Biomedical subjects

M Hashimoto

Publications and source records attributed to M Hashimoto.

At least 19 recordsLinked to original sources

PubMed1992

Cloning and characterization of genes involved in the biosynthesis of delta-aminolevulinic acid in Escherichia coli.

Several mutants of Escherichia coli that had lost their ability to synthesize delta-aminolevulinic acid (ALA) via the C5 pathway were isolated. Their defective loci were classified into two groups, AlaA- and AlaB-. The genes that complemented these mutations were cloned. Nucleotide sequencing indicated that the gene that complemented AlaA- was identical to hemL which is located at 4 min on the E. coli chromosome and encodes glutamate 1-semialdehyde aminotransferase. The gene complementing AlaB- contained an open reading frame (ORF) encoding a polypeptide of 207 amino acids that was found to be a new gene involved in the synthesis of ALA via the C5 pathway. Thus, we designated the gene hemM. The hemM gene was adjacent to hemA that is located at 27 min and previously thought to encode glutamyl-tRNA dehydrogenase. However, we found that hemA complemented both the AlaA- (hemL) and AlaB- (hemM) mutants defective in the C5 pathway although the transformants showed small colonies on the selective medium without ALA. These results suggest that hemA is not involved in the C5 pathway, but controls a second, minor pathway for the synthesis of ALA.

Amino Acid Sequence↗

PubMed1992

[Clinical evaluation of lumbosacral nerve root and lateral stenosis using coronal MR imaging].

MR imaging is being used more frequently to study the lumbar spine and is becoming the modality of choice in the assessment of patient with low back pain. Using a new technique of coronal and half coronal scan with MR imaging, it was possible to visualize L4, L5 and S1 nerve roots accurately. We described the MR findings of lateral stenosis using this technique. Several characteristic MR findings were identified, and the most important one was nerve root impingement in the intervertebral foramen. We consider that coronal and half coronal scan with MR imaging is useful in diagnosis of lateral stenosis.

Adult↗

PubMed1992

Induction of differentiation of the human promyelocytic cell line HL-60 by activin/EDF.

A human promyelocytic cell line, HL-60, treated with activin/EDF was found to differentiate into monocyte/macrophage-like cells. This was shown not only by morphology but by the loss of myeloperoxidase granules and the appearance of nonspecific esterase. Dose-dependent inhibition of the differentiation by follistatin, an activin-binding protein, confirmed that it was indeed caused by activin. Thus, activin/EDF exerts its effect on hematopoietic cells not only on erythroid differentiation but also on at least a part of myeloid cell differentiation.

Activins↗

PubMed1992

[The effect of the thyrotropin releasing hormone (TRH) on the motor speech disorder in spinocerebellar degeneration].

A prospective study regarding the effect of TRH on the motor speech disorder of three patients with spinocerebellar degeneration (SCD), the first with hereditary cortical cerebellar atrophy, the second and third with sporadic olivo-ponto-cerebellar atrophy, was performed. The effect was analyzed by using speech evaluation, such as the auditory impression, the questionnaire of the consciousness for verbal communication, the phonetic evaluation and the acoustic analysis. The results of the analysis and the mechanism of the improvement of the motor speech disorder are discussed. Only the first patient showed a remarkable improvement subjectively. In addition, the improvement of phonation and articulation was demonstrated quantitatively in the evaluation of the first patient. On the other hand, by phonation analysis using VISI-PITCH, it was seen that there were a decrease in the perturbation of the voice pitch and an increase in voice range in all three patients. Therefore, it was concluded that the improvement of phonation plays a major role in the improvement of the motor speech disorder. Such improvement of the phonation seems to have resulted from the improvement of coordination, mainly due to the normalization of the muscle tone of the larynx by TRH administration. Although a remarkable beneficial effect of TRH may be obtained in exceptional patients of SCD, the mechanism of such an effect of TRH should be more extensively studied using the quantitative clinical evaluation of phonation and articulation.

Articulation Disorders↗

PubMed1992

The effects of season and exercise on the levels of plasma polyunsaturated fatty acids and lipoprotein cholesterol in young rats.

