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Cytomegalovirus (CMV) can cause a broad range of diseases, with severity depending on immune status, comorbidities, and age. Initial CMV infection usually occurs in childhood and is typically asymptomatic, leading to lifelong latency. In immunocompromised patients, CMV can affect multiple organs, but salivary gland infections are rare. This study presents a case of a 66-year-old woman with B-cell acute lymphoblastic leukemia who developed swelling and pain in the right preauricular region during pre-transplant consolidation therapy. Despite a recent bone marrow biopsy indicating morphological remission and a flow cytometry analysis detecting only 0.04 % B lymphoblasts, she exhibited these symptoms. A CT scan revealed enlargement, hyperdensity, and enhancement of the right parotid glands, with accompanying subcutaneous edema. A biopsy of the right parotid gland showed a dense interstitial lymphoplasmacytic infiltrate with numerous Cowdry bodies and smaller granular cytoplasmic inclusions, all testing positive for CMV immunohistochemistry. The findings confirm the diagnosis of CMV sialadenitis in an immunocompromised patient. This case underscores the importance of considering CMV infections in similar clinical scenarios, particularly in patients with compromised immune systems., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

Background: Nerve block utility has been extensively described in the operating room, however, there is a paucity of evidence regarding blocks in the interventional radiology (IR) suite, with no studies examining its safety and efficacy in children., Methods: A retrospective study was conducted at a single tertiary-care children's hospital to evaluate the analgesic utility of nerve blocks during IR-performed sclerotherapy for bone cysts, venous malformations, and lymphatic malformations. Lymphatic and venous malformations were combined for final analysis. Patients between January 2016 and September 2022 had their medical records reviewed for procedural data, postprocedural pain scores, and analgesic administration data., Results: 309 patients were included in the final analysis. Opioids were required significantly less frequently intraprocedurally and postprocedurally across subgroups. The proportion of patients who received opioids during their hospital course was significant between block and non-block patients, respectively: bone cyst: 62.7% vs 100% (p<0.001); venous and lymphatic malformation: 65.7% vs 97.4% (p<0.001). Average maximum postanesthesia care unit (PACU) pain scores were significantly lower in bone cyst patients with no significant difference seen in pain scores among venous and lymphatic malformation patients. There were no reported nerve block-related complications., Discussion: Nerve blocks demonstrated an opioid-sparing effect intraprocedurally and postprocedurally for all subgroups. Their use among bone cyst patients was associated with significant reductions in average maximum PACU pain scores. Nerve blocks may constitute an effective opioid-sparing component of multimodal analgesia in pediatric patients undergoing IR sclerosis procedures. Prospective data are needed to establish the optimal utility of nerve blocks in the IR setting., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

KRAS-mutant pancreatic ductal adenocarcinoma (PDAC) is highly immunosuppressive and resistant to targeted and immunotherapies. Among the different PDAC subtypes, basal-like mesenchymal PDAC, which is driven by allelic imbalance, increased gene dosage and subsequent high expression levels of oncogenic KRAS, shows the most aggressive phenotype and strongest therapy resistance. In the present study, we performed a systematic high-throughput combination drug screen and identified a synergistic interaction between the MEK inhibitor trametinib and the multi-kinase inhibitor nintedanib, which targets KRAS-directed oncogenic signaling in mesenchymal PDAC. This combination treatment induces cell-cycle arrest and cell death, and initiates a context-dependent remodeling of the immunosuppressive cancer cell secretome. Using a combination of single-cell RNA-sequencing, CRISPR screens and immunophenotyping, we show that this combination therapy promotes intratumor infiltration of cytotoxic and effector T cells, which sensitizes mesenchymal PDAC to PD-L1 immune checkpoint inhibition. Overall, our results open new avenues to target this aggressive and therapy-refractory mesenchymal PDAC subtype., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

A considerable percentage of dental implant patients experience biofilm-mediated peri-implant disease following transmucosal abutment application. Bacterial adhesion is an early step in biofilm development. Our purpose was to assess adhesion of specific bacterial species to titanium over short exposure periods. Eight bacterial species were selected for this analysis: Streptococcus oralis, Streptococcus mitis, Gemella haemolysans, Streptococcus gordonii, Streptococcus sanguinis, Neisseria flavescens, Streptococcus salivarius, and Pseudomonas aeruginosa. We cultured each species with appropriate media and exposed titanium foil discs to the bacteria for 60, 15, 5, 1, or 0.25 minutes. Optical density at 600-nm wavelength (OD600) was assessed for the baseline inoculum and each species/exposure combination. The proportion of bacteria adherent to titanium was determined for each experimental condition. Striking titanium adhesion was noted for all evaluated species even when exposure time was limited to 15 seconds. Strategies to limit bacterial adhesion at dental implant surfaces may offer potential for improved treatment outcomes and preservation of peri-implant health.

Transcriptional factors play an important role in gene regulation in all organisms, especially in Bacteria. Here special emphasis is placed in the AraC/XylS family of transcriptional regulators. This is one of the most abundant as many predicted members have been identified and more members are added because more bacterial genomes are sequenced. Given the way more experimental evidence has mounded in the past decades, we decided to update the information about this captivating family of proteins. Using bioinformatics tools on all the data available for experimentally characterized members of this family, we found that many members that display a similar functional classification can be clustered together and in some cases they have a similar regulatory scheme. A proposal for grouping these proteins is also discussed. Additionally, an analysis of surveyed proteins in bacterial genomes is presented. Altogether, the current review presents a panoramic view into this family and we hope it helps to stimulate future research in the field., (© The Author(s) 2021. Published by Oxford University Press on behalf of FEMS.)

