VISCOELASTIC CHARACTERIZATION OF RABBIT NUCLEUS PULPOSUS TISSUE IN TORSIONAL CREEP

Recently, molecular therapy approaches have been shown to favorably alter the course of intervertebral disc degeneration (IDD) in a rabbit model. Typical experimental outcome measures for the rabbit model of IDD include MRI, x-ray, histology, and gene expression. Biomechanical function is another desirable parameter through which to compare treatments, although this is difficult due to limited availability of data for small animal models. In the current study, nucleus pulposus tissue was taken from the healthy rabbit intervertebral disc and tested in torsional creep to establish a database of healthy tissue behavior for future use in assessing the functional efficacy of molecular therapy treatments of IDD. Nucleus pulposus tissue was excised from the L5-L6 intervertebral disc, mounted between the cone and plate of an AR1000 Rheometer, and various torsional creep experiments were performed. Several creep models were fit to the data and modeling analyses were conducted. Of the models compared, the Andrade creep model provides the most reliable data extrapolation. It appears that the tissue is nonlinearly viscoelastic since it does not adhere to the Boltzmann superposition principle. A nonlinear viscoelastic constitutive model, derived for Andrade creep and used to predict the strain behavior obtained at higher levels of stress, provides consistent prediction results. The application of this model to degenerated rabbit NP tissue is expected to result in altered model parameters - thus providing quantifiable, functional benchmarks of success for molecular therapy approaches to the treatment of IDD

Symptomatic Cavernous Malformation Presenting with Seizure without Hemorrhage: Analysis of Factors Influencing Clinical Presentation

BACKGROUND: Supratentorial cavernous malformations (CMs) can be epileptogenic lesions. However, little is known about clinical comorbidities, medication use, and radiologic features that predict a first seizure presentation without associated CM hemorrhage.METHODS: We queried a prospective registry of consecutive patients with CM established in January 2015. Data regarding clinical presentation, comorbid conditions, daily medication use, and radiologic CM characteristics were collected. Univariate and multivariate regression analysis was performed assessing variables for presentation with seizure without hemorrhage with P values, odds ratios, and 95% confidence intervals reported.RESULTS: Of 202 patients, 58.4% were women, and the average age at diagnosis was 43.7 +/- 16.5 years. Of the patients, 59.4% were symptomatic. In 40.6%, the CM was an incidental finding. Of the 30 patients who presented with a first-time seizure without concomitant hemorrhage, the mean age at diagnosis was 38.4 +/- 14.6 years, and 56.7% were women. Compared with incidental CM, patients with seizure without hemorrhage were younger, had a cortically based, supratentorial lesion, and were less likely to have chronic inflammatory disease or to use aspirin, vitamin D, or statin. Compared with other supratentorial lesions, patients with seizure without hemorrhage more commonly had a temporal lobe CM.CONCLUSIONS: These prospective data provide possible clues to radiologic factors, clinical comorbidities, and medication influences on seizure presentation in patients with CM. Further multicenter studies would be helpful to determine if disease-modifying agents in addition to epileptic medications or surgery might be helpful

Aprovechamiento de materiales locales en la estructura de pavimentos urbanos económicos

Se estudiaron las propiedades de un suelo representativo del partido de 25 de Mayo (Prov. de Buenos Aires) y su zona de influencia, con el objeto de conocer la posibilidad de utilizarlo como base y sub-base de pavimentos urbanos. Se analizó el comportamiento del suelo, realizando mezclas con emulsión bituminosa superestable EBL2, como así también mezclas de suelo-cemento. De la comparación de ambos casos surgen consideraciones técnico-económicas, en base a las cuales se dan posibles soluciones de pavimento.In this paper were studied the properties of a representative soil of 25 de Mayo district, in the Buenos Aires Province, with the object to establish the possibility of its use as a base and sub-base in urban pavements. The soil behaviour vms analyzed making mixtures with su- perstnble EBL2 bituminous emulsions and also with soil-cement mixtures. The results obtained with both mixtures were compared and technical and economical considerations were given

Community next steps for making globally unique identifiers work for biocollections data

Biodiversity data is being digitized and made available online at a rapidly increasing rate but current practices typically do not preserve linkages between these data, which impedes interoperation, provenance tracking, and assembly of larger datasets. For data associated with biocollections, the biodiversity community has long recognized that an essential part of establishing and preserving linkages is to apply globally unique identifiers at the point when data are generated in the field and to persist these identifiers downstream, but this is seldom implemented in practice. There has neither been coalescence towards one single identifier solution (as in some other domains), nor even a set of recommended best practices and standards to support multiple identifier schemes sharing consistent responses. In order to further progress towards a broader community consensus, a group of biocollections and informatics experts assembled in Stockholm in October 2014 to discuss community next steps to overcome current roadblocks. The workshop participants divided into four groups focusing on: identifier practice in current field biocollections; identifier application for legacy biocollections; identifiers as applied to biodiversity data records as they are published and made available in semantically marked-up publications; and cross-cutting identifier solutions that bridge across these domains. The main outcome was consensus on key issues, including recognition of differences between legacy and new biocollections processes, the need for identifier metadata profiles that can report information on identifier persistence missions, and the unambiguous indication of the type of object associated with the identifier. Current identifier characteristics are also summarized, and an overview of available schemes and practices is provided

