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Immune Interactions (immune + interaction)
Selected AbstractsPhotoperiod,Testicular,Immune Interaction in a Seasonal Breeder Indian Palm Squirrel Funambulus pennanti During the Reproductively Inactive and Active PhasesJOURNAL OF NEUROENDOCRINOLOGY, Issue 1 2009R. Ahmad The differential effect of long (LD; 16 : 8 h light/dark), short (SD; 10 : 14 h light/dark) and natural day length (NDL; 12 : 12 h light/dark) during the reproductively inactive (RIP) and active (RAP) phases was assessed in relation to immunity and reproductive function of a tropical rodent Funambulus pennanti. They presented high immunity and low testicular activity during RIP and an opposite during RAP. SD increased spleen and thymus weight, leukocyte and lymphocyte counts, cell mediated immunity [i.e. blastogenic response in terms of percentage stimulation ratio of splenocytes and thymocytes (when challenged with concanavalin A)] and delayed type hypersensitivity to oxazolone. SD during RIP increased the above mentioned parameters and reduced testes weight compared to NDL groups. During RAP, LD reduced all the immunological parameters when compared with NDL and SD experiencing groups of RIP and RAP phases. The LD group reduced the immunological parameters compared to RAP, suggesting that LD had always an inhibitory effect on immune status being independent of reproductive phases. The intensity of the stimulatory effects of SD and inhibitory effects of LD during both reproductive phases was significantly different. We exposed another set of squirrels to the above photoperiodic schedule for prolonged period (30 weeks) during RAP. A clear testicular refractoriness followed by immunorefractoriness was observed in the group experiencing SD and LD for 30 weeks. The photorefractoriness presented by the testes was inversely related to the immunorefractoriness. The peripheral melatonin level of those squirrels reflected the photoperiodic signal perceived by squirrels for immunomodulation and gonadal function, suggesting that immune system and gonadal function might have coevolved. [source] The macrophage and the apoptotic cell: an innate immune interaction viewed simplistically?IMMUNOLOGY, Issue 1 2004Christopher D. Gregory Summary Macrophages play important roles in the clearance of dying and dead cells. Typically, and perhaps simplistically, they are viewed as the professional phagocytes of apoptotic cells. Clearance by macrophages of cells undergoing apoptosis is a non-phlogistic phenomenon which is often associated with actively anti-inflammatory phagocyte responses. By contrast, macrophage responses to necrotic cells, including secondarily necrotic cells derived from uncleared apoptotic cells, are perceived as proinflammatory. Indeed, persistence of apoptotic cells as a result of defective apoptotic-cell clearance has been found to be associated with the pathogenesis of autoimmune disease. Here we review the mechanisms by which macrophages interact with, and respond to, apoptotic cells. We suggest that macrophages are especially important in clearing cells at sites of histologically visible, high-rate apoptosis and that, otherwise, apoptotic cells are removed largely by non-macrophage neighbours. We challenge the view that necrotic cells, including persistent apoptotic cells are, of necessity, proinflammatory and immunostimulatory and suggest that, under appropriate circumstances, persistent apoptotic cells can provide a prolonged anti-inflammatory stimulus. [source] Cytokines and Cognition,The Case for A Head-to-Toe Inflammatory ParadigmJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 12 2002Craig J. Wilson MBBS The brain is not only immunologically active of its own accord, but also has complex peripheral immune interactions. Given the central role of cytokines in neuroimmmunoendocrine processes, it is hypothesized that these molecules influence cognition via diverse mechanisms. Peripheral cytokines penetrate the blood-brain barrier directly via active transport mechanisms or indirectly via vagal nerve stimulation. Peripheral administration of certain cytokines as biological response modifiers produces adverse cognitive effects in animals and humans. There is abundant evidence that inflammatory mechanisms within the central nervous system (CNS) contribute to cognitive impairment via cytokine-mediated interactions between neurons and glial cells. Cytokines mediate cellular mechanisms subserving cognition (e.g., cholinergic and dopaminergic pathways) and can modulate neuronal and glial cell function to facilitate neuronal regeneration or neurodegeneration. As such, there is a growing appreciation of the role of cytokine-mediated inflammatory processes in neurodegenerative diseases such as Alzheimer's disease and vascular dementia. Consistent with their involvement as mediators of bidirectional communication between the CNS and the peripheral immune system, cytokines play a key role in