The first target of ricin in the liver appears to be the Kupffer cells which are heavily damaged as early as four hours after the intravenous inoculation of 6 LD100 into mice. At that time, the only endothelial cell damage is constituted by more or less extended interruptions of the fenestrated cytoplasm. Hepatocyte injury affects the endoplasmic reticulum, the glycogen, the mitochondria as well as the plasmic membrane; however, it never results in cytolysis or complete necrosis. The intravascular coagulation observed may be induced either by the endotoxins, which are no longer cleared by the Kupffer cells, or as a result of the loss of the sinusoidal lining with the ensuing platelet activation.
The cytoskeleton of Tritrichomonas foetus was studied by immunofluorescence microscopy, using anti-actin, anti-filamin, anti-myosin and anti-tubulin monospecific antibodies, and by high voltage electron microscopy of Triton X-100 extracted cells. Actin, filamin and myosin were distributed throughout the cytoplasm of T. foetus. Filamin, however, is more concentrated at the cell periphery. The peltar-axostylar system could be seen in interphasic and dividing cells using anti-tubulin antibodies. High voltage electron micrographs showed the spatial distribution of the microtubules and their association with the hydrogenosomes, and the association of the costa with the recurrent flagellum.
The effects of prenatal exposure to ethanol on the lateral (contiguous) plasma membrane of newborn rat hepatocytes was investigated using qualitative and quantitative freeze-fracture. The number of free intramembranous particles decreased by 11% and 17% in P- and E-faces, respectively. Alcohol also induced the appearance of particle-free areas within the gap junctions, in addition to a three-fold increase in the mean area and an increment in the percent of plasma membrane occupied by these elements. However, no differences in either the size of gap junction particles or in the mean interparticle distance were found between control and alcohol-treated animals. On the other hand, prenatal exposure to ethanol did not alter the structure of tight junctions.
The deletion of ABH blood group antigens from the luminal surface of the bladder mucosa in cases of well differentiated transitional cell carcinomata, and the formation of pleomorphic microvilli have both been associated with aggressive biological behaviour and invasiveness of the tumors. We have studied cold cup biopsies from 8 normal mucosae and 17 papillary transitional cell carcinomata of the urinary bladder. The aim of our study was to correlate the formation of uniform or pleomorphic microvilli with the extent of deletion of the ABH blood group antigens on the surface of normal and transformed bladder urothelium. Immunogold scanning electron microscopy (SEM) in the backscattered electron (BE) imaging mode was used for this purpose. In the normal urothelium, uniform labeling of the luminal cells was demonstrated. In well differentiated tumors, the superficial cells exhibited uniform microvilli and a heterogeneous expression of the ABH antigens, giving characteristic 'mosaic' patterns of the antigenic labeling across the mucosal surface. These patterns were sharply delimitated at cell junctions when viewed by SEM; these observations were confirmed by transmission electron microscopy. In higher grade tumors, decreased ABH antigen expression, pleomorphic microvilli and/or featureless luminal cells were observed. In the transformed urothelium, the formation of uniform microvilli appeared to precede the loss of ABH antigen in most cases.
The structure of the transverse-axial tubular system (TAxTS) in ventricular and atrial myocytes of the rat heart was investigated by examining thick (as much as 0.2 micron) and thin sections stained by the ferrocyanide-osmium method. Ventricular myocytes contain longitudinally and transversely oriented tubules which represent invaginations of the plasma membranes and form orderly latticeworks. These tubules are irregular in diameter and course tortuously. Dilated, triangular cisterns are often seen at the points of interconnections between longitudinal and transverse elements. The junctional sarcoplasmic reticulum forms 'couplings' with both transversely and longitudinally oriented TAxTS tubules, and a large proportion of the surface area of the TAxTS tubules is involved in such couplings. In atrial myocytes, the TAxTS tubules are poorly developed and pleomorphic, often with a beaded appearance, and show an irregular distribution from one cell to another and from one area to another within a given cell. The osmium-ferrocyanide stain reveals the TAxTS to be much more extensive than is evident from examination of routinely stained preparations.
