1,456 research outputs found
Stimulation of Haemopoetic Activity in Bone Marrow and Deformation of Red Blood Cells in Albino Mice, Mus musculus Exposed to Radiations from GSM Base Stations
The levels of radiofrequency radiations around two global systems for mobile communication (GSM) base stations located around a residential quarter and workplace complex were measured. The effects of the radiofrequency radiations on albino mice placed in exposure cages and located around the base stations over a six months period were investigated. The levels of radiofrequency (RF) radiations around the base stations were found to range between 383 mV/m to 730 mV/m compared to 59 mV/m in control stations. In the exposed mice, a pattern of pancytosis was observed and significant increases were observed in the Packed Cell Volume (PCV), White Cell Count (WBC), Platelet count (PLT) and Red Cell Count (RCC) throughout the period of exposure in both stations when compared with control values. No significant (p>0.05) differences were observed in these values when both stations were compared. After 90 days of exposure, marginal increases occurred in the mean cell volume of exposed mice at station 1 and 2 (53.1±3.6fl Vs 55.9±1.8fl and 57.9±0.25fl respectively), with the mean cell haemoglobin concentration showing significant reduction after 180 days of exposure at station 2 (27.9±2.4g/dl Vs 25.7±0.29g/dl;
Duplication cyst of pyloroduodenal canal: a rare cause of neonatal gastric outlet obstruction: a case report
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Subcellular FIH-1 expression patterns in invasive breast cancer in relation to HIF-1α expression
Schmallenberg virus pathogenesis, tropism and interaction with the innate immune system of the host
Schmallenberg virus (SBV) is an emerging orthobunyavirus of ruminants associated with outbreaks of congenital malformations in aborted and stillborn animals. Since its discovery in November 2011, SBV has spread very rapidly to many European countries. Here, we developed molecular and serological tools, and an experimental in vivo model as a platform to study SBV pathogenesis, tropism and virus-host cell interactions. Using a synthetic biology approach, we developed a reverse genetics system for the rapid rescue and genetic manipulation of SBV. We showed that SBV has a wide tropism in cell culture and “synthetic” SBV replicates in vitro as efficiently as wild type virus. We developed an experimental mouse model to study SBV infection and showed that this virus replicates abundantly in neurons where it causes cerebral malacia and vacuolation of the cerebral cortex. These virus-induced acute lesions are useful in understanding the progression from vacuolation to porencephaly and extensive tissue destruction, often observed in aborted lambs and calves in naturally occurring Schmallenberg cases. Indeed, we detected high levels of SBV antigens in the neurons of the gray matter of brain and spinal cord of naturally affected lambs and calves, suggesting that muscular hypoplasia observed in SBV-infected lambs is mostly secondary to central nervous system damage. Finally, we investigated the molecular determinants of SBV virulence. Interestingly, we found a biological SBV clone that after passage in cell culture displays increased virulence in mice. We also found that a SBV deletion mutant of the non-structural NSs protein (SBVΔNSs) is less virulent in mice than wild type SBV. Attenuation of SBV virulence depends on the inability of SBVΔNSs to block IFN synthesis in virus infected cells. In conclusion, this work provides a useful experimental framework to study the biology and pathogenesis of SBV
Comments on ‘Sweep algorithm for solving optimal control problem with multi-point boundary conditions’ by M Mutallimov, R Zulfuqarova, and L Amirova
Optimality of mutation and selection in germinal centers
The population dynamics theory of B cells in a typical germinal center could
play an important role in revealing how affinity maturation is achieved.
