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Biomedical subjects

M Hata

Publications and source records attributed to M Hata.

At least 163 records · Page 9Linked to original sources
PubMed1994

Influence of ammonia solution on gastric mucosa and acetic acid induced ulcer in rats.

Aqueous ammonia in concentrations of 0.02 or 0.1% was continuously administered to rats to study its effect on the gastric mucosa histologically and cell kinetically. Furthermore, acetic acid ulcer, which is a model of chronic gastric ulcer, was experimentally induced in the stomachs of rats to assess the influence of 0.02% ammonia on the course of this ulcer. Male Donryu rats were divided into three groups given 0.02% ammonia, 0.1% ammonia or tap water. On several occasions (1, 3 and 5 days and 1, 4, 8, 12 and 24 weeks from the beginning of the experiment), the gastric mucosa in the fundic gland region and the antrum was examined histologically, and from the viewpoint of cell kinetics. The assessment in the 8th and 24th weeks employed the double labeling technique with bromodeoxyuridine and 3H-thymidine. The assessment on the other occasions used the flash labeling technique with bromodeoxyuridine. Both the 0.02% and 0.1% ammonia treatment groups showed a decrease in PAS-positive mucus and an enhanced cell cycling in the early stage of the experiment. After long periods of treatment, these groups showed a reduction in the gland height, a recovery in PAS-positive mucus and a suppression of cell cycle, suggesting direct toxicity of ammonia on the gastric mucosa. Although glandular atrophy was observed in these animals, infiltration of inflammatory cells was not observed. Thus, the relationship between ammonia and gastritis remained obscure. No ulcer developed in any group. Subsequently, we experimentally induced Ul-IV or Ul-V acetic acid ulcers in the stomachs of rats, according to the method of Okabe et al. (1971, 1972). These rats were divided into two groups given 0.02% ammonia or tap water. In the 4th and 8th weeks of the experiment, the stomachs of these rats were examined histologically and from the viewpoint of cell kinetics. The 0.02% ammonia treatment group showed a significant increase in the ulcer index (long diameter x short diameter; mm2) in the 4th and 8th weeks. This group also showed suppressed cell cycling of the regenerative epithelium and fibroblasts in the ulcer margin, suggesting direct toxicity of ammonia. Thus, healing of peptic ulcer was delayed by continuous administration of 0.02% ammonia.

Acetates↗
PubMed1994

[Concomitant graft replacement of the total aortic root and the transverse aortic arch for type A aortic dissection associated with Marfan syndrome: report of a case].

A 25-year-old man of Marfan syndrome with chronic stage aortic dissection of Stanford type A underwent concomitant graft replacement of the total aortic root and transverse aortic arch. The surgical procedure were performed with an aid of extracorporeal circulation, blood cardioplegia, using the techniques of "open distal anastomosis" under the deep hypothermic circulatory arrest and continuous retrograde cerebral perfusion for cerebral protection during circulatory arrest. The operative techniques consisted of total aortic root replacement using a composite graft with Piehler's and Carrel patch technique for left and right coronary artery, and total arch replacement using en bloc distal arch reconstruction and a composite graft replacement for innominate artery. There were no neurological complications. In the case of Marfan syndrome, type A aortic dissection involving aortic arch should be treated by concomitant graft replacement of the total aortic root and the transverse aortic arch in order to reduce the late risk of aortic dissection or annular dilatation.

Adult↗
PubMed1994

Multiple functions of raf proto-oncogene during development from analysis of a temperature-sensitive mutation of Drosophila.

