Impact of the Femoral Head Position on Moment Arms in Total Hip Arthroplasty: A Parametric Finite Element Study.

BACKGROUND: Although the importance of accurate femoral reconstruction to achieve a good functional outcome is well documented, quantitative data on the effects of a displacement of the femoral center of rotation on moment arms are scarce. The purpose of this study was to calculate moment arms after nonanatomical femoral reconstruction. METHODS: Finite element models of 15 patients including the pelvis, the femur, and the gluteal muscles were developed. Moment arms were calculated within the native anatomy and compared to distinct displacement of the femoral center of rotation (leg lengthening of 10 mm, loss of femoral offset of 20%, anteversion ±10°, and fixed anteversion at 15°). Calculations were performed within the range of motion observed during a normal gait cycle. RESULTS: Although with all evaluated displacements of the femoral center of rotation, the abductor moment arm remained positive, some fibers initially contributing to extension became antagonists (flexors) and vice versa. A loss of 20% of femoral offset led to an average decrease of 15% of abductor moment. Femoral lengthening and changes in femoral anteversion (±10°, fixed at 15°) led to minimal changes in abductor moment arms (maximum change of 5%). Native femoral anteversion correlated with the changes in moment arms induced by the 5 variations of reconstruction. CONCLUSION: Accurate reconstruction of offset is important to maintaining abductor moment arms, while changes of femoral rotation had minimal effects. Patients with larger native femoral anteversion appear to be more susceptible to femoral head displacements.

Review of the synthesis of layered double hydroxides: a thermodynamic approach

The synthesis of layered double hydroxides (LDHs) by hydrothermal-LDH reconstruction and coprecipitation methods is reviewed using a thermodynamic approach. A mixture model was used for the estimation of the thermodynamics of formation of LDHs. The synthesis and solubility of LDHs are discussed in terms of standard molar Gibbs free energy change of reaction. Data for numerous divalent and trivalent metals as well as for some monovalent and tetravalent metals that may be part of the LDH structure have been compiled. Good agreement is found between theoretical and experimental data. Diagrams and tables for the prediction of possible new LDH materials are provided.

Structure and dynamics of the membrane attaching nitric oxide transporter nitrophorin 7

Nitrophorins represent a unique class of heme proteins that are able to perform the delicate transportation and release of the free-radical gaseous messenger nitric oxide (NO) in a pH-triggered manner. Besides its ability to bind to phospholipid membranes, the N-terminus contains an additional Leu-Pro-Gly stretch, which is a unique sequence trait, and the heme cavity is significantly altered with respect to other nitrophorins. These distinctive features encouraged us to solve the X-ray crystallographic structures of NP7 at low and high pH and bound with different heme ligands (nitric oxide, histamine, imidazole). The overall fold of the lipocalin motif is well preserved in the different X-ray structures and resembles the fold of other nitrophorins. However, a chain-like arrangement in the crystal lattice due to a number of head-to-tail electrostatic stabilizing interactions is found in NP7. Furthermore, the X-ray structures also reveal ligand-dependent changes in the orientation of the heme, as well as in specific interactions between the A-B and G-H loops, which are considered to be relevant for the biological function of nitrophorins. Fast and ultrafast laser triggered ligand rebinding experiments demonstrate the pH-dependent ligand migration within the cavities and the exit route. Finally, the topological distribution of pockets located around the heme as well as from inner cavities present at the rear of the protein provides a distinctive feature in NP7, so that while a loop gated exit mechanism to the solvent has been proposed for most nitrophorins, a more complex mechanism that involves several interconnected gas hosting cavities is proposed for NP7.

