Comparative genomic hybridization analysis of hepatoblastoma reveals high frequency of X-chromosome gains and similarities between epithelial and stromal components

Hepatoblastoma (HB) is the most common liver tumor in childhood and differs in its environmental risk factors and genetic background from hepatocellular carcinoma. HB is associated with inherited conditions such as familial adenomatous polyposis and Beckwith-Wiedemann syndrome, suggesting the importance of genetic abnormalities in the pathogenesis and progression of this disease. It has a very polymorphous morphology. A diverse range of cytogenetic alterations has been reported to date, the most frequent being trisomy 2 and trisomy 20. Thirty-five HB specimens from 31 patients (22 purely epithelial, 4 purely mesenchymal, 9 mixed) were examined by comparative genomic hybridization (CGH), a technique that enables us to screen the entire tumor genome for genetic losses and gains. Our aims were as follows: (1) to characterize chromosome abnormalities that appear in this tumor and (2) to identify possible differences between different histologic subtypes of HB. We found significant gains of genetic material, with very little difference in the number and type of alterations between the different histologic components of HB. The most frequent alterations were gains of Xp (15 cases, 43%) and Xq (21 cases, 60%). This finding was also confirmed by fluorescent in situ hybridization performed on nuclei extracted from 6 specimens. Other common alterations were 1p-, 2q+, 2q-, 4q-, and 4q+. We found no difference between different histologic subtypes, a finding that may be in agreement with the hypothesis of a common clonal origin for the different components. An hitherto-unreported high frequency of X chromosome gains may support the assumption that X-linked genes are involved in the development of this neoplasm.     

Diagnostic value of anti-Saccharomyces cerevisiae and antineutrophil cytoplasmic antibodies for inflammatory bowel disease: high prevalence in patients with celiac disease

Both celiac disease and inflammatory bowel disease (IBD) are characterized by chronic diarrhea and the presence of distinct (auto)antibodies. In the present study we wanted to determine the prevalence of serological markers for inflammatory bowel disease, i.e., perinuclear antineutrophil cytoplasmic antibodies (pANCA) and/or anti-Saccharomyces cerevisiae antibodies (ASCA), in 37 patients with biopsy-confirmed celiac disease (Marsh IIIb/c). The majority of the patients was positive for IgA (auto)antibodies typically associated with celiac disease, i.e., antiendomysium antibodies (EMA) (86.5%), antigliadin antibodies (AGA) (73%), and antirecombinant human tissue transglutaminase antibodies (rh-tTGA) (86.5%). Four patients with selective IgA deficiency could be identified by analyzing EMA, AGA, and rh-tTGA for the IgG isotype. The prevalence of pANCA and ASCA, markers that are used for IBD, was unexpectedly high in our cohort of patients with celiac disease: 8 patients were positive for pANCA (IgG) and 16 patients were positive for ASCA (IgG and/or IgA). These results indicate that the presence of pANCA or ASCA in the serum of patients with chronic diarrhea does not exclude celiac disease. A prospective study is required to determine whether pANCA and/or ASCA identify patients at risk for developing secondary autoimmune disease.     

Sex chromosome mosaicism in couples undergoing intracytoplasmic sperm injection

BACKGROUND: Several studies have shown an increased frequency of constitutional chromosome aberrations in male and female partners of couples examined prior to ICSI. We conducted a cohort study to determine whether there was an increase in numerical sex chromosome mosaicism among couples undergoing ICSI compared with fertile couples. METHODS: Cytogenetic investigations were performed in 228 females and 208 males seen for ICSI between January 1997 and March 2001. They were matched to control females and males. RESULTS: Sex chromosome loss or gain was observed in at least one cell from 24.1% of ICSI women in comparison with 22% of controls (not significant). A significant difference between these two groups was found when X chromosome loss in at least two cells was considered, 9.6% for ICSI females versus 4.8% for controls (P = 0.01). No significant difference was observed between male groups concerning loss or gain of the X or Y chromosome. CONCLUSION: Our results support previously published studies indicating that the loss of an X chromosome in a single cell in females undergoing ICSI is probably an artefact. However, they suggest that a woman could have true sex chromosome mosaicism when two 45,X0 cells are found.     

