Trichobezoars in children: therapeutic complications.

Trichobezoars are concretions formed by the accumulation of hair or fibers in the gastrointestinal tract, usually associated with underlying psychiatric disorders in females between 13 and 20 years old. Endoscopy, the gold standard for diagnosis, brings some additional advantages: sample taking, size reducing and, rarely, mass removal. This study shows that endoscopy can cause severe complications resulting in a surgical emergency.

[Interventionnal bronchoscopy for the treatment of tracheobronchomalacia]. / Place de la bronchoscopie interventionnelle dans la prise en charge des trachéobronchomalacies.

Tracheobronchomalacia is usually characterized by more than 50% expiratory narrowing in diameter of the trachea and the bronchi. The expiratory collapse includes two entities: (1) the TBM related to the weakness of the cartilaginous rings, and (2) the Excessive Dynamic Airway Collapse (EDAC) due to the excessive bulging of the posterior membrane. Patients have nonspecific respiratory symptoms like dyspnea and cough. Diagnosis is confirmed by dynamic tests: flexible bronchoscopy and/or computed tomographic scan of the chest. There are different forms of tracheobronchomalacia in adults: primary (genetic, idiopathic) or secondary to trauma, tracheotomy, intubation, surgery, transplantation, emphysema, infection, inflammation, chronic bronchitis, extrinsic compression; or undiagnosed in childhood vascular rings. Some management algorithms have been proposed, but no specific recommendation was established. Only symptomatic patients should be treated. Medical treatments and noninvasive positive pressure ventilation should be the first line therapy, after evaluation of various quality measures (functional status, performance status, dyspnea and quality of life scores). If symptoms persist, therapeutic bronchoscopy permits: (1) patient's selection by stent trial to determine whether patient benefit for surgical airway stabilization; (2) malacic airways stenting in patients who are not surgical candidates, improving QOL despite a high complication rate; (3) the management of stent-related complication (obstruction, plugging, migration granuloma); (4) alternative therapeutics like thermo-ablative solution. Lasty, the development of new types of stents would reduce the complication rates. These different options remained discussed.

Expression of the three human major histocompatibility complex class II isotypes exhibits a differential dependence on the transcription factor RFXAP.

Major histocompatibility complex class II (MHCII) molecules play a pivotal role in the immune system because they direct the development and activation of CD4(+) T cells. There are three human MHCII isotypes, HLA-DR, HLA-DQ, and HLA-DP. Key transcription factors controlling MHCII genes have been identified by virtue of the fact that they are mutated in a hereditary immunodeficiency resulting from a lack of MHCII expression. RFXAP-one of the factors affected in this disease-is a subunit of RFX, a DNA-binding complex that recognizes the X box present in all MHCII promoters. To facilitate identification of conserved regions in RFXAP, we isolated the mouse gene. We then delimited conserved domains required to restore endogenous MHCII expression in cell lines lacking a functional RFXAP gene. Surprisingly, we found that 80% of RFXAP is dispensable for the reactivation of DR expression. Only a short C-terminal segment of the protein is essential for this isotype. In contrast, optimal expression of DQ and DP requires a larger C-terminal segment. These results define an RFXAP domain with an MHCII isotype-specific function. Expression of the three MHCII isotypes exhibits a differential requirement for this domain. We show that this is due to a differential dependence on this domain for promoter occupation and recruitment of the coactivator CIITA in vivo.

A functionally essential domain of RFX5 mediates activation of major histocompatibility complex class II promoters by promoting cooperative binding between RFX and NF-Y.

Major histocompatibility complex class II (MHC-II) molecules occupy a pivotal position in the adaptive immune system, and correct regulation of their expression is therefore of critical importance for the control of the immune response. Several regulatory factors essential for the transcription of MHC-II genes have been identified by elucidation of the molecular defects responsible for MHC-II deficiency, a hereditary immunodeficiency disease characterized by regulatory defects abrogating MHC-II expression. Three of these factors, RFX5, RFXAP, and RFXANK, combine to form the RFX complex, a regulatory protein that binds to the X box DNA sequence present in all MHC-II promoters. In this study we have undertaken a dissection of the structure and function of RFX5, the largest subunit of the RFX complex. The results define two distinct domains serving two different essential functions. A highly conserved N-terminal region of RFX5 is required for its association with RFXANK and RFXAP, for assembly of the RFX complex in vivo and in vitro, and for binding of this complex to its X box target site in the MHC-II promoter. This N-terminal region is, however, not sufficient for activation of MHC-II expression. This requires an additional domain within the C-terminal region of RFX5. This C-terminal domain mediates cooperative binding between the RFX complex and NF-Y, a transcription factor binding to the Y box sequence of MHC-II promoters. This provides direct evidence that RFX5-mediated cooperative binding between RFX and NF-Y plays an essential role in the transcriptional activation of MHC-II genes.

