Degree of Glomerulosclerosis in Procurement Kidney Biopsies from Marginal Donor Kidneys and Their Implications in Predicting Graft Outcomes.

Background: This study aimed to assess the association between the percentage of glomerulosclerosis (GS) in procurement allograft biopsies from high-risk deceased donor and graft outcomes in kidney transplant recipients. Methods: The UNOS database was used to identify deceased-donor kidneys with a kidney donor profile index (KDPI) score > 85% from 2005 to 2014. Deceased donor kidneys were categorized based on the percentage of GS: 0-10%, 11-20%, >20% and no biopsy performed. The outcome included death-censored graft survival, patient survival, rate of delayed graft function, and 1-year acute rejection. Results: Of 22,006 kidneys, 91.2% were biopsied showing 0-10% GS (58.0%), 11-20% GS (13.5%), >20% GS (19.7%); 8.8% were not biopsied. The rate of kidney discard was 48.5%; 33.6% in 0-10% GS, 68.9% in 11-20% GS, and 77.4% in >20% GS. 49.8% of kidneys were discarded in those that were not biopsied. Death-censored graft survival at 5 years was 75.8% for 0-10% GS, 70.9% for >10% GS, and 74.8% for the no biopsy group. Among kidneys with >10% GS, there was no significant difference in death-censored graft survival between 11-20% GS and >20% GS. Recipients with >10% GS had an increased risk of graft failure (HR = 1.27, p < 0.001), compared with 0-10% GS. There was no significant difference in patient survival, acute rejection at 1-year, and delayed graft function between 0% and 10% GS and >10% GS. Conclusion: In >85% KDPI kidneys, our study suggested that discard rates increased with higher percentages of GS, and GS >10% is an independent prognostic factor for graft failure. Due to organ shortage, future studies are needed to identify strategies to use these marginal kidneys safely and improve outcomes.

Na+/Taurocholate Cotransporting Polypeptide and Apical Sodium-Dependent Bile Acid Transporter Are Involved in the Disposition of Perfluoroalkyl Sulfonates in Humans and Rats.

Among the perfluoroalkyl sulfonates (PFASs), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) have half-lives of several years in humans, mainly due to slow renal clearance and potential hepatic accumulation. Both compounds undergo enterohepatic circulation. To determine whether transporters involved in the enterohepatic circulation of bile acids are also involved in the disposition of PFASs, uptake of perfluorobutane sulfonate (PFBS), PFHxS, and PFOS was measured using freshly isolated human and rat hepatocytes in the absence or presence of sodium. The results demonstrated sodium-dependent uptake for all 3 PFASs. Given that the Na(+)/taurocholate cotransporting polypeptide (NTCP) and the apical sodium-dependent bile salt transporter (ASBT) are essential for the enterohepatic circulation of bile acids, transport of PFASs was investigated in stable CHO Flp-In cells for human NTCP or HEK293 cells transiently expressing rat NTCP, human ASBT, and rat ASBT. The results demonstrated that both human and rat NTCP can transport PFBS, PFHxS, and PFOS. Kinetics with human NTCP revealed Km values of 39.6, 112, and 130 µM for PFBS, PFHxS, and PFOS, respectively. For rat NTCP Km values were 76.2 and 294 µM for PFBS and PFHxS, respectively. Only PFOS was transported by human ASBT whereas rat ASBT did not transport any of the tested PFASs. Human OSTα/ß was also able to transport all 3 PFASs. In conclusion, these results suggest that the long half-live and the hepatic accumulation of PFOS in humans are at least, in part, due to transport by NTCP and ASBT.

Mechanisms of acetaminophen-induced cell death in primary human hepatocytes.

