Vergleichend-anatomische Untersuchungen über einen transepithelialen Flüssigkeitsstrom in das Lumen der Kloake von Vögeln

Comparative anatomical studies on transepithelial fluid migration into the lumen of the cloaca in birds In the rooster the fluid migration originates principally from lymph capillaries and ends in the interstitium of the lymphfolds. In the male duck, coot and pigeon this phenomenon occurs in a corresponding zone of transudation. In these birds the fluid migration originates principally in blood capillaries, however. From the interstitium the fluid passes through intercellular spaces of the epithelium into the lumen of the cloaca where it appears as a transparent fluid. In all examined species immunocompetent cells migrate into the cloaca with the fluid. These cells produce the immunoglobulins which have been found in the transparent cloacal fluid of the rooster.     

Immunohistochemical identification of lymphatic vessels in the periodontium of equine cheek teeth

Immunohistochemical detection of lymphatic capillaries was performed in the periodontium of maxillary and mandibular cheek teeth from 6 horses (aged 3-23 years). Tissue sections of the periodontium were taken at 4 different horizontal levels along the long axis of the tooth. The specimens were processed for immunoreaction with anti-Prox1, in order to distinguish lymphatic endothelium from blood vascular endothelium. Lymphatic vessels were detected in all periodontal tissues except for the dental cementum. Lymphatic capillaries were most densely distributed in the gingiva compared to other tissues of the periodontium. Lymphatic capillaries were found most consistently in samples taken from the gingival and subgingival regions in all horses examined. Within these levels, the gingiva as well as the spongiosa of the maxillary and mandibular bone had the greatest incidence of lymphatic vessels. Considering the distinct distribution of the lymphatic capillaries in the periodontium of the maxillary and mandibular cheek teeth, two complementary lymphatic drainage pathways are proposed: (1) superficial lymph drainage via the gingiva, emptying into the mandibular lymph nodes; (2) deep lymph drainage via the mandibular and maxillary spongiosa, emptying into the mandibular and retropharyngeal lymph nodes, respectively.     

Lymphsystem und Lymphdrainage im Hoden des Pekingerpels (Anas platyrhynchos, L.)

Lymph system and lymphatic drainage in the testis of the Peking drake ( Anas platyrhynchos , L.)
After perfusion fixation the lymph vascular system can be distinguished sharply from the blood vascular system because the formation of lymph proteins is a reliable distinguishing criterion. Prelymphatic spaces without endothelial lining among seminiferous tubules partially communicate with lymph capillaries that are continuous with lymph sinusoids. Lymphatic vessels whose walls as yet contain no muscle are already present between the seminiferous tubules. The lymph then flows to the tunica albuginea in which it was possible to demonstrate, by injection of Prussian Blue, an narrow-mesh lymphatic network. Collecting vessels converge on the hilus and carry the lymph to the thoracoabdominal trunk. Right and left trunks, singly or after joining, enter the blood vascular system close to the left angle of veins.     

Über die intramuralen Blutgefäße des Enddarms vom Pferd (Equus przewalskii f. caballus)

The vascular system of the large intestine of 12 horses was examined by means of vascular corrosion casts, histology and transmission electron microscopy providing the following results. The Aa. et Vv. breves et longae leave the mesenteric vessels, respectively the subserously on the teniae lying cecal vessels to reach the tela subserosa at the mesenteric margin. The short vessels enter the deeper layers of the wall instantly, whereas the Aa. et Vv. longae move towards the submucosa by penetrating the muscular layers after a variable subserous course. The tela submucosa contains an arterial and a venous vascular plexus. In broader areas of the submucosa a three-dimensional vascular network can be found. This consists of a deep and a superficial vascular plexus, which are closely interconnected. The deep plexus is applied to the inner circular muscles, whereas the superficial plexus is adjacent to the muscularis mucosae. The (deep) arterial plexus receives its afflux from the Aa. breves et longae and supplies parts of the circular muscle layer with recurrent muscle branches. The vascularisation of the mucosa also originates from the submucosal (superficial) plexus. In the basal tunica mucosa, the ascending arteries form a transversal network from which arterioles branch into periglandular capillaries around each Lieberkühn crypt. Close to the lumen, a polygonal subepithelial capillary system is formed. The capillaries turn into postcapillary venules immediately below the epithelium of the mucosal surface. Veins move vertically through the submucosa to enter the submucosal plexus after few inflowing side branches. Branches of the subserous-submucosal connections form an intermuscular plexus between the circular and longitudinal muscular layer. This plexus supplies the capillaries of the tunica muscularis. The subepithelial capillaries are predominantly lined with a fenestrated endothelium, whereas the capillaries of the pericryptal mucosa mainly show a continuous endothelial lining. The latter contain multiple vesicles, which may fuse in order to form transcytoplasmic channels. Sphincter-like muscle bundles at the transition points from capillaries to venules may provide hemodynamic regulatory structures in the submucosa of the horse. Veins with circumferential cushions of smooth muscle fibres, so-called ‘throttle veins’, are also found.     

