Prelimbic cortex is a common brain area activated during cue‐induced reinstatement of cocaine and heroin seeking in a polydrug self‐administration rat model

Many preclinical studies examined cue‐induced relapse to heroin and cocaine seeking in animal models, but most of these studies examined only one drug at a time. In human addicts, however, polydrug use of cocaine and heroin is common. We used a polydrug self‐administration relapse model in rats to determine similarities and differences in brain areas activated during cue‐induced reinstatement of heroin and cocaine seeking. We trained rats to lever press for cocaine (1.0 mg/kg per infusion, 3‐hr/day, 18 day) or heroin (0.03 mg/kg per infusion) on alternating days (9 day for each drug); drug infusions were paired with either intermittent or continuous light cue. Next, the rats underwent extinction training followed by tests for cue‐induced reinstatement where they were exposed to either heroin‐ or cocaine‐associated cues. We observed cue‐selective reinstatement of drug seeking: the heroin cue selectively reinstated heroin seeking and the cocaine cue selectively reinstated cocaine seeking. We used Fos immunohistochemistry to assess cue‐induced neuronal activation in different subregions of the medial prefrontal cortex, dorsal striatum, nucleus accumbens, and amygdala. Fos expression results indicated that only the prelimbic cortex (PL) was activated by both heroin and cocaine cues; in contrast, no significant cue‐induced neuronal activation was observed in other brain areas. RNA in situ hybridization indicated that the proportion of glutamatergic and GABAergic markers in PL Fos‐expressing cells was similar for the heroin and cocaine cue‐activated neurons. Overall, the results indicate that PL may be a common brain area involved in both heroin and cocaine seeking during polydrug use.     

Ancient origin of placental expression in the growth hormone genes of anthropoid primates

In anthropoid primates, growth hormone (GH) genes have undergone at least 2 independent locus expansions, one in platyrrhines (New World monkeys) and another in catarrhines (Old World monkeys and apes). In catarrhines, the GH cluster has a pituitary-expressed gene called GH1; the remaining GH genes include placental GHs and placental lactogens. Here, we provide cDNA sequence evidence that the platyrrhine GH cluster also includes at least 3 placenta expressed genes and phylogenetic evidence that placenta expressed anthropoid GH genes have undergone strong adaptive evolution, whereas pituitary-expressed GH genes have faced strict functional constraint. Our phylogenetic evidence also points to lineage-specific gene gain and loss in early placental mammalian evolution, with at least three copies of the GH gene present at the time of the last common ancestor (LCA) of primates, rodents, and laurasiatherians. Anthropoid primates and laurasiatherians share gene descendants of one of these three copies, whereas rodents and strepsirrhine primates each maintain a separate copy. Eight of the amino-acid replacements that occurred on the lineage leading to the LCA of extant anthropoids have been implicated in GH signaling at the maternal-fetal interface. Thus, placental expression of GH may have preceded the separate series of GH gene duplications that occurred in catarrhines and platyrrhines (i.e., the roles played by placenta-expressed GHs in human pregnancy may have a longer evolutionary history than previously appreciated).     

Mechanical reperfusion is associated with post-ischemic hemorrhage in rat brain

A major complication of recanalization therapy after an acute arterial occlusion in brain is hemorrhagic transformation (HT). Although it is known that prolonged ischemia is important in the development of HT, the role of reperfusion in ischemia–reperfusion induced HT is less well studied. To address the effect of reperfusion on HT, we assessed the incidence and severity of hemorrhage in rats after 5 h of middle cerebral artery occlusion (MCAO) followed by 19-hour reperfusion compared to rats with permanent occlusion (PMCAO) at the same 24-hour time point. The incidence and amount of hemorrhage, neurological function, and mortality rates were measured. MCAO (5 h) with 19-hour reperfusion was associated with a significantly higher incidence of cortical hemorrhage compared to PMCAO (81.8% vs 18.2%, p < 0.05). Hemorrhage scores were higher in the 5-hour MCAO/reperfusion group compared to PMCAO rats (17.6 ± 11.5 vs 2.4 ± 5.3 in cortex, 20.4 ± 4.6 vs 9.7 ± 4.5 in striatum, p < 0.01). Neurological function was worse in the ischemia–reperfusion group compared to PMCAO (p < 0.05) and mortality rates were insignificantly higher in the 5-hour MCAO/reperfusion group vs PMCAO group (54.5% vs18.1%; p < 0.08). The results suggest that reperfusion after prolonged ischemia is associated with increased hemorrhagic transformation and neurological deterioration as compared to permanent ischemia. Whether pharmacological treatments prior to reperfusion attenuate post-ischemic HT requires further study.     

Skin Prick Test in Patients with Chronic Allergic Skin Disorders

Background:

Chronic allergic skin disorders are the inflammatory and proliferative conditions in which both genetic and environmental factors play important roles. Chronic idiopathic urticaria (CIU) and atopic dermatitis (AD) are among the most common chronic allergic skin disorders. These can be provoked by various food and aeroallergens. Skin prick tests (SPTs) represent the cheapest and most effective method to diagnose type I hypersensitivity. Positive skin tests with a history suggestive of clinical sensitivity strongly incriminate the allergen as a contributor to the disease process.

Aims and Objectives:

To determine the incidence of positive SPT in patients with chronic allergic skin disorders and to identify the various allergens implicated in positive SPT.

Methods:

Fifty patients of chronic allergic disorders were recruited in this study. They were evaluated by SPT with both food and aeroallergens.

Results:

In our study, SPT positivity in patients of CIU was 63.41% and in AD was 77.78%. Out of the 41 patients of CIU, the most common allergen groups showing SPT positivity were dust and pollen, each comprising 26.83% patients. SPT reaction was positive with food items (21.6%), insects (17.07%), fungus (12.20%), and Dermatophagoides farinae, that is, house dust mite (HDM) (7.32%). The allergen which showed maximum positivity was grain dust wheat (19.51%). Among nine patients of AD, maximum SPT positivity was seen with Dermatophagoides farinae, pollen Amaranthus spinosus, grain dust wheat, and cotton mill dust; each comprising 22.22% of patients.

Conclusion:

Our study showed that a significant number of patients of CIU and AD showed sensitivity to dust, pollen, insects, Dermatophagoides farinae, and fungi on SPT. Thus, it is an important tool in the diagnosis of CIU and AD.     

Elevated Plasma S100B,Psychotic Symptoms,and Cognition in Schizophrenia

S100B is a calcium binding protein mainly produced by glial cells. Previous studies have shown elevated levels of S100B in patients with schizophrenia. We measured S100B levels in fasting plasma of 39 patients with schizophrenia and 19 adult healthy controls. We used linear regression to compare S100B between patients and controls. In patients only, we also investigated the relationship between S100B levels and psychotic symptoms (assessed by the Positive and Negative Syndrome Scale), and cognitive function (assessed by the NIH Toolbox Cognition Battery), respectively by calculating Pearson’s correlation coefficients. Mean plasma S100B was significantly higher in the patient group than in the control group. There were no significant correlations between plasma S100B and psychotic symptoms or cognition.