UNLABELLED: Acetaminophen (APAP) overdose is the most prevalent cause of drug-induced liver injury in western countries. Numerous studies have been conducted to investigate the mechanisms of injury after APAP overdose in various animal models; however, the importance of these mechanisms for humans remains unclear. Here we investigated APAP hepatotoxicity using freshly isolated primary human hepatocytes (PHH) from either donor livers or liver resections. PHH were exposed to 5mM, 10mM or 20mM APAP over a period of 48 h and multiple parameters were assessed. APAP dose-dependently induced significant hepatocyte necrosis starting from 24h, which correlated with the clinical onset of human liver injury after APAP overdose. Interestingly, cellular glutathione was depleted rapidly during the first 3h. APAP also resulted in early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria) and mitochondrial dysfunction, indicated by the loss of mitochondrial membrane potential after 12h. Furthermore, APAP time-dependently triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria. Both co-treatment and post-treatment (3h) with the JNK inhibitor SP600125 reduced JNK activation and significantly attenuated cell death at 24h and 48h after APAP. The clinical antidote N-acetylcysteine offered almost complete protection even if administered 6h after APAP and a partial protection when given at 15 h. CONCLUSION: These data highlight important mechanistic events in APAP toxicity in PHH and indicate a critical role of JNK in the progression of injury after APAP in humans. The JNK pathway may represent a therapeutic target in the clinic.

Protein expression profiling of nuclear membrane protein reveals potential biomarker of human hepatocellular carcinoma.

BACKGROUND: Complex molecular events lead to development and progression of liver cirrhosis to HCC. Differentially expressed nuclear membrane associated proteins are responsible for the functional and structural alteration during the progression from cirrhosis to carcinoma. Although alterations/ post translational modifications in protein expression have been extensively quantified, complementary analysis of nuclear membrane proteome changes have been limited. Deciphering the molecular mechanism that differentiate between normal and disease state may lead to identification of biomarkers for carcinoma. RESULTS: Many proteins displayed differential expression when nuclear membrane proteome of hepatocellular carcinoma (HCC), fibrotic liver, and HepG2 cell line were assessed using 2-DE and ESI-Q-TOF MS/MS. From the down regulated set in HCC, we have identified for the first time a 15 KDa cytochrome b5A (CYB5A), ATP synthase subunit delta (ATPD) and Hemoglobin subunit beta (HBB) with 11, 5 and 22 peptide matches respectively. Furthermore, nitrosylation studies with S-nitrosocysteine followed by immunoblotting with anti SNO-cysteine demonstrated a novel and biologically relevant post translational modification of thiols of CYB5A in HCC specimens only. Immunofluorescence images demonstrated increased protein S-nitrosylation signals in the tumor cells and fibrotic region of HCC tissues. The two other nuclear membrane proteins which were only found to be nitrosylated in case of HCC were up regulated ATP synthase subunit beta (ATPB) and down regulated HBB. The decrease in expression of CYB5A in HCC suggests their possible role in disease progression. Further insight of the functional association of the identified proteins was obtained through KEGG/ REACTOME pathway analysis databases. String 8.3 interaction network shows strong interactions with proteins at high confidence score, which is helpful in characterization of functional abnormalities that may be a causative factor of liver pathology. CONCLUSION: These findings may have broader implications for understanding the mechanism of development of carcinoma. However, large scale studies will be required for further verification of their critical role in development and progression of HCC.

Two-channel gastric pacing in patients with diabetic gastroparesis.

BACKGROUND: Our primary goals were to investigate the effects of two-channel gastric pacing on gastric myoelectrical activity, and energy consumption with the secondary intent to monitor gastric emptying and symptoms in patients with severe diabetic gastroparesis. METHODS: Four pairs of temporary pacing wires were inserted on the serosa of the stomach at the time of laparotomy to place the Enterra™ System in 19 patients with severe gastroparesis not responding to standard medical therapies. Two of the pairs were for electrical stimulation and the other two for recording. Five days after surgery the optimal pacing parameters for the entrainment of gastric slow waves in each patient were identified by serosal recordings. Two-channel gastric pacing was then initiated for 6 weeks using a newly developed external multi-channel pulse generator. Electrogastrogram (EGG), Total Symptom Score (TSS), and a 4-h gastric emptying test were assessed at baseline and after 6 weeks of active gastric pacing. Enterra™ device was turned OFF during the duration of this study. KEY RESULTS: Two-channel gastric pacing at 1.1 times the intrinsic frequency entrained gastric slow waves and normalized gastric dysrhythmia. After 6 weeks of gastric pacing, tachygastria was decreased from 15 ± 3 to 5 ± 1% in the fasting state and from 10 ± 2 to 5 ± 1% postprandially (P < 0.05), mean TSS was reduced from 21.3 ± 1.1 to 7.0 ± 1.5 (P < 0.05) and mean 4-h gastric retention improved from 42 to 28% (P = 0.05). CONCLUSIONS & INFERENCES: Two-channel gastric pacing is a novel treatment approach which is able to normalize and enhance gastric slow wave activity as well as accelerate gastric emptying in patients with diabetic gastroparesis with a goal safety profile.

