[Submandibular gland resection via subclavian into the road under the endoscope].

Objective:To evaluate resection of submandibular gland through a minimal skin incision under the endoscope. Method:A retrospective analysis of the clinical data from 28 cases of submandibular gland resection by endoscope surgery via subclavian approach, 14 cases of preoperative diagnosis of pleomorphic adenoma, submandibular gland of chronic inflammation in 11 cases, 3 cases of the submandibular gland stone,one case of lymphatic cyst,all cases were evaluated by preoperative imaging or 3 d sonography. Result:All patients' submandibular gland and tumors were resected totally under the endoscope, no open surgery, no surgical complications, and postoperative aesthetic outcome was good, patients were satisfied, pleomorphic adenoma patients were postoperative followed up of 4 to 24 months, and no recurrence. Conclusion:Under the cavity mirror via subclavian path submandibular gland resection is safe and feasible, and has a good cosmetic effect.

Development of the lymph nodes in the very young, and their evolution in the mature, nude rat.

We recently revised the concepts on the morphology of the lymph nodes of the young adult athymic nude rat. The present work studied the postnatal development of its nodal structures and their evolution with aging. The structural development of the deep cortex "units" was found to progress as usual. However, while the concentration of lymphocytes appeared to develop normally in the periphery of a unit, the center of the unit remained lymphocyte-depleted. Further, the peripheral cortex failed to develop over the middle part of a unit center. With aging, the peripheral cortex over the remainder of a unit center could atrophy and disappear completely. The present findings did not yield information as to whether thymic elements are necessary to trigger the development of a unit, but they revealed that its further development is determined by stimuli. It was concluded that, in the absence of T-cells, stimuli for cellular immune responses provoke the proliferation of the reticular or interdigitating cells of a unit center. On the other hand, an increase of these stimuli was concluded to cause the peripheral cortex to fail to develop over part of a unit center and, later, to atrophy over the remainder of the unit center. The mechanisms of the phenomena are discussed.

Ectasias of the subcapsular sinus in lymph nodes of athymic and euthymic rats: a relation to immunodeficiency.

This paper describes a morphologically unusual feature occurring in lymph nodes of some aged euthymic animals but mostly athymic animals. It initially consists of small alveole-like excrescences of the cortical wall of the subcapsular sinus. With dilatation, an excrescence becomes an ectasia which expands into the cortex. Observations suggest that ectasias enlarge under the influence of an increased pressure of the afferent lymph of a node. Such condition conceivably results from a greater lymph formation due to inflammation of the drained tissue site, combined with an impairment to the flow of lymph from the subcapsular sinus into medullary sinuses. A probable relation of ectasia formation to immunodeficiency is discussed. This formation results in the atrophy of the affected lymphoid cell populations of a node which likely contributes to aggravate the deficiency of the immune system.

Dilatation of high endothelial venules in compartments of rat lymph nodes with abundant cortical mast cells.

Previous work has shown that the method of killing animals and of fixation of lymph nodes determines the appearance of high endothelial venules. Routine procedures produce a narrowing of the high endothelial venules whilst in situ fixation of lymph nodes results in their dilatation. More recently, routine procedures have demonstrated that lymph nodes from athymic and some euthymic ageing rats have occasional compartments in which the high endothelial venules are dilated in association with an increased population of cortical mast cells. These observations suggest that mast cell products may influence the physiological state of the high endothelial venules and affect the recruitment of blood lymphocytes.

Distribution pattern of drained antigens and antibodies in the subcapsular sinus of the lymph node of the rat.

A recent study of lymph nodes of the rat showed that they are morphologically and physiologically compartmentalized. A compartment of a node includes a portion of subcapsular sinus into which the lymph, entering via the related afferent lymphatic opening, is filtered. The study also showed that colloidal carbon injected locally in a small dose becomes predominantly associated with the areas of the inner wall of the subcapsular sinus that cover the extra-follicular zone of the peripheral cortex. Little carbon is seen over the folliculo-nodules (follicles with a nodule or germinal center). The question arose as to whether drained natural substances, as antigens and antibodies, follow the same pattern of distribution in the subcapsular sinus as the carbon. Therefore, small doses of fluorescein isothyocyanate (FITC)-conjugated antigens were injected locally into normal rats whose own antibodies in the nodes were stained by immunofluorescence. The pattern of distribution of the antigens in the draining nodes was found to be the same as that of the carbon. Furthermore, the lymph-carried antibodies of the rats were found to follow the same pattern. The morphological basis for such a pattern is explained. The results are further discussed with regard to the probable normal entry route of lymph-carried antigens in the parenchyma of nodes.

Evidence for the existence of a subsinus layer of the peripheral cortex in the lymph node of the rat.

The peripheral cortex of a lymph node consists of folliculo-nodules (follicles with a nodule or germinal center) and an extrafollicular zone. In the course of an analysis of the nodes in rats under various experimental or abnormal conditions, our attention became focused on the particularities of a thin layer of peripheral cortex underlying the subcapsular sinus. The present paper reports on observations which led to the identification of the "subsinus layer" of the peripheral cortex. The observations suggest that this layer complements the activity of the inner wall of the subcapsular sinus. The layer probably contributes to the selection of certain elements from the afferent lymph and guides them towards the node area where they can join the cell population involved in the immunological activity in which they are to participate.

