Histological and enzyme histochemical investigation of the hemal nodes of the hair goat

We investigated the structure of the hemal node in six healthy hair goats using histological and enzyme histochemical methods. After processing, tissue sections were stained with Crossman's trichrome, Gordon-Sweet's silver and Pappenheim's panoptic stains. Alpha-naphthyl acetate esterase (ANAE) and acid phosphatase (ACP-ase) were demonstrated in frozen sections. Hemal nodes were encapsulated by connective tissue and few smooth muscle cells. Several trabeculae originated from the capsule and extended into the hemal node. A subcapsular sinus was present beneath the capsule and was continuous with the deeper sinuses. Subcapsular and deep sinuses were filled with erythrocytes. The parenchyma consisted of lymphoid follicles, diffuse interfollicular lymphocytes and irregular wide lymphoid cords. Cortical and medullary regions were not distinct. ANAE (+) and ACP-ase (+) cells were located mainly in the germinal centers of the lymphoid follicles and also were scattered equally in the interfollicular region and lymphoid cords. Monocytes, macrophages and reticular cells displayed a diffuse positive reaction, whereas localized granular positivity was observed in lymphocytes. We demonstrated that the general structure of the hair goat hemal nodes is similar to that of other ruminant species.     

The localization of CD3, CD79a,CD68 and S100 protein immunoreactive cells in hemal nodes of Saanen goat (Capra hircus)

We investigated the structure of hemal nodes in Saanen goats using immunohistochemical staining. We examined the distribution of CD3 positive T lymphocytes, CD79a positive B lymphocytes, CD68 positive macrophages and S100 protein positive follicular dendritic cells. Hemal nodes of six healty adult female goats were used. Hemal nodes were removed from the thoracic and abdominal cavities. The oval to round hemal nodes were observed especially between the abdominal aorta and vena cava, and near the kidneys and adrenal glands. Tissue sections were stained with Crossmon’s modified triple stain to demonstrate general histological structure. The avidin-biotin-peroxidase technique using anti-CD3, anti-CD79a, anti-CD68 and anti-S100 primary antibodies was used for immunohistochemistry. Many CD3 positive T lymphocytes were found in the germinal center of the lymph follicles and in the lymphatic cords of hemal nodes; CD3 positive cells also were observed in the sinuses. CD79a and CD68 positive cells were found at the germinal center of the lymph follicles. In the lymph follicles near the subcapsular sinuses, CD79a and CD68 positive cells were found especially in e areas bordering the mantle zone. S100 positive cells were found in the lymph follicles, lymphatic cords and sinuses.     

Histology of hemal nodes of the water buffalo (Bos bubalus)

Hemal nodes are independent lymphoid organs found in various mammals but are ignored by most immunologists. They seem to play a role in defense against blood-borne infections in some species. The structure of the hemal node has been described in various species but, so far, not in the water buffalo. Specimens were obtained from ten clinically healthy male animals (five calves: 2–3 months old; five bulls: 2–8 years old). Six hemal nodes were obtained from each animal from the mesenteric and perirectal region. The samples were studied by light and transmission electron microscopy. The hemal nodes are bean-shaped or spherical, with one hilus through which the hilus arteries and nerves enter the node and from which veins and lymphatics leave it. The buffalo hemal node has a thin capsule of connective tissue and a few smooth muscle cells. Trabeculae extend from the capsule partially dividing the parenchyma. Subcapsular and trabecular blood sinuses are present. The parenchyma is composed of irregular lymphoid cords rich in erythrocytes, macrophages, and plasma cells and is separated by blood sinuses of variable size engorged with blood. These blood sinuses drain into the trabecular sinuses and then into the subcapsular sinus. In calves, the size of the lymphoid cords is larger than that in adult bulls. Buffalo hemal nodes can be classified as typical hemal nodes, because they are definitely different from hemolymph nodes in other species. They may play a role in filtering the blood.     

Histology of the caprine hemal node

Caprine hemal nodes were studied by light microscopy after glutaraldehyde fixation and epoxy resin embedding. A node consisted of a capsule, subcapsular and other sinuses, cortex, medulla and hilus. Elements of circulating blood filled the interstices of the reticular meshwork and associated macrophages which traversed the lumina of subcapsular and medullary sinuses. The latter were rare in 1-month-old goats, progressively increased in number and size in 2- to 4-month-old goats and coalesced with each other and the subcapsular sinus in adult animals. The cortical tissue appeared as lymphoid nodules. Circumferential lymphatic vessels abutted on outer margins of the nodules and gave origin to several radial lymphatics which branched and anastomosed between the medullary blood sinuses. Medullary cords were organized around the radial lymphatics. A single efferent lymphatic was formed at the hilum by confluence of the radial lymphatics. Our study, in contrast to earlier reports, shows that caprine hemal nodes possess efferent lymphatics. The present data suggest that the hemal nodes are involved, in addition to classical functions, in blood storage by hemoconcentration.     

A microscopic investigation of the lymphoid organs of the beluga,Delphinapterus leucas

Lymphoid organs from belugas, Delphinapterus leucas, ranging in age from less than one to 16 years, were harvested during a sanctioned hunt to investigate morphology. The spleen is divisible into red and white pulp and a stroma consisting of a reticular network, a collagenous capsule, and trabeculae containing smooth muscle bundles. White pulp areas appear to be devoid of follicles and consist mainly of periarteriolar lymphatic sheaths (PALS), that are larger in younger than in older belugas. Definitive marginal zones between red and white pulp are difficult to discern in older belugas. Lymph nodes are similar to those of other mammals; they possess a follicular cortex surrounding a vascular medulla composed of lymphatic cords and sinuses. Smooth muscle is abundant in the medullary region, usually in close proximity to sinuses. The expansive nodular mass at the root of the mesentery, often referred to as the “pseudopancreas,” is similar to lymph nodes in microscopic architecture. Pharyngeal tonsils and gut-associated lymphoid tissue (GALT) are found along the digestive tract and display an “active” morphology. Tonsils are comprised of lobules of follicles separated by vascular connective tissue. Epithelial-lined crypts communicate with the pharyngeal lumen. GALT consists of diffuse and follicular lymphocytes within the intestinal mucosa and submucosa. The thymus is well developed in the younger belugas, with lobules divisible into densely packed cortical zones of thymocytes and more loosely arranged medullary lymphocytes. Hassall's corpuscles are occasionally visible within the medulla. Cetaceans diverged evolutionarily from other mammals over 55 million years ago. This study investigates changes in lymphoid organ morphology in a species that now inhabits a unique ecological niche. This study also lays the groundwork for functional investigation of the beluga immune system, particularly as it relates to differences between healthy and stranded animals. © 1993 Wiley-Liss, Inc.     

Effects of long term oral acrylamide administration on alpha naphthyl acetate esterase and acid phosphatase activities in the peripheral blood lymphocytes of rats

ABSTRACT

Acrylamide is an important industrial chemical; it also is formed in starch-rich foodstuffs during baking, frying and roasting. Most acrylamide exposure occurs by ingestion of processed foods. We investigated possible immunotoxic effects of extended administration of low doses of acrylamide in rats. To do this, we measured alpha-naphthyl acetate esterase (ANAE) and acid phosphatase (ACP-ase) activities in peripheral blood lymphocytes. Male and female weanling Wistar rats were administered 2 or 5 mg acrylamide/kg/day in drinking water for 90 days. Peripheral blood was sampled at the end of the administration period. We found ANAE staining in eosinophils and T-lymphocytes, but not in monocytes, platelets, B-lymphocytes and neutrophils. ACP-ase was found in B-lymphocytes. We found a significant reduction of the ratio of ANAE:ACP-ase in lymphocytes of the experimental animals compared to controls. We found no statistically significant differences between the doses or sexes. We found that acrylamide ingested in processed foods might affect the immune system adversely by decreasing the population of mature T- and B-lymphocytes.     

