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Heavy load exercise induced dysfunction of immunity and neuroendocrine responses in rats.

To determine whether immunity and neuroendocrine system is altered by different loads of exercise training in rats, eight-week-old male Sprague-Dawley rats were randomly assigned to one of the three groups: 1) cage control group (CCG); 2) moderate load training (MLT) (swimming at the intensity of 1.4 m/sec water flowing for 60 min per day); 3) heavy load training (HLT) (swimming at the intensity of 1.8 m/sec water flowing for 120 min per day). MLT and HLT rats were assigned to swim for 6 days per week for total of 6 weeks. All rats were sacrificed 36 h after their last training session. Splenocytes were pooled for assay of cell proliferation and neuropeptide contents in the hypothalamus, hypophysis and plasma were determined by radioimmunoassay while glucocorticoid specific binding in intact thymus was measured by radioligand binding assay. All rats were weighed weekly. The results showed that after 6-week training, rat splenocyte proliferation in response to Con A and LPS decreased in HLT rats compared with MLT and CCG rats. In addition, the contents of beta-endorphin, dynorphin A, arginine vasopressin and oxytocin in the hypothalamus, hypophysis and plasma were altered by HLT, as shown by increased plasma concentration of glucocorticoids and decreased glucocorticoids specific binding in intact thymus compared with MLT and CCG. Furthermore, a decreased body mass in HLT rats has been observed. The body mass of HLT rats was significantly lower than that in CCG and MLT rats at the end of the swimming training period. These data suggest that 6-week heavy load training induces the dysfunction of immunity and neuroendocrine responses, which might be one of the underlying mechanisms of immune dysfunction in overtraining.

Animals↗

Effects of Qigong on immune cells.

The aim of this study was to investigate the influence of two acute Qigong interventions (Qi-training and Qi-therapy) on immune cells. The Qigong interventions were compared with placebo training and placebo therapy in which no attempt was made to gather or move Qi. Immune cell numbers were measured pre-intervention, immediately post-intervention and 1 or 2 hours post-intervention. White blood cells increased significantly 2 hours after actual Qi-training (p < 0.05) but not sham training compared with pre-intervention There were significant increases in lymphocytes 2 hours after actual but not sham Qi-training (p < 0.05) and monocyte numbers were significantly increased immediately after both actual Qi-training (p < 0.01) and sham training (p < 0.05). NK cell numbers decreased significantly both immediately after Qi-training and after sham movements done without concomitant Qi-training (p < 0.01). There were no significant effects on neutrophils. Actual Qi-therapy but not sham therapy increased monocyte numbers immediately after Qi-therapy, and lymphocytes increased more after real than after sham therapy. Neutrophils were again little changed The data indicate that a single Qigong intervention can increase the monocyte and lymphocyte numbers.

Breathing Exercises↗

Effects of stretch-based progressive relaxation training on the secretion of salivary immunoglobulin A in orofacial pain patients.

There is a growing body of evidence that psychologic stressors can affect physical health and proneness to disease through depletion of the body's immune system. Relatively little research, however, has investigated the potential immunoenhancing effect of stress-relieving strategies such as progressive muscle relaxation. This study explored the relationship between immune functioning and relaxation training with persons experiencing persistent facial pain. In a single experimental session, 21 subjects either received relaxation training or rested for an equivalent time period. Salivary immunoglobulin A, mood, pain, and tension levels were measured before and after relaxation and rest periods. Results indicated that a greater proportion of those receiving relaxation training had increases in secretion of salivary immunoglobulin A. These findings suggest that immunoenhancement may be another potential benefit of progressive relaxation training for persons with chronic pain conditions.

Analysis of Variance↗

Impaired lymphocyte stimulation induced by long-term training.

In recent there has been increasing interest in the definition of hormone influence on the immune system. Physical stress provides a suitable model for studying the interactions between the immune system and the neuroendocrine factors which have been shown to modulate the lymphoid cellular compartment. Our approach has been devoted to defining the stable modifications induced in the immune system in athletes during agonistic training. The results show that the circulating compartment of the immune system tends to modulate its different subsets under the continuous influence of stress hormones, together with a specific functional impairment of the helper subset in the proliferative response after stimulation with PHA, and particularly with PWM.

