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At least 685 records · Page 38Linked to original sources
PubMed1975

New kind of cytoplasmic inclusions of plasma cells in acid maltase deficiency.

Extensive 'vacuolization' could be demonstrated in nearly all plasma cells and in some lymphocytes of an adult with glycogenosis type II (Pompe's disease). The biochemically defined diagnosis acid maltase deficiency (AMD) could be ascertained by examination of the maltase activity of the patient's leukocytes. Electron microscopical, microspectrographic, and cytochemical investigations revealed electron dense inclusions, which show an UV absorption at 276 nm and a positive reaction after PAS staining of plastic embedded material. Since no other abnormalities of the plasma cells could be found, our results are presumably indicative for a connection of AMD and a glycoprotein storage in the plasma cells of the patient.

Adult↗
PubMed1988

Long-term propranolol administration alters myocyte and ventricular geometry in rat hearts with and without infarction.

To determine the effects of long-term beta-adrenergic receptor blockade on adult rats with myocardial infarction, we studied 24 female Sprague-Dawley rats with myocardial infarction induced at 20-22 weeks of age. Two days after surgery, the animals were randomized to receive either propranolol (750 mg/l) in their drinking water or water alone for 5 weeks. Plastic, embedded, longitudinal and cross sections of septum (1 micron thick) were prepared for morphometric measurements. In untreated rats, infarction was followed by myocardial hypertrophy, as shown by significant increases in septal area (23%), myocyte length (19%), cross-sectional area (20%), and volume (43%) (p less than or equal to 0.05). In rats with and without infarction, beta-blockade resulted in decreased myocyte dimensions and increased left ventricular cavity dimensions. Propranolol had special effects in rats with infarction, resulting in significant blunting of increased cross-sectional area (15% less, p = 0.04) and a greater increase in left ventricular cavity dimensions (38% more, p = 0.04). Thus, propranolol blunts myocardial hypertrophy and increases left ventricular cavity dimensions in rats with myocardial infarction.

Analysis of Variance↗
PubMed1991

Does vasospasm occur in small pial arteries and arterioles of rabbits?

BACKGROUND: Vasospasm is a serious complication associated with subarachnoid hemorrhage. Successful management of vasospasm will ultimately depend on a clear understanding of the scope of this phenomenon, including whether arterial elements of different calibers are equally affected. We therefore examined the responses to subarachnoid hemorrhage in rabbit basilar arteries, small pial arteries, and arterioles. SUMMARY OF REPORT: We compared the brain stem pial arteries of 10 perfusion-fixed male New Zealand White rabbits after experimental subarachnoid hemorrhage to those of five control rabbits using morphological analysis of cross-sections of plastic-embedded vessels. After subarachnoid hemorrhage, the internal elastic lamina was highly corrugated in all basilar arteries (mean diameter 319 +/- 51 microns). These arteries were severely constricted in comparison with the control group, in which the mean diameter was 691 +/- 17 microns, and corrugation of the internal elastic lamina was not present. In contrast, small pial arteries and arterioles very rarely demonstrated a vasoconstrictive configuration after subarachnoid hemorrhage. The contractility of the smaller vessels was confirmed by injecting 2 mg/kg BaCl2 intracisternally. Following BaCl2 injection, corrugation of the internal elastic lamina was detected in the small arteries and arterioles as well as the basilar arteries. CONCLUSIONS: We conclude that experimental chronic vasospasm after subarachnoid hemorrhage in rabbits tends to occur in large conducting arteries rather than in smaller pial arteries and arterioles.

Animals↗
PubMed1992

Goblet cell hyperplasia in large intrapulmonary airways after intratracheal injection of cathepsin B into hamsters.

