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Biomedical subjects

T Kasai

Publications and source records attributed to T Kasai.

At least 55 records · Page 3Linked to original sources
PubMed2000

Application of acid-treated yeast cell wall (AYC) as a pharmaceutical additive. II: effects of curing on the medicine release from AYC-coated tablets.

Acid-treated yeast cell wall (AYC) was newly prepared by acidifying brewers' yeast cell wall. Core tablets containing 3% of acetaminophen (AAP) were coated with the AYC aqueous dispersion containing 5% (w/v) of AYC and 0.35% (w/v) of glycerol. The curing of AYC-coated tablets was performed at various curing periods of time and temperatures. The effects of curing on AAP release from AYC-coated tablets, the weight and thickness of the coated layer of AYC and the water sorption into the AYC-coated tablets were studied. The tensile strength and pore size distribution of the AYC cast film were measured. In the case of 60, 80, or 100 degrees C curing, AAP release from AYC-coated tablets showed a sigmoidal release profile with an initial lag time. The duration of the lag time increased with the increasing curing time and temperature, though the release rate after the lag time hardly changed. At 120 degrees C curing, the release rate after the lag time decreased with the increasing curing time and a sustained release was observed. The weight and thickness of the AYC-coated layer and the water sorption rate into AYC-coated tablets decreased with the increasing curing time and temperature. The tensile strength of the AYC cast film increased with increasing the curing temperature, particularly at 120 degrees C curing. It is considered that the water was evaporated from the AYC-coated layer and the adhesion force between AYC particles increased during curing, making the structure of the AYC-coated layer densely firm. The changes in the duration of lag time and the release rate may be due to changes in the structure of the AYC-coated layer caused by curing. These results show that it is feasible to control the lag time and the release rate of AAP from AYC-coated tablets by varying the curing time and temperature.

Acetaminophen↗
PubMed2000

Pleiotropic effects of HTLV type 1 Tax protein on cellular metabolism: mitotic checkpoint abrogation and NF-kappaB activation.

Tax protein expressed by human T cell leukemia virus type 1 (HTLV-1) is a strong trans-activator of its own LTR promoter; it also affects the function of multiple cellular genes involved in cell cycle control and transcription. One way in which Tax exerts its pleiotropic effects is through protein-protein interaction with cellular cofactors. By using yeast two-hybrid technology, we have isolated several cellular proteins that bind to Tax. Two of these are MAD1, a mitotic checkpoint control protein, and TXBP151, a suppressor of tumor necrosis factor alpha-induced apoptosis. Here we discuss findings describing the role of MAD1 in exit of cells from mitosis and TXBP151 in NF-kappaB activation.

Carrier Proteins↗
PubMed2000

Application of acid-treated yeast cell wall (AYC) as a pharmaceutical additive I. AYC as a novel coating material.

Acid-treated yeast cell wall (AYC) was newly prepared by acidifying the cell wall of brewer's yeast and the potential to use AYC as a novel coating material was studied. AYC had an oval shape with the diameter of several microm. The rheogram of AYC aqueous dispersion showed the plastic fluid property that is generally observed in the suspension. Core tablets containing 3% of acetaminophen (AAP) were coated with the AYC aqueous dispersion containing 5% (w/v) of AYC and 0.35% (w/v) of glycerol at various coating percents. The AAP release profile from the AYC-coated tablets was studied by the JP13 paddle method using solutions at various pH. Tensile strength and permeability of oxygen and water vapor of AYC cast film were measured. The AAP release from the AYC-coated tablets showed sigmoidal release profile with an initial lag time and the duration of the lag time depended on the coating percent of AYC. The pH of the dissolution fluid or the storage at room temperature for 120 days had little affect on AAP release from the AYC-coated tablets. These results suggest that it is possible to control the start time of medicine release independent of the pH by coating of AYC, that is the time-controlled release. The AYC cast film showed a large tensile strength and an extremely small oxygen permeability coefficient and a sufficient level of water permeability coefficient in order to protect from moisture. These results present that AYC has the high utility as a novel aqueous coating material for DDS preparations.