Myxoid leiomyosarcoma of the liver.

This is the first report of a myxoid leiomyosarcoma arising in a cirrhotic liver. The tumor was resected from a 64-year-old man. On gross examination, it was soft and hemorrhagic. The tumor was composed of deceptively benign-looking smooth muscle cells with clear cytoplasm suspended in a myxoid stroma with foci of hemorrhage. Immunohistochemistry and electron microscopy confirmed that this was a smooth muscle cell neoplasm. The abundance of glycogen and ultrastructural signs of smooth muscle differentiation were considered consistent with an immature smooth muscle cell phenotype consistent with the diagnosis of myxoid leiomyosarcoma. Since myxoid leiomyosarcomas are aggressive tumors, it is important to recognize them histologically and also bear in mind that these tumors can occur even in unusual extrauterine locations such as a cirrhotic liver.

Mechanisms of high-frequency electrical stimulation of the stomach in gastroparetic patients.

Previous studies have demonstrated that high frequency and low energy gastric electrical stimulation (GES) reduced nausea and vomiting in gastroparetic patients without improving gastric emptying. The mechanisms of action for this have not been clarified. The aim of our study was to investigate the effects of GES on autonomic function, gastric distention and tone, and central control mechanism in gastroparetics patients. 10 gastroparetic patients refractory to standard medical therapy participated in this study and data were collected at baseline session, within two weeks before surgery for implantation of GES system, and at follow-up sessions between 6 to 12 weeks after GES therapy. In each session, electrocardiogram and gastric barostat measurements were conducted before and after a caloric liquid meal. Positron Emission Tomography (PET) brain scans were performed on a separate day. Analysis of autonomic function was accomplished through power spectral analysis of heart rate variability which revealed that the sympthovagal balance was significantly decreased after GES therapy, indicating a significant increase in vagal activity. Results from gastric barostat measurements demonstrated that during GES there was a significant increase in the discomfort threshold for both pressure and volume. Quantitative analysis of PET imaged cerebral activity showed that chronic GES increased thalamic activity. This study suggests that the symptomatic efficacy achieved by GES may be partly attributed to enhanced vagal autonomic function, decreasing gastric sensitivity to volume distention which simulates a postprandial adaptation and the activation of central control mechanisms for nausea and vomiting through thalamic pathways during GES.

Fibrolamellar hepatocellular carcinoma arising in a background of focal nodular hyperplasia: a report of 2 cases.

BACKGROUND: Fibrolamellar carcinoma, a rare variant of hepatocellular carcinoma, and focal nodular hyperplasia, a benign lesion, are rare hepatic lesions that are known to occur in young women with noncirrhotic livers. Some have suggested that fibrolamellar carcinoma might be the malignant counterpart of focal nodular hyperplasia. The coexistence of the 2 lesions is very rare. CASES: Two cases of fibrolamellar hepatocellular carcinoma arising in a background of focal nodular hyperplasia followed long-term oral contraception, and 1 of the 2 occurred during pregnancy. CONCLUSION: Distinguishing fibrolamellar carcinoma from focal nodular hyperplasia has important implications for treatment and prognosis. One should be aware of such conditions, especially in patients with a long history of oral contraception.

Chronic gastric electrical stimulation for gastroparesis reduces the use of prokinetic and/or antiemetic medications and the need for hospitalizations.