However, the existing models encountered some conflicts with experiments. To
resolve these conflicts, we present a coarse-grained model to calculate the B
cell population development in affinity maturation, which allows a
comprehensive analysis of its parameter space to look for optimal values of
mutation rate, selection strength, and initial antibody-antigen binding level
that maximize the affinity improvement. With these optimized parameters, the
model is compatible with the experimental observations such as the ~100-fold
affinity improvements, the number of mutations, the hypermutation rate, and the
"all or none" phenomenon. Moreover, we study the reasons behind the optimal
parameters. The optimal mutation rate, in agreement with the hypermutation rate
in vivo, results from a tradeoff between accumulating enough beneficial
mutations and avoiding too many deleterious or lethal mutations. The optimal
selection strength evolves as a balance between the need for affinity
improvement and the requirement to pass the population bottleneck. These
findings point to the conclusion that germinal centers have been optimized by
evolution to generate strong affinity antibodies effectively and rapidly. In
addition, we study the enhancement of affinity improvement due to B cell
migration between germinal centers. These results could enhance our
understandings to the functions of germinal centers.Comment: 5 figures in main text, and 4 figures in Supplementary Informatio
Population genetic characterization and family reconstruction in brood bank collections of the Indian major carp Labeo rohita (Cyprinidae:Cypriniformes)
Transcription of toll-like receptors 2, 3, 4 and 9, FoxP3 and Th17 cytokines in a susceptible experimental model of canine Leishmania infantum infection
Canine leishmaniosis (CanL) due to Leishmania infantum is a chronic zoonotic systemic disease resulting from complex interactions between protozoa and the canine immune system. Toll-like receptors (TLRs) are essential components of the innate immune system and facilitate the early detection of many infections. However, the role of TLRs in CanL remains unknown and information describing TLR transcription during infection is extremely scarce. The aim of this research project was to investigate the impact of L. infantum infection on canine TLR transcription using a susceptible model. The objectives of this study were to evaluate transcription of TLRs 2, 3, 4 and 9 by means of quantitative reverse transcription polymerase chain reaction (qRT-PCR) in skin, spleen, lymph node and liver in the presence or absence of experimental L. infantum infection in Beagle dogs. These findings were compared with clinical and serological data, parasite densities in infected tissues and transcription of IL-17, IL-22 and FoxP3 in different tissues in non-infected dogs (n = 10), and at six months (n = 24) and 15 months (n = 7) post infection. Results revealed significant down regulation of transcription with disease progression in lymph node samples for TLR3, TLR4, TLR9, IL-17, IL-22 and FoxP3. In spleen samples, significant down regulation of transcription was seen in TLR4 and IL-22 when both infected groups were compared with controls. In liver samples, down regulation of transcription was evident with disease progression for IL-22. In the skin, upregulation was seen only for TLR9 and FoxP3 in the early stages of infection. Subtle changes or down regulation in TLR transcription, Th17 cytokines and FoxP3 are indicative of the silent establishment of infection that Leishmania is renowned for. These observations provide new insights about TLR transcription, Th17 cytokines and Foxp3 in the liver, spleen, lymph node and skin in CanL and highlight possible markers of disease susceptibility in this model
Lactate Regulates Metabolic and Proinflammatory Circuits in Control of T Cell Migration and Effector Functions
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RASSF1A–LATS1 signalling stabilizes replication forks by restricting CDK2-mediated phosphorylation of BRCA2
Genomic instability is a key hallmark of cancer leading to tumour heterogeneity and therapeutic resistance. BRCA2 has a fundamental role in error-free DNA repair but also sustains genome integrity by promoting RAD51 nucleofilament formation at stalled replication forks. CDK2 phosphorylates BRCA2 (pS3291-BRCA2) to limit stabilizing contacts with polymerized RAD51; however, how replication stress modulates CDK2 activity and whether loss of pS3291-BRCA2 regulation results in genomic instability of tumours are not known. Here we demonstrate that the Hippo pathway kinase LATS1 interacts with CDK2 in response to genotoxic stress to constrain pS3291-BRCA2 and support RAD51 nucleofilaments, thereby maintaining genomic fidelity during replication stalling. We also show that LATS1 forms part of an ATR-mediated response to replication stress that requires the tumour suppressor RASSF1A. Importantly, perturbation of the ATR–RASSF1A–LATS1 signalling axis leads to genomic defects associated with loss of BRCA2 function and contributes to genomic instability and ‘BRCA-ness’ in lung cancers
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