Soziodemografische und soziale Korrelate selbstberichteter Resilienz im Alter – Ergebnisse der populationsbasierten LIFE-Adult-Studie

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Resilienz bezeichnet eine gute Anpassung an Widrigkeiten und ist ein bedeutsamer Faktor für das Wohlbefinden im Alter. Erste...     

A quantitative analysis of movement detecting neurons in the frog's retina

Summary In the frog's retina (Rana esculenta, Rana pipiens) two classes of neurons which are especially sensitive to stimuli moved through the receptive fields were investigated. It was found that the following stimulus parameters determine the response of these class-2 and class-3 neurons: angular velocity (v), stimulus size (A), contrast of stimulus against a white or a black background (c), position of the path of traverse in the receptive field (P), and the time (t) between the movement of identical stimuli along the same path through the receptive field. These parameters were changed within a considerable range; the relation between the parameter change and the neuronal response is given in different equations. A final formula, which allows one to calculate the average response of a class-2 or a class-3 neurons to a stimulus moved through the excitatory receptive field is given in equations 6a and 6b.

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Zusammenfassung In der Froschretina (Rana esculenta, Rana pipiens) gibt es zwei Klassen bewegungsspezifischer Neurone. Ihre Aktionspotentiale wurden mit metallgefüllten Mikropipetten von den Endigungen der Opticusfasern in den oberflächlichen Tectumschichten registriert. Durch maschinelle visuelle Reizung mit einer Perimeterapparatur wurde gefunden, daß die folgenden Reizparameter in gesetzmäßiger Weise die Reaktionen dieser retinalen Neurone bestimmen: Winkelgeschwindigkeit (v), Größe des bewegten Reizes (A), Kontrast des Reizes gegen einen weißen oder schwarzen Hintergrund (c), Position (P) der Strecke im rezeptiven Feld, entlang welcher der Reiz durch das rezeptive Feld bewegt wurde und die Zeit (t), die zwischen der Reizung mit gleichen bewegten Mustern auf derselben Strecke durch das rezeptive Feld verstrichen ist. Auf Grund der experimentellen Befunde konnten Gleichungen aufgestellt werden (1–6), welche die Antwort der bewegungsspezifischen Neurone der Klasse 2 und der Klasse 3 der Froschnetzhaut beschreiben.

     

Effects of benzodiazepine receptor ligands on the performance of an operant delayed matching to position task in rats: opposite effects of FG 7142 and lorazepam

The effects of a series of benzodiazepine (BZ) receptor ligands, ranging from a full agonist through to partial inverse agonists, were examined on short term working memory in the rat. The behavioural paradigm used was a discrete trial, operant delayed matching to position task, as originally described by Dunnett (1985), with delays of 0, 5, 15 and 30 s. The benzodiazepine receptor (BZR) full agonist lorazepam (0.25, 0.375 and 0.5 mg/kg) dose and delay dependently impaired matching accuracy. Lorazepam also increased the latency to respond and decreased the number of nose pokes made into the food tray during the delays. In contrast, the BZR partial agonist ZK 95 962 (1, 3, 10 mg/kg) did not affect matching accuracy, but did increase the speed of responding. The BZR antagonist ZK 93 426 (1.25, 5, 25 mg/kg) had no effects in this paradigm. The BZR weak partial inverse agonists Ro 15-4513 (0.1, 1 and 10 mg/kg) and ZK 90 886 (1, 3 and 10 mg/kg) did not affect accuracy of performance. However, both of these drugs increased the latency to respond and decreased nose poke responses. These motoric effects were particularly strong following 10 mg/kg Ro 15-4513. This shows that the effects of drugs on the accuracy of responding and on the speed of responding can be dissociated. The BZR partial inverse agonist FG 7142 had effects on matching accuracy that were dependent upon dose. The lowest dose of FG 7142 (1 mg/kg) significantly improved accuracy, whereas the highest dose (10 mg/kg) impaired accuracy. This impairment induced by FG 7142 (10 mg/kg) was accompanied by an increase in the latency to respond and a decrease in the number of nose pokes. Taken together, these results show that the accuracy of delayed matching performance can be modulated in opposite ways by the BZR full agonist lorazepam and a low dose of the BZR partial inverse agonist, FG 7142.     

