Oxidative stress response system in Escherichia coli arising from diphenyl ditelluride (PhTe)2 exposure.

The toxicity of diphenyl ditelluride (PhTe)2 is associated with its ability to oxidize sulfhydryl groups from biological molecules. Therefore, we evaluated possible molecular mechanisms of toxicity induced by this organochalcogen in Escherichia coli (E. coli) by evaluating oxidative damage markers, relative expression of genes associated with the cellular redox state in bacteria, such as katG, sodA, sodB, soxS, and oxyR, as well as the activity of enzymes responsible for cellular redox balance. After exposure of (PhTe)2 (6, 12, and 24 µg/mL), there was a decrease in non-protein thiols (NPSH) levels, an increase in protein carbonylation and lipid peroxidation in E. coli. Intra- and extracellular reactive species (RS) was increased at concentrations of 6, 12, and 24 µg/mL. The superoxide dismutase (SOD) activity was increased at the three concentrations tested, while catalase (CAT) activity was higher at 12 and 24 µg/mL. The soxS gene showed lower expression at the three concentrations tested, while the oxyR gene was supressed at 24 µg/mL. The katG antioxidant response gene showed lower expression, and sodA and sodB were positively activated, except for sodB at 6 µg/mL. Our findings demonstrate that exposure to (PhTe)2 induced RS formation, NPSH depletion and changes in transcriptional factors regulation, characterizing it as a multi-target compound, causing disruption in cellular oxidative state, as well as molecular mechanisms associated in E. coli.

The role of renal biomarkers to predict the need of surgery in congenital urinary tract obstruction in infants.

INTRODUCTION: The diagnosis of renal function impairment and deterioration in congenital urinary tract obstruction (UTO) continues to be extremely challenging. The use of new renal biomarkers in this setting may favor early renal injury detection, allowing for a reliable choice of optimal therapeutic options and the prevention or minimization of definitive renal damage. OBJECTIVE: The aim of the study was to investigate a selection of promising biomarkers of renal injury with the intention of evaluating and comparing their profile with clinically based decisions for surgical intervention of infants with congenital obstructive uropathies. STUDY DESIGN: The first-year profile of renal biomarkers, serum creatinine (sCr), serum and urine cystatin C (CyC), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), transforming growth factor beta-1 (TGF-ß1), retinol-binding protein (RBP), and microalbuminuria (µALB), was analyzed in a cohort of 37 infants with congenital UTO, divided into three subgroups, 14 cases with grade III unilateral hydro(uretero)nephrosis, 13 cases with grade III bilateral hydro(uretero)nephrosis, and 10 cases with low urinary tract obstruction (LUTO), compared with 24 healthy infants matched by gestational age and birth weight. Serum and urine samples were stored at -70 °C and thereafter analyzed by quantitative enzymatic immunoassay. RESULTS: Compared with the control group (Figure), all renal biomarker values were significantly increased in patients (P ≤ 0.02). In the unilateral hydronephrosis and LUTO group, RBP (P ≤ 0.043), NGAL (P ≤ 0.043), KIM-1 (P ≤ 0.03), and TGF-ß1 (P ≤ 0.034) values dropped significantly after surgery. Neutrophil gelatinase-associated lipocalin alone and in combination with urine and serum CyC demonstrated the best performance in determining the need for surgery (area under the curve, 0.801 and 0.881, respectively). Biomarker profile analysis was suggestive of surgical intervention in 55.4% (7/13) of non-operated cases, and most of the biomarker values were above the cutoff levels within at least 3 months before the clinically based surgical decision in 58% (14/24) of all operated patients. DISCUSSION: To the best of the authors' knowledge, this is the first study to present the clinical use of selected group of serum and urinary biomarkers in the setting of UTO to distinguish between patients who would benefit from surgery intervention. The most promising results were obtained using NGAL, RBP, TGF-ß1, and KIM-1, especially in the unilateral hydro(uretero)nephrosis and LUTO subgroups when compared with the control group. CONCLUSIONS: Urine biomarkers, alone and in combination, demonstrated high potential as a non-invasive diagnostic tool for identifying infants who may benefit from earlier surgical intervention.

Anaphylaxis to clavulanic acid: a 7-year survey

No disponible

Rate of CRL4(CRBN) substrate Ikaros and Aiolos degradation underlies differential activity of lenalidomide and pomalidomide in multiple myeloma cells by regulation of c-Myc and IRF4.

