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Journal ArticleDOI

A comparative morphological and enzyme histochemical study on blood cells of the freshwater snails Lymnaea stagnalis, Biomphalaria glabrata, and Bulinus truncatus.

01 Jul 1980-Journal of Morphology (Wiley Subscription Services, Inc., A Wiley Company)-Vol. 165, Iss: 1, pp 31-39
TL;DR: The morphology and ultrastructure of the blood cells of the freshwater snails Lymnaea stagnalis, Biomphalaria glabrata, and Bulinus truncatus were studied and special attention was paid to the role of theBlood cells in phagocytosis of foreign particles.
Abstract: The morphology and ultrastructure of the blood cells of the freshwater snails Lymnaea stagnalis, Biomphalaria glabrata, and Bulinus truncatus were studied. By performing in vitro experiments and enzyme histochemical studies, special attention was paid to the role of the blood cells in phagocytosis of foreign particles. No fundamental differences were found in the ultrastructure, lysosomal enzyme contents, and phagocytic capacities of the blood cells of these species. It is concluded that only one type of blood cell, the amoebocyte, exists in the freshwater snails. Amoebocytes constitute a morphologically and functionally heterogeneous population of cells, ranging from round (electron-dense) cells with the morphological characteristics of young cells to highly phagocytic spreading cells with a prominent lysosomal system. In addition to acid phosphatase, nonspecific esterase and peroxidase were found within the lysosomes. The presence of enzyme activity in the RER and the Golgi bodies indicates that amoebocytes are able to synthesize lysosomal enzymes continuously.
Citations
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Journal ArticleDOI
TL;DR: The morphology, tinctorial properties, ultrastructure and some functions of bivalve haemocytes are reviewed in relation to the simple division of these cells into granular and agranular haemocyte types, as suggested by Cheng.

249 citations

Journal ArticleDOI
TL;DR: This review focuses on research into the immune system and stress response conducted on abalone and on aspects that can be monitored in vitro, and suggests phagocytic activity of haemocytes and their efficiency in clearing bacteria are reliable parameters to measure.

199 citations

Book ChapterDOI
01 Jan 1983

129 citations

Journal ArticleDOI
TL;DR: Dynamic aspects of the cellular responses of juvenile Biomphalaria glabrata to newly penetrated Schistosoma mansoni strains were studied at the ultrastructural level and evidence was found to suggest that hemocytes were lysed, or formed multinuclear syncytia, during the encapsulation response.
Abstract: Dynamic aspects of the cellular responses of juvenile (2-3 mm shell diameter) 10-R2 strain Biomphalaria glabrata to newly penetrated Schistosoma mansoni (NIH-Sm-PR-1 strain) were studied at the ultrastructural level. As early as 3 hr postexposure (PE), host hemocytes had contacted the parasite's surface and by 7.5 hr, had phagocytosed sporocyst microvilli and small pieces of underlying tegument. Most sporocysts observed at 24 hr PE lacked tegumental cytoplasm, and germinal cells and other internal structures showed extensive pathological changes. By 48 hr, capsules were filled with hemocytes containing numerous, large phagosomes, and only scattered remnants of sporocyst material remained. Capsules were difficult to find at 4 days PE, suggesting that hemocytes participating in the encapsulation response had dispersed. Hemocytes responsible for the rapid and consistent destruction of S. mansoni sporocysts in the head-foot region typically formed extensive pseudopodia and contained large numbers of lysosomelike bodies, characteristics associated with granulocytes of B. glabrata. No evidence was found to suggest that hemocytes were lysed, or formed multinuclear syncytia, during the encapsulation response.

114 citations

Journal ArticleDOI
TL;DR: These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrates-parasite interactions.
Abstract: We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions.

103 citations


Cites methods from "A comparative morphological and enz..."

  • ...For hemocytes the collected hemolymph [52] was divided in two tubes for extraction of protein and for extraction of RNA....

