Differences in the vascular tree of the femoral trochlear growth cartilage at osteochondrosis‐susceptible sites in foals revealed by SWI 3T MRI

Focal ischemic chondronecrosis of epiphyseal growth cartilage (EGC) during endochondral ossification is believed to be a key early event on the pathway to osteochondrosis (OC) in both animals and humans. The lateral ridge of the equine trochlea is a site where severe osteochondritis dissecans lesions frequently arise and is a model for the study of naturally occurring disease. Non‐invasive imaging to investigate EGC vascularity may help elucidate why focal ischemia occurs. 3T MRI susceptibility‐weighted imaging (SWI) of femoral trochlea of OC predisposed (n = 10) and control (n = 6) day‐old foals, with minimal joint loading after birth, was performed. SWI and 3D images revealed the EGC vascular architecture without a contrast agent, and matched histologic observations. No vascular lesions were identified. There was no difference in the vascular density and architecture between control and OC specimens, but a striking difference in vascular pattern was seen at the OC‐predilected site in the lateral ridge of the trochlea in all specimens, when compared to the medial ridge of the trochlea, where OC lesions are rarely observed. This site was less ossified with more perichondrial vessels not yet bridging with the subchondral bone. Furthermore, the mean vascular density of all specimens was significantly higher at this site. We speculate that joint morphology and focal internal trauma on this site with a unique vascular architecture may trigger ischemic events at this site. SWI permitted visualization of EGC in young foals with a clinical 3T MRI and paves the way for non‐destructive longitudinal studies to improve understanding of OC in all species. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1539–1546, 2016.     

Clinically relevant concentrations of propofol but not midazolam alter in vitro dendritic development of isolated gamma-aminobutyric acid-positive interneurons

BACKGROUND: Recent laboratory studies showed that exposure to supraclinical concentrations of propofol can induce cell death of immature neurons. However, no data are available regarding the effects of clinically relevant concentrations of this agent on neuronal development. The authors addressed this issue by evaluating the effect of propofol on dendritic growth and arbor expansion of developing gamma-aminobutyric acid-positive (GABAergic) interneurons. METHODS: Immature neuroblasts were isolated from the newborn rat subventricular zone and differentiated into GABAergic interneurons in culture. In addition to cell death, the effects of increasing concentrations and durations of propofol exposure on neuronal dendritic development were evaluated using the following morphologic parameters: total dendritic length, primary dendrites, branching point, and Scholl analysis. RESULTS: The authors demonstrate that propofol induced cell death of GABAergic neurons at concentrations of 50 microg/ml or greater. As little as 1 microg/ml propofol significantly altered several aspects of dendritic development, and as little as 4 h of exposure to this agent resulted in a persistent decrease in dendritic growth. In contrast, application of midazolam did not affect neuronal development. CONCLUSION: Short-term exposure of immature developing GABAergic neurons to clinically relevant concentrations of propofol can induce long-term changes in dendritic arbor development. These results suggest that propofol anesthesia during central nervous system development could interfere with the molecular mechanisms driving the differentiation of GABAergic neurons and thus could potentially lead to impairment of neural networks.     

Inhibition of NF-κB-dependent cytokine and inducible nitric oxide synthesis by the macrocyclic ellagitannin oenothein B in TLR-stimulated RAW 264.7 macrophages

Immunomodulatory effects of oenothein B (1), a macrocyclic ellagitannin from various Onagraceae species, have been described previously. However, the mechanisms underlying the anti-inflammatory activity of 1 have not been fully clarified. The effects of 1 were investigated on inducible nitric oxide synthase, TLR-dependent and TLR-independent signal transduction cascades, and cytokine expression using murine macrophages (RAW 264.7). Compound 1 (10-60 μg/mL) reduced NO production, iNOS mRNA, and iNOS protein levels in a dose-dependent manner, without inhibition of iNOS enzymatic activity. It reduced the binding of the NF-κB p50 subunit to the biotinylated-consensus sequence and decreased nuclear p65 translocation. Gallic acid as a subunit of the macrocyclic ellagitannin 1 showed a far lower inhibitory activity. Nitric oxide production was reduced by 1 after stimulation using TLR2 (Pam2CSK4) and TLR4 (Kdo2) agonists, but this compound did not inhibit inducible nitric oxide synthesis after stimulation using interferon-gamma. IL-1beta, IL-6, and TNF-alpha mRNA synthesis was clearly reduced by the addition of 1. Oenothein B (1) inhibits iNOS after stimulation with LPS, TLR2, and TLR4 agonists via inhibition of TLR/NF-κB-dependent inducible nitric oxide and cytokine synthesis independent from IFN-gamma/JAK/STAT pathways. The full molecular structure of this macrocyclic ellagitannin seems to be required for its immunomodulatory actions.     

