Search PubMed⌕ Search

Biomedical subjects

H Yoshimoto

Publications and source records attributed to H Yoshimoto.

At least 73 records · Page 4Linked to original sources
PubMed1995

Purification and characterization of a major kyotorphin-hydrolyzing peptidase of rat brain.

We purified a major kyotorphin (L-Tyr-L-Arg)-hydrolyzing peptidase (KTPase) from the rat brain, to electrophoretic homogeneity using conventional chromatographic techniques. KTPase was purified 1,660-fold with a specific activity of 161 mumol/min/mg protein and 6.8% recovery. The purified enzyme was composed of a single polypeptide with a molecular mass of 67 kDa and an isoelectric point (pI) of 5.5. KTPase has the ability to hydrolyze a variety of natural dipeptides. It also liberated NH2-terminal tyrosine from Tyr-Gly-Gly and Tyr-Tyr-Leu. Bestatin and arphamenine B were potent inhibitors of this enzyme, while amastatin and puromycin had little effect. An excess of anti-KTPase antibody raised in a white rabbit precipitated approximately 80% of the kyotorphin-hydrolyzing activity in the cytosol of rat brain. These data suggested that 67 kDa KTPase has a role in the degradation of kyotorphin within neuronal cells of the rat brain.

Amino Acid Sequence↗
PubMed1995

[Pharmacological properties of chitosan-coated dialdehyde cellulose (chitosan DAC), a newly developed oral adsorbent (I). Effect of chitosan DAC in normal rats].

The effects of chitosan-coated dialdehyde cellulose (chitosan DAC), a newly developed oral adsorbent of urea and ammonia, were examined in an in vitro adsorption study and in normal rats. Chitosan DAC showed high adsorption capacity for urea and ammonia in an in vitro study using the diluted supernatant of rat gastrointestinal fluid. In contrast, Kremezin, an oral charcoal adsorbent (AST-120), had little influence on these substances. In normal rats fed diets containing chitosan DAC (1, 2, 3, 4, 5, 7, and 10% content) for three weeks, increases in fecal wet weight, fecal dry weight and fecal water content were observed in a dose-dependent manner. In addition, chitosan DAC feeding increased fecal excretion of nitrogen and electrolytes (sodium, potassium and chloride ions) and decreased the apparent protein ratio in a dose-dependent manner. There were no obvious effects in serum parameters except that increased levels of protein and albumin and decreased levels of blood urea nitrogen, cholesterol and glucose were observed in rats fed a high concentration of chitosan DAC. In conclusion, these findings suggest the possibility that chitosan DAC treatment might be effective for improving chronic renal failure.

Administration, Oral↗
PubMed1995

[Pharmacological properties of chitosan-coated dialdehyde cellulose (chitosan DAC), a newly developed oral adsorbent (II). Effect of chitosan DAC on rats with chronic renal failure induced by adriamycin].

The effects of chitosan-coated dialdehyde cellulose (Chitosan DAC), a newly developed oral adsorbent of urea and ammonia, were examined in rats with progressive chronic renal failure (CRF) induced by adriamycin. CRF rats induced by repeated injections of adriamycin were fed a diet containing chitosan DAC (5% content) or Kremezin (5% content), an oral charcoal adsorbent (AST-120) under strict paired-feeding for four months. CRF rats that received both a normal diet and Kremezin showed progressive azotemia, hyperphosphatemia, hyperlipidemia, proteinuria, and anemia, and began to die from 9 weeks after feeding started. In contrast, chitosan DAC-treatment showed marked prolongation of the survival period and decreases in blood urea nitrogen, serum creatinine, and serum phosphate. In addition, chitosan DAC-treatment ameliorated anemia in CRF rats, although hyperlipidemia and proteinuria were not improved. Furthermore, fecal weight, fecal water content, fecal nitrogen and fecal sodium were markedly increased, and the apparent protein ratio was decreased in CRF rats fed a diet containing chitosan DAC for 9 weeks. In contrast, none of these effects were observed in CRF rats receiving Kremezin. These observations suggest the further possibility of using oral adsorbent therapy for CRF patients.