Recent discoveries suggest that the critical events leading to the anti-proliferative activity of the IMiD immunomodulatory agents lenalidomide and pomalidomide in multiple myeloma (MM) cells are initiated by Cereblon-dependent ubiquitination and proteasomal degradation of substrate proteins Ikaros (IKZF1) and Aiolos (IKZF3). By performing kinetic analyses, we found that the downregulation or proteasomal degradation of Ikaros and Aiolos led to specific and sequential downregulation of c-Myc followed by IRF4 and subsequent growth inhibition and apoptosis. Notably, to ensure growth inhibition and cell death, sustained downregulation of Ikaros and Aiolos, c-Myc or IRF4 expression was required. In addition, we found that the half-maximal rate, rather than the final extent of Ikaros and Aiolos degradation, correlated to the relative efficacy of growth inhibition by lenalidomide or pomalidomide. Finally, we observed that all four transcription factors were elevated in primary MM samples compared with normal plasma cells. Taken together, our results suggest a functional link between Ikaros and Aiolos, and the pathological dysregulation of c-Myc and IRF4, and provide a new mechanistic understanding of the relative efficacy of lenalidomide and pomalidomide based on the kinetics of substrate degradation and downregulation of their downstream targets.

Advanced modelling of the transport phenomena across horizontal clothing microclimates with natural convection.

The ability of clothing to provide protection against external environments is critical for wearer's safety and thermal comfort. It is a function of several factors, such as external environmental conditions, clothing properties and activity level. These factors determine the characteristics of the different microclimates existing inside the clothing which, ultimately, have a key role in the transport processes occurring across clothing. As an effort to understand the effect of transport phenomena in clothing microclimates on the overall heat transport across clothing structures, a numerical approach was used to study the buoyancy-driven heat transfer across horizontal air layers trapped inside air impermeable clothing. The study included both the internal flow occurring inside the microclimate and the external flow occurring outside the clothing layer, in order to analyze the interdependency of these flows in the way heat is transported to/from the body. Two-dimensional simulations were conducted considering different values of microclimate thickness (8, 25 and 52 mm), external air temperature (10, 20 and 30 °C), external air velocity (0.5, 1 and 3 m s(-1)) and emissivity of the clothing inner surface (0.05 and 0.95), which implied Rayleigh numbers in the microclimate spanning 4 orders of magnitude (9 × 10(2)-3 × 10(5)). The convective heat transfer coefficients obtained along the clothing were found to strongly depend on the transport phenomena in the microclimate, in particular when natural convection is the most important transport mechanism. In such scenario, convective coefficients were found to vary in wavy-like manner, depending on the position of the flow vortices in the microclimate. These observations clearly differ from data in the literature for the case of air flow over flat-heated surfaces with constant temperature (which shows monotonic variations of the convective heat transfer coefficients, along the length of the surface). The flow patterns and temperature fields in the microclimates were found to strongly depend on the characteristics of the external boundary layer forming along the clothing and on the distribution of temperature in the clothing. The local heat transfer rates obtained in the microclimate are in marked contrast with those found in the literature for enclosures with constant-temperature active walls. These results stress the importance of coupling the calculation of the internal and the external flows and of the heat transfer convective and radiative components, when analyzing the way heat is transported to/from the body.

In vivo murine model of acquired resistance in myeloma reveals differential mechanisms for lenalidomide and pomalidomide in combination with dexamethasone.

The development of resistance to therapy is unavoidable in the history of multiple myeloma patients. Therefore, the study of its characteristics and mechanisms is critical in the search for novel therapeutic approaches to overcome it. This effort is hampered by the absence of appropriate preclinical models, especially those mimicking acquired resistance. Here we present an in vivo model of acquired resistance based on the continuous treatment of mice bearing subcutaneous MM1S plasmacytomas. Xenografts acquired resistance to two generations of immunomodulatory drugs (IMiDs; lenalidomide and pomalidomide) in combination with dexamethasone, that was reversible after a wash-out period. Furthermore, lenalidomide-dexamethasone (LD) or pomalidomide-dexamethasone (PD) did not display cross-resistance, which could be due to the differential requirements of the key target Cereblon and its substrates Aiolos and Ikaros observed in cells resistant to each combination. Differential gene expression profiles of LD and PD could also explain the absence of cross-resistance. Onset of resistance to both combinations was accompanied by upregulation of the mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK pathway and addition of selumetinib, a small-molecule MEK inhibitor, could resensitize resistant cells. Our results provide insights into the mechanisms of acquired resistance to LD and PD combinations and offer possible therapeutic approaches to addressing IMiD resistance in the clinic.

