Cytoplasmic Damage Research Articles

Ultrastructural changes in the respiratory tract of rats following methyl isocyanate inhalation.

The static exposure of rats to 0.25 mg/l methyl isocyanate for 1 h resulted in damage to the epithelium of the proximal bronchioles and upper airways. Bronchiolar cells exhibited both nuclear and cytoplasmic damage; many epithelial cells, particularly in the bronchi and trachea, were killed and/or dislodged from the basement membrane. A "raft" of cell debris and fibrin lined most of the airways during the 1st week after exposure but repair to the underlying epithelium was well advanced within 2-3 days. The majority of airways were lined by a normal epithelium within 3 weeks of exposure, but isolated foci of hyperplasia and occluded airways probably accounted for continued respiratory impairment.

Hyperoxia Produces Neuronal Necrosis in the Rat

Widespread cerebral neuronal necrosis occurred in newborn Sprague-Dawley rats submitted to three hours of pure oxygen (100% O2) at normal atmospheric pressure. Neuronal necrosis (NN) was most severe in the immediate newborn period and less marked with advanced maturation. It was minimal and different in its morphological characteristics in rats 10, 15 and 20 days old, and in adults breathing pure oxygen at normal atmospheric pressure for three hours. In the newborn rat, hyperoxemic NN was different in topography and cytopathology from that induced by hypoxia in the same animals. Hyperoxemic NN was similar to the NN described in human premature infants submitted to episodic hyperoxemia. Neuronal damage with karyorrhexis was most prominent in the subiculum of the hippocampus, thalamus, reticular nuclei of the brain stem and the granular cells of the cerebellum. Ultrastructural studies demonstrated nuclear and cytoplasmic membrane damage in neurons and the cellular accumulation of electron-dense lipid droplets. The pathogenesis of NN produced by hyperoxia in the human premature newborn infant may be related to lipid peroxidation of cell membranes such as that induced by oxygen-free radicals in other experimental and in vitro studies, when the anti-oxidant cellular defenses (mainly enzymes such as superoxide dismutase) are overwhelmed.

Investigation of a test system for the rapid differentiation of nuclear and cytoplasmic damage in eucaryotes

The effect of various agents which cause cell inactivation on the growth curves and RNA synthesis rates of yeast cells has been studied. On the basis of these investigations it was concluded that such studies can be used as a rapid test system for drawing preliminary conclusions as to whether a particular agent primarily damages the DNA of the cell nucleus or cytoplasmic structures.

Lens epithelium and radiation cataract. V. Observations on acid phosphatase and meridional row nuclear fragmentation

The influence of X-radiation on acid phosphatase activity in differentiating meridional row cells of rat lens epithelia was examined by ultrastructural cytochemistry. X-ray doses of 10–12 Gy (1000–1200 rads) produced clearly observable nuclear and cytoplasmic damage at 13–19 hr postirradiation. In those cells, acid phosphatase reaction product was associated with much of the electron dense material of fragmented nuclei and various parts of the cytoplasm. In addition, many irradiated cells without observable damage were positive for reaction product. The presence of acid phosphatase activity in these otherwise normal-appearing cells is suggestive of more subtle radiation damage than that observed in the more severely damaged cells.

The effect of heavy metals on the cytoplasmic fine structure ofSkeletonema costatum (Bacillariophyta)

The marine diatomSkeletonema costatum (Greville) Cleve was grown in batch culture in the presence of mercury (6.5 μg 1−1), cadmium (50 μg 1−1) and zinc (265 μg 1−1). Alterations in cytoplasmic morphology were observed in cells treated with these sublethal concentrations of the metals. Swollen organelles, dilated membranes and vacuolated cytoplasm indicated plasma membrane damage and subsequent osmotic disorganization. Electron-dense inclusions in vesicles, multivesiculate bodies and cytoplasmic “tubules” apparently derived from the Golgi body are interpreted as mechanisms of sequestering the metals. Mercury and zinc had a marked effect on the fine structure whereas treatment with cadium resulted in little to no cytoplasmic damage.

