Casting methods of scanning electron microscopy applied to hemal lymph nodes in rats

Hemal lymph nodes of the para-aortic group in rats were examined by scanning electron microscopy (SEM) using the corrosion cast technique. The vasoarchitecture of hemal lymph nodes was described in cast specimens filled from the abdominal aorta. A dense system of capillaries arranged in the mode of a meshwork could be represented in the nodal cortex. The postcapillary venule (PCV) with wide vascular lumina provided the prevailing vessel type of the deep cortex. Sphincter-like narrowings of the capillary lumen appeared at the sites where capillaries merged with the PCV. These vascular segments were interpreted as structures controlling the hemodynamics of the joining PCV thereby providing appropriate conditions for homing lymphocytes. No evidence was obtained from the casts for an open circulation in hemal lymph nodes. The intranodal lymphatic pathways were studied in specimens interstitially injected with resin. The fine lymphoid tissue spaces were characterized by special cast patterns reflecting the structural differentiation of certain nodal compartments. Afferent lymphatics could be clearly identified in casts with a retrograde filling from the subcapsular sinus. Very spacious intermediary sinuses and wide meshed medullary sinuses could be represented in those casts as well, thus allowing ample space for the encounter of large macrophages with red blood cells.     

Strategy of lymph nodes dissection for the lower thoracic esophageal cancer without metastasis to the upper-mediastinal lymph nodes

The incidence of metastasis to the lymph nodes in preoperative untreated patients with Ei, T2 or T3 esophageal cancer is 70.7% (41 of 58 cases) in our institute. Especially, a high incidence of metastasis to the abdominal lymph nodes has been noted. In contrast, metastasis to the cervical lymph nodes is not common. The majority of recurrence appear as a distant metastasis to the liver, lung or bone through the hematogenic route. However, recurrence in the peritoneum through the lymphatogenic route is not uncommon. Therefore, current strategy of lymph nodes dissection for esophageal carcinoma would be inadequate for the complete inhibition of recurrence, so that chemotherapy remains to be needed. Since the diagnostic procedure with ultrasonographic endoscopy and computerized tomography is highly accurate for the assessment of metastasis to the uppermediastinal lymph nodes, operative procedure suitable for each case should be determined on the basis of preoperative examination.     

Changes in lymphocyte subsets in the intestine and mesenteric lymph nodes in caprine paratuberculosis

In five normally hearing subjects and seven subjects with damaged cochleas, detection thresholds for sinusoidal frequency modulation (FM) and amplitude modulation (AM) were measured using 1 s stimuli with a 500 Hz carrier frequency (Fc) at a 'comfortable' loudness (given by subject-dependent SPLs and SLs). The modulation frequency (Fmod) was 2 Hz or 10 Hz. FM (but not AM) detection was poorer in the hearing-impaired group, especially when the hearing loss at Fc exceeded 50 dB. Fmod had a different effect on FM and AM detection. The corresponding interaction was essentially identical for the two groups of subjects. Previous studies strongly suggested that normal listeners use mainly neural phase-locking cues for the detection of FM when Fmod = 2 Hz, but mainly tonotopic cues when Fmod = 10 Hz. The present results suggest that cochlear damages reduce the usefulness of these two types of cues to an approximately equal degree.     

Echography of the superficial lymph nodes

We reviewed the literature on the echographic examination of diseased superficial lymph nodes in the cervical, axillary, the internal mammary and inguinal regions. The anatomy and the technique of the echographic examination were reviewed followed by the role and limitations of computed tomography and magnetic resonance imaging. The echographic presentation of normal, inflammatory and tumoral lymph nodes was discussed in light of the indications for echography of the superficial lymph nodes in ear-nose-throat and breast cancer and in cases of lymphomas.     

Effect of cyclosporine on immune responses in submaxillary lymph nodes of pituitary-grafted rats