Uterine vascular degeneration is present throughout the uterine wall of multiparous mares. Colinearity between elastosis, endometrial grade, age and parity.

Vascular degeneration is present in endometrial vessels of multiparous aged mares. The lesions associated with vascular degeneration consist of enlargement, duplication and splitting of the membrana elastica interna and perivascular deposits of elastin. However, there are no similar data available for deep myometrial vessels and the vascular layer. The objectives of the present study were to characterize the status of vasculature in full-thickness uterine necropsy samples and to correlate these findings to endometrial grade, age, and parity. Elastosis was present in myometrial vessels, as well as in large arteries and veins located between the circular and longitudinal myometrial layers. Vascular degeneration was associated with number of foals (P < 0.001) and endometrial grade (P < 0.05), but not with mare age (P > 0.05). Endometrial grade was associated with age (P < 0.001) and vascular grade (P < 0.05), but not with number of foals (P > 0.05). The presence of elastosis in the myometrial vessels was related to problems associated with chronic uterine infection (CUI) and delayed uterine clearance (DUC) of infertile mares. Uterine contractility was impaired in mares affected by CUI and/or DUC and could be related to a lack of myometrial blood flow. Additionally, degeneration of large vessels in the vascular layer may indicate a general compromise in uterine blood flow and fertility. The main conclusions were the presence of vascular elastosis in large deep myometrial vessels as well as in endometrial vessels, and that the factor with the strongest association with vascular degeneration was number of foals (P < 0.001), followed by endometrial grade (P < 0.05), but no association with mare age.

Morphologic manifestations of gene-specific molecular alterations ("genetic addictions") in mouse models of disease.

Neoplasia in both animals and humans results in part from lasting activation of tumor-promoting genes ("oncogenes") or diminished function of genes responsible for preventing neoplastic induction ("tumor suppressor genes"). The concept of "genetic addiction" has emerged to indicate that neoplastic cells cannot maintain a malignant phenotype without sustained genotypic abnormalities related to aberrant activity of oncogene(s) and/or inactivity of tumor suppressor gene(s). Interestingly, some genetic abnormalities reliably produce distinct morphologic patterns that can be used as structural signatures indicating the presence of a specific molecular alteration. Examples of such consistent genetic/microanatomic pairings have been identified for mutated oncogenes, such as rising mucin-producing capacity with RAS overexpression, and mutated tumor suppressor genes-including PTEN eliciting cell hypertrophy, RB1 dictating neuroendocrine differentiation, and TRP53 encouraging sarcomatous transformation. Familiarity with the concept of genetic addiction, as well as the ability to recognize such regular genomic-phenotypic relationships, are of paramount importance for comparative pathologists who are engaged in phenotyping genetically engineered mice to help unravel genomic intricacies in both health and disease.

Internet and print resources to facilitate pathology analysis when phenotyping genetically engineered rodents.

Genetically engineered mice and rats are increasingly used as models for exploring disease progression and mechanisms. The full spectrum of anatomic, biochemical, and functional changes that develop in novel, genetically engineered mouse and rat lines must be cataloged before predictions regarding the significance of the mutation may be extrapolated to diseases in other vertebrate species, including humans. A growing list of reference materials, including books, journal articles, and websites, has been produced in the last 2 decades to assist researchers in phenotyping newly engineered rodent lines. This compilation provides an extensive register of materials related to the pathology component of rodent phenotypic analysis. In this article, the authors annotate the resources they use most often, to allow for quick determination of their relevance to research projects.

The pathologist's slide reveals more than meets the eye: loss of heterozygosity and cancer biology.

In the postgenomic era, the accumulation of massive amounts of molecular and genetic data is quickly transforming the landscape of cancer research. A deeper understanding of cancer biology will allow pathologists studying genetically engineered mouse models and spontaneous tumors to ask novel questions and provide useful insights into disease mechanisms. Although tumor suppressor gene loss is known to be an essential step in the pathogenesis of many tumors, the variety of mechanisms that lead to such loss are poorly understood. This article provides an overview of loss of heterozygosity as an important mechanism of tumor suppressor gene loss; it also emphasizes the importance of loss of heterozygosity detection as a tool for tumor suppressor gene discovery. Understanding the applications of the array of molecular techniques currently available in cancer research will enable pathologists to further contribute to the advancement the field.