Affective,anxiety, and substance-related disorders in patients undergoing herniated disc surgery

Purpose  

At present only a small number of studies have investigated psychiatric comorbidity in disc surgery patients. Objectives of this study are (1) to examine the prevalence rate of comorbid affective, anxiety, and substance-related disorders in nucleotomy patients in comparison to the German general population and (2) to investigate associations between psychiatric comorbidity and socio-demographic and illness-related characteristics.     

Frequency and circumstances of placebo use in clinical practice - a systematic review of empirical studies

Background  

The use of placebo interventions outside clinical trials is ethically, professionally and legally controversial. Little is known about the frequency and circumstances of placebo use in clinical practice. Our aim was to summarize the available empirical studies addressing these issues.     

Early activation of inflammation- and immune response-related genes after experimental detachment of the porcine retina

PURPOSE: To determine early alterations in retinal gene expression in a porcine model of rhegmatogenous retinal detachment. METHODS: Local detachment was created in eyes of adult pigs by subretinal application of sodium hyaluronate. The gene expression in control tissues and retinas detached for 24 hours was analyzed with a pig genome microarray. Genes with at least three-fold expression changes were detected in the detached retina and in the attached retinal tissue surrounding the local detachment in situ. Structural alterations of the retina were examined by light and electron microscopy. RESULTS: Identified were 85 genes that were upregulated and 7 that were downregulated in the detached retina. Twenty-eight genes were identified as upregulated in the nondetached retina of the surgical eyes. The genes upregulated in detached retinas were related to inflammation and immune responses (n = 52), antioxidants and metal homeostasis (n = 7), intracellular proteolysis (n = 6), and blood coagulation/fibrinolysis (n = 4). The upregulation of at least 15 interferon-stimulated genes indicates elevated interferon levels after detachment. Gene expression of blue-sensitive opsin was not detectable in the detached retinal tissue, suggesting an early reduction in phototransduction, especially in blue cones. Electron microscopy revealed an accumulation of microglial cells in the inner retinal tissue and of polymorphonuclear leukocytes in the vessels of detached and peridetached retinas. CONCLUSIONS: Differentially expressed genes in the retina early after experimental detachment are mainly related to inflammation and immune responses, intracellular proteolysis, and protection against oxidative stress. A local immune and inflammatory response may represent a major causative factor for reactive changes in the retina after detachment. The inflammatory response is not restricted to the detached retina but is also observed in the nondetached retina; this response may underlie functional changes in these regions described in human subjects.     

Characteristics of untreated AIDS-related cytomegalovirus retinitis. II. Findings in the era of highly active antiretroviral therapy (1997 to 2000)

PURPOSE: To describe host characteristics (use of highly active antiretroviral therapy [HAART]; CD4+ T-lymphocyte count; HIV ribonucleic acid [RNA] blood level) of people who were diagnosed with AIDS-related cytomegalovirus (CMV) retinitis after HAART became available and to investigate effects of HAART on ophthalmic findings. DESIGN: Retrospective, observational case series. METHODS: We collected demographic, medical, laboratory, and ophthalmic data for all patients with AIDS and newly diagnosed, untreated CMV retinitis from January 1997 through December 2000 at 10 sites in Los Angeles and Orange Counties, California. RESULTS: The proportions of Hispanic and African-American patients were equivalent to or greater than their prevalences in the AIDS and general populations of Los Angeles County. Most patients (n = 80; 63.5%) were known to be receiving HAART at the time of CMV retinitis diagnosis; only 22 patients (17.5%) were HAART-na?ve. Median CD4+ T-lymphocyte count was 15 cells/microl and median HIV RNA blood level was 103,000 copies/ml for all patients, but in 10 patients, CMV retinitis developed despite good immunologic and virologic responses to HAART. When compared with HAART-na?ve patients, HAART-failure patients with CMV retinitis had more asymptomatic disease (P = .073), better visual acuity in the better eye (P = .003), more bilateral disease (P = .007), less zone 1 involvement (P = .042), and lower lesion border opacity scores (P = .054). CONCLUSIONS: Most patients with AIDS and newly diagnosed CMV retinitis in an urban setting are HAART-experienced. HAART may influence characteristics of new CMV retinitis lesions at presentation, despite laboratory evidence of treatment failure, possibly because of residual CMV-specific immunity.