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Biomedical subjects

S Kasai

Publications and source records attributed to S Kasai.

At least 91 records · Page 5Linked to original sources
PubMed1997

Production of hepatocyte growth factor is increased in chronic renal failure.

Hepatocyte growth factor (HGF) facilitates recovery from tissue injuries. We previously reported that serum HGF levels were elevated in chronic renal failure (CRF) patients. In the present study Western blot analysis of CRF patients' sera showed the majority of their serum HGF was a single-chain precursor molecule. In CRF rats developed by 5/6 nephrectomy or high adenine diet, both HGF mRNA expression levels and tissue HGF concentrations were increased in liver and spleen. The results suggest that HGF production increases in CRF, which may be a response to chronic progressive renal injuries in an endocrine manner.

Adult↗
PubMed1997

Hepatocyte growth factor in glycerol-induced acute renal failure.

Hepatocyte growth factor (HGF) facilitates the regeneration of injured kidney in acute renal failure (ARF). Here we investigated the HGF production in glycerol-induced ARF rats. HGF mRNA expression levels were elevated in liver, spleen, and lung 6-24 h after glycerol injection. Tissue HGF protein levels determined by an enzyme-linked immunosorbent assay also increased in liver and spleen, whereas they decreased in the injured kidney 24 h after injection. Immunohistochemical studies showed that the number of HGF-producing cells did not increase in the liver. HGF receptor/c-Met mRNA levels were elevated only in the kidney. These results indicate that HGF supplied in an endocrine manner may play an important role in the regenerating process following ARF.

Acute Kidney Injury↗
PubMed1997

A new trocar approach insertion site for laparoscopic surgery: the xiphoidal approach.

Laparoscopic cholecystectomy (LC) has become the standard treatment for removing a diseased gallbladder. Endoscopic surgical techniques are used to perform appendectomies, bowel resections, and gastrectomies. This minimally invasive surgery is favored because it decreases the patients' postoperative pain and length of hospitalization. However the incidence of complications with this technique is not negligible. As a new technique is evolving, the potential for complications is high. This increase in complication rate is undoubtedly due to inexperience during the initial phase of the surgeon's learning curve. Demand for the procedure has required rapid training and credentialing of many surgeons with limited experience in endoscopy and the use of instruments that allow only limited viewing of abdominal structures.

Journal Article↗
PubMed1997

Genetic progression and heterogeneity in intraductal papillary-mucinous neoplasms of the pancreas.

Intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas are ideal neoplasms to study clonal progression and genetic diversity because of their large size and prominent intraductal component. We microdissected 55 histologically defined areas from 13 IPMNs, extracted the DNA from each, and performed polymerase chain reaction (PCR)-based microsatellite analysis to detect loss of heterozygosity on chromosome arms 1p, 3p, 6q, 8p, 9p, 17p, 18q, and 22q. LOH was identified at 1p in two cases, at 3p in four cases, at 6q in seven cases, at 8p in four cases, at 9p in eight cases, at 17p in five cases, at 18q in five cases, and at 22q in one of the IPMNs examined. In one of the IPMNs, the allelic losses were uniform throughout multiple microdissected areas, and in four of the IPMNs, there was evidence of clonal progression. In contrast, in three of the IPMNs, substantial allelic heterogeneity was seen. This remarkable heterogeneity may, in part, be due to the slow growth rate of these neoplasms.

Adenocarcinoma, Mucinous↗
PubMed1996

Hepatocyte growth factor is a paracrine regulator of rat prostate epithelial growth.

Hepatocyte growth factor (HGF) is a mesenchymal-derived growth factor which predominantly targets various epithelial and endothelial cells. We here investigated the biological function of HGF in rat dorsolateral prostatic tissue. HGF stimulated proliferation and DNA synthesis of prostatic epithelial cells in primary culture. c-Met/HGF receptor mRNA was specifically expressed in isolated epithelial cells. An immunohistochemical study revealed that HGF is located in prostatic stromal cells. When stromal cells were isolated and cultured, they produced significant amounts of HGF, which was further stimulated by prostaglandin E2, 12-O-tetradecanoylphorbol-13-acetate, and dibutyryl cyclic AMP, but not by testosterone. These results indicate that HGF is a stromal-derived potent mitogen for dorsolateral prostatic epithelial cells which may function as a paracrine regulator for growth of the prostatic glands.

