Necrobiotic xanthogranuloma without a monoclonal gammopathy.

Necrobiotic xanthogranuloma (NXG) is an indolent non-Langerhans cell histiocytosis characterized by yellow xanthomatous plaques that tend to ulcerate. Necrobiotic xanthogranulomas have a predilection for the bilateral periorbital region and often present with consequential ophthalmic findings. Histopathology usually reveals a distinctive pattern of histiocytic xanthogranuloma with hyaline necrobiosis. Necrobiotic xanthogranuloma has been documented to have a close association with paraproteinemia. We report the case of a 76-year-old man with periorbital NXG without development of a monoclonal gammopathy. Clinically, the patient presented with dry eyes and substantial periorbital edema with multiple yellow indurated plaques. He developed the condition 30 years prior to presentation at which time it was initially diagnosed as xanthelasma. He underwent surgical excision of the lesions 10 years prior to the current presentation and biopsy results revealed a diagnosis of NXG. The periorbital lesions recurred several years prior to presentation, prompting annual computed tomography scans to rule out ocular invasion. Periorbital edema and plaques improved during a 6-month regimen of acitretin but returned to baseline just months after discontinuation.

Genetic polymorphism analysis of patients with primary hyperhidrosis.

BACKGROUND: Hyperhidrosis affects 220 million people worldwide. The hallmark of this condition is excessive sweating, which negatively impacts the social, emotional, and occupational lives of these individuals. A familial predisposition has been established; however, the specific genes involved have yet to be identified. OBJECTIVE: The aim of this study was to determine possible genetic variations contributing to primary hyperhidrosis, specifically single-nucleotide polymorphisms (SNPs). PATIENTS AND METHODS: Twenty-one case and 21 control DNA samples were extracted and genotyped for 20 SNPs associated with the Butyrylcholinesterase (BCHE) and Cholinergic Receptor Nicotinic Alpha-7 subunit (CHRNA7) genes. RESULTS: For rs1126680, the -116A variant allele (P-value=0.15) was found only in hyperhidrosis patients who also had the K-variant allele (P-value=0.65) in rs1803274. Further analysis testing the null hypothesis of independence between the combined genotypes and case/control status yielded a P-value of 0.30. CONCLUSION: Our results are consistent with previous research that shows the K-variant requires the -116A variant to be present in order to observe a decrease in BChE activity levels. These results are not statistically significant (P-value >0.05), but the exclusive association between the -116A and K-variants on the BCHE gene in hyperhidrosis patients warrants further investigation using a larger sample size.

Requirement for direct cross-talk between B1 and B2 kinin receptors for the proliferation of androgen-insensitive prostate cancer PC3 cells.

Stimulation of endogenous kinin receptors promotes growth of androgen-independent prostate cancer PC3 cells via activation of the mitogenic extracellular-signal-regulated kinase (ERK) pathway. In the present study, we show that kinin-mediated mitogenic signalling and prostate-cell growth involves two subtypes of bradykinin (BK) receptors, B1R and B2R. Specific stimulation of either B1R or B2R by their respective agonists des-Arg(9)-BK and Lys-BK promoted ERK activation and cell growth, whereas selective blockade with specific antagonists des-Arg(9)-[Leu(8)]BK and Hoe 140 respectively obliterated this effect, indicating the presence of both receptor subtypes. However, blockade of B1R also inhibited B2R-mediated ERK activation and cell growth, and, similarly, antagonism of B2R inhibited the B1R-mediated response. Furthermore, both B1R and B2R agonists promoted internalization of B1R, whereas both receptor antagonists blocked this effect. The B1R ligands des-Arg(9)-BK and des-Arg(9)-[Leu(8)]BK had no effect on the binding of BK to B2R, as demonstrated by radioligand competitive binding studies. However, blockade of either B1R or B2R impaired the ability of the reciprocal receptor to produce inositol phosphates, suggesting that the interaction between B1R and B2R is proximal to activation of phospholipase C. These results provide evidence for the existence of B1R-B2R complexes in prostate cancer PC3 cells and demonstrate that antagonism of one receptor interferes with the signalling ability of the other, possibly at the level of receptor-Galpha(q) protein coupling. Selective inhibition of B1R, which is up-regulated in injured and cancerous tissue, may be beneficial for the treatment of advanced prostate cancer.

Targeting Gbetagamma signaling to inhibit prostate tumor formation and growth.

Prostate cancer starts as androgen-dependent malignancy and responds initially to androgen ablative therapy. Beneficial effects of androgen ablation, however, are often temporary and the cancer reappears as androgen-independent tumor, suggesting the existence of additional factors responsible for progression of the disease. Attention has focused on receptor tyrosine kinases as the growth mediators of androgen-independent prostate cancer; overexpression of epidermal growth factor receptors or their ligand heparin-bound epidermal growth factor, for example, promotes transition to androgen independence. Emerging data demonstrate involvement of another class of cell membrane-anchored receptors, the heterotrimeric guanine-binding (G) protein-coupled receptors (GPCRs) in prostate cancer. In vitro, stimulation of many endogenous GPCRs induces mitogenic signaling and growth of prostate cancer cells. The GPCRs transduce mitogenic signals via activated G proteins in the form of Galpha-GTP and Gbetagamma subunits. Here, we show that expression of a Gbetagamma inhibitor peptide derived from carboxy terminus of G protein-coupled receptor kinase 2 obliterates serum-regulated prostate cancer cell growth in vitro and prevents prostate tumor formation in vivo. We also demonstrate that inhibition of Gbetagamma signaling retards growth of existing prostate tumors by inducing cell death. These data establish a central role for heterotrimeric G proteins in prostate cancer and suggest targeted inhibition of Gbetagamma signaling may serve as specific molecular therapy tool to limit pathologic growth of advanced prostate cancer.