Seasonal changes characterise the shark and ray assemblages in a subtropical shallow sandy habitat in the iSimangaliso Wetland Park, South Africa

Understanding how environmental drivers influence shark and ray spatial and temporal patterns can provide crucial knowledge for their evidence-based protection and long-term monitoring. However, information on which drivers of variation are most important for elasmobranch communities on soft sediments is limited. Using baited remote underwater stereo-video systems (stereo-BRUVs), we investigated how seasonal and environmental variables affected the elasmobranchs of the iSimangaliso Wetland Park marine protected area (MPA) in South Africa (SA). In total, 11 species were identified from 48 sites between 12 m and 33 m water depth in a sandy habitat. While species richness was similar across seasons, the total abundance of elasmobranchs recorded was higher in winter than summer. The species assemblage composition varied significantly between seasons, with the Human's whaler shark Carcharhinus humani prevalent in summer and the Critically Endangered whitespotted wedgefish Rhynchobatus djiddensis more abundant during winter. Most species were sighted throughout the entire depth range, but rays were more common in shallower waters (< 25 m depth), while C. humani and R. djiddensis were more common in the deeper depth zone of this study. This research provides baseline information about this previously unexplored sandy habitat for elasmobranchs in a site of regional and global significance. Records of species of conservation concern in the sampling area highlight the importance of protecting sand environments within an MPA.

Adolescent and parental decision-making for the MenACWY vaccination: influential predictors and parental-adolescent differences among households in the Netherlands

BACKGROUND

Between 2015 and 2018 The Netherlands experienced increases of invasive meningococcal disease (IMD) serogroup W (MenW). Therefore in 2018 the MenACWY vaccination was introduced in the National Immunisation Programme (NIP) and a catch-up campaign was initiated targeting adolescents. This study aimed to gain insight into what factors played a role in the decision-making process regarding the MenACWY vaccination. The focus was on the differences in the decision-making of parents and adolescents in order to assess what factors influence the decisions made.

METHODS

An online questionnaire was offered to adolescents and one of their parents. We used random forest analyses to determine which factors best predict the outcome of the MenACWY vaccination decision. We carried out ROC (receiver-operator characteristics) analyses to confirm the predictive value of the variables.

RESULTS

Among parents several factors stand out, centring on the process of the decision, their attitude about the MenACWY vaccination, trust in the vaccination, and ideas of important people around them. Among adolescents the three stand-out predictors are the ideas of important people around them, the process of the decision and trust in the vaccination. Parents have prominent influence in the decision-making, while the adolescent's influence in the household decision-making is more limited. Adolescents tend to be less engaged and spend less time thinking about the decision compared to parents. Opinions of parents and adolescents from the same households concerning the factors that are influential do not differ a lot in the final decision-making.

CONCLUSIONS

Information about MenACWY vaccination might be mainly addressed to the parents of the adolescents and whereby the dialogue about MenACWY vaccination between parents and adolescents will be stimulated. With regard to the predictor trust in vaccination, raising the frequency of use of certain sources, especially those deemed very reliable among households such as conversations with a GP or the provider of the vaccination (GGD/JGZ), might prove a useful strategy to solidify vaccination uptake numbers.

Gelatin methacryloyl hydrogel as an injectable scaffold with multi-therapeutic effects to promote antimicrobial disinfection and angiogenesis for regenerative endodontics

Regenerative endodontics represents a paradigm shift in dental pulp therapy for necrotic young permanent teeth. However, there are still challenges associated with attaining maximum root canal disinfection while supporting angiogenesis and preserving resident stem cells viability and differentiation capacity. Here, we developed a hydrogel system by incorporating antibiotic-eluting fiber-based microparticles in gelatin methacryloyl (GelMA) hydrogel to gather antimicrobial and angiogenic properties while prompting minimum cell toxicity. Minocycline (MINO) or clindamycin (CLIN) was introduced into a polymer solution and electrospun into fibers, which were further cryomilled to attain MINO- or CLIN-eluting fibrous microparticles. To obtain hydrogels with multi-therapeutic effects, MINO- or CLIN-eluting microparticles were suspended in GelMA at distinct concentrations. The engineered hydrogels demonstrated antibiotic-dependent swelling and degradability while inhibiting bacterial growth with minimum toxicity in dental-derived stem cells. Notably, compared to MINO, CLIN hydrogels enhanced the formation of capillary-like networks of endothelial cells in vitro and the presence of widespread vascularization with functioning blood vessels in vivo. Our data shed new light onto the clinical potential of antibiotic-eluting gelatin methacryloyl hydrogel as an injectable scaffold with multi-therapeutic effects to promote antimicrobial disinfection and angiogenesis for regenerative endodontics.

Tissue-specific melt electrowritten polymeric scaffolds for coordinated regeneration of soft and hard periodontal tissues

Periodontitis is a chronic inflammatory condition that often causes serious damage to tooth-supporting tissues. The limited successful outcomes of clinically available approaches underscore the need for therapeutics that cannot only provide structural guidance to cells but can also modulate the local immune response. Here, three-dimensional melt electrowritten (i.e., poly(ε-caprolactone)) scaffolds with tissue-specific attributes were engineered to guide differentiation of human-derived periodontal ligament stem cells (hPDLSCs) and mediate macrophage polarization. The investigated tissue-specific scaffold attributes comprised fiber morphology (aligned vs. random) and highly-ordered architectures with distinct strand spacings (small 250 μm and large 500 μm). Macrophages exhibited an elongated morphology in aligned and highly-ordered scaffolds, while maintaining their round-shape on randomly-oriented fibrous scaffolds. Expressions of periostin and IL-10 were more pronounced on the aligned and highly-ordered scaffolds. While hPDLSCs on the scaffolds with 500 μm strand spacing show higher expression of osteogenic marker (Runx2) over 21 days, cells on randomly-oriented fibrous scaffolds showed upregulation of M1 markers. In an orthotopic mandibular fenestration defect model, findings revealed that the tissue-specific scaffolds (i.e., aligned fibers for periodontal ligament and highly-ordered 500 μm strand spacing fluorinated calcium phosphate [F/CaP]-coated fibers for bone) could enhance the mimicking of regeneration of natural periodontal tissues.

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Polymeric tissue-specific scaffolds were engineered via melt electrowriting.

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Tissue-specific scaffolds supported ligamentogenic and osteogenic differentiation.

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Tissue-specific scaffolds mediated an immunomodulatory effect on macrophages (M2).

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Tissue-specific scaffolds guided in vivo soft/hard periodontal tissue regeneration.

Self-assembling peptide-laden electrospun scaffolds for guided mineralized tissue regeneration

OBJECTIVES

Electrospun scaffolds are a versatile biomaterial platform to mimic fibrillar structure of native tissues extracellular matrix, and facilitate the incorporation of biomolecules for regenerative therapies. Self-assembling peptide P11-4 has emerged as a promising strategy to induce mineralization; however, P11-4 application has been mostly addressed for early caries lesions repair on dental enamel. Here, to investigate P11-4's efficacy on bone regeneration, polymeric electrospun scaffolds were developed, and then distinct concentrations of P11-4 were physically adsorbed on the scaffolds.

METHODS

P11-4-laden and pristine (P11-4-free) electrospun scaffolds were immersed in simulated body fluid and mineral precipitation identified by SEM. Functional groups and crystalline phases were analyzed by FTIR and XRD, respectively. Cytocompatibility, mineralization, and gene expression assays were conducted using stem cells from human exfoliated deciduous teeth. To investigate P11-4-laden scaffolds potential to induce in vivo mineralization, an established rat calvaria critical-size defect model was used.

