Inflammatory signaling regulates embryonic hematopoietic stem and progenitor cell production

Identifying signaling pathways that regulate hematopoietic stem and progenitor cell (HSPC) formation in the embryo will guide efforts to produce and expand HSPCs ex vivo. Here we show that sterile tonic inflammatory signaling regulates embryonic HSPC formation. Expression profiling of progenitors with lymphoid potential and hematopoietic stem cells (HSCs) from aorta/gonad/mesonephros (AGM) regions of midgestation mouse embryos revealed a robust innate immune/inflammatory signature. Mouse embryos lacking interferon γ (IFN-γ) or IFN-α signaling and zebrafish morphants lacking IFN-γ and IFN-ϕ activity had significantly fewer AGM HSPCs. Conversely, knockdown of IFN regulatory factor 2 (IRF2), a negative regulator of IFN signaling, increased expression of IFN target genes and HSPC production in zebrafish. Chromatin immunoprecipitation (ChIP) combined with sequencing (ChIP-seq) and expression analyses demonstrated that IRF2-occupied genes identified in human fetal liver CD34⁺ HSPCs are actively transcribed in human and mouse HSPCs. Furthermore, we demonstrate that the primitive myeloid population contributes to the local inflammatory response to impact the scale of HSPC production in the AGM region. Thus, sterile inflammatory signaling is an evolutionarily conserved pathway regulating the production of HSPCs during embryonic development.     

Mixing real and virtual components in automated manufacturing systems using PLM tools

The automation of manufacturing systems is one of the most important aspects that need to be taken care of during a design process. The Product Lifecycle Management (PLM) tools allow for the designing of automated systems even before acquiring all the hardware and/or software. This paper shows the use of this PLM kind of tools for mixing virtual and real components on an automated manufacturing system through the implementation of four different case scenarios: using the real process/real controller to the virtual process/virtual controller, real process/real controller to real process/virtual controller and finally, virtual process/real controller to virtual process/virtual controller. These scenarios will be described along with their purposes and the tools used to achieve them. Dassault Systemes DELMIA Automation is used as a PLM tool and is combined with the hardware and software required to achieve each case scenario. The case study used is the Flexible Manufacturing System in the Mechatronics laboratory at the Tecnológico de Monterrey; it’s also presented an implementation of these scenarios in a Manufacturing Systems Automation laboratory class. This study examines students’ use of technology for learning compared to more traditional learning methods. Results suggest that there is more than one good way to learn.     

