Atomic force microscopy characterization of silver nanoparticles interactions with marine diatom cells and extracellular polymeric substance

This study highlights the capacity of atomic force microscopy (AFM) for investigating nanoparticle (NP) algal cell interaction with a subnanometer resolution. We designed a set of AFM experiments to characterize NP size, shape, and structure to visualize changes in the cell morphology induced by NPs and to characterize NP interaction with the extracellular polymeric substance (EPS). Samples for AFM imaging were prepared using the same protocol-drop deposition on mica and imaged in air. Here we address the interactions of Ag NPs with ubiquitous, lightly silicified marine diatoms Cylindrotheca fusiformis and Cylindrotheca closterium and their EPS. In natural seawater used throughout this study, the single Ag NPs adopted truncated tetrahedron morphology with particle heights of 10, 20, 30, and 40 nm. This size class Ag NPs penetrates the cell wall through the valve region built of silica NPs embedded in organic matrix. The Ag NPs cause a local damage inside the cell without disintegration of the cell wall. The EPS production has been shown to increase as a feedback response to Ag NP exposure and may contribute to detoxification mechanisms. Imaging EPS at high resolution revealed the incorporation of Ag NPs and their aggregates into the EPS-gel matrix, proving their detoxifying capacity.     

Temporomandibular joint disorder in a patient with multiple sclerosis--review of literature with a clinical report

Temporomandibular disorders are a form of musculoskeletal disorders, which reduce the function of stomatognathic system and they are related to some other diseases causing painful conditions and disorders of oral function. The aim of this paper is to describe a one year follow up clinical case of a female patient with comorbid multiple sclerosis and a relatively rare form of articular disc disorder. Primary clinical diagnostics encompassed manual methods of TMJ examination. Definite diagnosis included radiologic examination. Clinical hyperextensive condyle position was palpated bilaterally and subsequently confirmed by a functional panoramic radiograph of TMJ. The anterior displacement of disc with reduction was diagnosed by magnetic resonance and in the right joint there was a disc displacement upon excursive movement. From relevant literature, the relationship of a number of diseases that can be related to functional disorder of the orofacial system, such as multiple sclerosis, has been described from many aspects. Also, apart from the standard classification of one form of anterior displacement of the disc, made primarily by magnetic resonance, cases of disc displacement upon excursive mandibular movement can rarely be found in literature.     

The PNPLA3 Ile148Met interacts with overweight and dietary intakes on fasting triglyceride levels

The Ile148Met (rs738409, G-allele) in the patatin-like phospholipase domain-containing protein 3 gene (PNPLA3) associates with liver fat content and may lead to loss-of-function (hydrolysis) or gain-of-function (CoA-dependent lysophosphatidic acid acyltransferase) defects. PNPLA3 is up-regulated by dietary carbohydrates, and interactions between rs738409 and carbohydrates, and sugar and ω6:ω3-polyunsaturated fatty acid (PUFA) ratio on hepatic fat accumulation have been reported. We examined interaction between rs738409 and overweight, and between rs738409 and dietary intakes (carbohydrates, sucrose and ω6:ω3-PUFA ratio), on fasting triglyceride levels. From the Malmo Diet and Cancer Study-Cardiovascular Cohort, 4,827 individuals without diabetes aged 58 ± 6 years, 2,346 with BMI ≤ 25 kg/m² and 2,478 with BMI > 25 kg/m², were included in cross-sectional analyses. Dietary data were collected by a modified diet history method. Overweight modified the association between rs738409 and fasting triglyceride levels (P_interaction = 0.003). G-allele associated with lower triglycerides only among overweight individuals (P = 0.01). Nominally, significant interaction on triglyceride levels was observed between rs738409 and sucrose among normal-weight individuals (P_interaction = 0.03). G-allele associated with lower triglycerides among overweight individuals in the lowest tertiles of carbohydrate and ω6:ω3-PUFA ratio (P = 0.04 and P = 0.001) and with higher triglycerides among normal-weight individuals in the highest tertile of sucrose (P = 0.001). We conclude that overweight and dietary sucrose may modify the association between rs738409 and fasting triglyceride levels.

Electronic supplementary material

The online version of this article (doi:10.1007/s12263-014-0388-4) contains supplementary material, which is available to authorized users.     