DENDROCLIMATOLOGICAL RECONSTRUCTION OF SPRING-SUMMER PRECIPITATION FOR FAZENDA RIO GRANDE, PR, WITH SAMPLES OF Araucaria angustifolia (Bertol.) Kuntze

ABSTRACT Samples of Araucaria angustifolia were collected at Fazenda Rio Grande, Paraná, Brazil (25°39'S 49 18'O) in January 2011. The 32 samples from 8 trees were subjected to treatments following dendrochronological techniques. The cores were measured and dated using optical and computational methodology, and then standardized to obtain a growth-ring time series, which considers the 1907-2009 time range and represents Fazenda Rio Grande. Tree-ring indices were analyzed and correlated to temperature and precipitation averages from the 1961-2009 range. This procedure aimed to study and understand the influence of the local climate on the plant growth and if this influence can be quantified. A. angustifolia trees produce visible annual growth rings, and their earlywood and latewood are clearly defined. The present study shows that A. angustifolia is sensitive to climate variables (e.g., low temperatures in wintertime tend to stop the growth rate). The correlation between tree rings and monthly precipitation series showed a common trend, making it possible to estimate the seasonal rainfall behavior for the entire 1907-2009 range.

Correlation between the oropharyngo-laryngoscopic findings and the severity of obstructive sleep apnea

Objective: To correlate anatomical and functional changes of the oral cavity, pharynx and larynx to the severity of obstructive sleep apnea syndrome (OSAS). Methods : We conducted a cross-sectional study of 66 patients of both genders, aged between 21 and 59 years old with complaints of snoring and / or apnea. All underwent full clinical evaluation, including physical examination, nasolarybgoscopy and polisonography. We classified individuals into groups by the value of the apnea-hypopnea index (AHI), calculated measures of association and analyzed differences by the Kruskal-Wallis and chi-square tests. Results : all patients with obesity type 2 had OSAS. We found a relationship between the uvula projection during nasoendoscopy and OSAS (OR: 4.9; p-value: 0.008; CI: 1.25-22.9). In addition, there was a major strength of association between the circular shape of the pharynx and the presence of moderate or severe OSAS (OR: 9.4, p-value: 0.002), although the CI was wide (1.80-53.13). The septal deviation and lower turbinate hypertrophy were the most frequent nasal alterations, however unrelated to gravity. Nasal obstruction was four times more common in patients without daytime sleepiness. The other craniofacial anatomical changes were not predictors for the occurrence of OSAS. Conclusion : oral, pharyngeal and laryngeal disorders participate in the pathophysiology of OSAS. The completion of the endoscopic examination is of great value to the evaluation of these patients.

Occurrence of parasitism by Dioctophyma renale in ring-tailed coatis (Nasua nasua) of the Tiete Ecological Park, São Paulo, Brazil

Dioctophymosis is a worldwide renal parasitosis caused by the Dioctophyma renale nematode, which results in progressive destruction of renal tissue. Aquatics annelids are considered the main intermediate hosts and the literature refers as permanent hosts of dogs, wild mammals and even humans. During procedures for population control of coatis (Nasua nasua) in the Ecological Park of Tietê (PET), was noticed the presence of parasitosis by D. renale. From 68 animals, males and females, young and adults, submitted to exploratory laparotomy, 51 were positive for the presence of worms, 9 were found only in the right kidney. In 10 cases, in addition to right kidney parasitism, worms were also observed in the abdominal cavity. In 24 cases D. renale was found only in the abdominal cavity and in 8 animals the right kidney was reduced to a small rigid structure. The study showed that the preferred site for parasitism of the worm, considered erratic, was the abdominal cavity in 66.66% of the cases.

Lectin histochemical aspects of the ovarian lamellae epithelium of Genypterus blacodes (Schneider, 1801)

The composition and distribution of the glycoconjugates (GCs) secreted by the epithelium of ovarian lamellae with reference to the reproductive biology of Genypterus blacodes (Schneider, 1801) through lectin hi stochemistry is here discussed. In this species, the epithelial cells that line the ovarian cavity presented sharp morphological variations along the reproductive cycle related to the mucus secretion that accompanies oocyte ma turation. During sp awning season, residues of mannose and N-acetylglucosamine were detected in the glycocalyx of those cells using lectinhistochemistry. N- acetylgalactosamine and fucose were also observed in the same zone. The greatest variations in the lectinhistochemical pattern were found in the apical cytoplasm composition in comparison to the basal zone of the cells. The results of the present study were discussed by comparing their possible functional implications.