This work was undertaken to analyze the interrelationships between prolactin and cyclosporine in affecting immune responsiveness in submaxillary lymph nodes. Male rats received an anterior pituitary graft within breast muscles on day 5, or under the kidney capsule, on day 30 or 60 of life. On day 70 (rats operated on day 5 or 30) or on day 100 (rats operated on day 60) animals were injected with Freund's complete adjuvant and cyclosporine (5 mg/kg for 5 days), and were killed 2 days after immunization. Natural killer (NK) activity in submaxillary lymph node decreased in neonatally pituitary-grafted rats and increased in rats grafted on day 30 or 60, as did lymph node cellularity. Lipopolysaccharide (LPS)- and concanavalin A (ConA)-induced proliferation diminished in lymph nodes of rats grafted on day 30 or 60, respectively. Cyclosporine treatment diminished lymph node cell number and NK activity and increased the proliferative response to ConA. Cyclosporine depressive effect on lymph node cellularity was counteracted by the presence of a pituitary graft, as were the inhibition of NK activity and the stimulatory effect on ConA-induced cell proliferation. In pituitary-grafted rats, cyclosporine decreased submaxillary lymph node LPS-induced proliferation. Cyclosporine decreased the high circulating prolactin levels found in pituitary-grafted rats. The results are compatible with age-dependent, inhibitory and promoting activities of hyperprolactinemia on immune responses in lymph nodes, affected in a complex antagonistic and synergistic way by cyclosporine immunosuppression.     

The lymph nodes of the porta hepatis

The area under the liver was dissected in 27 human autopsy specimens to search for lymph nodes in the fissures. Nodes were present in all instances. They were in the transverse fissure, posterior to the portal vein, posterior to pars transversus of the left portal vein and associated with the left hepatic artery. The size varied from 2 millimeters to 2 centimeters. Each node was histologically confirmed. Nodes were infrequent and small on the right. Nodes were not found between the portal vein, hepatic artery and bile ducts in the fissures. Nodes were found outside the fissures in the fascia between the bile duct and hepatic artery. Occlusion of the portal vein and hepatic artery could be expected before occlusion of the bile duct. Node enlargement in the transverse fissure is anticipated as a rare cause of jaundice.     

Molecular mechanisms of lymphocyte homing to peripheral lymph nodes

To characterize the adhesion cascade that directs lymphocyte homing to peripheral lymph nodes (PLNs), we investigated the molecular mechanisms of lymphocyte interactions with the microvasculature of subiliac lymph nodes. We found that endogenous white blood cells and adoptively transferred lymph node lymphocytes (LNCs) tethered and rolled in postcapillary high endothelial venules (HEVs) and to a lesser extent in collecting venules. Similarly, firm arrest occurred nearly exclusively in the paracortical HEVs. Endogenous polymorphonuclear (PMNs) and mononuclear leukocytes (MNLs) attached and rolled in HEVs at similar frequencies, but only MNLs arrested suggesting that the events downstream of primary rolling interactions critically determine the specificity of lymphocyte recruitment. Antibody inhibition studies revealed that L-selectin was responsible for attachment and rolling of LNCs, and that LFA-1 was essential for sticking. LFA-1-dependent arrest was also abolished by pertussis toxin, implicating a requirement for G alpha i--protein-linked signaling. alpha 4 integrins, which play a critical role in lymphocyte homing to Peyer's Patches, made no significant contribution to attachment, rolling, or sticking in resting PLNs. Velocity analysis of interacting LNCs revealed no detectable contribution by LFA-1 to rolling. Taken together, our results suggest that lymphocyte- HEV interactions within PLNs are almost exclusively initiated by L-selectin followed by a G protein-coupled lymphocyte-specific activation event and activation-induced engagement of LFA-1. These events constitute a unique adhesion cascade that dictates the specificity of lymphocyte homing to PLNs.     

In situ analysis of lymphocyte migration to lymph nodes

Blood-borne lymphocytes migrate continuously to peripheral lymph nodes (PLN) and other organized lymphoid tissues where they are most likely to encounter their cognate antigen. Lymphocyte homing to PLN is a highly regulated process that occurs exclusively in specialized high endothelial venules (HEV) in the nodal paracortex. Recently, it has become possible to explore this vital aspect of peripheral immune surveillance by intravital microscopy of the subiliac lymph node microcirculation in anesthetized mice. This paper reviews technical and experimental aspects of the new model and summarizes recent advances in our understanding of the molecular mechanisms of lymphocyte homing to PLN which were derived from its use. Both lymphocytes and granulocytes initiate rolling interactions via L-selectin binding to the peripheral node addressin (PNAd) in PLN HEV. Subsequently, a G protein-coupled chemoattractant stimulus activates LFA-1 on rolling lymphocytes, but not on granulocytes. Thus, granulocytes continue to roll through the PLN, whereas LFA-1 activation allows lymphocytes to arrest and emigrate into the extravascular compartment. We have also identified a second homing pathway that allows L-selectin low/(activated/memory) lymphocytes to home to PLN. P-selectin on circulating activated platelets can mediate simultaneous platelet adhesion to PNAd in HEV and to P-selectin glycoprotein ligand (PSGL)-1 on lymphocytes. Through this mechanism, platelets can form a cellular bridge which can effectively substitute for the loss of L-selectin on memory cell subsets.     