An anti-Axl monoclonal antibody attenuates xenograft tumor growth and enhances the effect of multiple anticancer therapies.

Axl is expressed in various types of cancer and is involved in multiple processes of tumorigenesis, including promoting tumor cell growth, migration, invasion, metastasis as well as angiogenesis. To evaluate further the mechanisms involved in the expression/activation of Axl in various aspects of tumorigenesis, especially its roles in modulating tumor stromal functions, we have developed a phage-derived mAb (YW327.6S2) that recognizes both human and murine Axl. YW327.6S2 binds to both human and murine Axl with high affinity. It blocks the ligand Gas6 binding to the receptor, downregulates receptor expression, inhibits receptor activation and downstream signaling. In A549 non-small-cell lung cancer (NSCLC) and MDA-MB-231 breast cancer models, YW327.6S2 attenuates xenograft tumor growth and potentiates the effect of anti-VEGF treatment. In NSCLC models, YW327.6S2 also enhances the effect of erlotinib and chemotherapy in reducing tumor growth. Furthermore, YW327.6S2 reduces the metastasis of MDA-MB-231 breast cancer cells to distant organs. YW327.6S2 induces tumor cell apoptosis in NSCLC, reduces tumor-associated vascular density and inhibits the secretion of inflammatory cytokines and chemokines from tumor-associated macrophages in the breast cancer model. In conclusion, anti-Axl mAb can enhance the therapeutic efficacy of anti-VEGF, EGFR small-molecule inhibitors as well as chemotherapy. Axl mAb affects not only tumor cells but also tumor stroma through its modulation of tumor-associated vasculature and immune cell functions.

Enzymatic biotransformation of synthetic dyes.

Environmental pollution by discharge of dye-containing effluents represents a serious ecological concern in many countries. Public demands for colour-free discharges to receiving waters have made decolouration of a variety of industrial wastewater a top priority. The current existing techniques for dye removal have several drawbacks such as high cost, low efficiency, use of large amounts of chemicals and formation of toxic sub-products. This has impelled the search for alternative methods such as those based on oxidative enzymes. This approach is believed to be a promising technology since it is cost-effective, environmentally friendly and does not produce sludge. Enzymatic transformation of synthetic dyes can be described as the conversion of dye molecules by enzymes into simpler and generally colourless molecules. Detailed characterisation of the metabolites produced during enzymatic transformation of synthetic dyes as well as ecotoxicity studies is of great importance to assess the effectiveness of the biodegradation process. However, most reports on the biotreatment of dyes mainly deal with decolouration and there are few reports on the reduction in toxicity or on the identification of the biodegradation products. This implies a limitation to assess their true technical potential.

Necrotizing meningoencephalitis in five Chihuahua dogs.

An acute to chronic idiopathic necrotizing meningoencephalitis was diagnosed in 5 Chihuahua dogs aged between 1.5 and 10 years. Presenting neurologic signs included seizures, blindness, mentation changes, and postural deficits occurring from 5 days to 5.5 months prior to presentation. Cerebrospinal fluid analyses from 2 of 3 dogs sampled were consistent with an inflammatory disease. Magnetic resonance imaging of the brain of 2 dogs demonstrated multifocal loss or collapse of cortical gray/white matter demarcation hypointense on T1-weighted images, with T2-weighted hyperintensity and slight postcontrast enhancement. Multifocal asymmetrical areas of necrosis or collapse in both gray and white matter of the cerebral hemispheres was seen grossly in 4 brains. Microscopically in all dogs, there was a severe, asymmetrical, intensely cellular, nonsuppurative meningoencephalitis usually with cystic necrosis in subcortical white matter. There were no lesions in the mesencephalon or metencephalon except in 1 dog. Immunophenotyping defined populations of CD3, CD11d, CD18, CD20, CD45, CD45 RA, and CD79a immunoreactive inflammatory cells varying in density and location but common to acute and chronic lesions. In fresh frozen lesions, both CD1b,c and CD11c immunoreactive dendritic antigen-presenting cells were also identified. Immunoreactivity for canine distemper viral (CDV) antigen was negative in all dogs. The clinical signs, distribution pattern, and histologic type of lesions bear close similarities to necrotizing meningoencephalitis as described in series of both Pug and Maltese breed dogs and less commonly in other breeds.

Evaluation of P-glycoprotein expression in feline lymphoma and correlation with clinical outcome.