Administration, Oral↗
PubMed1995

[A sporadic dentatorubral-pallidoluysian atrophy (DRPLA) diagnosed by gene analysis].

We report a 48-year-old woman with dentatorubral-pallidoluysian atrophy (DRPLA). She is the only patient in her 15 family members in two generations. She developed cerebellar ataxia and epilepsy at age 43. On admission at 48, she showed mild dementia and choreic movement in her face and extremities as well as truncal and limb ataxia. Routine laboratory examinations were normal. The point mutations in the tRNALys gene of mitochondrial DNA specific for MERRF were not found. A cranial CT scan and MRI showed mild atrophy of the cerebellum and prominent atrophy in the pons, especially in the tegmentum. Although she was thought to have DRPLA from the clinical point of view, absence of family history made the diagnosis difficult. Her parents were healthy until their 80's and died of cerebrovascular diseases and her 5 siblings had no symptoms. Hereditary DRPLA is known as an autosomal dominant disorder, with a high rate of penetrance and low rate of new mutation. According to our recent findings of a CAG repeat expansion in the DRPLA gene, this patient was diagnosed as a sporadic DRPLA. Considering the wide varieties of clinical manifestations, it is essential to examine this gene abnormality for diagnosing sporadic DRPLA.

Atrophy↗
PubMed1993

Genetic transformation of Porphyromonas gingivalis by electroporation.

Porphyromonas gingivalis was transformed by electroporation using the DNA of plasmid pE5-2, or its derivative, pYT7. Prior to transformation, pE5-2 was transferred from Escherichia coli to P. gingivalis strains by conjugation (mobilization with R751), and the plasmid DNA was purified from the P. gingivalis transconjugants. Transformation occurred when the recipient strain and the donor strain from which the plasmid DNA was purified were homologous. If they were heterologous, transformation did not take place or did so at a very low frequency. This suggested that a restriction-modification system is present in P. gingivalis strains. Plasmid pYT7 was derived by removing an 8.0 kb AvaI fragment from pE5-2 that was purified from P. gingivalis cells. It has several single-cutting restriction sites such as EcoRI, AvaI and ClaI usable for gene cloning, though it was not stable enough in P. gingivalis cells, probably because the rep gene was derived from a relatively distant species, Bacteroides eggerthii.

Conjugation, Genetic↗
PubMed1993

Intracerebral arteriovenous malformation fed by the anterior ethmoidal artery--case report.

A 66-year-old male presented with a left frontal intracerebral arteriovenous malformation (AVM) fed by the anterior ethmoidal artery. The nidus was located intracerebrally, although the feeder was a dural artery, and was drained by the ascending frontal vein which showed varicose dilatation. The AVM was associated with an unruptured right anterior choroidal artery aneurysm. The AVM was removed and the aneurysm was clipped in a two-stage operation. The etiology of AVMs fed by the ethmoidal artery is still uncertain, but is probably due to a disturbance in normal embryonic development. The association with aneurysm seemed to be incidental.

Aged↗
PubMed1993

[A case of intraocular histiocytosis X].

A solitary massive tumor developed in the left eye of a 61-year-old female who had a history of insulin-independent diabetes mellitus for 20 years and whose left eye had become blind due to repeated anterior uveitis in the recent several years. The eyeball was enucleated and used for further examinations. Intraocular tissues were widely infiltrated by histiocytes, though no extraocular invasion or further metastasis was found. Histological examination including alpha 1-anti-chymotrypsin and S100 staining revealed the features characteristic of histiocytosis X. This is probably a case of intraocular histiocytosis X with no evidence of systemic symptoms.

