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Biomedical subjects

H Ohyanagi

Publications and source records attributed to H Ohyanagi.

137 records · Page 8Linked to original sources

Therapeutic plasmapheresis for liver failure after hepatectomy.

Therapeutic plasmapheresis (PP) for liver failure following the resection of primary liver cancer was evaluated retrospectively. PP was repeated two to three times per week using plasma exchange (PE) with fresh frozen plasma as a substitution fluid in all eight cases and direct hemoperfusion (DHP) in two cases. PE effectively decreased serum bilirubin and/or improved hepatic encephalopathy in six of eight patients and prolonged survival time (p less than 0.05, chi-square test). DHP was not effective. Liver failure following the resection of damaged liver differs from acute liver failure in both the condition itself and the reaction to PP. Fractionation of serum bilirubin using high performance liquid chromatography showed differences in the ratio of delta bilirubin in one survivor versus two who died and was effective in selecting a patient who would respond to PE. In conclusion, PE is effective in prolonging survival time after liver failure in hepatectomized patients compared to conventional therapy.

Bilirubin↗

Effects of nucleosides and a nucleotide on DNA and RNA syntheses by the salvage and de novo pathway in primary monolayer cultures of hepatocytes and hepatoma cells.

Studies were made on the effects of inosine, guanosine 5'-monophosphate (GMP), cytidine, uridine, thymidine, and their mixture (4:4:4:3:1, OG-VI) on DNA and RNA syntheses in primary monolayer cultures of normal hepatocytes and cultures of hepatoma cells, AH130, to use these compounds for total parenteral nutrition. Addition of an appropriate amount of inosine, GMP, uridine, or thymidine to primary cultures of hepatocytes enhanced both DNA and RNA syntheses by the salvage and de novo pathways. Cytidine appeared to have lower optimal concentration for enhancing these pathways. The OG-VI mixture also enhanced the syntheses of DNA and RNA, but the composition of the mixture was not optimal. Additions of inosine, GMP, uridine, and thymidine to cultured hepatoma cells also enhanced their DNA and RNA syntheses, but the cells consumed more of the added nucleic acid compounds than hepatocytes did. Addition of cytidine had no effect on proliferation of the cells. The OG-VI mixture at relatively higher concentration inhibited the syntheses of DNA and RNA by hepatoma cells. Addition of high concentrations of nucleic acid compounds was found to suppress the proliferation of both hepatocytes and hepatoma cells. These results suggest that addition of optimal amounts of nucleic acid compounds such as nucleosides and nucleotides would enhance growth of hepatocytes, particularly during liver regeneration, but that they may also enhance proliferation of tumor cells in the liver.

Animals↗

Effect of methionine-deprived nutrition on cell growth and cell kinetics in cell cultures and experimental tumors.

The effect of methionine-deprived nutrition on cell growth and cell kinetics was investigated in cell cultures and in tumor-bearing rats using the total parenteral nutrition (TPN) technique. A simultaneous flow cytometric measurement of the cellular DNA content and the amount of 5-bromodeoxyuridine incorporated into cellular DNA was performed for analysis of cell kinetics. The methionine-free medium demonstrated a cytocidal effect on the growth of SLC cells after 6 hours of culturing. It decreased viability from 80% in the control medium to 23%, and it decreased the S phase and increased the G0/G1 phase of the cell cycles. The methionine-deprived medium showed a concentration-dependent inhibition in cellular growth. Methionine-deprived TPN was seen to inhibit AH109A and SLC tumor growth compared with conventional TPN and decreased the S phase and increased the G0/G1 phase of cell cycles. These results confirm that methionine deprivation blocks cells from processing into the G1 phase and recycling, and that it is effective in inhibiting tumor growth in cultures and in vivo.

Animals↗

Improved large-scale isolation of breeder porcine islets: possibility of harvesting from nonheart-beating donor.