Glucocorticoids are frequently used as anti-inflammatory and immunosuppressive agents. However, high doses and/or prolonged use induce undesired secondary effects such as muscular atrophy. Recently, de novo expression of connexin43 and connexin45 hemichannels (Cx43 HCs and Cx45 HCs, respectively) has been proposed to play a critical role in the mechanism underlying myofiber atrophy induced by dexamethasone (Dex: a synthetic glucocorticoid), but their involvement in specific muscle changes promoted by Dex remains poorly understood. Moreover, treatments that could prevent the undesired effects of glucocorticoids on skeletal muscles remain unknown. In the present work, a 7-day Dex treatment in adult mice was found to induce weight loss and skeletal muscle changes including expression of functional Cx43/Cx45 HCs, elevated atrogin immunoreactivity, atrophy, oxidative stress and mitochondrial dysfunction. All these undesired effects were absent in muscles of mice simultaneously treated with Dex and vitamin E (VitE). Moreover, VitE was found to rapidly inhibit the activity of Cx HCs in freshly isolated myofibers of Dex treated mice. Exposure to alkaline pH induced free radical generation only in HeLa cells expressing Cx43 or Cx45 where Ca 2+ was present in the extracellular milieu, response that was prevented by VitE. Besides, VitE and two other anti-oxidant compounds, Tempol and Resveratrol, were found to inhibit Cx43 HCs in HeLa cells transfectants. Thus, we propose that in addition to their intrinsic anti-oxidant potency, some antioxidants could be used to reduce expression and/or opening of Cx HCs and consequently reduce the undesired effect of glucocorticoids on skeletal muscles.

Recent studies indicate that connexin hemichannels do not act as freely permeable non-selective pores, but they select permeants in an isoform-specific manner with cooperative, competitive and saturable kinetics. The aim of this study was to investigate whether the treatment with a mixture of IL-1β plus TNF-α, a well-known pro-inflammatory condition that activates astroglial connexin 43 (Cx43) hemichannels, could alter their permeability to molecules. We found that IL-1β plus TNF-α left-shifted the dye uptake rate vs. dye concentration relationship for Etd and 2-NBDG, but the opposite took place for DAPI or YO-PRO-1, whereas no alterations were observed for Prd. The latter modifications were accompanied of changes in K d (Etd, DAPI, YO-PRO-1 or 2-NBDG) and Hill coefficients (Etd and YO-PRO-1), but not in alterations of V max . We speculate that IL-1β plus TNF-α may distinctively affect the binding sites to permeants in astroglial Cx43 hemichannels rather than their number in the cell surface. Alternatively, IL-1β plus TNF-α could induce the production of endogenous permeants that may favor or compete for in the pore-lining residues of Cx43 hemichannels. Future studies shall elucidate whether the differential ionic/molecule permeation of Cx43 hemichannels in astrocytes could impact their communication with neurons in the normal and inflamed nervous system.

Denervation of skeletal muscles induces severe muscle atrophy, which is preceded by cellular alterations such as increased plasma membrane permeability, reduced resting membrane potential and accelerated protein catabolism. The factors that induce these changes remain unknown. Conversely, functional recovery following denervation depends on successful reinnervation. Here, we show that activation of nicotinic acetylcholine receptors (nAChRs) by quantal release of acetylcholine (ACh) from motoneurons is sufficient to prevent changes induced by denervation. Using in vitro assays, ACh and non-hydrolysable ACh analogs repressed the expression of connexin43 and connexin45 hemichannels, which promote muscle atrophy. In co-culture studies, connexin43/45 hemichannel knockout or knockdown increased innervation of muscle fibers by dorsal root ganglion neurons. Our results show that ACh released by motoneurons exerts a hitherto unknown function independent of myofiber contraction. nAChRs and connexin hemichannels are potential molecular targets for therapeutic intervention in a variety of pathological conditions with reduced synaptic neuromuscular transmission.

[This corrects the article DOI: 10.3389/fphys.2019.01574.]., (Copyright © 2020 Figueroa, Jara, Oliva, Ezquer, Ezquer, Retamal, Martínez, Altenberg and Vargas.)

Connexin (Cx) proteins form gap junction channels (GJC) and hemichannels that a allow bidirectional flow of ions and metabolites between the cytoplasm and extracellular space, respectively. Under physiological conditions, hemichannels have a very low probability of opening, but in certain pathologies, hemichannels activity can increase and induce and/or accelerate cell death. Several mechanisms control hemichannels activity, including phosphorylation and oxidation (i.e., S-nitrosylation). Recently, the effect of polyunsaturated fatty acids (PUFAs) such as linoleic acid (LA), were found to modulate Cxs. It has been seen that LA increase cell death in bovine and human lens cells. The lens is a structure allocated in the eye that highly depends on Cx for the metabolic coupling between its cells, a condition necessary for its transparency. Therefore, we hypothesized that LA induces lens cells death by modulating hemichannel activity. In this work, we characterized the effect of LA on hemichannel activity and survival of HLE-B3 cells (a human lens epithelial cell line). We found that HLE-B3 cells expresses Cx43, Cx46, and Cx50 and can form functional hemichannels in their plasma membrane. The extracellular exposure to 10-50 μM of LA increases hemichannels activity (dye uptake) in a concentration-dependent manner, which was reduced by Cx-channel blockers, such as the Cx-mimetic peptide Gap27 and TATGap19, La 3+ , carbenoxolone (CBX) and the Akt kinase inhibitor. Additionally, LA increases intracellular calcium, which is attenuated in the presence of TATGap19, a specific Cx43-hemichannel inhibitor. Finally, the long exposure of HLE-B3 cells to LA 20 and 50 μM, reduced cell viability, which was prevented by CBX. Moreover, LA increased the proportion of apoptotic HLE-B3 cells, effect that was prevented by the Cx-mimetic peptide TAT-Gap19 but not by Akt inhibitor. Altogether, these findings strongly suggest a contribution of hemichannels opening in the cell death induced by LA in HLE-B3 cells. These cells can be an excellent tool to develop pharmacological studies in vitro ., (Copyright © 2020 Figueroa, Jara, Oliva, Ezquer, Ezquer, Retamal, Martínez, Altenberg and Vargas.)