T helper 17 cells play a critical pathogenic role in lung cancer

Lung cancer development is associated with extensive pulmonary inflammation. In addition, the linkage between chronic obstructive pulmonary disease (COPD) and lung cancer has been demonstrated in population-based studies. IL-17–producing CD4 helper T cells (Th17 cells) play a critical role in promoting chronic tissue inflammation. Although Th17 cells are found in human COPD and lung cancer, their role is not understood. We have thus used a mouse model of lung cancer, in which an oncogenic form of K-ras (K-ras^G12D), frequently found in human lung cancer, is restrictedly expressed in lung epithelial cells [via Clara cell secretory protein (CCSP^cre)]. In this model, Th17 and Treg but not Th1 cells were found enriched at the tumor tissues. When CCSP^cre/K-ras^G12D mice were weekly challenged with a lysate of nontypeable Haemophilus influenza (NTHi), which induces COPD-type inflammation and accelerates the tumor growth, they showed greatly enhanced Th17 cell infiltration in the lung tissues. Lack of IL-17, but not IL-17F, resulted in a significant reduction in lung tumor numbers in CCSP^cre/K-ras^G12D mice and also those treated with NTHi. Absence of IL-17 not only resulted in reduction of tumor cell proliferation and angiogenesis, but also decreased the expression of proinflammatory mediators and reduced recruitment of myeloid cells. Depletion of Gr-1⁺CD11b⁺ myeloid cells in CCSP^cre/K-ras^G12D mice suppressed tumor growth in lung, indicating Gr-1⁺CD11b⁺ myeloid cells recruited by IL-17 play a protumor role. Taken together, our data demonstrate a critical role for Th17 cell-mediated inflammation in lung tumorigenesis and suggest a novel way for prevention and treatment of this disease.Inflammation plays an important role in tumor development (1, 2). Although targeting inflammation and tumor microenvironment has been considered as a new direction of cancer therapy, the mechanisms underlying cancer-associated inflammation have not been well understood. Lung cancer is a leading cause of death in the world. Accumulating evidence has shown that inflammation is associated with pathogenesis of lung cancer, especially those induced by cigarette smoke (3). The primary risk factor among smokers to develop lung cancer is the presence of chronic obstructive pulmonary disease (COPD) (4), which is characterized by chronic pulmonary inflammation, airway remodeling and destruction of lung parenchyma. Human lung cancers are inflicted with alterations in various subsets of lymphocytes and myeloid cells (5, 6), reminiscent of immune activation during chronic inflammation. Several studies have shown NFκB signaling as a mechanistic link between inflammation and lung cancer using a mouse model of lung adenocarcinoma (7, 8). However, the specific inflammatory cell types or molecules potentiating lung cancer are not understood clearly.We and others have identified a novel subset of CD4 helper T cells that produce IL-17 and are referred as Th17 cells (9, 10). Th17 cells have been associated with inflammatory diseases such as rheumatoid arthritis, asthma, lupus, and allograft rejection. An important function of IL-17 is to promote tissue inflammation through the up-regulation of proinflammatory cytokines and chemokines (11). Consistently, we have shown that transgenic overexpression of IL-17 in the lungs resulted in chemokine up-regulation and tissue infiltration by leukocytes, although mice treated with neutralizing IL-17–specific antibody were also found to be resistant to the induction of experimental autoimmune encephalomyelitis (9). These and other studies collectively demonstrated that IL-17 and Th17 cells play nonredundant function in promoting inflammation.Increased frequencies of IL-17 and Th17 cells have been reported in patients with different types of tumors (12), including lung adenocarcinoma (13). The density of intratumoral IL-17–positive cells in primary human nonsmall cell lung cancer was inversely correlated with patient outcome and correlated with smoking status of the patients (14). Th17 cells specific for a common tumor antigen were found in lung cancer patients as part of their spontaneous immune response to the autologous tumor (15). However, the function of Th17 cells and IL-17 in the development of lung cancer remains to be shown. Animal model studies have revealed contrasting roles of IL-17 in various tumors (16). Tumor-promoting effect of IL-17 was shown in some models such as colon cancer (17–20), whereas in others, IL-17 supported anti-tumor immunity, including in B16 melanoma model (21–24). Thus, the role of IL-17 could be complex and tumor-specific.To properly evaluate the role of IL-17 in inflammation-associated lung cancer, we used a model of oncogenic K-ras mutation expressed only in the lung. Mice expressing K-ras mutation in Clara cells (CCSP^cre/K-ras^G12D mice) spontaneously develop lung adenocarcinoma (25). In addition, we induced COPD-type lung inflammation by challenging mice with lysates of nontypeable Haemophilus influenza (NTHi). Inflammation driven by NTHi can promote tumor growth in CCSP^cre/K-ras^G12D mice (25). These experiments collectively indicate a tumorigenic role of IL-17–mediated inflammation in the development of lung cancer.     

