Sulfur Interaction and Regeneration of CaMn0.775Ti0.125Mg0.1O2.9-δ Perovskite as Oxygen Carrier during Combustion of Sour Gas in a 500 Wth Chemical Looping Combustion Unit

In the present study, the performance of a CaMn0.775Ti0.125Mg0.1O2.9-δ perovskite used as an oxygen carrier to burn sour gas with different H2S concentrations (up to 3000 vppm) in a continuous 500 Wth chemical looping combustion (CLC) prototype was investigated. After 29 h of sour gas combustion, the combustion efficiency had dropped by 18% in comparison with the reference test without sulfur addition. The characterization of the used particles of the perovskite confirmed that the presence of sulfur in the fuel gas had a poisonous effect through the formation of undesired compounds, such as CaSO4. The reactivity with CH4 and oxygen uncoupling capacity decreased, which could explain the decrease in the combustion efficiency. Two regeneration processes, one at high temperature (1273 K) and another one at low temperature (773-873 K), were carried out in a batch fluidized bed reactor to remove the amount of sulfur accumulated in the oxygen carrier particles. The detection of appreciable amounts of gaseous sulfur-based compounds (SO2 and H2S) during the experimentation and the postcharacterization results obtained through different techniques such as X-ray diffraction, ultimate analysis, and thermogravimetric analysis confirmed the effectiveness of both processes. Finally, the feasibility of implementation of the regeneration processes in a commercial CLC unit was thoroughly analyzed.

Characterization of mutant versions of the R-RAS2/TC21 GTPase found in tumors

The R-RAS2 GTP hydrolase (GTPase) (also known as TC21) has been traditionally considered quite similar to classical RAS proteins at the regulatory and signaling levels. Recently, a long-tail hotspot mutation targeting the R-RAS2/TC21 Gln⁷² residue (Q72L) was identified as a potent oncogenic driver. Additional point mutations were also found in other tumors at low frequencies. Despite this, little information is available regarding the transforming role of these mutant versions and their relevance for the tumorigenic properties of already-transformed cancer cells. Here, we report that many of the RRAS2 mutations found in human cancers are highly transforming when expressed in immortalized cell lines. Moreover, the expression of endogenous R-RAS2^Q72L is important for maintaining optimal levels of PI3K and ERK activities as well as for the adhesion, invasiveness, proliferation, and mitochondrial respiration of ovarian and breast cancer cell lines. Endogenous R-RAS2^Q72L also regulates gene expression programs linked to both cell adhesion and inflammatory/immune-related responses. Endogenous R-RAS2^Q72L is also quite relevant for the in vivo tumorigenic activity of these cells. This dependency is observed even though these cancer cell lines bear concurrent gain-of-function mutations in genes encoding RAS signaling elements. Finally, we show that endogenous R-RAS2, unlike the case of classical RAS proteins, specifically localizes in focal adhesions. Collectively, these results indicate that gain-of-function mutations of R-RAS2/TC21 play roles in tumor initiation and maintenance that are not fully redundant with those regulated by classical RAS oncoproteins.

Hematopoietic Cells Influence Vascular Development in the Retina

Hematopoietic cells play a crucial role in the adult retina in health and disease. Monocytes, macrophages, microglia and myeloid angiogenic cells (MACs) have all been implicated in retinal pathology. However, the role that hematopoietic cells play in retinal development is understudied. The temporal changes in recruitment of hematopoietic cells into the developing retina and the phenotype of the recruited cells are not well understood. In this study, we used the hematopoietic cell-specific protein Vav1 to track and investigate hematopoietic cells in the developing retina. By flow cytometry and immunohistochemistry, we show that hematopoietic cells are present in the retina as early as P0, and include microglia, monocytes and MACs. Even before the formation of retinal blood vessels, hematopoietic cells localize to the inner retina where they eventually form networks that intimately associate with the developing vasculature. Loss of Vav1 lead to a reduction in the density of medium-sized vessels and an increased inflammatory response in retinal astrocytes. When pups were subjected to oxygen-induced retinopathy, hematopoietic cells maintained a close association with the vasculature and occasionally formed 'frameworks' for the generation of new vessels. Our study provides further evidence for the underappreciated role of hematopoietic cells in retinal vasculogenesis and the formation of a healthy retina.

Characterization of the spectrum of trivalent VAV1-mutation-driven tumors using a gene-edited mouse model

Mutations in the VAV1 guanine nucleotide exchange factor 1 have been recently found in peripheral T cell lymphoma and nonsmall‐cell lung cancer (NSCLC). To understand their pathogenic potential, we generated a gene‐edited mouse model that expresses a VAV1 mutant protein that recapitulates the signalling alterations present in the VAV1 mutant subclass most frequently found in tumours. We could not detect any overt tumourigenic process in those mice. However, the concurrent elimination of the Trp53 tumour suppressor gene in them drives T cell lymphomagenesis. This process represents an exacerbation of the normal functions that wild‐type VAV1 plays in follicular helper T cells. We also found that, in combination with the Kras oncogene, the VAV1 mutant version favours progression of NSCLC. These data indicate that VAV1 mutations play critical, although highly cell‐type‐specific, roles in tumourigenesis. They also indicate that such functions are contingent on the mutational landscape of the tumours involved.

The Rho guanosine nucleotide exchange factors Vav2 and Vav3 modulate epidermal stem cell function

It is known that Rho GTPases control different aspects of the biology of skin stem cells (SSCs). However, little information is available on the role of their upstream regulators under normal and tumorigenic conditions in this process. To address this issue, we have used here mouse models in which the activity of guanosine nucleotide exchange factors of the Vav subfamily has been manipulated using both gain- and loss-of-function strategies. These experiments indicate that Vav2 and Vav3 regulate the number, functional status, and responsiveness of hair follicle bulge stem cells. This is linked to gene expression programs related to the reinforcement of the identity and the quiescent state of normal SSCs. By contrast, in the case of cancer stem cells, they promote transcriptomal programs associated with the identity, activation state, and cytoskeletal remodeling. These results underscore the role of these Rho exchange factors in the regulation of normal and tumor epidermal stem cells.

Cancer-associated mutations in VAV1 trigger variegated signaling outputs and T-cell lymphomagenesis

Mutations in VAV1, a gene that encodes a multifunctional protein important for lymphocytes, are found at different frequencies in peripheral T‐cell lymphoma (PTCL), non‐small cell lung cancer, and other tumors. However, their pathobiological significance remains unsettled. After cataloguing 51 cancer‐associated VAV1 mutations, we show here that they can be classified in five subtypes according to functional impact on the three main VAV1 signaling branches, GEF‐dependent activation of RAC1, GEF‐independent adaptor‐like, and tumor suppressor functions. These mutations target new and previously established regulatory layers of the protein, leading to quantitative and qualitative changes in VAV1 signaling output. We also demonstrate that the most frequent VAV1 mutant subtype drives PTCL formation in mice. This process requires the concurrent engagement of two downstream signaling branches that promote the chronic activation and transformation of follicular helper T cells. Collectively, these data reveal the genetic constraints associated with the lymphomagenic potential of VAV1 mutant subsets, similarities with other PTCL driver genes, and potential therapeutic vulnerabilities.

Tomography of irregular rough particles using the error-reduction algorithm with multi-views interferometric particle imaging

This work reports the 3D reconstruction of a particle from a set of three simulated interferometric images of this particle (from three perpendicular angles of view). The reconstruction of each view from its corresponding interferometric pattern uses the error-reduction (ER) algorithm. The 3D reconstruction enables an estimation of the volume of the particle. The method is tested on a dendrite-like particle. An experimental demonstration of the technique is done using a digital micromirror device (DMD) that generates the interferometric images of "programmable" rough particles.

Distinct Roles of Vav Family Members in Adaptive and Innate Immune Models of Arthritis

Genetic evidence suggests that three members of the VAV family (VAV1, VAV2 and VAV3) of signal transduction proteins could play important roles in rheumatoid arthritis. However, it is not known currently whether the inhibition of these proteins protects against this disease and, if so, the number of family members that must be eliminated to get a therapeutic impact. To address this issue, we have used a collection of single and compound Vav family knockout mice in experimental models for antigen-dependent (methylated bovine serum albumin injections) and neutrophil-dependent (Zymosan A injections) rheumatoid arthritis in mice. We show here that the specific elimination of Vav1 is sufficient to block the development of antigen-induced arthritis. This protection is likely associated with the roles of this Vav family member in the development and selection of immature T cells within the thymus as well as in the subsequent proliferation and differentiation of effector T cells. By contrast, we have found that depletion of Vav2 reduces the number of neutrophils present in the joints of Zymosan A-treated mice. Despite this, the elimination of Vav2 does not protect against the joint degeneration triggered by this experimental model. These findings indicate that Vav1 is the most important pharmacological target within this family, although its main role is limited to the protection against antigen-induced rheumatoid arthritis. They also indicate that the three Vav family proteins do not play redundant roles in these pathobiological processes.

