Interaction of cattle health/immunity and nutrition.
(9/1258)
The usual means of assessing the health of newly received beef cattle susceptible to bovine respiratory disease (BRD) are subjective, typically involving visual evaluation aided by minimal clinical measurements. Recent evidence based on the occurrence of pneumonic lung lesions at slaughter indicates a need for more accurate methods of diagnosing BRD. Inadequate passive immune transfer at birth may be an important risk factor in susceptibility to BRD, suggesting the need for management to improve passive transfer success rates. Preweaning management and vaccination practices offer opportunities for beef cattle producers to improve the immune status of newly weaned calves and decrease postweaning BRD. Feeding diets with higher levels of concentrate typically improves performance by newly weaned or received cattle, as does feeding diets supplemented with protein; however, limited data suggest that increasing concentrate and protein in receiving diets increases the rate and severity of subjectively determined BRD morbidity. Research with receiving diet concentrate/protein level relative to humoral and cell-mediated immune function coupled with indicators of health and performance is needed. Supplemental B vitamins are sometimes useful in receiving diets, but the effects have been variable, presumably reflecting differences in stress and associated feed intake responses. Vitamin E added to receiving diets to supply > or = 400 IU/animal daily seems beneficial for increasing gain and decreasing BRD morbidity; however, further dose titration experiments are needed. Supplemental Zn, Cu, Se, and Cr can alter immune function of newly received calves, and some field trials have shown decreases in BRD morbidity rate with supplementation; however, several experiments have shown no performance or health/immune benefits from supplementation of these trace minerals. Formulation of receiving diets should take into account decreased feed intake by highly stressed, newly received beef cattle and known nutrient deficiencies, but fortification of such diets with trace minerals beyond the levels needed to compensate for these effects is difficult to justify from present data. (+info)
Exposure to exogenous estrogens in food: possible impact on human development and health.
(10/1258)
There has been increasing concern about the impact of environmental compounds with hormone-like action on human development and reproductive health over the past decades. An alternative but neglected source of hormone action that may be considered in this connection is hormone residues in meat from husbandry animals treated with sex steroid hormones for growth promotion. Treatment of cattle with naturally occurring or synthetic sex hormones may enhance lean muscle growth and improve feed efficiency and is therefore a very cost effective procedure for cattle producers who have used it for decades in some Western countries, including the USA and Canada. The Joint Food and Agricultural Organisation/World Health Organisation (FAO/WHO) expert committee on food additives (JECFA) and the US Food and Drug Administration (FDA) considered, in 1988, that the residues found in meat from treated animals were safe for the consumers. We have re-evaluated the JECFA conclusions regarding the safety of estradiol residues in meat in the light of recent scientific data, with special emphasis on estradiol levels in prepubertal children. These levels are needed for estimates of the normal daily production rates of estradiol in children, who may be particularly sensitive to low levels of estradiol. In our opinion, the conclusions by JECFA concerning the safety of hormone residues in meat seem to be based on uncertain assumptions and inadequate scientific data. Our concerns can be summarized as follows. 1) The data on residue levels in meat were based on studies performed in the 1970's and 1980's using radioimmunoassay (RIA) methods available at the time. The sensitivity of the methods was generally inadequate to measure precisely the low levels found in animal tissues, and considerable variation between different RIA methods for measuring steroids exists. Therefore the reported residue levels may be subject to considerable uncertainty. 2) Only limited information on the levels of the various metabolites of the steroids was given despite the fact that metabolites also may have biological activity. 3) Reliable data on daily production rates of steroid hormones were and are still lacking in healthy prepubertal children. This lack is crucial as previous guidelines regarding acceptable levels of steroid residues in edible animal tissues have been based on very questionable estimates of production rates in children. Thus, even today the US FDA bases its guidelines on the presumably highly overestimated production rates in prepubertal children given in the JECFA 1988 report. 4) The possible biological significance of very low levels of estradiol is neglected. In conclusion, based on our current knowledge possible adverse effects on human health by consumption of meat from hormone-treated animals cannot be excluded. (+info)
Myofibroblasts. I. Paracrine cells important in health and disease.
