Explore the vast range of titles available.

Mice have been increasingly used as preclinical model to elucidate mechanisms and test therapeutics for treating intervertebral disc degeneration (IDD). Several intervertebral disc (IVD) histological scoring systems have been proposed, but none exists that reliably quantitate mouse disc pathologies. Here, we report a new robust quantitative mouse IVD histopathological scoring system developed by building consensus from the spine community analyses of previous scoring systems and features noted on different mouse models of IDD. The new scoring system analyzes 14 key histopathological features from nucleus pulposus (NP), annulus fibrosus (AF), endplate (EP), and AF/NP/EP interface regions. Each feature is categorized and scored; hence, the weight for quantifying the disc histopathology is equally distributed and not driven by only a few features. We tested the new histopathological scoring criteria using images of lumbar and coccygeal discs from different IDD models of both sexes, including genetic, needle‐punctured, static compressive models, and natural aging mice spanning neonatal to old age stages. Moreover, disc sections from common histological preparation techniques and stains including H&E, SafraninO/Fast green, and FAST were analyzed to enable better cross‐study comparisons. Fleiss's multi‐rater agreement test shows significant agreement by both experienced and novice multiple raters for all 14 features on several mouse models and sections prepared using various histological techniques. The sensitivity and specificity of the new scoring system was validated using artificial intelligence and supervised and unsupervised machine learning algorithms, including artificial neural networks, k‐means clustering, and principal component analysis. Finally, we applied the new scoring system on established disc degeneration models and demonstrated high sensitivity and specificity of histopathological scoring changes. Overall, the new histopathological scoring system offers the ability to quantify histological changes in mouse models of disc degeneration and regeneration with high sensitivity and specificity. We have developed a new Mouse intErveRtebral disC histopathologY (MERCY) system using a step‐wise approach that included building consensus in the spine community, testing reliability using various mouse disc degeneration models for agreement by multiple raters, validating for high sensitivity and specificity using AI and machine learning algorithms, and applied on established models of murine disc degeneration. Hence, this new system can be broadly applied to quantify mouse IVD histopathology in disc degeneration and regeneration models.

Central nervous system (CNS) invasion during acute-stage HIV-infection has been demonstrated in a small number of individuals, but there is no evidence of neurological impairment at this stage and virus infection in brain appears to be controlled until late-stage disease. Using our reproducible SIV macaque model to examine the earliest stages of infection in the CNS, we identified immune responses that differentially regulate inflammation and virus replication in the brain compared to the peripheral blood and lymphoid tissues. SIV replication in brain macrophages and in brain of SIV-infected macaques was detected at 4 days post-inoculation (p.i.). This was accompanied by upregulation of innate immune responses, including IFNbeta, IFNbeta-induced gene MxA mRNA, and TNFalpha. Additionally, IL-10, the chemokine CCL2, and activation markers in macrophages, endothelial cells, and astrocytes were all increased in the brain at four days p.i. We observed synchronous control of virus replication, cytokine mRNA levels and inflammatory markers (MHC Class II, CD68 and GFAP) by 14 days p.i.; however, control failure was followed by development of CNS lesions in the brain. SIV infection was accompanied by induction of the dominant-negative isoform of C/EBPbeta, which regulates SIV, CCL2, and IL6 transcription, as well as inflammatory responses in macrophages and astrocytes. This synchronous response in the CNS is in part due to the effect of the C/EBPbeta on virus replication and cytokine expression in macrophage-lineage cells in contrast to CD4+ lymphocytes in peripheral blood and lymphoid tissues. Thus, we have identified a crucial period in the brain when virus replication and inflammation are controlled. As in HIV-infected individuals, though, this control is not sustained in the brain. Our results suggest that intervention with antiretroviral drugs or anti-inflammatory therapeutics with CNS penetration would sustain early control. These studies further suggest that interventions should target HIV-infected individuals with increased CCL2 levels or HIV RNA in the CNS.

Sudden cardiac death kills 180,000 to 450,000 Americans annually, predominantly males. A locus that confers a risk for sudden cardiac death, cardiac conduction disease and a newly described developmental disorder (6p22 syndrome) is located at 6p22. One gene at 6p22 is CAP2, which encodes a cytoskeletal protein that regulates actin dynamics. To determine the role of CAP2 in vivo , we generated knockout (KO) mice. cap2 − / cap2 − males were underrepresented at weaning and ~70% died by 12 weeks of age, but cap2 − / cap2 − females survived at close to the expected levels and lived normal life spans. CAP2 knockouts resembled patients with 6p22 syndrome in that mice were smaller and they developed microphthalmia and cardiac disease. The cardiac disease included cardiac conduction disease (CCD) and, after six months of age, dilated cardiomyopathy (DCM), most noticeably in the males. To address the mechanisms underlying these phenotypes, we used Cre-mediated recombination to knock out CAP2 in cardiomyocytes. We found that the mice developed CCD, leading to sudden cardiac death from complete heart block, but no longer developed DCM or the other phenotypes, including sex bias. These studies establish a direct role for CAP2 and actin dynamics in sudden cardiac death and cardiac conduction disease.

