A rare case of odontoameloblastoma in a geriatric patient.

Odontoameloblastoma is an extremely rare tumor derived from odontogenic epithelium and mesenchyme. In the fewer than 20 reported cases, odontoameloblastoma is described as occurring in the maxilla or mandible of young men with a history of unerupted teeth. Here we report a case of a 73-year-old woman who presented to the dentist for routine cleaning and x-rays, which displayed a mandibular lesion. After referral to multiple providers, a biopsy of two involved teeth was obtained and computed tomography of the neck was performed, revealing a large, destructive lesion of the mandible. Histology was consistent with odontoameloblastoma. The patient underwent wide segmental mandibular resection and scapula tip free flap reconstruction. She recovered uneventfully and continues to have close follow-up, given the risk of recurrence. To the best of our knowledge, this is the first reported case of odontoameloblastoma in a patient over age 50. The goal of the authors is to raise awareness of this rare pathology and its diagnostic and management modalities.

Question of ALT flare during switch to adefovir from lamivudine: A single center open-label, randomized, safety study (June 17, 2005 to February 5, 2009).

Earlier clinical studies have reported an ALT flare greater than 10 times the upper limit of normal in some patients with chronic hepatitis B when their lamivudine (LAM) treatment was switched to adefovir (ADV) therapy. The current study compared the safety of switching directly to ADV versus overlapping LAM and ADV for 3 months followed by ADV monotherapy. Patients with chronic hepatitis B receiving LAM therapy for > or = 6 months were eligible for the study regardless of the presence of LAM resistance, HBeAg status or serum ALT levels. Eighteen patients (13 males) were randomized to direct switch to ADV and 17 patients (10 males) to overlap. HBV-DNA, ALT, albumin, and total bilirubin were assayed at baseline, 3, 6, 9, and 12 months. Study drugs were discontinued at the end of 12 months with the follow up at 3 and 6 months. The decision to continue antiviral therapy was made at the discretion of the investigator. Baseline ALT levels were similar between the direct switch and overlap group: median ALT (U/L) was 44.0 (16-266) and 33.0 (19-367) for direct switch for overlap group, respectively (P = 0.42). No ALT flare was noted at 3 months in either group: median ALT decreased from 44.0 to 34.5 U/L in the direct switch group, and from 33.0 to 23.0 in the overlap group. Furthermore, no patient in either group exhibited ALT flare throughout the 12 months. This study did not show an ALT flare during switch to ADV at 3 months or at any time later.

Analysis of GP73 in patients with HCC as a function of anti-cancer treatment.

In this study, we examined the level of Golgi protein 73 (GP73) in the serum of 9 patients as a function of anti-liver cancer treatment. Although the numbers are small, a clear trend was observed. Patients who remained tumor free (up to 6 years post-treatment) showed reductions in GP73 at the first time point available post-treatment. In contrast, patients who had high levels GP73 post treatment all had re-occurrence within a 5 year period. These data are preliminary but dramatically imply that this marker may have value in the monitoring of HCC patients and may be elevated even when small, undetectable tumors are present.

Human oligodendrocytes express Cx31.3: function and interactions with Cx32 mutants.

Murine oligodendrocytes express the gap junction (GJ) proteins connexin32 (Cx32), Cx47, and Cx29. CNS phenotypes in patients with X-linked Charcot-Marie-Tooth disease may be caused by dominant effects of Cx32 mutations on other connexins. Here we examined the expression of Cx31.3 (the human ortholog of murine Cx29) in human brain and its relation to the other oligodendrocyte GJ proteins Cx32 and Cx47. Furthermore, we investigated in vitro whether Cx32 mutants with CNS manifestations affect the expression and function of Cx31.3. Cx31.3 was localized mostly in the gray matter along small myelinated fibers similar to Cx29 in rodent brain and was co-expressed with Cx32 in a subset of human oligodendrocytes. In HeLa cells Cx31.3 was localized at the cell membrane and appeared to form hemichannels but no GJs. Cx32 mutants with CNS manifestations were retained intracellularly, but did not alter the cellular localization or function of co-expressed Cx31.3. Thus, Cx31.3 shares many characteristics with its ortholog Cx29. Cx32 mutants with CNS phenotypes do not affect the trafficking or function of Cx31.3, and may have other toxic effects in oligodendrocytes.

Cx29 and Cx32, two connexins expressed by myelinating glia, do not interact and are functionally distinct.

In rodents, oligodendrocytes and myelinating Schwann cells express connexin32 (Cx32) and Cx29, which have different localizations in the two cell types. We show here that, in contrast to Cx32, Cx29 does not form gap junction plaques or functional gap junctions in transfected cells. Furthermore, when expressed together, Cx29 and Cx32 are not colocalized and do not coimmunoprecipitate. To determine the structural basis of their divergent behavior, we generated a series of chimeric Cx32-Cx29 proteins by exchanging their intracellular loops and/or their C-terminal cytoplasmic tails. Although some chimerae reach the cell membrane, others appear to be largely localized intracellularly; none form gap junction plaques or functional gap junctions. Substituting the C-terminus or the intracellular loop and the C-terminus of Cx32 with those of Cx29 does not disrupt their colocalization or coimmunoprecipitation with Cx32. Substituting the C-terminus of Cx29 with that of Cx32 does not disrupt the coimmunoprecipitation or the colocalization with Cx29, whereas substituting both the intracellular loop and the C-terminus of Cx32 with those of Cx29 diminishes the coimmunoprecipitation with Cx29. Conversely, the Cx32 chimera that contains the intracellular loop of Cx29 coimmunoprecipitates with Cx29, indicating that the intracellular loop participates in Cx29-Cx29 interactions. These data indicate that homomeric interactions of Cx29 and especially Cx32 largely require other domains: the N-terminus, transmembrane domains, and extracellular loops. Substituting the intracellular loop and/or tail of Cx32 with those of Cx29 appears to prevent Cx32 from forming functional gap junctions.