Goblet cell hyperplasia (GCH) is a frequent histologic finding in the airways of smokers. Experimental observations suggest that the process may be caused by increased proteinase activity in the airways. To investigate the possible role of cathepsin B in the development of GCH, male Syrian golden hamsters were given three intratracheal injections of bovine spleen cathepsin B or buffer (pH 5.5) at 2-day intervals. Six weeks later, we found by review of PAS-hematoxylin-stained 1-micron sections of plastic-embedded lung tissue that large intrapulmonary airways of animals given cathepsin B contained a significantly greater number of secretory cells per millimeter of airway (64.8 +/- 7.3 versus 47.5 +/- 10.3 for control animals, p less than 0.005) in association with a significant increase in the number of total cells per millimeter of airway, from 149 +/- 14 for control animals to 164 +/- 11 for cathepsin-B-treated animals (p less than 0.025). No change was observed in the number of ciliated cells (93.9 +/- 8.1/mm for control animals versus 94.8 +/- 10.3/mm for cathepsin-B-treated animals) or other cells (3.0 +/- 2.2/mm for control versus 4.3 +/- 4.1/mm for cathepsin B), indicating that selective expansion of the secretory cell population occurred. In contrast, in the main bronchi of animals given cathepsin B, no significant alterations were found in the number or percentage of secretory cells. The findings reveal that cathepsin B induces secretory cell hyperplasia in hamsters and suggest the possibility that cysteine proteinases may contribute to GCH in smokers.

Animals↗
PubMed1992

Effects of treatment on airway inflammation and thickening of basement membrane reticular collagen in asthma. A quantitative light and electron microscopic study.

We have obtained airway mucosal biopsies by fiberoptic bronchoscopy for light and electron microscopic analysis of three distinct airway levels of the left lung in three subject groups. Group A: 11 subjects with mild atopic asthma (mean age, 29 yr; %FEV1, 89 to 116%; mean PC20 histamine, 2.42 mg/ml), each biopsied twice, one prior to 4 wk of treatment with either inhaled terbutaline (250 micrograms, two puffs four times daily; n = 5) or inhaled budesonide (200 micrograms, one puff twice daily; n = 6) followed by a second biopsy to allow determination of the effects of treatment. Group B: 10 subjects with severe asthma receiving long-term (average, 3.7 yr) corticosteroid treatment were biopsied once only (mean age, 28 yr; %FEV1, 86 to 129%; mean PC20 histamine, 1.85 mg/ml). Group C: 12 normal healthy control subjects (mean age, 35 yr; %FEV1, 92 to 135%; PC20 histamine greater than 16 mg/ml) biopsied once. By light microscopy of plastic-embedded sections, Group A asthmatics had an increased cellular infiltrate when compared with either the healthy control group or the Group B asthmatics (p less than 0.05). Both asthma groups had a thickening of basement membrane reticular collagen compared with the healthy control group (p less than 0.01). Compared with the control group, there was an increase in the percentage of the total cells that were mast cells (p less than 0.01) and eosinophils (p less than 0.05) in Group A and of eosinophils (p less than 0.01) and histiocytes (p less than 0.01) in Group B. The results of cell counts by electron microscopy largely supported these findings, and, in addition, they demonstrated an increased frequency of foci of free eosinophil granules and decreased numbers of neutrophils (p less than 0.01). By light microscopy, budesonide reduced the percentage of mast cells and eosinophils (p less than 0.05). But for the percentage of lymphocytes, which increased (p less than 0.05), terbutaline was without effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2003

Early thickening of the reticular basement membrane in children with difficult asthma.

Remodeling of the airway wall occurs in adults with asthma, and reticular basement membrane (RBM) thickening is pathognomonic of the asthma process. To investigate whether RBM thickening is present in children with difficult asthma and comparable to that seen in adults with asthma, we used light microscopy to measure RBM thickness in plastic-embedded endobronchial biopsy sections from 19 children with difficult asthma who were prescribed 1,600 microg/day or more of inhaled steroids (age range, 6-16 years), 10 children without asthma (7-16 years), and three adult groups: 8 healthy control subjects (21-42 years), 10 mild steroid-naive subjects with asthma (18-41 years), and 6 adults (3 steroid naive and 3 on inhaled steroids) intubated after a life-threatening attack of asthma (20-64 years). RBM thickness in the children with asthma was similar to that in adults with either mild or life-threatening asthma (median 8.2 [range 5.4-11.1] versus 8.1 [5.8-10.0] and 7.2 [2.8-10.0] microm, respectively) and greater than either adult or pediatric control subjects (8.2 [5.4-11.1] versus 4.4 [3.2-6.3] microm, p < 0.01, and 4.9 [3.7-8.3] microm, p < 0.01). We conclude that RBM thickening is already present in children with difficult asthma and to a similar extent to that seen in adults with asthma. In addition, we find no association with age, symptom duration, lung function, or concurrent eosinophilic airway inflammation.

