Concurrent chemoradiation for oesophageal cancer: Factors influencing myelotoxicity

Concurrent chemotherapy and radiation (CT/RT) for localized oesophageal cancer can cause life-threatening myelo-suppression. This non-randomized study examines 95 patients from three Australasian centres treated on the Trans-Tasman Radiation Oncology ‘definitivechemoradiation ‘ study. Duration of fluorouracil infusion and patient age were independently predictive of myelotoxicity after the first cycle of CT/RT. Overall rates of grade III and IV neutropaenia were 23% and of thrombocytopaenia 8% following the first cycle of chemotherapy. Five neutropaenic septic episodes followed the first cycle and six the second. All five patients recovered after the first cycle but there were four treatment-related deaths occurring after the second cycle of CT/RT. Recommendations are made concerning initial dosing, dose reductions and delays to minimize adverse patient outcomes from myelosuppression.     

Induction of anaphylaxis in mouse intestine by orally administered antigen and its prevention with soluble high affinity receptor for IgE

Early symptoms of food allergy, including diarrhea, are caused by IgE-mediated anaphylactic reactions. To clarify the mechanisms of IgE-mediated anaphylactic reactions in the intestine induced by orally administered antigen, a mouse model was established by s.c. implantation of a murine hybridoma capable of producing monoclonal anti-trinitrophenyl IgE antibody. Morphologic and immunologic changes in the intestine, as well as the effect of the soluble high affinity IgE receptor alpha chain, were investigated after oral challenge with antigen in this mouse model. Diarrhea, a decrease in s.c. blood flow, an increase in vascular permeability, a substantial increase in serum histamine levels, and noticeable infiltration of mast cells and IgE-bearing cells into the lamina propria were observed around 30 min after antigen challenge. However, these changes were efficiently prevented by pretreatment of the mice with the soluble high affinity IgE receptor alpha chain. These findings suggested that oral administration of antigen actually induced anaphylactic shock in our mouse model. This reaction was most likely to be mediated by mast cell activation, in response to the IgE-antigen complex, and a soluble form of the high-affinity IgE receptor efficiently prevented this IgE-mediated anaphylactic reaction by trapping free IgE.     

Application of the genome sequence to address concerns that Mycobacterium avium subspecies paratuberculosis might be a foodborne pathogen

Johne's disease, a chronic inflammatory disease caused by infection with Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis), is one of the most prevalent and costly diseases of dairy cattle worldwide. This ruminant pathogen is closely related to the ubiquitous animal and human pathogen Mycobacterium avium subspecies avium (M. avium), confounding the development of specific diagnostic reagents. Exacerbating this problem further is that most existing microbiological, serological, and immunologic assays for the identification of infected animals are inadequate. This is primarily because of the slow-growing nature of the organism, genetic intractability and the previous lack of information on M. paratuberculosis subspecies-specific genes or proteins that may enable the development of specific and sensitive assays. New detection tools are critically needed to definitively answer questions surrounding M. paratuberculosis as a foodborne pathogen as well as aid in determining if it is a contributing factor in Crohn's disease. Thus, the recent characterization of the complete genome sequence of M. paratuberculosis in our laboratories has been a major step forward in meeting this need. We have performed studies that utilize genomic information for the identification of specific DNA sequences and protein antigens in M. paratuberculosis. Based on a preliminary in silico comparison of the M. paratuberculosis genome sequence with that of M. avium, we have now identified at least 35 novel coding sequences that are unique to M. paratuberculosis. These in silico data were then confirmed and expanded by PCR amplification analysis with DNA from several species and isolates of mycobacteria. Finally, these unique sequences have been incorporated into an antigen discovery project that may allow reliable detection of the bacterium in antigen-based diagnostic tests. Application of these new tools in addressing foodborne related issues of M. paratuberculosis is discussed.     

A case of a retinitis pigmentosa and asteroid hyalosis

Asteroid hyalosis is a rare degenerative condition of the vitreous. No causal relationship between retinitis pigmentosa and asteroid hyalosis has been established. We report a case of a 65-year-old male admitted for progressive hemeralopia. Visual acuities were 2/10e in the right eye and 4/10e in the left eye. Ophthalmic examination revealed a large number of asteroid and refringent bodies, a typical retinitis pigmentosa with a cystoid macular oedema confirmed by fluorescein angiography. Electrodiagnostic testing revealed an altered electroretinogram. Visual fields showed a typical generalized constriction. We discuss the clinical aspects and physiopathogenic mechanisms of this rare association through this case and other cases found in the literature.     

