Search

In this study, nanofibrous biohybrid scaffolds were developed by electrospinning using poly(ε-caprolactone) (PCL) and decellularized bovine tissue derived extracellular matrix (ECM). At the first part of the study, bovine ECM was decellularized by treatment with detergent for 24h and then combined with PCL. Following the evaluation of the decellularization efficiency via spectrophotometric DNA content analysis, the composite scaffolds were characterized by using SEM and FT-IR spectroscopy. Moreover, to assess the biocompatibility of the scaffolds an in vitro cell culture based cytotoxicity test was performed. The results indicated that, DNA content of the bovine tissue was reduced by ~80% compared to the native tissue after decellularization. While FT-IR results indicated the presence of ECM in the composite scaffolds, SEM findings showed that the porous nanofibrous structure of the scaffold changed depending on the incorporated ECM amount. Cell culture based studies also revealed that, the scaffolds containing different amounts of ECM did not have any toxic effect on cell viability during 48 hours of culture period.

Background Vascular prosthetic graft infections are rare but associated with high morbidity and mortality. Treatment involves removal of the infected graft requiring arteriotomy closure. Previously this was performed with autologous graft, but bovine tissue has increasingly been used. The objective of this paper is to review the community hospital experience with bovine tissue repair in an infected vascular field. Materials and Methods A retrospective review of all cases performed by a single surgeon in a community hospital for infected prosthetic grafts was completed. Sixteen cases were included where bovine tissue was used for repair. Presentation, location of graft, and causative organism were reviewed, and outcomes including reoperation and mortality were recorded. Results Of the 16 patients, 15 (94%) had positive cultures of the graft. Methicillin-Resistant Staph Aureus was the most commonly isolated organism (50%). There were 3 unplanned reoperations including a revision from below to above knee amputation, drainage of a hematoma, and a wound debridement within the first year. Over the 1 year follow up period, 3 patients died for a mortality of 19%. There were no reinfections during follow-up. Discussion Prosthetic graft infection is a rare but serious vascular surgery complication. The causative organism has shifted in the last few years to become increasingly drug resistant. Treatment requires excision, and bovine tissue has been demonstrated to provide a safe and durable method of repair.

Background: More than 400,000 Americans require dialysis, and many receive it via a prosthetic arteriovenous graft. Infection of these grafts is rare, but associated with significant morbidity and mortality. The gold standard is total graft excision with arteriotomy closure. This was previously done with autologous vein, but bovine tissue offers a reasonable alternative. The objective of this article is to evaluate a community hospital experience with bovine tissue arterial repair after total graft excision of infected prosthetic arteriovenous graft. Methods: A retrospective review was performed of all cases of infected prosthetic arteriovenous graft removal with bovine tissue arterial repair was performed. Thirteen cases were identified. Presentation, location of graft, and causative organism were reviewed; outcomes including reoperation and mortality were recorded. Results: Of the 13 patients, 12 (92%) had positive cultures of the graft, bloodstream, or wound. Methicillin-resistant Staphylococcus aureus was the most commonly isolated organism (54%). There were two unplanned reoperations including hematoma drainage and wound debridement within the first year. Over the 1-year follow-up period, 1 patient died for a mortality of 8%. There were no re-infections during follow-up. Discussion: Prosthetic arteriovenous graft infection remains a difficult challenge and is associated with significant morbidity and mortality. It presents in a variety of ways, including within an old thrombosed graft. Over the last several years, the causative organism has increasingly become drug resistant. Treatment with total graft excision requires arteriotomy closure, and for this bovine tissue has been demonstrated to be a viable option.

Bovine tuberculosis (bTB) is an ongoing issue in several countries within the European Union. Microbiological culture is the official confirmation technique for the presence of Mycobacterium tuberculosis complex (MTBC) members in bovine tissues, but several methodological issues, such as moderate sensitivity and long incubation times, require the development of more sensitive and rapid techniques. This study evaluates the analytical and diagnostic performance, comparative to culture, of a real-time PCR targeting the MTBC-specific IS6110 transposon using a panel of bovine tissue samples sourced from the Spanish bTB eradication campaign. Robustness and repeatability were evaluated in an interlaboratory trial between European Union National Reference Laboratories. The limit of detection with 95% confidence was established at 65 fg/reaction of purified genomic equivalents. Diagnostic sensitivity (Se) and specificity (Sp) were, respectively, 96.45% and 93.66%, and the overall agreement (κ) was 0.88. Cross-reactivity was detected against two mycobacterial isolates identified as Mycobacterium marinum and "Mycobacterium avium subsp. hominissuis," and whole-genome sequencing (WGS) analysis of the latter isolate revealed an IS6110-like sequence with 83% identity. An identical IS-like element was found in other Mycobacterium avium complex species in the NCBI nucleotide and WGS databases. Despite this finding, this methodology is considered a valuable alternative to culture, and the strategy of use should be defined depending on the control or eradication programs.

OBJETIVO: Comparar la capacidad de disolución de tejido orgánico de dos soluciones (NaOCl y HOCl), sometiéndolas a diferentes protocolos de tiempo y temperatura MATERIALES y MÉTODOS: Para el presente estudio se obtuvieron 120 muestras de tejido vacuno ex vivo, el cual fue dividido en 10 grupos de 12 muestras cada uno. Se utilizaron 4 soluciones de NaOCl con concentraciones de: 5.25%, 2.5%, 1% y 0.5% respectivamente y una solución de HOCl al 5%. Las muestras fueron observadas a distintos intervalos de tiempo: 1 minuto, 5 minutos, 15 minutos, 30 minutos, 45 minutos y 60 minutos. Así los datos recogidos de las observaciones se basaron en cambios macroscópicos presentes en la superficie de cada muestra y posteriormentefueronanalizadosestadísticamenteendiferentespruebas. RESULTADOS:Los datos fueron analizados con el programa informático Statistica 7.0. El análisis 1 comparó, en los distintos intervalos de tiempo, la capacidad de disolución de tejido orgánico entre las distintas concentraciones del NaOCl y el HOCl, a los 5 minutos y a los 15 minutos, no arrojaron diferencias significativas mientras que 30 a 60 minutos, sí permitieron observar diferencias significativas. En la segunda parte del análisis estadístico se comparó, en los distintos intervalos de tiempo, la valoración entre las dos temperaturas probadas 21oC y37 oC, los resultados obtenidos para los tiempos 1 minuto, 45 minutos y 60 minutos, no permiten observar diferencias significativas. Para los intervalos de 5 minutos, 15 minutos y 30 minutos, sí se observaron diferencias, siempre a favor de las muestras tratadas a 37oC.

The objective of this study is to analyze the efficiency of different antennas proposed for microwave ablation therapy using numerical simulation and experimental approach. The simulation was done with COMSOL MULTIPHYSICS® software to design antenna prototypes and evaluate its reflection coefficient, power dissipation distribution, power dissipation density, specific absorption rate and temperature distribution in tissue. Antennas were fabricated from a 50 Ω RG405/U semi-rigid coaxial cable to match the geometric prototypes generated during simulation. Ex vivo bovine livers were ablated with the fabricated antennas using 50 W for 5 and 10 min. Ablation diameters, ablation lengths and aspect ratios were determined. Sleeved antenna produced lowest reflection coefficient, high power dissipation, low power dissipation density, high SAR and high temperature in the simulation. Sleeved antenna provides excellent localization, large ablative diameter, low backward heating and high aspect ratio than single slot, dual slot and monopole antennas.

