Telomerase activity exclusively in cervical carcinomas and a subset of cervical intraepithelial neoplasia grade III lesions: Strong association with elevated messenger RNA levels of its catalytic subunit and high-risk human papillomavirus DNA

In this study, we investigated telomerase activity and human telomerase reverse transcriptase (hTERT) mRNA expression in relation to high-risk human papillomavirus (HPV) DNA presence in the spectrum of cervical premalignant lesions. Reconstruction experiments revealed that telomerase activity determined by the telomeric repeat amplification protocol assay and hTERT mRNA by reverse transcriptase-PCR could be detected in down to 100 and 1 SiHa cervical cancer cells, respectively. Telomeric repeat amplification protocol analysis on cervical tissue specimens revealed that none of the histomorphologically normal cervical samples (n = 8) and cervical intraepithelial neoplasia (CIN) grade I (n = 10) and grade II (n = 8) lesions had detectable telomerase activity. However, telomerase activity was shown in 40% of CIN grade III lesions (n = 15) and 96% of squamous cell carcinomas (n = 24). Despite the fact that hTERT mRNA was found at much higher frequencies, semiquantitative reverse transcriptase-PCR revealed that elevated hTERT mRNA levels were strongly correlated with detectable telomerase activity. Furthermore, telomerase activity and elevated hTERT mRNA levels were only detected in cases that contained high-risk HPV DNA. In contrast, low or undetectable hTERT mRNA levels were demonstrated in both high-risk HPV positive and negative cases. These data indicate that telomerase activity detectable with the assay used and concomitant elevated levels of hTERT mRNA reflect a rather late step in the CIN to squamous cell carcinoma sequence, which follows infection with high-risk HPV

Podocyte foot process effacement as a diagnostic tool in focal segmental glomerulosclerosis.

Contains fulltext : 71431.pdf (publisher's version ) (Closed access)Podocyte foot process effacement is characteristic of proteinuric renal diseases. In minimal change nephrotic syndrome (MCNS) foot processes are diffusely effaced whereas the extent of effacement varies in focal segmental glomerulosclerosis (FSGS). Here we measured foot process effacement in FSGS and compared it to that in MCNS and in normal kidneys. A clinical diagnosis was used to differentiate idiopathic FSGS from secondary FSGS. Median foot process width, determined morphometrically by electron microscopy, was 3236 nm in 17 patients with idiopathic FSGS, 1098 nm in 7 patients with secondary FSGS, and 1725 nm in 15 patients with MCNS, as compared to 562 nm in 12 control patients. Multivariate analysis showed that foot process width did not correlate with proteinuria or serum albumin levels but was significantly associated as an independent factor with the type of disease. Foot process width over 1500 nm differentiated idiopathic from secondary FSGS with high sensitivity and specificity. Our results show that quantitative analysis of foot processes may offer a potential tool to distinguish idiopathic from secondary FSGS

Family involvement and helping behaviour in teams

Helping behavior at work has become increasingly important, with organizations making more and more use of cooperative work practices. The difficulty is that employees are facing growing demands beyond the workplace. This study investigates the mechanisms by which family involvement (family structure, family tasks, family support) affects helping behavior in teams. Based on a sample of 495 team members, the results show that having a supportive partner and performing care tasks increase helping behavior via enhanced fulfillment and skills. Having young children is directly and negatively related to helping behavior. The authors also conducted separate analyses for men and women.

Downstream E-Box–mediated Regulation of the Human Telomerase Reverse Transcriptase (hTERT) Gene Transcription: Evidence for an Endogenous Mechanism of Transcriptional Repression

Regulation of the hTERT gene encoding the telomerase catalytic subunit plays an important role in human cell senescence, immortalization, and carcinogenesis. By examining the activity of various deleted or mutated hTERT promoter fragments, we show that an E-box element downstream of the transcription initiation site is critical to differential hTERT transcription between the telomerase/hTERT-positive renal cell carcinoma cell line (RCC23) and its telomerase/hTERT-negative counterpart containing a transferred, normal chromosome 3 (RCC23+3). This E-box element mediated repression of hTERT transcription in RCC23+3 but not in RCC23. A copy number–dependent enhancement of the repression suggested active repression, rather than loss of activation, in RCC23+3. Endogenous expression levels of c-Myc or Mad1, which could activate or repress hTERT transcription when overexpressed, did not account for the differential hTERT transcription. Gel mobility shift assays identified the upstream stimulatory factors (USFs) as a major E-box–binding protein complex in both RCC23 and RCC23+3 and, importantly, detected an RCC23+3-specific, E-box–binding factor that was distinct from the USF and Myc/Mad families. The E-box–mediated repression was also active in normal human fibroblasts and epithelial cells and inactive in some, but not all, telomerase/hTERT-positive cancer cells. These findings provide evidence for an endogenous, repressive mechanism that actively functions in telomerase/hTERT-negative normal cells and becomes defective during carcinogenic processes, e.g., by an inactivation of the telomerase repressor gene on chromosome 3