Neurocognitive effects of treatment interruption in stable HIV-positive patients in an observational cohort

OBJECTIVE

Prior studies have shown improved neurocognition with initiation of antiretroviral treatment (ART) in HIV. We hypothesized that stopping ART would be associated with poorer neurocognitive function.

METHODS

Neurocognitive function was assessed as part of ACTG 5170, a multicenter, prospective observational study of HIV-infected subjects who elected to discontinue ART. Eligible subjects had CD4 count >350 cells/mm(3), had HIV RNA viral load <55,000 cp/mL, and were on ART (>or=2 drugs) for >or=6 months. Subjects stopped ART at study entry and were followed for 96 weeks with a neurocognitive examination.

RESULTS

A total of 167 subjects enrolled with a median nadir CD4 of 436 cells/mm(3) and 4.5 median years on ART. Significant improvements in mean neuropsychological scores of 0.22, 0.39, 0.53, and 0.74 were found at weeks 24, 48, 72, and 96 (all p < 0.001). In the 46 subjects who restarted ART prior to week 96, no significant changes in neurocognitive function were observed.

CONCLUSION

Subjects with preserved immune function found that neurocognition improved significantly following antiretroviral treatment (ART) discontinuation. The balance between the neurocognitive cost of untreated HIV viremia and the possible toxicities of ART require consideration.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that discontinuing ART is associated with an improvement in 2 neuropsychological tests (Trail-Making Test A & B and the Wechsler Adult Intelligence Scale-Revised Digit Symbol subtest) for up to 96 weeks. Resuming ART was not associated with a decline in these scores for up to 45 weeks.

Hip protectors: recommendations for conducting clinical trials--an international consensus statement (part II)

INTRODUCTION

While hip protectors are effective in some clinical trials, many, including all in community settings, have been unable to demonstrate effectiveness. This is due partly to differences in the design and analysis. The aim of this report is to develop recommendations for subsequent clinical research.

METHODS

In November of 2007, the International Hip Protector Research Group met to address barriers to the clinical effectiveness of hip protectors. This paper represents a consensus statement from the group on recommended methods for conducting future clinical trials of hip protectors.

RESULTS AND CONCLUSIONS

Consensus recommendations include the following: the use of a hip protector that has undergone adequate biomechanical testing, the use of sham hip protectors, the conduct of clinical trials in populations with annual hip fracture incidence of at least 3%, a run-in period with demonstration of adequate adherence, surveillance of falls and adherence, and the inclusion of economic analyses. Larger and more costly clinical trials are required to definitively investigate effectiveness of hip protectors.

Clinical presentation and initial management of black men and white men with prostate cancer in the United Kingdom: the PROCESS cohort study

Background:

In the United States, Black men have a higher risk of prostate cancer and worse survival than do White men, but it is unclear whether this is because of differences in diagnosis and management. We re-examined these differences in the United Kingdom, where health care is free and unlikely to vary by socioeconomic status.

Methods:

This study is a population-based retrospective cohort study of men diagnosed with prostate cancer with data on ethnicity, prognostic factors, and clinical care. A Delphi panel considered the appropriateness of investigations and treatments received.

Results:

At diagnosis, Black men had similar clinical stage and Gleason scores but higher age-adjusted prostate-specific antigen levels (geometric mean ratio 1.41, 95% confidence interval (95% CI): 1.15–1.73). Black men underwent more investigations and were more likely to undergo radical treatment, although this was largely explained by their younger age. Even after age adjustment, Black men were more likely to undergo a bone scan (odds ratio 1.37, 95% CI: 1.05–1.80). The Delphi analysis did not suggest differential management by ethnicity.

Conclusions:

This UK-based study comparing Black men with White men found no evidence of differences in disease characteristics at the time of prostate cancer diagnosis, nor of under-investigation or under-treatment in Black men.

Diamond-metal contacts: interface barriers and real-time characterization

A review of diamond-metal contacts is presented with reference to reported values of interfacial potential (Schottky) barriers and their dependence on macroscopic and microscopic properties of the diamond surface, the interface and the metal. No simple model can account for the overall spread of p-diamond barriers, although there are, for certain metals, correlations with metal electronegativity, interface chemistry and diamond surface preparation. Detailed studies are presented for a selected contact (Al-p-diamond) using real-time monitoring during metal growth from sub-nanometre to bulk films and subsequent in situ heating to 1000 °C. This contact, prepared in a clean vacuum environment on characterized single-crystal substrates, provides a case study for a combined in situ electrical and spectroscopic investigation using IV measurements for macroscopic diodes and real-time photoelectron spectroscopy for nanoscale metal films. Band bending during growth leads to a rectifying contact with a measured IV barrier height of 1.05 V and an ideality factor of 1.4. A transition from layered to clustered growth of the metal film is revealed in the real-time measurements and this is confirmed by AFM. For the annealed contact, a direct correlation is revealed by real-time photoemission between the onset of interfacial carbide formation and the change from a rectifying to an ohmic contact at 482 °C.

