Browsing by Subject "Spleen"

Now showing 1 - 9 of 9
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    Cocaine abuse and its impact on the thymus and spleen
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Aki, Toshihiko; Unuma, Kana; Biología Celular e Histología
    Cocaine is a psychostimulant abused worldwide. Its pharmacotoxicological properties are derived mainly from its impact on the neurotransmission of sympathomimetic nerves. Cocaine enhances and prolongs the neurotransmission of monoamines, such as dopamine, serotonin, and adrenaline, which are responsible not only for cocaine’s euphoric effects, but also its cardiovascular toxicity. In addition to these effects on central as well as peripheral nerves, immunosuppression is also implicated in cocaine toxicity. The thymus and spleen are lymphoid organs that are essential in lymphocyte maturation and erythrocyte homeostasis. Reductions in thymus and spleen size, which are observed under both physiological and pathological conditions, are known as thymic involution and splenic contraction, respectively. These phenomena are also observed in experimental animal models of binge cocaine abuse. In this brief review, we describe the mechanisms of cocaine toxicity, thymic involution, and splenic contraction, followed by discussions about the possible role of the latter two phenomena in cocaine intoxication.
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    Dialéctica del spleen en Charles Baudelaire
    (Universidad de Murcia, Servicio de Publicaciones, 2020) León Tribaldos, Irene
    A partir del texto Sobre algunos motivos en Baudelaire de Walter Benjamin y la propia obra del poeta Charles Baudelaire, pretendemos mostrar dos lecturas de sus escritos para exponer tanto el encuentro entre ambas interpretaciones, que tiene lugar en su obra mediante el spleen, como la Vieldeutigkeit de Theodor W. Adorno de estos mismos. Este término, que se ha traducido por “multivocidad”, aparece en la obra Prismas (Adorno, 1962) expresando la posibilidad de múltiples interpretaciones de una realidad. De esta forma, estudiaremos el dinamismo entre lo que hemos llamado “la hendidura del spleen” y “la huida del spleen”, dos momentos de la obra baudelairiana que consiguen objetivar en sus poemas la realidad histórica que vivió este autor. Trataremos de descifrar, asimismo, si el spleen que tanto pesó al poeta queda, o puede quedar redimido, mediante su literatura.
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    Differential expression of HIF-1α and its hypoxia-related inducers in the spleens of plateau yaks and plain yellow cattle
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Zhou, Manlin; Dong, Shihui; Wang, Jun; Luo, Xuehui; Li, Rui; Zhang, Yiyang; Ding, Haie; Tan, Xiao; Qiao, Zilin; Yang, Kun; Chen, Weiji
    The present study aims to investigate the distribution and expression characteristics of HIF-1α, VEGF, VEGFR-2, VCAM-1, and IL-4 in the spleen of plateau yaks and plain yellow cattle and to speculate the possible regulatory role of HIF-1α and its related hypoxia-inducible factors in the adaptation of the yak spleen to the plateau hypoxic environment. Histological features were observed using H&E and PAS stains. Immunohistochemical staining and optical density analysis were applied to investigate the distribution and differences in the expression of HIF-1α, VEGF, VEGFR-2, VCAM-1, and IL-4 in the spleen of yaks and cattle. The results showed that the area of splenic trabeculae and splenic nodules was significantly larger in the yak than in yellow cattle (P<0.05). Glycogen was mainly distributed in splenic arterial endothelial cells, vascular smooth muscle cells, splenic blood sinusoidal endothelial cells, and fibroblasts, and the distribution was significantly higher in the spleen of yaks than in cattle (P<0.05). HIF-1α, VEGF, VEGFR-2, VCAM-1, and IL-4 were mainly expressed in lymphocytes, arterial endothelial cells, vascular smooth muscle cells, splenic blood sinusoidal endothelial cells, and fibroblast cytoplasm, with higher expression in yak spleen (P<0.05). In conclusion, combining the differences in spleen tissue structure, glycogen distribution, and expression distribution of several hypoxia-related factors between yaks and cattle, we suggest that HIF-1α, VEGF, VEGFR-2, VCAM-1, and IL-4 may be important factors in the adaptation of yak spleen to the plateau environment, which provides a theoretical basis for further exploring the adaptation mechanism of plateau hypoxia in yaks.
