78 resultados para Ribonuclease H, Calf Thymus


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The term 'paunch calf syndrome' encompasses the multi-organic lethal developmental dysplasia reported in the Romagnola breed of cattle and is characterised by facial deformities, an enlarged and floating abdomen containing considerable abdominal effusion, and hepatic fibrosis. Paunch calf syndrome is caused by a missense mutation in the KDM2B gene (c.2503G>A) that is thought to lead to an amino acid exchange (p.D835N). In this study, the prevalence of carriers of the mutant KDM2B allele (and thus the frequency of the allele) was assessed in selected subpopulations of Romagnola cattle. The prevalence of carriers within top-ranked Romagnola sires over the years 2007-2012 was 29.3% (allele frequency 14.6%). In young bull calves, 30.9% were carriers with an allele frequency of 15.4%.

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Mutations in MITF lead to a large variety of phenotypes in human, mice and other species. They mostly affect pigmentation and hearing, whereas in mice, they may additionally cause microphthalmia and osteopetrosis. In this study, we report a single case of a Holstein calf with lack of pigmentation and microphthalmia born to healthy parents. Mendelian analysis of high-density SNP genotypes reveals a large number of parentage errors showing missing paternal alleles in the offspring, indicating a deletion encompassing 19 Mb on BTA 22. The genomic deletion affects the paternal allele and includes MITF and 131 other annotated genes. As the calf shows only one copy of the BTA 22 segment, the observed phenotype is probably caused by haploinsufficiency of the genes in that genomic region. Both the observed lack of skin pigmentation and reduced eye size can most likely be explained by a lack of MITF function.

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Mycoplasma bovis is a wall-less bacterium causing bovine mycoplasmosis, a disease showing a broad range of clinical manifestations in cattle. It leads to enormous economic losses to the beef and dairy industries. Antibiotic treatments are not efficacious and currently no efficient vaccine is available. Moreover, mechanisms of pathogenicity of this bacterium are not clear, as few virulence attributes are known. Microscopic observations of necropsy material suggest the possibility of an intracellular stage of M. bovis. We used a combination of a gentamicin protection assay, a variety of chemical treatments to block mycoplasmas entry in eukaryotic cells, and fluorescence and transmission electron microscopy to investigate the intracellular life of M. bovis in calf turbinate cells. Our findings indicate that M. bovis invades and persists in primary embryonic calf turbinate cells. Moreover, M. bovis can multiply within these cells. The intracellular phase of M. bovis may represent a protective niche for this pathogen and contribute to its escape from the host's immune defense as well as avoidance of antimicrobial agents.

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Missense mutations in ATP2A1 gene, encoding SERCA1 protein, cause a muscle disorder designed as congenital pseudomyotonia (PMT) in Chianina and Romagnola cattle or congenital muscular dystonia1 (CMD1) in Belgian Blue cattle. Although PMT is not life-threatening, CMD1 affected calves usually die within a few weeks of age as a result of respiratory complication. We have recently described a muscular disorder in a double muscle Dutch Improved Red and White cross-breed calf. Mutation analysis revealed an ATP2A1 mutation identical to that described in CMD1, even though clinical phenotype was quite similar to that of PMT. Here, we provide evidence for a deficiency of mutated SERCA1 in PMT affected muscles of Dutch Improved Red and White calf, but not of its mRNA. The reduced expression of SERCA1 is selective and not compensated by the SERCA2 isoform. By contrast, pathological muscles are characterized by a broad distribution of mitochondrial markers in all fiber types, not related to intrinsic features of double muscle phenotype and by an increased expression of sarcolemmal calcium extrusion pump. Calcium removal mechanisms, operating in muscle fibers as compensatory response aimed at lowering excessive cytoplasmic calcium concentration caused by SERCA1 deficiency, could explain the difference in severity of clinical signs.

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BACKGROUND: This study describes the transmission of border disease virus (BDV) from a persistently infected calf to seronegative heifers in early pregnancy, resulting in persistently infected fetuses. On day 50 of pregnancy (= day 0 of the infection phase), six heifers were co-housed in a free stall with a bull calf persistently infected with BDV (pi BVD) for 60 days. The heifers underwent daily clinical examination, and blood samples were collected regularly for detection of pestiviral RNA and anti-pestivirus antibodies. After day 60 (= day 110 of pregnancy), the heifers were slaughtered, and the fetuses and placentae underwent post-mortem and immunohistochemical examination and RT-PCR for viral RNA detection. RESULTS: Three heifers had mild viraemia from day 8 to day 14, and by day 40 all heifers had pestivirus antibodies identified as anti-BDV antibodies in the serum neutralisation test. The placenta of the three viraemic heifers had histological evidence of inflammation, and fetal organs from these heifers were positive for pestivirus antigen by immunohistochemical examination and for BD viral RNA by RT-PCR and sequencing. Thus, co-housing of heifers in early pregnancy with a pi-BDV calf led to seroconversion in all heifers and persistent fetal infection in three. CONCLUSIONS: Considering that pi-BDV cattle can infect other cattle and lead to persistent infection of the fetus in pregnant cows, BDV should not be ignored in the context of the mandatory BVDV eradication and monitoring program. This strongly suggests that BDV should be taken into account in BVD eradication and control programs.