Background In medical training and research fresh human tissue is often replaced by preserved human or fresh animal tissue, due to availability and ethical reasons. Newer preservation approaches, such as the Thiel method, promise more realistic mechanical properties than conventional formaldehyde fixation. Concerning animal substitute material, porcine and bovine tissue is often chosen, as it is easily obtainable and certain similarity to human tissue is assumed. However, it has not been thoroughly investigated how Thiel preservation changes non-linear and viscoelastic behaviour of soft organ tissues. Furthermore, differences in these properties between animal tissue and human tissue have not been previously corroborated. Methods We conducted ramp and relaxation tensile tests on fresh human and Thiel preserved hepatic tissue, extracting strain-specific elastic moduli, and viscoelastic properties. The results for fresh human liver were then compared to corresponding results for Thiel preserved liver, as well as previously published results for porcine and bovine liver. Results Our results showed that Thiel preservation seems to be associated with increased stiffness as well as decreased viscoelastic damping behaviour. Porcine liver was stiffer than human liver with similar viscoelastic properties. Bovine liver exhibited similar stiffness as human liver, however lower viscoelastic damping. Conclusions The differences between human and animal liver tissue, concerning their mechanical properties, can be explained by their characteristic histology. Changes in mechanical properties due to Thiel preservation might stem from altered protein cross-linking and dehydration. The results illustrate that appropriate materials for medical training systems must be selected based on which mechanical properties are relevant for the respective application.

The content of total iron and total bioaccessible iron were determined in beef through visible spectrophotometry by the method of 1,10-Phenanthroline. The samples were cooked, dehydrated and prepared as jerked beef. They were submitted to a simulation of gastrointestinal digestion for the evaluation of bioaccessibility. Among the samples analyzed, the heart and the liver had the highest levels of total iron and total bioaccessible iron. After cooking the samples, there was an increased bioaccessibility of iron. The cooked liver and heart contributed respectively with 28% and 20% in terms of bioaccessibility. The insertion of bioaccessibility in food composition tables is important, as it comes to nutritional information closer to reality. Furthermore it was performed the iron speciation.

PURPOSE: In the operating theatre surgeons are accustomed to using spatially navigated tools in conjunction with standard clinical imaging during a procedure. This gives them a good idea where they are in the patients’ anatomy but doesn’t provide information about the type of tissue they are dissecting. In this paper we demonstrate an integrated system consisting of a spatially navigated surgical electrocautery combined with real-time molecular analysis of the dissected tissue using mass spectrometry. METHODS: Using the 3D Slicer software package, we have integrated a commercially available neurosurgical navigation system with an intra-operative mass spectrometer (colloquially referred to as the intelligent knife, or iKnife) that analyzes the charged ions in the smoke created during cauterization. We demonstrate this system using a simulated patient comprised of an MRI scan from a brain cancer patient deformably registered to a plastic skull model. On the skull model we placed porcine and bovine tissues to simulate cancerous and healthy tissue, respectively. We built a PCA/LDA model to distinguish between these tissue types. The tissue classifications were displayed in a spatially localized manner in the pre-operative imaging, in both 2D and 3D views. RESULTS: We have demonstrated the feasibility of performing spatially navigated intra-operative analysis of tissues by mass spectrometry. We show that machine learning can classify our sample tissues, with an average computed confidence of 99.37 % for porcine tissue and 99.36% for bovine tissue. CONCLUSION: In this paper we demonstrate a proof of concept system for navigated intra-operative molecular analysis. This system may enable intra-operative awareness of spatially localized tissue classification during dissection, information that is especially useful in tumor surgeries where margins may not be visible to the unassisted eye.

Although the post-mortem diagnosis of bovine tuberculosis is mainly achieved through microbiological culture, the development of other techniques to detect Mycobacterium tuberculosis complex (MTBC) members directly from tissue samples has been pursued. The present study describes the development, optimization and validation of a Real-Time PCR based on the mpb70 gene to detect MTBC members in clinical tissue samples from cattle. Specific primers and a hybridization probe were used to amplify MTBC-specific sequences in order to avoid cross-reaction with non-MTBC species. An Internal Amplification Control (IAC) was included in order to assess the presence of PCR inhibitors in the samples. The PCR was optimized to achieve maximum efficiency, and the limit of detection, limit of quantification and dynamic range of the reaction were determined. The specificity of the reaction was tested against 34 mycobacterial and non-mycobacterial species. The diagnostic sensitivity, specificity and positive and negative predictive values (PPV and NPV) of the method were assessed on 200 bovine tissue samples in relation to bacteriological culture. The dynamic range of the reaction spanned from 5 ng/reaction (106 genome equivalents) to 50 fg/reaction (10 genome equivalents). The efficiency of the reaction was 102.6% and the achieved R2 was 0.999. The limit of detection with 95% confidence was 10 genome equivalents/reaction. No cross-reactions with non-MTBC species were observed. The diagnostic sensitivity and specificity values of the mpb70 specific Real-Time PCR respect to culture were 94.59% (95% CI: 86.73–98.51%) and 96.03% (95% CI: 90.98–98.70%), respectively, with a PPV of 93.33% (95% CI: 85.55–97.07%) and a NPV of 96.80% (95% CI: 92.10–98.74%). The concordance of the Real-Time PCR based on mpb70 is comparable to that of culture (K = 0.904) showing a great potential for the detection of members of the MTBC in animal tissues.

Introduction We present a case of a patient with prior bioprosthetic aortic valve replacement who underwent Left Ventricular Assist Device (LVAD) explant and was found to have fused valve leaflets at the time of surgery. Case Report The patient is a 30 year old woman with a history of a congenital quadricuspid aortic valve (frequency Summary Patients with prior tissue aortic valve replacement require careful preoperative evaluation before LVAD explant. Though we had a good outcome, pre-procedural knowledge of valve dysfunction is critical in surgical planning. We have developed an algorithm which may be utilized in the future to improve outcomes (Figure 2).