Adolescent↗
PubMedDate not supplied

Quantitative histology of the mucous membrane of the accessory nasal sinus and mastoid cavities.

The mucous membranes of the accessory nasal sinuses and of the mastoid labyrinth were measured in undecalcified, plastic-embedded specimens from nonpathologic postmortem cases. Epithelial thicknesses, lamina propria thicknesses and the ratio of nuclear to total cell area of the epithelia are presented for these organs to provide a quantitative basis for dosimetric calculations of alpha-emitting radionuclides. These data will be of value for studies in populations at risk for head carcinomas from the intake of radium and related nuclides.

Adult↗
PubMedDate not supplied

Regional cochlear blood flow studied by observation of microspheres in serial sections.

Using the microsphere method combined with light microscopic observation of serially sectioned plastic-embedded cochleas, the distribution of microspheres trapped within the cochlea can be observed and the regional blood flow can be determined. In the guinea pig, the blood flow is greatest in the lateral wall, high in the modiolus, and low under the organ of Corti.

Animals↗
PubMed2004

Immunocytochemical localization of histatins in human salivary glands.

Histatins are a family of salivary proteins with bactericidal and fungicidal activities that contribute to the innate defense of the oral cavity. Histatins are present in the serous granules of the parotid and submandibular glands. The important role of histatins in saliva, and the limited information on their cellular and subcellular distribution, prompted us to further define the localization of histatins in the major salivary glands. Immunogold-silver staining of 1- micro m sections of plastic-embedded tissue with anti-histatin antibody revealed histatin immunoreactivity in the serous acinar cells of the parotid and submandibular glands, the serous demilune cells of the submandibular and sublingual glands, and in occasional intercalated duct cells. No reactivity was seen in mucous cells or in striated or excretory duct cells. Electron microscopic observations of thin sections labeled with anti-histatin and gold-labeled secondary antibodies revealed immunoreactivity associated with the rough endoplasmic reticulum and Golgi complex and in secretory granules of serous acinar and demilune cells. The granules of parotid acinar cells exhibited relatively uniform labeling of their content, whereas the granules of serous cells in the submandibular and sublingual glands showed variable labeling of the dense and light regions of their content. A few intercalated duct cells adjacent to the acinar cells also exhibited labeled granules. These results suggest that the serous cells of the major glands are the main source of histatins in human saliva. They are also consistent with several previous studies demonstrating the variable distribution of different proteins within the granule content.

Adult↗
PubMed1990

Basic pathologic processes in the nervous system.

The methods for pathological assessment of the central nervous system and the peripheral nervous system differ, and there are also differences in the level of cellular resolution routinely achieved in screening techniques. In the PNS, plastic-embedded sections and teased nerve fibers from multiple regions provide satisfactory screening techniques; in the CNS, differential staining of paraffin sections provides the most practical screening approach. In both the CNS and PNS, the basic pathological processes are similar; these include Wallerian degeneration, distal axonal degeneration, and primary demyelination. In the future, new screening techniques based on immunocytochemical analyses and measurement of specific mRNA levels can be anticipated.

Animals↗
PubMed1989

Crystal morphology and decalcification patterns compared in rat and human enamel and synthetic hydroxyapatite.