Bullous Pemphigoid, and Ultrastructural Study of the Inflammatory Response: Eosinophil, Basophil and Mast Cell Granule Changes in Multiple Biopsies from One Patient

We have studied by electron and light microscopy the inflammatory reaction in lesions at various stages of clinical development from a patient with bullous pemphigoid. The evolution of clinical lesions was associated with a sequence of histopathologic events which began with alterations of mast cells and proceeded to infiltration, first with lymphocytes and later with eosinophils and basophils. Mast cells in the papillary and reticular dermis demonstrated a unique, focal, irregular loss of granule contents. Intact eosinophils demonstrated intracytoplasmic losses of granule contents and karyorrhectic and karyolytic eosinophils had released membranebound granules. Partially and completely degranulated basophils were present within a fibrin gel which formed in the dermis. Thus, the sequence of histopathologic events in the pathogenesis of bullous pemphigoid includes mast cell granule alterations and release of granule contents from eosinophils which are undergoing nuclear and cytoplasmic damage.

Studies on the mechanism of synergistic action with synergisidin and imidazole antimycotics.

The investigation of mechanism of synergistic action with SYN and ECZ was performed using C. albicans SC5314 so that SYN was confirmed to show strong synergistic effects against Candida sp. in particular with addition of extremely small quantities under the MICs of imidazole antimycotics such as ECZ, MCZ and CTZ. The synergistic effect of antifungal activity against C. albicans SC5314 with a combination of SYN and ECZ (SYN + ECZ) showed fungistatic action. Effect of SYN + ECZ on osmotic resistance was not recognized and protoplast was not observed under a microscope. Accordingly, SYN + ECZ was considered not to take part in cell wall synthesis directly. For effect of SYN + ECZ on release of intracellular components, slow release of 260 nm-absorbing substances was occurred, so that SYN + ECZ was seemed not to affect cytoplasmic membrane damage directly. Also, it was suggested clearly that SYN + ECZ affected lipid metabolism and glycolysis including TCA cycle from the investigation on antagonism by growth recovery of C. albicans SC5314 by 106 kinds of substances such as fatty acids, isoprenoids, phospholipids, vitamins, amino acids, nucleic acid-related substances and TCA cycle-related substances. From the above results, it was suggested that the mechanism of synergistic action with SYN and ECZ against C. albicans SC5314 was due to affect the different reactions in lipid metabolism and the similar reactions in glycolysis including TCA cycle, respectively, in consideration of respective mechanism of actions of SYN alone and ECZ alone. A part of this work was presented at the Annual Meeting of the Agricultural Chemical Society of Japan, 1981 (Kyoto).

A possible biochemical basis for the use of hyperthermia in the treatment of cancer and virus infection.

There are numerous reports of tumors that have regressed or disapeared after artificial hyperthermia or a concurrent disease that caused high fever. Generally, local or whole body hyperthermia in the range of 41°–45°C has been involved. Overgaard (1978) has reviewed this literature. Current aspects of hyperthermia in the treatment of cancer has been the subject of several recent conferences (Converence on Hyperthermia in Cancer Treatment 1979; Thermal Characteristics of Tumors: Applications in Detection and Treatment 1980). A number of hypotheses have been advanced to account for these phenomena. Most of these have emphasized elevated blood glucose levels, hyperacidification, and breakdown of capillary circulation (Ardenne and Krüger 1979) or cytoplasmic damage resulting from changes in certain environmental factors such as hypoxia, increased acidity, and insufficient nutrition (Overgaard 1978).KeywordsInhibit Protein SynthesisHeat StableElevated Blood Glucose LevelRecent ConferenceSpecific Protein KinaseThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Paraquat tolerant and susceptible perennial ryegrasses: effects of paraquat treatment on carbon dioxide uptake and ultrastructure of photosynthetic cells

Abstract. Paraquat treatment of susceptible Lolium perenne seedlings (cultivar Kent Indigenous) rapidly inhibited CO2 uptake and after 1 h chloroplasts exhibited abnormal fusions of the thylakoid membranes. Further ultrastructural changes occurred within the chloroplasts until 8 h after treatment, when cytoplasmic damage also became evident. The localization of primary damage within the chloroplast differs from previous reports of paraquat toxicity in other species. Paraquat treatment of tolerant L. perenne seedlings (line PRP IX) resulted in little change in CO2 uptake and ultrastructural effects were generally confined to the gradual development of deposits in the chloroplast stroma. These observations are discussed in relation to the mechanism of action of the herbicide and the proposed mechanism of paraquat tolerance in L. perenne.