Reliability and reproducibility of the method of assessment of midpalatal suture maturation: A tomographic study

Objectives:To assess reliability and reproducibility of the individual assessment of midpalatal suture maturation in computed tomography among orthodontists and radiologists for potential diagnosis application.Materials and Methods:Sixty axial slices from cone-beam computed tomography and multi-slice CT scans of patients aged between 11 and 21 years old (33 females and 27 males) were selected. For the investigation of reliability and reproducibility of the method, two groups of examiners were established. The first group consisted of 11 orthodontists and the second consisted of 10 radiologists. Each group examined the images and performed individual assessment of the midpalatal suture maturation method twice within an interval of 21 days. During the first and second analyses, the sequence of images was randomized to reduce potential bias. Weighted Cohen''s kappa was performed to assess inter- and intra-examiners'' agreement. The percentage of perfect agreement and the number of stages apart for each disagreement were calculated. The significance level was P < .05.Results:The overall inter-examiner agreement was satisfactory in the first (kappa_w: 0.37) and the second (kappa_w: 0.34) analyses. Intra-examiner agreement outcomes were similar between orthodontists (kappa_w: 0.44) and radiologists (kappa_w: 0.41). The percentage of perfect agreement was 43.2%.Conclusions:The method for individual assessment of midpalatal suture maturation revealed potential reliability and reproducibility. However, the agreement rate observed in the present study was not high enough for a method designed for routine clinical applications.     

FACTORS ASSOCIATED TO ADHERENCE TO DIFFERENT TREATMENT SCHEMES WITH MEGLUMINE ANTIMONIATE IN A CLINICAL TRIAL FOR CUTANEOUS LEISHMANIASIS

The favorable outcome of the treatment of a disease is influenced by the adherence to therapy. Our objective was to assess factors associated with adherence to treatment of patients included in a clinical trial of equivalence between the standard and alternative treatment schemes with meglumine antimoniate (MA) in the treatment of cutaneous leishmaniasis (CL), in the state of Rio de Janeiro. Between 2008 and 2011, 57 patients with CL were interviewed using a questionnaire to collect socioeconomic data. The following methods were used for adherence monitoring: counting of vial surplus, monitoring card, Morisky test and modified Morisky test (without the question regarding the schedule); we observed 82.1% (vial return), 86.0% (monitoring card), 66.7% (Morisky test) and 86.0% (modified Morisky test) adherence. There was a strong correlation between the method of vial counting and the monitoring card and modified Morisky test. A significant association was observed between greater adherence to treatment and low dose of MA, as well as with a lower number of people sleeping in the same room. We recommend the use of the modified Morisky test to assess adherence to treatment of CL with MA, because it is a simple method and with a good performance, when compared to other methods.     

Baroreflex Sensitivity and its Association with Arrhythmic Events in Chagas Disease

Background

Sudden death is the leading cause of death in Chagas disease (CD), even in patients with preserved ejection fraction (EF), suggesting that destabilizing factors of the arrhythmogenic substrate (autonomic modulation) contribute to its occurrence.

Objective

To determine baroreflex sensitivity (BRS) in patients with undetermined CD (GI), arrhythmogenic CD with nonsustained ventricular tachycardia (NSVT) (GII) and CD with spontaneous sustained ventricular tachycardia (STV) (GIII), to evaluate its association with the occurrence and complexity of arrhythmias.

Method

Forty-two patients with CD underwent ECG and continuous and noninvasive BP monitoring (TASK force monitor). The following were determined: BRS (phenylephrine method); heart rate variability (HRV) on 24-h Holter; and EF (echocardiogram).

Results

GIII had lower BRS (6.09 ms/mm Hg) as compared to GII (11.84) and GI (15.23). The difference was significant between GI and GIII (p = 0.01). Correlating BRS with the density of ventricular extrasystoles (VE), low VE density (<10/h) was associated with preserved BRS. Only 59% of the patients with high VE density (> 10/h) had preserved BRS (p = 0.003). Patients with depressed BRS had higher VE density (p = 0.01), regardless of the EF. The BRS was the only variable related to the occurrence of SVT (p = 0.028).

Conclusion

The BRS is preserved in undetermined CD. The BRS impairment increases as disease progresses, being more severe in patients with more complex ventricular arrhythmias. The degree of autonomic dysfunction did not correlate with EF, but with the density and complexity of ventricular arrhythmias.     

