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Sectioning
Kinds of Sectioning Selected AbstractsSectioning of radiolarians under continuous observationFOSSIL RECORD-MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE, Issue 1 2002Joachim Stanek Abstract A new method to study the internal structure of fossil radiolarians in presented. The core of the method is (1) freezing the radiolarian in a drop of water using a Peltier module and (2) slicing the radiolarian with a specially equipped electric tooth-brush under an optical microscope. With this method the internal structure of diagenetically altered radiolarians can be studied even if internal sediment cannot be removed. Eine neue Methode zur Analyse der Internstrukturen von Radiolarien wird vorgestellt. Die Methode beinhaltet (1) Einfrieren einzelner Radiolarien in einem Wassertropfen mit Hilfe eine Peltier-Elements und (2) Schleifen der Radiolarien mit Hilfe eine modifizierten elektrischen Zahnbürste unter einem Binokular. Mit dieser Methode ist es möglich Internstrukturen von Radiolarien zu untersuchen, selbst wenn diese diagenetisch verändert sind oder fest verbackenes Internsediment aufweisen. [source] Vitreous cryo-sectioning of cells facilitated by a micromanipulatorJOURNAL OF MICROSCOPY, Issue 2 2006MARK S. LADINSKY Summary Sectioning vitrified cells and tissues for cryo-electron microscopy is more challenging than room-temperature sectioning of plastic-embedded samples. As the sample must be kept very cold (<,130 °C) and because there is no liquid upon which the sections can float as they are cut, transferring the sections from the knife edge to a grid is one of the more difficult steps in the process. We employed a micromanipulator to hold and control the cryo-sections as they come off the knife. This allows slower cutting speeds than are typically used in vitreous cryo-sectioning and contributes to better control during cutting, which facilitates repeatable placement of a ribbon of sections onto a grid. The ribbon is kept under tension during the entire cutting process, which may decrease folding and/or compression, features that are inherent to vitreous sections. Furthermore, the added control afforded by this technique makes it easier for multiple ribbons to be placed on a single grid, thereby increasing the number of sections that can be examined and imaged during a microscopy session. It even allows for serial cryo-electron microscopy. As such, this approach is an advance in the cryo-microtomy of vitreous sections. [source] Characterization of the Grain-Boundary Character and Energy Distributions of Yttria Using Automated Serial Sectioning and EBSD in the FIBJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2009Shen J. Dillon A dual-beam focused ion beam scanning electron microscope was used to collect a series of parallel electron backscatter diffraction maps of polycrystalline yttria. Using characteristics of the triple junctions, the individual layers were aligned and the geometries of the grain-boundary planes between the layers were determined. This information was used to calculate the five-parameter grain-boundary character distribution (GBCD) and grain-boundary energy distribution (GBED). The GBCD derived from the three-dimensional data was qualitatively the same as that derived from a stereological analysis of the same data. The anisotropy in the GBCD of yttria is relatively weak compared with other ceramics and is inversely correlated to the GBED. [source] Gene deletion of either interleukin-1,, interleukin-1,,converting enzyme, inducible nitric oxide synthase, or stromelysin 1 accelerates the development of knee osteoarthritis in mice after surgical transection of the medial collateral ligament and partial medial meniscectomyARTHRITIS & RHEUMATISM, Issue 12 2003Kristen M. Clements Objective To investigate the development of osteoarthritis (OA) after transection of the medial collateral ligament and partial medial meniscectomy in mice in which genes encoding either interleukin-1, (IL-1,), IL-1,,converting enzyme (ICE), stromelysin 1, or inducible nitric oxide synthase (iNOS) were deleted. Methods Sectioning of the medial collateral ligament and partial medial meniscectomy were performed on right knee joints of wild-type and knockout mice. Left joints served as unoperated controls. Serial histologic sections were obtained from throughout the whole joint of both knees 4 days or 1, 2, 3, or 4 weeks after surgery. Sections were graded for OA lesions on a scale of 0,6 and were assessed for breakdown of tibial cartilage matrix proteoglycan (aggrecan) and type II collagen by matrix metalloproteinases (MMPs) and aggrecanases with immunohistochemistry studies using anti-VDIPEN, anti-NITEGE, and Col2-3/4Cshort neoepitope antibodies. Proteoglycan depletion was assessed by Alcian blue staining and chondrocyte cell death, with the TUNEL technique. Results All knockout mice showed accelerated development of OA lesions in the medial tibial cartilage after surgery, compared with wild-type mice. ICE-, iNOS-, and particularly IL-1,,knockout mice developed OA lesions in the lateral cartilage of unoperated limbs. Development of focal histopathologic lesions was accompanied by increased levels of MMP-, aggrecanase-, and collagenase-generated cleavage neoepitopes in areas around lesions, while nonlesional areas showed no change in immunostaining. Extensive cell death was also detected by TUNEL staining in focal areas around lesions. Conclusion We postulate that deletion of each of these genes, which encode molecules capable of producing degenerative changes in cartilage, leads to changes in the homeostatic controls regulating the balance between anabolism and catabolism, favoring accelerated cartilage degeneration. These observations suggest that these genes may play important regulatory roles in maintaining normal homeostasis in articular cartilage matrix turnover. [source] The physical scale modelling of braided alluvial architecture and estimation of subsurface permeabilityBASIN RESEARCH, Issue 3 2002D. J. Moreton ABSTRACT The quantitative modelling of fluvial reservoirs, especially in the stages of enhanced oil recovery, requires detailed three-dimensional data at both the scale of the channel belt and within-channel. Although studies from core, analogue outcrop and modern environments may partially meet these