Reticular fibroblasts in peripheral lymphoid organs identified by a monoclonal antibody

We have produced a panel of monoclonal antibodies directed against nonlymphoid cells in central and peripheral lymphoid organs. In this paper we present the reactivity of one of these antibodies, ER-TR7. This antibody detects reticular fibroblasts, which constitute the cellular framework of lymphoid and nonlymphoid organs and their products. In frozen sections of the spleen incubated with this antibody, the red pulp and white pulp are clearly delineated. Furthermore, the major white pulp compartments--the follicles and periarteriolar lymphoid sheath as well as the marginal zone--are recognized by their characteristic labeling patterns. In lymph nodes, the capsule, sinuses, follicles, paracortex, and medullary cords are clearly delineated. In the thymus and bone marrow no such specialized compartments were demonstrated. ER-TR7 reacts with an intracellular component of fibroblasts. Since ER-TR7 does not react with purified laminin, collagen types I-V, fibronectin, heparan sulfate proteoglycan, entactin, or nidogen, it detects a hitherto uncharacterized antigen. The possible role of the ER-TR7 positive reticular fibroblasts in the cellular organization of peripheral lymphoid organs will be discussed.     

CTL fail to accumulate at sites of HIV-1 replication in lymphoid tissue

The inability of HIV-1-specific CTL to fully suppress virus replication as well as the failure of administration of exogenous CTL to lower viral loads are not understood. To evaluate the hypothesis that these phenomena are due to a failure of CTL to localize at sites of HIV-1 replication, we assessed the distribution of HIV-1 RNA and HIV-1-specific CTL identified by HIV-1 peptide/HLA class I tetrameric complexes (tetramers) within lymph nodes of 14 HIV-1-infected individuals who were not receiving antiretroviral therapy. A median of 0.04% of follicular compared with 0.001% of extrafollicular CD4(+) cells were estimated to be producing HIV-1 RNA, a 40-fold difference (p = 0.0001). Tetramer-stained cells were detected by flow cytometry in disaggregated lymph node cells from 11 subjects and constituted a significantly higher fraction of CD8(+) cells in lymph node (mean, 2.15%) than in PBMC (mean, 1.52%; p = 0.02). In situ tetramer staining in three subjects' lymph nodes, in which high frequencies of tetramer-stained cells were detected, revealed that tetramer-stained cells were primarily concentrated in extrafollicular regions of lymph node and were largely absent within lymphoid follicles. These data confirm that HIV-1-specific CTL are abundant within lymphoid tissues, but fail to accumulate within lymphoid follicles where HIV-1 replication is concentrated, suggesting that lymphoid follicles may be immune-privileged sites. Mechanisms underlying the exclusion of CTL from lymphoid follicles as well as the role of lymphoid follicles in perpetuating other chronic pathogens merit further investigation.     

Fluoride resistant alpha-naphthyl acetate esterase and combined enzyme histochemistry in the study of normal and pathologic lymphoid tissues

Alpha-Naphthyl acetate esterase (ANAE) and fluoride resistant alpha-naphthyl acetate esterase (FRANAE) have been compared as histochemical methods to identify T lymphocytes in sections of normal and pathological human lymphoid tissues. In addition, the FRANAE method was combined with alkaline phosphatase (ALP) in order to simultaneously evaluate the relationship between T lymphocytes and fibroblastic reticular cells (ALP) positive). The "dot like" esterase positivity of T lymphocyte was better evaluated by using FRANAE when compared to ANAE because of fluoride inhibitor of the strong esterase activity of dendritic cells and most macrophages. The combined ALP-FRANAE method clearly demonstrated a large number of fibroblastic reticular cells within the T-areas in various normal and pathological tissues such as hyperplastic lymph nodes and especially in the lymph nodes and spleens from patients with Hodgkin's disease.     