VAV2 signaling promotes regenerative proliferation in both cutaneous and head and neck squamous cell carcinoma

Regenerative proliferation capacity and poor differentiation are histological features usually linked to poor prognosis in head and neck squamous cell carcinoma (hnSCC). However, the pathways that regulate them remain ill-characterized. Here, we show that those traits can be triggered by the RHO GTPase activator VAV2 in keratinocytes present in the skin and oral mucosa. VAV2 is also required to maintain those traits in hnSCC patient-derived cells. This function, which is both catalysis- and RHO GTPase-dependent, is mediated by c-Myc- and YAP/TAZ-dependent transcriptomal programs associated with regenerative proliferation and cell undifferentiation, respectively. High levels of VAV2 transcripts and VAV2-regulated gene signatures are both associated with poor hnSCC patient prognosis. These results unveil a druggable pathway linked to the malignancy of specific SCC subtypes.

The Rho signalling pathway is frequently activated in squamous carcinomas. Here, the authors find that the Rho GEF VAV2 is over expressed in both cutaneous and head and neck squamous cell carcinomas and that at the molecular level VAV2 promotes a pro-tumorigenic stem cell-like signalling programme.

Determination of Thiabendazole in Fruit Juices by a New Monoclonal Enzyme Immunoassay

A competitive, indirect enzyme-linked immunosorbent assay (ELISA) for thiabendazole has been developed and applied to the analysis of fruit juices spiked with this fungicide. The immunoassay is based on a new monoclonal antibody derived from a hapten functionalized at the nitrogen atom in the 1-position of the thiabendazole structure. To our knowledge, such a structure has not been previously used to obtain antibodies to thiabendazole. The l50 value and the detection limit of the ELISA for standards were 0.2 and 0.05 ng/mL, respectively. Fruit juices were analyzed by diluting samples in assay buffer, without extraction or cleanup. Samples were not even centrifuged or filtered to remove fruit pulp. Under these conditions, the immunoassay was able to accurately determine thiabendazole down to 1 ng/mL in orange and grapefruit juices, down to 5 ng/mL in banana juice, and down to 20 ng/mL in apple and pear juices. Sensitivity differences of the ELISA were caused by the minimum dilution required by each juice to minimize matrix effects: 1/10 for orange and grapefruit juices, 1/50 for banana juice, and 1/100 for apple and pear juices. In an attempt to further increase the sensitivity of the immunoassay for matrixes showing the strongest interferences, apple and pear juices spiked with thiabendazole at low levels (1–20 ng/mL) were extracted with ethyl acetate before analysis. This simple procedure entailed a significant reduction of matrix effects, which in fact allowed us to determine accurately as low as 5 ng/mL thiabendazole in apple and pear juices. Irrespective of whether samples were analyzed by the direct dilution method or after extraction, the simplicity, sensitivity, and sample throughput of this monoclonal immunoassay makes it a very convenient method for the routine monitoring of thiabendazole residues in fruit juices.

Vagal afferents contribute to sympathoexcitation-driven metabolic dysfunctions

Multiple crosstalk between peripheral organs and the nervous system are required to maintain physiological and metabolic homeostasis. Using Vav3-deficient mice as a model for chronic sympathoexcitation-associated disorders, we report here that afferent fibers of the hepatic branch of the vagus nerve are needed for the development of the peripheral sympathoexcitation, tachycardia, tachypnea, insulin resistance, liver steatosis and adipose tissue thermogenesis present in those mice. This neuronal pathway contributes to proper activity of the rostral ventrolateral medulla, a sympathoregulatory brainstem center hyperactive in Vav3-/- mice. Vagal afferent inputs are also required for the development of additional pathophysiological conditions associated with deregulated rostral ventrolateral medulla activity. By contrast, they are dispensable for other peripheral sympathoexcitation-associated disorders sparing metabolic alterations in liver.

Regiospecific and Stereoselective Ene Reaction of the A-Ring Methylcyclohexene Moiety of Polycyclic Terpenoid Systems with Dimethyl Acetylenedicarboxylate

Polycyclic terpenoid compounds with a methylcyclohexene moiety at the A-ring, such as 1 and 7, give a regio- and stereoselective ene reaction when heated at low temperatures with dimethyl acetylenedicarboxylate. The structure and stereochemistry of the compound formed in the case of 1, e.g. 5, is determined by X-ray analysis.

