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Relevance of Catalytic Anti-VIP Antibodies to the Airway
Published in Sami I. Said, Proinflammatory and Antiinflammatory Peptides, 2020
Upon local challenge with antigens, lymphocytes in airway-associated lymph nodes produce antigen-specific antibodies (85–88). The predominant response is of the IgG isotype, although other isotypes are also formed. The local response is far stronger than the systemic response if antigen is directly instilled or aerosolized into the airways (85,86), it can occur even without adjuvant (87), and it is strong enough to lead to detectable circulating antibody levels (88). Antibody synthesis occurs in cells in tracheobronchial lymph nodes and in mucosal lymphocytes in the lung parenchyma. These considerations lead to the following hypothesis: Natural intra-pulmonary immunization with VIP or a homologous polypeptide leads to local synthesis of antibodies that bind and hydrolyze VIP. The concentration of the antibodies in the airway is greater than in other VIP-containing tissues, resulting in airway-selective interference in the physiological functions of VIP.
The Lymphoid System
Published in Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard, Toxicologic Pathology, 2018
The histologic presentation of normal peripheral lymph nodes can be highly variable and often overlaps with that of pathologically altered nodes. Moreover, minor differences in collection, embedding, and sectioning combined with high intrinsic variability make consistent histologic characterization of peripheral lymph nodes problematic (Haley 2008). Other than the mandibular lymph node, it is not recommended to collect and examine peripheral lymph nodes unless they drain the site of xenobiotic application. Lymph nodes that drain the site of drug administration represent a site of high, first pass drug exposure of lymphoid tissue and may, therefore, provide clues to the potential effects on the immune system. The gut-associated lymphoid tissue (GALT), including the PP and mesenteric lymph nodes, should be collected in any standard necropsy, and are considered the nodes most proximal to exposure by oral administration. The bronchus-associated lymphoid tissue (BALT) and tracheobronchial lymph nodes are appropriate for examination following intrapulmonary administration of agents, while the nasal-associated lymphoid tissue (NALT) should be considered if the nasal route of exposure is used.
The oesophagus
Published in Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie, Bailey & Love's Short Practice of Surgery, 2018
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie
Most oesophageal diverticula are pulsion diverticula that develop at a site of weakness as a result of chronic pressure against an obstruction. Symptoms are mostly caused by the underlying disorder unless the diverticulum is particularly large. Traction diverticula (Figure62.61) are much less common. They are mostly a consequence of chronic granulomatous disease affecting the tracheobronchial lymph nodes due to tuberculosis, atypical mycobacteria or histoplasmosis. Fibrotic healing of the lymph nodes exerts traction on the oesophageal wall and produces a focal outpouching which is usually small and has a conical shape. There may be associated broncholithiasis, and additional complications may occur, such as aerodigestive fistulation (Figure62.62) and bleeding.
Organ burden of inhaled nanoceria in a 2-year low-dose exposure study: dump or depot?
Published in Nanotoxicology, 2020
Jutta Tentschert, Peter Laux, Harald Jungnickel, Josephine Brunner, Irina Estrela-Lopis, Carolin Merker, Jan Meijer, Heinrich Ernst, Lan Ma-Hock, Jana Keller, Robert Landsiedel, Andreas Luch
For organ and tissue sampling, animals were sacrificed under pentobarbitone at BASF SE Ludwigshafen, Germany. For the 2-year study, the following tissues were removed after 3, 12, and 24 months of exposure (n = 3 for time points 3 and 12 month; n = 4 for the 24 month time point): brain, olfactory bulbs, lungs, kidneys, liver, heart, spleen, and small intestine (jejunum) and immediately stored at –80 °C (Kittel et al. 2004; Morawietz et al. 2004; Ruehl-Fehlert et al. 2003). Feces were taken directly from the intestine of the sacrificed animals of the appropriate dose group. Additionally, bone, bone marrow, and blood samples were taken at the same time points. For further details of the techniques used for bone and bone marrow sample extraction and blood sampling see the work by Konduru et al. (2014). Information about the preparation of the bone sections are given in the Supplementary Information section. For the lymph nodes, a distinction was made between tracheobronchial, mediastinal, and mesenteric lymph nodes. The tracheobronchial lymph nodes were analyzed after 3, 12, and 24 months of exposure, while the mesenteric lymph nodes were removed at 12 and 24 month time points and the mediastinal at 24 months. During sample preparation, special attention was paid to prevent cross contamination. Organ weights are given in Supplementary Table S2.
A review of the fate of inhaled α-quartz in the lungs of rats
Published in Inhalation Toxicology, 2019
It is acknowledged that distribution of dust particles in the lungs and their excretion is highly associated with the pulmonary toxicity mechanism of dust particles. Although it has been believed for a long time that the persistent lung burden may be associated with the persistent and severe pulmonary inflammation by crystalline silica (WHO, 2000), the precise fate of crystalline silica particles in the lungs has not been elucidated. The present review hypothesized that inhaled α-quartz particles are translocated from the alveoli to the ciliated airway lumen through the “interstitial route” (Bowden, 1984; Brundelet, 1965; Lauweryns & Baert, 1977). The location of granulomas and increased LALN burden of silica following inhalation exposure to α-quartz support this concept. However, it was presumed that silica particles translocated from the alveoli to the interstitium mostly in free form rather than in macrophages. As a reference, Lee & Kelly (1993) speculated the following for translocation of amorphous silica in rats exposed to Ludox colloidal silica: (i) inhaled silica particles were mostly phagocytized by AM in the alveolar duct region, and dust cells directly penetrated the bronchiolar interstitium from the alveoli and then accumulated in the BALT, peribronchiolar, or perivascular interstitium; (ii) dust cells in BALT transmigrated directly into the bronchial lumen through the epithelium; and, (iii) some dust cells in the interstitium further migrated into peribronchial/perivascular lymphatics and accumulated in the tracheobronchial lymph nodes.
The health effects of short fiber chrysotile and amphibole asbestos
Published in Critical Reviews in Toxicology, 2022
Bronchus-associated lymphoid tissue (BALT) in rodents and isolated aggregations of lymphoid cells (IALC) in humans describe small clusters of cells found near large airways, usually bronchi. BALT and IALC increase following inhalation exposure which accumulates and likely transport particles cleared by the lymphatic system. Through the one-way valves, the lymphatics reach the larger peri-tracheobronchial lymph nodes. The lymphoid tissue and lymph nodes can accumulate the short fibers. Dodson et al. (2000) reported that even in non-occupationally exposed individuals, short non-commercial amphibole asbestos fibers could be found.