Impact of Prolonged Cold Ischemia Time on One Year Kidney Transplant Outcomes.

BACKGROUND: Prolonged cold ischemia times (CIT) of kidney allografts remains a significant reason for graft refusal in the new allocation system. We sought to investigate the effect of prolonged CIT on kidney transplant outcomes at a center without an international airport. METHODS: Retrospective study of kidney transplant patients treated at an academic medical center from January 1, 2018 to May 1, 2020. The 117 patients were divided into 2 categories. Fifty-four patients (46%) had CIT of 30-35.99 hours, and 63 (54%) had CIT of 36± hours. Kidney function was evaluated using creatinine and at 12 months, which was the primary endpoint. RESULTS: All of the transplanted allografts were carefully selected and had ≤ 20% glomerulosclerosis and an average kidney donor profile index of 54%. Among the 117 patients analyzed in this study, there was no significant difference in creatinine at 12 months between groups with CIT above 36 hours and < 35.99 hours (2.07 vs 1.78; P value .2339). There were a total of 18 rejection events (15%) and no cases of primary non-function in either group. Patients that were able to be maintained on calcineurin inhibitors had improved graft function at 12 months (1.69 vs 2.96; P value .0267). CONCLUSIONS: Our study indicated that prolonged CITs over 36 hours were not associated with poorer patient outcomes at 1 year when using creatinine as an endpoint. They also had similar rates of rejection, consistent with previously published rates for kidney transplantation.

Usefulness of Controlled Attenuation Parameter and Liver Stiffness Measurement for the Identification of Extended-criteria Donors and Risk-assessment in Liver Transplantation.

BACKGROUND: Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) are noninvasive surrogates for hepatic steatosis and fibrosis, respectively, and could help identify extended criteria donors in liver transplantation (LT). We aimed to determine the accuracy of CAP/LSM in deceased donors along with post-LT changes. METHODS: Accuracy of preprocurement CAP/LSM to grade/stage steatosis/fibrosis was determined using liver biopsy as reference. Transplant outcomes, including primary nonfunction (PNF) and early allograft dysfunction, were recorded. Recipients underwent CAP/LSM as outpatients. Areas under the receiver operating characteristic curve and regression models were constructed to analyze data. RESULTS: We prospectively evaluated 160 allografts (138 transplanted). Same-probe paired baseline/post-LT CAP was 231 dB/m (181-277)/225 (187-261) (P = 0.61), and LSM 7.6 kPa (6.3-10.8)/5.9 (4.6-8.7) (P = 0.002), respectively. CAP reading was affected by BMI and LSM by ALT, race and bilirubin. Although CAP did not correlate with steatosis from frozen sections (ρ = 0.08, P = 0.47), it correlated with steatosis from permanent sections (ρ = 0.32, P < 0.001) and with oil red O histomorphometry (ρ = 0.35, P = 0.001). CAP identified moderate-to-severe steatosis with an areas under the receiver operating characteristic curve curve of 0.79 (0.66-0.91), for a negative predictive value of 100% at a cutoff value of 230 dB/m. LSM correlated with fibrosis staging (ρ = 0.22, P = 0.007) and it identified discarded allografts with advanced fibrosis/cirrhosis. Patients with no to minimal fibrosis had an LSM of 7.6 (6-10.1) kPa. CONCLUSIONS: Our results are proof-of-concept of the utility of CAP/LSM during organ procurement. Establishing the precise role of these noninvasive tools in the organ allocation process mandates confirmatory studies.

Hydrastine pharmacokinetics and metabolism after a single oral dose of goldenseal (Hydrastis canadensis) to humans.