RESULTS

We successfully synthesized nanofibrous (∼ 500 nm fiber diameter) scaffolds and observed that functionalization with P11-4 did not affect the fibers' diameter. SEM images indicated mineral precipitation, while FTIR and XRD confirmed apatite-like formation and crystallization for P11-4-laden scaffolds. In addition, P11-4-laden scaffolds were cytocompatible, highly stimulated cell-mediated mineral deposition, and upregulated the expression of mineralization-related genes compared to pristine scaffolds. P11-4-laden scaffolds led to enhanced in vivo bone regeneration after 8 weeks compared to pristine PCL.

SIGNIFICANCE

Electrospun scaffolds functionalized with P11-4 are a promising strategy for inducing mineralized tissues regeneration in the craniomaxillofacial complex.

A Highly Ordered, Nanostructured Fluorinated CaP-Coated Melt Electrowritten Scaffold for Periodontal Tissue Regeneration

Periodontitis is a chronic inflammatory, bacteria-triggered disorder affecting nearly half of American adults. Although some level of tissue regeneration is realized, its low success in complex cases demands superior strategies to amplify regenerative capacity. Herein, highly ordered scaffolds are engineered via Melt ElectroWriting (MEW), and the effects of strand spacing, as well as the presence of a nanostructured fluorinated calcium phosphate (F/CaP) coating on the adhesion/proliferation, and osteogenic differentiation of human-derived periodontal ligament stem cells, are investigated. Upon initial cell-scaffold interaction screening aimed at defining the most suitable design, MEW poly(ε-caprolactone) scaffolds with 500 µm strand spacing are chosen. Following an alkali treatment, scaffolds are immersed in a pre-established solution to allow for coating formation. The presence of a nanostructured F/CaP coating leads to a marked upregulation of osteogenic genes and attenuated bacterial growth. In vivo findings confirm that the F/CaP-coated scaffolds are biocompatible and lead to periodontal regeneration when implanted in a rat mandibular periodontal fenestration defect model. In aggregate, it is considered that this work can contribute to the development of personalized scaffolds capable of enabling tissue-specific differentiation of progenitor cells, and thus guide simultaneous and coordinated regeneration of soft and hard periodontal tissues, while providing antimicrobial protection.

Personalized and Defect-Specific Antibiotic-Laden Scaffolds for Periodontal Infection Ablation

Periodontitis compromises the integrity and function of tooth-supporting structures. Although therapeutic approaches have been offered, predictable regeneration of periodontal tissues remains intangible, particularly in anatomically complex defects. In this work, personalized and defect-specific antibiotic-laden polymeric scaffolds containing metronidazole (MET), tetracycline (TCH), or their combination (MET/TCH) were created via electrospinning. An initial screening of the synthesized fibers comprising chemo-morphological analyses, cytocompatibility assessment, and antimicrobial validation against periodontopathogens was accomplished to determine the cell-friendly and anti-infective nature of the scaffolds. According to the cytocompatibility and antimicrobial data, the 1:3 MET/TCH formulation was used to obtain three-dimensional defect-specific scaffolds to treat periodontally compromised three-wall osseous defects in rats. Inflammatory cell response and new bone formation were assessed by histology. Micro-computerized tomography was performed to assess bone loss in the furcation area at 2 and 6 weeks post implantation. Chemo-morphological and cell compatibility analyses confirmed the synthesis of cytocompatible antibiotic-laden fibers with antimicrobial action. Importantly, the 1:3 MET/TCH defect-specific scaffolds led to increased new bone formation, lower bone loss, and reduced inflammatory response when compared to antibiotic-free scaffolds. Altogether, our results suggest that the fabrication of defect-specific antibiotic-laden scaffolds holds great potential toward the development of personalized (i.e., patient-specific medication) scaffolds to ablate infection while affording regenerative properties.

Injectable Multifunctional Drug Delivery System for Hard Tissue Regeneration under Inflammatory Microenvironments

Engineering multifunctional hydrogel systems capable of amplifying the regenerative capacity of endogenous progenitor cells via localized presentation of therapeutics under tissue inflammation is central to the translation of effective strategies for hard tissue regeneration. Here, we loaded dexamethasone (DEX), a pleotropic drug with anti-inflammatory and mineralizing abilities, into aluminosilicate clay nanotubes (halloysite clay nanotubes (HNTs)) to engineer an injectable multifunctional drug delivery system based on photo-cross-linkable gelatin methacryloyl (GelMA) hydrogel. In detail, a series of hydrogels based on GelMA formulations containing distinct amounts of DEX-loaded nanotubes was analyzed for physicochemical and mechanical properties and kinetics of DEX release as well as compatibility with mesenchymal stem cells from human exfoliated deciduous teeth (SHEDs). The anti-inflammatory response and mineralization potential of the engineered hydrogels were determined in vitro and in vivo. DEX conjugation with HNTs was confirmed by FTIR analysis. The incorporation of DEX-loaded nanotubes enhanced the mechanical strength of GelMA with no effect on its degradation and swelling ratio. Scanning electron microscopy (SEM) images demonstrated the porous architecture of GelMA, which was not significantly altered by DEX-loaded nanotubes' (HNTs/DEX) incorporation. All GelMA formulations showed cytocompatibility with SHEDs (p < 0.05) regardless of the presence of HNTs or HNTs/DEX. However, the highest osteogenic cell differentiation was noticed with the addition of HNT/DEX 10% in GelMA formulations (p < 0.01). The controlled release of DEX over 7 days restored the expression of alkaline phosphatase and mineralization (p < 0.0001) in lipopolysaccharide (LPS)-stimulated SHEDs in vitro. Importantly, in vivo data revealed that DEX-loaded nanotube-modified GelMA (5.0% HNT/DEX 10%) led to enhanced bone formation after 6 weeks (p < 0.0001) compared to DEX-free formulations with a minimum localized inflammatory response after 7 days. Altogether, our findings show that the engineered DEX-loaded nanotube-modified hydrogel may possess great potential to trigger in situ mineralized tissue regeneration under inflammatory conditions.

Innovations in Craniofacial Bone and Periodontal Tissue Engineering - From Electrospinning to Converged Biofabrication

From a materials perspective, the pillars for the development of clinically translatable scaffold-based strategies for craniomaxillofacial (CMF) bone and periodontal regeneration have included electrospinning and 3D printing (biofabrication) technologies. Here, we offer a detailed analysis of the latest innovations in 3D (bio)printing strategies for CMF bone and periodontal regeneration and provide future directions envisioning the development of advanced 3D architectures for successful clinical translation. First, the principles of electrospinning applied to the generation of biodegradable scaffolds are discussed. Next, we present on extrusion-based 3D printing technologies with a focus on creating scaffolds with improved regenerative capacity. In addition, we offer a critical appraisal on 3D (bio)printing and multitechnology convergence to enable the reconstruction of CMF bones and periodontal tissues. As a future outlook, we highlight future directions associated with the utilization of complementary biomaterials and (bio)fabrication technologies for effective translation of personalized and functional scaffolds into the clinics.

Do not underestimate the blood urea nitrogen-to-creatinine ratio in heart failure

Funding Acknowledgements

Type of funding sources: None.

Introduction

The blood urea nitrogen-to-creatinine ratio (BUN/SCr) has been proposed as a prognostic marker in heart failure (HF). We aimed to evaluate whether BUN/SCr predicts mortality outcomes in a real-world Southern European population with decompensated chronic HF.

Methods

We retrospectively studied 1057 patients with chronic HF admitted to our emergency department between November 2016 and December 2017 with acute decompensation. We excluded patients with a GFR &lt;15mL/min/m2 or on dialysis. The incidence of cardiovascular (CV) and all-cause death was evaluated through multivariable logistic regression models and by Kaplan-Meyer survival curves.