Macroscopic description of the external and middle ear of paca (Cuniculus paca Linnaeus, 1766)

Abstract: Paca (Cuniculus paca), one of the largest rodents of the Brazilian fauna, has inherent characteristics of its species which can conribute as a new option for animal experimantation. As there is a growing demand for suitable experimental models in audiologic and otologic surgical research, the gross anatomy and ultrastructural ear of this rodent have been analyzed and described in detail. Fifteen adult pacas from the Wild Animals Sector herd of Faculdade de Ciências Agrárias e Veterinárias, Unesp-Jaboticabal, were used in this study. After anesthesia and euthanasia, we evaluated the entire composition of the external ear, registering and ddescribing the details; the temporal region was often dissected for a better view and detailing of the tympanic bulla which was removed and opened to expose the ear structures analyzed mascroscopically and ultrastructurally. The ear pinna has a triangular and concave shape with irregular ridges and sharp apex. The external auditory canal is winding in its path to the tympanic mebrane. The tympanic bulla is is on the back-bottom of the skull. The middle ear is formed by a cavity region filled with bone and membranous structures bounded by the tympanic membrane and the oval and round windows. The tympanic membrane is flat and seals the ear canal. The anatomy of the paca ear is similar to the guinea pig and from the viewpoint of experimental model has major advantages compared with the mouse ear.

Morphology and anatomy of the fruit and seed in development of Chorisia speciosa A. St.-Hil. - Bombacaceae

The structure of the fruit and seed in development of Chorisia speciosa are described with the main purpose of clarifying the origin and nature of the hairs that cover the seeds and aiding future taxonomical and ecological studies of the group. The fruit is an ellipsoid loculicide capsule and presents the exocarp formed by 7-10 cells layers, with very thick walls and evident simple pits. A great number of mucilage secretory cavities and ramified vascular bundles, accompanied by fibers, occur in the parenchymatic mesocarp. The endocarp derives from the ventral epidermis of the ovary wall, whose cells undergo a gradual elongation, become lignified, and constitute the trichomes which cover the mature seeds. The fruit aperture occurs by means of a suture evident in the ovarian wall in the middle region of the carpel leaf. Anatropous and bitegmic ovules, provided by a hypostase, give rise to campilotropous and bitegmic seeds. The testa is uniseriate, the exotegmen is completely formed by macrosclereids, and mucilage secretory cavities occur in the mesotegmen. The endotegmen, which is differentiated in the endothelium, is crushed in the mature seed. The plicate embryo, which occupies practically the entire seminal cavity, is found between endosperm layers, both being rich in lipids.

Cytotoxic activity of the dichloromethane fraction from Vernonia scorpioides (Lam.) Pers. (Asteraceae) against Ehrlich's tumor cells in mice

Vernonia scorpioides has been widely used in Brazil to treat skin problems and chronic wounds, such as ulcers of the lower limbs and diabetic lesions. In the present study, we investigated the effect of a dichloromethane (DCM) fraction of V. scorpioides leaf extract on Ehrlich ascitic and solid tumor-bearing mice. The animals were treated once a day with the DCM fraction at a concentration of 5 mg/kg, administered ip during and after the development of the tumor. The lifespan, weight, number and type of leukocytes, number of tumor cells, volume of solid and ascitic tumors were measured. The development of the tumor with pre-treated tumor cells in vitro with the DCM fraction (5 mg/kg) was analyzed and the animals were sacrificed after 7 days. The DCM fraction (5 mg/kg) totally inhibited tumor development when in direct contact with tumor cells, and also ascitic tumor development with in vitro treatment or when administered ip, in loco (after 7 days). Animals treated with the DCM fraction increased their lifespan ca. 2 weeks and maintained their body weight for 30 days. When applied immediately after the inoculation of the tumor cells in vivo, it totally abolished tumor development, with tumor development only decreasing when treatment was started 3 days after the tumor challenge. These data suggest an antineoplastic activity of the fraction. Oral or ip administration of DCM fraction (5 mg/kg) for 7 days did not reduce the solid tumor volume. The cytotoxic activity described here differs from the conventional immune suppressing profile of standard chemotherapy because it increases neutrophil influx to the peritoneal cavity. These results show that, besides exhibiting a tumoricidal activity, the DCM fraction also exhibits inflammatory activity.

