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F O Belzer

Publications and source records attributed to F O Belzer.

At least 127 records · Page 7Linked to original sources
PubMed1991

A comparison of the effects of hyperbaric oxygen culture on survival of murine and canine thyroid gland grafts.

Canine thyroid tissue (CTy) was subjected to hyperbaric oxygen culture (HOC) under conditions that affect immunoalteration in murine thyroid tissue (MTy). Survival of autografts and allografts implanted under the kidney capsule was determined after 21 days by 125I uptake and histology. Unlike MTy, autograft CTy subjected to normothermic HOC (95% O2, 5% CO2; 1.76 kg/cm2) for 48 h did not survive (0/8) whereas decrease of culture duration to 24 h resulted in autograft CTy survival (3/3). Under hypothermia (5 degrees C), HOC could be extended to 7 days with autograft CTy survival (3/3 after 4 days and 3/3 after 7 days). Allograft CTy after 24 h of normothermic HOC and 7 days of hypothermic HOC was rejected. Indicators of oxygen free radical injury were determined:catalase activity was comparable in MTy and CTy (means 14.82 and 6.3-10.8 mm/mg protein, respectively) but superoxide dismutase activity was low in CTy (means 0.01-0.29 and 4.75 U/mg protein, respectively). Malondialdehyde content after 48 h of normothermic HOC was higher in CTy than in MTy (means 2215 and 1275 nmol/g, respectively). The results show that CTy is injured by HOC under conditions tolerated by MTy, and that this difference is related to the greater sensitivity of CTy to oxygen free radical injury.

Animals↗
PubMed1991

Effect of polyethylene glycol on lipid peroxidation in cold-stored rat hepatocytes.

A mechanism suggested to cause injury to preserved organs is the generation of oxygen free radicals either during the cold-storage period or after transplantation (reperfusion). Oxygen free radicals can cause peroxidation of lipids and alter the structural and functional properties of the cell membranes. Methods to suppress generation of oxygen free radicals of suppression of lipid peroxidation may lead to improved methods of organ preservation. In this study we determined how cold storage of rat hepatocytes affected lipid peroxidation by measuring thiobarbituric acid reactive products (malondialdehyde, MDA). Hepatocytes were stored in the UW solution +/- glutathione (GSH) or +/- polyethylene glycol (PEG) for up to 96 h and rewarmed (resuspended in a physiologically balanced saline solution and incubated at 37 degrees C under an atmosphere of oxygen) after each day of storage. Hepatocytes rewarmed after storage in the UW solution not containing PEG or GSH showed a nearly linear increase in MDA production with time of storage and contained 1.618 +/- 0.731 nmol MDA/mg protein after 96 h. When the storage solution contained PEG and GSH there was no significant increase in MDA production after up to 72 h of storage and at 96 h MDA was 0.827 +/- 0.564 nmol/mg protein. When freshly isolated hepatocytes were incubated (37 degrees C) in the presence of iron (160 microM) MDA formation was maximally stimulated (3.314 +/- 0.941 nmol/mg protein). When hepatocytes were stored in the presence of PEG there was a decrease in the capability of iron to maximally stimulate lipid peroxidation. The decrease in iron-stimulated MDA production was dependent upon the time of storage in PEG (1.773 nmol/mg protein at 24 h and 0.752 nmol/mg protein at 48 h).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Glycine prevention of cold ischemic injury in isolated hepatocytes.

