Expression and alterations of the PTEN / AKT / mTOR pathway in ameloblastomas.

OBJECTIVES: Recently, an allelic loss of phosphatase and tensin homologue (PTEN) was shown to occur in ameloblastomas. In carcinogenesis, loss of PTEN allows for overactivity of the phosphatidylinositol-3-kinase/protein kinase B (PI3K / AKT) pathway inducing an upregulation of mammalian-target of rapamycin (mTOR) and its downstream effector ribosomal-subunit-6 kinase (S6K); allowing for uncontrolled cell proliferation, apoptosis inhibition and cell cycle deregulation. METHODS: Thirty ameloblastomas and five dental follicles were studied, looking at the immunohistochemical expression of total PTEN and AKT, as well as their phosphorylated (p) active forms, and the downstream effector and indicator of mTOR activity p70 ribosomal-subunit-6 kinase (pS6K). Also assessed was the expression of extracellular-signal-regulated kinase (ERK), which cross talks with AKT. RESULTS: Total PTEN was absent in 33.3% of ameloblastomas, while its stabilized, phosphorylated(ser380 / thr382 / thr383) form was absent in 83.3% of tumors. In contrast, AKT was expressed in 83.3% of ameloblastomas, showing high expression of the p-thr(308)AKT and p-ser(473) AKT forms in 93.3% and 56.6% of cases, respectively. Further, the mTOR activated pS6K(ser240 / 244) was detected in 86.7% of ameloblastomas, while ERK was overexpressed in 70.0% of the cases. CONCLUSION: Immunohistochemical analysis of aberrant signaling in the PI3K/AKT/mTOR pathway in ameloblastomas may represent a valuable tool for elucidating pathogenesis, aggressiveness and selecting optimal therapeutics.

Survivin is a downstream target and effector of sulindac-sensitive oncogenic Stat3 signalling in head and neck cancer.

Sulindac exerts its antitumorigenic effects in oral squamous cell carcinoma (SCC) cells by modulating survivin in a Stat3-dependent manner. Immunohistochemistry was used to detect the protein levels of phosphorylated-tyrosine Stat3 (p-tyr Stat3) and survivin in SCC tissues. Western blot, reverse transcriptase polymerase chain reaction, Annexin-V and cell proliferation assays were used to determine p-tyr Stat3 and survivin protein and mRNA expression, and cell viability following treatment with cyclooxygenase (COX) inhibitors, Stat3 siRNA, or the forced expression of Stat3 or survivin. Immunohistochemical analysis revealed an overexpression of p-tyr Stat3 in T1 SCCs. The importance of constitutive Stat3 activation in tumourigenesis was confirmed by siRNA inhibition of Stat3, resulting in cell growth inhibition and apoptosis, via a downregulation of survivin mRNA and protein expression. The forced expression of survivin partially reversed these effects of Stat3 inhibition. Sulindac, but not other COX inhibitors, downregulated Stat3, which correlated to an inhibition of cell proliferation, survival and survivin expression. Transfection of constitutively active Stat3 restored survivin expression and partially rescued SCC cells from sulindac-induced antitumorigenic effects. These data indicate that survivin is a downstream target and effector of oncogenic Stat3 signalling in SCC, which is targeted by sulindac in a COX-2-independent manner.

Generalized Hyperalgesia in Children and Adults Diagnosed With Hypermobility Syndrome and Ehlers-Danlos Syndrome Hypermobility Type: A Discriminative Analysis.