The Jamaican Haemophilia Registry: Describing the burden of disease

INTRODUCTION

Jamaica has an estimated 200 persons with haemophilia (PWH), who face significant constraints in access to specialized haemophilia care, including access to clotting factor concentrates.

AIM

The aim of this paper is to establish the current burden of disease in PWH in Jamaica.

METHODS

PWH were enrolled through the University Hospital of the West Indies, Jamaica. The impact of haemophilia was assessed using a comprehensive battery of heath outcome measures that included the following: laboratory, clinical information and validated outcome measures of joint structure and function, activity, and health-related quality of life (HRQoL) to provide a health profile of the Jamaican haemophilia population.

RESULTS

In all, 45 PWH were registered (mean age: 29, range: 0.17-69 years), including 13 children (<18 years of age) and 32 adults. In this sample, 41 had haemophilia A (30 severe) and 4 had haemophilia B (3 severe); 10 patients with haemophilia A were inhibitor positive. The results indicate that adults with haemophilia in Jamaica have significant joint damage: mean Haemophilia Joint Health Score (HJHS) = 42.1 (SD = 17.3); moderate activity levels - mean Haemophilia Activities List (HAL) score = 64.8 (SD = 17.8); and low HRQoL scores - mean Haemo-QoL-A score = 62.3 (SD = 19.4). Results for children are also reported but should be interpreted with caution due to the small sample size.

CONCLUSIONS

There is a very high burden of disease in PWH in Jamaica. The health profiles reported in this paper are an essential first step in advocating for a multidisciplinary Comprehensive Care Program for assessment and care of PWH in Jamaica.

A Paradoxical Tumor-Suppressor Role for the Rac1 Exchange Factor Vav1 in T Cell Acute Lymphoblastic Leukemia

Rho guanine exchange factors (GEFs), the enzymes that stimulate Rho GTPases, are deemed as potential therapeutic targets owing to their protumorigenic functions. However, the understanding of the spectrum of their pathobiological roles in tumors is still very limited. We report here that the GEF Vav1 unexpectedly possesses tumor-suppressor functions in immature T cells. This function entails the noncatalytic nucleation of complexes between the ubiquitin ligase Cbl-b and the intracellular domain of Notch1 (ICN1) that favors ICN1 ubiquitinylation and degradation. Ablation of Vav1 promotes ICN1 signaling and the development of T cell acute lymphoblastic leukemia (T-ALL). The downregulation of Vav1 is essential for the pathogenesis of human T-ALL of the TLX⁺ clinical subtype, further underscoring the suppressor role of this pathway.

Comparing the burden of illness of haemophilia between resource-constrained and unconstrained countries: the São Paulo-Toronto Hemophilia Study

INTRODUCTION

Although the regular replacement of clotting factor concentrates (prophylaxis) has been well established as the standard of care for severe haemophilia, the high cost of factor concentrates has limited access to prophylaxis in countries with under-developed or developing economies.

AIMS

We studied the health gap that could be addressed by providing unlimited access to clotting factor concentrates with implementation of long-term prophylaxis initiated from an early age in life.

METHODS

We performed a cross-sectional study of a random, representative sample of boys with moderate and severe haemophilia at three haemophilia treatment centres in Sao Paulo, Brazil, and one centre in Toronto, Canada.

RESULTS

Canadian subjects were more often treated with prophylaxis, and began treatment at an earlier age. Fewer Canadian subjects had bleeds within the preceding 6 months (19 vs. 34, P = 0.003). Canadian subjects had lower (better) Pettersson radiographic scores (1.5 vs. 6.0, P = 0.0016), lower (better) Hemophilia Joint Health Scores (5.5 vs. 10.5, P = 0.0038), higher (better) Activity Scale for Kids scores (96.6 vs. 92.0, P = 0.033), more time spent in vigorous activity, and higher (better) social participation scores.

CONCLUSIONS

Our findings suggest that increasing access to clotting factor concentrates for young boys with severe haemophilia is a global imperative.

Pilot study of once-a-day prophylaxis for youth and young adults with severe haemophilia A

INTRODUCTION

Standard prophylaxis has been shown to be an effective treatment for severe haemophilia A. According to pharmacokinetic principles, daily factor infusions of smaller doses can maintain similar trough factor VIII (FVIII) levels, and perhaps the same protection as standard prophylaxis.

