Do Patient Assessments of Hospital Quality Correlate With Kidney Transplantation Surgical Outcomes?

BACKGROUND: Currently, transplant patients have limited metrics available to understand transplant center quality. Graft and patient survival do not capture the patient experience, and patients may use more general consumer assessments of hospital care to help select transplant centers. We evaluated whether consumer assessments of hospital quality correlate with short- and long-term kidney transplant center performance. MATERIALS AND METHODS: CMS uses the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) to publicly report patients' perspectives on hospital care. We merged 2012 SRTR kidney transplant (n = 200 centers), HCAHPS and American Hospital Association survey data. Center performance was determined by variation in observed-to-expected (O/E) ratios for 1-month and 1-year graft failure. We used multivariate regression to determine whether HCAHPS measures correlate with center performance, after risk-adjusting for structural characteristics and volume. RESULTS: Center-specific graft failure varied significantly (30 day O/E range: 0-4.1). At 30 days, compared to average centers, cleanliness (OR = 1.26, P = .001), patient recommendation (OR = 1.18, P = .005), and high overall ratings (OR = 1.11, P = .036) predicted high performance. Poor nursing-patient communication (OR = 0.70, P = .030), lower cleanliness (OR = 0.67, P < .001), poor overall ratings (OR = 0.79, P = .038), and no recommendation (OR = 0.68, P = .019) correlated with average/low performance. There was no significant correlation between HCAHPS measures and 1-year outcomes. CONCLUSIONS: The association between hospital consumer assessments of hospital care and center performance after kidney transplantation is limited. More specific metrics oriented to capturing transplant patient perspectives may be valuable in further defining transplant quality.

Rapid Resolution of Donor-Derived Glomerular Fibrin Thrombi After Deceased Donor Kidney Transplantation.

The aim of this study was to determine the clinical and histologic outcomes related to transplanting kidneys from deceased donors with glomerular fibrin thrombi (GFT). We included all cases transplanted between October 2003 and October 2014 that had either a preimplantation biopsy or an immediate postreperfusion biopsy showing GFT. The study cohort included 61 recipients (9.9%) with GFT and 557 in the control group without GFT. Delayed graft function occurred in 49% of the GFT group and 39% in the control group (p = 0.14). Serum creatinine at 1, 4, and 12 months and estimated GFR at 12 months were similar in the two groups. Estimated 1-year graft survival was 93.2% in the GFT group and 95.1% in the control group (p = 0.22 by log-rank). Fifty-two of the 61 patients in the GFT group (85%) had a 1-month protocol biopsy, and only two biopsies (4%) showed residual focal glomerular thrombi. At the 1-year protocol biopsy, the prevalence of moderate to severe interstitial fibrosis and tubular atrophy was 24% in the GFT group and 30% in the control group (p = 0.42). We concluded that GFT resolves rapidly after transplantation and that transplanting selected kidneys from deceased donors with GFT is a safe practice.

Robotic resection of choledochocele in an adult with intracorporeal hepaticojejunostomy and Roux-en-Y anastomosis: encouraging progress for robotic surgical treatment of biliary disease.

BACKGROUND: Robotic surgery offers three-dimensional visualization and precision of movement that could be of great value to hepatobiliary surgeons. Previous reports of robotic choledochocele resections in adults have detailed extracorporeal jejunojejunostomies. We describe a total robotic excision of a choledochal cyst with hepaticojejunostomy and intracorporeal Roux-en-Y anastomosis. METHODS: A 58-year-old woman underwent a robotic excision of a small choledochocele with hepaticojejunostomy and intracorporeal Roux-en-Y. RESULT: Port placement was determined via collaborative surgical discussion and previously reported robotic right hepatectomies. Total operative time was 386 min and total robot working time was 330 min. The hepaticojejunostomy was performed using 5-0 PDS suture with parachute-style back wall and running front wall sutures. The jejunojejunostomy was a stapled anastomosis. Estimated blood loss was less than 100 mL. The patient was ambulating and tolerating oral intake on post-operative day 1, and was discharged home on post-operative day 2. CONCLUSIONS: Robotic resection of choledochal cyst with intracorporeal Roux-en-Y anastomosis is feasible, with advantages over open surgery such as superior visualization, precision, and post-operative patient recovery.