Null mutation in human ciliary neurotrophic factor gene confers higher body mass index in males

Ciliary neurotrophic factor (CNTF) administration reduces weight in leptin-resistant mice via the signalling pathway normally activated by leptin. A G>A null mutation in the CNTF gene results in complete absence of protein. We hypothesised that absence of CNTF could lead to diminished initiation of anorectic pathways, with consequent increase in body mass. In 575 Caucasian men aged 59-73 years, the A/A genotype (frequency 1.9%) was associated with a 10 kg increase in weight (P=0.03, 2 df) and 3 kg/m(2) greater BMI (P=0.02, 2 df). There was no effect in women. The CNTF G>A null mutation therefore confers a moderate effect on obesity in males of A/A genotype, who represent 1% of the general population.     

Ras-transfection up-regulated HaCaT cell migration: Inhibition by Marimastat

Cell migration is an essential process in physiological and pathological conditions such as wound healing and tumor invasion. This phenomenon involves cell adhesion on the extracellular matrix mediated by integrins, and cell detachment promoted in part by metalloproteinases (MMPs). In the present study, the migration of two HaCaT-ras clones (metastatic or not), was compared with HaCaT cells, and normal human primary cultured keratinocytes. Using colloidal gold migration assay, the migration index on type I and type IV collagen was similar for primary cultured keratinocytes and HaCaT, whereas it was markedly higher for the HaCaT-ras clones. High motility of ras-transfected cells was confirmed from an in vitro wound healing assay. It was not correlated with changes in integrin expression or related to a different adhesion on extracellular matrix. The Marismastat (BB-2516), a MMP inhibitor, inhibited in a dose-dependent effect the migration in both assays, demonstrating the important role of MMPs in the migration process. Under our experimental conditions, MMP-1 activity was not detected in HaCaT and MMP-9 activity was secreted by these cells only after their stimulation by EGF. Here, MMP-2 was the major gelatinolytic activity secreted by all the cells and its secretion was markedly higher for HaCaT-ras clones compared with HaCaT. In addition, Western blotting results confirmed a higher expression of MMP-2 associated with a lower expression of TIMP-2 in HaCaT-ras compared with HaCaT. These results suggest that Ha-ras oncogene could be a stimulating factor of migration and might modified the balance between MMP-2 and TIMP-2 in keratinocyte cell lines. This revised version was published online in July 2006 with corrections to the Cover Date.     

Sequential Measurements of Chemokines in Urosepsis and Experimental Endotoxemia

Chemokines are a superfamily of small chemotactic proteins. While increased levels of interleukin-8 have been measured in serum and urine during urinary tract infection, little is known about other chemokines in this condition. Monocyte chemoattractant protein (MCP)–1, macrophage inflammatory protein (MIP)–1, MIP-1 and interferon- inducible protein (IP)–10 were measured in 30 patients with culture-proven urosepsis during a 3-day follow-up and in 11 healthy humans after intravenous injection of endotoxin (4 ng/kg). Urine and serum levels of MCP-1, MIP-1, and IP-10, but not of MIP-1, were elevated in patients on admission, and decreased after initiation of antibiotic treatment. Endotoxin administration to healthy subjects induced increases in plasma and urine concentrations of all four chemokines. These data indicate that clinical and experimental gram-negative infection in humans is associated with enhanced production of chemokines that act mainly on mononuclear cells and that these chemokines are at least in part locally produced.     

