Acute administration of methionine and/or methionine sulfoxide impairs redox status and induces apoptosis in rat cerebral cortex

Metabolic Brain Disease - High plasma levels of methionine (Met) and its metabolites such as methionine sulfoxide (MetO) may occur in several genetic abnormalities. Patients with hypermethioninemia...     

Oxidative stress in plasma from maple syrup urine disease patients during treatment

Maple Syrup Urine Disease (MSUD) is an autossomal recessive metabolic disorder caused by a deficiency of branched-chain α-keto acid dehydrogenase complex activity leading to accumulation of the branched-chain amino acids leucine, isoleucine and valine and their corresponding branched-chain α-keto acids. Affected patients usually present hypoglycemia, ketoacidosis, convulsions, poor feeding, coma, psychomotor delay and mental retardation. Considering that the pathophysiology of MSUD is still poorly understood, in this study we evaluated some parameters of oxidative stress, namely thiobarbituric acid-reactive substances (TBARS), total antioxidant reactivity (TAR) and total antioxidant status (TAS) in plasma from treated MSUD patients presenting high and low plasma leucine levels. We verified a significant increase of TBARS (lipid peroxidation) and a decrease of TAR (capacity to rapidly react with free radicals) in plasma from treated MSUD patients with low and with high plasma levels of leucine compared to the control group. It was also verified that TAS (quantity of tissue antioxidants) was not altered in plasma from treated MSUD patients with low and high blood leucine levels. Finally, we found no correlation between leucine, valine and isoleucine levels with the various parameters of oxidative stress. These results are indicative that increased lipid oxidative damage and decreased antioxidant defenses occur in plasma of MSUD patients and that the accumulating branched-chain amino acids are probably not directly associated to oxidative stress in this disorder.     

Usefulness and limitations of rapid urine dipstick testing for joint-fluid analysis. Prospective single-center study of 98 specimens

ObjectiveTo evaluate the diagnostic performance of rapid urine reagent strip testing of joint fluid in separating mechanical from inflammatory disease.MethodsIn a prospective single-center 12-month study of joint fluid specimens, leukocyte esterase reagent strip testing (LERST) was compared to leukocyte counts used as the reference standard. Leukocyte counts greater than 2000/mm³ were taken to indicate inflammation. Reproducibility of LERST was evaluated by testing 73 specimens twice and computing Cohen's kappa coefficient.ResultsNinety-eight joint fluid specimens (26 with mechanical and 72 with inflammatory characteristics) were evaluated. LERST had 79.2% sensitivity, 92.3% specificity, 96.6% positive predictive value, 61.5% negative predictive value, a positive likelihood ratio of 10.3, and a negative likelihood ratio of 0.23. The kappa coefficient was 0.70 (0.53–0.87). Two negative LERSTs a few minutes apart had 80% negative predictive value and a negative likelihood ratio of 0.08.ConclusionLERST of joint fluid is a rapid means of satisfactorily separating mechanical from inflammatory joint fluids.     

Inefficacy of infliximab in primary Sjögren's syndrome: results of the randomized, controlled Trial of Remicade in Primary Sjögren's Syndrome (TRIPSS)

OBJECTIVE: There is no effective treatment for patients with primary Sj?gren's syndrome (SS). Since tumor necrosis factor alpha (TNF alpha) could be a key element in the pathogenesis of primary SS, we conducted a multicenter, randomized, double-blind, placebo-controlled trial to evaluate the effect of infliximab in primary SS. METHODS: A total of 103 patients with primary SS were randomly assigned to receive infliximab infusions (5 mg/kg) or placebo at weeks 0, 2, and 6 and were followed up for 22 weeks. All patients fulfilled the new American-European Consensus Group criteria for SS and had active disease as assessed by values >50 mm on 2 of 3 visual analog scales (VAS) (0-100 mm) that evaluated joint pain, fatigue, and buccal, ocular, skin, vaginal, or bronchial dryness. A favorable overall response was defined as the patient having > or =30% improvement between weeks 0 and 10 in the values on 2 of the 3 VAS. Secondary end points were values on each VAS separately, the number of tender and swollen joints, the basal salivary flow rate, results of the Schirmer test for lacrimal gland function, the focus score on labial salivary gland biopsy, the level of C-reactive protein, and the erythrocyte sedimentation rate evaluated at weeks 0, 10, and 22, as well as quality of life evaluated by use of the generic Short Form 36 questionnaire administered at weeks 0, 10, and 22. RESULTS: At week 10, 26.5% of patients receiving placebo and 27.8% of patients treated with infliximab had a favorable overall response (P = 0.89), and at week 22, 20.4% of the placebo group and 16.7% of the infliximab group had a favorable response (P = 0.62). In addition, the 2 groups did not differ in any of the secondary end points over the 22 weeks of the trial. Severe adverse events reported in the infliximab group did not differ from those observed in previous studies. CONCLUSION: This randomized, double-blind, placebo-controlled study of an anti-TNF agent did not show any evidence of efficacy of infliximab in primary SS.     