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    Enhanced autophagy and phagocytosis of apoptotic lymphocytes in splenic macrophages of acute ethanol-treated rats: Light and electron microscopic studies
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2024) Betsuyaku, Tsubasa; Ito, Yuko; Peake, Nicholas; Al Bari, Abdul Alim; El Akabawy, Gehan; Eid, Nabil
    Autophagy is a prosurvival mechanism for the clearance of damaged cellular components, specifically upon exposure to various stressors. In lymphoid organs, excessive ethanol consumption increases lymphocyte apoptosis, resulting in immunosuppression. However, ethanol-induced autophagy and related phagocytosis of apoptotic lymphocytes in the spleen have not been studied yet. Adult male Wistar rats were injected intraperitoneally either with 5 g/kg ethanol or phosphate-buffered saline (as a control group) and then sacrificed 0, 3, 6, and 24 hours after injection. Light and transmission electron microscopy (TEM) findings indicated enhanced T cell apoptosis in the white pulps of ethanol-treated rats (ETRs) compared with the control group, which peaked at 6h and was associated with the accumulation of tingible body macrophages (TBMs). These macrophages exhibited an upregulated autophagic response, as evidenced by enhanced LC3-II (a specific marker of autophagosomes) expression, which peaked at 24h. In addition, double labeling immunofluorescence of LC3-II with lysosomal markers revealed the enhanced formation of autolysosomes in TBMs of ETRs, which was associated with suppression of p62 immunostaining, indicating the enhanced autophagic flux. Interestingly, this elevated autophagic response in ETR TBMs was accompanied by evidence of LC3-associated phagocytosis (LAP) of apoptotic splenocytes. This is based on TUNEL/LC3-II double labeling and TEM observations of phagosomes containing apoptotic bodies, enclosed within phagosomal membranes adjacent to the autophagic vacuoles. It can be concluded that enhanced prosurvival autophagy in splenic TBMs of ETRs and clearing of apoptotic lymphocytes via LAP may contribute to preventing secondary necrosis and autoimmune diseases.
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    Histopathology of the spleen in non-Hodgkin´s lymphoma
    (Murcia : F. Hernández, 1990) van Krieken, J.H.J.M.
    The human spleen has several different lymphoid compartments, which may be preferentially involved by non-Hodgkin's lymphomas. Low grade Bcell lymphomas tend to involve the compartments of the spleen where their normal physiological counterparts are found. High grade B-cell lymphomas grow more destructively without respecting lymphoid compartments. T-cell lymphomas involve mainly the T-cell areas, but may also involve follicles and the red pulp. Since non-Hodgkin's lymphomas can be regarded as clonal proliferations of lymphocytes frozen at a stage in differentiation, one posible conclusion is that low grade lymphomas are governed by normal homing mechanisms. High grade lymphomas may have lost their homing properties.
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    Stereological study of splenic tissue com partments in FK506-treated rats
    (Murcia : F. Hernández, 1997) Milicevic, N.M.; Milicevic, Z.
    Model-based stereology was used to study the changes of splenic structure and proportions of splenic tissue compartments in FK506-treated male Wistar rats (0.1 mg/kg three times a week for 14 days). The point-counting method was utilized to study the volume densities of the following tissue compartments: red pulp; white pulp (this compartment was divided in two subcompartments: follicles and periarteriolar lymphocyte sheath); marginal zone; aed connective tissue. The following stereological parameters of lymphoid follicles were also determined: areal numerical density (the number of follicles per mm2 of tissue section); the numerical density (number of follicles per mm3 of tissue); and the mean follicle diameter. After FK506 treatment a significant reduction of volume density of white pulp was observed, which was due to the very prominent decline in the amount of periarteriolar lymphocyte sheath, whereby the cellular density of this tissue compartment was decreased. In the marginal zone of FK506-treated spleens the presence of numerous, large, densely packed lymphoblastic cells of very uniform appearance was registered. These observations are in very good keeping with the changes of splenic morphology registered in cyclosporin Atreated rats, which further documents the parallelism in actions between these imrnunosuppressive agents.