Fate of the type II pneumocyte following tracheal occlusion in utero: a time-course study in fetal sheep

 Tracheal occlusion in utero has been shown to cause accelerated fetal lung growth and is now being considered as a therapeutic modality for pulmonary hypoplasia. We report the effects of tracheal ligation on the surfactant-producing type II pneumocyte population. Three groups of fetal lambs underwent tracheal ligation of 2 weeks’, 4 weeks’ and 6 weeks’ duration, respectively, and all were sacrificed at 136 days’ gestation (9 days pre-term). Nonoperated twins served as controls. The type II pneumocyte population was studied morphometrically using a combination of anti-surfactant protein B immunohistochemistry and computer-assisted stereologic morphometry at light and electron microscopic levels. Single-factor ANOVA was used for statistical analysis. Two weeks of tracheal ligation resulted in doubling of the total lung volume as a result of airspace distension and, to lesser extent, growth of the tissue compartment. With increasing duration of tracheal ligation, there was no additional lung growth. However, more prolonged tracheal occlusion was found to result in significant reduction of the surfactant system, as reflected in the marked decrease of total pneumocyte type II volume (3.14 cm³, 0.95 cm³, and 0.46 cm³, after 2, 4, and 6 weeks of ligation, compared with 5.96 cm³ for controls) and total pneumocyte type II number (13.9 × 10⁹, 3.8 × 10⁹, and 2.4 × 10⁹, compared with 53.2 × 10⁹ for controls). Ultrastructural analysis of the type II cells in obstructed lungs showed vacuolar degenerative changes that, after 6 weeks of ligation, were apparently irreversible. In utero tracheal ligation causes fetal lung hyperplasia, but results in reduction of and injury to the surfactant-producing cell population. Before tracheal occlusion can find widespread clinical application, its pathophysiology needs to be further elucidated. Received: 30 April 1997 / Accepted: 10 July 1997     

Contribution of HLA class II genes to susceptibility in achalasia

Abstract: Achalasia is a motor disorder of the esophagus resulting in functional obstruction. The cause of the lesion is unknown although genetic and immunologic factors have been suggested. An association with serological HLA epitopes has been previously reported. In this study, we have further examined this HLA class II association with susceptibility to achalasia by DNA based methods. Achalasia patients ( n =40) and healthy controls ( n = 275), all Caucasians and unrelated, were included in the analysis. The strongest associations were with HLA-DQAl*0101 and two HLA-DQαβ heterodimers having their a chain encoded by this allele. Moreover, relative risk was significantly higher in DQAl*0101 homozygotes as compared to heterozygotes and results suggested that DQB1*02 may have a protective role.     

Probiotic lactobacilli: an innovative tool to correct the malabsorption syndrome of vegetarians?

Vegetarians may have subtle nutritional deficiencies which have been related to the occurrence of an unrecognized malabsorption syndrome. The excess phytate content in cereals, nuts, legumes and oilseeds which represent the mainstay of their food intake, seems to play a central role in the pathogenesis of this malabsorption syndrome as an inverse relationship has been shown to link the phytate content of the diet with the intestinal absorption of trace minerals and proteins. We postulate that manipulating the endogenous digestive microflora of subjects on a vegetarian diet through administering probiotic lactic bacteria would represent an innovative tool to counteract the occurrence of the malabsorption syndrome dependent on the high phytate content of their diet. Even though there are no data about the composition of endogenous digestive microflora in subjects on a vegetarian diet, we expect that probiotic lactobacilli can interact with or affect distinct yet interrelated components within the intestinal milieu, such as epithelial cells, enteric flora, and/or mucosal immune cells. This would ultimately translate into the correction of the unregulated mechanisms implicated in the altered intestinal absorption of trace metals and proteins commonly seen in vegetarians. Clinical experience with probiotic therapy of patients with inflammatory bowel disease fully agrees with this view. One additional point of interest is that probiotic lactobacilli, and other species of the endogenous digestive microflora as well, are an important source of the enzyme phytase which catalyses the release of phosphate from phytate and hydrolyses the complexes formed by phytate and metal ions or other cations, rendering them more soluble ultimately improving and facilitating their intestinal absorption. The regular intake of probiotic preparation, may represent a cheap and safe tool in order to convert a diet with a low potential for bioavailability of trace minerals and proteins, such as the vegetarian diet, into a diet with a high bioavailability potential. The benefit of such an approach would not be restricted to vegetarians.