The disposition and metabolism of hydrastine was investigated in 11 healthy subjects following an oral dose of 2.7 g of goldenseal supplement containing 78 mg of hydrastine. Serial blood samples were collected for 48 hours, and urine was collected for 24 hours. Hydrastine serum and urine concentrations were determined by Liquid Chromatography-tandem mass spectrometry (LC-MS/MS). Pharmacokinetic parameters for hydrastine were calculated using noncompartmental methods. The maximal serum concentration (Cmax) was 225 ± 100 ng/ml, Tmax was 1.5 ± 0.3 hours, and area under the curve was 6.4 ± 4.1 ng ⋅ h/ml ⋅ kg. The elimination half-life was 4.8 ± 1.4 hours. Metabolites of hydrastine were identified in serum and urine by using liquid chromatography coupled to high-resolution mass spectrometry. Hydrastine metabolites were identified by various mass spectrometric techniques, such as accurate mass measurement, neutral loss scanning, and product ion scanning using Quadrupole-Time of Flight (Q-ToF) and triple quadrupole instruments. The identity of phase II metabolites was further confirmed by hydrolysis of glucuronide and sulfate conjugates using bovine ß-glucuronidase and a Helix pomatia sulfatase/glucuronidase enzyme preparation. Hydrastine was found to undergo rapid and extensive phase I and phase II metabolism. Reduction, O-demethylation, N-demethylation, hydroxylation, aromatization, lactone hydrolysis, and dehydrogenation of the alcohol group formed by lactone hydrolysis to the ketone group were observed during phase I biotransformation of hydrastine. Phase II metabolites were primarily glucuronide and sulfate conjugates. Hydrastine undergoes extensive biotransformation, and some metabolites may have pharmacological activity. Further study is needed in this area.

Clinical improvement of nephrogenic systemic fibrosis after kidney transplantation.

Nephrogenic systemic fibrosis (NSF) has been observed with increased frequency in recent years. Progressive hardening of the skin advancing to severe woody induration and the development of thickened hyperpigmented plaques on the extremities and the trunk are the main clinical features. Further progression of the disease results in flexion contractures of the upper and lower extremities, resulting in immobilization and severe morbidity. In this study, we reviewed our experience with seven end-stage renal disease patients who were referred to our center between January 2004 and June 2005 for kidney transplant evaluation or for diagnosis and treatment of their deteriorating condition. Diagnosis in all patients was confirmed by skin and muscle biopsy. Three of these patients underwent renal transplantations, and softening of the skin and improved mobility of the joints was noted after kidney transplantation. Three of the four patients who remained on dialysis showed further deterioration of their NSF despite a trial of immunosuppressive therapy. Improvement after transplantation could be secondary to immunosuppression, increased renal clearance and/or more effective fluid management.

Clinical assessment of CYP2D6-mediated herb-drug interactions in humans: effects of milk thistle, black cohosh, goldenseal, kava kava, St. John's wort, and Echinacea.

Cytochrome P450 2D6 (CYP2D6), an important CYP isoform with regard to drug-drug interactions, accounts for the metabolism of approximately 30% of all medications. To date, few studies have assessed the effects of botanical supplementation on human CYP2D6 activity in vivo. Six botanical extracts were evaluated in three separate studies (two extracts per study), each incorporating 16 healthy volunteers (eight females). Subjects were randomized to receive a standardized botanical extract for 14 days on separate occasions. A 30-day washout period was interposed between each supplementation phase. In study 1, subjects received milk thistle (Silybum marianum) and black cohosh (Cimicifuga racemosa). In study 2, kava kava (Piper methysticum) and goldenseal (Hydrastis canadensis) extracts were administered, and in study 3 subjects received St. John's wort (Hypericum perforatum) and Echinacea (Echinacea purpurea). The CYP2D6 substrate, debrisoquine (5 mg), was administered before and at the end of supplementation. Pre- and post-supplementation phenotypic trait measurements were determined for CYP2D6 using 8-h debrisoquine urinary recovery ratios (DURR). Comparisons of pre- and post-supplementation DURR revealed significant inhibition (approximately 50%) of CYP2D6 activity for goldenseal, but not for the other extracts. Accordingly, adverse herb-drug interactions may result with concomitant ingestion of goldenseal supplements and drugs that are CYP2D6 substrates.

Gauging the clinical significance of P-glycoprotein-mediated herb-drug interactions: comparative effects of St. John's wort, Echinacea, clarithromycin, and rifampin on digoxin pharmacokinetics.

