The adaptor Grb7 is a novel calmodulin-binding protein: functional implications of the interaction of calmodulin with Grb7

We demonstrate using Ca2+-dependent calmodulin (CaM)-affinity chromatography and overlay with biotinylated CaM that the adaptor proteins growth factor receptor bound (Grb)7 and Grb7V (a naturally occurring variant lacking the Src homology 2 (SH2) domain) are CaM-binding proteins. Deletion of an amphiphilic basic amino-acid sequence (residues 243-256) predicted to form an alpha-helix located in the proximal region of its pleckstrin homology (PH) domain demonstrates the location of the CaM-binding domain. This site is identical in human and rodents Grb7, and shares great homology with similar regions of Grb10 and Grb14, and the Mig10 protein from Caenorhabditis elegans. We show that Grb7 and Grb7V are present in the cytosol and bound to membranes, while the deletion mutants (Grb7Delta and Grb7VDelta) have less capacity to be associated to membranes. Grb7Delta maintains in part the capacity to bind phosphoinositides, and CaM competes for phosphoinositide binding. Activation of ErbB2 by heregulin beta1 decreases the pool of Grb7 associated to membranes. The cell-permeable CaM antagonist W7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide), but not the CaM-dependent protein kinase II inhibitor KN93, prevents this effect. Highly specific cell-permeable CaM inhibitory peptides decrease the association of Grb7 to membranes. This suggests that CaM regulates the intracellular mobilization of Grb7 in living cells. Direct interaction between enhanced yellow fluorescent protein (EYFP)-Grb7 and enhanced cyan fluorescent protein (ECFP)-CaM chimeras at the plasma membrane of living cells was demonstrated by fluorescence resonance energy transfer (FRET). The FRET signal dramatically decreased in cells loaded with a cell-permeable Ca2+ chelator, and was significantly attenuated when enhanced yellow fluorescent protein-Grb7 chimera (EYFP-Grb7)Delta instead of EYFP-Grb7 was used. Finally, we show that conditioned media from cells transiently transfected with Grb7Delta and Grb7VDelta lost its angiogenic activity, in contrast to those from cells transiently transfected with their wild-type counterparts.     

Absence/disappearance of gallbladder in a patient diagnosed with cholelithiasis

We report the case of a patient with preoperatively demonstrated cholecystitis due to cholelithiasis but with no presence of gallbladder at laparoscopy or on conversion to open surgery. Gallbladder ectopy was ruled out and the possibility of gallbladder agenesia was discussed. However, four preoperative ultrasound scans performed within a protocol of treatment with octreotide, in the setting of acute cholecystitis, ruled out this possibility. We discuss the possibility of gallbladder destruction and digestion after a severe inflammatory process, as well as Frey's criteria for gallbladder agenesia. We believe that this is a case of complete gallbladder lysis due to an inflammatory process.     

Non-alcoholic Steatohepatitis (NASH) and Hepatocellular Carcinoma

Non-alcoholic fatty liver disease (NAFLD) is characterized by an excessive accumulation of fatty acids and triglycerides within the cytoplasm of the hepatocytes of non-alcohol users. The natural history varies according to the initial histological diagnosis. A current consideration is that cryptogenic cirrhosis may be representative of a late stage of non-alcoholic steatohepatitis (NASH), which has lost its features of necroinflammatory activity and steatosis in up to 80% of patients. Since NASH is able to progress to cirrhosis, hepatocellular carcinoma (HCC) development may be an end-stage of this disease. We report below two clinical cases of patients diagnosed with NASH who developed HCC. The relationship between NAFLD and HCC is reviewed.     

Pneumoscrotum secondary to a massive subcutaneous emphysema after expontaneous pneumothorax drainage

We present a case of a pneumoscrotum and pneumopenis which appeared after a trocar drainage placement for treatment of a recidivated expontaneous pneumothorax. In spite of is an entity with easy diagnosis and conservative management, maybe be confused with other more aggressive entities which treatment should be invasive.     

Efficacy of reteplase in poorly functioning hemodialysis catheters

AIM: This is a retrospective study of reteplase efficacy for restoration of flow in occluded and poorly functioning hemodialysis catheters. PATIENTS AND METHODS: From May 1, 2001 to December 31, 2001, all hemodialysis patients seen at our university dialysis center with occluded or poorly functioning (< 200 ml/min blood flow) catheters treated with reteplase were included in the study. All catheters had been in place for more than 48 hours. Reteplase 0.4 U was instilled into each port; dwell time was 30 minutes. If aspiration had not been possible, reteplase had remained in the catheter for an additional 30 minutes. If flow was established (> 200 ml/min), the catheter was used for dialysis. If flow was not adequately established after 1 hour, the patient was referred for catheter exchange. RESULTS: Reteplase (0.4 U) was used in 50 instances to restore or improve blood flow rates in a total of 23 catheters in 19 patients. Reteplase was effective in establishing adequate blood flow rates during the current and next dialysis session in 44/50 (88%) cases; 6 cases required 1-hour dwell time. Six cases (in 5 patients) required catheter exchange; in these, an anatomic or pathologic complication was responsible for catheter malfunction. No adverse events were related to reteplase instillation during the study. CONCLUSION: Data suggest that reteplase is safe and effective in restoring flow to malfunctioning hemodialysis catheters. Results are comparable to those achieved with alteplase.     

