Polar and brown bear genomes reveal ancient admixture and demographic footprints of past climate change

Polar bears (PBs) are superbly adapted to the extreme Arctic environment and have become emblematic of the threat to biodiversity from global climate change. Their divergence from the lower-latitude brown bear provides a textbook example of rapid evolution of distinct phenotypes. However, limited mitochondrial and nuclear DNA evidence conflicts in the timing of PB origin as well as placement of the species within versus sister to the brown bear lineage. We gathered extensive genomic sequence data from contemporary polar, brown, and American black bear samples, in addition to a 130,000- to 110,000-y old PB, to examine this problem from a genome-wide perspective. Nuclear DNA markers reflect a species tree consistent with expectation, showing polar and brown bears to be sister species. However, for the enigmatic brown bears native to Alaska's Alexander Archipelago, we estimate that not only their mitochondrial genome, but also 5-10% of their nuclear genome, is most closely related to PBs, indicating ancient admixture between the two species. Explicit admixture analyses are consistent with ancient splits among PBs, brown bears and black bears that were later followed by occasional admixture. We also provide paleodemographic estimates that suggest bear evolution has tracked key climate events, and that PB in particular experienced a prolonged and dramatic decline in its effective population size during the last ca. 500,000 years. We demonstrate that brown bears and PBs have had sufficiently independent evolutionary histories over the last 4-5 million years to leave imprints in the PB nuclear genome that likely are associated with ecological adaptation to the Arctic environment.     

Direct effects of furosemide and amiloride on the perfused and ischaemic rat heart

The present study was undertaken in order to assess direct effects of furosemide and furosemide plus amiloride upon the perfused and ischaemic isolated rat heart. Furosemide in concentrations ranging between 4-400 mg/l in the perfusate increased coronary flow in a concentration dependent manner. There was no evidence for a negative inotropic effect of furosemide. However, very high doses of furosemide (400 mg/l) decreased the post-ischaemic values of left ventricular developed pressure, coronary flow rate, adenosine triphosphate, creatine phosphate and potassium, and increased the myocardial content of calcium and sodium. Furosemide 4 mg/l and 40 mg/l had no effect on post-ischaemic parameters compared to the control group except that furosemide 40 mg/l increased the recovery of coronary flow. Although amiloride 13.3 mg/l alone did not affect post-ischaemic recovery, the addition of this dose to furosemide 400 mg/l improved the post-ischaemic recovery of left ventricular developed pressure, coronary flow rate and adenosine triphosphate. The myocardial content of magnesium and potassium was higher indicating protection of amiloride by its magnesium- and potassium-sparing properties opposing ischaemic losses aggravated by the exposure to furosemide.     

The immunoregulatory protein human B7H3 is a tumor-associated antigen that regulates tumor cell migration and invasion

The monoclonal antibody (mAb) 376.96 has been used for detection of micrometastatic tumor cells due to its high binding specificity for a wide range of tumor cells, but the identity and function of its target antigen have not been known. Here, using immunoprecipitation and siRNA technology, we demonstrate that the antigen is the human 4Ig-B7H3 (4Ig-hB7H3) protein, previously known as an immunoregulatory protein in immune cells. Immunoblots of whole cell lysates, subcellular fractionation and tunicamycin treatment of human tumor cells indicated that 4Ig-hB7H3 is a approximately 100-kDa N-linked glycosylated membrane protein. The tumor promoter phorbol 12-myristate 13-acetate (PMA) enhanced the expression of 4Ig-hB7H3 in FEMX-I (melanoma), MA11 (breast cancer), and OHS (osteosarcoma) cells, suggesting that 4Ig-hB7H3 may be implicated in tumorigenesis. Most importantly, siRNA-downregulation of hB7H3 reduced cell adhesion to fibronectin of melanoma and breast cancer cells by up to 50 %, and migration and matrigel-invasion by more than 70 %, but surprisingly had no apparent impact on cell proliferation. In conclusion, our data present 4Ig-hB7H3 as a tumor-associated antigen and suggests a novel biological role of 4Ig-hB7H3 in tumor progression and metastasis.     

Initial attachment of fibroblast-like cells to periodontally-diseased root surfaces in vitro

The precise factors mediating both initial cell attachment and longer term connective tissue reattachment after tissue destruction due to periodontal disease are not known. An in vitro model was used to assess initial attachment of fibroblast-like cells to periodontally-diseased root surfaces. Root fragments were obtained from freshly extracted teeth from 6 different patients. Individual roots were prepared such that a comparison could be made of initial attachment to non-instrumented diseased root surface, curetted diseased root surface and the non-diseased, non-instrumented portion of the same root. The amount of hard tissue removed by instrumentation was quantitated and kept constant between 0.9-1.0 mm. The unsterilized fragments were incubated with human gingival fibroblasts (HGF) for 1 h at 37 degrees, after which the roots were first washed to remove non-adherent cells and then photographed. The number of attached cells per unit area was quantitated from the photographs using a grid system. No significant differences could be detected between the numbers of cells attached to the 3 types of root surfaces studied on the individual roots or between any of the roots studied. Thus, initial attachment of HGF to diseased root surfaces is not inhibited by the presence of plaque or endotoxins.     