Multistage disruption of protoplasts by dikegulac

Dikegulac (2,3:4,6 di-o-isopropylidine-2-keto-I-gulonate) is a growth regulator used to differentially kill terminal apices, and it analogously inhibits basic metabolic functions in dividing cells, but not stationary cells, in suspension culture. This report demonstrates an analogous situation in isolated tobacco protoplasts. At the lowest concentrations, dikegulac partially suppresses division of the protoplasts. Higher concentrations are required to produce visual cytoplasmic damage to the protoplasts, which probably first occurs at the level of the plasmalemma, as the vacuoles can be released intact. Later, tonoplast disruption occurs.

Schistosoma Mansoni Infections in T-Cell Deprived Mice, and the Ameliorating Effect of Administering Homologous Chronic Infection Serum

Liver changes occurring in mice deprived of their T-cells by a combination of thymectomy and anti-mouse thymocyte serum, and in immunologically intact control mice, were followed during the early stages of heavy Schistosoma mansoni infections. Lesions in both groups began developing by day 38 and were maximal by day 48. Hepatic changes in control mice culminated in large hypersensitivity granulomas, tissue eosinophilia, portal periphlebitis, fibrosis, vascular obstruction, and infarction leading to arterialization and preferential sinusoidal channeling. Deprived mice showed greatly reduced egg reactions composed principally of macrophages, monocytes, and occasional neutrophils, and only minimal alteration of liver architecture; however, focal and disseminated hepatocellular lesions became prominent as the infections progressed, and by day 48 virtually every hepatocyte was affected. Typically, hepatocytes showed microvesicular cytoplasmic damage (steatosis) or ballooning degeneration with accompanying nuclear pyknosis or karyorrhexis. This cellular pathology may be attributed to the direct or indirect effect of eggs or egg products on liver cells. The administration of chronic infection serum obtained from immunocompetent mice to T-cell deprived mice dramatically eliminated the hepatocellular lesions. It also increased eosinophil participation and fibrosis in the egg reactions but did not restore the size and other cellular features typical of egg hypersensitivity granulomas. Serum from uninfected normal mice was found to lack these effects.

Schistosoma Mansoni Infections in T-cell Deprived Mice, and the Ameliorating Effect of administering Homologous Chronic Infection Serum

Liver changes occurring in mice deprived of their T-cells by a combination of thymectomy and anti-mouse thymocyte serum, and in immunologically intact control mice, were followed during the early stages of heavy Schistosoma mansoni infections. Lesions in both groups began developing by day 38 and were maximal by day 48. Hepatic changes in control mice culminated in large hypersensitivity granulomas, tissue eosinophilia, portal periphlebitis, fibrosis, vascular obstruction, and infarction leading to arterialization and preferential sinusoidal channeling. Deprived mice showed greatly reduced egg reactions composed principally of macrophages, monocytes, and occasional neutrophils, and only minimal alteration of liver architecture; however, focal and disseminated hepatocellular lesions became prominent as the infections progressed, and by day 48 virtually every hepatocyte was affected. Typically, hepatocytes showed microvesicular cytoplasmic damage (steatosis) or ballooning degeneration with accompanying nuclear pyknosis or karyorrhexis. This cellular pathology may be attributed to the direct or indirect effect of eggs or egg products on liver cells. The administration of chronic infection serum obtained from immunocompetent mice to T-cell deprived mice dramatically eliminated the hepatocellular lesions. It also increased eosinophil participation and fibrosis in the egg reactions but did not restore the size and other cellular features typical of egg hypersensitivity granulomas. Serum from uninfected normal mice was found to lack these effects.

The ultrastructural effects of acute decompression on the lung of rats: the influence of frusemide.

Rats were placed in a decompression chamber and the chamber and the pressure reduced to 265 mm Hg over a period of 1 hr. Other rats were subjected to the same treatment after having been given an injection of frusemide. An ultrastructural study of the lungs of these rats showed that acute decompression of this magnitude can cause swelling and disintegration of type I alveolar epithelial cells. Although capillary endothelial cells showed only minor cytoplasmic damage many capillaries were ruptured with diapedesis of red cells. This is believed to be caused by gross capillary dilatation associated with pulmonary congestion. Pretreatment with frusemide prevented capillary rupture and reduced the degree of epithelial degeneration. However, frusemide induced swelling of capillary endothelial cells which was unassociated with acute decompression.