A temperature-sensitive (ts) mutation of Drosophila melanogaster for D-raf, encoding a serine/threonine protein kinase, was newly induced by EMS-treatment. Temperature-shift experiments on the ts mutant revealed that D-raf is required during most of the developmental stages, and confirmed the previously reported roles of D-raf in the regulation of cell proliferation and in the determination of cell fates at terminal regions of the embryo (Nishida et al., EMBO J. 7:775-781, 1988; Ambrosio et al., Nature 342:288-291, 1989a). Detailed analysis of cell proliferation demonstrated the role of D-raf at other than M-phase in cell cycle. TSP analysis during pupal stages revealed yet another role of D-raf in eclosion. Mosaic analysis of an eclosion-defective hypomorphic mutation revealed the tissue responsible for this defect to be the muscle and/or nervous system in the thorax. Molecular lesion associated with the ts mutation was found to be an alteration of an amino acid residue in a highly conserved region that defines the kinase subdomain VIII. Molecular analysis of null mutations also suggested the importance of the kinase domain for the biological functions of D-raf. Elucidation of the multi-functional nature of signal transducers is of great importance for our understanding of the molecular mechanisms of development, and the ts mutation for pleiotropic D-raf obtained in this study promises to be useful for dissecting signal transduction pathways during development.

Animals↗
PubMed1994

[Insertion of prosthetic tricuspid valve two years after the tricuspid valvulectomy].

A case of a 14-year-old boy who underwent a prosthetic tricuspid valve insertion two years after the tricuspid valvulectomy due to intractable right-sided active endocarditis is presented. At the initial operation, the tricuspid valve was thoroughly resected because of marked destruction and attachment of vegetations, and a concomitant ventricular septal defect was directly closed. When a prosthetic valve was placed in the tricuspid portion, a semicircular Dacron patch was attached to the right side of the interventricular septum in a fashion of up-chord and down-arc to cover the bundle of His. The straight edge of the patch was located near the AV node and was not sutured to the tricuspid valve annulus. A 31 mm of CarboMedics prosthetic valve was sutured to the tricuspid valve annulus and to the free edge of the patch at the position near the AV node to prevent AV block. Postoperative course was uneventful and ECG showed regular sinus rhythm.

Child↗
PubMed1994

[Evaluation of renal function by factor analysis using 99mTc-MAG3].

The kinetics of 99mTc-mercapto-acetyltriglycine (MAG3), a new renal scintigraphic agent, was studied by factor analysis in patients with chronic renal disorders, and its application to assessment of the renal function was evaluated. Data were collected for 30 minutes from immediately after intravenous injection of MAG3 at 370 MBq, the first pass image and serial renal scintigrams were obtained, and factor analysis was attempted simultaneously. Since most of MAG3 is excreted via the kidney during the first pass, factor analysis was performed. Two factors reflecting renal parenchymal components and pelvic components could be separated in 8 (Cre < or = 2.9 mg/dl) of 10 patients, and they corresponded with respective segmental renograms. In the remaining 2 (Cre > or = 3.0 mg/dl), separation was impossible by 2-factor analysis, and 3-factor analysis was needed. Factor analysis is considered to allow objective evaluation of renal function without setting the ROI.

Adult↗
PubMed1994

Tricuspid valve myxoma in a child with coronary artery occlusion and aneurysms.

The case of a 13-year-old boy with a tricuspid valve myxoma and coronary artery occlusion and aneurysms suspected to be caused by Kawasaki's disease is presented. Simultaneous extirpation of the myxoma and coronary artery bypass grafting to the left anterior descending artery using the left internal mammary artery was performed. His postoperative course was satisfactory. Coronary artery bypass grafting in a child is also discussed.

Adolescent↗
PubMed1993

Big endothelin-1 structure important for specific processing by endothelin-converting enzyme of bovine endothelial cells.

Phosphoramidon-sensitive endothelin-converting enzyme of bovine endothelial cells showed substrate selectivity for big endothelin-1 (ET-1) when compared to big ET-1(1-38), big ET-2(1-37), big ET-2(1-38) and big ET-3(1-41). To investigate the big ET-1 structure important for specific conversion by the endothelin-converting enzyme, we synthesized a series of truncated analogues of big ET-1, measured the hydrolysis of their Trp21-Val22 bonds, and found that a 16-residue peptide, big ET-1(19-34), is the minimal peptide sequence. This suggests that an unusually long carboxy-terminal sequence is required for big ET-1 conversion. Alanine substitution for individual amino acids in the carboxy-terminal region of big ET-1(19-34) demonstrated that His27, Val29, Pro30, Tyr31, Gly32, Leu33 and Gly34 are more important than Asn23, Thr24, Pro25, Glu26 and Val28 for eliciting efficient hydrolysis of the Trp21-Val22 bond, even though the former residues are located at more distant positions from the cleavage sites than are the latter. These results, together with the fact that big ET-2 and big ET-3 show heterogeneity in the big ET-1 residues His27, Val28, Val29 and Gly34, suggest that the His27-Val-Val-Pro-Tyr-Gly-Leu-Gly34 sequence in the carboxy-terminal region of big ET-1 plays the most important role in selective conversion by endothelin converting enzyme.