Lymph nodes of the N:NIH(S)II-nu/nu mouse.

In N:NIH(S)II-nu/nu mice, which express the nu and the Xid genes, T and B lymphocytes are deleted. We studied their lymph nodes in the light of new knowledge of the morphology of the nodes of normal and athymic animals. Histologic preparations of the nodes from various anatomical sites were analyzed in 9-week-old mice. Node sections were also stained for IgM or IgG. The study revealed that, the frameworks of the peripheral cortex, the deep cortex, and the medulla were developed in these nodes, although they were quite devoid of lymphocytes or plasmocytes. However, the outermost (or subsinus) layer of the peripheral cortex of some nodes was populated with lymphocytes. In some cervical nodes, a few follicles, lymphocyte clusters, and a well-developed plasmocyte population were also present. The lymphocytes of the subsinus layer and the clusters were B cells with an increased expression of IgM. The modifications of these nodes are discussed on the basis of recently developed concepts of node functioning.

Formation of morphologically unusual features, associated with immunodeficiencies, in lymph nodes of gnotobiotic rats exposed to a conventional milieu.

Athymic animals are characterized by unusual features in lymph nodes, which are indicative of immunodeficiencies. These features include hypertrophy of follicles, atrophy of the peripheral cortex above the center of deep cortex units, and the formation of lymphocyte clusters at the periphery of these units as well as of compartment replicas in the capsules. Such features were recently observed in some nodes of a minority of aged euthymic animals and we concluded that they probably also reflected immunodeficiencies, since immunodeficiencies may emerge in aging euthymic animals. In an attempt to validate this conclusion, we exposed one-year-old gnotobiotic animals to a conventional milieu, thereby presumably rendering these euthymic animals somewhat immunodeficient, and checked their nodes for unusual features. Nodal unusual features, similar to those encountered in nodes of athymic and of some aged euthymic animals, arose rapidly and the ex-gnotobiotic animals either manifested signs of infections or died. These findings support our previous conclusion that the arising of such features reflects a progressive emergence of a certain state of immunodeficiency with aging.

Mast cells and fibrosis in compartments of lymph nodes of normal, gnotobiotic, and athymic rats.

Reports vary on the amount and distribution of mast cells in lymph nodes. We analysed the mast-cell population in compartments of nodes of diverse sites, from euthymic and athymic animals of various ages. Nodal mast cells were few in young animals, occurring mostly in medullary sinuses. Aging is often accompanied by a moderate increase of nodal mast cells. In compartments of a few nodes of some aged athymic and euthymic animals, the mast cells were greatly increased in the extrafollicular zone overlying medulla directly. In certain cases, this great increase was accompanied by pronounced mast-cell degranulation and by fibrosis in the mast cell-rich extrafollicular zone. It is suggested that the mast cells of medullary sinuses relate to non-immunological events, while those of the lymphoid parenchyma relate to elements that can induce humoral immune responses or are somehow involved in nodal processes of such responses. It is further suggested that an occasional emergence, with aging, of a deficiency of particular humoral immune responses may induce an excessive increase of cortical mast cells, and that activities of the resulting dense mast-cell population contribute to the onset of fibrosis.

The formation of "compartment replicas" in the lymph nodes of athymic animals.

This communication describes a new anomaly that can affect the capsule of lymph nodes of athymic animals. Lymphocytes infiltrate a segment of the capsule above the variably atrophied peripheral cortex overlying the center of the deep-cortex unit of a node compartment. Lymphocytes thereafter form a capsular mass. The developing mass of lymphocytes is invaded by outgrowths of the node's subcapsular sinus while it fuses with the parenchyma of the related node compartment. Eventually, this new nodal element acquires structures resembling those of nodes and becomes a more or less exact replica of the original node compartment. Replicas stem from node compartments that are overchallenged by uncontrolled antigens. Aspects of the formation of replicas are explained by recent findings on events occurring in nodes of athymic animals and on the pattern of antigen distribution in the subcapsular sinus of a node. It is concluded that the formation of a compartment replica constitutes a mechanism allowing the organism to compensate somewhat for the partial atrophy or deficiency of a node compartment.

Diffusion of a lymph-carried antigen in the fiber network of the lymph node of the rat.

A lymph-carried antigen is retained preferentially in those areas of the subcapsular sinus of a lymph node overlying the extrafollicular zone of the peripheral cortex. There, it becomes associated with the reticular fibers crossing these particular sinus areas. We wondered whether the antigen thereafter diffuses along the extensions of these fibers which form a peculiar network in the "cortical pathways of migration of circulating lymphocytes" (CPMCL), leading to the different cell populations effecting the immune responses. Fluorescein isothiocyanate (FITC)-conjugated antigens were injected locally into rats sacrificed 0.5-24 h later. The antigens diffused along the fibers of the CPMCL. It is proposed that this diffusion constitutes one mechanism of stimulation of recruited circulating lymphocytes and of orientation of their migration towards the proper effector-cell population.

