Scanning and Transmission Electron Microscopy of a Craniopharyngioma: X-ray Microanalytical Study of the Intratumoral Mineralized Deposits

This paper discusser the value of scanning electron microscopy (SEM) and x-ray microanalysis in the classification of craniopharyngiomas. This neoplasm shows epithelial nests, cords of cuboid cells, foci of squamous metaplasia, and microcystic degeneration. SEM reveals that the epithelial cysts are lined with elongated cells that possess numerous microvilli and blebs and that some cysts are lined with polyhedral cells. The microvilli are interpreted as characteristic of the fast growing craniopharyngiomas. A microanalytical study of the calcified areas reveals the presence of magnesium, phosphorus, and calcium.     

Bronchopulmonary Dysplasia: A Correlative Study by Light, Scanning, and Transmission Electron Microscopy

The sequential stages of bronchopulmonary dysplasia occurring in 18 infants after intensive respiratory therapy supplemented by oxygen in high concentrations were studied by correlative light, scanning, and transmission electron microscopy. Infant survival ranged from 3 to 225 days. The earliest stage was an exudative reaction with a predominance of hyaline membranes. This merged with a subacute reparative response that was replaced by a chronic fibroproliferative stage in infants of longest survival; this stage was complicated by pulmonary fibrosis and emphysema. Correlative scanning and transmission electron microscopy demonstrated that type 2 pneumocytes contributed significantly to the reparative fibroproliferative response by organization of hyaline membranes and reepithelialization of damaged septal walls.     

Correlative Study of Adult Respiratory Distress Syndrome by Light,Scanning, and Transmission Electron Microscopy

The sequential pulmonary changes occurring in the evolution of adult respiratory distress syndrome (ARDS) were studied in 35 patients by correlative light, scanning, and transmission electron microscopy. The causes of ARDS were diverse, the major ones being sepsis or aspiration. Patient survival ranged from 3 to 51 days. The acute stage in patients surviving 2 to 7 days was characterized by an exudative reaction with a predominance of hyaline membranes. This acute stage merged with and was replaced by a subacute reparative stage in patients surviving 7 to 14 days, which in turn was replaced by a chronic fibroproliferative stage complicated by interstitial pulmonary fibrosis and a deranged acinar architecture. Correlation of findings by scannning electron microscopy with those by light and transmission electron microscopy provided an added dimension to understanding of the evolving stages of ARDS and demonstrated that type 2 pneumocytes contributed to the fibroproliferative stage through organization of hyaline membranes and re-epithelialization of alveoli.     

Correlative Study of Adult Respiratory Distress Syndrome by Light, Scanning, and Transmission Electron Microscopy

The sequential pulmonary changes occurring in the evolution of adult respiratory distress syndrome (ARDS) were studied in 35 patients by correlative light, scanning, and transmission electron microscopy. The causes of ARDS were diverse, the major ones being sepsis or aspiration. Patient survival ranged from 3 to 51 days. The acute stage in patients surviving 2 to 7 days was characterized by an exudative reaction with a predominance of hyaline membranes. This acute stage merged with and was replaced by a subacute reparative stage in patients surviving 7 to 14 days, which in turn was replaced by a chronic fibroproliferative stage complicated by interstitial pulmonary fibrosis and a deranged acinar architecture. Correlation of findings by scannning electron microscopy with those by light and transmission electron microscopy provided an added dimension to understanding of the evolving stages of ARDS and demonstrated that type 2 pneumocytes contributed to the fibroproliferative stage through organization of hyaline membranes and re-epithelialization of alveoli.     

Immunogold-Silver Staining Method for Lymphocyte Cell Surface Antigens with Light,Transmission Electron,and Scanning Electron Microscopy

Abstract

The immunogold-silver staining (IGSS) method combined with light, transmission electron, and scanning electron microscopy (LM, TEM and SEM, respectively) was used for detecting lymphocyte surface antigens. Two different sizes of colloidal gold particles (5 nrn and 15 nm) were applied as markers and IntenSEII kit as a physical developer for gold particles.