The prediction of pregnancy outcome by haemoglobin measurement before 20 weeks` gestation

Maternal haemoglobin levels were measured before 21 weeks' gestation in a prospective study of 1276 singleton pregnancies. Reference ranges were constructed and then applied to a further cohort of 1227 singleton pregnancies to determine the ability of haemoglobin level before 21 weeks' gestation to predict pregnancy outcome. Haemoglobin level decreased significantly with advancing gestational age from 6 to 21 weeks (P < 0.05). Low haemoglobin level was associated with a decreased risk of pregnancy-induced hypertension (adjusted odds ratio 0.51, 95% CI 0.35-0.74). High haemoglobin level was positively correlated with subsequent pregnancy-induced hypertension (P = 0.002) with values > 95th percentile for gestational age having positive and negative predictive values of 33% and 94% respectively. Haemoglobin values (either high or low) were not predictive of proteinuric pre-eclampsia, preterm prelabour rupture of the membranes, preterm birth, low birth weight or the need for neonatal resuscitation of admission to the special care baby unit. The finding of a high maternal haemoglobin before 21 weeks' gestation is not sufficiently predictive of pregnancyinduced hypertension to be of clinical use, but the ability of a low level to predict favourable outcome may be of use in a scoring system designed to identify women suitable for midwifery-based care.

Epidemiological studies of the non-specific effects of vaccines: II--methodological issues in the design and analysis of cohort studies

We review sources of bias which can affect non-randomized cohort studies of non-specific effects of vaccines on child mortality. Using examples from the literature on non-specific effects, we describe different sources of selection and information bias, and, where possible, outline analysis strategies to mitigate or eliminate such biases.

Increasing physical function through physiatric intervention for children with paediatric neurotransmitter disorders

Most children with paediatric neurotransmitter diseases have global functional deficits secondary to central nervous system damage. Paediatric physiatrists, working in conjunction with a multi-disciplinary team, help to improve physical function by normalizing muscle tone and improving body position. Components of spasticity, rigidity, and dystonia may all need to be considered in a comprehensive treatment programme. Complications of disordered tone include skin breakdown, pain, sleep disturbance, and dysphagia. With an integrated approach to use of medications and equipment as well as implementation of therapy and therapeutic exercise, physiatrists can help maximize functional independence for children with this group of disorders. Pharmacological treatment includes GABA-agonists including baclofen and benzodiazepines, alpha-2 adrenergic agonists, L: -dopa and dopaminergic agents, and dantrolene. Intrathecal baclofen may be used in patients refractory to these medications. In addition, physicians may utilize botulinum toxin, phenol, or surgical interventions such as selective dorsal rhizotomy or tendon lengthening. Pharmacological treatment must be used in conjunction with appropriate adaptive equipment in order to maximize therapeutic benefit. Focus on function in an attempt to increase independence is targeted to improve the child's quality of life. We present a framework and rationale to the management of the functional consequences of the paediatric neurotransmitter diseases.

Functional profiling in stage IV colorectal cancer: A phase II trial of individualized therapy

e15124

Background: The introduction of new classes of agents has improved survival in colorectal cancer (CRC) yet the accurate selection of candidates for these often costly & toxic drugs remains a challenge. Genomic platforms have identified several prognostic & predictive factors e.g. ERCC1, TS, kRas mutations but the comparatively small number of known cellular analytes has limited their broad application. Methods: To address the complexity and redundancy of cell-death signaling pathways, we applied Ex Vivo Analysis of Programmed Cell Death (EVA/PCD) (Nagourney, R. Curr Treat Options in Oncol. 2006) to select therapies for chemo-naïve pts with metastatic CRC. This functional platform uses morphologic and metabolic endpoints to gauge cellular response to drugs & signal transduction inhibitors in human tumor microspheroids isolated from surgical biopsies. Modified Z-scores & synergy analyses (median-effect) were used to identify the ex vivo best regimen (EVBR) for each pt. from FDA-approved CRC drugs. All pts signed informed consent. Results: 12/13 (92%) pts are evaluable. Of the 12 there was 1/12 (8%) CR; 7/12 (58%) PR; 3/12 (25%) SD & 1/12 (8%) PD for an ORR = 8/12 (66%) & CBR = 11/12 (92%). 1st line EVBR were FOLFOX 3/12 (25%); FOLFIRI 2/12 (16%); FOLFOX/Erbitux 2/12(16%); FOLFOX/Avastin 1/12 (8%); FOLFOX/Avastin/Erbitux 1/12(8%); Irinotecan/Avastin/Erbitux 2/12(16%); IROX/Avastin 1/12(8%). Three of 12 inoperable pts (25%) converted to surgical candidates. There was 1 treatment-related death. Accrual continues with current TTP ranges from 1.2–17.3 months and OS from 2.5 to 30 months. Conclusions: EVA/PCD ORR in Stage IV CRC of 66%, many durable, compares favorably with reports in this population. By examining drug-induced cell death events in native-state microspheroids, this platform has the unique capacity to capture stromal, vascular and inflammatory cell interactions with tumor cells, now known to be crucial for clinical response prediction. EVA/PCD analysis warrants further evaluation in CRC. Supported by the Memorial Medical Center Foundation of Long Beach.