Challenges to research and innovation to optimize deceased donor organ quality and quantity.

Solid organ transplantation is encumbered by an increasing number of waitlisted patients unrequited by the current organ supply. Preclinical models suggest that advances in deceased donor management and treatment can increase the quantity and quality of organs available for transplantation. However, the science of donor intervention and the execution of high quality, prospective, multi-center, randomized-controlled trials are restricted by a myriad of logistical challenges mired in regulatory and ethical ambiguity. By highlighting the obstacles to conducting research in deceased donors, this report endeavors to stimulate the creation of a multi-disciplinary framework to facilitate the design, implementation and supervision of innovative trials that increase the quantity and/or quality of deceased donor organs.

Genetic differences in Native Americans and tacrolimus dosing after kidney transplantation.

Tacrolimus pharmacokinetics vary due to single nucleotide polymorphisms (SNPs) in metabolizing enzymes and membrane transporters that alter drug elimination. Clinically we observed that Native Americans require lower dosages of tacrolimus to attain trough levels similar to Caucasians. We previously demonstrated that Native Americans have decreased oral clearance of tacrolimus, suggesting that Native Americans may have more variant SNPs and, therefore, altered tacrolimus pharmacokinetic parameters. We conducted 12-hour pharmacokinetic studies on 24 adult Native American kidney transplant recipients on stable doses of tacrolimus for at least 1 month posttransplantation. Twenty-four Caucasian kidney transplant recipients were compared as controls. SNPs encoding the genes for the enzymes (CYP3A4, CYP3A5) and transporters (ABCB1, BCRP, and MRP1) were typed using TaqMan. The mean daily tacrolimus dose in the Native Americans was 0.03 ± 0.02 compared with the Caucasians 0.5 ± 0.3 (mg/kg/d; P = .002), with no significant differences in trough levels, (6.7 ± 3.1 vs 7.4 ± 2.1 ng/dL; P = .4). Many Native Americans, but not Caucasians, demonstrated the 3/*3 - C3435T CC and the *3/*3 -G2677T GG genotype combination previously associated with low tacrolimus dosing. Native Americans required significantly lower tacrolimus doses than Caucasians to achieve similar tacrolimus trough levels, in part due to lower tacrolimus clearance from decreased drug metabolism and excretion.

Domino liver transplantation in maple syrup urine disease: a case report and review of the literature.

BACKGROUND: Improved outcomes have expanded the indications for liver transplantation, thus aggravating the already limited supply of donor organs. Domino liver transplantation (DLT) has been one strategy to augment the supply of donor organs in cases of inborn errors of metabolism. One such disease is maple syrup urine disease (MSUD), an inherited disorder of branched-chain amino acid (BCAA) metabolism. METHODS: We report on the transplantation of a deceased donor liver into a patient with MSUD, and the sequential transplantation of the explanted liver into a patient with hemophilia A, HIV, hepatitis C, and a low priority on the transplant waiting list. RESULTS: At 30 months, the MSUD recipient has had significant correction of BCAA metabolism on a protein-unrestricted diet and no progression of neuropsychiatric symptoms. The DLT recipient has been cured of hemophilia and has normal BCAA homeostasis. This case provides further evidence that elective orthotopic liver transplantation for MSUD attenuates the disease with restoration of BCAA metabolism, and that DLT in this setting can achieve excellent results in ESLD patients. CONCLUSION: It is possible that domino grafts from patients with MSUD could be used in more conventional recipients, but additional studies and longer-term outcomes are needed to determine the validity of DLT in MSUD.

Polycystic liver disease and liver transplantation: single-institution experience.

Adult polycystic liver disease (PLD) can cause massive hepatomegaly leading to pain, caval obstruction, and hemorrhage. Many surgical techniques including aspiration, fenestration, and resection have been used to treat PLD. In addition to substantial morbidity and mortality, conservative surgery may have limited success, and palliation may be temporary. With improved results of liver transplantation, it has become the definitive treatment for PLD. We retrospectively reviewed our experience in patients with PLD between 1998 and 2007. Thirteen patients underwent liver only or liver-kidney transplantation. All surgical procedures were performed with preservation of the recipient inferior vena cava and without venovenous bypass (piggyback technique). Our patients experienced a high rate of perioperative morbidity. However, long-term patient and graft survival were excellent.

