Mannose-binding lectin-low genotypes are associated with milder systemic and immunological disease expression in primary Sjögren's syndrome.

OBJECTIVE: To investigate the association of mannose-binding lectin (MBL)-low genotypes with the clinical and immunological expression of primary SS. METHODS: Eighty-one patients with primary SS who fulfilled the 2002 classification criteria were included in the study. MBL2 polymorphisms were investigated by sequence-based DNA typing of the promoter and exon 1. Genotypes 0/0, 0/XA or XA/XA were considered as MBL-low and XA/A, A/0 and A/A as MBL-sufficient. Control groups included 46 patients who exclusively fulfilled the 1993 SS criteria, 114 SLE patients and 104 healthy individuals. RESULTS: Twelve (15%) SS patients had MBL-low genotypes, of whom six (7%) had genotype 0/XA, five (6%) had genotype 0/0 and one (1%) had genotype XA/XA. A higher prevalence of the XA/A genotype (32 vs 17%, P = 0.01) was found in primary SS patients in comparison with SLE patients. No patient with primary SS carrying MBL-low genotypes had purpura, glomerulonephritis or neurological involvement (0 vs 29%, P = 0.025). Immunologically, patients carrying MBL-low genotypes had a lower frequency of anti-Ro/SS-A antibodies (17 vs 55%, P = 0.014), anti-La/SS-B antibodies (8 vs 48%, P = 0.009) and low C4/C3 levels (0 vs 32%, P = 0.016). No patient with primary SS carrying the homozygous MBL-deficient genotype 0/0 had anti-Ro/SS-A or anti-La/SS-B antibodies, low C3/C4 levels or circulating cryoglobulins. CONCLUSION: SS patients with MBL-low genotypes have a less pronounced systemic and immunological disease expression in comparison with those carrying MBL-sufficient genotypes. In primary SS, MBL deficiency may represent a protective factor against the development of more aggressive autoimmune damage.

Lipidomics reveals insights on the biological effects of copper oxide nanoparticles in a human colon carcinoma cell line.

Engineered nanomaterials have unique properties compared to their bulk counterparts. Copper oxide nanoparticles (CuO NPs) are one example of nanomaterials used in a wide range of consumer products due to their conductivity and biocidal properties. While CuO NPs can induce toxicity in various organisms, their interactions with different organisms and how they affect cellular homeostasis is yet to be fully understood. In this work, the toxicity of CuO NPs was evaluated in different human cell lines (colorectal carcinoma, cervical cancer, embryonic kidney, and lung fibroblast), showing a dose-dependent toxicity. An untargeted lipidomics approach using liquid chromatography-quadrupole time of flight mass spectrometry was employed in a human colon carcinoma cell line to investigate the impact of CuO NP exposure at the cellular level. A 24 h CuO NP exposure at 2.5 and 5 µg mL-1 resulted in upregulation of different metabolites: triacylglycerols, phosphatidylcholines, and ceramides accumulated. The most profound increase in a dose-dependent manner was observed in ceramides, specifically in C18:0, C18:1, and C22:0 species, with up to ∼10 fold accumulations. Further experiments suggested that activation of autophagy and oxidative stress could be responsible for the toxicity observed in these cell lines. Increases in the level of glutathione oxide (∼7 fold) also supported the activation of oxidative stress upon CuO NP treatment. Based on the changes in different metabolites induced by CuO NP exposure and previous studies from our laboratory, we propose that autophagy and oxidative stress could play a role in CuO NP-induced toxicity.

A mutation in mitochondrial 12S rRNA, A827G, in Argentinean family with hearing loss after aminoglycoside treatment.

