Antimutagenic activity of extracts of natural substances in the Salmonella/microsome assay

Scientific information regarding plants used in folk medicine in the form of teas and their effect on human health or on genetic material has been the subject of many different types of investigation. The antimutagenic activity of two plants Maytenus ilicifolia and Peltastes peltatus, both rich in compounds of the flavonoid and tannin groups and frequently employed in folk medicine, was studied. Antimutagenicity was determined against known mutagenic substances (4-oxide-1-nitroquinoline, sodium azide, 2-nitrofluorene, aflatoxin B(1), 2-aminofluorene and 2-aminoanthracene), using the Salmonella/microsome assay. Infusions of P.peltatus showed high cytotoxicity and a co-mutagenic effect for induction of base pair substitution mutations with 4-oxide-1-nitroquinoline (-S9 mix). Infusions of M.ilicifolia produced similar effects for frameshift and base pair substitution mutations. With the mutagens 2-nitrofluorene (TA98) and sodium azide (TA100) no significant enhancement effects (co-mutagenic effects) were observed and inhibition of mutagenic activity and cytotoxicity were also diminished. In assays evaluating antimutagenic activity in the presence of metabolic activation utilizing S9 mix, high and significant inhibition of aflatoxin B(1)-, 2-aminofluorene- and 2-aminoanthracene-induced mutagenicity was observed in the presence of the infusions using both TA98 and TA100 and employing doses ranging from 25 to 500 mg/plate. Seventy-five percent of the doses tested exhibited a significant or suggestive decrease in induced mutagenicity with the infusion of M.ilicifolia. With the infusion of P.peltatus significant or suggestive antimutagenic responses were observed with 50% of the doses evaluated. Complexity was clearly noted in the responses observed in the interaction of aqueous extracts of M.ilicifolia and P.peltastes with the genetic material and metabolites generated by the S9 mix played an important role in the protection of DNA.     

Reduced folate carrier polymorphism (80A-->G) and neural tube defects

Transport of folates in mammalian cells occurs by a carrier-mediated mechanism. The human folate carrier (RFC-1) gene has been isolated and characterized. Within this gene, a common polymorphism, 80A-->G, changing a histidine to an arginine in exon 2 (H27R), was recently identified. Defects in folate metabolism, such as defective carrier molecules, could be implicated in the etiology of neural tube defects (NTDs). In the present case-control study, we recruited 174 Italian probands with nonsyndromic NTD, 43 mothers, 53 fathers and 156 control individuals and evaluated the impact of RFC-1 variant on NTD risk. A statistically significant risk was calculated for the 80GG genotype of the NTD cases (OR=2.35; 95% CI 1.21-4.58) and mothers (OR=2.74; 95% CI 0.92-8.38). On the contrary, the heterozygous genotype of the mothers and both heterozygous and homozygous genotypes of the fathers did not seem to be significant NTD risk factors. Furthemore, according to the multifactorial inheritance of NTDs, we demonstrated that the combined genotypes for MTHFR 1298A-->C and RFC-1 80A-->G polymorphisms of cases resulted in greater NTD risk than heterozygosity or homozygosity for RFC-1 80A-->G variant alone. Conversely, our data provide no evidence for an association between NTD phenotype and combined MTHFR C677T/RFC-1 A80G genotypes. Moreover, here we describe the combinations of the two MTHFR polymorphic sites (677CT and 1298AC) with RFC-1 genotypes. We found that both patients and controls could have at most quadruple-mutation combinations. Interestingly, 27% (7/26) of the mothers and 18.75% (30/160) of the cases genotyped presented four mutant alleles in comparison with 8.5% (11/129) of the controls. Finally, the frequency of NTD cases and mothers carrying combined heterozygosity for the two MTHFR polymorphisms and RFC-1 80GG homozygosity (677CT/1298AC/80GG) (cases=11.3%; mothers 11.5%) was increased compared with controls (1.6%). Altogether, our findings support the hypothesis that RFC-1 A80G variant may contribute to NTD susceptibility in the Italian population.     

