Our goal was to study physiologic responses of human T lymphocytes to OKT3 in the human peripheral blood lymphocyte-severe combined immunodeficiency (hu-PBL-SCID) mouse model.
SCID mice were ...pretreated with anti-asialo-GM1 (alpha-ASGM1) and radiation, then engrafted with human peripheral blood lymphocytes (PBLs). Seven to 14 days after engraftment, when most human T cells in the spleen of these mice are CD3+/CD4+ and CD3+/CD8+, mice were treated with OKT3 or control antibody. Mice were killed for histopathologic examination, for flow cytometric assessment of the engrafted human lymphocytes, and for analysis of human tumor necrosis factor-alpha serum levels.
Intravenous injection of 5 microg of OKT3 resulted in early antigenic modulation of engrafted human T lymphocytes, with the emergence of CD3-/CD4+ and CD3-/CD8+ cells in the spleen of hu-PBL-SCID mice. There was an increase in the serum concentration of human tumor necrosis factor-alpha within 4 hr after OKT3 injection, suggesting early T-cell activation. Antigenic modulation and activation of the human lymphocytes in the spleen was followed by their depletion within 24 hr. This human T-cell response to OKT3 in hu-PBL-SCID mice is analogous to the response in humans treated with OKT3 and in BALB/c mice injected with an anti-murine CD3 monoclonal antibody. Graft-versus-host disease in the mice was abrogated by OKT3 treatment, and OKT3-treated mice lived longer than controls. Histopathologic studies showed clearance of lymphocytic infiltration in the liver and lungs of OKT3-treated mice.
These findings provide further evidence of functional human immune T cells in the hu-PBL-SCID mouse. This model may have useful applications in the study of transplantation immunology.
Immunoscintigraphy of the axilla has potential utility for the diagnostic and prognostic assessment of patients with breast adenocarcinoma. mAb-170H.82 is a murine monoclonal antibody (mAb) derived ...against synthetic Thomsen-Friedenreich (TF) antigen. Tru-Scint AD, a 99mTc-mAb-170H.82 immunoconjugate, has previously been shown to localize in various human adenocarcinomas. The purpose of this study was to evaluate the accuracy of this immunoconjugate in the pre-operative assessment of axillary lymph nodes in patients with known breast adenocarcinoma. Sixteen patients with documented primary breast cancer were injected intravenously with 1 mg of immunoconjugate (radioactivity 1.8 GBq) and imaged 22-24 hrs post-injection. Both planar and single photon emission computed tomographic (SPECT) images were obtained and reviewed in a blinded fashion. Imaging results were compared with surgical and pathological findings. Seven of 16 patients were found to have histologically positive axillary nodes: 5 of these sites were detected by immunoscintigraphy (sensitivity = 71%). Nine patients had pathologically disease-free axillary nodes: only 1 of these was misidentified as positive by immunoscintigraphy (specificity = 89%). These results suggest that immunoscintigraphy with 99mTc-mAb-170H.82 has promise in the detection of axillary lymph node involvement in patients with breast cancer. Further studies are warranted to define the role of immunoscintigraphy in axillary staging.
It is now recognized that occlusion of the mesenteric veins not only may complicate a number of disease processes but may occur as a life-threatening complication after abdominal surgery. A ...32-year-old woman had mesenteric venous thrombosis after resection of a duodenal inflammatory pseudotumour by pancreatoduodenectomy. She recovered fully after treatment, which consisted of thrombectomy, flushing with urokinase and intravenous administration of heparin. Papaverine infused for 4 days substantially improved bowel viability. Current concepts in mesenteric vein occlusion and the principles of clinical management are reviewed.
The Ontario Familial Colon Cancer Registry (OFCCR) is a novel registry that collects family history information, epidemiologic data, blood samples and tumour specimens from a population-based sample ...of colorectal cancer patients and their families. Families are classified as either high familial risk, intermediate familial/other risk or low (sporadic) risk for colorectal cancer. Obtaining high response rates in genetic family studies is especially challenging because of both the time commitment required and issues of confidentiality. The first-year response rate was 61%, resulting in 1,395 participating probands. In an attempt to assess potential response bias, we compared participants with non-participants. The age and sex of participants did not differ from non-participating probands; however, cases in rural areas were somewhat more likely to participate. To date, 57% of 1,587 relatives participated; females were more likely to participate, and relatives of low familial risk were least likely to participate. The OFCCR is an excellent resource that will facilitate the study of genetic and environmental factors associated with colorectal cancer.
PDF