Mutations in mitochondrial DNA (mtDNA) have been found to be associated with sensorineural hearing loss. We report the clinical, genetic, and molecular characterization of one Argentinean family with aminoglycoside-induced impairment in two of their members. Clinical evaluation revealed the variable phenotype of hearing impairment including audiometric configuration in these subjects. Mutational analysis of the mtDNA in these pedigrees showed the presence of homoplasmic 12S rRNA A827G mutation, which has been associated with hearing impairment. The A827G mutation is located at the A-site of the mitochondrial 12S rRNA gene which is highly conserved in mammals. It is possible that the alteration of the tertiary or quaternary structure of this rRNA by the A827G mutation may lead to mitochondrial dysfunction, thereby playing a role in the pathogenesis of hearing loss and aminoglycoside hypersensitivity. However, incomplete penetrance of hearing impairment indicates that the A827G mutation itself is not sufficient to produce clinical phenotype.

siRNA-mediated AML1/MTG8 depletion affects differentiation and proliferation-associated gene expression in t(8;21)-positive cell lines and primary AML blasts.

The chromosomal translocation t(8;21) is associated with 10-15% of all cases of acute myeloid leukaemia (AML). The resultant fusion protein AML1/MTG8 interferes with haematopoietic gene expression and is an important regulator of leukaemogenesis. We studied the effects of small interfering RNA (siRNA)-mediated AML1/MTG8 depletion on global gene expression in t(8;21)-positive leukaemic cell lines and in primary AML blasts using cDNA arrays, oligonucleotide arrays and real-time reverse transcription-polymerase chain reaction (RT-PCR). Suppression of AML1/MTG8 results in the increased expression of genes associated with myeloid differentiation, such as AZU1, BPI, CTSG, LYZ and RNASE2 as well as of antiproliferative genes such as IGFBP7, MS4A3 and SLA both in blasts and in cell lines. Furthermore, expression levels of several genes affiliated with drug resistance or indicative of poor prognosis AML (BAALC, CD34, PRG2, TSPAN7) are affected by AML1/MTG8 depletion. In conclusion, siRNA-mediated suppression of AML1/MTG8 cause very similar changes in gene expression pattern in t(8;21)-positive cell lines and in primary AML blasts. Furthermore, the results suggest that the specific targeting of AML1/MTG8 function may be a promising approach for complementing existing treatment strategies.

A randomized trial comparing two corticosteroid regimens combined with mycophenolate mofetil and cyclosporine for prevention of acute renal allograft rejection.

INTRODUCTION: The launching of mycophenolate mofetil (MMF) has reduced the incidence of acute rejection episodes. We sought to evaluate the efficacy of decreasing the steroid dose. MATERIALS AND METHODS: This was a quasiexperimental, randomized, prospective trial. We enrolled 150 patients who received de novo renal transplantations from living or cadaveric donors, fulfilling the screening criteria. Patients were randomized to one of the following two arms: (A) MMF at a 2 g/d dose, cyclosporine (CsA) at a dose necessary to achieve target levels, and corticosteroids at the usual doses; (B) MMF at a 2 g/d dose, CsA at a dose necessary to achieve target levels, and corticosteroids at doses 50% lower than those of group A. RESULTS: Group A included 72 (48%) and group B, 78 patients (52%). There were no differences among the variables: leukopenia occurred in 11 patients in group A, and five patients in group B. Complications occurred in 67.4% (56) of group A, but only 32.6% (27) were related to infections. One case of urinary infection occurred in group B, while six occurred in group A. There was one case of acute rejection in group A, and none in group B. One graft loss occurred in group A. There were no differences in the remaining variables under study. DISCUSSION: The results showed an increased complication rate related to receiving usual steroid doses. There was no increase in acute rejection episodes among patients receiving 50% of the usual steroid dose.

Orthotopic Liver Transplantation in an Adult With Biliary Atresia, Situs Inversus, and Inferior Cava Vein Absence: A Case Report.