AIM

This multicentre study examined the feasibility of daily prophylaxis for youth and young adults with severe haemophilia A in Montreal and Toronto.

METHODS

Bleeding rates, joint status, quality of life and physical activity were monitored for 14 patients during this study. At baseline, subjects continued their regular treatment regimen and switched to daily prophylaxis after 4 months; nine had begun daily prophylaxis before enrolment. Additional visits occurred at 8 and 12 months which included a physical examination, inhibitor testing, HJHS and FISH assessments, the CHO-KLAT/Haemo-QoL-A and PDPAR. Treatment satisfaction was assessed using the Treatment Satisfaction Questionnaire for Medication ver.II and perceived difficulty questions at the end of study.

RESULTS AND CONCLUSIONS

There were no significant changes in quality of life except for concerns with the demanding daily infusion schedule. The number of bleeds did not statistically differ from the initial 4 months of the study to the last 8 months. Monthly bleeding rates from the year prior to the study and during the intervention phase were not statistically different. It was also found that daily prophylaxis used 24% less FVIII compared to standard prophylaxis. Taking all of this into account, we have found that providing daily prophylaxis is feasible and that it is feasible to prospectively study daily prophylaxis in youth and young adults.

Validity of the Portuguese CHO-KLAT in Brazil

INTRODUCTION

It is essential to assess the health-related quality of life outcomes of boys with haemophilia in Brazil. The Canadian Haemophilia Outcomes-Kids Life Assessment Tool (CHO-KLAT) was recently adapted for this population.

AIM

To test the construct validity of the Portuguese version of the CHO-KLAT.

METHODS

We recruited 50 boys, with moderate [factor VIII (FVIII) level 1-5%] or severe (FVIII level <1%) haemophilia, to participate in a descriptive study to establish a baseline understanding of the current status of boys with haemophilia in Brazil. All boys were required to complete the Brazilian CHO-KLAT and Brazilian Pediatric Quality of Life Inventory (PedsQL) by self-report. We examined the correlation between the CHO-KLAT and PedsQL scores to establish the construct validity of the Brazilian version of the CHO-KLAT.

RESULTS

We obtained CHO-KLAT and PedsQL data from 35 boys with severe haemophilia and 15 with moderate haemophilia. They ranged in age from 7.3 to 18.0 years, with a mean of 13.0 years. They reported a mean CHO-KLAT score of 72.3 (range = 44.1-93.9). The mean PedsQL score was 79.9 (range = 45.7-96.7), with physical health (mean of 83.9) being better than psychosocial health (77.8). The Pearson's correlation between CHO-KLAT and PedsQL was 0.47 respectively (P < 0.001). The CHO-KLAT had a moderate and inverse relationship with the degree to which they were bothered by their haemophilia (ρ = -0.53), while the PedsQL had a weaker relationship (ρ = -0.27).

CONCLUSION

The results confirm the validity of the Portuguese version of the CHO-KLAT. This measure is now available for clinical trials in boys with haemophilia in Brazil.

Risk factors for accidents among cocaine-dependent patient seeking treatment

Introduction

Accident rate have a high social cost. Cocaine consumption increases the risk of traffic crashes (Monras, 2011; Fierro, 2011). However, there is not extensively studies in addicts.

Objective

Compare and analyze the history of accidents and risk behaviors while driving in cocaine dependent patients (DC) and of other substances (OtherD).

Methods

One hundred and eighty-two patients seeking treatment since January 2014 to September 2015. Sociodemographic and accident-related variables were collected, also administered the MDBQ. Descriptive analysis and bivariate analysis using Chi-square test for categorical variables and Student t test was performed for quantitative.

Results

Of women, 30.3%, and 69.7% men, mean age 43.67 years (SD = 13). 65.6% currently driving or above. 45.2% DC vs. 54.8 DOther (35.6% alcohol, cannabis 8.3%, 5.8% opioid and 5.1% other drugs).

Comparing accident rate on the DC is a tendency to have suffered more accidents (χ2: 2.62 P=.072). Patients addicted to cocaine referred further potentially dangerous activities both under the influence of consumption (65.9% vs. 33.3%) and abstinence (41.7% vs. 12%).

As for the results of MDBQ, it has been detected that cocaine addicts show more errors and traffic violations. No differences in the lapses identified by patients of different groups.

Conclusion

Patients with cocaine dependence have more accidents, reduced risk perception and recognize more mistakes and traffic violations. Cocaine implies a high risk of road accidents and exposure to high-risk situations compared to the use of other substances.

