Peak Expiratory Flow as an Index of Frailty Syndrome in Older Adults: A Cross-Sectional Study.

OBJECTIVES: to compare the obtained and predicted peak expiratory flow (PEF) values between frail, pre-frail, and non-frail older adults; verify the association between PEF and FS; and establish cut-off points for PEF as determinants of frailty syndrome (FS). DESIGN: Cross-sectional study. LOCATION: Macapá, Amapá, Brazil. PARTICIPANTS: Community-based study community-dwelling older people. METHODS: PEF was evaluated using a peak-flow meter and FS was evaluated using Fried's frailty phenotype. The statistical analyses performed included a multinomial logistic regression model and Receiver Operating Characteristic (ROC) curves to establish cut-off points for discriminating FS. RESULTS: 409 older adults with a mean age of 70.09±7.22 years were evaluated; of these, 58.7% were pre-frail, and 12.7% were frail. PEF was lower in frail than in pre-frail participants, and lower in pre-frail than in non-frail. Frail and pre-frail older adults obtained lower PEF values than predicted. PEF (% Predicted) was inversely associated with frailty and pre-frailty even after adjustment. Cut-off points were established to discriminate the presence of frailty in older men (PEF≤350L/min; AUC=0.669; sensitivity=76.92%; specificity=52%) and women (PEF≤220L/min; AUC=0.597; sensitivity=71.79%; specificity=46.98%). CONCLUSIONS: Frail and pre-frail older adults presented significantly lower PEF than non-frail participants, and these values were lower than predicted. PEF was inversely associated with frailty and pre-frailty. PEF cut-off points can be used as a complementary method to indicate frailty in community-dwelling older adults.

Cross-Sectional Study on the Association between Pulmonary Function and Sarcopenia in Brazilian Community-Dwelling Elderly from the Amazon Region.

OBJECTIVES: To compare the obtained and expected values of pulmonary function variables between sarcopenic and non-sarcopenic elderly; verify the association between the pulmonary function and the indicators and diagnosis of sarcopenia; and establish cut-off points for pulmonary function variables to predict sarcopenia. DESIGN: Cross-sectional study. LOCATION: Macapá, Brazil. PARTICIPANTS: community-dwelling elderly ≥ 60 years old (n=383), both sexes. MEASURES: Were evaluated according to variables of pulmonary function (spirometry) and sarcopenia, according to the EWGSOP consensus. The association between pulmonary function and sarcopenia was performed using logistic regression and cut-off points established from the ROC Curve. RESULTS: The prevalence of sarcopenia was 12.53% (n = 48). Sarcopenic individuals had significantly lower mean values for FVC, FEV1, FEF25-75% and PEF than non-sarcopenic. After adjustment, spirometric variables were inversely associated with sarcopenia (the increase by one unit of liter in FVC, FEV1 and FEF25-75% decreased the probability of sarcopenia by 59%, 67% and 39%, respectively), and the majority of these variables with the muscular strength indicator. Cut-off points, for elderly men and women, were discriminant criteria for the presence of sarcopenia: FVC (≤2.52 L and ≤1.82 L), FEV1 (≤2.1 L and ≤1.39 L), PEF (≤3.45 L/s and ≤2.93 L/s) and FEF5-75% (≤1.97 L/s and ≤1.74 L/s). CONCLUSIONS: There was loss of pulmonary function in sarcopenic elderly patients and an inverse association with the diagnosis of sarcopenia and its indicators. Cut-off points of pulmonary function variables can be used as a useful tool to discriminate sarcopenia.

Suitability of 3D printed pieces of nanocrystalline zirconia for dental applications.

OBJECTIVES: The main goal of this work is to evaluate the suitability of nanostructured zirconia pieces obtained by robocasting additive manufacturing (AM), for dental applications. METHODS: The density, crystalline structure, morphology/porosity, surface roughness, hardness, toughness, wettability and biocompatibility of the produced samples were compared with those of samples obtained by conventional subtractive manufacturing (SM) of a similar commercial zirconia material. Chewing simulation studies were carried out against dental human cusps in artificial saliva. The wear of the material was quantified and the wear mechanisms investigated, as well as the influence of glaze coating. RESULTS: AM samples, that revealed to be biocompatible, are slightly less dense and more porous than SM samples, showing lower hardness, toughness and wettability than SM samples. After chewing tests, no wear was found both on AM and SM samples. However, the dental wear was significantly lower when AM samples were used as counterbody. Concerning the glazed samples, both coated surfaces and dental cusps suffered wear, being the cusps' wear higher than that found for unglazed samples. More, cusps tested against AM coated samples suffered less wear comparatively to those opposed to SM coated samples. SIGNIFICANCE: Overall, the results presented in this paper show that AM processed nanostructured zirconia can be used in dental restorations, with important advantages from the point of view of processing and tribological performance. Moreover, the option for glaze finishing should be carefully considered both in SM and AM processed specimens.

Respiratory Muscle Strength as a Discriminator of Sarcopenia in Community-Dwelling Elderly: A Cross-Sectional Study.

