Soft Tissue Samples Research Articles

Establishing and evaluation of a polymerase chain reaction for the detection of Echinococcus multilocularis in human tissue.

BackgroundAlveolar echinococcosis (AE) is caused by metacestode larva of the tapeworm Echinococcus multilocularis. AE diagnostics currently rely on imaging techniques supported by serology, but unequivocal detection of AE is difficult. Although polymerase chain reaction (PCR)-based methods to detect tapeworm DNA in biopsies have been suggested for several species, no validated protocol adhering to accepted guidelines has so far been presented for AE diagnostics. We herein established a PCR protocol for metacestode biopsies and technically evaluated the method using isolated parasite DNA and cells, biopsies of clinically relevant material, and formalin fixed paraffin-embedded (FFPE) human tissue blocks. We compared the results with an immunochemical (IHC) approach using the monoclonal antibody Em2G11 specific for the antigen Em2 of E. mulitlocularis.Methodology/Principal findingsBased on tapeworm 12S rDNA sequences we established and validated a PCR protocol for robust detection of as little as 50 parasite cells per specimen and report 127 cases of positive identification of Echinococcus species in samples from humans and animals. For further validation, we analyzed 45 liver, heart, brain, and soft tissue samples as well as cytological probes of aspirates of FFPE-material from 18 patients with clinically confirmed AE. Of each patient we analyzed (i) fully viable lesions with laminated layer; (ii) tissue with mAbEm2G11-positive small particles of E. multilocularis (spems); (iii) mAbEm2G11-negative tissue adjacent to the main lesion; and (iv) lymph node tissue with mAbEm2G11-positive spems. To identify the areas for the PCR-based approach, we performed IHC-staining with the monoclonal antibody Em2G11. Micro-dissected tissue of these areas was then used for PCR-analysis. 9 of 15 analyzed samples with viable E. multilocularis lesions with laminated layer were positive by PCR. Of this group, all samples preserved for less than 6 years (6/6) were tested positive. 11 of 15 samples of spems and 7 of 9 samples of the control group mAbEm2G11-negative tissue were negative by PCR. We further show that all probes from lymph nodes with spems are PCR negative.Conclusions/SignificanceWe present a sensitive PCR method for the detection of E. multilocularis in human tissue, particularly in fresh biopsy material and tissue blocks stored for less than 5 years. While the diagnostic sensitivity of material containing only spems was higher using IHC, PCR detection was possible in IHC negative liver tissue and in patients with negative serology. Our results support the view that spems do not contain parasitic DNA or viable cells of the parasite. spems thus most probably do not directly contribute to metastasis formation during AE.

Treating osteoarticular infections in a Role 2 in Chad: a bacterial epidemiological study

IntroductionThe treatment of osteoarticular infections in Africa is a medical and surgical challenge due to the difficulties in managing antibiotic therapy after the surgical procedure. The objectives of this study...

Development of phantom materials with independently adjustable CT- and MR-contrast at 0.35, 1.5 and 3 T

Quality assurance in magnetic resonance (MR)-guided radiotherapy lacks anthropomorphic phantoms that represent tissue-equivalent imaging contrast in both computed tomography (CT) and MR imaging. In this study, we developed phantom materials with individually adjustable CT value as well as - and -relaxation times in MR imaging at three different magnetic field strengths. Additionally, their experimental stopping power ratio (SPR) for carbon ions was compared with predictions based on single- and dual-energy CT. Ni-DTPA doped agarose gels were used for individual adjustment of and at and 3.0 T. The CT value was varied by adding potassium chloride (KCl). By multiple linear regression, equations for the determination of agarose, Ni-DTPA and KCl concentrations for given and CT values were derived and employed to produce nine specific soft tissue samples. Experimental and CT values of these soft tissue samples were compared with predictions and additionally, carbon ion SPR obtained by range measurements were compared with predictions based on single- and dual-energy CT. The measured CT value, and of the produced soft tissue samples agreed very well with predictions based on the derived equations with mean deviations of less than While single-energy CT overestimates the measured SPR of the soft tissue samples, the dual-energy CT-based predictions showed a mean SPR deviation of only To conclude, anthropomorphic phantom materials with independently adjustable CT values as well as and relaxation times at three different magnetic field strengths were developed. The derived equations describe the material specific relaxation times and the CT value in dependence on agarose, Ni-DTPA and KCl concentrations as well as the chemical composition of the materials based on given and CT value. Dual-energy CT allows accurate prediction of the carbon ion range in these materials.