References not available.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Location of the sciatic nerve at the popliteal fossa in the adult population: Relationship with gender and anthropometric data studied. Implications for daily practice

OBJECTIVE

To determine whether the location of the sciatic nerve (SN) at the popliteal fossa is related to anthropometric variables in the adult population, and to identify possible anatomical variations and their possible implications for clinical practice.

MATERIALS AND METHOD

Prospective observational study in elective ambulatory surgery patients. Patients were examined using ultrasound, looking at depth, laterality and distance at which the SN bifurcates at the level of the popliteal fossa. These measurements were linked to gender and the anthropometric data of the patients.

RESULTS

A total of 62 patients were included, with 124 measurements. A statistically significant association was found between SN depth and the diameter of the thigh measured at 10 cm from the popliteal crease (P<.001). Mean depth: 3.32 ± 0.8 cm, mean laterality: 1.43 ± 0.9 cm, mean SN bifurcation distance: 61.78 ± 12 mm and mean SN diameter: 7.45 ± 1.17 mm. There were no statistical differences when comparing the measured variables with the age and gender. Similar results were obtained between measurements when comparing both lower limbs in the same patient. There was no statistical difference between height and distance at which the SN bifurcates.

CONCLUSIONS

The depth and laterality of SN are independent of gender, weight and height. The depth at which the SN is located at the level of the popliteal fossa is related to the diameter of the thigh. The bifurcation of SN in popliteal fossa is not related to height.

Breath methane in functional constipation: response to treatment with Ispaghula husk

BACKGROUND

Colonic fermentation produces hydrogen (H2 ), and also produces methane (CH4 ) in subjects with methanogenic flora (M+). Methane production has been associated with chronic constipation (CC) and with changes in gut motility. To determine CH4 production in CC compared to controls, and to assess whether the therapeutic response to Ispaghula husk in CC differs between CH4 -producers and non-producers.

METHODS

Forty-eight patients with functional constipation or irritable bowel syndrome-constipation and 19 healthy age-and-sex-matched volunteers (HV) filled in a 1-week symptom diary and a dietary questionnaire. They then underwent a lactulose breath test (LBT) to measure H2 and CH4 production (peak and area under the time-concentration curve, AUC-) and a colonic transit time (CTT) assessment. In patients, measurements were repeated after a 4-week treatment with Ispaghula husk.

KEY RESULTS

Prevalence of M+ in patients was 60.5% vs 52.6% in HV (p = 0.37). Patients had significantly longer CTT and greater production of both H2 and CH4 during LBT. There was a significant correlation between CH4 production and CTT (r = 0.51; p = 0.07). Treatment response rate was similar for M+ and M- patients (58.3% vs 52.9%; p = 0.76) as were the increases in bowel movements and Bristol score, changes in abdominal discomfort and bloating. In M+, treatment reduced CTT (-10 ± 35 h; p = 0.029 vs baseline) and CH4 levels: peak CH4 (-13 ± 24 ppm; p = 0.014) and CH4 -AUC (-817 ± 3100 ppm/min; p = 0.04).

CONCLUSIONS & INFERENCES

Although CH4 production has been associated with CC pathophysiology, we found that CH4 status did not negatively affect the response to Ispaghula husk treatment. The measurement of CH4 levels as a biomarker tool for CC requires further appraisal.

[Cost-effectiveness analysis of aflibercept in combination with FOLFIRI in the treatment of patients with metastatic colorectal cancer]

OBJECTIVES

To estimate the incremental cost per life-year gained (LYG) of aflibercept in combination with FOLFIRI as second-line treatment in metastatic colorectal cancer (mCRC) patients previously treated with oxaliplatin.

METHODS

Based on clinical trial VELOUR results, a three-state Markov model (stable disease, progression and death) with 2-week cycle duration was designed. Transition to health state «progression» implied the interruption of second-line treatment and administration of a third-line treatment (post-second line chemotherapy). Cost estimation included disease management cost (pharmaceutical, adverse event management, administration costs, etc.). Both cost and outcomes were discounted (3% annually). Sensitivity analyses (SA) were performed to test model robustness.

RESULTS

Administration of aflibercept + FOLFIRI as second-line treatment provided 1.78 LYG (21 life-months gained). With FOLFIRI 1.43 LYG (17 months) were obtained. The cost of the clinical management of aflibercept + FOLFIRI implied an additional investment of Euros 13,564 compared with FOLFIRI for a lifetime horizon, being total costs for aflibercept + FOLFIRI of Euros 38,346, compared to Euros 24,782 with FOLFIRI. In the cost-effectiveness analysis Euros 38,931/LYG was obtained with aflibercept in combination with FOLFIRI versus FOLFIRI.

