The functioning in unanaesthetized sheep of the popliteal lymph node after the surgical removal of its blood supply.

Operations were performed to cannulate the efferent duct of the popliteal node of sheep and, at the same time, the blood vascular system was removed surgically from the popliteal fossa so that the node was deprived of it blood supply. Twelve preparations were technically successful in that lymph flowed spontaneously from the unanaesthetised sheep for from 3 to 30 days after the operation. Eight control preparations were established in which the blood supply of the node with the cannulated efferent duct was left intact. In only four of the test preparations was the function of the node decisively impaired so that dendritic macrophages appeared in the lymph, the output of lymphocytes remained very low, and later histological examination showed the nodes to be grossly depleted of lymphocytes. In two of these four preparations the surgical devascularization of the node was aided by arterial embolization. In the remaining eight test preparations the outputs of lymphocytes in the lymph gradually regained normal values, and the nodes then responded normally to antigenic stimuli.     

Lymphatic and blood vessels of the popliteal node in sheep

Our aim was to describe the lymphatic and blood vascular pathways to and from the popliteal lymph node in sheep. The blood vessels and lymphatics were filled with Microfil, and were cleared in methyl salicylate. Afferent lymphatics divide and anastomose as they pass dorsally along the lateral saphenous vein, and 6–12 lymphatics reach the node. Each branches extensively on the surface of the node giving rise to 20–50 terminal afferents which enter the node over a roughly circular area. Most enter the subcapsular sinus, but some penetrate deeply into the node. Lymph leaves the node through numerous initial efferent lymphatics, many of which contain valves. These join forming progressively larger vessels, and 2–4 efferent trunks emerge from the hilus. The hilus varies considerably in shape, depth and location, and it is filled with fat. Either a single artery, or up to 10–12 arteries derived from an anastomotic network or circle, enter the node from the hilar fat pad. Arteries may also enter at other sites. The arteries originate from the caudal femoral, or the medial circumflex femoral artery; a single node may receive blood from both arteries. This arrangement may help to maintain blood flow especially during an immune response, and despite external pressures applied to the arteries and node during movements of the animal.     

Blood supply of the caudal mediastinal lymph node in sheep

We investigated the arterial supply to, and the venous drainage from, the caudal mediastinal lymph node (CMN) in 18 anesthetized and exsanguinated sheep. The purpose of this gross anatomic investigation was to determine the CMN's blood supply so that a structural base can be used to interpret studies of the bronchial circulation's role in the pathogenesis of pulmonary edema. In ten sheep, we cannulated the bronchoesophageal artery at its origin from the aorta and injected Microfil. This artery, which branches into cranial and caudal divisions 2-4 mm distal to its origin, supplied the esophagus, trachea, bronchi, and visceral pleura. The CMN is supplied by the caudal division, as it courses between the CMN and aorta. Microfil injected through the thoracic aorta did not enter the CMN when the bronchoesophageal artery was ligated at its origin. These results indicate that only the bronchoesophageal artery supplies the CMN. In eight sheep we cannulated the vein at the head of the CMN (dorsal mediastinal vein) and injected Microfil, both peripherally and centrally. Peripherally, injected veins reached the CMN and esophagus. The dorsal mediastinal vein extended posteriorly to the CMN in three of the eight sheep, eventually emptying into the left azygos vein near the diaphragm. Centrally, the dorsal mediastinal vein joined the left azygos vein near the heart in six of the eight sheep, including the three in which the dorsal mediastinal vein extended posteriorly to the CMN. In the remaining two sheep the dorsal mediastinal vein drained centrally into the right azygos vein. We conclude that the bronchoesophageal artery supplies the CMN and that either the left or right azygos vein drains it.     

淋巴结切除在颈动脉体瘤手术治疗中的作用

目的 总结手术治疗良恶性颈动脉体瘤的经验,探讨颈动脉体瘤手术中瘤体周围淋巴结切除的临床价值。方法 回顾性分析中国医学科学院肿瘤医院1976年1月—2013年10月手术治疗的106例良、恶性颈动脉体瘤患者的临床资料。其中男37例,女69例;年龄7～67岁;肿瘤发生于左侧62例,右侧42例,双侧2例。术前诊断为颈动脉体瘤86例,另20例术前诊断为颈部肿物待查;无一例术前诊断为恶性颈动脉体瘤。根据术中是否行瘤体周围淋巴结切除活检分为淋巴结切除组(54例)和未切除组(52例),随访其术后生存及复发情况。采用Kaplan-Meier生存分析法计算并比较两组患者术后无复发生存率。结果 106例患者中,98例获随访,8例失访,其中淋巴结切除组失访5例,未切除组失访例3例。随访时间7个月~38年,中位随访时间8年。淋巴结切除组术后无复发生存率为97.0%,高于淋巴结未切除组的73.7%(χ²=9.938, P＜0.01);明确诊断良恶性者术后无复发生存率93.4%,高于未行淋巴结切除从而诊断恶性证据不足者的14.0%(χ²=45.054, P＜0.01)。淋巴结切除组神经损伤发生率为35.2%(19/54),低于淋巴结未切除组的55.8%(29/52),差异有统计学意义(χ²=4.530, P＜0.05)。结论 颈动脉体瘤手术中,瘤体周围淋巴结切除活检有助于明确诊断、指导治疗,从而提高颈动脉体瘤手术治疗后无复发生存率;同时,还有利于暴露术野,降低神经损伤发生率。     