Donor lymphocytes transferred with the graft to kidney recipients. Potential for establishing microchimerism.

After solid organ transplantation donor lymphocytes have been shown to survive and multiply in the organ recipient for a prolonged period. It is not clear whether this chimerism detected is the result of immunosuppression or the cause of allograft acceptance. The number of cells transferred, as well as the type of cells, and the degree of activation are likely to be of importance for the establishment of microchimerism. The cells that are flushed out of the vascular tree may be of particular importance since when an antigen primarily bypasses or secondarily avoids organised lymphoid collections, the immune system in the recipient may remain or become "indifferent" to its presence. In the present study we examined the amount of residual donor blood cells that we could flush out from the vascular tree of living donor kidneys and cadaveric donor kidneys immediately prior to transplantation, with special emphasis on T and B lymphocytes. Our study shows that perfusion of donor kidneys just prior to transplantation releases from 0.1 to 1.8x10(6) B-lymphocytes, with an average of 0.7x10(6) and from 0.5x10(6) to 2.6x10(6) T-lymphocytes, with an average of 1.8x10(6), for CD kidneys, and somewhat less for LD kidneys. These cells would otherwise have been flushed out into the organ recipient's circulation, where they might play a role in the establishment of microchimerism.     

Tissue protection by verapamil in the calcium paradox

The effect of verapamil (+/- 2 mumol/l verapamil) on calcium paradox injuries, as well as on hearts subjected to calcium-free perfusion alone, was studied in isolated perfused rat hearts. Three different protocols for calcium depletion (5 min) were followed: 5 or 45 ml of nominally calcium-free solution (1 or 9 ml/min), or 45 ml of nominally calcium-free solution to which 20 mumol/l CaCl2 was added. Ultrastructural analyses showed that verapamil protects against cellular injuries upon readmission of calcium to hearts subjected to partial calcium depletion (5 ml calcium-free solution, or 45 ml to which 20 mumol/l CaCl2 was added) by reducing the number of affected cells. No protection was found after more extensive calcium washout. However, in all groups examined, we found an inverse relationship between the number of injured cells and ATP content. Verapamil protected against contracture development and reduced the increase in tissue calcium content observed after readmission of calcium to hearts perfused with 5 ml calcium free solution, whereas no significant effect of verapamil on tissue calcium content was found in hearts perfused with 45 ml nominally calcium-free solution. In hearts studied after calcium-free perfusion no effect of verapamil treatment on the separation of the intercalated disc was found. The protective effect of verapamil could not be explained by differences in calcium or cAMP levels after calcium-free perfusion.     

Efficacy and safety of an inactivated vaccine against Salmonid alphavirus (family Togaviridae)

Pancreas disease (PD) in salmonid fish is caused by an infection with Salmonid alphavirus (SAV) and remains as one of the major health problems in the European fish farming industry. Sequence studies have revealed a genetic diversity among viral strains. A subtype of SAV (SAV3) is causing an epizootic in farmed salmonids in Norway. Here we evaluate efficacy and safety of an inactivated virus vaccine based on ALV405, a strain of SAV3 that was isolated from Norwegian salmon. The vaccine provided an average relative percent survival (RPS) of 98.5 in an intraperitoneal challenge model, and induced nearly total protection against PD in a cohabitant challenge model. It provided significant protection against SAV-induced mortality also in a field trial under industrial conditions. Local reactions seen as melanization and adhesions in the visceral cavity were less severe than those induced by two commercial vaccines. Finally, we demonstrated that the protection is not impaired when the ALV405 antigen is combined with other viral or bacterial antigens in a polyvalent vaccine. The results confirm that efficient and safe protection against SAV infection and development of PD is possible using an inactivated virus vaccine, both alone and as a component in a polyvalent vaccine.     

Strong and weak aspects of an established post-resuscitation treatment protocol-A five-year observational study

Aim of study

Favourable hospital survival increased from 26% to 56% in the implementation phase of a new standard operating procedure (SOP) for treatment after out-of hospital cardiac arrest (OHCA) in 2003. We now evaluate protocol adherence and survival rates after five years with this established SOP.

Methods

This observational study is based on prospectively collected registry data from all OHCA patients with cardiac aetiology admitted with spontaneous circulation to Ulleval Hospital between September 2003 and January 2009. Three patient categories are described based on early assessment in the emergency department: conscious, comatose, and comatose patients receiving only palliative care, with main focus on comatose patients receiving active treatment.

Results

Of 248 patients, 22% were consciousness on admission, 70% were comatose and received active treatment, while 8% received only palliative care. Favourable survival from admittance to discharge remained at 56% throughout the study period. Among actively treated patients 83% received emergency coronary angiography and 48% underwent subsequent percutaneous coronary intervention. In this cohort 63% had an acute myocardial infarction, ten of whom did not receive emergency coronary angiography. Among actively treated comatose patients, 6% survived with unfavourable neurology, while 51% of the deaths followed treatment withdrawal after prognostication of severe brain injury.

Conclusion

The previously reported doubling in survival rate remained throughout a five-year study period. Establishing reliable indication for emergency coronary angiography and interventions and validating prognostication rules in the hypothermia era are important challenges for future studies.