Amino Acid Sequence↗
PubMed1993

A protein kinase similar to MAP kinase activator acts downstream of the raf kinase in Drosophila.

D-raf, a Drosophila homolog of Raf-1, plays key roles in multiple signal transduction pathways. Dsor1, a putative factor downstream of D-raf, was genetically identified by screening of dominant suppressors of D-raf. Dsor1Su1 mapped on X chromosome significantly suppressed the D-raf mutant phenotypes, and the loss-of-function mutations of Dsor1 showed phenotypes similar to those of the D-raf null mutations. Dsor1Su1 also significantly suppressed the mutations of other terminal class genes acting further upstream of D-raf. Molecular cloning of Dsor1 revealed its product with striking similarity to the microtubule-associated protein (MAP) kinase activator and yeast PBS2, STE7, and byr1. Our genetic results demonstrate the connection between raf and the highly conserved protein kinase cascade involving MAP kinase in vivo.

Amino Acid Sequence↗
PubMed1993

Establishment of a hepatocytic epithelial cell line from the murine fetal liver capable of promoting hemopoietic cell proliferation.

Although the fetal liver has been thought to be the main hemopoietic organ in the embryonal period, whether or not hepatocytes play a major role in hemopoiesis remains obscure. We have established an epithelial cell line from the murine fetal liver, which can support hemopoiesis in vitro. The proliferation of the epithelial cells was promoted synergistically by both epidermal growth factor (EGF) and insulin. The cells were identified as epithelial cells by the presence of desmosomes and tight junctions. Cytoplasmic organelles including small mitochondria and dilated Golgi apparati as well as intercellular canalicular structures similar to bile canaliculus also helped in confirming the hepatic origin of the cell line (designated as FHC). The cells in the primary culture were positive for both alpha-fetoprotein and albumin, indicating the hepatocytic nature of the cell line. Cloned FHC cells were demonstrated to have the ability to maintain hemopoietic progenitors in fetal liver and adult bone marrow in the coculture, and among them, FHC-4D2 clone displayed the greatest activity. Hemopoiesis-supporting function could also be seen even when bone marrow cells were separated from FHC-4D2 cells by nitrocellulose membrane. Column chromatography revealed three distinct peaks of hemopoietic activities with different molecular sizes in the supernatant of FHC-4D2. Neutralization test with antibodies and proliferative response to interleukin-3 (IL-3)/granulocyte-macrophage colony stimulating factor (GM-CSF)-responding IC2 cells demonstrated that the hemopoietic activities were attributed to GM-CSF and macrophage colony stimulating factor (M-CSF). Transcripts of GM-CSF and M-CSF were readily detectable in Northern blot analysis, whereas no messages for IL-3, IL-6, CSF for granulocytes (G-CSF) or erythropoietin (EPO) were identified. Therefore, this is the first report on the fetal hepatocyte cell line capable of supporting hemopoiesis.

Animals↗
PubMed1993

Functional effects of glucocorticoid exposure during fetal life.

