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The ultrastructure of rat hepatocytes was investigated at once at 30 min liver ischemia and at different periods after it. In 24 h of recirculation the processes of the recovery of hepatocyte ultrastructure dominated in the liver parenchyma, but even in 14 days of recirculation no complete reconstruction of hepatocyte ultrastructure was observed.
The histology and ultrastructure of the hyaloid vascular system was studied in 16 monkeys, ages 85 days in utero to 3 years old. The well-developed hyaloid artery is identifiable ultrastructurally as an arteriole consisting of a nonfenestrated intima, a multilayered smooth muscular media, a connective tissue adventitia, and a perivascular sheath. By the fourth week after birth, the vessel walls appear hyalinized and acellular; the lumen is occluded by a thrombus. The time of the complete disappearance of the hyaloid artery varied considerably in individual monkeys; remnants of the hyaloid artery were often present on the disc (Bergmeister's papilla) in adult life. The vasa hyaloidea propria and tunica vasculosa lentis are small branches of the hyaloid artery which fill the primary vitreous. Ultrastructurally, they are Type A-1-alpha capillaries having a nonfenestrated endothelium, incomplete pericyte layer, and basement membranes surrounding each. Fluorescein angiography of several newborn monkeys revealed nonleakage of dye from the hyaloid artery and its branches, thus correlating with the presence of endothelial tight functions.
Ultrastructure of epithelial surface of the esophageal mucous membrane has been studied in nine practically healthy persons at the age of 32-46 years. The material has been obtained at prophylactic esophagoscopy. The surface of the epithelial layer cells is covered with microfolds 100-200 nm wide and 200-600 nm tall forming labyrinth-like patterns. According to the ultrastructural character of the apical surface of the cells, it is possible to judge about their functional state. The characteristics of the ultrastructure of the fracture surface of the epithelial layer is presented. The data obtained can serve as a base for estimation and differential diagnosis of pathological processes in the organ.
Immunizations of chickens with bovine glomerular basement membrane (GBM) results in the development of experimental autoimmune glomerulonephritis (EAG). Animals lacking antibody to GBM develop nephritis comparable to those with antibody. The present study examined the ultrastructural lesions of EAG. Normal and bursectomized (Bsx) chickens were immunized with complete Freund's adjuvant (CFA) or CFA-GBM. We studied 3 CFA controls, 5 CFA-Bsx controls, 5 GBM immunized, 4 Bsx-GBM immunized antibody positive birds, and 6 Bsx-GBM immunized birds with no antibody. Ultrastructure of control animals was consistent with previous descriptions in chickens. In nephritic GBM-immunized animals the proliferative glomerulonephritis was associated with an increase in resident mesangial (type I) cells identified by small regularly shaped nuclei with coarsely clumped chromatin and scanty cytoplasm. (p less than 0.05). Glomerulonephritis was also associated with the occurrence of type II cells characterized by an irregular folded lobulated nucleus, finely granular chromatin, abundant cytoplasm, and dense granules and vacuoles in the cytoplasm with an appearance similar to macrophages. The presence of type II cells was highly associated with the development of glomerulonephritis, p less than 0.05. The increase in type II cells was observed in animals with and without antibody along the GBM. A third type of cell was also observed in intimate contact with type II cells and had the morphology of a lymphocyte. The lymphocytoid cells were only seen in nephritic animals. Bsx was associated with trabeculation and lucencies of the GBM not found in normal birds, p less than 0.05. EAG in chickens occurs regardless of the presence or absence of GBM-bound anti-GBM antibody. Other studies have shown that the disease can be transferred by specifically sensitized lymphocytes, but not by antibody. The present ultrastructural findings provide further evidence for the role of cell mediated immunity in the pathogenesis of this model of EAG in chickens.
