Accidental Involution Of Thymus Research Articles

Морфологическое исследование лимфоидных органов на ранних этапах экспериментального канцерогенеза простаты

the aim of our study was to identify of structural transformations in the thymus and lymph nodes at the early stages of the development of an experimental prostate cancer. Experiments were performed on 60 adult male CBA mice weighing 28-30 g. An experimental model of a prostate cancer was created by inoculating a diluted cell strain of Ehrlich Ascites Carcinoma cells into the prostatic parenchyma through midline laparotomy under ether anesthesia. The animals were divided into three groups of 20 each: 1) control (intact animals) 2) animals on the 5th day of experimental prostate tumor growth and 3) animals on the 18th day of experimental prostate tumor growth. The pathological examination of the prostate, thymus, and pelvic lymph nodes was performed. The selection of structural components and cellular elements in the thymus and lymph nodes was carried out according to the International histological nomenclature. According to the results, there was an increase in the percentage of connective tissue elements and glandular tissue increased in the thymus and the number of immunoblasts increased on the 5th day of the experiment. However, disorganization of the thymus structure was detected on the 18th day as well as an increase in the cortical substance, the number of epithelial reticular cells and decrease in the number of immunoblasts. On the 5th day, paracortical hyperplasia, sinus histiocytosis and activation of the blast transformation were detected in lymphatic nodes. On the 18th day, metastases, follicular reaction and activation of the transport function were determined. Our data suggest that the accidental thymus involution and impairment of transport and immune functions of pelvic lymph nodes in experimental prostate cancer. The severity of disturbances depends on the stage of prostate carcinogenesis.

Study of the accidental thymus involution during the formation of hierarchic communities by a novel physical method for recording the social stress

A novel method for recording the aggressive behavior in newly formed hierarchic communities has been developed. A temporal and age-related dynamics of the accidental thymus involution in mammals has been studied.

Histophysiology of the Immune System of Wistar Rats at Delayed Terms after Ovariectomy

We studied histophysiological changes in organs of the immune system, liver, and lungs of Wistar rats at delayed terms after ovariectomy. On day 52 after surgical castration leading to a decrease in estradiol, progesterone, and testosterone levels, activation of the immune system was revealed characterized by stage I accidental thymus involution, while pulp depletion in the spleen, and enhanced IL-2 and IFN-γ production. We also observed small-droplet degeneration of hepatocytes and reactive changes in the lungs manifested in increased number of neutrophils in the interalveolar septa.

The Grade of Acute Thymus Involution in Neonates Correlates with the Duration of Acute Illness and with the Percentage of Lymphocytes in Peripheral Blood Smear

In various stressful conditions, the thymus is subjected to incidental involution, mostly due to the thymocytolytic effect of secreted glucocorticosteroids. The aim of this study was to examine acute thymic involution in sick neonates and to compare the morphological grade with some clinical and laboratorial parameters. The influence of the illness on thymus tissue was investigated in 100 neonates who were treated and died in a neonatology intensive care unit. The preterm infants (n = 73) were born before the 37th week of gestation. Analysis of 57 placentas showed inflammation in 32% and circulatory disturbances in 23% of the cases. The causes of death were confirmed by autopsy: 35 were preterm infants with respiratory distress syndrome without infection, 22 were malformed, and 10 had birth trauma or asphyxia. In contrast, 29 of the preterm infants had an infection, mostly pneumonia or sepsis, and 4 of the term infants had such infections. Acute thymus involution was histologically graded (0–4) according to the method of van Baarlen (see text). Resting state (grade 0) was found in 25 of 38 neonates who lived <12 h. In 13 of 38 neonates who lived <12 h, thymus involution suggested prenatal stress. The grade of thymus involution related to the duration of illness (p < 0.001). Placental inflammation was associated with features of thymus involution (p < 0.048). Infection as a cause of death was connected to advanced thymus involution (p < 0.001). In preterm newborns, infection was more often connected with acute thymus involution than was respiratory distress syndrome (p < 0.003). Among the parameters measured in all avaiable peripheral blood samples taken 24 h before death, only the lymphocyte count related to the grade of acute thymus involution (p < 0.05), with an increase in percentage of lymphocytes in peripheral blood smears from grade 0 to 2 and a decrease from grade 2 to 4. Although the white blood cell count is highly variable, a low percentage of lymphocytes might be a sign of advanced accidental thymus involution following acute stress.

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

The thymic epithelial reticulum and interdigitating cells in SIV-induced thymus atrophy and its comparison with other forms of thymus involution

Alterations in the thymus were investigated in the early course of SIV infection of rhesus monkeys and compared with age-related and acute accidental thymus atrophy. The SIV-induced pathology was characterized by shrinkage of the thymic parenchyma and capsule, whereas in age-related thymus atrophy, the size of the capsule remained unaltered and the emerging space was filled by fatty tissue. Acute accidental thymus involution is characterized by massive cell death of the thymocytes, but there was no increase in pycnotic thymocytes either in SIV-induced or in age-related thymus atrophy. Ultrastructural analysis revealed no major differences between the juvenile control and the aged thymus. In contrast, SIV-induced thymus atrophy exhibited severe alterations of the epithelial cells of the cortex and the interdigitating dendritic cells, which were not found in the aged thymus nor in the juvenile control cortex.

ON THE ASSERTED NON-EXISTENCE OF THE AGE INVOLUTION OF THE THYMUS GLAND

The regressive changes brought about in the thymus gland by transient circumstances, particularly those of nutritive kind, have for more than 250 years far too often been confused with those occurring in the existence of every individual at a certain period of normal development. To what confusion this intermingling of the accidental thymus involution with the age involution of the organ has led is clearly evidenced by the survey of the literature on the subject published elsewhere by the author (Hammar, 1926). During all this time, however, the existence of the age involution has for all intents and purposes never been doubted. It has been the privilege of the most recent times to create a new phase in the history of scientific mistakes by classing the phenomenon of age involution with the viewpoints of accidental involution