Eye Diseases↗
PubMed1993

[Retinal ischemic changes in diabetic rats treated with pancreatic islet transplantation beneath the renal capsule].

The effect of pancreatic islet transplantation beneath the renal capsule on retinal and choroidal structure was studied using Lewis rats. Rats were divided into 3 groups: an untreated diabetic group induced by intravenous injection of streptozotocin 65 mg/kg; an islet transplanted group 1 month after induction of diabetic state; and an untreated control group. Whole retinochoroidal units were examined by light and electron-microscopy. In 6 out of 9 cases in the transplanted group, the retina showed marked destructive changes in the outer layer including pigment epithelial cells and vacuolization of the inner layer 6 months after islet transplantation. Occlusion and fibrosis of the choriocapillaris adjoining the degenerated retina were also observed. Such changes were not observed in the other groups. On electron microscopy, occlusion of capillaries and destruction of endothelial cells were frequently found in the degenerated retina. These retinal ischemic lesions appear to be caused by microvascular obstruction.

Animals↗
PubMed1993

[Histological study on idiopathic epimacular membrane in three cases of different age].

Histological features of idiopathic premacular membrane were studied in 3 cases of different ages. All cases were female and complained of blurred vision without any causative moment. The age was 7 year in Case 1, 29 year in Case 2 and 68 year in Case 3. The cases underwent vitreous surgery with easy removal of the membranes. On light and electron microscopical observation, the membranes composed of retinal glial cells, connective tissue and the inner limiting membrane in Case 1, fibroblastic cells and connective tissues in Case 2, and connective tissues and the inner limiting membrane lacking any cellular component in Case 3. These findings strongly suggest the possibility of existence of various pathogeneity and developmental stages and types in idiopathic epimacular membrane.

Adult↗
PubMed1993

[Endoscopic sphincteroplasty (not sphincterotomy) using the clips--a preliminary report].

Reports exist that incomplete division of the papilla by endoscopic sphincterotomy may lead to restenosis, cholangitis, and stone recurrence. In view of evolution of surgical sphincterotomy to sphincteroplasty, we studied feasibility of endoscopic sphincteroplasty. In 36 dogs, at laparatomy, the papilla was divided using a diathermy sphincterotome to create retroperitoneal perforation. Twelve dogs underwent approximation of the bile duct and duodenal walls with silk sutures. Another 12 dogs had the walls approximated with clips using an endoscopic clip appliance. The other 12 dogs had no approximation. Blood chemistry was obtained before and serially after surgery. Duodenobiliary barium regurgitation was determined in 2-3 weeks. Four dogs each in each group were sacrificed at 1, 2, and 4 weeks to examine the papilla macro- and microscopically. In regard to hemostasis and prevention of leakage, the effect of the clips was similar to the sutures, resulting in a wide opening with free regurgitation. The no treatment group had persistent abnormal liver function tests and amylase levels. Three dogs died on leakage with abscess and the other nine had stenosis of the papilla. These data suggest that endoscopic sphincteroplasty may be feasible using the clips. A first clinical case where the clips were used to obtain a wide opening which passed a 15-mm balloon is briefly described.

Ampulla of Vater↗
PubMed1992

The Saccharomyces cerevisiae GAM2/SIN3 protein plays a role in both activation and repression of transcription.

We have cloned GAM2, which is required for transcription of STA1, a gene encoding an extracellular glucoamylase in Saccharomyces cerevisiae var. diastaticus. DNA sequence analysis revealed that GAM2 is the same gene as SIN3, known to be a general negative regulator of yeast genes. RNA blot analysis indicated that GAM2/SIN3 also acts as a positive regulator of GAM3/ADR6, which in turn is required for transcription of STA1 and ADH2. These results suggest that GAM2 regulates STA1 expression through transcriptional activation of GAM3 and indicate that GAM2/SIN3 protein is a transcriptional regulator that can play a role in both activation and repression of transcription.