Results

1025 patients were included, median age 80 years (IQR 73-85), 52.4% male, mean LVEF 42.8 ± 12.7%, and mean GFR 57.2 ± 23.9 mL/min/m2. Mean BUN/SCr was 24.9 ± 8.2 and mean SBP was 139 ± 29mmHg (r=-0.17, p &lt; 0.001). After a median follow-up of 5 months (IQR 3-11 months), CV and all-cause death occurred in 8.0% and 21.6%, respectively. Mean BUN/SCr was higher in patients with fatal outcomes both for CV (31.3 vs. 24.3, p &lt; 0.001) and all-cause death (28.6 vs. 23.8, p &lt; 0.001). BUN/Scr was grouped by terciles: T1 (&lt;20.78), T2 (20.78-27.15), T3 (&gt;27.15). In the T3 group, the multivariable-adjusted  OR for CV and all-cause death was 5.43 (95% CI 2.20-13.37) and 2.72 (95% CI 1.66-4.46), respectively, compared to the T1 group. No significant differences between T1 and T2 groups.

Conclusions

BUN/SCr at admission predicts CV and all-cause death in patients with chronic HF after an episode of decompensation. BUN/SCr, as an easy-to-use tool, helps to identify those patients who benefit from tight monitoring both during hospitalization and after discharge.

Abstract Figure_1

Does lipoprotein(a) predict cardiovascular events in a long-term follow-up?

Funding Acknowledgements

Type of funding sources: None.

Background

Elevated plasma lipoprotein(a) [Lp(a)] concentrations are associated with an increased risk of atherosclerotic cardiovascular disease and its role in risk categorizing was recognized in the new ESC guidelines for the management of dyslipidaemias. We investigated 1) the association between baseline Lp(a) levels and incident long-term cardiovascular (CV) events and 2) its relationship with type 2 diabetes mellitus (T2DM) in a Southern European population.

Methods

We retrospectively assessed baseline Lp(a) concentrations in a total of 499 patients of a primary prevention cohort followed at the Lipidology Clinic of our hospital, with a median follow-up time of 15 (IQR 12-17) years. Lp(a) was analysed as a continuous variable, as a categorical variable with a 180mg/dL cut-off and by quartiles. We collected data on major CV events (CV death, myocardial infarction, stroke) as a composite outcome. Cox proportional hazard regression analyses were used to estimate hazard ratios (HR) and 95% confidence interval (CI).

Results

Mean age was 48.30 ± 14.41 years and 61.70% were male (n = 499). Median Lp(a) was 36.60 (IQR 0-396) mg/dL and 12.4% of patients had very high Lp(a) (≥180mg/dL); T2DM prevalence was 13.60%. The composite outcome incidence was 10%. At the baseline, individuals with T2DM had lower Lp(a) levels (11.85 IQR 3-330 mg/dL vs. 46.40 IQR 0-396, p &lt; 0.01 mg/dL). There was a moderate inverse correlation between Lp(a) and HbA1c (r = -0.67, p &lt; 0.01) but no significant correlations with lipid profile (total, LDL or HDL), risk scores (SCORE or the ACC pooled cohort equation), age nor gender. We found no relationship between baseline Lp(a) quartiles and composite outcome’s incidence (age-, sex-, and diabetes-adjusted HR: 1.15, 95%CI: 0.71-1.87, p = 0.57) (Figure 1), neither with the individual CV endpoints. Exploratory analysis showed that patients on aspirin had lower Lp(a) levels (29.55 IQR 0-264 mg/dL vs. 63.60 IQR 1-396 mg/dL, p &lt; 0.01).

Conclusion

In a single centre cohort of a primary prevention southern European population, we did not find an association between Lp(a) levels and incident CV events in a 15-year median follow-up time.

Myocardial infarction in young adults: are the risk profile and mortality outcomes different from older patients?

Funding Acknowledgements

Type of funding sources: None.

Introduction

The incidence of acute myocardial infarction (AMI) among young patients is increasing. The YOUNG-MI Registry reported that those under 40 years had similar risk profiles and outcomes compared to those aged 41 to 50. We aimed to evaluate cardiovascular risk factors and mortality outcomes in two age cohorts from southern European.

Methods

We retrospectively evaluated 4758 patients admitted to our coronary intensive care unit between 2004 and 2017 with AMI. We only included patients &lt;60 years in two subgroups: cohort A &lt; 50 years and cohort B 50-60 years. 

Results

From the 1233 patients included (mean age 50.5 ± 6.5 years, 82.2% male), 53% had STEMI. Cohort B had higher rates of hypertension (59.8 vs. 42.9%, p &lt; 0.001), diabetes (41.8 vs. 28.9%, p &lt; 0.001), and dyslipidemia (59.4 vs. 46.4%, p &lt; 0.001), while cohort A had higher rates of familial premature coronary artery disease (20.9 vs. 13.2%, p &lt; 0.001) and smoking habits (54.4 vs. 40.0%, p &lt; 0.001). Regarding coronary angiography, cohort B had higher rates of obstructive disease in each epicardial artery, except for left main involvement and non-obstructive disease (Fig. 1). Cohort A had lower all-cause mortality rates at the index hospitalization (1.3 vs. 3.2%, p = 0.045), 6-months (2.9 vs.5.4, p = 0.038), 1-year (3.1 vs. 6.3%, p = 0.014), and 3-years (3.6 vs 8.4, p = 0.001). After multivariable adjustment, we found no relationship between age cohorts and all-cause mortality for any follow-up timing: HR 1.57 (95% CI 0.56-4.37), 1.37 (95% CI 0.50-3.74), and 0.92 (95% CI 0.35-2.39) at 6-months, 1-year, and 3-years, respectively.

Conclusion

Among patients who suffer AMI, those under 50 years old have a different risk profile, compared to the 50-60 years cohort. However, there is no significant difference in all-cause mortality.

Abstract Figure.

Metformin-loaded nanospheres-laden photocrosslinkable gelatin hydrogel for bone tissue engineering

The aim of this investigation was to engineer metformin (MF)-loaded mesoporous silica nanospheres (MSNs)-laden gelatin methacryloyl (GelMA) photocrosslinkable hydrogels and test their effects on the mechanical properties, swelling ratio, drug release, cytocompatibility, and osteogenic differentiation of stem cells from human exfoliated deciduous teeth (SHEDs). As-received and carboxylated MSNs (MSNs-COOH) were characterized by scanning and transmission electron microscopies (SEM and TEM), as well as Fourier-transform infrared spectroscopy (FTIR) prior to hydrogel modification. MF-MSNs-COOH were obtained by loading MF into MSNs at a 1:1 mass ratio. Upon MSNs-COOH laden-hydrogels fabrication, the mechanical properties, swelling ratio and MF release were evaluated. SHEDs were seeded on the hydrogels and cytocompatibility was examined. The effects of the MF-MSNs-COOH/GelMA on the osteogenic differentiation of SHEDs were measured by ALP activity, Alizarin Red assay, and Real-time PCR. Statistics were performed using one-way ANOVA (α = 0.05). Morphological (SEM and TEM) analyses of pristine and carboxylated MSNs revealed a mean particle size of 200 nm and 218 nm, respectively. Importantly, an intrinsic nanoporous structure was noticed. Incorporation of MSNs-COOH at 1.5 mg/mL in GelMA led to the highest compressive modulus and swelling ratio. The addition of MSNs-COOH (up to 3 mg/mL) in GelMA did not impact cell viability. The presence of MF in MSNs-COOH/GelMA significantly promoted cell proliferation. Significant upregulation of osteogenic-related genes (except OCN) were seen for modified (MSNs-COOH and MF-MSNs-COOH) hydrogels when compared to GelMA. Altogether, the engineered MF-MSNs-COOH/GelMA shows great promise in craniomaxillofacial applications as an injectable, cell-free and bioactive therapeutics for bone regeneration.

