Rectificación taxonómica y nomenclatural del presente status del taxon Liolaemus melanops Burmeister 1888

The real status of the localised Liolaemus melanops Burmeister 1888 from Quelé Curá, Chubut, on the basis of its rediscovered original type, previously given as lost, is established. A reconsideration of the population units included in a general taxon “melanops”, is carried out. The formerly synonymized Liolaemus goetschi Müller & Hellmich 1938 from Río Negro sandy habitats is revalidated as separated species from L. melanops

Designer Leptin Receptor Antagonist Allo-aca Inhibits VEGF Effects in Ophthalmic Neoangiogenesis Models

Experimental and clinical data suggest that pro-angiogenic, pro-inflammatory and mitogenic cytokine leptin can be implicated in ocular neovascularization and other eye pathologies. At least in part, leptin action appears to be mediated through functional interplay with vascular endothelial growth factor (VEGF). VEGF is a potent regulator of neoangiogenesis and vascular leakage with a proven role in conditions such as proliferative diabetic retinopathy, age-related macular degeneration and diabetic macular edema. Accordingly, drugs targeting VEGF are becoming mainstream treatments for these diseases. The crosstalk between leptin and VEGF has been noted in different tissues, but its involvement in the development of eye pathologies is unclear. Leptin is coexpressed with VEGF during ocular neovascularization and can potentiate VEGF synthesis and angiogenic function. However, whether or not VEGF regulates leptin expression or signaling has never been studied. Consequently, we addressed this aspect of leptin/VEGF crosstalk in ocular models, focusing on therapeutic exploration of underlying mechanisms.Here we show, for the first time, that in retinal (RF/6A) and corneal (BCE) endothelial cells, VEGF (100 ng/mL, 24 h) stimulated leptin mRNA synthesis by 70 and 30%, respectively, and protein expression by 56 and 28%, respectively. In parallel, VEGF induced RF/6A and BCE cell growth by 33 and 20%, respectively. In addition, VEGF upregulated chemotaxis and chemokinesis in retinal cells by ~40%. VEGF-dependent proliferation and migration were significantly reduced in the presence of the leptin receptor antagonist, Allo-aca, at 100-250 nmol/L concentrations. Furthermore, Allo-aca suppressed VEGF-dependent long-term (24 h), but not acute (15 min) stimulation of the Akt and ERK1/2 signaling pathways. The efficacy of Allo-aca was validated in the rat laser-induced choroidal neovascularization model where the compound (5 μg/eye) significantly reduced pathological vascularization with the efficacy similar to that of a standard treatment (anti-VEGF antibody, 1 μg/eye).Cumulatively, our results suggest that chronic exposure to VEGF upregulates leptin expression and function. As leptin can in turn activate VEGF, the increased abundance of both cytokines could amplify pro-angiogenic and pro-inflammatory environement in the eye. Thus, combined therapies targeting ObR and VEGF should be considered in the treatment of ocular diseases

Patagonian herpetology: XII. The iguanids of the Liolaemus fitzingeri group in Chubut: serological data and taxonomic position

Immunological tests and morphological observations are carried out on the polymorphic populations of Liolaemus fitzingeri melanops, from Peninsula Valdés and Puerto Madryn (Chubut). The identity of this form and the sympatric specimens referred to Liolaemus goetschi Müller and Hellmich is supported. The probable active speciation of the fitzingeri complex is pointed out, in accordance with the increasing serological distance between the still recognized subspecific taxa Liolaemus fitzingeri fitzingeri, Liolaemus fitzingeri canqueli and Liolaemus fitzingeri melanops.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Patagonian herpetology. XV. Further immunological research on Argentine iguanids of the Liolaemus fitzingeri group

Immunological tests by means of the precipitin reactions support nearby serological relationships between the Liolaemus (fitzingeri) melanops populations from Chubut and the populations belonging to the same morphological group found North of the Colorado River (Argentina). Cross-reactions between samples from Mendoza (Carrizal), San Juan (Bermejo), La Rioja (Baldecitos, Talampaya) provinces and samples from Chubut (Puerto Madryn) emphasize a very high percentage of identical specific antigens. Evolutive trends of this peculiar and widespread group of psammophilous iguanid lizards are briefly analyzed.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Patagonian herpetology: XII. The iguanids of the Liolaemus fitzingeri group in Chubut: serological data and taxonomic position

Immunological tests and morphological observations are carried out on the polymorphic populations of Liolaemus fitzingeri melanops, from Peninsula Valdés and Puerto Madryn (Chubut). The identity of this form and the sympatric specimens referred to Liolaemus goetschi Müller and Hellmich is supported. The probable active speciation of the fitzingeri complex is pointed out, in accordance with the increasing serological distance between the still recognized subspecific taxa Liolaemus fitzingeri fitzingeri, Liolaemus fitzingeri canqueli and Liolaemus fitzingeri melanops.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Patagonian herpetology. XV. Further immunological research on Argentine iguanids of the Liolaemus fitzingeri group

Immunological tests by means of the precipitin reactions support nearby serological relationships between the Liolaemus (fitzingeri) melanops populations from Chubut and the populations belonging to the same morphological group found North of the Colorado River (Argentina). Cross-reactions between samples from Mendoza (Carrizal), San Juan (Bermejo), La Rioja (Baldecitos, Talampaya) provinces and samples from Chubut (Puerto Madryn) emphasize a very high percentage of identical specific antigens. Evolutive trends of this peculiar and widespread group of psammophilous iguanid lizards are briefly analyzed.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Patagonian herpetology. XV. Further immunological research on Argentine iguanids of the Liolaemus fitzingeri group

Immunological tests by means of the precipitin reactions support nearby serological relationships between the Liolaemus (fitzingeri) melanops populations from Chubut and the populations belonging to the same morphological group found North of the Colorado River (Argentina). Cross-reactions between samples from Mendoza (Carrizal), San Juan (Bermejo), La Rioja (Baldecitos, Talampaya) provinces and samples from Chubut (Puerto Madryn) emphasize a very high percentage of identical specific antigens. Evolutive trends of this peculiar and widespread group of psammophilous iguanid lizards are briefly analyzed.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Patagonian herpetology. XIII. The identity of Liolaemus goetschi with the melanops form of the Liolaemus fitzingeri complex (Rio Negro and Chubut)

The synonymy of Liolaemus goetschi Müller and Hellmich and Liolaemus fitzingeri melanops Burmeister is supported by the serological evidence. Individuals morphologically indistinguishable from Liolaemus goetschi are present in the polymorphic populations of Liolaemus fitzingeri melanops from Puerto Madryn (Chubut). The present biological and evolutionary trends of the fitzingeri complex and its several “incipient species” are analyzed.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Patagonian herpetology. XIII. The identity of Liolaemus goetschi with the melanops form of the Liolaemus fitzingeri complex (Rio Negro and Chubut)

The synonymy of Liolaemus goetschi Müller and Hellmich and Liolaemus fitzingeri melanops Burmeister is supported by the serological evidence. Individuals morphologically indistinguishable from Liolaemus goetschi are present in the polymorphic populations of Liolaemus fitzingeri melanops from Puerto Madryn (Chubut). The present biological and evolutionary trends of the fitzingeri complex and its several “incipient species” are analyzed.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse