The Use of Ultrasound-Measured Optic Nerve Sheath Diameter to Predict Ventriculoperitoneal Shunt Failure in Children.

OBJECTIVE: The goal of this study was to assess the accuracy of ultrasound-measured optic nerve sheath diameter (ONSD) as a screen for ventriculoperitoneal shunt failure. METHODS: We prospectively enrolled a convenience sample of children presenting to the ED with suspected shunt failure. The ONSD was measured by ultrasound and compared with computed tomography/magnetic resonance imaging (CT/MRI) and neurosurgical impression. We defined shunt failure on ultrasound as an ONSD greater than 4.0 mm in infants 12 months and younger or greater than 4.5 mm in children older than 12 months. A single emergency radiologist at our institution read all CTs and MRIs for categorical determination of shunt failure. We defined shunt failure based on neurosurgical impression as a decision to admit and perform shunt revision. We report test characteristics and 95% confidence intervals of ONSD as a predictor for shunt failure. RESULTS: We enrolled 32 subjects. The sensitivities of ONSD compared with CT/MRI and neurosurgical impression, 60.0% and 75.0%, respectively, were low. However, the negative predictive values of ONSD compared with CT/MRI and neurosurgical impression were 90.0% and 95.0%, respectively. CONCLUSIONS: Optic nerve sonography may be a useful tool to identify children presenting with suspected ventriculoperitoneal shunt failure who do not require further imaging. This would reduce the use of CT scan and exposure to ionizing radiation in children with suspected shunt malfunction who do not require neurosurgical intervention. Consideration of additional risk factors and a larger sample size may yield stronger results.

Multipotent Basal Stem Cells, Maintained in Localized Proximal Niches, Support Directed Long-Ranging Epithelial Flows in Human Prostates.

Sporadic mitochondrial DNA mutations serve as clonal marks providing access to the identity and lineage potential of stem cells within human tissues. By combining quantitative clonal mapping with 3D reconstruction of adult human prostates, we show that multipotent basal stem cells, confined to discrete niches in juxta-urethral ducts, generate bipotent basal progenitors in directed epithelial migration streams. Basal progenitors are then dispersed throughout the entire glandular network, dividing and differentiating to replenish the loss of apoptotic luminal cells. Rare lineage-restricted luminal stem cells, and their progeny, are confined to proximal ducts and provide only minor contribution to epithelial homeostasis. In situ cell capture from clonal maps identified delta homolog 1 (DLK1) enrichment of basal stem cells, which was validated in functional spheroid assays. This study establishes significant insights into niche organization and function of prostate stem and progenitor cells, with implications for disease.

Renal differentiation from adult spermatogonial stem cells.

There is considerable interest in the use of multi-potent stem cells in kidney tissue regeneration. We studied if spermatogonial stem cells have the ability to undergo kidney differentiation. Spermatogonial stem cell differentiation was induced using in vitro and ex vivo co-culture techniques. Conditioned media from human kidney fibroblasts induced the expression of epithelial and endothelial lineages in spermatogonial stem cells, consistent with nephrogenesis. Furthermore, we showed that these cells up-regulated renal tubular-specific markers alkaline phosphatase, mineralocorticoid receptor, renal epithelial sodium channel and sodium-glucose transporter-2 (p<0.05). GFP-labeled spermatogonial stem cells were engrafted into metanephric kidney organ cultures harvested from E12.5 mouse embryos. After 5 days of organ culture, focal anti-GFP staining was detectable in all inoculated kidneys demonstrating integration of spermatogonial stem cells into the developing kidney (p<0.01). Histological assessment showed early nephron-like architecture. In summary, we show that spermatogonial stem cells have the potential to generate renal tissue and lay the foundations for further investigations into a novel therapeutic approach for renal insufficiency.

Side population in human non-muscle invasive bladder cancer enriches for cancer stem cells that are maintained by MAPK signalling.

Side population (SP) and ABC transporter expression enrich for stem cells in numerous tissues. We explored if this phenotype characterised human bladder cancer stem cells (CSCs) and attempted to identify regulatory mechanisms. Focusing on non-muscle invasive bladder cancer (NMIBC), multiple human cell lines were used to characterise SP and ABC transporter expression. In vitro and in vivo phenotypic and functional assessments of CSC behaviour were undertaken. Expression of putative CSC marker ABCG2 was assessed in clinical NMIBC samples (n = 148), and a role for MAPK signalling, a central mechanism of bladder tumourigenesis, was investigated. Results showed that the ABCG2 transporter was predominantly expressed and was up-regulated in the SP fraction by 3-fold (ABCG2(hi)) relative to the non-SP (NSP) fraction (ABCG2(low)). ABCG2(hi) SP cells displayed enrichment of stem cell markers (Nanog, Notch1 and SOX2) and a three-fold increase in colony forming efficiency (CFE) in comparison to ABCG2(low) NSP cells. In vivo, ABCG2(hi) SP cells enriched for tumour growth compared with ABCG2(low) NSP cells, consistent with CSCs. pERK was constitutively active in ABCG2(hi) SP cells and MEK inhibition also inhibited the ABCG2(hi) SP phenotype and significantly suppressed CFE. Furthermore, on examining clinical NMIBC samples, ABCG2 expression correlated with increased recurrence and decreased progression free survival. Additionally, pERK expression also correlated with decreased progression free survival, whilst a positive correlation was further demonstrated between ABCG2 and pERK expression. In conclusion, we confirm ABCG2(hi) SP enriches for CSCs in human NMIBC and MAPK/ERK pathway is a suitable therapeutic target.

