Human immunology studies using organ donors: Impact of clinical variations on immune parameters in tissues and circulation.

Organ donors are sources of physiologically healthy organs and tissues for life-saving transplantation, and have been recently used for human immunology studies which are typically confined to the sampling of peripheral blood. Donors comprise a diverse population with different causes of death and clinical outcomes during hospitalization, and the effects of such variations on immune parameters in blood and tissues are not known. We present here a coordinate analysis of innate and adaptive immune components in blood, lymphoid (bone marrow, spleen, lymph nodes), and mucosal (lungs, intestines) sites from a population of brain-dead organ donors (2 months-93 years; n = 291) across eight clinical parameters. Overall, the blood of donors exhibited similar monocyte and lymphocyte content and low serum levels of pro-inflammatory cytokines as healthy controls; however, donor blood had increased neutrophils and serum levels of IL-8, IL-6, and MCP-1 which varied with cause of death. In tissues, the frequency and composition of monocytes, neutrophils, B lymphocytes and T cell subsets in lymphoid or mucosal sites did not vary with clinical state, and was similar in donors independent of the extent of clinical complications. Our results reveal that organ donors maintain tissue homeostasis, and are a valuable resource for fundamental studies in human immunology.

The role of natural killer cells in combinatorial anti-cancer therapy using Sindbis viral vectors and irinotecan.

Oncolytic viruses (OVs) have shown great anti-cancer potential in animal models, but only modest success in early clinical trials. A better understanding of the mechanisms underlining OV efficacy is needed to resolve this discrepancy. In the clinic, OV therapy will likely be combined with traditional chemotherapy, underscoring the need to also evaluate the interactions between these therapeutic modalities. Here we show that combining Sindbis viral vector therapy with the topoisomerase inhibitor irinotecan (CPT-11) results in the long-term survival of about 35% of SCID mice bearing aggressively growing ES2 human ovarian cancer. Single-agent treatments did not result in long-term survival. Flow cytometry analysis, bioluminescent imaging and survival experiments revealed that Sindbis and CPT-11 utilize non-overlapping natural killer (NK)-cell-dependent and -independent anti-cancer mechanisms, respectively. Notably, the combinatorial therapy was only effective in the presence of NK cells. These results highlight the hidden role of immune cell activation in combinatorial cancer therapy involving OVs and provide a potential method for tackling tumor cell resistance to cancer therapy while limiting treatment-related side effects.

Enhanced specific delivery and targeting of oncolytic Sindbis viral vectors by modulating vascular leakiness in tumor.

Genetic instability of cancer cells generates resistance after initial responses to chemotherapeutic agents. Several oncolytic viruses have been designed to exploit specific signatures of cancer cells, such as important surface markers or pivotal signaling pathways for selective replication. It is less likely for cancer cells to develop resistance given that mutations in these cancer signatures would negatively impact tumor growth and survival. However, as oncolytic viral vectors are large particles, they suffer from inefficient extravasation from tumor blood vessels. Their ability to reach cancer cells is an important consideration in achieving specific oncolytic targeting and potential vector replication. Our previous studies indicated that the Sindbis viral vectors target tumor cells by the laminin receptor. Here, we present evidence that modulating tumor vascular leakiness, using VEGF and/or metronomic chemotherapy regimens, significantly enhances tumor vascular permeability and directly enhances oncolytic Sindbis vector targeting in tumor models. Because host-derived vascular endothelium cells are genetically stable and less likely to develop resistance to chemotherapeutics, a combined metronomic chemotherapeutics and oncolytic vector regimen should provide a new approach for cancer therapy. This mechanism could explain the synergistic treatment outcomes observed in clinical trials of combined therapies.

Decline in pulmonary function in patients with breast cancer receiving dose-dense chemotherapy: a prospective study.

BACKGROUND: Prompted by complaints of dyspnea in breast cancer patients receiving adjuvant dose-dense chemotherapy (DDC), we sought to evaluate the possible association of DDC with pulmonary dysfunction. PATIENTS AND METHODS: A total of 34 consecutive patients receiving adjuvant DDC were enrolled. The chemotherapy regimen consisted of i.v. doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2) (AC) every 14 days x4 with growth factor support followed by weekly i.v. paclitaxel 80 mg/m(2) x12. The following parameters were prospectively measured before and after the AC protocol (P1, P2) and at completion of paclitaxel treatment (P3): presence of dyspnea, blood pressure, pulse rate, hemoglobin, erythrocyte sedimentation rate, C-reactive protein level, cardiac ejection fraction, and pulmonary function. Repeated measures analysis was used to evaluate differences among the time points, and paired t-test was used to evaluate differences between consecutive time points. RESULTS: Although only five patients (15%) complained of dyspnea, there was a significant decrease in mean carbon monoxide diffusing capacity (DLCO), in all patients from P1 (22.09 ml/min/mmHg) to P3 (15 ml/min/mmHg) and in 29 of 32 patients (90.6%) from P1 to P2 (15.96 ml/min/mmHg) (P<0.001). CONCLUSIONS: DDC is associated with a statistical significant reduction in DLCO. Awareness of this potential toxicity may be important in women with preexisting lung disease.

Caspase-dependent and -independent cell death of Jurkat human leukemia cells induced by novel synthetic ceramide analogs.

Ceramide metabolism has emerged as a potential target for anticancer therapy. Here, the potential usefulness of two novel synthetic ceramide analogs as anti-leukemic drugs was investigated. Compounds AD2646 and AD2687 were able to dose-and time-dependently decrease the viability of Jurkat leukemic cells. This was accompanied by an accumulation of endogenous ceramide owing to perturbed ceramide metabolism. Cytotoxicity involved caspase activation but also necrotic-like features, as evidenced by phosphatidylserine externalization, membrane permeability, hypodiploidy, caspase processing and only partial protection from cell death by a pan-caspase inhibitor. Ceramide analogs also induced cell death in Jurkat mutants that are deficient in cell death signaling proteins, including FADD, caspase-8 and 10, and RIP. While overexpression of Bcl-xL did not suppress ceramide accumulation, it conferred robust protection from caspase activation and cell death. Altogether, these novel ceramide analogs are able to kill leukemic cells through distinct pathways implicating caspase activation and mitochondrial events, and represent a new group of bioactive molecules with potential applications in anticancer therapy.

Nursing students' right to refuse to treat patients and the relationship between year of study and altitude towards patient care.

Nursing students are taught the nursing code of ethics and how to deal with ethical questions and dilemmas. After graduation, they are expectedto adhere to this code, but as students do they? We examined student nurses' and their instructors' position regarding students' obligations in treating patients. In order to identify the students' perspectives towards these obligations, students and instructors were asked if a student has the right to refuse to treat a patient. A cross-sectional descriptive design was used in examining 162 academic nursing students and 16 faculty members' attitudes towards refusing to treat a patient. The results of this study indicate that significant relationships exist between clinical and ethical knowledge and the perception of obligations to ensure and protect patients' rights. Clinical and ethical knowledge are significantly related to the development of ethical conduct in nursing students.