Background. During the era of highly active antiretroviral therapy (HAART), the prevalence of HIV-associated central nervous system (CNS) disease has increased despite suppression of plasma viremia. Methods. In a simian immunodeficiency virus (SIV) model system in which all animals develop AIDS and 90% develop CNS disease by 3 months after inoculation, pigtailed macaques were treated with a regimen of tenofovir disoproxil fumarate, saquinavir, atazanavir, and an integrase inhibitor starting at 12 days after inoculation and were euthanized at ∼175 days after inoculation. Results. Plasma and cerebrospinal fluid (CSF) viral loads declined rapidly after the initiation of HAART. Brain viral RNA was undetectable at necropsy, but viral DNA levels were not different from those in untreated SIVinfected macaques. CNS inflammation was significantly reduced, with decreased brain expression of major histocompatibility complex class II and glial fibrillary acidic protein and reduced levels of CSF CCL2 and interleukin 6. Brain from treated macaques had significantly lower levels of interferon γ, type 1 interferon-inducible gene myxovirus (influenza) resistance A, and indolamine 2, 3-dioxygenase messenger RNA, suggesting that immune hyperactivation was suppressed, and fewer CD4+ and CD8+ T cells, suggesting that trafficking of T cells from peripheral blood was reduced. Brain levels of CD68 protein and tumor necrosis factor a and interferon g RNA were reduced but were not significantly lower, indicating continued CNS inflammation. Conclusions. These data, generated in a rigorous, high-viral-load SIV-infected macaque model, showed that HAART provided benefits with respect to CNS viral replication and inflammation but that no change in the level of viral DNA and continued CNS inflammation occurred in some macaques.

Treatment of human immunodeficiency virus (HIV) infection with highly active antiretroviral therapy (HAART) is effective but can be associated with toxic effects and is expensive. Other options may be useful for longterm therapy. The immunomodulatory antibiotic minocycline could be an effective, low-cost adjunctive treatment to HAART. Minocycline mediated a dose-dependent decrease in single-cycle CXCR4-tropic HIV infection and decreased viral RNA after infection of CD4+ T cells with HIV NL4-3. Reactivation from latency was also decreased in a primary CD4+ T cell-derived model and in resting CD4+ T cells from HIV-infected patients. Minocycline treatment resulted in significant changes in activation marker expression and inhibited proliferation and cytokine secretion of CD4+ T cells in response to activation. This study demonstrates that minocycline reduces HIV replication and reactivation and decreases CD4+ T cell activation. The anti-HIV effects of minocycline are mediated by altering the cellular environment rather than directly targeting virus, placing minocycline in the class of anticellular anti-HIV drugs.

Chronic liver inflammation progressively evokes fibrosis and cirrhosis resulting in compromised liver function, and often leading to cancer. Early diagnosis and staging of fibrosis is crucial because the five-year survival rate of early-stage liver cancer is high. This study investigates the progression of hepatic fibrosis induced in rats following ingestion of diethylnitrosamine (DEN). Changes in oxygen saturation and hemoglobin concentration resulting from chronic inflammation were assayed longitudinally during DEN ingestion by photoacoustic imaging (PAI). Accompanying liver tissue changes were monitored simultaneously by B-mode sonographic imaging. Oxygen saturation and hemoglobin levels in the liver increased over 5 weeks and peaked at 10 weeks before decreasing at 13 weeks of DEN ingestion. The oxygenation changes were accompanied by an increase in hepatic echogenicity and coarseness in the ultrasound image. Histology at 13 weeks confirmed the development of severe fibrosis and cirrhosis. The observed increase in PA signal representing enhanced blood oxygenation is likely an inflammatory physiological response to the dietary DEN insult that increases blood flow by the development of neovasculature to supply oxygen to a fibrotic liver during the progression of hepatic fibrosis. Assessment of oxygenation by PAI may play an important role in the future assessment of hepatic fibrosis.

Hepatic fibrosis and cirrhosis are a growing global health problem with increasing mortality rates. Early diagnosis and staging of hepatic fibrosis represent a major challenge. Currently liver biopsy is the gold standard for fibrosis assessment; however, biopsy requires an invasive procedure and is prone to sampling error and reader variability. In the current study we investigate using quantitative analysis of computer-extracted features of B-mode ultrasound as a non-invasive tool to characterize hepatic fibrosis. Twenty-two rats were administered diethylnitrosamine (DEN) orally for 12 weeks to induce hepatic fibrosis. Four control rats did not receive DEN. B-mode ultrasound scans sampling throughout the liver were acquired at baseline, 10, and 13 weeks. Computer extracted quantitative parameters representing brightness (echointensity, hepatorenal index) and variance (heterogeneity, anisotropy) of the liver were studied. DEN rats showed an increase in echointensity from 37.1 ± SD 7.8 to 53.5 ± 5.7 (10 w) to 57.5 ± 6.1 (13 w), while the control group remained unchanged at an average of 34.5 ± 4.5. The three other features studied increased similarly over time in the DEN group. Histologic analysis showed METAVIR fibrosis grades of F2-F4 in DEN rats and F0-F1 in controls. Increasing imaging parameters correlated with increasing METAVIR grades, and anisotropy showed the strongest correlation (ρ = 0.58). Sonographic parameters combined using multiparametric logistic regression were able to differentiate between clinically significant and insignificant fibrosis. Quantitative B-mode ultrasound imaging can be implemented in clinical settings as an accurate non-invasive tool for fibrosis assessment.

