No abstract

This study was conducted to gain further insight into the role of androgen in maintaining a balanced prostate gland growth in dogs. Effects of castration on prostatic cell were assessed by comparing the expression level of high molecular weight cytokeratin (HMW), alpha-actin, and vimentin in intact and castrated dogs. Mature dogs were castrated while they were under general anesthesia and were killed after 1 month. Mature prostate gland structures from intact dogs are characterized by the presence of differentiated columnar secretary epithelial cells and progenitor basal cells that are located within acini and ducts embedded in a thin fibromuscular tissue. Basal cells were distinguished from secretory epithelial cells by HMW cytokeratin immunostaining, which is expressed specifically by basal cells but not by epithelial cells. Castration-induced secretory epithelial cell death, leave the basal cells intact to form a continuous layer lining the atrophied acini. However, the survived basal cells lost their capacity to differentiate to secretory epithelial cells. In addition, androgen ablation induced remarkable reorganization of the cellular components of the fibromuscular compartment. In intact dogs, this compartment of prostate gland is composed mainly of differentiated smooth muscles and scattered mesenchymal muscles as reflected by the high and low actin and vimentin expressions, respectively. Castration for 1 month induced a progressive shift toward mesenchymal cells, which appeared to occupy most of the fibromuscular compartment. Based on these findings, it appears that androgen acts to maintain a steady state of prostate gland by driving the differentiation of prostatic cells and by maintaining its fully differentiated state.

BackgroundThe phylogeographical structure of Mycobacterium tuberculosis is generally bimodal in low tuberculosis (TB) incidence countries, where genetic lineages of the isolates generally differ with little strain clustering between autochthonous and foreign-born TB patients. However, less is known on this structure in Saudi Arabia—the most important hub of human migration as it hosts a total population of expatriates and pilgrims from all over the world which is equal to that of its citizens.MethodologyWe explored the mycobacterial phylogenetic structure and strain molecular clustering in Saudi Arabia by genotyping 322 drug-resistant clinical isolates collected over a 12-month period in a national drug surveillance survey, using 24 locus-based MIRU-VNTR typing and spoligotyping.Principal FindingsIn contrast to the cosmopolitan population of the country, almost all the known phylogeographic lineages of M. tuberculosis complex (with noticeable exception of Mycobacterium africanum/West-African 1 and 2) were detected, with Delhi/CAS (21.1%), EAI (11.2%), Beijing (11.2%) and main branches of the Euro-American super-lineage such as Ghana (14.9%), Haarlem (10.6%) and Cameroon (7.8%) being represented. Statistically significant associations of strain lineages were observed with poly-drug resistance and multi drug resistance especially among previously treated cases (p value of < = 0.001 for both types of resistance), with relative over-representation of Beijing strains in the latter category. However, there was no significant difference among Saudi and non-Saudi TB patients regarding distribution of phylogenetic lineages (p = 0.311). Moreover, 59.5% (22/37) of the strain molecular clusters were shared between the Saudi born and immigrant TB patients.ConclusionsSpecific distribution of M. tuberculosis phylogeographic lineages is not observed between the autochthonous and foreign-born populations. These observations might reflect both socially favored ongoing TB transmission between the two population groups, and historically deep-rooted, prolonged contacts and trade relations of the peninsula with other world regions. More vigorous surveillance and strict adherence to tuberculosis control policies are urgently needed in the country.

No abstract

No abstract