Urinary metabolomic biomarker candidates for skeletal muscle wasting in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disease that affects the joints, leading to chronic synovial inflammation and local tissue destruction. Extra-articular manifestations may also occur, such as changes in body composition. Skeletal muscle wasting is often observed in patients with RA, but methods for assessing loss of muscle mass are expensive and not widely available. Metabolomic analysis has shown great potential for identifying changes in the metabolite profile of patients with autoimmune diseases. In this setting, urine metabolomic profiling in patients with RA may be a useful tool to identify skeletal muscle wasting. METHODS: Patients aged 40-70 years with RA have been recruited according to the 2010 ACR/EULAR classification criteria. Further, the Disease Activity Score in 28 joints using the C-reactive protein level (DAS28-CRP) determined the disease activity. The muscle mass was measured by Dual X-ray absorptiometry (DXA) to generate the appendicular lean mass index (ALMI) by summing the lean mass measurements for both arms and legs and dividing them by height squared (kg/height2 ). Finally, urine metabolomic analysis by 1 H nuclear magnetic resonance (1 H-NMR) spectroscopy was performed and the metabolomics data set analysed using the BAYESIL and MetaboAnalyst software packages. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to the 1 H-NMR data, followed by Spearman's correlation analysis. The combined receiver operating characteristic curve (ROC) was calculated, as well as the logistic regression analyses to establish a diagnostic model. The significance level at P < 0.05 was set for all analyses. RESULTS: The total set of subjects investigated included 90 patients with RA. Most patients were women (86.7%), with a mean age of 56.5 ± 7.3 years old and a median DAS28-CRP of 3.0 (IQR 1.0-3.0). Fifteen metabolites were identified in the urine samples with high variable importance in projection (VIP scores) by MetaboAnalyst. Of these, dimethylglycine (r = 0.205; P = 0.053), oxoisovalerate (r = -0.203; P = 0.055), and isobutyric acid (r = -0.249; P = 0.018) were significantly correlated with ALMI. Based on the low muscle mass (ALMI ≤6.0 kg/m2 for women and ≤8.1 kg/m2 for men) a diagnostic model have been established with dimethylglycine (area under the curve [AUC] = 0.65), oxoisovalerate (AUC = 0.49), and isobutyric acid (AUC = 0.83) with significant sensitivity and specificity. CONCLUSIONS: Isobutyric acid, oxoisovalerate, and dimethylglycine from urine samples were associated with low skeletal muscle mass in patients with RA. These findings suggest that this group of metabolites may be further tested as biomarkers for identification of skeletal muscle wasting.

Full-length model of the human galectin-4 and insights into dynamics of inter-domain communication.

Galectins are proteins involved in diverse cellular contexts due to their capacity to decipher and respond to the information encoded by ß-galactoside sugars. In particular, human galectin-4, normally expressed in the healthy gastrointestinal tract, displays differential expression in cancerous tissues and is considered a potential drug target for liver and lung cancer. Galectin-4 is a tandem-repeat galectin characterized by two carbohydrate recognition domains connected by a linker-peptide. Despite their relevance to cell function and pathogenesis, structural characterization of full-length tandem-repeat galectins has remained elusive. Here, we investigate galectin-4 using X-ray crystallography, small- and wide-angle X-ray scattering, molecular modelling, molecular dynamics simulations, and differential scanning fluorimetry assays and describe for the first time a structural model for human galectin-4. Our results provide insight into the structural role of the linker-peptide and shed light on the dynamic characteristics of the mechanism of carbohydrate recognition among tandem-repeat galectins.

The Use of Glabrous Skins Grafts in the Treatment of Pediatric Palmar Hand Burns.

BACKGROUND: An often overlooked, yet useful, technique in the treatment of palmar hand burns is the use of glabrous skin grafting, particularly in dark-skinned individuals. Pediatric palmar burns are a particularly unique subset of burns. The typical split-thickness or full-thickness skin grafts leave a notably different skin texture and pigmentation. It is also known that the psychological aspects of a pediatric burn can be quite burdensome for a child as he or she progresses through childhood and adolescence. For a dark-skinned patient the placement a standard full-thickness skin graft in a nonpigmented palm provides for a constant reminder of a traumatic event. We report a case series of pediatric patients who were managed with glabrous skin grafting from the plantar aspect of the foot. METHODS: A retrospective review of palmar skin burns requiring grafting at a single pediatric burn center experience over a 2 and a half year time period was performed. Seventeen patients were identified. Our treatment algorithm for deep partial thickness burns first relies on a combination of operative and nonoperative measures to expedite the demarcation of the burn injury. If the burn is full thickness in nature or if a lack of progression of healing is identified within the first 14 days of injury, then skin grafting is recommended. Our technique for performing the graft is described. RESULTS: The average age at time of surgery was 2.05 years (6 months to 6.8 years). Fourteen of the 17 patients had darker skin types (Fitzpatrick Type III-VI) and identified themselves as either Hispanic or African American. The average size of the area requiring skin graft after debridement was 0.94% total body surface area (0.5%-2.0%). Of the patients that were not lost to follow-up, 1 patient required additional grafting after developing a finger contracture for splint noncompliance. Aesthetically, the wounds went on to heal with an excellent pigment match and an inconspicuous donor site. CONCLUSIONS: In the management of deep-partial or full-thickness palmar skin burns in the pediatric population that require grafting, the use of plantar glabrous skin grafts offers a reliable option for coverage. The aesthetic and functional results are improved over standard techniques.

