Extraction of the inner coil of a pacemaker lead slid into the pulmonary artery

A patient required lead extraction for chronic draining sinus, due to abandoned leads. Preoperatively, the chest film showed a filament in the right pulmonary artery: it was the inner coil of an old atrial lead that, while remaining anchored to the auricle, slid outside the outer coil. By right subclavian approach, the old ventricular lead and the outer coil of the atrial lead were removed. Then, by right jugular approach, the freely floating end of the inner atrial coil was grasped by a pig-tail catheter, drawn back into the superior vena cava, exteriorized by a Lasso catheter, and finally extracted.     

Digital breast tomosynthesis and contrast‐enhanced dual‐energy digital mammography alone and in combination compared to 2D digital synthetized mammography and MR imaging in breast cancer detection and classification

To compare diagnostic performance of contrast‐enhanced dual‐energy digital mammography (CEDM) and digital breast tomosynthesis (DBT) alone and in combination compared to 2D digital mammography (MX) and dynamic contrast‐enhanced MRI (DCE‐MRI) in women with breast lesions. We enrolled 100 consecutive patients with breast lesions (BIRADS 3‐5 at imaging or clinically suspicious). CEDM, DBT, and DCE‐MRI 2D were acquired. Synthetized MX was obtained by DBT. A total of 134 lesions were investigated on 111 breasts of 100 enrolled patients: 53 were histopathologically proven as benign and 81 as malignant. Nonparametric statistics and receiver operating characteristic (ROC) curve were performed. Two‐dimensional synthetized MX showed an area under ROC curve (AUC) of 0.764 (sensitivity 65%, specificity 80%), while AUC was of 0.845 (sensitivity 80%, specificity 82%) for DBT, of 0.879 (sensitivity 82%, specificity 80%) for CEDM, and of 0.892 (sensitivity 91%, specificity 84%) for CE‐MRI. DCE‐MRI determined an AUC of 0.934 (sensitivity 96%, specificity 88%). Combined CEDM with DBT findings, we obtained an AUC of 0.890 (sensitivity 89%, specificity 74%). A difference statistically significant was observed only between DCE‐MRI and CEDM (P = .03). DBT, CEDM, CEDM combined to tomosynthesis, and DCE‐MRI had a high ability to identify multifocal and bilateral lesions with a detection rate of 77%, 85%, 91%, and 95% respectively, while 2D synthetized MX had a detection rate for multifocal lesions of 56%. DBT and CEDM have superior diagnostic accuracy of 2D synthetized MX to identify and classify breast lesions, and CEDM combined with DBT has better diagnostic performance compared with DBT alone. The best results in terms of diagnostic performance were obtained by DCE‐MRI. Dynamic information obtained by time‐intensity curve including entire phase of contrast agent uptake allows a better detection and classification of breast lesions.     

A Protein Kinase A–Independent Pathway Controlling Aquaporin 2 Trafficking as a Possible Cause for the Syndrome of Inappropriate Antidiuresis Associated with Polycystic Kidney Disease 1 Haploinsufficiency