Although the post-mortem diagnosis of bovine tuberculosis is mainly achieved through microbiological culture, the development of other techniques to detect Mycobacterium tuberculosis complex (MTBC) members directly from tissue samples has been pursued. The present study describes the development, optimization and validation of a Real-Time PCR based on the mpb70 gene to detect MTBC members in clinical tissue samples from cattle. Specific primers and a hybridization probe were used to amplify MTBC-specific sequences in order to avoid cross-reaction with non-MTBC species. An Internal Amplification Control (IAC) was included in order to assess the presence of PCR inhibitors in the samples. The PCR was optimized to achieve maximum efficiency, and the limit of detection, limit of quantification and dynamic range of the reaction were determined. The specificity of the reaction was tested against 34 mycobacterial and non-mycobacterial species. The diagnostic sensitivity, specificity and positive and negative predictive values (PPV and NPV) of the method were assessed on 200 bovine tissue samples in relation to bacteriological culture. The dynamic range of the reaction spanned from 5 ng/reaction (106 genome equivalents) to 50 fg/reaction (10 genome equivalents). The efficiency of the reaction was 102.6% and the achieved R2 was 0.999. The limit of detection with 95% confidence was 10 genome equivalents/reaction. No cross-reactions with non-MTBC species were observed. The diagnostic sensitivity and specificity values of the mpb70 specific Real-Time PCR respect to culture were 94.59% (95% CI: 86.73–98.51%) and 96.03% (95% CI: 90.98–98.70%), respectively, with a PPV of 93.33% (95% CI: 85.55–97.07%) and a NPV of 96.80% (95% CI: 92.10–98.74%). The concordance of the Real-Time PCR based on mpb70 is comparable to that of culture (K = 0.904) showing a great potential for the detection of members of the MTBC in animal tissues.

Thoracoscopic lobectomy in infants requires advanced minimally invasive skills. Simulation-based education has the potential to improve complex procedural skills without exposing the patient to undue risks. The study purposes were (1) to create a size-appropriate infant lobectomy simulator and (2) to evaluate validity evidence to support or refute its use in surgical education.In this Institutional Review Board-exempt study, a size-appropriate rib cage for a 3-month-old infant was created. Fetal bovine tissue completed the simulator. Thirty-three participants performed the simulated thoracoscopic lobectomy. Participants completed a self-report, 26-item instrument consisting of 25 4-point rating scales (from 1=not realistic to 4=highly realistic) and a one 4-point Global Rating Scale. Validity evidence relevant to test content and response processes was evaluated using the many-facet Rasch model, and evidence of internal structure (inter-item consistency) was estimated using Cronbach's alpha.Experienced surgeons (observed average=3.6) had slightly higher overall rating than novice surgeons (observed average=3.4, P=.001). The highest combined observed averages were for the domain Physical Attributes (3.7), whereas the lowest ratings were for the domains Realism of Experience and Ability to Perform Tasks (3.4). The global rating was 2.9, consistent with "this simulator can be considered for use in infant lobectomy training, but could be improved slightly." Inter-item consistency for items used to evaluate the simulator's quality was high (α=0.90).With ratings consistent with high physical attributes and realism, we successfully created an infant lobectomy simulator, and preliminary evidence relevant to test content, response processes, and internal structure was supported. Participants rated the model as realistic, relevant to clinical practice, and valuable as a learning tool. Minor improvements were suggested prior to its full implementation as an educational and testing tool.

The U.S. Department of Agriculture, Food Safety Inspection Service regulatory method for monensin, Chemistry Laboratory Guidebook CLG-MON, is a semiquantitative bioautographic method adopted in 1991. Official Method of AnalysisSM (OMA) 2011.24, a modern quantitative and confirmatory LC-tandem MS method, uses no chlorinated solvents and has several advantages, including ease of use, ready availability of reagents and materials, shorter run-time, and higher throughput than CLG-MON. Therefore, a bridging study was conducted to support the replacement of method CLG-MON with OMA 2011.24 for regulatory use. Using fortified bovine tissue samples, CLG-MON yielded accuracies of 80–120% in 44 of the 56 samples tested (one sample had no result, six samples had accuracies of >120%, and five samples had accuracies of 40–160%), but the semiquantitative nature of CLG-MON prevented assessment of precision, whereas OMA 2011.24 had accuracies of 88–110% and RSDr of 0.00–15.6%. Incurred residue results corroborated these results, demonstrating improved accuracy (83.3–114%) and good precision (RSDr of 2.6–20.5%) for OMA 2011.24 compared with CLG-MON (accuracy generally within 80–150%, with exceptions). Furthermore, χ2 analysis revealed no statistically significant difference between the two methods. Thus, the microbiological activity of monensin correlated with the determination of monensin A in bovine tissues, and OMA 2011.24 provided improved accuracy and precision over CLG-MON.

An experimental setup for consecutive measurement of ion and x-ray absorption in tissue or other materials is introduced. With this setup using a 3D-printed sample container, the reference stopping-power ratio (SPR) of materials can be measured with an uncertainty of below 0.1%. A total of 65 porcine and bovine tissue samples were prepared for measurement, comprising five samples each of 13 tissue types representing about 80% of the total body mass (three different muscle and fatty tissues, liver, kidney, brain, heart, blood, lung and bone). Using a standard stoichiometric calibration for single-energy CT (SECT) as well as a state-of-the-art dual-energy CT (DECT) approach, SPR was predicted for all tissues and then compared to the measured reference. With the SECT approach, the SPRs of all tissues were predicted with a mean error of (-0.84 $\pm$ 0.12)% and a mean absolute error of (1.27 $\pm$ 0.12)%. In contrast, the DECT-based SPR predictions were overall consistent with the measured reference with a mean error of (-0.02 $\pm$ 0.15)% and a mean absolute error of (0.10 $\pm$ 0.15)%. Thus, in this study, the potential of DECT to decrease range uncertainty could be confirmed in biological tissue., 17 pages, 4 figures, 5 tables

We propose a novel framework for enhancement and localization of steeply inserted hand-held needles under in-plane 2D ultrasound guidance. Depth-dependent attenuation and non-axial specular reflection hinder visibility of steeply inserted needles. Here, we model signal transmission maps representative of the attenuation probability within the image domain. The maps are employed in a contextual regularization framework to recover needle shaft and tip information. The needle tip is automatically localized by line-fitting along the local-phase-directed trajectory, followed by statistical optimization. The proposed method was tested on 300 ex vivo ultrasound scans collected during insertion of an epidural needle into freshly excised porcine and bovine tissue. A tip localization accuracy of $$0.55\pm 0.06\,\hbox {mm}$$ was achieved. The proposed method could be useful in challenging procedures where needle shaft and tip are inconspicuous. Improved needle localization results compared to previously proposed methods suggest that the proposed method is promising for further clinical evaluation.

Laparoscopic hysterectomy is a procedure that involves the removal of the uterus through an abdominal keyhole incision. Morcellators have been specifically designed for this task, but their use has been discouraged by the food and drug administration (FDA) since November 2014 because of risks of cancerous tissue spread. The use of laparoscopic bags to catch and contain tissue debris has been suggested, but this does not solve the root cause of tissue spread. The fundamental problem lies in the tendency of the tissue mass outside the morcellation tube to rotate along with the cutting blade, causing tissue to be spread through the abdomen. This paper presents a bio-inspired concept that constrains the tissue mass in the advent of its rotation in order to improve the overall morcellation efficacy and reduce tissue spread. A design of gripping teeth integrated into the inner diameter of the morcellation tube is proposed. Various tooth geometries were developed and evaluated through an iterative process in order to maximize the gripping forces of these teeth. The maximum gripping force was determined through the measurement of force–displacement curves during the gripping of gelatin and bovine tissue samples. The results indicate that a tooth ring with a diameter of 15 mm can provide a torque resistance of 1.9 Ncm. Finally, a full morcellation instrument concept design is provided.

