Comparison of ventilation effectiveness of the bag valve mask and the LMA Air-Q SP in nurses during simulated CPR.

In a case of sudden cardiac arrest (SCA) in a health facility there is a procedure to summon a resuscitation team. Nurses are obliged to begin cardiopulmonary resuscitation with chest compressions and implement ventilation using the bag valve mask of 30:2 compressionventilation ratio. Nurses are not allowed to implement methods of advanced airway management. However, the laryngeal mask airway (LMA) was designed for people inexperienced in intubation who would be able to provide advanced airway management quickly and effectively after a short training. It is advisable to check how nurses, who in case of SCA are often the first responders, deal with advanced airway management. AIM: The aim of the study was to evaluate the quality of ventilation using the bag valve mask and the LMA Air-Q SP by professionally active nurses. MATERIALS AND METHODS: The study was conducted on a 38-person group of professionally active nurses working or affiliated with the District Health Care Facility in Piotrków Trybunalski. After a short pre-training lecture the nurses were assigned to ventilate the manikin with the bag valve mask (BVM) using 30:2 compressionventilation ratio and then asynchronously with the use of the LMA Air-Q SP. RESULTS: The average time elapsed from the beginning of CPR to the onset of ventilation was 18 ± 5,4 s. as for the BVM and 16,15 ± 4,4 s regarding the LMA. Minute ventilation achieved with the BVM was 3,47 ± 1,43 l / min, and in case of the LMA it amounted 5,54 ± 1,73 l / min. There was no case of gastric insufflation in case of the LMA, while as for the BVM it occurred in five cases. There are very few studies focused on the LMA Air-Q SP, but some research (Jagannathan, Alexandera or Gruber) devoted to the use of the LMA in nurses, demonstrate that ventilation with the use of the LMA is effective and ensure more appropriate ventilation parameters than with the use of the BVM. CONCLUSIONS: The nurses achieved better ventilation results when using the LMA. Attempts to insert the LMA were shorter than in case of the BVM.

Hepatocyte transplants improve liver function and encephalopathy in portacaval shunted rats.

AIM: Rats with portacaval shunt (PCS) are useful experimental models of human hepatic encephalopathy in chronic liver dysfunction. We have previously shown that PCS modifies amine neurotransmitter systems in the CNS and increases voluntary alcohol intake by rats. Hepatocyte transplantation, used in acute liver failure, has recently also been applied to chronic liver diseases, which prompted us to investigate whether the altered brain amine system and the drinking behavior in long-term shunted rats could be normalized by hepatocyte transplants. METHODS: Hepatocytes, isolated from syngeneic donors by collagenase digestion, were injected (3 × 10(6) cells/rat) into the pancreatic tail region, 6 months after PCS. Hepatic function was evaluated by measuring urine urea and plasma L-histidine concentrations. A free choice test with two bottles (tap water and 10% ethyl alcohol) was performed for 3 days to assess the rats' preference for alcohol. The rats were euthanized 2 months posttransplantation. Brain histamine and 5-hydroxyindoleacetic acid (5-HIAA) levels were measured by radioenzymatic assay and by HPLC-EC, respectively, N-tele-methylhistamine by GC/MS while MAOA and MAOB activities by isotopic procedures. RESULTS: Portacaval shunt rats with hepatocyte transplants gave more urea than before transplantation, with lower plasma L-His levels and higher body weight versus the PCS counterparts. Also, those rats consumed less alcohol. The CNS amines and 5-HIAA concentrations, as well as MAO-B activity, being abnormally high in untreated PCS rats, significantly reduced after PCS hepatocyte treatment. CONCLUSIONS: The results support the therapeutic values of hepatocyte transplants in chronic liver diseases and the temporary character of PCS-exerted CNS dysfunctions.

The response of spleen dendritic cell-enriched population to bacterial and allogeneic antigens.

