2 research outputs found
Supplementary Material for: Cytogenetic Insights into the Evolution of Chromosomes and Sex Determination Reveal Striking Homology of Turtle Sex Chromosomes to Amphibian Autosomes
Turtle karyotypes are highly conserved compared to other vertebrates; yet, variation in diploid number (2n = 26-68) reflects profound genomic reorganization, which correlates with evolutionary turnovers in sex determination. We evaluate the published literature and newly collected comparative cytogenetic data (G- and C-banding, 18S-NOR, and telomere-FISH mapping) from 13 species spanning 2n = 28-68 to revisit turtle genome evolution and sex determination. Interstitial telomeric sites were detected in multiple lineages that underwent diploid number and sex determination turnovers, suggesting chromosomal rearrangements. C-banding revealed potential interspecific variation in centromere composition and interstitial heterochromatin at secondary constrictions. 18S-NORs were detected in secondary constrictions in a single chromosomal pair per species, refuting previous reports of multiple NORs in turtles. 18S-NORs are linked to ZW chromosomes in <i>Apalone</i> and<i>Pelodiscus </i>and to X (not Y) in <i>Staurotypus</i>. Notably, comparative genomics across amniotes revealed that the sex chromosomes of several turtles, as well as mammals and some lizards, are homologous to components of <i>Xenopus tropicalis </i>XTR1 (carrying <i>Dmrt1</i>). Other turtle sex chromosomes are homologous to XTR4 (carrying<i>Wt1</i>). Interestingly, all known turtle sex chromosomes, except in Trionychidae, evolved via inversions around <i>Dmrt1 </i>or <i>Wt1</i>. Thus, XTR1 appears to represent an amniote proto-sex chromosome (perhaps linked ancestrally to XTR4) that gave rise to turtle and other amniote sex chromosomes
Supplementary Material for: Are Transrectal Prostate Biopsies Routinely Indicated in Patients with Incidentally Diagnosed Prostate Cancer following Transurethral Resection of the Prostate for Benign Disease?
<b><i>Objective:</i></b> To determine the indication of routine transrectal ultrasound-guided needle biopsy (TRUSBx) of the prostate gland following incidental cancer diagnosis after transurethral resection of the prostate (TURP) for benign prostatic hyperplasia. <b><i>Materials and Methods:</i></b> A multi-institutional search identified 63 patients with incidental TURP-diagnosed prostate cancer from 2001 to 2010, who underwent subsequent TRUSBx or radical prostatectomy (RP). The Gleason scores from TURP were compared to those from TRUSBx or RP. Whole mount maps from RP were analysed to provide an anatomical basis for the correlation observed. To determine the clinical impact of this problem, the incidence of TURP-diagnosed prostate cancer in the population was also determined. <b><i>Results:</i></b> Of 22 patients who underwent TRUSBx, the rates of Gleason score concordance, upgrading and downgrading were 32, 14 and 54% respectively (Spearman correlation coefficient 0.20). Most cases of pathological downgrading consisted of benign cores at biopsy. Therefore, TRUSBx did not give additional Gleason score (GS) information in 86% of patients. Of 41 RP patients, the respective rates were 61, 22 and 17% (Spearman correlation coefficient 0.15). The majority of them retained a similar or lower GS between TURP and RP. Of 13 whole mount maps analysed, 6 (46%) were found with anterior/transitional zone (AZ/TZ) tumours, 6 (46%) with multifocal tumours and 1 (8%) with a large peripheral zone (PZ) tumour extending into the TZ. Regional population data show that despite a gradual reduction in the proportion of TURP-diagnosed cases over the past decade, they still account for 8.5-13% of all new cases. <b><i>Conclusion:</i></b> TURP-diagnosed prostate cancers represent predominantly AZ tumours. A TRUSBx does not give additional GS information in a majority of cases, and therefore is not routinely indicated. It may be selectively useful prior to active surveillance, but not in all pursuing radical treatment. These findings may help reduce unnecessary TRUSBx in the population