In vivo identification of genes that modify ether-a-go-go-related gene activity in Caenorhabditis elegans may also affect human cardiac arrhythmia

Human ether-a-go-go-related gene (HERG) encodes the pore-forming subunit of I(Kr), a cardiac K(+) channel. Although many commonly used drugs block I(Kr), in certain individuals, this action evokes a paradoxical life-threatening cardiac rhythm disturbance, known as the acquired long QT syndrome (aLQTS). Although aLQTS has become the leading cause of drug withdrawal by the U.S. Food and Drug Administration, DNA sequencing in aLQTS patients has revealed HERG mutations only in rare cases, suggesting that unknown HERG modulators are often responsible. By using the worm Caenorhabditis elegans, we have developed in vivo behavioral assays that identify candidate modulators of unc-103, the worm HERG orthologue. By using RNA-interference methods, we have shown that worm homologues of two HERG-interacting proteins, Hyperkinetic and K channel regulator 1 (KCR1), modify unc-103 function. Examination of the human KCR1 sequence in patients with drug-induced cardiac repolarization defects revealed a sequence variation (the substitution of isoleucine 447 by valine, I447V) that occurs at a reduced frequency (1.1%) relative to a matched control population (7.0%), suggesting that I447V may be an allele for reduced aLQTS susceptibility. This clinical result is supported by in vitro studies of HERG dofetilide sensitivity by using coexpression of HERG with wild-type and I447V KCR1 cDNAs. Our studies demonstrate the feasibility of using C. elegans to assay and potentially identify aLQTS candidate genes.     

Gamma interferon induces rapid and coordinate activation of mitogen-activated protein kinase (extracellular signal-regulated kinase) and calcium-independent protein kinase C in human monocytes.

Gamma interferon plays an important role in regulating the functional properties of mononuclear phagocytes. In the present study, the role of activated protein kinases in the mechanism of action of gamma interferon cell signaling in human peripheral blood monocytes was investigated. Analysis in vitro of 100,000 x g cytosolic fractions from untreated and interferon-treated cells showed that agonist treatment resulted in time- and concentration-dependent increases in phosphotransferase activity when myelin basic protein (MBP) was used as the substrate. Anion-exchange chromatography of high-speed supernatants prepared from detergent extracts of interferon-treated cells revealed two discrete peaks of MBP phosphotransferase activity. Immunoblotting of fractions from these peaks with antiphosphotyrosine antibodies and with antibodies that specifically recognize the family of mitogen-activated protein (MAP) kinases detected a MAP kinase with a subunit M(r) of 42,000 in the earliest-eluting peak (peak 1). Phosphorylation of the 42,000-M(r) protein on tyrosine was observed only after treatment of cells with interferon. The contribution of MAP kinase to the interferon-stimulated activity in peak 1 was confirmed by quantitative immunoprecipitation with anti-MAP kinase and antiphosphotyrosine antibodies. The conclusion that the interferon-activated MBP kinase in peak 1 could be accounted for by an activated MAP kinase was also supported by the finding that fractions from Mono Q peak 1 demonstrated activity towards a MAP kinase-specific substrate. The later-eluting peak of interferon-activated MBP phosphotransferase activity appeared to be accounted for by an activated protein kinase C (PKC). This conclusion is based upon analyses of immunoblotting and immunoprecipitation experiments with antibodies to PKC and was also supported by the observed inhibition of this kinase with a PKC pseudosubstrate peptide. The interferon-stimulated PKC present in Mono Q peak 2 was active in the absence of calcium ions, suggesting that it is a calcium-independent isoform of PKC.     

Pathologic changes in murine leishmaniasis (Leishmania donovani) with special reference to the dynamics of granuloma formation in the liver

The histopathologic changes in liver, spleen, and bone marrow of BALB/c mice infected for 6 months with Leishmania donovani are described. Granulomas were the most important histologic lesions found; and the dynamics of their formation, collagen deposition, and resolution in the liver were studied. The number of hepatic granulomas increased until the eighth week and then decreased steadily. In contrast to the liver granulomas, those of spleen and bone marrow do not mature or show collagen deposition. Actual granuloma counts in the liver support the idea that mature granulomas revert to poorly formed ones and finally resolve without scarring. BALB/c mice are suitable for the study of the dynamics of granuloma formation and resolution and the survival of L donovani in an in vivo system. The relevance of these changes to the pathology of L donovani infection in man are discussed.     

