Re-engineered p53 activates apoptosis in vivo and causes primary tumor regression in a dominant negative breast cancer xenograft model

Inactivation of p53 pathway is reported in more than half of all human tumors and can be correlated to malignant development. Missense mutation in the DNA binding region (DBD) of p53 is the most common mechanism of p53 inactivation in cancer cells. The resulting tumor-derived p53 variants, similar to wild-type (wt) p53, retain their ability to oligomerize via the tetramerization domain (TD). Upon hetero-oligomerization, mutant p53 enforces a dominant negative effect over active wt-p53 in cancer cells. To overcome this barrier, we have previously designed a chimeric superactive p53 (p53-CC) with an alternative oligomerization domain capable of escaping transdominant inhibition by mutant p53 in vitro. In this report, we demonstrate the superior tumor suppressor activity of p53-CC and its ability to cause tumor regression of the MDA-MB-468 aggressive p53-dominant negative breast cancer tumor model in vivo. In addition, we illustrate the profound effects of the dominant negative effect of endogenous mutant p53 over wt-p53 in cancer cells. Finally, we investigate the underlying differential mechanisms of activity for p53-CC and wt-p53 delivered using viral-mediated gene therapy approach in the MDA-MB-468 tumor model.

STARTING A LAPAROSCOPIC SURGERY PROGRAMME IN THE SECOND LARGEST TEACHING HOSPITAL IN GHANA

BACKGROUND

Komfo Anokye Teaching Hospital (KATH) is the second largest hospital in Ghana. Two years have elapsed after performance of the first laparoscopic cholecystectomy.

OBJECTIVES

To examine our experience and lessons learned.

DESIGN

Retrospective review.

SETTING

Komfo Anokye Teaching Hospital (KATH).

SUBJECTS

We reviewed leadership support, the role of a surgeon champion, training of physician and OR staff, influence of surgeons from outside Ghana and equipment status. The results of laparoscopic cholecystectomies performed from 2010-2012 were compared with information available from open cholecystectomies over the same period.

RESULTS

Evidence of leadership support included equipment purchase and invitation of outside experts yearly from 2008. A KATH surgeon champion was identified in 2010. A dedicated OR team received training and exhibited excellent ownership of equipment preparation. Since 2010, 25 laparoscopic cholecystectomies have been performed, 17 independently by a single surgeon. Average operative time was 1.41 hours and length of stay (LOS) 1.5 days. Conversion rate was 4.0% (1/25). Complication rate was 20.0% (5/25), none involving haemorrhage or injuries to bile ducts or bowel. Median patient satisfaction score was 5 on a scale of 1-5 where 5 is most satisfied. Complication rates and hospital stay were lower than for open cholecystectomy (20.0% vs 34.5%, p > 0.05 and 1.5 days vs 6.6 days, p < 0.001 respectively). Operative times were on average 27 min onger for laparoscopic cholecystectomy (p < 0.01).

CONCLUSION

Laparoscopic cholecystectomy at KATH has become a reality with less complications rates, shorter LOS, and trends towards improved patient satisfaction. Expanding laparoscopic surgery in Ghana requires its inclusion into residency training programmes and public education about its benefits for both patients and physicians.

NeuroGame Therapy to improve wrist control in children with cerebral palsy: a case series

OBJECTIVE

This case series examines the feasibility, specificity, and preliminary effectiveness of NeuroGame Therapy (NGT) for improving wrist control in four children with cerebral palsy (CP). NGT uses surface electromyographic (sEMG) signals routed through motivating computer games to improve motor control.

METHODS

Primary outcomes of NGT included feasibility (hours of play) and specificity (changes in sEMG activity during game play). Secondary outcomes included changes in co-contraction, range of motion, segmental alignment, and spontaneous upper extremity function following intervention.

RESULTS

Participants completed a mean of 8.8 hours of NGT over 5-6 weeks. Participants demonstrated dramatic improvement of the sEMG activity during game play. Several participants also showed improvements in range of motion, co-contraction, and spontaneous upper extremity function following NGT.

