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J W Dobbie

Publications and source records attributed to J W Dobbie.

58 records · Page 4Linked to original sources
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Surfactant protein A and lamellar bodies: a homologous secretory function of peritoneum, synovium, and lung.

OBJECTIVE: To review recent discoveries on the existence of lamellar body secreting cells in extrapulmonary sites with respect to their constitution as a previously unrecognized coherent biological system and to evaluate the role of mesothelial research in peritoneal dialysis in initiating this new field of medical research. DATA SOURCES: Studies in the literature on the production and metabolism of pulmonary surfactant with respect to lamellar bodies and surfactant protein A (SP-A). Published investigations on the identification of lamellar bodies and SP-A in extrapulmonary sites and their possible role in systemic expression of autoimmune disorders. RESULTS: It is now established that lamellar bodies of identical periodicity and ultrastructural geometry are present in lung (type II pneumocytes), serosal mesothelium (peritoneum, pleura, and pericardium), and joints (type A and type B synoviocytes). Not only pulmonary lamellar bodies but those at extrapulmonary sites are found in association with SP-A, while SP-A or SP-A-like proteins are present in measurable quantities in normal serosal fluids. These findings have disclosed totally new avenues of research into multisystem disorders, where for the first time an organelle and associated protein provide a link between diverse tissues affected by rheumatoid disease. Evidence of shared epitopes between SP-A and mycobacterial 65-kD heat shock protein indicates a possible etiologic mechanism. CONCLUSIONS: A hitherto ultrastructurally hidden system of lamellar body secretion is now being revealed as a major biological system which appears to subserve surfactant, lubricant, surface protection, and sealant functions in body surfaces and tissue interfaces. This new frontier was born out of investigations into the hitherto neglected biology of peritoneal mesothelium, research which was vital for advancing the therapy of peritoneal dialysis and for preservation of the dialyzing membrane.

Autoantigens↗
PubMedDate not supplied

Ultrastructure, distribution, and density of lamellar bodies in human peritoneum.

OBJECTIVE: To determine the ultrastructure, relative density, and location of lamellar bodies in the various regions, structures, cells, and intercellular matrix in normal human peritoneum; to carry out engineering analysis of the role of lamellar structures in serosal lubricancy and deduce what effect this system may have on the process of peritoneal dialysis. DESIGN: Five samples of normal human parietal peritoneum obtained at elective operation were fixed in a tannic acid-glutaraldehyde mixture and submitted to examination by transmission electron microscopy. Detailed analysis using reconstruction of serial electron micrographs and tracings of montages were employed in determining location, and disposition, density, and geometric patterns of lamellar bodies in all levels of the peritoneal membrane. RESULTS: Lamellar profiles were found in greatest density enmeshed in surface microvilli and in mesothelial cytoplasm. Lamellar bodies were frequently observed capping the external portion of mesothelial junctional complexes, and within intercellular junctions. Lamellar bodies were also encountered in macrophages, both in the peritoneal cavity and submesothelial tissue, and also in fibroblasts. Lamellar bodies were present in low density in the matrix ground substance of submesothelial connective tissue, in blood vessel walls between smooth muscle, in endothelial cell cytoplasm, and in vascular lumina. CONCLUSIONS: Three-dimensional analysis of lamellae on mesothelial surfaces indicates that an arrangement of constantly changing microscopic spheres and cylinders would act at "ball and roller bearings" among the microvilli for the lubrication of opposing surfaces. The entrapment of fluid in lamellar bubbles, which in normal peritoneum fill the microvillous layer, would, if maintained in peritoneal dialysis, constitute a stagnant layer of considerable stability and inertia.

Absorption↗