To establish a large-scale isolation procedure for adult porcine islets usable as a donor source for xenotransplantation and as a model of human islet isolation, we improved several characteristics of the conventional isolation procedure. At a slaughterhouse we first selected a breeder pig over 1.5 years old (and over 200 kg in weight) with warm ischemic time (WIT) of 15 +/- 2 minutes as nonheart-beating donors. Then, we made a special enzymic mixture that consisted of collagenase S-1 (260 U/mg, NittaZelatin, Japan), collagenase P (1.86 U/ml Lyo Boehringer-Mannheim, USA), DNase (Sigma, St. Louis, Mo), Disparse (NittaZelatin, Japan), and protease inhibitor (Sigma). Third, this mixture was injected very gently into the pancreatic duct at the time of pancreatic harvesting. To prevent overdigestion of the pancreas, the mixture was first cooled to less than 10 degrees C. Fourth, during the warm digestion of pancreas, the pancreas with the enzymic mixture was quietly put in a water bath at 37 degrees C without mechanical shaking. Fifth, we purified the islets with a COBE 2991 cell processor by the Dextran 70 gradient method, because Dextran 70 is very cheap and has the same purification effect as the Ficoll gradient. The results of 10 consecutive breeder porcine islet isolations are reported. The total yield of isolations of islets over 50 microm in the longest diameter after staining with Dithizone (DTZ) was 85,900 +/- 19,954 islets, 291,667 +/- 240,452 IEQ (2,900 +/- 2,324 IEQ/g). The purity of the isolated islets was very high: 90.2 +/- 3.8%. Glucose stimulation during in vitro incubation induced significant insulin release from isolated breeder porcine islets. In two of the diabetic rats receiving encapsulated islets grafts using a mesh-reinforced polyvinyl alcohol hydrogel bag (MRPB), a prominent reduction in serum glucose levels (less than 200 mg/dL) persisted for 13 and 19 days, respectively, after intraperitoneal xenotransplantation islets without immunosuppression. In conclusion, we succeeded in a more efficient and less-expensive isolation of a large amount of adult porcine islets from a nonheart-beating donor.

Animals↗

Effectiveness of acidic oxidative potential water in preventing bacterial infection in islet transplantation.

At a number of points in the current procedures of islet isolation and islet culture after the harvesting of donor pancreata, microorganisms could potentially infect the islet preparation. Furthermore, the use of islets from multiple donors can compound the risks of contamination of individual recipients. Acidic oxidative potential water (also termed electrolyzed strong acid solution, function water, or acqua oxidation water), which was developed in Japan, is a strong acid formed on the anode in the electrolysis of water containing a small amount of sodium chloride. It has these physical properties: pH, from 2.3 to 2.7; oxidative-reduction potential, from 1,000 to 1,100 mV; dissolved chlorine, from 30 to 40 ppm; and dissolved oxygen, from 10 to 30 ppm. Because of these properties, acidic oxidative potential water has strong bactericidal effects on all bacteria including methicillin-resistant Staphylococcus aureus (MRSA), viruses including HIV, HBV, HCV, CMV, and fungi as a result of the action of the active oxygen and active chlorine that it contains. We conducted this study to evaluate the effect of acidic oxidative potential water irrigation on bacterial contamination on the harvesting of porcine pancreata from slaughterhouses for islet xenotransplantation by counting the number of pancreatic surface bacteria using the Dip-slide method, and on the results of islet culture; and to evaluate the direct effect on isolated islets when it is used to prevent bacterial contamination by the static incubation test and by morphological examination. Direct irrigation of the pancreas by acidic oxidative potential water was found to be very effective in preventing bacterial contamination, but direct irrigation of isolated islets slightly decreased their viability and function.

Abattoirs↗

Acute appendicitis complicated with necrotizing soft tissue infections in the elderly: report of a case.

A case of acute appendicitis complicated with necrotizing soft tissue infections (NSTIs) in an extremely elderly woman (98 years-old) is reported. She was admitted to our hospital with a history of increasing pain localized in the right lower abdomen. Abdominal ultrasonography revealed appendicolithiasis and periappendiceal fluid. An appendectomy and closure of the perforated cecum was performed. On the 5th post-operative day, the patient developed skin erythemas and crepitation in the right lower quadrant. An exploration and drainage of the recent operative incision was performed under the diagnosis of NSTIs. Despite the declining overall incidence of appendicitis, it has been increasing among the elderly. The elderly patients are associated with underlying defects in immune function. NSTIs, which are characterized by rapidly progressing inflammation and necrosis of soft tissue, comprise a spectrum of disease ranging from necrosis of the skin to life-threatening infections. The most common etiology of NSTIs was post-operative infections of the abdominal wall, which primarily occurred after operations with extensive fecal contamination. NSTIs are no longer a rare post-operative complication in the elderly and initial treatment should be selected according to the condition of the patient.

Abdominal Muscles↗

In vivo evaluation of long-term patency of pancreaticoenterostomy after Whipple operation.

