Identification of a doublet missense substitution in the bovine LRP4 gene as a candidate causal mutation for syndactyly in Holstein cattle

Syndactyly in Holstein cattle is an autosomal recessive abnormality characterized by the fusion of the functional digits. This disorder has been previously mapped to the telomeric part of bovine chromosome 15. Here, we describe the fine-mapping of syndactyly in Holstein cattle to a 3.5-Mb critical interval using a comparative mapping approach and an extended pedigree generated by embryo transfer. We report genetic evidence for the exclusion of two genes previously suggested as candidates (EXT2 and ALX4) and describe the identification of a doublet mutation in complete linkage disequilibrium with syndactyly in one gene of the critical interval: LRP4. Finally, based on recent discoveries concerning the mouse mutants dan and mdig and a mouse knockout for Lrp4, we present solid evidence that the subsequent substitution in LRP4 exon 33 is a strong candidate causal mutation for syndactyly in Holstein cattle.     

Differential cellular FGF-2 upregulation in the rat facial nucleus following axotomy, functional electrical stimulation and corticosterone: a possible therapeutic target to Bell's palsy

Background

The etiology of Bell's palsy can vary but anterograde axonal degeneration may delay spontaneous functional recovery leading the necessity of therapeutic interventions. Corticotherapy and/or complementary rehabilitation interventions have been employed. Thus the natural history of the disease reports to a neurotrophic resistance of adult facial motoneurons leading a favorable evolution however the related molecular mechanisms that might be therapeutically addressed in the resistant cases are not known. Fibroblast growth factor-2 (FGF-2) pathway signaling is a potential candidate for therapeutic development because its role on wound repair and autocrine/paracrine trophic mechanisms in the lesioned nervous system.

Methods

Adult rats received unilateral facial nerve crush, transection with amputation of nerve branches, or sham operation. Other group of unlesioned rats received a daily functional electrical stimulation in the levator labii superioris muscle (1 mA, 30 Hz, square wave) or systemic corticosterone (10 mgkg^-1). Animals were sacrificed seven days later.

Results

Crush and transection lesions promoted no changes in the number of neurons but increased the neurofilament in the neuronal neuropil of axotomized facial nuclei. Axotomy also elevated the number of GFAP astrocytes (143% after crush; 277% after transection) and nuclear FGF-2 (57% after transection) in astrocytes (confirmed by two-color immunoperoxidase) in the ipsilateral facial nucleus. Image analysis reveled that a seven days functional electrical stimulation or corticosterone led to elevations of FGF-2 in the cytoplasm of neurons and in the nucleus of reactive astrocytes, respectively, without astrocytic reaction.

Conclusion

FGF-2 may exert paracrine/autocrine trophic actions in the facial nucleus and may be relevant as a therapeutic target to Bell's palsy.     

Reconstitution of CD4 T Cells in Bronchoalveolar Lavage Fluid after Initiation of Highly Active Antiretroviral Therapy

