262 research outputs found
Preparation and Using Phantom Lesions to Practice Fine Needle Aspiration Biopsies
Currently, health workers including residents and fellows do not have a suitable phantom model to practice the fine- needle aspiration biopsy (FNAB) procedure. In the past, we standardized a model consisting of latex glove containing fresh cattle liver for practicing FNAB. However, this model is difficult to organize and prepare on short notice, with the procurement of fresh cattle liver being the most challenging aspect. Handling of liver with contamination-related problems is also a significant draw back. In addition, the glove material leaks after a few needle passes, with resulting mess.
We have established a novel simple method of embedding a small piece of sausage or banana in a commercially available silicone rubber caulk. This model allows the retention of vacuum seal and aspiration of material from the embedded specimen, resembling an actual FNAB procedure on clinical mass lesions.
The aspirated material in the needle hub can be processed similar to the specimens procured during an actual FNAB procedure, facilitating additional proficiency in smear preparation and staining.
View accompanying video at http://www.jove.com/details.php?id=1404
Spin-label scanning reveals conformational sensitivity of the bound helical interfaces of IA<sub>3</sub>
IA3 is an intrinsically disordered protein (IDP) that becomes helical when bound to yeast proteinase A (YPRA) or in the presence of the secondary stabilizer 2,2,2-trifluoroethanol (TFE). Here, site-directed spin-labeling (SDSL) continuous wave electron paramagnetic resonance (CW-EPR) spectroscopy and circular dichroism (CD) are used to characterize the TFE-induced helical conformation of IA3 for a series of spin-labeled cysteine scanning constructs and varied amino acid substitutions. Results demonstrate that the N-terminal concave helical surface of IA3, which is the buried interface when bound to YPRA, can be destabilized by the spin-label or bulky amino acid substitutions. In contrast, the helical tendency of IA3 is enhanced when spin-labels are incorporated into the convex, i.e., solvent exposed, surface of IA3. No impact of the spin-label within the C-terminal region was observed. This work further demonstrates the utility and sensitivity of SDSL CW-EPR for studies of IDPs. In general, care must be taken to ensure the spin-label does not interfere with native helical tendencies and these studies provide us with knowledge of where to incorporate spin-labels for future SDSL investigations of IA3
Pathology and molecular analysis of ' Hapalotrema mistroides ' (Digenea: Spirorchiidae) infecting a Mediterranean loggerhead turtle ' Caretta caretta '
Turtle blood flukes belonging to the family Spirorchiidae (Digenea) represent a major threat for sea turtle health and are considered the most important parasitic cause of turtle stranding and mortality worldwide. Despite the large diversity of spirorchiid species found globally, there are only 2 records for free-ranging Mediterranean sea turtles that date back to the late 1800s involving just Hapalotrema mistroides Monticelli, 1896. This study describes the first fatal confirmed case of spirorchiidiasis in a free-ranging Mediterranean loggerhead turtle Caretta caretta (Linnaeus) and, owing to the complexities of taxonomic identification of these parasites, provides the first molecular characterization and phylogenetic analysis of H. mistroides from the Mediterranean Sea. The loggerhead turtle showed cachexia and digestive disorders associated with severe damage to the pancreas and intestinal ganglia, caused by deposition of Hapalotrema eggs forming granulomas. Massive Hapalotrema egg emboli in several tissues and organs and encephalitis were the most probable contributions to the death of the turtle. The congruence between the phylogenetic analysis of both the ITS2 and 28S rDNA resolved the Italian and USA H. mistroides as the same species, confirming the parasite identification. The case here described clearly indicates that the blood flukes should be considered in the differential diagnosis of Mediterranean sea turtle diseases
The value of circulating microRNAs for early diagnosis of B-cell lymphoma:A case-control study on historical samples
Micromechanical study of the load transfer in a polycaprolactone-collagen hybrid scaffold when subjected to unconfined and confined compression
Scaffolds are used in diverse tissue engineering applications as hosts for cell proliferation and extracellular matrix formation. One of the most used tissue engineering materials is collagen, which is well known to be a natural biomaterial, also frequently used as cell substrate, given its natural abundance and intrinsic biocompatibility. This study aims to evaluate how the macroscopic biomechanical stimuli applied on a construct made of polycaprolactone scaffold embedded in a collagen substrate translate into microscopic stimuli at the cell level. Eight poro-hyperelastic finite element models of 3D printed hybrid scaffolds from the same batch were created, along with an equivalent model of the idealized geometry of that scaffold. When applying an 8% confined compression at the macroscopic level, local fluid flow of up to 20 [Formula: see text]m/s and octahedral strain levels mostly under 20% were calculated in the collagen substrate. Conversely unconfined compression induced fluid flow of up to 10 [Formula: see text]m/s and octahedral strain from 10 to 35%. No relevant differences were found amongst the scaffold-specific models. Following the mechanoregulation theory based on Prendergast et al. (J Biomech 30:539-548, 1997. https://doi.org/10.1016/S0021-9290(96)00140-6 ), those results suggest that mainly cartilage or fibrous tissue formation would be expected to occur under unconfined or confined compression, respectively. This in silico study helps to quantify the microscopic stimuli that are present within the collagen substrate and that will affect cell response under in vitro bioreactor mechanical stimulation or even after implantation
Nonthrombogenic, Biodegradable Elastomeric Polyurethanes with Variable Sulfobetaine Content
For applications where degradable polymers are
likely to have extended blood contact, it is often important for
these materials to exhibit high levels of thromboresistance.