Highly tunable bioactive fiber-reinforced hydrogel for guided bone regeneration

One of the most damaging pathologies that affects the health of both soft and hard tissues around the tooth is periodontitis. Clinically, periodontal tissue destruction has been managed by an integrated approach involving elimination of injured tissues followed by regenerative strategies with bone substitutes and/or barrier membranes. Regrettably, a barrier membrane with predictable mechanical integrity and multifunctional therapeutic features has yet to be established. Herein, we report a fiber-reinforced hydrogel with unprecedented tunability in terms of mechanical competence and therapeutic features by integration of highly porous poly(ε-caprolactone) fibrous mesh(es) with well-controlled 3D architecture into bioactive amorphous magnesium phosphate-laden gelatin methacryloyl hydrogels. The presence of amorphous magnesium phosphate and PCL mesh in the hydrogel can control the mechanical properties and improve the osteogenic ability, opening a tremendous opportunity in guided bone regeneration (GBR). Results demonstrate that the presence of PCL meshes fabricated via melt electrowriting can delay hydrogel degradation preventing soft tissue invasion and providing the mechanical barrier to allow time for slower migrating progenitor cells to participate in bone regeneration due to their ability to differentiate into bone-forming cells. Altogether, our approach offers a platform technology for the development of the next-generation of GBR membranes with tunable mechanical and therapeutic properties to amplify bone regeneration in compromised sites. STATEMENT OF SIGNIFICANCE: In this study, we developed a fiber-reinforced hydrogel platform with unprecedented tunability in terms of mechanical competence and therapeutic features for guided bone regeneration. We successfully integrated highly porous poly(ε-caprolactone) [PCL] mesh(es) into amorphous magnesium phosphate-laden hydrogels. The stiffness of the engineered hydrogel was significantly enhanced, and this reinforcing effect could be modulated by altering the number of PCL meshes and tailoring the AMP concentration. Furthermore, the fiber-reinforced hydrogel showed favorable cellular responses, significantly higher rates of mineralization, upregulation of osteogenic-related genes and bone formation. In sum, these fiber-reinforced membranes in combination with therapeutic agent(s) embedded in the hydrogel offer a robust, highly tunable platform to amplify bone regeneration not only in periodontal defects, but also in other craniomaxillofacial sites.

Bioactive amorphous magnesium phosphate-polyetheretherketone composite filaments for 3D printing

OBJECTIVE

The aim of this study was to develop bioactive and osseointegrable polyetheretherketone (PEEK)-based composite filaments melt-blended with novel amorphous magnesium phosphate (AMP) particles for 3D printing of dental and orthopedic implants.

MATERIALS AND METHODS

A series of materials and biological analyses of AMP-PEEK were performed. Thermal stability, thermogravimetric and differential scanning calorimetry curves of as-synthesized AMP were measured. Complex viscosity, elastic modulus and viscous modulus were determined using a rotational rheometer. In vitro bioactivity was analyzed using SBF immersion method. SEM, EDS and XRD were used to study the apatite-forming ability of the AMP-PEEK filaments. Mouse pre-osteoblasts (MC3T3-E1) were cultured and analyzed for cell viability, proliferation and gene expression. For in vivo analyses, bare PEEK was used as the control and 15AMP-PEEK was chosen based on its in vitro cell-related results. After 4 or 12 weeks, animals were euthanized, and the femurs were collected for micro-computed tomography (μ-CT) and histology.

RESULTS

The collected findings confirmed the homogeneous dispersion of AMP particles within the PEEK matrix with no phase degradation. Rheological studies demonstrated that AMP-PEEK composites are good candidates for 3D printing by exhibiting high zero-shear and low infinite-shear viscosities. In vitro results revealed enhanced bioactivity and superior pre-osteoblast cell function in the case of AMP-PEEK composites as compared to bare PEEK. In vivo analyses further corroborated the enhanced osseointegration capacity for AMP-PEEK implants.

SIGNIFICANCE

Collectively, the present investigation demonstrated that AMP-PEEK composite filaments can serve as feedstock for 3D printing of orthopedic and dental implants due to enhanced bioactivity and osseointegration capacity.

Extracellular Matrix/Amorphous Magnesium Phosphate Bioink for 3D Bioprinting of Craniomaxillofacial Bone Tissue

Bioprinting, a promising field in regenerative medicine, holds great potential to create three-dimensional, defect-specific vascularized bones with tremendous opportunities to address unmet craniomaxillofacial reconstructive challenges. A cytocompatible bioink is a critical prerequisite to successfully regenerate functional bone tissue. Synthetic self-assembling peptides have a nanofibrous structure resembling the native extracellular matrix (ECM), making them an excellent bioink component. Amorphous magnesium phosphates (AMPs) have shown greater levels of resorption while maintaining high biocompatibility, osteoinductivity, and low inflammatory response, as compared to their calcium phosphate counterparts. Here, we have established a novel bioink formulation (ECM/AMP) that combines an ECM-based hydrogel containing 2% octapeptide FEFEFKFK and 98% water with AMP particles to realize high cell function with desirable bioprintability. We analyzed the osteogenic differentiation of dental pulp stem cells (DPSCs) encapsulated in the bioink, as well as in vivo bone regeneration, to define the potential of the formulated bioink as a growth factor-free bone-forming strategy. Cell-laden AMP-modified bioprinted constructs showed an improved cell morphology but similar cell viability (∼90%) compared to their AMP-free counterpart. In functional assays, the cell-laden bioprinted constructs modified with AMP exhibited a high level of mineralization and osteogenic gene expression without the use of growth factors, thus suggesting that the presence of AMP-triggered DPSCs' osteogenic differentiation. Cell-free ECM-based bioprinted constructs were implanted in vivo. In comparison with the ECM group, bone volume per total volume for ECM/1.0AMP was approximately 1.7- and 1.4-fold higher at 4 and 8 weeks, respectively. Further, a significant increase in the bone density was observed in ECM/1.0AMP from 4 to 8 weeks. These results demonstrate that the presence of AMP in the bioink significantly increased bone formation, thus showing promise for in situ bioprinting strategies. We foresee significant potential in translating this innovative bioink toward the regeneration of patient-specific bone tissue for regenerative dentistry.

Injectable MMP-Responsive Nanotube-Modified Gelatin Hydrogel for Dental Infection Ablation

A photocrosslinkable gelatin methacryloyl (GelMA) hydrogel has been widely examined in regenerative engineering because of its good cell-tissue affinity and degradability in the presence of matrix metalloproteinases. A halloysite aluminosilicate nanotube (HNT) is a known reservoir for the loading and sustained delivery of therapeutics. Here, we formulate injectable chlorhexidine (CHX)-loaded nanotube-modified GelMA hydrogel that is cytocompatible and biodegradable and provides sustained release of CHX for infection ablation while displaying good biocompatibility. The effects of HNTs and CHX on hydrogel degradability and mechanical properties, as well as on the kinetics of CHX release, and on the antimicrobial efficacy against oral pathogens were systematically assessed. Cytocompatibility in stem cells from human exfoliated deciduous teeth and inflammatory response in vivo using a subcutaneous rat model were determined. Our hydrogel system, that is, (CHX)-loaded nanotube-modified GelMA showed minimum localized inflammatory responses, supporting its ability for drug delivery applications. Moreover, we showed that the incorporation of CHX-loaded nanotubes reduces the mechanical properties, increases the swelling ratio, and diminishes the degradation rate of the hydrogels. Importantly, the presence of CHX-loaded nanotubes inhibits bacterial growth with minimal cell toxicity. Our findings provide a new strategy to modify GelMA hydrogel with chlorhexidine-loaded nanotubes for clinical use as an injectable drug delivery strategy for dental infection ablation.

