Bisphenol-A and residual monomer leaching from orthodontic adhesive resins and polycarbonate brackets: a systematic review

INTRODUCTION The objective of this systematic review was to assess the short- and long-term release of components of orthodontic adhesives and polycarbonate brackets in the oral environment. METHODS Electronic database searches of published and unpublished literature were performed. The following electronic databases with no language and publication date restrictions were searched: MEDLINE (via Ovid and PubMed), EMBASE (via Ovid), Cochrane Oral Health Group's Trials Register, and CENTRAL. Unpublished literature was searched on ClinicalTrials.gov, the National Research Register, and Pro-Quest Dissertation Abstracts and Thesis database. The reference lists of all eligible studies were checked for additional studies. Two review authors performed data extraction independently and in duplicate using data collection forms. Disagreements were resolved by discussion or the involvement of an arbiter. RESULTS No randomized controlled trial was identified. In the absence of randomized controlled trials, observational studies were included. Eleven studies met the inclusion criteria. All were observational studies conducted in vivo or in vitro. The bisphenol-A release from orthodontic bonding resins was found to be between 0.85 and 20.88 ng per milliliter in vivo, and from traces to 65.67 ppm in vitro. Polycarbonate brackets released amounts of 22.24 μg per gram in ethanol solution and 697 μg per gram after 40 months in water. Bis-GMA and TEGDMA leaching in vitro reached levels of 64 and 174 mg per 10 μL, respectively. Because of the heterogeneity in methodologies and reporting, only qualitative synthesis was performed. CONCLUSIONS The available evidence on this topic derived from observational in-vivo and in-vitro studies that represent a moderate level of evidence. The variety of setups and the different units allied to the diversity of reporting among studies did not allow calculation of pooled estimates.

Transapical access closure: the TA PLUG device

OBJECTIVES Percutaneous closure of the transapical (TA) access site for large-calibre devices is an unsolved issue. We report the first experimental data on the TA PLUG device for true-percutaneous closure following large apical access for transcatheter aortic valve implantation. METHODS The TA PLUG, a self-sealing full-core closure device, was implanted in an acute animal study in six pigs (60.2 ± 0.7 kg). All the pigs received 100 IU/kg of heparin. The targeted activated clotting time was left to normalize spontaneously. After accessing the left ventricular apex with a 39 French introducer, the closure plug device was delivered with a 33 French over-the-wire system under fluoroscopic guidance into the apex. Time to full haemostasis as well as rate of bleeding was recorded. Self-anchoring properties were assessed by haemodynamic push stress under adrenalin challenge. An additional feasibility study was conducted in four pigs (58.4 ± 1.1 kg) with full surgical exposure of the apex, and assessed device anchoring by pull-force measurements with 0.5 Newton (N) increments. All the animals were electively sacrified. Post-mortem analysis of the heart was performed and the renal embolic index assessed. RESULTS Of six apical closure devices, five were correctly inserted and fully deployed at the first attempt. One became blocked in the delivery system and was placed successfully at the second attempt. In all the animals, complete haemostasis was immediate and no leak was recorded during the 5-h observation period. Neither leak nor any device dislodgement was observed under haemodynamic push stress with repeated left ventricular peak pressure of up to 220 mmHg. In the feasibility study assessing pull-stressing, device migration occurred at a force of 3.3 ± 0.5 N corresponding to 247.5 mmHg. Post-mortem analyses confirmed full expansion of all devices at the intended target. No macroscopic damage was identified at the surrounding myocardium. The renal embolic index was zero. CONCLUSIONS True-percutaneous left ventricular apex closure following large access is feasible with the self-sealing TA PLUG. The device allows for immediate haemostasis and a reliable anchoring in the acute animal setting. This is the first report of a true-percutaneous closure for large-calibre transcatheter aortic valve implantation access.