P-glycoprotein (Pgp) is a transmembrane protein pump involved in drug resistance in canine and human lymphoma. There are no published clinical studies evaluating Pgp expression in feline lymphoma. The purpose of this study is to evaluate the level of Pgp expression in feline lymphoma and correlate it with clinical outcome. Two human Pgp monoclonal antibodies, C219 and C494, were used to detect Pgp expression in tissue samples from 63 cats with lymphoma. Demographic results appear comparable to recently published feline lymphoma studies. The Kaplan-Meier median remission and survival times were 164 and 571 days, respectively. Fourteen cats had positive expression of Pgp using MAb C219, and 40 were positive with C494. Variables statistically associated with survival included bone marrow involvement, stage, substage, and use of radiation therapy as a part of treatment. Pgp expression as assessed by MAb C219 and C494 is not predictive of remission or survival time in cats with lymphoma.

Decolouration of industrial azo dyes by crude laccase from Trametes hirsuta.

The decolouration of several azo dyes, commonly used in the leather industry, by crude laccase obtained from Trametes hirsuta cultivation was assessed. Among the six dyes studied four showed a decolouration percentage higher than 50% in 4h, whereas the other two showed more resistance to degradation. These results show the ability of laccase towards different dye structures as well as its enormous potential for the decolouration of recalcitrant azo dyes.

Mycobacterium fortuitum pneumonia in a cat and the role of lipid in the pathogenesis of atypical mycobacterial infections.

Mycobacterium fortuitum is a saprophytic, fast-growing, nontuberculous, and nonlepromatous mycobacterium that can cause infections in animals and humans. In dogs and cats, it is one of the most common agents of ulcerative dermatitides and panniculitides caused by atypical mycobacteria. In humans, it is frequently found in lipoid pneumonias or contaminated surgical sites. We report a cat with granulomatous pneumonia caused by M fortuitum resembling lipoid pneumonia in humans. The similarity between the histopathology of the lung and skin lesions caused by this organism in dogs and cats is emphasized. We discuss the role of lipids in the pathogenesis of mycobacterioses and suggest an association between atypical mycobacteria and lipid-rich environments. We conclude that M fortuitum should be included as a differential in cases of lipid-rich pneumonias that do not respond to common antibiotics.

Laccase activity from the fungus Trametes hirsuta using an air-lift bioreactor.

AIM: To produce high laccase activities from the white-rot fungus Trametes hirsuta in an in-house air-lift bioreactor (ALB). METHODS AND RESULTS: Trametes hirsuta was grown in a 6-l ALB. A fed-batch strategy with glycerol as an addition resulted in maximum laccase activity of 19,400 U l(-1), which was the highest reported from the fungus. CONCLUSION: The ALB configuration with additional glycerol resulted in high laccase activities. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides useful information on how to produce high concentrations of laccase.

Decolourization of synthetic dyes by Trametes hirsuta in expanded-bed reactors.

The present paper studies the decolourization of different synthetic dyes (Indigo Carmine, Bromophenol Blue, Methyl Orange and Poly R-478) by the white-rot fungus Trametes hirsuta at bioreactor scale under solid-state conditions, operating with ground orange peelings as a support-substrate. Dye decolourization was performed in both batch and continuous mode. Batch cultivation led to high decolourization percentages in a short time (100% for Indigo Carmine in 3h and 85% for Bromophenol Blue in 7 h). As for continuous cultivation, different hydraulic retention times (HRT) were studied (0.8, 1, 1.5 and 3d). The highest decolourization percentages were obtained operating at a HRT of 3d, especially for the dyes Methyl Orange and Poly R-478 (81.4% and 46.9%, respectively). This is a very interesting result, since there are few studies dealing with the continuous decolourization of dyes at bioreactor scale by fungal laccases.

Inhibition of laccase activity from Trametes versicolor by heavy metals and organic compounds.

Due to the numerous biotechnological applications of laccase enzyme, it is essential to know the influence of different agents usually present in the natural environment on its enzymatic action, especially for in situ treatment technologies. In the present work, a simple and rapid method to determine the inhibitory or inducer effect of different compounds on laccase activity was developed. The compounds tested were copper-chelating agents and heavy metals. It was found that using syringaldazine as a substrate, all copper-chelating agents (except EDTA) highly inhibited laccase activity (around 100%) at an inhibitor concentration lower than 20 mM. Moreover, 40% of inhibition, which was detected at a concentration of 20 mM for both Cd(2+) and Cu(2+) increased with concentration until nearly complete inhibition at 80 mM.