P320 Left atrial mechanics in moderate mitral valve disease: earlier markers of damage

BACKGROUND

Left atrial (LA) mechanics is impaired in mitral valve disease, but it is not clear whether reservoir, conduit or contractile functions are differentially impaired in stenosis (MS) or regurgitation (MR). We aimed to study LA mechanics in patients with moderate MR or moderate MS and identify discriminators of disease.

METHODS

We conducted a prospective, observational study of 100 patients with isolated moderate MR and 100 patients with moderate MS. LA mechanics with speckle tracking echocardiography (STE) assessed LA reservoir (LA ɛsys and SRs), conduit(LAɛe, SRe), and contractile (LAɛa, SRa) functions. Left ventricle (LV) functional parameters were assessed as well, including LV ejection fraction (LVEF), LV end-diastolic diameter (LVDD) and LV global longitudinal strain (LV-GLS).

RESULTS

The mean age was 67 ± 14 years and 75% were female. Mean left ventricular ejection fraction (LVEF), LV end-diastolic diameter (LVDD), LV global longitudinal strain (LV-GLS) and systolic pulmonary artery pressure (sPAP) did not differ between MR and MS (table 1).LA indexed volume (LAVi) and LA strain did not vary between MR and MS, but strain rate did. SRs and SRe had better values in MR, whereas SRa had worse values in MR (table 1). SRe (&lt;-0.7%) had the superior discriminative power for MR, with an area under the curve of 0.85, sensitivity of 76% and specificity of 85%.

CONCLUSIONS

LA strain rate phases were the only parameters that varied between MR and MS. Contractile phase strain rate was more impaired in MR and conduit phase strain rate in MS. This highly specific data reflect the earlier hemodynamic changes occurring in LA in the setting of mitral valve disease.

mMR mMS P value LVEF (±SD,%) 57.4 ± 6.4 59.6 ± 4.6 0.145 LV-GLS (±SD, %) -17.7 ± 4.5 -17.1 ± 3.5 0.587 sPAP (±SD, mmHg) 30.3 ± 10.5 32.4 ± 8.3 0.387 LAVi (± SD, ml/m2) 46.3 ± 6.4 48.2 ± 7.4 0.281 LAɛs (± SD, %) 15.8 ± 7.3 13.3 ± 9 0.062 LAɛe (± SD, %) 8.4 ± 4.7 7.1 ± 5.4 0.074 LAɛa (± SD, %) 6.3 ± 4.8 7.4 ± 4.5 0.081 LA SRs (± SD, %) 0.8 ± 0.4 0.6 ± 0.3 0.004 LA SRe (± SD, %) -0.9 ± 0.5 -0.5 ± 0.3 &lt;0.001 LA SRa (± SD, %) -0.5 ± 0.4 -0.8 ± 0.5 0.007

Curcumin-A Natural Medicament for Root Canal Disinfection: Effects of Irrigation, Drug Release, and Photoactivation

INTRODUCTION

Curcumin incorporation into polymeric fibers was tested for its antimicrobial properties and potential use in root canal disinfection.

METHODS

Curcumin-modified fibers were processed via electrospinning and tested against a 7-day old established Actinomyces naeslundii biofilm. The medicaments tested were as follows: curcumin-modified fibers at 2.5 and 5.0 mg/mL, curcumin-based irrigant at 2.5 and 5.0 mg/mL, saline solution (negative control), and the following positive controls: 2% chlorhexidine, 1% sodium hypochlorite, and triple antibiotic paste (TAP, 1 mg/mL). All medicaments, except for the positive controls, were allocated according to the light exposure protocol (ie, photoactivation with a light-emitting diode every 30 seconds for 4 minutes or without photoactivation). After treatment, the medicaments were removed, and 1 mL saline solution was added; the biofilm was scraped from the well and used to prepare a 1:2000 dilution. Spiral plating was performed using anaerobic blood agar plates. After 24 hours, colony-forming units (colony-forming units/mL, n = 11/group) were counted to determine the antimicrobial effects.

RESULTS

Data exhibited significant antimicrobial effects on the positive control groups followed by the curcumin irrigants and, lastly, the photoactivated curcumin-modified fibers. There was a significant reduction of viable bacteria in curcumin-based irrigants, which was greater than the TAP-treated group. Curcumin-free fibers, saline, and the nonphotoactivated curcumin-modified fibers did not display antimicrobial activity.

CONCLUSIONS

Curcumin seems to be a potential alternative to TAP when controlling infection, but it requires a minimal concentration (2.5 mg/mL) to be effective. Photoactivation of curcumin-based medicaments seems to be essential to obtain greater antibiofilm activity.

Prevalence and incidence of surgical site infections in the European Union/European Economic Area: how do these measures relate?

BACKGROUND

In 2011-2012, the European Centre for Disease Prevention and Control (ECDC) initiated the first European point prevalence survey (PPS) of healthcare-associated infections (HCAIs) in addition to targeted surveillance of the incidence of specific types of HCAI such as surgical site infections (SSIs).

AIM

To investigate whether national and multi-country SSI incidence can be estimated from ECDC PPS data.

METHODS

In all, 159 hospitals were included from 15 countries that participated in both ECDC surveillance modules, aligning surgical procedures in the incidence surveillance to corresponding specialties from the PPS. National daily prevalence of SSIs was simulated from the incidence surveillance data, the Rhame and Sudderth (R&S) formula was used to estimate national and multi-country SSI incidence from the PPS data, and national incidence per specialty was predicted using a linear model including data from the PPS.

FINDINGS

The simulation of daily SSI prevalence from incidence surveillance of SSIs showed that prevalence fluctuated randomly depending on the day of measurement. The correlation between the national aggregated incidence estimated with R&S formula and observed SSI incidence was low (correlation coefficient = 0.24), but specialty-specific incidence results were more reliable, especially when the number of included patients was large (correlation coefficients ranging from 0.40 to 1.00). The linear prediction model including PPS data had low proportion of explained variance (0.40).

CONCLUSION

Due to a lack of accuracy, use of PPS data to estimate SSI incidence is recommended only in situations where incidence surveillance of SSIs is not performed, and where sufficiently large samples of PPS data are available.

A functional glycoproteomics approach identifies CD13 as a novel E-selectin ligand in breast cancer

BACKGROUND

The glycan moieties sialyl-Lewis-X and/or -A (sLe^X/A) are the primary ligands for E-selectin, regulating subsequent tumor cell extravasation into distant organs. However, the nature of the glycoprotein scaffolds displaying these glycans in breast cancer remains unclear and constitutes the focus of the present investigation.

METHODS

We isolated glycoproteins that bind E-selectin from the CF1_T breast cancer cell line, derived from a patient with ductal carcinoma. Proteins were identified using bottom-up proteomics approach by nanoLC-orbitrap LTQ-MS/MS. Data were curated using bioinformatics tools to highlight clinically relevant glycoproteins, which were validated by flow cytometry, Western blot, immunohistochemistry and in-situ proximity ligation assays in clinical samples.

RESULTS

We observed that the CF1_T cell line expressed sLe^X, but not sLe^A and the E-selectin reactivity was mainly on N-glycans. MS and bioinformatics analysis of the targeted glycoproteins, when narrowed down to the most clinically relevant species in breast cancer, identified CD44 glycoprotein (HCELL) and CD13 as key E-selectin ligands. Additionally, the co-expression of sLe^X-CD44 and sLe^X-CD13 was confirmed in clinical breast cancer tissue samples.

CONCLUSIONS

Both CD44 and CD13 glycoforms display sLe^X in breast cancer and bind E-selectin, suggesting a key role in metastasis development. Such observations provide a novel molecular rationale for developing targeted therapeutics.