To investigate the effect of chronic gastric electrical stimulation (GES) on the daily use of prokinetics and antiemetics, hospitalizations, total symptom score (TSS), SF-36 status for health-related quality of life (HQOL), and gastric emptying of a solid meal, we evaluated 37 gastroparetic patients preoperatively and 1 year after undergoing GES implant. Prokinetic and antiemetic use was significantly reduced. Of 27 patients on at least one prokinetic at baseline, 8 were off at 1 year. Twenty-six patients requiring antiemetics before surgery decreased to 17. Mean TSS was significantly reduced and the reduction for patients off medications was significantly better than for patients still on medications. Overall SF-36 scores for HQOL were significantly improved, and patients off antiemetics had a significantly higher HQOL score than for patients on antiemetics at 1 year. Hospitalizations decreased from 50 +/- 10 days for the year prior to GES therapy to 14 +/- 3 days (P < 0.05). However, gastric emptying was not significantly improved. Conclusions are as follows. (1) Chronic GES significantly reduced the use of prokinetic/antiemetic medications and the need for hospitalization in gastropraretic patients, whose clinical and quality of life outcomes also significantly improved. (2) These data provide evidence of the positive economic impact of this new therapy on long-term clinical outcomes in gastroparetic patients not responding to standard medical therapy.

Absence of the interstitial cells of Cajal in patients with gastroparesis and correlation with clinical findings.

The interstitial cells of Cajal (ICCs) are fundamental in the generation of gastric slow waves. The role of these cells in gastroparesis has not been established. We studied 14 gastroparetic patients (9 diabetic, 4 idiopathic, and 1 postsurgical) for whom standard medical therapy had failed and who had been treated with a gastric electrical stimulator for at least 3 months. All patients had a full-thickness antral gastric wall biopsy at the time of surgery. The biopsy samples were stained with c-kit and scored for the presence of ICCs. Baseline electrogastrogram recordings were obtained for 30 minutes in the fasting state and for 2 hours after a test meal. The patients assessed their total symptom score at baseline and at 3 months. Five patients had almost no ICCs and were compared with nine patients with 20% to normal cell numbers. Both groups did respond symptomatically to gastric electrical stimulation. However, patients with depleted ICCs had significantly more tachygastria and had significantly greater total symptom scores at baseline and after 3 months of gastric electrical stimulation. ICCs are absent in some patients (up to a third) with diabetic or idiopathic gastroparesis, and the absence of these cells is associated with abnormalities of gastric slow waves, worse symptoms, and less improvement with gastric electrical stimulation.

Further experience with gastric stimulation to treat drug refractory gastroparesis.

BACKGROUND: Gastric electrical stimulation (GES) has been introduced for patients with gastroparesis refractory to pharmacological therapy. METHODS: From April 1998 until November 2001, 55 patients underwent GES implantation at Kansas University Medical Center. All patients had prolonged gastric retention of a solid meal by scintigraphy at baseline. The etiologies were diabetes mellitus in 39, related to previous surgery in 9, and idiopathic in 7. Symptoms were graded using a 5-point scale and quality of life was assessed with the SF-36 questionnaire. Body mass index and nutritional parameters were monitored. Hemoglobin A1C was measured in the diabetic patients. RESULTS: Total symptom scores and the physical and mental composite scores of quality of life improved significantly. On average, gastric emptying did not change. Body mass index and body weight increased significantly. And days spent in hospital admissions were significantly decreased. At 1 year, diabetic patients experienced reduced hemoglobin A1C. Four devices were removed. One patient died of a pulmonary embolus postoperatively. CONCLUSIONS: In a large series of patients with gastroparesis, GES significantly improved symptoms and quality of life.

Primary malignant gastrointestinal stromal tumor of the liver.

We report the case of a malignant, primary, hepatic gastrointestinal stromal tumor (GIST) that was resected from the liver of a 79-year-old woman. To our knowledge, this is the first primary, hepatic GIST on record. The tumor expressed CD117 (c-Kit protein) and vimentin and had the ultrastructural features of GISTs. Sixteen months after partial hepatectomy and resection of the tumor, a hilar lymph node metastasis was found. The metastatic tumor had the same morphologic features as the primary tumor, but in addition it contained numerous multinucleated giant cells. This case shows that GIST can occur as a primary liver tumor, and accordingly, we point out that not all hepatic tumors with a GIST phenotype should be automatically considered to be metastases from a primary gastrointestinal site.

Effects of prototypical microsomal enzyme inducers on cytochrome P450 expression in cultured human hepatocytes.