Changes in the distribution of cells expressing tumour-associated antigen in lymph nodes during the progression of enzootic bovine leukosis

A monoclonal antibody (MAb), c143, that recognizes a tumour-associated antigen that is "upregulated" on neoplastic B cells in cattle with enzootic bovine leukosis (EBL), was used as a marker to study disease progression. An immunohistochemical examination of neoplastic tissue and superficial cervical lymph nodes from 14 animals with EBL revealed three morphologically definable stages of change in the structure of lymph nodes, associated with the distribution of c143-positive cells: (1) the presence of c143-positive cells at the marginal sinus with no apparent changes in lymph node structure; (2) the presence of positive cells extending into and distorting the architecture of the lymph node, with clear evidence of proliferation before overt changes (enlargement of lymph nodes) were evident; and (3) the presence of positive cells throughout the lymph node with total disruption of lymph node structure when clinical signs of lymph node enlargement were evident. The results indicated that the bovine leukaemia virus-transformed lymphocytes or neoplastic cells in peripheral blood accumulate in the marginal sinus area at the earliest stages, and subsequently proliferate and infiltrate into follicles, leading to the development of clinical signs of lymphosarcoma.     

Skip metastasis to the mediastinal lymph nodes in non-small cell lung cancer

BACKGROUND: Whether any difference exists in clinical characteristics between resected non-small cell lung cancer with either skip or ordinary mediastinal lymph node metastases (N2 disease) needs to be clarified. METHODS: There were 110 patients with stage IIIA N2 disease. Thirty-three patients demonstrating no metastasis at the hilar nodes [skip (+) group] were compared with the other 77 patients [skip (-) group]. To investigate the extent of nodal involvement, we classified the mediastinal lymph nodes into three regions (superior, inferior, or aortic). RESULTS: There were no significant differences regarding histologic type, T status, or the site of the primary tumors between the skip (+) and the skip (-) N2 groups. In the skip (+) group, mediastinal node metastasis was found in only one region (level 1) in 30 patients (90.9%) and in two regions (level 2) in 3 (9.1%), whereas 28 patients (36.4%) from the skip (-) group revealed mediastinal metastasis at two or three regions (level 2 or 3). The overall survival rate at 5 years after operation was 35% in the skip (+) group and 12.7% in the skip (-) group (p = 0.054). This favorable clinical outcome in the skip (+) group could be explained partially by the higher proportion of patients with level 1 metastases. Furthermore, regarding patients with level 1 disease, the skip (+) group tended to have a better prognosis than the skip (-) group (p = 0.096). CONCLUSIONS: These results suggest that patients with skip mediastinal lymph node metastases represent a unique subgroup of N2 disease.     

Malignant neoplastic disease of the parotid lymph nodes

OBJECTIVES: To review the management and outcome of patients with malignant neoplastic disease of the parotid lymph nodes excluding those with primary salivary gland tumors. STUDY DESIGN: Retrospective review of 14 patients who had malignant parotid lymph nodes from metastatic cutaneous malignancies, direct extension from primary cutaneous malignancies, or lymphoproliferative disorders. METHODS: Charts were reviewed from three institutions and tabulated for age, gender, histopathology, treatment, and outcome. RESULTS: Fourteen patients met the criteria for study. Ten patients had neoplastic nodes from cutaneous malignancies. Seven involved squamous cell carcinoma, two were metastatic from melanoma, and one was metastatic from basal cell carcinoma. Four patients had involvement from lymphoproliferative disorders. CONCLUSIONS: Metastatic disease to the parotid nodes or direct extension to nodes from primary cutaneous malignancy demonstrates a poor prognosis in this series. Prognosis of lymphoproliferative disorder is more favorable.     

Pathology of the lymph nodes in patients with malignant melanoma

The poor survival rate for patients with regional lymph node metastases of malignant melanoma reflects the strong association between lymph node and subsequent visceral metastases. The authors discuss clinical considerations, pathologic risk factors, selective lymphadenectomy, examination of lymph node dissections, difficulties of diagnosis, and prognosis.     