Isolated hepatocytes suspended in a liver preservation solution (University of Wisconsin (UW) solution) and exposed to cold (5 degrees C) ischemia lose viability (LDH release) after 3 (76.5 +/- 2.6% extracellular LDH) and 4 days (90.3 +/- 5.7% extracellular LDH) storage when rewarmed (37 degrees C) in Krebs-Henseleit buffer. However, if 3 mM glycine is added to Krebs-Henseleit buffer the loss of LDH on rewarming was suppressed (% LDH = 24.4 +/- 2.2% and 33.2 +/- 3.0%, at 3 and 4 days, respectively). The protection by glycine could also be obtained by storing the hepatocytes in the UW solution containing 15 mM glycine and rewarming in the absence of glycine in Krebs-Henseleit buffer. There did not appear to be a relationship between the protection by glycine and glutathione concentration of the hepatocytes as shown by the lack of effect of a glutathione synthetase inhibitor (butathionine sulfoximine) on the protective effects of glycine. Other amino acids did not provide protection to hepatocytes exposed to cold ischemia. The mechanism of action of glycine is not known, but this compound may be important in improving cold storage of livers for transplantation.

Animals↗
PubMed1991

Effect of cold storage on tissue and cellular glutathione.

One of the mechanisms thought to cause injury in preserved organs is the formation of oxygen free radicals. The cell is protected from oxidative stress by many defense mechanisms. A major defense mechanism involves glutathione and glutathione-dependent enzymes. During organ preservation by simple cold storage the loss of glutathione may sensitize the organ to free radical damage after transplantation. In this study we show that glutathione is depleted from the rabbit liver, kidney, and heart cold-stored (5 degrees C) for up to 72 h in the UW solution without glutathione. In the first 24 h kidney glutathione decreased to 84 +/- 3% of control values, liver glutathione decreased to 49 +/- 3% of control values, and heart glutathione decreased to 73 +/- 3% of control values. After 48 h of storage the kidney and liver lost an additional 30 and 20%, respectively, whereas heart glutathione changed very little. By 72 h all three organs had lost more than 50% of the glutathione found in freshly obtained tissue. To determine if glutathione added to the UW solution can effectively prevent this loss of glutathione during preservation, hepatocytes were cold-stored for up to 72 h in a preservation solution with and without glutathione. We found that adding glutathione to the preservation solution slowed the rate of loss of glutathione from the cells. These data suggest that at hypothermia the cell may be permeable to GSH. Methods to suppress the loss of glutathione during preservation of organs may be an important factor in suppressing oxygen free radical injury.

Animals↗
PubMed1991

Effects of method of preservation on functions of livers from fed and fasted rabbits.

Livers from fed, fasted (48 h) and glucose-fed rabbits were preserved for 24 and 48 h by either simple cold storage (CS) or continuous machine perfusion (MP) with the University of Wisconsin preservation solutions. After preservation liver functions were measured by isolated perfusion of the liver (at 37 degrees C) for 2 h. Fasting caused an 85% reduction in the concentration of glycogen in the liver but no change in ATP or glutathione. Glucose feeding suppressed the loss of glycogen (39% loss). After 24 h preservation by CS livers from fed or fasted animals were similar including bile production (6.2 +/- 0.5 and 5.6 +/- 0.4 ml/2 h, 100 g, respectively), hepatocellular injury (LDH release = 965 +/- 100 and 1049 +/- 284 U/liter), and concentrations of ATP (1.17 +/- 0.15 and 1.18 +/- 0.04 mumol/g, glutathione (1.94 +/- 0.51 and 2.35 +/- 0.26 mumol/g, respectively), and K:Na ratio (6.7 +/- 1.0 and 7.7 +/- 0.5, respectively). After 48 h CS livers from fed animals were superior to livers from fasted animals including significantly more bile production (5.0 +/- 0.9 vs 2.0 +/- 0.3 ml/2 h, 100 g), less LDH release (1123 +/- 98 vs 3701 +/- 562 U/liter), higher concentration of ATP (0.50 +/- 0.16 vs 0.33 +/- 0.07 mumol/g) and glutathione (0.93 +/- 0.14 vs 0.30 +/- 0.13 mumol/g), and a larger K:Na ratio (7.4 vs 1.5). Livers from fed animals were also better preserved than livers from fasted animals when the method was machine perfusion. The decrease in liver functions in livers from fasted animals preserved for 48 h by CS or MP was prevented by feeding glucose. Glucose feeding increased bile formation after 48 h CS preservation from 2.0 +/- 0.3 (fasted) to 6.9 +/- 1.2 ml/2 h, 100 g; LDH release was reduced from 3701 +/- 562 (fasted) to 1450 +/- 154 U/liter; ATP was increased from 0.33 +/- 0.07 (fasted) to 1.63 +/- 0.18 mumol/g; glutathione was increased from 0.30 +/- 0.01 (fasted) to 2.17 +/- 0.30 mumol g; and K:Na ratio was increased from 1.5 +/- 0.9 to 5.3 +/- 1.0. This study shows that the nutritional status of the donor can affect the quality of liver preservation. The improvement in preservation by feeding rabbits only glucose suggests that glycogen is an important metabolite for successful liver preservation. Glycogen may be a source for ATP synthesis during the early period of reperfusion of preserved livers.