Multiplexed barcoded CRISPR-Cas9 screening enabled by CombiGEM

The orchestrated action of genes controls complex biological phenotypes, yet the systematic discovery of gene and drug combinations that modulate these phenotypes in human cells is labor intensive and challenging to scale. Here, we created a platform for the massively parallel screening of barcoded combinatorial gene perturbations in human cells and translated these hits into effective drug combinations. This technology leverages the simplicity of the CRISPR-Cas9 system for multiplexed targeting of specific genomic loci and the versatility of combinatorial genetics en masse (CombiGEM) to rapidly assemble barcoded combinatorial genetic libraries that can be tracked with high-throughput sequencing. We applied CombiGEM-CRISPR to create a library of 23,409 barcoded dual guide-RNA (gRNA) combinations and then perform a high-throughput pooled screen to identify gene pairs that inhibited ovarian cancer cell growth when they were targeted. We validated the growth-inhibiting effects of specific gene sets, including epigenetic regulators KDM4C/BRD4 and KDM6B/BRD4, via individual assays with CRISPR-Cas–based knockouts and RNA-interference–based knockdowns. We also tested small-molecule drug pairs directed against our pairwise hits and showed that they exerted synergistic antiproliferative effects against ovarian cancer cells. We envision that the CombiGEM-CRISPR platform will be applicable to a broad range of biological settings and will accelerate the systematic identification of genetic combinations and their translation into novel drug combinations that modulate complex human disease phenotypes.New therapeutic strategies are needed to treat complex human diseases. Because disease phenotypes are often regulated by interwoven genetic networks, exploiting combination therapy to target multiple pathways, as opposed to only single ones, can enhance treatment efficacy (1). However, discovering effective combination therapies for human diseases is challenging with existing methods, due to the cost, effort, and labor required to construct and analyze each combination (2). For example, the National Cancer Institute tested ∼5,000 pairwise combinations of 100 cancer drugs against the NCI-60 panel in a study that took 2 y and cost about USD $4 million (3). Thus, there is a need for technological advances to accelerate the identification of effective combinatorial therapies. Here, we used our combinatorial genetics en masse (CombiGEM)-CRISPR platform to perform rapid pooled screening of pairwise genetic knockouts against genes coding for epigenetic regulators and then translated our screen hits into drug combinations against human ovarian cancer cells.CRISPR-Cas9 technology has been used for large-scale genetic perturbation screens with single-guide RNA (sgRNA) libraries for gene knockouts (4–7), repression, and activation (8, 9). Despite its simplicity for multiplexed genetic perturbations (10–12), new methods are needed to enable high-throughput CRISPR-Cas9–based screening with combinatorial sets of guide RNAs (gRNAs), which would be broadly useful for studying combinatorial gene functions in multigenic phenotypes and diseases. By using CombiGEM-based DNA assembly (13, 14), we developed a strategy for the simple and efficient assembly of barcoded combinatorial gRNA libraries. These libraries can be delivered into human cells by lentiviruses to create genetically ultradiverse cell populations harboring unique gRNA combinations that can be tracked via barcode sequencing in pooled assays. This strategy, termed CombiGEM-CRISPR, uses one-pot cloning steps to enable the assembly of combinatorial gRNA libraries, thus simplifying and accelerating the workflow toward systematic analysis of combinatorial gene functions.     

Continuation of treatment with infliximab in ankylosing spondylitis: 2-yr open follow-up

OBJECTIVE: To evaluate the continuation and safety of treatment with infliximab in ankylosing spondylitis (AS) over a 2-yr period. METHODS: This study was an open, observational, 2-yr extension study of an open-label study of three induction infusions of infliximab in refractory AS. The fourth infusion was performed only in case of relapse. Thereafter, infliximab was to be administered as needed according to the rheumatologist's opinion; however, for some patients, infusions were performed systematically. RESULTS: None of the 50 recruited patients was lost to follow-up. Thirteen patients (26%) interrupted their treatment by infliximab: four for inefficacy, seven for adverse events, of which four were for allergic reactions to the infusion, and two for other reasons. For all of the 46 patients who had had three infusions judged efficacious and well tolerated, a fourth infusion was performed because of a flare of the disease, after a mean interval of 20.3+/-9.9 weeks (range 7.3-57.9). Over the 24 months, the mean interval between infusions was 11.6+/-9.0 weeks. This interval was longer when patients were treated only as needed (mean 14.3+/-12.1 weeks) than systematically (mean 9.8+/-5.7 weeks). Side-effects were similar to those noted in shorter-term studies; seven patients suffered serious adverse events. There were no deaths, no malignancies and no tuberculosis. CONCLUSION: This study confirms the long-term treatment continuation of infliximab in AS, and shows an acceptable safety profile. It appears that for some patients the disease can be controlled with long intervals between infusions; these findings warrant further studies.     

