Biochemical characterization of P4-ATPase mutations identified in patients with progressive familial intrahepatic cholestasis.

Mutations in the P4-ATPase ATP8B1 cause the inherited liver disease progressive familial intrahepatic cholestasis. Several of these mutations are located in conserved regions of the transmembrane domain associated with substrate binding and transport. Assays for P4-ATPase-mediated transport in living yeast cells were developed and used to characterize the specificity and kinetic parameters of this transport. Progressive familial intrahepatic cholestasis mutations were introduced into the yeast plasma membrane P4-ATPase Dnf2p, and the effect of these mutations on its catalysis of phospholipid transport were determined. The results of these measurements have implications for the basis of the disease and for the mechanism of phospholipid transit through the enzyme during the reaction cycle.

Assessing the value of routine upper gastrointestinal contrast studies following bariatric surgery: a systematic review and meta-analysis.

BACKGROUND: Understanding both the efficacy of upper gastrointestinal (UGI) contrast studies and the factors that impact their accuracy is necessary to optimize postoperative imaging protocols. However, a consensus as to the value of UGI performed after bariatric surgery remains elusive. The objective was to determine the sensitivity and specificity of UGI conducted routinely within 2 days after bariatric surgery for detecting anastomotic leaks. METHODS: We conducted an electronic search of MEDLINE for all English language articles published between 2003 and 2013 concerning diagnostic imaging after bariatric surgery. Nineteen studies evaluating a total of 10,139 patients met the inclusion criteria. The methodological quality of each included study was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 procedure. RESULTS: UGI has an overall sensitivity of .54 and a specificity of 1.00. The standard deviation of the reported sensitivities was .36. Positive and negative predictive values were .67 and .98, respectively. Sensitivity and specificity were negatively correlated. CONCLUSIONS: The sensitivity of UGI for detecting the presence of anastomotic leaks within 2 days of bariatric surgery is moderate overall but fluctuates substantially. The negative correlation between sensitivity and specificity could indicate that the threshold used to distinguish between positive and negative test results varies between institutions. Accordingly, clinicians may consider shifting the threshold for declaring a UGI positive; treating marginal radiological evidence of leakage as presumptively positive may be a simple way to lower specificity, increase sensitivity, and in turn maximize UGI's clinical value.

Primary human cervical carcinoma cells require human papillomavirus E6 and E7 expression for ongoing proliferation.

Repression of human papillomavirus (HPV) E6 and E7 oncogenes in established cervical carcinoma cell lines causes senescence due to reactivation of cellular tumor suppressor pathways. Here, we determined whether ongoing expression of HPV16 or HPV18 oncogenes is required for the proliferation of primary human cervical carcinoma cells in serum-free conditions at low passage number after isolation from patients. We used an SV40 viral vector expressing the bovine papillomavirus E2 protein to repress E6 and E7 in these cells. To enable efficient SV40 infection and E2 gene delivery, we first incubated the primary cervical cancer cells with the ganglioside GM1, a cell-surface receptor for SV40 that is limiting in these cells. Repression of HPV in primary cervical carcinoma cells caused them to undergo senescence, but the E2 protein had little effect on HPV-negative primary cells. These data suggest that E6 and E7 dependence is an inherent property of human cervical cancer cells.