Cytotoxic and pro-apoptotic activities of cynaropicrin, a sesquiterpene lactone, on the viability of leukocyte cancer cell lines

Cynaropicrin, a sesquiterpene lactone from Saussurea lappa, has been reported to possess immunomodulatory effects on cytokine release, nitric oxide production and immunosuppressive effects. In this study, we have examined cytotoxic effect of cynaropicrin against several types of cell lines such as macrophages, eosinophils, fibroblasts and lymphocytes. Cynaropicrin potently inhibited the proliferation of leukocyte cancer cell lines, such as U937, Eol-1 and Jurkat T cells, but some other cells such as Chang liver cells and human fibroblast cell lines were not strongly suppressed by cynaropicrin treatment. The cytotoxic effect of cynaropicrin was due to inducing apoptosis and cell cycle arrest at G1/S phase, according to flow-cytometric, DNA fragmentation and morphological analyses using U937 cells. Evidence that combination treatment with l-cysteine and N-acetyl-l-cysteine, reactive oxygen species scavengers, or rottlerin (1-[6-[(3-acetyl-2,4,6-trihydroxy-5-methylphenyl)methyl]-5,7-dihydroxy-2, 2-dimethyl-2H-1-benzopyran-8-yl]-3-phenyl-2-propen-1-one), a specific protein kinase (PK) Cdelta inhibitor, abolished cynaropicrin-mediated cytotoxicity and morphological change, and that cynaropicrin-induced proteolytic cleavage of PKCdelta suggests that reactive oxygen species and PKCdelta may play an important role in mediating pro-apoptotic activity by cynaropicrin. Taken together, these results indicate that cynaropicrin may be a potential anticancer agent against some leukocyte cancer cells such as lymphoma or leukemia, through pro-apoptotic activity.     

Gemcitabine and cisplatin in refractory malignant lymphoma

OBJECTIVE: We performed a pilot study to evaluate the effect of the high-dose gemcitabine-cisplatin combination in a brief weekly regimen in the treatment of primary refractory diffuse large cell lymphoma with high or high-intermediate clinical risk. METHODS: Thirty patients refractory to first-line anthracycline-based chemotherapy were treated with a combination of gemcitabine (1.5 g/m(2) i.v.) and cisplatin (50 mg/m(2) i.v.) on days 1, 8, 22, 29, 42 and 49. No further treatment was administered. RESULTS: Complete response rate was 53%; and only two relapses have been observed at the last follow-up. Thus actuarial disease-free survival at the 3-year follow-up was: 87% (95% confidence interval, CI: 70-93%) and overall survival 53% (95% CI: 44-63%). Toxicity was mild, and treatment was well tolerated. No treatment-related death was observed. CONCLUSIONS: The gemcitabine-cisplatin combination appears to be promising in the treatment of refractory lymphoma patients, with a low toxicity. However, a longer follow-up is needed to confirm the results. In our opinion, prolonged chemotherapy (6-8 cycles) did not improve outcome. At present, we are testing if the use of monoclonal antibodies (anti-CD20) employed as maintenance therapy may improve disease-free survival and overall survival.     

Herpes simplex virus thymidine kinase and granulocyte macrophage colony-stimulating factor combination gene therapy in a murine CT26 cell colon cancer model

We evaluated the antitumor effects of combination gene therapy on CT26 mouse colon cancer cells, using the genes for herpes simplex virus thymidine kinase gene HSV-TK combined with granulocyte macrophage colony-stimulating factor (GM-CSF) compared with HSV-TK alone. Cells, unmodified or retrovirally transduced with HSV-TK or GM-CSF, were inoculated subcutaneously into syngeneic BALB/c mice in various combinations. HSV-TK and GM-CSF were also delivered using different routes (in separate cells vs doubly transfected single cells). Both HSV-TK (with i.p. ganciclovir - GCV - treatment) and GM-CSF genes had independent antitumor effects, and given together they caused significant reduction in tumor volumes compared with the HSV-TK gene alone (P < 0.001). Following GCV treatment, however, the treated/control ratios for tumor volumes were not different between tumors containing either HSV-TK alone or both genes (0.27 vs 0.25, respectively). Thus, the presence of GM-CSF did not increase the bystander effect of HSV-TK. Tumors receiving genes transferred in separate cells tended to be more consistently suppressed after GCV treatment than when both genes were transferred in the same cells, although this was not statistically significant. Thus, combination GM-CSF and HSV-TK gene therapy produced greater therapeutic efficacy than HSV-TK alone, but the bystander effect was not enhanced by GM-CSF.