Renal water reabsorption is controlled by arginine vasopressin (AVP), which binds to V2 receptors, resulting in protein kinase A (PKA) activation, phosphorylation of aquaporin 2 (AQP2) at serine 256, and translocation of AQP2 to the plasma membrane. However, AVP also causes dephosphorylation of AQP2 at S261. Recent studies showed that cyclin-dependent kinases (cdks) can phosphorylate AQP2 peptides at S261 in vitro. We investigated the possible role of cdks in the phosphorylation of AQP2 and identified a new PKA-independent pathway regulating AQP2 trafficking. In ex vivo kidney slices and MDCK-AQP2 cells, R-roscovitine, a specific inhibitor of cdks, increased pS256 levels and decreased pS261 levels. The changes in AQP2 phosphorylation status were paralleled by increases in cell surface expression of AQP2 and osmotic water permeability in the absence of forskolin stimulation. R-Roscovitine did not alter cAMP-dependent PKA activity but specifically reduced protein phosphatase 2A (PP2A) expression and activity in MDCK cells. Notably, we found reduced PP2A expression and activity and reduced pS261 levels in Pkd1^+/− mice displaying a syndrome of inappropriate antidiuresis with high levels of pS256, despite unchanged AVP and cAMP. Similar to previous findings in Pkd1^+/− mice, R-roscovitine treatment caused a significant decrease in intracellular calcium in MDCK cells. Our data indicate that reduced activity of PP2A, secondary to reduced intracellular Ca²⁺ levels, promotes AQP2 trafficking independent of the AVP–PKA axis. This pathway may be relevant for explaining pathologic states characterized by inappropriate AVP secretion and positive water balance.In most mammals, regulation of water balance is critically dependent on water intake and excretion, which is under control of the antidiuretic hormone arginine vasopressin (AVP). In the kidney, AVP binds to the V2 vasopressin (V2R) receptor, activating the cAMP/protein kinase A (PKA) signal transduction cascade, promoting the fusion of intracellular vesicles containing aquaporin 2 (AQP2) to the apical plasma membrane, and increasing luminal permeability.^1–3 This translocation is accompanied by AVP-dependent phosphorylation of AQP2 at serine-256 (pS256).Mice in which S256 could not be phosphorylated (AQP2-S256L) develop polyuria and hydronephrosis because of a defect in AQP2 trafficking to the plasma membrane.⁴ Interestingly, it connects to polycystic kidney disease (PKD). Mutations in polycystin-1 (Pkd1^+/−) gene cause PKD, whereas PKD1 haplo-insufficient mice (Pkd1^+/−), showing an inappropriate antidiuresis, display significantly higher levels of pS256 compared with wild-type (WT) littermates; the prominent expression at the apical plasma membrane of collecting duct principal cells, despite normal V2R expression and normal cAMP levels, is associated with unchanged AVP expression in the brain, despite chronic hypo-osmolality.⁵These observations underscore the crucial role of AQP2 phosphorylation at S256 in controlling the cellular distribution and fate of AQP2.^1,6,7 As for many proteins, the function and the trafficking of AQP2 are modulated by a balance of reversible phosphorylation and dephosphorylation. Preventing dephosphorylation of AQP2 with okadaic acid, inhibitor of phosphatase 1 (PP1), inhibitor of phosphatase 2A (PP2A), and inhibitor of phosphatase 2B (PP2B) significantly increased AQP2-pS256.⁸ Proteomic analysis of inner medulla collecting duct identified PP2A as a phosphoprotein isolated from inner medullary collecting duct samples treated with either calyculin-A, a specific PP2A inhibitor, or vasopressin,⁹ suggesting the possible participation of this phosphatase in cellular events triggered by physiologic stimulus, such as vasopressin in renal collecting duct cells.The complexity of AQP2 regulation was further increased by phosphoproteomics studies showing that, other than S256, vasopressin modulates the phosphorylation status of three other sites within the C terminus (S261, S264, and S269). Although vasopressin increases S264 and S269 phosphorylation, it decreases S261 phosphorylation.^9–12 Regarding the potential kinases responsible for the phosphorylation of these sites, c-Jun N-terminal kinase, p38, and cyclin-dependent kinases (cdks) cdk1 and cdk5 can phosphorylate AQP2 peptides at S261 in vitro.^13,14 Here, in the attempt to investigate the potential involvement of cdks in AQP2 regulation, we discovered a new PKA-independent signal transduction pathway regulating AQP2 phosphorylation and localization. We found that selective inhibition of cdks with R-roscovitine is associated with a decrease of intracellular Ca²⁺ levels and a significant downregulation of the phosphatase PP2A activity, resulting in an increase of AQP2 phosphorylation at S256 and targeting to the apical membrane. Physiologically, this novel regulatory mechanism might be of clinical interest, because it better elucidates the molecular bases of pathologic states characterized by disturbances in water balance.     

Chiasmapexy for secondary empty sella syndrome: diagnostic and therapeutic considerations

Pituitary - Secondary empty sella syndrome (SESS) following pituitary surgery remains a diagnostic and therapeutic challenge. The aim of this study was to specify the diagnostic criteria, surgical...     

