Monoclonal antibody LICR-LON-M8 does not predict the outcome of operable breast cancer.

The prognostic value of the monoclonal antibody LICR-LON-M8, which has been shown to detect micrometastatic disease, was evaluated in a prospective, double-blind, clinical study of bone-marrow specimens from patients with operable breast cancer. Four bone-marrow specimens, obtained from each of 50 patients at the time of excision of the primary breast tumour, were examined immunohistochemically, with LICR-LON-M8 as the primary antibody. All of the primary tumour specimens demonstrated positive staining for malignant disease with LICR-LON-M8. The bone-marrow specimens of four patients demonstrated positive staining: three specimens were "suspicious" for malignant cells and one contained definite malignant cells on cytologic examination. This gave a 2% rate of detectable micrometastatic disease at the time the primary tumour was excised. Patient follow-up averaged 21.5 +/- 9.1 months. The test results did not correlate with outcome. A negative test result with LICR-LON-M8 did not imply a better prognosis. The authors conclude that examination of bone-marrow specimens stained with LICR-LON-M8 in patients with operable breast cancer is of no clinical value. Furthermore, the low rate of micrometastases detected is at variance with that reported by others. In view of the natural history of breast cancer, the authors believe that their results were not unexpected and they question the importance of other results.     

A prospective study of methylenetetrahydrofolate reductase and methionine synthase gene polymorphisms, and risk of colorectal adenoma

We examined the relationship between a functional polymorphism (667C-- >T, ala-->val) of the methylenetetrahydrofolate reductase gene (MTHFR) and the risk of colorectal adenomas in the prospective Nurses' Health Study. Among 257 incident polyp cases and 713 controls, the MTHFR val/val polymorphism [relative risk (RR) = 1.35, 95% confidence interval (CI) 0.84-2.17] was not significantly associated with risk of adenomas. This lack of association was observed for both small (RR = 1.36, 95% CI 0.76-2.45) and large (RR = 1.32, 95% CI 0.66-2.66) adenomas. Furthermore, there was no significant interaction between this polymorphism and consumption of either folate, methionine or alcohol. We also examined the relationship of a newly identified polymorphism (asp919gly) of the methionine synthase gene (MS) with the risk of colorectal adenomas in the same population. The MS gly/gly polymorphism was also not significantly associated with risk of colorectal adenomas (RR = 0.66, 95% CI 0.26-1.70). These results, which need to be confirmed in other studies, suggest that the MTHFR val/val polymorphism, which has been previously inversely associated with risk of colorectal cancer, plays a role only in a late stage (adenoma-- >carcinoma) of colorectal tumorigenesis, and/or may protect against malignant transformation in the subset of benign adenomas, which may progress to malignancy.      

Lymphoproliferative Läsionen der okulären Adnexe

The ocular adnexal lymphomas represent the malignant end of the spectrum of lymphoproliferative lesions which occur in the conjunctiva, eyelids, lacrimal gland and orbit. The new “W.H.O. Classification of Tumours of Haemopoietic and Lymphoid Tissues” is the most suitable for subdividing the ocular adnexal lymphomas, whereby the extranodal marginal zone B-cell lymphoma (EMZL) represents the most common lymphoma subtype. Management of patients with ocular adnexal lymphomas includes a systemic medical examination to establish the clinical stage of the disease. Most patients have stage IE disease and current recommended therapy for this is radiotherapy, while disseminated disease is treated with chemotherapy. Despite usually demonstrating an indolent course, EMZLs are renowned for recurrence in extranodal sites, including other ocular adnexal sites. Furthermore, blastic transformation of EMZL with a corresponding aggressive clinical course has been described. Long-term follow-up with half-yearly examinations are therefore recommended. Major prognostic criteria for the ocular adnexal lymphomas include the age of the patient, anatomical location of the tumour, stage of disease at first presentation, serum lactate dehydrogenase level at the time of diagnosis, lymphoma subtype as determined using the W.H.O. lymphoma classification and the tumour cell growth rate. The clinical symptoms and the histopathological findings of the differential diagnoses of lymphoproliferative lesions of the ocular adnexa are discussed.     

Flumazenil challenge in social phobia

The benzodiazepine antagonist, flumazenil, can provoke panic attacks in some panic disorder patients. It has been predicted that panic responses to flumazenil may be associated with situational fear. Patients with social phobia frequently experience situational anxiety and panic attacks. The current study tested whether flumazenil induces panic in patients with social phobia. Fourteen patients with social phobia (DSM-III-R) and 14 age- and sex-matched controls were tested in a single session, double blind crossover challenge design, using intravenous flumazenil 2 mg/20 ml or matched placebo infusions 1 hour apart. Panic attacks occurred during flumazenil challenge in 2/14 subjects with social phobia. The rate of panic attacks and the severity of panic symptoms following flumazenil were not significantly greater in patients than in controls. Situational fears that are provoked by social cues therefore do not predict panic responses to flumazenil.     

