New Experimental Facts on the Influence of Secondary Immunodeficiency on the Morphology and Biological Activity of Colorectal Tumor

Colorectal tumors were studied 5 months after carcinogen injection to outbred albino rats with secondary immunodeficiency by common histological and immunobiochemical methods with the use of monoclonal and polyclonal antibodies to Ki-67, Bcl-2, p53, and VEGF. Injection of carcinogen to intact animals led to the formation of adenocarcinomas with high and moderate cell differentiation in the colon, while injection of carcinogen to animals with immunodeficiency was associated with a 1.5-fold higher incidence of GRADE 2 and GRADE 3 adenocarcinomas with more aggressive morphological phenotype and appearance of distant metastases.

Morphology and Immunohistochemical Phenotype of the Thymus in Secondary Immunodeficiency

The thymus of outbred male rats 5 months after splenectomy (experimental secondary immunodeficiency) was studied by common histological and immunohistochemical methods using monoclonal and polyclonal antibodies to CD3, CD30, CD68, synaptophysin, to S100, p53, bcl-2, and Ki-67 proteins. Removal of the spleen led to acute involution of the thymic parenchyma, which was replaced by the adipose tissue and was associated with restructuring of the thymopoietic and nonthymopoietic components of the gland, changes in cellular composition and antigenic phenotype of the lobular cortical and medullary matter, and by reduction of cell proliferation.

[Morphological and immunohistochemical characteristics of the thymus during chemical carcinogenesis induced by 1,2-dimethylhydrazine administration]

The aim of the study was to examine the histological and immunohistochemical characteristics of the thymus 5 months after the intraperitoneal administration of the carcinogen (1,2-dimethylhydrazine in the dose of 20 mg/kg once a week for 2 weeks). The study was conducted on 50 outbred albino male rats. Paraffin sections of the thymus were stained with hematoxylin-eosin and were processed by an immunohistochemical method using antibodies against CD3, CD30, CD68, synaptophysin, S-100 protein, p53, bcl-2, Ki-67, as well as against IgM and IgG. It was found that carcinogen administration resulted in the increased number of thymic cells expressing bcl-2, S-100 and Ki-67, active T-lymphocytes and thymopoietic microenvironment cells, as well as in the change of the correlation between medullary and cortical CD3(+)-thymocytes with a predominance of the latter. Thus, the malignant tumor, developing in the colon, on the one hand, inhibits the supply of the precursors of thymopoiesis to the thymus, while on the other--enhances the proliferation and differentiation of thymocytes into mature forms.

[Morpho-functional changes of splenic autotransplants at the different time intervals after the operation]

This investigation was aimed at the study of splenic autotransplant cytoarchitectonics and cellular structures functional activity 3-60 days after the operation. The studies were carried out in 70 albino male rats including intact animals (n-10) and rats subjected to splenectomy and subsequent spleen heterotopic autotransplantation (n-60). Cryostat sections of transplants were processed for Falc and Cross luminescent-histochemical methods and were stained with hematoxylin and eosin. Biogenic amines content was measured using LUMAM-4 microscope with FMEL-1A spectrofluorimetric device. The number of luminescent cells in periarterial T-dependent zone was found to increase significantly after 7 days, while the unchanged lymphoid nodules were found in the zone of unaltered tissues. At day 15 "intrafollicular" luminescent granulocytes appeared in the newly formed lymphoid nodules. At days 15 to 45 the increased content of biogenic amines was detected in the "intrafollicular" cells, while the significant rise in the amount of amines was seen in the lymphocytes of nodule T-independent zone. It is suggested that the presence of intact nodules in transplant peripheral zone together with an increase in cell numbers in T-dependent zone, are the key events in the development of immune-correction effect of the transplanted spleen during the first two weeks after the operation.