The purpose of this investigation was to compare morphology and dissolution patterns by ultrastructural examination of rat and human enamel crystals as well as synthetic apatite crystals. Mature enamel crystals were of particular interest, since crystal maturation appears to be inhibited in amelogenesis imperfecta. Specimens were isolated from developing and mature rat incisor enamel. Rat enamel, mature human enamel, and synthetic apatite were thin-sectioned without decalcification and examined by transmission electron microscopy. Some sections were exposed to acid, and selected synthetic apatite sections were further treated for removal of embedding plastic, followed by vacuum-shadow-coating with carbon. Results showed that cross-sections of rat, human, and synthetic crystals had a distortion in the flattened hexagonal outline in regions where the growth of one crystal impinged on another. Crystal dissolution occurred preferentially along the c-axis, producing a central defect or hole in the crystals. Preliminary studies with weak acid on mature human enamel indicate that the relatively soluble crystal core is quickly dissolved, while the outer shell remains intact over a much longer period of time. In the mature rat and human enamel, this crystal hole formation had a consistent dimension of approximately 10-nm thickness. The crystal hole dimension was the same size as crystals that are formed during the early secretory phase in rat amelogenesis. Acid-treated synthetic apatite also showed dissolution of the crystal core along the c-axis, but dimensions of the hole were not consistent.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1977

Rapid chemical dehydration of biologic samples for scanning electron microscopy using 2,2-dimethoxypropane.

Acidified 2,2-dimethoxypropane (DMP) has been used as a rapid chemical dehydrating agent en route to plastic embedding and ulthrathin sectioning for conventional electron miscroscopy (J Histochem Cytochem 23:107, 1975). We have used DMP to dehydrate biologic specimens prior to critical point drying and metal coating for scanning electron microscopy. There is no difference in either the gross architecture or the fine surface structure of mouse small intestine and trachea, rat trachea and kidney, and cultured fibroblasts, between samples dehydrated in DMP for 5 min to 30 days and those conventionally dehydrated in ethanol or acetone. DMP dehydration is advantageous in speed, economy and apparent completeness.

Animals↗
PubMed1977

Electron probe x-ray microanalysis of small granulated cells in rat sympathetic ganglia after sequential aldehyde and dichromate treatment.

Rat adrenal medulla and celiac-mesenteric sympathetic ganglia were fixed by a glutaraldehyde/formaldehyde-potassium dichromate-osmium treatment sequence and plastic-embedded. Fine sections were examined by electron probe x-ray microanalysis. Comparable peaks for chromium (Kalpha = 5.4 keV) were obtained from cytoplasmic fields containing membrane-bounded inclusion granules in both adrenomedullary noradrenaline cells and a type (type II) of sympathetic small granulated cell whose inclusion granules closely resemble those of the adrenomedullary noradrenaline cell. Chromium was not detected in granules within adrenomedullary adrenaline cells nor in two other sympathetic small granualted cell types. In no material was chromium detected in agranular cytoplasmic or nuclear fields. Since chromium binds to the Schiff monobase formed by glutaraldehyde and noradrenaline during fixation, we infer that noradrenaline is present in the granules of the type II sympathetic small granulated cell, as well as in adrenomedullary noradrenaline cells.

Adrenal Medulla↗
PubMed1981

Autoradiography of phosphatidyl choline.

Saturated choline phosphatides are extracted during conventional tissue processing for electron microscopy. To facilitate autoradiographic subcellular localization of arrhythmogenic myocardial phospholipids, we evaluated tissue processing procedures for preservation of saturated phosphatidyl choline (PC). Suspensions, of a murine plasmacytoma were incubated with negative, unilamellar liposomes containing 14C-choline-labeled PC or 14C-1-palmitate dipalmitoyl PC. Extraction of radioactivity was monitored at each processing step by liquid scintillation spectrometry. Conventional fixation with glutaraldehyde and osmium tetroxide followed by acetone dehydration and Spurr's plastic embedding led to extraction of nearly all radioactivity. However, treatment of cells with 1.5% tannic acid after glutaraldehyde but before osmium tetroxide fixation preserved 93.1 +/- .6% of 14C-choline-labeled PC. Virtually identical results were obtained with dipalmitoyl PC. Autoradiography demonstrated no significant translocation of labeled PC from plasmacytoma cells to unlabeled avian erythrocytes, mixed in equal proportions after fixation but before dehydration and embedding.