This can be achieved with surface modification approaches, but
such modifications may be transient with degradation.
Alternatively, polymer design can be altered such that the
bulk polymer is thromboresistant and this is maintained with
degradation. Toward this end a series of biodegradable, elastic
polyurethanes (PESBUUs) containing different zwitterionic
sulfobetaine (SB) content were synthesized from a polycaprolactone-diol (PCL-diol):SB-diol mixture (100:0, 75:25, 50:50, 25:75
and 0:100) reacted with diisocyanatobutane and chain extended with putrescine. The chemical structure, tensile mechanical
properties, thermal properties, hydrophilicity, biodegradability, fibrinogen adsorption and thrombogenicity of the resulting
polymers was characterized. With increased SB content some weakening in tensile properties occurred in wet conditions and
enzymatic degradation also decreased. However, at higher zwitterionic molar ratios (50% and 75%) wet tensile strength exceeded
15 MPa and breaking strain was >500%. Markedly reduced thrombotic deposition was observed both before and after substantial
degradation for both of these PESBUUs and they could be processed by electrospinning into a vascular conduit format with
appropriate compliance properties. The mechanical and degradation properties as well as the acute in vitro thrombogenicity
assessment suggest that these tunable polyurethanes could provide options appropriate for use in blood contacting applications
where a degradable, elastomeric component with enduring thromboresistance is desired
Association between siesta (daytime sleep), dietary patterns and the presence of metabolic syndrome in elderly living in Mediterranean area (MEDIS study):The moderating effect of gender
Objectives: Several lifestyle parameters including diet, physical activity and sleep were associated in isolation with the presence of Metabolic Syndrome (MetS) in adults, to date there is a paucity of studies which evaluated their combined role aging populations and especially with respect to gender. Therefore, the aim of the present study was to provide a global consideration of the lifestyle factors associated with MetS among elderly individuals. Design: Cross-sectional observational study. Setting: 21 Mediterranean islands and the rural Mani region (Peloponnesus) of Greece. Participants: during 2005-2015, 2749 older (aged 65-100 years) from were voluntarily enrolled in the study. Measurements: Dietary habits, energy intake, physical activity status, sociodemographic characteristics, lifestyle parameters (sleeping and smoking habits) and clinical profile aspects were derived through standard procedures. The presence of MetS was defined using the definition provided by NCEP ATP III (revised) and cluster analysis was used to identify overall dietary habit patterns. Results: The overall prevalence of MetS in the study sample was 36.2%, but occurred more frequently in females (40.0% vs. 31.8%, respectively, p=0.03). Individuals with MetS were more likely to sleep during the day (89.4% vs. 76.8% respectively, p=0.039) and frequent ‘siesta’ was positively linked to the odds of MetS presence in females (Odds Ratio (OR) =3.43, 95% Confidence Intervals (CI): 1.08-10.9), but not for men (p=0.999). The lower carbohydrate (i.e., 45.2% of total daily energy, 120±16gr/day) dietary cluster was inversely associated with the odds for MetS presence, but only for men (OR=0.094, 95%CI: 0.010-0.883). Conclusions: Lifestyle parameters including sleep and diet quality are strongly associated with the presence of MetS in elderly cohort, but different their level of influence appears to be different, depending on gender. Further research is needed to better consider the role of lifestyle characteristics in the management of MetS in clinical practice
Efficacy of potential chemical control compounds for removing invasive American bullfrogs (Rana catesbeiana)
Illumina error profiles: resolving fine-scale variation in metagenomic sequencing data
New developments in the pathology of malignant lymphoma: a review of the literature published from August to December 2008
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