Mechanisms stress disorder

A number of skin diseases, mainly characterized by blistering, have been found to be due to mutations in genes encoding various keratins. Three of these disorders are epidermolysis bullosa simplex, epidermolytic hyperkeratosis, and epidermolytic pahnoplantar kerato-derma. The blistering probably reflects a diminished capacity of various layers of the skin to resist mechanical stresses due to abnormalities in microfilament strucmre. 

The mechanisms of flashbacks are probably mixed. Some cases may be similar to post-traumatic stress disorder induced by a bad trip (Paton et al., 1973). Abraham (1983) suggested that some of the visual phenomena, such as trailing and after-images, were due to failure of inhibition in visual pathways, possibly mediated in the lateral geniculate nucleus which (in the macaque monkey) contains on-off colour neurons with receptor fields similar to those described in flashbacks. The neurochemical causes of such flashbacks, which can be very disturbing, remains elusive and attempts at treatment are usually ineffective. 

Charney DS, Deutch AY, Krystal JH, Southwick SM, Davis M (1993) Psychobiologic mechanisms of posttraumatic stress disorder. Arch Gen Psychiatry 50 294-299... 

Anxiety represents a state of heightened vigilance and fear, but pathological anxiety can be distinguished from fear in that it is inappropriately evoked and may persist in the absence of real threat or danger. The study of conditioned fear has provided detailed information on the neural circuitry and intracellular mechanisms that are important to fear responses and their long-term retention. The description of neural circuitry and the mechanisms underlying disorders of fear memory such as posttraumatic stress disorder (PTSD) may also be relevant to other anxiety states that share common neural substrates. 

Friedman, M.J. (1990) Interrelationships between biological mechanisms and pharmacotherapy of post-traumatic stress disorder. In Wolfe, M.E. and Mosnian, A.D. eds. Posttraumatic Stress Disorder Etiology, Phenomenology, and Treatment. Washington, DC American Psychiatric Press pp. 204-225. 

O Donnell, T., K.M. Hegadoren, and N. C. Coupland. Noradrenergic Mechanisms in the Pathophysiology of Post-traumatic Stress Disorder. Biological Psychiatry 50 (2004) 273-283. 

Charney DS, Deutch AY, Krystal JH, et al Psychobiologic mechanisms of posttraumatic stress disorder. Arch Gen Psychiatry 50 294-305, 1993 Chassen JB Intensive design statistics and the single case, in Research Designs and Methods in Psychiatry. Edited by Fava M, Rosenbaum JF. Amsterdam, Elsevier, 1992, pp 173-183... 

Pall ML, Satterlee JD. Elevated nitric oxide/peroxynitrite mechanism for the common etiology of multiple chemical sensitivity, chronic fatigue syndrome and posttraumatic stress disorder. Ann NY Acad Sci 2001 933 323-9. 

When compared with the selective serotonin reuptake inhibitors (SSRIs), mirtazapine may show an earlier onset of action (although data are currently not well established). Mirtazapine has also been found to be efficacious in the treatment of elderly patients with depression. Mirtazapine has been shown to be effective in the treatment of panic disorder, social phobia, and post-traumatic stress disorder. In one study, mirtazapine combined with citalopram in obsessive-compulsive patients induced an earlier response when compared with citalopram plus placebo. It was suggested that antagonism of presynaptic a2-adrenergic receptors does not enhance serotonin neurotransmission directly, but rather disinhibits the norepinephrine activation of serotonergic neurons and thereby increases serotonergic neurotransmission by a mechanism that may not require a time-dependent desensitization of receptors. 

Grevin, F. (1996). Posttraumatic stress disorder, ego defence mechanisms and empathy among urban paramedics. Psychological Reports 79 483-95. 

Rapid advances in semiconductor techrwlogy, including thin film formation by deposition, interface preparation or microstructuring, demand characterization techniques that provide understanding of the fundamental processes involved, including information on structural order—disorder and spatial inhomogeneity. Raman spectroscopy is used both in process control and quality assessment [34]. Typical examples of semiconductor applications are composition determination, analysis of crystal structure, surface and interface analysis, phase determination, doping, point defects, temperature influence and mechanical stress. 

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