Performance assessment of the single photon emission microscope: high spatial resolution SPECT imaging of small animal organs

The single photon emission microscope (SPEM) is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT) images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl)] columnar scintillator, a demagnifying/intensifier tube, and an electron-multiplying charge-coupling device (CCD). Collimators have 300- and 450-µm diameter pinholes on tungsten slabs, in hexagonal arrays of 19 and 7 holes. Projection data are acquired in a photon-counting strategy, where CCD frames are stored at 50 frames per second, with a radius of rotation of 35 mm and magnification factor of one. The image reconstruction software tool is based on the maximum likelihood algorithm. Our aim was to evaluate the spatial resolution and sensitivity attainable with the seven-pinhole imaging device, together with the linearity for quantification on the tomographic images, and to test the instrument in obtaining tomographic images of different mouse organs. A spatial resolution better than 500 µm and a sensitivity of 21.6 counts·s-1·MBq-1 were reached, as well as a correlation coefficient between activity and intensity better than 0.99, when imaging 99mTc sources. Images of the thyroid, heart, lungs, and bones of mice were registered using 99mTc-labeled radiopharmaceuticals in times appropriate for routine preclinical experimentation of <1 h per projection data set. Detailed experimental protocols and images of the aforementioned organs are shown. We plan to extend the instrument's field of view to fix larger animals and to combine data from both detectors to reduce the acquisition time or applied activity.

Reconstruction of cranial bone defects with fiber-reinforced composite–bioactive glass implants

A cranial bone defect may result after an operative treatment of trauma, infection, vascular insult, or tumor. New biomaterials for cranial bone defect reconstructions are needed for example to mimic the biomechanical properties and structure of cranial bone. A novel glass fiber-reinforced composite implant with bioactive glass particulates (FRC–BG, fiber-reinforced composite–bioactive glass) has osteointegrative potential in a preclinical setting. The aim of the first and second study was to investigate the functionality of a FRC–BG implant in the reconstruction of cranial bone defects. During the years 2007–2014, a prospective clinical trial was conducted in two tertiary level academic institutions (Turku University Hospital and Oulu University Hospital) to evaluate the treatment outcome in 35 patients that underwent a FRC–BG cranioplasty. The treatment outcome was good both in adult and pediatric patients. A number of conventional complications related to cranioplasty were observed. In the third study, a retrospective outcome evaluation of 100 cranioplasty procedures performed in Turku University Hospital between years 2002–2012 was conducted. The experimental fourth study was conducted to test the load-bearing capacity and fracture behavior of FRC–BG implants under static loading. The interconnective bars in the implant structure markedly increased the load-bearing capacity of the implant. A loading test did not demonstrate any protrusions of glass fibers or fiber cut. The fracture type was buckling and delamination. In this study, a postoperative complication requiring a reoperation or removal of the cranioplasty material was observed in one out of five cranioplasty patients. The treatment outcomes of cranioplasty performed with different synthetic materials did not show significant difference when compared with autograft. The FRC–BG implant was demonstrated to be safe and biocompatible biomaterial for large cranial bone defect reconstructions in adult and pediatric patients.

Haplotype analysis suggest common founders in carriers of the recurrent BRCA2 mutation, 3398delAAAAG, in French Canadian hereditary breast and/ovarian cancer families