needs, they often cannot provide detail on the smaller-scale (i.e. channel-scale) heterogeneity, frequently suffer from limited three-dimensional exposure and cannot be used to examine the influence of different variables on the process,deposit relationship. Physical modelling offers a complementary technique that can address many of these quantitative requirements and holds great future potential for integration with reservoir modelling. Physical modelling provides the potential to upscale results and derive reservoir information on three-dimensional facies geometry, connectivity and permeability. This paper describes the development and use of physical modelling, which employs generic Froude-scaling principles, in an experimental basin that permits aggradation in order to model the morphology and subsurface depositional stratigraphy of coarse-grained braided rivers. An example is presented of a 1:50 scale model based on the braided Ashburton River, Canterbury Plains, New Zealand and the adjacent late Quaternary braided alluvium exposed in the coastal cliffs. Critically, a full, bimodal grain size distribution (20% sand and 80% gravel) was used to replicate the prototype, which allows the realistic reproduction of the surface morphology and importantly permits grain size sorting during deposition. Uncertainties associated with the compression of time, sediment mass balance and the hydrodynamics of the finest particle sizes do not appear to affect the reproducibility of stratigraphy between experimental and natural environments. Sectioning of the preserved sedimentary sequence in the physical model allows quantification of the geometry, shape, spatial distribution and internal sedimentary structure of the coarse- and fine-grained facies. A six-fold facies scheme is proposed for the model braided alluvium and a direct link is established between the grain size distribution and facies type: this allows permeability to be estimated for each facies, which can be mapped onto two-dimensional vertical cross-sections of the preserved stratigraphy. Results demonstrate the dominance of four facies based on permeability that range over three orders of magnitude in hydraulic conductivity. Quantification of such variability, and linkage to both vertical proportion curves for facies distribution and connectivity presents significant advantages over other methodologies and offers great potential for the modelling of heterogeneous braided river sediments at the within channel-belt scale. This paper outlines how physical models may be used to develop high-resolution, geologically-accurate, object-based reservoir simulation models. [source] Heart changes in 17-day-old fetuses of diabetic ICR (Institute of Cancer Research) mothers: Improvement with maternal immune stimulationCONGENITAL ANOMALIES, Issue 1 2009Juan Claudio Gutierrez ABSTRACT Maternal diabetes mellitus is associated with increased fetal teratogenesis, including cardiovascular defects. Non-specific maternal immune stimulation with Freund's complete adjuvant (FCA) or interferon gamma (IFN,) has been associated with protection against birth malformations. Using a diabetic mouse model, late-gestation fetal heart and great vessel morphology were analyzed. Four groups of mice were used: non-diabetic females as a control group, hyperglycemic females induced by streptozotocin as a diabetic group, and diabetic females injected either with FCA or IFN,. At day 17 of gestation, females were euthanized and one fetus was arbitrarily selected per litter for fixation and sectioning. Treatment-induced changes in cardiac development were assessed from digital images of serial sections taken at standardized levels in the thorax. One-way parametric and non-parametric ANOVA and ordinal logistic regression were performed to compare the difference among groups (P < 0.05). Maternal hyperglycemia altered morphology of the late-gestation fetal mouse heart by causing ventricular chamber dilation, sectional myocardial reduction, and an increase in transversal aortic area. FCA protected the fetal heart from cavitary dilation in diabetic mothers. FCA and IFN, protected the fetal heart against reduction of myocardial area, and ascending thoracic aorta dilation. Consequences of late gestation heart chamber dilation and myocardial reduction are not yet known. Maternal immune stimulation partially protected against these developmental defects by mechanisms that remain unclear. [source] Comparative in vitro study of the sealing efficiency of white vs grey ProRoot mineral trioxide aggregate formulas as apical barriersDENTAL TRAUMATOLOGY, Issue 2 2008Spyridon Stefopoulos Recently conventional grey MTA has been replaced by a new white MTA formula. The aim of this study was to compare the root canal adaptation of white MTA to that of grey MTA when used as an apical barrier in teeth with open apices. We also examined whether a previous calcium hydroxide intracanal medication affects MTA's sealing ability and investigated the ability to remove calcium hydroxide from the root canal walls. Forty-nine teeth were prepared in a manner to simulate a divergent open apex of immature teeth. Four teeth were used in a preliminary experiment to demonstrate the inefficacy of calcium hydroxide removal from the canal walls in teeth with open apices. Four groups of 10 teeth each were created: groups A and B were treated with calcium hydroxide intracanal medication and then received an apical plug of grey and white MTA respectively. Groups C and D received an apical plug of grey and white MTA respectively without previous intracanal medication. Four teeth served as negative and one as a positive control. The marginal adaptation and sealing ability of the apical barrier were tested by means of a dye tracer (basic fuchsine) after longitudinal sectioning. It was found that MTA apical barrier resisted displacement during gutta-percha condensation. Calcium hydroxide pretreatment, adversely affected white MTA sealing ability (P < 0.05). [source] Delayed axonal pruning in the ant brain: A study of developmental trajectoriesDEVELOPMENTAL NEUROBIOLOGY, Issue 6 2009Marc A. Seid Abstract The coordination of neuronal maturation and behavioral development is a vital component of survival. The degradation of excessive axonal processes and neuronal networks is a ubiquitous developmental process. In Drosophila, a