Efficacy of Palonosetron as Antiemetic Prophylaxis for Post Operative Patients.

Palonosetron is a new, potent and long-acting 5HT3-receptorsantagonist that had been approved by the FDA for use in postoperative nausea and vomiting (PONV) prophylaxis. The objective of this study was to investigate and compare the prophylactic effects of intravenously administered palonosetron, ondansetron and granisetron on prevention of postoperative nausea and vomiting after general anesthesia. This randomized double blind prospective clinical study was carried out in the Department of Anaesthesia, DMCH, Dhaka, Bangladesh from January 2014 to December 2015. A total of 102 patients who underwent laparoscopic cholecystectomy under general anesthesia, out of which patients who received Palonosetron were in Group A (n=34), patients who received Ondansetron were in group B (n=34) and patients who received Granisetron were in group C (n=34) and also the patients were selected randomly by lottery method. Statistical analyses of the results were obtained by using window based computer software devised with Statistical Packages for Social Sciences (SPSS-22). Nausea was found 3(8.8%) in group A, 8(23.5%) in group B and 6(17.6%) in group C. Vomiting was found 3(8.8%) in group A, 10(29.4%) in group B and 7(20.6%) in group C. Vomiting was significantly higher in group B compare with group A. For group B rescue anti-emetic injection motilon (metoclopramide hydrochloride) 5mg IV slowly was given. Palonosetron is effective prophylaxis against post operative nausea and vomiting.

Aspects of infection in intensive care unit--prevention and control.

Nosocomial infections are the main source of infection in a hospitalized patient. Source of contaminant may be multiple. In a cardiac ICU the vulnerable open heart surgery patients are with multiple invasive lines and monitors. Pediatrics and neonates are more vulnerable because of their poor immunity and nutritional debility. Frequent indwelling line access makes a patient more prone to systemic infection with variable organisms. Our aim is to minimize the chances of hospital acquired infection as far as possible by the use of systemic approach to the patients as guided by the international standard hospital protocol.

Antigen-specific B cells are required for the secondary response of T cells but not for their priming.

We studied the potential role of B cells in T cell responses using severe-combined immunodeficient (SCID) mice grafted with the thymus from fetal C.B-17 mice (TG mice). These mice developed both CD4+ and CD8+ T cells, but not B cells within 2 months after transplantation. TG mice showed normal delayed-type hypersensitivity responses against the immunizing antigen ovalbumin (OVA). Lymph node (LN) cells of TG mice proliferated well in response to concanavalin A (Con A). Further, Con A stimulation induced the production of interleukin (IL)-2, IL-6 and interferon (IFN)-gamma and the expression of IL-4 mRNA. Thus, TG mice were reconstituted without remarkable immunodeficiency. However, these T cells failed to proliferate to OVA stimulation. Response to OVA was also inhibited in SCID mice grafted with fetal C.B-17 liver cells when B cells were depleted in the proliferation assay. Unresponsiveness against immunizing antigen was restored by the addition of antigen-primed B cells, but not by naive B cells, lipopolysaccharide-activated B cells or B cells primed with sheep red blood cells. Next, we examined whether antigen-primed B cells could induce T cell responses without professional antigen-presenting cells (APC). T and B cells were purified from OVA-immunized mice by cell sorter. These T cells proliferated in response to OVA and produced IFN-gamma in the absence of non-B APC. When anti-CD80 or anti-CD86 was added in the assay, proliferation and IFN-gamma production was inhibited. These results indicate that B cells activated specifically with antigen are required for the secondary response of T cells, but not for their priming.

B cells are required as APC for antigen-specific T cell proliferation but not for the differentiation or priming of those T cells.

We studied the influences of B cells on functional differentiation of T cells using SCID mice grafted with fetal thymus of C.B-17 mice (TG mice). T cells were shown to be reconstituted in TG mice without B cell development. These mice showed normal DTH response to SRBC and OVA. LN cells of these mice produced cytokines including IL-2, IL-4, IL-6 and IFN-gamma according to Con A stimulation. Thus, majority of T cell functions seem to differentiate in the absence of B cells. However, T cells of TG mice failed to proliferate in response to immunizing antigens in vitro, although they responded well to stimulation with Con A. This unresponsiveness of T cells in TG mice to these antigens was restored when antigen-primed B cells were added to the proliferation assay. Such an inability of T cells in antigen-specific proliferation was not seen in SCID mice grafted with C.B-17 fetal liver cells, in which B cells as well as T cells were efficiently reconstituted (FLT mice). T cell proliferation to immunizing antigen was also abrogated in FLT mice when B cells were depleted from lymphoid population. These results indicate that T cells can functionally differentiate and be primed in the absence of B cells, but they require B cells to proliferate in response to foreign antigens.