Animals↗
PubMed1996

The beneficial effect of dibutyryl cyclic adenosine monophosphate on warm ischemic injury of the rat liver induced by cardiac arrest.

Dibutyryl cAMP (DBcAMP) has a high membrane permeability, and maintenance of the intracellular cAMP concentration may improve the viability of organs. In this study, the effect of DBcAMP pretreatment on warm ischemic injury of rat livers was evaluated. Warm ischemic liver injury was induced in adult Wistar rats weighing 250-280 g by leaving them at room temperature (22-25 degrees C) after cardiac arrest. The hepatic cAMP concentration, %ATP, and trypan blue-positive nuclear ratio were determined after different durations of warm ischemia. In addition, transaminase and endothelin-1 (ET-1) release into the perfusate were examined during 60 min of isolated liver perfusion with Krebs-Henseleit solution. The optimal dose and time of DBcAMP pretreatment were determined to be 15 mg/kg and 60 min prior to warm ischemia, respectively. Data on the trypan blue-positive nuclear ratio and the release of transaminases and ET-1 revealed that warm ischemia first damaged the endothelial cells and then the hepatocytes. DBcAMP pretreatment appeared to protect the liver from warm ischemic injury by increasing the intracellular cAMP concentration and stabilizing the cell membranes of endothelial cells and hepatocytes.

Adenosine Triphosphate↗
PubMed1996

Effect of hepatocyte growth factor on the proliferation of intrasplenically transplanted hepatocytes in rats.

The effect of human hepatocyte growth factor on the proliferation of intrasplenically transplanted hepatocytes was investigated. A human hepatocyte growth factor (360 micrograms/kg BW) was administered intravenously every 24 hr for 5 days following hepatocyte transplantation in rats. A significant increase in hepatocyte proliferation was observed morphologically and immunohistochemically (p < 0.05). The bromodexyuridine labeling index was significantly greater in human hepatocyte growth factor treated rats than in the control rats (p < 0.05). Hepatocyte growth factor may promote the proliferation of intrasplenically transplanted hepatocytes.

Animals↗
PubMed1996

Structure of flavoprotein FP390 from a luminescent bacterium Photobacterium phosphoreum refined at 2.7 A resolution.

The three-dimensional structure of a flavoprotein, FP(390), from a luminescent bacterium, Photobacterium phosphoreum, solved by the molecular-replacement method, was refined to an R factor of 24.0% for 17 433 independent reflections, from 6.0 to 2.7 A resolution, collected by synchrotron radiation. The asymmetric unit of the crystal (space group P4(3)22, a = b = 76.8 and c = 242 A) contains two monomer molecules related by a non-crystallographic twofold axis to form a dimer. There are two Q-flavin [flavin mononucleotide (FMN) with myristic acid] molecules in FP(390) monomer. One of them is located at the interface of dimer which is bound to both monomer and the another is at the molecular surface. The electron density of myristic acids of Q-flavins at the dimer interface in both monomer are weak and unclear, showing the possibility that the Q-flavins bound in this site are not a single species but a mixture of two components, 6-(3"-myristic acid)-FMN and 6-(4"- myristic acid)-FMN.

Journal Article↗
PubMed1996

Evaluation of functional recovery of regenerating rat liver after partial hepatectomy using 31P-NMR spectroscopy.