Adenosine Triphosphate↗
PubMed1991

Chlorpromazine, quinacrine, and verapamil as donor pretreatment in liver preservation, tested in the isolated perfused rat liver.

Rats were pretreated with a single iv dose of chlorpromazine (CPZ) 3 mg/kg, verapamil 1 mg/kg, or quinacrine 2 mg/kg. Livers were taken out and perfused with University of Wisconsin (UW) preservation solution and stored on ice for 48 h in the UW solution before reperfusion with erythrocyte-free and colloid-free Krebs-Hanseleit buffer at 38 degrees C in a nonrecirculating perfusion system for 2 h. CPZ- and quinacrine-pretreated livers produced significantly more bile than control livers and also released significantly less alanine aminotransferase into the perfusate at 30, 60, and 120 min of reperfusion. Aspartate aminotransferase levels were lower at 30 and 60 min of reperfusion for CPZ-pretreated livers but not at 120 min. The only difference between groups concerning lactate dehydrogenase (LDH) release into the perfusate was that CPZ decreased the amount of LDH released at 60 min. Total tissue water or tissue electrolyte content of the liver tissue at the end of the reperfusion did not differ between groups. In conclusion, verapamil was ineffective when given as single dose iv pretreatment to the liver donor but pretreatment with CPZ or quinacrine appeared to improve the function of the preserved liver.

Animals↗
PubMed1991

Experience with 100 consecutive simultaneous kidney-pancreas transplants with bladder drainage.

From December 1985 to December 1989, 100 consecutive simultaneous pancreas-kidney (SPK) transplants were performed at the University of Wisconsin Hospital and Clinics. Bladder drainage technique was used for all grafts. One- and three-year patient survival was 93% and 90%; kidney survival, 90% and 85%; and pancreas survival, 86% and 84%. Quadruple immunosuppressive therapy was used in all patients and consisted of either MALG or OKT3 induction, and cyclosporine, prednisone, and azathioprine maintenance therapy. OKT3 induction therapy was used in 42 patients and Minnesota antilymphocyte globule in 58 patients, with equivalent results except for more opportunistic infection with OKT3. The duodenal button technique was used in the first 17 patients with systemic anticoagulation and was associated with significantly more postoperative bleeding and infection compared with the duodenal segment technique. The most common surgical complication of the duodenal segment technique was urine leak (13%), which usually occurred from the distal duodenal segment. The most common urologic complication of bladder drainage was hematuria (13%), which was usually self-limited. Within 6 months of transplantation, 84% of patients developed urinary tract infections, and 25% of patients had opportunistic infections. The surgical techniques and immunosuppressive methods used in this series are reviewed, and strategies for preventing medical and surgical complications are outlined.

Adult↗
PubMed1991

The predictive value of donor liver biopsies for the development of primary nonfunction after orthotopic liver transplantation.

