Appearance of clasmatosis in the normal and pathological liver

It was established that clasmatosis of cytoplasmic fragments toward sinusoids occurred under normal physiological conditions (embryogenesis of chick liver, the liver of starved grass carp and silver carp) and pathological conditions (disturbance of rat hepato-intestinal circulation). The clasmosomes of rat and chick liver cells contained free ribosomes and small vesicles while those in the liver of starved fish consisted of glycogen. It was also shown that mitochondria with the signs of complete clasmatosis appeared in the hepatocyte cytoplasm immediately after the beginning of intensive bile secretion to the bile canaliculus (in liver cells of rat and chick embryo and in those of frogs after complete metamorphosis). Such mitochondria were partially disintegrated and were located near the bile canaliculi. It is assumed that clasmatosis of the fragments of the liver cell cytoplasm or mitochondria takes places where it is necessary to rapidly supply the body or cell with some products of metabolism or to remove something from the cell as is the case with erythroblasts, i. e. clasmatosis is one of the mechanisms of the adaptation of the cell and its organelles to changes in the environment.     

Degenerative regression of the digestive tract in the colonial ascidian Botryllus schlossen (Pallas)

Summary Degenerative changes in the digestive tract of zooids of Botryllus schlosseri were studied by light and electron microscopy. Three main processes occurred in the tissues: contraction, involution and phagocytosis. The contraction of epidermis and peribranchial epithelium in which cytoplasmic microfilaments probably participate, seemed to have a special role in compressing the underlying organs. During contraction most of the body cavities collapsed, the branchial walls disintegrated and the fragments were rapidly taken up by large phagocytes. The gut epithelium retained its apparent continuity longer, though isolated phagocytes infiltrated it to eliminate single cells. Cell degeneration came about chiefly either through swelling and lysis of cells or through loss of water and condensation of cytoplasm and nucleus.The fate of all regressed tissues was to be engulfed and digested by wandering phagocytes. However, it was also observed that numerous cells of different epithelia could act as fixed phagocytes by engulfing cell debris and entire cells into heterophagic vacuoles.     

Stellate cells as phagocytes of the anuran pars distalis

When the stellate cells (nongranulated cells) from dissociated-cell preparations of the anuran pars distalis were examined, they were seen to contain debris within phagocytic vacuoles (phagosomes). These phagosomes were variable; some contained granules from secretory cells while others were similar to lipid-like bodies and myelin figures. In situ partes distales from frogs were examined at the breeding season. The tissues were divided into lobules that were bounded by processes of stellate cells located between the secretory cells. Processes of stellate cells in the interior of a lobule interdigitate with processes extending inward from the stellate cells forming the border of the lobule. When these processes come together, a small cavity is formed. In many of the intact frogs the spaces between the stellate and secretory cells were greatly enlarged. At this particular time the processes of the stellate cells were attenuated and enclosed secretory granules that were also present as debris in these dilated, intercellular spaces. Within the cytoplasm of these stellate cells were not only phagosomes containing secretory granules but also organelles that appeared to be lipid bodies and lysosomes. Thus, the stellate cells of the pars distalis function in vivo, as well as in vitro, as phagocytes. In addition, macrophage-like cells moving from the blood may form another component of this system of phagocytes.     

Quantitative research on the cyclic fluctuations of the epidemic process in a number of infectious diseases in Bulgaria

The cyclic nature of the epidemic process in Bulgaria was studied by various methods (spectral analysis, etc.), forming a system. The morbidity dynamics in 10 infectious diseases (scarlet fever, rubella, measles, epidemic parotitis, whooping cough, diphtheria, typhoid fever, enterocolitis, bacterial dysentery, viral hepatitis) over the years of 1909-1983 were studied and cycles covering the periods of 3-4, 5-6, 10-11 and over 16 years were established. The data on the relative part of cyclic processes in the registered morbidity of infectious diseases, as well as information on the prognostication of the spread of infections in the absence of vaccinal prophylaxis, are presented.     