Alpha 1-interferon gene transfer into metastatic Friend leukemia cells abrogated tumorigenicity in immunocompetent mice: antitumor therapy by means of interferon-producing cells.

Highly metastatic alpha/beta-interferon (IFN-alpha/beta)-resistant Friend leukemia cells (FLC) were transfected with a retroviral vector (pLTneoL-5) containing the mouse IFN-alpha 1 gene. Transfected clones were isolated and tested for their capacity to secrete IFN-alpha 1 and their tumorigenicity when injected s.c. into immunocompetent syngeneic DBA/2 mice. Almost all FLC clones producing IFN in the range of 16-512 units/ml failed to grow when injected s.c. or i.p. into normal mice, whereas control FLC (transfected with a vector without the IFN gene) exhibited the highly malignant phenotype of the original FLC. High levels of IFN were detected in peritoneal fluid, tumor extracts, and sera of mice given injections of IFN-producing cells. Injection of mice with antibodies to IFN-alpha/beta resulted in the development of tumor ascites in mice transplanted i.p. with IFN-producing FLC. In contrast to the tumor rejection observed in immunocompetent mice, IFN-producing FLC were highly tumorigenic when transplanted into immunosuppressed nude mice. Mice given injections of IFN-producing FLC developed a long-lasting tumor-specific immune resistance to subsequent injection with highly metastatic FLC. Simultaneous s.c. injection of both metastatic FLC (approximately 10(3) 50% lethal doses) and IFN-producing cells resulted in potent inhibition of the tumor growth, with a survival rate of approximately 50% for injected mice. Contralateral injection (s.c.) of IFN-producing FLC into mice with established metastatic tumors produced a marked inhibition of tumor growth, with a survival rate of 10% for injected mice. These results indicate that: (a) the genetic modification of highly metastatic FLC by means of transfer of the IFN-alpha 1 gene results in potent tumor cell rejection, which is mediated by an IFN-induced host immune response; (b) injections of IFN-producing tumor cells are effective in inhibiting tumor growth in mice with established metastatic tumors. These data suggest that tumor cells transfected with the IFN-alpha gene might be used as an effective therapy for the treatment of certain human metastatic tumors, provided that suitable strategies are defined to prevent growth of the cytokine-producing cells.

Dissection of functional NF-Y-RFX cooperative interactions on the MHC class II Ea promoter.

Transcription of major histocompatibility complex (MHC) class II genes depends upon the trimeric complexes RFX and NF-Y binding to the conserved X-Y promoter elements. We produced and purified the RFX subunits from Escherichia coli, reconstituted DNA-binding to the mouse Ea X box and dissected the interactions with NF-Y. RFX and NF-Y do not interact in solution, but make cooperative interactions in EMSA: a minimal NF-Y, composed of the evolutionary conserved domains, is sufficient and the RFXAP N-terminal half is expendable. Altering the X-Y distance abolishes cooperativity, indicating that DNA imposes severe spatial constraints. When tested on a highly positioned nucleosome, RFX binds DNA well and NF-Y does not increase its affinity further. Transfections of NF-Y subunits, but not RFX, in class II negative cells improves basal transcription and coexpression of the two activators has a synergistic effect, while modestly increasing CIITA-mediated activation. These results show that interactions between the two trimers on DNA are key to MHC class II expression.

Characterization of the two H1(zero)-encoding genes from Xenopus laevis.

We have analyzed the promoter and the coding sequences of the two homologous histone H1(zero)-encoding genes from Xenopus laevis, here termed H1(zero)-1 and H1(zero)-2. Both genes encode proteins of 193 amino acids and differ at just 16 amino-acid residues. Putative regulatory sequences identified in the promoter region are the same and are highly conserved. However, significant differences exist in the 5' untranslated regions (UTR) of the transcribed sequences of these two genes, such as several deletions in the 5'-UTR of the H1(zero)-2 gene in comparison with the H1(zero)-1 gene 5'-UTR. The 3'-UTR is a short sequence of about 200 bp which is unexpected compared with the long 3'-UTR of mammalian H1(zero) mRNA, but it is in the same size range as in avian H5 mRNA. Thus, the main differences between these two genes are observed in sequences potentially involved in the regulation of the H1(zero) gene expression such as the 5'-UTR. The two genes are expressed during embryogenesis and in several adult tissues. We discuss these findings in terms of the evolution of histone H1(zero) genes in vertebrates and the appearance of histone H5 in avian species.

