Checklist para pacientes con diabetes mellitus tipo 2 en consulta telemática

Las circunstancias actuales provocadas por la COVID-19 nos obligan a los profesionales de atención primaria a idear nuevas formas de garantizar la atención sanitaria de nuestros pacientes con diabetes tipo 2 (DM2). Existen evidencias que respaldan la eficacia de la telemedicina en el control glucémico de los pacientes con DM2. Ante la rápida adaptación de la práctica clínica al uso de la telemedicina, el Grupo de Trabajo de Diabetes de la Sociedad Española de Medicina Familiar y Comunitaria (SemFyC) optó por elaborar un documento de consenso plasmado en un algoritmo de actuación/seguimiento telemático en la atención de los pacientes con DM2.Palabras clave: Telemedicina, Diabetes mellitus tipo 2, COVID-19     

Impact of a Standardized Titration Protocol with Carvedilol in Heart Failure: Safety,Tolerability, and Efficacy—A Report from the GESICA Registry

Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina (GESICA) studied whether a standardized protocol for the initiation and titration of the β-blocker carvedilol in a multicenter, open-label program would optimize β-blocker use in heart failure (HF) patients. The program included: (1) the carvedilol initiation and titration period, and (2) long-term follow-up at 6 and 12 months. Of 1299 patients in the registry, 504 were excluded due to current therapy; of the remaining 795 eligible patients, 293 were excluded due to contraindications. Of the included patients with follow-up data (n = 316), 93.3% tolerated carvedilol initiation and 47.7% of the patients reached the target dose of 50 mg/day for a mean dose of 39 mg/day. Rates were comparable in the elderly (n = 83), of which 53% achieved a target dose for a mean dose of 43.08 mg/day. This protocol improved therapy rates and achieved target doses quickly (average of 4 visits). Concomitant medications did not have to be adjusted and there were low withdrawal rates (10%) and hospital admissions (7.2%) for HF. Patients were able to maintain carvedilol therapy at 6 and 12 months. These results indicate that a standardized titration protocol, as used in GESICA, for the initiation and titration of β-blockers is well tolerated and may improve β-blocker use in carefully selected heart failure patients.The study authors are members of the GESICA Steering Committee and Subcommittees     

Structural basis for p50RhoGAP BCH domain–mediated regulation of Rho inactivation

Spatiotemporal regulation of signaling cascades is crucial for various biological pathways, under the control of a range of scaffolding proteins. The BNIP-2 and Cdc42GAP Homology (BCH) domain is a highly conserved module that targets small GTPases and their regulators. Proteins bearing BCH domains are key for driving cell elongation, retraction, membrane protrusion, and other aspects of active morphogenesis during cell migration, myoblast differentiation, and neuritogenesis. We previously showed that the BCH domain of p50RhoGAP (ARHGAP1) sequesters RhoA from inactivation by its adjacent GAP domain; however, the underlying molecular mechanism for RhoA inactivation by p50RhoGAP remains unknown. Here, we report the crystal structure of the BCH domain of p50RhoGAP Schizosaccharomyces pombe and model the human p50RhoGAP BCH domain to understand its regulatory function using in vitro and cell line studies. We show that the BCH domain adopts an intertwined dimeric structure with asymmetric monomers and harbors a unique RhoA-binding loop and a lipid-binding pocket that anchors prenylated RhoA. Interestingly, the β5-strand of the BCH domain is involved in an intermolecular β-sheet, which is crucial for inhibition of the adjacent GAP domain. A destabilizing mutation in the β5-strand triggers the release of the GAP domain from autoinhibition. This renders p50RhoGAP active, thereby leading to RhoA inactivation and increased self-association of p50RhoGAP molecules via their BCH domains. Our results offer key insight into the concerted spatiotemporal regulation of Rho activity by BCH domain–containing proteins.