Cultured human hepatocytes are a valuable in vitro system for evaluating new molecular entities as inducers of cytochrome P450 (P450) enzymes. The present study summarizes data obtained from 62 preparations of cultured human hepatocytes that were treated with vehicles (saline or dimethylsulfoxide, 0.1%), beta-naphthoflavone (33 microM), phenobarbital (100 or 250 microM), isoniazid (100 microM) and/or rifampin (20 or 50 microM), and examined for the expression of P450 enzymes based on microsomal activity toward marker substrates, or in the case of CYP2C8, the level of immunoreactive protein. The results show that CYP1A2 activity was markedly induced by beta-naphthoflavone (on average 13-fold, n = 28 preparations), and weakly induced by phenobarbital (1.9-fold, n = 25) and rifampin (2.3-fold, n = 22); CYP2A6 activity tended to be increased with phenobarbital (n = 7) and rifampin (n = 3) treatments, but the effects were not statistically significant; CYP2B6 was induced by phenobarbital (6.5-fold, n = 13) and rifampin (13-fold, n = 14); CYP2C8 was induced by phenobarbital (4.0-fold, n = 4) and rifampin (5.2-fold, n = 4); CYP2C9 was induced by phenobarbital (1.8-fold, n = 14) and rifampin (3.5-fold, n = 10); CYP2C19 was markedly induced by rifampin (37-fold, n = 10), but relatively modestly by phenobarbital (7-fold, n = 9); CYP2D6 was not significantly induced by phenobarbital (n = 5) or rifampin (n = 5); CYP2E1 was induced by phenobarbital (1.7-fold, n = 5), rifampin (2.2-fold, n = 5), and isoniazid (2.3-fold, n = 5); and, CYP3A4 was induced by phenobarbital (3.3-fold, n = 42) and rifampin (10-fold, n = 61), but not by beta-naphthoflavone. Based on these observations, we generalize that beta-naphthoflavone induces CYP1A2 and isoniazid induces CYP2E1, whereas rifampin and, to a lesser extent phenobarbital, tend to significantly and consistently induce enzymes of the CYP2A, CYP2B, CYP2C, CYP2E, and CYP3A subfamilies but not the 2D subfamily.

The treatment of gastroparesis in the age of the gastric pacemaker: a review.

Gastroparesis is a chronic disabling condition of impaired gastric motility that results in decreased quality of life. Currently available medical therapy consists of prokinetic medication combined with antiemetic therapy, dietary modifications, and nutritional supplementation. Many patients continue to have a suboptimal clinical response despite maximal use of these modalities. Instead of surgery, which involves irreversible stomach-modifying procedures, gastric electrical stimulation (GES) with a high-frequency/low-energy stimulus was approved by the US Food and Drug Administration (FDA) and can now be used in this setting. This approach has been shown to decrease symptom frequency and severity, reduce hospitalizations and medical costs, and improve quality of life. Occurrence of complications with this device are uncommon (< 5% of patients). Preliminary studies of new gastric stimulators that restore gastric contractility are promising, but additional investigation is needed. This article reviews the pathophysiology and epidemiology of gastroparesis and the role of conventional medical therapies, and discusses GES therapy with respect to its mechanisms of action, appropriate application, results and benefits, and future directions.

EUS guidance in gastric pacemaker implantation.

BACKGROUND: EUS provides excellent imaging of the gastric wall. The utility of EUS imaging in guiding the placement of a gastric pacemaker was investigated. METHODS: Fourteen patients underwent gastric pacemaker implantation for refractory gastroparesis at laparotomy. Placement of the lead into the muscle layer of the antrum of the stomach was imaged by intraoperative surface ultrasonography in the first 8 patients and by EUS in the subsequent 6 patients. RESULTS: Surface US examination of the lead placement revealed reverberation artifacts. The images were uniformly unsatisfactory and the position of the lead in the gastric wall could not be visualized in any patient. In contrast, the lead was clearly and easily identified by EUS as a bright linear echo in the gastric wall. This was observed uniformly in all of the patients evaluated by EUS. Compared with surface US, EUS provided better images of the gastric lead placement as well as less abdominal distension and thus easier closure of the incision. CONCLUSIONS: EUS is useful in confirming the accurate placement of pacemaker leads within the muscular coat of the stomach.