Endotoxemia caused by bacterial lipopolysaccharides (LPSs) leads to severe skeletal muscular deterioration, starting with higher membrane permeability and decline in resting membrane potential (RMP). However, the molecular mechanism of such changes remains unclear. Here, we evaluated the possible involvement of connexin43- and connexin45-based hemichannels (Cx43 and Cx45 HCs, respectively) as putative mediators of sarcolemmal dysfunctions induced by LPS in control (Cx43 fl/fl Cx45 fl/fl ) and Cx43/Cx45 expression-deficient (Cx43 fl/fl Cx45 fl/fl :Myo-Cre) skeletal mice myofibers. At 5 h of endotoxemia, control myofibers presented Cx43 and Cx45 proteins forming functional HCs. Additionally, myofibers from endotoxic control mice showed dye uptake in vivo, which was inhibited by carbenoxolone, a Cx HC blocker. A similar increase in membrane permeability was observed in myofibers freshly isolated from skeletal muscle of mice treated for 5 h with LPS, which was blocked by the Cx HC blocker and was absent in myofibers from mice simultaneously treated with LPS and boldine, which is a Cx HC blocker. The increase in sarcolemmal permeability was mimicked by isolated myofibers treated with pro-inflammatory cytokines (TNF-α and IL-1β) and occurred at 5 h after treatment. Endotoxemia also induced a significant increase in basal intracellular Ca 2+ signal and a drop in RMP in control myofibers. These two changes were not elicited by myofibers deficient in Cx43/Cx45 expression. Therefore, sarcolemmal dysfunction characterizing endotoxemia is largely explained by the expression of functional Cx43 and Cx45 HCs. Hence, current therapy options for individuals suffering from endotoxic shock could be greatly improved with selective Cx HC inhibitors avoiding the underlying skeletal muscle dysfunction., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: Structural and physiologic differences between pediatric and adult patients make management of the pediatric airway a challenge. Many initial airway device designs were modeled for adult patients and simply downsized for the pediatric population. This paper reviews the last decade's design improvements in video laryngoscopes and supraglottic airway devices (SGAs), as well as advances in noninvasive oxygenation/ventilation techniques for pediatric airway management., Areas Covered: Topic areas reviewed include basic principles of common and newer devices for video laryngoscopy, supraglottic airway management, and alternate ventilation techniques. A literature search was conducted in PubMed using device-specific keywords and limited to neonatal, infant, and pediatric populations. Articles were reviewed for evidence deemed high yield by the authors. Device specifications were obtained from manufacturer correspondences. Features, comparisons, advantages, and disadvantages are provided for each device class. We give expert commentary regarding the current state of clinical application, research considerations, as well as a 5-year outlook on potential areas of device design and development., Expert Commentary: Video laryngoscopes and SGAs are safe and effective for use in children and improvements continue to be made for neonates and infants. The most significant area of new research is in the area of noninvasive airway devices for oxygenation and ventilation in difficult airways.

Background: We have previously reported that about 30% of patients affected by a new variant of endemic pemphigus foliaceus (EPF) in El Bagre, Colombia (termed El Bagre-EPF or pemphigus Abreu-Manu) have systemic compromise. In the current study, we focused on studying autoreactivity to the kidney and its pathological correlations., Aim: To investigate patients with El Bagre-EPF for renal compromise., Methods: We performed a case-control study, enrolling 57 patients with El Bagre-EPF and 57 controls from the endemic area, matched by age, sex, race, work activity, demographics and comorbidities. We took skin and renal biopsies; performed direct and indirect immunofluorescence, immunohistochemistry (IHC), confocal microscopy, immunoblotting, direct and indirect immune electron microscopy; and tested kidney function in all living patients. We also used IHC to study seven kidney autopsy samples., Results: Of the 57 patients, 19 had autoantibodies to kidney, with polyclonal reactivity (P < 0.01). Most cases were positive along the basement membrane of the proximal tubules, but in some cases there was also positivity against the glomeruli and/or mixed patterns. Fifteen patients had increases in serum urea and creatinine compared with controls (P < 0.01). The autoantibodies colocalized with commercial antibodies to desmoplakins I and II, p0071, armadillo repeat gene deleted in velo-cardio-facial syndrome (ARCVF) and myocardium-enriched zonula occludens-1-associated protein (MYZAP) (P < 0.01). All of the kidney disease autopsies showed alterations, mostly in the vessels., Conclusion: We demonstrate for the first time that one-third of patients with El Bagre-EPF have polyclonal autoantibodies to kidney. The kidneys showed a mixed histological pattern resembling lupus nephritis, with a diffuse proliferative Class IV (G) global diffuse pattern in active lesions, and additional interposition of membranoproliferative glomerulonephritis., (© 2018 British Association of Dermatologists.)