Acetaminophen↗
PubMed2000

An overexpression of fibroblast growth factor (FGF) and FGF receptor 4 in a severe clinical phenotype of facioscapulohumeral muscular dystrophy.

We evaluated the expression of a select panel of growth factors and their receptors, including fibroblast growth factor 1 (FGF-1), fibroblast growth factor 2 (FGF-2), platelet-derived growth factor (PDGF), FGF receptor 1 (FGF-R1), FGF receptor 3 (FGF-R3), FGF receptor 4 (FGF-R4), PDGF receptor alpha (PDGF-Ralpha), PDGF receptor beta (PDGF-Rbeta), and heparan sulfate proteoglycan (HSPG), in muscle biopsy specimens from nine facioscapulohumeral muscular dystrophy (FSHD) patients using immunohistochemistry. Two cases of Duchenne-type muscular dystrophy (DMD), two of Becker-type muscular dystrophy (BMD), and one of limb-girdle-type muscular dystrophy (LGMD) were also investigated. Widespread immunostaining for FGF-1 and FGF-2 on the sarcolemma and overexpression of FGF-R4 in endomysial and perimysial connective tissue were seen in one patient with a severe clinical phenotype of FSHD who had respiratory failure. Standard histochemistry in this patient revealed marked interstitial fibrosis and lobulated fibers. The overexpression of FGF and FGF-R4 in this severe FSHD case may be associated with the muscle fibrosis and disease severity.

Adolescent↗
PubMed2000

Laminectomy performed using a micro bone saw.

In 154 clinical cases requiring laminectomy at any part of the spinal column, the laminae were removed using a micro bone saw. Immediately after the laminectomy two surgeons using a microscope examined the field for any damage to the dura, the spinal cord, the nerve roots and the epidural vessels. No injury to the spinal cord or the nerve roots was observed. In 5 patients the dura were lacerated for a length of up to 10 mm, and in all the patients adhesions were present due to previous operations. Epidural vessels were severed in 18 cases. The method is useful and less time-consuming than conventional laminectomy.

Adolescent↗
PubMed2000

Induction of pancreatic trypsin by dietary amino acids in rats: four trypsinogen isozymes and cholecystokinin messenger RNA.

We previously demonstrated that feeding a diet containing a high level of amino acid mixture simulating casein (AA) induced an increase in pancreatic protease activities in rats. In the present study, this effect of dietary AA was further characterized with three separate experiments. These experiments (1) examined periodic changes in pancreatic and small intestinal trypsin activities after switching from a 20% (a normal nitrogen level) AA diet to a 60% AA (a high nitrogen level) diet; (2) measured the abundance of mRNA for four trypsinogen isozymes and for intestinal cholecystokinin (CCK) and secretin in rats fed 20% and 60% AA diets for 10 days compared with rats fed 20% and 60% casein diets; and (3) measured the abundance of mRNA for four trypsinogen isozymes after chronic administration of CCK. Trypsin activities were gradually increased in both the pancreas and the small intestinal lumen and reached maximum at 5 days after the switch to the 60% AA diet (Exp. 1). This result is evidence that the increase in the protease activity in the pancreas is due to enhancement of pancreatic trypsin production. In experiment 2, pancreatic trypsinogen isozymes I, II, III, and IV mRNA abundance were evaluated by the Northern blotting method using cDNA probes specific for each isozyme mRNA. Abundance of trypsinogen mRNA without trypsinogen I tended to increase in the rats fed the 60% casein diet but tended to decrease in the rats fed the 60% AA diet compared with the respective normal nitrogen level diet groups without significant difference. CCK mRNA abundance in the jejunal mucosa increased as a result of feeding the 60% casein diet, but not the 60% AA diet. Subcutaneous CCK injections (3.5 nmole/kg body weight/day, twice daily, at 8:30 am and 7:30 pm) for 10 days resulted in increased pancreatic trypsin activity, whereas the changes in mRNA of the four trypsinogen isozymes was similar between the 20% and 60% casein groups but differed between the 20% and 60% AA groups (Exp. 3). These results suggest that CCK is not involved in the induction of pancreatic trypsin that occurs with feeding of a high AA diet and that the mechanism of protease induction by dietary AA is different from that in the case of dietary protein.