Positional guidelines for orthodontic mini-implant placement in the anterior alveolar region: a systematic review

PURPOSE To investigate the adequacy of potential sites for insertion of orthodontic mini-implants (OMIs) in the anterior alveolar region (delimited by the first premolars) through a systematic review of studies that used computed tomography (CT) or cone beam CT (CBCT) to assess anatomical hard tissue parameters, such as bone thickness, available space, and bone density. MATERIALS AND METHODS MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched to identify all relevant papers published between 1980 and September 2011. An extensive search strategy was performed that included the key words "computerized (computed) tomography" and "mini-implants." Information was extracted from the eligible articles for three anatomical areas: maxillary anterior buccal, maxillary anterior palatal, and mandibular anterior buccal. Quantitative data obtained for each anatomical variable under study were evaluated qualitatively with a scoring system. RESULTS Of the 790 articles identified by the search, 8 were eligible to be included in the study. The most favorable area for OMI insertion in the anterior maxilla (buccally and palatally) and mandible is between the canine and the first premolar. The best alternative area in the maxilla (buccally) and the mandible is between the lateral incisor and the canine, while in the maxillary palatal area it is between the central incisors or between the lateral incisor and the canine. CONCLUSIONS Although there is considerable heterogeneity among studies, there is a good level of agreement regarding the optimal site for OMI placement in the anterior region among investigations of anatomical hard tissue parameters based on CT or CBCT scans. In this context, the area between the lateral incisor and the first premolar is the most favorable. However, interroot distance seems to be a critical factor that should be evaluated carefully.

One-stage laparoscopic surgery for inspissated bile syndrome: case report and review of surgical techniques

Inspissated bile syndrome in a 6 week old boy was unresponsive to oral ursodesoxycholic acid. Intraoperative cholangiography revealed complete obstruction of the common bile duct. Therefore, the gallbladder fundus was pulled out through a laparoscopy port site and sutured to the fascia. A catheter was positioned into the infundibulum for irrigation with ursodesoxycholic acid. At day 8 complete resolution of the plug and free passage of contrast medium into the duodenum was documented radiologically. The catheter was removed, skin closed spontaneously without a second surgery for closure of the gall bladder.

Challenges and strategies in the repair of ruptured annulus fibrosus

Lumbar discectomy is the surgical procedure most frequently performed for patients suffering from low back pain and sciatica. Disc herniation as a consequence of degenerative or traumatic processes is commonly encountered as the underlying cause for the painful condition. While discectomy provides favourable outcome in a majority of cases, there are conditions where unmet requirements exist in terms of treatment, such as large disc protrusions with minimal disc degeneration; in these cases, the high rate of recurrent disc herniation after discectomy is a prevalent problem. An effective biological annular repair could improve the surgical outcome in patients with contained disc herniations but otherwise minor degenerative changes. An attractive approach is a tissue-engineered implant that will enable/stimulate the repair of the ruptured annulus. The strategy is to develop three-dimensional scaffolds and activate them by seeding cells or by incorporating molecular signals that enable new matrix synthesis at the defect site, while the biomaterial provides immediate closure of the defect and maintains the mechanical properties of the disc. This review is structured into (1) introduction, (2) clinical problems, current treatment options and needs, (3) biomechanical demands, (4) cellular and extracellular components, (5) biomaterials for delivery, scaffolding and support, (6) pre-clinical models for evaluation of newly developed cell- and material-based therapies, and (7) conclusions. This article highlights that an interdisciplinary approach is necessary for successful development of new clinical methods for annulus fibrosus repair. This will benefit from a close collaboration between research groups with expertise in all areas addressed in this review.

Congenital portosystemic shunt: characterization of a multisystem disease

OBJECTIVES Congenital portosystemic shunts (CPSSs) are rare but increasingly recognized as a cause of important multisystem morbidity. We present new cases and a systematic literature review and propose an algorithm for the identification and care of affected patients. METHODS We reviewed the charts of consecutive patients seen in our pediatric liver clinic between 2003 and 2010 and systematically reviewed the literature of cases with CPSS. RESULTS We identified 316 published cases and 12 patients in our own clinic. Of the published cases (177 male), 185 had an extrahepatic and 131 an intrahepatic portosystemic shunt. Diagnosis was made at any age, from prenatal to late adulthood. Cardiac anomalies were found in 22% of patients. The main complications were hyperammonemia/neurological abnormalities (35%), liver tumors (26%), and pulmonary hypertension or hepatopulmonary syndrome (18%). The spectrum of neurological involvement ranged from changes in brain imaging, subtle abnormalities on neuropsychological testing, through learning disabilities to overt encephalopathy. Spontaneous shunt closure occurred mainly in infants with intrahepatic shunts. Therapeutic interventions included shunt closure by surgery or interventional radiology techniques (35%) and liver transplantation (10%) leading to an improvement of symptoms in the majority. These findings mirror the observations in our own patients. CONCLUSIONS In this largest review of the reported clinical experience, we identify that children with CPSS may present with otherwise unexplained developmental delay, encephalopathy, pulmonary hypertension, hypoxemia, or liver tumors. When CPSS is diagnosed, children should be screened for all of these complications. Spontaneous closure of intrahepatic shunts may occur in infancy. Closure of the shunt is indicated in symptomatic patients and is associated with a favorable outcome.