Male Sprague-Dawley rats were treated with carminomycin i.v. in doses ranging from 1 to 40 mg/kg. Within 1 hr after the administration of carminomycin, 20 mg/kg, nucleoli of cardiac and skeletal muscle cells were segregated, while nucleoli of liver parenchyma cells were unaffected. Three and one-half hr after drug administration, cardiac muscle nucleoli reverted to normal ultrastructure. However, some skeletal muscle cell nucleoli were still segregated. Following treatment with carminomycin, 10 mg/kg, no significant ultrastructural changes were observed. These results demonstrate that at sufficiently high doses carminomycin induces ultrastructural lesions in nucleoli of both cardiac and muscle cells. The dose of carminomycin required to produce nucleolar segregation in cardiac and skeletal muscle is 6 times greater than the dose of Adriamycin (3.5 mg/kg) required to induce equivalent alterations.
A method is described for systematic semiquantitative investigation of glomerular ultrastructure in renal biopsies from patients with glomerulonephritis. Three glomeruli per biopsy were studied by electron microscopy. Ten systematically recorded micrographs at x12,000 and a montage covering the whole glomerular cross-section at x3,000 were analyzed from each glomerulus. The severity of each of 34 different ultrastructural lesions was semiquantitatively evaluated on a 4-degree scale, 0 to +++. The usefulness of the method was evaluated by calculating different parameters for the reproducibility of semiquantitative scoring, representativeness of micrographs, and representativeness of glomeruli. The reliability of the method was considered good or acceptable with respect to 17 of the lesions. Ten lesions obtained a high reproducibility of scoring but the usefulness of the scores was limited due to a segmental and/or focal distribution of these lesions. The evaluation of these lesions can be improved by analyzing a larger number of micrographs, or glomeruli, or both. Seven lesions were so rare in the present biopsies that no statistical evaluation was possible. When applied to a large number of biopsies, this practical and useful method allows a reproducible comparison of the patterns of ultrastructural lesions in various types of glomerulonephritis.
The ultrastructure of the trophozoite of Entamoeba histolytica cultivated in vitro on artificial media is described from electron-microscope studies made by the authors and from other published accounts. The authors point out that the description does not present a complete picture of the trophozoite of this species of amoeba since no detailed studies of the dysenteric form in infected host organs have yet been made and that nothing is known about the ultrastructure of cysts and the process of cyst formation, maturation and germination.The cytoplasm is confined by a 3-layered cytoplasmic membrane and contains many different organelles: subpellicular dark bodies, ribosomes, helical aggregates of ribosomes, osmiophilic lipoid granules, short dark tubular bodies of unknown origin and function, food vacuoles and some very small vacuoles thought to be lysosomes. Neither mitochondria nor a Golgi apparatus could be found. In the nucleus, the chromatin material is accumulated around the periphery and the nucleolus is centrally situated. The nuclear envelope is a double-layered membrane with numerous pores. Some groups of button-like particles were seen within the nucleus and it is thought that they are probably symbiotic virus-like particles.Some comparisons are made with the ultrastructure of other amoebae, both parasitic and free-living, and some further lines of study are suggested.
Although electron microscopy has been of limited value in detecting malignant neoplasms, some neoplasms do exhibit characteristic ultrastructural features. Intensive study of these features may offer insight into the etiology and activity of such tumors. In an attempt to characterize the ultrastructure of endometrial adenocarcinoma, tissue was examined with the electron microscope and compared with normal postmenopausal endometrium. Endometria from biopsy, hysterectomy, or curettage were processed routinely for light and electron microscopy. Several ultrastructural features of the adenocarcinoma were common both to previous descriptions of endometrium of the postovulatory phase and to the normal postmenopausal endometrium, described here, viz, atypical mitochondrial forms and cell surface modifications. Ribosomes were abundant in adenocarcinoma of the endometrium, normal postmenopausal endometrium, and normal cyclic endometrium in the preovulatory phase.
Electron-microscopic investigations on the human adrenal cortex have been carried out in order to elucidate ultrastructural differences in the various zones. These studies indicate that certain differences in the ultrastructure of the mitochondria may be particularly useful as criteria to differentiate the three cortical zones. In this regard, the appearance of two types of mitochondria in the zona glomerulosa as well as in the zona fasciculata is of obvious interest. The probability of a relationship between the activity of the different cortical zones and the predominant presence of one form of mitochondria has been suggested. In addition, ultrastructural transformations following stress situations as well as problems dealing with the so-called 'dark and light cells' and the basal membrane are discussed.