Clasmatosis: Certain qualitative and quantitative peculiarities of this phenomenon in the lymphoid organs of the rat

Summary Clasmatosis in the spleen, thymus, submaxillary lymph nodes, Peyer's patches and bone marrow has been studied in Wistar male rats by standard cytological methods, and a method of obtaining a fraction of cytoplasmic fragments (leptons) from the spleen has been elaborated. A conjectural scheme of the successive stages of this phenomenon has been drawn up; according to this scheme, the lepton detached from the clasmatocyte undergoes a series of transformations and again splits off a fragment from itself (secondary clasmatosis).Micrometric measurements of the diameters of free lymphocytes, clasmatocytes, and bound and free leptons have made it possible to establish that: 1. the size of the lepton does not depend on the size of its producer cell; 2. the largest percentage of clasmatocytes occurs among cells with a diameter of 9 (about 35%); 3. the lymphocytes of the spleen are smaller than the clasmatocytes of the same organ, and the free leptons are smaller than the bound leptons. The assumption is made that this difference is due in the former case to clasmatosis itself, and in the latter to formation of secondary leptons.Clasmatosis is traced in all stages of differentiation of lymphoid cells, which lose their pyroninophilic granularity along with their loss of cytoplasm.The different lymphoid organs have been compared according to their relative content of clasmatocytes and free leptons. The second, more distinct index increases in the following succession: thymus, submaxillary lymph nodes, spleen, Peyer's patches. The difference between the first and the last is 15.In the bone marrow of intact rats clasmatosis is practically absent.The results have been discussed in relation to the possible connection of clasmatosis with the differentiation of lymphoid cells.The authors are very grateful to N. S.Nikishova for her help in the cytological part of this work and to M. L.Kopnova for the microphotographs.     

Mononuclear phagocytes in the retina of developing rats

Mononuclear phagocytes were labeled with colloidal carbon injected into the circulation or stained with cytochemical techniques for the detection of marker enzymes in whole-mounted retinae of rats from birth to 10 days after birth. Positive cells were found apposed to or scattered among the blood vessels of the immature vascular network located just vitread to the developing retina. A few cells only had carbon distributed in the cytoplasm, but all retinae tested had positive cells. The enzymes located cytochemically in the phagocytes were non-specific esterase, acid phosphatase and endogenous peroxidase. When stained with aniline dyes, the phagocytes had a morphology similar to blood monocytes. Such cells were not found in the retina of adult rats. It is concluded that mononuclear phagocytes reside just vitread to the ganglion cell layer during the period of natural cell death in that layer. The phagocytes are probably associated with the removal of cell debris during the late period of retinal histogenesis.     

Isolation and Characterization of Mesenchymal Cells from the Tail of Bullfrog Tadpoles*

Mesenchymal cells were separated with the aid of EDTA, dispase, collagenase and hyaluronidase from tail fins of Rana catesbeiana tadpoles and were cultured to examine their morphology and response to thyroid hormone, which controls metamorphosis. The mensenchymal tissue consisted of two main types of cells, macrophage-like cells (M cells) and fibroblastic cells (F cells), distinguishable by their morphological and biochemical characteristics. M cells were preferentially located near the boundary between the mesenchyme and the epidermis. They were more adhesive to the plastic culture dishes than F cells. The M cells developed a bizarre rod-like branching process during one week of culture, which appeared to be identical to the process formed by mammalian macrophages undergoing clasmatosis. M cells cultured for more than one week tended to fuse together forming multinuclear giant cells. F cells were found uniformly in the tissue and were active in collagen biosynthesis. Thyroid hormone at a physiological concentration greatly reduced the life span of F cells, but did not reduce that of M cells.     

Mononuclear phagocytes in the retina of developing rats

Summary Mononuclear phagocytes were labeled with colloidal carbon injected into the circulation or stained with cytochemical techniques for the detection of marker enzymes in whole-mounted retinae of rats from birth to 10 days after birth. Positive cells were found apposed to or scattered among the blood vessels of the immature vascular network located just vitread to the developing retina. A few cells only had carbon distributed in the cytoplasm, but all retinae tested had positive cells. The enzymes located cytochemically in the phagocytes were non-specific esterase, acid phosphatase and endogenous peroxidase. When stained with aniline dyes, the phagocytes had a morphology similar to blood monocytes. Such cells were not found in the retina of adult rats. It is concluded that mononuclear phagocytes reside just vitread to the ganglion cell layer during the period of natural cell death in that layer. The phagocytes are probably associated with the removal of cell debris during the late period of retinal histogenesis.     

