Comparison of Low Dose Recombinant Factor VIIa and 4-Factor Prothrombin Complex Concentrate for Treatment of Bleeding Related to Cardiac Surgery.

Background: Recombinant factor VIIa (rFVIIa) and prothrombin concentrate complex (PCC) are used for uncontrolled bleeding in cardiac surgery (CS), however, there are limited direct comparisons of these agents. Objective: To evaluate the efficacy and safety of rFVIIa and PCC in CS related bleeding. Methods: This retrospective study included adult CS patients who received either low dose rFVIIa (<30 mcg/kg) or 4-factor PCC. The primary outcome was transfusion requirements of packed red blood cells (pRBC) within 6 hours of factor administration. Secondary efficacy outcomes included transfusion requirements 0-18 hours, doses of additional factor product, thrombotic events, and acute kidney injury (AKI). Results: A total of 179 patients were included (n = 78 rFVIIa; n = 101 PCC). Of patients who received blood products, there was no difference in the requirement of pRBCs within 6 hours (73.8 vs 68.9%, P = .5359) or in the median amount of pRBC transfused (500 mL vs 640 mL, P = .0723) in the rFVIIa and PCC groups respectively. Patients in the PCC group were more likely to require additional factor products (24.4% vs 47.5%, P = .0015), develop AKI (12.8% vs 25.7%, P = .0325), have longer ICU lengths of stay [2 (IQR 1-5) vs 4 (IQR 2-6), P = .0487] and greater in-hospital mortality (2.6% vs 10.9%, P = .033). There was no difference in thrombotic events. Conclusion: Although, there was no difference in pRBC transfusion requirements between PCC and rFVIIa, more patients in the PCC group required additional factor products and had increased adverse effects. Further comparisons of PCC and rFVIIa are warranted.

Association between imaging response and survival following neoadjuvant chemotherapy in patients with resectable colorectal liver metastases: A cohort study.

BACKGROUND: The association between the imaging response (structural or metabolic) to neoadjuvant chemotherapy (neoCT) before colorectal liver metastasis (CRLM) and survival is unclear. METHOD: A total of 201 patients underwent their first CRLM resection. A total of 94 (47%) patients were treated with neoCT. A multivariable, Cox proportional hazard regression analysis was performed to compare overall survival (OS) and progression-free survival (PFS) between response groups. RESULTS: Multivariable regression analysis of the CT/MRI (n = 94) group showed no difference in survival (OS and PFS) in patients who had stable disease/partial response (SD/PR) or complete response (CR) versus patients who had progressive disease (PD) (OS: HR, 0.36 (95% CI: 0.11-1.19) p = .094, HR, 0.78 (95% CI: 0.13-4.50) p = .780, respectively), (PFS: HR, 0.70 (95% CI: 0.36-1.35) p = .284, HR, 0.51 (0.18-1.45) p = .203, respectively). In the FDG-PET group (n = 60) there was no difference in the hazard of death for patients with SD/PR or CR versus patients with PD for OS or PFS except for the PFS in the small CR subgroup (OS: HR, 0.75 (95% CI: 0.11-4.88) p = .759, HR, 1.21 (95% CI: 0.15-9.43) p = .857), (PFS: HR, 0.34% (95% CI: 0.09-1.22), p = .097, HR, 0.17 (95% CI: 0.04-0.62) p = .008, respectively). CONCLUSION: There was no convincing evidence of association between imaging response to neoCT and survival following CRLM resection.

Less absorbed solar energy and more internal heat for Jupiter.

