Does the use of intrawound povidone-iodine irrigation and local vancomycin powder impact surgical site infection rate in adolescent idiopathic scoliosis surgery?

PURPOSE: Surgical site infection (SSI) is a major complication after adolescent idiopathic scoliosis (AIS) surgery, with an incidence ranging from 0.5 to 7%. Intraoperative wound decontamination with povidone-iodine (PVP-I) irrigation and/or vancomycin powder in adult spinal surgery has gained attention in the literature with controversial results. The aim of this study was to investigate the impact of using intrawound PVP-I irrigation and local vancomycin powder (LVP) on the incidence of early SSI in AIS surgery. METHODS: All AIS patients who underwent posterior spinal fusion between October 2016 and December 2019 were retrospectively reviewed. The incidence of early SSI was reported and compared between 2 groups defined by the treating spinal surgeons' preferences: group 1-intrawound irrigation with 2L of PVP-I and application of 3 g LVP before closure and control group 2-patients that did not receive either of these measures. RESULTS: Nine early cases of SSI (2.9%) were reported among the 307 AIS posterior spinal fusion patients. Incidence of SSI in group 1 (2/178 = 1.1%) was significantly lower than in group 2 (7/129 = 5.4%; p = 0.04). There were no adverse reactions to the use of PVP-I and LVP in our study. At latest follow-up, rate of surgical revision for mechanical failure with pseudarthrosis was significantly lower in group 1 (2/178 = 1.1%) than in group 2 (9/129 = 7.0%; p = 0.01). CONCLUSION: Intraoperative use of intrawound PVP-I irrigation and vancomycin powder is associated with a significant reduction of early SSI after AIS spine surgery. LEVEL OF EVIDENCE IV: Retrospective study.

Povidone Iodine: Properties, Mechanisms of Action, and Role in Infection Control and Staphylococcus aureus Decolonization.

Nasal decolonization is an integral part of the strategies used to control and prevent the spread of methicillin-resistant Staphylococcus aureus (MRSA) infections. The two most commonly used agents for decolonization are intranasal mupirocin 2% ointment and chlorhexidine wash, but the increasing emergence of resistance and treatment failure has underscored the need for alternative therapies. This article discusses povidone iodine (PVP-I) as an alternative decolonization agent and is based on literature reviewed during an expert's workshop on resistance and MRSA decolonization. Compared to chlorhexidine and mupirocin, respectively, PVP-I 10 and 7.5% solutions demonstrated rapid and superior bactericidal activity against MRSA in in vitro and ex vivo studies. Notably, PVP-I 10 and 5% solutions were also active against both chlorhexidine-resistant and mupirocin-resistant strains, respectively. Unlike chlorhexidine and mupirocin, available reports have not observed a link between PVP-I and the induction of bacterial resistance or cross-resistance to antiseptics and antibiotics. These preclinical findings also translate into clinical decolonization, where intranasal PVP-I significantly improved the efficacy of chlorhexidine wash and was as effective as mupirocin in reducing surgical site infection in orthopedic surgery. Overall, these qualities of PVP-I make it a useful alternative decolonizing agent for the prevention of S. aureus infections, but additional experimental and clinical data are required to further evaluate the use of PVP-I in this setting.

Long term results of the revisited Meary closing wedge tarsectomy for the treatment of the fixed cavo-varus foot in adolescent with Charcot-Marie-Tooth disease.

BACKGROUND: Various techniques have been proposed for the treatment of cavovarus feet (CVF). The aim of this study was to report outcomes of the revisited Meary's dorsal closing wedge tarsectomy for fixed CVF secondary to Charcot-Marie-Tooth (CMT) disease. METHODS: All CVF operated on between 1977 and 2011 were included. The tarsectomy design was modified from its original description and systemically combined with a plantar fascia release, a Dwyer osteotomy and a proximal extension osteotomy of the 1st metatarsal bone if required. Outcomes were assessed by 2 functional scores and radiographically. RESULTS: Among the 26 feet (20 patients), the Wicart and Seringe score was very good or good, fair and poor in respectively 58%, 23% and 19% of the feet. Hindfoot and midfoot AOFASs were of 95.5 and 75 respectively. All radiographic measures were significantly improved. CONCLUSIONS: This complete revisited procedure is an efficient and safe surgical technique for the treatment of the CMT disease CVF. LEVEL OF EVIDENCE: Level IV.