山羊心脏淋巴系的研究

在４０例山羊心外膜下多点注入３０％普鲁士蓝氯仿溶液，解剖观察心脏淋巴管及其淋巴流向；选择注射较好的心脏标本制成透明铺片，镜下观察测定淋巴管管径，并摄影记录。结果表明，山羊心脏的毛细淋巴管起自一盲端，并吻合成淋巴管丛，淋巴管有瓣膜，粗细不均。三级淋巴管汇入锥旁室间沟或冠状沟附近的四级淋巴管。四级淋巴管汇合成淋巴干，山羊心脏的淋巴干分２种类型，即双干型与单干型。淋巴干一般注入气管支气管左淋巴结，有时右淋巴干直接注入胸导管。心房壁薄，淋巴管比心室少而细     

Das Blutgefäßsystem des Enddarms vom Hund (Canis lupus f. familiaris)

The Vascular System in the Large Intestine of Dog (Canis lupus f. familiaris) The vascular System of the large intestine of 10 dogs was examined by means of vascular corrosion casts, histology and transmission-electron microscopy. The tela submucosa contains an arterial and a venous vascular plexus. In broader areas of the submucosa, a deep and a superficial vascular plexus, which are interconnected, can be found. The plexus are orientated parallel to the layers of the intestinal wall. On the one hand, these vessels naturally provide self-sufficiency and drainage of the submucosa, and, moreover, direct branches to the stratum circulare of the muscular layer. On the other hand, the submucosal vascular plexus is the ‘distributional network’ for the functional plexus of the tunica mucosa. The arteries, which ascend to the tunica mucosa, supply a flat arterial network underneath the intestinal glands. Bundles of only a few arteriolae originate from this in order to supply the pericryptal capillaries. In the vicinity of the cryptai orifices, these turn into a network of subepithelial capillaries, which is post-connected to the periglandular capillary plexus. From this ‘terminal circulatory pathway’, the blood is drained off by veins that enter the submucosal plexus. It is characteristic that the postcapillary venules often begin as part of the capillary network. As in other species, the subepithelial capillaries are predominantly lined with a ‘fenestrated endothelium’, whereas the capillaries of the pericryptal areas show a continuous endothelium. The latter contains multiple vesicles that may fuse in order to form transcytoplasmic channels as a morphological equivalent for transcappillar-epithelial and vice versa occurring transport of substances.     

Blood vessels within lymph nodes: a comparison between pigs and sheep

In sheep, most blood vessels enter the lymph nodes at a discrete hilus, which is where the capsule overlies medullary tissue. In pigs, vessels within the node arise from an extensive network of arteries on the surface, and most vessels penetrate the capsule where it overlies diffuse tissue--the counterpart of the sheep medulla. In both species the blood vessels divide extensively as they approach and supply the dense lymphoid tissue which contains lymph nodules. The blood vessels within sheep lymph nodules are surrounded by a thick layer of amorphous material. The dense lymphoid tissue has an abundant network of venules which have smooth muscle cells in their walls. These venules are involved in lymphocyte migration and in pigs they are lined by high endothelium which is similar to that in most other species, while in sheep the endothelium is much lower. Fenestrated capillaries occur in both pig and sheep lymph nodes.     

