinations. Based on these results, the NOEL (no-observed-effect level) of ammonium sulfate for F344 rats was judged to be 1.5% in males (886 mg/kg/day) and 3% in females (1975 mg/kg/day), and the MTD (maximally tolerated dose) for 2-year carcinogenicity studies in F344 rats was concluded to be 3.0% or more in the diet.

Ammonium Sulfate↗
PubMed1999

[A 13-week subchronic toxicity study of D-xylose in F344 rats].

A 13-week subchronic toxicity study of D-xylose was performed in male and female F344 rats at dose levels of 0%, 0.2%, 0.6%, 1.7%, and 5% D-xylose in the CRF-1 powder diet to determine the maximum tolerable dose (MTD) for subsequent investigation of carcinogenicity. Rats were randomly allocated to 5 groups each consisting of 10 males and 10 females. Rats were randomly allocated to 5 groups each consisting of 10 males and 10 females. No treated groups showed changes in body weight gain or food intake, and all animals survived until the end of the experiment. Hematological examination revealed significant increases in RBC, Hb, and Ht in the male groups treated with 0.6% and 5% concentrations, whereas these values decreased significantly in all of the female groups treated with D-xylose. However, no clear dose-response effect was observed in the hematological data in either males or females given D-xylose. Serum biochemistry studies revealed decreases in AsT in the 0.2% and 5% D-xylose group male and 0.2%, 1.7%, and 5% group female, compared to the control value. However, the changes were not considered specific because of the lack of any clear dose-response effect. In addition, no histopathological changes indicating obvious toxicity of D-xylose were observed in the livers of either sex treated with D-xylose. Based on these data, the MTD of D-xylose in F344 rats of both sexes is judged to be 5% or more in the diet.

Administration, Oral↗
PubMed1999

[A 90-day subchronic oral toxicity study of Bacillus subtilis gum in F344 rats].

A 90-day subchronic toxicity study of Bacillus subtilis gum was performed in both sexes of F344 rats by feeding of CRF-1 pellet diet containing 0%, 0.18%, 0.55%, 1.66% and 5%. Rats were randomly allocated to 5 groups, each consisting of 10 males and females. No animals died during the administration period and no differences in body weights and food intakes were found among groups of either sex. Kidney weight was significantly increased in both sexes in the groups given concentrations of 1.66% or more. However, the increases of kidney weight were slight in themselves and other data on serum biochemistry and histopathology did not show any apparent toxicological signs including renal toxicity. These findings indicate that the treatment of Bacillus subtilis gum in the diet for 90 days does not exert serious toxicity in rats even at the highest dose.

Animals↗
PubMed1999

[A 13-week subchronic oral toxicity study of orange color in F344 rats].

A 13-week subchronic toxicity study of orange color was performed in both sexes of F344 rats by feeding them a CRF-1 powder diet containing 0%, 0.18%, 0.55%, 1.66%, and 5% concentrations of the substance. No animals died during the administration period, and no changes in body weight or food intake were found in any of the dosage groups. There were significant increases in serum cholesterol in males given 1.66% or higher concentrations of orange color and in females given 0.55% or higher concentrations, and significant increases in alkaline phosphatase in males given 1.66% or higher concentrations, possibly due to the high-fat composition of the orange color diets. In addition, some hematological, serum biochemical, and histopathological changes were observed in the groups given greater than 0.55% concentrations, but they did not suggest obvious toxicity. These findings indicate that under these experimental conditions the no-observed-effect level (NOEL) of orange color in the diet for 13 weeks is 0.18% and the no-observed-adverse-effect level (NOAEL) is 5%.

Administration, Oral↗
PubMed1999

[A 13-week subchronic toxicity study of chitin in F344 rats].

A subchronic toxicity study of chitin, a natural structural component of crustacean shells, was performed in F344 rats by feeding of the powdered diet containing 5%, 1.7%, 0.6%, 0.2%, and 0% concentrations of the substance. Each group consisted of 10 males and 10 females. All animals survived until the end of the experiment. There were no changes indicating obvious toxicity of chitin in the clinical signs, body weight, food intake, hematology, serum biochemistry, or histopathological findings, except a slight decrease in body weight gain in the 5% chitin-treated males. Although the mechanism is unclear, the suppression of body weight gain may be due to the slight decrease in caloric content of the food in the 5% chitin-treated animals, a change unrelated to toxicity. Thus, there was no obvious toxicity of chitin in F344 rats at concentrations up to 5% in the diet for 13 weeks.

Administration, Oral↗
PubMed1998

Identification of the mammalian homologues of the Drosophila timeless gene, Timeless1.

We have identified novel mammalian homologues of a Drosophila clock gene, timeless, and designated them as human TIMELESS1 (hTIM1) and mouse Timeless1 (mTim1), respectively. These genes were mapped by FISH to chromosomal regions 12q12-13 in human and 10D3 in mouse. The deduced amino acid sequences of hTim1 and mTim1 proteins were 1208 and 1197 amino acids in length and shared 83% identity. Northern blot analysis identified a single transcript of 4.5 kb expressed widely in many tissues examined. Unlike the Drosophila counterpart, the levels of the mTim1 transcript exhibited no prominent circadian oscillation in the mouse brain.

Animals↗
PubMed1998

Detection of histo-blood group ABO mRNA in human chronic myeloid leukemia cell lines using reverse transcription-polymerase chain reaction (RT-PCR).

ABH carbohydrate antigens are cell surface carbohydrates which occur in three allelic forms, namely A, B and O blood groups. It is unknown how the ABO blood group is expressed in hemopoietic stem cells. In an attempt to verify the ABO mRNA expression in hemopoietic precursor cells, mRNAs were isolated from human chronic myeloid leukemia (CML) cell lines which are believed to be at the most immature level of hemopoietic differentiation among hemopoietic malignancies. In particular, K-562 and KOPM-28 cells were used with the reverse transcription-polymerase chain reaction (RT-PCR) technique for amplifying ABO gene transcripts. The amplified ABO cDNAs from two cell lines were characterized by the digestion of Kpn-I restriction enzyme. The blood types were determined by polymerase chain reaction of the specific allele (PASA) method. Both of the human chronic myeloid leukemia cell lines expressed ABO mRNA. The quantity of ABO mRNA in the K-562 cell line is significantly higher than that of the KOPM-28 cell line. The ABO blood type of these two cell lines was type O. Because the CML cell lines are presumed to be at the immature stem cell level of hematopoietic cell differentiation and because it is believed that the cultured cell lines from hematologic malignancy reflect the characteristics of normal corresponding hemopoietic cells, the hemopoietic stem cells should express mRNA of the ABO blood group.

ABO Blood-Group System↗