(1985). Chemically Induced Renal Papillary Necrosis and Upper Urothelial Carcinoma. Part 1. CRC Critical Reviews in Toxicology: Vol. 15, No. 3, pp. 217-329.

Chemically induced renal papillary necrosis and upper urothelial carcinoma. Part 1.

The urinary bladders of 27 human fetuses, aged 7 weeks to full term, were studied by light, transmission and scanning electron microscopy to establish the sequence of events in the development and maturation of the organ during fetal life. In the early specimens, 7-12 weeks old, the urinary bladder was lined by a bilayered, cuboidal and glycogen-rich epithelium. During the 13-17th weeks the epithelium thickened, a third layer developed and by light microscopy it now resembled urothelium. By 21 weeks this had evolved into a 3-4 layer thick epithelium with typical ultrastructural urothelial characteristics. Smooth muscle cells emerged from the condensed mesenchyme of the bladder wall by the 12th week of gestation, initially in the cephalic part of the organ but spreading within a week into the caudal end. Our findings indicate that the human fetal bladder undergoes a series of vital developmental changes during 13-21 weeks of gestation finally acquiring the typical urothelial lining and a well-developed muscular coat.

The fine structure of the human fetal urinary bladder. Development and maturation. A light, transmission and scanning electron microscopic study.

The urethra is the main place of entry for sexually transmitted pathogens However, there is little literature on the morphology of the urogenital system, principally the urethra and ducts of the sex accessory glands The Mongolian gerbil is an insectivorous, herbivorous and monogamous rodent with nocturnal habits; it has been used successfully as a laboratory animal since the 1960s Therefore, the objective of the present paper was to describe the structure and ultrastructure of the urethra and its relations to the ducts of the accessory sex glands of the Mongolian gerbil (Meriones unguiculatus), contributing to the understanding of the reproductive biology of the rodent and aiming to provide data for future experimental studies Conventional techniques of light and scanning electron microscopy were utilized The urethra and ducts of the accessory sex glands are similar to those of the albino rat and the mouse However, there is variation in drainage type among accessory sex glands for the inner urethra The ducts of the seminal vesicle, the ductus deferens, drain their contents independently into the ampullary duct that opens in the urethra The ducts of the prostate, coagulating and bulbourethral glands drain their contents independently into the urethra

Structure of the pelvic and penile urethra – relationship with the ducts of the sex accessory glands of the Mongolian gerbil (Meriones unguiculatus)

Catheter-associated urinary tract infections are the most common hospital-acquired infection, for which Escherichia coli is the leading cause. This study investigated the efficacy of 385nm and 420nm light for inactivation of E. coli attached to the silicone matrix of a urinary catheter. Using urine mucin media, inactivation of planktonic bacteria and biofilm formation was monitored using silicone coupons. Continuous irradiance with both 385nm and 420nm wavelengths with starting cell density population 103CFU ml-1 reduced planktonic suspensions of E. coli to below the detection level after 2h and 6h, respectively. Bacterial attachment to silicone was successfully prevented during the same treatment. Inactivation by 385nm and 420nm was found to be dependent on media, cell density and oxygen, with less inhibition on planktonic suspensions when higher starting cell densities were used. In contrast to planktonic suspensions in PBS, continuous irradiance of pre-established biofilms showed a greater reduction in survival compared to urine mucin media after 24h. Enhanced inhibition for 385nm and 420nm light in urine mucin media was associated with increased production of reactive oxygen species. These findings suggest 385nm and 420nm light as a promising antimicrobial technology for the prevention of biofilm formation on urethral catheters.

Visible and UVA light as a potential means of preventing Escherichia coli biofilm formation in urine and on materials used in urethral catheters.

Summary— The morphological response of the bladder surface to acute and chronic urinary tract infection (UTI) was investigated using both scanning and transmission electron microscopy of bladder biopsies taken during routine cystoscopy. Acute bacterial infection only minimally altered bladder epithelium, whereas in chronic infections the surface layers showed gross changes which included loss of the outer layers of epithelial cells and alteration of the bladder contour. In addition, more erythrocytes and polymorphonucleocytes were present in chronic infection. In both acute and chronic urinary infection, bacteria were confined to a limited number of sites on the bladder surface and appeared to be arranged in microcolonies, but more bacteria were attached to bladder surfaces in chronic than in acute UTI. These findings were confirmed by studying epithelial cells shed from patients with proven urinary infections.



A few patients who had been treated with antibiotics before cystoscopy and biopsy were also studied. These antibiotics included cephalosporins which had been previously shown to produce bacterial morphological variations in vitro. Some of these changes were subsequently observed in the biopsies and the results suggest mechanisms whereby bacteria involved in urinary tract infection can survive exposure to antibiotics.

Scanning Electron Microscopy of Human Bladder Mucosa in Acute and Chronic Urinary Tract Infection

The finding of cells with pleomorphic microvilli in urinary sediments has been proposed as an indicator for urothelial neoplasia. Recently, in addition to such cells, others with less bizarre, non-pleomorphic microvilli have also been found in urothelial cancers, and these cells are similar in appearance to others detected in the urinary sediments of healthy people. When using scanning electron microscopy as a diagnostic tool, these cells are a possible source of confusion. The entire lower urinary tracts from people free of urothelial neoplasia have therefore been examined to delineate the normal surface appearance of all cell types which could appear in the urine. There are 4 predominant cell types: the large, flat squamous cells of the urethral meatus which have abundant microridges; cells with mucus-coated, short, stubby microvilli lining the urethra and renal papilla; immature urothelial cells with chains and ridges of bleb-like processes in the ureters and bladder; and, also in the ureters and bladder, mature urothelial cells with microridges or ruffles. The lining epithelia of the normal urethra and renal papilla may thus contribute cells with non-pleomorphic stubby microvilli to urine sediments, which cannot be differentiated by scanning electron microscopy alone from similar cells derived from urothelial neoplasms. However, the normal complement of cells lining the adult lower urinary tract does not include any with prolific, long, pleomorphic microvilli such as characterize transitional-cell carcinomas of the urothelium.

Surface ultrastructure of the epithelia lining the normal human lower urinary tract.

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Surface ultrastructure of the epithelia lining the normal human lower urinary tract.