BACKGROUND: We report the case of a 34-year-old man who underwent Kasai portoenterostomy for biliary atresia at 6 weeks of age. In 2011, pulmonary hypertension was diagnosed and he began treatment with sildenafil. In 2012, he presented with an episode of upper gastrointestinal bleeding secondary to esophageal varices resistant to treatment. Later, he exhibited liver dysfunction. He was included on the waiting list for transplantation on May 29, 2013, with a Model for End-stage Liver Disease score of 24. METHODS: He underwent liver transplantation with an isogroup graft from a brain dead donor on June 9, 2013. Native hepatectomy was laborious owing to important collateral circulation and adhesions after previous operations, which had injured loops of the small bowel (SB). Orthotopic implantation was accomplished with direct anastomosis of the upper liver cava vein to the right atrium of the receiver. Portal and arterial anastomoses were performed as usual. Biliary reconstruction surgery by hepatojejunostomy was delayed 24 hours owing to SB loops injuries. RESULTS: Graft viability was confirmed by normal hepatic function. Postoperative complications included abdominal compartment syndrome treated by decompressing laparotomy, severe pulmonary alveolar hemorrhage resolved with artery embolization and endotracheal intubation, intraabdominal abscess requiring percutaneous drain, and stroke requiring long-term rehabilitation. He is currently asymptomatic, presents normal graft function, and receives sildenafil because of pulmonary hypertension. CONCLUSIONS: The association of situs inversus and biliary atresia is low. There is no consensus on the optimal operative approach to liver transplantation. An individualized assessment and multidisciplinary patient management are required.

Time course of biochemical and immunohistological alterations during experimental allergic encephalomyelitis.

A comprehensive biochemical, immunological and histological study was undertaken during different stages of experimental allergic encephalomyelitis (EAE). Wistar rats with EAE induced by sensitization with bovine myelin showed a maximum decrease of body weight 14-16 days post-inoculation (dpi), coincident with the appearance of the paralysis symptom (acute period). Quantitation of some brain components indicated a temporal dissociation among the alterations observed. The higher diminution of myelin basic protein (MBP) occurred at 6 dpi and then increased to reach 21 dpi, a normal value. Also, the activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase was reduced by 40% with respect to control animals only at 6 dpi. The total lipid content was normal; however, among the individual lipids, sulfatides were principally degraded during the acute stage but the amount of cerebrosides was decreased during the recovery period (29-40 dpi). Free cholesterol was similar in both groups of animals, whereas cholesterol esters were detected in EAE animals from 14 to 40 dpi. Central nervous system meningeal and parenchymal infiltration with mononuclear cells was recognized principally at 14 dpi, but some of cells were still present at 40 dpi. Deposits of immunoglobulins in the infiltrated regions as well as in spinal cord motor neurons were observed among 14-29 dpi. Total circulating antibodies to MBP began to increase at 14 dpi, reaching a plateau at 21 dpi and then maintaining this value until 40 dpi. However, the population of anti-MBP antibodies that also recognizes the neuronal protein synapsin was only present at 14 dpi. The present results suggest that the neurological symptoms can be related to some early changes in the myelin membrane followed by alterations involving neuronal structures. The existence of immunological factors against some epitopes in MBP that also recognize a synaptosomal protein might account, at least in part, for the axonal damage and disruption of the normal interneuronal activity in EAE and lead together with the alterations in some specific myelin constituents and the concomitant CNS inflammatory process to the observed hindlimb paralysis.

[Effects of sodium saccharin on the tracheal epithelium of mice]. / Effecto de la sacarina de sodio sobre el epitelio traqueal del ratón.

The present study evaluated the effect of sodium saccharin on mouse tracheal epithelium, in relation to its possible structural alterations. Mice of the C3H strain were fed with standard pellets supplemented with sodium saccharin for 180 days. At that time the mice were sacrificed and their trachea were processed for transmission electronic microscopy. We demonstrated that sodium saccharin produces alterations in cellular surface cilia, with cytoplasmic excrescences and ciliary malformations. These results suggest that sodium saccharin is not an innocuous sweetener and that it may cause structural alterations in epithelial tissues.

[Sodium saccharin effect on the mice large intestine]. / Efecto de la sacarina de sodio en el intestino grueso del ratón.