Sexual response of male Drosophila to honey bee queen mandibular pheromone: implications for genetic studies of social insects.

Honey bees secrete a queen mandibular pheromone that renders workers reproductively altruistic and drones sexually attentive. This sex-specific function of QMP may have evolved from a sexually dimorphic signaling mechanism derived from pre-social ancestors. If so, there is potential for pre-social insects to respond to QMP, and in a manner that is comparable to its normal effect on workers and drones. Remarkably, QMP applied to female Drosophila does induce worker-like qualities [Camiletti et al. (Entomol Exp Appl 147:262, 2013)], and we here extend this comparison to examine the effects of bee pheromone on male fruit flies. We find that male Drosophila melanogaster consistently orient towards a source of queen pheromone in a T-maze, suggesting a recruitment response comparable to the pheromone's normal effect on drones. Moreover, exposure to QMP renders male flies more sexually attentive; they display intensified pre-copulatory behavior towards conspecific females. We can inhibit this sexual effect through a loss-of-olfactory-function mutation, which suggests that the pheromone-responsive behavioral mechanism is olfactory-driven. These pheromone-induced changes to male Drosophila behavior suggest that aspects of sexual signaling are conserved between these two distantly related taxa. Our results highlight a role for Drosophila as a genetically tractable pre-social model for studies of social insect biology.

Specific interaction to PIP2 increases the kinetic rate of membrane binding of VILIPs, a subfamily of Neuronal Calcium Sensors (NCS) proteins.

VIsinin-LIke Proteins (VILIPs) are a subfamily of the Neuronal Calcium Sensor (NCS) proteins, which possess both N-myristoylation and EF-hand motifs allowing for a putative 'calcium-myristoyl switch' regulation mechanism. It has previously been established that myristoyl conjugation increases the affinity of proteins for membranes, but, in many cases, a second feature such as a cluster of positively-charged residues is needed for stable membrane binding. The interaction of two members of this family, VILIP-1 and VILIP-3, with Langmuir monolayers as membrane models has been investigated in order to study the effects of both myristoylation and the highly basic region containing conserved poly-lysine residues on membrane association kinetics and binding properties. Results show that in the presence of calcium, N-myristoylation significantly increases the kinetic rate of VILIP adsorption to the membrane. Additionally, the proteins bind to negatively charged phospholipids independently of the conjugated myristate moiety. Besides the regulatory effect of calcium on the rate of binding presumably due to exposure of the myristoyl moiety ascribed to their putative 'calcium-myristoyl switch', VILIP-1 and -3 also engage specific interactions with biomimetic membranes containing phosphatidylinositol 4,5-bisphosphate (PIP2). The presence of PIP2 increases the membrane association rates of both VILIPs. Taken together, these results show the major kinetic role of N-myristoylation for membrane binding, and highlight the critical role of specific phosphoinositide interactions for membrane association of members of the VILIP family.

Ripple formation in unilamellar-supported lipid bilayer revealed by FRAPP.

The mechanisms of formation and conditions of the existence of the ripple phase are fundamental thermodynamic questions with practical implications for medicine and pharmaceuticals. We reveal a new case of ripple formation occurring in unilamellar-supported bilayers in water, which results solely from the bilayer/support interaction, without using lipid mixtures or specific ions. This ripple phase is detected by FRAPP using diffusion coefficient measurements as a function of temperature: a diffusivity plateau is observed. It occurs in the same temperature range where ripple phase existence has been observed using other methods. When AFM experiments are performed in the appropriate temperature range the ripple phase is confirmed.

Performance of automatic exposure control on dose and image quality: comparison between slot-scanning and flat-panel digital radiography systems.