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Although porcine circovirus type 2 (PCV2)-associated diseases have been evaluated for known immune evasion strategies, the pathogenicity of these viruses remained concealed for decades. Surprisingly, the same viruses that cause panzootics in livestock are widespread in young, unaffected animals. Recently, evidence has emerged that circovirus-like viruses are also linked to complex diseases in humans, including children. We detected PCV2 genome-carrying cells in fetal pig thymi. To elucidate virus pathogenicity, we developed a new pig infection model by in vivo transfection of recombinant PCV2 and the immunosuppressant cofactor cyclosporine A. Using flow cytometry, immunofluorescence and fluorescence in situ hybridization, we found evidence that PCV2 dictates positive and negative selection of maturing T cells in the thymus. We show for the first time that PCV2-infected cells reside at the corticomedullary junction of the thymus. In diseased animals, we found polyclonal deletion of single positive cells (SPs) that may result from a loss of major histocompatibility complex class-II expression at the corticomedullary junction. The percentage of PCV2 antigen-presenting cells correlated with the degree of viremia and, in turn, the severity of the defect in thymocyte maturation. Moreover, the reversed T-cell receptor/CD4-coreceptor expression dichotomy on thymocytes at the CD4(+)CD8(interm) and CD4SP cell stage is viremia-dependent, resulting in a specific hypo-responsiveness of T-helper cells. We compare our results with the only other better-studied member of Circoviridae, chicken anemia virus. Our data show that PCV2 infection leads to thymocyte selection dysregulation, adding a valuable dimension to our understanding of virus pathogenicity.

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The serine and threonine kinase MST1 is the mammalian homolog of Hippo. MST1 is a critical mediator of the migration, adhesion, and survival of T cells; however, these functions of MST1 are independent of signaling by its typical effectors, the kinase LATS and the transcriptional coactivator YAP. The kinase NDR1, a member of the same family of kinases as LATS, functions as a tumor suppressor by preventing T cell lymphomagenesis, which suggests that it may play a role in T cell homeostasis. We generated and characterized mice with a T cell-specific double knockout of Ndr1 and Ndr2 (Ndr DKO). Compared with control mice, Ndr DKO mice exhibited a substantial reduction in the number of naïve T cells in their secondary lymphoid organs. Mature single-positive thymocytes accumulated in the thymus in Ndr DKO mice. We also found that NDRs acted downstream of MST1 to mediate the egress of mature thymocytes from the thymus, as well as the interstitial migration of naïve T cells within popliteal lymph nodes. Together, our findings indicate that the kinases NDR1 and NDR2 function as downstream effectors of MST1 to mediate thymocyte egress and T cell migration.

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The objective of this survey was to determine herd level risk factors for mortality, unwanted early slaughter, and metaphylactic application of antimicrobial group therapy in Swiss veal calves in 2013. A questionnaire regarding farm structure, farm management, mortality and antimicrobial use was sent to all farmers registered in a Swiss label program setting requirements for improved animal welfare and sustainability. Risk factors were determined by multivariable logistic regression. A total of 619 veal producers returned a useable questionnaire (response rate=28.5%), of which 40.9% only fattened their own calves (group O), 56.9% their own calves and additional purchased calves (group O&P), and 2.3% only purchased calves for fattening (group P). A total number of 19,077 calves entered the fattening units in 2013, of which 21.7%, 66.7%, and 11.6% belonged to groups O, O&P, and P, respectively. Mortality was 0% in 322 herds (52.0%), between 0% and 3% in 47 herds (7.6%), and ≥3% in 250 herds (40.4%). Significant risk factors for mortality were purchasing calves, herd size, higher incidence of BRD, and access to an outside pen. Metaphylaxis was used on 13.4% of the farms (7.9% only upon arrival, 4.4% only later in the fattening period, 1.1% upon arrival and later), in 3.2% of the herds of group O, 17.9% of those in group O&P, and 92.9% of those of group P. Application of metaphylaxis upon arrival was positively associated with purchase (OR=8.9) and herd size (OR=1.2 per 10 calves). Metaphylaxis later in the production cycle was positively associated with group size (OR=2.9) and risk of respiratory disease (OR=1.2 per 10% higher risk) and negatively with the use of individual antimicrobial treatment (OR=0.3). In many countries, purchase and a large herd size are inherently connected to veal production. The Swiss situation with large commercial but also smaller herds with little or no purchase of calves made it possible to investigate the effect of these factors on mortality and antimicrobial drug use. The results of this study show that a system where small farms raise the calves from their own herds has a substantial potential to improve animal health and reduce antimicrobial drug use.