Tityus discrepans scorpion venom activates platelets through GPVI and a novel Src-dependent signaling pathway.

In humans and other mammals, Tityus discrepans (Td) scorpion envenomation produces a variety of systemic effects including respiratory distress, a generalized inflammatory reaction, modulation of blood pressure, fibrin formation, and platelet activation. For many of these effects, the venom components and underlying mechanisms are not known. In the present study, we demonstrate that Td venom (TdV) stimulates integrin αIIbß3-dependent aggregation of washed human and mouse platelets downstream of Src kinase activation. The pattern of increase in tyrosine phosphorylation induced by TdV in human platelets is similar to that induced by the collagen receptor GPVI, and includes FcR γ-chain, Syk, and PLC γ 2. Confirmation of GPVI activation by TdV was achieved by expression of human GPVI in chicken DT40 B cells and use of a reporter assay. To our surprise, TdV was able to activate mouse platelets deficient in the GPVI-FcR γ-chain complex through a pathway that was also dependent on Src kinases. TdV therefore activates platelets through GPVI and a second, as yet unidentified Src kinase-dependent pathway.

The brazilian version of the Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA): Four-stage translation and validation / Versão brasileira do questionário "Quality of Life - Assessment of Growth Hormone Deficiency in Adults" (QoL-AGHDA): Tradução e validação em quatro estágios

OBJECTIVE: This study reports on the Brazilian Portuguese adaptation of the QoL-AGHDA (Quality of Life Assessment of Growth Hormone Deficiency in Adults) for use in adult growth hormone deficient (GHD) patients. MATERIALS AND METHODS: The translation process adopted the dual panel methodology. The questionnaire was tested through field-test interviews (16 GHD patients). In the final stage, data from 120 GHD patients (81 included in a test-retest analysis) were analyzed for internal consistency, test-retest reliability, convergent validity and validity among known groups. RESULTS: The translation panels were successful and the draft version was amended to improve the wording as a result of the field-test interviews. Cronbach's alpha was 0.90 and test-retest reliability 0.88. QoL-AGHDA scores had the expected pattern of association with NHP scale scores and QoL-AGHDA was able to differentiate significantly between patients based on patient-reported general health (p < 0.01) and QoL (p < 0.01). CONCLUSIONS: The adaptation of the QoL-AGHDA for a Brazilian population was successful and the adapted questionnaire was shown to be reliable and valid.

OBJETIVO: Este estudo relata o processo de adaptação da versão brasileira do questionário QoL-AGHDA (Quality of Life - Assessment of Growth Hormone Deficiency in Adults) para pacientes com deficiência do hormônio de crescimento (DGH). MATERIAIS E MÉTODOS: A tradução adotou a metodologia de duplo painel. O questionário foi testado por intermédio de entrevistas direcionadas com 16 pacientes com DGH. No estágio final, dados de 120 pacientes com DGH (81 com teste/reteste) foram analisados para consistência interna, confiabilidade teste/reteste, validade convergente e validade entre grupos conhecidos. RESULTADOS: Os grupos de tradução foram bem-sucedidos e a versão final foi adaptada seguindo sugestões obtidas das entrevistas com os 16 pacientes. O coeficiente alfa de Cronbach foi 0,90, confiabilidade teste/reteste 0,88, escores QoL-AGHDA se correlacionaram com o NHP (p < 0,01) e também com a saúde geral relatada pelos pacientes (p < 0,01). CONCLUSÕES: A adaptação do QoL-AGHDA para a população brasileira foi bem-sucedida, e a nova versão demonstrou ser válida e confiável.

The brazilian version of the Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA): Four-stage translation and validation.

OBJECTIVE: This study reports on the Brazilian Portuguese adaptation of the QoL-AGHDA (Quality of Life Assessment of Growth Hormone Deficiency in Adults) for use in adult growth hormone deficient (GHD) patients. MATERIALS AND METHODS: The translation process adopted the dual panel methodology. The questionnaire was tested through field-test interviews (16 GHD patients). In the final stage, data from 120 GHD patients (81 included in a test-retest analysis) were analyzed for internal consistency, test-retest reliability, convergent validity and validity among known groups. RESULTS: The translation panels were successful and the draft version was amended to improve the wording as a result of the field-test interviews. Cronbach's alpha was 0.90 and test-retest reliability 0.88. QoL-AGHDA scores had the expected pattern of association with NHP scale scores and QoL-AGHDA was able to differentiate significantly between patients based on patient-reported general health (p < 0.01) and QoL (p < 0.01). CONCLUSIONS: The adaptation of the QoL-AGHDA for a Brazilian population was successful and the adapted questionnaire was shown to be reliable and valid.