Thirty-three patients presenting with dyspepsia were examined with the Olympus Fiber-gastroscope. An endoscopic diagnosis was made in each case and multiple gastric biopsies were obtained for histological and ultrastructural assessment. The endoscopic, histological and ultrastructural findings were compared with each other. Of 33 patients endoscoped, 29 were found to have endoscopic evidence of various types of gastritis and all of these latter had histological evidence of some form of gastritis. Histological confirmation of specific types of endoscopically diagnosed gastritis, however, was only found in 3/9 cases of chronic atrophic gastritis (CAG), 10/14 cases of chronic (superficial) gastritis (CG) and in none of six cases of acute gastritis (AG), indicating that endoscopic diagnosis of specific types of gastritis is relatively inaccurate. Endoscopic diagnosis should thus be restricted to presence or absence of gastritis, leaving the specific typing to histological assessment of the gastric biopsies. Multiple gastric biopsies should be obtained even though the gastric mucosa appears normal endoscopically, since histological evidence of gastritis was found in three out of four cases with endoscopically normal gastric mucosa. Comparison of histological diagnosis with electron microscopy showed that generally there is good correlation between the severity of the histological changes and the ultrastructural grade of damage as defined in this study. It would appear that E.M. examination of the gastric biopsies will not significantly increase the diagnostic accuracy of light microscopy, although it has elucidated the various cellular changes which characterize chronic gastritis. The rough surface contours, the large gastric pit and the increasing number of surface microvilli, seen by scanning E.M., aid the grading of the disease process. Some of these changes are reflected in observations made by transmission E.M. where in addition the basal intercellular edema of the mucosal layer and the appearance of electron-dense mucosal lining cells are observed. The latter, which are the counterpart of "intestinal metaplasia", possess mucus granules which resemble those of gastric mucosal lining cells or intestinal goblet cells, or both.
In non-trained mice subjected to a single and repeated swimming up to complete wearness, fibres in the skeletal muscles demonstrated certain ultrastructural alterations in their nuclei. Twenty-four and 48 h after a single swimming many muscular nuclei have only non-condensed chromatin. After repeated swimming large clumps of condensed chromatin appear in most of the muscular fibre nuclei. These nuclear changes are accompanied by segregation of separate fibrillar areas containing nuclei. Similar phenomena are also noticed in muscular fibres of non-trained people after a single physical loading. Ultrastructural changes in skeletal muscular fibres of volunteers, nonsportsmen are of individual character and depend on the degree of wearness resulting from the loading. In people subjected to the experiment and having severe fatigue (disability to work) significant shifts in submicroscopical structure of the fibrillar components were observed: in mitochondria, sarcoplasmic reticulum, T-system, contractile apparatus, etc. In this case, matrix becomes clear, lysis in mitochondrial crysts, dilatation of terminal cysterns of the sarcoplasmic reticulum and T-system tubes, destructive and regenerative processes in the contractile apparatus are observed. The data obtained demonstrate varied changes in ultrastructure of different components composing skeletal muscles of the non-trained organism subjected to physical loading.
Alterations induced by the cholinesterase inhibitor armin (5.10(-7) g/ml) in the ultrastructure of motor nerve endings of the rat phrenic diaphragmal preparations at rest or electric stimulation of the nerve were studied. It was shown that armin at rest induced ultrastructural lesions in the endings similar to those in the control preparations during nerve stimulation. Electric stimulation did not produce additional changes in the ultrastructure of the neuromuscular junction under armin action. It is suggested that the disorder of the nerve ending function may be of importance in the mechanism of the blocking action of armin on the neuromuscular transmission.
Mouse embryos which are homozygous for the c25H deletion at the albino locus are developmentally arrested at the 2- to 6-cell cleavage stages. This study reveals that the mutant embryos cease development before they can be distinguished ultrastructurally from their normal litter-mates. After prolonged developmental delay (24--48 h), the nuclei of the mutant embryos become extremely aberrant in shape, whereas other subcellular organelles remain normal and there are no signs of pyknosis. Eventually, the mutant embryos do become pyknotic and begin to degenerate. The striking effects of this deletion on nuclear ultrastructure of cleavage-stage embryos are discussed in relation to biochemical and ultrastructural defects caused by other lethal deletions at the albino locus.