great portion of axonal pruning occurs during metamorphosis and transpires within hours after pupation. In contrast, we show, using EM-serial sectioning and 3D-reconstructions, that axonal pruning occurs after eclosion and over the course of 60 days in Cataglyphis albicans. Using the mushroom bodies of the brains of Cataglyphis, which have well-developed lip (olfactory integrator) and collar (visual integrator) regions, we show that axonal pruning is dependent upon the differences in the developmental trajectory of the lip and the collar brain regions and happens after eclosion. The elimination of the axonal boutons is most delayed in the collar region, where it is postponed until the ant has had extensive visual experience. We found that individual brain components within a single neuropil can develop at different rates that correlate with the behavioral ecology of these ants and suggest that glia may be mediating the axonal pruning. Our study provides evidence that adult ants may have relatively neotenous brains, and thus more flexibility, allowing them to neuronally adapt to the environment. This neoteny may, in part, explain the neural basis for age-dependent division of labor and the amazing behavioral flexibility exhibited by ants. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2009 [source] Noncorrelating Pap tests and cervical biopsies: Histological predictors of subsequent correlationDIAGNOSTIC CYTOPATHOLOGY, Issue 5 2005Nancy E. Joste M.D. Abstract Lack of correlation between dysplastic cervicovaginal Papanicolaou (Pap) tests and subsequent cervical biopsies raises the concern that a significant squamous intraepithelial lesion (SIL) may go unconfirmed. Additional tissue sections of cervical biopsies may detect SILs after noncorrelation on initial sections. Complete step sectioning of paraffin blocks was undertaken on 111 noncorrelating biopsy specimens from 95 patients and selected slides were reviewed for the presence of SIL. The initial negative biopsy slides were evaluated for four histological features: chronic cervicitis, acute cervicitis, mucosal erosion, and squamous atypia. Twenty-seven biopsies (24.3%) demonstrated the presence of a SIL in deeper levels. The presence of squamous atypia was significantly associated with the presence of dysplasia deeper in the block (P < 0.002). Acute and chronic cervicitis was seen roughly equally. Additional tissue levels are a productive way of confirming SILs, and squamous atypia allows a refined selection of negative cervical biopsies most likely to reveal an SIL on review of deeper levels. Diagn. Cytopathol. 2005;32:310,314. © 2005 Wiley-Liss, Inc. [source] Genital system anatomy and development of Ovatella myosotis by three-dimensional computer visualizationACTA ZOOLOGICA, Issue 2 2009Bernhard Ruthensteiner Abstract Adult anatomy as well as organogenesis of the genital system of the ellobiid pulmonate Ovatella myosotis is investigated in detail by means of serial sectioning and three-dimensional computer reconstruction and visualization. From the middle portion of the adult, which has four nidamental glands, a spermoviduct leads to a common genital aperture. From here two separate structures, the vas deferens and a groove on the body surface, lead anteriorly. The latter is termed the egg groove because it carries the egg ribbon anteriorly, a function that is recognized here for the first time in the Ellobiidae. The evolution of this structure is discussed. In development, the organ system arises from four separate anlagen: (1) the ovotestis anlage, (2) the pallial anlage giving rise to the hermaphrodite duct, fertilization pouch,spermatheca complex, nidamental glandular complex and spermoviduct, (3) the bursa copulatrix anlage and (4) the anlage of the copulatory organ, vas deferens and egg groove. This development mode strongly resembles that of the siphonariid Williamia radiata, supporting its interpretation as a plesiomorphy in Pulmonata. Similarities in development of primitive pulmonates and evolution in gastropods lead to the assumption that ontogenesis of this organ system reflects evolution to some degree. [source] Usefulness of Live/Real Time Three-Dimensional Transthoracic Echocardiography in Evaluation of Prosthetic Valve FunctionECHOCARDIOGRAPHY, Issue 10 2009Preeti Singh M.D. We studied 31 patients with prosthetic valves (PVs) using two-dimensional and three-dimensional transthorathic echocardiography (2DTTE and 3DTTE, respectively) in order to determine whether 3DTTE provides an incremental value on top of 2DTTE in the evaluation of these patients. With 3DTTE both leaflets of the St. Jude mechanical PV can be visualized simultaneously, thereby increasing the diagnostic confidence in excluding valvular abnormalities and overcoming the well-known limitations of 2DTTE in the examination of PVs, which heavily relies on Doppler. Three-dimensional transthorathic echocardiography provides a more comprehensive evaluation of PV regurgitation than 2DTTE with its ability to more precisely quantify PV regurgitation, in determining the mechanism causing regurgitation, and in localizing the regurgitant defect. Furthermore, 3DTTE is superior in identifying, quantifying, and localizing PV thrombi and vegetations, in addition to the unique feature of providing a look inside mass lesions by serial sectioning. These preliminary results suggest the superiority of 3DTTE over 2DTTE in the evaluation of PVs and that it provides incremental knowledge to the echocardiographer. [source] Incremental Value of Live/Real Time Three-Dimensional Transthoracic Echocardiography in the Assessment of Right Ventricular MassesECHOCARDIOGRAPHY, Issue 5 2009Venkataramana K. Reddy M.D. This case series demonstrates the incremental value of three-dimensional transthoracic echocardiography (3D TTE) over two-dimensional transthoracic echocardiography (2D TTE) in the assessment of 11 patients with right ventricular (RV) masses or mass-like lesions (three cases of RV thrombus, one myxoma, one fibroma, one lipoma, one chordoma, and one sarcoma and three cases of RV noncompaction, which are considered to be mass-like in nature). 