Blink reflex abnormalities in children with Tourette syndrome

Tourette syndrome (TS) is a common disorder which typically occurs during childhood or early adolescence. There is no definitive diagnostic test for TS. The objective of this study was to demonstrate whether neurophysiological abnormalities of the blink reflex can be observed in children with TS. We enrolled 15 children with TS, diagnosed according to DSM IV Diagnostic Criteria, and 15 controls. The blink reflex was elicited by stimulating the supraorbital nerve in order to measure the early response (R1), homolateral and contralateral R2 (late) responses, amplitude of R1 and duration of R2. The mean duration of R2 was significantly longer in TS patients than in the controls ( P  < 0.001, Student's t -test). An abnormal pattern of the blink reflex can be, even in childhood, an early neurophysiologic marker of TS, which is not related to the duration of TS or to the age of onset.     

Detection of Apoptosis in Peripheral Blood Cells of 31 Subjects Affected by Down Syndrome Before and After Zinc Therapy

Thirty-one patients affected by Down syndrome (DS) were investigated to study the presence of apoptosis in peripheral blood cells in relation to the plasma levels of zinc. Twelve patients had undergone therapy with ZnSO₄, while the remaining 19 were untreated. The presence of programmed cell death was evaluated by means of electron microscopy, in situ nick translation (NT), and agarose gel electrophoresis of DNA. These approaches evidenced the presence of apoptosis in peripheral blood cells of patients before therapy with ZnSO₄, while after zinc supplementation there was a reduction in the number of apoptotic cells. These results suggest that the process of programmed cell death in peripheral blood cells of patients with Down syndrome is related to the plasma levels of zinc ion.     

Variable-ratio schedules of timeout from avoidance: effects of anxiolytic drugs

Concurrent performances in rats were studied under conditions where responses on one lever postponed shock on an unsignaled avoidance schedule, and responses on another level produced periods of signaled timeout from avoidance on a variable-ratio schedule. This procedure resulted in relatively high rates of responding on the timeout lever, and provided a baseline which permitted simultaneous evaluation of drug effects on two different types of negative reinforcement (shock postponement vs timeout). Chlordiazepoxide and ethanol selectively increased responding on the timeout lever at low doses, while higher doses decreased responding on both levers. Two 5-HT(1A) agonists, buspirone and 8-OH-DPAT, had different effects. Buspirone decreased responding across all effective doses, but 8-OH-DPAT increased responding on both the timeout and avoidance levers, with greater increases noted in responding maintained by timeout. These results replicate and extend previous findings, and support the notion that traditional anxiolytic drugs like chlordiazepoxide and ethanol may increase the reinforcing properties of escape from an avoidance schedule. Differences between the behavioral effects of buspirone and 8-OH-DPAT may reflect differential activity at the 5-HT(1A) receptor or the dopaminergic properties of buspirone.     

Synthesis and Ring‐Opening Polymerization of Cyclic Butylene 2,5‐Furandicarboxylate

A new synthetic pathway for the polymerization of furan based polyesters is reported in this work. First, poly(butylene 2,5‐furandicarboxylate) cyclic oligoesters (COEs) are chemically synthesized by semi‐batch esterification. The structure of the COEs is confirmed by infrared spectroscopy, ¹H, and ¹³C‐NMR, while the molecular weight distribution of the COEs is determined by matrix‐assisted laser desorption/ionization time of flight mass spectroscopy. The cyclic oligoesters are then successfully polymerized via ring‐opening polymerization using tetrakis(2‐ethylhexyl)‐titanate as catalyst. Differential scanning calorimetry and ¹H‐NMR analysis unambiguously proves the formation of polymeric species. Both end‐group analysis from ¹H‐NMR spectrum and calculation through Flory–Fox equation give comparable estimates of the number average molecular weight: 5.8 × 10³ g mol^?1 and 7.8 × 10³ g mol^?1, respectively.

     

Stress hormones,sleep deprivation and cognition in older adults

Cognition can be deteriorated in older persons because of several potential mechanisms including the hormonal changes occurring with age. Stress events cause modification in hormonal balance with acute and chronic changes such as increase in cortisol and thyroid hormones, and simultaneous alterations in dehydroepiandrosterone sulphate, testosterone and insulin like growth factor-1 levels. The ability to cope with stress and regain previous healthy status, also called resiliency, is particularly impaired in older persons Thus, stressful conditions and hormonal dysregulation might concur to the onset of cognitive impairment in this population.     

Efficacy of platelet-rich fibrin compared with triamcinolone acetonide as injective therapy in the treatment of symptomatic oral lichen planus: a pilot study

Clinical Oral Investigations - Oral lichen planus (OLP) is a chronic immune-mediated disease that affects the oral cavity. Topical steroids are considered the treatment of choice for painful...