[Motility disorders of the esophagus]. / Motilitätsstörungen des Ösophagus.

Motility disorders of the esophagus comprise a heterogeneous spectrum of diseases. Primary malformations of the esophagus are now amenable to improved surgical and gastroenterological therapies; however, they often lead to persistent long-term esophageal dysmotility. Achalasia originates from impaired relaxation of the gastroesophageal sphincter apparatus. Systemic diseases may give rise to secondary disorders of esophageal motility. A number of visceral neuromuscular disorders show an esophageal manifestation but aganglionosis rarely extends into the esophagus. The growing group of myopathies includes metabolic and mitochondrial disorders with increasing levels of genetic characterization and incipient emergence of therapeutic strategies. Esophagitis with an infectious etiology causes severe dysmotility particularly in immunocompromised patients. Immunologically mediated inflammatory processes involving the esophagus are increasingly better understood. Finally, rare tumors and tumor-like lesions may impair esophageal motor function.

Do NK cells contribute to the pathophysiology of transplant-associated thrombotic microangiopathy?

Transplant-associated thrombotic microangiopathy (TA-TMA) is a life-threatening complication caused by the aggregation of platelets exposed to the thrombogenic subendothelial matrix of injured endothelial cells. Here, we present a case of a patient transplanted for idiopathic aplastic anemia with a T-cell depleted hematopoietic stem cell graft from an HLA-C mismatched unrelated donor. At day 7 posttransplant, she suffered from acute renal failure with hematuria. The presence of numerous schistocytes, an increased level of lactate dehydrogenase and a renal biopsy with multiple vascular injuries confirmed the diagnosis of severe TA-TMA. At day 14, she developed graft versus host disease and died 7 months posttransplantation of multiorgan failure. At day 15, we observed a sizable population of natural killer (NK) cells in the peripheral blood, the number of which reached 0.8 G/L at 4 months posttransplant. Most NK cells lacked inhibitory killer immunoglobulin-like receptors (KIR) specific for the KIR-ligands expressed in the patient. NK cells were also abundantly present in pericardial and pleural fluids and had invaded the kidney, where they colocalized with the renal vasculopathy. Because there are several mechanisms through which NK cells and platelets can activate each other reciprocally, it is conceivable that NK cells contribute to TA-TMA and its progression.

[Trophoblastic diseases: a multidisciplinary approach, a first Swiss center]. / Maladies trophobtastiques: une prise en charge pluridisciplinaire, un premier centre suisse.

Trophoblastic diseases are rare and complex. The Center for trophoblastic diseases, the first in Switzerland, was founded in Geneva in January 2009 to formalize the collaboration between obstetricians-gynecologists, pathologists, geneticists, radiologists and oncologists. At the physician's request and with patient consent, an integrative diagnosis is proposed after centralized review of the histological slides, anti-p57KIP2 immunohistochemistry, and ploidy analysis by QF-PCR (Quantitative fluorescent polymerase chain reaction). The referring physician receives treatment and beta-hCG dosage recommendations. This pluridisciplinary diagnostic and therapeutic approach allows optimal surveillance and treatment of patients.

New insights on congenital pulmonary airways malformations revealed by proteomic analyses.

BACKGROUND: Congenital Pulmonary Airway Malformation (CPAM) has an estimated prevalence between 0.87 and 1.02/10,000 live births and little is know about their pathogenesis. To improve our knowledge on these rare malformations, we analyzed the cellular origin of the two most frequent CPAM, CPAM types 1 and 2, and compared these malformations with adjacent healthy lung and human fetal lungs. METHODS: We prospectively enrolled 21 infants undergoing surgical resection for CPAM. Human fetal lung samples were collected after termination of pregnancy. Immunohistochemistry and proteomic analysis were performed on laser microdissected samples. RESULTS: CPAM 1 and 2 express mostly bronchial markers, such as cytokeratin 17 (Krt17) or α-smooth muscle actin (ACTA 2). CPAM 1 also expresses alveolar type II epithelial cell markers (SPC). Proteomic analysis on microlaser dissected epithelium confirmed these results and showed distinct protein profiles, CPAM 1 being more heterogeneous and displaying some similarities with fetal bronchi. CONCLUSION: This study provides new insights in CPAM etiology, showing clear distinction between CPAM types 1 and 2, by immunohistochemistry and proteomics. This suggests that CPAM 1 and CPAM 2 might occur at different stages of lung branching. Finally, the comparison between fetal lung structures and CPAMs shows clearly different protein profiles, thereby arguing against a developmental arrest in a localized part of the lung.