Described here is a novel method for automatic detection and enhancement of needles under 3D ultrasound guidance. We develop a detector consisting of a linear learning-based pixel classifier that utilizes Histogram of Oriented Gradients descriptors extracted from local phase projections. The detector automatically identifies slices of the volume that contain needle data, reducing the needle search space. Needle tip enhancement is performed on a projection of the extracted sub-volume, followed by automatic tip localization using spatially distributed image statistics within the trajectory constrained region. Evaluation of the proposed method on 40 volumes of ex vivo bovine tissue shows \(88\%\) detection precision, \(98\% \) recall rate, mean classification time per slice of 0.06 s and mean tip localization error of \(0.44\pm 0.13\) mm. The promising results indicate potential of the method for further evaluation on clinical pain management procedures.

Within the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantitè de Matiére (CCQM), key comparison CCQM-K141 and associated pilot study CCQM-P178 were coordinated by the National Research Council Canada (NRC). This comparison was a Track A key comparison that formed part of the OAWG 10-year strategic plan. The comparison demonstrated capabilities for measuring high-polarity analytes in a high-fat and high-protein matrix. The measurand chosen as the model system was enrofloxacin and sulfadiazine in bovine tissue. Thirteen National Metrology Institutes or Designated Institutes participated in the CCQM-K141, while two National Metrology Institutes participated in CCQM-P178. The bovine muscle tissue study material was derived from a single live animal that was administered with chemical based pharmaceutical agents prior to processing. Therefore, the study material was naturally incurred, providing a true test of extraction procedures relative to more commonly encountered spiked materials. NRC confirmed excellent homogeneity and stability of the material prior to shipping. Three 10 g bottles of freeze dried powdered muscle tissue were supplied. NRC also provided isotopically labelled solutions of the two measurands, 13C6-sulfadiazine and enrofloxacin-d5 (HI Salt), to those interested in using isotope dilution mass spectrometry (IDMS) methodologies. Procurement and purity assignment with appropriate metrological traceability of native calibrants were the responsibility of individual participants. The study required extraction, clean-up, analytical separation, and selective detection of the analytes. The level of agreement was reasonable given the measurands and matrix were new for most laboratories. The KCRV values and their uncertainties at the 95% confidence level of 57.81 ± 2.57 μg/kg for enrofloxacin and 2285 ± 68 μg/kg for sulfadiazine were calculated using the DSL means. While one participant's value was voluntarily excluded from the KCRV calculations for enrofloxacin, all other participants demonstrated equivalence for both measurands. Significant effort was undertaken post-study to identify the major sources of variability between results. In particular, the various extraction conditions used by participants were investigated thoroughly. While there appeared to be a correlation between highly acidic conditions and higher recovery, this was not definitive and could not be confirmed. The form of standards employed (i.e. free base vs salts) and potential differential solubility between forms was also a suspected source of variability. Biases could also have been introduced with the choice of solvents used for standard preparation, with some solvents better able to minimize adsorption of the analytes to glass surfaces. KEY WORDS FOR SEARCH enrofloxacin, sulfadiazine, bovine tissue, incurred, key comparison Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

During the last two decades, acellular dermal matrices (ADM) have been more widely used in reconstructive procedures i.e. breast reconstructions. Several, both synthetic and biologic products derived from human, porcine and bovine tissue, have been introduced. Until this point postoperative complications for the acellular dermal matrices, as a group, have been the main focus. The purpose of this literature review is to summarize the current knowledge on the each biologic product used in breast reconstructions, including product specific complication frequencies. A systematic search of the literature was performed in the PubMed and EMBASE databases, identifying 55 relevant articles, mainly evidence level III. AlloDerm seems to be associated with severe complicating matters in the reconstructive process compared to other products. This could be due to the higher number of investigating studies relative to the others. The surgical area faces certain challenges comparing results, due to surgical variance, the data collection and follow-up. More well-defined guidelines and more high-evidence randomized studies could increase the overall level of evidence in this area.

The current scenario of international beef trading has increased the pressure for better and faster diagnosis of bovine tuberculosis. Although traditional culture remains the gold standard method to confirm Mycobacterium bovis infection, it is exceedingly time consuming, and demands viable mycobacteria. Molecular methods overcome the flaws of the bacteriological methods with faster detection and identification. However, mycobacterial features like a complex cell wall and pathogen–host interaction make the molecular detection a challenge. Three protocols for DNA extraction (A, B and C) from bovine tissues were tested to verify the most suitable technique for routine diagnostic assessment of their specificity and sensitivity. Thirty culture-positive and thirty culture-negative granulomatous lesions were included in the trial. From each sample, three tissue suspensions at different dilutions (10-1, 10-2 and 10-3) were prepared and submitted to DNA extraction. PCR procedures targeting IS6110 were performed, employing two volumes of DNA: 5 µL of all three dilutions, and 2.5 µL of the 10-1 dilution. Protocol A was able to detect members of the M. tuberculosis complex in most samples. The sensitivity of the test decreased with increase in tissue-suspension dilution. Although Protocol A presented the highest sensitivity followed by C and B, it showed the lowest specificity, which can be due to a failure in primary isolation caused by the lack of viable organisms or incubation time. Regardless classical bacteriological methods are still recommended by OIE, after evaluating the sensitivity of DNA extraction protocols and PCR procedures, we conclude that the best strategy for M. bovis detection is to follow Protocol A on concentrated tissue suspensions.

Our purpose was to investigate the influence of phantom and biological materials on a 3-component decomposition using dual-energy mammography protocol 3CB. Materials and Methods: A novel dual-energy 3CB mammography technique concludes in quantifying of the lipid, protein, and water thicknesses. The protocol was designed to be used on full-field digital mammography system by including an additional high-energy image with the clinical image. We study influence of calibration phantom and regression techniques on three component outputs. Two types of phantoms were used: solid water/wax/Delrin phantom and bovine phantom consisted of fat and lean muscle compartments. The linear and quadratic model equations were analyzed using linear and ridge regressions. The elaborated calibration protocol was applied to breast images with different compositions and sizes. In addition, the protocol was validated using cadaver breasts of known compositions. Results: We found that there were many negative values of protein components when we applied our solid water/wax/Delrin calibrations using 51 ROIs for clinical dual energy mammogram analysis. This behavior could be explained by potential over fitting and not exact correspondence of biological and phantom material. Creating a calibration related to bovine tissue provided higher accuracy and realizable thicknesses for clinical breast composition components, and achieved satisfactory results for cadaver breast compositions. Conclusion: Using a bovine calibration, the 3CB technique provides higher accuracy for lipid, water and protein compositional breast measurements than using plastic tissue equivalents alone.