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    Stereological study of tissue compartments of the human spleen
    (Murcia : F. Hernández, 1996) Milicevic, Z.; Cuschieri, A.; Xuereb, A.; Milicevic, N.M.
    Morphometric reports on animal and human spleen are very few and no studies have been carried out using stereological methods to investigate all of the tissue compartments of the human spleen. Eighteen samples of spleens, which were either surgically removed after traumatic injury or during treatment for early stage carcinoma or gastric ulcer, were investigated. The point-counting method was used to study the volume densities of the following tissue compartments: red pulp, perifollicular zone, white pulp (this tissue compartment was divided in two subcompartments: follicles and periarteriolar lymphatic sheath), marginal zone and connective tissue of trabeculas. The following stereological parameters of the follicles were investigated: the number of follicles per mm2 of spleen section, numerical density, volume density, and the mean follicular diameter. The identity of spleen tissue compartments was verified using immunohistochemical staining for B- and T-lymphocytes. The volume densities of tissue compartments, as well as stereological parameters of lymphoid follicles, were similar in both groups of splenic samples, except for the volume densities of perifollicular zone and periarteriolar lymphatic sheath, where a statistically significant difference was registered.
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    The novel histological evidence of the blood-spleen barrier in duck (Anas platyrhynchos)
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Sun, Xuejing; Liu, Enxue; Wang, Taozhi; Zhang, Qian; Yang, Ping; Ahmed, Nisar; Zhao, Qiaoya; Chen, Qiusheng
    To identify the existence and composition of the blood-spleen barrier (BSB) in ducks, the microanatomical structures of the duck spleen were investigated by light and transmission electron microscopy, silver staining, enzymatic histochemistry and intravenous injection of ink. The endothelial cells of the sheathed capillaries were cuboidal-shaped and surrounded by an ellipsoid consisting of reticular cells, similar to high endothelial venules (HEVs). After ink injection, carbon particles were initially restricted to the ellipsoid and later trapped in the periellipsoidal lymphatic sheaths (PELS), and then transferred to the periarteriolar lymphatic sheaths (PALS) and splenic nodules over time. Reticular fibers were primarily distributed at the basement membrane of the sheathed capillaries and the periphery of the PELS. Macrophages were primarily distributed at the border between red pulp and PELS. These results suggested that the BSB was present in the ellipsoid and PELS and consisted of the mechanical barrier composed of endothelial cells of the sheathed capillaries, reticular cells and reticular fibers and the biological barrier composed of ellipsoidassociated macrophages. In conclusion, the BSB was identified in the duck spleen for the first time, including cuboidal endothelial cells, ellipsoid-associated macrophages, reticular cells and fibers, and resisting circulating pathogen invasions. The study of BSB in ducks provides a theoretical foundation for the structural composition of the avian immune system.
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    The ruputure spleen. A hisological, morphometrical an immunohistochemical study
    (Murcia : F. Hernández, 1990) Barnard, H.; Dreef, E.J.; van Krieken, J.H.J.M.
    A traumatically ruptured spleen is regarded as a proper control in many histological and immunological studies on the human spleen. This paper compares spleens that ruptured due to trauma and spleens which were removed during surgery in patients without splenic pathology. Based on a histological, morphometrical, and immunohistochemcial description of the control spleens it is shown that the traumatically ruptured spleens contain alterations in the lymphoid tissue. The amount of white pulp is increased due to a larger amount of CD4- positive lymphocytes. Furthermore there are alterations in lymphocyte populations in the different splenic compartments. It is concluded that spleens that rupture may be predisposed due to immunological stimulation.