1. Pregnant rats were exposed to hydrocortisone in a dose of 10 mg/kg on days 9-11 or days 13-15 of gestation. The offsprings born to these mothers were observed for their behavioral development and the response to kainic acid during the infantile period. The response to kainic acid was assessed by the frequency of wet-dog shakes behavior and limbic seizures. 2. The growth rate in the infantile offspring of the 13-15dHc-F1 group showed a slight but significant decrease. 3. All the 13-15dHc-F1 rats exhibited the rearing activity in an open-field at 17 days of age, earlier than in the controls. 4. The ambulatory activity in the 9-11dHc-F1 rats showed a significant decrease at 15 and 17 days of age, whereas no change was shown in the 9-11dHc-F1 rats. 5. The frequency of the wet-dog shakes during the 60 minutes observation after the s.c. injection of 9 mg/kg kainic acid was significantly low in both the 9-11dHc-F1 and 13-15dHc-F1 groups as compared with that in the controls when tested at 25 days of age. The decrease in the response to kainic acid was slightly greater in the 9-11dHC-F1 rats. 6. The frequency of seizures with forelimb clonus and rearing during the 60 minutes observation in the 13-15dHc-F1 was less than that in the controls, whereas no significant difference in the frequency of seizures between the 9-11dHc-F1 and paired control groups was noted. 7. The second generation rats raised from the 9-11dHc-F1 rats by brother-sister mating showed a decrease in the frequency in the kainic acid-induced wet-dog shakes as shown in the F1 offspring. No change in the response to kainic acid was shown in the 13-15dHc-F2 rats.

Animals↗
PubMed1993

Prognostic significance of bromodeoxyuridine high labeled bladder cancer measured by flow cytometry: does flow cytometric determination predict the prognosis of patients with transitional cell carcinoma of the bladder.

We studied whether flow cytometric determination of proliferative cell activity estimated by the bromodeoxyuridine in vitro labeling technique provides significant prognosticators beyond the classical histological evaluation in the patient with bladder cancer. We evaluated 81 patients with transitional cell carcinoma of the bladder using fresh bladder specimens. Clinical followup of at least more than 24 months was requested, with the mean followup being 37.9 +/- 10.5 months. Tumor grade and stage were the histological prognostic parameters. Flow cytometric bivariate measurements of deoxyribonucleic acid (DNA) ploidy and bromodeoxyuridine labeled cell index were evaluated. Tumors with a bromodeoxyuridine labeled cell index of more than 10.7%, which was the value of the mean plus 2 times the standard deviation obtained in grade 1 bladder tumors, were designated as high bromodeoxyuridine labeled cell index tumors. A total of 51 patients with low bromodeoxyuridine labeled cell index tumors demonstrated a 98.0% 3-year actuarial survival rate estimated by the Kaplan-Meier method, compared to 42.9% for those with high index tumors. Multivariate survival analysis was performed with Cox's proportional regression model to study statistical individual prognostic values of histological and flow cytometric parameters. Histological tumor grade was the single most important prognostic factor (risk ratio 13.2, p < 0.05), with tumor stage being the second most important (risk ratio 9.2, p < 0.05), followed by bromodeoxyuridine labeled cell index status (risk ratio 6.9, p < 0.05). DNA ploidy status did not influence the clinical outcome. When grade 3 tumors were classified as low and/or high bromodeoxyuridine labeled cell index tumors, 3-year actuarial survival rates were 85.7% and 27.3%, respectively. These results indicate that DNA/bromodeoxyuridine bivariate analysis can be used as an effective adjunct to histological examination for prognostication and decision-making in treatment of bladder cancer patients.

Actuarial Analysis↗
PubMed1993

[Long-term results and risk factors of tumor recurrence in patients with superficial bladder cancer who were treated by intravesical bacillus Calmette-Guerin (BCG) instillation].

An evaluation was made of the long-term results and risk factors of tumor recurrence in patients with superficial bladder cancer who were treated with intravesical bacillus Calmette-Guerin (BCG) and who had a mean follow-up period of 57 months. Eligible for the study were a total of 102 patients who were treated by transurethral resection of tumors and were considered to be free from tumor from 1984 to 1989. A suspension containing 80 mg Tokyo 172 strain BCG in 50 ml normal saline was given intravesically to 50 patients once a week for six weeks without further maintenance instillation. To the other 52 patients was additionally given monthly intravesical BCG instillation for 12 months. The actuarial nonrecurrent rates according to sex, different BCG treatment protocol, tumor grade, tumor status including primary or recurrent tumors, and solitary or multiple tumors were estimated by Kaplan-Meier method. The estimated three-, five- and seven-year actuarial nonrecurrent rates in all 102 cases were 77.3%, 68.5% and 60.6%, respectively. When nonrecurrent rates were compared to tumor characteristics, no statistically significant differences were observed between primary and recurrent tumors or between solitary and multiple tumors estimated by generalized Wilcoxon method. On the other hand, when nonrecurrent rates were compared with tumor grades, grade 3 tumor showed a 40.0% three-year nonrecurrent rate. The differences between grade 3 and grade 1 and between grade 3 and grade 2 were statistically significant (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intravesical↗
PubMed1993

Intravenous digital subtraction angiography of the internal jugular veins.

