X-ray micro-computed tomography in the assessment of penile cavernous fibrosis in a rabbit castration model

BACKGROUND

Current assessment methods of penile cavernous fibrosis in animal models have limitations due to the inability to provide complex and volume analysis of fibrotic alterations.

OBJECTIVE

The aim was to evaluate micro-computed tomography (micro-CT) for assessment of cavernous fibrosis and compare it with histological, histochemical, immunohistochemical, and RT-PCR analysis.

MATERIALS AND METHODS

A controlled trial was performed involving 25 New Zealand male rabbits with induced testosterone deficiency by orchidectomy. Penile samples were obtained before and after 7, 14, 21, 84 days from orchidectomy. We consistently performed: a) gray value analysis of corpora cavernosa 3D models reconstructed after micro-CT; b) morphometry of smooth muscles/connective tissue ratio, collagen type I/III ratio, and area of TGF-beta-1 expression in corpora cavernosa; c) RT-PCR of TGF-beta-1 expression.

RESULTS

Micro-CT allowed visualization of penile structures at the resolution comparable to light microscopy. Gray values of corpora cavernosa decreased from 1673 (1512-1773) on the initial day to 1184 (1089-1232) on 21 day (p < 0,005); however, on 84 day, it increased to 1610 (1551-1768). At 21 and 84 days, there were observed a significant decrease in smooth muscle/connective tissue ratio and a significant increase in collagen type I/III ratio (p < 0,05). TGF-beta1 expression increased on 84 day according to immunohistochemistry (p < 0,005). RT-PCR was impossible to conduct due to the absence of RNA in obtained samples after micro-CT.

DISCUSSION AND CONCLUSIONS

Micro-CT provided 3D visualization of entire corpora cavernosa and assessment of radiodensity alterations by gray value analysis in fibrosis progression. We speculate that gray value changes at early and late fibrosis stages could be related to tissue reorganization. RT-PCR is impossible to conduct on tissue samples studied by micro-CT due to RNA destruction. We also suggest that micro-CT could negatively affect the immunohistochemical outcome, as a significant increase of TGF-beta-1 expression occurs later than histological fibrotic signs. This article is protected by copyright. All rights reserved.

[Microbiota of lower urine tract and genital organs of healthy men and in infertility]

AIM

Study microflora of urine, ejaculate, urethra scrape in normal state and infertility.

MATERIALS AND METHODS

2 groups of men were examined: I (28)--control, conditionally healthy men (20 - 25 years of age), II (26)--infertile patients (25 - 35 years of age). Middle portion of morning urine, ejaculate, urethra scrape were studied in group I, in II--ejaculate. Bacteriologic study of urine and ejaculate was carried out in an extended kit of nutrient media (HiMedia) for facultative- anaerobic (FAB) and non-clostridia anaerobic bacteria (NAB). Urethra scrape and ejaculate were studied by PCR in group I.

RESULTS

In urethra scrape and ejaculate a wide spectrum of FAB and NAB was detected in group I. Corynebacterium spp. and coagulase-negative staphylococci (67.9% each) were the dominant cluster of FAB. Eubacterium spp.--in NAB. Bacteriologic study of ejaculate corresponded in PCR with similar results of dominating bacteria. Among FAB the same clusters dominated during bacteriologic study of ejaculate from group II patients, among NAB--Propionibacterium spp., Peptococcus spp. and Peptostreptococcus spp. Quantitative characteristics of ejaculate of group I and II differed insignificantly.

CONCLUSION

The frequency of detection of certain genera of FAB and NAB was significantly higher in patients with infertility than in conditionally healthy men, however quantitative parameters of the isolated microorganisms practically did not differ between groups.

[Non-clostridial anaerobic bacteria can cause acute pyelonephritis (an experimental trial)]

Acute obstructive pyelonephritis (PN) caused by Peptococcus niger (Pn), E. coli and mixed infection (Pn + E. coli) was modeled in rabbits. Morphologic examination showed that in animals with peptococcal infection renal lesions were identical to those in escherichial PN. Hemorrhagic infarctions and vasculitis develop in animals with mixed infection. These morphological findings were confirmed bacteriologically. The experimental trial confirms the role of Pn in development of acute obstructive PN in animals.

[Kidney carcinosarcoma]

A kidney tumour in a 36 year old female is described. The tumor was soft, of gray-brown color, size 12 x 11 cm. Histological, immunohistochemical and ultrastructural findings have demonstrated the signs of biphasic epithelial and mesenchymal cell differentiation. These data allowed the authors to define this tumor as a renal carcinosarcoma. Histogenesis of this tumor and differential diagnosis with other malignant renal tumors are discussed.

[Modern histological classification of renal neoplasms]

The review presents current literary information on basic forms of kidney cancer (clear cell carcinoma, chromophil or papillary cancer, chromophobe renal cell carcinoma, oncocytoma, Bellini carcinoma, sarcomatoid carcinoma and neuroendocrine carcinoma), their morphological characteristics and principles of classification. Modern histological classification of renal cancer is based on immunohistochemical evidence on markers of various nephron segments, this allowing to specify histogenesis of separate forms of renal cell carcinoma. In addition, cytogenetic studies of renal carcinoma reveal correlations between genetic changes in cancer cells and tumor phenotype found at light microscopy. Thus, current classification of renal carcinoma characterizes biology of these neoplasms. This should be taken into account in prognostication and design of new treatment methods.