A serial section study was executed on a lymph node from a case of AIDS (acquired immune deficiency syndrome) to determine the true three-dimensional morphology and mode of genesis of tubular confronting cisternae which are found in the lymphocytes in this condition. Serial sections from over a hundred such structures show that these are tubular structures and that the 'test-tube and ring-shaped' forms described in the literature are no more than profiles one expects to see when a tubular structure is sectioned. The view at times expressed in the literature that these structures are truly test-tube-shaped (i.e. one end closed) appears to be erroneous, for our serial section study did not reveal a single instance where one end was closed; all were tubular structures with both ends open. We found that tubular confronting cisternae develop by a process of twisting and spiralling of ribbon-shaped confronting cisternae, and that at one stage of development there is a spiralling groove on the wall of this structure. Microtubuloreticular structures were seen in several lymphoid cells, sometimes they were found in cells containing tubular confronting cisternae. At times microtubules (similar to those seen in microtubuloreticular structures) were seen lying within and/or outside the profiles of dense lamina of tubular confronting cisternae.
Light microscopy morphology and cytochemistry, immunology, and ultrastructural morphology, cytochemistry and immunocytochemistry studies were performed in 18 cases of acute myeloid leukemia (8 M1, 1 M2, 7 M3 and 2 M4, according to the FAB classification). The aim of the investigation was to assess the value of electron microscopy, particularly the immunogold method, in the different FAB subclasses. Transmission electron microscopy with its more recent techniques of investigation was shown to have an important role in diagnosis of early myeloid (M0-M1) and mixed (M4) cases, where it was determinant in correlating ultrastructural morphology with cytochemistry and immunology and thus identifying the different cell populations. On the contrary, in cases in which the leukemic cells showed homogeneous features, light microscopy was adequate and sufficient for correct diagnosis.
The surface epithelium of the mucosa of the nose, sinus maxillaris, trachea and bronchi of the human respiratory tract has been investigated with respect to surface differentiations, glycocalyx and glycocalyceal bodies. The luminal surface mainly is formed by ciliated, undifferentiated, and secretory cells; occasionally metaplastic epithelial regions, composed of flattened squamous cells are found. Ciliated cells as well as differentiating progenitor cells, recognizable by branched, microvillus-like surface differentiations - 'cytofila' which on mature ciliated cells are interposed between the cilia, exhibit a delicate glycocalyx. On the contrary, secretory, undifferentiated, and metaplastic squamous cells possess unbranched microvilli of different length and diameter, and exhibit a prominent glycocalyx of varying, individual expression. These latter cell types, in healthy control persons as well as in patients suffering from different diseases, showed glycocalyceal bodies. By means of the high number of investigated samples, more than 350, the occurrence and distribution of glycocalyceal bodies could be defined more exactly: in all investigated regions of the human respiratory tract--nose, sinus maxillaris, trachea, and bronchi--glycocalyceal bodies were found at the apical surface of undifferentiated cells, secretory cells, and metaplastic squamous cells; ciliated cells and their differentiating progenitor cells never showed glycocalyceal bodies; glycocalyceal bodies were found likewise in healthy control persons as well as in patients suffering from different diseases of the airways.
Spermatozoa of the white-naped crane were examined with the light and electron microscopes. The relatively simple spermatozoa have a small acrosome, a short midpiece, and a flagellum lacking both dense fibers and fibrous sheath. Crane spermatozoa are unique in that the degree of condensation varies among spermatozoa, but in no spermatozoon does chromatin become highly compacted. Incomplete condensation of chromatin may be responsible in part for the variety of sperm head shapes, including elongate, curved, 'S'-shaped, droplet and spherical forms. Crane sperm may provide a system to better understand the mechanism and function of chromatin condensation in spermatozoa.
Palladium salt has been used for some time in experimental therapy protocols; with this in mind, we carried out a study of the effect of tetramine dichloro-palladium (soluble salt) upon kidney cells. Using an electron microprobe, we were able to detect the presence of palladium associated with sulfur and iron in the lysosomes of the proximal tubule cells. Our results were compared with those obtained using Cis-diaminedichloro-platinum (Cis-DDP), an anti-cancer drug used in the treatment of diverse tumors. The mechanism of intralysosomal concentration of palladium as a non soluble salt associated with sulfur appeared to be related to local sulfatase activity. Finally, iron concentration appeared to be related to the inhibition process of erythropoiesis.
