Study of the ureter structure in anencephalic fetuses

Purpose The objective of this paper is to analyze the structure of the ureter in normal and anencephalic human fetuses. Materials and Methods We studied 16 ureters from 8 human fetuses without congenital anomalies aged 16 to 27 weeks post-conception (WPC) and 14 ureters from 7 anencephalic fetuses aged 19 to 33 WPC. The ureters were dissected and embedded in paraffin, from which 5 µm thick sections were obtained and stained with Masson trichrome, to quantify smooth muscle cells (SMC) and to determine the ureteral lumen area, thickness and ureteral diameter. The samples were also stained with Weigert Resorcin Fucsin (to study elastic fibers) and Picro-Sirius Red with polarization and immunohistochemistry analysis of the collagen type III fibers to study collagen. Stereological analysis of collagen, elastic system fibers and SMC were performed on the sections. Data were expressed as volumetric density (Vv-%). The images were captured with an Olympus BX51 microscope and Olympus DP70 camera. The stereological analysis was done using the Image Pro and Image J programs. For biochemical analysis, samples were fixed in acetone, and collagen concentrations were expressed as micrograms of hydroxyproline per mg of dry tissue. Means were statistically compared using the unpaired t-test (p < 0.05). Results The ureteral epithelium was well preserved in the anencephalic and control groups. We did not observe differences in the transitional epithelium in the anencephalic and control groups. There was no difference in elastic fibers and total collagen distribution in normal and anencephalic fetuses. SMC concentration did not differ significantly (p = 0.1215) in the anencephalic and control group. The ureteral lumen area (p = 0.0047), diameter (p = 0.0024) and thickness (p = 0.0144) were significantly smaller in anencephalic fetuses. Conclusions Fetuses with anencephaly showed smaller diameter, area and thickness. These differences could indicate ...

Does prolonged pneumoperitoneum affect the kidney? Oxidative stress, stereological and electron microscopy study in a rat model

Purpose: Pneumoperitoneum (Pp) at 12 to 15 mmHg in rats is associated with kidney damage. However, Pp at 8 mmHg is now known to best correlate to working pressures used in humans. Thus the aim of this work was to study the kidney of rats submitted to prolonged Pp at 8 mmHg. Materials and Methods: Rats were divided into a Sham group (n = 14), submitted to anesthesia, and a Pp group (n = 14), submitted to Pp at 8 mmHg, followed by deflation. In both groups, 7 animals were immediately killed and their kidneys were used for oxidative stress analyses. The remaining 7 rats in each group were evaluated after 6 weeks for the number of glomeruli and podocyte morphology. Results: For all analyzed parameters Sham and Pp groups presented no statistical difference. Conclusion: When submitted to adequate Pp pressures (8 mmHg), no kidney damage occurs in rats. .

Stereological and biochemical analysis of the urethral edges in patients submitted to end-to-end anastomosis for bulbar urethral stricture

PURPOSE: To study the morphologic alterations in the proximal and distal urethral edges from patients submitted to end-to-end bulbar urethroplasty. MATERIALS AND METHODS: We analyzed 12 patients submitted to anastomotic urethroplasty to treat bulbar strictures less than 2.0 cm in length. After excision of the fibrotic segment to a 28Fr urethral caliber, we obtained biopsies from the spongious tissue of the free edges (proximal: PROX and distal: DIST). Controls included normal bulbar urethras obtained from autopsies of 10 age matched individuals. The samples were histologically processed for smooth muscle cells (SMC), elastic system fibers and collagen. Stereological analysis was performed to determine the volumetric density (Vv) of each element. Also, a biochemical analysis was performed to quantify the total collagen content. RESULTS: Vv of SMC was reduced in PROX (31.48 ± 7.01 p < 0.05) and similar in DIST when compared to controls (55.65 ± 9.60%) with no statistical difference. Elastic fibers were increased in PROX (25.70 ± 3.21%; p < 0.05) and were similar to controls in DIST (15.87 ± 4.26%). Total collagen concentration in PROX (46.39 ± 8.20 μg/mg), and DIST (47.96 ± 9.42 μg/mg) did not differ from controls (48.85 ± 6.91 μg/mg). Type III collagen was similarly present in all samples. CONCLUSIONS: After excision of the stenotic segment to a caliber of 28Fr, the exposed and macroscopically normal urethral edges may present altered amounts of elastic fibers and SMC, but are free from fibrotic tissue. When excising the peri-stenotic tissue, the surgeon should be more careful in the proximal end, which is the most altered.

Structural alterations of foreskin caused by chronic smoking may explain high levels of urethral reconstruction failure using foreskin flaps

OBJECTIVES: The aim of the present study was to perform a stereological and biochemical analysis of the foreskin of smoker subjects. MATERIALS AND METHODS: Foreskin samples were obtained from 20 young adults (mean = 27.2 years old) submitted to circumcision. Of the patients analyzed, one group (n = 10) had previous history of chronic smoking (a half pack to 3 packs per day for 3 to 13 years (mean = 5.8 ± 3.2). The control group included 10 nonsmoking patients. Masson's trichrome stain was used to quantify the foreskin vascular density. Weigert’s resorcin-fucsin stain was used to assess the elastic system fibers and Picrosirius red stain was applied to study the collagen. Stereological analysis was performed using the Image J software to determine the volumetric densities. For biochemical analysis, the total collagen was determined as µg of hydroxyproline per mg of dry tissue. Means were compared using the unpaired t-test (p < 0.05). RESULTS: Elastic system fibers of smokers was 42.5% higher than in the control group (p = 0.002). In contrast, smooth muscle fibers (p = 0.42) and vascular density (p = 0.16) did not show any significant variation. Qualitative analysis using Picrosirius red stain with polarized light evidenced the presence of type I and III collagen in the foreskin tissue, without significant difference between the groups. Total collagen concentration also did not differ significantly between smokers and non-smokers (73.1µg/mg ± 8.0 vs. 69.2µg/mg ± 5.9, respectively, p = 0.23). CONCLUSIONS: The foreskin tissue of smoking patients had a significant increase of elastic system fibers. Elastic fibers play an important role in this tissue’s turnover and this high concentration in smokers possibly causes high extensibility of the foreskin. The structural alterations in smokers’ foreskins could possibly explain the poor results in smoking patients submitted to foreskin fasciocutaneous flaps in urethral reconstruction surgery.

Implications of naturally occurring variations in arterial glycosaminoglycans for the pathogenesis of atherosclerosis

Proteoglycans and their constituent glycosaminoglycan (GAG) side chains participate in the pathogenesis of atherosclerosis by holding and modifying plasma lipoproteins (LDL). Of the GAGs existing in arteries, only chondroitin sulfate and dermatan sulfate interact with LDL.In addition, these LDL-binding GAGs show some naturally occurring variations that have direct consequences to their participation in atherogenesis. These variations are: (1) Polydispersity: GAGs normally vary widely in molecular weight and in human aortas there are longer chains of chondroitin sulfate/dermatan sulfate presenting stronger affinity to LDL; (2) Ageing: steric factors play a role in GAG-LDL interaction, and with ageing there is an increase in the relative content of the 6-sulfated isomer of aortic chondroitin sulfate; this isomer binds to LDL, whereas the 4-sulfated isomer does not: (3) Anatomic heterogeneity: The risk to develop atherosclerotic lesions is different among arteries, and the composition and LDL binding affinity of chondroitin sulfate/dermatan sulfate from normal arteries correlate with their susceptibility to atherosclerosis. The participation of GAGs in atherosclerosis should therefore be viewed as variable.