BACKGROUND: EOSedge™* (EOS Imaging, Paris, France) is an X-ray imaging system using automatic exposure control (AEC) with tube current modulation, in order to optimize dose deposition in patients. PURPOSE: This study aims at characterizing EOSedge organ dose deposition in comparison to a digital radiography (DR) system and the previous EOS system (EOS-1st generation), in relation to their respective image quality levels. METHOD: Organ doses were measured in an anthropomorphic female adult phantom and a 5-year-old pediatric phantom using optically stimulated luminescence (OSL) dosimeters, which were carefully calibrated within the studied energy range. Organ doses were recorded on the EOSedge and the Fuji Visionary DRF (Fujifilm Medical Systems U.S.A., Inc, Lexington, MA). The resulting effective doses were compared to the EOS-1st-generation values present in the literature. Image quality assessment was carried out on end-user images. Quantitative image quality metrics were computed for all tested modalities on a quality assurance phantom. Qualitative assessment of EOSedge image quality was based on anthropomorphic phantom acquisitions against the EOS-1st-generation system, and on clinical images against the tested DR system. RESULTS: For a full-spine exam, and on the female adult phantom (respectively, the pediatric phantom), an effective dose of 92 µSv (respectively, 32 µSv) was obtained on EOSedge, and 572 µSv (respectively, 179 µSv) on the DR system; these values were compared to effective dose values of 290 µSv (respectively, 200 µSv) from the literature on EOS-1st generation, leading to an effective dose reduction factor of 6 with respect to the DR system, and of 3-6 with respect to EOS-1st generation. EOSedge provides the best compromise between contrast-to-noise ratio (CNR) and dose, with more consistent CNR values than the other tested modalities, in a range of attenuation from 10 to 40 cm of poly(methyl methacrylate) (PMMA). Within this range, EOSedge is also comparable to DR for 10 and 20 cm of PMMA, and better than DR for 30 and 40 cm of PMMA, both in terms of spatial resolution and low-contrast detection. The anatomical landmarks of interest in the follow-up of spinal deformities can be detected in all tested modalities. CONCLUSION: Results showed that EOSedge provides significant dose reduction factors for full spine imaging in both adults and children compared to the other tested modalities, without compromising image quality. We believe that this work could help raise awareness on the capabilities of modern X-ray systems, when equipped with appropriate AEC strategies, to perform ultra-low-dose, long-axis images.

Annexin-A6 presents two modes of association with phospholipid membranes. A combined QCM-D, AFM and cryo-TEM study.

Annexins are soluble proteins that bind to biological membranes in a Ca(2+)-dependent manner. Annexin-A6 (AnxA6) is unique in the annexin family as it consists of the repeat of two annexin core modules, while all other annexins consist of a single module. AnxA6 has been proposed to participate in various membrane-related processes, including endocytosis and exocytosis, yet the molecular mechanism of association of AnxA6 with biological membranes, especially its ability to aggregate membranes, is still unclear. To address this question, we studied the association of AnxA6 with model phospholipid membranes by combining the techniques of quartz crystal microbalance with dissipation monitoring (QCM-D), (cryo-) transmission electron microscopy (TEM) and atomic force microscopy (AFM). The properties of membrane binding and membrane aggregation of AnxA6 were compared to two reference systems, annexin A5 (AnxA5), which is the annexin prototype, and a chimerical AnxA5-dimer molecule, which is able to aggregate two membranes in a symmetrical manner. We show that AnxA6 presents two modes of association with lipid membranes depending on Ca(2+)-concentration. At low Ca(2+)-concentration ( approximately 60-150microM), AnxA6 binds to membranes via its two coplanar annexin modules and is not able to associate two separate membranes. At high Ca(2+)-concentration ( approximately 2mM), AnxA6 molecules are able to bind two adjacent phospholipid membranes and present a conformation similar to the AnxA6 3D crystallographic structure. Possible biological implications of these novel membrane-binding properties of AnxA6 are discussed.

Efficacy of early treatment of acute hepatitis C infection with pegylated interferon and ribavirin in HIV-infected patients.