Skeletal muscles (∼50% of the body weight) are affected during acute and late sepsis and represent one sepsis associate organ dysfunction. Cell membrane changes have been proposed to result from a channelopathy of yet unknown cause associated with mitochondrial dysfunction and muscle atrophy. We hypothesize that the channelopathy might be explained at least in part by the expression of non-selective channels. Here, this possibility was studied in a characterized mice model of late sepsis with evident skeletal muscle atrophy induced by cecal ligation and puncture (CLP). At day seven after CLP, skeletal myofibers were found to present de novo expression (immunofluorescence) of connexins 39, 43, and 45 and P2X7 receptor whereas pannexin1 did not show significant changes. These changes were associated with increased sarcolemma permeability (∼4 fold higher dye uptake assay), ∼25% elevated in intracellular free-Ca concentration (FURA-2), activation of protein degradation via ubiquitin proteasome pathway (Murf and Atrogin 1 reactivity), moderate reduction in oxygen consumption not explained by changes in levels of relevant respiratory proteins, ∼3 fold decreased mitochondrial membrane potential (MitoTracker Red CMXRos) and ∼4 fold increased mitochondrial superoxide production (MitoSox). Since connexin hemichannels and P2X7 receptors are permeable to ions and small molecules, it is likely that they are main protagonists in the channelopathy by reducing the electrochemical gradient across the cell membrane resulting in detrimental metabolic changes and muscular atrophy.

Although connexins (Cxs) are broadly expressed by cells of mammalian organisms, Cx39 has a very restricted pattern of expression and the biophysical properties of Cx39-based channels [hemichannels (HCs) and gap junction channels (GJCs)] remain largely unknown. Here, we used HeLa cells transfected with Cx39 (HeLa-Cx39 cells) in which intercellular electrical coupling was not detected, indicating the absence of GJCs. However, functional HCs were found on the surface of cells exposed to conditions known to increase the open probability of other Cx HCs (e.g., extracellular divalent cationic-free solution (DCFS), extracellular alkaline pH, mechanical stimulus and depolarization to positive membrane potentials). Cx39 HCs were blocked by some traditional Cx HC blockers, but not by others or a pannexin1 channel blocker. HeLa-Cx39 cells showed similar resting membrane potentials (RMPs) to those of parental cells, and exposure to DCFS reduced RMPs in Cx39 transfectants, but not in parental cells. Under these conditions, unitary events of ~75 pS were frequent in HeLa-Cx39 cells and absent in parental cells. Real-time cellular uptake experiments of dyes with different physicochemical features, as well as the application of a machine-learning approach revealed that Cx39 HCs are preferentially permeable to molecules characterized by six categories of descriptors, namely: (1) electronegativity, (2) ionization potential, (3) polarizability, (4) size and geometry, (5) topological flexibility and (6) valence. However, Cx39 HCs opened by mechanical stimulation or alkaline pH were impermeable to Ca 2+ . Molecular modeling of Cx39-based channels suggest that a constriction present at the intracellular portion of the para helix region co-localizes with an electronegative patch, imposing an energetic and steric barrier, which in the case of GJCs may hinder channel function. Results reported here demonstrate that Cx39 form HCs and add to our understanding of the functional roles of Cx39 HCs under physiological and pathological conditions in cells that express them.

Background: The prevalence of glomerular disease (GD) varies according to the different socio-demographic characteristics of each population. For the first time we present the prevalence of the different forms of GD among patients from several different areas of Columbia., Methods: Data from 12,613 renal biopsies studied at our University Hospital between 2003 and 2015 was reviewed. Pathology results were classified according to a list of renal diseases proposed by various authors., Results: Focal segmental glomerulosclerosis was present in 22%, IgA disease in 21%, Lupus nephritis in 17%, membranous glomerulonephritis in 13% and thin basal membrane disease in 9%., Conclusions: This study confirms that focal segmental glomerulosclerosis and IgA disease are the most prevalent GDs found in Columbian patients. This is the first study to analyze GDs in a Columbian population and we recommend that a national registry system be created to collect comprehensive information from future research., (Copyright © 2016 Sociedad Española de Anatomía Patológica. Publicado por Elsevier España, S.L.U. All rights reserved.)