Long-term results of slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia: simple approach

AimsThe aim of this study was to report the short- and long-term results of slow pathway radiofrequency (RF) ablation in patients with atrioventricular (AV) nodal reentrant tachycardia (AVNRT) using a simplified approach (2 catheters and short applications of RF).Materials and MethodsThis was a retrospective study that included consecutive patients with AVNRT. We used an anatomical approach with only 2 catheters. Decremental AV nodal conduction and atrial-His conduction interval jump were measured. To detect the onset of the QRS, we used surface lead II. During the stimulation protocol, we performed S2-QRS and S3-QRS measurements. An increase in the S3-QRS3 interval of 50 milliseconds or greater in response to a decrease in the S2-QRS2 coupling interval of 10 milliseconds was defined as a discontinuous AV nodal function curve and taken as evidence of dual antegrade AV pathways. Atrioventricular nodal reentrant tachycardia was demonstrated by the presence of dual AV nodal physiology, atrial echoes, and tachycardia induction with a 1:1 AV relationship and a VA interval of less than 70 milliseconds. Short RF applications (10-15 seconds) were delivered at an intermediate point between the posteroseptal and medioseptal regions of the Koch triangle. The applications were considered effective when junctional rhythm appeared. The end point was the demonstration of slow pathway modification without AVNRT induction.ResultsThree hundred forty-four patients (age, 49.22 ± 17.47 years; 254 were female) were included. Discontinuous AV nodal function curves were found in 271 patients (78.77%), and short-term success was achieved in all patients. The anterograde jump in AV nodal conduction was abolished after RF in 222 patients (81.91%), and discontinuous AV nodal conduction and single AV nodal echo beats persisted in 49 cases (18%). The mean number of RF application was 7.79 ± 2.23, the mean number of effective applications was 4.63 ± 0.62, and the mean RF application time was 54.92 ± 8.03 seconds. The total procedure and fluoroscopy time was 29.45 ± 9.6 and 10.87 ± 2.36 minutes, respectively. After the procedure, all patients were followed up for a mean of 46.44 ± 18.89 months, and 7 patients (2%) presented AVNRT recurrences. Complications were observed in 4 patients (1.16%); no permanent AV block was observed.ConclusionIn this study, slow pathway RF ablation using a simplified approach technique is an effective and safe approach for the treatment of AVNRT.     

Mechanical elasticity as a physical signature of conformational dynamics in a virus particle

In this study we test the hypothesis that mechanically elastic regions in a virus particle (or large biomolecular complex) must coincide with conformationally dynamic regions, because both properties are intrinsically correlated. Hypothesis-derived predictions were subjected to verification by using 19 variants of the minute virus of mice capsid. The structural modifications in these variants reduced, preserved, or restored the conformational dynamism of regions surrounding capsid pores that are involved in molecular translocation events required for virus infectivity. The mechanical elasticity of the modified capsids was analyzed by atomic force microscopy, and the results corroborated every prediction tested: Any mutation (or chemical cross-linking) that impaired a conformational rearrangement of the pore regions increased their mechanical stiffness. On the contrary, any mutation that preserved the dynamics of the pore regions also preserved their elasticity. Moreover, any pseudo-reversion that restored the dynamics of the pore regions (lost through previous mutation) also restored their elasticity. Finally, no correlation was observed between dynamics of the pore regions and mechanical elasticity of other capsid regions. This study (i) corroborates the hypothesis that local mechanical elasticity and conformational dynamics in a viral particle are intrinsically correlated; (ii) proposes that determination by atomic force microscopy of local mechanical elasticity, combined with mutational analysis, may be used to identify and study conformationally dynamic regions in virus particles and large biomolecular complexes; (iii) supports a connection between mechanical properties and biological function in a virus; (iv) shows that viral capsids can be greatly stiffened by protein engineering for nanotechnological applications.