Search PubMed⌕ Search

Biomedical subjects

Jeffrey A Woods

Publications and source records attributed to Jeffrey A Woods.

8 recordsLinked to original sources
PubMed2006

Higher antibody, but not cell-mediated, responses to vaccination in high physically fit elderly.

The purpose of this study was to examine whether cardiovascular fitness, independent of confounding factors, was associated with immune responsiveness to clinically relevant challenges in older adults (60-76 yr). Thirteen sedentary, low-fit (LF; maximal O(2) uptake = 21.1 +/- 1.1 ml.kg(-1).min(-1)) and 13 physically active, high-fit (HF; maximal O(2) uptake = 46.8 +/- 3.4 ml.kg(-1).min(-1)) older adults participated in this study. Dietary intake was assessed, and a battery of psychosocial tests was administered. In vivo antibody and ex vivo proliferative and cytokine responses to influenza (Fluzone) and tetanus toxoid (TT) vaccination and delayed-type hypersensitivity skin tests were performed. HF elderly individuals displayed a higher antibody response to two of the three strains included in the Fluzone vaccine as measured by hemagluttination inhibition, but there was no difference between groups in influenza-specific ex vivo proliferation or IFN-gamma or IL-10 production. HF elderly individuals exhibited a lower IgG(1) response and a tendency for a higher IgG(2) response to the TT vaccine. There were, however, no differences in TT-specific ex vivo proliferation or IFN-gamma or IL-10 production. In contrast, HF subjects had higher proliferative responses to phytohemagluttinin. In addition, there were no differences in delayed-type hypersensitivity responses to fungal antigens between groups. These results suggest that, after accounting for confounding factors, HF elderly individuals have higher antibody responses to Fluzone vaccine and a Th2 skewing of the antibody response to TT. There was little evidence that HF mounted better cell-mediated immune responses to the Fluzone or TT vaccine measured in peripheral blood cells or to other recall antigens in vivo.

Aged↗
PubMed2006

Exercise, inflammation, and innate immunity.

Regular exercise is protective against several chronic diseases ranging from physiologic diseases such as cardiovascular disease to neurologic diseases such as dementia and depression. Exciting recent research points to chronic inflammation as an underlying contributor to many age-related chronic diseases. Cross-sectional and longitudinal studies in animals and humans have shown both an acute and a chronic anti-inflammatory effect. Because innate immunity is a key regulator of inflammatory processes, and chronic inflammation contributes to many illnesses, the effect of regular exercise on innate immunity, most importantly macrophages, holds much promise in terms of defining these mechanisms. Unfortunately, the mechanisms responsible for the observed anti-inflammatory effect of regular exercise have not been elucidated. This article presents several compelling potential mechanisms for the anti-inflammatory effect of exercise, including loss of body fat, reductions in macrophage accumulation in adipose tissue, altered macrophage phenotype in adipose tissue, exercise-induced muscle production of IL-6, or alterations in the balance between the sympathetic and parasympathetic nervous systems. Further investigation to confirm or reject these testable hypotheses will allow better application of exercise therapy to treat and prevent illnesses associated with chronic inflammation.

Animals↗
PubMed2006

Moderate exercise early after influenza virus infection reduces the Th1 inflammatory response in lungs of mice.

We have previously shown that moderate exercise significantly increased survival after influenza virus (A/PR/8/34) infection in mice. We hypothesized that this brief duration of exercise would either increase innate immune defences and/or shift the immune response from a Th1 inflammatory to a Th2 anti-inflammatory response resulting in decreased lung pathology. Adult male BALB/cByJ mice (5-6 months old) were infected with 50 microL of A/PR/8/34 virus (40HAU) intranasally and randomized to either an exercise (EX) or sedentary (SED) group. EX mice performed 20-30 min of moderate exercise (8-12 m/min) on a motorized treadmill 4 hr post-infection and then exercised similarly for 4 consecutive days. SED mice were exposed to similar environmental conditions but did not exercise. Mice from both EX and SED groups were sacrificed 1, 3, or 5 days post-infection (p.i.) and lungs, mediastinal lymph nodes (MLNs) and spleens were harvested. EX significantly reduced total cellular infiltration and IFN-gamma gene expression in lungs at Days 3 and 5 p.i. and there was a qualitative shift in the expression of cytokines in the lung from a Th1 to a Th2 response. There was also a tendency toward a reduction in influenza M1 protein mRNA expression. There was no difference in IFN-beta protein levels between groups. These data suggest that moderate exercise when applied early after infection shifts the immune response away from a Th1 profile in mice infected with influenza virus. This exercise-induced shift in immune response may be responsible for improved survival after influenza virus infection.

Animals↗
PubMed2005

Moderate exercise protects mice from death due to influenza virus.

