中华鳖脾脏椭球的微细结构及其循环特征

目的 观察和分析12只中华鳖脾脏椭球的显微和亚显微结构,阐明其循环特点。 方法 应用光镜和透射电镜技术,结合心脏注射墨水悬液方法,显示脾脏椭球的组成、结构与循环。 结果 中华鳖脾脏白髓由动脉周围淋巴鞘（PALS）和椭球周围淋巴鞘（PELS）两种结构组成,缺乏淋巴小结。红髓包括脾索和脾窦,未发现边缘区。中央微动脉穿出PALS后,呈笔毛状分成数条椭球毛细血管,后者周围由PELS包绕。椭球毛细血管的末端直接开口于红髓的脾索,血流注入脾索,而后穿过脾窦内皮间隙进入脾窦。不同于普通血管内皮,椭球毛细血管内皮一般为立方状,基膜不完整,其外即为椭球结构。椭球壁由支持细胞、椭球相关细胞和网状纤维等构成。常见淋巴细胞和红细胞穿过椭球壁。注射墨水悬浮液后40min,可见整段椭球壁上分布着大量墨水碳粒。 结论 中华鳖脾脏椭球毛细血管相当于哺乳动物的高内皮后微静脉,是淋巴细胞和血细胞进出淋巴组织的重要通道。中华鳖脾脏循环属于开放式循环。     

Splenic white pulp and associated vascular channels in chicken spleen

We have studied the chicken spleen by light and transmission electron microscopy. Germinal centers are located at the beginning of the central artery which is surrounded by the periarterial lymphatic sheath (PALS). The central artery has no branch crossing the PALS, and there is no histologically identifiable marginal zone in the chicken spleen. The central artery continues as penicilliform capillaries. The mid-portion of the penicilliform capillary is surrounded by the ellipsoid or Schweigger-Seidel sheath. The endothelial lining of this part of the pencilliform capillary contains small channels, formed between neighboring endothelial cells, which enter the ellipsoid. These channels allow circulating substances to accumulate in the ellipsoid. The cells of the ellipsoid are reticular cells, round or ovoid in shape, exhibiting a limited number of cell junctions. At the surface of the ellipsoid are ellipsoid-associated cells (EAC) which have an affinity for toluidine blue. After perfusion fixation, the majority of the cells in the ellipsoid are lost; this suggests weak cellular connections between the ellipsoid cells. The ellipsoid-associated cells remain in loco. On the basis of their shape and cytological features, two stages of EACs can be distinguished. The round or ovoid EACs elaborate active Golgi zones surrounded by numerous small vesicles containing an electron-dense substance. Occasionally, mitotic figures can be seen among them which may suggest that they are immature forms. In the second or more mature stage, the EACs assume an elongated spindle shape. The spindle-shaped EACs reveal inactive Golgi cis-ternae and fewer but larger granules than the round or immature EACs. Unmyelinated nerve fibers and nerve ending were observed in the ellipsoid. Perfusion fixation reveals that the distal portions of the penicilliform capillaries extend into the red pulp and become the sinuses. Therefore, the circulation of the chicken spleen is anatomically closed except for the channels in the mid-portion of the penicilliform capillary. The periellipsoid white pulp (PWP) possesses a few small lymphocytes, macrophages, and plasma cells with the majority of cells being young blastlike cells which may replenish the EACs and ellipsoidal cells. Carbon, injected intravenously, appears on the EAC membrane by 30 minutes, while Brucella abortus is completely phagocytized at this time. Binding the carbon triggers the EAC to detach from the ellipsoid and migrate to the periellipsoidal white pulp (PWP). The EACs phagocytize carbon by 2 hours, and by 5 and 8 days are present in the red pulp and surround the germinal centers at the border of the periarterial lymphatic sheath, respectively. Secretory cells which have been identified in germinal centers might originate from EACs.     

The role of various compartments in the chicken spleen during an antigen-specific humoral response.