Transplantation of hepatocytes for prevention of intracranial hypertension in pigs with ischemic liver failure.

Intracranial hypertension leading to brain stem herniation is a major cause of death in fulminant hepatic failure (FHF). Mannitol, barbiturates, and hyperventilation have been used to treat brain swelling, but most patients are either refractory to medical management or cannot be treated because of concurrent medical problems or side effects. In this study, we examined whether allogeneic hepatocellular transplantation may prevent development of intracranial hypertension in pigs with experimentally induced liver failure. Of the two preparations tested--total hepatectomy (n = 47), and liver devascularization (n = 16)--only pigs with liver ischemia developed brain edema provided, however, that animals were maintained normothermic throughout the postoperative period. This model was then used in transplantation studies, in which six pigs received intrasplenic injection of allogeneic hepatocytes (2.5 x 10(9) cells/pig) and 3 days later acute liver failure was induced. In both models (anhepatic state, liver devascularization), pigs allowed to become hypothermic had significantly longer survival compared to those maintained normothermic. Normothermic pigs with liver ischemia had, at all time points studied, ICP greater than 20 mmHg. Pigs that received hepatocellular transplants had ICP below 15 mmHg until death; at the same time, cerebral perfusion pressure (CPP) in transplanted pigs was consistently higher than in controls (45 +/- 11 mmHg vs. 16 +/- 18 mmHg; p < 0.05). Spleens of transplanted pigs contained clusters of viable hepatocytes (hematoxylin-eosin, CAM 5.2). It was concluded that removal of the liver does not result in intracranial hypertension; hypothermia prolongs survival time in both anhepatic pigs and pigs with liver devascularization, and intrasplenic transplantation of allogeneic hepatocytes prevents development of intracranial hypertension in pigs with acute ischemic liver failure.

Loss and recovery of liver regeneration in rats with fulminant hepatic failure.

We earlier described a model of fulminant hepatic failure (FHF) in the rat where partial hepatectomy is combined with induction of right liver lobes necrosis. After this procedure, lack of regenerative response in the residual viable liver tissue (omental lobes) was associated with elevated plasma hepatocyte growth factor (HGF) and transforming growth factor beta (TGF-beta1) levels and delayed expression of HGF and c-met mRNA in the remnant liver. Here, we investigated whether syngeneic isolated hepatocytes transplanted in the spleen will prolong survival and facilitate liver regeneration in FHF rats. Inbred male Lewis rats were used. Group I rats (n = 46) received intrasplenic injection of 2 x 10(7) hepatocytes and 2 days later FHF was induced. Group II FHF rats (n = 46) received intrasplenic injection of saline. Rats undergoing partial hepatectomy of 68% (PH; n = 30) and a sham operation (SO; n = 30) served as controls. In 20 FHF rats (10 rats/group), survival time was determined. The remaining 72 FHF rats (36 rats/group) were used for physiologic studies (liver function and regeneration and plasma growth factor levels). In Group I rats survival was longer than that of Group II controls (73 +/- 22 hr vs. 33 +/- 9 hr; P < 0. 01). During the first 36 hr, Group I rats had lower blood ammonia, lactate, total bilirubin, PT, and PTT values, lower activity of liver enzymes, and higher monoethylglycinexylidide (MEGX) production than Group II rats. In Group I rats, livers increased in weight at a rate similar to that seen in PH controls and showed distinct mitotic and DNA synthetic activity (incorporation of bromodeoxyuridine and proliferation cell nuclear antigen expression). Plasma HGF and TGF-beta1 levels in these rats decreased and followed the pattern seen in PH rats; additionally, c-met expression in the remnant liver was accelerated. Hepatocyte transplantation prolonged survival in FHF rats and facilitated liver regeneration. Even though the remnant liver increased in weight four times reaching 30% of the original liver mass, the transplant-bearing rats expired due to inability of the regenerating liver to support the rat.

Clinical experience with a bioartificial liver in the treatment of severe liver failure. A phase I clinical trial.

