Home About us Contact
|
Home About us Contact | ||
|
|
||
Electron Microscopic Study (electron + microscopic_study)
Kinds of Electron Microscopic Study Selected AbstractsLight and Scanning Electron Microscopic Study on the Tongue and Lingual Papillae of the Common Hippopotamus, Hippopotamus amphibius amphibiusTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 7 2009Ken Yoshimura Scanning electron microscopic micrograph of the connective tissue core of fungiform papillae distributed in the dorsal surface of the tongue in the common hippopotamus (Hippopotamus amphibius amphibius). There are various kinds of lingual papillae distributed on the dorsal surface of the tongue among mammal species. It has been revealed that there were morphological differences found on each lingual papilla; filiform, fungiform, conical, foliate, and vallate papillae depend on the mammalian species, especially on the connective tissue cores beneath the epithelial surface. The fungiform connective tissue core of hippopotamus exhibited are quite similar to those found in the other artiodactyls; however, it lacked other typical morphological types of the lingual papillae found on the artiodactyl species. The unique mosaic-like morphological characteristics of the hippopotamus' lingual papillae may represent the unique evolutional or dietary background of this species. See Yoshimura et al., on page 921, in this issue. (Scanning electron micrograph courtesy of the authors). [source] A Light and Scanning Electron Microscopic Study of the Closing Apparatus in Tintinnid Ciliates (Ciliophora, Spirotricha, Tintinnina): A Forgotten SynapomorphyTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 4 2010SABINE AGATHA ABSTRACT. A membranous closing apparatus shuts the lorica opening in disturbed tintinnids of six genera belonging to four families. The homology of the apparatuses is investigated, using data from the literature and Mediterranean tintinnids studied in vivo and by scanning electron microscopy. Morphological and functional similarities indicate that the foldable closing apparatus is not only a synapomorphy of the genera Codonella (Codonellidae) and Dictyocysta (Dictyocystidae), as suggested 80 years ago, but also of Codonaria (Codonellidae) and Codonellopsis (Codonellopsidae). In Codonaria, Codonella, and Dictyocysta, the apparatuses merge posteriorly into membranous lorica sacs, which probably represent homologous structures. The diagnoses of these genera are improved according to the new findings. The close relationship of Codonella, Codonellopsis, and Dictyocysta is also inferred from small subunit rRNA phylogenies and the ultrastructure of the capsules. It contradicts the current lorica-based classification of the tintinnids. The assumption that the diaphragm-like apparatus in the genera Salpingacantha and Salpingella is not homologous to the foldable ones in the genera mentioned above is supported by molecular and cytological features. [source] Scanning Electron Microscopic Study of the Lingual Papillae in the Arctic Fox (Alopex lagopus L., 1758)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2009H. Jackowiak Summary This study aims to show the distribution and the three-dimensional structure of the lingual papillae in the arctic fox. The macro- and microscopic structure of the tongue and its lingual papillae was studied in 11 adult arctic foxes. Two types of mechanical papillae were distinguished on the dorsal surface of the tongue , filiform papillae and conical papillae. The gustatory papillae in the arctic fox are represented by fungiform, vallate and foliate papillae. The keratinized filiform papillae on the anterior part of tongue are composed of one big posterior process accompanied by 10,12 secondary anterior processes. The number of anterior processes of filiform papillae undergo a complete reduction within the area between the posterior part of the body of the tongue and area of the vallate papillae. The conical papillae cover the whole dorsal surface of the root of the tongue, including the lateral parts surrounding the area of the vallate papillae and the posterior part of the root. The size of the conical papillae increases towards the root of the tongue but their density decreases. In the arctic fox, there are three pairs of vallate papillae distributed on the plan of a triangle. The diameter of vallate papillae in each successive pair is bigger. The wall surrounding the body of the vallate papilla and its gustatory trench is composed of six to eight conical papillae joined at various degree. The foliate papillae on both margins of the tongue consist of seven to nine laminae. [source] Electron Microscopic Study of the Porcine Choroid Plexus EpitheliumANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2008W. De Spiegelaere Summary The choroid plexus (CP) is a highly vascularized organ in the brain ventricles which acts as the main producer of cerebrospinal fluid (CSF). A study of the surface ultrastructure of the porcine CP was performed using scanning and transmission electron microscopy. The vascular walls of the capillaries were fenestrated. Epiplexus cells of different morphology were abundant on top of the epithelial surface. Two types of epithelial cells were present, characterized by the presence or absence of microvilli. Some epithelial cells contained cilia while other cells had large secretory protrusions called blebs. In the choroid epithelium of the lateral ventricles, some cells with large depressions were present. Cells with peduncles, such as recently discovered in the buffalo, could not be recognized. The variability of the choroidal surface structures clearly indicates the active role of the CP in the formation and maintenance of the CSF and its components. [source] Light and Scanning Electron Microscopic Study on the Blood Vascular System of the Donkey PlacentaANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2008A. Saber Summary The donkey placenta is diffuse and epitheliochorial with numerous microplacentomes consisting of a fetal microcotyledonary and a maternal microcaruncular part. The microplacentomal vasculature during the last third of pregnancy has been investigated by light microscopy in comparison to scanning electron microscopy of the materno-fetal contact surface and corrosion casts of blood vessels after plastic instillation from either the microcotyledonary or the microcaruncular side, and, for the first time in a perissodactyle, from both sides. Morphological data were semiquantitatively evaluated. The supplying parts of both, the microcotyledonary and the microcaruncular vascular system are strictly proximo-distally oriented, thus reaching the capillary systems or working parts in the shortest way possible. The straight course of the vasculature, particularly on the fetal side, suggests the occurrence of venulo-arteriolar back diffusion. The fetal capillary system consists of convolutes confronting the maternal septal capillary complexes in a countercurrent way. This materno-fetal blood flow interrelationship is highly efficient in terms of placental exchange, which is further supported (1) by dilations and increasing coiling of the fetal venular capillary limbs in particular and (2) by a decrease in the interhaemal distance from 12.5 to 7.2 ,m between the two capillary systems. Besides the countercurrent blood flow interrelationship, some maternal branch arterioles reach the septal capillary system from the maternally oriented pole of the microplacentome or microcaruncle, respectively, resulting in the less efficient crosscurrent blood flow. Hence, in the donkey placenta fetal and maternal blood vessels meet in a mix of countercurrent and crosscurrent flow patterns. [source] The Spleen of Zaedyus pichiy, (Mammalia, Dasypodidae): a Light and Electron Microscopic StudyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2003E. J. Galíndez Summary Armadillos are ancient mammals important as models for biomedical, evolutive and ecological studies, because they have adaptive and primitive morpho-physiological characteristics. In this work we study the splenic microarchitecture of the ,Patagonian Piche', Zaedyus pichiy, as an attempt to understand the relationship between the organizational plan of the organ and the particular features of this species. The organ samples were classically processed for light and electron microscopic study. The microanatomy of the organ as well as its different cell types are studied. The spleen is non-sinusoidal, with the typical arrangement for storage functions. White pulp is well defined. Red pulp is a meshwork of circulating, immunocompetent and haemopoietic cells. The general structure of the organ agrees with the semi-fossorial habit and the adaptability of the species. Comparative aspects with other armadillos or other less specialized groups are discussed. Persistence of haemopoietic spleen activity in the adult suggests the existence of specific inductive functions of the stroma. Better knowledge of spleen structure and function in ancient mammals may give important information about their phylogeny. [source] Light and Electron Microscopic Study of the Thyroid Gland of the Camel (Camelus dromedarius)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2000E. M. Abdel-Magied The thyroid gland of sexually immature dromedary camels was studied using both light and electron microscopy. The thyroid gland contained follicles of different sizes in both summer and winter. However, most of the follicles were large in summer and small in winter. The large follicles were lined by very low cuboidal or semi-squamous follicular cells whereas the small ones were lined by high cuboidal or low columnar follicular cells. Electron microscopy showed that the very low cuboidal follicular cells were poor in organelles and were considered hypoactive. High cuboidal follicular cells on the other hand, were rich in organelles that included mitochondria, cisternae of rough endoplasmic reticulum, secretory vesicles, colloid droplets, heterosomes and autophagic vacuoles; they were considered to be very active. The possible role played by these organelles in synthesis of thyroglobulin and liberation of tri- and tetraiodothyronine is discussed. A few degenerate follicular cells were infrequently encountered in the camel thyroid. Parafollicular (C) cells were not seen in this study either with light or electron microscopy. [source] Electron microscopic study to compare preclinical Cushing's syndrome with overt Cushing's syndromeINTERNATIONAL JOURNAL OF UROLOGY, Issue 4 2002Daisaku Hirano Abstract Background: No significant differences in gross and light- microscopic features have been reported between preclinical and overt Cushing's adenomas. In this study, the ultrastructural differences between the two syndromes was attempted to be clarified. Methods: Two preclinical Cushing's syndrome adenomas and two overt Cushing's syndrome adenomas obtained from surgical extirpation were examined in an electron microscopic study. Results: Light microscopically, the adenomas of both syndromes were composed predominantly of clear cells, with few compact cells. Ultrastructurally, the prominent differences were of development in each organelle: the preclinical Cushing's adenomas had undeveloped mitochondria, which were smaller in size and had sparse cristae, lysosomes and polysomes, whereas the overt Cushing's adenomas contained well-developed mitochondria which were larger in size and were filled with abundant cristae, smooth endoplasmic reticulum (SER), lysosomes and polysomes. Conclusions: Preclinical Cushing's syndrome adenomas were ultrastructurally characterized by a reduced number of cellular organelles such as mitochondria and SER, which are necessary to synthesize glucocorticoid