Altered Schistosome Granuloma Formation in Nude Mice *

Schistosome egg-induced lesions in congenitally athymic mice differed from those found in normal heterozygous controls. Heterozygote liver granulomas were chareacterized by poorly phagocytic epithelioid macrophages, and were rich in eosinophils and fibroblasts, with peripheral lymphocytes and plasma cells. Hepatic lesions in nude mice were much smaller and lacked epithelioid macrophages, with lesions about mature eggs, typically consisting of monocytes and macrophages filled with pigment, occasional neutrophils, and rarely one or more eosinophils or giant cells. While heterozygote granulomas damaged liver cells mainly by encroachment or by their vascular effects, in the nudes hepatocytes bordering the lesions showed microvesicular cytoplasmic damage and either hydropic degeneration or focal acidophilic necrosis of individual liver cells. In heterozygotes, immunofluorescent-stainable schistosome egg antigen (SEA) was concentrated in the granuloma center. In nude mice, SEA, was distributed throughout the infiltrates and in and around hepatocytes adjacent to egg lesions corresponding to the observed pattern of hepatocyte necrosis. We conclude that, in contrast to heterozygotes, nude mice lack hypersensitivity granulomas and fail to sequester toxic egg products, this resulting in zonal hepatocellular damage. Alternative explanations include the possibility of a latent hepatitis virus being activated by the schistosome infection; however, several cogent arguments are presented against that alternative.

Effect of hyperthermia on malignant cells in vivo. A review and a hypothesis.

The relevant literature is reviewed in an attempt to clarify the mechanism of heat-dependent tumor cell destruction in vivo. Malignant cells in vivo appear to be selectively destroyed by hyperthermia in the range of 41-43 degrees C. Heat evidently affects nuclear function, expressed by an inhibited RNA, DNA and protein synthesis and characteristic arrest or delay of cells in certain locations of the cell cycle. However, as these effects appear to be reversible and are observed in normal cells as well as malignant cells, they probably do not explain the hyperthermic induced selective in vivo destruction of malignant cells. Heat-induced cytoplasmic damage appears to be of more importance. Increased lysosomal activation is observed, and is further intensified by a relatively increased anaerobic glycolysis which develops selectively in tumor cells. A hypothesis is proposed and discussed which explains the marked and selective in vivo tumor cell destruction as a consequence of the enhancing effect on the cytoplasmic damage of certain environmental factors (e.g. increased acidity, hypoxia and insufficient nutrition.

The interaction of nuclear and cytoplasmic damage after treatments with toxic chemicals

An attempt is made to show how the interaction of different degrees of nuclear and cytoplasmic damage may contribute to the ultimate whole cell damage by a chemical. It suggests that cytoplasmic, as well as nuclear damage, may be important in the action of chemical carcinogens. Using Amoeba proteus as a single cell model where nuclear and cytoplasmic damage can be separated by micrurgy, the mortality curves for the nucleus, the cytoplasm and the whole cell are examined after four different treatments: exposure to N-methyl-N-nitroso urethane, a potent carcinogen in mammalian systems; exposure to ββ 1 (dichlorodiethyl) methyl amine, an alkylating agent used in chemotherapy; exposure to methylmercury chloride, a very toxic organo-metal; and irradiation with X-rays. These illustrate how different relative nuclear/cytoplasmic sensitivities contribute to the death of the cell. The evidence for nuclear and cytoplasmic damage after treatment with the N-methyl-N-nitroso urethane is detailed, and possibilities of nuclear repair after the four different types of treatment examined. Work on Amoeba proteus makes no attempt to assess separately changes in structure or activity of any one of the cells many enzyme systems, but looks at the balance between nuclear and cytoplasmic damage as a whole.

A novel class of Saccharomyces cerevisiae mutants specifically UV-sensitive to "petite" induction.

