Hirschsprung associated GDNF mutations do not prevent RET activation

Hirschsprung disease (HSCR) is a complex disorder characterised by aganglia of distal gastrointestinal tracts. The highest proportion of both familial and sporadic cases is due to mutations of the RET proto-oncogene. Five germline mutations in the glial cell-line-derived neurotrophic factor (GDNF) gene, one of the RET ligands, have been detected in HSCR patients. Pedigrees analysis and the observed association between these GDNF alterations and RET variants in the same patients raised the question of whether the GDNF gene plays any causative/predisposing role in HSCR pathogenesis. In the present work, we have studied the ability of GDNF proteins, each bearing one of the reported mutations, to activate RET by performing a functional test in cultured neuroblastoma cells. Consistently with the lack of genotype/phenotype correlation in human subjects, our results indicate absence of detectable alterations of mutant GDNF induced RET activation.     

Correction to: Rarely occurring mutation of ACVR1 gene in Moroccan patient with fibrodysplasia ossificans progressiva

Clinical Rheumatology - One of the author’s name on this article was incorrectly spelled as “Renata Borcciadi”. The correct spelling is “Renata Bocciardi” and is now...     

EEC‐ and ADULT‐Associated TP63 Mutations Exhibit Functional Heterogeneity Toward P63 Responsive Sequences

TP63 germ‐line mutations are responsible for a group of human ectodermal dysplasia syndromes, underlining the key role of P63 in the development of ectoderm‐derived tissues. Here, we report the identification of two TP63 alleles, G134V (p.Gly173Val) and insR155 (p.Thr193_Tyr194insArg), associated to ADULT and EEC syndromes, respectively. These alleles, along with previously identified G134D (p.Gly173Asp) and R204W (p.Arg243Trp), were functionally characterized in yeast, studied in a mammalian cell line and modeled based on the crystal structure of the P63 DNA‐binding domain. Although the p.Arg243Trp mutant showed both complete loss of transactivation function and ability to interfere over wild‐type P63, the impact of p.Gly173Asp, p.Gly173Val, and p.Thr193_Tyr194insArg varied depending on the response element (RE) tested. Interestingly, p.Gly173Asp and p.Gly173Val mutants were characterized by a severe defect in transactivation along with interfering ability on two DN‐P63α‐specific REs derived from genes closely related to the clinical manifestations of the TP63‐associated syndromes, namely PERP and COL18A1. The modeling of the mutations supported the distinct functional effect of each mutant. The present results highlight the importance of integrating different functional endpoints that take in account the features of P63 proteins' target sequences to examine the impact of TP63 mutations and the associated clinical variability.     

Passerini-glazel feminizing genitoplasty: a long-term followup study

PURPOSE: We report our experience with early 1-stage Passerini-Glazel feminizing genitoplasty with special emphasis on long-term results of vaginoplasty. MATERIALS AND METHODS: A total of 66 patients with ambiguous genitalia underwent 1-stage Passerini-Glazel feminizing genitoplasty. Long-term followup included an outpatient visit at 1 year postoperatively and a genital assessment with the patient under general anesthesia performed before menarche courses in those operated on at age 6 months to 8 years, and at 2 years postoperatively for those operated on at 9 years or older. RESULTS: All patients underwent the first long-term followup evaluation and no major complications were observed. The second long-term followup evaluation was performed in 46 patients (70%). In all cases the vaginal introitus was located in the physiological position and was large and elastic. Vaginal caliber at the suture line between the tubularized flap and vaginal mucosa was the same size as the vaginal introitus and distal native vagina in 20 of 46 patients (43%), slightly smaller in 10 (22%) and stenotic in 16 (35%). Stenosis at the suture line was corrected with simple Y-V introitoplasty performed at the same followup visit. CONCLUSIONS: Early 1-stage Passerini-Glazel feminizing genitoplasty is a safe and effective procedure that allows total surgical correction of ambiguous genitalia in infancy and good cosmetic results. Incidence of vaginal stenosis at the suture line is high but it can be repaired with simple introitoplasty performed before menarche occurs. Good functional results are presumed.     

Neural crest neuroblasts can colonise aganglionic and ganglionic gut in vivo.

INTRODUCTION: Neural crest (NC) cells differentiate IN VITRO into neuroblasts, precursors of the enteric nervous system (ENS), when stimulated by specific agents. We developed a study aimed at establishing whether NC-derived neuroblasts can survive and colonise IN VIVO when injected into a recipient mouse gut. MATERIALS AND METHODS: The neuroblast precursors of the ENS were obtained from the vagal portion of the neural tubes of 296 CD-1 and GTROSA26 mouse embryos. The embryonic cells of GTROSA26 mice are identifiable through beta-galactosidase activity which allows recognition by blue staining. The host used in this study was the DOM/+ mouse, an animal model for Hirschsprung's disease (aganglionic megacolon). DOM/+ mouse pups (n = 43) received NC-derived cells inoculated into the seromuscular layer of the gut (33/43) or directly into the peritoneal abdominal cavity (10/43). RESULTS: All DOM/+ mice survived the procedure and were sacrificed after 7 or 14 days. Histochemical staining detected implanted cells in all mice. These showed specific myenteric colonisation into the aganglionic and ganglionic gut. CONCLUSION: The striking result of this study was the specific tropism of the injected NC-derived cells to target sites under the action of unknown chemotactic agents. This experimental procedure might represent a possible treatment option for specific forms of human ENS anomaly such as total intestinal aganglionosis.     

Detection of lymph-node metastases with integrated [11C]choline PET/CT in patients with PSA failure after radical retropubic prostatectomy: results confirmed by open pelvic-retroperitoneal lymphadenectomy

OBJECTIVES: To prospectively evaluate the accuracy of integrated [(11)C]choline-PET/CT in the diagnosis of lymph-node recurrence in prostate cancer patients with biochemical failure after surgery. METHODS: Since October 2002, 25 patients with biochemical recurrence (median PSA: 1.98 ng/ml), based on evidence of lymph-node metastases on [(11)C]choline-PET/CT scan (21 cases) or conventional imaging (4 cases), were scheduled for either bilateral pelvic (12 cases) or both pelvic and retroperitoneal lymph-node dissection (13 patients). RESULTS: Sixty-three nodal sites were evaluated histologically. The mean number of nodes removed and positive nodes were 21.92+/-16.91 (range: 4-74) and 8.84+/-9.65 (range: 1-31), respectively. Of the four patients with negative [(11)C]choline-PET/CT and positive magnetic resonance, none had nodal metastases. Nineteen of the 21 patients (90%) with positive [(11)C]choline-PET/CT had nodal metastases of prostate adenocarcinoma at histologic evaluation. A lesion-based analysis showed that [(11)C]choline-PET/CT sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 64%, 90%, 86%, 72%, and 77%, respectively. The mean maximum diameter of true positive metastases was larger than false-negative ones (15.0 vs. 6.3mm; p=0.0004). CONCLUSIONS: [(11)C]Choline-PET/CT is an accurate diagnostic tool for the detection of lymph-node metastases of recurrent prostate cancer. The low negative predictive value seems to depend on the limited capability of [(11)C]choline-PET/CT to detect microscopic lesions. The high positive predictive value, even with low PSA values, provides a basis for further treatment decisions.