92 patients with various head-related symptoms were underwent study with IV-DSA. The width and density of the internal jugular veins were compared with the width and density of the common carotid arteries. The right internal jugular vein was more than twice as broad as the common carotid artery in 58 patients (63%), and was denser than the common carotid artery in 14 patients (15%). On the other hand, the left internal jugular vein was broader than the common carotid artery in 76 patients (83%) and more than twice as broad as the common carotid artery in 19 patients (21%). However, the left jugular vein was narrower than the common carotid artery in 12 patients (13%), and in 5 patients (5%) could not be demonstrated. If it is recalled that the internal jugular veins are sometimes congenitally aplastic or hypoplastic as developmental variations of the confluence of sinuses, the occurrence of complications associated with retrograde catheterization can be minimized.

Adolescent↗
PubMed1993

[A case of multiple colon cancer appeared after thymectomy for thymoma with myasthenia gravis].

A 62-year-old woman was admitted to our hospital because of diarrhea and melena. Thymectomy for thymoma with myasthenia gravis was carried out on this patient four years ago. Barium enema revealed four tumor shadows in the ascending and transverse colon. Multiple colon cancer was diagnosed and extended right hemicolectomy was carried out. The postoperative course was uneventful and she has been free from any symptom. In this paper, we discussed the relationship between thymoma and the incidence of nonthymic malignancy.

Adenocarcinoma↗
PubMed1993

Effect on the dentofacial complex of Macaca irus of functional tongue forces imparted on a palatal bar.

I determined the effect tongue forces imparted on a palatal bar has on the growth and development of the dentofacial complex of the Macaca irus. Ten female Macaca irus monkeys with mixed dentition were used in this experiment. The animals were divided into four groups, two animals were treated for 30 days, two for 90 days, and four for 180 days, with the remaining two animals serving as controls. The following results were obtained. 1. There was disocclusion on the maxillary and mandibular first molars. 2. Elongation of the mandibular first molars resulted from intrusion of the maxillary first molars. 3. The maxillary complex displayed a positional change with slight clockwise rotation. 4. Growth of the frontozygomatic site in the anteroinferior direction was inhibited. 5. There was no anterosuperior mandibular growth. 6. Changes in the maxillary suture and positioning of the teeth were mainly due to the effects of the tongue function imparted on the palatal bar. With enough control of the vertical growth of the maxilla can be validated. This is one of many methods of treating Class II malocclusion.

Animals↗
PubMed1993

Relationship between exercise capacity and the severity of emphysema as determined by high resolution CT.

We investigated the relationship between exercise capacity or exercise-induced hypoxaemia and the severity of pulmonary emphysema in 20 patients with pulmonary emphysema. The patients underwent pulmonary function tests, high resolution computed tomography and incremental treadmill exercise testing. Computed tomography scans were obtained at four levels in the lungs, and emphysema scores were determined by the visual assessment of low attenuation areas as a measure of the severity of parenchymal destruction. The emphysema score correlated significantly with diffusing capacity (r = -0.69) in the pulmonary function tests. Among the exercise test parameters, the emphysema score correlated significantly with the total distance walked (r = -0.74), with maximal oxygen consumption (VO2max) (r = -0.77), with arterial oxygen tension (PaO2) at rest (r = -0.50) and at the maximum workload (r = -0.58), and with the decrement of arterial oxygen tension per litre of oxygen consumed (r = -0.64). These results suggest that exercise capacity and exercise-induced hypoxaemia are related to the extent of destruction of lung parenchyma in patients with pulmonary emphysema.

Aged↗