A LANT6-like substance that is distinct from neuromedin N is present in pallidal and striatal neurons in monkeys

The basal ganglia of rhesus and squirrel monkeys were examined using immunohistochemical techniques with antibodies against the neurotensin-related hexapeptides Lys8-Asn9-Neurotensin(8-13) (LANT6) and Neuromedin N. A high percentage of neurons in both segments of globus pallidus and many large neurons of the striatum were found to label for LANT6, but not Neuromedin N. Previous studies have shown that LANT6 or a LANT6-like substance is present in many pallidal neurons in a wide range of vertebrate species. The current results indicate that a LANT6-like substance that is distinct from Neuromedin N is also present in many pallidal neurons in primates. This raises the possibility that this substance may be involved in neurotransmission between the pallidum and its projection targets.     

Natural killer cell activities of patients with breast cancer against different target cells

Summary Natural killer (NK) cell activity against K 562 erythroleukemic- and MCF-7 breast carcinoma-derived cells was monitored in short-term (3h/ K 562) and long-term (18h/MCF-7) chromium release tests for 60 patients with untreated primary breast disease. Target cell lysis was the same for patient groups with benign (n=13) and malignant (n=47) breast disease (27% versus 36% mean chromium release; target: effector ratio 40:1 for K 562 and 28% versus 40% for MCF-7 cells). NK activity as defined by short-term lysis of K 562 cells did not correlate with MCF-7 cell lysis in long-term assays for the carcinoma patients. This functional heterogeneity of natural cytotoxic activities of breast cancer patients was confirmed by a different age distribution for K 562 and MCF-7 cell lysis and high levels of MCF-7-directed NK activity in the grade I tumor group (56.2%). Our results indicate that measurement of peripheral blood NK activity against a breast carcinoma-derived cell line (MCF-7) defines a disease-related natural cytotoxic acitivity which correlates better with prognostic tumor parameters (tumor grading) than NK activity as defined by the lysis of K 562 erythroleukemic cells. NK activity testing against breast carcinoma cell lines should be used to monitor natural cytotoxic activities in breast cancer patients and its modulation by different routes of treatment.Supported by Jubiläumsfond der österreichischen Nationalbank, Project No. 2227     

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.