Morphological anomalies associated with immunodeficiencies in the lymph nodes of aging mice.

Immunodeficiencies can emerge in aging normal animals. We wondered whether the morphological taking place in nodes of normal but aging animals comprise anomalies associated with immunodeficiencies. We analyzed the nodes of various anatomical sites in 20 normal mice, aged 12 or 24 months. The same morphological anomalies described recently in nodes of young athymic animals and reflecting immunodeficiencies were found to develop in present mice, though varying in extent with age, individuals, anatomical site of a node, and compartments of a given node. Some anomalies reflect deficiencies of cellular immune responses; others reflect deficiencies of humoral immune responses. Practicality restricts the variety of antigens which can be tested to recognize the possible emergence of immunodeficiencies in an aging animal. A morphological analysis of its nodes can thus indicate if immunodeficiencies occur with respect to a fraction of the challenging antigens.

Atrophy of compartments of rat lymph nodes related to an entry of lethally altered lymphocytes.

This paper reports the occurrence of an accumulation of lethally altered lymphocytes in the subcapsular sinus of a compartment or compartments of some lymph nodes, an unusual feature best developed in nodes of the mesenteric site in aging athymic animals. Many of these cells are rod-like. In other compartments, similar lymphocytes occurred at various depths in the nodal parenchyma. This was accompanied by the disappearance of a compartment's populations of normal lymphoid cells. The observations reveal that lymphocytes, altered in a tissue, may reach the subcapsular sinus of the draining node compartment and migrate into its parenchyma which then undergoes atrophy. The likely involvement of mast cells is discussed.

Retention of lymphocytes in the subcapsular sinus of lymph nodes: a physiological event?

This study examined the lymphocyte content of the subcapsular sinus of lymph nodes of diverse anatomical sites, from euthymic and athymic animals of various ages. One unusual feature which prevailed in young euthymic animals consisted of the accumulation of lymphocytes on the outer wall of the subcapsular sinus, following differential patterns with respect to diverse domains or areas of the subcapsular sinus of a node compartment. It is concluded that such an accumulation is due to the retention of lymphocytes on the sinus outer wall. Whether the retention reflects a step in unspecific defence mechanisms, in an immunological reaction pathway, or a transient state of the misfunctioning of lymph-carried cells, is considered. Some findings favor the latter possibility. In this case, retention would be due to a mild form of lymphocyte alteration caused by the emergence of an abnormal milieu in a drained tissue, and conceivably involving mast cell products. Whatever the case, the retention on the outer wall of the subcapsular sinus, instead of on its inner wall, would prevent any hindering of the usual activity of the latter wall.

Atrophy of lymph node compartments lacking lymph-carried lymphocytes in athymic rats.

This paper reports on a form of atrophy of lymph node compartments occurring in mesenteric nodes of athymic nude rats whose perinodal tissue had become unusually rich in mast cells and fibrotic. The subcapsular sinus of an affected compartment was depleted of lymphocytes, while the medullary sinuses were loaded with macrophages. A progressive expansion of medullary sinuses into the medullary cords, the extrafollicular zone, the deep cortex unit and, finally, the folliculo-nodules of the compartment was accompanied by a gradual atrophy of the usual lymphoid cell populations of these nodal components. The occurrence of such a mode of atrophy of a compartment, associated with a lack of lymphocytes in the afferent lymph, agrees with our previous proposal that lymphocytes of the afferent lymph provide the stimuli for the development and maintenance of the structures of the node. The involvement of mast cells and fibrosis in the emergence of the present form of nodal atrophy, which further weakens the immune system of an immunodeficient animal, is considered.

High endothelial venules of the rat lymph node. A review and a question: is their activity antigen specific?

BACKGROUND: The high endothelial venules (HEVs) of the lymph nodes are sites for transvascular lymphocyte traffic. Due mostly to the wide scale of variations manifested by the HEVs and to frequently restricted conditions of observation, reports often differed on their morphological or functional features, which has led to opposing views on aspects of the functioning of HEVs. METHODS: In the present review, we analyze previous reports and attempt to derive comprehensive proposals to reconcile variations in actual observations under diverse conditions. RESULTS: This analysis shows that the features typical of the HEV endothelial cells (HEV cells) are stimulated to emerge by antigens and the proper lymphocytes and mediators. The stimulation would implicate drained lymphocytes migrating in the perivascular channel, immediately cuffing an HEV's endothelium. A marked pleomorphism of HEV cells betrays the fact that they undergo individual stimulation and a somewhat heterogeneous activity. Other facts indicate that the subendothelial spaces of HEV cells are sites of interactions between drained lymphocytes, HEV cells, and recruited blood lymphocytes. Facts also reveal time- and site-related variations in the intensity of recruitment of blood lymphocytes by HEV cells and topographically related variations in the nature of the recruited cells. CONCLUSIONS: Analysis of some other observations, often ignored, lead to the conclusion that recruitment of lymphocytes by HEV cells for the sake of participating in local specific immune activities is antigen specific, despite the implication of homing receptors of lymphocytes.