Decade-scale stability and change in a marine bivalve microbiome.

Predicting how populations and communities of organisms will respond to anthropogenic change is of paramount concern in ecology today. For communities of microorganisms, however, these predictions remain challenging, primarily due to data limitations. Information about long-term dynamics of host-associated microbial communities, in particular, is lacking. In this study, we use well-preserved and freshly collected samples of soft tissue from a marine bivalve host, Donax gouldii, at a single site to quantify the diversity and composition of its microbiome over a decadal timescale. Site-level measurements of temperature, salinity and chlorophyll a allowed us to test how the microbiome of this species responded to two natural experiments: a seasonal increase in temperature and a phytoplankton bloom. Our results show that ethanol-preserved tissue can provide high-resolution information about temporal trends in compositions of host-associated microbial communities. Specifically, we found that the richness of amplicon sequence variants (ASVs) associated with D.gouldii did not change significantly over time despite increases in water temperature (+1.6°C due to seasonal change) and chlorophyll a concentration (more than ninefold). The phylogenetic composition of the communities, on the other hand, varied significantly between all collection years, with only six ASVs persisting over our sampling period. Overall, these results suggest that the diversity of microbial taxa associated with D.gouldii has remained stable over time and in response to seasonal environmental change over the course of more than a decade, but such stability is underlain by substantial turnover in the composition of the microbiome.

Methodology for the Implementation of Internal Standard to Laser-Induced Breakdown Spectroscopy Analysis of Soft Tissues.

The improving performance of the laser-induced breakdown spectroscopy (LIBS) triggered its utilization in the challenging topic of soft tissue analysis. Alterations of elemental content within soft tissues are commonly assessed and provide further insights in biological research. However, the laser ablation of soft tissues is a complex issue and demands a priori optimization, which is not straightforward in respect to a typical LIBS experiment. Here, we focus on implementing an internal standard into the LIBS elemental analysis of soft tissue samples. We achieve this by extending routine methodology for optimization of soft tissues analysis with a standard spiking method. This step enables a robust optimization procedure of LIBS experimental settings. Considering the implementation of LIBS analysis to the histological routine, we avoid further alterations of the tissue structure. Therefore, we propose a unique methodology of sample preparation, analysis, and subsequent data treatment, which enables the comparison of signal response from heterogenous matrix for different LIBS parameters. Additionally, a brief step-by-step process of optimization to achieve the highest signal-to-noise ratio (SNR) is described. The quality of laser–tissue interaction is investigated on the basis of the zinc signal response, while selected experimental parameters (e.g., defocus, gate delay, laser energy, and ambient atmosphere) are systematically modified.

Biomonitoring study of trace metals (Al, As, Li) in mussels from Al Hoceima coastline of Moroccan Mediterranean Sea

Mytilus galloprovincialis are commonly used as heavy metal biomonitors across the world. In the present work, the contents of three elements (Al, As, Li) were analyzed in Mytilus galloprovincialis using Inductively Coupled Plasma – Optical Emission Spectrometry (ICP-OES 720-ES). Samples of soft tissues are collected monthly in 2020, from three sites of the mussel farming facilities installed in the Al Hoceima Sea. The decreasing order of the mean element contents in mussel tissues was Al > As > Li. The lowest values of metallic elements were found in summer and the highest contents were indicated in winter. Positive correlations were indicated between these elements and chlorophyll a indicating the importance of diet for the bioaccumulation of metals in mussels. In addition, our results show that the temperature and the salinity increase with the decreasing of metals bioavailability suggesting the influence of chemical properties and physical kinetics changes in the solution. On the other hand, the strong correlations observed for metal contents in mussel tissues can be elucidated by their common sources. The results of this study may be useful in the use of M. galloprovincialis, in the environmental biomonitoring studies.

A method for imaging single molecules at the plasma membrane of live cells within tissue slices.

