The Tre2 (USP6) oncogene is a hominoid-specific gene

Gene duplication and domain accretion are thought to be the major mechanisms for the emergence of novel genes during evolution. Such events are thought to have occurred at early stages in the vertebrate lineage, but genomic sequencing has recently revealed extensive amplification events during the evolution of higher primates. We report here that the Tre2 (USP6) oncogene is derived from the chimeric fusion of two genes, USP32 (NY-REN-60), and TBC1D3. USP32 is an ancient, highly conserved gene, whereas TBC1D3 is derived from a recent segmental duplication, which is absent in most other mammals and shows rapid amplification and dispersal through the primate lineage. Remarkably, the chimeric gene Tre2 exists only in the hominoid lineage of primates. This hominoid-specific oncogene arose as recently as 21-33 million years ago, after proliferation of the TBC1D3 segmental duplication in the primate lineage. In contrast to the broad expression pattern of USP32 and TBC1D3, expression of Tre2 is testis-specific, a pattern proposed for novel genes implicated in the emergence of reproductive barriers. The sudden emergence of chimeric proteins, such as that encoded by Tre2, may have contributed to hominoid speciation.     

Evaluating imaging and computer-aided detection and diagnosis devices at the FDA

This report summarizes the Joint FDA-MIPS Workshop on Methods for the Evaluation of Imaging and Computer-Assist Devices. The purpose of the workshop was to gather information on the current state of the science and facilitate consensus development on statistical methods and study designs for the evaluation of imaging devices to support US Food and Drug Administration submissions. Additionally, participants expected to identify gaps in knowledge and unmet needs that should be addressed in future research. This summary is intended to document the topics that were discussed at the meeting and disseminate the lessons that have been learned through past studies of imaging and computer-aided detection and diagnosis device performance.     

Age Effects in Implicit Memory: The Role of Response Competition Induced by Relative Word Frequency

Background/Study Context: This study examined the effect of age and response competition on implicit memory performance.

Methods: Younger and older adults studied high- and low-frequency words and took a word stem completion test that could be completed with multiple solutions. To manipulate response competition, the test list consisted of word stems that could be completed with target low-frequency words, as well as multiple other solutions with higher frequencies than the target (the high response competition condition) and word stems that could be completed with target high-frequency words, as well as multiple other solutions with lower frequencies than the target (the low response competition condition).

Results: Relative to younger adults, older adults showed reduced levels of priming only under conditions of high response competition (low-frequency targets with high-frequency competitors).

Conclusion: In support of a response competition mechanism, older adults were more likely to complete stems with nonstudied high-frequency solutions than were younger adults. Results demonstrate that older adults have reduced priming compared with younger adults under some conditions of high response competition.     

Low power interstitial Nd YAG laser photocoagulation in normal and neoplastic rat colon.

The effects of low power (1-2 Watts), long exposure (30-400 seconds), interstitial Nd YAG laser therapy on dimethylhydrazine induced rat colonic neoplasms and normal rat colon have been studied. After a single exposure with appropriate laser parameters, dimethylhydrazine induced rat colonic neoplasms underwent coagulative necrosis, sloughed off over a four day period, and left an ulcer which healed within 28 days. Inadequate laser energy resulted in incomplete tumour necrosis whilst excessive laser power or energy increased the likelihood of perforation. Treatment of normal colon with 1 Watt for 30 seconds or longer resulted in coagulative damage which healed by granulation. Mean colonic bursting pressures were significantly decreased one hour after treatment with 1 Watt for 75 or 100 seconds compared with untreated colon (p less than 0.05 and p less than 0.001 respectively) but not in colon treated with 1 Watt for 30 or 50 seconds. In animals treated with 1 Watt for 100 seconds mean bursting pressures were significantly lower than untreated animals when the animals were killed two, four, and seven days after lasering (p less than 0.001 in each case) but not in animals killed at 11, 17, or 21 days. The technique may be of value in the treatment of some inoperable colorectal cancers and sessile polyps in man.     

Psychological stress in undergraduate dental students: baseline results from seven European dental schools

OBJECTIVES: To determine the degree of psychological distress, the experience of emotional exhaustion, and the extent of stress associated with course work in dental students and to compare these measurements among seven European dental schools. DESIGN: Multi-centred survey. SETTING: Dental Schools at Amsterdam, Belfast, Cork, Greifswald, Helsinki, Liverpool and Manchester. PARTICIPANTS: 333 undergraduate first-year dental students. MEASURES: General Health Questionnaire (GHQ12), Maslach Burnout Inventory (MBI), Dental Environment Stress Questionnaire (DES), demographic variables. PROCEDURE: Questionnaire administered to all students attending first year course. Completed questionnaires sent to central office for processing. RESULTS: Seventy-nine percent of the sampled students responded. Over a third of the students (36%) reported significant psychological distress (morbidity) at the recommended cut-off point (>3 on GHQ). These scores were similar to those reported for medical undergraduates. Twenty-two percent recorded comparatively high scores on emotional exhaustion. A wide variation in these 2 measurements was found across schools (p's<0.001). Stress levels indicated by the DES were less variable (p>0.5). Some evidence showed that contact with patients and the level of support afforded by living at home may be protective. CONCLUSION: Higher than expected levels of emotional exhaustion were found in a large sample of first-year undergraduate dental students in Europe.     

POTENTIATION OF AN EFFECT OF ALLOPURINOL ON PYRIMIDINE METABOLISM BY CHLOROTHIAZIDE IN MAN

SUMMARY 1. Treatment with allopurinol leads to increased excretion of the pyrimidine compounds orotic acid and orotidine, and to increased levels in erythrocytes of the enzymes orotate phosphoribosyltransferase and orotidylate decarboxylase.
2. The effects of allopurinol on pyrimidine metabolism are enhanced by concurrent treatment with chlorothiazide.
3. This interaction between allopurinol and chlorothiazide does not appear to give rise to any disadvantageous effects. Knowledge of such interactions could lead to more rational drug therapy.