Methods of accurately assessing the suitability of donor livers prior to transplantation are required if the incidence of primary nonfunction (PNF) is to be reduced. This study evaluated the ability of donor liver biopsies to predict the development of primary nonfunction after transplantation. From June 1987 until May 1990, 170 liver transplants were performed in 147 patients. A total of 124 donor liver biopsies were obtained and divided into three groups. Group 1 biopsies (n = 77) were obtained after revascularization of the liver, group 2 biopsies (n = 19) were obtained prior to donor hepatectomy but examined only after implantation, and group 3 biopsies (n = 28) were obtained as in group 2, but were examined prior to implantation. Three of 89 (3.4%) livers interpreted as having normal histology developed primary nonfunction, while one of 26 (3.8%) biopsies interpreted as having a minimal or moderate amount of fatty infiltration developed primary nonfunction. PNF occurred in 7 of 8 livers with severe fatty infiltration (3), hydropic degeneration (3), and centrilobular necrosis (1). A fourth liver with hydropic degeneration and poor function ultimately failed requiring retransplantation 8 weeks later. Analysis of liver function revealed progressive elevation in aspartate-aminotransferase, alanine-aminotransferase, lactate dehydrogenase, and serum ammonia (NH3) with increasing degrees of fatty infiltration. Donor age and weight was also found to be significantly higher in livers with fatty infiltration. This study suggests that donor liver biopsies demonstrating normal histology or minimal-to-moderate fatty infiltration function adequately, but that donor livers with severe fatty infiltration or hydropic degeneration function poorly and should not be transplanted.

Biopsy↗
PubMed1991

Multivariate analysis of donor-specific versus random transfusion protocols in haploidentical living-related transplants.

A total of 127 haploidentical living-related transplants have been performed at our institution since March 1986. A donor-specific transfusion plus azathioprine protocol was used until July 1988 (n = 74) and a random transfusion (RT) protocol without AZA used thereafter (n = 53) in an effort to decrease risk of recipient sensitization and reduce the burden on the prospective donor. All patients were given cyclosporine 8 mg/kg/day orally beginning 1 week prior to transplantation. Immunosuppression was similar in both groups and consisted of triple induction therapy with prednisone, CsA, and AZA. A positive T cell crossmatch eliminated the potential donor. Seven individuals (9.6%) were sensitized in the DST group and 1 (1.9%) in the RT group, leaving 67 and 52 patients in the two groups of the study, respectively. Groups were similar with respect to age, sex, history of pregnancy in female patients, peak and baseline panel-reactive antibody (PRA), DR match, and prior transplants. The groups differed slightly with respect to AB antigens shared, with an advantage in the RT group. Actuarial graft survival was not statistically significantly different between the two groups, with 2-year graft survival of 95% in the DST and 91% in the RT group (log rank, P = 0.16). Patients in the RT group had significantly more rejection episodes and had them sooner than their counterparts in the DST group. At the end of 1 year, 50% of patients in the DST group had at least 1 rejection episode, compared with 75% of patients in the RT group (P = 0.0008). Multivariate (Poisson) analysis of 10 variables was performed, with an overall model P-value of 0.0001. Only DST (P = 0.0001) and pregnancy (P = 0.015) were significant predictors of rejection episodes, both protective. The difference in rejection episodes and the timing with which they occur has not yet translated into a significant difference in graft survival between DST and RT groups.

Adult↗
PubMed1991

Orthotopic liver transplantation in patients 60 years of age and older.

Cyclosporine appears to have abrogated age as a contraindication to kidney transplantation in the elderly, although it is unclear whether this is true for other types of solid organ transplantation. We performed a retrospective analysis of liver transplant recipients who were 60 years of age and older (n = 23) versus recipients of primary transplants who were 18 to 59 years of age (n = 84). Indications in recipients over 60 included alcoholism (6), postnecrotic cirrhosis (6), cancer (4), primary biliary cirrhosis (3), sclerosing cholangitis (2), and one patient with polycystic liver disease. There were no important differences in the initial transplant hospitalization or the incidence of infection and rejection between the two groups. No patient in the over-60 population required retransplantation. Actuarial patient survival is 83% at 2 years for recipients 60 years of age and above compared to 76% patient survival in adult recipients who are under the age of 60. Liver transplant recipients over the age of 60 years have excellent patient and graft survival and the same postoperative morbidity as recipients who are under 60 years of age. Therefore, advanced age does not appear to be a contraindication to orthotopic liver transplantation.