Can the Kattan nomogram still accurately predict prognosis in renal cell carcinoma using the revised 2010 tumor-nodes-metastasis reclassification?

The Kattan nomogram has been used in renal cell cancer to predict progression-free survival after nephrectomy. Tumor-nodes-metastasis staging is essential for the calculation of this score. The effect of the recent 2010 revision to the tumor-nodes-metastasis classification on the predictive ability of the Kattan nomogram was studied. All patients having radical nephrectomy for renal cell cancer in the 5-year period of 2004-2008 at a tertiary referral center were included. Pathological and radiological records were reviewed to identify tumor-nodes-metastasis stage (2002 and 2010 classifications). Kattan scores were calculated for the 2002 and 2010 tumor-nodes-metastasis stages, and the effect on survival predictions were compared with actual outcomes. A total of 291 patients with non-metastatic renal cell cancer were identified. Revision of the tumor-nodes-metastasis staging from the 2002 to 2010 classification resulted in an increase in the number of patients with stage pT3a (from 30 to 75), a reduction in the patients with stage pT3b (from 57 to 10) and a small increase in stage pT4 cases (1 to 3). This altered the proportion of patients in the Kattan prognostic of "good" (from 61% to 69%), "intermediate" (from 29% to 22%) and "poor" (from 10% to 8%). The overall median predicted 5-year progression-free survival was 79.8% with 2002 tumor-nodes-metastasis, and 81.8% with 2010 tumor-nodes-metastasis. Actual 5-year progression-free survival was 83.0%, which was not significantly different from that predicted using either tumor-nodes-metastasis classification (P = 0.66). On comparing the new 2010 and old 2002 tumor-nodes-metastasis classification in our cohort, we showed the predictive ability of the Kattan nomogram remained unaltered.

Twenty-nine Leydig cell tumors: histological features, outcomes and implications for management.

Leydig cell tumors are the most common interstitial neoplasm of the testes. Metastatic progression is historically quoted at over 10%, fuelling uncertainty as to the safety of testis sparing surgery. Between June 1998 and March 2009, 29 patients underwent surgery for Leydig cell tumor of the testis in our cancer network. We reviewed their histological features and clinical outcomes. Four patients with sub-5 millimetre lesions underwent testis sparing surgery and 25 were treated with radical orchidectomy. Histopathological characteristics that have been linked with risk of malignant progression were seen infrequently in our cohort: diameter greater than 50 mm, 0%; nuclear atypia, 14%; >3 mitoses per 10 high-power fields, 3%; infiltrative borders, 10%; necrosis, 3%; and vascular invasion 0%. No patient developed local or distant recurrent disease over a median follow up of 49 months, including seven and four patients disease-free at 5 and 10 years, respectively. The rate of metastatic progression is likely to be significantly less than 10%. Our data suggest that, in the absence of high-risk histopathological features, this tumor can be safely regarded as benign, pending a longer-term follow-up evaluation.

Regulation of gene expression by the RNA-binding protein Sam68 in cancer.

Sam68 (Src-associated in mitosis 68 kDa) is the prototypical member of the STAR (signal transducer and activator of RNA) family of RNA-binding proteins. Sam68 is implicated in a number of cellular processes including signal transduction, transcription, RNA metabolism, cell cycle regulation and apoptosis. In the present review, we summarize the functions of Sam68 as a transcriptional and post-transcriptional regulator of gene expression, with particular relevance to cancer.

Organization of human papillomavirus productive cycle during neoplastic progression provides a basis for selection of diagnostic markers.

The productive cycle of human papillomaviruses (HPVs) can be divided into discrete phases. Cell proliferation and episomal maintenance in the lower epithelial layers are followed by genome amplification and the expression of capsid proteins. These events, which occur in all productive infections, can be distinguished by using antibodies to viral gene products or to surrogate markers of their expression. Here we have compared precancerous lesions caused by HPV type 16 (HPV16) with lesions caused by HPV types that are not generally associated with human cancer. These include HPV2 and HPV11, which are related to HPV16 (supergroup A), as well as HPV1 and HPV65, which are evolutionarily divergent (supergroups E and B). HPV16-induced low-grade squamous intraepithelial lesions (CIN1) are productive infections which resemble those caused by other HPV types. During progression to cancer, however, the activation of late events is delayed, and the thickness of the proliferative compartment is progressively increased. In many HPV16-induced high-grade squamous intraepithelial lesions (CIN3), late events are restricted to small areas close to the epithelial surface. Such heterogeneity in the organization of the productive cycle was seen only in lesions caused by HPV16 and was not apparent when lesions caused by other HPV types were compared. By contrast, the order in which events in the productive cycle were initiated was invariant and did not depend on the infecting HPV type or the severity of disease. The distribution of viral gene products in the infected cervix depends on the extent to which the virus can complete its productive cycle, which in turn reflects the severity of cervical neoplasia. It appears from our work that the presence of such proteins in cells at the epithelial surface allows the severity of the underlying disease to be predicted and that markers of viral gene expression may improve cervical screening.