The curious case of Gαs gain-of-function in neoplasia.

BACKGROUND: Mutations activating the α subunit of heterotrimeric Gs protein are associated with a number of highly specific pathological molecular phenotypes. One of the best characterized is the McCune Albright syndrome. The disease presents with an increased incidence of neoplasias in specific tissues. MAIN BODY: A similar repertoire of neoplasms can develop whether mutations occur spontaneously in somatic tissues during fetal development or after birth. Glands are the most "permissive" tissues, recently found to include the entire gastrointestinal tract. High frequency of activating Gαs mutations is associated with precise diagnoses (e.g., IPMN, Pyloric gland adenoma, pituitary toxic adenoma). Typically, most neoplastic lesions, from thyroid to pancreas, remain well differentiated but may be a precursor to aggressive cancer. CONCLUSIONS: Here we propose the possibility that gain-of-function mutations of Gαs interfere with signals in the microenvironment of permissive tissues and lead to a transversal neoplastic phenotype.

Diaphragmatic hernia in a pediatric emergency department.

Diaphragmatic hernia in pediatric emergency department poses a diagnostic challenge because of the acute or subtle timing of onset and the wide variety of clinical features. We describe 3 different late presentations of Bochdalek diaphragmatic hernia in a pediatric emergency department. These reports may help physicians avoid delayed diagnosis of late-presenting congenital diaphragmatic hernia, thereby reducing the risk of inappropriate treatments and life-threatening conditions in children.

Hypercapnia and acidosis during open and thoracoscopic repair of congenital diaphragmatic hernia and esophageal atresia: results of a pilot randomized controlled trial.

OBJECTIVE: We aimed to evaluate the effect of thoracoscopy in neonates on intraoperative arterial blood gases, compared with open surgery. BACKGROUND: Congenital diaphragmatic hernia (CDH) and esophageal atresia with tracheoesophageal fistula (EA/TEF) can be repaired thoracoscopically, but this may cause hypercapnia and acidosis, which are potentially harmful. METHODS: This was a pilot randomized controlled trial. The target number of 20 neonates (weight > 1.6 kg) were randomized to either open (5 CDH, 5 EA/TEF) or thoracoscopic (5 CDH, 5 EA/TEF) repair. Arterial blood gases were measured every 30 minutes intraoperatively, and compared by multilevel modeling, presented as mean and difference (95% confidence interval) from these predictions. RESULTS: Overall, the intraoperative PaCO2 was 61 mm Hg in open and 83 mm Hg [difference 22 mm Hg (2 to 42); P = 0.036] in thoracoscopy and the pH was 7.24 in open and 7.13 [difference -0.11 (-0.20 to -0.01); P = 0.025] in thoracoscopy. The duration of hypercapnia and acidosis was longer in thoracoscopy compared with that in open. For patients with CDH, thoracoscopy was associated with a significant increase in intraoperative hypercapnia [open 68 mm Hg; thoracoscopy 96 mm Hg; difference 28 mm Hg (8 to 48); P = 0.008] and severe acidosis [open 7.21; thoracoscopy 7.08; difference -0.13 (-0.24 to -0.02); P = 0.018]. No significant difference in PaCO2, pH, or PaO2 was observed in patients undergoing thoracoscopic repair of EA/TEF. CONCLUSIONS: This pilot randomized controlled trial shows that thoracoscopic repair of CDH is associated with prolonged and severe intraoperative hypercapnia and acidosis, compared with open surgery. These findings do not support the use of thoracoscopy with CO2 insufflation and conventional ventilation for the repair of CDH, calling into question the safety of this practice. The effect of thoracoscopy on blood gases during repair of EA/TEF in neonates requires further evaluation. (ClinicalTrials.gov Identifier: NCT01467245).

G Protein-Coupled Receptors and the Rise of Type 2 Diabetes in Children.