The massive depletion of gastrointestinal-tract CD4 T cells is a hallmark of the acute phase of HIV infection. In contrast, the depletion of the lower-respiratory-tract mucosal CD4 T cells as measured in bronchoalveolar lavage (BAL) fluid is more moderate and similar to the depletion of CD4 T cells observed in peripheral blood (PB). To understand better the dynamics of disease pathogenesis and the potential for the reconstitution of CD4 T cells in the lung and PB following the administration of effective antiretroviral therapy, we studied cell-associated viral loads, CD4 T-cell frequencies, and phenotypic and functional profiles of antigen-specific CD4 T cells from BAL fluid and blood before and after the initiation of highly active antiretroviral therapy (HAART). The major findings to emerge were the following: (i) BAL CD4 T cells are not massively depleted or preferentially infected by HIV compared to levels for PB; (ii) BAL CD4 T cells reconstitute after the initiation of HAART, and their infection frequencies decrease; (iii) BAL CD4 T-cell reconstitution appears to occur via the local proliferation of resident BAL CD4 T cells rather than redistribution; and (iv) BAL CD4 T cells are more polyfunctional than CD4 T cells in blood, and their functional profile is relatively unchanged after the initiation of HAART. Taken together, these data suggest mechanisms for mucosal CD4 T-cell depletion and interventions that might aid in the reconstitution of mucosal CD4 T cells.The assessment of the degree of memory CD4 T-cell depletion at mucosal sites during human immunodeficiency virus (HIV) infection is perhaps the most comprehensive way to estimate the impact of HIV on the T-cell pool. As such, the massive depletion of gastrointestinal CD4 T cells is a hallmark of HIV and simian immunodeficiency virus (SIV) infection (5, 12, 17, 19, 20, 30). This depletion occurs during the acute phase of infection and is maintained throughout the chronic phase. Mechanisms underlying this depletion have been shown to include the direct consequence of target cell infection (4, 19) and virus-induced Fas-mediated apoptosis (17). However, while it is clear that the substantial depletion of CD4 T cells occurs in the gastrointestinal (GI) tract and vaginal mucosa (31) of SIV-infected macaques and HIV-infected individuals (5, 12, 20, 30), similar depletion does not manifest at all mucosal sites, particularly the lung, in human studies (4).Highly active antiretroviral therapy (HAART) has significantly improved the prognosis of HIV-infected individuals (15, 16). Individuals who initiate HAART before their CD4 T-cell counts in peripheral blood (PB) fall below 350 cells/μl have significantly improved survival compared to that of individuals who initiate HAART with CD4 T-cell counts less than 350 cells/μl (15). Several studies also have shown that when HAART is initiated after CD4 T-cell counts fall below 350 cells/μl, the reconstitution of CD4 T cells in the GI tract is very poor, even after years of therapy (10, 12, 21). However, HIV-infected individuals treated with HAART during the early phase of infection may reconstitute CD4 T cells in the GI tract (18, 21). In contrast to the GI tract, little is known regarding CD4 T-cell reconstitution in the lung compartment during the course of HIV treatment. Nevertheless, the timing of HAART initiation after infection appears to be an important predictor of successful mucosal T-cell reconstitution.The massive depletion of CD4 T cells during the acute phase of infection does not occur at all mucosal sites, as CD4 T cells in bronchoalveolar lavage (BAL) are relatively spared and are slowly depleted during the chronic phase of infection (4). Despite this preservation of lung CD4 T cells, diminished BAL T-cell immune responses to certain pathogens have been reported in HIV-infected subjects (14). Given that many patients worldwide have access to and will receive antiretroviral therapy, the study of mucosal responses longitudinally during the course of treatment is likely to enhance our understanding of immune restoration. In addition, the early cellular events following HAART initiation are likely to skew the immune system toward both protective (i.e., immunosurveillance) and pathological (i.e., immune reconstitution inflammatory syndrome) responses. In this context, the study of the human pulmonary immune response remains an important aspect of HIV infection and treatment. To examine the dynamics of lung CD4 T-cell reconstitution, we studied the treatment of naïve HIV-infected individuals longitudinally during their course of HAART. We sampled peripheral blood and BAL T cells prior to, at 1 month, and after 1 year of HAART. From each subject and within each compartment, we examined the proliferative and functional capacity of stimulated CD4 and CD8 T cells.     

Performance Evaluation of Shared Mesh Protection in WDM Networks

The efficient use of network capacity in shared restoration schemes strongly depends upon the path selection procedure. In this paper we propose and evaluate path selection algorithms for sharable and restorable connections in optical networks. Namely, two distributed path selection algorithms are proposed. The first approach maintains global information on network resource usage to determine link sharability and compute optimal shared paths. The second approach only relies upon local information maintained at each node. Subsequently, we present an analytical model to evaluate the performance of these path selection algorithms and show its accuracy through numerical examples. Results indicate that path selection algorithms that maximally exploit the use of reserved sharable channels do not necessarily result in fast restoration; rather these two optimality criteria can conflict most of the time. Additionally, algorithms that maximally exploit the sharability condition typically result in lower scalability and higher complexity.     

Malignant arrhythmia in apical ballooning syndrome: risk factors and outcomes

Objectives

We sought to determine the frequency and outcomes with symptomatic arrhythmia in patients with apical ballooning syndrome (ABS).

Methods

A retrospective review of the Mayo Clinic Angiography database was conducted to identify patients who met the Mayo criteria for ABS. Patients with documented arrhythmias formed the study group, and 31 randomly selected patients with ABS but without arrhythmia formed the control group.

Results

Out of 105 patients identified with ABS, 6 (5.7%) women aged 69 +/- 9 years experienced significant arrhythmia (ventricular fibrillation, asystole), 2 patients died, and 1 required permanent pacemaker implantation. When compared with controls, the study group showed no significant difference with respect to ECG characteristics (QT, QRS duration or axis) except for R-R interval variability (see comments below) (30.6±6 vs 14.5±17 p = 0.0004), QTc, and P-R interval. Patients without arrhythmia were more likely to be on beta-blocker therapy than the study population (33% vs 80.6% p = 0.02).

