Percutaneous vertebroplasty: a new animal model.

Background Context: Percutaneous vertebroplasty (PVP) is a minimally invasive surgical procedure and is frequently performed in humans who need surgical treatment of vertebral fractures. PVP involves cement injection into the vertebral body, thereby providing rapid and significant pain relief.

Purpose: The testing of novel biomaterials depends on suitable animal models.

In vivo measurement of the pressure signal in the intervertebral disc of an anesthetized sheep.

The purpose of the present study was to measure the intradiscal pressure signal of an anesthetized sheep under spontaneous breathing. An ultra-miniature fiber optic high-pressure sensor was implanted into the nucleus pulposus of the fifth lumbar intervertebral using a dorsolateral transforaminal approach. Results suggested the periodicity of the intradiscal pressure signal was similar to the mean respiratory rate of the animal.

A new piezoelectric actuator induces bone formation in vivo: a preliminary study.

This in vivo study presents the preliminary results of the use of a novel piezoelectric actuator for orthopedic application. The innovative use of the converse piezoelectric effect to mechanically stimulate bone was achieved with polyvinylidene fluoride actuators implanted in osteotomy cuts in sheep femur and tibia. The biological response around the osteotomies was assessed through histology and histomorphometry in nondecalcified sections and histochemistry and immunohistochemistry in decalcified sections, namely, through Masson's trichrome, and labeling of osteopontin, proliferating cell nuclear antigen, and tartrate-resistant acid phosphatase.

Chronic in vivo multi-circuit neurophysiological recordings in mice.

While genetically modified mice have become a widely accepted tool for modeling the influence of gene function on the manifestation of neurological and psychiatric endophenotypes, only modest headway has been made in characterizing the functional circuit changes that underlie the disruption of complex behavioral processes in various models. This challenge partially arises from the fact that even simple behaviors require the coordination of many neural circuits vastly distributed across multiple brain areas. As such, many independent neurophysiological alterations are likely to yield overlapping circuit disruptions and ultimately lead to the manifestation of similar behavioral deficits.

Integrated biomimetic carbon nanotube composites for in vivo systems.

As interest in using carbon nanotubes for developing biologically compatible systems continues to grow, biological inspiration is stimulating new directions for in vivo approaches. The ability to integrate nanotechnology-based systems in the body will provide greater successes if the implanted material is made to mimic elements of the biological milieu especially through tuning physical and chemical characteristics. Here, we demonstrate the highly successful capacity for in vivo implantation of a new carbon nanotube-based composite that is, itself, integrated with a hydroxyapatite-polymethyl methacrylate to create a nanocomposite.

Effect of condensed tannin ingestion in sheep and goat parotid saliva proteome.

Saliva appears as a defence mechanism, against potential negative effects of tannins, in some species of animals which have to deal with these plant secondary metabolites in their regular diets. This study was carried out to investigate changes in parotid saliva protein profiles of sheep (Ovis aries) and goats (Capra hircus), induced by condensed tannin ingestion. Five Merino sheep and five Serpentina goats were maintained on a quebracho tannin enriched diet for 10 days.

In vitro studies of multiwalled carbon nanotube/ultrahigh molecular weight polyethylene nanocomposites with osteoblast-like MG63 cells.

Carbon nanotubes are highly versatile materials; new applications using them are continuously being developed. Special attention is being dedicated to the possible use of multiwalled carbon nanotubes in biomaterials contacting with bone. However, carbon nanotubes are also controversial in regards to effects exerted on living organisms.

Polymeric piezoelectric actuator substrate for osteoblast mechanical stimulation.

Bone mass distribution and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels. Mechanical stimulation of bone induces new bone formation in vivo and increases the metabolic activity and gene expression of osteoblasts in culture. A wide variety of devices have been tested for mechanical stimulation of cells and tissues in vitro.

Sheep and goat saliva proteome analysis: a useful tool for ingestive behavior research?

Sheep and goats differ in diet selection, which may reflect different abilities to deal with the ingestion of plant secondary metabolites. Although saliva provides a basis for immediate oral information via sensory cues and also a mechanism for detoxification, our understanding of the role of saliva in the pre-gastric control of the intake of herbivores is rudimentary. Salivary proteins have important biological functions, but despite their significance, their expression patterns in sheep and goats have been little studied.

Hyperdopaminergia and NMDA receptor hypofunction disrupt neural phase signaling.