In the chicken spleen, certain aspects of the complex of ellipsoid, peri-ellipsoid lymphocyte sheath (PELS), and ring of macrophages are morphologically and functionally similar to the marginal zone in the mammalian spleen. In this study, the role of this marginal zone-like complex was examined during the humoral immune response against a thymus-dependent antigen. The antigen peroxidase-conjugated rabbit anti-peroxidase (PAP) was injected intravenously in chickens and subsequently visualized by its enzymatic activity. Anti-PAP antibody-containing cells (ACC) were detected by incubation with PAP and subsequent peroxidase staining. Shortly after injection, PAP antigen was located in the ellipsoids. Within 24 hr most PAP had relocated to the B lymphocytes of the PELS. After this, most PAP disappeared, although minute amounts of PAP were detected in peri-arteriolar T-cell areas (PALS). At 48 hr, the PALS contained the first anti-PAP ACC; later ACC were also located in the red pulp. During the immune response, the isotype of the ACC switched from IgM to IgG. From 72 hr, PAP antigen and anti-PAP antibodies were trapped on follicular dendritic cells in immature and mature germinal centres. These results demonstrate that humoral immune responses are induced by the interaction of the PALS and the complex of ellipsoid, PELS and macrophages. These results, along with earlier ones, suggest that this complex is analogous to the marginal zone in the mammalian spleen.     

Periarterial lymphoid sheath in the rat spleen: a light, transmission, and scanning electron microscopic study.

The periarterial lymphoid sheath (PALS) in the rat spleen was studied by light, transmission, and scanning electron microscopy. The PALS was divided into three regions: the central region, peripheral region, and marginal zone bridging channel. In the central region, lymphocytes were easily washed away by perfusion. Large spaces were found between flat reticular cells or in large meshworks of stellate reticular cells; these may be deep lymphatic vessels. True lymphatic vessels were found in the central region near the hilus. In the marginal zone bridging channel, flat reticular cells surrounded the central artery in a circumferential pattern and formed channel-like spaces between the flat reticular cells. These spaces were connected with the meshwork of the red pulp reticular cells and may be a route for lymphocytes between the deep lymphatic vessels and the red pulp. In the peripheral region of the PALS, it was usually difficult to wash away free cells by perfusion, and free cells were found among the reticular cells. In places in the peripheral region, however, free cells were washed away. It is suggested that the lymph flow may start from the region surrounding the PALS, and that the peripheral region of the PALS may also be another route for lymphocyte migration.     

降钙素基因相关肽免疫反应神经纤维在大鼠脾的分布

用免疫组织化学ＡＢＣ法，研究了降钙素基因相关肽免疫反应神经纤维在大鼠脾内的分布，在大鼠脾内有丰富的ＣＧＲＰ免疫反应神经纤维，它们多呈串珠状，主要分布于红髓。尤其是脾血窦和一些小血管，也见于边缘区的淋巴组织中，偶见于动脉周围淋巴鞘，脾内ＣＧＲＰ免疫反应神经纤维与淋巴细胞关系密切，可能参与调节脾淋巴细胞的发育和功能。     

Periarterial lymphoid sheath in the rat spleen: A light,transmission, and scanning electron microscopic study

The periarterial lymphoid sheath (PALS) in the rat spleen was studied by light, transmission, and scanning electron microscopy. The PALS was divided into three regions: the central region, peripheral region, and marginal zone bridging channel. In the central region, lymphocytes were easily washed away by perfusion. Large spaces were found between flat reticular cells or in large meshworks of stellate reticular cells; these may be deep lymphatic vessels. True lymphatic vessels were found in the central region near the hilus. In the marginal zone bridging channel, flat reticular cells surrounded the central artery in a circumferential pattern and formed channel-like spaces between the flat reticular cells. These spaces were connected with the meshwork of the red pulp reticular cells and may be a route for lymphocytes between the deep lymphatic vessels and the red pulp. In the peripheral region of the PALS, it was usually difficult to wash away free cells by perfusion, and free cells were found among the reticular cells. In places in the peripheral region, however, free cells were washed away. It is suggested that the lymph flow may start from the region surrounding the PALS, and that the peripheral region of the PALS may also be another route for lymphocyte migration.     