The human genome counts hundreds of GPCRs specialized to sense thousands of different extracellular cues, including light, odorants and nutrients in addition to hormones. Primordial GPCRs were likely glucose transporters that became sensors to monitor the abundance of nutrients and direct the cell to switch from aerobic metabolism to fermentation. Human ß cells express multiple GPCRs that contribute to regulate glucose homeostasis, cooperating with many others expressed by a variety of cell types and tissues. These GPCRs are intensely studied as pharmacological targets to treat type 2 diabetes in adults. The dramatic rise of type 2 diabetes incidence in pediatric age is likely correlated to the rapidly evolving lifestyle of children and adolescents of the new century. Current pharmacological treatments are based on therapies designed for adults, while youth and puberty are characterized by a different hormonal balance related to glucose metabolism. This review focuses on GPCRs functional traits that are relevant for ß cells function, with an emphasis on aspects that could help to differentiate new treatments specifically addressed to young type 2 diabetes patients.

cAMP Response Element-Binding Protein Controls the Appearance of Neuron-Like Traits in Chorion Mesenchymal Cells.

BACKGROUND: Mesenchymal stromal cells (MSC) from bone marrow have been reported to undergo the initial phases of neural differentiation in response to an increase of intracellular cAMP. We investigated the possibility that a similar effect applies to chorion-derived MSC. METHODS: The intracellular concentration of cAMP was increased either by forskolin, to promote its synthesis, or by inhibitors of its degradation. The consequent reduction in the expression of mesenchymal markers was associated with the appearance of neuron-like morphology in a subset of cells. The effect was measured and characterized using biomarkers and an inhibitor of cAMP response element-binding protein (CREB). RESULTS: The dramatic morphological change induced by all the treatments that promoted intracellular cAMP was transient and peaked on the third day. After that, cells returned to the typical fibroblast-like appearance within 24 hours. The distinctive morphology was associated to the expression of neuregulin 1, doublecortin, neuron-specific class III ß-tubulin, and required cAMP response element-binding protein activity. Basic-fibroblast growth factor (b-FGF) treatment increased both the timeframe and number of cells undergoing the morphological change induced by the effect of forskolin. As opposite, arginine-vasopressin (AVP) and sphingosine-1-phosphate (S1P) reduced it. CONCLUSIONS: We conclude that cAMP and the ensuing CREB activation trigger a preliminary step towards neuronal differentiation of chorion-derived MSC. However, likewise other MSC, the stimulus is not sufficient to promote stable differentiation.

Gα15 in early onset of pancreatic ductal adenocarcinoma.

The GNA15 gene is ectopically expressed in human pancreatic ductal adenocarcinoma cancer cells. The encoded Gα15 protein can promiscuously redirect GPCR signaling toward pathways with oncogenic potential. We sought to describe the distribution of GNA15 in adenocarcinoma from human pancreatic specimens and to analyze the mechanism driving abnormal expression and the consequences on signaling and clinical follow-up. We detected GNA15 expression in pre-neoplastic pancreatic lesions and throughout progression. The analysis of biological data sets, primary and xenografted human tumor samples, and clinical follow-up shows that elevated expression is associated with poor prognosis for GNA15, but not any other GNA gene. Demethylation of the 5' GNA15 promoter region was associated with ectopic expression of Gα15 in pancreatic neoplastic cells, but not in adjacent dysplastic or non-transformed tissue. Down-modulation of Gα15 by shRNA or CRISPR/Cas9 affected oncogenic signaling, and reduced adenocarcimoma cell motility and invasiveness. We conclude that de novo expression of wild-type GNA15 characterizes transformed pancreatic cells. The methylation pattern of GNA15 changes in preneoplastic lesions coincident with the release a transcriptional blockade that allows ectopic expression to persist throughout PDAC progression. Elevated GNA15 mRNA correlates with poor prognosis. In addition, ectopic Gα15 signaling provides an unprecedented mechanism in the early steps of pancreas carcinogenesis distinct from classical G protein oncogenic mutations described previously in GNAS and GNAQ/GNA11.

Images from 18F-DOPA Scan in Congenital Hyperinsulinism: Not Always a Clue for Diagnosis.

Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycaemia in childhood (Horm Res 70:65-72, 2008; J Clin Endocr Metab 93:869-875, 2008). 18-Fluoro-L-dihydroxy-phenylalanine (18F-DOPA) positron emission tomography (PET) can detect areas of increased activity in the pancreas and may differentiate focal from diffuse CHI (J Clin Endocr Metab 93:869-875, 2008; Radiology 253:216-222, 2009). We here report the case of a girl who complained of recurrent episodes of severe hypoglycaemia despite previous partial pancreatectomy. To evaluate the need for additional surgical intervention, we performed 18F-DOPA PET/computed tomography (CT), which showed a focal lesion corresponding to the anatomical region of the pancreatic tail. On the other hand, abdominal magnetic resonance imaging (MRI) clearly demonstrated that the 18F-DOPA uptake was in a loop of bowel occupying the previous surgical bed. Our case highlights that bowel uptake can be a possible pitfall in the interpretation of 18F-DOPA PET/CT in children affected by CHI, suggesting that when 18F-DOPA PET/CT results do not fit the clinical picture, magnetic resonance imaging (MRI) may allow a more accurate correlation of the radiotracer activity with the underlying anatomical or pathological structure.

Pleiotropic effects of sphingosine-1-phosphate signaling to control human chorionic mesenchymal stem cell physiology.

Chorionic stem cells represent a promising opportunity for regenerative medicine. A deeper understanding of the stimuli that regulate their physiology, could lead to innovative clinical approaches. We revealed the presence of multiple sphingosine-1-phosphate (S1P) receptor isoforms in chorion-derived mesenchymal stem cells (CMSCs). Their activation simultaneously propagated from the plasma membrane through Gi and other heterotrimeric G proteins and further diverged toward extracellular-signal-regulated kinase 1/2 (ERK1/2), p38 and protein kinase D 1. At a functional level, S1P signaling inhibited CMSC migration, while promoting proliferation. Instead, a reduction of cell density was obtained when S1P was combined to treatments that increased cAMP intracellular concentration. Such surprising reduction of cell viability was relatively specific as it was not observed with stromal stem cells from bone marrow. Neither it was observed by activating analogous G proteins with bradykinin nor by inducing cell death via a cAMP-independent pathway. S1P could thus reveal novel keys to improve CMSC differentiation programs acting on cAMP concentration. Furthermore, S1P receptor agonists/antagonists could become instrumental in favoring CMSC engraftment by controlling cell motility.

GNAS Mutations: Drivers or Co-Pilots? Yet, Promising Diagnostic Biomarkers.

Over 25 years ago, GNAS mutations were discovered associated with McCune-Albright syndrome (MAS) and pituitary tumors. The mutant gene, encoding the heterotrimeric Gs protein, was named 'derived from Gs Protein' (gsp) oncogene. For a long time, gsp remained associated with specific endocrine tumors. Recently, high frequencies of gsp were reported for a rapidly growing number of neoplasms in the gastrointestinal tract. Will heterotrimeric G-proteins follow small G-proteins and become recognized as cancer biomarkers and therapeutic targets?

Wandering spleen with a ten-time twisted vascular pedicle.

Torsion of a wandering spleen is a rare cause of acute abdomen in children, usually diagnosed with color-Doppler ultrasonography and enhanced computed tomography. We report a pediatric case of torsion of wandering spleen.

Immune regulatory properties of CD117(pos) amniotic fluid stem cells vary according to gestational age.

Amniotic Fluid Stem (AFS) cells are broadly multipotent fetal stem cells derived from the positive selection and ex vivo expansion of amniotic fluid CD117/c-kit(pos) cells. Considering the differentiation potential in vitro toward cell lineages belonging to the three germ layers, AFS cells have raised great interest as a new therapeutic tool, but their immune properties still need to be assessed. We analyzed the in vitro immunological properties of AFS cells from different gestational age in coculture with T, B, and natural killer (NK) cells. Nonactivated (resting) first trimester-AFS cells showed lower expression of HLA class-I molecules and NK-activating ligands than second and third trimester-AFS cells, whose features were associated with lower sensitivity to NK cell-mediated lysis. Nevertheless, inflammatory priming with interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) enhanced resistance of all AFS cell types to NK cytotoxicity. AFS cells modulated lymphocyte proliferation in a different manner according to gestational age: first trimester-AFS cells significantly inhibited T and NK cell proliferation, while second and third trimester-AFS cells were less efficient. In addition, only inflammatory-primed second trimester-AFS cells could suppress B cell proliferation, which was not affected by the first and third trimester-AFS cells. Indolamine 2,3 dioxygenase pathway was significantly involved only in T cell suppression mediated by second and third trimester-AFS cells. Overall, this study shows a number of significant quantitative differences among AFS cells of different gestational age that have to be considered in view of their clinical application.

