All polyethylene tibia - results of functional and radiological outcome at 5 years follow-up

Background: Earlier, all-polyethylene tibial (APT) components were the only option available for TKA. APT components improved over years and have shown results similar or superior to MBT components with respect to survivorship and rate of complications. This study aimed to assess the functional and radiological outcome of TKA with APT components with 5 years follow-up.Methods: This longitudinal study was conducted in a tertiary care center in Mumbai in year 2018. All patients who underwent TKA with APT components during the year 2012 were included in the study. Total of 147 knees were operated in 120 patients. Ninty patients (111 knees) followed up at 5 years. Preoperative and postoperative assessment of patients was done for function, pain and radiological outcome. Functional scores used were Knee society score, WOMAC osteoarthritis index, Bristol score and Oxford knee score. Visual analogue scale (VAS) score was used for pain assessment. Pre and postoperative X-rays were done and component alignment angles (α, β, γ and δ) were calculated.Results: Statistically significant difference was found in pre and postoperative values of VAS score, knee society score, WOMAC osteoarthritis index, Bristol score and Oxford knee score (p value <0.001). Component alignment angles were found to be same pre and postoperatively. None of the patients had radiologic evidence of loosening of implants.Conclusions: APT components have good to excellent functional outcome and good radiological outcome at 5 years. They are safe in view of radiologic component migration at 5-year follow-up

A murine herpesvirus closely related to ubiquitous human herpesviruses causes T-cell depletion

ABSTRACT The human roseoloviruses human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 comprise the Roseolovirus genus of the human Betaherpesvirinae subfamily. Infections with these viruses have been implicated in many diseases; however, it has been challenging to establish infections with roseoloviruses as direct drivers of pathology, because they are nearly ubiquitous and display species-specific tropism. Furthermore, controlled study of infection has been hampered by the lack of experimental models, and until now, a mouse roseolovirus has not been identified. Herein we describe a virus that causes severe thymic necrosis in neonatal mice, characterized by a loss of CD4 + T cells. These phenotypes resemble those caused by the previously described mouse thymic virus (MTV), a putative herpesvirus that has not been molecularly characterized. By next-generation sequencing of infected tissue homogenates, we assembled a contiguous 174-kb genome sequence containing 128 unique predicted open reading frames (ORFs), many of which were most closely related to herpesvirus genes. Moreover, the structure of the virus genome and phylogenetic analysis of multiple genes strongly suggested that this virus is a betaherpesvirus more closely related to the roseoloviruses, HHV-6A, HHV-6B, and HHV-7, than to another murine betaherpesvirus, mouse cytomegalovirus (MCMV). As such, we have named this virus murine roseolovirus (MRV) because these data strongly suggest that MRV is a mouse homolog of HHV-6A, HHV-6B, and HHV-7. IMPORTANCE Herein we describe the complete genome sequence of a novel murine herpesvirus. By sequence and phylogenetic analyses, we show that it is a betaherpesvirus most closely related to the roseoloviruses, human herpesviruses 6A, 6B, and 7. These data combined with physiological similarities with human roseoloviruses collectively suggest that this virus is a murine roseolovirus (MRV), the first definitively described rodent roseolovirus, to our knowledge. Many biological and clinical ramifications of roseolovirus infection in humans have been hypothesized, but studies showing definitive causative relationships between infection and disease susceptibility are lacking. Here we show that MRV infects the thymus and causes T-cell depletion, suggesting that other roseoloviruses may have similar properties. </jats:p

Toxoplasma gondii infection drives conversion of NK cells into ILC1-like cells

Innate lymphoid cells (ILCs) were originally classified based on their cytokine profiles, placing natural killer (NK) cells and ILC1s together, but recent studies support their separation into different lineages at steady-state. However, tumors may induce NK cell conversion into ILC1-like cells that are limited to the tumor microenvironment and whether this conversion occurs beyond this environment remains unknown. Here, we describ

Murine roseolovirus does not accelerate amyloid-β pathology and human roseoloviruses are not over-represented in Alzheimer disease brains

BACKGROUND: The role of viral infection in Alzheimer Disease (AD) pathogenesis is an area of great interest in recent years. Several studies have suggested an association between the human roseoloviruses, HHV-6 and HHV-7, and AD. Amyloid-β (Aβ) plaques are a hallmark neuropathological finding of AD and were recently proposed to have an antimicrobial function in response to infection. Identifying a causative and mechanistic role of human roseoloviruses in AD has been confounded by limitations in performing in vivo studies. Recent -omics based approaches have demonstrated conflicting associations between human roseoloviruses and AD. Murine roseolovirus (MRV) is a natural murine pathogen that is highly-related to the human roseoloviruses, providing an opportunity to perform well-controlled studies of the impact of roseolovirus on Aβ deposition. METHODS: We utilized the 5XFAD mouse model to test whether MRV induces Aβ deposition in vivo. We also evaluated viral load and neuropathogenesis of MRV infection. To evaluate Aβ interaction with MRV, we performed electron microscopy. RNA-sequencing of a cohort of AD brains compared to control was used to investigate the association between human roseolovirus and AD. RESULTS: We found that 5XFAD mice were susceptible to MRV infection and developed neuroinflammation. Moreover, we demonstrated that Aβ interacts with viral particles in vitro and, subsequent to this interaction, can disrupt infection. Despite this, neither peripheral nor brain infection with MRV increased or accelerated Aβ plaque formation. Moreover, -omics based approaches have demonstrated conflicting associations between human roseoloviruses and AD. Our RNA-sequencing analysis of a cohort of AD brains compared to controls did not show an association between roseolovirus infection and AD. CONCLUSION: Although MRV does infect the brain and cause transient neuroinflammation, our data do not support a role for murine or human roseoloviruses in the development of Aβ plaque formation and AD