X-ray evaluation of interferential femoral screw positioning in ACL reconstruction.

In a total of 27 patients the authors performed reconstruction of the anterior cruciate ligament using the mid third of the free patellar tendon (bone-tendon-bone), stabilized with two interferential wires, using a mini-arthrotomic half-tunnel in-out method. X-ray examination in two orthogonal views allows for an evaluation of the orientation of the femoral screw in relation to the joint plane and the diaphyseal axis, and its relationship with the bone graft, thus obtaining useful information on its anchoring. The method used is that reported by Lemos et al. (1993). The results obtained agree with those reported by the American author and substantiate the reliability of the method.

[Cytomegaloviral infection in autopsy material using molecular biologic methods]. / Izuchenie tsitomegalovirusnoi infektsii na sektsionnom materiale s privlecheniem molekuliarno-biologicheskikh metodov.

The results of polymerization chain reaction (PCR) and morphological study are compared. The presence of cytomegalovirus (CMV) DNA in the organs of dead children is demonstrated by PCR in 13 of 16 cases. In 3 of 13 cases structural changes typical for CMV infection were absent; slight symptoms of the damage produced by DNA-virus were present in 4 cases. The results indicate that there exist variants of CMV infection with a minimum manifestation of the infectious process. The presence of mutations in the CMV genome was revealed in 6 cases.

Laparoscopic versus open appendectomy in the management of acute appendicitis in children: a multicenter retrospective study.

AIM: Acute appendicitis is one of the most common indications for emergency surgery in children. Open appendectomy (OA) has been the gold standard treatment for over 100 years. In the last three decades, the introduction of minimally invasive techniques, such as laparoscopic appendectomy (LA) and transumbilical laparoscopically assisted appendectomy (TULAA), has changed the approach to the disease. However, there is still no agreement with benefits of these new therapeutic options, especially in children. The aim of this retrospective study is comparing the outcomes of OA, LA and TULAA in the paediatric patient. METHODS: Children suffering from acute appendicitis were treated with LA or TULAA in the Department of Paediatric Surgery and with OA in the Department of General Surgery. Data were abstracted from database of both centers' archives. Operator, operating time, length of hospitalization (LOH), intra- and postoperative complications and histological finding were analyzed. RESULTS: We recruited 196 patients: 46 treated with LA, 62 with TULAA and 88 with OA. Operative time was significantly shorter in OA. The three techniques had the same incidence of intraoperative and postoperative complications. The incidence of wound infection was higher with the TULAA approach. LOH was significantly shorter in the TULAA group. There was no correlation between LOH and histological finding. CONCLUSION: We demonstrated that LA, TULAA and OA are similar in most respects and are equally safe modalities in paediatric patients. Further randomized controlled studies are necessary.

The evolution of the differentiation-specific histone H1 gene basal promoter.

The comparison of the rat H1 zero gene promoter sequence with that of known H1 zero genes showed a high evolutionary conservation of regulatory elements involved in the control of the basal transcription of the gene. This finding suggests that the regulation of H1 zero gene expression is also controlled by a very conserved mechanism within vertebrates. In order to confirm this hypothesis, we destroyed three major cis-acting elements in the H1 zero gene promoter by site-directed mutagenesis and showed that these mutations affect significantly the activity of this promoter in cell lines representative of different vertebrate classes (fishes, amphibians, reptiles, birds, and mammals). We concluded that H1 zero gene activity, which is a developmentally regulated process, has been under a great selective pressure during evolution to ensure the expression of the protein at crucial periods of vertebrate development. One of these elements, the H4 box, helps to define within vertebrate H1 genes those encoding differentiation-specific subtypes. Indeed, it is only present in the proximal promoter region of H1 zero and H5 encoding genes. Regarding this feature of the vertebrate differentiation-specific H1 genes, they appear closer to the invertebrate (sea urchin) H1 genes than to those encoding vertebrate replication-dependent (RD) H1. This observation suggests that histone H1 zero and H5 are members that diverged from the main group of histone H1 before the vertebrate histone H1 and that the regulation of vertebrate RD H1 genes has probably evolved toward a coordinate regulation with that of core histone genes.

[Hemiplegic migraine. A series of 5 patients]. / Emicrania emiplegica. Una serie di 5 pazienti.

We describe the occurrence of five pediatric patients presenting an aura encompassing neurovegetative and unilateral neurological manifestations persisting during and after the migrainous attack are described. All investigations were normal and the symptoms completely disappeared within 24-48 hours with non specific treatment. A diagnosis of hemiplegic migraine was made. The importance is underlined for the pediatrician to consider migraine in the differential diagnosis of a child first presenting with neurological symptoms even without symptoms of migraine.

