Ectopic expression of neurogenin 3 in neonatal pig pancreatic precursor cells induces (trans)differentiation to functional alpha cells

AIMS/HYPOTHESIS

Neurogenin 3 (NEUROG3), a basic helix-loop-helix transcription factor that is needed for endocrine cell development in the embryonic pancreas, has been shown to induce transdifferentiation of duct cells from adult pancreas towards a neuro-endocrine phenotype. Our study explored the endocrine transdifferentiation potential of NEUROG3 in neonatal pancreatic precursor cells.

MATERIALS AND METHODS

A replication-deficient adenovirus expressing Neurog3 and green fluorescent protein (GFP) (Ad-NEUROG3) was used to infect neonatal pig pancreatic cell preparations enriched for endocrine islet and cytokeratin-positive precursor cells. GFP-positive cells were sorted using flow cytometry on days 3 and 8 after infection and characterised at the transcript and protein level. For in vivo experiments, the total population of Ad-NEUROG3-infected pancreatic cells was transplanted, then later removed for determination of graft hormone content and immunohistochemistry.

RESULTS

Among the GFP-positive cells, the fraction of precursor cells decreased by more than 85% at day 8 after infection, while the fraction of glucagon-positive cells increased 2.5-fold and the beta cell number remained the same. Transplantation of the Ad-NEUROG3-infected pancreatic cell preparation failed to reverse streptozotocin-induced hyperglycaemia, while non-infected cells and a control cell preparation infected with replication-deficient adenovirus expressing only GFP were able to do so. At day 109 after transplantation, kidneys grafted with Ad-NEUROG3-infected pancreatic cells contained significantly decreased insulin and increased glucagon levels. Abundant glucagon-immunopositive cells were seen in Ad-NEUROG3-infected grafts, which were virtually devoid of proliferating insulin-positive cells.

CONCLUSIONS/INTERPRETATION

In summary, adenoviral delivery of NEUROG3 to pancreatic precursor cells from neonatal pig pancreas promotes alpha cell differentiation in vitro and in vivo.

Comparison of quality of life, work productivity and medical resource utilization of peginterferon alpha 2a vs the combination of interferon alpha 2b plus ribavirin as initial treatment in patients with chronic hepatitis C

The on-treatment impact of interferon-based therapies on quality of life (QOL), work productivity, and medical resource utilization has not been systematically studied. We evaluated the effects of treatment with peginterferon alpha (pegIFNalpha) 2a monotherapy and the combination of interferon alpha (IFNalpha) 2b plus ribavirin (RBV) on health-related QOL, work productivity and resource utilization. A total of 412 patients with hepatitis C infection were randomized to open-label treatment with either pegIFNalpha 2a (n = 206) or IFNalpha 2b/RBV (n = 206). PegIFNalpha 2a was administered subcutaneously at a dose of 180 microg once weekly for 48 weeks; and IFNalpha 2b/RBV at doses of 3 MU thrice weekly subcutaneously and 1000-1200 mg/day orally. Outcome measures included the SF-36 Health Survey Questionnaire and additional generic and specific scales. During treatment, for all SF-36 summary and Hepatitis Quality of Life Questionnaire (HQLQ)-specific scales, the pegIFNalpha 2a group experienced less impairment than did the IFNalpha 2b/RBV patients. The between-treatment differences were significant for many of the scores particularly in the first 24 weeks of treatment. Across all measures of work functioning and productivity at each visit, patients randomized to pegIFNalpha 2a treatment showed less impairment relative to the group treated with IFNalpha 2b/RBV. Hence treatment with pegIFNalpha 2a relative to IFNalpha 2b/RBV minimizes the adverse impact of therapy on health-related QOL. Patients randomized to pegIFNalpha 2a had improved work productivity, less activity impairment, decreased need for prescription drugs to treat adverse effects, and better adherence to therapy.

A comparison of hepatitis C treatment and outcomes at academic, private and Veterans' Affairs treatment centres

BACKGROUND

Currently, there is a lack of published data examining hepatitis C treatment practices in different care settings.

AIM

To provide data describing treatment practices for patients with hepatitis C virus infection in actual clinical practice, and to examine clinical outcomes in patients treated with interferon alpha-2b/ribavirin combination therapy in academically affiliated centres, private treatment centres and Veterans' Affairs treatment centres.

