A Rare Case of Systemic AL Amyloidosis with Muscle Involvement: A Misleading Diagnosis

Muscle involvement in AL amyloidosis is a rare condition, and the diagnosis of amyloid myopathy is often delayed and underdiagnosed. Amyloid myopathy may be the initial manifestation and may precede the diagnosis of systemic AL amyloidosis. Here, we report the case of a 73-year-old man who was referred to our center for a monoclonal gammopathy of undetermined significance (MGUS) diagnosed since 1999. He reported a progressive weakness of proximal muscles of the legs with onset six months previously. Muscle biopsy showed mild histopathology featuring alterations of nonspecific type with a mixed myopathic and neurogenic involvement, and the diagnostic turning point was the demonstration of characteristic green birefringence under cross-polarized light following Congo red staining of perimysial vessels. Transmission electron microscopy (TEM) con firmed amyloid fibrils around perimysial vessels associated with collagen fibrils. A stepwise approach to diagnosis and staging of this disorder is critical and involves confirmation of amyloid deposition, identification of the fibril type, assessment of underlying amyloidogenic disorder, and evaluation of the extent and severity of amyloidotic organ involvement

Genetic Variation Patterns of “Algarrobos” from the “Great American Chaco” (Prosopis alba, P. nigra, P. hassleri, P. fiebrigii, P. ruscifolia, P. chilensis, and P. flexuosa)

Instituto de Fisiología y Recursos Genéticos VegetalesFil: Vega, Carmen Delcira . Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil:Vega, Carmen Delcira. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA); ArgentinaFil: Aguilar, Dana. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal ( IMBIV). Laboratorio Ecología Evolutiva – Biología Floral; ArgentinaFil: Bessega, Cecilia. Universidad de Buenos Aires. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA). Departamento de Ecología, Genética y Evolución. Laboratorio de Genética; ArgentinaFil: Teich, Ingrid. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Teich, Ingrid. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA); ArgentinaFil: Acosta, María Cristina. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal ( IMBIV). Laboratorio Ecología Evolutiva – Biología Floral; ArgentinaFil: Cosacov, Andrea. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal (IMBIV). Laboratorio de Ecología Evolutiva - Biología Floral; ArgentinaFil: Ewens, Mauricio. Universidad Católica de Santiago del Estero. Estación Experimental Fernández; ArgentinaFil: Vilardi, Juan. Universidad de Buenos Aires. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA). Departamento de Ecología, Genética y Evolución. Laboratorio de Genética; ArgentinaFil: Sérsic, Alicia N. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal ( IMBIV). Laboratorio Ecología Evolutiva – Biología Floral; ArgentinaFil: Verga, Anibal. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Agencia De Extensión Rural La Rioja; Argentin

Interacting signals in the control of hepcidin expression

The amount of iron in the plasma is determined by the regulated release of iron from most body cells, but macrophages, intestinal enterocytes and hepatocytes play a particularly important role in this process. This cellular iron efflux is modulated by the liver-derived peptide hepcidin, and this peptide is now regarded as the central regulator of body iron homeostasis. Hepcidin expression is influenced by systemic stimuli such as iron stores, the rate of erythropoiesis, inflammation, hypoxia and oxidative stress. These stimuli control hepcidin levels by acting through hepatocyte cell surface proteins including HFE, transferrin receptor 2, hemojuvelin, TMPRSS6 and the IL-6R. The surface proteins activate various cell signal transduction pathways, including the BMP-SMAD, JAK-STAT and HIF1 pathways, to alter transcription of HAMP, the gene which encodes hepcidin. It is becoming increasingly apparent that various stimuli can signal through multiple pathways to regulate hepcidin expression, and the interplay between positive and negative stimuli is critical in determining the net hepcidin level. The BMP-SMAD pathway appears to be particularly important and disruption of this pathway will abrogate the response of hepcidin to many stimuli