Molecular genetics of the Bare lymphocyte syndrome.

Major Histocompatibility Complex class II (MHC-II) molecules play a pivotal role in the adaptive immune system because they direct the development, activation and homeostasis of CD4+ T helper cells. Hereditary defects leading to the absence of MHC-II expression result in a severe autosomal recessive immunodeficiency disease called the Bare Lymphocyte Syndrome (BLS), also referred to as MHC-II deficiency. The genetic lesions responsible for BLS do not lie within the MHC-II locus itself, but reside instead in genes encoding transcription factors controlling MHC-II expression. Mutations in four different MHC-II regulatory genes are known to lead to BLS. These genes encode CIITA, RFXANK, RFX5 and RFXAP. CIITA (Class II Transactivator) is a transcriptional coactivator that functions as a master control factor dictating the cell type specificity, induction and level of MHC-II expression. RFXANK, RFX5 and RFXAP are the three subunits of RFX (regulatory factor X), a DNA-binding complex that binds to a conserved cis-acting sequence, the X box, present in the promoters of all MHC-II genes. Elucidation of the molecular defects underlying BLS has led to major advances in our understanding of the mechanisms regulating expression of MHC-II genes.

Synergistic anti-tumor effects of combined IL-1/IFN-alpha/beta therapy in mice injected with metastatic Friend erythroleukemia cells.

Peritumoral injection of relatively low doses of either mouse interferon (IFN)-alpha/beta (10,000-20,000 units/injection) or of recombinant human interleukin-1 (IL-1) beta (125-250 ng/injection) in mice transplanted s.c. with Friend erythroleukemia cells (FLC) resulted in some inhibition of primary tumor growth, inhibition of liver and splenic metastases and increased survival time. A synergistic anti-tumor effect was observed in mice injected with both IL-1 and IFN-alpha/beta. Highly purified mouse IFN-beta also exerted a synergistic anti-tumor effect when combined with IL-1-beta in mice injected with FLC. The anti-tumor action of IL-1/IFN was markedly reduced in mice treated with antibodies to CD4 antigens. Antibodies to asialo-GM1 also diminished the anti-tumor effect by the combined cytokine treatment. The combined IL-1/IFN therapy was effective in NK-deficient bg/bg mice, although the extent of the anti-tumor response in these mice was less than that observed in bg/+mice.

Comparison of blood lead levels in three groups of Sardinian children.

This paper reports blood lead levels in children from three Sardinian municipalities: Portoscuso, Iglesias, and Sestu. Portoscuso, chosen as the control area, is located about 2 km from one of the most important industrial complexes of the island. Iglesias was once an important zinc-lead mining centre. Sestu is a semi-urban centre located about 10 km from Cagliari (the islands's capital), and may be considered unexposed to lead pollution. Blood lead concentration was evaluated in heparinized venous blood samples by graphite furnace atomic absorption spectrophotometry. Children living in Portoscuso show a higher mean of blood lead levels (8.43 micrograms/dl) as compared to that of children of the same age living in Iglesias (6.92 micrograms/dl) and Sestu (5.71 micrograms/dl). By the Bonferroni t-tests procedure these mean differences appear to be statistically significant. The mean of PbB levels obtained in this investigation for children from Portoscuso showed a decrease of 33.62% with respect to that reported in a previous investigation carried out in 1987 (12.7 micrograms/dl).

Lessons from the bare lymphocyte syndrome: molecular mechanisms regulating MHC class II expression.

Major histocompatibility complex class II (MHCII) molecules drive the development, activation and homeostasis of CD4* T-helper cells. They play a central role in key processes of the adaptive immune system, such as the generation of T-cell-mediated immune responses, the regulation of antibody production and the development and maintenance of tol erance. It is thus not surprising that the absence of MHCII expression results in a severe primary immunodeficiency disease (the bare lymphocyte syndrome (BLS)). The genetic defects responsible for BLS do not lie within the MHCII locus, but in genes encoding transcription factors required for MHCII expression. A great deal of our current knowledge about the mechanisms regulating expression of MHCII genes has been derived from the study of BLS. Four different MHCII regulatory genes have been identified. These genes encode RFXANK, RFXS, RFXAP and CIITA. The first three are subunits of RFX, a ubiquitously expressed factor that binds to the promoters of all MHCII genes. RFX binds co-operatively with other factors to form a highly stable multiprotein complex referred to as the MHCII enhanceosome. This enhanceosome serves as a landing pad for the co-activator CIITA, which is recruited via protein-protein interactions CIITA is the master control factor for MHCII expression. The highly regulated expression pattern of CIITA ultimately dictates the cell type specificity, induction and level of MHCII expression.