LONG‐TERM FOLLOW UP OF PATIENTS WITH SMALL GASTROINTESTINAL STROMAL TUMORS IN THE STOMACH USING ENDOSCOPIC ULTRASONOGRAPHY‐GUIDED FINE‐NEEDLE ASPIRATION BIOPSY

Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed.     

Rationale,design, and protocol for the prevention of low back pain in the military (POLM) trial (NCT00373009)

Background  

There are few effective strategies reported for the primary prevention of low back pain (LBP). Core stabilization exercises targeting the deep abdominal and trunk musculature and psychosocial education programs addressing patient beliefs and coping styles represent the current best evidence for secondary prevention of low back pain. However, these programs have not been widely tested to determine if they are effective at preventing the primary onset and/or severity of LBP. The purpose of this cluster randomized clinical trial is to determine if a combined core stabilization exercise and education program is effective in preventing the onset and/or severity of LBP. The effect of the combined program will be compared to three other standard programs.     

A Mono-Percoll separation technique improves sperm recovery of normal and male factor specimens when compared with the swim-up technique

The purpose of this study was to determine the effects of asimplified 80% Mono-Percoll sperm separation procedure on bothnormal and male factor semen samples compared with the standardswim-up technique. The parameters examined include sperm concentration,motility and morphology, total motile functional spermatozoaand percentage recovery. Normal patients demonstrated enhancedsperm parameters with the Mono-Percoll compared with the swim-uptechnique for concentration (67x10⁶ versus 42x10⁶/ml, P <0.001), motility (66 versus 59%, P < 0.001), morphology (56versus 49%, P < 0.005) and percentage recovery (60 versus42%, P < 0.005). Male factor patients showed enhanced spermparameters with the Mono-Percoll procedure compared with theswim-up technique for motility (53 versus 42%, P < 0.05)and percentage recovery (54 versus 29%, P < 0.005), withno significant difference in concentration and morphology. Insummary, the Mono-Percoll sperm recovery procedure is significantlybetter than the swim-up technique for male factor patients andpatients with normal sperm parameters.     

Evaluation of a new enzyme-linked immunosorbent assay test for rotavirus antigen in faeces

A new commercial test for the diagnosis of rotavirus gastroenteritis was assessed. With some modifications it compared favourably with electron microscopy and immunofluorescence.     

Competitive control of the self-renewing T cell repertoire

We develop a mathematical model for the self-renewing part of the T cell repertoire. Assuming that self-renewing T cells have to be stimulated by immunogenic MHC-peptide complexes presented on the surfaces of antigen-presenting cells, we derive a model of T cell growth in which competition for MHC-peptide complexes limits T cell clone sizes and regulates the total number of self-renewing T cells in the animal. We show that for a sufficient diversity and/or degree of cross-reactivity, the total T cell number hardly depends upon the diversity of the T cell repertoire or the diversity of the set of presented peptides. Conversely, for repertoires of lower diversity and/or cross-reactivity, steady-state total T cell numbers may be limited by the diversity of the T cells. This provides a possible explanation for the limited repertoire expansion in some, but not all, mouse T cell re-constitution experiments. We suggest that the competitive interactions described by our model underlie the normal T cells numbers observed in transgenic mice, germ-free mice and various knockout mice.