OBJECTIVE: The purpose of this study was to develop a bioartificial liver (BAL) to treat patients with severe liver failure until they can be either transplanted or recover spontaneously. SUMMARY BACKGROUND DATA: Severe acute liver failure is associated with high mortality. Liver transplantation has emerged as an effective therapy for patients who did not respond to standard management. However, because of the donor organ shortage and urgent need for transplantation, many patients die before they can be transplanted and others do not survive after transplantation, primarily because of intracranial hypertension. METHODS: Three groups of patients with severe acute liver failure were treated with the BAL. In group 1 (n = 18) were patients with fulminant hepatic failure (FHF), in group 2 (n = 3) were patients with primary nonfunction (PNF) of a transplanted liver, and in group 3 (n = 10) were patients with acute exacerbation of chronic liver disease. Patients in groups 1 and 2 were candidates for transplantation at the time they entered the study, whereas patients in group 3 were not. RESULTS: In group 1, 16 patients were "bridged" successfully to transplantation, 1 patient was bridged to recovery without a transplant, and 1 patient died because of concomitant severe pancreatitis. In group 2, all patients were bridged successfully to retransplantation. In group 3, two patients were supported to recovery and successful transplants at later dates; the other eight patients, although supported temporarily with the BAL, later died because they were not candidates for transplantation. CONCLUSIONS: The authors' clinical experience with the BAL has yielded encouraging results. A randomized, controlled, prospective trial (phase II-III) is being initiated to determine the efficacy of the system.

Fulminant hepatic failure in rats: survival and effect on blood chemistry and liver regeneration.

A reproducible experimental animal model of fulminant hepatic failure (FHF) resembling the clinical condition is needed. We have developed such a model in the rat by combining resection of the two anterior liver lobes (68% liver mass) with ligation of the right lobes pedicle (24% liver mass), resulting in liver necrosis; the remaining two omental lobes (8% liver mass) are left intact. Adult Sprague-Dawley rats (250-300 g) were used. Survival time was determined in 60 rats. Because maintenance of body temperature at 37 degrees C shortened survival time by half, FHF rats were not warmed during the postinduction period and were allowed to gradually enter a state of mild to moderate hypothermia (29-32 degrees C). Additionally, 42 FHF rats were killed in batches of six rats each 2, 6, 12, 18, 24, 30, and 36 hours postoperatively to evaluate changes in blood chemistry (glucose, lactate, liver function tests, prothrombin time) and to assess liver regenerative response in the residual omental liver lobes (weight, protein content, incorporation of bromodeoxyuridine [BrdU], expression of proliferation cell nuclear antigen [PCNA], mitotic activity), plasma levels of hepatocyte growth factor (HGF) and transforming growth factor beta (TGF-beta1), and tissue expression of the HGF and it's receptor c-met. Rats undergoing partial hepatectomy of 68% (PH; n = 42) and a sham operation (SO; n = 42) served as controls. All SO and PH controls survived. PH rats showed only transient decreases in body temperature, signs of modest early hepatic dysfunction (hyperlactemia, hyperammonemia, prolonged PT time), and normal restitution of liver mass. All FHF rats became comatose by 24 hours postoperatively. Most animals (90%) died within 24-48 hours postoperatively (mean, 39 +/- 11 hours). Changes in blood chemistry reflected rapid development of liver failure. Plasma HGF levels were markedly elevated and at all time points were higher than in PH controls (P < .05). At the same time, expression of HGF and c-met messenger RNA in the remnant liver was delayed. Plasma TGF-beta1 levels increased early (18 hours) and remained twofold to threefold higher than that of PH and SO controls (P < .05). There was only a 20% increase in the weight of the remnant liver lobes due to swelling. No hepatocytes stained positively for BrdU and PCNA, and none showed mitotic figures. In contrast, all PH controls showed vigorous liver regeneration. In conclusion, we have developed and characterized a novel model of FHF in rats that has a number of physiological and biochemical features seen clinically in FHF, including severely impaired ability of the residual liver tissue to regenerate.

Clinical experience with a porcine hepatocyte-based liver support system.

