Molecular pathology endpoints useful for aging studies

The first clinical trial aimed at targeting fundamental processes of aging will soon be launched (TAME: Targeting Aging with Metformin). In its wake is a robust pipeline of therapeutic interventions that have been demonstrated to extend lifespan or healthspan of preclinical models, including rapalogs, antioxidants, anti-inflammatory agents, and senolytics. This ensures that if the TAME trial is successful, numerous additional clinical trials are apt to follow. But a significant impediment to these trials remains the question of what endpoints should be measured? The design of the TAME trial very cleverly skirts around this based on the fact that there are decades of data on metformin in humans, providing unequaled clarity of what endpoints are most likely to yield a positive outcome. But for a new chemical entity, knowing what endpoints to measure remains a formidable challenge. For economy’s sake, and to achieve results in a reasonable time frame, surrogate markers of lifespan and healthy aging are desperately needed. This review provides a comprehensive analysis of molecular endpoints that are currently being used as indices of age-related phenomena (e.g., morbidity, frailty, mortality) and proposes an approach for validating and prioritizing these endpoints.     

The composition of surrogate alcohols consumed in Russia

BACKGROUND: In the course of a case-control study examining determinants of premature death among working age men, it became clear that a significant percentage of the population (7.3%) were drinking a variety of surrogate alcohol products (products not legally sold for consumption). In this population, where there is a high death rate from alcohol-related causes, including acute alcohol poisoning, it was important to know what these products contained. METHODS: The identity of products being consumed was identified from the survey of controls. Representative samples were obtained and subjected to analysis using gas chromatography and mass spectrometry to determine their composition. RESULTS: Three broad groups of product were identified: samogon (home-produced spirits); medicinal compounds; and other spirits (mainly sold as aftershaves). Commercially produced vodkas were used for comparison. Samogon contained lower quantities of ethanol than vodka [mean, 39 vs. 44 volumetric percentage (v/v%), respectively] but in addition contained certain toxic long-chain alcohols. Medicinal compounds contained only ethanol, at a higher concentration that vodka (mean, 66 v/v%), while the other spirits, which were also essentially pure ethanol, contained a mean of 94 v/v%. CONCLUSIONS: A significant number of Russian men are drinking products that have either very high concentrations of ethanol or contaminants known to be toxic. These products are untaxed and thus much less expensive than vodka. There is an urgent need for policy responses that target their production and consumption.     

ACE Inhibitors and Chronotherapy

Chronotherapy can improve the effectiveness and reduce the adverse reactions of drugs and actually is used for several conditions including cardiovascular diseases. Although angiotensin converting enzyme (ACE) inhibitors are available for the therapy of patients with hypertension and/or heart failure, these agents have some characteristic adverse effects such as angioedema and dry cough. It has been reported that the dosing of ACE inhibitor at an inactive period has a better protective effect against cardiac hypertrophy in hypertensive rats, and changing dosing time from morning to evening reduces the severity and frequency of the drug-induced dry cough of hypertensive patients treated in the morning. Thus, the dosing of ACE inhibitors in the inactive span is more effective and safe. Dosing in the evening may be an alternative for hypertensives with dry cough with a morning dose of ACE inhibitors, if one ascertains that no circadian hyperamplitude tension is induced by the evening dose of this or any other antihypertensive drug.     

Plasma S100beta and NSE levels and progression in multiple sclerosis

Plasma levels of the glial cell marker S100beta and the neuronal marker neuron-specific enolase (NSE) are elevated in various conditions of central nervous system damage. In this study we investigated whether plasma levels of S100beta and NSE are related to disease progression in multiple sclerosis (MS). Plasma levels of S100beta and NSE were measured in 25 patients with relapsing remitting MS (RRMS), 23 with secondary progressive MS (SPMS) and 16 with primary progressive MS (PPMS). All MS patients were in a clinically stable phase. Progression and disability were evaluated during a follow-up period of five years. We found that plasma NSE levels were lower in patients with clinically relevant worsening on the Expanded Disability Status Scale (EDSS), defined as 1 point increase from EDSS <6.0 or 0.5 point increase from EDSS> or =6 after five years (p=0.042), and in patients with a progressive disease course (p=0.01). There was a significant negative correlation between plasma NSE levels and both EDSS and Multiple Sclerosis Severity Status (MSSS) scores at baseline and after five years of follow-up (r=-0.33 and -0.38, p=0.027 and 0.003). There were no significant differences between patient groups in plasma S100beta levels. Plasma NSE levels appear inversely related to disease progression in MS.     

Posttreatment prostatic-specific antigen doubling time as a surrogate endpoint for prostate cancer-specific survival: an analysis of Radiation Therapy Oncology Group Protocol 92-02

PURPOSE: We evaluated whether posttreatment prostatic-specific antigen doubling time (PSADT) was predictive of prostate cancer mortality by testing the Prentice requirements for a surrogate endpoint. METHODS AND MATERIALS: We analyzed posttreatment PSA measurements in a cohort of 1,514 men with localized prostate cancer (T2c-4 and PSA level <150 ng/mL), treated and monitored prospectively on Radiation Therapy Oncology Group Protocol 92-02. From June 1992 to April 1995, men were randomized to neoadjuvant androgen deprivation and 65-70 Gy of radiation therapy (n = 761), or in combination with 24 months of adjuvant androgen deprivation (n = 753). Using an adjusted Cox proportional hazards model, we tested if PSADT was prognostic and independent of randomized treatment in this cohort. The endpoints were time to PSADT (assuming first-order kinetics for a minimum of 3 rising PSA measurements) and cancer-specific survival (CSS). RESULTS: After a median follow-up time of 5.9 years, randomized treatment was a significant predictor for CSS (p(Cox) = 0.002), PSADT <6 months (p(Cox) < 0.001), PSADT <9 months (p(Cox) < 0.001), and PSADT <12 months (p(Cox) < 0.001) but not for PSADT <3 (p(Cox) = 0.4). The significant posttreatment PSADTs were also significant predictors of CSS (p(Cox)< 0.001). After adjusting for T stage, Gleason score and PSA, all of Prentice's requirements were not met, indicating that the effect of PSADT on CSS was not independent of the randomized treatment. CONCLUSIONS: Prostatic specific antigen doubling time is significantly associated with CSS, but did not meet all of Prentice's requirements for a surrogate endpoint of CSS. Thus, the risk of dying of prostate cancer is not fully explained by PSADT.