The radiant energy budget and internal heat are fundamental properties of giant planets, but precise determination of these properties remains a challenge. Here, we report measurements of Jupiter's radiant energy budget and internal heat based on Cassini multi-instrument observations. Our findings reveal that Jupiter's Bond albedo and internal heat, 0.503 ± 0.012 and 7.485 ± 0.160 W m-2 respectively, are significantly larger than 0.343 ± 0.032 and 5.444 ± 0.425 Wm-2, the previous best estimates. The new results help constrain and improve the current evolutionary theories and models for Jupiter. Furthermore, the significant wavelength dependency of Jupiter's albedo implies that the radiant energy budgets and internal heat of the other giant planets in our solar system should be re-examined. Finally, the data sets of Jupiter's characteristics of reflective solar spectral irradiance provide an observational basis for the models of giant exoplanets.

Epigenetic Control of Early Mouse Development.

Although the genes sequentially transcribed in the mammalian embryo prior to implantation have been identified, understanding of the molecular processes ensuring this transcription is still in development. The genomes of the sperm and egg are hypermethylated, hence transcriptionally silent. Their union, in the prepared environment of the egg, initiates their epigenetic genomic reprogramming into a totipotent zygote, in which the genome gradually becomes transcriptionally activated. During gametogenesis, sex-specific processes result in sperm and eggs with disparate epigenomes, both of which require drastic reprogramming to establish the totipotent genome of the zygote and the pluripotent inner cell mass of the blastocyst. Herein, we describe the factors, DNA and histone modifications, activation and repression of retrotransposons, and cytoplasmic localizations, known to influence the activation of the mammalian genome at the initiation of new life.

Lytic to temperate switching of viral communities.

Microbial viruses can control host abundances via density-dependent lytic predator-prey dynamics. Less clear is how temperate viruses, which coexist and replicate with their host, influence microbial communities. Here we show that virus-like particles are relatively less abundant at high host densities. This suggests suppressed lysis where established models predict lytic dynamics are favoured. Meta-analysis of published viral and microbial densities showed that this trend was widespread in diverse ecosystems ranging from soil to freshwater to human lungs. Experimental manipulations showed viral densities more consistent with temperate than lytic life cycles at increasing microbial abundance. An analysis of 24 coral reef viromes showed a relative increase in the abundance of hallmark genes encoded by temperate viruses with increased microbial abundance. Based on these four lines of evidence, we propose the Piggyback-the-Winner model wherein temperate dynamics become increasingly important in ecosystems with high microbial densities; thus 'more microbes, fewer viruses'.

Reprogramming and differentiation in mammals: motifs and mechanisms.

The natural reprogramming of the mammalian egg and sperm genomes is an efficient process that takes place in less than 24 hours and gives rise to a totipotent zygote. Transfer of somatic nuclei to mammalian oocytes also leads to their reprogramming and formation of totipotent embryos, albeit very inefficiently and requiring an activation step. Reprogramming of differentiated cells to induced pluripotent stem (iPS) cells takes place during a period of time substantially longer than reprogramming of the egg and sperm nuclei and is significantly less efficient. The stochastic expression of endogenous proteins during this process would imply that controlled expression of specific proteins is crucial for reprogramming to take place. The fact that OCT4, NANOG, and SOX2 form the core components of the pluripotency circuitry would imply that control at the transcriptional level is important for reprogramming to iPS cells. In contradistinction, the much more efficient reprogramming of the mammalian egg and sperm genomes implies that other levels of control are necessary, such as chromatin remodeling, translational regulation, and efficient degradation of no longer needed proteins and RNAs.

Genome plasticity in the mouse oocyte and early embryo.

In dissecting the molecules and molecular mechanisms that control mammalian oocyte-to-embryo transition, we found abundant transcripts representing developmentally regulated ERVs (endogenous retroviruses) in mouse oocyte and two-cell stage embryo cDNA libraries. These retrotransposons can act as alternative promoters and first exons for diverse genes, synchronizing their expression. Heritable genetic change due to replication of these retrotransposons probably occurs specifically in oocytes and early embryos. ERVs are usually epigenetically silenced, through DNA methylation and chromatin-based mechanisms. Their activation and silencing indicates a change in the epigenetic state of the genome. The thousands of endogenous retro-elements in the mouse genome provides potential scope for large-scale co-ordinated epigenetic fluctuations and leads to the hypothesis that differential transposable element expression triggers sequential reprogramming of the embryonic genome during the oocyte-to-embryo transition.