Implication of unfavorable histology, MYCN amplification and diploidy for stage I and II neuroblastomas.

BACKGROUND: Surgery is the first line treatment for low-grade neuroblastomas. In stage I tumors, the presence of MYCN amplification is rarely detected and the Shimada histology is not always taken into consideration when deciding on the treatment. This study concerns the significance of these two factors in the evolution of children with low-grade neuroblastomas. METHODS: We analyzed the assessment and follow-up of children with low-grade neuroblastomas (stages I and II) with or without MYCN amplification, with either a favorable or unfavorable histology and with or without tumor cell diploidy. Favorable histology was defined as stroma-poor tumors with more than 5 % differentiating neuroblasts and a mitosis karyorrhexis index (MKI) of less than 100/5000 cells. RESULTS: From 1995 to 2006, out of 114 neuroblastomas, nine (7.9 %) were stage I and 21 (18.4 %) stage II. Of these 30 patients, 27 underwent surgery alone and three received chemotherapy after surgery. The combination of MYCN amplification, unfavorable histology and diploidy was noted in one patient who developed metastases within two months. MYCN amplification alone was noted in two cases who are still tumor-free after two years. Unfavorable histology alone was noted in four patients, of whom one suffered a recurrence of the tumor (previously stage I) and three are tumor-free after six years. Tumor cell diploidy alone was present in 11 patients whose evolution is satisfactory. CONCLUSION: Because MYCN amplification and unfavorable histology are rare in early stage neuroblastomas, these tumors may be misclassified if they are not investigated further. It seems that no single clinical or biological feature can be considered a significant factor in establishing a prognosis or determining whether additional treatment is required.

[Duplication of the gallbladder with heterotopic mucosa: A case report and proposal for a classification for gastrointestinal duplications]. / Duplication de la vésicule biliaire avec hétérotopie : cas clinique et proposition de classification des duplications gastro-intestinales.

BACKGROUND: Gastrointestinal duplications are rare congenital malformations that can occur anywhere between the mouth and the anus, including the digestive annexes. Numerous classifications of these malformations exist, varying from one author to another. This study describes a rare case of gallbladder duplication and suggests a unified classification of gastrointestinal duplications in order to merge epidemiological and clinical considerations. CASE REPORT: A 13-year-old boy presented with acute abdominal pain. Investigations revealed a cystic structure located in the gallbladder combined with lithiasis. Following an elective laparoscopic cholecystectomy, the diagnosis of gallbladder duplication in association with heterotopic gastrointestinal mucosa and pancreatic micro-clusters was made. The patient is in excellent health 4 years after surgery. COMMENTARY AND CONCLUSION: This atypical duplication is rare and can most likely be explained by the proximity between the pancreas and gastrointestinal tract during their development: the intestinal metaplasia and the development of the gastric mucosa may further represent congenital lesions due to aberrant migration of normal tissue, or could be secondary to a chronic inflammatory response in the gallbladder. The revised standardized classification we propose is based on the accurate identification, precise location and detailed histology of the lesions.

The NADPH oxidase NOX5 protects against apoptosis in ALK-positive anaplastic large-cell lymphoma cell lines.