CONCLUSION

This case series provides evidence for the feasibility, specificity, and effectiveness of NGT. Future studies will pair NGT with functional practice to improve transfer of learning to daily activities.

Improved neuropsychological and neurological functioning across three antiretroviral regimens in diverse resource-limited settings: AIDS Clinical Trials Group study a5199, the International Neurological Study

BACKGROUND

AIDS Clinical Trials Group (ACTG) A5199 compared the neurological and neuropsychological (NP) effects of 3 antiretroviral regimens in participants infected with human immunodeficiency virus type 1 (HIV-1) in resource-limited settings.

METHODS

Participants from Brazil, India, Malawi, Peru, South Africa, Thailand, and Zimbabwe were randomized to 3 antiretroviral treatment arms: A (lamivudine-zidovudine plus efavirenz, n = 289), B (atazanavir, emtricitabine, and didanosine-EC, n = 293), and C (emtricitabine-tenofovir-disoproxil fumarate plus efavirenz, n = 278) as part of the ACTG PEARLS study (A5175). Standardized neurological and neuropsychological (NP) screening examinations (grooved pegboard, timed gait, semantic verbal fluency, and finger tapping) were administered every 24 weeks from February 2006 to May 2010. Associations with neurological and neuropsychological function were estimated from linear and logistic regression models using generalized estimating equations.

RESULTS

The median weeks on study was 168 (Q1 = 96, Q3 = 192) for the 860 participants. NP test scores improved (P < .05) with the exception of semantic verbal fluency. No differences in neurological and neuropsychological functioning between treatment regimens were detected (P > .10). Significant country effects were noted on all NP tests and neurological outcomes (P < .01).

CONCLUSIONS

The study detected no significant differences in neuropsychological and neurological outcomes between randomized ART regimens. Significant improvement occurred in neurocognitive and neurological functioning over time after initiation of ARTs. The etiology of these improvements is likely multifactorial, reflecting reduced central nervous system HIV infection, better general health, and practice effects. This study suggests that treatment with either of the World Health Organization -recommended first-line antiretroviral regimens in resource-limited settings will improve neuropsychological functioning and reduce neurological dysfunction.

CLINICAL TRIALS REGISTRATION

NCT00096824.

WE-G-BRB-01: Per-Frame Analysis of MatriXX Data

PURPOSE

One of the most widely used IMRT QA devices (MatriXX) is an array of ionization chambers which are periodically read during plan delivery. Although the ionization chambers are not expected to exhibit strong angular dependence, the measured dose distribution is often found to significantly differ from the planned dose distribution. We identify the origin of all factors that affect the measurement accuracy of the MatriXX and develop a per-frame post-processing strategy that reduces their impact on the passing rate of IMRT and VMAT plans.

METHODS

We developed software that reads the dose frame sequence recorded by the MatriXX and applies a number of correction factors to each frame. Angular correction factors are computed as ratios of measured dose at the isocenter of the phantom and planned dose at the same location for all clinically used photon energies. For every clinical case, the recorded movie file is read and the dose for every frame is corrected according to the angle of the beam. In addition, the background evolution is tracked in the 'beam-off' frames which are subsequently subtracted from the 'beam-on' frames according to a predictive model. Machine output correction is also implemented, which significantly improves the absolute dose measurements. The IMRT effective plane of measurement of the MatriXX was identified and found not to coincide with the isocentric plane.

RESULTS

The clinical passing rates are significantly improved when the per-frame analysis software was introduced in our IMRT QA procedure. For a group of 800 patients with no corrections the average passing rate was 93.6%, while for the first 300 cases with per frame corrections the average passing rate was 97.3%.

CONCLUSIONS

We identify all factors that impact the measurement accuracy of the MatriXX (angular effects, background evolution, machine output, plane of measurement) and propose a strategy for their elimination.