The commentary emphasizes the immediate necessity to find alternative sources for the production of pharmaceutical heparin to meet the ton-amount world's demand of the glycosaminoglycan. The recent development of a synthetic approach brings considerable new technical and scientifically relevant knowledge to the field, with a strong potential for application in the future. However, the artificial approach does not offer a rapid alternative for the current world crisis affecting the production of heparin, which has to respond to an increasing worldwide demand. It is important to call attention for the availability of marine organisms that are rich sources of heparin analogs with significant anticoagulant activity, low bleeding effect that have been cultivated in very large amounts for years in different parts of the world. Additionally, alternative sources of mammalian heparin, such as bovine intestine and lung have been continually used in countries from South America, Africa and Asia, since the outbreak of the BSE without any report of prion contamination in humans. Recently, it has been shown that bovine and porcine intestinal heparins are composed by different proportions of a mixture of the same fractions that can be simply separated by anion exchange chromatography. In other words, high quality porcine heparin can be obtained from bovine tissue. We believe that alternative animal sources of heparin are currently a more realistic solution than artificial heparin to respond to the increasing demand for heparin.

PURPOSE Currently, there is no accepted standard for measuring breast density. Dual energy mammography, which has demonstrated accurate measurement in phantoms, has been proposed as one possible method. To examine the use of chemical analysis as a possible means to validate breast density measurements from dual energy mammography, a bovine tissue model was investigated. Known quantities of lean and adipose tissue were compared with composition values measured from dual energy images and chemical analysis. METHODS Theoretical simulations were performed to assess the impact variations in breast composition would have on measurement of breast density from a single calibration. Fourteen ex-vivo tissue samples composed of varying amounts of pure lean tissue and pure adipose tissue (lean percentage) from 0 to 100%, in increments of 10%, were imaged using dual energy mammography. This was followed by chemical analysis based on desiccation, trituration, and fat extraction with petroleum ether to determine water, lipid, and protein content. The volumetric lean percentage (VLP) as measured from images (VLP(I)) and as derived from chemical analysis data (VLP(CA)) were compared with the VLP calculated from measurements of sample mass with a scale (VLP(M)). Finally, data from the bovine tissue model in this study were compared to compositional data from a previous report of human tissue composition. RESULTS The results from simulation suggest a substantial impact on measuring breast density is likely due to changes in anatomical breast composition. VLP(I) was related to the VLP(M) by VLP(I) = 1.53 VLP(M) + 10.0 (r2 > 0.99). VLP(CA) was related to VLP(M) by VLP(CA) = 0.76 VLP(M) + 22.8 (r2 > 0.99). VLP(I) was related to VLP(CA) by VLP(I) = 2.00 VLP(CA) - 35.6 (r2 > 0.99). Bovine adipose tissue was shown to be very similar to human adipose tissue in terms of water, lipid, and protein content with RMS differences of 1.2%. Bovine lean tissue was shown to be very similar to human skeletal muscle tissue and somewhat similar to human mammary gland tissue with RMS differences of 0.4 and 22.2%, respectively. CONCLUSIONS The results of this study show strong linear relationships between volumetric lean percentage measurements using dual energy mammography, chemical analysis and the actual mass. Determining the existence of a relationship between VLP(I) and VLP(CA) was necessary before comparing density results from the dual energy technique to composition data from chemical analysis for samples of unknown composition.

Tooth-surface pH is lowered, during drinking, to a value close to the pH of the drink itself. After the drink is swallowed, the pH rises to baseline values but this process can take several minutes. Few techniques can quantify enamel erosion at timescales representative of single drinks. The objective of this study was to compare human and bovine erosion over acid-exposure times of 2 s to 1 h. Human and bovine enamel softening was compared in vitro using nanoindentation (2-60 s of exposure to acid) and tissue loss was compared using optical profilometry (1-60 min of exposure to acid). Nanoindentation revealed statistically significant softening after 2 s (human) and 5 s (bovine); there were no significant differences in hardness reduction for the two tissues at any time-point. Profilometry demonstrated statistically significant tissue loss after 20 min (human) and 10 min (bovine); bovine tissue loss progressed 30% faster than human tissue loss. These results support the use of bovine enamel as a substitute for human enamel in erosion studies, with the understanding that for moderate exposure times bovine enamel erodes 30% faster than human enamel. Nanoindentation can be used to detect enamel dissolution at timescales comparable to the oral dwell-time of a single 'mouthful' of a beverage.

In this paper, a feasibility study of the application of the tissue sensing adaptive radar technique for imaging of the knee is presented. Selected tissues of the knee joints were characterized, from the dielectric properties point of view, through measurements on bovine tissue samples using a high precision dielectric probe. Based on the acquired data, numerical studies were conducted on a realistic finite-difference time-domain model of a meniscus, as well as on a model of a patellar tendon to investigate the possibility of detecting lesions. To confirm our observations, measurements on healthy and experimentally torn menisci and tendons from bovines were performed. Overall, the results suggest that microwave imaging has potential for knee imaging.

The purpose of this study was to evaluate an aspiration-type semiautomatic cutting biopsy needle for biopsy of bovine tissue.Aspiration-type semiautomatic cutting biopsy needles (18 gauge × 160 mm) with aspiration (Group A), aspiration-type semiautomatic biopsy needles without aspiration (Group Wo), or normal-type semiautomatic biopsy needles (18 gauge × 150 mm) (Group N) were used in 10 biopsies each of bovine liver or lung. The specimens were weighed with an electronic balance.Mean (standard deviation) weights for bovine liver specimens in Groups A, Wo, and N were 6.80 (0.615) mg, 5.62 (0.843) mg, and 4.19 (0.140) mg, respectively. Mean weights of bovine lung specimens from Groups A, Wo, and N were 2.98 (0.828) mg, 2.67 (0.832) mg, and 1.94 (0.864) mg, respectively. A significant difference was seen between the 3 groups for bovine liver. However, a significant difference was only seen between Groups A and N for bovine lung.Bovine liver and lung specimens obtained using the aspiration-type semiautomatic cutting biopsy needle were heavier than those obtained using the normal-type semiautomatic biopsy needle.

While the methods for diagnostic and screening imaging for breast cancer are numerous, each method has its limitations. Multimodality imaging has increasingly been shown to improve the effectiveness of these imaging. Imaging of dense breast tissue has its own set of challenges. Combining MR and gamma for imaging of breast lesions may increase the sensitivity and specificity in theory especially with dense breasts. This experiment was designed as a proof-of-concept for combining MR and gamma images in a pre-clinical setting using an ex vivo bovine tissue model. Keeping the tissue in the same orientation for both imaging modalities was deemed important to increase accuracy. Using the information of the combined images could assist with localization for biopsy.

The majority of edible gelatin in Europe is derived from pigskin, but a significant portion is extracted from bovine tissue. Because of the bovine spongiform encephalopathy crisis, consumers might be concerned about the gelatin used in various products. To assure consumers of the quality and safety of edible gelatin, European Union directive 1999/724/EC described general guidelines for gelatin production, including requirements for documentary proof confirming that raw materials are from animals fit for human consumption. Analytical methods to confirm gelatin documentation or raw material animal species source in the finished product are lacking. In this study, several published species-specific PCR systems were evaluated as potential molecular methods for determining the origin of the raw material used in making gelatin. A recently validated bovine species-specific PCR primer set targeting the ATPase 8 subunit gene in bovine mitochondrial DNA was suitable for detection of bovine material in gelatin. This PCR primer set was optimized using conventional and real-time PCR approaches. An evaluation of these two PCR methods confirmed the high specificity for the adopted primer set in various gelatin matrices of known origin. The inclusion of bovine gelatin in pork or fish gelatin can be detected at 0.1 to 0.001%. These PCR assays are potential molecular detection tools that can be used to routinely detect bovine gelatin either alone or as an inclusion in gelatin made from other species.