Comparative study of immune regulatory properties of stem cells derived from different tissues.

Allogeneic stem cell (SC)-based therapy is a promising tool for the treatment of a range of human degenerative and inflammatory diseases. Many reports highlighted the immune modulatory properties of some SC types, such as mesenchymal stromal cells (MSCs), but a comparative study with SCs of different origin, to assess whether immune regulation is a general SC property, is still lacking. To this aim, we applied highly standardized methods employed for MSC characterization to compare the immunological properties of bone marrow-MSCs, olfactory ectomesenchymal SCs, leptomeningeal SCs, and three different c-Kit-positive SC types, that is, amniotic fluid SCs, cardiac SCs, and lung SCs. We found that all the analyzed human SCs share a common pattern of immunological features, in terms of expression of activation markers ICAM-1, VCAM-1, HLA-ABC, and HLA-DR, modulatory activity toward purified T, B, and NK cells, lower immunogenicity of inflammatory-primed SCs as compared to resting SCs, and indoleamine-2,3-dioxygenase-activation as molecular inhibitory pathways, with some SC type-related peculiarities. Moreover, the SC types analyzed exert an anti-apoptotic effect toward not-activated immune effector cells (IECs). In addition, we found that the inhibitory behavior is not a constitutive property of SCs, but is acquired as a consequence of IEC activation, as previously described for MSCs. Thus, immune regulation is a general property of SCs and the characterization of this phenomenon may be useful for a proper therapeutic use of SCs.

Decreased cerebral oxygen saturation during thoracoscopic repair of congenital diaphragmatic hernia and esophageal atresia in infants.

BACKGROUND/PURPOSE: Congenital diaphragmatic hernia (CDH) and esophageal atresia with tracheoesophageal fistula (EA/TOF) can be repaired thoracoscopically, but this may cause hypercapnia, acidosis, and reduced cerebral oxygenation. We evaluated the effect of thoracoscopy in infants on cerebral oxygen saturation (cSO(2)), arterial blood gases, and carbon dioxide (CO(2)) absorption. METHODS: Eight infants underwent thoracoscopy (6 CDH and 2 EA/TOF). Serial arterial blood gases were taken. Regional cSO(2) was measured using near-infrared spectroscopy. Absorption of insufflated CO(2) was calculated from exhaled (13)CO(2)/(12)CO(2) ratio measured by mass spectrometry. RESULTS: CO(2) absorption increased during thoracoscopy with a maximum 29% ± 6% of exhaled CO(2) originating from the pneumothorax. Paco(2) increased from 9.4 ± 1.3 kPa at the start to 12.4 ± 1.0 intraoperatively and then decreased to 7.6 ± 1.2 kPa at end of operation. Arterial pH decreased from 7.19 ± 0.04 at the start to 7.05 ± 0.04 intraoperatively and then recovered to 7.28 ± 0.06 at end of operation. Cerebral hemoglobin oxygen saturation decreased from 87% ± 4% at the start to 75% ± 5% at end of operation. This had not recovered by 12 (74% ± 4%) or 24 hours (73% ± 3%) postoperatively. CONCLUSIONS: This preliminary study suggests that thoracoscopic repair of CDH and EA/TOF may be associated with acidosis and decreased cSO(2). The effects of these phenomena on future brain development are unknown.

Thoracoscopic repair of congenital diaphragmatic hernia: intraoperative ventilation and recurrence.

INTRODUCTION: Thoracoscopic repair of congenital diaphragmatic hernia (CDH) has been described, but its efficacy and safety have not been validated. The aim was to compare our experience of thoracoscopy with laparotomy repair. METHODS: After ethics approval, we reviewed the notes of neonates with CDH operated in our institution between 2003 and 2008. Two historical groups were compared: infants who underwent laparotomy (2003-2008) or thoracoscopy (2007-2008). Data were compared by t test or Mann-Whitney tests. RESULTS: Thirty-five children had open repair of CDH, and 13 had thoracoscopic repair. Groups were homogeneous for age and weight. Five (38%) neonates who had thoracoscopy were converted to open for surgical difficulties (n = 4) and O(2) desaturation (n = 1). Patch repair was used in 12 (34%) open and 6 (46%) thoracoscopic repairs. End-tidal CO(2) was significantly elevated during thoracoscopy, but this was not reflected in arterial CO(2) or pH. There were 3 (8%) recurrences after open repair and 2 (25%) after thoracoscopy (P = .19). CONCLUSION: Thoracoscopic repair of CDH is feasible. Arterial blood gases should be closely monitored. Despite higher EtCO(2), conversion to open was mainly because of difficult repair. A randomized trial is necessary to assess the effect of thoracoscopy on ventilation and recurrences.