Distribution of Trypanosoma congolense in infected multimammate rats (Mastomys coucha): light and electron microscopical studies

In an attempt to determine whether Trypanosoma congolense occurs both within and outside the blood vessels in an infected animal host, multimammate rats (Mastomys coucha) were infected with T. congolense and samples from spleen, lymph nodes, bone marrow, liver, kidney, lungs, brain, heart, intestines, ovaries and testes were collected. The tissue samples were fixed and processed for light and electron microscopical examination. In all the tissues examined, trypanosomes were found only within the lumen of large and small blood vessels, capillaries and sinuses. It is concluded that following entry into the blood circulation after intra-peritoneal infection of M. coucha, T. congolense remains restricted to the bloodstream.     

Lymphocyte migration in the intestinal mucosa: entry, transit and emigration of lymphoid cells and the influence of antigen

Lymphocyte migration is important to transport immunological information between the different compartments of the intestinal immune system. Large numbers of lymphocytes emigrate from the Peyer's patches and reach the blood circulation after expansion and maturation within the mesenteric lymph nodes. So far the frequency of antigen specific lymphocytes emigrating from the Peyer's patches after oral stimulation is not known. After mesenteric lymph node resection those cells emigrating from the intestinal wall are accessible by calculating the major intestinal lymph duct. The first antigen specific cells draining from the intestines are obviously not lymphocytes but dendritic cells, thus the antigen is rapidly trapped in the parenchyma of the lymph nodes in vivo. When lymphocytes were taken from intestinal lymph, labeled in vitro and retransfused, marked numbers of B-cells were re-detected in intestinal lymph. Later preferentially T-cells recirculated through the gut wall. After immigration into the intestinal lamina propria the lymphocytes may enter the space between epithelial cells, where they are present as intraepithelial lymphocytes. Lymphoid cells in the S-phase of the cell cycle have been detected in all compartments of the intestinal wall. Apoptosis is probably a further important mechanism for the regulation of intestinal immunity in removing cells reacting against harmless dietary antigens to maintain oral tolerance.     

斯氏艾美耳球虫子孢子的移行途径

关于斯氏艾美耳球虫Ｅｉｍｅｒｉａ ｓｔｉｄｅａｉ子孢子的移行途径争议尚大。作者借光镜和电镜互补的手段研究了子孢子从肠腔到肝内胆管上皮细胞的移行。所取材料为人工感染５－５０万卵囊的１月龄幼兔的血液，肠道，淋巴结，脾和肝，取材料时间为感染后２－７２ｈ至４－６ｄ。依据子孢子大量出现于肠系膜淋巴结和小量出现于脾脏而未见于其它部位淋巴结，以及肝内胆管周围营养血管中有大量子孢子出现等观察结果，提出了子孢子移行     

Inflammatory cytokines IL-6 and TNF-α regulate lymphocyte trafficking through the local lymph node

Lymphocyte trafficking from blood to lymph and back is a tightly regulated process. Given appropriate stimuli, trafficking of cells through the lymph node changes from a 'steady-state' to a bimodal flow. Initially, a 'shutdown' phase occurs, leading to a dramatic reduction in efferent cell output. This is followed by a 'recruitment' phase whereby the efferent cell output becomes greatly elevated before returning to baseline levels. The shutdown/recruitment process is hypothesised to promote encounters between Ag-specific lymphocytes and APCs in an environment conducive to immune response induction. Cytokines, such as TNF-α have been shown to play an important role in regulating lymphocyte trafficking. Here, we unravel the role of cytokines in the regulation of cell trafficking using an in vivo sheep lymphatic cannulation model whereby the prefemoral lymph nodes were cannulated and recombinant cytokines were injected subcutaneously into the draining area of the cannulated node. We demonstrate that local injection of purified IL-6 or TNF-α stimulates shutdown/recruitment in the draining lymph node. While the effect of IL-6 appears to be direct, TNF-α may mediate shutdown/recruitment through IL-6.     