Congenital infection with human herpesvirus 6 variant B associated with neonatal seizures and poor neurological outcome

Human herpesvirus 6 (HHV 6) has neurotropic and neuroinvasive properties. The virus has been found in the cerebrospinal fluid of many children with aseptic meningoencephalitis. Intrauterine transmission has been documented by HHV 6 DNA detection in cord blood specimens of apparently healthy newborns and in fetuses following spontaneous abortions. A patient is described with early neonatal afebrile seizures resulting from a congenital HHV 6 variant B infection disclosed by repeated detection of viral genome by polymerase chain reaction (PCR) in cerebrospinal fluid in the first days of life. At follow-up, magnetic resonance imaging (MRI) studies disclosed hyperintensities in the periventricular white matter and basal ganglia, associated with cerebral atrophy. Further follow-up at 18 months revealed poor neurological outcome with mild neurodevelopmental retardation, strabismus and hypertonia of legs. This report provides evidence of neurological involvement after HHV 6 vertical transmission, and the association with neurological sequelae.     

HER-2/neu and bcl-2 in ovarian carcinoma: clinicopathologic, immunohistochemical, and molecular study in patients with shorter and longer survival.

The bcl-2 protein is a membrane protein involved in prolonging cell survival by inhibiting apoptosis. The HER-2 oncogene, which is located on chromosome 17 and encodes for a tyrosine-kinase growth factor receptor, is amplified and HER-2/neu is overexpressed in 25% to 30% of breast carcinomas. The authors analyzed the bcl-2 expression and the bcl-2 gene and HER-2/neu overexpression and amplification in FIGO stage IIIC, serous, G3, ovarian carcinomas obtained from living patients who had no evident disease 5 years after primary treatment compared with ovarian carcinomas obtained from patients, matched for stage, grade of differentiation, and treatment, who had died of progression of disease no later than 2 years after primary treatment. bcl-2 overexpression was statistically correlated with progression of disease during first-line chemotherapy (P=0.021). The HER-2/neu status was found not to correlate with progression of disease during first-line chemotherapy. Both bcl-2 and HER-2/neu expression were not statistically associated with the clinical outcome of ovarian cancer patients. Gene amplification of the HER-2/neu chromosome 17 was found in all the HER-2/neu, 3+ score, positive-staining ovarian carcinomas. None of the analyzed samples revealed a translocation t(14;18)(q32;q21) in the bcl-2 gene. The knowledge of additional prognostic or even predictive factors, such as bcl-2 expression, in patients with advanced ovarian carcinoma before the primary chemotherapeutic treatment may help in the management of patients who require a more tailored treatment. In addition, the gene amplification of the HER-2/neu suggests that HER-2 is a potential target for treatment in ovarian cancer.     

Gastrointestinal zygomycosis caused by Mucor indicus in a patient with acute traumatic brain injury.

We report a gastrointestinal infection caused by Mucor indicus in a patient with severe head injuries. Monotherapy with high-dose liposomal amphotericin B successfully eradicated the mucormycosis. Nevertheless, subsequently a hemicolectomy was necessary due to recurrent bleeding from a deep ulcer. Mucor indicus is an uncommon fungal pathogen, typically found in starters used for food fermentation. Reviewing other reports on Mucor indicus infections, primary gastrointestinal manifestations seem to be typical and indicate an oral route of infection.     

The role of computational models of the immune system in designing vaccination strategies

Mathematical and computational models are designed to improve our understanding of biological phenomena, to confirm/reject hypotheses, and to find points of intervention by altering the behavior of the studied systems. Here we describe the role of mathematical/computational models of the immune system. In particular, we analyze some examples of how mathematical modeling can contribute to finding optimal vaccination strategies. Indeed, computational modeling offers an intriguing opportunity from the theoretical point of view, and it will be of interest for clinically oriented investigators who wish to find optimal therapeutic strategies and for pharmaceutical industries that want to produce effective and successful drugs.     