Autoradiography↗
PubMed1982

Application of the avidin-biotin-peroxidase complex (ABC) method to the light microscopic localization of pituitary hormones.

The avidin-biotin-peroxidase complex (ABC) method was applied to semithin (0.5-1 micron) plastic-embedded sections of intact male rat pituitaries with the use of techniques previously developed for the peroxidase-antiperoxidase complex (PAP) method. Stains for adrenocorticotropin (ACTH), thyroid stimulating hormone (TSH), luteinizing hormone (LH), and follicle stimulating hormone (FSH) were cleaner, more reliable, and more efficient. The ABC method allowed the use of the same high dilutions of primary antisera used with the PAP method. Incubation time was cut to a third of the time used for the PAP stain. Furthermore, if the incubation time matched that used with the PAP method, (24-48 hr), the antisera could be diluted 2- to 4-fold further. This enhanced specific staining and allowed the use of dilutions similar to those used in the radioimmunoassay. In agreement with Hsu and Raine (J Histochem Cytochem 29:1349, 1981), the ABC method produced staining after only a 1-4 hr incubation in primary antibody that was diluted optimally for the PAP complex method. The stain was weak, however, and cell counts showed that it was restricted to the fraction of the specific cell population which stored the most hormone. Our tests showed that the most convenient incubation times for optimal staining were 12-16 hr. Furthermore, the ABC method appeared to stabilize greatly the reaction for FSH and thus improved its precision and reliability.

Adrenocorticotropic Hormone↗
PubMed1984

A simple and reliable method for the localization in cell culture of single identifiable cells for ultrastructural analyses.

A simple method for relocating single cells in monolayer cultures for subsequent morphological or ultrastructural analysis is reported. This consists of producing, on the culture dish surface, a nontoxic carbon grid that is preserved during processing for either transmission (TEM) or scanning (SEM) electron microscopy. For TEM studies these grids are readily transferred along with the cells into the embedding plastic, and thus individual grid squares containing a cell(s) of interest can be quickly located, remounted, and sectioned. These grids may be useful for ultrastructural analyses of single cells previously studied electrophysiologically or after microinjection of macromolecules.

Animals↗
PubMed1986

Neurites and growth cones in the chick embryo. Enhanced tissue preservation and visualization of HRP-labeled subpopulations in serial 25-microns plastic sections cut on a rotary microtome.

Study of axonal guidance in developing vertebrates has been hindered by an inability to readily visualize individual growth cones, determine the neuronal population from which they originate, trace their trajectories, and discern their interactions with their embryonic environment. We report a method that combines plastic embedding and serial sectioning with horseradish peroxidase labeling of subpopulations of neurons in the chick embryo. This method labels individual neurites from the soma to the tip of the growth cones, allowing their trajectory to be inferred and their identity to be determined by the position of the somata. As sections are up to 25 micron thick, entire growth cones can often be visualized without laborious reconstruction. Tissue preservation is much better than with similar material embedded in paraffin. Sections are cut relatively quickly using a steel knife on a standard rotary microtome and are suitable for subsequent electron microscopy.

Animals↗
PubMed1988

Colloidal gold immunostaining on deplasticized ultra-thin sections.

We localized tissue antigens on ultra-thin sections by deplasticizing the sections while on the grid, incubating in primary antiserum followed by immunoglobulin-conjugated colloidal gold, and ultimately re-embedding in dilute Epon. This procedure permitted ultrastructural localization of tissue antigens that were previously masked by the embedding plastic surrounding tissue components. In addition, replacement of the plastic matrix on the thin section after immunostaining prevented development of the drying artifacts that occur in unsupported tissue sections. Optimal preservation of components in the tissue sections was achieved despite extensive steps involved in plastic removal and immunostaining. This method may be useful in situations where the number of exposed epitopes on the surface of a thin section is low. The procedure also allows the use of antisera at greater dilutions and provides enhanced immunostaining specificity with low background.

Actins↗