UNLABELLED: The only clinically proven effective treatment of fulminant hepatic failure (FHF) is orthotopic liver transplant (OLT). However, many patients die before an organ becomes available. Thus, there is a need for development of an extracorporeal liver support system to "bridge" these patients either to OLT or spontaneous recovery. We developed a bioartificial liver (BAL) based on plasma perfusion through a circuit of a hollow-fiber cartridge seeded with matrix-anchored porcine hepatocytes to treat patients with severe acute liver failure. Two groups of patients were studied. Group 1 (n = 12): patients with FHF. All patients were successfully "bridged" to OLT. "Bridge" time to OLT was 21-96 hr (mean: 39.3 hr). All patients were discharged neurologically intact. Reversal of decerebration was noted in all 11 deep stage 4 coma patients. There was reduction in intracranial pressure (ICP mmHg, 18.2 +/- 2.2 to 8.5 +/- 1.2; p < 0.004) and increase in cerebral perfusion pressure (CPP mmHg, 71.1 +/- 4.0 to 84.7 +/- 2.6; p < 0.006). Laboratory values pre- and post-BAL treatment: glucose (mg/dl) 122 +/- 11 to 183 +/- 21, p < 0.002; ammonia (mumol/l) 155.6 +/- 13.2 to 121.6 +/- 9.5, p < 0.02; total bilirubin (mg/dl) 21.6 +/- 2.8 to 18.2 +/- 2.2, p < 0.001; PT (sec) 23.2 +/- 1.7 to 21.9 +/- 1.0, p < 0.3. Group II (n = 8): patients with chronic liver failure experiencing acute exacerbation. Two patients survived and later underwent OLT. Six patients (not OLT candidates) died 1-14 days after last BAL treatment. Laboratory values pre- and post-treatment: ammonia (mumol/l) 201 +/- 47 to 143 +/- 25, p < 0.06; total bilirubin (mg/dl) 22.8 +/- 5.2 to 19.5 +/- 4.4, p < 0.01; PT (sec) 22.5 +/- 2.0 to 21.8 +/- 1.1, p < 0.6. CONCLUSION: our clinical experience with the BAL suggests that it may serve as "bridge" to OLT in patients with FHF primarily by reversing intracranial hypertension, but it is not a substitute for OLT in patients with end-stage liver disease who are non-transplant candidates.

Treatment of hypercholesterolemia in the Watanabe rabbit using allogeneic hepatocellular transplantation under a regeneration stimulus.

Numerous studies have reported successful allotransplantation of hepatocytes. However, none have shown long-term correction of a liver-related metabolic defect. In this study, we used a method of regional hepatocyte transplantation and subsequent induction of transplanted cell proliferation by regeneration response in the transplant-bearing liver lobes. New Zealand White rabbits were used as cell donors and Watanabe heritable hyperlipidemic (WHHL) rabbits were used as cell recipients (2 x 10(8) cells/rabbit). All recipient rabbits were maintained on daily cyclosporine. Two weeks after baseline serum cholesterol determination, group I WHHL rabbits (n = 7) received an infusion of cells into the right lateral liver lobe, and a loose ligature was placed around the portal venous branch supplying the anterior lobe. After 1 week, to allow engraftment, the portal venous branch was ligated, which resulted in the atrophy of the affected liver parenchyma and induction of hyperplasia in the transplant-bearing liver tissue. Group II rabbits (n = 6) were transplanted with New Zealand White hepatocytes without portal branch ligation (PBL) and group III rabbits (n = 4) were subjected to sham transplantation (saline) and PBL. The experimental period extended to 150 days after transplantation. All WHHL rabbits transplanted with normal hepatocytes showed reduction in serum cholesterol and low-density lipoprotein (LDL) levels. Group I (PBL-stimulated) recipients demonstrated a more pronounced and sustained effect than group II animals (P < 0.05). Group III controls showed only a slight, typical for aging decrease in serum cholesterol. Group I recipient livers perfused with LDL labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethyl indocarbocyanine perchlorate (DiI) showed much higher numbers of DiI-LDL-positive hepatocytes than those of group II recipients. In conclusion, a liver regeneration stimulus enhanced the population of transplanted hepatocytes and their functional effect in a large animal model of inborn error of liver metabolism.