OBJECTIVES: To compare the values obtained from maximum respiratory pressures (MRP) between sarcopenic and non-sarcopenic elderly; to verify the association of maximum respiratory pressures with sarcopenia and its indicators; and to establish cut-off points for MRP as a discriminator of sarcopenia. DESIGN: Cross-sectional study. LOCATION: Macapá, Brazil. PARTICIPANTS: Community-dwelling elderly ≥ 60 years old, both sexes. MEASURES: Evaluation of respiratory muscle strength (maximal inspiratory pressure - MIP and maximal expiratory pressure - MEP) and sarcopenia, according to the European Working Group on Sarcopenia in Older People (EWGSOP), in which the diagnosis of this condition considered the reduction of muscle mass (muscle mass index - MMI) associated with muscle strength reduction (hand grip strength - HGS) and / or impairment in physical performance (gait speed - GS). RESULTS: The sample consisted of 383 elderly individuals, with a mean age of 70.02 ± 7.3 years and a prevalence of sarcopenia of 12.53% (n = 48). Sarcopenic individuals presented significantly lower (obtained, obtained versus predicted) mean values for the maximal respiratory pressures compared to the non-sarcopenic elderly, and these were inversely associated with sarcopenia (an increase by 1 cmH2O in MIP and MEP reduced by 5% and 3%, respectively, the probability of sarcopenia). In relation to the association with the sarcopenia indicators, the increase by 1 cmH2O in MIP and MEP decreased, respectively, the probability of decreasing muscle strength (3% and 2%), GS (3% and 4%) and MMI (3 % - MIP). Cut-off points ≤60 cmH2O and ≤50 cmH2O for MEP and ≤55 cmH2O and ≤45 cmH2O for MEP, respectively for elderly men and women, served as a discriminant criterion for the presence of sarcopenia (area under the ROC curve superior to 0.70). CONCLUSIONS: Elderly patients with sarcopenia had lower MIP and MEP values when compared to non-sarcopenic individuals, and respiratory muscle strength was inversely associated with the diagnosis of sarcopenia and its indicators (HGS, gait speed and MMI). Furthermore, cut-off points for MIP and MEP can be used in clinical practice as discriminators of sarcopenia in community-dwelling elderly.

A morphoanatomical approach to the adaptive features of the epidermis and proboscis of a marine Polychaeta: Eulalia viridis (Phyllodocida: Phyllodocidae).

Eulalia viridis is a marine Polychaeta of the rocky intertidal that, despite its simple anatomy, is an active predator of much larger invertebrates, from which it extracts pieces of soft tissue through suction. This uncanny feeding strategy triggered the pursuit for the morphological mechanisms that enable adaptation to its environment. The evaluation of the worm anatomy and microanatomy, combining electron and optical microscopy, revealed a series of particular adaptations in the epidermis and in the proboscis (the heavily muscled eversible pharynx). Besides its function in feeding, the proboscis is the main sensory organ, being equipped with numerous sensorial papillae holding chemoreceptors. Additionally, the proboscis possesses tentacles that become exposed when the organ is everted. These provide fast release of mucus and toxins, from mucocytes and special serous cells, respectively (the latter involving both merocrine and apocrine processes), whenever contact with a prey occurs. In its turn, the epidermis provides protection by cuticle and mucus secretion and has a sensorial function that may be associated to the worm's uncommon green pigment cells. Eulalia viridis presents a series of elegant adaptive tools to cope with its environment that are evolutionarily designed to counterbalance its relatively simple body plan.

Comparison of simple sucrose and percoll based methodologies for synaptosome enrichment.

Synaptosomes are isolated nerve terminals. They represent an extremely attractive in vitro model system to study synaptic physiology since they preserve morphological and functional characteristics of the synapse. As such they have been used to investigate synaptic dysfunctions associated with neuropathologies like Alzheimer's disease. In the present work two simple methodologies for isolating synaptosomal-enriched fractions were compared for the first time. The starting points of both protocols were rat cortical or hippocampal homogenized tissues that underwent several differential centrifugation steps followed by a final purification of synaptosomal-enriched fractions using either a Percoll gradient or a Sucrose gradient. Comparison of the fractions obtained was carried out, using both biochemical and electron microscopy approaches. In the biochemical analysis the protein levels of pre-synaptic, post-synaptic, nuclear and mitochondrial markers were evaluated. Additional characterization of the synaptosomal-enriched fractions was performed using transmission electron microscopy. In summary, the results indicate that under the conditions tested the Sucrose based protocol is more efficient for the isolation of synaptosomal-enriched fractions from both neuronal tissues, being particularly efficient for hippocampus that is a less abundant brain tissue. Further, the sucrose protocol apparently results in a higher yield of viable synaptosomes suitable for further assays, including structural and functional studies of synapses; making this an attractive procedure to study processes associated with neuropathologies.

About the effect of eye blinking on drug release from pHEMA-based hydrogels: an in vitro study.

The development of new ophthalmic drug delivery systems capable of increasing the residence time of drugs in the eye and improve its bioavailability relatively to eyedrops has been object of intense research in recent years. Several studies have shown that drug-loaded therapeutic soft contact lenses (SCLs) constitute a promising approach, with several potential advantages as compared with collyria. The main objective of this work is to study the effect of repetitive load and friction cycles caused by the eye blinking, on the drug release from hydrogels used in SCLs which, as far as we know, was never investigated before. Two poly-2-hydroxyethylmethacrylate-based hydrogels, pHEMA-T and pHEMA-UV, were used as model materials. Levofloxaxin was chosen as model drug. The hydrogels were fully characterized in what concerns structural and physicochemical properties. pHEMA-UV revealed some superficial porosity and a lower short-range order than pHEMA-T. We observe that the load and friction cycles enhanced the drug release from pHEMA-UV hydrogels. The application of a simple mathematical model, which takes into account the drug dilution caused by the tear flow, showed that the enhancement of the drug release caused by blinking on this hydrogel may be relevant in in vivo conditions. Conversely, the more sustained drug release from pHEMA-T is not affected by load and friction cycles. The conclusion is that, depending on the physicochemical and microstructural characteristics of the hydrogels, blinking is a factor that may affect the amount of drug delivered to the eye by SCLs and should thus be considered.