(11/1258)
Myofibroblasts are a unique group of smooth-muscle-like fibroblasts that have a similar appearance and function regardless of their tissue of residence. Through the secretion of inflammatory and anti-inflammatory cytokines, chemokines, growth factors, both lipid and gaseous inflammatory mediators, as well as extracellular matrix proteins and proteases, they play an important role in organogenesis and oncogenesis, inflammation, repair, and fibrosis in most organs and tissues. Platelet-derived growth factor (PDGF) and stem cell factor are two secreted proteins responsible for differentiating myofibroblasts from embryological stem cells. These and other growth factors cause proliferation of myofibroblasts, and myofibroblast secretion of extracellular matrix (ECM) molecules and various cytokines and growth factors causes mobility, proliferation, and differentiation of epithelial or parenchymal cells. Repeated cycles of injury and repair lead to organ or tissue fibrosis through secretion of ECM by the myofibroblasts. Transforming growth factor-beta and the PDGF family of growth factors are the key factors in the fibrotic response. Because of their ubiquitous presence in all tissues, myofibroblasts play important roles in various organ diseases and perhaps in multisystem diseases as well. (+info)
Challenge of Goodness II: new humanitarian technology, developed in croatia and bosnia and Herzegovina in 1991-1995, and applied and evaluated in Kosovo 1999.
(12/1258)
This paper presents improvements of the humanitarian proposals of the Challenge of Goodness project published earlier (1). In 1999 Kosovo crisis, these proposals were checked in practice. The priority was again on the practical intervention - helping people directly - to prevent, stop, and ease suffering. Kosovo experience also prompted us to modify the concept of the Challenge of Goodness. It should include research and education (1. redefinition of health, 2. confronting genocide, 3. university studies and education, and 4. collecting experience); evaluation (1. Red Cross forum, 2. organization and technology assessment, 3. Open Hand - Experience of Good People); activities in different stages of war or conflict in: 1. prevention (right to a home, Hate Watch, early warning), 2. duration (refugee camps, prisoners-of-war camps, global hospital, minorities), 3. end of conflict (planned, organized, and evaluated protection), 4. post conflict (remaini ng and abandoned populations, prisoners of war and missing persons, civilian participation, return, and renewal). Effectiveness of humanitarian intervention may be performed by politicians, soldiers, humanitarian workers, and volunteers, but the responsibility lies on science. Science must objectively collect data, develop hypotheses, check them in practice, allow education, and be the force of good, upon which everybody can rely. Never since the World War II has anybody in Europe suffered in war and conflict so much as peoples in Croatia, Bosnia and Herzegovina, and Kosovo. We should search for the meaning of their suffering, and develop new knowledge and technology of peace. (+info)
Essential fatty acids in health and chronic disease.
(13/1258)
Human beings evolved consuming a diet that contained about equal amounts of n-3 and n-6 essential fatty acids. Over the past 100-150 y there has been an enormous increase in the consumption of n-6 fatty acids due to the increased intake of vegetable oils from corn, sunflower seeds, safflower seeds, cottonseed, and soybeans. Today, in Western diets, the ratio of n-6 to n-3 fatty acids ranges from approximately 20-30:1 instead of the traditional range of 1-2:1. Studies indicate that a high intake of n-6 fatty acids shifts the physiologic state to one that is prothrombotic and proaggregatory, characterized by increases in blood viscosity, vasospasm, and vasoconstriction and decreases in bleeding time. n-3 Fatty acids, however, have antiinflammatory, antithrombotic, antiarrhythmic, hypolipidemic, and vasodilatory properties. These beneficial effects of n-3 fatty acids have been shown in the secondary prevention of coronary heart disease, hypertension, type 2 diabetes, and, in some patients with renal disease, rheumatoid arthritis, ulcerative colitis, Crohn disease, and chronic obstructive pulmonary disease. Most of the studies were carried out with fish oils [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)]. However, alpha-linolenic acid, found in green leafy vegetables, flaxseed, rapeseed, and walnuts, desaturates and elongates in the human body to EPA and DHA and by itself may have beneficial effects in health and in the control of chronic diseases. (+info)
Review article: the pharmacokinetics of rabeprazole in health and disease.