Advanced glycoxidation end products in commonly consumed foods

OBJECTIVE: Advanced glycoxidation end products (AGEs), the derivatives of glucose-protein or glucose-lipid interactions, are implicated in the complications of diabetes and aging. The objective of this article was to determine the AGE content of commonly consumed foods and to evaluate the effects of various methods of food preparation on AGE production. DESIGN: Two-hundred fifty foods were tested for their content in a common AGE marker (epsilon)N-carboxymethyllysine (CML), using an enzyme-linked immunosorbent assay based on an anti-CML monoclonal antibody. Lipid and protein AGEs were represented in units of AGEs per gram of food. RESULTS: Foods of the fat group showed the highest amount of AGE content with a mean of 100+/-19 kU/g. High values were also observed for the meat and meat-substitute group, 43+/-7 kU/g. The carbohydrate group contained the lowest values of AGEs, 3.4+/-1.8 kU/g. The amount of AGEs present in all food categories was related to cooking temperature, length of cooking time, and presence of moisture. Broiling (225 degrees C) and frying (177 degrees C) resulted in the highest levels of AGEs, followed by roasting (177 degrees C) and boiling (100 degrees C). CONCLUSIONS: The results indicate that diet can be a significant environmental source of AGEs, which may constitute a chronic risk factor for cardiovascular and kidney damage.     

Effect of exercise on the diameter of arteriovenous fistulae in hemodialysis patients

Physicians routinely recommend hand squeezing exercises for end-stage renal disease patients with newly placed arteriovenous fistulae (AVF) to increase the rate of fistula maturation. However, this practice has never been shown to actually work. To determine whether hand squeezing has an acute effect on fistula diameter, we examined 23 patients with newly created AVF (1 week to 10 months before study, mean 2.8 months). Using duplex ultrasound, we measured the diameter of the fistula three times before and three times after 5 min of squeezing a rubber ball. Fistula diameter increased in 20 of 23 patients; the mean change in fistula diameter was 9.3% (p < .0001). These data suggest that fistulae do dilate acutely after hand squeezing exercise and that this exercise should continue to be recommended.     

Fibrilación auricular en pacientes con COVID-19. Utilidad de la puntuación CHA2DS2-VASc: un análisis del registro internacional HOPE COVID-19

Introduction and objectivesCoronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2. Atrial fibrillation (AF) is common in acute situations, where it is associated with more complications and higher mortality.MethodsAnalysis of the international HOPE registry (NCT04334291). The objective was to assess the prognostic information of AF in COVID-19 patients. A multivariate analysis and propensity score matching were performed to assess the relationship between AF and mortality. We also evaluated the impact on mortality and embolic events of the CHA₂DS₂-VASc score in these patients.ResultsAmong 6217 patients enrolled in the HOPE registry, 250 had AF (4.5%). AF patients had a higher prevalence of cardiovascular risk factors and comorbidities. After propensity score matching, these differences were attenuated. Despite this, patients with AF had a higher incidence of in-hospital complications such as heart failure (19.3% vs 11.6%, P = .021) and respiratory insufficiency (75.9% vs 62.3%, P = .002), as well as a higher 60-day mortality rate (43.4% vs 30.9%, P = .005). On multivariate analysis, AF was independently associated with higher 60-day mortality (hazard ratio, 1.234; 95%CI, 1.003-1.519). CHA₂DS₂-VASc score acceptably predicts 60-day mortality in COVID-19 patients (area ROC, 0.748; 95%CI, 0.733-0.764), but not its embolic risk (area ROC, 0.411; 95%CI, 0.147-0.675).ConclusionsAF in COVID-19 patients is associated with a higher number of complications and 60-day mortality. The CHA₂DS₂-VASc score may be a good risk marker in COVID patients but does not predict their embolic risk.     

Accelerated phase of idiopathic pulmonary fibrosis

The natural history of idiopathic pulmonary fibrosis is characterized by a slow progression resulting in respiratory failure and death. The progression to the fulminant form is rapid in a small percentage of cases, however. Within weeks or months, patients develop respiratory distress, and extensive ground-glass patterns can be seen in computed tomography scans and hyaline membranes in biopsy samples. This is described as an accelerated phase of idiopathic pulmonary fibrosis, in which elevated levels of acute-phase reactants and tumor markers have been reported. To date, the monoclonal tumor marker, CA 15/3 has not been associated with the accelerated phase.