Using 31P-NMR spectroscopy, we studied the process of the functional recovery of the regenerating rat liver at 1-5 weeks after a 65% partial hepatectomy from the viewpoint of phosphate metabolism. Portal vein clamping (20 min) or fructose administration (250 mg/kg body weight) was performed to temporarily reduce adenosine triphosphate (ATP) content in the remnant liver. Changes in ATP level were observed for 60 min after declamping the portal vein or after fructose administration. Significant differences in the increased ATP levels after declamping the portal vein or after fructose administration were observed in each hepatectomized group. Until 3 weeks after hepatectomy, ATP levels during 60 min after declamping the portal vein or after fructose administration were significantly lower than those in the nonresected control rats. However, the increase in ATP in the 4-week group was almost identical to the increase in the control group throughout the 60 min. Remnant liver weight already returned to the nonresected control level 1 week after hepatectomy, and remained constant thereafter. On the other hand, the final ATP levels 60 min after declamping the portal vein or after fructose administration returned to the nonresected control level only after 4 weeks following hepatectomy. These results demonstrate that from the viewpoint of ATP synthesis, functional recovery of the regenerating liver to normal can be observed within 4 weeks after partial hepatectomy.

Adenosine Triphosphate↗
PubMed1996

Protective effects of dibutyryl cyclic AMP on acute hepatic failure in rats.

To study the effect of cyclic AMP on liver dysfunction, dibutyryl cyclic AMP (DBcAMP, 15 mg/kg) was given to rats with acute hepatic failure induced by D-galactosamine (D-Gal; 500 mg/kg) and lipopolysaccharide (i.e., endotoxin) (Et; 0.5 mg/kg). The survival rate was only 7% for rats given D-Gal and Et (control group), while it was 100% for rats given seven doses of DBcAMP, and 53% for rats given two doses. The ALT level was high at 3475 +/- 488 KU in group III, while it was 242 +/- 69 KU in group I, and 376 +/- 49 KU in group II. The hepaplastin test level was decreased at 24 hr in all groups except group I, in which it was high at 55 +/- 11%. The serum tumor necrosis factor (TNF) level was 155 +/- 42 IU/ml in group I, 463 +/- 30 IU/ml in group II, and 1334 +/- 328 IU/ml in group III. The results of the blood biochemistry and liver tissue blood flow studies were better in the DBcAMP-treated groups, and the serum TNF levels were also lower in the treated groups. Histological examination of the liver showed extensive necrosis in the control group, but mild necrosis and inflammatory cell infiltration in the DBcAMP-treated groups. Therefore, treatment with DBcAMP suppressed acute hepatic failure induced by D-Gal and Et, resulting in a significant increase in the survival rate.

Alanine Transaminase↗
PubMed1996

Design and synthesis of new mitochondrial cytotoxin N-thiadiazolylanilines that inhibit tumor cell growth.

New N-thiadiazolylanilines were designed and synthesized to develop mitochondrial cytotoxins superior to SF 6847. The mitochondrial cytotoxin N-thiadiazolylanilines, TX-108 and TX-109, inhibited EMT6/KU mammary sarcoma cell growth at a low micromolar concentration. Their inhibitory activities were parallel to their mitochondrial cytotoxicity, such as uncoupling oxidative phosphorylation and inhibiting ATP synthesis. This report also supports the notion that the inhibition of tumor cell growth of inhibitor of protein tyrosine kinase AG17, which is identical to SF 6847, may be due to its mitochondrial cytotoxicity.

Adenosine Triphosphate↗
PubMed1996

A new technique for laparoscopic cholecystectomy--retrograde laparoscopic cholecystectomy: an analysis of 81 cases.

BACKGROUND AND STUDY AIMS: A new technique of laparoscopic cholecystectomy is presented here. This new method, retrograde laparoscopic cholecystectomy (RLC) from fundus to cystic duct downward, may have advantages when exposure of the cystic duct and the common duct are difficult and therefore hazardous. PATIENTS AND METHODS: We carried out laparoscopic cholecystectomy in 173 patients; RLC was performed in 81, The operative procedure is as follows: first, the cystic duct and artery are exposed at the junction of the ampulla. The cystic duct is clipped, and the artery is divided. Removal of the gallbladder is then started from the fundus to cystic duct downward. After the gallbladder has been dissected from the liver bed, the cystic duct is double-clipped and divided. This approach provides better visualization of the gallbladder, cystic duct, and common duct, with less chance of common duct injury, due to clear identification of the ductal system, without the need for intraoperative cholangiography. RESULTS: Eighty-one RLCs were performed without severe complications, either immediate or late. The mean operating time was 23 minutes shorter in RLC than in the usual laparoscopic cholecystectomy, because intraoperative cholangiography was used much less often. CONCLUSION: RLC appears to be a safe procedure, and does not affect the conventional method.