GENERAL SIGNIFICANCE

While HCELL expression in breast cancer has been previously reported, this is the first study indicating that CD13 functions as an E-selectin ligand in breast cancer. This observation supports previous associations of CD13 with metastasis and draws attention to this glycoprotein as an anti-cancer target.

Evaluation of sedation-related medication errors in patients on contact isolation in the intensive care unit

BACKGROUND

Patients in intensive care units (ICUs) may be placed on contact isolation for meticillin-resistant Staphylococcus aureus (MRSA) colonization to prevent transmission. Prior studies suggest that isolated patients may receive substandard care compared with non-isolated patients. An optimal level of sedation is required to facilitate mechanical ventilation (MV) and to minimize adverse outcomes.

AIM

To determine if patients on MV and isolated for MRSA colonization are at increased risk of oversedation compared with non-isolated patients.

METHODS

Retrospective chart review of adult patients on MV who received an MRSA nasal polymerase chain reaction assay and sedation within 24 and 48 h of ICU admission, respectively. Endpoints included rate of inappropriate sedation, length of ICU stay, length of time on MV, and incidence of ventilator-associated complications.

FINDINGS

In total, 226 patients were included (114 MRSA positive, 112 MRSA negative). Baseline demographics were similar between the groups, with the exception of ICU admission diagnosis. Fifty-six (55%) isolated patients experienced inappropriate sedation compared with 49 (50%) non-isolated patients (P=0.482). Isolated patients spent longer in the ICU (10.4 vs 6.8 days, P=0.0006), longer on MV (8.98 vs 4.81 days, P<0.001), and required tracheostomies more frequently [37 (32%) vs 14 (13%), P=0.0003] than non-isolated patients.

CONCLUSIONS

Isolated patients were not at increased risk of oversedation compared with non-isolated patients. There was an association between the use of contact isolation for MRSA nares colonization and prolonged ICU stay and prolonged MV.

Response of high-risk of recurrence/progression bladder tumours expressing sialyl-Tn and sialyl-6-T to BCG immunotherapy

Background:

High risk of recurrence/progression bladder tumours is treated with Bacillus Calmette-Guérin (BCG) immunotherapy after complete resection of the tumour. Approximately 75% of these tumours express the uncommon carbohydrate antigen sialyl-Tn (Tn), a surrogate biomarker of tumour aggressiveness. Such changes in the glycosylation of cell-surface proteins influence tumour microenvironment and immune responses that may modulate treatment outcome and the course of disease. The aim of this work is to determine the efficiency of BCG immunotherapy against tumours expressing sTn and sTn-related antigen sialyl-6-T (s6T).

Methods:

In a retrospective design, 94 tumours from patients treated with BCG were screened for sTn and s6T expression. In vitro studies were conducted to determine the interaction of BCG with high-grade bladder cancer cell line overexpressing sTn.

Results:

From the 94 cases evaluated, 36 had recurrence after BCG treatment (38.3%). Treatment outcome was influenced by age over 65 years (HR=2.668; (1.344–5.254); P=0.005), maintenance schedule (HR=0.480; (0.246–0.936); P=0.031) and multifocallity (HR=2.065; (1.033–4.126); P=0.040). sTn or s6T expression was associated with BCG response (P=0.024; P<0.0001) and with increased recurrence-free survival (P=0.001). Multivariate analyses showed that sTn and/or s6T were independent predictive markers of recurrence after BCG immunotherapy (HR=0.296; (0.148–0.594); P=0.001). In vitro studies demonstrated higher adhesion and internalisation of the bacillus to cells expressing sTn, promoting cell death.

Conclusion:

s6T is described for the first time in bladder tumours. Our data strongly suggest that BCG immunotherapy is efficient against sTn- and s6T-positive tumours. Furthermore, sTn and s6T expression are independent predictive markers of BCG treatment response and may be useful in the identification of patients who could benefit more from this immunotherapy.

Suppression of tritium retention in remote areas of ITER by nonperturbative reactive gas injection

A technique based on reactive gas injection in the afterglow region of the divertor plasma is proposed for the suppression of tritium-carbon codeposits in remote areas of ITER when operated with carbon-based divertor targets. Experiments in a divertor simulator plasma device indicate that a 4  nm/min deposition can be suppressed by addition of 1  Pa·m³ s⁻¹ ammonia flow at 10 cm from the plasma. These results bolster the concept of nonperturbative scavenger injection for tritium inventory control in carbon-based fusion plasma devices, thus paving the way for ITER operation in the active phase under a carbon-dominated, plasma facing component background.

Toward a full exploitation of the helium beam edge diagnostic

In this article, extension of the He beam diagnostic, which is routinely applied in fusion devices for the characterization of the edge electronic parameters-ne and Te-and their profile, to the measurement of ion temperature and plasma rotation is proposed. The theoretical background for these new applications is reviewed and examples of their use in TJ-II are provided. Also, the shortcomings and their possible solutions are addressed. Finally, the field of application of the technique to other beam-based diagnostics is discussed.

Vagus nerve stimulation for pharmacoresistant epilepsy: clinical symptoms with end of service

PURPOSE

Limited capability exists to predict when vagus nerve stimulation (VNS) battery deterioration becomes significant. Initial models last 2-5 years. We evaluated the first 18 patients with pharmacoresistent epilepsy after reimplantation to examine the clinical course observed during VNS end of service (EOS).

METHODS

Of 72 patients with VNS, 18 patients had generator replacement. EOS was estimated based on duration of use and stimulus parameters in accordance with manufacturer guidelines. Eight males and ten females had pharmacoresistent epilepsy for a mean of 17.9 years. Thirteen with localization-related epilepsy (LRE) and 5 nonverbal patients with symptomatic generalized epilepsy (SGE) failed a mean of 11.1 antiepileptic drugs (AEDs) over 21.5 years. Seven had intracranial evaluations and five failed epilepsy surgery. Reimplantation was performed after a mean of 34.4 months. Symptoms at end of service (EOS) were addressed by postoperative survey submitted at initial reprogramming within 2 weeks of reimplantation. Stimulus parameters were compared before and after surgery.

RESULTS

Nine of thirteen (69.2%) verbal patients and 11 of 18 (61.1%) total patients had signs or symptoms prior to replacement, suggesting clinical EOS, and 4 of 18 (22.2%) failed interrogation denoting battery failure without symptoms; however, this did not reach significance (chi2=0.359,p=0.54). Increased seizures were the most frequent sign in 8 of 18 (44.4%), with intensification in 7 of 18 (38.9%). Irregular stimulation was detected in 5 of 18 (27.7%), with less intense stimulation in 4 of 18 (22.2%). Painful stimulation and behavioral worsening each occurred in 2 of 18 (11.1%). A subjective improvement in function after reimplantation was noted in 12 of 13 (92.3%) verbal patients, with greater intensity and consistency. Maximally tolerated reimplant current averaged -0.56 mA less. All but one (94.4%) felt surgery should be performed before clinical EOS occurred.

CONCLUSIONS

We conclude that clinical signs and symptoms may arise during VNS EOS and following replacement. Seizure increase or a change in seizure pattern was most frequently observed. The tolerated reimplant current was less than the preoperative output current in most cases. Battery replacement before EOS appears desirable from a patient perspective.

Predicting outcome in hypoxic-ischemic brain injury

Predicting the neurologic outcome of children after a hypoxic-ischemic event continues to be a challenge for intensivists and pediatric neurologists. Nevertheless, with accurate history taking, serial neurologic examination, and some ancillary studies, the clinician can predict accurately whether a child will die or have profound neurologic damage. Aggressive resuscitation should be offered to all children when found in CPA. A simple ingestion might have led to this clinical scenario, and complete neurologic recovery may be possible if effective resuscitation is implemented. In cases of drowning, several factors, if present, are consistent with profound neurologic sequelae or death. These include prolonged submersions with asystole, delayed onset of CPR, no spontaneous respirations on arrival to the emergency department, and low initial pH value. The options of withdrawal of life support or a DNR status should be offered to families of children who have survived a devastating hypoxic-ischemic event but who are in a PVS. If brain-death criteria have been fulfilled, the patient must then be disconnected from life support after organ donation has been discussed with the family.