Plasma concentrations of polyunsaturated fatty acids (20:4(n - 6), 20:5(n - 3), 22:6(n - 3)) and high- or low-density lipoprotein cholesterols (HDL-C, LDL-C) in young rats were measured to elucidate a possible relationship between the levels of [20:5(n - 3)] [20:4(n - 6)]-1, [22:6(n - 3)] [20:4(n - 6)]-1 and [LDL-C] [HDL-C]-1. Seasonal change in [LDL-C] [HDL-C]-1 in the sedentary and exercised rats was found to correlate with the respective values of [20:5(n - 3)] [20:4(n - 6)]-1 and/or [22:6(n - 3)] [20:4(n - 6)]-1. Moderate exercise in summer decreased plasma arachidonic acid (20:4(n - 6)). With the decrement of the 20:4(n - 6) acid, the ratios of [20:5(n - 3)] [20:4(n - 6)]-1 and [22:6(n - 3)] [20:4(n - 6)]-1 increased to a greater degree. The [LDL-C] [HDL-C]-1 values in this case were inversely associated with the levels of [22:6(n - 3)] [20:4(n - 6)]-1. We therefore suggest that moderate physical training in summer protects arteries from thrombogenesis and lipid accumulation.

Animals↗

PubMed1992

Assay of gamma-glutamyltransferase with amino acid dehydrogenases from Bacillus stearothermophilus as auxiliary enzymes.

A spectrophotometric assay for serum gamma-glutamyltransferase (gamma-GT, EC 2.3.2.2) based on the increasing absorbance at 340 nm due to NADH formation is described. Using gamma-glutamyl dipeptides as the donor substrate, amino acids formed by the gamma-glutamyl transfer from the donor substrate to the acceptor substrate glycylglycine are stoichiometrically converted by the corresponding amino acid dehydrogenases from Bacillus stearothermophilus to produce their keto acids and NADH. gamma-Glutamylalanine was found to be the most specific and sensitive donor substrate. The method can be mechanized, is free of interference and correlates well with conventional methods.

Amino Acid Oxidoreductases↗

PubMed1992

Follistatin is a developmentally regulated cytokine in neural differentiation.

Activin acts mitogenically on P19 cells as well as being inhibitory of the differentiation of retinoic acid-treated P19 cells and some neuroblastoma cell lines. Here, we show some lines of evidence that follistatin, an activin-binding protein, is also involved in neural differentiation. Counteracting the activity of activin, addition of follistatin suppresses the anchorage-independent growth of P19 cells in soft agar and stimulates neurite outgrowth of a neuroblastoma cell line, IMR-32 cells. While activin does not seem to be expressed significantly, follistatin is demonstrated in the conditioned medium of these cells. Furthermore, the expression of follistatin in P19 cells is subject to dynamic fluctuations in response to retinoic acid treatment. These neural cells may produce follistatin in a cell stage-specific manner in order to interact with exogenously derived activin.

Activin Receptors↗

PubMed1992

Functional regulation of osteoblastic cells by the interaction of activin-A with follistatin.

A high number of 125I-activin-A binding sites (an apparent Kd of 260 pM and 5,600 sites/cell) were observed on MC3T3-E1 cells, a well characterized osteoblastic cell line. Activin-A has a mitogenic effect on these cells, with the greatest influence being observed on cells in an undifferentiated state, as well as a suppressive effect on the alkaline phosphatase activity. Northern and ligand blotting analyses revealed that these osteoblastic cells produce follistatin, which was down-regulated by retinoic acid treatment. Because follistatin is an activin-A-binding protein, we suggest that activin-A modulates the function of osteoblastic cells by being regulated by follistatin during differentiation.

Activins↗

PubMed1992

Antitumor effect of triphenylethylene derivative (TAT-59) against human breast carcinoma xenografts in nude mice.

The antitumor activity of a newly synthesized triphenylethylene derivative [(E)-4-[1-[4-[2-(dimethylamino)ethoxy-phenyl]-2-(4-isopropyl)phenyl-1- butenyl] phenyl monophosphate] (TAT-59) was investigated against human breast carcinoma xenografts in nude mice with reference to the changes of hormone receptors. Five strains (MCF-7, Br-10, R-27, ZR-75-1, and T-61) used for the experiments possessed cytosol estrogen receptor (ER), and their growth was estradiol dependent. Five mg of TAT-59 and tamoxifen citrate (TAM) per kg were administered p.o. daily except Sunday. TAT-59 showed a positive antitumor effect against MCF-7 and R-27, whereas TAM was effective on MCF-7, and their adverse effects detected by mortality rate, body weight loss, and spleen weight loss were similar to each other. The reduction of ER and production of progesterone receptor (PgR) after the treatment with TAT-59 were more potent than after TAM, suggesting that TAT-59 exerts its antitumor effect through binding to ER. These findings suggest that TAT-59 might merit use in clinical trials with breast cancers.