The dendritic cells (DC) play crucial role in initiation and modulation of immune response especially innate immune response. We investigated the influence bacterial (E. coli and S. epidermidis) and allogeneic antigens (heart, skin and bone marrow transplants) on splenic DC- enriched population. We found that 1) the in culture stimulation of rat splenic DC-enriched population by E. coli, S.epidermidis, LPS and CpG DNA caused increase in class II-positive cells. Simultaneously, a decrease in percentage of EDI, B cells and OX62 migrating DC upon treatment with S.epidermidis was observed. LPS caused decreased frequency of OX62 and NK cells. 2) Similarly to the in vitro the in vivo stimulation by E. coli, S.epidermidis, LPS and CpG DNA increased the percentage of class II-positive cells. There was a decrease in the ED1, OX62 and B cell populations following stimulation by S. epidermidis. 3) Mixed DC-enriched population and donor PBM culture showed high level of response in both populations. 4) Syngeneic and allogeneic transplants of heart, skin and BMC caused increase in class II-positive cells. Moreover, there was an increase in frequency of the ED1 and W3/13 populations after both syn- and allogeneic transplantation. The OX62 cells did not react, whereas the B cell frequency rose only after allogeneic transplantation. A significant decrease in NK cell population was noticed. 5) The in vitro and in vivo bacterial stimulation brought about expression of TLR receptors and Hsp. Mixed recipient DC with donor PBM culture caused expression of Hsp 90 but not TLRs. Allogeneic stimulation by transplanted tissues did not evoke expression of the investigated receptors and proteins. 6) Recipient DC-enriched population produced IFN gamma upon stimulation with bacteria and skin but not heart and BMC. Further studies on simultaneous stimulation of splenic DCs by bacterial and allo-antigens will throw light on additive effects of bacterial activation in allograft rejection.

Repopulation of the heart graft with recipient immature dendritic cells prior to transplantation does not prolong its survival.

Experimental studies on allogeneic transplantation have shown that recipient dendritic cells (DC) play a role in peripheral tolerance as well as in rejection of allografts. It is not known whether DC exert their tolerogenic function in the graft or in recipient lymphoid tissue. To answer this question we created a chimeric heart model deprived of its own DC and repopulated by recipient DC. The rationale for this model was to observe whether recipient mature and immature DC located in the graft attenuate recruitment and stimulation of recipient lymphocytes, subsequently prolonging graft survival. Vascularized bone marrow transplants (VBMTx) from the prospective recipient to the lethally irradiated heart donor, which function for a period of 14 days, were used to replace donor DC with prospective recipient either mature or immature DC. Replacement of the donor heart with either of these cellsdid not prolong graft survival. The intra-graft microchimerism did not mitigate the allogeneic rejection reaction.

Spleen dendritic cells of recipients of allogeneic but not syngeneic heart grafts internalize donor DNA fragments.

Microchimerism after allogeneic organ transplantation has been widely documented using DNA identification techniques. However, the question as to whether the detected donor DNA is present in the surviving donor cells, recipient macrophages phagocytizing rejected donor cells or recipient dendritic cells internalizing donor apoptotic bodies or cell fragments has not been answered. We provide evidence that allogeneic organ transplantation is followed not only by cellular microchimerism caused by release of graft passenger cells but also dissemination of donor DNA from the rejecting graft cells and its internalization in recipient dendritic cells (DC). Identification of allogeneic donor DNA was based on detection of the male Sry-PCR product in extracts of DNA from recipient tissues, dendritic cells and their nuclei. Most interestingly, donor DNA could be detected at high concentration in all recipient tissues at the time of rejection. Search for specific localization of allogeneic donor Sry fragments in recipient cells revealed its presence preferrentially in the DC. No donor Sry fragments were detected in recipient DC after syngeneic transplantation. Detection of allogeneic but not syngeneic donor Sry in DC nuclei further strengthens our concept that DC specifically incorporate allogeneic donor DNA fragments. The mechanism of this process requires further studies.