Sodium saccharin has found to be a tumoral promoter in the rat's bladder epithelium, property not demonstrated in humans. Nevertheless, at present there's no references on the possible alterations produced by sodium saccharin in the epithelium of the mice colon. In this work we describe the alterations produced by low doses of sodium saccharin in the epithelium of the mice colon. The changer produced by sodium saccharin consist in pleomorphic microvill with variations of form, length diameter and curvature and demonstrate by transmission electron microscopy.

Pontin is a critical regulator for AML1-ETO-induced leukemia.

The oncogenic fusion protein AML1-ETO, also known as RUNX1-RUNX1T1 is generated by the t(8;21)(q22;q22) translocation, one of the most frequent chromosomal rearrangements in acute myeloid leukemia (AML). Identifying the genes that cooperate with or are required for the oncogenic activity of this chimeric transcription factor remains a major challenge. Our previous studies showed that Drosophila provides a genuine model to study how AML1-ETO promotes leukemia. Here, using an in vivo RNA interference screen for suppressors of AML1-ETO activity, we identified pontin/RUVBL1 as a gene required for AML1-ETO-induced lethality and blood cell proliferation in Drosophila. We further show that PONTIN inhibition strongly impaired the growth of human t(8;21)(+) or AML1-ETO-expressing leukemic blood cells. Interestingly, AML1-ETO promoted the transcription of PONTIN. Moreover, transcriptome analysis in Kasumi-1 cells revealed a strong correlation between PONTIN and AML1-ETO gene signatures and demonstrated that PONTIN chiefly regulated the expression of genes implicated in cell cycle progression. Concordantly, PONTIN depletion inhibited leukemic self-renewal and caused cell cycle arrest. All together our data suggest that the upregulation of PONTIN by AML1-ETO participate in the oncogenic growth of t(8;21) cells.

Leukemic fusion genes MLL/AF4 and AML1/MTG8 support leukemic self-renewal by controlling expression of the telomerase subunit TERT.

MLL/AF4 and AML/MTG8 represent two leukemic fusion genes, which are most frequently found in infant acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML), respectively. We examined the influence of MLL/AF4 and AML1/MTG8 fusion genes on the expression of TERT coding for the telomerase protein subunit, and subsequently telomerase activity in t(4;11)-positive ALL and t(8;21)-positive cell lines, respectively. MLL/AF4 suppression diminished telomerase activity and expression of TERT. Blocking pro-apoptotic caspase activation in conjunction with MLL/AF4 knockdown enhanced the inhibition of TERT gene expression, which suggests that MLL/AF4 depletion does not reduce TERT expression levels by inducing apoptosis. Knockdown of HOXA7, a direct transcriptional target of MLL/AF4 fusion gene, caused a reduction of telomerase and TERT to an extent similar to that observed with MLL/AF4 suppression. Chromatin immunoprecipitation of SEM cells, using ectopically expressed FLAG-tagged Hoxa7, indicates HOXA7 binding site in the TERT promoter region. Furthermore, suppression of the AML1/MTG8 fusion gene was associated with severely reduced clonogenicity, induction of replicative senescence, impaired TERT expression and accelerated telomere shortening. We thus present findings that show a mechanistic link between leukemic fusion proteins, essential for development and maintenance of leukemia, and telomerase, a key element of both normal and malignant self-renewal.

Previous antimalarial therapy in patients diagnosed with lupus nephritis: influence on outcomes and survival.