The effects of a prolonged treatment with prolactin on the morphology and hormone secretion of rat adrenal zona fasciculata and zona reticularis, were investigated by coupled morphometric and radio-immunological techniques. Chronic prolactin administration provoked a notable atrophy of zona fasciculata cells and a small but significant increase in the corticosterone plasma level, which can be the result of the prolactin-induced inhibition of the intra-adrenal 5 alpha-reductase. Therefore, the atrophy of the zona fasciculata may be reasonably supposed to be not a direct effect of prolactin, but indirectly caused by a negative feed-back mechanism blocking ACTH release. On the contrary, prolonged prolactin treatment induced a conspicuous hypertrophy of zona reticularis cells, as well as a notable rise in the plasma concentration of testosterone, which cannot be due to gonad stimulation by prolactin since orchiectomized rats were employed. As the zona reticularis, like zona fasciculata, is ACTH-dependent, it must be concluded that prolactin exerts a direct stimulating effect on the growth of the zona reticularis, whose functional counterpart conceivably is an enhanced production of androgen hormones.
The transendothelial transport across the lymph vessel wall is connected to the morphological and ultrastructural features of the lymph vessel endothelium. In the present study the lymph vessel wall and the adhesion areas between contiguous endothelial cells of the rabbit heart were examined also by means of serial sections. This examination allowed us to reconstruct the whole intercellular connecting areas and to clarify some discussed adhesion structures. The adjoining cells are connected by three types of contact: end to end, overlapping and interdigitation. In addition the cellular processes form intraendothelial, tortuous channels with focal specialized junctional areas. Only occasional open junctions are present. Our features are discussed and compared with the sometimes conflicting literature data on the morphological properties of these adjoining areas for their significance in the mechanisms of lymph formation.
During the course of our studies on the cerebellum of a dog we found large eosinophilic inclusions in Purkinje cells. Ultrastructural studies revealed that these inclusion bodies are composed of aggregates of stacks of confronting cisternae or modified confronting cisternae. The nature and significance of these unusual inclusions is obscure.
Surface topographical detail in human buccal smears of normal and irradiated tissue have been studied with scanning electron microscopy. Cells collected by buccal smearing show patterns of microplicae and microvilli, although such detail is occasionally masked by mucus and to a lesser extent by debris and bacteria. Buccal smearing permits collection of numerous specimens with little discomfort to the patient, but requires caution in identification of superficial and deep cell layers and of upper and lower surfaces. The analysis of specimens derived in this way shows that variations in the pattern of surface microplicae reflect the radiotherapeutic regimes of the patients from which they were obtained. Straight parallel microplicae characteristic of normal control and pre-irradiated specimens were absent in specimens collected during early irradiation treatments (between 24-48 Gy), but instead were present as short discontinuous ridges and microvillous projections. At the highest levels of radiation treatment (54-60 Gy) cells exhibited small areas devoid of any surface projections in addition to a range of normal and early irradiated microplicae patterns. From these results it is suggested that the patterns of microplications and microvilli on cell surfaces can be used to obtain information on the state of the stratified squamous epithelium from which they come.
The cell line T47D is extensively used as model in studying the role of hormones in human breast cancer. On the other hand the study of their morphology is largely incidental and does not take into account the age of culture. We studied therefore the morphology of T47D cell line with the electron microscope from the third day of culture to the seventh without adding new medium and serum to find out if the age of culture affects their characteristics. Our results suggest that there is a constant change of the cell morphology and architecture. Thus some cell organelles as the nucleus, tonofilaments, endoplasmic reticulum, mitochondria and intercellular secretory ductules are affected by the age of culture. Also we observed signs of degeneration, necrobiosis and even necrosis on the seventh day of culture. These observations suggest that the age of culture of these cells should be taken into account in experiment planning.
Three types of cell degeneration were observed at early embryonic stages of the development of cerebellar cortex of Gallotia galloti (Reptilia: Lacertidae). One is characterized by overall cell shrinkage whereas in the other two the degenerative process is recognized by a differential appearance of the cellular nucleus. We have also studied the further phagocytosis of the resultant cellular debris.