The silver enhanced gold particles were clearly observed on cell surfaces as black dots in LM and TEM and as white dots in SEM equipped with a mixed signal of secondary electron and back-scattered electron (SE/BE) signals. Monoclonal antibody (MAb)-positive cells possessing the complexes on their well preserved surfaces were easily identified among other lymphoid cells at low magnifications of LM or SEM equipped with SE/BE signals. Thus, the IGSS method has a great advantage for a qualitative screening such as the percentage of lymphocyte subsets in a cell suspension. However, the IGSS method was inadequate for semiquantitative study with antigen density on cell surfaces because gold particles enhanced with the physical developer were considerably enlarged, and a silver-gold complex was not considered to show one antigen site on cell surface. (The J Histotechnol 16:217, 1993)     

Correlative Light Optical, Scanning Electron, and Transmission Electron Microscopy of Skeletal Muscle in Muscular Dystrophy and Muscular Atrophy: A Pilot Study

Biopsies of skeletal muscle from three different cases of muscular dystrophy and one case of spinal muscular atrophy that had been fixed with Karnovsky's fluid were either routinely prepared for scanning electron microscopy (SEM) or were frozen to-20°C and sectioned on a steel knife in a cryostat at 5-10 μm. The sections were coverslipped and examined using a light microscope equipped with polarizing optics (Pol). After areas were selected, the sections were prepared for SEM and thereby examined. The tissues on the slides that had been observed with light microscopy (LM) and SEM were prepared further for transmission electron microscopy (TEM) by infiltrating them with Epon and cutting sections at approximately 100 nm on an ultramicrotome. It is shown that the stage of contraction in one pathologic myofiber may vary along its length. The following advantages may be realized by using correlative (Pol → SEM → TEM) microscopy on skeletal muscle biopsies: 1) lesions can be differentiated from “normal” surrounding tissue; 2) doubtful structures can be reexamined with the SEM and TEM; and 3) the SEM image of different states of muscle contraction can be reinterpreted in the light of the Pol or TEM image.     

Correlative Light Optical,Scanning Electron,and Transmission Electron Microscopy of Skeletal Muscle in Muscular Dystrophy and Muscular Atrophy: A Pilot Study

Biopsies of skeletal muscle from three different cases of muscular dystrophy and one case of spinal muscular atrophy that had been fixed with Karnovsky's fluid were either routinely prepared for scanning electron microscopy (SEM) or were frozen to-20°C and sectioned on a steel knife in a cryostat at 5-10 μm. The sections were coverslipped and examined using a light microscope equipped with polarizing optics (Pol). After areas were selected, the sections were prepared for SEM and thereby examined. The tissues on the slides that had been observed with light microscopy (LM) and SEM were prepared further for transmission electron microscopy (TEM) by infiltrating them with Epon and cutting sections at approximately 100 nm on an ultramicrotome. It is shown that the stage of contraction in one pathologic myofiber may vary along its length. The following advantages may be realized by using correlative (Pol → SEM → TEM) microscopy on skeletal muscle biopsies: 1) lesions can be differentiated from “normal” surrounding tissue; 2) doubtful structures can be reexamined with the SEM and TEM; and 3) the SEM image of different states of muscle contraction can be reinterpreted in the light of the Pol or TEM image.     

Scanning Electron Microscopy of Disseminated Superficial Actinic Porokeratosis

A typical skin lesion from a patient with biopsy-confirmed disseminated superficial actinic porokeratosis (DSAP) was examined by scanning electron microscopy. The lesion was rimmed by a prominent but discontinuous cornoid lamella. The cornoid lamella was found to consist of a packed layer of keratinocytes whose orientation varied from parallel to the epidermis at the base of the lesion to perpendicular at the summit of the porokeratotic column. The central core of the cornoid lamella consisted of a tightly packed mass of keratin.     

Acellular Scanning Electron Microscopy of Spicular Renal Amyloidosis

Two human renal biopsies containing glomerular amyloid deposits organized into spicular formations (spicular amyloid) were studied by scanning electron microscopy following removal of the cellular components (acellular SEM). Following SEM studies, portions of the same acellular tissue were embedded in paraffin and plastic for light microscopy and transmission electron microscopy, respectively. Spicular deposits by acellular SEM appear as tapering conical formations interconnected by a delicate branching network of fibrils, which imparts a higher degree of organization than previously appreciated by two-dimensional LM and TEM. Silver stains of paraffin-and plastic-embedded acellular tissue showed persistence of argyrophilia in spicular deposits, while acellular TEM showed that the spicules appeared comprised “purely” of amyloid fibrils without visible contaminating material. We conclude that the argyrophilia of spicular amyloid is an inherent feature of the parallel organization of fibrils rather than a result of incorporation of glomerular basement membrane or cell components and that spicular amyloid deposits have a higher degree of organization than is apparent by two-dimensional studies.     

Bacteria in Biopsies of Human Hypochloridric Stomach: A Scanning Electron Microscopy Study

A long-lasting condition of hypochloridria leads to a bacterial growth both in the gastric lumen and biopsies of human stomach. Some of these bacteria are probably involved in gastric carcinogenesis, due to their capacity of nitrosation. This study was carried out on biopsies taken during endoscopy from both gastric antrum and the body of patients with or without hypochloridria. Scanning electron microscopy observation shows that bacteria, other than Helicobacter pyloridout, found in hypochloridria, can be located not only over but also into and under the mucus layer covering the gastric epithelium. In such areas, mechanical and biochemical damage may occur.     

Argyria: Microanalytic—Morphologic Correlation Using Paraffin-Embedded Tissue

Scanning electron microscopes, which have energy dispersive spectroscopy (x-ray microanalysis) capability, can provide accurate identification of the composition of inorganic deposits in tissue. We report a case of florid argyria in which the same deparaffinized 4-μm sections were sequentially examined by light microscopy, scanning electron microscopy, backscattered electron imaging, and x-ray microanalysis to confirm the clinical impression of argyria. We recommend the use of x-ray microanalysis of paraffin-embedded tissue as a simple, rapid and inexpensive means of precise identification of inorganic deposits of heavy elements in tissue sections.     

Detection of Villous Conidia of Conidiobolus coronatus in a Blood Sample by Scanning Electron Microscopy Investigation

Conidiobolus coronatus is a major insect pathogen belonging to the fungal order Entomophthorales, causing a rare subcutaneous infection of the nasofacial region, resulting in swelling of predominantly the nose, mouth, and perinasal tissue. Later in the course of the infection firm, painless, subcutaneous nodules develop that are attached to the underlying tissues but not to the skin. No morphological studies are available in the literature on the morphology of C. coronatus in vivo and all morphological studies have been conducted on in vitro cultures. Here the authors report on the ultrastructural pathology as seen with a scanning electron microscope (SEM) of villous conidia of C. coronatus, detected in a 37-year-old woman who presented to the casualty department at Pretoria Academic Hospital, South Africa with left-sided facial pain and headache. The diagnosis of C. coronatus was confirmed by LightCycler real-time flourescence PCR technique. Research shows that typically diagnosis of the pathogen is established only on histological examination, and in over 85% of cases cultures for the causative organism is negative. This pathogen has not previously been found in a blood sample and the authors present for the first time the morphology of C. coronatus in blood using the SEM.     

Correlative Light and Scanning Electron Microscopy of Intestinal Giardiasis, Cryptosporidiosis, and Spirochetosis

Cases of intestinal giardiasis, spirochetosis, and cryptosporidiosis were examined by scanning electron microscopy (SEM) using hematoxylin and eosin (H&E)-stained tissue sections from which the coverslips were removed and the sections coated with gold. The technique is simple and reliably provides excellent morphologic detail that is preserved in the deparaffinized 4 microsections. We present examples of nine intestinal parasites examined in this manner and compare this technique with standard H&E staining and special stains with regard to relative costs, turnaround time, labor input, and morphologic preservation. Scanning electron microscopy is a useful adjunct in providing confirmatory evidence in the diagnosis of intestinal giardiasis, spirochetosis, and cryptosporidiosis.     

Correlative Light and Scanning Electron Microscopy of Intestinal Giardiasis,Cryptosporidiosis, and Spirochetosis

Cases of intestinal giardiasis, spirochetosis, and cryptosporidiosis were examined by scanning electron microscopy (SEM) using hematoxylin and eosin (H&E)-stained tissue sections from which the coverslips were removed and the sections coated with gold. The technique is simple and reliably provides excellent morphologic detail that is preserved in the deparaffinized 4 microsections. We present examples of nine intestinal parasites examined in this manner and compare this technique with standard H&E staining and special stains with regard to relative costs, turnaround time, labor input, and morphologic preservation. Scanning electron microscopy is a useful adjunct in providing confirmatory evidence in the diagnosis of intestinal giardiasis, spirochetosis, and cryptosporidiosis.     