AMPA RECEPTOR ALLOSTERISM: MEASUREMENT OF THE CONFORMATIONAL CHANGES IN THE LIGAND BINDING DOMAIN OF A FUNCTIONAL RECEPTOR

Ionotropic glutamate receptors are important excitatory neurotransmitter receptors in the mammalian central nervous system that have been implicated in a number of neuropathologies such as epilepsy, ischemia, and amyotrophic lateral sclerosis. Glutamate binding to an extracellular ligand binding domain initiates a series of structural changes that leads to the formation of a cation selective transmembrane channel, which consequently closes due to desensitization of the receptor. The crystal structures of the AMPA subtype of the glutamate receptor have been particularly useful in providing initial insight into the conformational changes in the ligand binding domain; however, these structures are limited by crystallographic constraint. To gain a clear picture of how agonist binding is coupled to channel activation and desensitization, it is essential to study changes in the ligand binding domain in a dynamic, physiological state. In this dissertation, a technique called Luminescence Resonance Energy Transfer was used to determine the conformational changes associated with activation and desensitization in a functional AMPA receptor (ÄN*-AMPA) that contains the ligand binding domain and transmembrane segments; ÄN*-AMPA has been modified such that fluorophores can be introduced at specific sites to serve as a readout of cleft closure or to establish intersubunit distances. Previous structural studies of cleft closure of the isolated ligand binding domain in conjunction with functional studies of the full receptor suggest that extent of cleft closure correlates with extent of activation. Here, LRET has been used to show that a similar relationship between cleft closure and activation is observed in the “full length” receptor showing that the isolated ligand binding domain is a good model of the domain in the full length receptor for changes within a subunit. Similar LRET investigations were used to study intersubunit distances specifically to probe conformational changes between subunits within a dimer in the tetrameric receptor. These studies show that the dimer interface is coupled in the open state, and decoupled in the desensitized state, similar to the isolated ligand binding domain crystal structure studies. However, we show that the apo state dimer interface is not pre-formed as in the crystal structure, hence suggesting a mechanism for functional transitions within the receptor based on LRET distances obtained.

Effect of progressive mandibular advancement on pharyngeal airway size in anesthetized adults.

BACKGROUND: General anesthesia in adult humans is associated with narrowing or complete closure of the pharyngeal airway. The purpose of this study was to determine the effect of progressive mandibular advancement on pharyngeal airway size in normal adults during intravenous infusion of propofol for anesthesia. METHODS: Magnetic resonance imaging was performed in nine normal adults during wakefulness and during propofol anesthesia. A commercially available intraoral appliance was used to manually advance the mandible. Images were obtained during wakefulness without the appliance and during anesthesia with the participants wearing the appliance under three conditions: without mandibular advancement, advancement to 50% maximum voluntary advancement, and maximum advancement. Using computer software, airway area and maximum anteroposterior and lateral airway diameters were measured on the axial images at the level of the soft palate, uvula, tip of the epiglottis, and base of the epiglottis. RESULTS: Airway area across all four airway levels decreased during anesthesia without mandibular advancement compared with airway area during wakefulness (P < 0.007). Across all levels, airway area at 50% advancement during anesthesia was less than that at centric occlusion during wakefulness (P = 0.06), but airway area with maximum advancement during anesthesia was similar to that during wakefulness (P = 0.64). In general, anteroposterior and lateral airway diameters during anesthesia without mandibular advancement were decreased compared with wakefulness and were restored to their wakefulness values with 50% and/or maximal advancement. CONCLUSIONS: Maximum mandibular advancement during propofol anesthesia is required to restore the pharyngeal airway to its size during wakefulness in normal adults.