3D TTE was of incremental value in the assessment of these masses in that 3D TTE has the capacity to section the mass and view it from multiple angles, giving the examiner a more comprehensive assessment of the mass. This was particularly helpful in the cases of thrombi, as the presence of echolucencies indicated clot lysis. In addition, certainty in the number of thrombi present was an advantage of 3D TTE. Also, sectioning of cardiac tumors allowed more confidence in narrowing the differential diagnosis of the etiology of the mass. In addition, 3D TTE allowed us to identify precise location of the attachments of the masses as well as to determine whether there were mobile components to the mass. Another noteworthy advantage of 3D TTE was that the volumes of the masses could be calculated. Additionally, the findings by 3D TTE correlated well with pathologic examination of RV tumors, and some of the masses measured larger by 3D TTE than by 2D TTE, which was also validated in one case by surgery. As in the case of RV fibroma, another advantage was that 3D TTE actually identified more masses than 2D TTE. RV noncompaction was also well studied, and the assessment with 3D TTE helped to give a more definitive diagnosis in these patients. [source] Injection of the insertion of the deep digital flexor tendon in horses using radiographic guidanceEQUINE VETERINARY EDUCATION, Issue 7 2008J. D. C. Anderson Summary Insertional tendinopathies of the DDFT have been reported both as the sole lesion and as part of a multifocal lesion (Dyson et al. 2003). Computed tomography (CT) and magnetic resonance imaging allow specific diagnosis of deep digital flexor tendon lesions within the hoof capsule; however, direct intralesional treatment of such lesions is difficult because of the hoof's rigid structure. A technique designed to mimic intralesional injection of insertional tendinopathies of the DDFT in the standing horse using radiographic guidance was assessed. Radiographic and contrast CT imaging and sectioning of the limbs confirmed accurate injection in all cases although inadvertant administration of injectate into adjacent structures was also evident. [source] Standing oral extraction of cheek teeth in 100 horses (1998-2003)EQUINE VETERINARY JOURNAL, Issue 2 2005P. M. DIXON Summary Reasons for performing study: Extraction of cheek teeth (CT) by the conventional repulsion technique requires general anaesthesia and carries a high rate of post operative complications. Consequently, an alternative method of extraction, i.e. orally in standing horses, was evaluated. Hypothesis: The need for and risks of general anaesthesia could be avoided and post extraction sequelae reduced by performing extractions orally in standing horses. Methods: One hundred mainly younger horses (median age 8, range 2-18 years) with firmly attached CT that required extraction because of apical infections, displacements, diastemata, idiopathic fractures and the presence of supernumerary CT had the affected teeth (n = 111) extracted orally under standing sedation. Follow-up information was obtained for all cases, a median of 16 months later. Results: Oral extraction was successful in 89 horses and unsuccessful in 11 due to damage to the CT clinical crown (n = 9) during extraction, for behavioural reasons (n = 1) and because the apex of a partly extracted CT fell back into the alveolus following sectioning (n = 1). Predispositions to extraction-related CT fractures were present in 5 of the 9 cases, i.e. advanced dental caries (n = 2) and pre-existing ,idiopathic' fractures (n = 3). The iatrogenically fractured CT were later repulsed under standing sedation (n = 3) and under general anaesthesia (n = 6). Eighty-one of the remaining 89 horses had successful oral CT extraction with no or minimal intra- or post operative complications occurring. Post operative complications in the other 8 cases included post extraction alveolar sequestration (n = 3), alveolar sequestration and localised osteomyelitis (n = 1), localised osteomyelitis (n = 1), incorporation of alveolar packing material into alveolar granulation tissue (n = 1), and nasal discharge due to continued intranasal presence of purulent food material (n = 1) and to ongoing sinusitis (n = 1). The above sequelae were treated successfully in all cases, with general anaesthesia required in just one case. Following oral extraction, significantly (P<0.001) fewer post operative problems developed in 54 horses with apically infected CT in comparison with 71 previous cases that had repulsion of apically infected CT at our clinic. Conclusions and potential relevance: Oral extraction of cheek teeth is a successful technique in the majority of younger horses with firmly attached CT and greatly reduces the post operative sequelae, compared with CT repulsion. Additionally, the costs and risks of general anaesthesia are avoided. Further experience and refinement in the described protocol could potentially increase the success of this procedure and also reduce the incidence of post operative sequelae. [source] Garnet-filled trails associated with carbonaceous matter mimicking microbial filaments in Archean basaltGEOBIOLOGY, Issue 4 2009K. LEPOT The study of the earliest traces of life on Earth can be complicated by abiotically formed biomorphs. We report here the finding of clustered micrometer-sized filaments of iron- and calcium-rich garnets associated with carbonaceous matter in an agate amygdale from a 2.7-billion-year-old basalt of the Maddina Formation, Western Australia. The distribution of carbonaceous matter and the mineral phases composing the filaments were analyzed using a combination of confocal laser scanning microscopy, laser-Raman micro-spectroscopy, focused ion beam sectioning and transmission electron microscopy. The results allow consideration of possible biogenic and abiotic processes that produced the filamentous structures. The filaments have a range of sizes, morphologies and distributions similar to those of certain modern iron-mineralized filamentous bacteria and some ancient filamentous structures interpreted as microfossils. They also share a high morphological similarity with tubular structures produced by microbial boring activity. However, the microstructures and the distribution of carbonaceous matter are more suggestive of an abiotic origin for the filaments. They are characteristic features of trails produced by the displacement of inclusions associated with local dissolution of their silica matrix. Organic compounds found in kerogen or bitumen inclusions may have contributed significantly