Endocardial cushion and myocardial defects after cardiac myocyte-specific conditional deletion of the bone morphogenetic protein receptor ALK3

Receptors for bone morphogenetic proteins (BMPs), members of the transforming growth factor-beta (TGFbeta) superfamily, are persistently expressed during cardiac development, yet mice lacking type II or type IA BMP receptors die at gastrulation and cannot be used to assess potential later roles in creation of the heart. Here, we used a Cre/lox system for cardiac myocyte-specific deletion of the type IA BMP receptor, ALK3. ALK3 was specifically required at mid-gestation for normal development of the trabeculae, compact myocardium, interventricular septum, and endocardial cushion. Cardiac muscle lacking ALK3 was specifically deficient in expressing TGFbeta2, an established paracrine mediator of cushion morphogenesis. Hence, ALK3 is essential, beyond just the egg cylinder stage, for myocyte-dependent functions and signals in cardiac organogenesis.     

A model for undertaking effectiveness and cost-effectiveness analyses of primary preventive strategies in cardiovascular disease.

BACKGROUND: Clinical trials generally provide strong evidence of the efficacy of cardiovascular preventive strategies, but poor evidence of their 'real-life' utility, in terms of effectiveness and cost-effectiveness. DESIGN AND METHODS: The Cardiovascular Disease Prevention Model is presented, which represents a means of extrapolating the results of clinical trials to a broader, more relevant context. The model is configured as a decision-analysis tree, and underpinned by life-course analysis and Markov processes. Uncertainty and sensitivity analyses are undertaken by Monte Carlo simulation. RESULTS: The results of effectiveness and cost-effectiveness analyses of a hypothetical preventive intervention are presented to demonstrate the outputs of the model. The potential impact and efficiency of the intervention are made obvious. CONCLUSIONS: The Cardiovascular Disease Prevention Model offers a means to translate the results of trials of cardiovascular preventive interventions, in order to inform clinical and public health practice, as well as health policy.     

What's the hold up? Factors contributing to delays in discharge of trauma patients after medical clearance

Background

One area of potential savings in healthcare spending is the identification of nonmedical delays in discharge. The purpose of this study was to identify factors associated with discharge delays.

Methods

All patients admitted to our trauma center over a 1-year period with a social work consult were retrospectively evaluated to identify delays in discharge after medical clearance.

Results

Over half of our patients experienced a delay in discharge. Age was not associated with delay in discharge. Higher injury severity score, intensive care unit admission, and hospital length of stay greater than 1 week were all associated with increased delays in discharge. Other factors such as disposition to a rehabilitation/nursing facility and mechanism of injury were also associated with a nonmedical delay.

Conclusions

We have identified nonmedical factors associated with delays in discharge. Strategies using these data could be used to improve discharge planning and may help decrease healthcare costs.     

Gene expression in fetal murine keratinocytes and fibroblasts

Background

Early fetuses heal wounds without the formation of a scar. Many studies have attempted to explain this remarkable phenomenon. However, the exact mechanism remains unknown. Herein, we examine the predominant cell types of the epidermis and dermis—the keratinocyte and fibroblast—during different stages of fetal development to better understand the changes that lead to scarring wound repair versus regeneration.

Materials and methods

Keratinocytes and fibroblasts were harvested and cultured from the dorsal skin of time-dated BALB/c fetuses. Total RNA was isolated and microarray analysis was performed using chips with 42,000 genes. Significance analysis of microarrays was used to select genes with >2-fold expression differences with a false discovery rate <2. Enrichment analysis was performed on significant genes to identify differentially expressed pathways.

Results

By comparing the gene expression profile of keratinocytes from E16 versus E18 fetuses, we identified 24 genes that were downregulated at E16. Analysis of E16 and E18 fibroblasts revealed 522 differentially expressed genes. Enrichment analysis showed the top 20 signaling pathways that were downregulated in E16 keratinocytes and upregulated or downregulated in E16 fibroblasts.

Conclusions

Our data reveal 546 differentially expressed genes in keratinocytes and fibroblasts between the scarless and scarring transition. In addition, a total of 60 signaling pathways have been identified to be either upregulated or downregulated in these cell types. The genes and pathways recognized by our study may prove to be essential targets that may discriminate between fetal wound regeneration and adult wound repair.     

Assurance of neuroattenuation of a live vaccine against West Nile virus: A comprehensive study of neuropathogenesis after infection with chimeric WN/DEN4Δ30 vaccine in comparison to two parental viruses and a surrogate flavivirus reference vaccine