Chromosome Deletion↗
PubMed1992

[The existence of vasomotor nerve in the retina of the rabbit and monkey].

In the first stage of this study, peri- or intravascular unmyelinated nerve axon which was clearly different from that of the optic nerve was confirmed in the rabbit retina transmission electron microscopically. In the second stage, the correlation of these unmyelinated nerves and autonomic nerve was studied in rabbits and monkeys. For the purpose, wheat germ agglutinin horseradish peroxidase (WGA-HRP) was injected into the superior cervical ganglion. Electron microscopic observation of the retina 48 hrs after the injection of WGA-HRP showed deposit of its reaction product in the axon of the unmyelinated nerve located around the vascular wall and in the adventitia and smooth muscle cell in both rabbits and monkeys. This result clearly reveals the existence of an autonomic vasomotor in the retinal vessels at least in rabbits and monkeys.

Animals↗
PubMed1992

[A case report of metastatic colonic carcinoma in the liver effectively treated by long-term, ambulatory and continuous, intra-hepatic-arterial infusion of 5-fluorouracil using disposable multi-day-type infusor].

A 42-year-old female was diagnosed as having sigmoid colonic carcinoma with multiple metastases in the liver. Following sigmoid colectomy and descending colostomy, a catheter was inserted from the right gastroepiploic artery to the proper hepatic artery. From the day of surgery 5-Fluorouracil was administered in doses of 250 mg/day continuously through a catheter over the 2-month period of hospitalization. After the patient was discharged, 250 mg/day of 5-Fluorouracil was administered at home using Vaxter Infusor according to a regimen of 10-day continuous infusion and subsequent 4-day rest. Five months after the initial operation, the serum CEA level decreased dramatically, and CT scan of the liver revealed the complete disappearance of the metastases. The patient underwent a second operation in which the colostomy was closed, and she is doing well at this writing. This case suggests that long-term, ambulatory, continuous and intra-hepatic-arterial infusion of 5-Fluorouracil can be a very effective treatment not only in reducing the hepatic metastases but also in improving the quality of life of patients with colonic carcinoma.

Adult↗
PubMed1991

The GAM1/SNF2 gene of Saccharomyces cerevisiae encodes a highly charged nuclear protein required for transcription of the STA1 gene.

We have cloned and sequenced the GAM1 gene which is required for transcription of the STA1 gene encoding an extracellular glucoamylase in Saccharomyces cerevisiae var. diastaticus. Complementation tests indicated that GAM1 is the same gene as SNF2 which is required for derepression of the SUC2 gene encoding invertase. Accumulation of SNF2 RNA was not regulated by the GAM2 and GAM3 genes which are also required for STA1 expression. The SNF2 gene was predicted to encode a 194 kDa highly charged protein with a glutamine-rich tract. A bifunctional SNF2-lacZ fusion protein was shown by immunofluorescence microscopy to be localized to the nucleus, suggesting that the SNF2 protein is located in the nucleus.

Adenosine Triphosphatases↗
PubMed1991

[Combined chronic toxicity/carcinogenicity test of tris(2-chloroethyl)phosphate (TCEP) applied to female mouse skin].

Tris(2-chloroethyl)phosphate (TCEP), a widely used flame retardant, was tested for its skin chronic toxicity/carcinogenicity using female Slc: ddY mice. TCEP (5 and 50%) dissolved in ethanol was applied to the shaved skin twice a week for 79 weeks. The control group received ethanol under similar condition. In addition, 5 animals in each group were killed at 6 and 12 months and used for the chronic toxicity study. In body weight, food consumption and survival rate, there was no significant difference between the control and treated groups. Spleen weight was decreased in the 50% group. No significant difference in the incidence of tumors and other non-neoplastic lesions of the skin and other organs was found between the control and treated groups. The results indicate that under the conditions of the present study, TCEP has no carcinogenicity and toxicity for the skin.

Administration, Topical↗