Cancer metastases to the cervical lymph nodes in an unknown primary location of the tumor

Out of 120 patients hospitalized with the diagnosis of metastases to the cervical lymph nodes and unknown primary location of the tumor, tumors were detected in 29 and lymphosarcoma in 10. In 24 (82.7%) patients the tumor was located in the upper respiratory tract and gastrointestinal tract. Malignant tumors of the naso- and stomatopharynx and vestibular part of the larynx most often metastasize into the lymph nodes. Radiotherapy was administered to all 81 patients with metastases and unknown location of the primary tumor and to 10 patients with lymphosarcoma of the cervical lymph nodes. The protocol of radiotherapy took account of the site of the metastases and probable primary tumor. A radical course provides cure in 15% of cases, as shown by follow-up of at least 2 years.     

Treatment of the regional lymph nodes in squamous carcinoma of the penis

OBJECTIVES: We evaluated the management of the regional lymph nodes to determine the appropriate treatment for carcinoma of the penis. METHODS: The records of 36 patients with carcinoma of the penis were reviewed. Lymphadenectomy was performed in 18 patients, 17 were managed conservatively (watchful waiting) and 1 patient had a biopsy and received radiotherapy. RESULTS: Positive nodes were found in 2 of 2 pT4, 2 of 3 pT3, 8 of 13 pT2 and 2 of 12 pT1 patients submitted to lymphadenectomy. Concerning the histological grade, positive nodes were found in all of the 4 G3, 5 of 12 G2 and 3 of 20 G1 patients. The survival rate was 100% for the patients with negative lymph nodes (pNO = 6) or a single positive inguinal lymph node (pN1 = 5). A correlation was found between the T and the histological grade and the likelihood of lymph node invasion. CONCLUSIONS: The T and the histological grade of the primary lesion must be considered when deciding the approach in the management of the lymph nodes as unnecessary lymphadenectomy can be avoided and those at high risk of lymph node invasion can be treated radically and timely.     

Dexamethasone stimulation of glutaminase expression in mesenteric lymph nodes

Cystic lymphatic malformations (CLM) are superficial vascular hemodynamically inactive malformations of the lymphatic compartment. We propose a new approach which uses a sclerosing agent as an alternative to surgical resection. In the past nine years we treated 70 patients with CLM. Fifty-five percent were younger than five years of age with a male preponderance and most (80%) of the CLM were located in the maxillofacial region. They usually presented with functional impairment from the mass effect; others had infections, bleeding, or inflammation. The CLM were injected under fluoroscopic control with a sclerosing agent, Ethibloc, which dries up the pockets and reduces the mass. On follow-up the results were good in 62%, unchanged in 5%, and continued progression in 20%. Fifteen percent underwent surgery failures (24%) occurred in mixed forms of cystic and cellular lymphangiomas. Complications were minors. Percutaneous embolization is useful for CLM, with minimal risk, absence of scar, and it avoids surgery. It should be the first line of treatment for these lesions.     

Giant cell tumor of bone with selective metastases to mediastinal lymph nodes

We examined the efficiency of disease-specific "standard" chemotherapies epirubicin, cyclophosphamide (EC); cyclophosphamide, vincristine, doxorubicin, etoposide, prednisolone (CHOEP); epirubicin, ifosfamide (EPI/IFOS) for peripheral blood progenitor cell (PBPC) mobilization in comparison to well-characterized mobilization protocols, i.e. etoposide, ifosfamide, cisplatin, epirubicin (VIPE) and dexamethasone, carmustine, etoposide, cytarabine, melphalan (DexaBEAM). Twenty-seven patients with various malignancies underwent 75 apheresis procedures for PBPC collection. Median cell yields from all 75 aphereses were 1.18 x 10(5) mononuclear cells/kg [range (0.28-3.7) x 10)8)], 1.4 x 10(5) granulocyte/macrophage-colony-forming units (CFU-GM)/kg [range (0.2-11) x 10(5)] and 3.3 x 10(6) CD34+cells/kg [range (0.35-17.7) x 10(6). CD34+/ CD90+ cells could be mobilized by all mobilization regimens used. The difference observed in the mobilization of CD34+ cells was only of low significance when the mobilization regimens were compared, whereas the mobilizations of MNC and CFU-GM were significantly different between the groups. Breast cancer patients treated with the VIPE regimen (including pretreated women) had a significantly higher CFU-GM rate than patients treated with EC (P=0.0005). Mobilized CD34+ PBPC were correlated with CFU-GM in all apheresis products. The linear correlation coefficients differed for the various mobilization groups: DexaBEAM (r=0.9, P < 0.0001), VIPE (r=0.68, P=0.0024), CHOEP (r=0.52, P=0.022), EPI/ IFOS (r=0.34, P=0.11) and EC (r=0.23, P=0.2). We conclude that clonogenic assays can provide additional information about the autotransplant quality, particularly when alternative or new mobilization regimens are being investigated.