Antibodies, Monoclonal↗

[The immunomodulating action of polyunsaturated phospholipids].

Intravenous injection of essential to Wistar rats stimulates the immune response to sheep's red cells and also induces the appearance of heavy red cells in animal's blood, thus causing the secretion of immunomodulating factor by sticking spleen's cells to glass. Physical training (swimming) suppresses the immune response to sheep's red cells. This effect is connected with light red cells. Essential injection to swimming rats normalizes the immune response and prevents the appearance of light red cells in blood of animals which possess the immunosuppressing activity.

Adjuvants, Immunologic↗

Provider characteristics and behaviors as predictors of immunization coverage.

BACKGROUND: Most studies of immunization behaviors measure adherence to standard immunization practices, relying on surveys without linking reported behaviors to objectively measured immunization rates. This study attempts to close that gap. METHODS: In 1997, pediatric, family, and general providers in Pennsylvania serving children aged < 36 months (N = 251) completed immunization behavior surveys. We linked these responses to patient chart audits for practice-level immunization rates. RESULTS: Immunization rates for our sample fell short of national goals (average up-to-date immunization status at 12 months = 69%). They were significantly higher for pediatricians than for family/general practitioners (78% vs 58%, p < 0.001) and for practices treating > or = 100 children in the past 30 working days than for those treating < 100 children (77% vs 62%, p < 0.001). Behaviors with significant associations to higher immunization coverage were: (1) appropriately giving diphtheria, tetanus toxoids, and pertussis immunization under false contraindications versus withholding it (73% vs 66%, p < 0.05); (2) willingness to give at least four injections at one visit versus fewer injections (74% vs 65%, p < 0.01); and (3) holding immunization in-service training versus no training (71% vs 65%, p < 0.05). However, multivariate analysis showed that only provider specialty remained a significant predictor of coverage. CONCLUSIONS: Pediatricians have higher coverage rates than family/general practitioners. Although pediatricians see more children, the number of immunization-delayed children at 12 months is approximately the same for both provider groups. Therefore, efforts to improve coverage should continue to be directed toward both groups.

Child, Preschool↗

Mimicking microbial 'education' of the immune system: a strategy to revert the epidemic trend of atopy and allergic asthma?

Deficient microbial stimulation of the immune system, caused by hygiene, may underly the atopy and allergic asthma epidemic we are currently experiencing. Consistent with this 'hygiene hypothesis', research on immunotherapy of allergic diseases also centres on bacteria-derived molecules (eg DNA immunostimulatory sequences) as adjuvants for allergen-specific type 1 immune responses. If we understood how certain microbes physiologically 'educate' our immune system to interact safely with environmental nonmicrobial antigens, we might be able to learn to mimic their beneficial actions. Programmed 'immunoeducation' would consist of safe administration, by the correct route, dose and timing, of those microbial stimuli that are necessary to 'train' the developing mucosal immune system and to maintain an appropriate homeostatic equilibrium between its components. Overall, this would result in a prevention of atopy that is not limited to certain specific allergens. Although such a strategy is far beyond our present potential, it may in principle revert the epidemic trend of atopy and allergic asthma without jeopardizing the fight against infectious diseases.

Asthma↗

Adoption of reminder and recall messages for immunizations by pediatricians and public health clinics.