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References
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Book
01 Jan 1961
TL;DR: The new Pearse bids fair to become the leader, even amongst so notable a collection of books devoted entirely or largely to histochemical techniques.
Abstract: A. G. E. Pearse is a relative newcomer to the field of histochemistry. He holds an M.D. degree from the University of Cambridge and is now Lecturer in Histochemistry at the Postgraduate Medical School, University of London. One of his first contributions to histochemistry consisted of a critical review of its methodology and interpretation, written for pathologists and appearing in the British Journal of Clinical Pathology 4: 1 (1951). He has also introduced a number of new or modified techniques. Perhaps those having the greatest interest for endocrinologists are presented in a series of papers concerning the demonstration of the glycoprotein hormones of the anterior pituitary gland (Nature 162: 651, 1948; J. Path. & Bad. 61: 195, 1949, 64: 791 & 811, 1952; Stain Technol. 25: 95, 1950). The present volume comprises 17 chapters, beginning with a brief but fairly inclusive history of the development of this branch of science and continuing with 2 chapters on methods of fixation and sectioning, 3 on the staining of proteins, 4 on the demonstration of enzymes, 1 on the use of enzymes as histochemical reagents, and 1 each on carbohydrates, lipids, aldehydes and ketones, pigments, inorganic substances, and physical methods. The book concludes with appendices which give the detailed steps of the histochemical techniques which Dr. Pearse has himself found most useful for demonstrating various tissue constituents. Complete author and subject indices follow. A further valuable feature of the book consists of numerous black-and-white and a few colored photomicrographs illustrating the appearance of sections prepared by some of the histochemical methods discussed. A rash of books devoted entirely or largely to histochemical techniques has appeared in the last few years. Outstanding are the treatises by Lillie (1948), Romeis (1948, 15th ed., German), Glick (1949), Gatenby and Beams (1950, 11th ed.), Gomori (1952), and Lison (1953, 2nd ed., French). In this reviewer's opinion, the new Pearse bids fair to become the leader, even amongst so notable a collection. In each chapter, Dr. Pearse reviews the chemistry and biological importance of the substances in question and then goes on to discuss critically the methods used for their demonstration and differentiation. The bibliographic references are numerous and appear to include most of the major contributions in each area. Pearse has omitted some references which appear fundamental, for example, the definitive experimental paper and review by Marcus Singer concerning the nature of acidic and basic staining of proteins (/. Biol. Chem. 75: 133, 1948; Internal. Rev. Cytol. I: 211, 1952). Likewise, the techniques which he has selected to give in detail represent his particular preferences, whereas numerous methods which are possibly equally satisfactory are barely mentioned. While Pearse's omissions in this respect are not serious, the usefulness of some methods which he has overlooked should not be lost sight of. Needless to say, in a field which is growing so rapidly and to which several journals are now entirely devoted, no book can long remain up-to-date.

7,499 citations

Journal ArticleDOI
TL;DR: ‘[he use of freslsbv diazotizecl pararosanilin w-itim a-msaphthyb pisosphate its a sinmultaneous coupling azo dye method for acid phosphatase resulted in significant improveumment because of the nmaumy desirable characteristics of the final azo dyed (1, 2).
Abstract: pimatase activity is largely vitiated by the insperfections of the available histochenmical methods. The sources of error its the lead sulfide nmetimod weme appreciated by Gomori, but this ha.s usot discouraged the uncritical use of this technique in the area of “appbied” histochenmsistmy. ‘[he azo (lye nmethods have suffered fronms two deficiencies : a sui)strate that would yield a hydrolysis iroduct (If low soiubilitv and Imigh substantivity, amsd a capture reagent tisat would couple rapidly ins acid nmedia to productaum ussoluble anmsorphous azo dye. TIme pisos mhate esters of various usapimthob AS derivatives, as developed by Burstone (9), gave imimroved localizatious its freeze-dried material because of the increased l)roteius affinity aumci cxtrenumeby low’ solubibity of the naphtlmobic isycirolysis product. On the other sicica major refineummeust in diazomuiunms coupling tec-immmique followed time introduction of hexazonium b)ararosausilin by Davis and Ornstein (13). ‘[he use of freslsbv diazotizecl pararosanilin w-itim a-msaphthyb pisosphate its a sinmultaneous coupling azo dye method for acid phosphatase (4) resulted in significant improveumment because of the nmaumy desirable characteristics of the final azo dye (1, 2). Several logical msmodificatiomss that conmbimse time advantages of time naphthol AS sui)strates and the isexazonium pararosanibin coupler have givo-us reproducible artifact-free bocabizatioum of acid

1,627 citations

Journal ArticleDOI
TL;DR: It is concluded that migration of phagocytes to the exterior via various epithelia, as found in other molluscs, is of minor importance.
Abstract: The morphology and the ultrastructure of the blood and connective tissue cells of Lymnaea stagnalis were studied. Special attention was paid to the role of these cells in the cellular defense mechanism (phagocytosis). This problem was investigated in injection experiments with enzyme histochemistry and electron microscopy.

245 citations

Journal ArticleDOI
TL;DR: Only when all of the parameters that influence or affect the phagocytosis and degradation of microorganisms that enter mollusks are understood can the authors devise methods to enhance this innate self-cleansing process and bring about the total and efficient clearing of real and potential pathogens from oysters, clams, and other edible shellfish.
Abstract: In studies designed to elucidate the mechanisms that may effect or influence the susceptibility and/or nonsusceptibility of mollusks to invading microorganisms, it is essential that consideration be given toward understanding how the internal defense mechanisms of mollusks function when confronted with nonself substances. It should be apparent that such information is essential if rational approaches are to be taken for the development of potential biologic control agents for undesirable mollusks or, on the other hand, if we are to understand and possibly prevent the microbial diseases that weaken or destroy economically important mollusks. Since Tripp 2-.L demonstrated that microorganisms experimentally introduced into a pelecypod, the American oyster, Crassostrea virginica, and a pulmonate gastropod, Biomphularia glabrata, are phagocytized and degraded intracellularly, it has become evident that phagocytosis by molluscan hemolymph cells is the major line of defense in at least these species of mollusks against invading microorganisms. This information is extremely important for a third practical reason. Specifically, only when we have elucidated the biochemical bases for the recognition of self and nonself, the phagocytosis of nonself materials, and the intracellular degradation of foreign substances can we logically and rationally develop and design methods to depurate edible mollusks that have become biologically polluted. In other words, only when all of the parameters that influence or affect the phagocytosis and degradation of microorganisms that enter mollusks are understood can we devise methods to enhance this innate self-cleansing process and bring about the total and efficient clearing of real and potential pathogens from oysters, clams, and other edible shellfish. When one considers the various types of reactions of hosts exposed to microorganisms, the development of antibody-mediated immunity naturally comes to mind. This, however, does not appear to be the case in mollusks. The evidence for this is as follows. Cheng,5 as a result of a quantitative electrophoretic analysis of the serum of the pulmonate Helisomu duryi normale, has concluded that hyperglobulinemia does not occur when this snail is challenged with different species of bacteria and has also concluded that immunoglobulins are not synthesized in mollusks. It is noted, however, that Feng and Canzonier fi and Gress and Cheng have demonstrated that in C. virginica parasitized by larvae of the trematode Bu-