Journal Article↗
PubMed2000

Dentinogenic ghost cell tumor: histologic aspects, immunohistochemistry, lectin binding profiles, and biophysical studies.

Dentinogenic ghost cell tumor accompanied with calcifying odontogenic cyst (COC) was described in terms of its clinical, histological, immunohistochemical, lectin binding and biophysical properties. The case was a 38-year-old Japanese female, in whom the tumor had arisen in the right mandibular premolar and molar region. Material obtained by partial mandibulectomy was used. Decalcified paraffin sections were used to detect keratins, involucrin, and lectin binding; and non-decalcified thin sections were used for biophysical analysis. The lesion comprising dentinogenic ghost cell tumor and COC contained odontogenic epithelium with ghost cells, eosinophilic amorphous materials and osteodentin. Some of the eosinophilic material had undergone transformation into osteodentin. Keratins in odontogenic epithelia showed positive PKK1 staining in peripheral tumor cells, and stainings with KL1 and involucrin were positive in centrally located cells. Lectin binding in the amorphous materials was comparatively strong for PNA, and SBA, moderate for WGA, RCA-1, and UEA-1, and slight for DBA and ConA. Lectin binding affinities were higher in the amorphous materials than in the osteodentin. Elemental analysis with an electron probe X-ray microanalysis of the amorphous materials and osteodentin showed a pattern similar to that found in the normal dentin. The biologic properties of the eosinophilic amorphous materials suggested the material to be poorly calcified osteodentin, which gradually transformed into the well-calcified type.

Adult↗
PubMed2000

Human T-lymphocyte virus type I (HTLV-I)-induced myeloneuropathy in rats: oligodendrocytes undergo apoptosis in the presence of HTLV-I.

To investigate the pathogenetic role of human T-lymphocyte virus type I (HTLV-I) in central nervous system disease, a rat model for HTLV-I-associated myelopathy/tropical spastic paraparesis, designated as HAM rat disease, was examined with regard to chronological neuropathology, from early asymptomatic phase to late disease. In the thoracic spinal cord of rats with HTLV-I infection, the first event was the appearance of apoptosis of oligodendrocytes beginning at 7 months after induced infection, thereafter followed by the appearance of white matter degeneration, increase of macrophages/activated microglia and of gemistocytic astrocytes at 12, 15 and 20 months, respectively. In the spinal cord, HTLV-I provirus DNA was evident as early as 4 months after the infection, and HTLV-I pX and the tumor necrosis factor (TNF)-alpha messages began to be expressed at age 7 months, just before or at the same time as the appearance of apoptotic cells. Collective evidence suggests that the apoptotic death of oligodendrocytes, which may be induced either directly by the local expression of HTLV-I or indirectly by TNF-alpha, through the transactive function of p40Tax, is the major cause of chronic progressive myeloneuropathy in Wistar-King-Aptekman-Hokudai rats with HTLV-I infection.

Aging↗
PubMed2000

Cytokeratin expression of apocrine and eccrine poromas with special reference to its expression in cuticular cells.

BACKGROUND: There are no immunohistochemical studies on cytokeratin (CK) expression in large series of cases of apocrine poroma. In addition, detailed immunohistochemical analysis of cuticular cells, a specific type of constituent cells of poromas, has not been reported. METHODS: Using the avidin-biotin method, we compared immunostaining patterns of eleven different anti-CK antibodies in 12 cases of apocrine and 21 cases of eccrine poromas, and normal adult skin. RESULTS: Poroid cells were exclusively positive for CK1/5/10/14, CK5/8 and CK14, which were expressed in the outer cells of normal dermal sweat ducts. Poroid cells were heterogeneously stained with anti-CK7, CK8/18, CK 10/11 and CK19 antibodies, which reacted in the inner cells of dermal ducts and in the secretory cells of sweat glands. The cuticular cells showed constant expression of CK1/5/ 10/14 and CK10/11, and various expression patterns of CK5/8, CK6, CK7, CK14, CK8/18, CK17, and CK19. CONCLUSIONS: Based on the keratin immunohistochemistry, the neoplastic cells in eccrine and apocrine poromas are considered to be closely related to the cells of dermal sweat ducts. Also the cuticular cells are considered to occupy an intermediate spectrum between the inner and outer cells of the dermal ducts. Although it is difficult to differentiate apocrine poroma from eccrine poroma by keratin expression patterns alone, the data obtained here can be helpful in differentiation of apocrine poroma from other hair follicle-related neoplasms.