Das Blutgefäßsystem des Enddarms vom Schwein (Sus scrofa f. domestica)

The circulatory system of the large intestine of 27 pigs was examined by means of corrosion anatomy (vascular casts), histology and electron microscopy. The results were as follows: The Aa. et Vv. breves et longae leave the mesenteric vessels and reach the wall of the intestine at the mesenteric margin. The short vessels enter the deeper layers of the wall, whereas the Aa. et Vv. longae, by taking a variable subserous course, reach the submucosa af ter penetrating the muscular layers. The tela submucosa contains an arterial and a venous vascular plexus. Where the submucosa is larger, there is a three-dimensional vascular network, a deep and superficial vascular plexus that are closely interconnected. The deep plexus is applied to the inner circular muscles, whereas the superficial plexus is adjacent to the muscularis mucosae. The deep arterial plexus receives its af flux from the Aa. breves et longae and provides part of the circular muscle layers with recurrent muscle branches. The vascularization of the mucosa is derived from the (superficial) submucosal plexus. The arteries that ascend the tunica mucosa ramify, in the form of a brush, into some arterioles. In the basal part of the mucosa, they turn into a periglandular capillary system, i.e. a network around each Lieberkühn crypt. Close to the lumen, a polygonal subepithelial capillary system is formed. Below the epithelium of the mucosal surf ace, the capillaries turn into postcapillary venules. These are running vertically through the submucosa, with few infiowing side branches, and finally enter the submucosal plexus. An intermuscular plexus is formed by anastomoses between the circular and the longitudinal muscular layers from the branches of the subserous-submucosal connections. This intermuscular plexus provides the capillaries for the tunica muscularis. The subepithelial capillaries are, above all, furnished with a so-called fenestrated endothelium, whereas the capillaries of the pericryptal mucosa mainly show a continuous endothelium. The latter contains multiple vesicles that can fuse to form transcytoplasmic channels. In the wall of the large intestine of the pig, there are no sure indications as to the existence of either arterio-venous anastomoses or haemodynamic regulatory structures.     

Microvasculature of the rat eye: scanning electron microscopy of vascular corrosion casts

Methylmethacrylate castings of the eye microvasculature were prepared from 10 Spargue-Dawley rats and studied by electron microscopy. The choroidal arterioles are larger in diameter than retinal arterioles, and have a shorter course to choroidal capillaries than retinal arterioles to retinal capillaries. Retinal capillaries are extremely thin in diameter and form a sparse retinal capillary network. The choriocapillaris is large and sinusoid-like, forming a compactly arranged network in the choroid. These differences in the microvasculature between the choroid and retina help explain the differences in ocular hemodynamics; that is, the blood flow in the choroid is faster than that in the retina. Capillaries of the iris show a zigzag configuration, which may be an accommodation for dilation and constriction of the pupil. Capillaries of the ciliary body are of large diameter forming leaf-like configurations, presumably to contribute to the secretion of the aqueous humor. Capillaries of the conjunctiva exhibit a somewhat coiled configuration, the arrangement of which reduce tension of the conjunctiva vessels caused by eyeball movement. Intra-arterial cushions, which control blood flow at the branching sites, are found in both choroidal or retinal arterioles.     

Recovery of Campylobacter jejuni in feces and semen of caged broiler breeder roosters following three routes of inoculation

We previously reported the recovery of Campylobacter (naturally colonized) from the ductus deferens of 5 of 101 broiler breeder roosters, and four of those five positive roosters had previously produced Campylobacter-positive semen samples. Those results prompted further evaluation to determine if inoculation route influenced the prevalence or level of Campylobacter contamination of semen, the digestive tract, or reproductive organs. Individually caged roosters, confirmed to be feces and semen negative for Campylobacter, were challenged with a marker strain of Campylobacter jejuni either orally using 1.0 ml of a diluted cell suspension (log(10)4.3 to 6.0 cells), by dropping 0.1 ml of suspension (log(10)5.3 to 7.0 cells) on the everted phallus immediately after semen collection or by dip coating an ultrasound probe in the diluted cell suspension (log(10)4.3 to 6.0 cells) and then inserting the probe through the vent into the colon. Six days postinoculation, individual feces and semen samples were again collected and cultured for Campylobacter. Seven days postinoculation, roosters were killed, the abdomen aseptically opened to expose the viscera, and one cecum, one testis, and both ductus deferens were collected. The samples were then suspended 1:3 (weight/volume) in Bolton enrichment broth for the culture of Campylobacter. Samples were also directly plated onto Cefex agar to enumerate Campylobacter. Campylobacter was recovered 6 days after challenge from feces in 82% of samples (log(10)4.1 colony-forming units [CFU]/g sample), 85% of semen samples (log(10)2.9 CFU/ml), and on the seventh day postchallenge from 88% of cecal samples (log(10)5.8 CFU/g sample). Campylobacter was not directly isolated from any testis sample but was detected following enrichment from 9% (3/33) of ductus deferens samples. Roosters challenged with Campylobacter orally, on the phallus, or by insertion of a Campylobacter dip-coated ultrasound probe were all readily colonized in the ceca and produced Campylobacter-positive semen and feces on day 6 after challenge. The low prevalence of recovery of Campylobacter from the ductus deferens samples and failure to recover from any testis sample suggests that semen may become Campylobacter positive while traversing the cloaca upon the everted phallus. The production of Campylobacter-positive semen could provide a route in addition to fecal-oral for the horizontal transmission of Campylobacter from the rooster to the reproductive tract of the hen.     