Should HIV status alter indications for hemorrhoidectomy?

PURPOSE: There is a widespread belief that performing hemorrhoidectomy on a patient infected with human immunodeficiency virus (HIV) is an invitation for disaster. Aim of this study was to compare morbidity of hemorrhoidectomy in HIV-positive (HIV+) with HIV-negative (HIV-) patients. METHODS: Charts of 27 HIV+ and 30 HIV- male patients less than age 50 years who underwent hemorrhoidectomy were reviewed. RESULTS: Mean age of the 57 study group patients was 38 years. Open hemorrhoidectomy was performed in 26 patients (46 percent), and a closed technique was used in 31 patients (54 percent). HIV+ and HIV- patient groups were well matched to all preoperative and intraoperative variables. Mean T-cell helper count in the HIV+ patient group was 301 (range, 9-1,040) cells/microliter. There were no deaths, and complications were seen in 15 patients (26 percent). There was no difference in overall complication rates between HIV+ and HIV- patient groups. Urinary retention was seen in ten patients (18 percent), three of whom were HIV+ (11 percent) vs. seven of whom were HIV- (23 percent) (P = not significant). Although no patient required reoperation for bleeding, postoperative hemorrhage was seen in three patients (1 HIV+, 2 HIV-). None of the patients developed fecal incontinence. Mean time to complete wound healing was 6.8 (range, 4-12) weeks for HIV+ patients vs. 6.6 (range, 4-14) weeks for HIV- patients (P = not significant). CONCLUSIONS: These data suggest that HIV status of a patient should not alter indications for surgical management of hemorrhoidal disease.

Liquid nitrogen treatment of hand and plantar warts.

The author reports on a study of the liquid nitrogen treatment of warts at the Rutgers University Student Health Center. He demonstrates that liquid nitrogen therapy is a safe, effective treatment method, appropriate for use by nurses and other primary providers in a college health setting.

Intrinsic susceptibility of the kidney to acetaminophen toxicity in middle-aged rats.

Acetaminophen (APAP)-induced nephrotoxicity is age-dependent in male Sprague-Dawley (SD) rats: middle-aged (9-12 months old) rats exhibit nephrotoxicity at lower dosages of APAP than do young adults (2-3 months old). The present study was designed to test the hypothesis that the intrinsic susceptibility of renal tissue to APAP toxicity is increased in middle-aged rats. APAP toxicity was evaluated in renal slices from naive 3- and 12-month-old male SD rats incubated with 0-50 mM APAP for 2-8 h. Renal slice glutathione (GSH) and APAP concentrations were determined; renal function was assessed by organic anion (para-aminohippurate, PAH) and cation (tetraethylammonium, TEA) accumulation; and cell viability was assessed by lactate dehydrogenase (LDH) leakage. At each concentration of APAP tested, accumulation of APAP by renal slices was similar in 3- and 12-month-olds. APAP toxicity in renal slices from both 3- and 12-month-old rats was characterized by concentration-dependent increases in LDH leakage. In contrast to APAP nephrotoxicity in vivo, APAP toxicity in renal slices was accompanied by decreased accumulation of PAH and TEA. Additionally, APAP produced marked reductions in renal slice GSH content in a concentration-dependent manner: however, in contrast to APAP nephrotoxicity in vivo, APAP-induced GSH depletion in vitro did not precede cytotoxicity. No consistent age-dependent differences in the time- and concentration-response curves for APAP nephrotoxicity were observed. These data suggest that APAP cytotoxicity in vitro is not increased in 12-month-old rats. However, since the pattern (and mechanisms) of APAP cytotoxicity in vitro appears to be different from that observed in vivo, extrapolation of in vitro cytotoxicity to in vivo nephrotoxicity is limited. Therefore, age differences in intrinsic susceptibility of the intact kidney cannot be excluded as a mechanism contributing to enhanced APAP nephrotoxicity in middle-aged rats.

Gentamicin-induced renal metabolic alterations in newborn rat kidney: lack of potentiation by vancomycin.