Denervated fast skeletal muscles undergo atrophy, which is associated with an increase in sarcolemma permeability and protein imbalance. However, the mechanisms responsible for these alterations remain largely unknown. Recently, a close association between de novo expression of hemichannels formed by connexins 43 and 45 and increase in sarcolemma permeability of denervated fast skeletal myofibers was demonstrated. However, it remains unknown whether these connexins cause the ionic imbalance of denervates fast myofibers. To elucidate the latter and the role of hemichannels formed by connexins (Cx HCs) in denervation-induced atrophy, skeletal myofibers deficient in Cx43 and Cx45 expression (Cx43 fl/fl Cx45 fl/fl :Myo-Cre mice) and control (Cx43 fl/fl Cx45 fl/fl mice) were denervated and several muscle features were systematically analyzed at different post-denervation (PD) times (1, 3, 5, 7 and 14days). The following sequence of events was found in denervated myofibers of Cx43 fl/fl Cx45 fl/fl mice: 1) from day 3 PD, increase in sarcolemmal permeability, 2) from day 5 PD, increases of intracellular Ca 2+ and Na + signals as well as a significant increase in protein synthesis and degradation, yielding a negative protein balance and 3) from day 7 PD, a fall in myofibers cross-section area. All the above alterations were either absent or drastically reduced in denervated myofibers of Cx43 fl/fl Cx45 fl/fl :Myo-Cre mice. Thus, the denervation-induced Cx HCs expression is an early event that precedes the electrochemical gradient dysregulation across the sarcolemma and critically contributes to the progression of skeletal muscle atrophy. Consequently, Cx HCs could be a therapeutic target to drastically prevent the denervation-induced atrophy of fast skeletal muscles., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Long-term treatment with high glucocorticoid doses induces skeletal muscle atrophy. However, the molecular mechanism of such atrophy remains unclear. We evaluated the possible involvement of connexin-based hemichannels (Cx HCs) in muscle atrophy induced by dexamethasone (DEX), a synthetic glucocorticoid, on control (Cx43(fl/fl)Cx45(fl/fl)) and Cx43/Cx45 expression-deficient (Cx43(fl/fl)Cx45(fl/fl):Myo-Cre) skeletal myofibers. Myofibers of Cx43(fl/fl)Cx45(fl/fl) mice treated with DEX (5h) expressed several proteins that form non-selective membrane channels (Cx39, Cx43, Cx45, Panx1, P2X7 receptor and TRPV2). After 5h DEX treatment in vivo, myofibers of Cx43(fl/fl)Cx45(fl/fl) mice showed Evans blue uptake, which was absent in myofibers of Cx43(fl/fl)Cx45(fl/fl):Myo-Cre mice. Similar results were obtained in vitro using ethidium as an HC permeability probe, and DEX-induced dye uptake in control myofibers was blocked by P2X7 receptor inhibitors. DEX also induced a significant increase in basal intracellular Ca(2+) signal and a reduction in resting membrane potential in Cx43(fl/fl)Cx45(fl/fl) myofibers, changes that were not elicited by myofibers deficient in Cx43/Cx45 expression. Moreover, treatment with DEX induced NFκB activation and increased mRNA levels of TNF-α in control but not in Cx43/Cx45 expression-deficient myofibers. Finally, a prolonged DEX treatment (7days) increased atrogin-1 and Murf-1 and reduced the cross sectional area of Cx43(fl/fl)Cx45(fl/fl) myofibers, but these parameters remained unaffected in Cx43(fl/fl)Cx45(fl/fl):Myo-Cre myofibers. Therefore, DEX-induced expression of Cx43 and Cx45 plays a critical role in early sarcolemma changes that lead to atrophy. Consequently, this side effect of chronic glucocorticoid treatment might be avoided by co-administration with a Cx HC blocker., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Skeletal muscles of patients with Duchenne muscular dystrophy (DMD) show numerous alterations including inflammation, apoptosis, and necrosis of myofibers. However, the molecular mechanism that explains these changes remains largely unknown. Here, the involvement of hemichannels formed by connexins (Cx HCs) was evaluated in skeletal muscle of mdx mouse model of DMD. Fast myofibers of mdx mice were found to express three connexins (39, 43 and 45) and high sarcolemma permeability, which was absent in myofibers of mdx Cx43(fl/fl)Cx45(fl/fl):Myo-Cre mice (deficient in skeletal muscle Cx43/Cx45 expression). These myofibers did not show elevated basal intracellular free Ca(2+) levels, immunoreactivity to phosphorylated p65 (active NF-κB), eNOS and annexin V/active Caspase 3 (marker of apoptosis) but presented dystrophin immunoreactivity. Moreover, muscles of mdx Cx43(fl/fl)Cx45(fl/fl):Myo-Cre mice exhibited partial decrease of necrotic features (big cells and high creatine kinase levels). Accordingly, these muscles showed similar macrophage infiltration as control mdx muscles. Nonetheless, the hanging test performance of mdx Cx43(fl/fl)Cx45(fl/fl):Myo-Cre mice was significantly better than that of control mdx Cx43(fl/fl)Cx45(fl/fl) mice. All three Cxs found in skeletal muscles of mdx mice were also detected in fast myofibers of biopsy specimens from patients with muscular dystrophy. Thus, reduction of Cx expression and/or function of Cx HCs may be potential therapeutic approaches to abrogate myofiber apoptosis in DMD.

Gemcitabine is a medication used to treat various types of malignant neoplasms. Its association with hemolytic uremic syndrome (HUS) has been described in few cases, although these cases have resulted in mortality rates of at least 50%. We report on the case of a 25-year-old patient with cholangiocarcinoma in remission who developed microangiopathic hemolytic anemia with acute anuric renal failure after receiving 5 cycles of gemcitabine chemotherapy; this condition was consistent with HUS caused by the side effects of this drug. The administration of gemcitabine was stopped, and hemodialysis, blood transfusions, plasma exchanges, steroids, doxycycline, and rituximab were used to treat the patient. A favorable outcome was achieved; in particular, hemolysis was controlled, and renal function was completely recovered.

The acquisition of myoblast commitment to the myogenic linage requires rises in intracellular free Ca(2+) concentration ([Ca(2+)]i). Putative cell membrane pathways involved in these [Ca(2+)]i increments are P2 receptors (P2Rs) as well as connexin (Cx) and/or pannexin (Panx) hemichannels and channels (Cx HChs and Panx Chs), respectively, which are known to permeate Ca(2+). Reserve cells (RCs) are uncommitted myoblasts obtained from differentiated C2C12 cell cultures, which acquire commitment upon replating. Regarding these cells, we found that extracellular ATP increases the [Ca(2+)]i via P2Rs. Moreover, ATP increases the plasma membrane permeability to small molecules and a non-selective membrane current, both of which were inhibited by Cx HCh/Panx1Ch blockers. However, RCs exposed to divalent cation-free saline solution, which is known to activate Cx HChs (but not Panx Chs), did not enhance membrane permeability, thus ruling out the possible involvement of Cx HChs. Moreover, ATP-induced membrane permeability was inhibited with blockers of P2Rs that activate Panx Chs. In addition, exogenous ATP induced the expression of myogenic commitment and increased MyoD levels, which was prevented by the inhibition of P2Rs or knockdown of Panx1 Chs. Similarly, increases in MyoD levels induced by ATP released by RCs were inhibited by Panx Ch/Cx HCh blockers. Myogenic commitment acquisition thus requires a feed-forward mechanism mediated by extracellular ATP, P2Rs, and Panx Chs.