Scientific Reports 5: Article number: 17256; published online: 30 November 2015; updated: 31 May 2016 This Article contains typographical errors in the legend of Supplementary Figure S1, “Physiology phenotyping (a and b) DEXA analysis of mice. (c) Grip strength of mice (d) Glucose tolerance test. Error bars ± S.

OBJECTIVES/GOALS: The detection of liver fibrotic changes at an early and reversible stage is essential to prevent its progression to end-stage cirrhosis and hepatocellular carcinoma. Liver biopsy, which is the current gold standard for fibrosis assessment, is accompanied by several complications due to its invasive nature in addition to sampling errors and reader variability. In this study, we evaluate the use of quantitative parameters extracted from hybrid ultrasound and photoacoustic imaging to detect and monitor fibrotic changes in a DEN rat model. METHODS/STUDY POPULATION: Liver fibrotic changes were induced in 34 Wistar male rats by oral administration of Diethylnitrosamine (DEN) for 12 weeks. 22 rats were imaged with B-mode ultrasound at 3 different time points (baseline, 10 weeks and 13 weeks) for monitoring liver texture changes. Texture features studied included tissue echointensity (liver brightness normalized to kidney brightness) and tissue heterogeneity. 12 rats were imaged with photoacoustic imaging at 4 time points (baseline, 5 wks, 10 wks, and 13 wks) to look at changes in tissue oxygenation. Hemoglobin oxygen saturation (sO2A) and hemoglobin concentration (HbT) in the right and left lobes of the liver were measured. 8 rats were used as controls. Liver tissue samples were obtained following 13 weeks from DEN start time for METAVIR histopathology staging of fibrosis. RESULTS/ANTICIPATED RESULTS: Texture features studied showed an increase with time in DEN rats. Normalized echointensity increased from 0.28 ± 0.06 at baseline to 0.46 ± 0.10 at 10 weeks ( p < 0.0005) and 0.53 ± 0.15 at 13 weeks in DEN rats ( p < 0.0005). In the control rats, echointensity remained at an average of 0.25 ± 0.05 ( p = 0.31). Tissue heterogeneity increased over time in the DEN-exposed rats from a baseline of 208.7 ± 58.3 to 344.6 ± 52.9 at 10 weeks ( p < 0.0005) and 376.8 ± 54.9 at 13 weeks ( p = 0.06) however it stayed constant at 225.7 ± 37.6 in control rats ( p = 0.58). The quantitative analyses of the photoacoustic signals showed that blood oxygen saturation significantly increased with time. At 5 weeks sO2AvT increased by 53.83 % (± 0.25), and HbT by 35.31 % (± 0.07). Following 10 weeks of DEN; sO2AvT by 92.04 % (± 0.29), and HbT by 55.24 % (± 0.1). All increases were significant p < 0.05. In the 13th week, however, the values of all of these parameters were lower than those in the 10th week, however, the decrease was statistically insignificant. DISCUSSION/SIGNIFICANCE OF IMPACT: Quantitative features from B-mode ultrasound and photoacoustic imaging consistently increased over time corresponding to hepatic damage, inflammation and fibrosis progressed. The use of this hybrid imaging method in clinical practice can help meet the significant need for noninvasive assessment of liver fibrosis.

The CNS remains vulnerable to HIV-induced damage despite highly active antiretroviral therapy (HAART). Using a rigorous simian immunodeficiency virus (SIV) macaque model of HAART that combines three classes of antiretroviral drugs (a protease inhibitor, a reverse transcriptase inhibitor, and an integrase inhibitor), we examined immune responses and virus replication in the plasma and cerebrospinal fluid (CSF) following HAART initiation during acute infection (4 days postinoculation (p.i.)). HAART-treated macaques did not experience the level of acute CD4+ and CD8+ T cell and NK cell count suppression in the peripheral blood normally observed during acute infection. Initiation of HAART produced a rapid four-log decline in viral load in plasma and a slower two-log decline of viral RNA in the CSF over the subsequent 17 days of infection. Despite a dramatic reduction of viral RNA levels in the brain at 21 days p.i., viral DNA levels were not different between the two groups. Expression of most cytokine mRNA in brain of HAART-treated macaques did not significantly differ from untreated controls. Expression of the IFN responsive gene MxA was significantly reduced in the brain of HAART-treated macaques, suggesting control of hyperactive immune responses. Control of virus replication likely was enhanced by significant increases in CD4+ and CD8+ T cell trafficking in the brain of infected animals on HAART therapy and the concomitant increase in levels of IFNγ. Collectively, these data indicate preserved innate and adaptive immune activity in the brain following HAART initiation during acute SIV infection in this macaque model, suggesting profound benefits following acute treatment of SIV.