Carbon dioxide absorption and elimination in breath during minimally invasive surgery.

Carbon dioxide (CO(2)) is the gas most commonly used to inflate the body cavities during 'keyhole' surgery (e.g. laparoscopy and thoracoscopy). However, CO(2) can be absorbed, leading to increased arterial CO(2) and increased CO(2) elimination from the lungs. These increases in CO(2) are observed following a wide variety of procedures both in adults and in infants and children. Although it is usually assumed that increases in arterial or end-tidal CO(2) directly reflect absorption of CO(2) from body cavities, this is not necessarily true, as either increases in metabolically produced CO(2) or respiratory compromise making it more difficult to eliminate CO(2) could also be responsible for these changes. Recently, a new technique has been introduced which enables absorbed CO(2) to be distinguished from metabolic CO(2).

Ductal carcinoma in situ in a 15-year-old boy with gynaecomastia: a case report.

Carcinoma in situ of the male breast is rare, especially when associated with bilateral gynaecomastia and during puberty. Only two cases in adults and one during puberty have been described in the literature. We present the case of a 15-year-old boy whom we have been observing for about 2 years for puberal bilateral gynaecomastia, treated with bilateral exeresis of the mammary gland and subsequently re-operated with total bilateral mastectomy because the tissue removed presented atypical features upon histological examination. The authors believe, after a careful review of relevant literature, that this is the second case of intraductal carcinoma in the presence of gynaecomastia described during adolescence.

Phimosis: stretching methods with or without application of topical steroids?

Phimosis has been defined as unretractable foreskin without adherences or a circular band of tight prepuce preventing full retraction. We suggested a new treatment protocol combining betamethasone with stretching exercises to reduce the number of patients requiring surgery for phimosis. Between January 2003 and September 2004, 247 boys aged 4 to 14 years (mean 7.6) were included in this consecutive, prospective, open study. Patients were treated with 0.05% betamethasone cream applied to the distal aspect of the prepuce twice daily for the first 15 days, then once daily for 15 more days. Preputial gymnastics started 1 week after topical application of betamethasone. Ninety-six percent of patients receiving 1 or more cycles of betamethasone showed complete resolution of phimosis. There was a significant difference (P < .001) in response rate between the study and control groups. Only 10 boys in the study group had no response to steroid and stretching. Treatment with topical steroids, combined with stretching exercises, is a suitable alternative to surgical correction (preputial plasty/circumcision).

Varicocele and retrograde adrenal metabolites flow. An experimental study on rats.

BACKGROUND: Idiopathic varicocele is one of the causes of potentially correctable male subfertility. The mechanisms causing spermatogenesis impairment have yet to be clarified. The aim of this study is to analyze the effects of renal and adrenal metabolite reflux on testicular exocrine function in a rat experimental model. MATERIALS AND METHODS: In the study, 45 male Lewis Stock adult rats, each weighing 300 g, were used. The rats were subdivided into three groups of 15 rats. In group A (control group) testicular volume and basal follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels were measured at the beginning of the study and after 9 months. In group B, varicocele was induced by means of rings introduced in the left renal vein in order to cause a renospermatic reflux. In group C, similarly to group B, varicocele was induced after removal of left adrenal gland. The effects of varicocele on testicular function were then analyzed 3, 6 and 9 months after surgery. After 9 months, all rats underwent testicular biopsy. RESULTS: Both groups B and C showed a reduction in testicular volume, an increase in FSH and a decrease in testosterone levels. These levels were higher in group B. Testicular histological assessment showed important structural abnormalities in group B rats. CONCLUSIONS: These data support the hypothesis that renal and adrenal metabolites enhance varicocele-induced testicular damage. This theory is supported both by hormonal impairment and testicular histological analysis.