Acrospiroma↗
PubMed2000

Peptide YY stimulates the expression of apolipoprotein A-IV gene in Caco-2 intestinal cells.

The effect of peptide YY, a gastrointestinal hormone, on the expression of the apolipoprotein A-IV gene in the intestinal epithelial cell line Caco-2 was examined by semiquantitative RT-PCR followed by Southern hybridization with an inner oligonucleotide probe. Apolipoprotein A-IV mRNA levels were increased in response to peptide YY in a dose- and time-dependent fashion. Western blotting revealed that the exogenous peptide YY increased the intracellular concentration of apolipoprotein A-IV. In contrast, apolipoprotein A-I, B, and C-III mRNA did not respond to peptide YY. Differentiated Caco-2 cells expressed Y1- but not Y2- and Y5-receptor subtype mRNA. The present results suggest that peptide YY modulates apolipoprotein A-IV gene expression, likely via the Y1-receptor subtype in intestinal epithelial cells.

Apolipoproteins A↗
PubMed2000

Intestinal fat suppresses protein-induced exocrine pancreatic secretion in chronically bile-pancreatic juice-diverted rats.

Previously, we showed that the increase in pancreatic enzyme secretion was lower after feeding a casein diet containing fat than that after feeding a fat-free casein diet in chronically bile-pancreatic juice (BPJ)-diverted rats. In the present study, we determined whether the suppressive effects of fats on flow volume of BPJ and pancreatic enzyme secretion depend on delaying gastric emptying and examined the characteristics of the suppression with intraduodenal instillation of soybean oil or lecithin in BPJ-diverted rats. The study was conducted as three separate experiments using conscious rats with chronic BPJ diversion by means of a common bile-pancreatic duct catheter. The flow volume of BPJ and the secretion of pancreatic amylase and trypsin were determined after intraduodenal instillation of the test solution. Exocrine pancreatic secretion was strongly stimulated by administration of guanidinated casein hydrolysate (HGC, 150 mg/ml) in chronic BPJ-diverted rats. However, pancreatic secretion after administration of an emulsion containing HGC with either soybean oil (100 mg/ml) or mixed fat (50 mg/ml soybean oil + 50 mg/ml lecithin) was much lower than that after administration of HGC alone. In contrast, administration of the soybean oil emulsion without HGC resulted in a small, but significant increase in the volume of BPJ. The suppressive effects of soybean oil (100 mg/ml) on the increases in the BPJ flow and enzyme secretion were similar to those of sodium taurocholate (10 mg/ml), and there was no additive effect of soybean oil on taurocholate suppression. In conclusion, duodenally instilled soybean oil suppressed increases in flow volume of BPJ and pancreatic enzyme secretion induced by HGC in chronic BPJ-diverted rats, showing that the suppressive effect of the fat does not depend on delaying gastric emptying.

Animals↗
PubMed2000

Contribution of the cecum and colon to zinc absorption in rats.

