An Evaluation of The Host Response to An Interspinous Process Device Based on A Series of Spine Explants: Device for Intervertebral Assisted Motion (DIAM®)

Background: The objective of this study was to evaluate the host response to an interspinous process device [Device for Intervertebral Assisted Motion (DIAM®)] based on a series of nine spine explants with a mean post-operative explant time of 35 months. Methods: Explanted periprosthetic tissues were processed for histology and stained with H&E, Wright-Giemsa stain, and Oil Red O. Brightfield and polarized light microscopy were used to evaluate the host response to the device and the resultant particulate debris. The host response was graded per ASTM F981-04. Quantitative histomorphometry was used to characterize particle size, shape, and area per ASTM F1877-05. The presence or absence of bone resorption was also evaluated when bony tissue samples were provided. Results: Periprosthetic tissues demonstrated a non-specific foreign body response composed of macrophages and foreign body giant cells to the DIAM® device in most of the accessions. The foreign body reaction was not the stated reason for explantation in any of the accessions. Per ASTM F981-04, a “very slight” to “mild” to “moderate” chronic inflammatory response was observed to the biomaterials and particulate, and this varied by tissue sample and accession. Particle sizes were consistent amongst the explant patients with mean particle size on the order of several microns. Osteolysis, signs of toxicity, necrosis, an immune response, and/or device related infection were not observed. Conclusions: Cyclic loading of the spine can cause wear in dynamic stabilization systems such as DIAM®. The fabric nature of the DIAM® device’s polyethylene terephthalate jacket coupled with the generation of polymeric particulate debris predisposes the device to a foreign body reaction consisting of macrophages and foreign body giant cells. Although not all patients are aware of symptoms associated with a foreign body reaction to a deeply implanted device, surgeons should be aware of the host response to this device

Effect of jumbo squid (Dosidicus gigas) skin extract on the microbial activity in chilled mackerel (Scomber scombrus)

6 páginas, 4 tablas, 2 figurasDuring the industrial processing of jumbo squid (Dosidicus gigas), large amounts of by-products containing biological active compounds are generated. In this study, aqueous solutions including acetic acid-ethanol extracts of jumbo squid skin (JSS) were tested at three different concentrations as icing media. The effects of the JSS extracts on the quality evolution of chilled mackerel (Scomber scombrus) were monitored. A significant inhibition (p < 0.05) of microbial activity was determined in the fish batch corresponding to the icing condition including the highest JSS concentration. Additionally, fish specimens corresponding to batches including any of the JSS concentrations tested showed lower (p < 0.05) proteolytic counts and pH values than control mackerel. Sensory analysis revealed a marked shelf life extension in chilled mackerel stored in ice including the highest JSS concentration; specimens from such batch were found to be still acceptable after 13 days of storage, while all other mackerel batches were rejectable. The marked microbial activity inhibition observed could be explained on the basis of the presence in ice of lipophilic compounds obtained by acetic acid-ethanol extraction of JSSThis work was supported by the CONACYT-Mexico grant 154046 and the Consejo Superior de Investigaciones Científicas (CSIC) through Research Project PIE 201370E001Peer reviewe

Sex Differences in Stress-Responsive Neural Substrates and the Development of Mood Disorder-Like Behavior Following a Rodent Model of Early-Life Adversity

Stress-related mood disorders, such as anxiety and depression, are the most common psychiatric conditions, occurring with a lifetime risk of 15-20%. Women are twice as likely to develop anxiety and depression than men, and this sex difference emerges during puberty. Exposure to abuse or maltreatment during early life increases mood disorder susceptibility, suggesting that females may be especially sensitive to long-lasting, negative effects of early-life stress. While the female-bias in mood disorders is one of the most robust sex differences in psychiatry, the origin of this difference remains unknown. Sexually dimorphic processing of stressors by the adolescent brain, or the sex-specific expression of stress-related neural substrates, may be mechanisms by which stress-related mood disorders are more prominent in females. We developed a novel animal model of early-life adversity, Juvenile Social Subjugation (JSS), to test the effect of chronic adolescent social stress on mood disorder-like pathology in adulthood. This dissertation addressed the following research questions: (1) Does chronic JSS induce sex-specific anxiety and depression-like behaviors and HPA axis dysfunction in adulthood? (2) Is JSS differentially processed by the male and female adolescent brain? (3) Is the corticotropin-releasing factor receptor (CRF) system sex-specifically expressed across development? Together our data point to regional sex differences in neuronal activation and CRF receptor expression in the brain as potential mechanisms by which stressors such as JSS induce sex-specific mood disorder-like behavior in adulthood