Alternation of Gene Expression in Trigeminal Ganglion Neurons Following Complete Freund’s Adjuvant or Capsaicin Injection into the Rat Face

The hyperexcitability of trigeminal ganglion (TG) neurons following inflammation or C-fiber stimulation is known to be involved in a variety of changes in gene expression in TG neurons, resulting in pain abnormalities in orofacial regions. We analyzed nocifensive behavior following complete Freund’s adjuvant (CFA) or capsaicin injection into the maxillary whisker pad, and gene expression in the TG neurons using microarray analysis. The head-withdrawal latency to capsaicin injection or the head-withdrawal threshold to mechanical stimulation of the whisker pad skin in CFA-treated rats was significantly decreased compared to vehicle-treated rats. Many up-regulated and down-regulated genes in the TG neurons of each model were reported. Genes which have not been linked to peripheral inflammation or C-fiber activation were detected. Moreover, microarray chip containing a number of non-coding sequences was also up-regulated by C-fiber activation. These findings suggest that the diverse gene expressions in TG neurons are differentially involved in the inflammatory chronic pain and the acute pain induced by C-fiber activation, and the hyperexcitation of C-fibers are associated with the activation of certain non-coding RNAs.     

MALT-type lymphoma of lacrimal gland: case report

A 72-year-old female presented with a lump in the left superior-lateral eyelid. The magnetic resonance imaging showed a well-delineated mass in the left lacrimal gland. The tumor was isointense on both the T1 and T2 weighted images, and it was homogenously enhanced with Gd-DTPA. Surgery via the trans-cranial approach revealed a pinkish and elastic-hard tumor. Total resection was successfully performed. The hematoxilyn-eosin staining of the surgical specimen showed a dense infiltrate of lymphocytes, which were composed predominantly of small lymphocytes, centrocyte-like cells, monocytoid cells, and occasionally transformed lymphocytes. The immunohistochemical findings for CD20, CD3, UCHL-1, CD23, CD5, cyclinD1, and bcl-2 were compatible with Mucosa Associated Lymphoid Tissue (MALT)-type lymphoma. The patient received local radiation therapy (30 Gy/15 fractions). She remained in complete clinical remission of the disease about one and a half years after treatment.