Thirty-six steers were used to determine the effects of acute cold (-20°C) and acute feed restriction (0.4× maintenance) on mRNA abundance of five candidate genes. To investigate adaptational physiology in cattle we evaluated gene expression patterns for uncoupling protein 2 (UCP-2), uncoupling protein 3 (UCP-3), leptin, leptin receptor and neuropeptide Y receptor (NPY receptor) in specific tissues. We measured relative mRNA abundance using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) on mRNA extracted from duodenum, iver, skeletal muscle, mesenteric adipose tissue, subcutaneous adipose tissue, and peri-renal adipose tissue. We obtained carcass grades for comparison to mRNA abundance profiles. Leptin receptor mRNA abundance was increased by acute feed restriction in the liver (P = 0.02) and trended to increase in the duodenum (P = 0.06) of acute feed-restricted steers. NPY receptor RNA abundance decreased (P = 0.02) in the liver of feed-restricted steers, and acute cold-stress-treated steers (P = 0.03), but increased (P = 0.03) in mesenteric adipose tissue of acute-cold-treated steers. Leptin mRNA abundance was decreased in subcutaneous adipose tissue (P = 0.04) by acute cold, but trended to increase in the peri-renal adipose tissue (P = 0.09). UCP-3 mRNA abundance was not significantly altered by our acute treatments. UCP-2 mRNA abundance increased in subcutaneous adipose tissue of both acute cold (P = 0.004) and acute feed-restricted steers (P = 0.03) and in biceps femoris, after acute cold (P = 0.003) and acute feed restriction (P = 0.002). There was an inverse relationship between the leptin mRNA abundance in subcutaneous adipose and the carcass grade, where the AAA , AA and A grade carcasses had mean values of 501.6 ± 30.0, 535.5 ± 14.0 and 653.4 ± 61.0. Our results show that tissue-specific mRNA abundance of these candidate genes may be altered by acute stressors, and that may relate to tissue-specific adaptational strategies in cattle. Furthermore, leptin mRNA abundance in subcutaneous adipose tissue may inversely reflect the maturity or finishing characteristics of beef cattle such that it is inversely related to the final carcass grade. Key words: Acute cold, acute feed restriction, UCP-2, UCP-3, leptin, leptin receptor, NPY receptor, cattle

Classified among the transmissible spongiform encephalopathies, bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD), are neurodegenerative conditions associated with the accumulation of an abnormal protein called PrP. Both conditions are thought to result from a novel type of infection that is mediated by a protein agent rather than a nucleic acid-containing particle. Amplified by the practice of feeding infected bovine tissue to other cattle, the BSE epidemic in the United Kingdom has now been largely controlled; BSE has, however, spread to other countries. Multiple lines of evidence support the hypothesis that BSE and vCJD are caused by the same agent. In the United States, a variety of measures have been implemented to survey for BSE and to prevent the development of an epidemic in this country. The recent identification of the first case of BSE in the U.S. has increased interest in these areas.

The commercial LCx amplification assay, usually employed to detect the Myocobacterium tuberculosis complex in respiratory specimens, was evaluated by comparing the results it gave with those obtained using Lowenstein-Jensen solid medium and pathological findings on 55 lymph nodes from cattle with positive and 10 lymph nodes from cattle with negative skin tests for tuberculosis. Fifty-three cultures (51 and 2, respectively) were positive for M. bovis, while the results for the LCx assay and the histological method were positive in 48 (45, 3) and 24 (20, 4) samples, respectively. None of the samples from cattle from certified tuberculosis-free herds were positive by any of the procedures. The results obtained with the LCx assay, compared with the culture procedure, regarded as the gold standard among the diagnostic techniques, gave a specificity of 91.6% and sensitivity of 90.5%. Although the sensitivity of LCx was suboptimal, DNA of M. bovis was detected in 81.8% of the skin test-positive animals. Amplification techniques could provide a rapid and reasonably reliable tool for detecting bovine tuberculosis.

Laparoscopic duodenal atresia (DA) repair is a relatively uncommon pediatric operation requiring advanced minimally invasive skills. Currently, there are no commercial simulators available that address surgeons' needs for refining skills associated with this procedure. The purposes of this study were (1) to create an anatomically correct, size-relevant model and (2) to evaluate the content validity of the simulator.Radiologic images were used to create an abdominal domain consistent with a full-term infant. Fetal bovine tissue was used to complete the simulator. Following Institutional Review Board exempt determination, 18 participants performed the simulated laparoscopic DA repair. Participants completed a self-report, six-domain, 24-item instrument consisting of 4-point rating scales (from 1=not realistic to 4=highly realistic). Validity evidence relevant to test content and response processes was evaluated using the many-facet Rasch model, and evidence of internal structure (inter-item consistency) was estimated using Cronbach's alpha.The highest observed averages were for "Value as a training and testing tool" (both observed averages=3.9), whereas the lowest ratings were "Palpation of liver" (observed average=3.3) and "Realism of skin" (observed average=3.2). The Global opinion rating was 3.2, indicating the simulator can be considered for use as is, but could be improved slightly. Inter-item consistency was high (α=0.89).We have successfully created a size-appropriate laparoscopic DA simulator. Participants agreed that the simulator was relevant and valuable as a learning/testing tool. Prior to implementing this simulator as a training tool, minor improvements should be made, with subsequent evaluation of additional validation evidence.

Despite the wide range and long history of ultrasound guided needle insertions, an unresolved issue in many cases is clear needle visibility. A well-known ad hoc technique to detect the needle is to move the stylet and look for changes in the needle appearance. We present a new method to automatically locate a moving stylet/catheter within a stationary cannula using motion detection. We then use this information to detect the needle trajectory and the tip. The differences between the current frame and the previous frame are detected and localized, to minimize the influence of tissue global motions. A polynomial fit based on the detected needle axis determines the estimated stylet shaft trajectory, and the extent of the differences along the needle axis represents the tip. Over a few periodic movements of the stylet including its full insertion into the cannula to the tip, a combination of polynomial fits determines the needle trajectory and the last detected point represents the needle tip. Experiments are conducted in water bath and bovine muscle tissue for several stylet/catheter materials. Results show that a plastic stylet has the best needle shaft and tip localization accuracy in the water bath with RMSE = 0:16 mm and RMSE = 0:51 mm, respectively. In the bovine tissue, the needle tip was best localized with the plastic catheter with RMSE = 0:33 mm. The stylet tip localization was most accurate with the steel stylet, with RMSE = 2:81 mm and the shaft was best localized with the plastic catheter, with RMSE = 0:32 mm.

Magnetic micro-machines capable of swimming through liquid or gel were fabricated. The micro-machines were driven by an external rotating magnetic field and featured a screw-shaped structure and permanent magnet. The machines could swim under condition of a Reynolds number ( Re ) of 10 −7 , and were able to run through agar or a bovine tissue sample using the same principle. Their running behavior was dependent on the frequency and strength of the external field, and on the surrounding media. These machines have great potential for medical applications in the human body.