Concomitant administration of botanical supplements with drugs that are P-glycoprotein (P-gp) substrates may produce clinically significant herb-drug interactions. This study evaluated the effects of St. John's wort and Echinacea on the pharmacokinetics of digoxin, a recognized P-gp substrate. Eighteen healthy volunteers were randomly assigned to receive a standardized St. John's wort (300 mg three times daily) or Echinacea (267 mg three times daily) supplement for 14 days, followed by a 30-day washout period. Subjects were also randomized to receive rifampin (300 mg twice daily, 7 days) and clarithromycin (500 mg twice daily, 7 days) as positive controls for P-gp induction and inhibition, respectively. Digoxin (Lanoxin 0.25 mg) was administered orally before and after each supplementation and control period. Serial digoxin plasma concentrations were obtained over 24 h and analyzed by chemiluminescent immunoassay. Comparisons of area under the curve (AUC)((0-3)), AUC((0-24)), elimination half-life, and maximum serum concentration were used to assess the effects of St. John's wort, Echinacea, rifampin, and clarithromycin on digoxin disposition. St. John's wort and rifampin both produced significant reductions (p < 0.05) in AUC((0-3)), AUC((0-24)), and C(max), while clarithromycin increased these parameters significantly (p < 0.05). Echinacea supplementation did not affect digoxin pharmacokinetics. Clinically significant P-gp-mediated herb-drug interactions are more likely to occur with St. John's wort than with Echinacea.

Hemodialysis access success: beyond the operating room.

BACKGROUND: Publication of the Kidney Disease Outcomes Quality Initiative (KDOQI) Guidelines has reinforced an already increased focus within the Veterans Health Administration (VHA) on arteriovenous (AV) hemodialysis (HD) vascular access. Meeting these KDOQI goals has been the responsibility of individual VHA centers. We responded by organizing a dedicated HD AV clinic to provide preoperative evaluation and postoperative follow-up. METHODS: The records of 130 patients referred from January 2004 through June 2006 to our AV HD clinic were retrospectively reviewed. A minimum of 6 months of postoperative follow-up was required. RESULTS: AV fistulae were performed in 71% of the patients, with approximately 45% being Brescia-Cimino fistulae. Importantly, only 38% of AV fistulae matured and were used without secondary intervention. The remaining 62% of AV fistulae each required 2.2 +/- .3 interventions. The final AV fistula use rate was approximately 85%. CONCLUSIONS: To meet these KDOQI guidelines, the VHA should continue to support the concept of dedicated AV HD teams and clinics. This is essential because the majority of our new AV fistulae required secondary intervention for AV fistulae maturation and use. A dedicated HD access team should better be able to assess AV fistula maturation and organize subsequent intervention to promote AV fistulae use.

Effect of goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum) supplementation on digoxin pharmacokinetics in humans.

Phytochemical-mediated modulation of P-glycoprotein (P-gp) and other drug transporters may give rise to many herb-drug interactions. Serial plasma concentration-time profiles of the P-gp substrate, digoxin, were used to determine whether supplementation with goldenseal or kava kava modified P-gp activity in vivo. Twenty healthy volunteers were randomly assigned to receive a standardized goldenseal (3210 mg daily) or kava kava (1227 mg daily) supplement for 14 days, followed by a 30-day washout period. Subjects were also randomized to receive rifampin (600 mg daily, 7 days) and clarithromycin (1000 mg daily, 7 days) as positive controls for P-gp induction and inhibition, respectively. Digoxin (Lanoxin, 0.5 mg) was administered p.o. before and at the end of each supplementation and control period. Serial digoxin plasma concentrations were obtained over 24 h and analyzed by chemiluminescent immunoassay. Comparisons of area under the curve (AUC)((0-3)), AUC((0-24)), C(max,) CL/F, and elimination half-life were used to assess the effects of goldenseal, kava kava, rifampin, and clarithromycin on digoxin pharmacokinetics. Rifampin produced significant reductions (p < 0.01) in AUC((0-3)), AUC((0-24)), CL/F, t(1/2), and C(max), whereas clarithromycin increased these parameters significantly (p < 0.01). With the exception of goldenseal's effect on C(max) (14% increase), no statistically significant effects on digoxin pharmacokinetics were observed following supplementation with either goldenseal or kava kava. When compared with rifampin and clarithromycin, supplementation with these specific formulations of goldenseal or kava kava did not appear to affect digoxin pharmacokinetics, suggesting that these supplements are not potent modulators of P-gp in vivo.

Sulfation of the isoflavones genistein and daidzein in human and rat liver and gastrointestinal tract.

