Chronic hyperglycemia is a common feature of all forms of diabetes mellitus and may contribute greatly to the increase in the incidence of atherosclerosis. It has been demonstrated that increasing arterial permeability to the macromolecules can cause low-density lipoproteins (LDLs) to infiltrate and accumulate in the intima. This event is crucial for developing the plaques in the arterial wall. in this study, we use Evans blue to study the permeability of arterial endothelium in the streptozotocin (STZ)-induced hyperglycemic rats. We also use colloidal gold-labeled LDL to investigate in situ the distribution of LDL in the aortic intima of hyperglycemic rats.

The hyperglycemia was induced in male Sprague-Dawley rats (7 weeks) by a single intraperitoneal injection of streptozotocin (60 mg/kg). The blood glucose concentration and hemoglobin glycation were measured once in every week. The uptake of drinking water is monitored in the regular time interval. After 3 months into the experiment, ten hyperglycemic and control rats were anesthetized.

Mechanical stimuli frequently trigger signals leading to increase gene expression, protein synthesis, or mitogenesis. Cardiac fibroblasts respond to changes in ventricular hemodynamic loading by increasing matrix production in models of pressure-overload hypertrophy and myocardial infarction. Recent studies have identified some of the intracellular signaling pathways that mediate the biological effects observed upon mechanical stimulation in vitro. These include mitogenactivated protein kinases (MAPKs) and protein kinase C (PKC) family. MAPKs include extracellular signal-regulated kinase (ERK), C-Jun NH2-terminal kinase (JNK), and p38 MAPK. ERK pathway is frequently stimulated in response to mitogen.

Previous studies demonstrated that mechanical stretch stimulated MAPK activities in normal adult rat cardiac fibroblasts. On the other hand, mechanical stretch also increases transcription and production of the matrix proteins collagen (type I and HI) and fibronectin in cardiac fibroblasts. MAPKs are activated by mechanical stretch during cardiac myocytes hypertrophy through both PKCdependent and independent pathways.

Fumagillin, an antibiotic isolated from the fungus Aspergillus famigatus and first utilized in the 1950’s for its antiprotozoal and antiamoebic properties, has recently been discovered to be a potent inhibitor of blood vessel growth, termed angiogenesis. A previous study indicated that fumagillin was toxic to murine erythroleukemic cells (MEL BB-88) and HeLa cervical carcinoma cells. This study was initiated to understand what effects the chemical has on the cell surface ultrastructural morphology of these two cancer cell lines.

MEL BB-88 cells were treated with 0.0, 5.0, or 10.0 μg/ml fumagillin for 24, 48, 72, and 96 hours, while HeLa cells received 0.0, 1.0, or 5.0 μg/ml fumagillin for the same time periods. Cells were fixed in 2% glutaraldehyde for two hours, postfixed in 1% osmium tetroxide for one hour, dehydrated in an ascending alcohol series, critically point dried, coated with gold palladium, and observed under an ISI Super III scanning electron microscope

Background: Lidocaine is a local anesthetic that is frequently used for spinal anesthesia. in clinical and animal studies, lidocaine is associated with an increased risk of spinal neurotoxicity following spinal anesthesia. The mechanism of lidocaine neurotoxicity has not been fully elucidated, but it does not involve blockade of sodium channels, the mechanism by which lidocaine causes local anesthesia. Previous in vitro studies assessing cytoplasmic calcium, nerve conduction and action potential generation, and cell death, have demonstrated overt neurotoxicity at higher concentrations of lidocaine (≥ 2% [74 mM] of the hydrochloride formulation), but equivocal results at lower concentrations. Clinically available preparations of lidocaine for spinal anesthesia contain 5% or 2.5% lidocaine hydrochloride. in most cases, lidocaine mixes rapidly with cerebrospinal fluid after injection for spinal anesthesia, so that lower concentrations are more clinically relevant. We have therefore evaluated morphologic assessment of plasma membrane blebbing as a more sensitive assay of neuronal injury by lidocaine.

Sulfur mustard [bis-(2-chloroethyl)sulfide; HD] causes incapacitating injuries to the eyes, respiratory tract, and skin. Despite decades of research, the mechanism of toxic action of HD is still poorly understood. One proposed toxicological mechanism that triggers cell death involves DNA damage induced by HD alkylation. According to this hypothesis, HD-induced DNA damage activates NAD+, requiring the enzyme poly(ADP-ribose) polymerase (PARP) to initiate DNA repair processes. Overactivation of PARP leads to depletion of NAD+, and, in efforts to resynthesize NAD+, cellular ATP is depleted, and the cell dies from intracellular energy. However, recent studies only partial support this hypothesis. Niacinamide, a substrate for NAD+ synthesis, prevented NAD+ depletion, but did not significantly prevent cell death following HD exposure. These studies suggest cell death occurs independently of depletion of cellular NAD+ with some other pathogenic processes operating in cell death following HD cytotoxicity.