Association of retinoic acid receptor genes with meningomyelocele.

BACKGROUND: Neural tube defects (NTDs) occur in as many as 0.5-2 per 1000 live births in the United States. One of the most common and severe neural tube defects is meningomyelocele (MM) resulting from failed closure of the caudal end of the neural tube. MM has been induced by retinoic acid teratogenicity in rodent models. We hypothesized that genetic variants influencing retinoic acid (RA) induction via retinoic acid receptors (RARs) may be associated with risk for MM. METHODS: We analyzed 47 single nucleotide polymorphisms (SNPs) that span across the three retinoic acid receptor genes using the SNPlex genotyping platform. Our cohort consisted of 610 MM families. RESULTS: One variant in the RARA gene (rs12051734), three variants in the RARB gene (rs6799734, rs12630816, rs17016462), and a single variant in the RARG gene (rs3741434) were found to be statistically significant at p < 0.05. CONCLUSION: RAR genes were associated with risk for MM. For all associated SNPs, the rare allele conferred a protective effect for MM susceptibility.

Association of folate receptor (FOLR1, FOLR2, FOLR3) and reduced folate carrier (SLC19A1) genes with meningomyelocele.

BACKGROUND: Meningomyelocele (MM) results from lack of closure of the neural tube during embryologic development. Periconceptional folic acid supplementation is a modifier of MM risk in humans, leading toan interest in the folate transport genes as potential candidates for association to MM. METHODS: This study used the SNPlex Genotyping (ABI, Foster City, CA) platform to genotype 20 single polymorphic variants across the folate receptor genes (FOLR1, FOLR2, FOLR3) and the folate carrier gene (SLC19A1) to assess their association to MM. The study population included 329 trio and 281 duo families. Only cases with MM were included. Genetic association was assessed using the transmission disequilibrium test in PLINK. RESULTS: A variant in the FOLR2 gene (rs13908), three linked variants in the FOLR3 gene (rs7925545, rs7926875, rs7926987), and two variants in the SLC19A1 gene (rs1888530 and rs3788200) were statistically significant for association to MM in our population. CONCLUSION: This study involved the analyses of selected single nucleotide polymorphisms across the folate receptor genes and the folate carrier gene in a large population sample. It provided evidence that the rare alleles of specific single nucleotide polymorphisms within these genes appear to be statistically significant for association to MM in the patient population that was tested.

Addressing Obesity: Fear of Crime, Perceptions of Disorder and Disaparities in Child and Adolescent Use of Public Parks

Abstract The objectives of this study were: 1) To determine factors which inhibit and facilitate child and adolescent use of outdoor spaces for healthy physical activity by race and ethnicity in four Houston communities and 2) To propose guidelines for encouraging and maintaining child and adolescent outdoor physical activity. Using local health data and Houston Police Department crime statistics, four communities were identified for the study that had the highest concentration of crime and the racial/ ethnic groups of interest. The researchers then identified public parks in the communities. At least two parks were observed in each of the four communities from 2010 to 2011 during spring, summer, fall and winter. The parks were observed for use by children and adolescents and to describe the condition of the park spaces. The communities were Alief (Asian), Sunnyside (Black), Eldridge- West Oaks (White) and Northside- Northline (Hispanic). Observations were made at varying hours of both day and night, weekdays and weekends. Photographs were taken and the condition of the spaces noted in detail. One hundred and twenty persons, 18 years and over, using the spaces or otherwise in these communities were conveniently sampled and interviewed about their health and the extent to which they, or any children or adolescents under their care, used the outdoor spaces of interest. Data were analyzed qualitatively and with basic descriptive statistics. The photographs, journal notes and observation notes of all investigators and key personnel were analyzed. Interview data were also coded to identify patterns and themes in the responses. The findings indicate disparities in the quality and quantity of park equipment and the maintenance of the areas. Where perceptions of disorder were described, there was often visible evidence to support the perceptions. In many cases, residents' perceptions of crime were corroborated by police data. While interview reports did not seem to support the expectation that the condition of the parks was a significant deterrent to their use by children and adolescents, the condition of the parks might be said to limit the extent of that use. Specific reports of disorder that inhibited use included hearing gunfire, seeing drug dependent homeless persons and/or suspected prostitutes in an area.