The upsurge of West Nile virus (WNV) human infections in 2012 suggests that the US can expect periodic WNV outbreaks in the future. Availability of safe and effective vaccines against WNV in endemic areas, particularly for aging populations that are at high risk of West Nile neuroinvasive disease (WNND), could be beneficial. WN/DEN4Δ30 is a live, attenuated chimeric vaccine against WNV produced by replacement of the genes encoding the pre-membrane and envelope protein genes of the vaccine virus against dengue virus type 4 (DEN4Δ30) with corresponding sequences derived from a wild type WNV. Following intrathalamic inoculation of nonhuman primates (NHPs), a comprehensive neuropathogenesis study was performed and neurovirulence of WN/DEN4Δ30 vaccine candidate was compared to that of two parental viruses (i.e., WNV and DEN4Δ30), as well as to that of an attenuated flavivirus surrogate reference (i.e., yellow fever YF 17D). Clinical and virological data, as well as results of a semi-quantitative histopathological analysis, demonstrated that WN/DEN4Δ30 vaccine is highly attenuated for the central nervous system (CNS) of NHPs in comparison to a wild type WNV. Importantly, based on the virus replicative ability in the CNS of NHPs and the degree of induced histopathological changes, the level of neuroattenuation of WN/DEN4Δ30 vaccine was similar to that of YF 17D, and therefore within an acceptable range. In addition, we show that the DEN4Δ30 vaccine tested in this study also has a low neurovirulence profile. In summary, our results demonstrate a high level of neuroattenuation of two vaccine candidates, WN/DEN4Δ30 and DEN4Δ30. We also show here a remarkable sensitivity of our WNV-NY99 NHP model, as well as striking resemblance of the observed neuropathology to that seen in human WNND. These results support the use of this NHP model for translational studies of WNV neuropathogenesis and/or testing the effectiveness of vaccines and therapeutic approaches.     

Stretch‐activated signaling is modulated by stretch magnitude and contraction

Introduction: Stretch therapy is commonly utilized to prevent shortening maladaptation of skeletal muscle. Stretch in combination with isometric contraction prevents shortening, but the signaling mechanisms are not understood. Methods: Using a soleus tenotomy + stretch rat model, the phosphorylation–activation of mechanosensitive kinases (Akt, p70^S6K, p38 MAPK, and ERK1/2) were measured for various stretch magnitudes, set relative to optimal soleus length (Lo). Results: The kinases were not activated by passive stretch until it exceeded the normal physiological range. Stretch + isometric contraction resulted in relatively strong phosphorylation, even at short lengths. Conclusions: Whereas passive stretch results in kinase phosphorylation only during extreme lengthening, isometric contraction generated pronounced phosphorylation of kinases at Lo and Lo + 25%, indicating stimulation of pathways that lead to the preservation or increase of muscle length. Understanding the effects of passive and active stretch with respect to Lo and contraction is essential for predicting therapeutic outcomes and influencing optimal muscle length. Muscle Nerve 49 : 98–107, 2014     

Roles of metabotropic glutamate receptors in glial function and glial-neuronal communication

The amino acid glutamate plays a key role in brain function. One of the major roles of glutamate is to mediate fast excitatory neurotransmission via activation of ionotropic glutamate receptors (iGluRs). More recently, however, it has become clear that glutamate also serves a regulatory function through activation of receptors coupled to modulation of second messenger systems [metabotropic glutamate receptors (mGluRs)]. A body of evidence suggests that mGluRs regulate neuronal function through modulation of ion channels and enzymes to modulate cellular excitability and synaptic transmission. Interestingly, it has become clear that in addition to activation of neuronal receptors, glutamate can activate both iGluRs and mGluRs on glia. A growing body of evidence suggests that the mGluRs on glia play important roles in both glial function and mediation of intercellular signaling. © 1996 Wiley-Liss, Inc.     

Common occurrence of an antiidiotypic antibody that recognizes T14+ anti-DNA antibodies in patients with systemic lupus erythematosus

Objective. To investigate whether antibodies to a T14 anti-DNA antibody can be found in patients with systemic lupus erythematosus (SLE). Methods. Seventy-six serum samples (37 from patients with SLE) were randomly selected from among sera submitted for routine antinuclear antibody testing. Short, overlapping peptides based on the partial V_H (variable region of the heavy chain) sequence of the T14 antibody were synthesized on multipins and screened for reactivity with SLE sera. In addition, selected peptides from T14 and related proteins were synthesized in bulk and screened for reactivity with both SLE and control sera. A monoclonal antibody was generated to determine the prevalence of the T14 idiotype (T14+ Id) in the different study populations. Results. Antibodies were detected by a peptide based on the third complementarity-determining region (CDR3) of the T14 protein in 15 (41%) of 37 patients with SLE or 15 (54%) of 28 who had anti-DNA antibodies, in 3 (9%) of 34 patients without anti-DNA antibodies (9 of whom had SLE), and in 6 (10%) of 57 healthy controls. In SLE sera, the antiidiotypic (anti-Id) responses (IgM and IgG) correlated well with the anti-DNA responses (IgG), and both responses correlated well with the T14+ Id activity in SLE sera. Control peptides based on the 18/2 (16/6+ Id) and S107 proteins detected low antibody activities in SLE sera, attributable to cross-reactivity with the T14 peptide. A peptide based on an unrelated human antibody was not reactive with these sera. Conclusion. Anti-Id antibodies directed to T14 V_HCDR3 were found commonly in the sera of patients with SLE, and they appeared to be induced by the anti-DNA antibodies present in the sera. Based on these findings, these secondary antibodies may be pathogenic in SLE.