METHODS

This multi-centre, retrospective, cohort study of 231 patients examined hepatitis C virus treatment practices in patients receiving interferon alpha-2b from January 1997 to May 2001 and explored outcomes in academically affiliated, private and Veterans' Affairs centres.

RESULTS

Differences in treatment practice and use of diagnostic procedures were found. Genotype testing was under-utilized in non-academic sites (academic centres, 79.2%; private centres, 33.7%; Veterans' Affairs centres, 35.9%; P<0.001). Liver biopsies were performed less often in private sites (academic centres, 95.8%; private centres, 80.0%; Veterans' Affairs centres, 92.2%; P<0.01). End-of-treatment viral response (academic centres, 40.0%; private centres, 31.3%; Veterans' Affairs centres, 17.2%; P<0.05) was lower than that found in published trial data. Multivariate analysis revealed genotype 1 as the single significant predictor of treatment failure (P<0.01).

CONCLUSIONS

Outside of the academic setting, there is significantly less diagnostic work-up performed prior to the initiation of hepatitis C virus therapy. This suggests a need for a standardization of care across treatment settings.

Lack of hepatotoxic effects of parenteral ketorolac in the hospital setting

BACKGROUND

No large controlled studies to date have examined the hepatic safety of parenteral ketorolac, which is used to treat acutely ill hospitalized patients who may be at greatest risk of liver injury.

OBJECTIVE

To measure the association between the use of parenteral ketorolac and subsequent liver injury.

METHODS

A nonexperimental cohort study conducted in 35 hospitals in the greater Philadelphia, Pa, region examined 10,272 courses of parenteral ketorolac (the exposed group) and 10,247 courses of parenteral opioid (the comparison group). Liver injury was defined by a modified international consensus definition that relied exclusively on liver function tests. Proportional hazards regression was used to calculate the rate ratio and 95% confidence interval for the association between ketorolac exposure and the occurrence of liver injury, controlling for potentially confounding factors, and to explore the possible effects of duration and dose.

RESULTS

The incidence of liver injury was 1.0% in the ketorolac group and 1.2% in the opioid group, yielding an unadjusted rate ratio of 0.77 (95% confidence interval, 0.59 1.01). Simultaneously adjusting for multiple potentially confounding factors did not change this result. There was no evidence for a duration-response relationship (P = .96) or a dose-response relationship (P = .23). We were unable to identify any subgroups that were susceptible to possible hepatotoxic effects of parenteral ketorolac.

CONCLUSIONS

This study failed to find evidence of a hepatotoxic effect of parenteral ketorolac use in the hospital setting and provides strong evidence against the existence of a clinically meaningful association between exposure to parenteral ketorolac in the hospital setting and liver injury.

Central venous catheter infections in AIDS patients receiving treatment for cytomegalovirus disease

Central venous catheters (CVC) are commonly used to deliver daily intravenous medications to patients with AIDS, and CVC-associated bacterial infections have been a cause of substantial morbidity in such patients. Although previous studies have reported rates of CVC-associated infections in AIDS patients, none has compared rates by type of intravenous drug regimen used or by whether CVCs were percutaneously placed or tunneled under the skin. The charts of all AIDS patients diagnosed with cytomegalovirus (CMV) end-organ disease at San Francisco General Hospital between 1985 and 1990 were reviewed for evidence of CVC use and CVC-associated infection. Infection rates and time to infection were analyzed for serious CVC-associated infections (requiring catheter removal or hospitalization for intravenous antibiotic therapy) by type of anti-CMV therapy administered (ganciclovir versus foscarnet) and by type of CVC (tunneled versus percutaneous placement). Fifty-four patients had 72 CVCs in use for 11,622 days of intravenous anti-CMV therapy. There were 36 CVC-associated infections of which 23 were categorized as serious (rate, 0.20/100 catheter days). In patients receiving either ganciclovir or foscarnet therapy, we found no significant difference in serious infection rates or in infection-free survival time (216 vs. 282 days, p = 0.7). However, serious CVC infection-free time was significantly longer in patients with tunneled than with percutaneous CVCs (419 vs. 195 days, p = 0.018). The use of ganciclovir compared to foscarnet in the treatment of AIDS-related CMV disease was not associated with a greater risk of serious catheter-related infection.(ABSTRACT TRUNCATED AT 250 WORDS)