Effects of erythropoiesis-stimulating agents on fatigue- and anaemia-related symptoms in cancer patients: systematic review and meta-analyses of published and unpublished data.

Background:Erythropoiesis-stimulating agents (ESAs) reduce the need for red blood cell transfusions; however, they increase the risk of thromboembolic events and mortality. The impact of ESAs on quality of life (QoL) is controversial and led to different recommendations of medical societies and authorities in the USA and Europe. We aimed to critically evaluate and quantify the effects of ESAs on QoL in cancer patients.Methods:We included data from randomised controlled trials (RCTs) on the effects of ESAs on QoL in cancer patients. Randomised controlled trials were identified by searching electronic data bases and other sources up to January 2011. To reduce publication and outcome reporting biases, we included unreported results from clinical study reports. We conducted meta-analyses on fatigue- and anaemia-related symptoms measured with the Functional Assessment of Cancer Therapy-Fatigue (FACT-F) and FACT-Anaemia (FACT-An) subscales (primary outcomes) or other validated instruments.Results:We identified 58 eligible RCTs. Clinical study reports were available for 27% (4 out of 15) of the investigator-initiated trials and 95% (41 out of 43) of the industry-initiated trials. We excluded 21 RTCs as we could not use their QoL data for meta-analyses, either because of incomplete reporting (17 RCTs) or because of premature closure of the trial (4 RCTs). We included 37 RCTs with 10 581 patients; 21 RCTs were placebo controlled. Chemotherapy was given in 27 of the 37 RCTs. The median baseline haemoglobin (Hb) level was 10.1 g dl(-1); in 8 studies ESAs were stopped at Hb levels below 13 g dl(-1) and in 27 above 13 g dl(-1). For FACT-F, the mean difference (MD) was 2.41 (95% confidence interval (95% CI) 1.39-3.43; P<0.0001; 23 studies, n=6108) in all cancer patients and 2.81 (95% CI 1.73-3.90; P<0.0001; 19 RCTs, n=4697) in patients receiving chemotherapy, which was below the threshold (⩾3) for a clinically important difference (CID). Erythropoiesis-stimulating agents had a positive effect on anaemia-related symptoms (MD 4.09; 95% CI 2.37-5.80; P=0.001; 14 studies, n=2765) in all cancer patients and 4.50 (95% CI 2.55-6.45; P<0.0001; 11 RCTs, n=2436) in patients receiving chemotherapy, which was above the threshold (⩾4) for a CID. Of note, this effect persisted when we restricted the analysis to placebo-controlled RCTs in patients receiving chemotherapy. There was some evidence that the MDs for FACT-F were above the threshold for a CID in RCTs including cancer patients receiving chemotherapy with Hb levels below 12 g dl(-1) at baseline and in RCTs stopping ESAs at Hb levels above 13 g dl(-1). However, these findings for FACT-F were not confirmed when we restricted the analysis to placebo-controlled RCTs in patients receiving chemotherapy.Conclusions:In cancer patients, particularly those receiving chemotherapy, we found that ESAs provide a small but clinically important improvement in anaemia-related symptoms (FACT-An). For fatigue-related symptoms (FACT-F), the overall effect did not reach the threshold for a CID.British Journal of Cancer advance online publication, 17 April 2014; doi:10.1038/bjc.2014.171 www.bjcancer.com.

