Expanding the Efflux In Vitro Assay Toolbox: A CRISPR-Cas9 Edited MDCK Cell Line with Human BCRP and Completely Lacking Canine MDR1

The Breast Cancer Resistance Protein (BCRP) is a key transporter in drug efflux and drug-drug interactions. However, endogenous expression of Multidrug Resistance Protein 1 (MDR1) confounds the interpretation of BCRP-mediated transport in in vitro models. Here we used a CRISPR-Cas9 edited Madin-Darby canine kidney (MDCK) II cell line (MDCK^cMDR1-KO) for stable expression of human BCRP (hBCRP) with no endogenous canine MDR1 (cMDR1) expression (MDCK-hBCRP^cMDR1-KO). Targeted quantitative proteomics verified expression of hBCRP, and global analysis of the entire proteome corroborated no or very low background expression of other drug transport proteins or metabolizing enzymes. This new cell line, had similar proteome like MDCK^cMDR1-KO and a previously established, corresponding cell line overexpressing human MDR1 (hMDR1), MDCK-hMDR1^cMDR1-KO. Functional studies with MDCK-hBCRP^cMDR1-KO confirmed high hBCRP activity. The MDCK-hBCRP^cMDR1-KO cell line together with the MDCK-hMDR1^cMDR1-KO easily and accurately identified shared or specific substrates of the hBCRP and the hMDR1 transporters. These cell lines offer new, improved in vitro tools for the assessment of drug efflux and drug-drug interactions in drug development.

Nonrelativistic and relativistic bound state solutions of the molecular Tietz potential via the improved asymptotic iteration method

We have obtained the approximate analytical solutions of the relativistic and nonrelativistic molecular Tietz potential using the improved asymptotic iteration method. By approximating the centrifugal term through the Greene–Aldrich approximation scheme, we have obtained the energy eigenvalues and wave functions for all orbital quantum numbers [Formula: see text]. Where necessary, we made comparison with the result obtained previously in the literature. The relative closeness of the two results reveal the accuracy of the method presented in this study. We proceed further to obtain the rotational-vibrational energy spectrum for some diatomic molecules. These molecules are CO, HCl, H2, and LiH. We have also obtained the relativistic bound state solution of the Klein−Gordon equation with this potential. In the nonrelativistic limits, our result converges to that of the Schrödinger system.

Osteonecrosis of the femoral head

Symptomatic hip osteonecrosis is a disabling condition with a poorly understood aetiology and pathogenesis. Numerous treatment options for hip osteonecrosis are described, which include non-operative management and joint preserving procedures, as well as total hip replacement (THR). Non-operative or joint preserving treatment may improve outcomes when an early diagnosis is made before the lesion has become too large or there is radiographic evidence of femoral head collapse. The presence of a crescent sign, femoral head flattening, and acetabular involvement indicate a more advanced-stage disease in which joint preserving options are less effective than THR. Since many patients present after disease progression, primary THR is often the only reliable treatment option available. Prior to the 1990s, outcomes of THR for osteonecrosis were poor. However, according to recent reports and systemic reviews, it is encouraging that with the introduction of newer ceramic and/or highly cross-linked polyethylene bearings as well as highly-porous fixation interfaces, THR appears to be a reliable option in the management of end-stage arthritis following hip osteonecrosis in this historically difficult to treat patient population.

Cite this article: Bone Joint J 2013;95-B, Supple A:46–50.

Effectiveness of ERCP in cholangitis: a community-based study

BACKGROUND

Although experts have demonstrated the efficacy of endoscopic retrograde cholangiopancreatography (ERCP) in cholangitis, the effectiveness of ERCP in unselected patients has not been measured. The aim was to investigate the clinical impact of ERCP performed at any time and of early ERCP (within 24 hours of admission) in patients with a primary discharge diagnosis of cholangitis.

METHODS

A retrospective record review of patients admitted to eight area hospitals with an International Classification of Diseases (ICD)-9 diagnosis consistent with cholangitis was performed. Extracted data included clinical characteristics, ERCP findings, and patient outcome. The associations of ERCP overall and early ERCP with length of stay were examined. Confounding factors including severity of illness, etiology of cholangitis, and hospital type were adjusted for in a multivariate analysis.

RESULTS

A total of 116 patients were studied. ERCP was performed in 71 patients with endoscopic therapy administered in 57 (80%). ERCP overall was not associated with any change in length of hospital stay. However, compared with other invasive biliary procedures, ERCP was associated with a shorter hospital stay (median 5 vs. 9.5 days, p = 0.01) and a 36% (95% CI [5%, 57%]) reduction in severity-adjusted length of stay. Patients who had early ERCP had a significantly shorter hospital stay than those who had delayed ERCP (median 4 vs. 7 days, p < 0.005) and early ERCP was associated with a 34% (95% CI [11%, 48%]) reduction in severity-adjusted length of stay.

CONCLUSION

Early ERCP may be an effective strategy for shortening the length of stay in patients hospitalized with cholangitis.

Pretreatment with methylprednisolone to prevent ERCP-induced pancreatitis: a randomized, multicenter, placebo-controlled clinical trial

OBJECTIVE

Pancreatitis remains the major complication of endoscopic retrograde cholangiopancreatography (ERCP). Uncontrolled data suggest a lower incidence of pancreatitis in patients with a history of iodine sensitivity when given pretreatment with corticosteroids. We conducted a clinical trial to assess the efficacy of a commonly prescribed corticosteroid, methylprednisolone, to prevent ERCP-induced pancreatitis.

METHODS

Patients were entered into a randomized, multicenter, double-blind, placebo-controlled study of intravenous methylprednisolone (125 mg) versus a saline placebo immediately before the ERCP. All patients were evaluated for early and late complications.

RESULTS

Two hundred eighty-six patients were randomized. Thirty-one randomized patients were excluded for technical reasons at the time of ERCP. Overall, the incidence of pancreatitis was 16 of 129 (12.4%, 95% CI: 6.7-18.1%) in the methylprednisolone group and 11 of 126 (8.7%, 95% CI: 4.4-15.1%) in the placebo group, which was not significantly different (p = 0.34). Although there was a higher rate of sphincterotomy performed in the methylprednisolone group compared to the control group (31.8% vs 16.8%, p = 0.005), the incidence of pancreatitis was not different when patients undergoing sphincterotomy were analyzed separately (13.6% in the methylprednisolone group and 9.6% in the placebo group,p = 0.50). There was no significant difference between the two groups for those with ERCP-induced pancreatitis in hospital length of stay (p = 0.22), days of parenteral analgesia (p = 0.09), or days of parenteral nutrition (p = 0.15).

CONCLUSION

Intravenous methylprednisolone is not beneficial in preventing ERCP-induced pancreatitis.

Large-cell carcinoma of the lung. With major bleeding and intussusception

We describe an unusual case of major small-bowel bleeding and intussusception due to jejunal metastases from a large-cell type carcinoma of the lung. Review of the surprisingly frequent case reports of small bowel metastases from primary lung tumors indicates that there is only one prior case report of intussusception and that ours is the first description of major intestinal hemorrhage due to metastatic pulmonary carcinoma.