Recent advances in light microscopy allow individual biological macromolecules to be visualized in the plasma membrane and cytosol of live cells with nanometer precision and ∼10-ms time resolution. This allows new discoveries to be made because the location and kinetics of molecular interactions can be directly observed in situ without the inherent averaging of bulk measurements. To date, the majority of single-molecule imaging studies have been performed in either unicellular organisms or cultured, and often chemically fixed, mammalian cell lines. However, primary cell cultures and cell lines derived from multi-cellular organisms might exhibit different properties from cells in their native tissue environment, in particular regarding the structure and organization of the plasma membrane. Here, we describe a simple approach to image, localize, and track single fluorescently tagged membrane proteins in freshly prepared live tissue slices and demonstrate how this method can give information about the movement and localization of a G protein-coupled receptor in cardiac tissue slices. In principle, this experimental approach can be used to image the dynamics of single molecules at the plasma membrane of many different soft tissue samples and may be combined with other experimental techniques.

Verification of tuberculosis infection among Vác mummies (18th century CE, Hungary) based on lipid biomarker profiling with a new HPLC-HESI-MS approach

Tuberculosis (TB) was a large burden of infections that peaked during the 19th century in Europe. Mummies from the 18th century CE, discovered in the crypt of a church at Vác, Hungary, had high TB prevalence, as revealed by amplification of key fragments of TB DNA and genome-wide TB analysis. Complementary methods are needed to confirm these diagnoses and one approach uses the identification of specific lipid biomarkers, such as TB mycocerosic acids (MCs). Previously, MC derivatives were profiled by specialised gas chromatography-mass spectrometry (GC-MS), so an alternative more direct approach has been developed. Underivatized MCs are extracted and analysed by high-performance liquid chromatography linked to a mass spectrometer, in heated electrospray ionisation mode (HPLC-HESI-MS). The method was validated using representatives of the Mycobacterium tuberculosis complex and other mycobacteria and tested on six Vác mummy cases, previously considered positive for TB infection. Analysing both rib and soft tissue samples, four out of six cases gave profiles of main C32 and major C29 and C39 mycocerosates correlating well with those of M. tuberculosis. Multidisciplinary methods are needed in the diagnosis of ancient tuberculosis; this new protocol accesses important confirmatory evidence, as demonstrated by the confirmation of TB in the Vác mummies.

Bioaccumulation of trace metals and speciation of copper and zinc in Pacific oysters (Crassostrea gigas) using XANES/EXAFS spectroscopies

Copper (Cu) and zinc (Zn) concentrations in oyster soft tissues can be particularly high due to contamination, leading to extremely green/blue colors. This raises key questions regarding the behavior and speciation of trace metals in oyster soft tissues. This study investigated trace metal concentration profiles of contaminated Pacific oyster (Crassostrea gigas) soft tissues collected from trace metal-contaminated coastal area of Xiangshan District using inductively coupled plasma optical emission spectrometry (ICP-OES), energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Moreover, Cu and Zn speciation in contaminated and non-contaminated oyster soft tissues were investigated by X-ray absorption near edge structure spectroscopy/extended X-ray absorption fine structure (XANES/EXAFS) spectroscopic methods. The contents of Cu (1,100–1,400 mg/kg) and Zn (500–700 mg/kg) dry weight were high in oyster soft tissue samples. The XANES/EXAFS results revealed that Cu and Zn existed primarily as copper (II) oxide (CuO) and zinc oxide (ZnO) in contaminated oysters. Furthermore, Cu and Zn formed clusters with Cu–O and Zn–O interatomic distances of 1.97 and 2.21 Å, (coordination numbers 1.0 and 5.6), respectively. In non-contaminated oysters, the less abundant Cu and Zn existed mainly as copper(I) sulfide (Cu2S) and zinc sulfide (ZnS) forming clusters with Cu–S and Zn–S (thiolates) bond distances of 2.09 and 1.23 Å (coordination numbers of 4.6 and 2.4). These results provide further understanding on the chemical speciation of Cu and Zn in contaminated and non-contaminated oyster soft tissues as well as the bioaccumulation of trace metals in the oyster soft tissues.