OBJECTIVE: Strong scientific evidence and national recommendations support the use of reminder and recall messages to improve immunization coverage rates, yet reports have suggested that only a minority of pediatric practices use such messages. Our aims were to 1) determine the proportions of pediatric practices and public clinics that currently use practice-based reminder or recall messages and routinely undergo immunization assessment efforts, 2) evaluate barriers and supports to implementing these practices, and 3) identify predictors of either current use or plans for future adoption of these practices. METHODS: This study combined qualitative and quantitative methods in sequential phases. In the qualitative phase, we conducted semistructured, open-ended interviews with a convenience sample of 18 clinician-administrators representing adopters and nonadopters of these messages in both private practices and public health clinics. In the subsequent quantitative phase, we mailed a structured, closed-ended survey to national samples of randomly selected pediatricians (n = 600) and public clinics (n = 600). RESULTS: Response rates were 75% for pediatricians and 77% for public clinics. Among pediatricians, 38% were conducting regular assessments of immunization coverage but only 16% were currently using routine reminder or recall messages. Among public clinics, 85% were conducting regular assessments and 51% were using reminder or recall messages. Among pediatricians' practices, the most commonly reported barriers to the adoption of reminder or recall messages were lack of time and funding and the inability to identify children at specified ages. For pediatricians' practices, the strongest predictors of current use of reminder or recall messages were having a champion who led efforts to improve immunization delivery (odds ratio: 1.85; 95% confidence interval: 1.08-3.18) and current use of regular immunization assessments (odds ratio: 2.30; 95% confidence interval: 1.33-3.84). Likewise, for public health clinics, having a champion to lead immunization improvement efforts and believing that their current system needed improvement was associated with current use of reminder or recall messages. CONCLUSIONS: Reminder and recall messages remain underused by both pediatricians and public health clinics. Promising strategies to promote adoption of these approaches in both the private and the public sectors include identifying and training champions to promote immunization delivery improvement efforts and helping practices develop methods to identify children at specific ages.

Ambulatory Care Facilities↗

Modulation of the immune system by the autonomic nervous system and its implication in immunological changes after training.

This review examines the role of the autonomic nervous system in the regulation of the immune system to understand the alteration of immunological parameters under the influence of stressors and exercise. Sympathetic innervation in secondary lymphoid organs plays a major role in immune regulation. Catecholamine released from the nerve terminal serves as the major mediator when bound to adrenergic receptors present on immunocompetent cells. Experiments using chemical and surgical denervation, catecholamine knock-out mice, and receptor antagonist and agonists revealed several important points. Sympathetic nerve activity is generally suppressive for the immunocompetent cells in the blood stream except neutrophils. Sympathetic activity facilitates detachment of T cells and NK cells from blood vessels without affecting functional adhesion molecule expression. Th1 cells express more beta 2 adrenergic receptors than Th2 cells, indicating a greater influence of sympathetic activity on Th1 response. Sympathetic action was also shown to regulate the production of chemokines. Taken together, the sympathetic nervous system does not simply suppress the immune system but might help organize the immune response sequentially and spatially by modulating the distribution of immunocompetent cells.

Animals↗

Physician perceptions about administration of immunizations outside of physician offices.

BACKGROUND: Expanding nonphysician participation in the administration of immunizations has been suggested as a means of increasing immunization rates. However, there is little information about physician interest in collaborating with nonphysicians to provide out-of-office immunizations. METHODS: All active members of the Iowa Academy of Family Physicians were surveyed by mail. Physicians reported on their collaboration histories, their willingness to collaborate in the future, their concerns with collaboration, and whether they approved of their patients' using nonphysicians for immunizations. RESULTS: Of 898 eligible physicians, 476 (53%) returned questionnaires that were analyzed. Seventy-five percent (n = 357) of the physicians reported that they had voluntarily collaborated with a person outside their office to provide immunizations. Ninety-five percent (n = 452) of physicians indicated a willingness to collaborate in some form in the future. However, physicians had concerns about (a) being able to be kept informed about immunizations their patients receive outside of their offices, (b) adequate training of the nonphysician to administer immunizations and respond to complications of immunization, and (c) loss of preventive health opportunities if patients ceased coming to physicians for routine immunizations. CONCLUSION: The majority of family physicians have collaborated to deliver immunizations and indicate support for nonphysician participation. Almost all physicians would consider future collaborative arrangements although they have concerns about record keeping and the safety of out-of-office immunization programs.

Adult↗

A review of the impact of hypnosis, relaxation, guided imagery and individual differences on aspects of immunity and health.