the hypothalamic-pituitary-adrenal axis activation seen in stress and depression. In addition, complex cognitive systems such as those that underlie religious beliefs, can modulate the effects of stress on the immune system. Indirect means by which peripheral or central cytokine dysregulation could affect cognition include impaired sleep regulation, micronutrient deficiency induced by appetite suppression, and an array of endocrine interactions. Given the multiple levels at which cytokines are capable of influencing cognition it is plausible that peripheral cytokine dysregulation with advancing age interacts with cognitive aging. [source] Kisspeptin: A Novel Regulator of Reproductive FunctionJOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2008W. S. Dhillo Young Neuroendocrinologists Prize Reviews Michael Harbuz Young Investigator Prize Lecture The UK and international neuroendocrine community was deeply shocked and saddened the unbelievably premature death of Michael Harbuz in Bristol in 2006. Mick was a superb friend and colleague, and played a huge part in the development and activities of the British Neuroendocrine Group/British Society for Neuroendocrinology (BSN), serving as both Membership Secretary and Treasurer between 1999 and 2004. Mick was a leader in the field of neuroendocrine,immune interactions, and brought a great deal of charisma, humour and ability to meetings and conferences. He was also a passionate and committed supporter of the progress of young researchers and of their participation in neuroendocrine events. He recognised that today's postgraduate students and postdoctoral research fellows are tomorrow's neuroendocrine researchers, be it in academia, the health services or industry. To recognise Mick's great commitment to and enthusiasm for postgraduate education both in the University of Bristol and in the BSN, we decided to honour and remember him by instituting the ,Michael Harbuz Young Investigator Prize Lecture' to be delivered annually. Dr Waljit Dhillo from Imperial College London was the inaugural recipient of this award, and presented his lecture at the Annual Meeting of the BSN in Nottingham in September 2007, upon which this review is based. Recent evidence demonstrates that the neuropeptide kisspeptin and its receptor, GPR54, have a fundamental role in initiating the onset of puberty and are important in regulating reproductive function. This review discusses the evidence available from animals and humans demonstrating that kisspeptin potently stimulates the release of gonadotrophins by stimulating the release of gonadotrophin-releasing hormone and that a lack of kisspeptin or GPR54 results in reproductive failure. [source] Diabetes and the enteric nervous systemNEUROGASTROENTEROLOGY & MOTILITY, Issue 12 2007B. Chandrasekharan Abstract, Diabetes is associated with several changes in gastrointestinal (GI) motility and associated symptoms such as nausea, bloating, abdominal pain, diarrhoea and constipation. The pathogenesis of altered GI functions in diabetes is multifactorial and the role of the enteric nervous system (ENS) in this respect has gained significant importance. In this review, we summarize the research carried out on diabetes-related changes in the ENS. Changes in the inhibitory and excitatory enteric neurons are described highlighting the role of loss of inhibitory neurons in early diabetic enteric neuropathy. The functional consequences of these neuronal changes result in altered gastric emptying, diarrhoea or constipation. Diabetes can also affect GI motility through changes in intestinal smooth muscle or alterations in extrinsic neuronal control. Hyperglycaemia and oxidative stress play an important role in the pathophysiology of these ENS changes. Antioxidants to prevent or treat diabetic GI motility problems have therapeutic potential. Recent research on the nerve,immune interactions demonstrates inflammation-associated neurodegeneration which can lead to motility related problems in diabetes. [source] Special Article: Modulation of natural immunity in the gut by Escherichia coli strain Nissle 1917NUTRITION REVIEWS, Issue 8 2010Ilja Trebichavsky The beneficial effect of probiotic Escherichia coli strain Nissle 1917 (EcN) suggests the gut epithelium plays a basic role in immune interactions with bacteria. Contrary to other commensal strains of Escherichia coli, EcN profoundly modulates the gut barrier to elevate its resistance to microbial pathogens. The present review documents the properties of EcN that have led to the protection of gnotobiotic pigs against lethal enteric infections. This effect could be important in light of the growing number of acquired deficiencies that paralyze gut immunity in humans. [source] Unravelling synergistic immune interactions between respiratory virus infections and allergic airway inflammationCLINICAL & EXPERIMENTAL ALLERGY, Issue 8 2004J. Schwarze No abstract is available for this article. [source] | ||||||||||