Equilibrium unfolding of the PDZ domain of β2-syntrophin

b2-syntrophin, a dystrophin-associated protein, plays a pivotal role in insulin secretion by pancreatic b-cells. Itcontains a PDZ domain (b2S-PDZ) that, in complex with protein-tyrosine phosphatase ICA512, anchors the dense insulin gran-ules to actin filaments. The phosphorylation state of b2-syntrophin allosterically regulates the affinity of b2S-PDZ for ICA512,and the disruption of the complex triggers the mobilization of the insulin granule stores. Here, we investigate the thermal unfold-ing of b2S-PDZ at different pH and urea concentrations. Our results indicate that, unlike other PDZ domains, b2S-PDZ is margin-ally stable. Thermal denaturation experiments show broad transitions and cold denaturation, and a two-state model fit revealsa significant unfolded fraction under physiological conditions. Furthermore, Tm and Tmax denaturant-dependent shifts andnoncoincidence of melting curves monitored at different wavelengths suggest that two-state and three-state models fail toexplain the equilibrium data properly and are in better agreement with a downhill scenario. Its higher stability at pH >9 andthe results of molecular dynamics simulations indicate that this behavior of b2S-PDZ might be related to its charge distribution.All together, our results suggest a link between the conformational plasticity of the native ensemble of this PDZ domain and theregulation of insulin secretion.Fil: Torchio, Gabriela María. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Expresion y Plegamiento de Proteinas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ermacora, Mario Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Expresion y Plegamiento de Proteinas; ArgentinaFil: Sica, Mauricio Pablo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Expresion y Plegamiento de Proteinas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Equilibrium unfolding of the PDZ domain of β2-syntrophin

β2-syntrophin, a dystrophin-associated protein, plays a pivotal role in insulin secretion by pancreatic β-cells. It contains a PDZ domain (β2S-PDZ) that, in complex with protein-tyrosine phosphatase ICA512, anchors the dense insulin granules to actin filaments. The phosphorylation state of β2-syntrophin allosterically regulates the affinity of β2S-PDZ for ICA512, and the disruption of the complex triggers the mobilization of the insulin granule stores. Here, we investigate the thermal unfolding of β2S-PDZ at different pH and urea concentrations. Our results indicate that, unlike other PDZ domains, β2S-PDZ is marginally stable. Thermal denaturation experiments show broad transitions and cold denaturation, and a two-state model fit reveals a significant unfolded fraction under physiological conditions. Furthermore, Tm and Tmax denaturant-dependent shifts and noncoincidence of melting curves monitored at different wavelengths suggest that two-state and three-state models fail to explain the equilibrium data properly and are in better agreement with a downhill scenario. Its higher stability at pH > 9 and the results of molecular dynamics simulations indicate that this behavior of β2S-PDZ might be related to its charge distribution. All together, our results suggest a link between the conformational plasticity of the native ensemble of this PDZ domain and the regulation of insulin secretion.Instituto Multidisciplinario de Biología Celula

A case of diffuse persistent pulmonary emphysema: When is difficult the diagnosis?

AbstractPersistent pulmonary interstitial emphysema (PPIE) is a rare condition that occurs in both preterm and term infants. It is thought to arise from a disruption of the basement membrane of the alveolar wall allowing air entry into the interstitial space. The characteristic CT scan appearance of PPIE can be used to differentiate it from other congenital cystic lesions that may present similarly. The management of infants suffering from diffuse persistent interstitial pulmonary emphysema varies according to severity and stability of the patient, being either conservative treatment or aggressive surgical treatment by pneumonectomy. We report a case of an unstable patient with diffuse persistent interstitial pulmonary emphysema successfully treated by lobectomy as a form of conservative surgical approach

Split-appendix technique: Alternative urinary diversion for pediatric complete incontinence