神经营养素在小鼠脾的定位研究

为了解神经营养素与免疫系统的关系，用免疫组织化学方法对神经营养素包括神经生长因子（ＮＧＦ）、脑源性神经营养因子（ＢＤＮＦ）、神经营养素３（ＮＴ－３）进行小鼠脾的定位研究。结果表明：３种神经营养素的免疫反应均存在于脾内，但分布特点各不相同。ＮＧＦ主要分布于白髓动脉周围淋巴鞘（ＰＡＬＳ）外层、边缘区（ＭＺ）和红髓（ＲＰ）的巨噬细胞样和淋巴细胞样细胞；ＢＤＮＦ除具有与ＮＧＦ相似的分布特点外，还见于脾淋巴小结生发中心的淋巴细胞样细胞；ＮＴ－３则存在于白、红髓的网状细胞样细胞。这一结果提示，脾的免疫和非免疫细胞均可能产生神经营养素，并提示不同类型的神经营养素对免疫系统有不同的作用。     

The whale (Odontoceti) spleen: a type of primitive mammalian spleen.

Three spleens from two Odontoceti species were studied histo-anatomically. These spleens consisted of lymphatic nodules, the red pulp (broad sense), and the trabeculo-capsular system composed of the elasto-fibroleiomyocytic tissue. The periarterial lymphatic sheath (PALS) was unclear. Two layers, the intermediate zone and perivenous layer, were distinguishable in the red pulp (broad sense). The perivenous layer was narrow in width and consisted of venules and the intervascular reticular tissue rich in myeloid cells. The collecting and drainage veins were enclosed in this layer. The perivenous layer corresponds to the red pulp (narrow sense) of the common mammalian spleen and may be under involution in a process that probably relates to the remodelling of the intrasplenic vein. The pattern of the arteriovenous communication seemed to be closed, and no ellipsoids were noted around arterial terminals. The Odontoceti spleen has two venous drainage routes (hilar and capsular systems), suggesting a primitive state of evolution, and may be an additional example of the primitive mammalian spleen.     

Effect of surgical bursectomy on the ellipsoid, ellipsoid-associated cells, and periellipsoid region of the chicken's spleen

Surgical bursectomy resulted in cellular depletion of the periellipsoid white pulp, confirming its bursa dependency. Also, in bursectomized birds, the ellipsoid could not be identified, although a small number of abnormal ellipsoid-associated cells (EAC) were observed in the periellipsoid region. The most characteristic finding was the degeneration of the EAC. Degeneration of EAC indicated that the intact bursa was mandatory for normal differentiation of cells of the periellipsoid white pulp into EAC. The promoting effect of the bursa might take place by a bursal hormone. The histological impairment of the EAC was followed by reduced carbon binding and migrating capabilities. Bursectomy resulted in a shift in bacterial phagocytosis in that many cells of the periellipsoid phagocytosed Salmonella. The reduced heterophil infiltration of the ellipsoid in bursectomized birds might be explained by the impaired granular content of the EAC. The impaired migration capability of the EAC might contribute to the low number of germinal centers in bursectomized birds.     

GAP-43免疫反应神经纤维在小鼠脾脏的分布及其性质的研究

用免疫组化方法研究了GAP－43免疫反应阳性神经纤维在成年小鼠脾脏的分布及其性质。结果显示，GAP43样免疫反应阳性纤维不仅广泛分布于脾内血管周围，还存在于白髓、红髓的淋巴细胞之间。应用6-羟多巴（6－OHDA）损毁儿茶酚胺能神经后，TH、NPY免疫组化染色不能显示任何阳性神经纤维，而GAP－43免疫反应阳性神经纤维尚有部分存留．它们多位于较大的血管周围，较直且平滑、膨体少。此结果表明，成熟小鼠脾内绝大部分单胺能神经纤维和少部分非单胺能神经纤维含有GAP－43，是具有可塑性的神经纤维。     

Localization of splenic cells with antigen-transporting capability in the chicken

