Natural and synthetic iminosugars as carbohydrate processing enzyme inhibitors for cancer therapy

Iminosugars, featuring a basic nitrogen at the hetero atom position in carbohydrate rings, gain increasing interest in the search for novel approaches towards cancer drug development. This compound class is known as competitive inhibitors of carbohydrate manipulation enzymes, such as glycosidases, which are involved in tumor cell invasion and migration. Such enzymes are also responsible for the attachment of oligosaccharides to the cell surface of tumor cells, displayed as glycoproteins, glycolipids, and proteoglycans, which play an important role in malignant phenotype and tumor growth. Furthermore, cancer cells show an extremely active lysosomal system which is reflected by enhancement of glycoprotein turnover. Iminosugars were found to interact with glycosyl hydrolases responsible for this kind of action in cancer cells and thus open a new compound class in the research field of finding new anti-cancer activities. This review will focus on the role of iminosugars in cancer therapy and will give an overview of their properties.     

Oppositional COMT Val158Met effects on resting state functional connectivity in adolescents and adults

Prefrontal dopamine levels are relatively increased in adolescence compared to adulthood. Genetic variation of COMT (COMT Val158Met) results in lower enzymatic activity and higher dopamine availability in Met carriers. Given the dramatic changes of synaptic dopamine during adolescence, it has been suggested that effects of COMT Val158Met genotypes might have oppositional effects in adolescents and adults. The present study aims to identify such oppositional COMT Val158Met effects in adolescents and adults in prefrontal brain networks at rest. Resting state functional connectivity data were collected from cross-sectional and multicenter study sites involving 106 healthy young adults (mean age 24 ± 2.6 years), gender matched to 106 randomly chosen 14-year-olds. We selected the anterior medial prefrontal cortex (amPFC) as seed due to its important role as nexus of the executive control and default mode network. We observed a significant age-dependent reversal of COMT Val158Met effects on resting state functional connectivity between amPFC and ventrolateral as well as dorsolateral prefrontal cortex, and parahippocampal gyrus. Val homozygous adults exhibited increased and adolescents decreased connectivity compared to Met homozygotes for all reported regions. Network analyses underscored the importance of the parahippocampal gyrus as mediator of observed effects. Results of this study demonstrate that adolescent and adult resting state networks are dose-dependently and diametrically affected by COMT genotypes following a hypothetical model of dopamine function that follows an inverted U-shaped curve. This study might provide cues for the understanding of disease onset or dopaminergic treatment mechanisms in major neuropsychiatric disorders such as schizophrenia and attention deficit hyperactivity disorder.     

Employee Health in the Mental Health Workplace: Clinical,Administrative, and Organizational Perspectives

Issues of mental health and employee health have risen to increasing prominence in recent years. However, there have been few explorations of the clinical and administrative challenges that these issues raise, particularly in settings that are themselves mental health workplaces. In order to identify and understand such challenges, a brief case of acute employee illness in a mental health workplace is described followed by a discussion of salient clinical, administrative, and organizational considerations. The case raises questions about medicolegal responsibilities and relationships between clinicians and patients in mental health settings, illuminates tensions between clinical staff and human resources processes, and draws attention to the need for illness prevention and mental health promotion initiatives in the workplace. Increased awareness of these issues, complications, and potential solutions would benefit clinicians, administrators, and mental health institutions.     