The kinetics of the visible growth of a primary melanoma reflects the tumor aggressiveness and is an independent prognostic marker: a prospective study

Primary melanoma (MM) could be a good model to test an intuitive concept: a cancer that is growing fast in its early phase is likely to have a high aggressiveness. Since MMs are visible tumors, many patients can provide information to indirectly assess the kinetics of their lesion. A prospective study was designed to assess if the kinetics of the visible growth of a primary MM, as described by the patient, could be a noninvasive prognostic marker. The ratio of MM thickness to delay between MM appearance and MM removal was used as a surrogate value for the kinetics of the MM growth. To assess the delay between MM appearance and removal, 362 patients with self-detected invasive MM fulfilled a detailed questionnaire, which provided 2 types of estimations of this delay and thus 2 melanoma kinetics indexes (MKI and MKI*). After a median follow-up of 4 years, univariate and multivariate analyses assessed whether relapse-free survival was linked to MKI or MKI*. MKI was significantly predictive of relapse-free survival (HR = 1.84 [1.51-2.25]) and relapse at 1 year (RR = 2.93 [1.84-4.69]), independently from Breslow thickness. MKI was retained in multivariate prognostic models, just after thickness and before other usual markers. MKI* was also a significant independent risk marker, although less predictive. In this model, the initial growth kinetics of a cancer reflects its aggressiveness and a high index predicts a short-term relapse. The "subjective" data obtained from patients about their MM history, although usually neglected, can thus provide a better prognostic marker than many "objective" tests.     

Analysis of TNFalpha microsatellites in 35 patients with primary Sjögren's syndrome

OBJECTIVES: Although the cause of Sj?gren's syndrome remains unknown, many arguments suggest a role for both environmental and genetic factors. An association with HLA molecules has been established. Other genes on the short arm of chromosome 6 may be involved, most notably the TNF gene, which may be pivotal in the development of the epithelial lesions. METHODS: We investigated TNFalpha microsatellites in 35 patients with primary Sjogren's syndrome and in 146 healthy controls. RESULTS: The frequency of the TNFalpha10 allele showed a non-significant increase in the Sj?gren's disease group (28.6% vs 15.8%; P = NS). We found significant increases when we considered only those Sj?gren's disease patients with joint manifestations (N = 24; 37.5% vs 15.7%; P < 0.05) or only those with anti-Ro(SSA) antibodies (N = 10; 50% vs 15.7%; P < 0.05). CONCLUSION: Our data support a role for the TNFalpha10 allele in primary Sj?gren's syndrome, particularly those forms with joint symptoms and anti-Ro(SS-A) antibodies.     

First prospective study of the recognition process of melanoma in dermatological practice

BACKGROUND: Early detection is crucial to improve melanoma prognosis. Different diagnostic guides such as the ABCD rule (asymmetry [A], irregularity of borders [B], unevenness of distribution of color [C], and diameter [D]) have been proposed to identify melanoma, but their efficacy in real life is questionable. We investigated the recognition process of melanoma by dermatologists to use as a model to improve self-detection in the general population and to train students and general practitioners. OBJECTIVES: To understand the major principles of the recognition process of nevi and melanoma unconsciously used by dermatologists. DESIGN: Prospective survey recording the immediate perceptions of dermatologists of the morphologic features of the lesion and intuitive diagnostic opinion about 4036 consecutive resected nevi and melanoma. SETTING: One hundred thirty-five volunteer dermatologists in their daily practices. MAIN OUTCOME MEASURES: Perceptions of the image best explaining the diagnostic opinion and best predicting the final diagnosis by univariate and multivariate analysis. RESULTS: The immediate diagnostic opinion of the dermatologist is mainly explained by an unconscious reference to the overall pattern compared with the common nevi, but also compared with the other nevi of the individual (the "ugly duckling sign"). The dermatologist's ability to discriminate between nevi and melanoma relies on the assessment of the overall pattern, the ugly duckling sign, and the knowledge of a recent change. A separate or combined analysis of individual morphologic criteria such as ABCD does not seem to play a major role in this recognition process. CONCLUSIONS: Persons most skilled at the clinical detection of melanoma seem to unconsciously rely on cognitive (overall pattern) and comparative (ugly duckling sign) processes rather than an algorithm of morphologic criteria (ABCD). These concepts could be tested in the medical training of general practitioners and education of the general population, where they might be more efficient than algorithms such as the ABCD criteria.     

The genetic basis for systemic lupus erythematosus

Genetic factors play a major role in the development of lupus. More than 5% of cases are familial, and the concordance rate between identical twins is 40%. Genetic studies in mice suggest a complex mechanism of transmission involving interactions among several susceptibility genes and, probably, protective genes. Genetic studies in humans have identified nearly 50 chromosomal areas possibly involved in lupus transmission. Significant linkage has been found for at least six regions, two on chromosome 1, one near the HLA region on chromosome 6, and three on chromosomes 2, 4, and 16, respectively. Many candidate genes have been identified based on their location or possible pathogenic effects. Specific characteristics of the HLA region, as well as complement factor deficiencies, may promote nuclear antigen presentation, thereby triggering autoantibody production. The genetic polymorphism of cytokines and, perhaps, of the T-cell receptor (TCR) may contribute to deregulate lymphocyte activity. The polymorphism of the Fc receptors of immunoglobulins may affect immune complex clearance, thereby promoting tissue damage. Further genetic studies are needed to enrich the fund of knowledge on lupus and to identify new targets for treatment.