Morphology and ultrastructure of the somatic cells in Astacus leptodactylus ovary

We defined the somatic environment in which female germinal cells develop, and performed ultrastructural analyses of various somatic cell types, with particular reference to muscle cells and follicle cells, that reside within the ovary at different stages of oogenesis. Our findings show that ovarian wall of the crayfish is composed of long muscle cells, blood cells, blood vessels and hemal sinuses. The follicle and germinal cells lie within a common compartment of ovarian follicles that is defined by a continuous basal matrix. The follicle cells form branching cords and migrate to surround the developing oocytes. A thick basal matrix separates the ovarian interstitium from ovarian follicles compartment. Transmission electron microscopy shows that inner layer of basal matrix invaginates deeply into the ovarian compartment. Our results suggest that before being surrounded by follicle cells to form follicles, oogonia and early previtellogenic oocytes reside within a niche surrounded by a basal matrix that separates them from ovarian interstitium. We found coated pits and coated vesicles in the cortical cytoplasm of previtellogenic and vitellogenic oocytes, suggesting the receptor mediated endocytosis for transfer of material from the outside of the oocytes, via follicle cells. The interstitial compartment between the inner muscular layer of the ovarian wall and the basal matrix of the ovarian follicle compartment contains muscle cells, hemal sinuses, blood vessels and blood cells. Granular hemocytes, within and outside the vessels, were the most abundant cell population in the ovarian interstitium of crayfish after spawning and in the immature ovary. J. Morphol. 277:118–127, 2016. © 2015 Wiley Periodicals, Inc.     

Histochemical study on human germinal centre, mantle-zone and extra-follicular area lymphoid cell subpopulations. Immunological and cytochemical correlations with lymphomatous cells, peripheral normal and leukemic lymphocytes

Tissue sections of lymph nodes, appendices and tonsils, together with smears of immunologically separated peripheral lymphoid cells from a B-CLL and lymphomatous cells from an immunocytoma were submitted to combined enzyme cytochemical investigations with acid alpha-naphthyl acetate esterase (ANAE), beta-glucuronidase (B-G), acid phosphatase (AcPh), adenosine triphosphatase (ATPase), a,d 5'nucleotidase (5'N). T-cells were Acph+, ATPase- and 5'N-. The vast majority of T- and B-cells displayed ANAE and B-G activities with two distinct staining patterns (T-like and B-like pattern). A high proportion of lymphoid cells in the germinal centre (G.C.) and the vast majority of lymphoid cells in the mantle-zone (M.Z.) were shown to belong to B-cell system because of the expression of ATPase and 5'N in their membranes. Some lymphoid cells positive for ANAE and B-G with a B-like pattern and for AcPh were recognizable in the G.C. In the M.Z. only a few lymphoid cells being ANAE+, with a T-like pattern, and AcPh+ were shown to belong to the T-cell system. In contrast, in this zone a high proportion of small lymphoid cells (64% +/- 10%) showed ANAE activity, mostly with B-like pattern. Therefore, these findings indicate that in the M.Z. a high proportion of B-cells ATPase+ and 5'N+ also display ANAE activity. By comparison of the results obtained from lymphoid tissue sections, B-CLL and immunocytoma cell suspensions and normal circulating lymphocytes we can conclude that B-ANAE-positive cells of the M.Z. do not usually appear in the peripheral blood. They circulate in large numbers only in some pathological conditions (like our reported B-CLL). Therefore, B-ANAE-positive lymphoid cells of the mantle, with a B-like staining pattern, include a wide range of subsets which exclude large lymphoid cells and plasma cells.     

The distribution of N-acetyl-beta-glucosaminidase, beta-glucuronidase, acid alpha-naphthyl acetate esterase and alpha-naphthyl acetate esterase in subpopulations of thymocytes, bone marrow cells and other lymphoid organs in mice

