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.     

Autologous whole plasma fibrin gel. Intraoperative procurement.

Fibrin glue is a relatively recent addition to the armamentarium of hemostatic agents for surgical use. Its efficacy has been repeatedly demonstrated in almost all surgical disciplines and subspecialties. Its use in the United States has been limited because of the risk of viral transmission associated with the use of human plasma. Previous authors have described techniques that limit this risk, but they are frequently impractical, expensive, or cumbersome. We describe the use of patients' own fresh plasma to make fibrin gel at the operative field. It provided hemostasis at least as good as that from heterologous plasma glue in 40 cardiac surgical patients. Autologous whole plasma fibrin gel is inexpensive and safe and eliminates the risk of viral transmission associated with glue derived from heterologous donor plasma.     

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.      

Validity of the beck depression inventory,hospital anxiety and depression scale,SCL-90, and hamilton depression rating scale as screening instruments for depression in stroke patients

Most instruments used to assess poststroke depression have never been specifically validated in stroke patients. This study evaluated the depression screening abilities of three questionnaires and one observer-rated scale in 202 consecutive patients 1 month after they experienced their first-ever ischemic stroke. At their respective optimum cutoff values, the sensitivity of the self-rated scales varied between 80% and 90%, while the specificity was about 60%. For the observer-rated scale (Hamilton Depression Rating Scale), sensitivity was 78.1%, and specificity was 74.6%. The instruments clearly performed better in men than in women. Despite this difference, it was concluded that all scales were acceptable screening instruments for poststroke depression.     

Muscle lactate transport studied in sarcolemmal giant vesicles: dependence on fibre type and age.

Lactate transport was studied in sarcolemmal giant vesicles obtained from rat or rabbit skeletal muscle. With this technique it is possible to obtain quantitative information on sarcolemmal transport characteristics. In equilibrium exchange experiments with 10, 30 and 60 mM lactate, vesicles from 'red' rat muscles had a 50% higher lactate transport capacity than vesicles from 'white' muscles. Giant vesicles made from rabbit red muscles had a 39% higher lactate transport capacity than vesicles from white muscles. These differences probably reflect a different number of lactate transporters, whereas the lactate affinity in red and white muscles are identical. Lactate transport capacity decreased with age. Sarcolemmal giant vesicles made from 22-month-old rats had a 28% lower transport capacity than vesicles from 2-month old rats. In absolute terms, the initial exchange flux with 30 mM lactate was 92 and 127 pmol cm-2 sec-1 for old and young rats, respectively. In supplementary studies in which microelectrode measurements were made in single mouse muscle fibers, it was shown that the cellular acidification rate due to lactate incubation, was 38% lower in fibres from 18-month old mice than in fibres from 2-month old mice.