SATB2 is not a reliable diagnostic marker for distinguishing between oral osteosarcoma and fibro-osseous lesions of the jaws

Special AT-rich binding protein 2 (SATB2) is an immunohistochemical marker for osteoblast differentiation. Our aim was to investigate SATB2 expression in oral osteosarcoma and other bone-producing oral tumors/reactive lesions to evaluate its usefulness as a diagnostic marker. A total of 74 intraosseous and soft tissue bone-producing surgical samples and 10 samples of reactive bone tissue were stained with SATB2, including osteosarcoma/chondrosarcoma (n=16), fibro-osseous lesions (n=42), central giant cell granuloma (n=6), osteoblastoma (n=1), and gingival lesions (n=9). Nuclear labeling of the stromal spindle cells and intensity of staining was scored and analyzed. The intraosseous (n=65/65) and soft tissue samples (n=9/9) diffusely expressed SATB2. The strongest expression was observed in juvenile aggressive ossifying fibroma (n=2/2). Weak SATB2 expression was observed in the stromal spindle cells adjacent to reactive bone tissue (periosteal bone reaction). Our results indicate that SATB2 is not a reliable diagnostic marker for oral osteosarcoma but has practical use in detecting cells with osteoblast differentiation in histologic samples with scant bone production or in differentiating between a periosteal bone reaction and neoplastic bone induced by the tumor mesenchymal cells. Targeting SATB2 as an alternative therapy in oral osteosarcoma, fibro-osseous lesions, and central giant cell granuloma should be further investigated.

Organochlorine pesticides in Baikal bivalve mollusc Colletopterum ponderosum sedakovi

For the first time, the bivalve mollusc Colletopterum ponderosum sedakovi (Siemaschko, 1848) was used as a universal bioindicator of pollution of Lake Baikal ecosystem with organochlorine pesticides (OCPs). OCPs were identified and quantified in soft tissue samples, collected from Lake Baikal. Dichlorodiphenyltrichloromethylmethane (DDT) and its metabolites, isomers of hexachlorocyclohexane (HCH) and hexachlorobenzene (HCB) were identified using modern gas-chromatography-mass spectrometry. The obtained data on OCPs levels have been compared with those reported earlier for molluscs from other world regions. Levels, sources and trends of OCPs contamination of Lake Baikal ecosystem and its basin were established. The recommendations on using Colletopterum ponderosum sedakovi as a bioindicator of OCPs in aquatic ecosystems in further research have been proposed.

Changes of biochemical indicators of blood serum and the skeletal muscle homogenate of the hind limbs of the rats in acute ischemia-reperfusion and in the condition of using of the carbacetam