We wanted to determine if different doses of exercise, performed in the initial days after infection when the host is mounting an immune response, altered mortality, and morbidity to influenza virus infection in mice. Forty hemagglutinating units of influenza virus (A/Puerto Rico/8/34) were administered intranasally to lightly anesthetized mice. Male Balb/cByJ mice were randomized to one of three groups: sedentary control (CON); moderate (MOD) exercise (20-30 min at 8-12 m/min); or prolonged (PRO) exercise (2.5 h at 8-12 m/min). Mice exercised on a treadmill 4 h post-infection and for three more consecutive days before symptom onset. Mortality, morbidity, bodyweight, and food intake were assessed. MOD had a significantly (p = .007) higher survival (18 of 22; 82%) rate when compared to CON (10 of 23; 43%). There was no difference in morbidity between MOD and CON, despite improved survival. PRO exhibited a survival rate of 30% (p = .29 vs. CON) and demonstrated significantly higher morbidity on several days. While all groups exhibited anorexia and significant body weight loss (approximately 30-35%) post-infection, exercise had little effect on these variables. We demonstrate that moderate exercise, performed in the initial days after influenza infection, significantly decreased mortality in mice. Prolonged exercise led to increased morbidity and tended to decrease survival.

Animals↗
PubMed2004

Exercise delays allogeneic tumor growth and reduces intratumoral inflammation and vascularization.

This investigation determined whether daily strenuous exercise would alter the progression and regression of an allogeneic lymphoid tumor in mice. We also determined whether exercise would alter the cellular composition and vascularity of the tumor. Female BALB/c mice (age 6-8 wk) were randomly assigned to sedentary control (Con) or daily exercised groups (EXH). EXH mice ran on a treadmill at incremental speeds (20-40 m/min) for 3 h or until fatigue. Each mouse was subcutaneously injected with 20 x 10(6) EL-4 lymphoma cells immediately after the first exercise bout (day 1) and run daily. Tumor volume was measured daily with calipers. In some experiments, mice were euthanized on days 5-10, 12, and 14. Tumors were excised and stained with hematoxylin and eosin or for Factor VIII-associated antigen using immunohistochemistry and analyzed in a blinded fashion under a light microscope. There was no significant treatment main effect found for tumor volumes. Interestingly, a significant treatment x time interaction was found, such that there was a 2-day delay in peak tumor volume and a more rapid tumor regression in EXH. Tumors isolated from Con exhibited significantly higher numbers of apoptotic bodies, blood vessels, macrophages, and neutrophils when compared with EXH. Intratumoral lymphocytes were higher in Con early in tumor growth but higher in EXH at peak tumor size. These data indicate that daily strenuous exercise may influence tumor growth by affecting the microenvironment of the tumor, resulting in a delay in tumor growth and a more rapid regression.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2002

The phytoestrogen genistein induces thymic and immune changes: a human health concern?

Use of soy-based infant formulas and soy/isoflavone supplements has aroused concern because of potential estrogenic effects of the soy isoflavones genistein and daidzein. Here we show that s.c. genistein injections in ovariectomized adult mice produced dose-responsive decreases in thymic weight of up to 80%. Genistein's thymic effects occurred through both estrogen receptor (ER) and non-ER-mediated mechanisms, as the genistein effects on thymus were only partially blocked by the ER antagonist ICI 182,780. Genistein decreased thymocyte numbers up to 86% and doubled apoptosis, indicating that the mechanism of the genistein effect on loss of thymocytes is caused in part by increased apoptosis. Genistein injection caused decreases in relative percentages of thymic CD4(+)CD8(-) and double-positive CD4(+)CD8(+) thymocytes, providing evidence that genistein may affect early thymocyte maturation and the maturation of the CD4(+)CD8(-) helper T cell lineage. Decreases in the relative percentages of CD4(+)CD8(-) thymocytes were accompanied by decreases in relative percentages of splenic CD4(+)CD8(-) cells and a systemic lymphocytopenia. In addition, genistein produced suppression of humoral immunity. Genistein injected at 8 mg/kg per day produced serum genistein levels comparable to those reported in soy-fed human infants, and this dose caused significant thymic and immune changes in mice. Critically, dietary genistein at concentrations that produced serum genistein levels substantially less than those in soy-fed infants produced marked thymic atrophy. These results raise the possibility that serum genistein concentrations found in soy-fed infants may be capable of producing thymic and immune abnormalities, as suggested by previous reports of immune impairments in soy-fed human infants.

Animals↗
PubMed2002

Can exercise training improve immune function in the aged?

Many strategies have been used to improve immune function in the aged. Unfortunately, many of these interventions have been disappointing, impractical, costly to develop and administer, or accompanied by adverse side effects. Aside from dietary manipulation (caloric restriction without malnutrition or antioxidant supplementation), research involving behavioral preventative or restorative therapies has been lacking. Moderate exercise training has been shown to elicit beneficial outcomes in both the prevention and rehabilitation of many diseases of the elderly. It has been hypothesized that moderate levels of exercise improves, whereas strenuous exercise or overtraining suppresses, various immune function measures. Three general approaches have been implemented to study the impact of exercise on immune functioning in the elderly: (1) cross-sectional studies, (2) longitudinal studies, and (3) animal studies. In general, cross-sectional studies examining highly active elderly have demonstrated improved in vitro T cell responses to polyclonal stimulation when compared to sedentary elderly. This is corroborated by several animal studies that have shown improved splenic T cell responses in vitro. Unfortunately, human prospective studies have failed to demonstrate consistent improvements in various measures of immune function in older adults. However, it should be cautioned that these studies have included small samples followed over a short duration, measuring a limited number of in vitro immune parameters, with some failing to account for potential confounding influences. Although such findings have the potential to be of substantial public health importance, very few systematic studies have been conducted.

Aging↗