Clasmatosis: Ultrastructure of cytoplasmic fragments from the spleen,lymph nodes,and thymus of the rat

Summary The cytoplasmic fragments forming as a result of clasmatosis were isolated by centrifugation from cellular suspensions of the spleen, submandibulur lymph nodes and thymus of August rats and were studied electron microscopically. It has been established that the cytoplasmic fragments widely vary in organelle saturation within the same organ and that this saturation diminishes in the spleen-lymphatic nodes-thymus series. With the exception of the centrioles and the Golgi complex the cytoplasmic fragments may contain any cytoplasmic organelles and inclusions characteristic of lymphoid cells. The results have been discussed from the point of view of the possible relation of clasmatosis to the process of lymphocyte maturation.     

Formation of "ghost" bodies and calcification in experimental atherosclerosis in nonhuman primates. An ultrastructural study

Aortic lesions from African green monkeys fed a cholesterol diet for up to 24 months were studied by electron microscopy. The lesions, grossly classified as fatty dots and fatty streaks consisted of foam cells, increased amounts of interstitial connective tissues and osmiophilic lipid material. In addition, in the interstitial spaces, there were membrane-bound detached cytoplasmic fragments and deeply osmiophilic calcium spherules. The smooth muscle cells had a frayed appearance and bulbous cytoplasmic pseudopodlike processes. Figures suggestive of transition between these cell processes and the detached cytoplasmic fragments were observed. The detached cytoplasmic fragments or ghost bodies often contained lipid droplets, myelin-like figures and calcific material. The process of budding off cytoplasmic fragments was interpreted as a form of clasmatosis enabling smooth muscle cells to eliminate substances which could not be degraded intracellularly. It is proposed that material presented within the ghost bodies may become a nucleation site for calcium salts deposition. Cell necrosis was not a feature observed in this material.     

Immunofluorescent localization of alpha-1-antitrypsin in human polymorphonuclear leukocytes

The presence of proteases in polymorphonuclear leukocytes and other phagocytes has been well documented. Their role in physiological and pathologic conditions is of great importance. The presence of active proteases inside those phagocytes argues for some control mechanism that prevents self digestion. Antiproteolytic substances have been found in the cytosol of PMNs and A_lAT in the cytoplasm of alveolar macrophages and mast cells. Our study was designed to detect antigenic determinants of A_lAT in the cytoplasm of PMNs with immunofluorescent techniques. It was observed that A_lAT antigenic determinants are present in the cytoplasm of PMNs and monocytes. This finding gives further support to the idea that intracytoplasmic proteases are held inactive because of the formation of a protease-antiprotease complex in the cellular cytoplasm.     

Comparative evaluation of Yersinia interaction with HEp-2 cells

In experiments on HEp-2 cells, the comparative characterization of the mechanism of invasion and the cytotoxic action of a number of Y. pseudotuberculosis strains, serovar 1, and Y. enterocolitica strains 03 and 09 (24 strains newly isolated from human patients and rodents and 5 laboratory strains at different degrees of attenuation) has been made on the basis of data obtained by optical and electron microscopy, as well as by cytoenzymological analysis. As revealed in these experiments, the invasion of Yersinia into epithelial cells and their capacity for intracellular multiplication depend on the cytotoxicity of the bacteria, most pronounced in Y. pseudotuberculosis, serotype 1, considerably less pronounced in Y. enterocolitica 09, and poorly pronounced (or absent) in Y. enterocolitica 03. Cytopathic changes are manifested by vacuolization, the exocytosis (clasmatosis) of the peripheral cytoplasm, impoverishment in organellae, the formation of autophagosomes, the shriveling of the nuclei and the perinuclear cytoplasm, the rounding of the cells and their separation from the glass surface. The development of these changes is accompanied by the increased activity of phosphatases diffusing into the cytoplasm and by the inhibition of cell respiration and dehydrogenase activity.     