hormones. However, examination of a greater number of adenomas will be required to be able to draw conclusions on the ultrastructural differences between the two syndromes. [source] Critical roles of VEGF-C-VEGF receptor 3 in reconnection of the collecting lymph vessels in miceMICROCIRCULATION, Issue 7 2008FUMITAKA IKOMI M.D, Ph.D ABSTRACT Molecular mechanisms of reconnection of collecting lymph vessels were analyzed by using murine popliteal prenodal lymph vessels. At 1 and 2 weeks after being divided by cutting the lymph vessel, lymphatic reconnection was frequently observed accompanied by mesh-like lymphatic channels. Electron microscopic study also showed a monolayer of endothelial cells in the newly developed lymph vessels. Smooth muscle markers were immunofluorescently demonstrated in the wall of the new vessels. At 1 week after the procedure of cutting, augmented expressions of VEGF receptors 1, 2 and 3 were found immunohistochemically at the site of the reconnected lymph vessels. The expression of mRNA for VEGF receptor 3 was enhanced at 5 days and 1 week in small pieces of the tissues containing the reconnected lymph vessels, compared with that in the corresponding tissues obtained with sham operated ones. The administration of VEGF-C at the cutting site of the collecting lymph vessel significantly increased the rate of the reconnected lymph vessels, whereas additional treatment with Flt4/Fc chimera protein significantly reduced the rate of the reconnected ones. These results suggest that activation of VEGF-C-VEGF receptor 3 has critical roles in reconnection of the collecting lymph vessels in adult mice. [source] Light and electron microscopic study of the anterior oesophagus of Bulla striata (Mollusca, Opisthobranchia)ACTA ZOOLOGICA, Issue 2 2010Alexandre Lobo-da-Cunha Abstract Lobo-da-Cunha, A., Oliveira, E., Alves, Â., Coelho, R. and Calado, G. 2010. Light and electron microscopic study of the anterior oesophagus of Bulla striata (Mollusca, Opisthobranchia). ,Acta Zoologica (Stockholm) 91: 125,138. The anterior oesophagus of Bulla striata was investigated with light and electron microscopy. In the most anterior region, the ridges of the oesophageal wall are covered by a ciliated columnar epithelium forming large apical blebs which are released into the lumen, an activity that is particularly intense in the oesophageal pouch. In the last two-thirds of the anterior oesophagus, the epithelium is covered with microvilli embedded in a cuticle, but apocrine secretion and cilia are absent. Subepithelial secretory cells are very abundant in the oesophageal wall, except in the roof of the pouch. They have a long neck that crosses the epithelium, whereas the cell body containing the nucleus is embedded in the connective tissue. Large electron-lucent secretory vesicles and many Golgi stacks fill most of their cytoplasm. The histochemical and cytochemical assays show that these cells secrete acid mucopolysaccharides. With the current and future studies we aim to obtain data for the establishment of relationships between morphofunctional features of the digestive system and food types in cephalaspideans. Additionally, the new data about the oesophageal pouch of B. striata may be useful for the establishment of eventual homologies with the oesophageal diverticula of other opisthobranchs. [source] Desmocollin 1 expression and desmosomal remodeling during terminal differentiation of human anagen hair follicle: an electron microscopic studyEXPERIMENTAL DERMATOLOGY, Issue 5 2004Elena Donetti Abstract:, The terminal differentiation (TD) program of keratinocytes of the human hair follicle (HF) occurs with specific temporal and spatial features in the various layers of the inner root sheath (IRS) and in the innermost layer of the outer root sheath (companion layer). This process is characterized by complex nuclear and cytoplasmic morphological changes, accompanied by profound modifications in intercellular junctions. As no correlation exists between the structure and the molecular composition of desmosomes during TD of the IRS/companion unit, the aim of our study was to investigate by transmission electron microscopy the remodeling of desmosomes in keratinizing cells of these compartments. By immunogold post embedding technique, we studied in anagen HFs the modulation of the synthesis of desmocollin 1 (Dsc1), a transmembrane glycoprotein specifically synthesized in the IRS and in the companion layer. Dsc1 immunoreactivity was actually confined to these compartments and tended to increase just before the level of TD, particularly in the Henle's layer and in the IRS cuticle. In Huxley's layer, the immunolabeling was patchy and in the companion layer Dsc1 synthesis was detected above the level of keratinization of Huxley's layer. In the whole IRS, concomitantly with TD, there was an abrupt and almost complete disappearance of Dsc1 synthesis. An asymmetric distribution of Dsc1 was noticed (i) between cells at different stages of differentiation and (ii) between cells belonging to layers with different spatial/temporal features of TD. Our results show that the ultrastructural modifications of desmosomes during TD of HF are paralleled by the modulation of the synthesis of desmocollin 1. [source] Lysosomal abnormalities during benzo(a)pyrene-induced experimental lung carcinogenesis , defensive role of capsaicinFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 1 2009P. Anandakumar Abstract The objective of the present study was to investigate whether lysosome is a target in benzo(a)pyrene-induced, oxidative stress-mediated lung cancer in Swiss albino mice and the plausible role of the phytochemical substance capsaicin in mitigating lysosomal damage. Oxidative stress was assessed based on the level of carbonyl content. The activities of lysosomal proteases like cathepsin-D, cathepsin-B, ,- d -glucosidase, ,- d -galactosidase, ,- d -glucuronidase, ,- d - N -acetylglucosaminidase and acid phosphatase were assessed to evaluate lysosomal function. Administration of benzo(a)pyrene (50 mg/kg body weight) to mice induced a increase in the activities of lysosomal enzymes and oxidative stress was evident by the increase in carbonyl content. Treatment with capsaicin (10 mg/kg body weight) decreased carbonyl content and restored the activities of lysosomal enzymes to near normalcy. Transmission electron microscopic study of lysosomes further showed the defensive action of capsaicin against the lysosomal damage caused in benzo(a)pyrene-induced lung cancer. From the present study, it can be concluded that lysosomal damage is an indispensable event in benzo(a)pyrene-induced lung cancer, and capsaicin was able to effectively prevent it, which proves the chemoprotective effect of capsaicin against benzo(a)pyrene-induced experimental lung carcinogenesis. [source] Effectiveness in cleaning oval-shaped root canals using Anatomic Endodontic Technology, ProFile and manual instrumentation: a scanning electron microscopic studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2005O. Zmener Abstract Aim, To compare in vitro the cleanliness of root canal walls in oval-shaped root canals following automated or manual instrumentation. Methodology, Forty-five oval-shaped single-rooted maxillary and mandibular premolars with straight canals were divided into three groups of 15. Automated canal preparation was performed using Anatomic Endodontic Technology (AET, group 1) and the ProFile system (group 2). Manual instrumentation (group 3) was performed with K-Flexofiles. Irrigation was performed using alternately 5.25% NaOCl and 17% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined at ×200 and ×400 in a scanning electron microscope. The presence of debris and smear layer was recorded at distances of 1, 5 and 10 mm from the working length using a three-step scoring scale and a 300 ,m square grid. Mean scores for debris and smear layer were calculated and statistically analysed for significance (P < 0.05) between and within groups, using the Kruskal,Wallis nonparametric anova and Dunn's tests. Results, At 1, 5 and 10-mm levels the root canals prepared with AET had significantly less surface debris and smear layer on the canal walls compared with canals prepared with ProFile or manual instrumentation. For all three groups significantly lower mean smear layer scores (P < 0.05) were recorded at 5 and 10-mm levels compared with the 1 mm level. Significantly lower mean debris scores (P < 0.05) were also recorded at 5 and 10-mm levels for the AET group whereas no significant differences were found between the three levels for the ProFile and manual instrumentation groups. Conclusions, Although better instrumentation scores were obtained in canals prepared with AET, complete cleanliness was not achieved by any of the techniques and instruments investigated. [source] Effects of rotary instruments and ultrasonic irrigation on debris and smear layer scores: a scanning electron microscopic studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2002B. E. Mayer Abstract Aim This study evaluated debris and smear layer scores after two types of instruments manufactured from different alloys were used to ultrasonically activate irrigants during canal preparation. The influence of two rotary preparation techniques on cleanliness of the shaped canals was also studied. Methodology Apical stops were prepared to size 45 in 42 single-canalled extracted premolars and canines, which were divided into six equal groups. Groups 1, 2 and 3 were prepared by ProFile .04 (PF) while groups 4, 5 and 6 were prepared by Lightspeed (LS). All groups were irrigated using 5.25% NaOCl and 17% EDTA. Irrigants in groups 2 and 5 were ultrasonically activated using a size 15 steel K-file and by a blunt flexible nickel,titanium wire in groups 3 and 6. Groups 1 and 4 served as negative controls. Roots were split and canal walls examined at 15×, 200× and 400× magnification in an SEM. Smear layer and debris scores were recorded at 3, 6 and 9 mm levels using a 5-step scoring scale and a 200-µm grid. Means were tested for significance using nonparametric Mann,Whitney U and Kruskal,Wallis tests. Results Debris and smear layer scores for the six groups varied from 1.98 ± 1.04 to 3.47 ± 0.97 and from 1.37 ± 0.4 to 2.36 ± 0.99, respectively. Although all groups had significantly higher smear layer and debris scores at the 3 mm levels compared to the 9 mm levels (P < 0.05), no significant differences were recorded due to the ultrasonic energy transmitted by the two alloys. Conclusion Ultrasonically activated irrigants did not reduce debris or smear layer scores. This finding was not influenced by the material nor by the design of the instrument used to transmit ultrasonic activation. [source] A scanning electron microscopic study of debris and smear layer remaining following use of GT rotary instrumentsINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2002G. Gambarini Abstract Aim The aim of the present study was to assess debris and smear layer remaining following canal preparation with GT rotary instruments. Methodology Sixteen freshly extracted single-rooted premolar teeth were instrumented with GTÔ rotary instruments using a crown-down preparation technique. All specimens were flushed with 2 mL of 5% NaOCl between each rotary instrument. At the end of instrumentation the following final irrigation sequence was repeated two times: 2 mL of EDTA + Cetrimide for 1 min (Largal Ultra, Septodont, France) and 2 mL of 5% NaOCl for 5 min. A final flush with saline solution was made to halt any chemical activity. Two other uninstrumented teeth that were not irrigated served as controls. All teeth were split longitudinally and prepared for SEM evaluation. The presence of debris and smear layer was