Annotation. Simulation of ischemia-reperfusion causes the biochemical disorders and changes in the prooxidant-antioxidant system, both in the serum and skeletal muscles of the affected limb. The severity of local and systemic postischemic imbalance decreases in with correction with medicine from the group of nootropics – carabacetam. The aim of the study was determining the degree of metabolic disorders based on the analysis of changes in serum biochemical parameters and muscle homogenate in ischemic-reperfusion disorders caused by the imposition of an arterial tourniquet and under conditions of correction with carbacetam. Materials and methods. A biochemical study of blood serum and muscle homogenate of 60 rats was performed. Ischemia was simulated by applying SWAT rubber tourniquets on the hind limbs of the rats, on the inguinal fold, for 2 hours, and reperfusion was modeled by removing the tourniquet and restoring of blood circulation through 2 hours after its application. Observations of the animals were carried out during for 14 days. 30 rats in the reperfusion period were intraperitoneally administered the carbacetam at a dose of 5 mg per kilogram of body weight 1 time a day for 14 days of the reperfusion period. The Blood serum was separated and the soft tissue samples were taken below the turniquet site for the biochemical studies. Statistical processing of the material was performed using the package of programs “Microsoft Excel”. The largest deviations in serum were observed after 1 day of the reperfusion: an increase in creatinine by 28.16 % (p<0.005), total bilirubin by 20.75 % (p<0,005), ALT by 96.14 % (p<0,005), AST by 147.27 % (p<0.005) and alkaline phosphatase by 70.84 % (p<0.005), as well as an increase in prooxidant activity of CD by 77.27 % (p<0.005), CT 147.47 % (p<0,005) and TBC-AL by 82.52 % (p<0,005) against the background of a decrease in SOD activity by 9.77 % (p<0.005) and an increase in catalase levels by 15.37 % (p<0.005) relative to the value of the control group. The development of ischemia and reperfusion was accompanied by the largest increase in the level of prooxidants (CD – by 27.55 % (p<0.005), CT – by 47.34 % (p<0.05), TBC-AL – by 62.09 %) (p<0.005)) in the homogenate of the skeletal muscles after 2 hours after restoration of the blood supply. Antioxidant activity, on the other hand, decreased by 15.06 % (p<0.005) SOD and by 8.96 % (p<0.005) catalase after 1 day. After 14 days, a gradual increase and return of most of the studied values to the level of the control group. Under the influence of the carbacetam, the biochemical parameters of blood serum most significantly decreased in relative to the value of the groups without correction after 7 days of the experiment. The level of total bilirubin was lower by 29.65 % (p˂0.05), ALT by 14.95 % (p˂0.05), AST by 19.84 % (p˂0.05), alkaline phosphatase by 25.53 % (p˂0.05), and the difference in the content of diene, triene conjugates and TBC-LP was the largest after 1 day – by 17.09 % (p<0.005), 20,41 % (p<0.05) and 11.24 % (p<0.05), respectively. Under the conditions of correction, the indicators of SOD and catalase activity increased, being significantly higher than in the groups of the animals without correction, especially after 7 days of reperfusion – by 29.41 % (p<0.005) and by 15.71 % (p<0.05) in accordance. The content of the diene, triene conjugates and TBC-LP muscle homogenate was statistically significantly lower in the groups with the introduction of the carbacetam than in the groups of the animals without correction. The largest difference between the groups was found after 1 day with a difference of 9.16 % (p<0.05), 7.35 % (p<0.005) and 16.05 % (p<0.05), respectively. Antioxidant activity of SOD and catalase after 1 day was higher by 27.41 % (p<0.005) and by 25.13 % (p<0.005), compared with the group of the animals without introduction of the carbacetam. Thus, simulated ischemia-reperfusion is accompanied by the greatest biochemical disorders in the serum – after 1 day, and in the muscle homogenate – after 2 hours of the reperfusion. After 14 days of the experiment, most indicators still do not return to the level of the control group. The application of the correction helps to reduce the severity of biochemical disorders at the systemic and local levels, especially during periods of their greatest deviations.

Stable isotopes and morphology reveal spatial and annual patterns in trophic reliance of an invertivorous juvenile fish

AbstractEcological studies have traditionally treated fish species or populations as homogenous groups; however, numerous studies have shown that intrapopulation variation in resource use is widespread. Within‐species diet differences are evident in small and large freshwater systems and may influence trophic and population dynamics. In a previous study of young yellow perch, spatial intrapopulation diet variation was observed for stomach contents, a relatively short‐term diet indicator. In the current study, we build upon the earlier study of yellow perch in Saginaw Bay, Lake Huron, and assess patterns of long‐term diet indicators (stable isotopes and morphology) to assess consistency of diet variation over time and improve characterisation of trophic differences among sites. Specifically, we analysed soft tissue samples for carbon (δ13C) and nitrogen (δ15N) isotope ratios and used geometric morphometrics to describe morphological variation of young yellow perch. While both isotopes displayed significant spatial differences, δ15N values demonstrated a much clearer separation among sites, with greater δ15N values for yellow perch collected closer to the mouth of the Saginaw River. Morphological variation also was more apparent among sites rather than between years or months, with more streamlined yellow perch morphologies evident at sites where they consumed high proportions of zooplankton relative to benthic invertebrates. Somewhat unexpectedly, soft tissue δ13C values varied strongly between the two study years; however, the ultimate cause of such interannual variation in δ13C is unclear. These long‐term indicators showed consistent spatial differences, which suggests that individual fish are using resources at a particular site long enough to reflect a stable isotope or morphological signal. Yellow perch production at different locations seemingly relies on different prey resources, suggesting that annual variation in dominant trophic pathways may alter the performance of yellow perch at each location.

Comparative methodology for histological analysis of peri-implant soft tissue samples.

Comparative methodology for histological analysis of peri-implant soft tissue samples.

Immunohistological composition of peri-implantitis affected tissue around ceramic implants-A pilot study.