BACKGROUND/AIMS: The aim of this study was to examine the long-term patency of pancreaticoenterostomy in vivo. METHODOLOGY: Evaluation of the patency of the pancreaticoenterostomy was conducted in 12 patients who had undergone the Whipple procedure. After intravenous infusion of secretin (1 microgram/kg), the diameter of the pancreatic duct was taken at 1, 3, 5, 15, 20 and 25 min by means of ultrasonography. We estimated the degree of anastomotic stricture by the maximal dilatation ratio [MDR: Maximal value (Dmax)/basal value (D0)]. The patients underwent pancreatic exocrine function tests before and 1-2 years after surgery. RESULTS: Maximal ductal dilatation was noted from 3 min of 15 min after secretin infusion, thereafter ductal diameter gradually diminished and returned to its basal value at 25 min. Maximal dilatation ratio ranged from 1.3-2.5, 1.7 +/- 0.12. There was a good negative relationship between the maximal dilatation ratio and pancreatic exocrine function. Based on the result of chi 2 analysis, we judged anastomotic stricture to be present in 2 patients with maximal dilatation ratio above 2.0. In these 2 patients, preoperative pancreatic exocrine function recoveries were 69 and 48%, while postoperative pancreatic exocrine function recoveries were 13.8 and 18%, respectively. In the other 10 patients, there was no difference between preoperative and postoperative value of pancreatic exocrine function. CONCLUSIONS: The present method permits safe and non-invasive evaluation of the patency of pancreaticoenterostomy.

4-Aminobenzoic Acid↗

Hepatobiliary scintigraphy after biliary reconstruction--a comparative study on Roux-Y and ESCD.

BACKGROUND/AIMS: Reconstruction of extrahepatic biliary tract with benign lesion still has some unsettled problems, such as postoperative cholangitis. This study was conducted to compare bile through the remnant alimentary tract in patients undergoing end-to-side choledochoduodenostomy, and those undergoing Roux-Y choledochojejunostomy, using hepatobiliary scintigraphy. METHODOLOGY: Five normal human volunteers and 13 patients underwent end-to-side choledochoduodenostomy (n = 5), Roux-Y choledochojejunostomy (n = 8), using hepatobiliary scintigraphy. RESULTS: Postoperative acute cholangitis developed in 1 patient (12%) with Roux-Y choledochojejunostomy and none with end-to-side choledochoduodenostomy. Hepatobiliary scintigraphy showed prominent stasis of 99mTc in the proximal jejunum loop of the patients who underwent the Roux-Y choledochojejunostomy procedure, which was not found in the upper jejunum of the patients with end-to-side choledochoduodenostomy. The time taken before visualization of 99mTC at the upper jejunum in the patient who underwent Roux-Y choledochojejunostomy (66.5 +/- 5 min) was significantly longer than that in the healthy controls (40 +/- 5 min). On the other hand, the time taken before visualization of 99mTc at the upper jejunum in end-to-side choledochoduodenostomy (35 +/- 5 min) was similar to that of healthy controls. CONCLUSIONS: This data suggested that end-to-side choledochoduodenostomy procedure for reconstructing the extrahepatic biliary tract was more physiological with less postoperative complication than Roux-Y choledochojejunostomy procedure.

Anastomosis, Roux-en-Y↗

IGF-1 stimulates mucosal growth in ileal Thiry-Vella fistulas.

BACKGROUND/AIMS: We determined whether the trophic effects of IGF-1 (Insulin-like growth factor-1) on the small bowel mucosa are mediated by either nonluminal factors or endogenous luminal secretion. The gut hormone IGF-1 stimulates growth of small bowel mucosa. The mechanisms responsible for this trophic effect are not known. METHODOLOGY: Rats underwent construction of a Thiry-Vella fistula of ileum. On postoperative day 10, the two groups were subdivided to receive either saline (control) or IGF-1. After 7 days, rats were killed and the Thiry-Vella fistula was removed. The mucosa was scraped and weighed, and protein content and alkaline phosphatase activity was determined. RESULTS: IGF-1 significantly increased mucosal weight and alkaline phosphatase activity and protein content of ileal Thiry-Vella fistula compared with the control rats. CONCLUSIONS: IGF-1 mediated stimulation of small bowel mucosal growth is mediated by factors that are independent of luminal contents and pancreaticobiliary secretion. IGF-1 may prove to be an important enterotrophic factor for gut mucosal proliferation.

Alkaline Phosphatase↗