Contribution of lymph formation in the popliteal node to efferent lymph flow following stimulation of the sympathetic chain in the sheep

Lymph flow and contraction frequency were measured in popliteal efferent lymphatics. Stimulation of the ipsilateral sympathetic chain resulted in an approximate threefold increase in lymph flow, while contraction frequency increased 28% (n = 6). Occlusion of the metatarsal afferent lymphatics with a pneumatic cuff reduced efferent flow from 18 to 4 microliters/min after 25 min (n = 5), indicating that approximately 80% of popliteal efferent lymph is derived from the foot. After occlusion of the afferent lymphatics, sympathetic stimulation failed to increase efferent lymph flow significantly, while efferent contraction frequency still showed a significant rise. It is concluded that lymph formation in the popliteal node does not contribute to the rise in efferent lymph flow following sympathetic stimulation.     

Structure of the sinus-lining cells in the popliteal lymph node of the rabbit

The structure of the sinus walls in the popliteal lymph node of the rabbit was studied with the electron microscope. In the marginal sinus, the endothelial cells are connected by gap junctions, puncta adherentia, and surface specializations characterized by focal approximation of the adjoining membranes without fusion. They possess large numbers of simple and compound uncoated invaginations of the plasma membrane that are closed by a diaphragm with a central thickening. The tissue strands that straddle the lumen of the sinus consist of a fibrous core containing both collagen and elastic fibers, surrounded by endothelial cells identical to those composing the outer sinus wall. Cortical sinuses that run independently of the trabeculae were identified by exploiting the fact that their endothelial cells accumulate lymph-borne ferritin, and their lumen is outlined by horseradish peroxidase administered intravenously. They are lined by a flattened, continuous endothelium and lack luminal strands. The walls of the medullary sinuses consist of endothelial cells and macrophages. The endothelial cells are interconnected by specialized junctions and contain fewer plasmalemmal vesicles than in the cortex; furthermore, dense granules are present in their cytoplasm. Macrophages adhere to the surface of the endothelial cells; typically, none of the junctional specializations that characterize the interface between endothelial cells connect endothelial cells to macrophages. However, at points along the contact region with the endothelium, the plasmalemma of the macrophage is decorated by an attachment plaque of fluffy cytoplasmic material. Sinus endothelial cells slowly accumulate lymph-borne ferritin like vascular endothelial cells elsewhere in the body, whereas macrophages contain both ferritin and engulfed erythrocytes.     

The flow and composition of lymph from the caudal mediastinal lymph node of sheep

By cannulating the efferent duct of the caudal mediastinal lymph node in sheep, lymph from the lower respiratory tract was collected under physiological conditions for several days. In 18 such preparations the flow rate varied from 4 to 12 ml/hr between individuals and the lymphocyte count between 4000 and 117,000/mm3. The protein content of the lymph plasma averaged nearly 60% of that of the blood, and this indication of the high permeability of the capillary bed of the lungs was confirmed by measuring the time taken for intravenous doses of 125I-albumin to equilibrate between the blood and mediastinal lymph plasma. The concentration of immunoglobulin A was higher in the mediastinal lymph than in blood serum, while the reverse was true of the concentrations of IgG1, IgG2, and IgM. This evidence for the local production of IgA by the intra thoracic lymphoid tissue was supported by the demonstration by immunoperoxidase techniques of IgA-containing plasma cells in sections cut from the caudal mediastinal nodes, and of IgA-containing immunoblasts in the lymph.     