Phytoestrogens, in particular the isoflavone aglycones genistein and daidzein, are thought to be the bioactive components of soy. Like estrogens, isoflavones can be sulfur-conjugated. However, although isoflavones in the serum are found largely in the form of glucuronide and sulfur conjugates following soy consumption, little is known regarding the relative contributions of sulfotransferases in the liver and small intestine to isoflavone sulfation. Since the sulfates may be deconjugated in target tissues, circulating isoflavone sulfates may act as a source of tissue aglycones. In the current study genistein and daidzein sulfotransferase activities were measured in cytosol from human and rat liver and gastrointestinal tract. Isoflavone sulfation in the human gastrointestinal (GI) tract was correlated with activities towards substrates for previously characterized human sulfotransferases. Western blots of human cytosols were also conducted using antisera towards human sulfotransferases SULT1E1 and SULT2A1. Whereas rat liver was almost fourfold more active than small intestine in sulfation of genistein, in the human, activities in the two tissues were comparable. In contrast, intestinal sulfation of daidzein was comparable to hepatic sulfation in the rat and significantly greater in the human. Genistein and daidzein sulfation occurred throughout the human GI tract, but with a different distribution and different interindividual variability. Whereas genistein sulfation in the human GI tract correlated significantly with sulfation of the prototypical human phenolic sulfotransferase SULT1A family substrate 2-naphthol (r2 = 0.71), daidzein sulfotransferase activity did not correlate with activities towards any prototypical sulfotransferase substrate or with genistein sulfation. Our results suggest that metabolism in the human GI tract has an important role in the generation of potentially bioactive isoflavone sulfates and a major role for the human phenolic sulfotransferase SULT1A family in metabolism of genistein in the gut. However, human intestinal daidzein sulfation appears to be catalyzed by a separate enzyme.

Differential expression of insulin-like growth factor binding protein-5 in pancreatic adenocarcinomas: identification using DNA microarray.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by its aggressiveness and resistance to both radiation and chemotherapeutic treatment. To better understand the molecular pathogenesis of pancreatic cancer, DNA array technology was employed to identify genes differentially expressed in pancreatic tumors when compared to non-malignant pancreatic tissues. RNA isolated from 11 PDACs and 14 non-malignant bulk pancreatic duct specimens was used to probe Affymetrix U95A DNA arrays. Genes that displayed at least a fourfold differential expression were identified and real-time quantitative PCR was used to verify the differential expression of selected upregulated genes. Interrogation of the DNA array revealed that 73 genes were upregulated in PDACs and 77 genes were downregulated. The majority of the 150 genes identified have not been previously reported to be differentially expressed in pancreatic tumors, although a number of the upregulated transcripts have been reported previously. Immunohistochemistry was used to correlate calponin and insulin-like growth factor binding protein-5 (IGFBP-5) RNA levels with protein expression in PDACs and revealed peritumoral calponin staining in the reactive stroma and intense focal staining of islets cells expressing IGFBP-5 at the edge of tumors; thus implicating the interplay of various cell types to promote neoplastic cell growth within pancreatic carcinomas. As a potential modulator of cell proliferation, the overexpression of IGFBP-5 may, therefore, play a significant role in the malignant transformation of normal pancreatic epithelial cells.

Effect of milk thistle (Silybum marianum) and black cohosh (Cimicifuga racemosa) supplementation on digoxin pharmacokinetics in humans.

