Biotransformation of ferulic acid and vanillylamine to capsaicin and vanillin in immobilized cell cultures of Capsicum frutescens

Plant tissue culture medium which contained FeEDTA as sole iron source was incubated aseptically in light (16-h photoperiod, 100 mol m^-2 s^-1 PAR) at 20°C without plant tissue. Soluble iron dropped from an initial concentration of 4 mg 1^-1 to less than 0.1 mg 1^-1 in 4 weeks. This occurred in both glass and plastic culture vessels. No loss occurred when medium was incubated at 20°C in darkness. A further experiment showed that soluble iron concentration fell to <0.2 mg 1^-1 in only 4 days but the loss was slower at lower irradiances.Effects of the loss of soluble iron on plantlet growth were assessed by culturing single node stem segments of in vitro potato (Solanum tuberosum L. cv. Arran Banner) plantlets on medium previously exposed to light. Pre-exposure sufficient to reduce soluble iron concentration to <0.1 mg 1^-1 had no inhibitory effect on plantlet development in solidified medium or in liquid medium, except when the liquid medium had been centrifuged before inoculation to remove iron precipitated during pre-exposure to light. The plantlets then became chlorotic.     

Electrophoretic mobility shift in native gels indicates calcium-dependent structural changes of neuronal calcium sensor proteins

In proteins of the neuronal calcium sensor (NCS) family, changes in structure as well as function are brought about by the binding of calcium. In this article, we demonstrate that these structural changes, solely due to calcium binding, can be assessed through electrophoresis in native gels. The results demonstrate that the NCS proteins undergo ligand-dependent conformational changes that are detectable in native gels as a gradual decrease in mobility with increasing calcium but not other tested divalent cations such as magnesium, strontium, and barium. Surprisingly, such a gradual change over the entire tested range is exhibited only by the NCS proteins but not by other tested calcium-binding proteins such as calmodulin and S100B, indicating that the change in mobility may be linked to a unique NCS family feature—the calcium–myristoyl switch. Even within the NCS family, the changes in mobility are characteristic of the protein, indicating that the technique is sensitive to the individual features of the protein. Thus, electrophoretic mobility on native gels provides a simple and elegant method to investigate calcium (small ligand)-induced structural changes at least in the superfamily of NCS proteins.     

Cercopithecine Herpesvirus 9 (Simian Varicella Virus) Infection after Total-Body Irradiation in a Rhesus Macaque (Macaca mulatta)

This case report describes a rhesus macaque (Macaca mulatta; male; age, 5 y; weight, 6.7 kg) with anorexia, dehydration, lethargy, ataxia, and generalized skin rashes that occurred 30 d after total-body irradiation at 6.5 Gy (⁶⁰Co γ-rays). Physical examination revealed pale mucus membranes, a capillary refill time of 4 s, heart rate of 180 bpm. and respirations at 50 breaths per minute. Diffuse multifocal maculopapulovesicular rashes were present on the body, including mucocutaneous junctions. The CBC analysis revealed a Hct of 48%, RBC count of 6.2 × 10⁶/µL, platelet count of 44 × 10³/µL, and WBC count of 25 × 10³/µL of WBC. The macaque was euthanized in light of a grave prognosis. Gross examination revealed white foci on the liver, multifocal generalized petechiation on serosal and mucosal surfaces of the gastrointestinal tract, hemorrhagic lymph nodes, and hemorrhagic fluid in the thoracic cavity. Microscopic examination revealed cutaneous vesicular lesions with intranuclear eosinophilic viral inclusions within the epithelial cells, consistent with herpesvirus. Immunohistochemistry was positive for herpesvirus. The serum sample was negative for antibodies against Macacine herpesvirus 1 and Cercopithecine herpesvirus 9 (simian varicella virus, SVV). Samples submitted for PCR-based identification of the etiologic agent confirmed the presence of SVV DNA. PCR analysis, immunohistochemistry, and histology confirmed that lesions were attributed to an active SVV infection in this macaque. This case illustrates the importance of screening for SVV in rhesus macaques, especially those used in studies that involve immunosuppressive procedures.Abbreviations: SVV, simian varicella virus; TBI, total-body irradiation     

A network map of Interleukin-10 signaling pathway

Interleukin-10 (IL-10) is an anti-inflammatory cytokine with important immunoregulatory functions. It is primarily secreted by antigen-presenting cells such as activated T-cells, monocytes, B-cells and macrophages. In biologically functional form, it exists as a homodimer that binds to tetrameric heterodimer IL-10 receptor and induces downstream signaling. IL-10 is associated with survival, proliferation and anti-apoptotic activities of various cancers such as Burkitt lymphoma, non-Hodgkins lymphoma and non-small scell lung cancer. In addition, it plays a central role in survival and persistence of intracellular pathogens such as Leishmania donovani, Mycobacterium tuberculosis and Trypanosoma cruzi inside the host. The signaling mechanisms of IL-10 cytokine are not well explored and a well annotated pathway map has been lacking. To this end, we developed a pathway resource by manually annotating the IL-10 induced signaling molecules derived from literature. The reactions were categorized under molecular associations, activation/inhibition, catalysis, transport and gene regulation. In all, 37 molecules and 76 reactions were annotated. The IL-10 signaling pathway can be freely accessed through NetPath, a resource of signal transduction pathways previously developed by our group.     

In vitro modulation of natural killer cell activity in non-Hodgkin's lymphoma patients after therapy

Summary The depressed natural killer (NK) activity, antibody-dependent cellular cytotoxicity (ADCC) and NK cytotoxic factor cytotoxicity in untreated non-Hodgkin's lymphoma patients were found to be elevated after chemotherapy. In vitro treatment of the effector NK cells with interferon could augment the NK activity in normal subjects and treated patients to a comparable degree. Chemotherapy mainly affected the post-binding events in the NK cytotoxic process by causing an increase in the active killing potential of the NK cells. This study provides a better understanding of changes in the NK cytotoxic mechanism in non-Hodgkin's lymphoma patients and the role of interferon in this process.B. A. Mehta is a recipient of the Lady Tata Memorial Trust, India, Senior Scholarship