Background: The objective of the present study is to investigate the migration pattern of the splenic dendritic cell of the chicken named the ellipsoid-associated cell (EAC) from the site of initial location at the periphery of the ellipsoid to the splenic T- and B-dependent areas. Methods: Bovine serum albumin bound to biotin and conjugated to gold particles was used as a histochemically identifiable antigen detected as a peroxidase reaction. The antigen was intravenously injected, and subsequently its pattern of distribution in a time sequence and within the tissue was examined at the light and electron microsocopy levels. In addition, an hour prior to sacrifice, the chickens received a single injection of the thymidine analogue 5-bromo-2′-deoxyuridine, in order to quantify the number of DNA synthesizing cells and to establish a relationship between the migrating EAC and the rate of mitosis in the white pulp. Results: The observations showed that between 12 hours and 3 days after the second antigen administration the labeled EAC, which was first located around the ellipsoid, progressively reached further areas with time towards the periarteriolar lymphoid sheaths, where newly formed germinal centers appeared. Furthermore, the rate of cell proliferation within the white pulp was associated with the arrival of the antigen-transporting EAC. Conclusions: The results suggest that migrating EAC have a role as both antigen-transporting cell and antigen-presenting cell in the T- and B-dependent areas, as a result of which migrating EAC is transiently found in periellipsoidal white pulp, then periarteriolar lymphoid sheaths, and finally germinal centers, where it may function as an interdigitating cell or as a follicular dendritic cell, depending on its location. Thus, we conclude that the EACs are precursors of both interdigitating and follicular dendritic cells. © 1995 Wiley-Liss, Inc.     

Glucocorticoid receptor and serum‐ and glucocorticoid‐induced kinase‐1 in esophageal adenocarcinoma and adjacent Barrett's esophagus

Barrett's esophagus (BE) is a consequence of gastroesophageal reflux disease and is predisposed to esophageal adenocarcinoma (EAC). EAC is an exemplar model of inflammation‐associated cancer. Glucocorticoids suppress inflammation through glucocorticoid receptor (GR) and serum‐ and glucocorticoid‐induced kinase‐1 (Sgk1) expressions. Therefore, we immunolocalized GR and Sgk1 in EAC and the adjacent BE tissues and studied their association with clinical disease course in 87 patients with EAC who underwent surgical resection (N = 58) or endoscopic submucosal dissection (N = 29). Low GR and Sgk1 expressions in adjacent BE tissues were associated with adverse clinical outcomes (P = 0.0008 and 0.034, respectively). Patients with low Sgk1 expression in EAC cells exhibited worse overall survival (P = 0.0018). In multivariate Cox regression analysis, low GR expression in the adjacent nonmalignant BE tissues was significantly associated with worse overall survival (P = 0.023). The present study indicated that evaluation of GR and Sgk1 expressions in both the EAC cells and adjacent nonmalignant BE tissues could help to predict clinical outcomes following endoscopic and surgical treatments. In particular, the GR status in BE tissues adjacent to EAC was an independent prognostic factor.     

Mobilization of iron and iron-related proteins in rat spleen after intravenous injection of lipopolysaccharides (LPS).

We used lipopolysaccharide (LPS) to provoke immune responses and observed the changes in the localization of iron and iron-related proteins, such as transferrin receptor, ferritin and hemosiderin in the rat spleen. After intravenous injection of 250 micrograms LPS (salmonella minnesota R595), spleen weight and serum IgM levels increased, cells incorporating 5-bromo-2'-deoxyuridine (BrdU), and transferrin receptor positive cells increased in the peripheral portion of the periarterial lymphoid sheath (PALS), the marginal zone (MZ) and the follicles. Ferritin positive cells increased markedly in the white pulp and stainable iron increased in the marginal metallophils (MM) and in the macrophages in the MZ and the outer PALS. Even in iron deficient rats, a similar change was observed for the localization of iron and iron-related proteins after injection of LPS. After injection of 0.4 mg keyhole limpet hemocyanin (KLH), changes similar to but less pronounced than that in the LPS injected rats were observed for serum IgM levels and for the localization of iron and iron-related proteins. These results showed that the iron in the MM and the macrophages in the white pulp have a dynamic response to immunological challenges and suggested that they play some role in immune responses.     

Bacterial entry to the splenic white pulp initiates antigen presentation to CD8+ T cells

The spleen plays an important role in host-protective responses to bacteria. However, the cellular dynamics that lead to pathogen-specific immunity remain poorly understood. Here we examined Listeria monocytogenes (Lm) infection in the mouse spleen via in situ fluorescence microscopy. We found that the redistribution of Lm from the marginal zone (MZ) to the periarteriolar lymphoid sheath (PALS) was inhibited by pertussis toxin and required the presence of CD11c(+) cells. As early as 9 hr after infection, we detected infected dendritic cells in the peripheral regions of the PALS and clustering of Lm-specific T cells by two-photon microscopy. Pertussis toxin inhibited both Lm entry into the PALS and antigen presentation to CD8(+) T cells. Our study suggests that splenic dendritic cells rapidly deliver intracellular bacteria to the T cell areas of the white pulp to initiate CD8(+) T cell responses.     