Soluble HLA class I induces NK cell apoptosis upon the engagement of killer-activating HLA class I receptors through FasL-Fas interaction

The engagement of the activating isoforms of C-type lectin inhibitory receptor (CLIR) or killer Ig-like receptor (KIR) by their natural ligands, represented by soluble HLA-I (sHLA-I) molecules, induced programmed cell death of natural killer (NK) cells. Indeed, NK cell apoptosis elicited by either putative HLA-E and HLA-F (sHLA-I non-A, -B, -C, and -G) or sHLA-I-Cw4 or -Cw3 from untransfected or -Cw4 or -Cw3 alleles transfected HLA-A(-), B(-), C(-), G(-), E(+), F(+) 721.221 lymphoblastoid cell line, respectively, was blocked by covering the corresponding activating receptor with either anti-CLIR- or anti-KIR-specific monoclonal antibodies (mAbs). After sHLA-I-activating receptor interaction, NK cells produced and released Fas ligand (FasL), which in turn led to NK cell apoptosis by interacting with Fas at the NK cell surface. Blocking anti-Fas mAb, or anti-FasL mAb, inhibited sHLA-I-mediated apoptosis via activating receptor in NK cell clones. This apoptosis was inhibited by NK cell treatment with cyclosporin A, whereas this drug had no effect on activating receptor-mediated activation of cytolysis. Conversely, concanamycin A, an inhibitor of vacuolar type H(+)-adenosine triphosphatase (H(+)-ATPase) of granules, inhibited activating receptor-induced NK cell cytolysis, suggesting that activating receptor-mediated apoptosis and cytolysis can use different intracellular pathways. Furthermore, a large amount of interferon-gamma (IFN-gamma) was detectable in culture supernatant of activating receptor(+) NK cells incubated with the appropriate sHLA-I ligand. Again, cyclosporin A, but not concanamycin A, strongly reduced activating receptor-mediated IFN-gamma production. This suggests that activating receptor-induced apoptosis of NK cells could play a role in eliminating potentially harmful NK cell clones and, at the same time, it leads to production of IFN-gamma, an antiviral cytokine able to amplify immune responses.     

Neuroendocrine response to the serotonin agonist M-chlorophenylpiperazine in women with menstrual status migrainosus

To assess the neuroendocrine correlates of menstrual status migrainosus (MSM) and menstrual migraine (MM), we evaluated the prolactin (PRL) and cortisol responses to the direct central serotoninergic (5-HT) agonist meta-chlorophenylpiperazine (m-CPP) administered orally (0.5 mg/kg) during the follicular (FP: +6, +8) and luteal phases (LP: -4, -6) of the same menstrual cycle. Ten women with MSM (migraine attacks occurring within 2 days of the onset of menstrual bleeding but lasting more than 72 h) and 9 women with MM (migraine occurring within 2 days of the onset of menstrual bleeding with a typical duration of attacks) were studied. Six healthy women served as controls. Blood samples were taken at times -30, 0 and every 30 min over 4 h. Statistical analysis was performed using MANOVA followed by Duncan's post hoc comparisons. We found that the PRL response to the m-CPP test was significantly blunted in MSM compared with MM and controls in both phases of the menstrual cycle (F = 4.6; p < 0.001). Indeed, the PRL area under the curve (AUC) after m-CPP was higher in both MM and controls compared with MSM (F = 12.7; p < 0.001). The m-CPP-induced cortisol response was absent in MSM compared with MM and controls in both FP and LP (F = 4.1; p < 0.001). On the other hand, the pattern of the plasma cortisol response to m-CPP was similar in MM and controls throughout the menstrual cycle. In addition, the basal plasma cortisol levels were significantly higher in MSM compared with controls (p < 0.001) and MM (p < 0.001) during FP, but not in LP, and progressively decreased over time. Thus, no significant effect of the menstrual cycle phase and diagnosis on the cortisol AUC was found, while a significant diagnosis effect (F = 25.6; p < 0.001) on %delta(max) plasma cortisol levels was evident and consistent with the lack of cortisol response to m-CPP in MSM during the FP and LP compared with MM and controls. A derangement in central 5-HT control of pituitary PRL, and even more so in cortisol release, is present in women with MSM, but not with MM, regardless of the phase of the menstrual cycle, suggesting the involvement of some 5-HT(1) and 5-HT(2) receptor subtypes in the occurrence of extremely severe migraine attacks triggered by menstruation.