The aim of this study was to analyze the effect of exposure to antimalarial drugs at diagnosis of lupus nephritis on the outcome of the disease, especially renal failure, comorbid processes, and survival. We analyzed a cohort of 206 consecutive patients with biopsy-proven lupus nephritis. Renal biopsies were categorized according to the classification proposed by the ISN/RPS in 2003. Exposure to antimalarial drugs (chloroquine and hydroxychloroquine) was defined as the use of these drugs before the diagnosis of lupus nephritis independent of dose and duration. Fifty-six (27%) patients had received antimalarials before the diagnosis of lupus nephritis. During the follow-up, these patients had a lower frequency of creatinine values >4 mg/dL (2% vs 11%, P = 0.029) and end-stage renal failure (2% vs 11%, P = 0.044) in comparison with those never treated with antimalarials. Patients exposed to antimalarials also had a lower frequency of hypertension (32% vs 50%, P = 0.027), infections (11% vs 29%, P = 0.006), and thrombotic events (5% vs 17%, P = 0.039). Twenty patients (10%) died during the study period. Patients exposed to antimalarials had a lower mortality rate at the end of the follow-up (2% vs 13% for those not exposed to antimalarials, P = 0.029). Multivariate analysis identified thrombosis and infections as statistically significant independent variables. Kaplan-Meier plots showed a lower rate of end-stage renal failure (log rank = 0.04) in patients exposed to antimalarials. In conclusion, exposure to antimalarials before the diagnosis of lupus nephritis was negatively associated with the development of renal failure, hypertension, thrombosis and infection, and with a better survival rate at the end of the follow-up. This, together with other published data, suggests that antimalarials should be considered a mandatory therapeutic option in all patients diagnosed with systemic lupus erythematosus.

beta-Thalassemia and hemoglobin types in Argentina: determination of most frequent mutations.

In order to know the spectrum of beta-thalassemia alleles and other mutations affecting the beta-globin gene, we analyzed the hemoglobin abnormalities in 24 patients from the Province of Cordoba in Argentina. Molecular screening of samples was performed by the polymerase chain reaction (PCR), using six sets of oligonucleotides to amplify fragments encompassing the whole beta-globin coding region and splice junctions, as well as the promoter and 3' untranslated regions. The altered fragments were determined by denaturing gradient gel electrophoresis (DGGE), and the corresponding mutations were identified by restriction enzyme analysis or by direct sequencing of PCR products. Using this approach, three different beta-thalassemia mutations were detected, codon 39 (C-->T), IVS-1-110 (G-->A), and IVS-1-1 (G-->A), and also the hemoglobin S trait. This is the first report of beta-thalassemia mutations described in Argentina. Our results show that these mutations are similar to those found in Spain and Italy, possibly due to the important Mediterranean migratory stream received in our country, and could be important for prenatal diagnosis of these diseases in Cordoba, Argentina.

Optimised helper virus-free production of high-quality adeno-associated virus vectors.

BACKGROUND: Clinical development of adeno-associated virus (AAV) requires standardised, safe, efficient and scalable procedures for the manufacture of the rAAV vector, including production, purification and testing. Several strategies have been reported for the approach to the manufacturing problem. We report a helper virus-free process that produces high quality rAAV stocks. METHODS: rAAV were produced by triple transfection, a helper virus-free process. After lysis of the cells in the presence of nuclease, the rAAV produced were purified by HPLC through two ion-exchange columns in tandem followed by dialysis. rAAV stocks were thoroughly characterised for biological activity and for the presence of residual contaminants. The titer of infectious particles and of rep + particles was determined by dRA assay. Contaminating DNA and RNA were determined by fluorescent dye binding and real-time PCR. The protein content of the rAAV stocks was characterised by SDS-PAGE, ELISA test, Western blot and specific enzymatic assays for putative residual contaminating protein. The in vivo biological activity of the stocks was evaluated in mouse muscle. RESULTS: rAAV stocks obtained following this procedure elicit: 2-5 x 10(12) pp/ml; 3-6 x 10(10) ip/ml; < 10(3) rep + particles/ml; <0.3 mUeq/ml of residual benzonase activity; non-detectable Ad or beta-galactosidase proteins; <35 pg/ml of cellular genomic DNA; in vivo expression in mouse muscle without any immune reaction detected. CONCLUSIONS: This work demonstrates the possibility of producing purified high-quality rAAV free of helper virus. The procedure described in this paper is easily adaptable for large-scale production of clinical rAAV vectors.