Cryopreservation and conservation of microalgae: the development of a Pan-European scientific and biotechnological resource (the COBRA project).

Microalgae are one of the most biologically important elements of worldwide ecology and could be the source of diverse new products and medicines. COBRA (The COnservation of a vital european scientific and Biotechnological Resource: microAlgae and cyanobacteria) is the acronym for a European Union, RTD Infrastructures project (Contract No. QLRI-CT-2001-01645). This project is in the process of developing a European Biological Resource Centre based on existing algal culture collections. The COBRA project's central aim is to apply cryopreservation methodologies to microalgae and cyanobacteria, organisms that, to date, have proved difficult to conserve using cryogenic methods. In addition, molecular and biochemical stability tests have been developed to ensure that the equivalent strains of microorganisms supplied by the culture collections give high quality and consistent performance. Fundamental and applied knowledge of stress physiology form an essential component of the project and this is being employed to assist the optimisation of methods for preserving a wide range of algal diversity. COBRA's "Resource Centre" utilises Information Technologies (IT) and Knowledge Management practices to assist project coordination, management and information dissemination and facilitate the generation of new knowledge pertaining to algal conservation. This review of the COBRA project will give a summary of current methodologies for cryopreservation of microalgae and procedures adopted within the COBRA project to enhance preservation techniques for this diverse group of organisms.

No effect of skin anesthesia on pain intensity ratings associated with elicitation of the H-reflex in the soleus muscle.

This experiment evaluated the effect of a topical anesthetic on the intensity of pain experienced in response to elicitation of the H-reflex in the soleus muscle. Ten college-aged males provided ratings of pain intensity in response to elicitation of the H-reflex before and after topical application of skin anesthetic (5g EMLA) or placebo cream at the site of electrical stimulation in the popliteal fossa. The results indicated that (1) pain was experienced in association with the elicitation of both the H-wave and M-wave components of the H-reflex, and the skin anesthetic did not impact the pain intensity ratings; and (2) the skin anesthetic did not impact the amplitude of the H-wave, M-wave, and H/M Ratio recorded in the soleus muscle. The authors conclude that elicitation of the H-reflex in the soleus muscle results in low intensity pain, and the pain appears to be caused by activation of subcutaneous nociceptive afferent fibers of the tibial nerve.

Systems biology of the 2-cell mouse embryo.

The transcriptome of the 2-cell mouse embryo was analyzed to provide insight into the molecular networks at play during nuclear reprogramming and embryonic genome activation. Analysis of ESTs from a 2-cell cDNA library identified nearly 4,000 genes, over half of which have not been previously studied. Transcripts of mobile elements, especially those of LTR retrotransposons, are abundantly represented in 2-cell embryos, suggesting their possible role in introducing genomic variation, and epigenetic restructuring of the embryonic genome. Analysis of Gene Ontology of the 2-cell-stage expressed genes outlines the major biological processes that guide the oocyte-to-embryo transition. These results provide a foundation for understanding molecular control at the onset of mammalian development.

Examination of pain ratings associated with elicitation of the maximal H-wave and maximal M-wave in the soleus and flexor carpi radialis muscles.

The present study involved an examination of pain ratings associated with elicitation of the maximal H-wave and maximal M-wave in the soleus and flexor carpi radialis (FCR) muscles. Sixteen male students provided pain intensity ratings associated specifically with elicitation of the maximal H-wave and maximal M-wave in the soleus and FCR muscles before and after a 1 h period of seated rest on two trials separated by 1 wk. There were no significant interactions or main effects of Muscle Group, Time, or Trials for the pain ratings associated with the maximal H-wave and maximal M-wave in the soleus and FCR muscles. Pain ratings and current were higher for the maximal M-wave than the maximal H-wave in both the soleus and FCR muscles. We concluded that pain ratings associated with the maximal H-wave and maximal M-wave do not differ between the soleus and the FCR muscles, and that pain ratings are higher for the maximal M-wave than the maximal H-wave.