[Public and occupational health aspects related to municipal solid waste management]

Based on a literature review, the paper calls attention to public and occupational health problems related to poor municipal solid waste management resulting from a development model that views environmental protection, public health, and workers' health as secondary issues. The authors emphasize the need for research to support a new waste management model highlighting the importance of environmental preservation and protection of human health, in addition to suggesting measures to achieve such goals. The discussion aims to incorporate solid waste management into the public health agenda.

Vagus nerve stimulation and drug reduction

The authors prospectively assessed drug reduction and patient satisfaction in 21 patients using vagus nerve stimulation (VNS) for refractory epilepsy and compared results to a case-matched control group with a mean follow-up of 13.2 months. Significant antiepileptic drug (AED) reduction occurred in 9/21 (42.9%) of VNS patients averaging 0.43 AED/patient, with dose reduction in four patients (19.0%). For 12/21 (57.1%) patients not reducing AED, dose reduction occurred in 6/21 (28.6%). Drug and dose reduction of AED is possible in patients using VNS for refractory epilepsy without loss of seizure control and with improved patient satisfaction.

Hydrophobic interactions between spin-label 5-SASL and humic acid as revealed by ESR spectroscopy

The spin-label probe 5-SASL (stearic acid spin-label with nitroxide free radical in position 5 of hydrocarbon chain), detectable by electron spin resonance (ESR), was tested to evaluate pH and reaction time dependencies of hydrophobic interactions with humic acid (HA). Strong changes were observed in 5-SASL ESR spectra in the presence of HA suspensions below pH 5, with disappearance of the three isotropic narrow hyperfine lines of the nitroxide group (typical of free spin-label) and formation of "immobilized" 5-SASL spectra. These changes were interpreted as due to 5-SASL bonding with hydrophobic groups of HA, by van der Waals forces and/or hydrogen bonds, in very hydrophobic sites (probably water-protected) existent in HA below pH 5. However, such sites are absent above pH 5, as demonstrated by a specific experiment to check 5-SASL spectra reversibility. On the other hand, the HA suspension was more efficient in dissolving 5-SASL than water above pH 5. This fact also suggests the existence of "surface" hydrophobic sites, where the spin-label binds to HA while maintaining the nitroxide group in contact with water, as evidenced by the typical free spin-label spectrum and hyperfine interaction splitting (a0 = 1.574 mT). Also experiments checking 5-SASL reversibility bonding with HA were consistent with the supramolecular association model to HA.

Water in toluene revisited: vibrational patterns in the stretching region

The symmetric (v1) and antisymmetric (v3) stretching bands of water monomers in toluene are revisited using two approaches: (i) calculation of dipole autocorrelation functions (ii) the solvatochromic behaviour of both vibration frequency shifts. The time constants extracted from the autocorrelations account for meaningful differences between the couplings established by the antisymmetric and symmetric vibrations with the solvent. The dipole autocorrelation function for the symmetric stretching band fits well a Lorentzian spectral density and shows a higher contribution to hindered rotation relatively to the one obtained from the antisymmetric stretching. The spectral shifts of stretching frequencies in toluene and in other relevant solvents were interpreted as arising from the electronic and orientational polarisations. Characteristic donor/acceptor interactions also contribute to the red shift and were tested by using empirical solvent basicity scales such as Kamlet-Taft beta and the recently proposed SB. The deviations detected in toluene as regards the continuum dielectric predictions are quantitatively treated and account for the specific interaction between the water and the molecular pi electron system referred to in the literature.

[The evaluation of the physiological workload in the Brazilian legislation should be revised! The case of garbage collectors in Rio de Janeiro]

The physiological workload (PW) involved in garbage collection was assessed in a probabilistic sample of 70 Rio de Janeiro city garbage collectors to determine the adequacy of Brazilian labor legislation regarding classification of work. PW was measured as energy expenditure (EE) and heart rate (HR) during total work time (TT) and actual time (AT) in garbage collection on 4 consecutive days. Median EE values were 288.4 and 319.1 kcal.h-1 during TT and AT, respectively, indicating moderately intense work according to Brazilian legislation. However, PW was considered heavy when work classifications based on individual response to work were used: 1) ratio of EE and resting metabolic rate was above 5.0, indicating heavy workload according to the WHO; 2) mean percentage of maximal EE was higher (36.2 and 41.1% for TT and AT, respectively) than the limit for garbage collection (30%) suggested as maximal for Dutch workers; and 3) percentage of maximal HR reserve was also higher than 30% (32.2 and 37.5% for TT and AT, respectively). These results indicate the need for a revision of the workload classification in the Brazilian legislation to take individual workers' characteristics into account.

Extra-adrenal pheochromocytoma (paraganglioma)

The authors describe the case of a 19-year-old female patient with an abdominal paraaortic extra-adrenal pheochromocytoma (paraganglioma), presenting arterial hypertension. The predominant catecholamine produced by the tumor was norepinephrine (4110 pg/ml; normal < 450 pg/ml). 131I metaiodobenzylguanidine (131I-MIBG), computed tomography and magnetic resonance imaging allowed location and characterization of the tumor. Histologically the tumor (weight = 34.2 g; 5.8 x 4 x 3 cm) was a typical pheochromocytoma.

Ventricular asystole during vagus nerve stimulation for epilepsy in humans

Electrical stimulation of the vagus nerve, a recently available option for patients with refractory epilepsy, has demonstrated safety and efficacy. We report four patients with refractory epilepsy who experienced ventricular asystole intraoperatively during initial testing for implantation of the vagus nerve stimulator. Acute intraoperative vagus nerve stimulation may create ventricular asystole in humans. Extracorporeal cervical vagus nerve stimulation testing with continuous EKG monitoring intraoperatively before generator implantation is warranted.

Transvaginal ultrasonography assessment of ovarian volumes in postmenopausal women

The authors evaluated ovarian volumes by transvaginal ultrasonography at different periods after menopause. Ninety-eight postmenopausal women with an average age of 51.9 years and a one- to eight-year postmenopausal period were studied. The control group consisted of 40 women during menacme with an average age of 31.8 years, who were also submitted to transvaginal ultrasonography to evaluate ovarian volume. There was no significant difference between right and left ovarian volumes in the study groups. There was a significant decrease in measure and standard deviations of the volumes after the first year of menopause (mean volume--2.2 +/- 0.9 cm3) when compared to the control group (mean volume--6.3 +/- 2.0 cm3), followed by a slow and gradual shrinking after this phase. Decrease in ovarian volume became significant after the fourth postmenopausal year. Transvaginal ultrasonography demonstrated great importance as an investigative method of ovarian diseases in postmenopausal women.

Mutational analysis of p80 coilin indicates a functional interaction between coiled bodies and the nucleolus

Coiled bodies are conserved subnuclear domains found in both plant and animal cells. They contain a subset of splicing snRNPs and several nucleolar antigens, including Nopp140 and fibrillarin. In addition, autoimmune patient sera have identified a coiled body specific protein, called p80 coilin. In this study we show that p80 coilin is ubiquitously expressed in human tissues. The full-length human p80 coilin protein correctly localizes in coiled bodies when exogenously expressed in HeLa cells using a transient transfection assay. Mutational analysis identifies separate domains in the p80 coilin protein that differentially affect its subnuclear localization. The data show that p80 coilin has a nuclear localization signal, but this is not sufficient to target the protein to coiled bodies. The results indicate that localization in coiled bodies is not determined by a simple motif analogous to the NLS motifs involved in nuclear import. A specific carboxy-terminal deletion in p80 coilin results in the formation of pseudo-coiled bodies that are unable to recruit splicing snRNPs. This causes a loss of endogenous coiled bodies. A separate class of mutant coilin proteins are shown to localize in fibrillar structures that surround nucleoli. These mutants also lead to loss of endogenous coiled bodies, produce a dramatic disruption of nucleolar architecture and cause a specific segregation of nucleolar antigens. The structural change in nucleoli is accompanied by the loss of RNA polymerase I activity. These data indicate that p80 coilin plays an important role in subnuclear organization and suggest that there may be a functional interaction between coiled bodies and nucleoli.