OBJECTIVE: Lowered pressure-pain thresholds have been demonstrated in adults with Ehlers-Danlos syndrome hypermobility type (EDS-HT), but whether these findings are also present in children is unclear. Therefore, the objectives of the study were to determine whether generalized hyperalgesia is present in children with hypermobility syndrome (HMS)/EDS-HT, explore potential differences in pressure-pain thresholds between children and adults with HMS/EDS-HT, and determine the discriminative value of generalized hyperalgesia. METHODS: Patients were classified in 1 of 3 groups: HMS/EDS-HT, hypermobile (Beighton score ≥4 of 9), and healthy controls. Descriptive data of age, sex, body mass index, Beighton score, skin laxity, and medication usage were collected. Generalized hyperalgesia was quantified by the average pressure-pain thresholds collected from 12 locations. Confounders collected were pain locations/intensity, fatigue, and psychological distress. Comparisons between children with HMS/EDS-HT and normative values, between children and adults with HMS/EDS-HT, and corrected confounders were analyzed with multivariate analysis of covariance. The discriminative value of generalized hyperalgesia employed to differentiate between HMS/EDS-HT, hypermobility, and controls was quantified with logistic regression. RESULTS: Significantly lower pressure-pain thresholds were found in children with HMS/EDS-HT compared to normative values (range -22.0% to -59.0%; P ≤ 0.05). When applying a threshold of 30.8 N/cm2 for males and 29.0 N/cm2 for females, the presence of generalized hyperalgesia discriminated between individuals with HMS/EDS-HT, hypermobility, and healthy controls (odds ratio 6.0). CONCLUSION: Children and adults with HMS/EDS-HT are characterized by hypermobility, chronic pain, and generalized hyperalgesia. The presence of generalized hyperalgesia may indicate involvement of the central nervous system in the development of chronic pain.

The development of the human placental villous tree.

The present investigation was undertaken in order to achieve a better understanding of the dynamics of placental villous differentiation. Villous trees from human placentas from different stages of pregnancy (first trimester to full term) were isolated and studied by light microscopy and scanning electron microscopy. For light microscopy the trees were serially sectioned and two-dimensionally reconstructed. For scanning electron microscopy complete villous trees or freeze-cracked villi were studied. The most important finding was that the mesenchymal villi are continuously newly formed out of the trophoblastic sprouts throughout pregnancy. Because of this they exist in all stages of pregnancy and have to be considered the basis for growth and differentiation of the villous trees. In the first two trimesters they are the forerunners of the immature intermediate villi, whereas in the last trimester the mesenchymal villi are transformed into mature intermediate villi. The immature intermediate villi formed during the first two trimesters are developmental steps towards the stem villi. On the other hand, the mature intermediate villi, which only are developed during the last trimester, produce numerous terminal villi. The latter are not active outgrowths caused by proliferation of the trophoblast, but rather passive protrusions induced by capillary coiling due to excessive longitudinal growth of the fetal capillaries within the mature intermediate villi.

Children with generalised joint hypermobility and musculoskeletal complaints: state of the art on diagnostics, clinical characteristics, and treatment.

INTRODUCTION: To provide a state of the art on diagnostics, clinical characteristics, and treatment of paediatric generalised joint hypermobility (GJH) and joint hypermobility syndrome (JHS). METHOD: A narrative review was performed regarding diagnostics and clinical characteristics. Effectiveness of treatment was evaluated by systematic review. Searches of Medline and Central were performed and included nonsymptomatic and symptomatic forms of GJH (JHS, collagen diseases). RESULTS: In the last decade, scientific research has accumulated on all domains of the ICF. GJH/JHS can be considered as a clinical entity, which can have serious effects during all stages of life. However research regarding the pathological mechanism has resulted in new potential opportunities for treatment. When regarding the effectiveness of current treatments, the search identified 1318 studies, from which three were included (JHS: n = 2, Osteogenesis Imperfecta: n = 1). According to the best evidence synthesis, there was strong evidence that enhancing physical fitness is an effective treatment for children with JHS. However this was based on only two studies. CONCLUSION: Based on the sparsely available knowledge on intervention studies, future longitudinal studies should focus on the effect of physical activity, fitness, and joint stabilisation. In JHS and chronic pain, the effectiveness of a multidisciplinary approach should be investigated.