This review considers psychological interventions involving relaxation and guided imagery targeting immune functions. The review provides evidence of immune control accompanied by reports of enhanced mood and well-being. Three recent investigations of the author and his colleagues with self-hypnosis training incorporating imagery of the immune system are outlined. In two studies, hypnosis buffered the effects of stress on immune functions in medical students at exam time, and the comparison of self-hypnosis with and without immune imagery confirmed advantages to targeted imagery for both immune function and mood, and importantly, fewer winter viral infections. The implications for health were investigated in a third study in patients with virulent and chronic herpes simplex virus-2 HSV-2). Six weeks of training almost halved recurrence, improved mood and reduced levels of clinical depression and anxiety. Immune functions were up-regulated, notably functional natural killer cell activity to HSV-1. Individual differences in hypnotic susceptibility and absorption have typically been found to predict efficacy. New replicable evidence is reviewed of the importance of cognitive activation, a personality difference whose neurophysiological underpinning is consistent with left hemispheric preferential influences over the immune system. Now that the validation of psychological interventions includes advantages for health, this field of enquiry, which has been characterised by modest, small scale, largely preliminary studies, warrants a greater investment in research.

Health↗

[Vaccinations in sports and recommendations for immunization against flu, hepatitis A and hepatitis B].

Intensive physical training in elite athletes can have an adverse effect on the immune system, and can increase the susceptibility to infectious diseases. The insult to the immune system includes the cellular, humoral and phagocitic pathways. The increased incidence of viral infections (in particularly of the upper respiratory tract) occurs mainly during periods of intense exercise training and competitions due to the combination of physiological and psychological stress. Other factors that may contribute to the decreased immunity and increased susceptibility to infections include eating disorders and nutritional deficiencies, jet lag, sleep deprivation, and lack of proper hygiene in shared food and sleeping quarters. For elite athletes, even a mild viral infection can be devastating due to loss of important training hours and/or compromise of competitive performance. Therefore, in addition to the goal of improving the athletes performance, another important responsibility/obligation of the staff working with athletes (physicians, nutritionists, physiotherapists, and psychologists), is to emphasize preventive medicine and maintenance of good health. In this article we define athletes, and especially elite athletes, as a population at risk of various infections, and recommend immunization against hepatitis A and B and a yearly immunization against influenza.

Hepatitis A↗

[Cost of tetanus toxoid injection using a jet-injector (Imule) in collective immunization in Senegal: comparison with injection using a syringe and resterilizable needle].

Needle-less jet injectors were developed by the US army after World War II. Their principal use, however, has been in the administration of lyophilized vaccines from multidose vials to at-risk populations in developing countries. In 1983, a hepatitis B epidemic occurred among customers of a beauty clinic in California (USA) following the use of jet-injectors, demonstrating a clear risk of cross-contamination associated with this technique. As a result, the WHO and Unicef stopped recommending jet-injectors for collective immunizations in developing countries. To eliminate the risk of contamination, Pasteur Mérieux Sérums et Vaccins (now Aventis Pasteur) developed, in 1990, jet-injectors for use with single-use vaccine cartridges. These injectors were tested for tetanus toxoid, DTP, influenza, hepatitis A and typhoid Vi vaccination. The immunogenic reaction was as strong and the injection as well tolerated as for injections using a standard needle and syringe. The additional cost of the Imule technique was evaluated in a district-wide (127,000 inhabitants) tetanus toxoid immunization program at Velingara, Senegal in 1993. The total cost was estimated to be 1.51 FF (76 F CSA, 0.32 US dollars) for one dose of tetanus vaccine given by needle and syringe and 2.41 FF (121 F CSA, 0.56 US dollars) for one dose given by Imule. Thus, the additional cost of injection by ImuleTM was 0.90 FF (45 F CSA, 0.21 US dollars). The cost of cross infection in sub-Saharan Africa has been estimated to be 2.37 FF (118 F CSA, 0.55 US dollars) per injection if injection practices are not supervised. Therefore, the Imule technique may be considered to be cost-effective. However, the technique is still not completely reliable, as shown by the total breakdown of four jet injectors during this vaccination session. Lyophilized vaccines have also not been tested in the field. Vaccinators prefer Imule, training is easy and immunization can be carried out on a day-to-day basis with no vaccine wastage. Imule is not yet in mass production, which would reduce costs. In the face of the ever-increasing risk of cross-contamination during vaccination sessions in sub-Saharan Africa, the Imule technique deserves considerable attention.