Potential application of small myristoylated protein-3 evaluated as recombinant antigen and a synthetic peptide containing its linear B-cell epitope for the serodiagnosis of canine visceral and human tegumentary leishmaniasis

Serological tests are important tools for the diagnosis of Leishmania infection. However, they are not effective markers to diagnose asymptomatic cases of visceral leishmaniasis (VL) and patients developing tegumentary leishmaniasis (TL), since antileishmanial antibodies can be encountered in low levels resulting in false-negative results in the serological trials. In this context, antigens able to be recognized by antibodies in sera from both VL and TL patients will be desirable to be employed in a more sensitivity and specific diagnosis of disease. In the present study, a conserved Leishmania protein, small myristoylated protein-3 (SMP-3), which was showed to be conserved in different Leishmania species and an effective vaccine candidate against Leishmania infantum infection in a murine model, was cloned and the recombinant protein was evaluated as a serological marker for the diagnosis of human TL and canine VL. In addition, a linear B cell-specific epitope (MQKDEESGEFKCEL) was identified, synthetized and also investigated as a serological marker. As antigen controls, rA2 protein and antigenic Leishmania extracts (SLA) were used. Results showed that ELISA-rSMP-3 and ELISA-Peptide presented sensitivity and specificity values higher than 90% in both diseases in humans and canids, having identified all asymptomatic cases and did not present cross-reaction with cross-reactivity diseases in both mammalian hosts. On the other hand, sensitivity and specificity values were worst when rA2 or SLA were used as antigens in humans and dogs. In conclusion, results showed the efficacy and Leishmania SMP-3 protein, employed as a recombinant antigen or a B cell epitope, for the improvement of the serodiagnosis of human TL and canine VL. This candidate can be tested in other diagnostic platforms, such as rapid immunochromatographic dipstick tests, aiming its use in epidemiological studies in remote areas where laboratories are not readily accessible for conventional assays.     

A biomarker for tegumentary and visceral leishmaniasis based on a recombinant Leishmania hypothetical protein

The measures for leishmaniasis control include the precise diagnosis of disease. However, although several recombinant antigens have been tested with this biotechnological purpose, no effective product exists, which could detects patients with the active disease, as well as differentiates them from cured and treated patients. In this study, a conserved Leishmania hypothetical protein, which was identified in Leishmania infantum parasites, but evaluated to presents high homology in the amino acid sequences between distinct parasite species, was evaluated for the diagnosis of tegumentary and visceral leishmaniasis. In addition, PBMCs collected from treated and untreated mucosal leishmaniasis (ML) and visceral leishmaniasis (VL) patients, as well as in healthy subjects living in endemic region of disease, were in vitro stimulated, when IFN-γ, IL-4 and IL-10 levels were evaluated in the cell supernatant. Regarding the serological analyses, ELISA experiments using the recombinant protein (rLiHyL) and a human serological panel revealed high sensitivity and specificity values to detect both diseases, while control antigens showed worst results. Regarding the cellular response, results showed that rLiHyL-stimulated cells produced higher IFN-γ and lower IL-4 and IL-10 levels in the supernatants. Also, the anti-protein antibody production was evaluated in these patients, and data showed higher IgG2 and lower IgG1 levels found in the treated patients and healthy controls, demonstrating the stimulation of a Th1-type response induced by the rLiHyL protein. In conclusion, this hypothetical protein can be considered as antigenic in TL and VL, as well as a vaccine candidate to be tested in future studies to protect against disease.     

Single and combined inhibition of tumor necrosis factor,interleukin‐1, and RANKL pathways in tumor necrosis factor–induced arthritis: Effects on synovial inflammation,bone erosion,and cartilage destruction

Objective

To investigate the efficacy of single and combined blockade of tumor necrosis factor (TNF), interleukin‐1 (IL‐1), and RANKL pathways on synovial inflammation, bone erosion, and cartilage destruction in a TNF‐driven arthritis model.

Methods

Human TNF–transgenic (hTNFtg) mice were treated with anti‐TNF (infliximab), IL‐1 receptor antagonist (IL‐1Ra; anakinra), or osteoprotegerin (OPG; an OPG‐Fc fusion protein), either alone or in combinations of 2 agents or all 3 agents. Synovial inflammation, bone erosion, and cartilage damage were evaluated histologically.

