Identification and development of TRPM4 antagonists to counteract neuronal excitotoxicity.

Neurodegeneration in central nervous system disorders is linked to dysregulated neuronal calcium. Direct inhibition of glutamate-induced neuronal calcium influx, particularly via N-methyl-D-aspartate receptors (NMDAR), has led to adverse effects and clinical trial failures. A more feasible approach is to modulate NMDAR activity or calcium signaling indirectly.

Eliapixant is a selective P2X3 receptor antagonist for the treatment of disorders associated with hypersensitive nerve fibers.

ATP-dependent P2X3 receptors play a crucial role in the sensitization of nerve fibers and pathological pain pathways. They are also involved in pathways triggering cough and may contribute to the pathophysiology of endometriosis and overactive bladder. However, despite the strong therapeutic rationale for targeting P2X3 receptors, preliminary antagonists have been hampered by off-target effects, including severe taste disturbances associated with blocking the P2X2/3 receptor heterotrimer.

The importance of being profiled: improving drug candidate safety and efficacy using ion channel profiling.

Profiling of putative lead compounds against a representative panel of relevant enzymes, receptors, ion channels, and transporters is a pragmatic approach to establish a preliminary view of potential issues that might later hamper development. An early idea of which off-target activities must be minimized can save valuable time and money during the preclinical lead optimization phase if pivotal questions are asked beyond the usual profiling at hERG. The best data for critical evaluation of activity at ion channels is obtained using functional assays, since binding assays cannot detect all interactions and do not provide information on whether the interaction is that of an agonist, antagonist, or allosteric modulator.

Uncertainty in the perioperative management of high-risk cutaneous squamous cell carcinoma among Mohs surgeons.

Objective: To evaluate whether Mohs surgeons' management of high-risk cutaneous squamous cell carcinoma (HRCSCC) is uniform regarding radiologic nodal staging (RNS) and adjuvant radiation therapy (ART).

Design: A survey study of randomly selected, fellowship-trained Mohs surgeons.

Setting: An academic medical center.

Ulceroglandular tularemia.

A 14-year-old boy presented with fevers and nonspecific flu-like symptoms, as well as an enlarging ulcerated plaque involving the upper back, lymphadenopathy, and bilateral pulmonary nodules. Bacterial cultures of ulcer tissue grew Francisella tularensis on enriched chocolate agar plates. Making the diagnosis requires a high index of suspicion, and communication with the laboratory to successfully and safely culture these highly pathogenic bacteria is imperative.

Primary cutaneous aggressive epidermotropic CD8+ T-cell lymphoma.

Cutaneous T-cell lymphomas most commonly have a CD4(+) memory T-cell phenotype with relatively indolent course, but may in rare cases present with a CD8(+) cytotoxic phenotype exhibiting strikingly more aggressive clinical behavior. We present two cases of the clinically aggressive subtype of primary cutaneous epidermotropic CD8(+) cutaneous T-cell lymphoma and review the current literature, clinical behavior, and recommendations for treatment distinct from that of more common CD4(+) variants of cutaneous T-cell lymphoma.

Development of the predictor HERG fluorescence polarization assay using a membrane protein enrichment approach.

The life-threatening consequences of acquired, or drug-induced, long QT syndrome due to block of the human ether-a-go-go-related gene (hERG) channel are well appreciated and have been the cause of several drugs being removed from the market in recent years because of patient death. In the last decade, the propensity for block of the hERG channel by a diverse and expanding set of compounds has led to the requirement that all new drugs be tested for hERG channel block in a functional patch-clamp assay. Because of the need to identify potential hERG blockers early in the discovery process, radiometric hERG binding assays are preferred over patch-clamp assays for compound triage, because of relative advantages in speed and cost.

IL-21 enhances antitumor responses without stimulating proliferation of malignant T cells of patients with Sézary syndrome.