Staphylococcus aureus subvert autophagy for induction of caspase-independent host cell death

Staphylococcus aureus is a common bacterial etiology of serious infectious diseases. S. aureus can invade various types of non-professional phagocytes to produce host cell death. We show here that shortly after invasion of HeLa cells S. aureus transit to autophagosomes was characterized by double membranes and co-localization with LC3. S. aureus were not able to replicate and produce cell death in autophagy-deficient atg5-/- mouse embryonic fibroblasts. S. aureus-containing autophagosomes do not acidify nor do they acquire lysosome-associated membrane protein-2, indicating that S. aureus inhibits autophagosome maturation and fusion with lysosomes. Eventually, S. aureus escape from autophagosomes into the cytoplasm, which results in caspase-independent host cell death. S. aureus strains deficient for agr, a global regulator of S. aureus virulence, were not targeted by autophagy and did not produce host-cell death. Autophagy induction by rapamycin restored both replication and cytotoxicity of agr-deficient S. aureus strains, indicating that an agr-regulated factor(s) is required for autophagy-mediated cytotoxicity. The results of this study suggest that rapid induction of autophagy is essential for S. aureus replication, escape into the cytoplasm, and host cell killing.     

The professional phagocytes of sea bass (Dicentrarchus labrax L.): cytochemical characterisation of neutrophils and macrophages in the normal and inflamed peritoneal cavity

In order to identify the phagocytic cells of sea bass, the peritoneal leucocyte population of fish injected intraperitoneally with Photobacterium damselae subspecies piscicida was studied by light microscopy using cytocentrifuge preparations stained by the Antonow technique for peroxidase detection. Among the leucocytes present in the peritoneal exudate of the infected fish (macrophages, neutrophils, eosinophilic granular cells, lymphocytes and thrombocytes), macrophages and neutrophils were the only phagocytic cells. Neutrophils were easily distinguished from macrophages in Antonow stained preparations by the pattern of peroxidase positivity. Using ultrastructural cytochemistry, neutrophils were found to have abundant cytoplasmic granules positive for peroxidase and arylsulphatase and were negative for alpha-naphthyl butyrate (ANB) esterase. In contrast, ANB esterase activity was detected in macrophages. These leucocytes were typically negative for peroxidase, but ocasionally, some macrophages with peroxidase or arylsulphatase-positive vacuoles were observed. Both phagocytes had cytoplasmic granules positive for acid phosphatase. Glycogen particles were found in the cytoplasm of the two phagocytic cells, but they were much more abundant in neutrophils. Macrophages were much more abundant than neutrophils in the peritoneal cavity of non-injected sea bass but early after the intraperitoneal injection of bacteria, the number of neutrophils increased quickly and extensively. Higher numbers of intraperitoneally injected bacteria were found inside macrophages as compared to neutrophils because macrophages strongly predominated in the peritoneal population at the time of injection. However, when the bacteria were injected into peritoneal cavities with high numbers of neutrophils (attracted by a previous injection of 12% casein), the percentage of neutrophils with phagocytosed bacteria increased, approaching that of infected macrophages. Taken together, these results show that in sea bass, as in many other organisms, in addition to macrophages, neutrophils are important phagocytic cells, the relative participation of each of the two phagocytes in defense mechanisms against infection depending on the opportunity to encounter the invading infectious agents.     

Study of smallpox vaccine virus distribution in the body of rabbits following oral immunization]

Virological and immunofluorescent methods were applied to the study of the distribution of the smallpox vaccine virus in the organs and tissues of rabbits immunized orally. It appeared that the vaccinal process developed with a predominant localization of the antigen in the regional (in respect to the site of administration) lymph nodes; the virus was revealed in the cell cytoplasm.     