Small GTPases are molecular switches that cycle between an active GTP-bound state and an inactive GDP-bound state and are primarily involved in cytoskeletal reorganization during cell motility, morphogenesis, and cytokinesis (1, 2). These small GTPases are tightly controlled by activators and inactivators, such as guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs), respectively (3, 4), which are multidomain proteins that are themselves regulated through their interactions with other proteins, lipids, secondary messengers, and/or by posttranslational modifications (5–7). Despite our understanding of the mechanisms of action of GTPases, GAPs, and GEFs, little is known about how they are further regulated by other cellular proteins in tightly controlled local environments.The BNIP-2 and Cdc42GAP Homology (BCH) domain has emerged as a highly conserved and versatile scaffold protein domain that targets small GTPases, their GEFs, and GAPs to carry out various cellular processes in a spatial, temporal, and kinetic manner (8–15). BCH domain–containing proteins are classified into a distinct functional subclass of the CRAL_TRIO/Sec14 superfamily, with ∼175 BCH domain–containing proteins (in which 14 of them are in human) present across a range of eukaryotic species (16). Some well-studied BCH domain–containing proteins include BNIP-2, BNIP-H (CAYTAXIN), BNIP-XL, BNIP-Sα, p50RhoGAP (ARHGAP1), and BPGAP1 (ARHGAP8), with evidence to show their involvement in cell elongation, retraction, membrane protrusion, and other aspects of active morphogenesis during cell migration, growth activation and suppression, myoblast differentiation, and neuritogenesis (17–21). Aside from interacting with small GTPases and their regulators, some of these proteins can also associate with other signaling proteins, such as fibroblast growth factor receptor tyrosine kinases, myogenic Cdo receptor, p38-MAP kinase, Mek2/MP1, and metabolic enzymes, such as glutaminase and ATP-citrate lyase (17–26). Despite the functional diversity and versatility of BCH domain–containing proteins, the structure of the BCH domain and its various modes of interaction remain unknown. The BCH domain resembles the Sec14 domain (from the CRAL-TRIO family) (16, 27, 28), a domain with lipid-binding characteristics, which may suggest that the BCH domain could have a similar binding strategy. However, to date, the binding and the role of lipids in BCH domain function remain inconclusive.Of the BCH domain–containing proteins, we have focused on the structure and function of p50RhoGAP. p50RhoGAP comprises an N-terminal BCH domain and a C-terminal GAP domain separated by a proline-rich region. We found that p50RhoGAP contains a noncanonical RhoA-binding motif in its BCH domain and is associated with GAP-mediated cell rounding (13). Further, we showed previously that deletion of the BCH domain dramatically enhanced the activity of the adjacent GAP domain (13); however, the full dynamics of this interaction is unclear. Previously, it has been reported that the BCH and other domains regulate GAP activity in an autoinhibited manner (18, 21, 29, 30) involving the interactions of both the BCH and GAP domains, albeit the mechanism remains to be investigated. It has also been shown that a lipid moiety on Rac1 (a Rho GTPase) is necessary for its inactivation by p50RhoGAP (29, 31), which may imply a role in lipid binding. An understanding of how the BCH domain coordinates with the GAP domain to affect the local activity of RhoA and other GTPases would offer a previously unknown insight into the multifaceted regulation of Rho GTPase inactivation.To understand the BCH domain–mediated regulation of p50RhoGAP and RhoA activities, we have determined the crystal structure of a homologous p50RhoGAP BCH domain from S. pombe for functional interrogation. We show that the BCH domain adopts an intertwined dimeric structure with asymmetric monomers and harbors a unique RhoA-interacting loop and a lipid-binding pocket. Our results show that the lipid-binding region of the BCH domain helps to anchor the prenylation tail of RhoA while the loop interacts directly with RhoA. Moreover, we show that a mutation in the β5-strand releases the autoinhibition of the GAP domain by the BCH domain. This renders the GAP domain active, leading to RhoA inactivation and the associated phenotypic effects in yeast and HeLa cells. The released BCH domain also contributes to enhanced p50RhoGAP–p50RhoGAP interaction. Our findings offer crucial insights into the regulation of Rho signaling by BCH domain–containing proteins.     

Iron deficiency anemia in the elderly: prevalence and endoscopic evaluation of the gastrointestinal tract in outpatients

Iron deficiency anemia (IDA), mostly due to chronic occult bleeding from the gastrointestinal tract, is a common problem in the elderly. This study aimed to determine the prevalence of IDA in the elderly and to investigate the gastrointestinal tract in elderly patients with IDA. 1,388 patients over 65 years were prospectively evaluated for IDA in our outpatient clinic. IDA was defined if decreased hemoglobin concentrations (<13 g/dl for men and <12 g/dl for women) were associated with low serum ferritin levels (<15 ng/ml in men and <9 ng/ml in women). We evaluated the gastrointestinal system of all patients with IDA by upper gastrointestinal endoscopy and colonoscopy regardless of fecal occult blood loss. The prevalence of anemia was found to be 25% (n = 347) in our study population, and 30.5% (n = 106) of these patients with anemia had iron deficiency. Upper gastrointestinal endoscopy and colonoscopy were performed in 96 patients with IDA. Fifty-eight upper gastrointestinal system lesions (55 patients, 57.3%) and 27 colonic lesions (26 patients, 27.1%) were detected. We diagnosed gastrointestinal malignancy in 15 (15.6%) elderly patients with IDA (8 colon, 1 esophageal and 6 gastric cancers). IDA is a common problem in elderly patients; consequently, before iron replacement therapy, patients should be thoroughly investigated regarding a possible association with gastrointestinal malignancy.