Scanning electron microscopic study on the microarchitecture of the vascular system in the pigeon lung

The resin casts of the respiratory and vascular systems in pigeon lung were examined using a scanning electron microscope. The primary bronchi branched to form many secondary bronchi that anastomosed with each other via the parabronchi. Numerous infundibula protruded from the parabronchi via the atria and ramified into the air capillaries. The pulmonary artery entered into the lung and branched into three vessels that coursed the interparabronchial parts. The intraparabronchial arterioles penetrated the gas-exchange tissue to form the anastomosing networks of blood capillaries. The observation of the double casts of the respiratory and vascular systems revealed three-dimensional complicated networks of air capillaries and blood capillaries.     

Transfer of immunoglobulins through the mammary endothelium and epithelium and in the local lymph node of cows during the initial response after intramammary challenge with E. coli endotoxin

Background

The first hours after antigen stimulation, interactions occur influencing the outcome of the immunological reaction. Immunoglobulins originate in blood and/or are locally synthesized. The transfer of Ig isotypes (Igs) in the udder has been studied previously but without the possibility to distinguish between the endothelium and the epithelium. The purpose of this study was to map the Ig transfer through each barrier, separately, and Ig transfer in the local lymph nodes of the bovine udder during the initial innate immune response.

Methods

The content of IgG1, IgG2, IgM, IgA and albumin (BSA) was examined in peripheral/afferent mammary lymph and lymph leaving the supramammary lymph nodes, and in blood and milk before (0 h) and during 4 hours after intramammary challenge with Esherichia coli endotoxin in 5 cows.

Results

Igs increased most rapidly in afferent lymph resulting in higher concentrations than in efferent lymph at postinfusion hour (PIH) 2, contrary to before challenge. Ig concentrations in milk were lower than in lymph; except for IgA at 0 h; and they increased more slowly. Afferent lymph:serum and efferent lymph:serum concentration ratios (CR) of Igs were similar to those of BSA but slightly lower. Milk:afferent lymph (M:A) CRs of each Ig, except for IgG2, showed strikingly different pattern than those of BSA. The M:A CR of IgG1, IgM and IgA were higher than that of BSA before challenge and the CR of IgA and IgG1 remained higher also thereafter. At PIH 2 there was a drop in Ig CRs, except for IgG2, in contrast to the BSA CR which gradually increased. The M:A CR of IgM and Ig A decreased from 0 h to PIH 4, in spite of increasing permeability.

Conclusion

The transfer of Igs through the endothelium appeared to be merely a result of diffusion although their large molecular size may hamper the diffusion. The transfer through the epithelium and the Ig concentrations in milk seemed more influenced by selective mechanisms and local sources, respectively. Our observations indicate a selective mechanism in the transfer of IgG1 through the epithelium also in lactating glands, not previously shown; a local synthesis of IgA and possibly of IgM, released primarily into milk, not into tissue fluid; that IgG2 transfer through both barriers is a result of passive diffusion only and that the content of efferent lymph is strongly influenced by IgG1, IgM and IgA in the mammary tissue, brought to the lymph node by afferent lymph.     

Respiratory adaptations to exercise

The primary function of the equine respiratory system is the exchange of oxygen and carbon dioxide at a rate that is matched to metabolism. Gas exchange requires ventilation, distribution of gas within the lung, perfusion of blood through pulmonary capillaries, matching of ventilation and blood flow, diffusion of gases between air and blood, and transport of gases to and from the muscles. In this article, the author reviews what is known about each of these processes in the resting and exercising horse.     