(14/1258)
Rabeprazole, a newly developed proton pump inhibitor, has been shown to be effective for the treatment of gastric and duodenal ulcers and for gastro-oesophageal reflux disease. It is a rapid and potent inhibitor of gastric H+,K(+)-ATPase, the gastric acid (proton) pump. The maximum plasma concentration (Cmax) and the area under the plasma concentration time curve (AUC) are linearly related to dose, while the time to maximum plasma concentration (tmax) and elimination half-life (t1/2) are dose-independent. Rabeprazole is extensively metabolized in the liver via the cytochrome P450 enzyme system, and its metabolites are excreted primarily in the urine. Rabeprazole does not accumulate with repeated dosing. Its bioavailability is not influenced by the coingestion of either food or antacids. The pharmacokinetic profile of rabeprazole is substantially altered in the elderly and patients with stable compensated chronic cirrhosis; however, these alterations are not associated with clinically significant abnormalities in laboratory parameters or serious adverse events. The influence of severe decompensated liver disease on the pharmacokinetics of rabeprazole has not been assessed. The pharmacokinetic profile of rabeprazole is not significantly altered by renal dysfunction requiring maintenance haemodialysis. These findings suggest that dosage adjustment is not required in these special patient populations. Caution should be exercised, however, in patients with severe liver disease. (+info)
Workplace as an origin of health inequalities.
(15/1258)
OBJECTIVE: To investigate the effect of the workplace on the socioeconomic gradient of sickness absence. DESIGN: Comparison of the relation between socioeconomic status and employee sickness absence in three different towns. SETTINGS: The towns of Raisio, Valkeakoski, and Nokia in Finland. They are equal in size and regional social deprivation indices, located in the neighbourhood of a larger city, and produce the same services to the inhabitants. SUBJECTS: All permanent local government employees from Raisio (n = 887), Valkeakoski (n = 972), and Nokia (n = 934) on the employer's registers during 1991 to 1993. MAIN OUTCOME MEASURES: Rates of short (1-3 days) and long (> 3 days) spells of sickness absence, irrespective of cause, and separately for infection, musculoskeletal disorder, and trauma. RESULTS: In blue collar male and female workers, compared with the same sex higher grade white collar workers, the age adjusted numbers of long sick leaves were 4.9 (95% CI 4.2, 5.8) and 2.8 (2.6, 3.1) times higher, respectively. The risk varied significantly between the towns, in men in relation to long sick leaves irrespective of cause and resulting from musculoskeletal disorders, and in women in relation to long leaves resulting from infection. The numbers of long sick leaves were 3.9 (95% CI 2.8, 5.4) times higher in blue collar male workers than in higher grade white collar male workers in Raisio, 4.9 (95% CI 3.8, 6.3) times higher in Valkeakoski, and 5.8 (95% CI 4.5, 7.5) times higher in Nokia. Sickness absence of blue collar employees differed most between the towns. The rates of long sick leaves in blue collar men were 1.46 times greater (95% CI 1.25, 1.72) in Valkeakoski and 1.85 times greater (95% CI 1.58, 2.16) in Nokia than in Raisio. In men, no significant differences were found between the towns as regards the numbers of long sick leaves of higher grade white collar male workers. The socioeconomic gradients differed more between the towns in men who had worked for four years or more in the same employment than in men who had worked for shorter periods. No consistent health gradients of socioeconomic status were evident for short sick leaves among either sex. CONCLUSIONS: In men and to a lesser extent in women, the workplace is significantly associated with health inequalities as reflected by medically certified sickness absence and the corresponding socioeconomic gradients of health. (+info)
Prenatal diagnosis and selective abortion: a challenge to practice and policy.
(16/1258)
Professionals should reexamine negative assumptions about the quality of life with prenatally detectable impairments and should reform clinical practice and public policy to improve informed decision making and genuine reproductive choice. Current data on children and families affected by disabilities indicate that disability does not preclude a satisfying life. Many problems attributed to the existence of a disability actually stem from inadequate social arrangements that public health professionals should work to change. This article assumes a pro-choice perspective but suggests that unreflective uses of prenatal testing could diminish, rather than expand, women's choices. This critique challenges the view of disability that lies behind the social endorsement of such testing and the conviction that women will or should end their pregnancies if they discover that the fetus has a disabling trait. (+info)