Aim of the pilot study was the histologic classification of the inflamed peri-implant soft tissue around ceramic implants (CI) in comparison with titanium implants (TI). Peri-implant tissue were retrieved from 15 patients (aged 34 to 88 years, seven males/eight females) with severe peri-implantitis (eight CI, seven TI). The peri-implant soft tissue samples were retrieved from the sites during scheduled removal of the implant and prepared for immunohistochemical analysis. Monoclonal antibodies (targeting CD3, CD20, CD138, and CD68) were used to identify T- and B-cells, plasma cells and macrophages. Quantitative assessment was performed by one histologically trained investigator. Linear mixed regression models were used. A similar numerical distribution of the cell population was found in peri-implantitis around CI compared with TI. CD3 (TI, 17% to 85%versus CI, 20% to 70% of total cell number) and CD138 (TI, 1% to 73% versus CI, 12% to 69% of total cell number) were predominantly expressed. Notably, patient-individual differences of numerical cell distribution were detected. Co-localization of B- and T-lymphocytes was observed. Peri-implantitis around CI in comparison with TI seems to have a similar histological appearance. Differences in cellular composition of peri-implantitis lesions might also depend on the patient's specific immune status and not only on the material used.

Determination of Median Lethal Concentration (LC50) and Nitrite Accumulation in the Blood and Tissue of Blood Cockle (Tegillarca granosa, Linnaeus 1758)

This study aimed to determine the nitrite toxicity of blood cockle Tegillarca granosa, with the objectives being to identify the median lethal concentration (LC50) and the accumulation level of nitrite in Tegillarca granosa, and to determine the relationship of nitrite accumulation with mortality percentage. The levels of LC50 and accumulation of nitrite were determined after 72 h of exposure to different nitrite concentrations (0, 0.5, 1.0, 1.5, and 2.0 mg/L). Nitrite accumulation was analysed using Method 8153 and a DR2800 spectrophotometer (HACH, Loveland, CO, USA). LC50 was identified at 1.53 mg/L, and nitrite accumulated in the ranges of 0.012 to 0.106 mg/L wet weight and 0.002 to 0.089 mg/L wet weight in the blood and soft tissue samples, respectively. Accumulation concentration in both tissue and blood cells increased proportionally with the exposure concentration, and had a strong positive relationship with the percentage of mortality. Our findings suggest that prolonged exposure of nitrite led to accumulation in the blood and tissues and caused cockle mortality.

Is there any objective and independent characterization and modeling of soft biological tissues?

The characterization of soft tissue raises several difficulties. Indeed, soft biological tissues usually shrink when dissected from their in vivo location. This shrinkage is characteristic of the release of residual stresses, since soft tissues are indeed often pre-stressed in their physiological configuration.During experimental loading, large extension at very low level of force are expected and assumed to be related to the progressive recruitment and stretching of fibers. However, the first phase of the mechanical test is also aiming at recovering the pre-stressed in vivo behavior. As a consequence, the initial phase, corresponding to the recovering of prestress and/or recruitment of fiberes, is questionable and frequently removed. One of the preferred methods to erase it consists in applying a preforce or prestress to the sample: this allows to easily get rid of the sample retensioning range. However this operation can impact the interpretation of the identified mechanical parameters.This study presents an evaluation of the impact of the data processing on the mechanical properties of a numerically defined material. For this purpose, a finite element simulation was performed to replicate a uniaxial tensile test on a biological soft tissue sample. The influence of different pre-stretches on the mechanical parameters of a second order Yeoh model was investigated.The Yeoh mechanical parameters, or any other strain energy density, depend strongly on any pre- and post-processing choices: they adapt to compensate the error made when choosing an arbitrary level of prestretch or prestress. This observation spreads to any modeling approach used in soft tissues. Mechanical parameters are indeed naturally bound to the choice of the pre-stretch (or pre-stress) through the elongation and the constitutive law. Regardless of the model, it would therefore be pointless to compare mechanical parameters if the conditions for the processing of experimental raw data are not fully documented.