evaluated from photomicrographs at ×200 and ×1000 magnification taken in the apical, middle and coronal thirds of the canals. Blind evaluation was performed by two trained observers and scores were compiled separately. A five category scoring system for debris and smear layer was used. Values obtained were tabulated and statistical analysis was carried out using a parametric chi-squared test. Results Statistical analysis showed that there was no significant difference between the three regions of the root canals (P > 0.05) for debris. Comparison of the removal of the smear layer between the three regions showed that there was a statistically significant difference between all parts, especially between the coronal and apical thirds (P < 0.001). Overall, the coronal sections were cleaner than the middle and apical sections. The uninstrumented canals showed walls completely covered with tissue, confirming that specimen preparation alone did not remove tissue. Conclusions Under the conditions of the present study GTÔ rotary instruments removed debris effectively, but left root canal walls covered with smear layer, particularly in the apical third. [source] Electron microscopic study to compare preclinical Cushing's syndrome with overt Cushing's syndromeINTERNATIONAL JOURNAL OF UROLOGY, Issue 4 2002Daisaku Hirano Abstract Background: No significant differences in gross and light- microscopic features have been reported between preclinical and overt Cushing's adenomas. In this study, the ultrastructural differences between the two syndromes was attempted to be clarified. Methods: Two preclinical Cushing's syndrome adenomas and two overt Cushing's syndrome adenomas obtained from surgical extirpation were examined in an electron microscopic study. Results: Light microscopically, the adenomas of both syndromes were composed predominantly of clear cells, with few compact cells. Ultrastructurally, the prominent differences were of development in each organelle: the preclinical Cushing's adenomas had undeveloped mitochondria, which were smaller in size and had sparse cristae, lysosomes and polysomes, whereas the overt Cushing's adenomas contained well-developed mitochondria which were larger in size and were filled with abundant cristae, smooth endoplasmic reticulum (SER), lysosomes and polysomes. Conclusions: Preclinical Cushing's syndrome adenomas were ultrastructurally characterized by a reduced number of cellular organelles such as mitochondria and SER, which are necessary to synthesize glucocorticoid hormones. However, examination of a greater number of adenomas will be required to be able to draw conclusions on the ultrastructural differences between the two syndromes. [source] Regression of blood vessels in the ventral velum of Xenopus laevis Daudin during metamorphosis: light microscopic and transmission electron microscopic studyJOURNAL OF ANATOMY, Issue 2 2000H. BARTEL Structural changes of the ventral velum of Xenopus laevis tadpoles from late prometamorphosis (stage 58) to the height of metamorphic climax (stage 62) were examined by light and transmission electron microscopy. Special emphasis was given to the blood vessel regression. Early changes of velar capillaries were formation of luminal and abluminal endothelial cell processes, vacuolation, and cytoplasmic and nuclear chromatin condensation. At the height of metamorphic climax, transmission electron microscopy revealed apoptotic endothelial cells with nuclear condensation and fragmentation, intraluminal bulging of rounded endothelial cells which narrowed or even plugged the capillary, and different stages of endothelial cell detachment (,shedding') into the vessel lumen. These changes explain the ,miniaturisation' of the velar microvascular bed as well as the typical features found in resin-casts of regressing velar vessels which have been observed in a previous scanning electron microscopy study of the ventral velum. [source] Ultrastructural study of skin and eye of UV-B irradiated ayu Plecoglossus altivelisJOURNAL OF FISH BIOLOGY, Issue 6 2005J. G. Sharma A scanning electron microscopic study of the skin and eye of UV-B radiated ayu Plecoglossus altivelis(age 30 days, mean ± s.e. total length: 16·25 ± 0·11 mm) under laboratory condition showed marked changes when compared with the control fish without UV-B radiation. The exposure of the fish to the radiation resulted in the destruction of microridges in the epidermis and exposed neuromast cells of the skin. Domed protrusions were also more common in the skin of UV-B radiated fish than in the control fish. The appearance of mucus in both groups was different. In the control skin the mucus was spread over a wide area whereas in the treated fish the mucus was concentrated in a small area. The anastomozing structures of the microridges of the eyes were lost in UV-B radiated fish and the microridges themselves were fewer in number, fragmented, and aggregated. Mucus cells, prominently visible in the control fish, were distorted in the treated fish. Cell contours were irregular in UV-B radiated fish and cell to cell contacts had been lost in this group. [source] Estimating the number of complex particles using the ConnEulor principleJOURNAL OF MICROSCOPY, Issue 3 2001J. P. Kroustrup An unbiased counting rule for the number of topologically simple objects of any shape, size and distribution in 3D space is a pertinent problem in stereology. Combining the disector principle with the object's 3D Euler number makes possible number estimation, which until now has been obtainable only by exhaustive serial sections. The disector is a set of two sections where the object's profiles in one section are compared with its profiles on the neighbouring section, and the number of new 2D topological events is recorded. In a disector of known volume the sum of topological events is a direct estimate of the disector contribution