Annals of the New York Academy of Sciences
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Ann. N. Y. Acad. Sci. · Jun 2002
Review Comparative StudyCell-mediated immune response in MDMA users after repeated dose administration: studies in controlled versus noncontrolled settings.
Acute administration of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") produces time-dependent immune dysfunction in humans. Recreational use of MDMA generally includes repeated drug consumption, often in association with other drugs, such as alcohol and cannabis. In the laboratory setting, repeated MDMA administration to healthy MDMA consumers produced a time-dependent immune dysfunction similar to that observed with the ingestion of a single dose, and the first of the two administrations paralleled the time-course of MDMA-induced cortisol stimulation kinetics and MDMA plasma concentrations. ⋯ By contrast, NK cells in MDMA consumers were reduced to one-third of those from healthy persons. A statistically significant decrease in affected immune parameters was recorded during a 2-year observation period in a subgroup of recreational MDMA users. These permanent alterations in immunologic homeostasis may result in impairment of general health and subsequent increased susceptibility to infection and immune-related disorders.
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Ann. N. Y. Acad. Sci. · Jun 2002
Review Comparative StudyNeuropeptides in experimental and degenerative arthritis.
Classical symptoms of both inflammatory and degenerative arthritides may contribute to neurogenic responses like wheal, flare, edema, and pain. Rheumatoid arthritis (RA) is an autoimmune disease with an immunogenetic background. Neurogenic inflammation has been considered to play an essential role in RA, in part because of the symmetrical involvement (cross-spinal reflexes) and the predominant involvement of the most heavily innervated small joints of the hands and the feet (highly represented in the hominiculus). ⋯ Neuropeptides serve as messengers, which modulate and mediate the actions in these cascades. Accordingly, many neuropeptides have been used successfully as experimental treatments, most recently VIP, which effectively controlled collagen-induced arthritis in mice. Therefore, it can safely be concluded that better treatment/control of disease activity and pain can be achieved by blocking the cascade leading to initiation and/or amplification of inflammatory process combined with effects on central nociceptive and neuroendocrine responses.
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Inflammation in the joint causes peripheral sensitization (increase of sensitivity of nociceptive primary afferent neurons) and central sensitization (hyperexcitability of nociceptive neurons in the central nervous system). The processes of sensitization are thought to be the basis of arthritic pain that appears as spontaneous pain (joints at rest) and hyperalgesia (augmented pain response on noxious stimulation and pain on normally nonpainful stimulation). Sensitization also facilitates efferent neuronal processes through which the nervous system influences the inflammatory process. ⋯ Central sensitization also is facilitated by mediators that have complex actions (e.g., prostaglandin E(2)). Spinal PGE(2) binds to receptors at presynaptic endings of primary afferent neurons (thus influencing synaptic release) and to receptors on postsynaptic spinal cord neurons. The administration of PGE(2) to the spinal cord surface produces changes of responsiveness of spinal neurons similar to peripheral inflammation, and spinal indomethacin to the spinal cord attenuates development of hyperexcitability significantly.
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Ann. N. Y. Acad. Sci. · Jun 2002
A single exposure to restraint stress induces behavioral and neurochemical sensitization to stimulating effects of amphetamine: involvement of NMDA receptors.
Evidence indicates that repeated exposure to stressful events sensitizes the motor and addictive effects of drugs of abuse in rats. Regarding a single exposure to one restraint stress, previous findings have shown that it is sufficient to induce behavioral sensitization to stimulating and reinforcing properties of abuse drugs (e.g., amphetamine and morphine), as measured by locomotor activity and conditioned place preference, respectively. It is well known that enhanced dopaminergic neurotransmission in the nucleus accumbens and striatum plays a critical role in the development and/or expression of repeated stress-induced or drug-induced sensitization. ⋯ MK-801 administered i.p. or intrastriatally blocked the restraint stress-induced sensitization to amphetamine. First, our results point out that a single restraint stress exposure is a pertinent stimulus to induce sensitization of amphetamine's stimulating effects on dopaminergic neurotransmission in the striatum. Secondly, NMDA-glutamatergic receptors, specifically those placed in the striatum, are implicated in the development of stress restraint-induced sensitization.
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Ann. N. Y. Acad. Sci. · Apr 2002
ReviewBeta cell rest and recovery--does it bring patients with latent autoimmune diabetes in adults to euglycemia?
Diabetes mellitus in humans is a heterogeneous disorder classified clinically into two main types. The diagnosis of type 1 versus type 2 diabetes is made phenotypically using criteria such as age at onset, abruptness of hyperglycemic symptoms, presence of ketosis, degree of obesity and the perceived need for insulin replacement. The pathogeneses of type 1 and type 2 diabetes are believed to be different. ⋯ The disease of these autoantibody-positive type 2 diabetics is often termed latent autoimmune diabetes in adults (LADA), slowly progressive type 1 diabetes, latent type 1 diabetes, and type 1.5 diabetes. This group of patients comprises approximately 10-15% of Caucasian type 2 diabetes patients. Type 1.5 diabetes patients tend to present with islet cell autoantibodies, islet-reactive T cells, higher HbA(1c) levels, lower C peptide, and a propensity toward insulin dependency compared to autoantibody-negative classic type 2 diabetes subjects.