We examined the role of the large intestine in zinc absorption in rats in three separate experiments. In the first experiment, we examined apparent zinc absorption in rats fed diets containing graded levels of zinc carbonate (0.015-0.535 mmol Zn/kg diet) and evaluated zinc status on the basis of the zinc concentrations in serum and several tissues. The zinc absorption and the serum zinc concentration increased with the zinc content of the diet up to 0. 153 mmol Zn/kg diet. Femoral and pancreatic zinc levels increased linearly up to 0.229 mmol Zn/kg diet. In the second experiment, a zinc carbonate suspension was administered into the cecum via an implanted cannula or into the stomach via an orogastric tube, and the rats were fed diets with or without a highly fermentable fiber, guar gum hydrolysate (GGH, 50 g/kg diet), with coprophagy prevention. The amount of instilled zinc corresponded to the amount of zinc ingested as a component of the diet by the rats of a control group, 0.229 mmol Zn/kg diet. Apparent absorption of cecally instilled zinc was approximately half that observed when zinc was administered into the stomach in both diet groups. Serum and femur zinc concentrations in the cecum-administered groups were approximately 50 and 25% lower, respectively, than those in rats administered zinc into the stomach. The results demonstrate that, in vivo, the absorptive efficiency in the large intestine is not sufficient to satisfy the rat's zinc requirement and does not change when the luminal environment is substantially altered by feeding GGH. In Experiment 3, the effects of cecocolonectomy on zinc absorption were examined in rats with gastric acid suppression. In the cecocolonectomized groups, serum zinc concentration was lower as a result of treatment with a proton pump inhibitor, omeprazole, than in vehicle-treated rats, but not in sham-operated groups. These findings suggest that the cecum and colon contribute to zinc absorption when absorption in the small intestine is impaired.

Analysis of Variance↗
PubMed2000

Intravenous infusion of hexamethonium and atropine but not propranolol diminishes apolipoprotein A-IV gene expression in rat ileum.

To clarify the role of neural factors in the regulation of apolipoprotein (apo) A-IV expression in the small intestine, we investigated the effect of neural blockers on mRNA levels of apo A-IV in rat small intestine. Either ganglionic blocker (hexamethonium), cholinergic blocker (atropine) or beta-adrenergic blocker (propranolol) was infused intravenously to unrestrained conscious rats for 8 h, and then total RNA was isolated from the small intestine and analyzed using Northern hybridization. Apo A-IV mRNA levels in the ileum were significantly lower in hexamethonium- or atropine-infused rats than in saline- (control) or propranolol-infused rats. Immunoblot analysis showed no difference in plasma apo A-IV concentrations between hexamethonium- and saline-infused groups. The lower mRNA levels of apo A-IV in the ileum of hexamethonium-infused rats were observed even in bile-drained rats, indicating that the lower expression was not due to any changes in bile availability. The ileal apo A-IV mRNA levels were significantly higher in rats infused with lipid emulsion into the ileum than in rats infused with glucose-saline, and the concomitant infusion of intravenous hexamethonium did not affect the higher levels of apo A-IV mRNA. These results suggest that the basal expression of the ileal A-IV gene is at least partially regulated in a site-specific manner by cholinergic neurons.

Adrenergic beta-Antagonists↗
PubMed2000

Birth cohort effects on incidence of lung cancers: a population-based study in Nagasaki, Japan.

Smoking prevalence remains high (around 60%) among Japanese males, but smoking initiation among males born in the 1930s decreased by approximately 10% due to economic difficulties following World War II. The present study was designed to examine whether this temporary decline in smoking initiation influenced the subsequent incidence of lung cancers, especially adenocarcinoma. Trends of lung cancer incidence by histological type in both sexes were investigated using data from the population-based cancer registry in Nagasaki, Japan, from 1986 through 1995. During this period, 5668 males and 2309 females were diagnosed as having lung cancer, and the overall incidence of lung cancers among both sexes remained stable. However, males aged 55 - 59 years showed a decrease in the age-specific incidence of adenocarcinoma and squamous-cell carcinoma (P < 0.05 and P < 0.01, respectively). In birth cohort analyses, the incidence of adenocarcinoma and squamous-cell carcinoma was lower in the 1935 - 1939 birth male cohort than in the successive cohorts. The incidence of lung cancers among females with low smoking prevalence did not change with birth cohort. The low smoking initiation among the 1935 - 1939 birth male cohort appeared to have resulted in a decreased incidence of adenocarcinoma and squamous cell carcinoma among middle-aged Japanese males. The present study suggests that smoking prevention has an effect in reducing the incidence of lung adenocarcinoma, as well as squamous-cell carcinoma, among smokers.