to the dissolution of the quartz (or silica gel) matrix driving filamentous growth. Discriminating the products of such abiotic organic-mediated processes from filamentous microfossils or microbial borings is important to the interpretation of the scarce Precambrian fossil record and requires investigation down to the nanoscale. [source] Sentinel node in head and neck cancer: Use of size criterion to upstage the no neck in head and neck squamous cell carcinoma,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 2 2007Lee W. T. Alkureishi MBChB Abstract Background. Anatomical imaging tools demonstrate poor sensitivity in head and neck squamous cell carcinoma (HNSCC) patients with clinically node-negative necks (cN0). This study evaluates nodal size as a staging criterion for detection of cervical metastases, utilizing sentinel node biopsy (SNB) and additional pathology (step-serial sectioning, SSS; and immunohistochemistry, IHC). Methods. Sixty-five patients with clinically N0 disease underwent SNB, with a mean of 2.4 nodes excised per patient. Nodes were fixed in formalin, bisected, and measured in 3 axes before hematoxylin-eosin staining. Negative nodes were subjected to SSS and IHC. SNB-positive patients underwent modified radical neck dissection. Results. Maximum diameter was larger in levels II and III (13.1 and 13.2 mm) when compared with level I (10.5 mm; p = .004, p = .018), while minimum diameter was constant. Positive nodes were larger than negative nodes (p = .007), but nodes found positive by SSS/IHC were not significantly larger than negative nodes for either measurement (p = .433). Sensitivity and specificity were poor for all measurements. Conclusions. Nodal size is an inaccurate predictor of nodal metastases and should not be regarded as an accurate means of staging the clinically N0 neck. © 2006 Wiley Periodicals, Inc. Head Neck, 2006 [source] Metastatic melanoma volume in sentinel nodes: objective stereology-based measurement predicts disease recurrence and survivalHISTOPATHOLOGY, Issue 7 2009Rikke Riber-Hansen Aims:, Sentinel lymph node (SLN) status is the most important prognostic factor in intermediate thickness melanoma. The amount of metastatic disease in positive SLNs varies greatly between patients, and this tumour burden appears to influence the prognosis of node-positive patients. The aim was to use objective stereological techniques to correlate accurately total SLN tumour burden with recurrence and patient survival. Methods and results:, SLNs from 327 patients were examined by complete step sectioning and immunohistochemistry. The total metastasis volume (TMV) of 156 positive SLNs from 99 patients (30.3%) was measured using stereological methods based on the 2D-nucleator and Cavalieri's principle. The maximum metastasis diameter was also measured. These two measurements were correlated with disease recurrence and patient survival. The mean TMV for SLN+ patients was 10.5 mm3 (median 0.05 mm3; range 0.0001,623.7 mm3). Median follow-up was 26.3 months. On multivariate analysis, TMV was an independent predictor of recurrence when corrected for primary tumour thickness (P = 0.001) and was a stronger prognosticator compared with the maximum metastasis diameter (P < 0.0001 versus P = 0.01). Conclusions:, Combining total step sectioning of SLNs with stereological assessment of metastases, we found metastasis volume to be a highly significant predictor of disease recurrence and survival. [source] Detailed examination of lymph nodes improves prognostication in colorectal cancerINTERNATIONAL JOURNAL OF CANCER, Issue 11 2010Fania S. Doekhie Abstract Up to 30% of stage II patients with curatively resected colorectal cancer (CRC) will develop disease recurrence. We evaluated whether examination of lymph nodes by multilevel sectioning and immunohistochemical staining can improve prognostication. Lymph nodes (n = 780) from 36 CRC patients who had developed disease recurrence (cases) and 72 patients who showed no recurrence of disease for at least 5 years (controls) were analyzed. Sections of 4 levels at 200-,m interval were immunohistochemically stained for cytokeratin expression. The first level was analyzed by conventional and automated microscopy, and the 3 following levels were analyzed by automated microscopy for the presence of tumor cells. Overall, cases showed more micrometastases (3 patients) than controls (1 patient). Analysis of a second level led to the additional detection of 1 patient with micrometastases (case) and 1 patient with macrometastasis (case). Examining more levels only led to additional isolated tumor cells, which were equally divided between cases and controls. Likewise, automated microscopy resulted only in detection of additional isolated tumor cells when compared with conventional microscopy. In multivariate analysis, micrometastases [odds ratio (OR) 26.3, 95% confidence interval (CI) 1.9,364.8, p = 0.015], T4 stage (OR 4.8, 95% CI 1.4,16.7, p = 0.013) and number of lymph nodes (OR 0.9, 95% CI 0.8,1.0, p = 0.028) were independent predictors for disease recurrence. Lymph node analysis of 2 levels and immunohistochemical staining add to the detection of macrometastases and micrometastases in CRC. Micrometastases were found to be an independent predictor of disease recurrence. Isolated tumor cells were of no prognostic significance. [source] Rapid detection of metastasis of gastric cancer using reverse transcription loop-mediated isothermal amplificationINTERNATIONAL JOURNAL OF CANCER, Issue 5 2007Daisuke Horibe Abstract Tailor-made surgeries for patients with solid malignancies have been under consideration on the basis of the development of new approaches for minor metastatic foci of malignant tumors. Accurate and reliable methods to detect metastases in biopsy specimens with certain rapidity are essential for the performance of these surgeries. The aim of this study was to develop a rapid and practical method to detect metastasis in specimens from patients with gastric carcinoma with the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) reaction, a novel technique for detecting mRNA expressions of targeted sequences with high sensitivity, specificity and rapidity under isothermal conditions. RT-LAMP primers to detect cytokeratin19 (CK19) mRNA were generated and 92 lymph nodes (LNs) obtained from 9 patients with gastric cancer were