Thymocytes, bone marrow lymphocytes, as well as lymphocytes from spleen, lymphoid nodes and peripheral blood were obtained from BALB/c mice. Subpopulations of BALB/c bone marrow T-lymphocyte precursors and immature (small) and mature (large) thymocytes, as established by the percentage of terminal deoxynucleotidyl transferase (TdT) and peanut agglutinin (PNA) positive cells, were obtained by centrifugation on discontinuous density gradients. The activities of N-acetyl-beta-glucosaminidase (NAG), beta-glucuronidase (BG), acid alpha-naphthyl acetate esterase (ANAE) and alpha-naphthyl acetate esterase (NAE) were determined by enzymatic assays of cell extracts of the diverse T-lymphocyte subpopulations, in order to follow their evolution with the maturation of the T-lymphocytes in the thymus. These activities were compared with that determined in lymphocytes from spleen, lymphoid nodes and peripheral blood. The glucidases BG and NAG and the esterases ANAE and NAE present a high decrease in their activities from bone marrow T-lymphocyte progenitors to immature thymocytes. BG, NAG and ANAE activities undergo an about 3-fold increase with the evolution of the thymocytes from small to large cells. Whereas the level of the NAE activity decreases (2-fold) with that evolution of the thymocytes. Lymphocytes from spleen and lymphoid nodes exhibit activities of the glucidases and, specially, the esterases marked by higher than those of thymocyte populations. Peripheral blood lymphocytes also present NAG, ANAE and NAE activities higher than in thymocytes, but their BG activity is lower.     

Topography,ultrastructure and phagocytic capacity of avian lymph nodes

Summary The structure of the avian lymph node (ALN) is characterized by a thin capsule, thin lymphoreticular cords, and an absence of trabeculae. It is not possible to subdivide the ALN into cortex, paracortex and medulla, or to subdivide the system of sinuses into marginal, trabecular and medullary divisions. The lymphoreticular cords contain avian germinal centers (AGC) with B-lymphocytes and the area of T-lymphocytes.Postcapillary venules are responsible for the recirculation of lymphocytes. Sinus reticular cells do not exist in the ALN, but free macrophages are present. The phagocytic capacity of the macrophages was determined by injection of vital dyes (India ink, Berlin blue) and inoculation with Candida cells. Macrophages filled with markers migrate from the lymph sinuses into the lymphoreticular cords and further into the AGC. The mobility of the macrophages is remarkably lower after phagocytosis of Candida cells.This study is dedicated to Prof. Dr. Dr. h.c. Hugo Grau (Weilheim) with sincere appreciation and respect     

Entamoeba histolytica: lymphoreticular changes in gerbils (Meriones unguiculatus) with experimentally induced cecal amebiasis

Antibody responses and changes in the lymphoreticular tissues of gerbils with experimental cecal amebiasis were studied from 5 to 60 days PI. Changes in the cecum consisted of lymphoid follicle hyperplasia and depletion of lymphocytes, followed by follicle atrophy and histiocytosis. Mesenteric lymphadenopathy, and histologic alterations in the lymph nodes paralleled the progressive development of amebic cecal lesions. Early in the infection (5 to 10 days PI) mesenteric lymph nodes showed cortical follicle hyperplasia, blastogenesis in the paracortical areas (PCA) and intense lymphoblast and plasma cell activity in the medullary cords. At 20 to 30 days PI, the cortical follicles, the PCA and the medulla were depleted of lymphocytes and there was histiocytosis throughout the organ. At 60 days PI, lymphocyte repopulation took place in the PCA, and cortical follicles had active germinal centers. Spleen follicles did not increase in number as the infection progressed, but became hyperplastic. Antibody titers to ameba were low throughout the cecal infection but rose whenever amebic metastasis to the liver occurred. The results of this study indicate that lymphocytes from the submucosal lymphoid follicles and the draining lymph nodes may control the pathogenesis of the infection. Lymphoreticular tissue alterations could result from antigenic stimulation and migration of cells to the sites of infection.     

Quantitative evaluation of the total number and distribution of lymphocytes in young pigs.