The present study examined the role of apoptosis in basal cell degeneration caused by HD exposure in the hairless guinea pig.

Intraspinal cyst formed of tissue proper to the tracheobronchial tract has been referred to as bronchogenic cyst. Six cell types of the cyst epithelium have been identified, i.e., ciliated cells, non-ciliated cells, goblet cells, basal cells, Kulchitsky's cells and undifferentiated cells. This report described the detailed morphological alterations of cilia of the lining epithelium of three cases of intraspinal bronchogenic cyst and compared the findings with the ciliary abnormalities of the tracheobronchial epithelium.

Ultrastructural abnormalities of cilia of the intraspinal bronchogenic cyst could be classified into five categories:

1. (A) Cilia showing addition, deletion or disorganization of axonemal minotubules.

2. (B) Swollen cilia containing a single axoneme in an excess amount of matrix: (a) normal 9 + 2 axoneme,(b) stretched axoneme bending toward one side, (c) abnormal axonemal pattern.

3. (C) Compound cilia with multiple axonemal microtubules ensheathed by a common ciliary membrane: (a) two or more normal 9 + 2 axonemes, (b) two or more normal 9 + 2 axonemes sharing doublets, (c) giant compound cilia with numerous normal and abnormal axoneme in random orientation, (d) compound cilia containing cytoplasmic organelles, (e) compound cilia with excessive matrix.

Postischemic lesion following reperfusion have been investigated in the gerbil by temporary occlusion of a common carotid artery. Two phenomena have been reported in injured ischemic cells: the inability to restore mitochondrial function and evidence of plasma membrane damage. For Further understanding the pathophysiological mechanism of ischemic lesion, we have evaluated the various ischemic period and early postischemic reperfusion. in addition to the morphological changes of the dentate gyrus by light microscopy, we employed the immunocytochemical staining for iNOS and eNOS.

The mongolian gerbil, Meriones unguiculatus, were anesthetized with α-chloralose (350mg/kg), bilateral common carotid artery occlusion was induced for 90 minutes. The right common carotid artery was ligated with 5-0 silk suture, and the left was clamped by a micro vascular/miniature aneurysmal clip. After an ischemic period of 90 minutes, restoration of the blood flow of the left common carotid artery was accomplished by withdrawing the microvascular clip.

Parkinson's disease (PD) is characterized by rigidity, tremor, bradykinesia, and postural instability. The proximate cause of these symptoms is striatal dopamine (DA) insufficiency. The motor symptoms of PD can be alleviated by DA replacement therapy. However, late in the course of the disease patients appear to become less responsive to DA replacement. This therapeutic change suggests the possibility of structural and/or functional defects in striatal medium spiny neurons, which receive convergent DA and cortical (glutamate) inputs.

To understand the neuronal reorganization occurring in Parkinson's disease, we used ultrastructural methods to examine the striatum of rats with striatal dopaminergic deafferentation induced by unilateral intranigral injection of 6-hydroxydopamine. After a six month survival, rats were deeply anesthetized with pentobarbital and perfused with 4% paraformaldehyde-1 % glutaraldehdyde solution in 0.1M Sorenson's phosphate buffer (pH 7.4). The brains were removed, post-fixed for 12 hours, embedded in paraffin, and coronal sections cut through the striatum and midbrain.

The cerebellar granule cells of hamsters, mice, primates and human have been examined to study their organisation, outer and inner surfaces, pattern of connectivity on granule cell groups and synaptic relationships with afferent mossy and climbing fibers in the granule cell layer and with Purkinje cell dendritic spines in the molecular layer.

Confocal laser scanning microscopy of hamster cerebellum cortex, using FM4-64 as an intracellular stain, showed in z-series of stacks of optodigital sections, the presence of granule cell groups formed by small, medium and large granule cells, ranging from 3-10 μm in diameter, surrounded by large Golgi cells. The granule cell/Golgi cell ratio was 50 to 4 (Fig. 1).

Cryofractured mouse cerebellar cortex showed the inner organization of granule cell nuclear and cytoplasmic compartments in samples examined with FEURSEM and coated with chromium (Fig. 2), which were compared with corresponding freeze-etching replica images.