Dynamics of reactions in the main components of the exocrine part of the rat pancreas (capillary, nerve, pancreocyte) was subjected to ultrastructural analysis at bilateral subdiaphragmatic vagotomy within 24 hours--30 days. It was stated that certain ultrastructural shifts developed in all the components mentioned above; at first they are within the limits of physiological parameters (the first three days), and then destructive processes occur (up to destruction of a part of cells) reaching their maximum by the end of the first--beginning of the second week and having a focal character. Then compensatory-recovery rearrangements begin to predominate, and by the 30th day they result in a considerable but not yet complete normalization of the ultrastructural organization of the gland. Three stages (phases) can be mentioned in the development of the neurodistrophic process: the first--stress reaction of the organ and the whole organism to the operation; the second--predominance of destructive changes; the third--development of compensatory-adaptive processes. Possible mechanisms of the rearrangements occurring are discussed.
The histologic and ultrastructural morphology of three cases of Ewing's sarcoma of soft tissue are described and the fine structural features of extraskeletal Ewing's sarcoma are compared to those of similar round-cell tumors that are considered in the differential diagnosis. By light microscopy, these tumors are indistinguishable from Ewing's sarcoma of bone. Ultrastructurally, the salient features are also comparable to Ewing's sarcoma of bone and include: 1) absence of surface modifications; 2) cell-contact sites in the form of small thickenings of apposed membranes and large desmosome-like specializations; 3) undifferentiated cytoplasm usually containing abundant glycogen and occasionally nonspecific microfilaments; 4) significant variation in shape and irregularity of nuclear profiles. The ultrastructural features of extraskeletal Ewing's sarcoma are sufficiently distinctive to allow separation from from other small-cell malignant neoplasms in the majority of cases.
In the present work the authors have observed the ultrastructure of different types of cartilage and connective tissues of four different species of animals affected with osteogenesis imperfecta (man dog cat and young fox. The ultrastructural pictures demonstrate that the morphological aspects of cartilage of different species are often comparable and all cartilage tissues present the following characters: 1) Some lipid droplets inside the cytoplasm. 2) A reduction of the number and diameter of collagen fibrils. 3) A sensible increase of diameter of the alcianophilic bands that are ultrastructural representation of glycosaminoglycans. Some abnormal aspect has been seen on the connective non cartilagineus tissues.
Ultrastructural examination of 28 human pituitary adenomas was performed. Findings were correlated to the clinical history and light microscopic observations. As revealed by light and electron microscopy 15 adenomas were of the chromophobe type causing no endocrine dysfunction. In 8 cases acidophilic adenomas were associated with endocrine symptoms. In this group two adenomas were of the densely granulated type, whereas 6 of the sparsely granulated type. The latter showed marked ultrastructural signs of enhanced secretory activity. Five cases corresponding electronmicroscopically to sparsely granulated acidophilic adenomas but causing no endocrine symptoms constituted a separate group. They suggest the possibility of the production of abnormal proteins by this type of adenoma cells. Oncocyte cell-groups were seen in chromophobe adenomas. Morphometric data on granule size and distribution proved to be useful in the differentiation of chromophobe and acidophilic adenomas. Hypertrophic cell organelles, filamentous and tubular structures are interpreted as ultrastructural signs of cellular adaptation.
Ten testicular biopsies from adult males with agenesis of the vas deferens have been investigated with light and electron microscopy. The ultrastructural study of SERTOLI cells has demonstrated that: (a) the junctions between SERTOLI cells and between SERTOLI and germinal cells retain their normal ultrastructural features. (b) Lanthanum permeates SERTOLI cells tight junctions, but its diffusion towards the adluminal compartment is prevented. (c) SERTOLI cells present unusual amounts of cytoplasmic inclusions, especially lipofuscin granules. A relationship between these inclusions and phagocytosis has not been demonstrated. (d) "Dark" SERTOLI cells which show alterations of their typical junctional complex have been frequently observed, although their frequency varies among the different patients. The results are discussed in relation to diagnostic significance of the ultrastructural study of testicular biopsies.