We report our series of selected patients with complete incontinence in whom the appendix was divided and utilized for creating two continent catheterizable stomas. All patients were treated for urinary and fecal incontinence by split appendix technique. The appendix was divided into two different parts preserving adequate perfusion and used for creating an appendicocecostomy (ACE) and an appendicovesicostomy at the same time. After a clinical and radiological follow up, our patients referred a good acceptance and an easily management of the stomas in order to stay dry for all day from urine and feces with improving of their quality of life. The combination of ACE and Mitrofanoff principle have revolutionized the management of urinary and fecal incontinence in patients who are unable to utilize their urethra to keep themselves dry

The Impact of Direct Oral Anticoagulant Prophylaxis for Thromboembolism in Thrombophilic Patients Undergoing Abdominoplastic Surgery

Congenital or acquired thrombophilia is observed in 10-15% of the general population; therefore, careful screening is carried out in patients at higher risk of venous thrombo-embolism (VTE). High risk of VTE is a contraindication in patients undergoing abdominoplasty. We evaluated rivaroxaban, an oral Xa inhibitor, with enoxaparin, a subcutaneously low molecular weight heparin (LMWH), in 48 female patients with documented thrombophilia, undergoing thrombo-prophylaxis after abdominoplasty. Patients were stratified into two groups according to thrombo-prophylaxis procedure: enoxaparin Group (n = 28) and rivaroxaban Group (n = 20). Hematologic outcomes were evaluated including VTE and hematoma. No episodes of VTE occurred in both groups; two patients during their course of enoxaparin presented severe hematoma for drainage and hemostasis revision. This study suggests that abdominoplasty, in patients with thrombophilia, in combination with thrombo-prophylaxis can be performed safely. Rivaroxaban was as effective as LMWH for preventing VTE, with only a moderate risk of clinically relevant bleeding. More research is needed to determine the optimal timing and duration of prophylaxis in patients undergoing plastic surgery

Congenital pouch colon associated with anorectal malformation: A rare anomaly of Asian Region-experience of Kurdish centre

Background: Congenital pouch colon (CPC) is an unusual malformation associated with anorectal malformations (ARMs) that are seen especially in Asia. The aim of this study was to analyse our series of CPC associated with ARM in our centre and report our experience based on the rarity of pathology. Materials and Methods: This is a retrospective study conducted at the Department of Paediatric Surgery in North Iraq. We identified patients from a prospectively kept database, including all patients managed between 1997 and 2014. Results: In total, 17 patients (3 females and 14 males) were included; all had CPC and high ARM; male:female ratio was 5.6:1. Two females had colo-vestibular fistula, 1 had a colo-cloacal fistula, all males had imperforate anus with colovesical fistula. Pre-operative diagnosis of CPC was made in eight patients (47%). Four patients (23.5%) had an incomplete pouch colon (Type III and IV), and 13 (76%) had complete pouch colon (Type I and II). All patients were managed with staged surgery. Mortality rate was 17.6% (3/17). Conclusions: CPC associated with ARM can be defined as 'Asian' complex malformation. Few cases are reported in Literature from Europe and USA. However, it is known that it is ever more frequent the collaboration between Asian and European surgeons (as in our study), so the suspicion should be considered in all patient high ARM who come from Asian region. We reviewed literature and report our experience of 15 years, after a retrospectively analysis, to share it and add our data to their reported

Equilibrium unfolding of the PDZ domain of β2-syntrophin

β2-syntrophin, a dystrophin-associated protein, plays a pivotal role in insulin secretion by pancreatic β-cells. It contains a PDZ domain (β2S-PDZ) that, in complex with protein-tyrosine phosphatase ICA512, anchors the dense insulin granules to actin filaments. The phosphorylation state of β2-syntrophin allosterically regulates the affinity of β2S-PDZ for ICA512, and the disruption of the complex triggers the mobilization of the insulin granule stores. Here, we investigate the thermal unfolding of β2S-PDZ at different pH and urea concentrations. Our results indicate that, unlike other PDZ domains, β2S-PDZ is marginally stable. Thermal denaturation experiments show broad transitions and cold denaturation, and a two-state model fit reveals a significant unfolded fraction under physiological conditions. Furthermore, Tm and Tmax denaturant-dependent shifts and noncoincidence of melting curves monitored at different wavelengths suggest that two-state and three-state models fail to explain the equilibrium data properly and are in better agreement with a downhill scenario. Its higher stability at pH > 9 and the results of molecular dynamics simulations indicate that this behavior of β2S-PDZ might be related to its charge distribution. All together, our results suggest a link between the conformational plasticity of the native ensemble of this PDZ domain and the regulation of insulin secretion.Instituto Multidisciplinario de Biología Celula