Phytochemical-mediated modulation of P-glycoprotein (P-gp) and other drug transporters may underlie many herb-drug interactions. Serial serum concentration-time profiles of the P-gp substrate, digoxin, were used to determine whether supplementation with milk thistle or black cohosh modified P-gp activity in vivo. Sixteen healthy volunteers were randomly assigned to receive a standardized milk thistle (900 mg daily) or black cohosh (40 mg daily) supplement for 14 days, followed by a 30-day washout period. Subjects were also randomized to receive rifampin (600 mg daily, 7 days) and clarithromycin (1000 mg daily, 7 days) as positive controls for P-gp induction and inhibition, respectively. Digoxin (Lanoxicaps, 0.4 mg) was administered orally before and at the end of each supplementation and control period. Serial digoxin serum concentrations were obtained over 24 h and analyzed by chemiluminescent immunoassay. Comparisons of area under the serum concentration time curves from 0 to 3 h (AUC(0-3)), AUC(0-24), Cmax, apparent oral clearance of digoxin (CL/F), and elimination half-life were used to assess the effects of milk thistle, black cohosh, rifampin, and clarithromycin on digoxin pharmacokinetics. Rifampin produced significant reductions (p < 0.01) in AUC(0-3), AUC(0-24), and Cmax, whereas clarithromycin increased these parameters significantly (p < 0.01). Significant changes in digoxin half-life and CL/F were also observed with clarithromycin. No statistically significant effects on digoxin pharmacokinetics were observed following supplementation with either milk thistle or black cohosh, although digoxin AUC(0-3) and AUC(0-24) approached significance (p = 0.06) following milk thistle administration. When compared with rifampin and clarithromycin, supplementation with these specific formulations of milk thistle or black cohosh did not appear to affect digoxin pharmacokinetics, suggesting that these supplements are not potent modulators of P-gp in vivo.

The postoperative care of the adult renal transplant recipient.

Advances in transplantation immunology management have contributed to more frequent transplants and better long-term graft survival. Nurses must consider many issues facing the transplant recipient such as medication management, infection prevention, chronic disease management, fluid balance, urine output, and the many psychological issues that surround receiving a transplant. Important guidelines of care of complex transplant patients in the postoperative period are provided.

A history of the PACU.

The specialized intense nursing care provided in the PACU is now well recognized as crucial to optimize outcomes for the patient undergoing modern anesthesia and surgical techniques. However, this fact has not always been recognized. Although anesthetic techniques have evolved since the mid-1800s, the widespread establishment of PACUs only began about 50 years ago, shortly after World War II. This article provides an historical review of the development of the PACU in the United States.

Sirolimus-induced thrombotic microangiopathy in a renal transplant recipient.

A rare but well-documented serious adverse reaction to the administration of the calcineurin inhibitors tacrolimus and cyclosporine in renal transplant recipients is the development of medication-induced thrombotic microangiopathy. The recently introduced immunosuppressive medication sirolimus has a very similar molecular structure to tacrolimus and also binds to the same intracellular proteins. Despite these similarities with tacrolimus, sirolimus has a different side-effect profile and reportedly lacks documented specific renal toxicity. This is a case report of the isolated administration of sirolimus without a concomitant calcineurin inhibitor being associated with the development of renal transplant biopsy-proven thrombotic microangiopathy. The patient is a 47-year-old African-American woman whose primary cause of renal failure was not thrombotic micrangiopathy, and she received a 5-antigen mismatched cadaveric renal transplant. Because of preexisting nephrosclerosis in the renal transplant, this patient was never administered a calcineurin inhibitor but was always maintained on sirolimus. With recent animal data showing that sirolmus can be nephrotoxic in a renal ischemic-reperfusion model (similar to what happens with a renal transplant), the authors speculate on a mechanism for this adverse reaction.

The postanesthesia care of an adult renal transplant recipient.

Renal transplantation is the most common type of solid organ transplant performed in this country. For the PACU nurse, the immediate postoperative care of a renal transplant recipient can present a very unique and interesting challenge. Like all patients arriving to the PACU, the initial assessment of an immediate postoperative renal transplant recipient should first address the routine postsurgical concerns of airway, respiration, and hemodynamics. Most renal transplant programs have set protocols for the care required during the immediate posttransplant stay in the PACU. The postanesthesia nurse caring for these patients must become knowledgeable of these protocols. The following is a review of the immediate postanesthesia care for both the "fresh" renal transplant and the care of the long-term renal transplant recipient who has had surgery.

Successful management of a nonmalignant esophageal perforation with a coated stent.

This case report details our experience in the management of an iatrogenic perforation that recurred after two surgical repairs. A self-expanding coated stent was eventually placed to seal the esophageal perforation with significant improvement in the clinical condition of the patient. At 1-year follow-up, the patient is tolerating an oral diet with no evidence of esophageal leak or gastroesophageal reflux. This case report and a literature review suggest that self-expanding coated stents may be a useful salvage option in the management of inveterate nonmalignant esophageal perforations.