Results

Synovial inflammation was inhibited by anti‐TNF (−51%), but not by IL‐1Ra or OPG monotherapy. The combination of anti‐TNF with either IL‐1Ra (−91%) or OPG (−81%) was additive and almost completely blocked inflammation. Bone erosion was effectively blocked by anti‐TNF (−79%) and OPG (−60%), but not by IL‐1Ra monotherapy. The combination of anti‐TNF with IL‐1Ra, however, completely blocked bone erosion (−98%). Inhibition of bone erosion was accompanied by a reduction of osteoclast numbers in synovial tissue. Cartilage destruction was inhibited by anti‐TNF (−43%) and was weakly, but not significantly, inhibited by IL‐1Ra, but was not inhibited by OPG monotherapy. The combination of anti‐TNF with IL‐1Ra was the most effective double combination therapy in preventing cartilage destruction (−80%). In all analyses, the triple combination of anti‐TNF, IL‐1Ra, and OPG was not superior to the double combination of anti‐TNF and IL‐1Ra.

Conclusion

Articular changes caused by chronic overexpression of TNF are not completely blockable by monotherapies that target TNF, IL‐1, or RANKL. However, combined approaches, especially the combined blockade of TNF and IL‐1 and, to a lesser extent, TNF and RANKL, lead to almost complete remission of disease. Differences in abilities to block synovial inflammation, bone erosion, and cartilage destruction further strengthen the rationale for using combined blockade of more than one proinflammatory pathway.

     

Immediate and late effects of coronary angiography on soluble endothelial cell markers and P-selectin in patients with and without coronary artery disease.

Endothelial cell injury and platelet activation are considered primary events in the pathogenesis of coronary artery disease (CAD) and are marked by plasma concentrations of von Willebrand factor (vWF) and soluble thrombomodulin, and by soluble P-selectin, respectively. Because both endothelial cells and platelets interact with contrast media, we aimed to detect immediate and 24-h changes in these markers following coronary angiography in patients with and without CAD. Sixteen patients with angiographically proven CAD and 14 patients without significant coronary stenosis were investigated. Blood samples were obtained from an antecubital vein before and 24 h after cardiac catheterization, and from the coronary sinus before and immediately after angiography. Concentrations of the markers were determined using enzyme-linked immunosorbent assays. In the coronary sinus samples, the only significant finding was an increase in levels of soluble P-selectin in the patients with CAD (P < 0.038). In the post-catheterization peripheral blood samples, concentrations of soluble P-selectin (P = 0.004), vWF (P = 0.0007) and soluble thrombomodulin (P = 0.0013) were all increased in patients with CAD. In contrast, patients without CAD demonstrated increased levels of vWF only (P = 0.0015) in peripheral blood samples obtained 24 h after angiography. We conclude that both immediate and 24-h changes take place in endothelial cells and platelet markers in response to cardiac catheterization, and that these changes are different in patients with angiographically proven CAD and in patients free of disease. These differences may reflect alterations in endothelial cell or platelet reactivity in patients with CAD.     

Altered gene expression in striatal projection neurons in CB1 cannabinoid receptor knockout mice

The basal ganglia, a brain structure critical for sensorimotor and motivational aspects of behavior, contain very high levels of CB1 cannabinoid receptors. These receptors are activated by endogenous lipophilic ligands, and they are thought to mediate behavioral effects of cannabinoid drugs. To evaluate the role of the endogenous cannabinoid system in the regulation of basal ganglia pathways, we have investigated the effects of targeted deletion of CB1 receptors on gene expression of various neuropeptides and transmitter-related enzymes in basal ganglia neurons. Mice without CB1 receptors are extremely hypoactive in a test for exploratory behavior (open-field test), showing markedly reduced locomotion and rearing. These CB1 mutants display significantly increased levels of substance P, dynorphin, enkephalin, and GAD 67 mRNAs in neurons of the two output pathways of the striatum that project to the substantia nigra and the globus pallidus. Our findings demonstrate that elimination of CB1 receptors results in behavioral abnormalities and functional reorganization of the basal ganglia.