Interferon and lamivudine vs. interferon for hepatitis B e antigen-positive hepatitis B treatment: meta-analysis of randomized controlled trials.

AIMS: To compare interferon monotherapy with its combination with lamivudine for hepatitis B e antigen (HBeAg)-positive hepatitis B treatment. METHODS: Two independent researchers identified pertinent randomized controlled trials. The trials were evaluated for methodological quality and heterogeneity. Rates of sustained virological and biochemical responses, and HBeAg clearance and seroconversion were used as primary efficacy measures. Quantitative meta-analyses were conducted to assess differences between groups for conventional and pegylated interferon, and overall. RESULTS: Greater sustained virological, biochemical and seroconversion rates were observed with addition of lamivudine to conventional [odds ratio (OR)=3.1, 95% confidence intervals (CI) (1.7-5.5), P<0.0001, OR=1.8, 95% CI (1.2-2.7), P=0.007 and OR=1.8, 95% CI (1.1-2.8), P=0.01 respectively], although not pegylated [OR=1.1, 95% CI (0.5-2.3), P=0.8, OR=1.0, 95% CI (0.7-1.3), P=0.94, and OR=0.9, 95% CI (0.6-1.2), P=0.34 respectively] interferon-alpha, with no significant affect on HBeAg clearance rates [OR=1.6, 95% CI (0.9-2.7), P=0.09, and OR=0.8, 95% CI (0.6-1.1), P=0.26 respectively]. Excluding virological response (P<0.001), pegylated interferon monotherapy and conventional interferon and lamivudine combination therapy were similarly efficacious (P>0.05), with the former studied in harder to treat patients, as evidenced by the superior virological response observed with conventional as compared with pegylated interferon monotherapy (P<0.0001). CONCLUSION: In comparable populations, pegylated interferon monotherapy is likely to be equally or more efficacious than conventional interferon and lamivudine combination therapy, thus constituting the treatment of choice, with no added benefit with lamivudine addition. However, when conventional interferon is used, its combination with lamivudine should be considered.     

Network remodeling of intramural coronary resistance arteries in the aged rat: A statistical analysis of geometry

AimsTo identify the geometrical alterations in the age-remodeled rat coronary artery network and to develop a useful technique to analyze network properties in the rat heart.Methods and resultsWe analyzed the networks of the left anterior descendent coronary arteries on in situ perfused hearts of young (3 months) and old (18 months) male rats. All segments and branching over >80 μm diameter were analyzed using 50 μm long cylindrical ring units of the networks. Arterial widening and paucity, increased tortuosity were typical features in the old network. In addition, axis angles deviated more from the mother branches in the old, whereas the diameters of daughter branches fit the Murray law in both groups. The detected changes in the old network resulted in a longer blood flow route for the same direct distance.ConclusionWe developed a useful method to investigate arterial network property changes in the rat heart. Ageing resulted in longer, more tortuous flow route in the LAD network that might be hemodynamically disadvantageous.     

Characterization of chemotherapy-induced morphonuclear modifications in the P388 leukaemia and the MXT mammary tumour models of the mouse

Chemotherapy-induced morphonuclear modifications were monitored in vivo by means of the digital cell image analysis of Feulgen-stained nuclei. Two experimental models were used, i.e. the P388 mouse leukaemia and the MXT mouse mammary carcinoma. The drugs used were doxorubicin, etoposide and cyclophosphamide. The results indicate that the chemotherrapy induced a significant decrease in the MXT tumour growth and a significant increase in the survival of the P388 leukaemic mice. These effects were accompanied at the morphonuclear level by an increase in the nuclear area, by modifications in the DNA content in accordance with the effects of the drugs on the cells cycle and by several modifications in the chromatin texture in accordance with the effects of the drugs on the cells cycle and by several modifications in the chromatin texture in accordance with the model or drugs studied. While there were neither homogeneous morphonuclear changes in all treatment groups nor clearcut correlations between the morphonuclear changes and tumour growth or the survival of the animals, the present study nertherless shows that it is possible, at least partly, to monitor in vivo certain chemotherapy-induced effects occurring at the morphonuclear level, and subsequently to obtain information on the mode of action of the drugs.