To investigate potential physiological interactions between the transcellular and paracellular pathways of water transport, we asked whether targeted deletion of Aquaporin 5 (AQP5), the major transcellular water transporter in salivary acinar cells, affected paracellular transport of 4-kDa FITC-labeled dextran (FITC-D), which is transported through the paracellular but not the transcellular route. After i.v. injection of FITC-D into either AQP5 wild-type or AQP5؊/؊ mice and saliva collection for fixed time intervals, we show that the relative amount of FITC-D transported in the saliva of AQP5؊/؊ mice is half that in matched AQP5؉/؉ mice, indicating a 2-fold decrease in permeability of the paracellular barrier in mice lacking AQP5. We also found a significant difference in the proportion of transcellular vs. paracellular transport between male and female mice. Freeze-fracture electron microscopy revealed an increase in the number of tight junction strands of both AQP5؉/؉ and AQP5؊/؊ male mice after pilocarpine stimulation but no change in strand number in female mice. Average acinar cell volume was increased by Ϸ1.4-fold in glands from AQP5؊/؊ mice, suggesting an alteration in the volumesensing machinery of the cell. Western blots revealed that expression of Claudin-7, Claudin-3, and Occludin, critical proteins that regulate the permeability of the tight junction barrier, were significantly decreased in AQP5؊/؊ compared with AQP5؉/؉ salivary glands. These findings reveal the existence of a genderinfluenced molecular mechanism involving AQP5 that allows transcellular and paracellular routes of water transport to act in conjunction.epithelium ͉ fluid absorption and secretion T he proper transport of electrolytes and water across epithelial barriers is of vital importance to the maintenance of normal physiological homeostasis in all animals (1, 2). Fluid is moved either across the plasma membranes of the cells that comprise the epithelial layer (transcellular transport) or between these cells, through the tight junction complex (TJC) that forms a barrier (paracellular transport). Together, the transcellular and paracellular pathways are capable of transporting large volumes of fluid, estimated at 200 liters per day in a 70-kg human (1).There is considerable complexity in the mechanisms that determine the usage of paracellular vs. transcellular routes of water transport. For example, in the kidney, transport of water is accomplished mainly through paracellular transport in the proximal nephron (3), whereas highly regulated transcellular transport is carried out in the distal nephron and collecting duct (4). Similar complexities are likely to exist in the secretion and absorption of water in the gut and the secretion of fluids by exocrine glands such as the salivary gland and pancreas.In an attempt to determine the ratio of paracellular to transcellular transport, Murakami et al. (5,6) used ex vivo perfused rat submandibular salivary glands and showed that the majority of water is transported through the paracellular ...
Improvement in the health of older people and changes in their lifestyles necessitate a scale that can better measure their competence at a higher level. This study describes the development process of the Japan Science and Technology Agency Index of Competence (JST-IC) by (a) refining conceptual definitions and developing preliminary items and (b) examining the basic properties of the items. Participants were 1,253 septuagenarians (539 men and 714 women) living in communities, who were asked to judge whether they were independent via 88 items. To examine the basic properties of the preliminary items, five different analyses were conducted. Thirty-four items were considered as inappropriate (6 overlapped between the analyses): (a) 9 due to very high or low ratios of responders who answered “yes,” (b) 4 due to gender or regional differences, (c) 5 due to their weak association with health status, (d) 9 due to low communalities in factor analysis, and (e) 13 due to redundancy of meaning with other items. Conceptual definitions and preliminary items were developed, and the basic properties of the items were examined to create the JST-IC. The next step would be to screen the remaining 54 items to create the final version of the scale.
To investigate the pathogenesis of human T lymphocyte virus type I (HTLV-I)- related diseases, the env-pX gene of HTLV-I was introduced into the germline of inbred Wistar-King-Aptekman-Hokudai rats. A wide spectrum of collagen vascular diseases was evident in the transgenic rats, including chronic destructive arthritis similar to rheumatoid arthritis, necrotizing arteritis mimicking polyarteritis nodosa, polymyositis, myocarditis, dermatitis, and chronic sialoadenitis and dacryoadenitis resembling Sjögren's syndrome in humans. Thymic atrophy with the depletion of CD4 and CD8 double-positive thymocytes was also observed. In these animals, a number of autoantibodies, including high titers of rheumatoid factor, were present in the serum. We propose that the HTLV-I env-pX gene region may play a pathogenetic role in the development of collagen vascular and autoimmune diseases associated with autoimmune phenomenon.
Postmortem MRI of the brain in all cases showed characteristic common SI changes. Global cerebral ischemia without following reperfusion and low body temperature explain these changes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.