Recommendations for myeloid-derived suppressor cell nomenclature and characterization standards

Myeloid-derived suppressor cells (MDSCs) have emerged as major regulators of immune responses in cancer and other pathological conditions. In recent years, ample evidence supports key contributions of MDSC to tumour progression through both immune-mediated mechanisms and those not directly associated with immune suppression. MDSC are the subject of intensive research with >500 papers published in 2015 alone. However, the phenotypic, morphological and functional heterogeneity of these cells generates confusion in investigation and analysis of their roles in inflammatory responses. The purpose of this communication is to suggest characterization standards in the burgeoning field of MDSC research

Retroperitoneoscopic Varicocelectomy in Adolescents: Long-term Follow-up in Two Italian Centres

Background: The varicocele is the most commonly diagnosed pre-pubertal andrological condition with an incidence of 10%-15% between adolescents. The aim of this study was to evaluate the efficacy of retroperitoneoscopic varicocelectomy (RV) in two Italian centres with particular attention to post-operative testicular volume and semen analysis after 18 years of life. Materials and Methods: From 1999 to 2010, 286 adolescents underwent retroperitoneoscopic left varicocelectomy. Of these patients, 67 were evaluated by clinical examination, ultrasound and semen analysis, allowing an adequate long-term follow-up. Results: Surgery was performed at a mean age of 13 years (range 10-17) without intraoperative complications. There were two recurrences (3%), two left testis hypotrophy (3%) and four hydroceles (6%), not yet undergone surgery because asymptomatic or without tension. Currently, 44 patients accepted to perform semen analysis which showed a reduction in sperm motility in 12 cases, with associated morphological alterations in 3 and reducing number of spermatozoa in one case. Conclusions: In consideration of morphological and biomolecular spermatic alterations reported in adolescent varicocele that could interfere with cellular migration, differentiation and nutrition, it is fundamental to consider the correction of varicocele, not only for the classical indications, but also as a choice for arresting the progressive damage that inevitably acts for several years on the adolescent testis. The RV in adolescents is a safe and feasible procedure for experienced paediatric laparoscopic surgeons with early good clinical outcomes, but more studies occur to understand the real impact of adolescent varicocelectomy on testicular function

Preoperative Localization in Colonic Surgery (PLoCoS Study): a multicentric experience on behalf of the Italian Society of Colorectal Surgery (SICCR)

The aim of this prospective multicentric study was to compare the accurate colonic lesion localization ratio between CT and colonoscopy in comparison with surgery. All consecutive patients from 1st January to 31st December 2019 with a histologically confirmed diagnosis of dysplastic adenoma or adenocarcinoma with planned elective, curative colonic resection who underwent both colonoscopy and CT scans were included. Each patient underwent conventional colonoscopy and CT to stage the tumour, and the localization results of each procedure were registered. CT and colonoscopic localization were compared with surgical localization, adopted as the reference. Our analysis included 745 patients from 23 centres. After comparing the accuracy of colonoscopy and CT (for visible lesions) in localizing colonic lesions, no significant differences were found between the two preoperative tools (510/661 vs 499/661 correctly localized lesions, p = 0.518). Furthermore, after analysing only the patients who underwent complete colonoscopy and had a visible lesion on CT, no significant difference was observed between conventional colonoscopy and CT (331/427 vs 340/427, p = 0.505). Considering the intraoperative localization results as a reference, a comparison between colonoscopy and CT showed that colonoscopy significantly failed to correctly locate the lesions localized in the descending colon (17/32 vs 26/32, p = 0.031). We did not identify an advantage in using CT to localize colonic tumours. In this setting, colonoscopy should be considered the reference to properly localize lesions; however, to better identify lesions in the descending colon, CT could be considered a valuable tool to improve the accuracy of lesion localization