Daily subcutaneous administration of 20 or 100 mg/kg gentamicin for 4 days significantly decreased pyridoxal-5'-phosphate and lysosomal specific phosphatidylinositol-phospholipase C (PI-PLC) in newborn rat kidney. The fall in PI-PLC was associated with an elevation in renal phosphatidylinositol, phosphatidylserine, and phosphatidylcholine. The 100 mg/kg gentamicin dose also produced a rise in renal sphingomyelin, phosphatidylethanolamine, phosphatidylglycerol, and total phospholipid (TPL) accompanied by inhibition in the activities of Na+,K+-ATPase and alkaline phosphatase. In contrast, daily intraperitoneal injection of 100 mg/kg vancomycin for 4 days failed to markedly alter renal metabolic parameters. However, the 500 mg/kg vancomycin dose increased kidney weight, TPL, and all individual phospholipid class concentrations accompanied by inhibition of lysosomal specific PI-PLC activity and reduced pyridoxal-5'-phosphate levels. Simultaneous administration of 20 mg/kg gentamicin with either vancomycin dose resulted in renal alterations similar to those produced by gentamicin alone. Concurrent treatment with 100 mg/kg aminoglycoside and either vancomycin dose produced changes in kidney which were similar to those produced by gentamicin alone, except for a synergistic rise in PI as well as a greater fall in alkaline phosphatase and pyridoxal-5'-phosphate. Surprisingly, the concentration of gentamicin and vancomycin was less in newborn kidneys of rats receiving a simultaneous high dose of vancomycin and aminoglycoside treatment compared to levels found in animals given either antibiotic separately. The lack of potentiation of nephrotoxicity in newborns administered a combination of vancomycin and gentamicin may be due to decreased accumulation of either antibiotic in kidney.

Age-related differences in susceptibility to renal ischemia in rats.

These experiments were designed to determine the influence of age on the response of the kidney to ischemia. Renal ischemia was induced in female Fischer-344 rats, 3-4 or 37-38 months old, by renal arterial and venous occlusion followed by 0, 1, 24, or 96 hr of reflow. Age-matched controls were sham operated but were not subjected to ischemia. A transient postischemic increase in blood urea nitrogen (BUN) and serum creatinine was observed in young rats. In old rats, BUN and serum creatinine remained markedly elevated through 96 hr postischemia. In vitro renal cortical slice accumulation of organic ions was inhibited to a greater extent in old rats than in young rats 96 hr postischemia. Histologically, renal tubular damage was more severe in old than in young rats 24 and 96 hr postischemia. Tubular regenerative activity was similar in old and young rats at 96 hr, but restoration of tubular architecture was more complete in young rats. Organic ion accumulation by renal cortical slices from naive old rats was inhibited by in vitro anoxia (treatment with 100% N2) to a greater extent than tissue from young rats. These data suggest that old rats are more susceptible to renal ischemia than are young rats and these differences in susceptibility may reflect intrinsic age-related differences in basal renal metabolism.

Cadmium toxicity in the isolated perfused rat liver.

Isolated perfused livers from male and female Sprague-Dawley rats were exposed to cadmium chloride (50 and 200 microM). Acute hepatotoxicity was investigated by measuring cadmium-induced changes in bile flow, urea synthesis and alanine aminotransferase (ALT) leakage. Cadmium-induced lipid peroxidation was estimated by formation of conjugated dieners and thiobarbituric acid (TBA) reactants. Cadmium, at both concentrations, caused a rapid decrease in bile flow (within 40 min) and complete cholestasis within 70 min exposure in livers perfused from both male and female rats. Cadmium exposure (50 and 200 microM) also resulted in the leakage of ALT into the perfusate within 60 min. In contrast, exposure of isolated rat hepatocytes to as high as 500 microM cadmium did not result in enzyme leakage until 180 min exposure. Sex differences in cadmium-induced cholestasis and ALT leakage were not observed at these concentrations. Malondialdehyde was not detected in the perfusate nor were conjugated dienes detected in liver tissue following 90 min cadmium exposure. These data demonstrate that the isolated perfused rat liver (IPRL) is a sensitive system in which to study chemically induced hepatotoxicity. Cadmium rapidly causes functional alterations and cellular damage in perfused livers from both male and female rats. Cadmium-induced liver injury was apparently not related to lipid peroxidation.