Neural phase signaling has gained attention as a putative coding mechanism through which the brain binds the activity of neurons across distributed brain areas to generate thoughts, percepts, and behaviors. Neural phase signaling has been shown to play a role in various cognitive processes, and it has been suggested that altered phase signaling may play a role in mediating the cognitive deficits observed across neuropsychiatric illness. Here, we investigated neural phase signaling in two mouse models of cognitive dysfunction: mice with genetically induced hyperdopaminergia [dopamine transporter knock-out (DAT-KO) mice] and mice with genetically induced NMDA receptor hypofunction [NMDA receptor subunit-1 knockdown (NR1-KD) mice].

RAPID MANUFACTURING SYSTEM OF ORTHOPEDIC IMPLANTS.

This study, aimed the development of a methodology for rapid manufacture of orthopedic implants simultaneously with the surgical intervention, considering two potential applications in the fields of orthopedics: the manufacture of anatomically adapted implants and implants for bone loss replacement. This work innovation consists on the capitation of the in situ geometry of the implant by direct capture of the shape using an elastomeric material (polyvinylsiloxane) which allows fine detail and great accuracy of the geometry. After scanning the elastomeric specimen, the implant is obtained by machining using a CNC milling machine programmed with a dedicated CAD/CAM system.

Comparison of electrophoretic protein profiles from sheep and goat parotid saliva.

Saliva provides a medium for short-term adaptation to changes in diet composition, namely, the presence of plant secondary metabolites. Salivary proteins have biological functions that have particular influence on oral homeostasis, taste, and digestive function. Some salivary proteins, such as proline-rich proteins, are present in browsers but absent in grazers.

Morphometry of ovarian structures by transrectal ultrasonography in Serrana goats.

The accuracy of transrectal real-time ultrasonography (RTU) scanning technique to detect ovarian structures (follicles and corpus luteum) of Serrana goats was compared to the data obtained by observation of ovarian sequential slices. This slicing technique (SLI) was considered as reference method. The laparoscopy and laparotomy techniques were also used for corpora lutea identification.

Identification of mammalian Sds3 as an integral component of the Sin3/histone deacetylase corepressor complex.

Silencing of gene transcription involves local chromatin modification achieved through the local recruitment of large multiprotein complexes containing histone deacetylase (HDAC) activity. The mammalian corepressors mSin3A and mSin3B have been shown to play a key role in this process by tethering HDACs 1 and 2 to promoter-bound transcription factors. Similar mechanisms appear to be operative in yeast, in which epistasis experiments have established that the mSin3 and HDAC orthologs (SIN3 and RPD3), along with a novel protein, SDS3, function in the same repressor pathway.

The Ink4a tumor suppressor gene product, p19Arf, interacts with MDM2 and neutralizes MDM2's inhibition of p53.

The INK4a gene encodes two distinct growth inhibitors--the cyclin-dependent kinase inhibitor p16Ink4a, which is a component of the Rb pathway, and the tumor suppressor p19Arf, which has been functionally linked to p53. Here we show that p19Arf potently suppresses oncogenic transformation in primary cells and that this function is abrogated when p53 is neutralized by viral oncoproteins and dominant-negative mutants but not by the p53 antagonist MDM2. This finding, coupled with the observations that p19Arf and MDM2 physically interact and that p19Rrf blocks MDM2-induced p53 degradation and transactivational silencing, suggests that p19Arf functions mechanistically to prevent MDM2's neutralization of p53.

Role for N-CoR and histone deacetylase in Sin3-mediated transcriptional repression.

Normal mammalian growth and development are highly dependent on the regulation of the expression and activity of the Myc family of transcription factors. Mxi1-mediated inhibition of Myc activities requires interaction with mammalian Sin3A or Sin3B proteins, which have been purported to act as scaffolds for additional co-repressor factors. The identification of two such Sin3-associated factors, the nuclear receptor co-repressor (N-CoR) and histone deacetylase (HD1), provides a basis for Mxi1/Sin3-induced transcriptional repression and tumour suppression.

Chemical, biological and immunological properties of pituitary gonadotropins from the donkey (Equus asinus): comparison with the horse (Equus caballus).

Donkey gonadotropins (donkey luteinizing hormone, dLH; donkey follicle-stimulating hormone, dFSH) have been isolated in purified form from 191 donkey pituitaries using essentially the same procedures previously employed for the purification of equine gonadotropins. Chemically, dLH and dFSH were observed to be similar to equine LH (eLH) and FSH (eFSH) in fractionation behavior and glycoprotein nature. Two forms of the dFSH molecule were observed, as is the case for eFSH.