Origin of the chicken splenic reticular cells influences the effect of the infectious bursal disease virus on the extracellular matrix

The effects of infectious bursal disease virus (IBDV) (strain F52/70) infection were studied by immunohistochemical methods on the splenic extracellular matrix (ECM). The major fibrillar components of the ECM, the type I and type III collagens and the main ECM organizing glycoproteins (laminin, tenascin and fibronectin) were monitored up to 11 days post-infection (d.p.i.). By 3 d.p.i., the collagens that form the basic scaffold of the antigen-trapping region of the spleen are destroyed, which is followed by deterioration of the glycoproteins. The ECM in the red pulp and the other regions of the white pulp (periarteriolar lymphatic sheath and germinal centre) seem to be normal. The reason for the significantly different pathological alterations in the ECM between the two regions of the spleen may be explained by the origin of the reticular cells. The reticular cells in the antigen-trapping zone and other splenic regions are of haemopoietic and mesenchymal origins, respectively. Possibly, the reticular cells of the haemopoietic origin are more susceptible for the IBDV infection than the mesenchymal ones. Development of the antigen-trapping, B-cell-dependent zone of the splenic white pulp precedes that of the periarteriolar lymphatic sheath and germinal centre, which suggests that this region may contribute to B-cell maturation. Damage of the ECM in the antigen-trapping zones results in impairment of tissue organization, which may contribute to the permanent immunosuppression.     

Immunocytochemical localization of corticotropin-releasing factor in the brain of the turtle, Mauremys caspica

Brain sections of the turtle, Mauremys caspica were studied by means of an antiserum against rat corticotropin-releasing factor. Immunoreactive neurons were identified in telencephalic, diencephalic and mesencephalic areas such as the cortex, nucleus caudatus, nucleus accumbens, amygdala, subfornical organ, paraventricular nucleus, hypothalamic dorsolateral aggregation, nucleus of the paraventricular organ, infundibular nucleus, pretectal nucleus, periventricular grey, reticular formation and nucleus of the raphe. Many immunoreactive cells located near the ependyma were bipolar, having an apical dendrite that contacted the cerebrospinal fluid. Immunoreactive fibers were seen in these locations and in the lamina terminalis, lateral forebrain bundle, supraoptic nucleus, median eminence, neurohypophysis, tectum opticum, torus semicircularis and deep mesencephalic nucleus. Parvocellular bipolar immunoreactive neurons from the paraventricular and infundibular nuclei projected axons that joined the hypothalamo-hypophysial tract and reached the outer zone of median eminence, and the neural lobe of the hypophysis where immunoreactive fibers terminated close to intermediate lobe cells. From these results it can be concluded that, as in other vertebrates, corticotropin-releasing factor in the turtle may act as a releasing factor and, centrally, as a neurotransmitter or neuromodulator.     

Periarterial macrophage sheaths (Ellipsoids) in cat spleen—an electron microscope study

Periarterial macrophage sheaths (PAMS), a term we introduce to replace “ellipsoids,” surround arterial capillaries in the red pulp of the spleen and are major sites for clearance of blood-borne particles. PAMS and their arterial capillaries in cat spleens in various states of congestion and contraction were studied by transmission electron microscopy. Thorotrast, a colloidal suspension of thorium dioxide, was injected to label macrophages. A PAMS consisted of a fine meshwork of reticular cells and reticular fibers which held macrophages and formed a cylindrical sheath around an arterial capillary lying in its longitudinal axis. Some PAMS were spongy due to loosening of cell associations by plasma infiltration; others were tightly compressed. Blood cells were both free in the interstices of the PAMS and attached to macrophages. Reticular cells formed a closely applied but incomplete layer adventitial to the arterial capillary and extended branches which contributed to the meshwork. Small villous processes on the major branches of reticular cells approached each other, sometimes forming intercellular junctions, and fit into complementary indentations in the surfaces of macrophages and endothelial cells. Thin filaments within reticular cells filled the villous processes and formed a border beneath the plasmalemma; intermediate filaments ran through the centers of the branches. Reticular fibers lay between reticular cells. Basement membrane fabricated of the same material as reticular fibers lay between the endothelium and reticular cells. Macrophages contained Thorotrast and abundant debris of phagocytized cells and were joined by extensive interdigitation of micropseudopodia. Endothelial cells were long rods which lay parallel and were joined along their bases by interdigitating lateral processes. Intercellular junctions were present at some points, but at others lateral processes were everted to form open interendothelial slits through which blood cells could pass. Endothelial cells possessed great numbers of randomly oriented intermediate filaments and small patches of thin filaments scattered along the basal plasmalemma and in lateral processes. Thin filaments may function to attach cells to one another and to the basement membrane and may assist in closing interendothelial slits. We believe that the endothelium responds to changes in arterial blood pressure and blood flow. It stretches to allow dilatation and recoils, probably due to the intermediate filaments, squeezing blood cells through interendothelial slits.     