In young pigs, the spleen, thymus and all lymph nodes were dissected out and weighed. The relative content of lymphoid cells was determined from histological sections. The number of nucleated cells was evaluated by two different methods: firstly, by measuring the DNA content of samples of lymphoid tissue and dividing by the DNA content of a single nucleus; and, secondly, by counting all lymphoid cells in histological sections of defined volumes of these organs. The number of lymphoid cells in tonsils, gut, bone marrow and lung were determined using histological evaluations and the volumes or weights of these organs. The resulting average number of lymphocytes was 321 times 10 (9) for a pig of 26 kg body weight. The lymphocytes showed the following distribution in lymphoid and non-lymphoid organs: thymus 44%, spleen 9%, mesenteric lymph nodes 17%, cervical lymph nodes 9%, other peripheral lymph nodes 3%, gut-associated lymphocytes 5%, tonsils 2%, bone marrow 5%, blood 3%, lung 0.2% and an estimated figure of 3% for all other tissues.     

Earliest lymphoid colonization of neonatal rat lymph nodes: an antigen-specific process?

The present work studied the little known process of lymphoid cell colonization of neonatal lymph nodes, while considering the nodal site of entry of circulating lymphoid cells and the either random or antigen-specific character of the process. Tissue sections of a mesenteric, cervical and popliteal node from each of 57 rats, aged 4 hours to 3 weeks, were analysed. Observations bear on the relative importance of the implication of the subcapsular sinus versus venules of nodes, and the composition of their emerging lymphoid cell population by determining the proportion of lymphocytes and blast-related cells. At 16-20 hours after birth, cell counts yielded a mean proportion of 84% for blast-related cells which decreased to 18% at 3 weeks. These percentages are compatible with values expected for a selective antigen-specific entry of lymphoid cells in nodes, not with values that would result from a random entry of lymphocytes. Moreover, observations revealed that by far most colonizing cells initially enter nodes carried by the afferent lymph, little via their venules.     

Morphology of mesenteric lymph nodes after balneologic procedures

Strong and weak sulfate baths produce certain increase in amount and in area of the lymphoid noduli with the germinative center, in the deep cortex and a decrease in the relative area of the medullary substance, while iodobromine baths facilitate to an outgrowth of the medullary cords and to ectasia of sinus lumens. After the balneoprocedures lymphoid noduli appear in the deep cortex; amount of destructive cells in the medullary sinuses, in the medullary cords and in the intermedullary zone decreases; amount of mast cells, eosinophiles and neutrophiles increases (slightly). Blast transformation of small lymphocytes and increase in number of middle lymphocytes are observed in the germinative centers.     

Tissue nature of the lining of the lymph node sinuses]

The lymphatic nodes of intact albino rats were investigated electron microscopically. It was shown that the lymphatic sinuses were restricted by a layer of flattened cells; the basal membrane was absent. Certain distinctions in the structure of the cell lining sinuses and the reticular cells comprising the reticular base of the lymphoid tissue of the lymphatic node were found. The structure of the "sinus network" strands is shown. The structure of the cells of the sinuses lining is shown to be identical to the structure of cells of the vascular endothelium. It suggests the endothelial nature of the lining of the lymphatic node sinuses.     

Detection of purine nucleoside phosphorylase in paraffin sections by the immunoperoxidase method

A method is described for immunohistochemical demonstration of purine nucleoside phosphorylase (PNP: EC 2.4.2.1) in paraffin sections from routine surgical histology specimens. A peroxidase-antiperoxidase (PAP) method was employed, using specific rabbit antiserum against human PNP, which was purified from postmature human erythrocytes. In human lymph nodes, intensive staining for PNP was observed in the vast majority of small lymphocytes in paracortical areas, in many small lymphocytes in medullary cords, and in a few small-to medium-sized lymphocytes in germinal centers. Small lymphocytes in the primary follicles and those in the mantle zones of secondary follicles were negative for PNP staining. Tingible body macrophages, lymphatic sinus cells, and most of the large cells in germinal centers did not stain with anti-human PNP (hPNP) antibody. Endothelial cells of small vessels in the cortex and plasma cells did not show any constant pattern of PNP staining intensity. Histochemistry revealed that the distribution pattern of PNP activity was quite similar to that demonstrated on paraffin sections by the PAP method.