Combined endoscopic endonasal transpterygoid and sublabial transmaxillary approaches for a large infratemporal fossa trigeminal schwannoma

Background Trigeminal schwannomas (TSs) with solitary extracranial location are rare, and surgical excision is challenging. In recent years, the endoscopic endonasal transmaxillary transpterygoid approach (EETPA) has been advocated as an effective strategy for TSs in the infratemporal fossa (ITF). Method We describe the steps of the EETPA combined with the sublabial transmaxillary approach for the surgical excision of a giant mandibular schwannoma of the ITF. Indications, advantages, and approach-specific complications are also discussed. The main surgical steps are shown in an operative video. Conclusion A combined EETPA and sublabial transmaxillary approach represents a safe and effective option for the surgical excision of extracranial TSs

Strain energy storage and dissipation rate in active cell mechanics

When living cells are observed at rest on a flat substrate, they can typically exhibit a rounded (symmetric) or an elongated (polarized) shape. Although the cells are apparently at rest, the active stress generated by the molecular motors continuously stretches and drifts the actin network, the cytoskeleton of the cell. In this paper we theoretically compare the energy stored and dissipated in this active system in two geometric configurations of interest: symmetric and polarized. We find that the stored energy is larger for a radially symmetric cell at low activation regime, while the polar configuration has larger strain energy when the active stress is beyond a critical threshold. Conversely, the dissipation of energy in a symmetric cell is always larger than that of a nonsymmetric one. By a combination of symmetry arguments and competition between surface and bulk stress, we argue that radial symmetry is an energetically expensive metastable state that provides access to an infinite number of lower-energy states, the polarized configurations

Anabolic steroids purchased on the Internet as a cause of prolonged hypogonadotropic hypogonadism

OBJECTIVE: To report a case of hypogonadotropic hypogonadism due to the chronic abuse of anabolic steroids purchased over the Internet. DESIGN: Case report. SETTING: Endocrinology unit of the University of Brescia. PATIENT(S): A 34-year-old man. INTERVENTION(S): A single dose (100 μg) of triptorelin (triptorelin test). MAIN OUTCOME MEASURE(S): Clinical symptoms, androgen normalization, levels of serum testosterone, follicle-stimulating hormone, and luteinizing hormone. RESULT(S): Within 1 month, the patient's serum testosterone was in the normal range, and he reported a return to normal energy and libido. CONCLUSION(S): The World Anti-Doping Code has proved to be a very powerful and effective tool in the harmonization of antidoping efforts worldwide, but it is insufficient to combat this illegal phenomenon. To tackle the serious side effects caused by doping we believe that it is necessary to increase monitoring and adopt severe sanctions, particularly with regard to Internet sites

Cranial ultrasound screening in term and late preterm neonates born by vacuum-assisted delivery: Is itworthwhile?

Background: Vacuum extraction is the most common choice to assist vaginal delivery, but there are still concerns regarding the neonatal injuries it may cause. This study aimed to evaluate the rate of intracranial injuries assessed by cranial ultrasound (cUS) among infants born by vacuum extraction, and the relationship with maternal and perinatal factors. Methods: This was a single-center retrospective study carried out in a level-3 neonatal unit. A total of 593 term and late preterm infants born by vacuum-assisted delivery were examined with a cUS scan within 3 days after birth. Results: Major head injuries were clinically silent and occurred in 2% of the infants, with a rate of intracranial haemorrhage of 1.7%. Regardless of obstetric factors, the risk of cranial injury was increased in infants requiring resuscitation at birth (p = 0.04, OR 4.1), admitted to NICU (p = 0.01, OR 5.5) or with perinatal asphyxia (p < 0.01, OR 21.3). Maternal age ≥40 years correlated both with adverse perinatal outcomes (p < 0.05) and the occurrence of major injury (p = 0.02, OR 4.6). Conclusion: Overall, vacuum extraction is a safe procedure for neonates. Head injuries are usually mild and asymptomatic, and with spontaneous recovery. However, the rate of major cranial injuries in our cohort warrants further investigation to support a cUS screening, particularly for infants requiring respiratory support at birth. Also, maternal age might be taken into account when evaluating the risk for neonatal complications after vacuum application