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PubMed1975

Coagulocyte alterations in clotting hemolymph of Carausius morosus L.

1. The structural changes in the coagulocytes of Carausius morosus during hemolymph coagulation in vitro have been studied under the PCM and in the TEM. 2. In agreement with former PCM observations on Carausius morosus, the coagulocytes are the only hemocytes to induce coagulation of the plasma. Immediately or after a few seconds upon withdrawal of the hemolymph, their structural changes consist of a considerable enlargement of the perinuclear cysterna and of direct ejection into the plasma of nuclear and cytoplasmic substances through microruptures of the cytoplasmic membrane. The other categories of hemocytes do not contribute to the plasma coagulation. Their structural alterations take place without breakage of the cytoplasmic membrane when the plasma reactions are already established. 4. These plasma reactions appear in the form of circular islands of granular material around the coagulocytes, of extension of the coagulum in the channels between the islands and of transformation of the clot into a network of threads. 5. As reported in other studies in the TEM, no specific organelle characteristic of the coagulocyte ultrastructure could be found in the coagulocytes of Carausius. 6. Owing to the absence of any specific structural criterion of identification, the results suggest that the functional difference between coagulocytes and the other categories of hemocytes as regards coagulation of the plasma might be caused in part by differences of permeability of the cell membranes.

Animals↗
PubMed1978

[Agglutination and acrosome reaction of ram spermatozoa incubated in the bovine folicular fluid].

Fresh-ejaculated sperm of ram was incubated at a temperature of 38 degrees C in the bovine follicular fluid and homologous blood serum (blood plasma). The spermatozoa were studied in native state under a microscope with phase contrast and as ultra-thin sections under a transmission electron microscope. In the follicular fluid and in the blood serum, strong agglutination of spermatozoa occurred, with its maximum after about two hours. Only the heads of spermatozoa agglutinated, the flagella being loose were arranged parallelly. Although the progressive motility of spermatozoa was not observed, the motility of flagella was not affected. The investigation under the electron microscope showed that the agglutination occurred only in acrosomes of intact spermatozoa. It was also found out that the follicular fluid induced the acrosome reaction of spermatozoa. The course of the acrosome reaction is similar to that in the other mammals: first of all plasma membrane becomes undulated, then it fuses with the outer acrosome membrane, giving origin to vesicles within the entire acrosome, except the equatorial segment. The acrosome reaction was found in about 5% spermatozoa, and therefore it may be assumed that secretions of the oviduct and uterus play their role to induce the acrosome reaction.

Acrosome↗
PubMed1979

[Comparison of the suitability of phase-contrast and immunofluorescence technics in the laboratory diagnosis of porcine dysentery].

Immunofluorescence technique, compared with the method of phase contrast, does not appear to be better for laboratory diagnostics of swine dysentery because neither of these methods can be used for distinguishing between pathogenic and nonpathogenic strains of treponemas. The number of treponemas contained in faeces should still be considered to be the main criterion in laboratory diagnostics. In clinically healthy pigs from stocks which never suffered from dysentery treponemas were found only in few cases and always in small numbers. The numbers of treponemas contained in the faeces of dysenteric pigs were several times higher. Antigenic relationship of one nonpathogenic and three pathogenic strains of Treponema hyodysenteriae was proved by the agglutination and fluoresence methods.

Animals↗
PubMed1976

Aggregation of platelets and inert particles induced by thrombin.

Thrombin-induced platelet aggregation and release were investigated in washed platelet suspensions and in suspensions of inert particles in order to evaluate the role of fibrinogen-fibrin transformation in aggregometer tracings. Thrombin (0.25-2.0 U/ml) produced two waves of light transmission increase (LTI) in both platelet and inert particle suspensions containing fibrinogen, and concomittantly aggregates were observed under phase microscopy. Without fibrinogen, thrombin induced rapid release of platelet ADP but failed to cause second wave of LTI. The kinetics of LTI in platelet and inert particle systems were related to both thrombin and fibrinogen concentrations. A rapid second wave of LTI could be produced by direct interaction of thrombin-treated platelets or inert particles with polymerizing fibrin, and was inhibited by sodium sulfite and low pH of 5.1 which prevent fibrin monomer polymerization. No fibrin strands were noted in platelet aggregates fixed at the completion of the second wave of LTI. Apyrase and PGE1 inhibited the rate of first but not that of second wave LTI. The results suggest that the release of platelet ADP induced by thrombin primarily affects the first phase aggregation, and the second phase may result from interaction of thrombin-exposed platelets and polymerizing fibrin. Thus, the blood coagulation mechanism may be directly involved in platelet aggregation.

Adenosine Diphosphate↗
PubMed1978

[Further study of the nature and characteristics of the rosette formation phenomenon by a modified Jerne's method].

Experiments were conducted on 105 mongrel female albino mice weighing 18--22 g (intact, irradiated in a dose of 700 r with gamma-rays 60Co or immunized with SRBC) and on intact hybrids F1, CBAxC57BL. Phase contract microscopy showed autoimmune hemolysis plaques to be large or irregular and to posses a girdle made up of deformed and lysed erythrocytes and to contain stroma "ghosts" of the latter around the central cell. Plaques obtained in hypertensive medium were always round and the bordering girdle consisted of intact erythrocytes, whereas the plaque filed was homogeneous or contained granules. The concentration of sodium, potassium, calcium, and magnesium atoms in the suspension fluid of the preparations failed to exceed their content in the cells (as demonstrated by Jerne's method modified by the authors on a mixture of spleen cells with autologous blood). Addition of antiglobulin serum into the preparation on a slide in a 1:5 dilution suppressed the formation of autoimmune plaques, and in a dilution of 1:50--increased it considerably.