Cellular immune response to sheep erythrocytes: interrelationship between proliferation of popliteal lymph node cells and footpad swelling

Mice were sensitized with graded doses of sheep erythrocytes by the intravenous or subcutaneous route and challenged for delayed-type hypersensitivity (DTH) at different times thereafter. The DTH response as assessed by footpad swelling (FPS) was compared to the spontaneous proliferative response of the popliteal lymph node cells (PLNC). Proliferation of PLNC was optimal after sensitization regimens resulting in optimal FPS. The same was true for mice sensitized under cyclophosphamide modulation. Proliferation of PLNC induced by SRBC was antigen-specific, although some crossreactivity with horse red blood cells was observed. Proliferation of PLNC could be abrogated by treatment with anti-Thy-1.2 antiserum plus complement demonstrating the T cell nature of proliferating cells. In accordance with published data, FPS of mice presensitized with a high dose of SRBC as well as FPS of recipients of spleen cells from high-dose-sensitized donors was suppressed. In marked contrast, PLNC proliferation was not diminished in these mice. Although proliferation of PLNC did not parallel FPS under all circumstances, it seems to be a correlate of the cellular immune response to SRBC.     

T-cell-dependent popliteal lymph node reactions to platinum compounds in mice.

The requirements for sensitization to complex salts of platinum were investigated in a mouse model by means of the popliteal lymph node (PLN) assay. A single subcutaneous injection of dissolved hexachloroplatinates without adjuvant induced a vigorous primary immune reaction in the draining PLN. Dose-dependent lymph node activation was determined by an increase in both PLN weight and cellularity. In C57BL/6 mice, peak reactions were obtained around day 6 after administration of 90-180 nmol Na2[PtCl6] or (NH4)2[PtCl6] per animal. Mice primed to [PtCl6]2- mounted an enhanced response upon local restimulation with suboptimal doses of the same but not unrelated compounds, indicating a specific secondary response. T cells were required to elicit PLN reactions to [PtCl6]2-, because athymic nude mice completely failed to respond, in contrast to their +/nu littermates. Differences between various inbred strains of mice revealed that Pt-induced PLN responses are genetically controlled. Moreover, the immunogenicity of Pt salts in mice is not confined to hexachloroplatinates, but other compounds, such as the antineoplastic agent cis-dichlorodiamine platinum, are able to induce comparable PLN reactions.     

Reaction of the popliteal lymph node to transcutaneous irradiation with helium-neon laser

Prolonged transcutaneous irradiation with helium-neon laser light decreases the transport ability of the popliteal and iliac lymph nodes. Laser radiation stimulates lymphocytes, predominantly T cells. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 123, No. 2, pp. 237–239, February, 1997     

The secondary immune response to Staphylococcus aureus vaccines in efferent popliteal lymph of sheep.

The secondary immune response to live and killed Staphylococcus aureus vaccines was studied in efferent popliteal lymph of sheep. Animals were immunized with either live or killed S. aureus intracutaneously on the lateral hock, in an area draining into the popliteal lymph node. Six weeks later, an efferent popliteal lymphatic vessel in the vaccinated leg was cannulated, and 48 hr after surgery a second inoculation (identical to the primary) was placed in the skin adjacent to the primary vaccination lesion. A dramatic decrease in lymphocyte output ('cell shutdown') was observed in lymph collected from sheep given the secondary inoculation of live S. aureus during the first 8 hr after inoculation. However, only a moderate decrease in lymphocyte output occurred in lymph from animals receiving killed S. aureus or from control animals. The proportion of eosinophils in lymph collected from animals given live S. aureus increased to a peak (14% of total leucocytes in lymph) between 6 hr and 8 hr, and returned to prechallenge levels by 24 hr post-inoculation. The percentage of neutrophils in lymph peaked between 8 hr and 1 day after injection of live bacteria. This granulocyte response was not observed in animals given killed S. aureus or control animals. IgM-, IgG1- and IgG2- containing cells (-cc) in lymph were quantified by indirect immunofluorescence. Animals given live S. aureus produced lymph with greater numbers of Ig-cc of these isotypes than those given killed organisms. The ratio of IgG2-cc:IgG1-cc was significantly greater in lymph from animals given live S. aureus from Day 2 to Day 6 post-challenge. IgM and IgG1 anti-staphylococcal antibody levels increased in lymph collected from all vaccinated animals, but only sheep given live S. aureus showed any increase in levels of IgG2 antibody.     

Sympathetic stimulation causes increased output of lymphocytes from the popliteal node in anaesthetized sheep

Stimulation of the lumbar sympathetic chain at a frequency of 4 Hz caused a threefold increase in the lymphocyte output in efferent lymph from the popliteal node in anaesthetized sheep. The increase was accounted for by a rise in both lymph flow and lymphocyte count. Intra-arterial infusion of phentolamine (10 micrograms kg-1 min-1) abolished the nerve-mediated increases in flow and cell count.     

Variation in the blood supply of the sinus node

Purpose  

The purpose of the study was to examine the anatomical variations in the blood supply to the sinus node.