Background and Purpose: Painful vertebral compression fractures in cancer patients reduce quality of life and may limit survival. We assessed pain relief, vertebral height restoration, and kyphosis correction following vertebral augmentation using a novel expandable titanium stent implant in cancer patients with painful vertebral compression fractures., Materials and Methods: Patients >18 years of age with metastatic disease who presented symptomatic compression fractures of vertebral bodies T5-L5, with or without a history of osteoporosis, were included in the study. Back pain at presentation, immediately after vertebral stenting, and at 1-, 3-, 6-, and 12-month follow-up was estimated using the visual analog scale (VAS). Vertebral height and local kyphotic angle (alpha angle) were measured on lateral standing X-ray before and 1-3 months after stenting., Results: Forty-one cancer patients with painful vertebral compression fractures underwent vertebral stenting procedures at 55 levels. There was no perioperative mortality and no significant complication. Median preoperative VAS was 8.0 (range 8-10), falling to 2.0 immediately postop (range 1-6, P  =  0.000) and 0 at all subsequent follow-up (P ≤ 0.012). Mean preoperative vertical height loss was 25.8% (range 0-84.0%) versus a postoperative mean of 18.0% (range 0-66.0%, P  =  0.000). Median pre- and postoperative kyphotic angle improved from 8.3° (range 0.2°-54.0°) to 7.1° (range 0.2°-25.0°, P  =  0.000). Wilcoxon signed rank test or student's t-test was used for comparisons., Conclusions: Vertebral augmentation using a novel vertebral stenting system provided immediate and enduring pain relief and improved vertebral height loss and kyphotic angle.

Superficial siderosis of the central nervous system is a syndrome caused by deposition of hemosiderin in the subpial layers of the central nervous system, occurring as a result of recurrent asymptomatic or symptomatic bleeding into the subarachnoid space. We report a rare case of superficial siderosis in a 33-year-old man who presented with sensorineural hearing loss. The diagnosis of superficial siderosis on MRI brain studies led to further investigations with detection of a spinal ependymoma at L1-L2, compressing the cauda equina. Gross total resection of the tumor arrested the progression of the neurological deterioration. Our report underlies the importance of early diagnosis and surgical management, with imaging examination of the full neuroaxis to identify the source of bleeding, to halt disease progression and improve prognosis., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Gap junction channels (GJCs) and hemichannels (HCs) are composed of protein subunits termed connexins (Cxs) and are permeable to ions and small molecules. In most organs, GJCs communicate the cytoplasm of adjacent cells, while HCs communicate the intra and extracellular compartments. In this way, both channel types coordinate physiological responses of cell communities. Cx mutations explain several genetic diseases, including about 50% of autosomal recessive non-syndromic hearing loss. However, the possible involvement of Cxs in the etiology of acquired hearing loss remains virtually unknown. Factors that induce post-lingual hearing loss are diverse, exposure to gentamicin an aminoglycoside antibiotic, being the most common. Gentamicin has been proposed to block GJCs, but its effect on HCs remains unknown. In this work, the effect of gentamicin on the functional state of HCs was studied and its effect on GJCs was reevaluated in HeLa cells stably transfected with Cxs. We focused on Cx26 because it is the main Cx expressed in the cochlea of mammals where it participates in purinergic signaling pathways. We found that gentamicin applied extracellularly reduces the activity of HCs, while dye transfer across GJCs was not affected. HCs were also blocked by streptomycin, another aminoglycoside antibiotic. Gentamicin also reduced the adenosine triphosphate release and the HC-dependent oscillations of cytosolic free-Ca(2+) signal. Moreover, gentamicin drastically reduced the Cx26 HC-mediated membrane currents in Xenopus laevis oocytes. Therefore, the extracellular gentamicin-induced inhibition of Cx HCs may adversely affect autocrine and paracrine signaling, including the purinergic one, which might partially explain its ototoxic effects.

Normal myotubes and adult innervated skeletal myofibers express the glycoprotein pannexin1 (Panx1). Six of them form a "gap junction hemichannel-like" structure that connects the cytoplasm with the extracellular space; here they will be called Panx1 channels. These are poorly selective channels permeable to ions, small metabolic substrate, and signaling molecules. So far little is known about the role of Panx1 channels in muscles but skeletal muscles of Panx1(-/-) mice do not show an evident phenotype. Innervated adult fast and slow skeletal myofibers show Panx1 reactivity in close proximity to dihydropyridine receptors in the sarcolemma of T-tubules. These Panx1 channels are activated by electrical stimulation and extracellular ATP. Panx1 channels play a relevant role in potentiation of muscle contraction because they allow release of ATP and uptake of glucose, two molecules required for this response. In support of this notion, the absence of Panx1 abrogates the potentiation of muscle contraction elicited by repetitive electrical stimulation, which is reversed by exogenously applied ATP. Phosphorylation of Panx1 Thr and Ser residues might be involved in Panx1 channel activation since it is enhanced during potentiation of muscle contraction. Under denervation, Panx1 levels are upregulated and this partially explains the reduction in electrochemical gradient, however its absence does not prevent denervation-induced atrophy but prevents the higher oxidative state. Panx1 also forms functional channels at the cell surface of myotubes and their functional state has been associated with intracellular Ca(2+) signals and regulation of myotube plasticity evoked by electrical stimulation. We proposed that Panx1 channels participate as ATP channels and help to keep a normal oxidative state in skeletal muscles.