One of Prof. Castaing’s most important gifts to the field of X-ray microanalysis was his insight that quantification could only effectively be carried out by procedures which relied on measurements relative to a suitable standard, because in this way is was the functional variation, rather than the absolute value, of most quantities that had to be known or approximated. At the time this was seen to be a necessary step because the state of knowledge about the fundamental parameters of electron solid interactions was regarded as poor. in the intervening fifty years this situation has not changed very much. Even more unfortunately the kinds of problems to which electron beam microanalysis is now applied - such as the analysis of highly inhomogeneous or very small samples - are of such a nature that quantitative methods based on standardization are no longer feasible.

Mechanisms in electrostatic charging of insulating materials during electron irradiation are very difficult to predict because they involve cross-correlated parameters: the surface potential, Vs and the secondary electron yield,δ, for bare specimens; the possible change of the bulk composition induced by the internal electric field for ground coated specimens. A better understanding of these mechanisms requires efforts from both the theoretical and the experimental points of view.

From the theoretical point of view, a two-layer model for distribution of the trapped charges (Q+ over the escape depth of the secondaries, s; Q‐ over the maximum penetration depth R of the incident electrons) often permits to account for many charging effects observed on bare specimens. For instance, the failure of the total yield approach may be partly explained by the fact that the charge distribution expected at the critical energy Ec2 (where δ+ η=l) corresponds to Q+=‐Q‐ but also to R ≫ s at the early beginning of the SEM and EDS investigation.

The studies of insulating specimen by using scanning electron microscopy (SEM) or associated microanalytical techniques such as electron probe microanalysis (EPMA), Auger electron spectroscopy (AES), etc., is limited by the charging phenomena. Different techniques have been found to minimize this problem: coating the specimen with a conductor, working at low energy [1], etc. But for a better knowledge of this effect, we have started a study of the mechanisms of charging as well as its effect on the electrons trajectories in the case of an insulating specimen. with the success, in past years, of Monte Carlo (MC) simulation of electron scattering in solid specimens [2], we have been developing a new Monte Carlo program for the simulation of the electron trajectory in insulators.

With this program, we want to understand the effect of the trapping charge on a insulating specimen. The new MC will be constructed by adding a succession of refined model. in each step, the model goes deeper in the mechanisms for the charging phenomena.

A common question, but one typically difficult to answer, is “How accurate is a microprobe or SEM analysis?” Commercial software for most EDS and WDS systems print out error limits that are typically calculated standard deviations using Gaussian counting statistics based on the accumulated peak and background counts. This is not a true measure of even the measurement precision, since random instrumental instabilities typically degrade “true” measurement precision (as determined by replicate measurements on standards) to 1.5 - 3+ times that predicted from Gaussian statistics. in addition to these random instrumental variations are a plethora of possible systematic and semirandom errors such as detector or faraday cup non-linearities, errors in estimation of background, EDS spectral deconvolution errors, WDS positional non-reproducibility, temperature and pressure variation effects on spectrometer efficiencies, high voltage drift or sample charging, surface contamination or oxidation, and sample roughness or tilt.

Quantitative procedures in electron probe microanalysis (EPMA) require the knowledge of various atomic parameters, the most fundamental of which is the ionization cross section. A number of semi-empirical, approximate analytical formulas have been proposed to calculate the ionization cross section. The simplicity of these formulas makes them suitable for quantitative EPMA procedures. However, it is difficult to assess their reliability because of the lack of accurate experimental data. Indeed, inspection of currently available data reveals that they are still scarce for many elements and, when they are available, one usually finds significant discrepancies between data from different authors. Fortunately, the inaccuracies in the semi-empirical cross section formulas used in EPMA have only a small effect on the analytical results when standards are used. Nonetheless, in quantitative EPMA studies at low overvoltages or using standardless methods, the evaluated compositions largely depend on the adopted ionization cross sections and, therefore, knowledge of accurate ionization cross sections is a requisite for the development of improved quantification methods.

Experimental conditions and setting up of an electron microprobe is directly linked to the assumption or the knowledge that can make the operator on the results of the measurements. Consequently, there is an increasing interest in modelling the X-ray spectrum in order to predict accurately and rapidly the response of the microprobe when a sample of approximately known composition is submitted to specific excitation conditions. Even if the spectra simulation is a current tool proposed in EDS, it always remains a challenge to create a complete absolute WDS spectrum. Indeed, the definition of the efficiency function was a limit to the calculation of absolute intensities.

In this work, we propose a new generation software for EPMA which uses the absolute simulation spectra to assist the operator in the choices of experimental conditions to achieve accurate measurements in a short time as well as to create new functionalities.