Histochemischer Nachweis von Aktin in den terminalen Darmgäßen des Huhnes*

Using fluorescence microscopy, cytoskeletal actin filaments were found in the terminal blood vessels of chicken intestine. Direct detection with Tetramethylrhodaminyl-Phalloidin showed a high concentration of actin filaments in the tunica media and a low concentration in the endothelium. Actin filaments were also present in the endothelial cells of capillaries and to a higher degree also in the pericytes. The wall of the veins in the villi, which were concentrically surrounded by bundles from the tunica muscularis mucosae, had a greater number of actin filaments than the wall of the venules present in the villi. The discussion touches on the possibility that the microfilaments play a role in blood regulation, especially in the capillaries.     

Angioarchitecture of the Branchial Arterial System of Carp (Cyprinus carpio L.)

The arterial system of the gills of carp and its histological structure were studied light and electron microscopically by making Mercox or Neoplane Latex corrosion cast preparations. Four pairs of afferent and efferent branchial arteries, and a pair of afferent and efferent pseudobranchial arteries were identified in the branchial arterial system. The 1st and 2nd afferent branchial arteries are given off directly from the ventral aorta, and the 3rd and 4th afferent arteries originate from their common trunk, which is branched off from the ventral aorta caudal to the origin of the former branchial arteries. Numerous afferent filamental arteries are connected to the lamellar blood capillary networks in the gill lamellae via afferent lamellar arterioles, and efferent filamental arteries followed the efferent lamellar arterioles are converged into four efferent branchial arteries that are connected to the dorsal aorta. To the pseudobranchia, afferent pseudobranchial arteries are connected with the ventral branches of the 1st efferent branchial arteries to provide arterial blood to the organ through the afferent mandibular arteries. Afferent pseudobranchial lamellar arterioles originating from the afferent pseudobranchial filamental arteries are connected with the blood capillary networks in the pseudobranchial lamellae, and blood in the capillary networks is drained into the efferent pseudobranchial filamental arteries via 2-4 pseudobranchial lamellar arterioles. Branches of the efferent pseudobranchial filamental arteries are connected with the arteries to the eyeballs and provide blood to choroid of the vascular tunic of them. Pseudobranchial cells surrounding lamellar capillaries in the pseudobranchia are furnished with abundant mitochondria and tubular structures, and the histological findings suggest the cells may share an ability to exchange physiological materials between the cells and the blood in the capillary networks of pseudobranchia.     

FEASIBILITY OF CONTRAST‐ENHANCED ULTRASOUND‐GUIDED BIOPSY OF SENTINEL LYMPH NODES IN DOGS

Our goal was to develop and validate a technique to identify the sentinel lymph nodes of the mammary glands of healthy dogs with contrast‐enhanced ultrasound, and evaluate the feasibility of obtaining representative samples of a sentinel lymph node under ultrasound guidance using a new biopsy device. Three healthy intact female adult hounds were anesthetized and each received an injection of octafluoropropane‐filled lipid microspheres and a separate subcutaneous injection of methylene blue dye around a mammary gland. Ultrasound was then used to follow the contrast agent through the lymphatic channel to the sentinel lymph node. Lymph node biopsy was performed under ultrasound guidance, followed by an excisional biopsy of the lymph nodes and a regional mastectomy procedure. Excised tissues were submitted for histopathologic examination and evaluated as to whether they were representative of the node. The ultrasound contrast agent was easily visualized with ultrasound leading up to the sentinel lymph nodes. Eight normal lymph nodes (two inguinal, one axillary in two dogs; two inguinal in one dog) were identified and biopsied. Lymphoid tissue was obtained from all biopsy specimens. Samples from four of eight lymph nodes contained both cortical and medullary lymphoid tissue. Contrast‐enhanced ultrasound can be successfully used to image and guide minimally invasive biopsy of the normal sentinel lymph nodes draining the mammary glands in healthy dogs. Further work is needed to evaluate whether this technique may be applicable in patients with breast cancer or other conditions warranting evaluation of sentinel lymph nodes in animals.