Biological aspects of limb transplantation: I. Migration of transplanted bone marrow cells into recipient.

The transplanted limb contains bone marrow tissue. The hematopoietic cells contained in the bone of the graft normally differentiate after transplantation and can be released to the recipient. The cells migrate to the recipient bone marrow cavities and lymphoid organs. This causes the immune reaction between the donor and the recipient, which develops not only in the graft itself but also in the recipient immune organs where donor bone marrow cells home. The purpose of this study was to investigate the process of migration of the hematopoietic cells from the donor limb to the recipient bone marrow cavities and lymphoid tissues. The questions the authors asked were: what is the rate of release of bone marrow cells from the transplanted bone, where do the released bone marrow cells home in the recipient, how fast are donor bone marrow cells rejected by the recipient, and can some bone marrow cells homing in the recipient tissues survive and create a state of microchimerism. Experiments were performed on Brown Norway and Lewis inbred rat strains (n = 30). Limb donors received intravenous chromium-51-labeled bone marrow cells. Twenty-four hours later, the limb with homing labeled bone marrow cells was transplanted to an allogeneic or syngeneic recipient. The rate of radioactivity of bone marrow cells released from the graft and homing in recipient tissues was measured after another 24 hours. To eliminate factors adversely affecting homing such as the "crowding effect" and allogeneic elimination of bone marrow cells by natural killer cells, total body irradiation and antiasialo-GM1 antiserum were applied to recipients before limb transplantation. In rats surviving with the limb grafts for 7 and 30 days, homing of donor bone marrow cells was studied by specific labeling of donor cells and flow cytometry as well as by detecting donor male Y chromosome. The authors found that transplantation of the limb with bone marrow in its natural spatial relationship with stromal cells and blood perfusion brings about immediate but low-rate release of bone marrow cells and their migration to recipient bone marrow and lymphoid tissues. Large portions of allogeneic bone marrow cells are rapidly destroyed in the mechanism of allogeneic elimination by radioresistant but antiasialo-GM1-sensitive natural killer cells. Some transplanted bone marrow cells remain in the recipient's tissues and create a state of cellular and DNA microchimerism. A low number of physiologically released donor bone marrow cells do not seem to adversely affect the clinical outcome of limb grafting. Quite the opposite, a slight prolongation of the graft survival time was observed.

Smooth-muscle progenitor cells of bone marrow origin contribute to the development of neointimal thickenings in rat aortic allografts and injured rat carotid arteries.

This study indicates that circulating progenitors of bone marrow origin give rise to cells with smooth muscle-like properties during formation of neointimal thickenings in the arterial wall after allotransplantation and after balloon injury. A segment of abdominal aorta was transplanted from female F344 to male LEW rats, and the grafts were analyzed for male cells by using the gene as a marker. Immunostaining demonstrated that CD45-positive leukocytes made up 35-45% of the neointimal cells during the 8-week period examined. Concurrently, up to 70% of the neointimal cells were of host origin, as shown by real-time polymerase chain reaction for the gene (Y chromosome). This suggests that the neointima contained host cells also of noninflammatory character. Accordingly, many cells positive for smooth-muscle alpha-actin were detected in this layer. To explore the possible bone marrow origin of allograft cells, female LEW rats were irradiated and substituted with bone marrow from male LEW rats. Subsequently, the animals received an aortic transplant from female F344 rats or were exposed to a balloon injury of the carotid artery. Immunostaining and real-time polymerase chain reaction confirmed the above findings, but the fractions of leukocytes and -positive cells were lower in the carotids than in the allografts. Combined primed in situ labeling and immunostaining verified that not only inflammatory but also smooth muscle-like cells of male origin appeared in the vessel wall in both situations. These observations suggest that the smooth-muscle cells that participate in the development of neointimal lesions during vascular disease may, in part, originate from circulating progenitors.