Resíduos sólidos e lixo hospitalar: uma discussão ética

O presente artigo trata da questão dos resíduos sólidos, discutindo os problemas decorrentes de um modo de ser e de agir, resultante das relações entre Primeiro Mundo e Terceiro Mundo e as perspectivas para o meio ambiente se não ocorrer uma ética renovada de solidariedade entre seres humanos e de respeito à vida. A partir dessa visão mais geral, o artigo trata, então, das questões específicas dos resíduos hospitalares, as interferências e imposições da "cultura" de Primeiro Mundo nos sistemas de manuseio, tratamento e disposição dos resíduos, no Brasil, procurando problematizar a questão da periculosidade (ou não) de tais resíduos.

Differential interaction of splicing snRNPs with coiled bodies and interchromatin granules during mitosis and assembly of daughter cell nuclei

In the interphase nucleus of mammalian cells the U1, U2, U4/U6, and U5 small nuclear ribonucleoproteins (snRNPs), which are subunits of spliceosomes, associate with specific subnuclear domains including interchromatin granules and coiled bodies. Here, we analyze the association of splicing snRNPs with these structures during mitosis and reassembly of daughter nuclei. At the onset of mitosis snRNPs are predominantly diffuse in the cytoplasm, although a subset remain associated with remnants of coiled bodies and clusters of mitotic interchromatin granules, respectively. The number and size of mitotic coiled bodies remain approximately unchanged from metaphase to early telophase while snRNP-containing clusters of mitotic interchromatin granules increase in size and number as cells progress from anaphase to telophase. During telophase snRNPs are transported into daughter nuclei while the clusters of mitotic interchromatin granules remain in the cytoplasm. The timing of nuclear import of splicing snRNPs closely correlates with the onset of transcriptional activity in daughter nuclei. When transcription restarts in telophase cells snRNPs have a diffuse nucleoplasmic distribution. As cells progress to G1 snRNP-containing clusters of interchromatin granules reappear in the nucleus. Coiled bodies appear later in G1, although the coiled body antigen, p80 coilin, enters early into telophase nuclei. After inhibition of transcription we still observe nuclear import of snRNPs and the subsequent appearance of snRNP-containing clusters of interchromatin granules, but not coiled body formation. These data demonstrate that snRNP associations with coiled bodies and interchromatin granules are differentially regulated during the cell division cycle and suggest that these structures play distinct roles connected with snRNP structure, transport, and/or function.

Postcatheterization femoral artery injuries: repair with color flow US guidance and C-clamp assistance

Color flow ultrasound-guided compression repair of postcatheterization femoral artery injuries was attempted with the assistance of a C-clamp device in 10 patients. The C-clamp device was designed to hold the transducer in the optimal compression position and eliminate operator fatigue. In nine patients, the lesion was eliminated in a mean compression time of 59 minutes. The C-clamp maintained the transducer in an effective compression position in six procedures; in the other four, intervention to prevent slippage was required.

Identification of mixed HIV-1/HIV-2 infections in Brazil by polymerase chain reaction

Analysis of sera from hospitalized Brazilian patients by whole-virus lysate-based enzyme immunoassay and Western blot indicated that 0.4% were reactive to HIV-2 alone while 4% were reactive to both HIV-1 and HIV-2. When these sera were tested for HIV antibody by type-specific peptide enzyme immunoassays, dual seropositivity was confirmed in only 0.4% of patients. To define genetically the HIV strains within the population, we analyzed peripheral blood mononuclear cells from selected seropositive patients for the presence of HIV-1 and HIV-2 proviral DNA using the polymerase chain reaction (PCR). Independent primers/probes sets were used for the amplification and detection of viral sequences from the long terminal repeat (LTR), gag, and protease (prt) gene regions. Our findings confirmed the serologic evidence of HIV-2 in Brazil and determined the extent of mixed HIV-1 and HIV-2 infections. Detailed evaluation of the amplified viral protease sequences by endonuclease restriction analysis and DNA sequencing independently confirmed mixed HIV-1 and HIV-2 infections in the two patients seropositive for HIV-1 and HIV-2. The data further indicated that these isolates are distinct from the HIV laboratory standards. We interpret the combination of culture and PCR findings to demonstrate the presence of both HIV-1 and HIV-2 in Brazil.

[Approach to urinary tract disorders in postmenopausal women]

Urinary disorders in the postmenopausal women are important due to their high incidence and to the negative influence on the quality of life of these women. The authors make a brief review of the pathophysiology of these disorders, emphasizing the significant effects of an estrogen fall on the urinary tract during this period of life. They present a modern approach to the current diagnostic and therapeutic aspects of urinary incontinence, urinary tract infections, and urethral syndrome. They also point out the importance of systemic and/or local estrogen therapy in these different aspects, observing the benefits and risks involved in these therapeutic procedures. They comment on the treatment with antibiotics, with adrenergic and/or anticholinergic drugs, surgical treatment, and the techniques of vesical reeducation in the case of detrusor instability. They recommend that physicians should inform and offer their patients the resources above which lead to the cure and/or improvement of the urinary symptoms of those women, given them an expectation of a longer and better life.

Quantitative determination of lymphocyte ACTH1-39

A method was developed for quantitative measurement of ACTH1-39, produced by human lymphocytes. It was shown that pH adjustment to 2 was essential for processing of the precursor molecule proopiomelanocortin (POMC). Linearity between time of incubation and ACTH production was shown. The existence of specific endopeptidases in lymphocytes for processing of the POMC molecule remains doubtful.

Morphologic and morphometric light and electron microscopic studies of the spleen in patients with hereditary spherocytosis and autoimmune haemolytic anaemia

With the aim of contributing to a better understanding of the haemolytic function of the spleen, a morphologic and morphometric study of this organ fixed by arterial perfusion was performed in nine patients with hereditary spherocytosis (HS), three with autoimmune haemolytic anaemia (AHA) and six with Hodgkin's disease without splenic involvement (controls). The spleen weight in HS and AHA (621 +/- 429 g, mean +/- SD) was significantly increased with respect to controls (168 +/- 36 g) (P = 0.003). In HS the red cell retention in the cords of Billroth was significantly increased (203 +/- 68 per 10(4) microns 2) with respect to the cases with AHA (93 +/- 35 per 10(4) microns 2) and to the controls (57 +/- 28 per 10(4) microns 2) (P = 0.004). In HS and AHA the number of macrophages per 10(4) microns 2 of red pulp was significantly increased (5.41 +/- 1.10 and 7.52 +/- 2.91, respectively) with respect to the controls (3.25 +/- 0.58) (P less than 0.003). There was no statistically significant difference between the number of macrophages in HS and AHA. The transmission (TEM) and scanning electron microscopy (SEM) studies demonstrated predominantly red cell retention in the cords of HS spleens, red cell phagocytosis by cordal macrophages in AHA spleens and in a lesser intensity in HS spleens, and phagocytosis of haematic corpuscles by sinus endothelial cells (SEC) in the cases of HS. These quantitative studies allow a better understanding of splenic red cell destruction in haemolytic syndromes.