Species Differences in Developmental Toxicity of Epoxiconazole and Its Relevance to Humans

Epoxiconazole, a triazole‐based fungicide, was tested in toxicokinetic, prenatal and pre‐postnatal toxicity studies in guinea pigs, following oral (gavage) administration at several dose levels (high dose: 90 mg/kg body weight per day). Maternal toxicity was evidenced by slightly increased abortion rates and by histopathological changes in adrenal glands, suggesting maternal stress. No compound‐related increase in the incidence of malformations or variations was observed in the prenatal study. In the pre‐postnatal study, epoxiconazole did not adversely affect gestation length, parturition, or postnatal growth and development. Administration of epoxiconazole did not alter circulating estradiol levels. Histopathological examination of the placentas did not reveal compound‐related effects. The results in guinea pigs are strikingly different to those observed in pregnant rats, in which maternal estrogen depletion, pathological alteration of placentas, increased gestation length, late fetal death, and dystocia were observed after administration of epoxiconazole. In the studies reported here, analysis of maternal plasma concentrations and metabolism after administration of radiolabeled epoxiconazole demonstrated that the different results in rats and guinea pigs were not due to different exposures of the animals. A comprehensive comparison of hormonal regulation of pregnancy and birth in murid rodents and primates indicates that the effects on pregnancy and parturition observed in rats are not applicable to humans. In contrast, the pregnant guinea pig shares many similarities to pregnant humans regarding hormonal regulation and is therefore considered to be a suitable species for extrapolation of related effects to humans. Birth Defects Res (Part B) 98:230–246, 2013. © 2013 Wiley Periodicals, Inc.     

A Re-Emerging Marker for Prognosis in Hepatocellular Carcinoma: The Add-Value of FISHing c-myc Gene for Early Relapse

Hepatocellular carcinoma is one leading cause of cancer-related death and surgical resection is still one of the major curative therapies. Recently, there has been a major effort to find mechanisms involved in carcinogenesis and early relapse. c-myc gene abnormality is found in hepatocarcinogenesis. Our aim was to analyze the role of c-myc as prognostic factor in terms of overall survival and disease-free survival and to investigate if c-myc may be an important target for therapy. We studied sixty-five hepatocellular carcinomas submitted to surgical resection with curative intent. Size, macro-microvascular invasion, necrosis, number of nodules, grading and serum alfa-fetoprotein level were registered for all cases. We evaluated the c-myc aberrations by using break-apart FISH probes. Probes specific for the centromeric part of chromosome 8 and for the locus specific c-myc gene (8q24) were used to assess disomy, gains of chromosomes (polysomy due to polyploidy) and amplification. c-myc gene amplification was scored as 8q24/CEP8 > 2. Statistical analysis for disease-free survival and overall survival were performed. At molecular level, c-myc was amplified in 19% of hepatocellular carcinoma, whereas showed gains in 55% and set wild in 26% of cases. The 1- and 3-year disease-free survival and overall survival for disomic, polysomic and amplified groups were significantly different (p=0.020 and p=.018 respectively). Multivariate analysis verified that the AFP and c-myc status (amplified vs. not amplified) were significant prognostic factors for overall patients survival. c-myc gene amplification is significantly correlated with disease-free survival and overall survival in patients with hepatocellular carcinoma after surgical resection and this model identifies patients with risk of early relapse (≤12 months). We suggest that c-myc assessment may be introduced in the clinical practice for improving prognostication (high and low risk of relapse) routinely and may have be proposed as biomarker of efficacy to anti-c-myc targeted drugs in clinical trials.     

The patients with clinically isolated syndrome and relapsing remitting multiple sclerosis show different levels of advanced protein oxidation products and total thiol content in plasma and CSF

Advanced oxidation protein products (AOPP) and total thiol (SH) groups levels in plasma and CSF were studied in a cohort of 50 clinically isolated syndrome (CIS) and 57 relapsing remittent multiple sclerosis (RRMS) patients related to 20 control group (CG) patients’ values. The obtained results were compared regarding patients demographic, biochemical, clinical (EDSS) and MRI features (total T2 weighted lesions number and Gd enhancement lesion volume).     