CELLULAR AND HUMORAL DYNAMICS IN THE PERIARTERIAL LYMPHATIC SHEATHS OF RAT SPLEENS

Humoral and cellular dynamics in the periarterial lymphatic sheath (PALS) of the splenic white pulp were investigated in regards to the lymph flow and the architecture of the deep lymphatics in rat spleens. The effects of the splenic venous pressure on the lymph flow were also examined. We found a remarkable depletion of lymphocytes in the PALS and strong lymph flow to the deep lymphatics from the red pulp when the spleen was perfused via the splenic artery at a high speed with a high venous pressure. It was evident that lymphocyte depletion in the PALS depended on the venous pressure during the perfusion. Hemorrhage and lymphocyte depletion in the PALS also occurred after the ligature of the splenic vein. The migration of charcoal particles into the PALS via the red pulp was observed after intravenous or direct injection of charcoal particles. However, the briding channels in the marginal zone (MZ were always free of charcoal particles. The existence of deep lymphatics was confirmed around the central arteries which were more than 20 μm in diameter. The ligature of the thoracic duct resulted in the dilatation of the deep lymphatics and intercellular spaces which were easily recognized as the termination of the splenic lymphatics. The terminal lymphatics were localized only in the PALS but not in the follicles. Therefore, the PALS might be considered to act as a central station of the extra-vascular pathway which is connected to both the deep lymphatics and the MZ bridging channels. ACTA PATHOL. JPN. 34: 1301–1311, 1984.     

Light and electron microscopic observations on the spleen and the splenic leukocytes of the newt triturus cristatus

The newt spleen has an outer region, the red pulp, that consists of reticular fibres, reticular cells, and fixed macrophages forming a framework within which erythropoiesis occurs, and an inner region, the white pulp, consisting of a reticular framework containing predominantly lymphocytes. The fine structure of the following leucocytes, namely lymphoid cells, reticular cells, macrophage, haemocytoblasts, plasma cells and neutrophilic, basophilic and eosinophilic granulocytes is, in general, similar to that of the corresponding mammalian blood cells. However, in contrast, all the nuclei contain large numbers of interchromatin granules and a differentiated region termed the nuclear light-staining zone because of its electron-scattering properties. Furthermore the specific granules of the eosinophilic granulocytes are structureless whereas those of the basophilic granulocyte have crystalline regions. The structure and distribution of the granular, fibrillar, tubular and vesicular components of the cytoplasm of each cell type is described.     

B‐Cell Lymphoma‐2 Localization in the Female Reproductive Tract of the Chinese Soft‐Shelled Turtle,Pelodiscus Sinensis and Its Relationship With Sperm Storage

The aim of the present study was to investigate the expression and localization of B‐cell lymphoma‐2 (Bcl‐2) in the oviduct of the Chinese soft‐shelled turtle, Pelodiscus sinensis, during the reproductive cycle to analyze the relationship between Bcl‐2 and sperm storage. Bcl‐2 expression was confirmed in the P. sinensis oviduct by western blot analysis. Hematoxylin‐eosin staining showed that female P. sinensis stored sperm from November to April of the following year. The oviduct showed positive immunostaining for Bcl‐2 of epithelial ciliated cells, gland ducts, and gland cells. Bcl‐2 expression in the oviduct was associated with sperm storage occurrence. This indicates that the survival factor Bcl‐2 may play a role in P. sinensis sperm storage. Anat Rec, 298:2011–2017, 2015. © 2015 Wiley Periodicals, Inc.