BACKGROUND: Treatment of acute hepatitis C (HCV) in HIV-infected patients has been poorly addressed. OBJECTIVE: To evaluate the efficacy and tolerability of a 24 week course of pegylated interferon alfa 2a (PegIFNalpha2a) and ribavirin for the treatment of acute HCV infection in HIV-infected patients. METHODS: This was a prospective pilot study of 25 consecutive HIV-infected men with acute HCV infection defined by documented HCV seroconversion to anti-HCV positive antibody and positive qualitative HCV RNA measurement. Patients with detectable HCV RNA (> 50 IU/ml) 12 weeks after diagnosis were offered treatment with PegIFNalpha2a (180 microg/week) and ribavirin (800 mg/day) for 24 weeks. Sustained virological response was defined by a negative qualitative HCV RNA measurement 24 weeks after the end of treatment. RESULTS: At baseline, 23 patients were taking HAART, 23 patients had HIV RNA < 200 copies/ml and a median CD4 count of 345 cells/microl. Only one patient, with genotype 3 HCV, had a spontaneous clearance of HCV RNA. Of the remaining 24 patients, four refused anti-HCV therapy, ribavirin was contraindicated in one and 19 initiated anti-HCV therapy. Median time between acute HCV diagnosis and initiation of study treatment was 14 weeks. Of the 14 patients who have achieved the post-treatment follow-up at 24 weeks, 10 had a sustained virological response (71%). Study treatment was well tolerated, with no change in CD4 cell count. CONCLUSION: Early treatment of acute HCV infection with PegIFNalpha2a and ribavirin for 24 weeks yields a high sustained virological response rate in HIV-infected patients.

Effectiveness of a new one-step self-etch adhesive in the restoration of non-carious cervical lesions: 2-year results of a randomized controlled practice-based study.

OBJECTIVES: The purpose of this practice-based randomized controlled trial was to evaluate the effectiveness of a new one-step self-etch adhesive to restore non-carious cervical lesions following CONSORT guidelines and to test the hypothesis that this adhesive is equally effective with or without beforehand selective etching of enamel. METHODS: Twenty-eight patients each received two restorations randomly assigned to the control or the experimental group. In the control group, the adhesive (Bond Force, Tokuyama) was applied without beforehand enamel phosphoric-acid-etching, whereas the latter was applied first in the experimental group. The restorative composites used for all restorations were Estelite Flow Quick followed by Estelite Sigma (Tokuyama). The clinical effectiveness was assessed at baseline, 6 months, 1 year and 2 years in terms of retention, marginal staining, restoration staining, and post-operative sensitivity. RESULTS: One restoration loss occurred in the control group before the 6-month recall. At the two-year recall, only 2 secondary endpoints showed significant differences between groups: marginal staining at the enamel occurred more often in the control group (29% vs. 5%) (hierarchical linear regression: p=0.011) and 'minor marginal defects' were significantly more frequent in the control group (29% vs. 0%) (hierarchical linear regression: p=0.009). SIGNIFICANCE: Although in a practice setting, the effectiveness of this new adhesive was very good after 2 years of clinical service. More minor defects and restoration staining at the enamel margin were noticed when enamel had not been selectively acid-etched. Selective enamel acid-etching might enhance the adhesive properties of this new one-step self-etch adhesive.

[Therapeutic patient education for children and adolescents: some dentofacial orthopedic reflections]. / Éducation thérapeutique de l'enfant et de l'adolescent: réflexions éthiques en orthopédie dento-faciale.

Non-compliance and, even more, abandonment of treatment raise many questions. From a medical and economic point of view, these occurrences affect the efficiency of the proposed therapy. These failures therefore invite us to question the nature and purpose of health care providers' mission. Adherence of the patient to medical advice is a key factor to the success of the therapy. Therefore, how can we modify the patient's behaviour, particularly when dealing with teenage patients? How can we adopt and make our own a therapeutic strategy encouraging cooperation of patients? Patient education, recently integrated into the French public health code (Code de la santé publique), brings new elements to answer these questions. The purpose of the present work is to question the concept of patient education, notably with regards to medical ethics. What can patient education bring to medical practices that face non compliance or deficiency of adherence to treatment recommendations? What new perspectives does patient education bring, notably regarding medical practices?