tested for tumor metastases with this technique. Among 92 LNs, 15 were metastasis-positive by routine histopathological examination. RT-LAMP reaction detected CK19 expression in all of the pathologically positive LNs and in 16 of 77 negative LNs. Nested RT-PCR assay for CK19 expression was also performed on 2 of the 9 cases including 32 LNs. The agreement rate of CK19 expression detection by RT-LAMP and RT-PCR analysis was 31/32 (97%). The RT-LAMP technique showed similar sensitivity to detect metastases as nested RT-PCR assay, with a rapidity comparable to that of intraoperative histopathological examination with frozen sectioning and hematoxylin and eosin staining. This method is expected to play an essential role in the performance of tailor-made surgeries in the near future. © 2006 Wiley-Liss, Inc. [source] A test of two methods of radiographically deriving long bone cross-sectional properties compared to direct sectioning of the diaphysisINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2002Jay T. Stock Abstract Numerous studies have made use of cross-sectional geometry to describe the distribution of cortical bone in long bone diaphyses. Several methods can be used to measure or estimate cross-sectional contours. Direct sectioning (DSM) of the diaphysis is not appropriate in most curatorial contexts, and is commonly substituted with methods based upon bi-planar radiography: a latex cast method (LCM) or an eccentric elliptical method (EEM). Previous studies have demonstrated that the EEM provides accurate estimates of area measurements, while providing less accurate estimates of second moments of area (Biknevicius & Ruff, 1992; Runestad et al., 1993; Lazenby, 1997). The LCM has been commonly employed, as a way to estimate section contours more accurately, yet the validity of this method has not been adequately documented. This study measures the agreement of these methods against DSM of long bone diaphyses using 21 sections of canine tibiae derived from a study of total hip arthroplasty. The accuracy and agreement of these methods is evaluated using reduced major axis regression, paired sample t-tests and tests for agreement (Bland & Altman, 1986). The results illustrate that the LCM provides a reasonable estimate of cross-sectional dimensions, producing cross-sectional properties that are on average within 5% of properties derived from the DSM. The EEM is found to provide adequate estimates of true cross-sectional areas, but poor estimates of second moments of area. The use of the LCM is supported for all cross-sectional properties, but the EEM is only accurate in total area, cortical area and percent cortical area estimates. Copyright © 2002 John Wiley & Sons, Ltd. [source] X-ray fluorescence microprobe imaging in biology and medicineJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2006Tatjana Paunesku Abstract Characteristic X-ray fluorescence is a technique that can be used to establish elemental concentrations for a large number of different chemical elements simultaneously in different locations in cell and tissue samples. Exposing the samples to an X-ray beam is the basis of X-ray fluorescence microscopy (XFM). This technique provides the excellent trace element sensitivity; and, due to the large penetration depth of hard X-rays, an opportunity to image whole cells and quantify elements on a per cell basis. Moreover, because specimens prepared for XFM do not require sectioning, they can be investigated close to their natural, hydrated state with cryogenic approaches. Until several years ago, XFM was not widely available to bio-medical communities, and rarely offered resolution better then several microns. This has changed drastically with the development of third-generation synchrotrons. Recent examples of elemental imaging of cells and tissues show the maturation of XFM imaging technique into an elegant and informative way to gain insight into cellular processes. Future developments of XFM,building of new XFM facilities with higher resolution, higher sensitivity or higher throughput will further advance studies of native elemental makeup of cells and provide the biological community including the budding area of bionanotechnology with a tool perfectly suited to monitor the distribution of metals including nanovectors and measure the results of interactions between the nanovectors and living cells and tissues. J. Cell. Biochem. 99: 1489,1502, 2006. © 2006 Wiley-Liss, Inc. [source] Lateral ridge augmentation by the use of grafts comprised of autologous bone or a biomaterial.JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 12 2002An experiment in the dog Abstract Objective: The present investigation was performed to determine if a block of Bio-Oss® used as an onlay graft can be used as a scaffold for new bone formation. Material and methods: Five mongrel dogs were used. The mandibular premolars were extracted. On both sides of the mandible, the buccal bone plate was resected and defects, about 25 mm long, 8 mm high and 5 mm wide, were produced After 3 months of healing, a second surgical procedure was performed. In the left side, a block of Bio-Oss® was adjusted to the buccal bone wall. The graft had the shape of a cylinder and was retained with a miniscrew and covered with a collagen membrane. In the contra-lateral side of the mandible, a block biopsy was first obtained from the ascending ramus. This bone graft had the shape of a cylinder that was 8 mm in diameter and 3 mm thick. The graft was transferred to the experimental site, adjusted to the buccal wall, retained with a miniscrew, and covered with a membrane. The flaps were repositioned and closed with sutures to ensure a complete coverage of the experimental sites. After 6 months of healing, the dogs were sacrificed and the experimental sites dissected. The biopsies were processed for ground sectioning. The sections were stained in toluidine blue, examined in the microscope, and a number of histo- and morphometric assessments made. Results: The study demonstrated that cortical bone used as an onlay graft in the lateral aspect of the alveolar ridge, during a 6-month period of healing integrated with the host bone but underwent marked peripheral resorption. Thus, close to 30% of the height and 50% of the length of the graft was replaced with connective tissue. It was further observed that while the