Adult↗
PubMed1996

Effect of low-power laser irradiation on impulse conduction in anesthetized rabbits.

Low-power laser analgesic effect was generally accepted in clinical cases, whereas there was no direct evidence to indicate that low-power laser irradiation suppressed an impulse conduction within a peripheral nerve. The effect of low-power laser irradiation on electrically evoked responses within the sural nerve was electrophysiologically analyzed in anesthetized rabbits. High threshold evoked responses (conduction velocity was about 11 m/sec, unmyelinated A delta), which were induced by an electrical stimulation to the peripheral stump of the nerve, were significantly suppressed (9 to 19% inhibition) during low-power laser irradiation, which applied to the exposed sural nerve between the stimulus site and the recording site. The suppressive effect was reversible and recovered to the control level after the irradiation. Experimental evidence indicated that low-power laser irradiation suppressed the impulse conduction of unmyelinated A delta afferents in peripheral sensory nerve, which caused a pain sensation. Our data suggest that low-power laser acts as a reversible direct suppressor of neuronal activity.

Animals↗
PubMed1996

Effect of low-power laser irradiation on procollagen synthesis in human fibroblasts.

The conflicting views of the effect of low-power laser (LPL) irradiation on procollagen synthesis have existed at the present time, whereas many clinical studies have tested usefulness of LPL irradiation for the wound healing. To evaluate the effect of LPL irradiation on the procollagen synthesis of human fibroblasts in vitro, LPL irradiation on human fibroblast was carried out using two different culture medium, serum-starved medium and fetal calf serum (FCS)-contained medium. In addition, to investigate the mechanism of the LPL on the procollagen synthesis of human fibroblasts, dexamethasone and methylene blue contained medium were used for inhibition of procollagen product at the pretranslational level and cGMP-mediated processes, respectively. Enhanced effect of LPL was consistently observed in the serum-starved medium (50% increase by a 3 min irradiation), not in the FCS-contained medium. The LPL enhanced effect was not blocked by dexamethasone (3% inhibition) but methylene blue (40% inhibition). Our data suggest that some factors in FCS might interfere with the enhanced effect of LPL on procollagen synthesis and the LPL might act as a direct stimulator of the procollagen synthesis. It seems probable that the LPL enhanced effects might be occurred at the translational level or at the pretranslational level, which is not affected by dexamethasone and cGMP, might be involved in the LPL enhanced effect of the procollagen synthesis in fibroblast.

Cells, Cultured↗
PubMed1996

Identification of nekoflavin as 7 alpha-hydroxyriboflavin.

Nekoflavin, which was found in cat's choroids [Matsui, K. (1965) J. Biochem. 57, 201-206], was identified as 7 alpha-hydroxyriboflavin by comparing the physicochemical properties of nekoflavin acetate with those of chemically synthesized 7 alpha-hydroxyriboflavin pentaacetate. 7 alpha-Hydroxyriboflavin was synthesized from 4-chloro-2-methylbenzonitrile through 7-cyano-7-demethylriboflavin and 7 alpha-aminoriboflavin, which are also new flavins.

Animals↗
PubMed1996

Colon cancer with a high serum alpha-fetoprotein level.

We report on a patient with colon cancer and a very high serum alpha-fetoprotein level. This 75-yr-old man presented with right lower quadrant abdominal pain. An abdominal CT scan as well as ultrasonography showed a tumor in the cecum. Serum alpha-fetoprotein level was extremely high (3,070 ng/ml). At laparotomy, a large mass was found in the cecum, and a right hemicolectomy was performed. Histological examination, including immunohistochemical study, showed an adenocarcinoma of the colon producing alpha-fetoprotein.

Adenocarcinoma↗