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PubMed1965

ELECTRON MICROSCOPY OF ABSORPTION OF TRACER MATERIALS BY TOAD URINARY BLADDER EPITHELIUM.

The absorption of Thorotrast and saccharated iron oxide by the epithelium of the toad urinary bladder was studied by electron microscopy. Whether the toads were hydrated, dehydrated, or given Pitressin, no significant differences in transport of colloidal particles by epithelial cells were observed. This implies that these physiological factors had little effect on the transport of the tracer particles. Tracer particles were encountered in three types of epithelial cells which line the bladder lumen, but most frequently in the mitochondria-rich cells. Tracer materials were incorporated into the cytoplasm of epithelial cells after being adsorbed to the coating layer covering the luminal surface of the cells. In the intermediate stage (1 to 3 hours after introducing tracer) particles were present in small vesicles, tubules, and multivesicular bodies. In the later stages (up to 65 hours), the particles were more commonly seen to be densely packed within large membrane-bounded bodies which were often found near the Golgi region. These large bodies probably were formed by the fusion of small vesicles. Irrespective of the stages of absorption, no particles were found in the intercellular spaces or in the submucosa. Particles apparently did not penetrate the intercellular spaces of the epithelium beyond the level of the tight junction.

Absorption↗
PubMed1965

STUDIES ON THE LYMPHOCYTOSIS INDUCED IN MICE BY BORDETELLA PERTUSSIS.

1. Intravenous injection into mice of phase I Bordetella pertussis vaccine resulted in a striking hyperleucocytosis with a predominating lymphocytosis. Intraperitoneal inoculation was less effective, and subcutaneous administration was inactive. 2. Active immunization prevented the hyperleucocytosis; passive immunization was less effective. 3. Reticuloendothelial blockage reduced the effect of the vaccine. 4. Extirpation of the spleen or thymus did not alter the leucocyte response. 5. Histologic studies suggested that the increase in circulating lymphocytes resulted from release of cells from lymphoid organs, including the thymus.

Animals↗
PubMed1965

PLATELETS AND THE SHWARTZMAN PHENOMENON.

Studies are reported on the effect of immunologically induced thrombocytopenia upon the local and generalized Shwartzman phenomena. Intravenous injection of antiplatelet serum to rabbits produced profound but transient thrombocytopenia unaccompanied by significant changes in circulating leucocytes. Platelet antiserum alone given to rabbits prepared with thorotrast produced renal lesions characteristic of the Shwartzman reaction. Thrombocytopenia induced by platelet antiserum did not inhibit the cutaneous hemorrhagic lesion of the local Shwartzman phenomenon produced by sequential injections of endotoxin intracutaneously and intravenously. The implications of these observations in the pathogenesis of the local cutaneous and generalized Shwartzman reaction are discussed.

Aminosalicylic Acid↗
PubMed1965

ENDOTOXEMIA AND ADRENAL HEMORRHAGE. A MECHANISM FOR THE WATERHOUSE-FRIDERICHSEN SYNDROME.

An experimental model that produces adrenal cortical hemorrhage with endotoxin has been described. When stimulated by thorotrast, endotoxin, or its tropic hormone (ACTH), the adrenal cortex is susceptible to the development of a hemorrhagic reaction during endotoxemia. The hemorrhagic reaction resembles that described in the Waterhouse-Friderichsen syndrome. A pathophysiologic mechanism for the occurrence of adrenal hemorrhage occurring during acute sepsis is presented. Increased metabolic activity associated with the production of corticosteroids seems to make the adrenal cortex susceptible to endotoxin-induced hemorrhage. Adrenal hemorrhage observed during sepsis, as in the Waterhouse-Friderichsen syndrome, may be attributable to endotoxemia occurring during or shortly after stimulation of the adrenal cortex by infection. Significant differences between adrenal cortical hemorrhage and the Shwartzman phenomenon are described.

Adrenal Gland Diseases↗
PubMed1965

MECHANISMS OF ENDOTOXIN TOLERANCE. 3. THE REFRACTORY STATE DURING CONTINUOUS INTRAVENOUS INFUSIONS OF ENDOTOXIN.

Bacterial endotoxins were administered by continuous intravenous infusions at constant rates to normal man and rabbits. An initial progressive febrile reaction was followed by progressive defervescence to baseline. The resulting pyrogenic refractory state was characterized as follows: (a) reticuloendothelial blockade with thorotrast neither prevented nor reversed its course; (b) passive transfer was unsuccessful with refractory phase plasma; (c) infusions of normal plasma or fresh whole blood failed to restore responsiveness; (d) a minimum of 4 hours of continuous endotoxin infusion was required for full development of unresponsiveness; (e) circulating antibody titers to endotoxin remained unaltered; (f) peripheral leukocytosis appeared; (g) infusion of febrile phase plasma reevoked an immediate, monophasic fever; (h) endotoxinemia could be demonstrated by pyrogen bioassay; (i) 10-fold increases in endotoxin infusion rates reevoked fever; (j) impaired responsiveness extended to heterologous endotoxins; (k) dermal inflammatory responses to endotoxin were suppressed in man while tuberculin reactivity remained unimpaired; dermal inflammatory responses to endotoxin were enhanced in rabbits; and (l) pyrogenic reactivity to endotoxin reappeared within 24 hours in man; refractoriness persisted in rabbits. It is concluded that the pyrogenic refractory state reflects an inability of the host to continue to mobilize endogenous pyrogen during sustained endotoxinemia. Such observations, together with previous studies, are consistent with two distinct immunologic mechanisms of resistance to endotoxin pyrogenicity: (a) desensitization at the cellular level; and (b) elaboration of circulating antibodies which assist reticuloendothelial clearance and destruction of endotoxin. Whereas both such mechanisms may contribute to pyrogenic tolerance, the characteristics of the pyrogenic refractory state suggest the participation only of the former.

Allergy and Immunology↗