Murine Roseolovirus

The study of herpesviruses has been fruitful, not only revealing mechanisms that drive disease, but also providing insight into diverse processes including oncogenesis and immune regulation . The Herpesviridae family includes several highly prevalent human pathogens. Many human herpesviruses belonging to the Alphaherpesvirinae {herpes simplex virus (HSV)}, Betaherpesvirinae {human cytomegalovirus (HCMV)}, and Gammaherpesvirinae {Epstein-Barr virus (EBV), Kaposi’s sarcoma-associated virus (KSHV)} subfamilies have been scrupulously characterized. However, human herpesvirus 6A (HHV6A), HHV6B, and HHV7 (HHV6A/6B/7) are highly related members of the less well characterized Roseolovirus genus of the human Betaherpesvirinae subfamily. HHV6B is among the most prevalent human herpesviruses but little is known about its pathogenesis, disease sequelae, or the host immune response. Murine models for each of the human herpesviruses, except the Roseoloviruses, have been established. We describe and characterize a natural murine virus highly related phenotypically and genetically to HHV6A/6B/7. We therefore classify it as the murine roseolovirus (MRV). We explore various aspects of the pathogenesis and immunology within this dissertation, with hopes of establishing MRV as a tractable model for study of roseolovirus biology

Detailed phenotypic and molecular analyses of genetically modified mice generated by CRISPR-Cas9-mediated editing.

The bacterial CRISPR-Cas9 system has been adapted for use as a genome editing tool. While several recent reports have indicated that successful genome editing of mice can be achieved, detailed phenotypic and molecular analyses of the mutant animals are limited. Following pronuclear micro-injection of fertilized eggs with either wild-type Cas9 or the nickase mutant (D10A) and single or paired guide RNA (sgRNA) for targeting of the tyrosinase (Tyr) gene, we assessed genome editing in mice using rapid phenotypic readouts (eye and coat color). Mutant mice with insertions or deletions (indels) in Tyr were efficiently generated without detectable off-target cleavage events. Gene correction of a single nucleotide by homologous recombination (HR) could only occur when the sgRNA recognition sites in the donor DNA were modified. Gene repair did not occur if the donor DNA was not modified because Cas9 catalytic activity was completely inhibited. Our results indicate that allelic mosaicism can occur following -Cas9-mediated editing in mice and appears to correlate with sgRNA cleavage efficiency at the single-cell stage. We also show that larger than expected deletions may be overlooked based on the screening strategy employed. An unbiased analysis of all the deleted nucleotides in our experiments revealed that the highest frequencies of nucleotide deletions were clustered around the predicted Cas9 cleavage sites, with slightly broader distributions than expected. Finally, additional analysis of founder mice and their offspring indicate that their general health, fertility, and the transmission of genetic changes were not compromised. These results provide the foundation to interpret and predict the diverse outcomes following CRISPR-Cas9-mediated genome editing experiments in mice

Primer Sequences.

<p>Primer sequences for sgRNA synthesis, sequencing, and mutagenesis are shown.</p><p>Primer Sequences.</p

Successful genome editing of <i>Tyr</i> is evident on the day of birth and confirmed by DNA sequencing.

<p><b>(a)</b> Phenotypic results of guide B editing of B6xAB6 fertilized eggs (Experiment 1) resulted in loss of eye pigmentation in two of three pups photographed on day 1 after birth, whereas one pups appeared unaltered (middle pup). Since sequencing analysis was not pursued in these pups, a disruptive indel on the AB6 allele and/or an in-frame indel on the B6 allele could also result in the same phenotypic finding. The mice in Experiment 1 did not survive because the cage housing the pups from guide B was flooded while pups from guide D were cannibalized by the mother. <b>(b)</b> Sequencing results of guide D editing from Experiment 1 are shown here. The <i>Tyr</i> alleles from guide B targeting were not analyzed. The B6 allele is indicated with the position of guide D as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116484#pone.0116484.g001" target="_blank">Fig. 1</a>. Mice are numbered with the following convention: (experiment#.mouse#.allele#). Mouse 1.1 (in-frame deletion on the B6 allele) and mouse 1.4 (no indels observed) had black eyes while the remaining mice had pink eyes at birth. Sequencing results from unaltered <i>Tyr</i> alleles are not shown. Deleted nt (-). Inserted nt in brackets.</p