dimensions of a graft which contained a scaffold of cancellous bovine bone mineral remained unchanged, only moderate amounts of new bone formed at the base of this graft. Conclusion: Grafts of autologous cortical bone, placed on the surface of a one-wall defect, may undergo marked resorption during healing. A similar graft of Bio-Oss® may retain its dimension, and limited amounts of new bone will form within the biomaterial. [source] Lymphedematous HIV-associated Kaposi's sarcomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 7 2006Pratistadevi K. Ramdial Background:, Advanced Kaposi's sarcoma is frequently associated with chronic lymphedema (cLO). The histopathological features of lymphedematous HIV-associated KS (KS) are poorly documented and the co-existence of fibroma-like nodules in lymphedematous KS is under-recognized. The aims of this study were to assess the clinicopathological spectrum and diagnostic difficulties associated with lymphedematous KS and to highlight the clinicopathological profile of fibroma-like nodules. In addition, the pathogenesis of fibroma-like nodules and cLO is revisited. Materials and methods:, Prospective 17-month clinicopathological study of all biopsies from patients with lymphedematous KS. Results:, Seventy-four biopsies, the majority from the lower limbs, from 41 patients were evaluated. Nineteen, 14, five and three patients had one, two, three or four biopsies each, respectively. In 14 biopsies, there was poor clinicopathological correlation of KS stage. Exclusive lesional KS (patch, plaque, nodule or lymphangioma-like) was identified in 29 biopsies; 23 and eight biopsies demonstrated KS or fibroma-like morphology and the adjacent dermis demonstrated cLO. There was variable intratumoral and peritumoral venous compression and lymphatic dilatation. Fourteen biopsies demonstrated cLO exclusively. Smaller fibroma-like nodules lacked KS spindle cells, whereas >5 mm nodules demonstrated focal KS spindle cell proliferation and aggregation on extensive sectioning. The subcutis of 42 biopsies demonstrated variable fibrosis, hemosiderin deposits, lymphocytes, plasma cells, KS, interstitial granular material and pools of lymph fluid. Subcutaneous abscesses were identified in six biopsies. All biopsies had variable epidermal features of cLO. Conclusions:, cLO influences clinicopathological correlation of KS stage and may also mask the presence of KS and the co-existence of subcutaneous abscesses. Smaller fibroma-like nodules are hypothesized to be a manifestation of cLO that have the potential to acquire the characteristics of KS. Lymphatic and venous obstruction, protein-rich interstitial fluid, tissue hemosiderin and subcutaneous infection are hypothesized to play a combined role in the evolution and perpetuation of cLO. [source] Early development of the chondrocranium in Salmo letnica(Karaman, 1924)(Teleostei: Salmonidae)JOURNAL OF FISH BIOLOGY, Issue 2 2006M. Ristovska The ontogenetic development of the chondrocranium of Ohrid trout Salmo letnica was studied from hatching until 92 days post-hatching (dph). Most of the samples were in toto trypsin cleared and stained, some specimens were used for serial histological sectioning. The serial histological sections of fish specimens at the age of 92 dph were used for a graphical reconstruction of the cartilaginous neurocranium. A chronological evaluation of the formation of the cartilaginous skull in the early development of S. letnica was performed. In order to investigate to what degree the ontogeny of the Ohrid trout is unique, the results were compared with data of the development of other salmonids, as well as some non-salmonid teleosts. The development of the cartilaginous structures of the Ohrid trout was found to be similar to that of other salmonids. Most of the cartilage structures of the neurocranium and the viscerocranium are present at the moment of hatching of this species. A fully developed chondrocranium was observed at the age of 92 dph, when the first signs of cartilage resorption could also be observed. [source] Mirrored pyramidal wells for simultaneous multiple vantage point microscopyJOURNAL OF MICROSCOPY, Issue 1 2008K.T. SEALE Summary We report a novel method for obtaining simultaneous images from multiple vantage points of a microscopic specimen using size-matched microscopic mirrors created from anisotropically etched silicon. The resulting pyramidal wells enable bright-field and fluorescent side-view images, and when combined with z -sectioning, provide additional information for 3D reconstructions of the specimen. We have demonstrated the 3D localization and tracking over time of the centrosome of a live Dictyostelium discoideum. The simultaneous acquisition of images from multiple perspectives also provides a five-fold increase in the theoretical collection efficiency of emitted photons, a property which may be useful for low-light imaging modalities such as bioluminescence, or low abundance surface-marker labelling. [source] Vitreous cryo-sectioning of cells facilitated by a micromanipulatorJOURNAL OF MICROSCOPY, Issue 2 2006MARK S. LADINSKY Summary Sectioning vitrified cells and tissues for cryo-electron microscopy is more challenging than room-temperature sectioning of plastic-embedded samples. As the sample must be kept very cold (<,130 °C) and because there is no liquid upon which the sections can float as they are cut, transferring the sections from the knife edge to a grid is one of the more difficult steps in the process. We employed a micromanipulator to hold and control the cryo-sections as they come off the knife. This allows slower cutting speeds than are typically used in vitreous cryo-sectioning and contributes to better control during cutting, which facilitates repeatable placement of a ribbon of sections onto a grid. The ribbon is kept under tension during the entire cutting process, which may decrease folding and/or compression, features that are inherent to vitreous sections. Furthermore, the added control afforded by this technique makes it easier for multiple ribbons to be placed on a single grid, thereby increasing the number of sections that can be examined and imaged during a microscopy session. It even allows for serial cryo-electron microscopy. As such, this approach is an advance in the cryo-microtomy of vitreous sections. [source] Cryoimmobilization and