Biomedical subjects

Helaine M Alessio

Publications and source records attributed to Helaine M Alessio.

5 recordsLinked to original sources

PubMed2005

Short-term isometric exercise reduces systolic blood pressure in hypertensive adults: possible role of reactive oxygen species.

OBJECTIVE: A short-term isometric exercise protocol was tested in ten hypertensive individuals to determine its efficacy as a high blood pressure-reducing intervention. DESIGN: The study was a prospective case study of 10 hypertensive individuals (8 men, 2 woman, mean age = 52 + 5 years) who underwent six weeks of isometric exercise training (three sessions/week). METHODS: Blood pressure, blood lipids and markers of oxidative stress were monitored before, during and following the isometric intervention. Electron spin resonance spectroscopy was used to directly measure radicals in the blood samples. RESULTS: After six weeks, systolic blood pressure decreased an average 13 mm Hg (p < 0.05) from a mean blood pressure of 146 to 133 mm Hg, a level that is below the usual 140 mm Hg hypertension threshold. Blood lipids were unchanged, but markers of oxidative stress were affected, with a dramatic decrease in exercise-induced oxygen centered radicals (-266%), (p < 0.05) and an increased resting whole blood glutathione:oxidized glutathione (+61%) in hypertensive adults following six weeks of isometric exercise. CONCLUSION: Six weeks of isometric exercise training was effective in lowering systolic but not diastolic blood pressure in pre-hypertensive and hypertensive individuals, and enhanced antioxidant protection is a likely underlying mechanism.

Age Distribution↗

PubMed2005

Exercise-induced changes in cardiac gene expression and its relation to spatial maze performance.

Cognitive performance is sensitive to both neural and non-neural changes induced by physical activity and inactivity. This study investigated whether access to physical activity outside a standard laboratory animal cage affected cognitive performance as measured by navigation of a spatial maze. It also examined gene expression in heart tissue for genes associated with cardiovascular function given recent reports of cognitive impairment associated with hyperlipidemia. Furthermore, we measured expression of neural-regulatory genes typically expressed in brain, but also found in cardiac tissue. Male Sprague-Dawley rats (n = 72) were separated into three groups having different access to physical activity: none outside a standard cage, twice-weekly physical activity, and every other day exercise on a running wheel. Compared with a sedentary group, spatial maze performance was enhanced in animals that had access to physical activity, either twice-weekly in a large box or every other day on a running wheel. Both the cardiovascular and neural-related genes expressed in the heart were distinguished by access to physical activity. Several genes that are associated with heart rate, cholesterol biosynthesis, blood pressure, and cell adhesion regulation, including GJA1, FDFT1, EDN1, and CD36, differed in animals based on access to physical activity. Neural-related genes expressed in cardiac tissue associated with neurite outgrowth, neuroplasticity, and neurogenesis including RTN4, HOMER2, ACTB, NCDN, KIF5B, and HMGB2, were expressed differently among the three groups. Significant shifts in ten cardiovascular and neural-related gene expressions in cardiac tissue were associated with physical activity and may have influenced learning and performance on a spatial maze.

Animals↗

PubMed2005

Access to exercise and its relation to cardiovascular health and gene expression in laboratory animals.

The interaction between genes and environment can influence cardiovascular disease (CVD). This 16 month study investigated if genes associated with cardiovascular (CV) regulation were expressed differently in animals having: 1) no access to physical activity or exercise (SED), 2) access to hour-long, twice weekly activity (PA), and 3) access every-other-day to a running wheel (EX). Out of 31,000 genes, a CV subset comprising 44 genes was investigated. Ten genes from this subset were expressed differently in EX compared with SED, and 34 genes were expressed differently in PA compared with SED (p<0.05). Total cholesterol (70+/-8 vs. 101+/-9 mg dl(-1)), triglycerides (104+/-8 vs. 127+/-4 mg dl(-1)), resting systolic blood pressure (130+/-3 vs. 141+/-3 mmHg), mean arterial pressure (110+/-2 vs. 120+/-2 mmHg) and heart rate (380+/-6 vs. 405+/-9 beats min(-1)) were lower in EX compared with SED (p<0.05), but intracellular adhesion molecule levels did not differ among groups. Mean gene expressions for Gja1, Fdft1, Edn1, Cd36, and Hmgb2 differed in animals according to access to physical activity. These genes play roles in heart rate, cholesterol biosynthesis, blood pressure, cell adhesion, and transcription and neurogenesis regulation, respectively. In conclusion, a total of 44 CV genes were expressed differently in SED compared to PA and EX; and SED showed more physiological evidence of CVD.

Animals↗

PubMed2004

Exercise improves biomarkers of health and stress in animals fed ad libitum.

Voluntary and forced exercise decrease morbidity and mortality in laboratory animals. Caloric restriction has similar effects on health and unique benefits on life span. Nonetheless, in most experiments, animals do not have access to physical activity and are fed ad libitum (AL). We hypothesized that with regular access to either unlimited running wheel exercise (EX) or limited physical activity (PA), key biomarkers of health would be enhanced enough to counter some consequences of a sedentary AL lifestyle. This 16-month study compared body weight, tumor number and size, tissue lesions, oxidative stress, and reactive stress in (1) sedentary animals with no access to physical activity (SED); (2) animals with access to hour-long, twice weekly activity in a large box (PA); and (3) animals with access every other day to a running wheel (EX). At the end of the study, EX body weight was 8-9% lower than PA and SED. In addition, EX had no kidney lesions versus 50% in PA and SED, and had smaller tumor size (10+/-2 vs. 14+/-4 and 30+/-4 mm). Exhaustive exercise lowered glutathione/oxidized glutathione ratio in EX and PA, but in SED, the ratio was depressed even in resting animals. In all treatments, prolactin (PRL) levels were lower in resting animals than in acutely exercised animals. In conclusion, EX had the most favorable health biomarkers while SED had the least. PA did not confer gross health benefits different than the SED group, but was biochemically more similar to EX animals.

Age Factors↗

PubMed2002

Anti-angiogenic property of edible berries.

Recent studies show that edible berries may have potent chemopreventive properties. Anti-angiogenic approaches to prevent and treat cancer represent a priority area in investigative tumor biology. Vascular endothelial growth factor (VEGF) plays a crucial role for the vascularization of tumors. The vasculature in adult skin remains normally quiescent. However, skin retains the capacity for brisk initiation of angiogenesis during inflammatory skin diseases such as psoriasis and skin cancers. We sought to test the effects of multiple berry extracts on inducible VEGF expression by human HaCaT keratinocytes. Six berry extracts (wild blueberry, bilberry, cranberry, elderberry, raspberry seed, and strawberry) and a grape seed proanthocyanidin extract (GSPE) were studied. The extracts and uptake of their constituents by HaCaT were studied using a multi-channel HPLC-CoulArray approach. Antioxidant activity of the extracts was determined by ORAC. Cranberry, elderberry and raspberry seed samples were observed to possess comparable ORAC values. The antioxidant capacity of these samples was significantly lower than that of the other samples studied. The ORAC values of strawberry powder and GSPE were higher than cranberry, elderberry or raspberry seed but significantly lower than the other samples studied. Wild bilberry and blueberry extracts possessed the highest ORAC values. Each of the berry samples studied significantly inhibited both H2O2 as well as TNF alpha induced VEGF expression by the human keratinocytes. This effect was not shared by other antioxidants such as alpha-tocopherol or GSPE but was commonly shared by pure flavonoids. Matrigel assay using human dermal microvascular endothelial cells showed that edible berries impair angiogenesis.

Angiogenesis Inhibitors↗