A mutant of Saccharomyces cerevisiae has been isolated which, though exhibiting a normal response to nuclear genetic damage by ultraviolet light (UV), is more sensitive than its wild type specifically in the production of the cytoplasmic (rho-) mutation by this agent. Some of the features of this mutation which has been designated uvsrho 5 are: i) The mutation is recessive, it exhibits a Mendelian, and hence presumably nuclear, pattern of segregation, but manifests its effects specifically and pleiotropically on mitochondrial functions. ii) Mutant cells resemble their wild type parents in a) growth characteristics on glucose; b) in their UV induced dose response to lethality or nuclear mutation and c) the ability of their mitochondrial genome, upon mating with appropriate testers, of transmitting and recombining various markers, albeit with enhanced efficiency. Similarly, d) they are able to modulate the expression of mitochondrial mutagenesis by ethidium bromide. Thus their mitochondrial DNA appears genetically as competent as that of the wild type. iii) Mutant cells differ from their wild type parents in a) growth characteristics on glycerol; b) susceptibility to induction of the mitochondrial (rho-) mutation by various mutagens, in that the rate of spontaneous mutation is slightly and that by UV is significantly enhanced, whild that by ethidium bromide is greatly diminished. Conversely, c) modulating influences resulting in the repair of initial damage are diminished fro UV and stimulated in the case of Berenil. iv) The amount of mitochondrial DNA per cell appears elevated in the mutant, relative to wild type, and its rate of degradation subsequent to a mutagenic exposure to either UV or ethidium bromide is diminished. v) A self-consistent scheme to account for this and all other information so far available for the induction and modulation of the (rho-) mutation is presented. In a previous study it was shown that some nuclear mutants of Saccharomyces cerevisiae, more sensitive to lethal damage induced by ultraviolet light (rad) than their parent wild type (RAD), also exhibit a concomitant modification in sensitivity to both nuclear and cytoplasmic genetic damage (Moustacchi, 1971). However, another class of rad mutants respond to the induction of the cytoplasmic "petite" also designated as rho- (or rho-) mutation by UV in a manner indistinguishable from that of the RAD strain. One possible interpretation of this last observation is that some of the steps in the expression of the UV damage on mitochondrial (mt)DNA may be governed by other nuclear and cytoplasmic genetic determinants, the products of which may then act specifically on mitochondrial lesions. If this assumption is correct, it should be possible to find mutants with a normal response to nuclear damage but specifically UV-sensitive towards induction of (rho-)...

The occurrence of bacteria and mycoplasma-like organisms in a monogenean parasite, Diclidophora merlangi

Bacteria are not normal residents of the gut caeca of Diclidophora merlangi and are found in the gut lumen only as a result of contamination of the culture medium. Mycoplasma-like organisms have been found in the cytoplasm of gland cells associated with the anterior alimentary tract of the worm. Their occurrence is infrequent and does not involve cytoplasmic damage in the gland cell. Unlike the gut luminal bacteria, the mycoplasmas can be found in fresh worms and in worms kept in culture media containing antibiotics.

Epidermal Lysosomes and Ultraviolet Light

Secondary lysosomes of guinea-pig keratinocytes were labeled, in vivo, with an electron microscopic marker (Thorotrast) that can he identified both within stable lysosomes and, after lysosome lysis, in extralysosomal locations. Immediately after irradiation with 10 and 20 minimal erythemal doses delivered from an ultraviolet light source in vivo, the large majority of epidermal lysosomes was intact but occasional lysosomes exhibited ruptured membranes and a spilling at tracer into the cytoplasm. Morphologic signs of early UV damage to the cytoplasm were present immediately alter irradiation but these occurred also in the absence of lysosome Lysis. Unirradiated controls showed no cytoplasmic damage but the same amount of lysosome lysis as the irradiated animals. With regard to lysosomes and lysosome lysis there was no difference between nonirradiated and irradiated animals biopsied immediately after UV-exposure. Two, 6, and 12 hr after irradiation the irradiated animals exhibited a greater degree of lysosome lysis than the controls. It is concluded that lysosome lysis accompanies the UV reaction of the epidermis but the present study provides no evidence that it represents an initial pathogenic event.

Ultrastructure of STH cells of the pars distalis of castrated male mice after hepatectomy

An electron microscopic study aimed at differentiation between “castration gonadotrophs” and “posthepatectomy STH cells” was performed on the pars distalis of the pituitary of castrated male mice, after partial hepatectomy. The ultrastructural features observed permit the distinction of both cell types. In the present experiments some remarkable ultrastructural changes, other than those described in a previous report, have been found in STH cells of hepatectomized mice with or without previous castration. Most of them contained masses of heterogeneous electron density, suggesting fusion of granules. These masses and some secretion granules were observed close to the plasma membrane, apparently in the process of discharging material into the pericapillary space. Granular extrusion was more frequent than normally. An increased number of lysosomes, probably related to the digestion of overproduced secretion material, was evident. The appearance of concentric lamellar formations might be related to an increase in cell movements. STH cells with severe cytoplasmic damage were also found, indicating an increased rate of cell loss.