IL-21, a common gamma-chain cytokine secreted by activated CD4+ T cells, influences both humoral and cell-mediated immune responses through the regulation of T, B, dendritic, and natural killer (NK) cells. Sézary syndrome is an advanced form of cutaneous T-cell lymphoma, a clonally derived malignancy of CD4+ T cells that is characterized by profound defects in host cellular immune function. As a modulator of both innate and adaptive immune responses, IL-21 could play an important role in augmenting cell-mediated immunity in these patients.

Association of change in clinical status and change in the percentage of the CD4+CD26- lymphocyte population in patients with Sézary syndrome.

Background: Because there are currently many effective therapies available for Sézary syndrome, close monitoring of disease progression is required in order for a clinician to know when to institute or change an intervention. It has been our clinical experience that changes in patients' CD4+CD26- T-cell populations of peripheral blood lymphocytes herald changes in their clinical status.

Objective: Our purpose was to evaluate whether a change in patients' CD4+CD26- population of T cells presages a change in their clinical status.

CTLA-4 blockade augments human T lymphocyte-mediated suppression of lung tumor xenografts in SCID mice.

Previous studies by others using transplantable murine tumor models have demonstrated that the administration of antibodies that block CTLA-4 interaction with B7 can provoke the elimination of established tumors, and that the tumor suppression is mediated by T-cells and/or cells expressing NK1.1. Studies from our lab have established in a human/severe combined immunodeficient (SCID) mouse chimeric model that autologous peripheral blood leukocytes (PBL) can suppress the growth of tumor xenografts in a PBL dose-dependent fashion, and that this suppression is dependent upon the patient's T and NK cells.

Recent advances in the modulation of voltage-gated ion channels for the treatment of epilepsy.

Regardless of the voltage-gated ion channel that is targeted in a drug discovery effort for the treatment of epilepsy, two routes have been followed historically: 1). a compound initially, and often surreptitiously, discovered due to activity in animal seizure models is further optimized by medicinal chemistry, or 2). a molecular target is identified based on the phenotype of transgenic animals, or linkage studies from humans with the disease, and compounds are then investigated within a mechanistic framework.

Human CD4+ T cells present within the microenvironment of human lung tumors are mobilized by the local and sustained release of IL-12 to kill tumors in situ by indirect effects of IFN-gamma.

By implanting nondisrupted pieces of human lung tumor biopsy tissues into SCID mice, it has been possible to establish viable grafts of the tumor, as well as the tumor-associated microenvironment, including inflammatory cells, fibroblasts, tumor vasculature, and the extracellular matrix. Using this xenograft model, we have evaluated and characterized the effects of a local and sustained release of human rIL-12 (rhIL-12) from biodegradable microspheres. In response to rhIL-12, the human CD45+ inflammatory cells present within the xenograft mediate the suppression or the complete arrest of tumor growth in SCID mice.

Human CD4+ effector T cells mediate indirect interleukin-12- and interferon-gamma-dependent suppression of autologous HLA-negative lung tumor xenografts in severe combined immunodeficient mice.

A human/severe combined immunodeficient mouse chimeric model was used to demonstrate that peripheral blood leukocytes (PBLs) from a patient with lung cancer completely suppress the growth of an autologous tumor in a PBL dose-dependent fashion repeatedly and over a 4-year period. Suppression of the patient's tumor required CD4+ T cells, CD56+ natural killer cells, and CD14+ monocytes/macrophages, but was completely independent of CD8+ T cells. The CD4+ effector cells promoted tumor killing indirectly because direct tumor recognition and killing are precluded by the absence of MHC class I and II molecules on the tumor cells.

SCID mouse models to study human cancer pathogenesis and approaches to therapy: potential, limitations, and future directions.

The successful engraftment of human tumors and human immunocompetent cells into severe combined immunodeficient (SCID) mice has led to the generation of a wide array of different experimental designs that have proven useful in studying the cell biology of human cancer, and for evaluating novel therapeutic approaches to the treatment of cancer. In this review five of the most frequently used embodiments of the SCID model are presented. The goals of this review are to discuss how each model has been utilized to study human cancer and its response to many different novel therapies, to provide an assessment of the strengths and limitations of each model, and to outline future directions with a focus on what is needed to overcome some of the current limitations and pitfalls of the SCID models.