Neural response to emotional stimuli during experimental human endotoxemia

Increases in peripheral cytokines during acute inflammation may affect various neuropsychological functions. The aim of this functional magnetic resonance imaging (fMRI) study was to investigate the effects of acute endotoxemia on mood and the neural response to emotionally aversive visual stimuli in healthy human subjects. In a double‐blind, randomized crossover study, 18 healthy males received a bolus injection of bacterial lipopolysaccharide (LPS; 0.4 ng/kg) or saline. Plasma levels of pro‐ and anti‐inflammatory cytokines and cortisol as well as mood ratings were analyzed together with the blood‐oxygen‐level dependent (BOLD) response during the presentation of aversive versus neutral pictures. Endotoxin administration induced pronounced transient increases in plasma levels of TNF‐α, IL‐1ra, IL‐6, IL‐10, and cortisol. Positive mood was decreased and state anxiety increased. In addition, activation of right inferior orbitofrontal cortex (OFC) in response to emotional visual stimuli was significantly increased in the LPS condition. Increased prefrontal activation during the presentation of emotional material may reflect enhanced cognitive regulation of emotions as an adaptive response during an acute inflammation. These findings may have implications for the putative role of inflammatory processes in the pathophysiology of depression. Hum Brain Mapp 34:2217–2227, 2013. © 2012 Wiley Periodicals, Inc.     

An adolescent with significant emotional and medically unexplained complaints: case report and proposal of an intervention

Background

Ethiopia is a country in which child and adolescent mental health needs are often not met. In order to promote capacity building, a Collaborative International Exchange Programme has been established between Jimma University at Jimma, Ethiopia, and Ludwig-Maximilian University in Munich, Germany. The programme focuses on training non-physician health professionals in mental health speciality. One of the courses in the training programme, child psychiatry, involves a child psychiatrist and a children’s nurse supporting the management of a patient described in this case report. Its conceptual framework is based on the section “significant emotional and medically unexplained complaints” of the “WHO mental health GAP intervention guide for mental, neurological and substance use disorders in non-specialized health settings”.

Objective

The purpose of this case report is to promote confidence in mental health professionals when managing patients with similar conditions, and to stimulate further evaluation of the conceptual approach in developing countries.

Patient

The subject of this case report is a 14-year-old adolescent girl admitted to the psychiatric clinic at Jimma University Teaching Hospital. She was admitted for intractable retching, inability to eat, weight loss, and inability to walk. Challenges included the combination of medical and psychiatric symptoms, and the significant impairment of functioning in this adolescent. The first aim in the management of this patient was to guarantee vital functions. In a problem-oriented approach, different domains were addressed to restore nutritional, social, emotional, and motor functions. Treatment consisted of various elements of psychosocial interventions. The patient improved in 2 weeks and the final diagnosis was conversion disorder.

Conclusion

Psychosocial interventions can be developed in cooperation, and applied in a setting where little child mental health expertise is available. Case-based learning relying on local expertise is suitable in meeting local needs and in developing mental health services for children and adolescents.

     

Immunohistochemical localization of DARPP-32 in striatal projection neurons and striatal interneurons: implications for the localization of D1-like dopamine receptors on different types of striatal neurons.

Immunohistochemical double-label techniques were used to study the localization of DARPP-32, a phosphoprotein that is enriched in neurons possessing members of the D1 subfamily of dopamine receptors, in several different types of striatal neurons in the rat basal ganglia. The vast majority (94.1%) of striatonigral projection neurons (the vast majority of which contain substance P), identified by retrograde labeling with fluorogold, were observed to contain DARPP-32. Similarly, the vast majority of striatopallidal projection neurons (87.7%), identified by immunofluorescence labeling for enkephalin (ENK), were found to label for DARPP-32. In contrast, cholinergic and neuropeptide Y-containing striatal interneurons were never observed to contain DARPP-32. These results suggest that essentially all major types of striatal medium spiny projection neurons may possess members of the D1 subfamily of dopamine receptors, but that striatal local circuit neurons do not possess members of the D1 subfamily of receptors.