A prospective study to evaluate methods of MRSA detection in patients with soft tissue and bone infection in a tertiary care centre

Staphylococcus aureus is a major pathogen causing bacteraemia, pneumonia, skin and soft tissue infections (SSTIs), and osteomyelitis. Over the past 50 years, it has acquired resistance to antimicrobials including the penicillinase-resistant ones like methicillin. Rapid identification and susceptibility testing are mandatory to prevent further dissemination of MRSA and to provide effective antimicrobial treatment. Hence, methods used to detect MRSA should be rapid with high sensitivity and specificity.1) To compare various phenotypic methods for MRSA detection. 2) To confirm the phenotypic results with Polymerase Chain Reaction. 3) To evaluate the susceptibility of MRSA isolates to other antimicrobial agents.Eighty four MRSA isolates from soft tissue and bone samples identified by the cefoxitin (30µg) disc diffusion method were subjected to Oxacillin Screen Agar (OSA), cefoxitin E-strip, automated identification & sensitivity testing using BD Phoenix system and Polymerase Chain Reaction using the GeneXpert for mecA gene detection.Although all 84 isolates were resistant by cefoxitin disk diffusion, 83 (95.4%) isolates were positive for the mecA gene. The sensitivities of the OSA, cefoxitin E-strip and BD Phoenix system were 79.5%, 80.7%, and 100%, respectively. All the isolates were sensitive to vancomycin and linezolid. 70% of the isolates were sensitive to cotrimoxazole whereas maximum resistance of 76% was seen to ciprofloxacin.Automated identification by BD Phoenix system, if available, can be considered as the most sensitive phenotypic method for MRSA detection, while cefoxitin E-strip is the most appropriate test in a resource poor setting.

A 3D Scanning System for Inverse Analysis of Moist Biological Samples: Design and Validation Using Tendon Fascicle Bundles.

In this article, we present the design and validation of a non-contact scanning system for the development of a three-dimensional (3D) model of moist biological samples. Due to the irregular shapes and low stiffness of soft tissue samples, the use of a non-contact, reliable geometry scanning system with good accuracy and repeatability is required. We propose a reliable 3D scanning system consisting of a blue light profile sensor, stationary and rotating frames with stepper motors, gears and a five-phase stepping motor unit, single-axis robot, control system, and replaceable sample grips, which once mounted onto the sample, are used for both scanning and mechanical tests. The proposed system was validated by comparison of the cross-sectional areas calculated based on 3D models, digital caliper, and vision-based methods. Validation was done on regularly-shaped samples, a wooden twig, as well as tendon fascicle bundles. The 3D profiles were used for the development of the 3D computational model of the sample, including surface concavities. Our system allowed for 3D model development of samples with a relative error of less than 1.2% and high repeatability in approximately three minutes. This was crucial for the extraction of the mechanical properties and subsequent inverse analysis, enabling the calibration of complex material models.

Pain After Cochlear Implantation Without Signs of Inflammation: A Systematic Review.

This review summarizes current evidence on causes and management strategies for delayed pain post-cochlear implantation (CI) surgery, without clinical evidence of inflammation or infection. The systematic review was undertaken in line with Preferred Reporting Items for Systematic review and Meta-Analysis Protocols 2015 guidelines. A literature search was undertaken, with inclusion of patients who underwent CI and presented with delayed pain (>3 months post-operatively) around their device site without an identifiable cause. Analysis was undertaken using MATLAB (MathWorks, Natick, MA) and the R-software package (www.r-project.org). 4 articles (48 patients), all retrospective case series, met inclusion criteria. The mean onset of pain post-CI was 60 months and mean follow-up was 15.8 months, there was no difference in the prevalence of pain between device brands (p=0.13). The majority (90%) did not have any hearing deterioration, and investigations did not reveal a cause for the pain in any of the patients. In terms of management, medical therapies, including oral therapy (analgesia, non-steroidal anti-inflammatories, antibiotics) and local treatments (topical, injections) resolved pain in 41% and 63%, respectively. Surgical intervention (explantation, magnet replacement, tympanic neurectomy), where undertaken, resolved pain in 100%. A minority had an identifiable infective microorganism cultured from intra-operative soft tissue or biofilm samples. Evidence for the causes and management of delayed pain post-CI without clinical evidence of inflammation is scarce. A stepwise approach is deemed best, with decisions being made on an individual basis, evaluating each patient's specific circumstances and priorities. Further evaluation of explanted devices would allow for better understanding of the causes and treatment of this group of patients.