Conclusion

Life-threatening arrhythmia is uncommon (5.7%) with ABS despite marked, structural abnormalities. When arrhythmias do occur, the outcome is poor. Prominent variability in R-R intervals appears to be predictive of significant arrhythmias in ABS. The role of beta-blocker therapy in preventing arrhythmia with ABS requires further investigation.     

Macrophages exposed to lymphotropic and monocytotropic HIV induce similar CTL responses despite differences in productive infection

Macrophages are accessory cells that are vulnerable to infection by HIV-1. HTLV-IIIB, a lymphotropic strain of HIV, infects macrophages poorly resulting in either no or low levels of virus expression compared to high levels of productive infection after exposure of macrophages to the monocytotropic HIV strain Ada-M. Whether this results in an impaired ability of HTLV-IIIB-exposed macrophages to initiate protective cytotoxic T lymphocyte (CTL) immune responses against these strains is not well defined. We investigated the ability of monocyte-derived macrophages (MDM) exposed to lymphotropic and monocytotropic HIV strains to initiate primary CTL responses in vitro. MDM exposed to HTLV-IIIB induced a specific primary CTL response that was comparable to MDM exposed to the monocytotropic strain Ada-M despite marked differences in productive HIV infection in MDM between the two strains. CTL generated in this model were MHC-restricted, strain-specific, and CD8+. These data demonstrate that high levels of productive HIV infection in accessory cells are not a prerequisite for the generation of a primary CTL response, suggesting a novel immunologic interaction between MDM and lymphotropic HIV strains.     

cDNA sequence of the horse (Equus caballus) LAMA3 gene and characterization of two intronic SNP markers.

Laminins are large heterotrimeric basement membrane glycoproteins composed of alpha, beta and gamma chains. The Laminin 5 isoform has an alpha3beta3gamma2 composition and is essential for the adhesion of basal keratinocytes to the underlying epithelial basement membrane where it is mainly located. Mutations in the genes coding for the 3 chains have been associated with a severe skin blistering disease, Herlitz's junctional epidermolysis bullosa (JEB), observed in different species as man, dog, cat and horse. In this study, we report the sequence of the 5.2 kb horse laminin alpha 3 cDNA (LAMA3) as well as the detection of two intronic SNPs. These data will be useful to further identify causal mutations for the disease in this gene.     

A nested deletion approach to generate Cre deleter mice with progressive Hox profiles

In mice, the loxP/Cre recombinase-dependent system of recombination offers powerful possibilities for engineering genetic configurations of interest. This system can also be advantageously used for conditional mutagenesis in vivo, whenever such an approach is required due to deleterious effects of either one mutation, or a combination thereof. Here, we report on the production of an allelic series of insertions of a Hoxd11/Cre fusion transgene at different positions within the HoxD complex, in order to produce the CRE recombinase with a 'Hox profile' progressively more extended. We used the R26R (R26R) reporter mouse line to functionally assess the distribution and efficiency of the CRE enzyme and discuss the usefulness of these various lines as deleter strains.     

Number and thickness of myelinic fibres of the phrenic nerve of young and aged rats]

The phrenic nerve of albino rats was studied for age changes in number of fibres, myelin sheath thickness and axon calibre. There is no significant morphological differences between nerves from young and aged rats and no difference with age was found in the number of fibres, myelin sheath thickness and axon calibre.     

Maintenance Integration in Manufacturing Systems: From the Modeling Tool to Evaluation

In manufacturing systems, wear-out and eventual failure are unavoidable. However, to reduce the rate of their occurrence and to prolong the life of equipment or the capacity for extended productive use of the equipment under the necessary technological functioning and servicing, maintenance can be performed. For large manufacturing systems, maintenance integration involves a particular development concerned with both complexity models and computing time. This paper presents an effective way of modeling complex manufacturing systems through hierarchical and modular analysis by using stochastic Petri nets and Markov chains. In the proposed approach, the integration of maintenance policies in a manufacturing system is facilitated by the development of a generic model. With this generic modeling, the user doesn't need to code the strategies but only to instantiate the generic model with the structure of the manufacturing system. This method allows various maintenance strategies to be coded in the generic model with the aim of studying their influence on system dependability and performance.