Purpose: To determine temperature changes associated with radiofrequency (RF) energy–induced heating of bovine capsular tissue using a bipolar RF electrode versus a temperature-controlled, monopolar RF electrode. Type of Study: In vitro laboratory investigation using bovine capsular tissue. Methods: Samples of bovine tissue were placed in a saline bath (37°C) and RF energy was applied using bipolar and monopolar RF electrodes at manufacturer-recommended settings for tissue shrinkage. Fluoroptic thermometry was used to record temperatures on the tissue surface and at depths of 1 mm and 2 mm during continuous delivery of RF energy at 1, 2, 3, 4, 5, and 10 second time increments. Results: The highest mean temperatures were recorded on the tissue surface, as follows (mean ± SD; * P R =.926) between mean surface temperatures versus time. The temperature-controlled, monopolar RF electrode did not appear to properly regulate the delivery of RF energy to maintain tissue temperatures at the selected level (i.e., 65°C). The bipolar RF electrode produced a smaller temperature gradient (average difference, 9.2°C) at the 1-mm tissue depth compared with the monopolar RF electrode (average difference, 14.6°C). Temperature profiles at the 2-mm tissue depth were comparable for both types of RF electrodes. Conclusions: These data provide basic information pertaining to the temperature profiles produced by bipolar and monopolar RF electrodes applied to collagen-based tissue. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 2 (February), 2001: pp 124–131

aspects of ‘‘Mycobacterium genavense,’’ a proposed species isolated from AIDS patients. J Clin Microbiol 30:3206–3212. 3. Eriks IS, Munck KT, Besser TE, et al.: 1996, Rapid differentiation of Mycobacterium avium and M. paratuberculosis by polymerase chain reaction and restriction enzyme analysis. J Clin Microbiol 34:734–737. 4. Gerlach H: 1994, Bacteria. In: Avian medicine: principles and applications, ed. Ritchie BW, Harrison GJ, Harrison LR, pp. 971–975. Winger’s, Lake Worth, FL. 5. Grange JM, Yates MD, Boughton E: 1990, The avian tubercle bacillus and its relatives. J Appl Bacteriol 68:411–431. 6. Hoop RK, Bottger EC, Ossent P, Salfinger M: 1993, Mycobacteriosis due to Mycobacterium genavense in six pet birds. J Clin Microbiol 31:990–993. 7. Hoop RK, Bottger EC, Pfyffer GE: 1996, Etiological agents of mycobacteriosis in pet birds between 1986 and 1995. J Clin Microbiol 34:991–992. 8. Jackson K, Sievers A, Ross BC, Dwyer B: 1992, Isolation of a fastidious Mycobacterium species from two AIDS patients. J Clin Microbiol 30:2934–2937. 9. Kiehn TE, Hoefer H, Bottger E, et al.: 1996, Mycobacterium genavense infections in pet animals. J Clin Microbiol 34:1840– 1842. 10. Kirschner P, Vogel U, Hein R, Bottger EC: 1994, Bias of culture techniques for diagnosing mixed Mycobacterium genavense and Mycobacterium avium infection in AIDS. J Clin Microbiol 32: 828–831. 11. Portaels F, Realini L, Bauwens L, et al.: 1996, Mycobacteriosis caused by Mycobacterium genavense in birds kept in a zoo: 11year survey. J Clin Microbiol 34:319–323. 12. Rogall T, Wolters J, Flohr T, Bottger E: 1990, Towards a phylogeny and definition of species at the molecular level within the genus Mycobacterium. Int J Syst Bacteriol 40:323–330. 13. Telenti A, Marchesi F, Balz M, et al.: 1993, Rapid identification of mycobacteria to the species level by polymerase chain reaction and restriction enzyme analysis. J Clin Microbiol 31:175– 178. 14. Thoen CO, Karlson AG: 1991, Tuberculosis. In: Diseases of poultry, ed. Calnek BW, pp. 172–185. Iowa State University Press, Ames, IA. 15. Van der Giessen JWB, Eger A, Haagsma J, et al.: 1992, Amplification of 16S rRNA sequences to detect Mycobacterium paratuberculosis. J Med Microbiol 36:255–263. 16. Van der Giessen JWB, Haring RM, Vauclare E, et al.: 1992, Evaluation of the abilities of three diagnostic tests based on the polymerase chain reaction to detect Mycobacterium paratuberculosis in cattle: application in a control program. J Clin Microbiol 30:1216–1219.

Objective: The purpose of this study was to compare the penetration of 808 and 980 nm laser light through bovine tissue samples 18–95 mm thick. Background data: Low-level laser therapy (LLLT) is frequently used to treat musculoskeletal pathologies. Some of the therapeutic targets are several centimeters deep. Methods: Laser light at 808 and 980 nm (1 W/cm2) was projected through bovine tissue samples ranging in thickness from 18 to 95 mm. Power density measurements were taken for each wavelength at the various depths. Results: For 808 nm, 1 mW/cm2 was achieved at 3.4 cm, but for 980 nm, 1 mW/cm2 was achieved at only 2.2 cm depth of tissue. Conclusions: It was determined that 808 nm of light penetrates as much as 54% deeper than 980 nm light in bovine tissue.

Purpose We sought to create and validate a high fidelity, anatomically correct real tissue simulation model for thoracoscopic esophageal atresia/tracheoesophageal fistula (EA/TEF) repair. Methods A scale reproduction of a neonatal rib cage was created. Surgically modified (EA/TEF) fetal bovine tissue completed the simulator. Nine pediatric surgery fellows and two attending pediatric surgeons (n = 11) performed the simulated thoracoscopic EA/TEF repair. Participants completed a self-report rating scale, ranging from 1 (Don’t know) to 5 (Highly realistic). Construct validity relevant to test content was evaluated by examining the ratings using the many-Facet Rasch model. Results Analyses indicated no differences when comparing faculty (Observed Average (OA) = 4.5/5.0) to fellow (OA = 3.3) ratings, p = .71. In descending order, observed averages of the domains were 4.7 (Relevance), 4.5 (Physical attributes), 4.5 (Realism of materials), 4.4 (Ability to perform task), and 4.2 (Value). The observed Global opinion rating indicated the simulator can be considered for teaching thoracoscopic EA/TEF repair but could be improved slightly. Conclusions Fellow and faculty ratings indicated the simulator was valuable as a learning tool with minor modifications. Comments were consistent with high physical attribute ratings.