Cost-Benefit Analysis↗

Regulation of neutrophil function during exercise.

In recent years there has been considerable interest in how exercise and training may affect the immune system. There is now substantial cross-sectional and epidemiological evidence that exercise causes significant changes in the distribution and function of a number of cellular and humoral immune parameters. Neutrophils represent one of the key nonspecific host defence cell populations responsible for the phagocytosis of many microbial, bacterial and viral pathogens. The neutrophil is also known to be involved in the synthesis and release of immunomodulatory cytokines that influence both T cell and B cell activities. Therefore, it plays an important role in both the efferent (phagocytosis and degranulation) and afferent (release of immunomodulatory molecules) limbs of the immune response. Neutrophils and macrophages respond both to phagocytosable particles (e.g. bacteria, viruses and cell debris) and to a number of soluble factors. There is an increase in the number of circulating neutrophils with exercise as a result of demargination of cells from endothelial tissues (mediated by catecholamines) and bone marrow (mediated by cortisol), or as part of the phagocytic and inflammatory response to exercise-induced tissue damage. Following exercise-induced mobilisation into the circulation and migration into tissues, neutrophils undergo adherence, phagocytosis (engulfment) of bacteria or tissue fragments, degranulation of cytoplasmic granules and, ultimately, activation of the respiratory burst. The capacity of the respiratory burst largely determines the cytotoxic potential of the neutrophil. The respiratory burst involves a sudden increase in nonmitochondrial oxidative metabolism, resulting in the production of the superoxide anion (O2-) and other reactive oxygen species by the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase enzyme complex located at the plasma membrane. Although the biochemistry of the respiratory burst has been well studied, the mechanisms by which exercise and training may influence its activity are not well characterised or understood. Studies on the acute effects of exercise show that exercise generally elicits an initial activation of neutrophils-evidenced by release of cytoplasmic enzymes (degranulation) with secondary changes in key effector functions such as the phagocytic and respiratory burst activity. The nature of the functional changes is still unclear, as some studies show a transient suppression of the respiratory burst and/or phagocytic capacity immediately after exercise, while others report that moderate intensity exercise elicits an enhanced response. The variability in findings may be attributable to differences in the age, gender and initial fitness levels of the people studied, the intensity and duration of the exercise protocols used, and the different methodological procedures employed.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell Degranulation↗

Effect of the Vaccines for Children program on physician referral of children to public vaccine clinics: a pre-post comparison.

OBJECTIVE: Started in late 1994, the Vaccines for Children (VFC) program is a major entitlement program that provides states with free vaccines for disadvantaged children. Some evaluation studies have been conducted, but they do not include individually matched pre-post comparisons of physician responses. This project studied the effect of the VFC on the physician likelihood of referring children to public vaccine clinics for immunizations. DESIGN: In 1999, trained personnel conducted a survey of a cohort of physicians who previously participated in surveys on barriers to childhood vaccination conducted before VFC implementation. Responses were matched, and pre- versus post-VFC comparisons were made. SETTING AND PARTICIPANTS: Minnesota and Pennsylvania primary care physicians selected by stratified random sampling and initially studied in 1990 to 1991 and 1993, respectively. MAIN OUTCOME MEASURES: Likelihood of referral of a child to a public vaccine clinic. RESULTS: On a scale of 0 to 10, physician likelihood of referring an uninsured child decreased by a mean of 1.9 (95% confidence interval: 1.2-2.5) from pre- to post-VFC. Two fifths (45%) of physicians reported that the VFC decreased the number of referrals from their practice to public vaccine clinics and 50% gave intermediate responses. Among physicians who participate in VFC, only 9% were likely to refer a Medicaid-insured child in contrast to 44% of those not participating. CONCLUSIONS: Physicians' reported referral and likelihood of referring Medicaid-insured and uninsured children has decreased because of VFC in Minnesota and Pennsylvania.vaccination/economics, vaccination/legislation and jurisprudence, immunization programs/economics, immunization programs/utilization, vaccines/economics, Medicaid/economics, national health programs United States, child health services.