Introduction: Endoscopic endonasal transsphenoidal surgery has gained increasing acceptance by otolaryngologists and neurosurgeons. In many centers throughout the world, this technique is now routinely used for the same indications as conventional microsurgical technique for pituitary tumors., Objective: To present a surgical experience of consecutive endoscopic endonasal trans-sphenoidal resections of pituitary adenomas., Methods: In this study, consecutive patients with pituitary adenomas submitted to endoscopic endonasal pituitary surgery were evaluated regarding the rate of residual tumor, functional remission, symptoms relief, complications, and tumor size., Results: Forty-seven consecutive patients were evaluated; 17 had functioning adenomas, seven had GH producing tumors, five had Cushing's disease, and five had prolactinomas. Of the functioning adenomas, 12 were macroadenomas and five were microadenomas; 30 cases were non-functioning macroadenomas. Of the patients with functioning adenomas, 87% improved. 85% of the patients with visual deficits related to optic nerve compression progressed over time. Most of the patients with complaints of headaches improved (76%). Surgical complications occurred in 10% of patients, which included with two carotid lesions, two cerebrospinal fluid leaks, and one death of a patient with a previous history of complications., Conclusion: Endoscopic endonasal pituitary surgery is a feasible technique, yielding good surgical and functional outcomes, and low morbidity.

Kinetics of permeation through connexin 43-EGFP hemichannels (Cx43-EGFP HCs) were evaluated in divalent cation-free solutions, which enhance HC open probability and thus, allow measurements during initial velocity. Three cations that become fluorescent upon binding to intracellular nucleic acids [ethidium (Etd), propidium (Prd) and 4',6-diamidino-2-phenylindole (DAPI)] and Cx43-EGFP or Cx43 wild type HeLa cell transfectants (Cx43-EGFP- and Cx43-WT-HeLa cells, respectively) were used. Levels of Cx43-EGFP at the cell periphery and rate of dye uptake were directly related. The rate of uptake of each dye reached saturation consistent with a facilitated transport mechanism. Before saturation, the relation between rate of uptake and concentration of each dye was sigmoidal with Hill coefficients >1, indicating positive cooperativity of transport at low concentrations. The maximal rate of Etd uptake was not affected by the presence of DAPI and vice versa, but under each condition the apparent affinity constant of the main permeant molecule increased significantly consistent with competitive inhibition or competition for binding sites within the channel. Moreover, Cx43-EGFP and Cx43-WT HCs had similar permeability properties, indicating that EGFP bound to the C-terminal of Cx43 does not significantly alter the permeability of Cx43 HCs to positively charged molecules. Thus, competitive inhibition of permeation through hemichannels might contribute to cellular retention of essential molecules and/or uptake inhibition of toxic compounds., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective: To evaluate the application of a limited transverse incision technique to treat the carpal tunnel syndrome, with concern to its safety and efficacy in the opening of the flexor retinaculum (FR)., Method: A prospective analysis of thirty FR release procedures performed on twenty-eight patients subjected to the proposed incision technique. Safety and total opening of the FR were evaluated through a questionnaire and an endoscopic inspection respectively., Results: No major complications were observed. Two cases presented small local hematoma. One patient presented with transient neuropraxia of digital branch. In two of the first five cases, incomplete FR opening was identified during endoscopic revision with need of complementary opening. All patients reported relief of paresthesias and nocturnal pain symptoms., Conclusion: The technique was safely performed on the prospection group, no major complications were detected and the opening of FR was observed in the majority of the patients.

Pleomorphic xanthoastrocytoma (PXA) is a rare superficial glioma that predominates in the young and has good prognosis. A long history of repeated seizures is commonly associated with PXA, which is frequently observed in neuroimaging scans as a solid-cystic, contrast-enhancing lesion. We report a case in which PXA diagnosis was favored by its histological features, such as pleomorphic multinucleated giant cells, with disproportionately few mitoses and necrotic areas. An eye-catching feature was widespread, pale-staining, circumscribed deposits in the cytoplasm of tumor cells, which turned out to be glycogen upon histochemical and electron-microscopical examination. The stored material was strongly PAS-positive and digested by diastase, and had a finely granular ultrastructural appearance. No evidence of lipid droplets was found on oil-red-O staining. The tumor was immunoreactive for glial fibrillary acidic protein and vimentin. Many cells were positive for CD34 on the external membrane, a feature which has been described in chronic CNS lesions associated with epilepsy. Intracytoplasmic immunostaining for EGFR was observed in most tumor cells, which might have favored neoplastic proliferation. Nuclear immunolabeling for p53 protein was rare and does not support a major role for p53 mutation in PXA tumorigenesis. Intracellular accumulation of glycogen in glial tumors is uncommon and may originate from abnormalities in carbohydrate metabolic pathways.

Objective: The objective of this study is to evaluate the value of angina pectoris as a predictor of CAD (coronary artery disease) in patients with AS (aortic stenosis) during and beyond the 5th decade of life., Methods: The study population consisted of 186 consecutive patients with AS and > or = 50 years of age, referred for surgical aortic valve replacement (AVR) between June 1989 and September 2004. Routine coronary angiography was performed for all patients. One hundred and one patients were males (54.3%) and 85 were females (45.7%), and the mean age was 66 +/- 8 years. One hundred and twenty-four patients (66.7%) had angina. The maximum transvalve gradient was 89.4 +/- 27.6 mmHg, and the aortic valve area measured 0.59 +/- 0.17 cm2. We calculated the sensitivity, specificity, positive and negative predictive values, as well as the likelihood ratio of a positive test result for angina in predicting the presence of CAD., Results: Ninety-three patients (50%) had CAD. Of the 124 patients with angina, 68 (54.8%) had CAD, whereas of the 62 patients without angina, 25 had CAD (40.3%) (p=0.087). Therefore, the diagnostic sensitivity of angina to detect CAD was 73.1%, specificity was 39.7%, positive predictive value was 54.8%, negative predictive value was 59.6%, and the likelihood ratio of a positive test result was 1.6., Conclusion: Angina pectoris is not a good predictor of CAD in patients with AS who are more than 50 years of age.