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Functional profiling in stage IV NSCLC: A phase II trial of individualized therapy

e19079

Background: The introduction of new classes of agents has improved survival in NSCLC yet the accurate selection of candidates for these often costly & toxic drugs remains a challenge. Genomic platforms have identified several prognostic & predictive factors e.g. ERCC1, RRM1/2, EGFr mutations but the comparatively small number of known cellular analytes has limited their broad application. Methods: To address the complexity and redundancy of cell-death signaling pathways, we applied Ex Vivo Analysis of Programmed Cell Death (EVA/PCD) (Nagourney, R. Curr Treat Options in Oncol. 2006) to select therapies for chemo- naïve pts with metastatic NSCLC. This functional platform uses morphologic and metabolic endpoints to gauge cellular response to drugs & signal transduction inhibitors in human tumor microspheroids isolated from surgical biopsies. Modified Z-scores & synergy analyses (median-effect) were used to identify the ex vivo best regimen (EVBR) for each pt. from FDA-approved NSCLC drugs. All pts signed informed consent. Results: 22/25 (88%) pts are evaluable with 3/25 (12%) excluded, 1 for CVA & 2 inadequate PFS at time of treatment. There were CR = 2/22 (9%); PR = 10/22 (45%); SD = 9/22 (41%) & PD = 1/22 (5%) for an ORR = 12/22 (54%) & CBR = 21/22 (95%). 1st line EVBR were CDDP/Gemcitabine 10/25 (40%); CDDP/Taxane 7/25(28%); Erlotinib 5/25(20%); CDDP/Vinorelbine 1/25 (4%); CDDP/Irinotecan1/25(4%) & Ifex/Gemcitabine1/25(4%). Six of 22 (27%) stage IV pts were converted to surgical and/or radiation candidates by therapy. Accrual continues with current TTP ranges from 1.2–35+ months and OS from 1.7 to 46+ months. Conclusions: EVA/PCD ORR in Stage IV NSCLC of 54%, many durable, compares very favorably with reports in this population. By examining drug-induced cell death events in native-state microspheroids, this platform has the unique capacity to capture stromal, vascular and inflammatory cell interactions with tumor cells, now known to be crucial for clinical response prediction. EVA/PCD analysis in NSCLC warrants further evaluation. Supported by the Memorial Medical Center Foundation of Long Beach.

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Therapeutic hypothermia can be induced and maintained using either commercial water bottles or a "phase changing material" mattress in a newborn piglet model

BACKGROUND

Therapeutic hypothermia, a safe and effective treatment for neonatal encephalopathy in an intensive care setting, is not available in low-resource settings. Aims/

METHODS

To assess two low-tech, low-cost cooling devices for use in low-resource settings: (i) commercially available water bottles filled with tepid water (25 degrees C); (ii) a mattress made of phase changing material (PCM) with a melting point of 32 degrees C (PCM works as a heat buffer at this temperature). Eleven anaesthetised newborn piglets were studied following transient hypoxia-ischaemia. The cooling device was applied 2-26 h after hypoxia-ischaemia with a target rectal temperature (T(rectal)) of 33-34 degrees C. T(rectal) undershoot was adjusted using cotton blankets; the cooling device was renewed when T(rectal) rose above 35 degrees C. T(rectal) data during cooling were dichotomised (within or without target) to assess: (a) the total period within the target T(rectal) range; (b) the stability and fluctuation of T(rectal) during cooling.

RESULTS

Therapeutic hypothermia was achieved with both water bottles (n = 5) and the PCM mattress (n = 6). The mean (SD) time to reach target T(rectal) was 1.8 (0.5) h with water bottles and 1.9 (0.3) h with PCM. PCM cooling led to a longer period within the target T(rectal) range (p<0.01) and more stable cooling (p<0.05). Water bottle cooling required device renewal (in four out of five piglets).

CONCLUSION

Simple, low-tech cooling devices can induce and maintain therapeutic hypothermia effectively in a porcine model of neonatal encephalopathy, although frequent fine tuning by adjusting the number of blankets insulating the piglet was required to maintain a stable temperature. PCM may induce more stable cooling compared with water bottles.