Sequential development of several RT-qPCR tests using LNA nucleotides and dual probe technology to differentiate SARS-CoV-2 from influenza A and B

Sensitive and accurate RT-qPCR tests are the primary diagnostic tools to identify SARS-CoV-2-infected patients. While many SARS-CoV-2 RT-qPCR tests are available, there are significant differences in test sensitivity, workflow (e.g. hands-on-time), gene targets and other functionalities that users must consider. Several publicly available protocols shared by reference labs and public health authorities provide useful tools for SARS-CoV-2 diagnosis, but many have shortcomings related to sensitivity and laborious workflows. Here, we describe a series of SARS-CoV-2 RT-qPCR tests that are originally based on the protocol targeting regions of the RNA-dependent RNA polymerase (RdRp) and envelope (E) coding genes developed by the Charité Berlin. We redesigned the primers/probes, utilized locked nucleic acid nucleotides, incorporated dual probe technology and conducted extensive optimizations of reaction conditions to enhance the sensitivity and specificity of these tests. By incorporating an RNase P internal control and developing multiplexed assays for distinguishing SARS-CoV-2 and influenza A and B, we streamlined the workflow to provide quicker results and reduced consumable costs. Some of these tests use modified enzymes enabling the formulation of a room temperature-stable master mix and lyophilized positive control, thus increasing the functionality of the test and eliminating cold chain shipping and storage. Moreover, a rapid, RNA extraction-free version enables high sensitivity detection of SARS-CoV-2 in about an hour using minimally invasive, self-collected gargle samples. These RT-qPCR assays can easily be implemented in any diagnostic laboratory and can provide a powerful tool to detect SARS-CoV-2 and the most common seasonal influenzas during the vaccination phase of the pandemic.     

Endocrine modulation of Brucella abortus-infected osteocytes function and osteoclastogenesis via modulation of RANKL/OPG

Osteoarticular brucellosis is the most frequent complication of active disease. A large amount of cells in bone are osteocytes. Since bone remodeling process is regulated by hormones we sought to study the effect of cortisol and DHEA in Brucella abortus-infected osteocytes. Cortisol treatment inhibited the expression of IL-6, TNF-α, MMP-2 and RANKL in B. abortus-infected osteocytes. DHEA could reverse the inhibitory effect of cortisol on MMP-2 production. B. abortus infection inhibited connexin 43 (Cx43) expression in osteocytes. This expression was increased when cortisol was incorporated during the infection and DHEA treatment partially reversed the effect of cortisol. Osteocytes-infected with B. abortus induced osteoclast's differentiation. Yet, the presence of cortisol, but not DHEA, during osteocyte infection inhibited osteoclastogenesis. Glucocorticoid receptor (GR) is implicated in the signaling of cortisol. Infection with B. abortus was able to increase GRα/β ratio. Levels of intracellular cortisol are not only dependent on GR expression but also a result of the activity of the isoenzymes 11β-hydroxysteroid dehydrogenase (11β-HSD)-1 (cortisone to cortisol conversion), 11β-HSD2 (cortisol to cortisone conversion). B. abortus infection increased 11β-HSD 1/2 ratio and cortisone mimicked the effect of cortisol. Our results indicated that cortisol and DHEA could modulate osteocyte responses during B. abortus infection.     

Monosodium Urate Crystals Promote Innate Anti-Mycobacterial Immunity and Improve BCG Efficacy as a Vaccine against Tuberculosis

A safer and more effective anti-Tuberculosis vaccine is still an urgent need. We probed the effects of monosodium urate crystals (MSU) on innate immunity to improve the Bacille Calmette-Guerin (BCG) vaccination. Results showed that in vitro MSU cause an enduring macrophage stimulation of the anti-mycobacterial response, measured as intracellular killing, ROS production and phagolysosome maturation. The contribution of MSU to anti-mycobacterial activity was also shown in vivo. Mice vaccinated in the presence of MSU showed a lower number of BCG in lymph nodes draining the vaccine inoculation site, in comparison to mice vaccinated without MSU. Lastly, we showed that MSU improved the efficacy of BCG vaccination in mice infected with Mycobacterium tuberculosis (MTB), measured in terms of lung and spleen MTB burden. These results demonstrate that the use of MSU as adjuvant may represent a novel strategy to enhance the efficacy of BCG vaccination.