to the total Euler number, which forms the basis for an ultimate number estimator in 3D, the ConnEulor. The method is illustrated by an electron microscopic study of the number of mitochondria in the exocrine cells of the pancreas. [source] Immunohistochemical and electron microscopic study of invasion and differentiation in spinal cord lesion of neural stem cells grafted through cerebrospinal fluid in ratJOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2002Sufan Wu Abstract Neurospheres were obtained by culturing hippocampal cells from transgenic rat fetuses (E16) expressing green fluorescent protein (GFP). The neurosphere cells were injected into the cerebrospinal fluid (CSF) through the 4th ventricle of young rats (4 weeks old) that had been given a contusion injury at T8,9 of the spinal cord. The injected neural stem cells were transported through the CSF to the spinal cord, attached to the pial surface at the lesion, and invaded extensively into the spinal cord tissue as well as into the nerve roots. The grafted stem cells survived well in the host spinal cord for as long as 8 months after transplantation. Immunohistochemical study showed that many grafted stem cells had differentiated into astrocytes at 1,4 months, and some into oligodendrocytes at 8 months postoperatively. Immunoelectron microscopy showed that the grafted stem cells were well integrated into the host tissue, extending their processes around nerve fibers in the same manner as astrocytes. In addition, grafted stem cells within nerve roots closely surrounded myelinated fibers or were integrated into unmyelinated fiber bundles; those associated with myelinated fibers formed basal laminae on their free surface, whereas those associated with unmyelinated fibers were directly attached to axons and Schwann cells, indicating that grafted stem cells behaved like Schwann cells in the nerve roots. © 2002 Wiley-Liss, Inc. [source] Pathology of lumbar nerve root compression Part 1: Intraradicular inflammatory changes induced by mechanical compressionJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2004Shigeru Kobayashi Study design: This study is to investigate the intraradicular inflammation induced by mechanical compression using in vivo model. Objectives: The relationship between the intraradicular edema and nerve fiber degeneration induced by mechanical compression was determined in the nerve root. Summary of background data: Recently some studies reported that mechanical compression increased microvascular permeability of the endoneurial capillaries and resulted in an intraradicular inflammation. These changes may be an important factor of the pathogenesis of radiculopathy. However, the natural courses of the intraradicular inflammation after mechanical compression are still poorly understood. Methods: In dogs, laminectomy was performed at L7 and the seventh nerve root was exposed to compression at 7.5 gram force (gf) clipping power. The animals were evaluated at 1 and 3 weeks after clipping. After the appropriate period of nerve root compression, Evans blue albumin (EBA) was injected intravenously. The nerve root sections were divided into two groups. The sections were used to investigate the status of the blood,nerve barrier function under the fluorescence microscope. The other sections were used for light and transmission electron microscopic study. Results: After 1 and 3 weeks, intraradicular edema was observed not only at the site of compression but also in the peripheral zone of a compressed anterior root and in the central zone of a compressed posterior root. The evidence of active Wallerian degeneration was also seen in the area of intraradicular edema. In addition, the nerve roots showing Wallerian degeneration were infiltrated by inflammatory cells, such as macrophages and mast cells. Conclusions: Inflammatory reaction, such as Wallerian degeneration, breakdown of blood,nerve barrier and appearance of macrophage, may be deeply involved in radiculitis arising from mechanical compression, and these factors seem to be important in the manifestation of radiculopathy. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Dense fimbrial meshwork enhances Porphyromonas gingivalis adhesiveness: a scanning electron microscopic studyJOURNAL OF PERIODONTAL RESEARCH, Issue 2 2007H. Hongo Background and Objective:, The aim of this study was to determine how the fimbriae of Porphyromonas gingivalis function in plaque formation. Material and Methods:, We used scanning electron microscopy to examine aggregates and hemaggregates of fimbria-rich ATCC33277 (parent) and fimbra-poor OZ6301C (pgmA -knockout, mutant) strains of P. gingivalis. We also assessed the hemagglutination activity of the two strains as an indicator of P. gingivalis adhesiveness. Results:, Aggregates of P. gingivalis were composed of bacterial chains and clusters. Rich fimbriae projecting from cells of the parent strain tended to bunch and form a dense meshwork among bacterial cells. In contrast, cells of the mutant strain projected fewer fimbriae and the meshwork was looser. Hemaggregates including cells of the parent strain contained a detached, dense fimbrial meshwork that adhered to erythrocytes. Hemaggregates comprising cells of the mutant strain included bacterial chains and clusters that adhered to erythrocytes by shorter fimbriae than those of the parent strain. The hemagglutination titer of the parent strain was 10-fold higher than that of the mutant strain, although the number of fimbriae per cell of the parent strain was only double that of the mutant strain. Conclusion:, The results indicate that P. gingivalis adhesiveness is prominently enhanced by the dense fimbrial meshwork. Thus, the virulence of P. gingivalis is increased by the presence of rich fimbriae. [source] Immunohistochemical and electron microscopic study of extrinsic hepatic reinnervation following