210 citations

Journal ArticleDOI
TL;DR: The observations indicate that the digestive gland of B. pfeifferi is not important as a storage organ for reserve material, and the main functions of the digestive cell are absorption and endocytosis of predigested food material, followed by intracellular digestion.
Abstract: The influence of infection with S. mansoni on reproduction, growth, food consumption and survival in B. pfeifferi was studied experimentally (Ch. II). The prepatent period in infected snails was shown to last 22-24 days under the conditions prevailing in the relevant experiment. The number of eggs laid by infected snails as compared with controls was significantly reduced from 7-10 days postinfection onwards. After day 13 postinfection it was completely suppressed in the majority of the infected snails. The increase in shell diameter in infected specimens was larger than that of the controls between 7 and 18 days, that in weight between 11 and 21 days postinfection. Gigantism did not occur. There was no difference in mortality between infected and control snails prior to the 11th week after the beginning of the experiment. After that, the mortality among infected specimens showed a sharp rise. Uninfected and infected snails consumed similar amounts of food (dried lettuce) in the first two weeks of the experiment. After that, infected snails consumed less food than controls. The digestive gland of B. pfeifferi was studied with histological, histochemical and ultrastructural methods (Ch. III). The highly folded epithelium of the ducts connecting the digestive gland with the pyloric part of the stomach, consists of cilia and/or microvilli bearing columnar cells with interspersed mucous cells. In the epithelium of the digestive gland two main cell types are distinguished: the digestive cell and the secretory cell. In addition some mucous cells occur. It is concluded that the main functions of the digestive cell are absorption and endocytosis of predigested food material, followed by intracellular digestion. Indigestible residues are accumulated in a large vacuole, which eventually is excreted. The secretory cell produces and secretes proteinaceous substances, presumably digestive enzymes. It does not store calcium. The so-called excretory cells, which are in fact degenerating secretory cells, have vacuoles containing yellow globules. These yellow globules together with cell debris are finally released into the lumen of the digestive gland. The observations indicate that the digestive gland is not important as a storage organ for reserve material. The lobules of the digestive gland are covered by a thin connective tissue sheath, consisting of ground substance, collagen-like fibrils, smooth muscle cells and cells with the appearance of pigment cells. The connective tissue between the lobules of the digestive gland and the acini of the ovotestis, and between these organs and the mantle, consists mainly of vesicular connective tissue cells. These cells are supposed to play an important metabolic role as storage cells for glycogen. The tegument of the daughter sporocyst of S. mansoni (Ch. IV), consisting of an outer syncytial anucleate layer which is joined by cytoplasmic connections to nucleated cell bodies (tegumental cells), has the same basic architecture as that described for various stages of trematodes and cestodes. Well-developed mitochondria, GER cisternae and tubules, free ribosomes and polysomes, and lipid droplets occur throughout the tegument. The ultrastructural features suggest that the outer layer is involved in uptake of nutrients by absorption and endocytosis. The poorly developed musculature is loosely arranged in two layers beneath the outer tegumental layer. The nucleated portions of the muscle fibres are situated between the tegumental cells. The protonephridial system consists of flame cells with efferent tubules. The bundle of cilia, implanted in the flame cell, beats in the cilia chamber or barrel. The proximal part of the barrel consists of alternating rib-like extensions of the flame cell and of the first tubule cell, respectively. Ultrafiltration probably takes place in the ribbed part of the barrel. The development of cercariae from germinal cells is briefly described. The pathological effects of infection with S. mansoni on the digestive gland epithelium of B. pfeifferi (Ch. V) are limited. From about 12 weeks after infection slight changes occur, but they are difficult to distinguish from changes due to ageing of the cells. The effect of starvation on the digestive gland epithelium is much more marked than the adverse influence of infection. Compression of digestive gland lumina by daughter sporocysts was not observed. Changes in the connective tissue of the digestive gland due to the presence of daughter sporocysts were: development of muscle cells into cells with the appearance of pigment cells and/or degeneration of these muscle cells, and an increase in the number of amoebocytes, which become involved in the elimination of cell debris and in the formation of a loose layer over the parasites.

164 citations