Oogenesis in hydra. II. Cytophotometric determination of DNA concentration in the nuclei of somatic and sex cells

During sexual reproduction in Hydra, interstitial cells in the female sex zone of the body (i-cells) undergo mitotic division and form a thickening in the epiderm. The proliferation of i-cells is accompanied by the increase of cytoplasm volume and by the appearance in the cytoplasm of a great number of membranous structures (rough endoplasmic reticulum, Golgi apparatus and mitochondria), enzymatic granules, lipid inclusions and glycogen. All cells of the epidermal thickening soon (in approximately twenty four hours) acquire the characteristics of typical phagocytes. However it is the cell situated inside the group of syncytially connected ones and adjacent to mesogloea that begins to grow rapidly and phagocytize surrounding cells. The cells of the epidermal thickening, though they are often given the name of oogonia, were found to have a tetraploid DNA content in their nuclei. The presence of four unseparated centrioles of equal size suggests that all preparatory processes for division were completed. A conclusion was drawn that cells of the epidermal thickening undergo premeiotic DNA synthesis prior to their phagocytizing by the growing oocyte and, thus, are oocytes themselves. The oogonial stage in Hydra coincides with the early period of mitotic reproduction of i-cells. The data obtained are discussed from the viewpoint of the formation of the accessory gonad apparatus.     

Immunological Consequences of Macrophage-Mediated Clearance of Apoptotic Cells

Apoptosis and the rapid clearance of apoptotic cells by professional or non-professional phagocytes are normal and coordinated processes that ensure controlled cell growth with a non-pathological outcome. Defects in clearance of apoptotic cells by macrophages have serious consequences often resulting in autoimmune disorders. Phagocyte-derived immunoregulatory cytokines such as Interleukin-12 and Interleukin-10 play pivotal roles in the etiology and pathology of many autoimmune diseases. Elucidation of the apoptotic cell-mediated signaling mechanisms involved in the control of pro- and anti-inflammatory cytokines during cell turnovers under normal and pathological conditions may help us counter the cytokine dysregulation and control inappropriate host immune reactions in pathological situations such as autoimmunity, infectious diseases, graft-versus-host disease, and cancer.     

Experimental study of intracellular ice growth in human umbilical vein endothelial cells

Study of the intracellular ice formation (IIF) and growth is essential to the mechanistic understanding of cellular damage through freezing. In the aid of high speed and high resolution cryo-imaging technology, the transient intracellular ice formation and growth processes of the attached human umbilical vein endothelial cells (HUVEC) were successfully captured during freezing. It was found that the intracellular ice nucleation site was on the cell membrane closer to the nucleus. The ice growth was directional and toward the nucleus, which covered the whole nucleus before growing into the cytoplasm. The crystal growth rate in the nucleus was much larger than that in the cytoplasm, and its morphology was influenced by the cooling rate. During the thawing process, small crystals fused into larger ones inside the nucleus. Moreover, the cumulative fraction of the HUVEC with IIF was mainly dependent on the cooling rate not the confluence of the cells attached.     

Immunoactive peptide obtained from the optical ganglia of squid

The data on the effect of a peptide from the squid optic ganglia named gangliin on some parameters of animal natural resistance are presented. It was shown that the prophylactic use of the peptide in mice 24 hours before their contamination with the lethal dose of E. coli protected 40 to 60 per cent of the animals from death. Gangliin accelerated elimination of E. coli from the host and increased the absorptive and digestive activity of the macrophages and polymorphonuclear leukocytes. With the use of gangliin it was possible to correct the phagocytosis defects in infectious processes having the phagocytic protection mechanism. Moreover, gangliin was supposed to be efficient in control of long-term persistence of various microbes in the cells of the system of mononuclear phagocytes.     

Effect of a live enteral dysentery vaccine from spontaneous Flexner mutant 2a 516m on the immunoglobulin-producing cell count in the large intestine mucosa in dysentery

The influence of vaccinal therapy with live oral dysentery vaccine prepared from S. flexneri 2a 516M on the content of immunoglobulin-producing cells in the mucous membrane of the large intestine was studied. A considerable increase in the number of IgA- and IgM-synthetizing cells was shown to occur in the course of the infectious process in acute dysentery. In chronic dysentery the content of IgA- and IgM-synthetizing cells in patients was considerably lower than in a smooth course of acute dysentery. The use of the vaccine for the therapy of patients with chronic and especially acute dysentery resulted in a considerable rise in the number of plasma cells synthetizing IgA, IgM and IgG.