orthotopic liver transplantation in ratsLIVER INTERNATIONAL, Issue 5 2001Tsuyoshi Takahashi Abstract:Background/Aims: Because little has been known about the morphological and functional consequences of liver transplantation on hepatic autonomic nerves, we examined the time-course of extrinsic hepatic innervation at the level of the porta hepatis of liver allografts. Methods: Orthotopic liver transplantation was performed using male Lewis rats. Crosscut tissue specimens were obtained postoperatively for up to 6 months from the porta hepatis of transplanted livers, and processed for immunohistochemical staining for protein gene product 9.5 (PGP 9.5) and growth-associated protein 43 (GAP-43), and for transmission electron microscopy (TEM). Results: Extrinsic nerve fibers at the porta hepatis stained positively for PGP 9.5 throughout the entire study period. In contrast, the immunoreactivity of GAP-43 was negative at postoperative day (POD) 1 and 2. GAP-43-positive nerves were first observed to appear in the porta hepatis at POD 3. The immunoreactivity of GAP-43 remained positive thereafter until 3 months post-OLT, and became negative in all the specimens at 4 months post-OLT. Transmission electron microscopy demonstrated a small number of regenerating axons existing among many degenerating axons at POD 3. At 3 months post-OLT, most regenerating axons had been fully ensheathed by the cytoplasm of Schwann cells, although their density remained at a lower level compared with normal. Conclusion: The results of this study suggest that liver allografts become extrinsically reinnervated, with the regenerating axons reaching the hepatic hilus 3 days after transplantation. The process of extrinsic hepatic reinnervation is considered to almost terminate 4 months after transplantation in rats. [source] MRT Letter: Spatial distribution of vancomycin-induced damage in Staphylococcus epidermidis biofilm: An electron microscopic studyMICROSCOPY RESEARCH AND TECHNIQUE, Issue 7 2010Rachna Singh Abstract This study was planned to elucidate the efficacy of antibiotics on Staphylococcus epidermidis and Staphylococcus aureus biofilms by scanning electron microscopy (SEM). Biofilms of S. epidermidis ATCC 35984 and S. aureus ATCC 29213 were grown on black, polycarbonate membranes placed on tryptic soy agar plates for 48 h at 37°C, and then exposed to vancomycin or amikacin or ciprofloxacin at clinically achievable levels for 24 h at 37°C. The morphology of antibiotic-treated and untreated biofilms was elucidated by SEM. SEM analysis indicated a differential affection of S. epidermidis ATCC 35984 in the center and periphery of biofilm upon treatment with vancomycin. The center of biofilm revealed damaged cells with sparse distribution, smaller size, and irregular shape, whereas cells in the periphery were unaffected. This differential distribution of susceptibility within S. epidermidis ATCC 35984 biofilms was specific for vancomycin only and was not observed on exposure to amikacin or ciprofloxacin. No such response was found in S.aureus ATCC 29213 biofilms. Thus, our study suggests a spatial distribution of vancomycin-induced damage in S. epidermidis biofilms. To our knowledge, this is the first report that indicates a differential affection of S. epidermidis in the center and periphery of biofilm upon treatment with vancomycin. Studies on the factors controlling this differential distribution could provide valuable insights into the mechanisms of antimicrobial resistance in S. epidermidis biofilms. Microsc. Res. Tech., 2010. © 2010 Wiley-Liss, Inc. [source] Ultrastructural changes in feline dental pulp with periodontal diseaseMICROSCOPY RESEARCH AND TECHNIQUE, Issue 5 2003Jamileh Ghoddusi Abstract A light and transmission electron microscopic study was conducted on dental pulp on cats suffering periodontal disease. After extraction, pulp tissues were fixed and embedded in Epon-Araldite. Thick layers of predentin (50 ,m) and odontoblasts (30 ,m) were observed. In thin sections, odontoblasts showed many mitochondria and secretary vesicles. Some capillaries with several fenestrations were located within the odontoblastic layer. All the sections of pulp examined displayed a generalized infiltration of chronic inflammatory cells. Fibroblasts displayed lytic changes in some areas. These findings imply that the pulp is significantly affected by periodontal disease and furcation-involved teeth should be a carefully considered factor when dental treatment is planned. Microsc. Res. Tech. 61:423,427, 2003. © 2003 Wiley-Liss, Inc. [source] An electron microscopic study,Correlation of gastroesophageal reflux disease and laryngopharyngeal reflux,THE LARYNGOSCOPE, Issue 7 2010Sanghoon Park MD Abstract Objectives/Hypothesis: Laryngopharyngeal reflux (LPR) originates from regurgitation of gastric contents, a mechanism seemingly identical to gastroesophageal reflux disease (GERD). Some researchers postulate a connection between LPR and GERD, whereas some assert LPR is a disease apart from GERD. We examined symptoms of GERD from LPR patients, and performed gastrointestinal endoscopy and transmission electron microscopy (TEM) to evaluate GERD findings from these patients. Study Design: Prospective study at an academic tertiary care center. Methods: Control subjects had no symptoms or signs of LPR/GERD. LPR was diagnosed with a Reflux Symptom Index >13 and Reflux Finding Score >7, and were questioned for GERD-related symptoms and examined with esophagogastroduodenoscopy, then allocated into either an LPR without GERD or LPR with GERD group. Esophageal tissues were obtained from the squamocolumnar junction and managed for TEM, and the intercellular space (IS) was measured to find dilatation, a characteristic GERD finding. Results: About 30% (8/26) of LPR patients showed GERD-related symptoms, connecting LPR with the GERD group. Most of the LPR patients