Leflunomide therapy following penetrating keratoplasty in the rat

Background: The isoxal derivative, leflunomide (LF), is a new potent immunosuppressive which has been shown to be effective in preventing autoimmune disorders and reactions leading to organ transplantation rejection. LF is thought to antagonise cytokine activity and thereby to interfere with T-helper-cell-dependent B- and T-lymphocyte proliferation. Methods: We used LF to treat corneal allograft rejection in the rat, comparing its effect with that of cyclosporin A (CSA). Corneal buttons were grafted from Lewis/Brown Norway rats to Lewis recipients. Animals were randomly assigned to the following treatment groups: I, untreated; II, CSA (10 mg/kg i.m.); III, LF (2.5 mg/kg p.o.); IV, LF (5 mg/kg p.o.); V, LF (10 mg/kg p.o.); VI, combined therapy (LF 10 mg/kg p.o. and CSA 10 mg/kg i.m). Treatment began on the first postoperative day and was continued until rejection occurred. Results: The mean graft rejection time in the untreated allogeneic group was 12 days. A significant delay in graft rejection was observed in all treatment groups compared with group I (P<0.001). Further, the delay in graft rejection resulting from combined therapy (group VI) was statistically significant compared with all other groups (P<0.001). Conclusion: These results suggest that (a) LF when used alone is as effective as CSA in treating corneal allograft rejection in the rat, and (b) when LF and CSA are combined they are more effective than either drug alone in the prolongation of allograft survival.Presented in abstract form at the Berlin-Brandenburg Eye Congress, 4–5 December 1993. None of the authors has any proprietary or financial interests in the compound leflunomide     

Transforming growth factor beta (TGF-beta), a potent inhibitor of erythropoiesis: neutralizing TGF-beta antibodies show erythropoietin as a potent stimulator of murine burst-forming unit erythroid colony formation in the absence of a burst-promoting activity

Transforming growth factor beta (TGF-beta) is a bifunctional regulator of the growth of myeloid progenitors and is here demonstrated to directly inhibit the growth of primitive erythroid progenitors by 95% to 100% regardless of the cytokines stimulating growth. Autocrine TGF- beta production of primitive hematopoietic progenitors has previously been reported. In the present study, a neutralizing TGF-beta antibody (anti-TGF-beta) added to serum-containing cultures, resulted in a 3-, 4- , and 25-fold increase in burst-forming unit erythroid (BFU-E) colony formation in response to interleukin-4 (IL-4) plus erythropoietin (Epo), SCF plus Epo, and IL-11 plus Epo, respectively. The growth of BFU-E progenitors has been suggested to require a burst-promoting activity in addition to Epo. Accordingly, we observed no BFU-E colony formation in serum-containing cultures in response to Epo alone. In contrast, 50 BFU-E colonies were formed when anti-TGF-beta was included in the culture. In serum-free cultures, Epo also stimulated BFU-E colony formation in the absence of other cytokines, whereas anti-TGF- beta had no effect on the number of colonies formed. Quantitation of TGF-beta 1 in serum by an enzyme-linked immunosorbent assay method showed predominantly the presence of precursor (latent) TGF-beta 1, but also showed active TGF-beta 1 at a concentration sufficient to potently inhibit erythroid colony formation. Thus, neutralization of active TGF- beta 1 in serum shows that Epo alone is sufficient to stimulate the growth of murine BFU-E progenitors.     

Fluorescent in vivo tracking of hematopoietic cells. Part I. Technical considerations

We report a new technology for in vivo tracking of hematopoietic cells, using fluorescent lipophilic probes. Because the probe is irreversibly bound in the lipids of the cell membrane; substantial numbers of dye molecules can be incorporated per cell and thus substantial signal to noise can be achieved. Although this technology can be used for all hematopoietic cells, these first findings are reported on red blood cells (RBCs) owing to the importance of the membrane to RBC function and integrity. We demonstrated that labeling 10% of the RBCs of a rabbit and reinjecting them into the animal makes possible the tracking of these cells at various times after injection. Furthermore, the labeling appears not to affect in vivo cell lifetime or cellular volume changes in response to hypotonic shock. The single cell fluorescence intensity of the labeled RBCs remains relatively constant for 60 days, and an immune response appears not to be generated against labeled cells. That labeled RBCs have lifetime kinetics in vivo, as shown in other studies, indicates that the membranes are functioning normally and are unaltered by the labeling technology. The technology we present is also applicable to white blood cells, bone marrow, and platelets.