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Biomedical subjects

W Ptak

Publications and source records attributed to W Ptak.

At least 127 records · Page 7Linked to original sources
PubMed1977

The effect of antibody on the migratory pattern of peritoneal macrophages.

51Cr-labeled peritoneal macrophages which interiorized sheep erythrocytes (SRBC) injected i.p. into syngeneic recipients accumulate in a typical fashion in different organs. The pattern of distribution can be altered by two maneuvers--when animals at the time of macrophages transfer are injected i.v. with cytophilic antibody, or when macrophages are fed with IgG-SRBC complexes instead of native SRBC. The possible role of modified migratory pattern of macrophages in antibody-induced suppression of the immune response is discussed.

Animals↗
PubMed1976

[Comparative morphological studies on the vascular systems of testes in cattle, swine, horse and dog under functional conditions].

The metacrylate and latex corrosion techniques were used to establish that the vascular system of testes is based on one coherent principle in common domestic mammals. The cone-shaped Plexus pampiniformis consists of numerous venous rami, between 0.25 mm and 1.0 mm in thickness and forming a dense vascular network, which practically encase the spiral-shaped A. spermatica interna (cooling coil principle). The testicular veins and arteries in the Tunica albuginea constitute a somewhat voluminous layer of vessels for dissipation of heat, with rami branching off radially into the testicular parenchyma. Most of the artieral rami with radial penetration of the testicular parenchyma turn towards the surface in the mediastinum testis for three-shape ramification. The vascular rami are characterised by countless meanders, primarily for temperature control, pulse flattening for more regular and even blood flow, and blood reflex pumping.

Animals↗
PubMed1976

Primary immune response to sheep red blood cells in mice treated with immunoregulatory alpha-globulins (IRA).

Alpha-Globulins from human and bovine sera or from mouse ascitic fluid were separated by ion-exchange chromatography on DEAE-cellulose into fractions A, B, and C. Fractions A and B had no immunosuppressive activity; fraction C injected into mice at the time of antigen administration, but not later, significantly reduced the number of anti-SRBC plaque-forming cells in the spleens of experimental animals. Single high dose inhibited the response better than the same doses given on 4 consecutive days. It is concluded that a critical level of alpha-globulins is necessary to render lymphocytes hyporesponsive, and when once stimulated by antigen they become less susceptible to alpha-globulin action.

Alpha-Globulins↗
PubMed1975

Cytotoxic macrophage in graft-versus-host reaction.

Peritoneal macrophages of F1 hybrid mice injected with parental strain spleen cells 8-14 days previously ("early" graft-versus-host (GVH) macrophages) develop an increased ability to destroy in vitro bystanding target cells of syngeneic, allogeneic, and xenogeneic origin. At later stages of GVH reaction, the nonspecific cytotoxicity of macrophages wanes ("late" GVH macrophages) and does not differ much from that of control macrophages. Trypsinization of early GVH macrophages or iodoacetate treatment significantly reduces their cytotoxicity, whereas anti-theta serum and complement have only a moderate effect. Antimouse IgM antibody significantly enhanced the cytotoxic potential of early GVH macrophages, but had no effect either on normal or late GVH macrophages. In contrast, antimouse IgG antibody enhanced, although slightly, only the cytotoxic activity of late GVH macrophages. Two possible explanations of the increased cytotoxicity of early GVH macrophages are offered: (1) cytophilic antibody of IgM type, directed against host antigens, renders macrophages capable of damaging nonspecifically bystanding target cells upon contact with antigen; (2) IgM alloantibody produced by parental cells changes the surface properties of macrophages and contributes to the cytotoxicity of these cells.

Animals↗
PubMed1975

Demonstration of cells with igg receptor in human placenta.

The presence of two types of cells with IgG surface receptors was demonstrated in mature and immature human placentas. One type corresponded morphologically to the Hofbauer cells and the second to the blood monocytes. Transitional forms between monocytes and Hofbauer cells were also observed.

Candida albicans↗
PubMed1975

Macrophage metabolism during phagocytosis and digestion of normal and IgG antibody-coated sheep erythrocytes.

The respiration rate, aerobic glycolysis and glycolytic enzyme activities of purified mouse peritoneal macrophages increase during phagocytosis of either free or antibody-coated SRBC. These changes, however, seem to be roughly parallel to the amount of phagocytized antigen. In the digestive phase, Ag-Ab complexes induce more marked changes in macrophage metabolism than a comparable amount of free antigen. Lactate production, activity of several glycolytic enzymes and alanine-aminotransferase as well as glycogen content are greatly affected. Since in cell transfer experiments macrophage-associated SRBC can prime normal recipients for antibody response, whereas cell-associated SRBC-antibody complexes cannot, it is concluded that the changed macrophage metabolism drives antibody-coated antigen into metabolic channels allowing its rapid and total degradation.

Aerobiosis↗
PubMed1975

Alloantibody-induced cytotoxicity of macrophages.

Alloantibodies substantially alter the in vitro nonspecific cytotoxic effect of macrophages on bystanding allogeneic and xenogeneic target cells. Although the specific IgM alloantibody increased significantly the ability to parental macrophages to damage target cells, IgG alloantibody had an opposite effect and suppressed the macrophage cytotoxicity. Macrophages of F1 hybrid mice were less affected by this treatment unless alloantibodies against both parental strains were added together. Parental macrophages exposed in vitro to the concomitant action of both IgM and IgG alloantibodies exhibited a diminished cytotoxicity toward target cells. It is proposed that IgM and IgG alloantibodies induce different conformational changes of the macrophage surface.

Absorption↗
PubMed1975

Contact sensitivity in alloxan-diabetic mice.

Alloxan-diabetic mice of Swiss, CBA and DBA/2 strains show a significant depression of contact sensitivity to oxazolone, as compared with normoglycaemic control animals, which is accompanied by the involution of the thymus and spleen. Insulin treatment partially restores the contact sensitivity in diabetic animals and also increases the weight of lymphatic organs. In contrast, the non-specific inflammatory response to oxazolone is not impaired in insulin-deficient mice. Further experiments have shown that neither sensitized lymphocytes of control animals given to diabetic mice, nor sensitized lymphocytes of diabetic mice injected into normoglycaemic recipients, were able to transfer passively any significant contact sensitivity. It is suggested that in alloxan-diabetic mice the function of T lymphocytes is affected.

Animals↗
PubMed1975

Immunosuppression effected by macrophage surfaces.

Heat-killed macrophages (but not six other types of cells tested) suppress Mishell-Dutton cultures by a mechanism that does not adversely affect cell viability. The suppressive effect is abolished by treatments that inactivate receptors for cytophilic antibody. We suggest macrophages may absorb, and thus render inoperative, factors which are necessary for lymphocyte cooperation.

Animals↗