A study of the immunological response to tumor ablation with irreversible electroporation

Immune cell recruitment during the treatment of sarcoma tumors in mice with irreversible electroporation was studied by immunohistochemistry. Irreversible electroporation is a non-thermal tissue ablation technique in which certain short duration electrical fields are used to permanently permeabilize the cell membrane, presumably through the formation of nanoscale defects in the membrane. Employing irreversible electroporation parameters known to completely ablate the tumors without thermal effects we did not find infiltration of immune cells probably because of the destruction of infiltration routes. We confirm here that immune response is not instrumental in irreversible electroporation efficacy, and we propose that irreversible electroporation may be, therefore, a treatment modality of interest to immunodepressed cancer patients.

Clinical Evaluation of Prior Suicide Attempts and Suicide Risk in Psychiatric Inpatients

Summary: Background: In practice psychiatrists rely on their own experience and intuition to evaluate the suicide potential of individual patients, but the algorithms for the decision-making process remain unclear. Objectives: (1) to establish models for the decision making process for evaluating suicide risk; (2) to simulate the impact of information concerning the number of previous suicide attempts on the clinician's ability to detect patients who performed medically serious suicide attempts (MSSAs). Methods: Four decision models (linear, dichotomized, hyperbolic, and undifferentiated) depicting the influence of the number of previous suicide attempts on the clinician's recognition of MSSAs in 250 psychiatric inpatients were elicited and tested by a series of discriminant analyses. Results: The dichotomized model (“all or none”) was found to be the most efficient in detecting medically serious suicide attempts. Conclusion: The “all or none” paradigm seems to be the most appropriate way to evaluate the weight of previous suicide attempts in the decision-making process identifying medically serious suicide attempt patients.

[Heparin induced thrombocytopenia: case report with acute thrombotic complications and literature review]

PURPOSE

Review of the frequency, clinical and biological features and treatment of type II heparin-induced thrombocyopenia.

METHODS

Case report and literature review.

RESULTS

A 65 years old woman received as antithrombotic prophylaxis low molecular weight heparin (LMWH) after prosthetic knee replacement. Day 8, asymptomatic deep vein thrombosis was discovered after systematic echodoppler examination. Curative anticoagulation was started with LMWH. A fall in the platelet count (17 G/L) was noted day 12. Danaparoid was immediately introduced and heparin discontinued. However, day 16 a massive pulmonary embolism occurred which required transfer to an intensive care unit. Danaparoid was changed for lepirudin the same day. It took longer than three weeks for platelet count to return to normal value after heparin discontinuation. The suspicion of heparin-induced thrombocyopenia was confirmed by specific tests.

DISCUSSION

HIT type II are rare but life-threatening and thrombosis events are the most frequent complications. The diagnosis is a high probability proved by both clinical and biological patterns. The treatment consists in alternative thrombin inhibitors such as danaparoid and lepirudin. The platelet count usually requires less than ten days to recover normal values after heparin withdrawal. Cases in which the delay to a normal platelet count exceeds 3 weeks have been reported specially after LMWH therapy.

CONCLUSION

Type II HIT are rare but life-threatening events can occur. The platelet count check-up during heparin therapy must be systematic.

Combining tumor destruction by electrochemotherapy and innate immunity by CpG-ODN: Toward a new combination treatment for melanoma with skin metastases

12507

Background: Electrochemotherapy (ECT), consisting of electroporating cytotoxic agents (bleomycin or cisplatinum) in tumors, is effective in inducing destruction of cutaneous or subcutaneous tumors and can be used as a palliative treatment for patients with skin melanoma metastases. Our objective was to combine the antigen release induced by ECT with a potent and adapted stimulation of the innate immune system in order to induce a systemic anti-tumor response. Methods: The preclinical work was performed on murine models of skin tumors: fibrosarcoma (LPB) and melanoma (B16F10). We found that electrochemotherapy induced the recruitment of immune cells expressing CD11-c and Mac-1 in the first 48h after the treatment. By quantitative RT-PCR, we showed that this immune cell infiltrate was associated with an increase of TLR9 RNA expression. Therefore, we decided to combine ECT with intra-tumoral injection of TLR9 ligands: unmethylated CpG oligodeoxynucleotides (CpG-ODN). The distant and local antitumoral effect of this association (ECT + CpG-ODN) were tested in mice bearing a tumour on the two flanks (fibrosarcoma or melanoma). Animals were treated on the left flank only by a unique ECT course followed by intratumoral injection of CpG-ODN. Tumor growth rates were monitored on both treated (left) and non-treated (right) sides in order to assess direct and systemic antitumor effects of the association respectively. Experiments were also performed on nude mice, in order to investigate the role of lymphocytes in the systemic antitumor effect. Results: Compared to the separated treatments alone we found an increased local efficacy of the ECT-CpG-ODN, but, more importantly, we demonstrated a clear systemic effect of the combination on the controlateral tumors. In nude mice, no effect was observed in controlateral tumors suggesting a mechanism mediated by T lymphocytes.

No significant financial relationships to disclose.

Clinical evaluation of prior suicide attempts and suicide risk in psychiatric inpatients

BACKGROUND

In practice psychiatrists rely on their own experience and intuition to evaluate the suicide potential of individual patients, but the algorithms for the decision-making process remain unclear.

OBJECTIVES

(1) to establish models for the decision making process for evaluating suicide risk; (2) to simulate the impact of information concerning the number of previous suicide attempts on the clinician's ability to detect patients who performed medically serious suicide attempts (MSSAs).

METHODS

Four decision models (linear, dichotomized, hyperbolic, and undifferentiated) depicting the influence of the number of previous suicide attempts on the clinician's recognition of MSSAs in 250 psychiatric inpatients were elicited and tested by a series of discriminant analyses.

RESULTS

The dichotomized model ("all or none") was found to be the most efficient in detecting medically serious suicide attempts.

CONCLUSION

The "all or none" paradigm seems to be the most appropriate way to evaluate the weight of previous suicide attempts in the decision-making process identifying medically serious suicide attempt patients.