showed grossly normal endoscopic findings. On TEM, IS of control group (n = 15) was measured as 0.35 ± 0.27 ,m, whereas the LPR without GERD group (n = 18) and LPR with GERD group (n = 8) revealed a dilated IS of 0.61 ± 0.47 ,m and 0.95 ± 0.44 ,m, respectively. This difference was statistically significant compared to the control group (P < .05). Conclusions: The mean IS of LPR was significantly increased, suggesting common pathogenesis between LPR and GERD. Laryngoscope, 2010 [source] The Spleen of Zaedyus pichiy, (Mammalia, Dasypodidae): a Light and Electron Microscopic StudyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2003E. J. Galíndez Summary Armadillos are ancient mammals important as models for biomedical, evolutive and ecological studies, because they have adaptive and primitive morpho-physiological characteristics. In this work we study the splenic microarchitecture of the ,Patagonian Piche', Zaedyus pichiy, as an attempt to understand the relationship between the organizational plan of the organ and the particular features of this species. The organ samples were classically processed for light and electron microscopic study. The microanatomy of the organ as well as its different cell types are studied. The spleen is non-sinusoidal, with the typical arrangement for storage functions. White pulp is well defined. Red pulp is a meshwork of circulating, immunocompetent and haemopoietic cells. The general structure of the organ agrees with the semi-fossorial habit and the adaptability of the species. Comparative aspects with other armadillos or other less specialized groups are discussed. Persistence of haemopoietic spleen activity in the adult suggests the existence of specific inductive functions of the stroma. Better knowledge of spleen structure and function in ancient mammals may give important information about their phylogeny. [source] Non-carious cervical lesions: a scanning electron microscopic studyAUSTRALIAN DENTAL JOURNAL, Issue 2 2010JA Michael Abstract Background:, Examining non-carious cervical lesions using scanning electron microscopy (SEM) provides an opportunity to clarify their complex aetiology. This study aimed to examine the morphological forms of non-carious cervical lesions found within a sample of extracted human permanent anterior teeth using scanning electron microscopy. Methods:, Five examples of non-carious cervical lesions from each of eight different morphologic categories were replicated and examined using scanning electron microscopy. Results:, In total, 40 non-carious cervical lesions were examined at magnifications ranging from 10× to 2605× magnification. Qualitative ultrastructural features evident in the lesions were described and classified according to their appearance. A total of 13 different qualitative features were observed throughout the sample of NCCLs. Conclusions:, SEM highlighted a broad range of microscopic features of NCCLs, providing valuable insights into their complex, multifactorial aetiology. [source] The cervical wedge-shaped lesion in teeth: a light and electron microscopic studyAUSTRALIAN DENTAL JOURNAL, Issue 3 2009TJ Daley Abstract Background:, The cervical non-carious wedged-shaped lesion is controversial in that its aetiology may involve attrition, erosion, abrasion and stress-corrosion (abfraction). This study examined the histopathology of anterior teeth with cervical wedge-shaped lesions by light and electron microscopy to elucidate their pathogenesis. Methods:, Ten undecalcified human teeth with cervical lesions were available for investigation. Patency of the dentine tubules was tested using red dye penetration from the pulp chamber. The morphology of normal and sclerotic dentine adjacent to the cervical wedge-shaped lesions was investigated by scanning electron microscopy. The numbers and diameters of dentinal tubules were measured at different levels beneath the surfaces of the lesions. Results:, The gross and microscopic features of the worn teeth were described. Red dye penetration tests showed white tracts of sclerotic tubules contrasted with red tracts of patent tubules. Numbers of tubules per square area and diameters of patent and sclerotic tubules varied at different levels within the dentine due to deposits of intratubular dentine. Conclusions:, The cervical wedge is shaped by interactions between acid wear, abrasion and dentinal sclerosis. No histopathological evidence of abfraction was found. Clinical diagnosis, conservation and restoration of non-carious cervical lesions need to take into account the extent of sclerotic dentine beneath wedge-shaped lesions. [source] Effect of 17% EDTA and MTAD on intracanal smear layer removal: A scanning electron microscopic studyAUSTRALIAN ENDODONTIC JOURNAL, Issue 1 2009Mohammad Ali Mozayeni dds Abstract The purpose of this study was to determine the effectiveness of MTAD as the final irrigant to remove the smear layer, compared with that of 17% EDTA, both following root canal irrigation with 5.25% sodium hypochlorite (NaOCl). Fifty-five extracted maxillary and mandibular single-rooted human teeth were prepared by a crown-down technique using rotary 0.04 and 0.06 taper nickel-titanium files. 5.25% sodium hypochlorite was used as the intracanal irrigant. The canals were then treated with 5 mL of one of the following solutions as final rinse: 5.25% sodium hypochlorite, 17% EDTA or MTAD. The presence or absence of smear layer in the coronal, middle and apical portion of each canal was examined with a scanning electron microscope. The results showed that MTAD is an effective final rinse solution for removing the smear layer in canals irrigated with sodium hypochlorite. When 17% EDTA was used as a final rinse, the smear layer was removed from the middle and coronal thirds of canal preparations, but it was less effective in the apical third of the canals. [source] | |||||||||||||||||||||||||