This paper presents the results of studies concerning the accuracy and precision of x-ray microanalysis (EDS) in the environmental scanning electron microscope (ESEM). The ESEM is distinguished by its use-of gas in the microscope specimen chamber for imaging and for charge neutralization. Previous work on EDS-ESEM has concentrated either on qualitative x-ray microanalysis or on correction methods to the enlarged x-ray spatial resolution due to the electron skirt. Recent work shows that quantitative analysis is possible once charge neutralization can be accomplished in practice.

Accuracy and precision were evaluated in the work presented here using NIST SRM 482 (goldcopper alloys) and NIST SRM K411 (glass beads). The gold-copper alloy wires were prepared by mounting them in epoxy mounts and polishing to a metallurgical finish. The glass spheres were prepared by sprinkling a small amount of the sample onto double-sided carbon tape mounted onto an aluminum SEM stub.

The National Institute of Standards and Technology’s (NIST) Standard Reference Material (SRM) 482 was issued by The National Bureau of Standards (NBS) in 1969 i has been continuously available to the public for over 30 years [1]. The standard cons of a set of 6 wires. Each wire is approximately 0.5 mm in diameter and 5 cm long. Tl wires represent different compositions within the binary copper-gold alloy system. Included in the set are the two end member compositions, pure copper and pure gold, along with 4 alloys of nominal composition: Au80-Cu20, Au60-Cu40, Au40-Cu60 an< Au20-Cu80. SRM 482 was produced specifically for the purpose of microanalysis usi the electron probe microanalyzer (EPMA).

Recent metallographic preparation of these wires revealed the presence of surface blemishes on some of the prepared wires (Figure la). Two of the authors from differei affiliations recently prepared cross-sections of SRM wires from separately purchased sets. Each was unaware of the procedures used by the other.

Lead lanthanum zirconium titanate (PLZT), or (Pb,La)(Zr,Ti)O3 solid solutions, ferroelectric ceramics are being studied for electro-optical applications, as well as for high-speed electrophoretic printing. Thin films of a related material, lead zirconium titanate, or Pb(Zr,Ti)O3 solid solutions (PZT), are used for non-volatile memories and actuators.1 Proper composition and compositional homogeneity of ferroelectric ceramics are essential for application, however the fabrication process may produce materials with element concentrations and thus physical characteristics that may differ from expectation. Therefore, a PLZT reference material for determining the composition of these ceramics would be useful. It will also be useful for quantitative microanalysis; it is stable under the point beam of the electron microprobe (EPMA) at excitation voltages up to 25 kV and probably higher at currents of more than 100 nA.

A specimen of PLZT prepared by the Ceramics Department of the Jozef Stefan Institute in Ljubljana, Slovenia was studied with the electron microprobe to determine the composition and the extent of heterogeneity.

Terrestrial experiments involving detached growth of GeSi crystals by the Bridgman technique have been performed in preparation for microgravity experiments to be conducted on the International Space Station. These experiments typically produce large GeSi crystals that are sectioned for microscopy, microprobe analysis, and electron-backscatter diffraction analysis. Accurate microanalysis of these crystals is essential for feedback to further growth experiments, but is problematic as the Ge-Si binary exhibits continuous solid solution and it is therefore difficult to prepare homogeneous intermediate standards. There are no experimental measurements on standards of known composition in the Ge-Si binary that could be used to evaluate analytical accuracy. The accuracy of analysis in mineral, oxide, and semiconductor systems has previously been studied using experimental x-ray intensity measurements, correction algorithms and their derived α-factors, and mass absorption coefficient data sets. This study continues that approach and includes results of Monte Carlo calculations in the Ge-Si binary.

The topic of this paper is to present a new Windows™ environment version of the CASINO Monte Carlo program. The goal of this program is to assist scanning electron microscope users in their routine analysis and also in more advanced topic such as electron beam lithography for example. Based on a single scattering algorithm, this software is specially designed for low beam interaction in a bulk and thin foil. This program uses tabulated Mott elastic cross-sections, which benefit of both fast calculation and accurate interaction at low beam energy. At the moment CASINO can either be used to generate X-rays or backscattered electron signals. The program used simple two-dimension geometry to represent real sample. in this version, vertical and horizontal planes can be generated to allow cross-section representation or multi-layers analysis. Then beam can be scanned across different regions to produce X-ray linescan or bascattered electron profiles.

Many new convenient features have been added to the version 2.0 of CASINO. The new interface lets the users to consult the results as the simulation is still in progress.