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BACKGROUND: Several adverse consequences are caused by mild perioperative hypothermia. Maintaining normothermia with patient warming systems, today mostly with forced air (FA), has thus become a standard procedure during anesthesia. Recently, a polymer-based resistive patient warming system was developed. We compared the efficacy of a widely distributed FA system with the resistive-polymer (RP) system in a prospective, randomized clinical study. METHODS: Eighty patients scheduled for orthopedic surgery were randomized to either FA warming (Bair Hugger warming blanket #522 and blower #750, Arizant, Eden Prairie, MN) or RP warming (Hot Dog Multi-Position Blanket and Hot Dog controller, Augustine Biomedical, Eden Prairie, MN). Core temperature, skin temperature (head, upper and lower arm, chest, abdomen, back, thigh, and calf), and room temperature (general and near the patient) were recorded continuously. RESULTS: After an initial decrease, core temperatures increased in both groups at comparable rates (FA: 0.33 degrees C/h +/- 0.34 degrees C/h; RP: 0.29 degrees C/h +/- 0.35 degrees C/h; P = 0.6). There was also no difference in the course of mean skin and mean body (core) temperature. FA warming increased the environment close to the patient (the workplace of anesthesiologists and surgeons) more than RP warming (24.4 degrees C +/- 5.2 degrees C for FA vs 22.6 degrees C +/- 1.9 degrees C for RP at 30 minutes; P(AUC) <0.01). CONCLUSION: RP warming performed as efficiently as FA warming in patients undergoing orthopedic surgery.

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Purpose: To report an angiographic investigation of midterm atherosclerotic disease progression in below-the-knee (BTK) arteries of claudicants. Methods: Angiograms were performed in 58 consecutive claudicants (35 men; mean age 68.3±8.7 years) with endovascular treatment of femoropopliteal arteries in 58 limbs after a mean follow-up of 3.6±1.2 years. Angiograms were reviewed in consensus by 2 experienced readers blinded to clinical data. Progression of atherosclerosis in 4 BTK arterial segments (tibioperoneal trunk, anterior and posterior tibial arteries, and peroneal artery) was assessed according to the Bollinger score. The composite per calf Bollinger score represented the average of the 4 BTK arterial segment scores. The association of the Bollinger score with cardiovascular risk factors and gender was scrutinized. Results: A statistically significant increase in atherosclerotic burden was observed for the mean composite per calf Bollinger score (5.7±8.3 increase, 95% CI 3.5 to 7.9, p<0.0001), as well as for each single arterial segment analyzed. In multivariate linear regression analysis, diabetes mellitus was associated with a more pronounced progression of atherosclerotic burden in crural arteries (β: 5.6, p=0.035, 95% CI 0.398 to 10.806). Conclusion: Progression of infrapopliteal atherosclerotic lesions is common in claudicants during midterm follow-up. Presence of diabetes mellitus was confirmed as a major risk factor for more pronounced atherosclerotic BTK disease progression.

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Stem cell based autologous grafting has recently gained mayor interest in various surgical fields for the treatment of extensive tissue defects. CD34(+) and CD133(+) cells that can be isolated from the pool of bone marrow mononuclear cells (BMC) are capable of differentiating into mature endothelial cells in vivo. These endothelial progenitor cells (EPC) are believed to represent a major portion of the angiogenic regenerative cells that are released from bone marrow when tissue injury has occurred. In recent years tissue engineers increasingly looked at the process of vessel neoformation because of its major importance for successful cell grafting to replace damaged tissue. Up to now one of the greatest problems preventing a clinical application is the large scale of expansion that is required for such purpose. We established a method to effectively enhance the expansion of CD34(+) and CD133(+) cells by the use of platelet-released growth factors (PRGF) as a media supplement. PRGF were prepared from thrombocyte concentrates and used as a media supplement to iscove's modified dulbecco's media (IMDM). EPC were immunomagnetically separated from human bone morrow monocyte cells and cultured in IMDM + 10% fetal calf serum (FCS), IMDM + 5%, FCS + 5% PRGF and IMDM + 10% PRGF. We clearly demonstrate a statistically significant higher and faster cell proliferation rate at 7, 14, 21, and 28 days of culture when both PRGF and FCS were added to the medium as opposed to 10% FCS or 10% PRGF alone. The addition of 10% PRGF to IMDM in the absence of FCS leads to a growth arrest from day 14 on. In histochemical, immunocytochemical, and gene-expression analysis we showed that angiogenic and precursor markers of CD34(+) and CD133(+) cells are maintained during long-term culture. In summary, we established a protocol to boost the expansion of CD34(+) and CD133(+) cells. Thereby we provide a technical step towards the clinical application of autologous stem cell transplantation.