Anatomic pathways of peripancreatic fluid draining to mediastinum in recurrent acute pancreatitis: visible human project and CT study

BACKGROUND In past reports, researchers have seldom attached importance to achievements in transforming digital anatomy to radiological diagnosis. However, investigators have been able to illustrate communication relationships in the retroperitoneal space by drawing potential routes in computerized tomography (CT) images or a virtual anatomical atlas. We established a new imaging anatomy research method for comparisons of the communication relationships of the retroperitoneal space in combination with the Visible Human Project and CT images. Specifically, the anatomic pathways of peripancreatic fluid extension to the mediastinum that may potentially transform into fistulas were studied. METHODS We explored potential pathways to the mediastinum based on American and Chinese Visible Human Project datasets. These drainage pathways to the mediastinum were confirmed or corrected in CT images of 51 patients with recurrent acute pancreatitis in 2011. We also investigated whether additional routes to the mediastinum were displayed in CT images that were not in Visible Human Project images. PRINCIPAL FINDINGS All hypothesized routes to the mediastinum displayed in Visible Human Project images, except for routes from the retromesenteric plane to the bilateral retrorenal plane across the bilateral fascial trifurcation and further to the retrocrural space via the aortic hiatus, were confirmed in CT images. In addition, route 13 via the narrow space between the left costal and crural diaphragm into the retrocrural space was demonstrated for the first time in CT images. CONCLUSION This type of exploration model related to imaging anatomy may be used to support research on the communication relationships of abdominal spaces, mediastinal spaces, cervical fascial spaces and other areas of the body.

Does the maxillary midline diastema close after frenectomy?

OBJECTIVE To analyze the closure, persistence or reopening of the maxillary midline diastema after frenectomy in patients with and without subsequent orthodontic treatment. METHOD AND MATERIALS All patients undergoing frenectomy with a CO2 laser were included in this retrospective study during the period of September 2002 to June 2011. Age and sex, the dimension of the diastema, eruption status of the maxillary canines, and the presence of an orthodontic treatment were recorded at the day of frenectomy and during follow-up. RESULTS Of the 59 patients fulfilling the inclusion criteria, 31 (52.5%) had an active orthodontic therapy, while 27 (45.8%) had a frenectomy without orthodontic treatment. For one patient, information concerning orthodontic treatment was not available. In the first follow-up (2 to 12 weeks), only four diastemas closed after frenectomy and orthodontic treatment, and none after frenectomy alone. In the second follow-up (4 to 19 months), statistically significantly (P = .002) more diastemas (n = 20) closed with frenectomy and orthodontic treatment than with frenectomy alone (n = 3). At the long-term (21 to 121 months) follow-up, only four patients had a persisting diastema, and in three patients orthodontic treatment was ongoing. CONCLUSION Closure of the maxillary midline diastema with a prominent frenum is more predictable with frenectomy and concomitant orthodontic treatment than with frenectomy alone. This study demonstrates the importance of an interdisciplinary approach to treat maxillary midline diastemas, ideally including general practitioners, oral surgeons, periodontists, and orthodontists.

Influence of the Central American Seaway and Drake Passage on ocean circulation and neodymium isotopes: A model study

The sensitivity of the neodymium isotopic composition (ϵNd) to tectonic rearrangements of seaways is investigated using an Earth System Model of Intermediate Complexity. The shoaling and closure of the Central American Seaway (CAS) is simulated, as well as the opening and deepening of Drake Passage (DP). Multiple series of equilibrium simulations with various intermediate depths are performed for both seaways, providing insight into ϵNd and circulation responses to progressive throughflow evolutions. Furthermore, the sensitivity of these responses to the Atlantic Meridional Overturning Circulation (AMOC) and the neodymium boundary source is examined. Modeled ϵNd changes are compared to sediment core and ferromanganese (Fe-Mn) crust data. The model results indicate that the North Atlantic ϵNd response to the CAS shoaling is highly dependent on the AMOC state, i.e., on the AMOC strength before the shoaling to shallow depths (preclosure). Three scenarios based on different AMOC forcings are discussed, of which the model-data agreement favors a shallow preclosure (Miocene) AMOC (∼6 Sv). The DP opening causes a rather complex circulation response, resulting in an initial South Atlantic ϵNd decrease preceding a larger increase. This feature may be specific to our model setup, which induces a vigorous CAS throughflow that is strongly anticorrelated to the DP throughflow. In freshwater experiments following the DP deepening, ODP Site 1090 is mainly influenced by AMOC and DP throughflow changes, while ODP Site 689 is more strongly influenced by Southern Ocean Meridional Overturning Circulation and CAS throughflow changes. The boundary source uncertainty is largest for shallow seaways and at shallow sites.