Reactive oxygen species (ROS) are key modulators of apoptosis and carcinogenesis. One of the important sources of ROS is NADPH oxidases (NOXs). The isoform NOX5 is highly expressed in lymphoid tissues, but it has not been detected in any common Hodgkin or non-Hodgkin lymphoma cell lines. In diverse, nonlymphoid malignant cells NOX5 exerts an antiapoptotic effect. Apoptosis suppression is the hallmark feature of a rare type of lymphoma, termed anaplastic lymphoma kinase-positive (ALK(+)) anaplastic large-cell lymphoma (ALCL), and a major factor in the therapy resistance and relapse of ALK(+) ALCL tumors. We applied RT-PCR and Western blot analysis to detect NOX5 expression in three ALK(+) ALCL cell lines (Karpas-299, SR-786, SUP-M2). We investigated the role of NOX5 in apoptosis by small-interfering RNA (siRNA)-mediated gene silencing and chemical inhibition of NOX5 using FACS analysis and examining caspase 3 cleavage in Karpas-299 cells. We used immunohistochemistry to detect NOX5 in ALK(+) ALCL pediatric tumors. NOX5 mRNA was uniquely detected in ALK(+) ALCL cells, whereas cell lines of other lymphoma classes were devoid of NOX5. Transfection of NOX5-specific siRNA and chemical inhibition of NOX5 abrogated calcium-induced superoxide production and increased caspase 3-mediated apoptosis in Karpas-299 cells. Immunohistochemistry revealed focal NOX5 reactivity in pediatric ALK(+) ALCL tumor cells. These results indicate that NOX5-derived ROS contribute to apoptosis blockage in ALK(+) ALCL cell lines and suggest NOX5 as a potential pharmaceutical target to enhance apoptosis and thus to suppress tumor progression and prevent relapse in pediatric ALK(+) ALCL patients that resist classical therapeutic approaches.

A novel biocompatible hyaluronic acid-chitosan hybrid hydrogel for osteoarthrosis therapy.

A conventional therapy for the treatment of osteoarthrosis is intra-articular injection of hyaluronic acid, which requires repeated, frequent injections. To extend the viscosupplementation effect of hyaluronic acid, we propose to associate it with another biopolymer in the form of a hybrid hydrogel. Chitosan was chosen because of its structural similarity to synovial glycosaminoglycans, its anti-inflammatory effects and its ability to promote cartilage growth. To avoid polyelectrolyte aggregation and obtain transparent, homogeneous gels, chitosan was reacetylated to a 50% degree, and different salts and formulation buffers were investigated. The biocompatibility of the hybrid gels was tested in vitro on human arthrosic synoviocytes, and in vivo assessments were made 1 week after subcutaneous injection in rats and 1 month after intra-articular injection in rabbits. Hyaluronic acid-chitosan polyelectrolyte complexes were prevented by cationic complexation of the negative charges of hyaluronic acid. The different salts tested were found to alter the viscosity and thermal degradation of the gels. Good biocompatibility was observed in rats, although the calcium-containing formulation induced calcium deposits after 1 week. The sodium chloride formulation was further tested in rabbits and did not show acute clinical signs of pain or inflammation. Hybrid HA-Cs hydrogels may be a valuable alternative viscosupplementation agent.

Hyperammonemia and neonatal cardiac failure.

Severe hyperammonemia (hyperNH3) in neonatal cardiac failure after cardiac surgery is rare. We report a case of a 2470-g female infant born at the week 37 of gestation with complex congenital heart disease (truncus arteriosus type III, interrupted aortic arch and tricuspid valve insufficiency) and hemodynamically non-significant intrahepatic arterio-venous malformation. She developed hyperNH3 (highest NH3 blood level: 467 µmol/L) without severe liver failure (INR of 1.9). The origin of the hyperNH3 was multifactorial including limited capacity of liver detoxification function due to congenital porto-caval shunt, liver ischemia, excessive protein intake and increased protein catabolic rate. HyperNH3 treatment partially succeeded in decreasing ammonia level and included discontinuation of protein intake, administration of phenylacetate and sodium benzoate. This case highlights the fact that NH3 detoxification by the liver has limitations for a neonate with multifactorial causes that decrease liver perfusion.