Animals↗

PubMed1992

Lymphangioma in the small intestine: report of a case and review of the Japanese literature.

We report herein a rare case of a 53 year old man with a benign lymphangioma of the small intestine. He presented with a complete obstruction of the small intestine and radiological examination revealed a small intestinal tumor. A long intestinal tube was passed, the intestinograms from which detected a submucosal tumor of the small intestine. Partial resection of the small intestine was thus performed and the tumor was found to be located mainly in the submucosa. The final pathological diagnosis was made as cavernous lymphangioma. This case is presented with a description of the roentgen appearance, followed by a review of the Japanese literature.

Adult↗

PubMed1992

Hemodynamic changes after resection of thoracic duct for en bloc resection of esophageal cancer.

An en bloc resection of esophageal cancer is one of the most radical forms of esophagectomy, and includes the resection of the thoracic duct, but a relatively high hospital mortality rate has been reported. There is very little knowledge on the pathophysiological changes after resection of the thoracic duct. We examined 24 patients who underwent en bloc resection. Some patients developed severe tachycardia or shock postoperatively which subsided after a massive infusion of plasma. Analysis of the fluid balance revealed that much more fluid was necessary during surgery and the postoperative 24 h than in patients treated by a standard esophagectomy. Postoperative lymphangiography or CT revealed abnormal collateral lymphatics around the kidneys or in the pelvic cavity. This suggests the development of the lymphaticovenous shunts, which differed depending on the anatomy of each patient. One patient with chronic hepatitis developed uncontrollable ascites. These are important findings which can hopefully reduce the high rate of hospital death after this operation.

Aged↗

PubMed1992

Suppression of pulmonary granulomatous inflammation by immunomodulating agents.

We demonstrated previously that macrophages and macrophage-derived cytokines including lymphocyte-activating factors (LAFs) play a critical role in lung granuloma formation in mice and that granulomas sizes correlated with LAF activity in the lesions. In the present study, we examined the effects of D-penicillamine (D-Pc), 2-acetylthiomethyl-3-(4-methyl-benzoyl)propionic acid (KE-298) and dexamethasone (Dex) on dextran bead-induced lung granulomas in mice. KE-298 is a newly synthesized compound containing sulfur (S) similar to D-Pc. Large granulomas developed, which reached peak intensity within 3 days and declined in size thereafter. Aqueous lung extracts of the mice contained high levels of LAF that were correlated with granuloma sizes. The lesions and local LAF activity were inhibited by administration of these agents. The most potent inhibitor was Dex. The suppressive effect of KE-298 was similar to that of D-Pc. These results suggest that suppression of granulomas may be attributed to inhibition of LAF activity/synthesis by these agents.

Animals↗

PubMed1992

A case of combined primary biliary cirrhosis, ulcerative colitis and chronic myelocytic leukemia.

A rare case of primary biliary cirrhosis, ulcerative colitis and chronic myelocytic leukemia is described in a 49-year-old Japanese diabetic woman. Primary biliary cirrhosis was diagnosed by characteristic liver histology and positive serum mitochondrial antibody test. Ulcerative colitis was diagnosed by typical findings of barium enema and colonoscopy, negative fecal test for pathogens and compatible rectal histology. Chronic myelocytic leukemia was determined by representative hematologic findings and positive result for Ph1 chromosome. This is the first case with combination of primary biliary cirrhosis, ulcerative colitis and chronic myelocytic leukemia.

Colitis, Ulcerative↗

PubMed1992

Overexpression of plant histidinol dehydrogenase using a baculovirus expression vector system.

A cDNA encoding cabbage histidinol dehydrogenase, including the chloroplast transit peptide sequence, was overexpressed using a baculovirus expression vector system. The maximum level of the expression of histidinol dehydrogenase was reached 5 days after infection of the insect cells. Two forms of recombinant histidinol dehydrogenase with molecular masses of 53 and 52 kDa, respectively, were obtained by a one-step purification from the cell homogenate. Compared with the 52-kDa form, the 53-kDa form contained 10 additional amino acids at the N-terminus derived from the transit peptide. By incubating the cell homogenate for 2 h at 30 degrees C, the 53-kDa form could be completely converted to the 52-kDa form. This conversion was blocked by leupeptin. Eighty percent of the converted 52-kDa form had Cys at position 31 at the N-terminal amino acid and the rest had Met 33. Kinetic properties of the recombinant enzyme were virtually identical to those of histidinol dehydrogenase isolated from cabbage plants. The overexpression of recombinant cabbage histidinol dehydrogenase in insect cells, the proteolytic processing of the preprotein next to the N-terminus (compared to the mature cabbage enzyme), and its easy purification allow the preparation of large amounts of the active enzyme for structural and functional studies.