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Background Purified thymus extracts (pTE) and synthetic thymic peptides (sTP) are thought to enhance the immune system of cancer patients in order to fight the growth of tumour cells and to resist infections due to immunosuppression induced by the disease and antineoplastic therapy. Objectives To evaluate the effectiveness of pTE and sTP for the management of cancer. Search methods We searched CENTRAL (The Cochrane Library 2010, Issue 3), MEDLINE, EMBASE, AMED, BIOETHICSLINE, BIOSIS, CATLINE, CISCOM, HEALTHSTAR, HTA, SOMED and LILACS (to February 2010). Selection criteria Randomised trials of pTE or sTP in addition to chemotherapy or radiotherapy, or both, compared to the same regimen with placebo or no additional treatment in adult cancer patients. Data collection and analysis Two authors independently extracted data from published trials. We derived odds ratios (OR) from overall survival (OS) and disease-free survival (DFS) rates, tumour response (TR) rates, and rates of adverse effects (AE) related to antineoplastic treatments. We used a random-effects model for meta-analysis. Main results We identified 26 trials (2736 patients). Twenty trials investigated pTE (thymostimulin or thymosin fraction 5) and six trials investigated sTP (thymopentin or thymosin α1). Twenty-one trials reported results for OS, six for DFS, 14 for TR, nine for AE and 10 for safety of pTE and sTP. Addition of pTE conferred no benefit on OS (RR 1.00, 95% CI 0.79 to 1.25); DFS (RR 0.97, 95% CI 0.82 to 1.16); or TR (RR 1.07, 95% CI 0.92 to 1.25). Heterogeneity was moderate to high for all these outcomes. For thymosin α1 the pooled RR for OS was 1.21 (95% CI 0.94 to 1.56, P = 0.14), with low heterogeneity; and 3.37 (95% CI 0.66 to 17.30, P = 0.15) for DFS, with moderate heterogeneity. The pTE reduced the risk of severe infectious complications (RR 0.54, 95% CI 0.38 to 0.78, P = 0.0008; I² = 0%). The RR for severe neutropenia in patients treated with thymostimulin was 0.55 (95% CI 0.25 to 1.23, P = 0.15). Tolerability of pTE and sTP was good. Most of the trials had at least a moderate risk of bias. Authors' conclusions Overall, we found neither evidence that the addition of pTE to antineoplastic treatment reduced the risk of death or disease progression nor that it improved the rate of tumour responses to antineoplastic treatment. For thymosin α1, there was a trend for a reduced risk of dying and of improved DFS. There was preliminary evidence that pTE lowered the risk of severe infectious complications in patients undergoing chemotherapy or radiotherapy.

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Combined extended nerve and soft tissue defects of the upper extremity require nerve reconstruction and adequate soft tissue coverage. This study focuses on the reliability of the free vascularized sural nerve graft combined with a fasciocutaneous posterior calf flap within this indication. An anatomical study was performed on 26 cadaveric lower extremities that had been Thiel fixated and color silicone injected. Dissection of the fasciocutaneous posterior calf flap involved the medial sural nerve and superficial sural artery (SSA) with its septocutaneous perforators, extended laterally to include the lateral cutaneous branch of the sural nerve and continued to the popliteal origin of the vascular pedicle and the nerves. The vessel and nerves diameter were measured with an eyepiece reticle at 4.5× magnification. Length and diameter of the nerves and vessels were carefully assessed and reported in the dissection book. A total of 26 flaps were dissected. The SSA originated from the medial sural artery (13 cases), the popliteal artery (12 cases), or the lateral sural artery (one case). The average size of the SSA was 1.4 ± 0.4 mm. The mean pedicle length before the artery joined the sural nerve was 4.5 ± 1.9 cm. A comitant vein was present in 21 cases with an average diameter of 2.0 ± 0.8 mm, in 5 cases a separate vein needed to be dissected with an average diameter of 3.5 ± 0.4 mm. The mean medial vascularized sural nerve length was 21.2 ± 8.9 cm. Because of inclusion of the vascularized part of the lateral branch of the sural nerve (mean length of 16.7 ± 4.8 cm), a total of 35.0 ± 9.6 cm mean length of vascularized nerve could be gained from each extremity. The free vascularized sural nerve graft combined with a fasciocutaneous posterior calf flap pedicled on the SSA offers a reliable solution for complex tissue and nerve defect. Clin. Anat. 2012. © 2012 Wiley Periodicals, Inc.