CONCLUSION

Aflibercept in combination with FOLFIRI increased overall survival versus FOLFIRI, so it is an effective strategy in the treatment of patients with mCRC. Aflibercept in combination with FOLFIRI is an efficient strategy for second-line mCRC treatment from the National Health System perspective.

The Rho exchange factors Vav2 and Vav3 favor skin tumor initiation and promotion by engaging extracellular signaling loops

The catalytic activity of GDP/GTP exchange factors (GEFs) is considered critical to maintain the typically high activity of Rho GTPases found in cancer cells. However, the large number of them has made it difficult to pinpoint those playing proactive, nonredundant roles in tumors. In this work, we have investigated whether GEFs of the Vav subfamily exert such specific roles in skin cancer. Using genetically engineered mice, we show here that Vav2 and Vav3 favor cooperatively the initiation and promotion phases of skin tumors. Transcriptomal profiling and signaling experiments indicate such function is linked to the engagement of, and subsequent participation in, keratinocyte-based autocrine/paracrine programs that promote epidermal proliferation and recruitment of pro-inflammatory cells. This is a pathology-restricted mechanism because the loss of Vav proteins does not cause alterations in epidermal homeostasis. These results reveal a previously unknown Rho GEF-dependent pro-tumorigenic mechanism that influences the biology of cancer cells and their microenvironment. They also suggest that anti-Vav therapies may be of potential interest in skin tumor prevention and/or treatment.

The Ras-like protein R-Ras2/TC21 is important for proper mammary gland development

R-Ras2/TC21 is a GTPase with high sequence and signaling similarity with Ras subfamily members. Although it has been extensively studied using overexpression studies in cell lines, its physiological role remains poorly characterized. Here we used RRas2-knockout mice expressing β-galactosidase under the regulation of the endogenous RRas2 promoter to investigate the function of this GTPase in vivo. Despite its expression in tissues critical for organismal viability, RRas2(-/-) mice show no major alterations in viability, growth rates, cardiovascular parameters, or fertility. By contrast, they display a marked and specific defect in the development of the mammary gland during puberty. In the absence of R-Ras2/TC21, this gland forms reduced numbers of terminal end buds (TEBs) and ductal branches, leading to a temporal delay in the extension and arborization of the gland tree in mammary fat pads. This phenotype is linked to cell-autonomous proliferative defects of epithelial cells present in TEBs. These cells also show reduced Erk activation but wild type-like levels of phosphorylated Akt. Using compound RRas2-, HRas-, and NRas-knockout mice, we demonstrate that these GTPases act in a nonsynergistic and nonadditive manner during this morphogenic process.

Joint health and functional ability in children with haemophilia who receive intensive replacement therapy

Joint physical examination is an important outcome in haemophilia; however its relationship with functional ability is not well established in children with intensive replacement therapy. Boys aged 4-16 years were recruited from two European and three North American treatment centres. Joint physical structure and function was measured with the Haemophilia Joint Health Score (HJHS) while functional ability was measured with the revised Childhood Health Assessment Questionnaire (CHAQ₃₈. Two haemophilia-specific domains were created by selecting items of the CHAQ₃₈ that cover haemophilia-specific problems. Associations between CHAQ, HJHS, cumulative number of haemarthroses and age were assessed. A total of 226 subjects - mean 10.8 years old (SD 3.8) - participated; the majority (68%) had severe haemophilia. Most severe patients (91%) were on prophylactic treatment. Lifetime number of haemarthroses [median=5; interquartile range (IQR)=1-12] and total HJHS (median = 5; IQR=1-12) correlated strongly (ρ = 0.51). Total HJHS did not correlate with age and only weakly (ρ=-0.19) with functional ability scores (median=0; IQR=-0.06-0). Overall, haemarthroses were reported most frequently in the ankles. Detailed analysis of ankle joint health scores revealed moderate associations (ρ=0.3-0.5) of strength, gait and atrophy with lower extremity tasks (e.g. stair climbing). In this population, HJHS summating six joints did not perform as well as individual joint scores, however, certain elements of ankle impairment, specifically muscle strength, atrophy and gait associated significantly with functional loss in lower extremity activities. Mild abnormalities in ankle assessment by HJHS may lead to functional loss. Therefore, ankle joints may warrant special attention in the follow up of these children.