Animals↗
PubMed1979

[Cell structure and the pathogenicity of Brucella at different stages of L transformation].

On the basis of changes in the biological properties and morphology of Br. abortus culture under the action of penicillin 3 stages of L-transformation in Brucella were determined. The prevalence of first bacilliform and then typical L-cells and rapid reversion hampering the determination of virulence were characteristic of the initial stage (passages 1-4). Typical L-cells with the wrinkled surface, deep depressions and holes as well as a decrease in virulence and slight pathomorphological changes in the organs of the infected animals were characteristics of the intermediate stage (passages 5-10). Typical L-cells and amorphous masses, a further decrease in virulence, pathomorphological changes of toxic character (only after the injection of L-culture in large doses) were characteristic of the late stage (from passage 11 and further on). At all stages of L-transformation Brucella cultures showed a high reproductive capacity, binary division, the formation of elementary bodies by budding both inside and on the surface of L-cells.

Animals↗
PubMedDate not supplied

[Isolation of erythroblastic islands. Study by optical and scanning electron microscopy (author's transl)].

1. A simple technique is described for isolation and estimation of number of erythroblastic islands (EBI) in rat bone marrow. The number of EBI decreases during hypertransfusion polycythemia, and increases during experimentally-induced hemolytic anemia. It has also been possible to maintain EBI in vitro, under culture conditions, for up to 36 hours. 2. Each EBI contains a central cell having the character of a macrophage-histiocyte which adheres to glass and spreads, while still retaining its connections with the erythroblasts. 3. In an EBI the erythroblasts are arranged in the form of concentric rings, with the outer cells being more mature than the inner. The outermost layer is frequently made up of reticulocytes even in the isolated island. The erythroblasts of a single ring appear to be at the same stage of maturation which suggests that they are derived from the same stem cell. 4. Using a coordinate reference system, studies of nuclear expulsion were made, by both optical microscopy and scanning electron microscopy.

Animals↗
PubMedDate not supplied

Necrotaxis: a scanning and transmission electron microscopy study.

This paper describes an easy method to determine a "necrotactic rosette forming index (NRI) of leucocytes" after destruction of a red cell by a laser beam. Among the drugs tested, only cytochalasin B (0.5 mug/ml) is found to significantly lower NRI. The lectins PHA and CON-A did not have any effect on the NRI. Patients with infections are found to have increased NRI. Transmission and scanning electron microscopy have permitted the study of fine structurale details of the entire phenomenon.

Animals↗
PubMed1975

Morphologic and functional characteristics of bone marrow macrophages from imferon-treated mice.

The iron storage macrophage has been isolated from the marrow of Imferon-treated mice and studied in vitro by morphologic, histochemical, and functional tests and isotope labeling techniques. These macrophages on stained preparations are large, many times binucleate cells (up to 150 mu), and show Prussian blue reactivity. In Epon-embedded, stained thick sections they contain elongated narrow basophilic inclusions. These macrophages are actively phagocytic and pinocytic; histochemical studies show that these cells are rich in acid phosphatase, nonspecific esterase, and PAS diastase-resistant activity. Iron storage macrophages do not incorporate the 3H-thymidine. The electron microscopic appearance of this macrophage shows that the cell has ferritin free in the cytoplasm and several types of cytoplasmic granules: those with large quantities of electron-dense ferritin and/or hemosiderin (type A), elongated granules (type B) with moderately electron dense homogeneous matrix and some ferritin at the periphery, and granules with heterogeneous content (type C). The above findings demonstrate that the iron storage cell is a mature macrophage which contains hydrolases, ferritin, and a unique population of cytoplasmic granules which are lysosomal in nature. There is some evidence to suggest that the unusual lysosome (type B granule) occurs after macrophages have ingested erythrocytes.

Acid Phosphatase↗
PubMed1975

Recognition by pregnancy serums of non-HL-A alloantigens selectively expressed on B lymphocytes.

A group of alloantibodies are found in pregnancy sera which react with antigens present on B lymphocytes and monocytes but are not detectable on the vast majority of unstimulated T cells. This specificity distinguishes them from HL-A antibodies which react with both cell types. They were readily recognized through indirect fluorescent antibody analysis by employing the combination of B-cell lymphoid lines and normal peripheral blood T cells. Different sera gave a variety of patterns of reactivity with a panel of 11 lymphoid lines. Similar differential patterns were also observed with normal B cells from different individuals particularly after concentrating the B cells. The antibodies were also cytotoxic to B cells and this procedure gave parallel results to the fluorescence method. The pattern of reactions obtained indicated a very heterogeneous system similar to that for HL-A. Special study of certain of the sera provided evidence that the lymphocyte-defined determinants of the mixed lymphocyte reaction system were involved. For convenience the term HL-B has been employed for these antigens.

Antibody Specificity↗