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.     

Limb-salvage treatment versus amputation for osteosarcoma of the distal end of the femur

A retrospective multi-institutional study of 227 patients with osteosarcoma of the distal end of the femur was done to compare rates of local recurrence, metastasis, and survival. Three cohorts of patients who had had either a limb-sparing procedure, an above-the-knee amputation, or disarticulation of the hip were compared. The results revealed prevalences of eight of seventy-three, nine of 115, and zero of thirty-nine as to local recurrence; forty-three of seventy-three, sixty-five of 115, and twenty-one of thirty-nine as to metastasis; and thirty-three of seventy-three, forty-eight of 115, and eighteen of thirty-nine as to death. Of the seventeen patients who had a local recurrence, sixteen died. In the limb-salvage group, eighteen patients required amputation, because of local recurrence in eight and other local complications in ten. The Kaplan-Meier estimates of the percentage of patients who survived and the percentage of patients without recurrent disease showed no difference among the three surgical groups (Mantel-Cox test statistic: p = 0.8) after a median length of follow-up of five and one-half years. Various covariant adjusted estimates yielded similar results. For the entire group of patients, the rate of continuously disease-free survival was 42 per cent, and the over-all rate of survival was 55 per cent at five years. It appears that, compared with above-the-knee amputation or disarticulation of the hip, the use of a limb-salvage procedure for osteosarcoma of the distal end of the femur did not shorten the disease-free interval or compromise long-term survival.     

Chronic exercise-induced compartment pressure elevation measured with a miniaturized fluid pressure monitor. A laboratory and clinical study

Increased pressure within an osteofascial compartment may produce a compartment syndrome, one of the principal causes of circulatory compromise in acute traumatic and chronic exercise-induced elevated compartment pressure. Acute and chronic diagnostic quantitation of compartment pressures are a valuable adjunct to clinical diagnosis, particularly when used to evaluate the athlete with exercise-induced pain. This study evaluated a prototype hand-held, digital, fluid pressure monitor used for the measurement of compartment pressure in the exercising athlete. A laboratory water and mercury manometer study, in which 50 paired, single-blind measurements were taken, revealed that the digital monitor was accurate to +/- 0.8 mm Hg (SD) of actual pressure with no individual reading more than 1 mm Hg from the actual pressure when compared directly with a mercury and a water column. Laboratory study of bovine muscle placed within a pressure chamber revealed that the digital monitor, when assembled in the same manner as used for clinical measurement, was accurate to +/- 0.9 mm Hg. The needle manometer technique was also found to be accurate to +/- 3 mm Hg from actual pressure. Twenty-one paired measurements of the anterolateral and posterior compartments of the hindlimbs of eight anesthetized New Zealand White rabbits by both the needle manometer and digital monitor methods by two examiners demonstrated the digital monitor to be reproducible to +/- 1.0 mm Hg [Coefficient of variation (CV) less than 7%] and needle manometer method to +/- 3.4 mm Hg (CV less than 16%) with r = 0.94.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.      

Extraosseous osteosarcoma presenting with intestinal hemorrhage: case report and literature review

A 23-year-old man presented with intestinal bleeding due to an extraosseous osteosarcoma of the jejunum. A lesion was also found in the deltoid muscle, and other metachronous soft tissue sites developed subsequently. The presence of malignant osteoid was documented by immunohistochemical studies of one of the lesions. The patient died of metastatic disease 19 months after diagnosis, despite surgical resections and adjuvant chemotherapy. This unique presentation is discussed, and the literature concerning extraosseous osteosarcoma is reviewed.