IMMUNOBIOCHEMICAL AND HAEMATOLOGICAL INDEXES OF RATS BLOOD AFTER THE REMOVAL OF SPLEEN

Background: The spleen is not a vitally important organ, but the removal of spleencan adversely affect the patient’s health, especially that of children. Abrupt decrementin antimicrobial resistance after the splenectomy is confirmed experimentally leadingto overwhelming postsplenectomic hyposplenism. Besides there are few researches inthe pathogenesis and mechanisms of development of serious infectious complicationsafter splenectomy. So in our research we studied some indexes of immunology, generallaboratory and biochemical tests of blood in different terms after splenectomy.Methods: The immunologic, general laboratory and biochemical studies were done in3, 7, 15, 30, 45, 60 and 120 days after the splenectomy on 90 white male laboratoryrats.Findings: Splenectomy causes great changes of immunologic indexes of blood: from 7day of the experiment there’s a fall of IgG level, some increase of complement activity,the decrease of neutrophile's phagocytosis activity. In 4 months after the removal ofspleen the level of IgG and IgM is almost half, the number of circulatedimmunocomplexes is raised three fold and the neutrophile's phagocytosis activityremains low. Besides there is a heavy haemolytic anaemia in 7 days after thesplenectomy, the leukaemoid reaction of myelocyte type, the thrombohemorragicsyndrome and as a result of it - the acute renal insufficiency symptoms of whichdisappear by 120 days after the operation.Conclusion: The removal of spleen causes the development of accidental involution ofthymus and because of it causes the development of secondary immunodeficiency,thrombohaemorrhagic syndrome and severe anaemia. It needs to have more consideredapproach to the splenectomy and if it can’t be avoided - to initiate immunocorrectiontherapy at the earliest.Key Words: Splenectomy, immunodeficiency, leukaemoid reaction, renal insufficiency

[Accidental involution of the thymus after splenectomy (an experimental study)]

Using immunological, general clinical and luminescent histochemical methods experimental study of immunological status and bioamine-containing thymus structures was performed on third, seventh and fifteenth postsplenectomy days in 90 outbred albino male rats. Splenectomy leads to significant changes in blood immunological parameters and morphofunctional state of thymus bioamine-containing structures. Significant increase of biogenic amines content in all thymus structures, leukocyte number, complement activity neutrophilic granulocytes phagocytic activity, were registered in 3 days. Further growth of bioamine content, decrease of cortical and medullary substances diameter, significant number growth of juvenile forms of mast cells were observed in 7 days. Essential decline in erythrocyte number, hemoglobin and IgG and IgA content, leukocytosis with leukemoid reaction development were defined in blood formula. On 15th postsplenectomy day maximal biogenic amine concentration, especially histamine was reached and further reduction in cortex and medulla as well as decline of all the immunoglobulins and decrease of neutrophilic granulocytes phagocytosis were determined. Thus, splenectomy and subsequent development of accidental involution leads to secondary immunodeficiency and severe anemia.

[The effect on an impulse electromagnetic field on the bioamine allowance of the spinal ganglion in rats under whole-body exposure]

In experiments with albino male rats subjected to whole-body pulse electromagnetic irradiation of 100 mTl magnetic induction, the luminescent histochemical methods and the subsequent microspectrofluorometry were used to determine the content of biogenic amines (catecholamines, serotonin, and histamine) in spinal ganglia neurons. Significant changes were revealed not only in the content of all studied bioamines but in the histamine/serotonin ratio as well.

[Reaction of the ultrastructure of the rat spinal ganglion to exposure to a pulsed electromagnetic field]

White noninbred male rats have been subjected to a total effect of the impulsive electromagnetic field (IEMF) of 100 mT for 1, 3, 5, 10 days, 15 min daily. IEMF produces an essential morphofunctional reorganization in neurons, gliocytes, blood vessels of the rat spinal ganglion. Light neurons demonstrate an earlier reaction. Manifestation of the ultrastructural changes depends on multiplicity of the IEMF action: at initial effects they concern predominantly cytoplasmic structures of the neurons, at multiple effects--nuclear structures also become involved, reactive changes in gliocytes appear and increase. Early and distinctly seen reaction to the IEMF effect demonstrates endothelium of blood vessels. The changes revealed in the spinal ganglion are reversible, but the time of restoration of the normal ultrastructure directly depends on multiplicity of the IEMF action.

[Histochemical study of the cholinesterase activity in the structures of the rat heart normally and during exposure to a pulsed electromagnetic field]

Histotopography and activity of true and false cholinesterases in the non-inbred white rat hearts, normal and at the effect of pulsed electromagnetic field (80 kA/m) have been demonstrated by Karnovsky-Roots histochemical method. It has been stated that a single 6 hours' application of the pulsed electromagnetic field results in an increased cholinesterase activity in all cardiac structures, besides neurocytes. If the application is continued, cholinesterase activity is progressively decreasing and its minimum is observed on the 10th day of the stimulation. From the 15th day on, increasing enzymatic activities are observed, various for different enzymes: that of acetylcholinesterase even by the 30th day of the stimulation by the magnetic field does not reach the normal level, while that of cholinesterase exceeds this level. Mast cells are noted to appear along the cholinergic neural fibres. A suggestion is made on possible exchange between them by mediator acetylcholine. Electrocardiographic data have demonstrated that certain correlation exists between acetylcholinesterase activity and the cardiac function.