Nicotine sensitization and analysis of brain‐derived neurotrophic factor in adolescent ß‐arrestin‐2 knockout mice

Nicotine sensitization and levels of brain‐derived neurotrophic factor (BDNF) were analyzed in adolescent ß‐arrestin‐2 knockout (ßA‐2 KO) and wild type (WT) mice. The ß‐arrestin‐2 protein has been shown to be important in G‐protein hydrolysis and receptor internalization. Four‐ to five‐week‐old adolescent ßA‐2 KO and WT C57/Bl6 mice were administered either nicotine (0.5 mg/kg free base) or saline 10 min before being placed into a locomotor arena on each of 7 (Experiment 1) or 14 (Experiment 2) consecutive days. A nicotine challenge was given 7 days after sensitization was complete. In Experiment 1, ßA‐2 KO mice administered nicotine or saline and WT mice administered nicotine demonstrated significant hypoactivity during early in testing, and neither WT nor ßA‐2 KO mice administered nicotine demonstrated sensitization. On the nicotine challenge, WT mice administered nicotine demonstrated significantly higher activity levels compared to all groups, and this same group demonstrated significantly higher levels of accumbal BDNF compared to all groups. In Experiment 2, ßA‐2 KO mice were again hypoactive compared to WT mice, whereas WT mice administered nicotine demonstrated significant hypoactivity during initial testing and significantly higher levels of activity compared to all other groups late in testing. On the nicotine challenge, WT mice that received nicotine demonstrated a significant increase in activity compared to all groups, and showed increased accumbal BDNF compared to all groups. These results show that the ß‐arrestin‐2 protein is important in induction and expression of nicotine sensitization as well as nicotine's effects on accumbal BDNF. Synapse 63:510–519, 2009. © 2009 Wiley‐Liss, Inc.     

Amygdala response to faces parallels social behavior in Williams syndrome

Individuals with Williams syndrome (WS), a genetically determined disorder, show relatively strong face-processing abilities despite poor visuospatial skills and depressed intellectual function. Interestingly, beginning early in childhood they also show an unusually high level of interest in face-to-face social interaction. We employed functional magnetic resonance imaging (fMRI) to investigate physiological responses in face-sensitive brain regions, including ventral occipito-temporal cortex and the amygdala, in this unique genetic disorder. Participants included 17 individuals with WS, 17 age- and gender-matched healthy adults (chronological age-matched controls, CA) and 17 typically developing 8- to 9-year-old children (developmental age controls, DA). While engaged in a face discrimination task, WS participants failed to recruit the amygdala, unlike both CA and DA controls. WS fMRI responses in ventral occipito-temporal cortex, however, were comparable to those of DA controls. Given the integral role of the amygdala in social behavior, the failure of WS participants to recruit this region during face processing may be a neural correlate of the abnormally high sociability that characterizes this disorder.     

Hepatitis C Prevalence in Patients With Hepatocellular Carcinoma Without Cirrhosis

BackgroundHepatocellular carcinoma (HCC) occurring in “noncirrhotic” hepatitis C virus (HCV)-infected patients has been reported; but the exact prevalence or incidence has not been described before.MethodsWe conducted a systematic review of literature: Ovid was used to search the literature from January 1, 1990, to September 1, 2008. Articles containing “HCC” keywords (hepatocellular carcinoma, hepatoma, liver cancer) were combined with the word “cirrhosis” or “fibrosis” and with “absence” keywords [noncirrhotic, absence, without]. Two hundred articles were selected and screened according to predesigned exclusion and inclusion criteria.ResultsNineteen articles met the inclusion criteria. The estimated prevalence of noncirrhotic HCC ranged from 6.7% to 50.1%. The pooled prevalence estimates for HCV in noncirrhotic HCC ranged from 0% and 68.4% according to the geographic location. Reports from Japan had the highest estimated pooled prevalence of HCV (55.01%) followed by Italy (29.95%).ConclusionsHCV can occur in patients with HCC without cirrhosis, but the true incidence and prevalence are very difficult to ascertain. Further studies are needed to define this group of patients.     

Tolerability and Safety of a Novel Ketogenic Ester,Bis-Hexanoyl (R)-1,3-Butanediol: A Randomized Controlled Trial in Healthy Adults

Nutritional ketosis is a state of mildly elevated blood ketone concentrations resulting from dietary changes (e.g., fasting or reduced carbohydrate intake) or exogenous ketone consumption. In this study, we determined the tolerability and safety of a novel exogenous ketone diester, bis-hexanoyl-(R)-1,3-butanediol (BH-BD), in a 28-day, randomized, double-blind, placebo-controlled, parallel trial ({"type":"clinical-trial","attrs":{"text":"NCT04707989","term_id":"NCT04707989"}}NCT04707989). Healthy adults (n = 59, mean (SD), age: 42.8 (13.4) y, body mass index: 27.8 (3.9) kg/m²) were randomized to consume a beverage containing 12.5 g (Days 0–7) and 25 g (Days 7–28) of BH-BD or a taste-matched placebo daily with breakfast. Tolerability, stimulation, and sedation were assessed daily by standardized questionnaires, and blood and urine samples were collected at Days 0, 7, 14, and 28 for safety assessment. There were no differences in at-home composite systemic and gastrointestinal tolerability scores between BH-BD and placebo at any time in the study, or in acute tolerability measured 1-h post-consumption in-clinic. Weekly at-home composite tolerability scores did not change when BH-BD servings were doubled. At-home scores for stimulation and sedation did not differ between groups. BH-BD significantly increased blood ketone concentrations 1-h post-consumption. No clinically meaningful changes in safety measures including vital signs and clinical laboratory measurements were detected within or between groups. These results support the overall tolerability and safety of consumption of up to 25 g/day BH-BD.     

Susac's syndrome: Intratympanic therapy for hearing loss and a review of the literature

Two cases of Susac's Syndrome are presented with a discussion of treatment modalities for the associated severe sensorineural deafness. Patients were managed with high dose oral steroids, anticoagulants and immunosuppressive drugs. The addition of intratympanic methylprednisolone injections were added to one patient's regimen with initial improvement but subsequent relapse and progression to profound deafness. The management of Susac's syndrome is difficult and still in need of innovative methods as the standard treatment continues to be ineffective in the long term. Laryngoscope, 119:141–144, 2009     

Australian funnel-web spiders: master insecticide chemists.

Arthropods are the most diverse animal group on the planet. Their ability to inhabit a vast array of ecological niches has inevitably brought them into conflict with humans. Although only a small minority are classified as pest species, they nevertheless destroy about a quarter of the world's annual crop production and transmit an impressive array of pathogens of human and veterinary public health importance. Arthropod pests have been controlled almost exclusively with chemical insecticides since the introduction of DDT in the 1940s. However, the evolution of resistance to many insecticides, coupled with increased awareness of the potential environmental and human and animal health impacts of these chemicals, has stimulated the search for new insecticidal compounds, novel molecular targets, and alternative control methods. Spider venoms are complex chemical cocktails that have evolved to kill or paralyze arthropod prey, and they represent a largely untapped reservoir of insecticidal compounds. This review focuses on several families of invertebrate-specific peptide neurotoxins that were isolated from the venom of Australian funnel-web spiders. These peptides are promising insecticide leads because of their selectivity for invertebrates and activity on previously unvalidated targets. These toxins should facilitate the development of novel target-based screens for new insecticide leads, while their mapped pharmacophores will provide templates for rational design of mimetics that act at these target sites. Furthermore, genes encoding these toxins can be used to improve the efficacy of insect-specific viruses.