Correlation of epidermal growth factor receptor expression with tumor microdensity vessels and with vascular endothelial growth factor expression in ovarian carcinoma

We analyzed in advanced ovarian serous G3 carcinoma the correlation between epidermal growth factor receptor (EGFR) overexpression and tumor angiogenesis and their relation with clinical outcome. Microvessel density (MVD) and vascular endothelial growth factor (VEGF) were statistically correlated with disease-free interval and death from disease both in univariate and multivariate analyses while EGFR expression was not correlated with clinical outcome. MVD was significantly associated with progression of disease during chemotherapy while VEGF and EGFR expression were not correlated with responsiveness to chemotherapy (Fisher's exact test). VEGF expression was correlated with MVD (Fisher's exact test). EGFR showed a trend to correlation with MVD. Further studies focusing on the use of angiogenesis inhibitors in addition to EGFR inhibitors on ovarian carcinoma cells may produce therapeutic strategies in the selection of tailored therapies in ovarian cancer patients.     

IFN-gamma-enhanced allergen penetration across respiratory epithelium augments allergic inflammation

BACKGROUND: Respiratory allergen contact is the critical event in the elicitation and boosting of allergen-specific immune responses, as well as in the induction of immediate and late inflammatory reactions. OBJECTIVE: We sought to investigate the influence of various factors of allergic inflammation on the integrity and barrier function of respiratory epithelium for allergens. METHODS: We cultured the human bronchial epithelial cell line 16HBE14o- in a transwell culture system as a surrogate of intact respiratory epithelium and used purified iodine 125-labeled recombinant major birch pollen allergen (rBet v 1) to study the extent, kinetics, and factors influencing transepithelial allergen penetration. RESULTS: Culture supernatants from activated allergen-specific T H 1 clones decreased transepithelial resistance. A screening of various factors (histamine, IFN-gamma, IL-1beta, IL-2, IL-3, IL-4, IL-5, IL-8, IL-12, and TNF-alpha) identified IFN-gamma as a potent factor capable of reducing epithelial barrier properties and enhancing transepithelial allergen penetration. Increased submucosal allergen concentrations caused by IFN-gamma-mediated reduction of epithelial barrier function provoked a more than 7-fold augmentation of histamine release from sensitized basophils. CONCLUSION: These results demonstrate that the T H 1 cell-derived cytokine IFN-gamma facilitates allergen penetration through the respiratory epithelium and thereby can aggravate allergic inflammation.     

Identification of sixty-two novel and twelve known FBN1 mutations in eighty-one unrelated probands with Marfan syndrome and other fibrillinopathies

Marfan Syndrome (MFS) is an autosomal dominant disorder of the connective tissue due to mutations of Fibrillin-1 gene (FBN1) in more than 90% of cases and Transforming Growth Factor-Beta-Receptor2 gene (TGFB2R) in a minority of cases. Genotyping is relevant for diagnosis and genotype-phenotype correlations. We describe the FBN1 genotypes and related phenotypes of 81 patients who were referred to our attention for MFS or Marfan-like phenotypes. Patients underwent multidisciplinary pertinent evaluation in the adult or paediatric setting, according to their age. The diagnosis relied on Ghent criteria. To optimise DHPLC analysis of the FBN1 gene, all coding regions of the gene were directly sequenced in 19 cases and 10 controls: heterozygous amplicons were used as true positives. DHPLC sensitivity was 100%. Then, DHPLC was used to screen 62 other cases. We identified 74 FBN1 mutations in 81 patients: 64 were novel and 17 known. Of the 81 mutations, 41 were missense (50.6%), 27, either nonsense or frameshift mutations and predicted a premature termination codon (PTC) (33%), 11 affected splice sites (13.6%), and two predicted in-frame deletions (2.5%). Most mutations (67.9%) occurred in cbEGF-like modules. Genotype was clinically relevant for early diagnosis and conclusion of the diagnostic work-up in patients with incomplete or atypical phenotypes.