Syringohydromyelia is defined as a longitudinal dilatation of the central canal of the spinal cord with accumulated cerebrospinal fluid. This condition may cause neurologic deficits when the cavity enlarges and compresses the spinal cord. We present the case of a 33 years-old female with progressive paraparesis caused by syringohydromyelia. This patient underwent previously multiple clinical and surgical treatments for severe form of neurocysticercosis. Surgical decompression of the posterior fossa and syringostomy resolved the neurologic symptoms. The possibility of syringohydromyelia should be considered in the case of patients who have previously undergone surgical and clinical treatment for severe form of neurocysticercosis.

Phenotypic and genetic characterization indicated that Hup+ bean rhizobial strains are type IIA and type IIB Rhizobium tropici. The Hup+ strain USDA 2840, which did not cluster with either of the two types of R. tropici in a restriction fragment length polymorphism analysis, had electrophoretic patterns of PCR products generated with primers for repetitive extragenic palindromic and enterobacterial repetitive intergeneric consensus sequences similar to those of three reference strains of R. tropici type IIA. The Hup+ strain USDA 2738, which clustered with the reference strain of R. tropici IIB in a restriction fragment length polymorphism analysis, had electrophoretic patterns of PCR products generated with primers for repetitive extragenic palindromic and enterobacterial repetitive intergeneric consensus sequences more closely resembling those of the reference strains of R. tropici type IIA than those of type IIB. DNA amplification with the Y1 and Y2 primers to generate a portion of the 16S rDNA operon was useful to distinguish R. tropici type IIA strains from other bean rhizobial strains. The phylogenetic position of the type IIA strain of R. tropici USDA 2840, determined from the partial 16S rDNA sequence, indicated a more distant relationship with the type IIB strain of R. tropici CIAT899 than with the as yet unnamed rhizobial species of Leucaena leucocephala, TAL 1145. Therefore, we suggest that it may be appropriate either to separate R. tropici types IIA and IIB into two different species or to identify TAL 1145 to the species level as a third type of R. tropici.

Strains of Rhizobium forming nitrogen-fixing symbioses with common bean were systematically examined for the presence of the uptake hydrogenase (hup) structural genes and expression of uptake hydrogenase (Hup) activity. DNA with homology to the hup structural genes of Bradyrhizobium japonicum was present in 100 of 248 strains examined. EcoRI fragments with molecular sizes of approximately 20.0 and 2.2 kb hybridized with an internal SacI fragment, which contains part of both bradyrhizobial hup structural genes. The DNA with homology to the hup genes was located on pSym of one of the bean rhizobia. Hup activity was observed in bean symbioses with 13 of 30 strains containing DNA homologous with the hup structural genes. However, the Hup activity was not sufficient to eliminate hydrogen evolution from the nodules. Varying the host plant with two of the Hup strains indicated that expression of Hup activity was host regulated, as has been reported with soybean, pea, and cowpea strains.

A case of spinal intramedullary cysticercosis in a 13-year-old Brazilian female and a case of spinal leptomeningeal infestation by cysticercosis in a 51 year-old Brazilian female are presented. A review of 95 published cases of medullar cysticercosis since 1856 shows the incidence of this condition. Extramedullary forms are explained by the downward migration of larvae from the cerebral to the spinal subarachnoid space and most larvae are expected to be stopped in the upper portions of the spinal canal due to peculiarities of the anatomy of the spinal cord.

An adult female patient presented with an exclusively spinal leptomeningeal infestation by cysticercosis (restricted to the cauda equina), verified in surgery. The rôle of the vertebral vein system in the spread of cysticercosis larvae is discussed. A commentary on the possibility that cysticercosis of the basal cisterns may be due to ascending migration of primarily spinal cysticerel, as originally proposed by Isamat de la Riva, is stated.

Lumbar-disc protrusions (LDP) constitute well-defined syndromes on clinical and anatomical grounds, and neurosurgeons are prone to rely upon the clinical signs to identify the level of disc protrusion when a "typical" case is found. Sometimes, non-contrasted computerized tomographic (CT) scans centered on the L5-S1, L4-L5 and L3-L4 interspaces and spine roentgenograms are the only special ancillary means in presurgical evaluation. We report three patients from our series, in which neoplastic spinal disease presented as classic LDP (one patient with a cauda equina schwannoma, and two with metastatic carcinoma). The cases were chosen because they posed special problems to the referred radiodiagnostic routine. Systematic CT-evaluation of the sacrum and conus medullaris zone is recommended in every patient with lumbosacral radiculopathy, and intrathecal contrast should be employed in patients with unreliable findings or normal CT-scans.

A case is reported of the so-called Tethered Cervical Spinal Cord Syndrome presenting as multiradicular pain on an upper limb in a 45-year old woman, in whom spina bifida occulta (C6) was associated with an intramedullary lipoma, intradural fibrous adhesions and the fusion of the sixth and seventh cervical vertebrae. Surgical release of the tether was ineffective, and the patient underwent a posterior rhizotomy for pain relief. The clinical and maldevelopmental aspects of this most uncommon form of spinal cord tethering are discussed briefly.

A case of progressive bulbar and long tract symptoms with hydrocephalus of eleven years duration in a 23-year-old man, in whom an arachnoid cyst of the cisterna magna cerebellomedullaris was disclosed at operation.