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Matrix vesicles (MVs) are a special class of extracellular vesicles released by mineralizing cells during bone and tooth mineralization that initiate the precipitation of apatitic minerals by regulating the extracellular ratio between inorganic phosphate (Pi), a calcification promoter, and pyrophosphate (PPi), a calcification inhibitor. The Pi/PPi ratio is thought to be controlled by two ecto-phosphatases present on the outer leaflet of the MVs' membrane: ectonucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) that produces PPi as well as Pi from ATP and tissue-nonspecific alkaline phosphatase (TNAP) that hydrolyzes both ATP and PPi to generate Pi. However, if and how these enzymes act in concert in MVs are still unclear. Herein, we investigated the role of NPP1 and TNAP in ATP hydrolysis during MV-mediated biomineralization using proteoliposomes as a biomimetic model for MVs. Proteoliposomes composed by 1,2-dipalmitoylphosphatidylcholine (DPPC) and harboring NPP1 alone, TNAP alone, or both together at different molar ratios (1:1, 10:1, and 1:10) were fabricated. After 48 h of incubation with ATP, TNAP-containing proteoliposomes consumed more ATP than NPP1-containing vesicles (270 and 210 nmol, respectively). Both types of vesicles comparatively formed ADP (205 and 201 nmol, respectively), while NPP1-containing vesicles hydrolyzed AMP less efficiently than TNAP-containing proteoliposomes (10 and 25 nmol, respectively). In vitro mineralization assays showed that in the presence of ATP, TNAP-harboring proteoliposomes mineralized through a sigmoidal single-step process, while NPP1-harboring vesicles displayed a two-step mineralization process. ATR-FTIR analyses showed that the minerals produced by TNAP-harboring proteoliposomes were structurally more similar to hydroxyapatite than those produced by NPP1-harboring vesicles. Our results with proteoliposomes indicate that the pyrophosphohydrolase function of NPP1 and the phosphohydrolase activity of TNAP act synergistically to produce a Pi/PPi ratio conducive to mineralization and the synergism is maximal when the two enzymes are present at equimolar concentrations. The significance of these findings for hypophosphatasia is discussed.

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This study presents an extension of the concept of "quasi-saturation" to a quasi-saturated layer, defined as the uppermost dynamic portion of the saturated zone subject to water table fluctuations. Entrapped air here may cause substantial reductions in the hydraulic conductivity (K) and fillable pore water. Air entrapment is caused by a rising water table, usually as a result of groundwater recharge. The most significant effects of entrapped air are recharge overestimation based on methods that use specific yield (Sy ), such as the water table fluctuation method (WTF), and reductions in K values. These effects impact estimation of fluid flow velocities and contaminant migration rates in groundwater. In order to quantify actual groundwater recharge rates and the effects of entrapped air, numerical simulations with the FEFLOW (Version 7.0) groundwater flow model were carried out using a quasi-saturated layer for a pilot area in Rio Claro, Brazil. The calculated recharge rate represented 16% of the average precipitation over an 8-year period, approximately half of estimates using the WTF method. Air entrapment amounted to a fillable porosity of 0.07, significant lower that the value of 0.17 obtained experimentally for Sy . Numerical results showed that the entrapped air volume in the quasi-saturated layer can be very significant (0.58 of the air fraction) and hence can significantly affect estimates of groundwater recharge and groundwater flow rates near the water table.

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Strontium ranelate (SrR) has been used as the ultimate choice for osteoporosis treatment. However, the development of more tolerable and bioactive Sr2+ carriers is still a need. The design of Sr2+-based platforms has moved towards the obtention of anion carriers that can also exhibit a positive effect on bone metabolism. In this sense, we used morin, a natural flavonoid, as a new arrangement for Sr2+ carriage in the synthesis of an Sr2+ complex. It has been claimed that phenolic compounds promote bone health. Therefore, we hypothesized that the association of Sr2+ with morin could improve its anabolic effects. Complexes with the general formula [(C15H9O7)Sr(H2O)2]Cl·3H2O were synthesized and characterized by elemental analysis, thermogravimetry, UV-Vis and infrared absorption spectroscopies and 1H-nuclear magnetic resonance. We showed that the complexation between morin and Sr2+ occurred among the 3-OH and 4C[double bond, length as m-dash]O groups of morin. Preosteoclasts cultures with the Sr-morin complex exhibited a reduced osteoclast differentiation rate and sustained osteoblast mineralization ability. The response of Sr-morin was higher than that observed for SrR at the same concentration range. Considering the above-mentioned observations, the Sr-morin complex could be an interesting approach to be further exploited not only as an alternative treatment for osteoporosis but also in the design of materials for faster osteointegration.

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During the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix (ECM) by promoting the synthesis of hydroxyapatite (HA) seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs). Several lipid and proteins present in the membrane of the MVs mediate the interactions of MVs with the ECM and regulate the initial mineral deposition and posterior propagation. Among the proteins of MV membranes, ion transporters control the availability of phosphate and calcium needed for initial HA deposition. Phosphatases (orphan phosphatase 1, ectonucleotide pyrophosphatase/phosphodiesterase 1 and tissue-nonspecific alkaline phosphatase) play a crucial role in controlling the inorganic pyrophosphate/inorganic phosphate ratio that allows MV-mediated initiation of mineralization. The lipidic microenvironment can help in the nucleation process of first crystals and also plays a crucial physiological role in the function of MV-associated enzymes and transporters (type III sodium-dependent phosphate transporters, annexins and Na+/K+ ATPase). The whole process is mediated and regulated by the action of several molecules and steps, which make the process complex and highly regulated. Liposomes and proteoliposomes, as models of biological membranes, facilitate the understanding of lipid-protein interactions with emphasis on the properties of physicochemical and biochemical processes. In this review, we discuss the use of proteoliposomes as multiple protein carrier systems intended to mimic the various functions of MVs during the initiation and propagation of mineral growth in the course of biomineralization. We focus on studies applying biophysical tools to characterize the biomimetic models in order to gain an understanding of the importance of lipid-protein and lipid-lipid interfaces throughout the process.