Affiliation: Faculté de médicine, Université de Montréal

Effect of fatty acids on hyphal growth in the pathogenic yeast Candida albicans

Candida albicans est une levure pathogène qui, à l’état commensal, colonise les muqueuses de la cavité orale et du tractus gastro-intestinal. De nature opportuniste, C. albicans cause de nombreuses infections, allant des candidoses superficielles (muguet buccal, vulvo-vaginite) aux candidoses systémiques sévères. C. albicans a la capacité de se développer sous diverses morphologies, telles que les formes levures, pseudohyphes et hyphes. Des stimuli environnementaux mimant les conditions retrouvées chez l’hôte (température de 37°C, pH neutre, présence de sérum) induisent la transition levure-à-hyphe (i.e. morphogenèse ou filamentation). Cette transition morphologique contribue à la pathogénicité de C. albicans, du fait que des souches présentant un défaut de filamentation sont avirulentes. Non seulement la morphogenèse est un facteur de virulence, mais elle constituerait aussi une cible pour le développement d’antifongiques. En effet, il a déjà été démontré que l’inhibition de la transition levure-à-hyphe atténuait la virulence de C. albicans lors d’infections systémiques. Par ailleurs, des études ont démontré que de nombreuses molécules pouvaient moduler la morphogenèse. Parmi ces molécules, certains acides gras, dont l’acide linoléique conjugué (CLA), inhibent la formation d’hyphes. Ainsi, le CLA posséderait des propriétés thérapeutiques, du fait qu’il interfère avec un déterminant de pathogénicité de C. albicans. Par contre, avant d’évaluer son potentiel thérapeutique dans un contexte clinique, il est essentiel d’étudier son mode d’action. Ce projet vise à caractériser l’activité anti-filamentation des acides gras et du CLA et à déterminer le mécanisme par lequel ces molécules inhibent la morphogenèse chez C. albicans. Des analyses transcriptomiques globales ont été effectuées afin d’obtenir le profil transcriptionnel de la réponse de C. albicans au CLA. L’acide gras a entraîné une baisse des niveaux d’expression de gènes encodant des protéines hyphes-spécifiques et des régulateurs de morphogenèse, dont RAS1. Ce gène code pour la GTPase Ras1p, une protéine membranaire de signalisation qui joue un rôle important dans la transition levure-à-hyphe. Des analyses de PCR quantitatif ont confirmé que le CLA inhibait l’induction de RAS1. De plus, le CLA a non seulement causé une baisse des niveaux cellulaires de Ras1p, mais a aussi entraîné sa délocalisation de la membrane plasmique. En affectant les niveaux et la localisation cellulaire de Ras1p, le CLA nuit à l’activation de la voie de signalisation Ras1p-dépendante, inhibant ainsi la morphogenèse. Il est possible que le CLA altère la structure de la membrane plasmique et affecte indirectement la localisation membranaire de Ras1p. Ces travaux ont permis de mettre en évidence le mode d’action du CLA. Le potentiel thérapeutique du CLA pourrait maintenant être évalué dans un contexte d’infection, permettant ainsi de vérifier qu’une telle approche constitue véritablement une stratégie pour le traitement des candidoses.

Facial artery musculomucosal flap for reconstruction of skull base defects

Facial Artery Musculomucosal Flap in Skull Base Reconstruction Xie L. MD, Lavigne F. MD, Rahal A. MD, Moubayed SP MD, Ayad T. MD Introduction: Failure in skull base defects reconstruction can have serious consequences such as meningitis and pneumocephalus. The nasoseptal flap is usually the first choice but alternatives are necessary when this flap is not available. The facial artery musculomucosal (FAMM) flap has proven to be successful in head and neck reconstruction but it has never been reported in skull base reconstruction. Objective: To show that the FAMM flap can reach some key areas of the skull base and be considered as a new alternative in skull base defects reconstruction. Methods: We conducted a cadaveric study with harvest of modified FAMM flaps, endoscopic skull base dissection and maxillectomies in 13 specimens. Measures were taken for each harvested FAMM flap. Results: The approximate mean area for reconstruction from the combination of the distal FAMM and the extension flaps is 15.90 cm2. The flaps successfully covered the simulated defects of the frontal sinus, the ethmoid areas, the planum sphenoidale, and the sella turcica. Conclusion: The FAMM flap can be considered as a new alternative in the reconstruction of skull base defects. Modifications add extra length to the traditional FAMM flap and can contribute to a tighter seal of the defect as opposed to the FAMM flap alone.