Acute bouts of active and passive leg cycling attenuate the amplitude of the soleus H-reflex in humans.

This study compared the immediate and prolonged effects of acute bouts of active and passive leg cycling on the soleus H-reflex among 12 young healthy men. The soleus H-reflex was measured immediately before and then 10 and 30 min after 20 min of active, unloaded leg cycling, passively induced leg cycling, and quiet rest. The primary novel finding was a significant reduction in the amplitude of the soleus H-reflex 10 and 30 min after both active and passive leg cycling compared to no change after quiet rest. These results suggest that cycling exercise produces an immediate and prolonged attenuation of the H-reflex, and this attenuation is likely caused by the influence of afferent mechanoreceptors rather than by the influence of central motor command.

Expression of genes involved in mammalian meiosis during the transition from egg to embryo.

The ooplasm of higher eukaryotes provides substances necessary for completing the last stages of meiosis and initiating the first mitotic division. These processes are firmly attuned to other events in the egg and newly formed embryo, such as switching from the use of maternal transcripts to the onset of zygotic transcription. In mammals little is known about the molecular mechanisms guiding this transition, largely due to the lack of information about genes expressed in the egg and early embryos. Studies of yeast mitosis have contributed much of what is known about the vertebrate cell cycle, and recent reports indicate that homologs of yeast DNA repair genes also function during mammalian gametogenesis. To examine whether this conservation can be expanded to include genes operative in oocyte meiosis, we performed a computer-based search for homologs of yeast genes that are induced during sporulation in C. elegans, Drosophila, and mammals. Results from this study suggest that yeast and higher eukaryotes share genes that coordinate the overall process of meiosis. However intriguing differences exist, reflecting the distinctive mechanisms governing the progression of meiosis in each organism. ESTs representing more than half of the mammalian homologs are present in mouse cDNA libraries that contains genes controlling the meiosis/mitosis transition. About 50% of these genes contain potential cis-elements for cytoplasmic polyadenylation in their 3'-UTR, suggesting the importance of controlled translation in the egg and zygote.

Expression and immune recognition of SV40 Tag in transgenic mice that develop metastatic osteosarcomas.

Mature adult mice of the C57BL/6-TgN(Amy1TAg)501Knw transgenic mouse lineage, 501, containing a liver alpha-amylase promoted-SV40 Tag hybrid gene, routinely develop SV40 Tag-induced metastatic osteosarcomas. This form of alpha-amylase was known to be expressed in the liver, salivary glands, pancreas, and fat. Cells in the normal rib adjacent to the periosteum also express alpha-amylase suggesting that transgene expression is correctly targeted to generate osteosarcomas. 501 mice express SV40 Tag in the salivary glands but do not develop abnormalities in these organs by the time of their death from SV40-induced osteosarcomas. Mice of the C57BL/6 strain make a strong and effective anti-tumor immune response to SV40 Tag immunization. However, immunization of 501 mice with SV40 Tag early in life does not alter or prevent SV40 Tag-induced osteosarcomagenesis. 501 mice mount a significantly less effective cytotoxic T-lymphocyte response following SV40 Tag immunization while 501 osteosarcoma-derived cells are fully susceptible to SV40 Tag-specific T-cell lysis. This suggests that partial tolerance, not loss of antigen presentation by tumor cells, characterizes this mouse model of endogenous bone tumor development. To determine whether the immune recognition of endogenous SV40 Tag could influence tumorigenesis, the metastatic potential and time of death from tumor was investigated in CD4-null mutant 501 mice and beta-2 microglobulin-null mutant 501 mice. The size and number of metastases in these strains and longevity of these strains varied. We suggest that components of both the innate and adaptive immune response control tumor appearance and progression.