Capitation Fee↗

Exercise and immune function. Recent developments.

Comparison of immune function in athletes and nonathletes reveals that the adaptive immune system is largely unaffected by athletic endeavour. The innate immune system appears to respond differentially to the chronic stress of intensive exercise, with natural killer cell activity tending to be enhanced while neutrophil function is suppressed. However, even when significant changes in the level and functional activity of immune parameters have been observed in athletes, investigators have had little success in linking these to a higher incidence of infection and illness. Many components of the immune system exhibit change after prolonged heavy exertion. During this 'open window' of altered immunity (which may last between 3 and 72 hours, depending on the parameter measured), viruses and bacteria may gain a foothold, increasing the risk of subclinical and clinical infection. However, no serious attempt has been made by investigators to demonstrate that athletes showing the most extreme post-exercise immunosuppression are those that contract an infection during the ensuing 1 to 2 weeks. This link must be established before the 'open window' theory can be wholly accepted. The influence of nutritional supplements, primarily zinc, vitamin C, glutamin and carbohydrate, on the acute immune response to prolonged exercise has been measured in endurance athletes. Vitamin C and glutamine have received much attention, but the data thus far are inconclusive. The most impressive results have been reported in the carbohydrate supplementation studies. Carbohydrate beverage ingestion has been associated with higher plasma glucose levels, an attenuated cortisol and growth hormone response, fewer perturbations in blood immune cell counts, lower granulocyte and monocyte phagocytosis and oxidative burst activity, and a diminished pro- and anti-inflammatory cytokine response. It remains to be shown whether carbohydrate supplementation diminishes the frequency of infections in the recovery period after strenuous exercise. Studies on the influence of moderate exercise training on host protection and immune function have shown that near-daily brisk walking compared with inactivity reduced the number of sickness days by half over a 12- to 15-week period without change in resting immune function. Positive effects on immunosurveillance and host protection that come with moderate exercise training are probably related to a summation effect from acute positive changes that occur during each exercise bout. No convincing data exist that moderate exercise training is linked with improved T helper cell counts in patients with HIV, or enhanced immunity in elderly participants.

Aged↗

Potential markers of heavy training in highly trained distance runners.

Markers of a heavy increase in training were examined in ten highly trained distance runners (mean(s.d.) age 29.8(1.7) years, maximal oxygen intake 65.3 ml kg-1 min-1, personal best 10-km time 31 min 4 s) who undertook a deliberate 38% increment of training over a 3-week period. Their running performance did not improve, and six of the ten subjects developed sustained fatigue, suggesting that training was excessive, although the full clinical picture of overtraining did not develop. The Profile of Mood States was the best single marker of disturbed function, indicating increased fatigue and decreased vigour. There were no useful changes of resting heart rate or perceived exertion during submaximal running, sleep was undisturbed, and there were no orthopaedic injuries. Two subjects developed rhinoviral infections following the heavy training, and a third complained of symptoms that were diagnosed 2 weeks later as exercise-induced asthma. The increase of serum cortisol normally induced by 30 min of submaximal exercise was no longer seen when the same acute exercise was performed after heavy training. Resting lymphocyte proliferation tended to increase in response to phytohaematoglutinin (PHA) and concanavalin A (Con A), the ratio of helper to suppressor cells (H/S) decreased, and pokeweed mitogen induced smaller increases in IgG and IgM synthesis. Whereas before heavy training, PHA-stimulated lymphocyte proliferation was unchanged by 30 min of acute submaximal exercise, after 3 weeks of heavy training the same bout of exercise caused an 18% suppression of proliferation. Likewise, heavy training brought about a decrease of T-lymphocytes in response to acute submaximal exercise, but an abolition of the acute exercise-induced decrease in the H/S ratio. The previously observed exercise-induced decrease of IgG synthesis did not occur when the same acute bout of exercise was performed after heavy training. We conclude that such minor and transient changes of immune function may possibly be a warning that training is becoming excessive, but they have only a limited significance for overall immune function.

Adult↗