Adenocarcinoma↗
PubMed2000

Detection of SYT-SSX fusion transcripts in both epithelial and spindle cell areas of biphasic synovial sarcoma using laser capture microdissection.

To investigate the distribution of tumour cells expressing the SYT-SSX fusion gene in biphasic synovial sarcoma, modified reverse transcription polymerase chain reaction (RT-PCR) analysis was performed using microdissected specimens from haematoxylin and eosin stained sections of archival paraffin wax embedded tissues. This modified RT-PCR included a stage with degenerate oligonucleotide primed (DOP) PCR, which randomly amplified cDNA after reverse transcription. SYT-SSX fusion transcripts were detected in both epithelial and spindle cell areas of all three biphasic synovial sarcomas examined. Subsequent sequence analysis confirmed that the detected messages were derived from the SYT-SSX1 fusion gene in two cases and from SYT-SSX2 in one. These results indicate that SYT-SSX fusion transcripts are found in both epithelial and spindle cell areas of biphasic synovial sarcoma, and RT-DOP-PCR-PCR analysis is a useful method for detection of extremely small amounts of mRNA in microdissected samples from archival formalin fixed, paraffin wax embedded tumour tissues.

Adenocarcinoma↗
PubMed2000

Gene expression of activin, activin receptors, and follistatin in intestinal epithelial cells.

Gene expression of activin, activin receptors, and follistatin was investigated in vivo and in vitro using semiquantitative RT-PCR in intestinal epithelial cells. Rat jejunum and the intestinal epithelial cell line IEC-6 expressed mRNA encoding the betaA-subunit of activin, alpha-subunit of inhibin, activin receptors IB and IIA, and follistatin. An epithelial cell isolation study focused along the crypt-villus axis in rat jejunum showed that betaA mRNA levels were eight- to tenfold higher in villus cells than in crypt cells. Immunohistochemistry revealed the expression of activin A in upper villus cells. The human intestinal cell line Caco-2 was used as a differentiation model of enterocytes. Four- to fivefold induction of betaA mRNA was observed in postconfluent Caco-2 cells grown on filter but not in those cells grown on plastic. In contrast, follistatin mRNA was seen to be reduced after reaching confluence. Exogenous activin A dose-dependently suppressed the proliferation and stimulated the expression of apolipoprotein A-IV gene, a differentiation marker, in IEC-6 cells. These results suggest that the activin system is involved in the regulation of such cellular functions as proliferation and differentiation in intestinal epithelial cells.

Activin Receptors↗
PubMed2000

A case of primary cardiac B cell lymphoma associated with ventricular tachycardia, successfully treated with systemic chemotherapy and radiotherapy: a long-term survival case.

We experienced a long-term survival case of primary cardiac lymphoma (PCL) demonstrating ventricular tachycardia (VT) as an initial sign, which was related to localized myocardial damage by lymphoma cells. A 70-year-old woman with sustained VT was admitted to the Kofu Municipal Hospital. VT ceased with the administration of disopyramide intravenously. The origin of the VT was the free wall of the right ventricular outflow tract (RVOT) as observed by electrocardiography on admission. A solitary mass in the free wall of the RVOT was found by echocardiography, chest computed tomographic scanning and magnetic resonance imaging. There was no evidence of extracardiac involvement. The patient was histologically diagnosed as PCL by endomyocardial biopsy. Chemotherapy started immediately after the diagnosis and the mass showed a marked reduction in size. After 8 cycles of chemotherapy, radiotherapy was performed. Pericardial thickness in the free wall of the RVOT developed without severe side effects. Complete remission has been maintained for 30 months after the initial diagnosis, and no recurrence and arrhythmias have been detected during the follow-up period. It was demonstrated that rapid diagnosis and chemotherapy followed by radiotherapy for PCL achieved better survival.

Aged↗