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Methods to impute HLA alleles based on dense single nucleotide polymorphism (SNP) data provide a valuable resource to association studies and evolutionary investigation of the MHC region. The availability of appropriate training sets is critical to the accuracy of HLA imputation, and the inclusion of samples with various ancestries is an important pre-requisite in studies of admixed populations. We assess the accuracy of HLA imputation using 1000 Genomes Project data as a training set, applying it to a highly admixed Brazilian population, the Quilombos from the state of São Paulo. To assess accuracy, we compared imputed and experimentally determined genotypes for 146 samples at 4 HLA classical loci. We found imputation accuracies of 82.9%, 81.8%, 94.8% and 86.6% for HLA-A, -B, -C and -DRB1 respectively (two-field resolution). Accuracies were improved when we included a subset of Quilombo individuals in the training set. We conclude that the 1000 Genomes data is a valuable resource for construction of training sets due to the diversity of ancestries and the potential for a large overlap of SNPs with the target population. We also show that tailoring training sets to features of the target population substantially enhances imputation accuracy.

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PURPOSE: To investigate the prognostic value of ictal scalp EEG patterns in drug-resistant temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) prior to undergoing temporal lobectomy. METHODS: Scalp EEGs of the first seizure recorded during presurgical long-term video-EEG monitoring of 284 patients were reviewed. Patients were divided according to seizure laterality as either unilateral, when the EEG was restricted to one cerebral hemisphere for the entire seizure, or bilateral, when there was involvement of both hemispheres during the seizure. In patients with unilateral hippocampal sclerosis (HS), seizures were subdivided according to the side of initial ictal activity in relation to the side of the HS, as concordant, non-lateralising or contralateral. Postsurgical seizure outcome, according to Engel's classification, was verified at 1, 2, and 5 years after surgery. RESULTS: There was no significant association between ictal EEG characteristics and postsurgical seizure outcome. An Engel I seizure outcome was observed in 87.1% of the patients with unilateral ictal EEGs and in 79.6% of those with bilateral ictal EEGs (p=0.092). CONCLUSION: Analysis of the localisation, morphology, and lateralisation of ictal EEG patterns did not provide prognostic information regarding seizure-free status in patients with MTLE-HS undergoing temporal lobectomy.

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Autoeroticism comprises behavior deviations aimed at producing sexual gratification through the manipulation of one's own body. The use of asphyxia and the induction of pain (masochism) are well-known examples. "Atypical forms" of such behaviors have appeared in the literature as isolated cases. Fatal air embolism is most common in women (causing abortion), being very rare in men (urethral trauma). The authors present a probable case of air embolism associated with signs of autoeroticism, instrumented by the delivery of air through a system formed by a compressor (typical of those used in refrigerators), a syringe barrel, a segment of latex tubing (tourniquet), and a needle, which was found inserted into the glans penis of an adult male. The hypothesis of accidental death was chosen due to the findings at the scene. The body was decomposing when found, which hampered the conduction of examinations.

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Tubal sterilization is the most common contraceptive method used by Brazilian HIV-positive women. This cross sectional study describes the main reasons why HIV-positive women decide to be sterilized and identifies factors associated with choosing sterilization in HIV-positive women in Ceará, northeast Brazil. Data from 229 non-sterilized women, 80 women sterilized before HIV diagnosis and 48 women sterilized after diagnosis were analysed. Of the women sterilized after HIV diagnosis, 96% had the procedure done in the postpartum, during a caesarean section. No desire for more children was the most common appointed reason to be sterilized (39.6%), followed by medical recommendation because of HIV (31.3%). Seventy-nine women (28.5%) had a child after HIV diagnosis. Of those, 46 (58.2%) were sterilized in the postpartum. Factors associated with sterilization for HIV-positive women were: having a child after diagnosis (AOR: 120.9; 95%CI: 27.8-525.4) and having at least three children (AOR: 2.8; 95%CI: 1.1-7.1). It is recommended that non-coercive counselling should be provided so that HIV-positive women can make informed decisions on their reproductive options.

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PURPOSE: To determine social and behavioral consequences of pregnancy and how these differed according to the pregnancy outcome (live birth or abortion) 1 year after the event. METHODS: This was a prospective study of two groups of young women aged 12-18 years, one attending prenatal services and the other admitted for abortion complications at the same hospital in northeast Brazil. Adolescents who gave birth were subsequently classified as having intended or unintended pregnancies, and those who aborted were divided between those who terminated their pregnancies and those who miscarried. Baseline data were collected between 1995 and 1997 from all teens who met the eligibility criteria. Information was collected through one-on-one interviews using a questionnaire that was structured and precoded. Multiple logistic regression was used to identify characteristics that predicted outcomes at 1 year. RESULTS: Teens who terminated their pregnancies were the most likely to be in school or working 1 year later. They also showed the greatest increase in self-esteem. The young mothers, however, had the highest self-esteem but perceived the impact of pregnancy on their lives as being more negative than they did initially. Group affiliation was not associated with the quality of partner relationships, which tended to deteriorate over time. The young mothers used contraception at 1 year at higher rates and had experienced fewer subsequent pregnancies than the two abortion groups. CONCLUSIONS: The experience of adolescent pregnancy for this group of teens produced mixed findings, some more negative than others. Interventions to decrease the adolescent's desire to have a baby will have to be tailored differently from those designed to prevent an unintended pregnancy, but both are needed.

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