Transcriptional factor aryl hydrocarbon receptor (Ahr) controls cardiovascular and respiratory functions by regulating the expression of the Vav3 proto-oncogene

Aryl hydrocarbon receptor (Ahr) is a transcriptional factor involved in detoxification responses to pollutants and in intrinsic biological processes of multicellular organisms. We recently described that Vav3, an activator of Rho/Rac GTPases, is an Ahr transcriptional target in embryonic fibroblasts. These results prompted us to compare the Ahr(-/-) and Vav3(-/-) mouse phenotypes to investigate the implications of this functional interaction in vivo. Here, we show that Ahr is important for Vav3 expression in kidney, lung, heart, liver, and brainstem regions. This process is not affected by the administration of potent Ahr ligands such as benzo[a]pyrene. We also report that Ahr- and Vav3-deficient mice display hypertension, tachypnea, and sympathoexcitation. The Ahr gene deficiency also induces the GABAergic transmission defects present in the Vav3(-/-) ventrolateral medulla, a main cardiorespiratory brainstem center. However, Ahr(-/-) mice, unlike Vav3-deficient animals, display additional defects in fertility, perinatal growth, liver size and function, closure, spleen size, and peripheral lymphocytes. These results demonstrate that Vav3 is a bona fide Ahr target that is in charge of a limited subset of the developmental and physiological functions controlled by this transcriptional factor. Our data also reveal the presence of sympathoexcitation and new cardiorespiratory defects in Ahr(-/-) mice.

Liver dysfunction related to hepatitis B and C in patients with inflammatory bowel disease treated with immunosuppressive therapy

BACKGROUND

There is no information about the frequency of liver dysfunction in patients with inflammatory bowel disease (IBD) treated with immunosuppressants and infected with hepatitis B (HBV) and/or C virus (HCV).

AIM

To assess the influence of immunosuppressants on the course of HBV and HCV infection in IBD.

METHODS

Patients with IBD with HBV and/or HCV infection from 19 Spanish hospitals were included. Clinical records were reviewed for the type of immunosuppressant used, treatment duration, liver function tests and viral markers before, during and after each immunosuppressant. Logistic and Cox regression analysis were used to identify predictors of outcome.

RESULTS

162 patients were included; 104 had HBV markers (25 HBsAg positive) and 74 had HCV markers (51 HCV-RNA positive), and 16 patients had markers of both infections. Liver dysfunction was observed in 9 of 25 HBsAg positive patients (36%), 6 of whom developed hepatic failure. Liver dysfunction in HCV was observed in 8 of 51 HCV-RNA positive patients (15.7%), and only one developed hepatic failure. The frequency and severity of liver dysfunction was significantly higher in HBV-infected patients than in HCV-infected patients (p=0.045 and p=0.049, respectively). Treatment with ≥2 immunosuppressants was an independent predictor of HBV reactivation (OR 8.75; 95% CI 1.16 to 65.66). The majority of patients without reactivation received only one immunosuppressant for a short period and/or prophylactic antiviral treatment. No definite HBV reactivations were found in anti-HBc positive patients lacking HBsAg.

CONCLUSION

Liver dysfunction in patients with IBD treated with immunosuppressants is more frequent and severe in those with HBV than in HCV carriers and is associated with combined immunosuppression.

Combination of RNA interference and U1 inhibition leads to increased inhibition of gene expression

RNA interference (RNAi) has been revolutionary for the specific inhibition of gene expression. However, the application of RNAi has been hampered by the fact that many siRNAs induce dose-dependent unwanted secondary effects. Therefore, new methods to increase inhibition of gene expression with low doses of inhibitors are required. We have tested the combination of RNAi and U1i (U1 small nuclear RNA—snRNA—interference). U1i is based on U1 inhibitors (U1in), U1 snRNA molecules modified to target a pre-mRNA and inhibit its gene expression by blocking nuclear polyadenylation. The combination of RNAi and U1i resulted in stronger inhibition of reporter or endogenous genes than that obtained using either of the techniques alone. The increased inhibition observed is stable over time and allows higher inhibition than the best obtained with either of the inhibitors alone even with decreased doses of the inhibitors. We believe that the combination of RNAi and U1i will be of interest when higher inhibition is required or when potent inhibitors are not available. Also, the combination of these techniques would allow functional inhibition with a decreased dose of inhibitors, avoiding toxicity due to dose-dependent unwanted effects.