three-dimensional visualization of C. elegans ultrastructureJOURNAL OF MICROSCOPY, Issue 1 2003T. Müller-Reichert Summary Caenorhabditis elegans is one of the most important genetic systems used in current biological research. Increasingly, these genetics-based research projects are including ultrastructural analyses in their attempts to understand the molecular basis for cell function. Here, we present and review state-of-the-art methods for both ultrastructural analysis and immunogold localization in C. elegans. For the initial cryofixation, high-pressure freezing is the method of choice, and in this article we describe two different strategies to prepare these nematode worms for rapid freezing. The first method takes advantage of transparent, porous cellulose capillary tubes to contain the worms, and the second packs the worms in E. coli and/or yeast paste prior to freezing. The latter method facilitates embedding of C. elegans in a thin layer of resin so individual worms can be staged, selected and precisely orientated for serial sectioning followed by immunolabelling or electron tomography. [source] Upregulation of intracellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 after unilateral nerve injury in the peripheral taste systemJOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2007Melissa Ann Cavallin Abstract In the peripheral taste system, activated macrophages are recruited to both sides of the tongue after unilateral sectioning of the chorda tympani nerve (CT). Neural degeneration elicits macrophage entry in other systems by upregulating vascular adhesion molecules. We hypothesized that CT sectioning leads to a bilateral increase in intracellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 expression on lingual vessels. To test this hypothesis, rats were euthanized at time points from 6 hr to 7 days post-sectioning. Frozen sections of tongue were processed for immunohistochemical staining for ICAM-1 and VCAM-1. Tongue homogenates from additional rats were analyzed with ELISA. ICAM-1 expression increases first on the denervated side of the tongue at 24 hr post-section and then on the uninjured side at 48 hr post-section. ICAM-1 remains elevated through Day 7 post-sectioning on both sides of the tongue. Dietary sodium restriction, which prevents the macrophage response to nerve sectioning, had no effect on ICAM-1 levels. VCAM-1+ vessels are increased on the denervated side of the tongue at 24,48 hr post-section in control-fed rats. However, dietary sodium restriction prevents the increase. These results indicate that vascular adhesion molecules are differentially regulated by CT sectioning. We suggest that macrophage entry, migration, and modulation of taste function are downstream of dynamic expression of adhesion molecules. © 2006 Wiley-Liss, Inc. [source] Tendon-defect and muscle-unloaded models for relating a rotator cuff tear to glenohumeral stabilityJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2000Horng-Chaung Hsu Rotator cuff tear and glenohumeral instability are closely related. Any tear may disturb muscle force generation due to pain inhibition. In addition, a full-thickness tear may foster instability by removing a structural element constraining the joint. It was hypothesized that the loss of both dynamic force and static constraint with a rotator cuff tear will affect glenohumeral stability. In a tendon-defect model, dynamic and static elements of the joint were sacrificed. In a muscle-unloaded model, only the dynamic element was removed. The location and size of the defect were also investigated. The effect on instability of a small tendon defect was less than that of muscle unloading, implying that a patient with a small tear would have less instability than a patient with weak or nonfunctioning supraspinatus and infraspinatus muscles. On the other hand, with a larger tear the defect had a greater effect than muscle-unloading because sectioning of the glenohumeral and coracohumeral ligaments was included in the model. Clinically, such a defect in the front is critical for anterior stability because it might insult the important anterior capsule ligamentous complex. Orthopaedic surgeons should pay attention, therefore, to the effect of possible associated lesions of static constraints based on the size and location of the tear in addition to the dynamic stabilizer. [source] Quantification of soil structural changes induced by cereal anchorage failure: Image analysis of thin sectionsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 3 2007Sacha J. Mooney Abstract Cereal anchorage failure, or lodging, is the permanent displacement of a crop from the vertical and results in significant annual yield losses globally. Several factors have been identified as contributors to this phenomenon but the precise mechanisms of failure are still largely unknown because of difficulties in observing these processes as they occur in situ. To identify potential soil management practices to minimize losses associated with cereal root failure, an understanding of the nature of root-soil interactions attributed to lodging is needed. An experiment was conducted that involved field impregnation and subsequent thin sectioning of lodged and unlodged root-soil complexes from contrasting soils, cereal crops, and management practices to elucidate the effects of lodging on soil structure and porous architecture. Using image analysis, size and distribution of pores in soils were quantified at both meso- (100,30 ,m) and microscales (<30 ,m). A significant effect of lodging on porosity was recorded whereby lodging reduced total porosity through compaction created by movement of the stem base, although this was variable among soil types. Pore-size distributions comprehensively supported these trends since alteration in the relative frequency of pores within specific size classes was clearly observed. The effects of lodging were more pronounced at the mesoscale because the data were more susceptible to variations created by natural soil heterogeneity at the microscale. These data suggested that sideways movement of the subterranean stem within the soil is a significant factor which is likely to affect the propensity for a cereal plant to lodge, indicating soil strength in the upper part of the soil profile is crucial. [source] | ||||||||||||||||||||||||||||||||||||||||