Ultrastructural Changes in Platelet Aggregates of HIV Patients: A Scanning Electron Microscopy Study

Several hematological abnormalities associated with HIV have been documented, but the mechanisms responsible for the cytopenias in AIDS patients are complex and not always completely understood. Thrombocytopenia, which occurs in about 40% of patients with HIV infection, may be caused by increased peripheral platelet destruction, a defect in platelet production due to the impaired formation of platelets by HIV-infected magakaryocytes, or a combination of these. The aim of this study was to compare the morphology of the platelet aggregates in platelet-rich plasma (PRP) clots prepared from HIV patients with those of controls without HIV. These platelet aggregates were studied using the scanning electron microscope to determine the effect of the virus on platelet ultrastructure. The results showed that although the platelets do aggregate, the morphology was changed with membrane blebbing as well as torn cellular membranes. Membrane blebbing is typically associated with apoptosis. It is concluded that the altered morphology of platelet aggregates in HIV patients may be related to thrombocytopenia as a result of peripheral platelet destruction.     

New Techniques Scanning Electron Microscopy of Acellular Glomeruli in Human Glomerulonephritis: Application of a Technique

Scanning electron microscopy (SEM) has been employed in studies of human and experimental glomerulonephritis (GN), a major contribution being the elucidation of podocyte morphology and the process of podocyte foot process retraction in proteinuric conditions. Application of SEM in GN has been limited however by an emphasis on cell surface alterations while the site of major disease processes, the glomeru-lar basement membrane, has remained hidden from view. A previously reported technique for the preparation of acellular glomeruli from fresh tissue has been adapted for use on frozen human renal biopsies. One case of minimal change disease (MCD) and one case of membranous glomerulonephritis (MGN) have been studied. The acellular glomerular basement membrane of MCD has a lightly textured or granular surface whereas in MGN a striking reticular network of basement membrane has formed perpendicular to the native basement membrane. The immune complexes have been removed. This technique provides a graphic visualization of GBM alterations occurring in glomerulonephritis and is applicable to the study of human as well as experimental model of glomerulonephritis.     

New Techniques Scanning Electron Microscopy of Acellular Glomeruli in Human Glomerulonephritis: Application of a Technique

Scanning electron microscopy (SEM) has been employed in studies of human and experimental glomerulonephritis (GN), a major contribution being the elucidation of podocyte morphology and the process of podocyte foot process retraction in proteinuric conditions. Application of SEM in GN has been limited however by an emphasis on cell surface alterations while the site of major disease processes, the glomeru-lar basement membrane, has remained hidden from view. A previously reported technique for the preparation of acellular glomeruli from fresh tissue has been adapted for use on frozen human renal biopsies. One case of minimal change disease (MCD) and one case of membranous glomerulonephritis (MGN) have been studied. The acellular glomerular basement membrane of MCD has a lightly textured or granular surface whereas in MGN a striking reticular network of basement membrane has formed perpendicular to the native basement membrane. The immune complexes have been removed. This technique provides a graphic visualization of GBM alterations occurring in glomerulonephritis and is applicable to the study of human as well as experimental model of glomerulonephritis.     

血管性痴呆小鼠第三脑室室管膜扫描电镜特征观察

目的:观察血管性痴呆(VD)小鼠第三脑室正中隆起室管膜表面扫描电镜特征变化并探讨其意义.方法:采用双侧颈总动脉线结、反复缺血-再灌注法,制作小鼠VD动物模型,并设假手术组作为对照.应用扫描电镜对两组小鼠上述区域进行观察.结果:(1)假手术组:室管膜上皮细胞表面可见较多的纤毛和大量的微绒毛.分泌颗粒丰富,呈圆球形.室管膜上神经元样细胞较多,胞体饱满,呈梭形或锥体形,突起较多.(2)VD模型组:纤毛和微绒毛均明显减少,且室管膜细胞表面凹凸不平.室管膜细胞分泌颗粒明显减少,且形态各异,有皱缩现象.室管膜上神经元样细胞数量减少,胞体不饱满,树突减少.结论:VD小鼠正中隆起室管膜细胞和室管膜上神经元样细胞存在着超微结构的损伤;本研究发现的上述改变是VD发生的重要病理学改变之一.