1. Masked long-chain alpha-hydroxyaldehydes were trapped in all subcellular fractions of bovine liver by application of pentafluorbenzyloxime derivatization [van Kuijk, Thomas, Stephens and Dratz (1986) Biochem. Biophys. Res. Commun. 139, 144-149] and quantified via GLC/MS using characteristic ion traces. 2. The chain-length profile of long-chain 2-hydroxyalkanales clearly indicates their relationship to plasmalogens as precursor molecules. 3. The previously postulated existence of alpha-acyloxyplasmalogens as precursor molecules of masked long-chain alpha-hydroxyaldehydes in bovine tissue lipids [Lutz and Spiteller (1991) Liebigs Ann. Chem. 1991, 563-567] was excluded. 4. The constant oxidation rate of plasmalogens in all subcellular fractions provides conclusive evidence for a non-enzymic plasmalogen epoxidation process (probably via hydroperoxy radicals). 5. The high reactivity of alpha-hydroxyaldehydes sheds some doubt on the postulation that plasmalogens protect mammalian cells against oxidative stress as postulated previously [Morand, Zoeller and Raetz (1988) J. Biol. Chem. 263, 11590-11596; Morand, Zoeller and Raetz (1988) J. Biol. Chem. 263, 11597-11606].

In der vorliegenden Arbeit wird eine Methode zur exakten Quantifizierung spezischer RNA, die kompetitive und damit quantitative Reverse-Transkriptase-Polymerase-Kettenreaktion (cRT-PCR) exemplarisch beschrieben. Im Vergleich mit konventionellen Verfahren hat diese Methode den Vorteil, das bereits geringe Mengen an Untersuchungsmaterial zur Analyse ausreichen. Die spezifischen mRNAs fur 2 Schlusselproteine des zellularen Cholesterinstoffwechsels, den Low-density-Lipoprotein(LDL)-Rezeptor und die 3-hydroxy-3-methylglutaryl-Coenzym A(HMG-CoA)-Reduktase wurde in verschiedenen bovinen Geweben gemessen. Dabei zeigte sich eine besonders hohe Expression beider mRNAs in den steroidhormonproduzierenden Geweben, i. e. Corpus luteum des Ovars und der Nebenniere, eine mittlere Expression in der Leber und eine niedrige bzw. nicht mesbare Expression im Dickdarm. Die hier am Beispiel des LDL-Rezeptors und der HMG-CoA-Reduktase exemplarisch vorgestellte Methode der quantitativen RT-PCR last sich nicht nur in der Routinediagnostik, sondern auch auf eine Vielzahl von wissenschaftlichen Fragestellungen auf dem Gebiet der Stoffwechsel-, Entzundungs- und Tumorpathologie anwenden.

Radiofrequency (RF) ablation has emerged as an effective method for treating liver tumors under 3 cm in diameter. Multiple applicator devices and techniques - using RF, microwave and other modalities - are under development for thermal ablation of large and irregularly-shaped liver tumors. Interstitial ultrasound (IUS) applicators, comprised of linear arrays of independently powered tubular transducers, enable 3D control of the spatial power deposition profile and simultaneous ablation with multiple applicators. We evaluated IUS applicator configurations (parallel, converging and diverging implants) suitable for percutaneous and laparascopic placement with experiments in ex vivo bovine tissue and computational models. Ex vivo ablation zones measured 4.6±0.5 x 4.2±0.5 × 3.3±0.5 cm 3 and 5.6±0.5 × 4.9±0.5 x 2.8±0.3 cm 3 using three parallel applicators spaced 2 and 3 cm apart, respectively, and 4.0±0.3 × 3.2±0.4 × 2.9±0.2 cm 3 using two parallel applicators spaced 2 cm apart. Computational models indicate in vivo ablation zones up to 4.5 × 4.4 × 5.5 cm 3 and 5.7 × 4.8 × 5.2 cm 3 , using three applicators spaced 2 and 3 cm apart, respectively. Converging and diverging implant patterns can also be employed for conformal ablation of irregularly-shaped tumor margins by tailoring power levels along each device. Simultaneously powered interstitial ultrasound devices can create tailored ablation zones comparable to currently available RF devices and similarly sized microwave antennas.

Danofloxacin (DANO) residue in bovine muscle was screened at 200 ng/g by terbium-sensitized luminescence (TSL) directly measured on 10 × 6 mm C18 sorbent strips. The analyte was first adsorbed on sorbent surface by immersion in defatted homogenates. After reagent application and desiccation, TSL was directly measured on sorbent surfaces at λ(ex) = 273 nm and λ(em) = 546 nm. The luminescence intensity was linearly dependent on DANO concentration in the 0-1000 ng/g range (R(2) = 0.9967). A threshold was established at x(200) - 3σ(200), where x(200) and σ(200) are the mean and standard deviation, respectively, of the DANO signals at 200 ng/g. Among 48 blind samples randomly fortified at 0-1000 ng/g, 45 were screened correctly and 3 negative samples were presumed positive. This simple screening protocol has the potential to significantly reduce sample numbers and hence improve sample throughput and save assay costs.

Background Transmission of the prion disease bovine spongiform encephalopathy (BSE) occurred accidentally to cattle and several other mammalian species via feed supplemented with meat and bone meal contaminated with infected bovine tissue. Prior to United Kingdom controls in 1996 on the feeding of mammalian meat and bone meal to farmed animals, the domestic chicken was potentially exposed to feed contaminated with the causal agent of BSE. Although confirmed prion diseases are unrecorded in avian species a study was undertaken to transmit BSE to the domestic chicken by parenteral and oral inoculations. Transmissibility was assessed by clinical monitoring, histopathological examinations, detection of a putative disease form of an avian prion protein (PrP) in recipient tissues and by mouse bioassay of tissues. Occurrence of a progressive neurological syndrome in the primary transmission study was investigated by sub-passage experiments. Results No clinical, pathological or bioassay evidence of transmission of BSE to the chicken was obtained in the primary or sub-passage experiments. Survival data showed no significant differences between control and treatment groups. Neurological signs observed, not previously described in the domestic chicken, were not associated with significant pathology. The diagnostic techniques applied failed to detect a disease associated form of PrP. Conclusion Important from a risk assessment perspective, the present study has established that the domestic chicken does not develop a prion disease after large parenteral exposures to the BSE agent or after oral exposures equivalent to previous exposures via commercial diets. Future investigations into the potential susceptibility of avian species to mammalian prion diseases require species-specific immunochemical techniques and more refined experimental models.

STR-based individualisation of biological deposits on bullets after perforation of tissue, can identify the person injured or killed by a particular bullet and comparison with the firearms used can identify the weapon and thus possibly the person who did the shooting. In this study, the effect of subsequent impacts on intermediate targets such as loss of cells was investigated by amplification of mitochondrial (mt) DNA. Bovine tissue was perforated and the 9 mm Luger FMJ bullets were recovered from the bullet collector. The mt cytochrome-b (cyt-b) gene could be amplified by the polymerase chain reaction (PCR) from 14 out of 15 bullets. Examination with a scanning electron microscope (SEM) and an energy-dispersive X-ray spectrometer (EDS) demonstrated the presence of minute dried tissue deposits on all bullets (n = 10) but was not able to establish preferential locations. In a series of 25 gunshots, various intermediate targets (glass, wood, car metal, gypsum board, asphalt) were perforated/ impacted following perforation of tissue and the cyt-b gene could be typed from all bullets. It is concluded that subsequent impacts on intermediate targets do not eliminate enough biological deposits to render DNA analysis impossible and that the amplification of mtDNA is a useful additional method.