Síndrome de Superposición de Esclerosis Sistémica y Lupus

Resumen Las patologías autoinmunes son condiciones causadas por una respuesta anormal del sistema inmune. La esclerosis sistémica es un trastorno autoinmune que afecta la microvasculatura del tracto gastrointestinal, pulmones, riñones, corazón, piel y articulaciones, con la consiguiente fibrosis de los órganos afectados, mientras que el lupus eritematoso sistémico se caracteriza por una actividad aberrante del sistema inmunológico considerada como un prototipo de enfermedad mediada por formación de inmunocomplejos, que conduce a síntomas clínicos variables; es poco usual la superposición de dos patologías del sistema inmune, sin hacer mención de la enfermedad mixta del tejido conectivo, y es de gran importancia identificar una patología combinada ya que tiene un gran impacto en las características clínicas, el diagnóstico, tratamiento y pronóstico del paciente.

Abstract Autoimmune pathologies are conditions caused by an abnormal response of the immune system. Systemic sclerosis is an autoimmune disorder that affects the microvasculature of the gastrointestinal tract, lungs, kidneys, heart, skin and joints, with consequent fibrosis of the affected organs, while systemic lupus erythematosus is characterized by an aberrant activity of the immune system considered as a prototype of immune complex-mediated disease, leading to variable clinical symptoms; the overlap of two pathologies of the immune system is unusual, without mentioning the mixed connective tissue disease, and it is of great importance to identify a combined pathology since it has a great impact on the clinical characteristics, diagnosis, treatment and prognosis of the patient.

Flotation techniques (FLOTAC and mini-FLOTAC) for detecting gastrointestinal parasites in howler monkeys.

BACKGROUND: Analyses of environmental correlates of the composition of gastrointestinal parasite communities in black howler monkeys (Alouatta pigra) have been hindered by inadequate calibration techniques of detection and quantification methods of the parasites. Here we calibrate samples and compare the likelihood of parasite detection using two flotation techniques, FLOTAC and Mini-FLOTAC, and compare flotation solution, preservation method and dilution ratio for egg detection and counts of the most common parasites (Controrchis spp. and Trypanoxyuris spp.) in howler monkeys. RESULTS: For samples preserved in 5% formalin, the Mini-FLOTAC technique was the best option for qualitative and quantitative copro-microscopic analysis. This technique displays an 83.3% and 100% detection of Controrchis spp. and Trypanoxyuris spp. infections, respectively. For the trematode Controrchis spp., more eggs per gram of feces (EPG) were recorded with the flotation solution (FS) #7 (zinc sulfate; specific gravity SG = 1.35) at 1:20 and 1:25 dilution than other methods. By contrast, for the nematode Trypanoxyuris spp., the best results were recorded with FS1 (sucrose and formaldehyde; SG = 1.20) at 1:10 dilution. CONCLUSIONS: We recommend the Mini-FLOTAC technique for general use with parasite analysis on frugivore/folivores like the howler monkey, especially if many samples are analyzed. The technique has a high detection rate and the best EPG counts, allowing the qualitative and quantitative analysis of parasite load among the species or populations without the need for specialized equipment.

Renal function and vasomotor activity in mice lacking the Cyp4a14 gene.

The production of 20-hydroxyeicosatetraenoic acid (20-HETE) in the kidney is thought to be involved in the control of renal vascular tone and tubular sodium and chloride reabsorption. Cytochrome (Cyp) P-450 enzymes of the Cyp4a family in the mouse, namely 4a10, -12 and 14, are involved in 20-HETE synthesis. Recent advances in the molecular genetics of the mouse have produced mice in which Cyp4a isoforms have been disrupted and the consequence of such an approach is examined. This study evaluated the effect of deletion of the Cyp4a14 gene on blood pressure, renal vascular responses and tubular function. When compared with the wild-type (WT) litter mates, systolic blood pressure was greater in Cyp4a14 null (KO) mice as were renal vascular responses to angiotensin II or phenyephrine, G protein-coupled receptor (GPCR) agonists, but not KCl, a non-GPCR agonist. Renal vascular responses to guanosine 5'-O-(gamma-thio)triphosphate, a non-hydrolyzable GTP analog, or NaF(4), an activator of G-proteins, were also enhanced. However, vasodilation to bradykinin or apocynin but not sodium nitroprusside was blunted in Cyp4a14 null (KO) kidneys. These changes in KO mice were accompanied by increased 20-HETE synthesis, reduced renal production of nitric oxide (NO), increased lipid hydroperoxides and increased apocynin-inhibitable vascular NADPH oxidase activity that was prevented by administration of NO synthase (NOS) inhibitor, suggesting endothelial nitric oxide synthase (eNOS) uncoupling. Cyp4a14 KO mice also exhibited a diminished capacity to excrete an acute sodium load (0.9% NaCl, 2.5 mL/kg). These data suggest that deletion of the Cyp4a gene conferred a prohypertensive status via mechanisms involving increased 20-HETE synthesis and eNOS uncoupling leading to increased oxidative stress, enhanced vasoconstriction but diminished vasodilation as well as a defect in the renal excretory capacity in Cyp4a14 KO mice. These mechanisms suggest that the Cyp4a14-deficient mouse may be a useful model for evaluation of NO/20-HETE interactions.