Alcohol Oxidoreductases↗

PubMed1992

Clinical evaluation of the gingiva around single-crystal sapphire endosseous implant after experimental ligature-induced plaque accumulation in monkeys.

This study was performed to evaluate clinical changes of the gingiva with plaque accumulation around the single-crystal sapphire implant. Four implants were inserted into mandibular and maxillary edentulous regions, and the superstructure was inserted 1 month after insertion of the implants in each of nine monkeys. Plaque control was maintained for 3 months after insertion to set up the baseline. Plaque was allowed to accumulate on one side by placing the ligature around the implant and natural teeth without any plaque control, and on the other side plaque control was continued for 9 months. Both the implant and natural teeth on the ligature side showed a significant increase in the clinical parameters of plaque index, gingival index, and probing depth. No significant difference was obtained between the implant and natural teeth. These findings indicate that plaque control is of great importance for maintaining the health of peri-implant gingiva.

Aluminum Oxide↗

PubMed1992

Medulla oblongata germinoma in association with Klinefelter syndrome.

A rare case of medulla oblongata germinoma in a 19-year-old Japanese man with Klinefelter syndrome is presented. Light microscopic examination of the resected specimen showed very few lymphocytes, and an immunohistochemical study for placental alkaline phosphatase was of great diagnostic value. Up to now there have been only five cases of intracranial germ cell tumors in association with Klinefelter syndrome. These tumors were situated along in the midline structure. It is emphasized that endocrinological factors at the time of embryogenesis as well as a genetic malignant potential are important in the pathogenesis of extragonadal germ cell tumors associated with Klinefelter syndrome.

Adult↗

PubMed1992

Spinal arachnoid cyst in a newborn infant.

A male infant was born with asphyxia following a prolonged breech delivery at 39 weeks of gestation. He had a chylohemothorax from birth. Soon after birth he exhibited flaccid paraplegia with an absence of deep tendon reflexes in the lower extremities. At 17 days of age, magnetic resonance imaging (MRI) disclosed a hypodense area in the thoracic cord between C7 and Th4 in T1-weighted images, and spinal sonography revealed an echo-free space compressing the spinal cord in the same region observed with MRI. A spinal cyst was removed surgically at 24 days of age. The cyst was confirmed by pathology to be a true arachnoid cyst between C7 and Th4. The cause of this cyst may have been a spinal cord injury during the perinatal period.

Arachnoid Cysts↗

PubMed1992

Responses of isolated Japanese monkey tracheal muscle to allergic mediators.

The responsiveness of isolated Japanese monkey (Macaca fuscata) tracheal muscle to antigen, carbachol, histamine, leukotriene C4 (LTC4), U-46619 and substance P (SP) was compared to that of isolated human trachea. Weak but persistent contraction was observed after the addition of antigen to isolated Japanese monkey tracheal muscle passively sensitized with monkey serum containing IgE antibody against Japanese cedar (Cryptomeria japonica) antigen. Unlike monkey tracheal muscle, a fair amount of contraction was caused by the antigen in human tracheal muscle passively sensitized with human atopic serum. When chopped, passively sensitized monkey or human lung tissue was challenged with antigen, a significant level of histamine was released from these tissues. In Japanese monkey tracheal muscle, histamine and SP produced no contraction of tracheal muscle, whereas carbachol, LTC4 and U-46619 caused contraction in a dose-dependent fashion. Contrary to the Japanese monkey, histamine and carbachol caused distinct contraction in tracheal muscle obtained from the cotton-headed tamarin (Saguinus oedipus). In human tracheal muscle, all test substances (carbachol, histamine, LTC4, U-46619 and SP) induced clear contraction. In lung parenchyma obtained from Japanese monkey, histamine induced a weak contraction, and this histamine-induced contraction was also inhibited by pyrilamine (H1 receptor antagonist). These results indicate that antigen-induced contraction of isolated Japanese monkey tracheal muscle, passively sensitized with monkey atopic serum, is not a useful model for human allergic bronchoconstriction in vitro because of the unresponsiveness of tracheal muscle to histamine and SP.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