Normal Ultrastructure of the Kidney and Lower Urinary Tract

Verlander, Jill W.

doi:10.1177/019262339802600101

Cited by 47 publications

(33 citation statements)

References 275 publications

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“…Classical methods of light microscopy were used in studies by Leeson (1962) and Ersoy et al (2006) in rats and Jost et al (1989) in humans. The methods of electron microscopy were used by Walker (1960) in mice, Burke (1976) and Verlander (1998) in rats, Richter & Moize (1963) in different mammalians, Monis & Zambrano (1968) in humans and Hoyes et al (1972) in human fetuses. In our work we described some histological methods (light microscopy, transmission and scanning electron microscopy) used for investigation of ultrastructure of human's urinary epithelium.…”

Section: Discussionmentioning

confidence: 99%

Options for histological study of the structure and ultrastructure of human urinary bladder epithelium

et al. 2012

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Abstract:The urothelium lines all urinary passages, with exception of the distal portions of the urethra. For the first time the structure of the human bladder was described by Leonardo Da Vinci in 15 th century, however, the exact ultrastructure and function of the bladder's epithelium have not been fully understood. The aim of our study was to investigate the structure of normal human urinary bladder epithelium with methods of classical histology, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). We obtained biopsies from non-tumor areas from the human urinary bladder of tumor-bearing patients during transurethral resections of these tumours in general or spinal anaesthesia. Totally we investigated biopsies from 20 patients, 16 males and 4 females. The mean age of this group of patients was averaged 66.5 years. The urothelium is comprised of three cell types including polyhedral basal cells, piriform intermediate cells, and superficial umbrella cells. In human urinary bladder epithelium we found a direct connection between intermediate cells and the basement membrane. These thin cytoplasmic projections are detectable not only on slides for light microscopy (semithin sections), but also in transmission electron-micrographs. In semi-thin sections we found also direct connections between superficial umbrella cells and basement membrane. These connections we were not able to verify via transmission electronmicroscopy. Nevertheless our results show that the human urinary bladder urothelium is a special type of pseudostratified epithelium and each cell has a thin cytoplasmic projection with a direct contact with basement membrane.

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Section: Discussionmentioning

confidence: 99%

Options for histological study of the structure and ultrastructure of human urinary bladder epithelium

et al. 2012

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“…26 The filtration barrier in the glomerulus has three layers: the fenestrated endothelium, the glomerular basement membrane and the podocytes together with a slit diaphragm between the digitations of the podocyte foot processes. 30 The basement membrane is negatively charged because of the presence of anionic sites of glycosaminoglycans, principally heparan sulfate in the lamina rara. Morphometric studies in rats have shown that the size of Bowman's capsule and the capillary tuft generally not only increases with advancing age but also may vary between strains.…”

Section: Glomerulusmentioning

confidence: 99%

Urinary Tract

Greaves

2012

Histopathology of Preclinical Toxicity Studies

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“…The morphology of renal tubular epithelium also varies considerably in different sections of the nephron. Proximal tubular cells have abundant long microvilli on the luminal side while other segments either have stubby microvilli or smooth surfaces [37]. These features also affect the flow velocity and crystal movement.…”

Section: Animal Modelsmentioning

confidence: 99%

Histological aspects of the “fixed-particle” model of stone formation: animal studies

Khan

2016

Urolithiasis

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Crystallization by itself is not harmful as long as the crystals are not retained in the kidneys and are allowed to pass freely down the renal tubules to be excreted in the urine. A number of theories have been proposed, and studies performed, to determine the mechanisms involved in crystal retention within the kidneys. It has been suggested that urinary transit through the nephron is too fast for crystals to grow large enough to be retained. Thus free particle mechanism alone cannot lead to stone formation, there must be a mechanism for crystal fixation within the kidneys. Animal model studies suggest that crystal retention is possible through both the free and fixed particle mechanisms. Crystal cell interaction leads to pathological changes which promote crystal attachment to either epithelial cells or their basement membrane. Alternatively, crystals aggregate and produce large enough particles to block the tubules particularly at sites where urinary flow is affected because of changes in the luminal diameter of the tubule. Crystal deposits plugging the openings of the ducts of Bellini may be the result of such a phenomenon. Intra-tubular crystals translocating to renal interstitium may produce osteogenic changes in the epithelial or endothelial cells resulting in the formation of the Randall’s plaques. Thus, fixation appears to be either through the formation of Randall’s plugs, crystal plugs clogging the openings of the ducts of Bellini or sub-epithelial crystal deposits, the Randall’s plaques.

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Normal Ultrastructure of the Kidney and Lower Urinary Tract

Cited by 47 publications

References 275 publications

Options for histological study of the structure and ultrastructure of human urinary bladder epithelium

Options for histological study of the structure and ultrastructure of human urinary bladder epithelium

Urinary Tract

Histological aspects of the “fixed-particle” model of stone formation: animal studies

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