Aged↗
PubMed1991

The use of myocytes as a model for developing successful heart preservation solutions.

The development of a successful method to preserve the heart for relatively long periods (24-48 hr) requires demonstrating successful orthotopic transplantation and long-term survival after preservation. There are, however, multiple variables that may affect the quality of heart preservation, and it is nearly impossible to systematically study all the variables in this complicated model. One model that may be useful to study how preservation parameters affect heart cell preservation is the isolated myocyte preparation. In this study myocytes were isolated from the rabbit heart and the effects of up to 24 hr cold storage on viability measured to determine if this would be a suitable preservation model. Myocytes were stored in various preservation solutions including; EuroCollins (EC), two cardioplegic solutions (Stanford [ST] and Bretschneider solution [HTK]) and the University of Wisconsin solution (UW) with or without the addition of polyethylene glycol. The viability of myocytes was judged by measuring the effects of preservation and rewarming after preservation on cellular morphology (percent rod-shaped cells), ATP concentration, and LDH release. Myocytes preserved in the cardioplegic solutions were least well preserved after 12 and 24 hr storage, as judged by the loss of rod-shaped morphology and lower ATP concentration. Preservation in EC resulted in a decrease in the percent rod-shaped cells after 12 hr and 24 hr storage that was greater than obtained in the UW solutions. The best preservation of myocyte morphology and highest content of ATP was obtained in myocytes stored in the UW solutions, especially those containing PEG. The myocyte model of heart preservation shows a loss of cell integrity that is related to the preservation solution (HTK greater than ST greater than EC greater than UW-PEG) and these results are similar to what has been shown in the past with other models of heart preservation. Thus the myocyte model appears to be a useful method to test how many preservation solutions and preservation variables affect heart cell metabolism. In the future, results from these types of studies may find use in developing improved heart preservation solutions for testing in the orthotopic transplant model.

Adenosine↗
PubMed1991

[Changes in glutathione levels in the renal cortex of dogs during preservation by continuous hypothermic pulsatile perfusion].

A loss of glutathione (GT) from the kidney can cause increased sensitivity to oxygen free radical-induced injury. In this study we investigated the effects of kidney preservation on GT concentration in the cortex tissue, and how various GT precursors affect GT concentration in the dog kidney. During five day continuous machine perfusion of the kidney at 5 degrees C, there was a loss of GT from the cortex tissue (524 +/- 1% GT remained after 5 days). Perfusion with reduced glutathione (GSH, 3 mM) suppressed this loss (77 +/- 11% of GT remained after 5 days). Oxidized glutathione (GSSG) did not prevent the loss of GT. The addition of the three amino acids that make up GT (glycine, glutamic acid, and cysteine, 3 mM each) stimulated the synthesis of GT in the kidney during hypothermic perfusion (137 +/- 23% of control values at 5 days). The increase in tissue GT stimulated by GSH or other precursors was sensitive to the GT synthetase inhibitor, buthionine sulfoximine. This indicated active GT metabolism even at 5 degrees C in perfused kidneys. This study showed that in kidney preservation there was a loss of GT that could be suppressed by the addition of various precursors for GT synthesis. The loss of GT from preserved kidneys may be one cause of post-transplant renal injury which could be prevented by utilization of the appropriate GT precursors.

Animals↗
PubMed1991

Transplantation of the right kidney: surgical technique revisited.

Transplantation of the right kidney with a short renal vein in a narrow pelvis with deep iliac vessels can be difficult and time-consuming. This technique requires minimal dissection, is fast and safe, and is now the author's preferred technique for transplantation of the right kidney.

Humans↗