Predictors of remission,erosive disease and radiographic progression in a Colombian cohort of early onset rheumatoid arthritis: a 3-year follow-up study

The objective of the study is to find predictors of remission, radiographic progression (RP), and erosive disease in a cohort of patients with early onset rheumatoid arthritis (EORA) that followed a therapeutic protocol aiming at remission, in a real world tight-control setting. EORA patients were enrolled in a 3-year follow-up study. Clinical, biological, immunogenetic, and radiographical data were analyzed. Radiographs were scored according to Sharp–van der Heijde (SvdH) method. RP was defined by an increase of 3 units in 36 months. Remission was defined as DAS28 <2.6. A stepwise multiple logistic regression model was used to identify independent predictors of the three target outcomes. One hundred twenty-nine patients were included. Baseline disease activity was high. Significant overall improvement was observed, but only 33.3 % achieved remission. At 36 month, 50.4 % (65) of patients showed erosions. RP was observed in 62.7 % (81) of cases. Statistical analysis showed that baseline SvdH score was the only predictive factor associated with the three outcomes evaluated. Lower HAQ-DI and absence of autoantibodies were predictive of remission. Higher levels of ESR and presence of erosions at entry were predictive of RP. Independent baseline predictors of incident erosive disease were anti-CCP and RF positivity, symptom duration at baseline >3 months, and presence of HLA-DRB1 shared epitope. Radiographic damage at baseline was the main predictor of outcomes. Autoantibodies, HAQ and ESR at baseline, symptom duration before diagnosis, and HLA-DRB1 status had influence on clinical course and development of structural joint damage in Colombian RA patients.     

Novel method for transdiaphragmatic pressure measurements in mice

The diaphragm muscle (DIAm) is responsible for breathing and determines the ability to generate both ventilatory and non-ventilatory behaviors. Size limitations of the mouse make transdiaphragmatic pressure (Pdi) measurement using a dual balloon system untenable. Adult C57BL/6J mice (n = 8) and C57BL/6 × 129 (n = 9), underwent Pdi measurements using solid-state pressure catheters spanning the thoracic and abdominal surfaces of the DIAm. Measurements were conducted during eupnea, hypoxia (10% O₂)–hypercapnia (5% CO₂), chemical airway stimulation (i.e., sneezing), spontaneously occurring deep breaths, sustained tracheal occlusion, and bilateral phrenic nerve stimulation. There was a difference in the Pdi generated across the range of ventilatory and non-ventilatory behaviors (p = 0.001). No difference in Pdi across behaviors was evident between mouse strains (p = 0.161). This study establishes a novel method to determine Pdi across a range of DIAm behaviors in mice that may be useful in evaluating conditions associated with reduced ability to perform expulsive, non-ventilatory behaviors.     

Respiratory muscle plasticity

Plasticity of respiratory muscles must be considered in the context of their unique physiological demands. The continuous rhythmic activation of respiratory muscles makes them among the most active in the body. Respiratory muscles, especially the diaphragm, are non-weight-bearing, and thus, in contrast to limb muscles, are not exposed to gravitational effects. Perturbations in normal activation and load known to induce plasticity in limb muscles may not cause similar adaptations in respiratory muscles. In this review, we explore the structural and functional properties of the diaphragm muscle and their response to alterations in load and activity. Overall, relatively modest changes in diaphragm structural and functional properties occur in response to perturbations in load or activity. However, disruptions in the normal influence of phrenic innervation by frank denervation, tetrodotoxin nerve block and spinal hemisection, induce profound changes in the diaphragm, indicating the substantial trophic influence of phrenic motoneurons on diaphragm muscle.     

Chagasic megacolon associated with Trypanosoma cruzi I in a Colombian patient

Chagasic megacolon has been reported in the southern cone countries of South America and is mainly associated with Trypanosoma cruzi II infection. Herein, we report the first case in Colombia of chagasic megacolon with cardiomyopathy associated with the T. cruzi I lineage. This finding suggests that in Colombia, as well as in other northern countries of South America and throughout Central America, where T. cruzi I is endemic, cardiomyopathy may not be the only clinical form of Chagas disease.     

Development of the olfactory system in turbot (Psetta maxima L.)

We have examined the histogenesis of the olfactory system during turbot development using histological and immunohistochemical methods. Proliferating cell nuclear antigen (PCNA) immunohistochemistry was used to detect dividing cells, whereas calretinin (CR) immunohistochemistry was used to distinguish some neuronal components of the olfactory system. Around hatching, the olfactory placode of embryos transforms into an olfactory pit, which enlarges progressively during development. In metamorphic turbots, the right olfactory organ moves to the tip of the head. Each olfactory chamber opens to the external medium by two nostrils and accessory nasal sacs develop during metamorphosis. The order of birth of olfactory receptor cells in the sensory epithelium follows the pattern of most teleosts: ciliated cells differentiate prior to microvillous cells in turbot larvae, and crypt cells are generated during metamorphosis. Axons of olfactory sensory neurons reach the rostral forebrain by hatching, and calretinin-immunoreactive (CR-ir) glomerular fields were apparent during the subsequent larval development. During metamorphosis olfactory bulbs become strongly distorted by head torsion and glomeruli acquire asymmetric organization. The spatio-temporal course of proliferation in the olfactory system reveals changes in the distribution of dividing cells in the sensory epithelium throughout the developmental period investigated. In the olfactory bulb, proliferative activity becomes restricted to the ventral periventricular zone in turbot larvae, as well as in metamorphic specimens.     

Lupus Nephritis in Colombians: Contrasts and Comparisons with Other Populations

Lupus nephritis (LN) is one of the most serious complications of systemic lupus erythematosus (SLE) since it is the major predictor of poor prognosis. The purpose of this study was to examine the clinical and immunological characteristics associated with LN development during the course of SLE in Colombians. Therefore, patients with SLE followed at five different referral centers in Medellin, Bogota, and Cali were included in this cross-sectional and multicenter study. Factors influencing LN were assessed by conditional logistic regression analysis, adjusting by gender, age at onset, duration of disease, and city of origin. The entire sample population included 467 patients, of whom 51% presented with LN. The presence of anti-dsDNA antibodies (adjusted odds ratio (AOR), 2.06; 95% confidence interval (CI), 1.16–3.65), pleuritis (AOR, 3.82; 95% CI, 1.38–10.54), and hypertension (AOR, 2.63; 95% CI, 1.23–5.62) were positively associated with LN, whereas the presence of anti-La antibodies was a protective factor against LN development (AOR, 0.4; 95% CI, 0.19–0.85). A review of literature on LN in different populations is made. The identified clinical- and laboratory-associated factors would assist earlier diagnosis and guide decisions on therapeutic interventions on this critical and frequent complication of SLE.