Monte Carlo GEANT4-based application for in vivo RBE study using small animals at LNS-INFN preclinical hadrontherapy facility.

Preclinical studies represent an important step towards a deep understanding of the biological response to ionizing radiations. The effectiveness of proton therapy is higher than photons and, for clinical purposes, a fixed value of 1.1 is used for the relative biological effectiveness (RBE) of protons considered 1.1. Recent in vitro studies have reported that the RBE along the spread-out Bragg peak (SOBP) is not constant and, in particular, the RBE value increases on the distal part of SOBP. The present work has been carried-out in the perspective of a preclinical hadrontherapy facility at LNS-INFN and was focused on the experimental preparation of an in vivo study concerning the RBE variation along the SOBP. The main purpose of this work was to determine, using GEANT4-based Monte Carlo simulations, the best configuration for small animal treatments. The developed GEANT4 application simulates the proton-therapy beam line of LNS-INFN (CATANA facility) and allows to import the DICOM-CT images as targets. The RBE will be evaluated using a deterministic radiation damage like myelopathy as end-point. In fact, the dose at which the 50% of animals will show the myelopathy is supposed to be LET-dependent. In this work, we studied different treatment configurations in order to choose the best two that maximize the LET difference reducing as much as possible the dose released to healthy tissue. The results will be useful to plan hadrontherapy treatments for preclinical in vivo studies and, in particular, for the future in vivo RBE studies.

Increased frequency of 20q gain and copy-neutral loss of heterozygosity in mismatch repair proficient familial colorectal carcinomas.

Many hereditary nonpolyposis colorectal cancers (CRCs) cannot be explained by Lynch syndrome. Other high penetrance genetic risk factors are likely to play a role in these mismatch repair (MMR)-proficient CRC families. Because genomic profiles of CRC tend to vary with CRC susceptibility syndromes, our aim is to analyze the genomic profile of MMR-proficient familial CRC to obtain insight into the biological basis of MMR-proficient familial CRC. We studied 30 MMR-proficient familial colorectal carcinomas, from 15 families, for genomic aberrations, including gains, physical losses, and copy-neutral loss of heterozygosity LOH (cnLOH) using SNP array comparative genomic hybridization. In addition, we performed somatic mutation analysis for KRAS, BRAF, PIK3CA and GNAS. The frequency of 20q gain (77%) is remarkably increased when compared with sporadic CRC, suggesting that 20q gain is involved in tumor progression of familial CRC. There is also a significant increase in the frequency of cnLOH and, as a consequence, a reduced frequency of physical loss compared with sporadic CRC. The most frequent aberrations observed included gains of 7p, 7q, 8q, 13q, 20p and 20q as well as physical losses of 17p, 18p and 18q. Most of these changes are also observed in sporadic CRC. Mutations in KRAS were identified in 37% of the MMR-proficient CRCs, and mutations in BRAF were identified in 16%. No mutations were identified in PIK3CA or chromosome 20 candidate gene GNAS. We show that the patterns of chromosomal instability of MMR-proficient familial CRC are clearly distinct from those from sporadic CRC. Both the increased gain on chromosome 20 and the increased levels of cnLOH suggest the presence of yet undiscovered germline defects that can, in part, underlie the cancer risk in these families.

Analysis of IL-6, IL-10 and IL-17 genetic polymorphisms as risk factors for sepsis development in burned patients.

Infection risk, sepsis and mortality after severe burn are primarily determined by patient age, burn size, and depth. Whether genetic differences contribute to otherwise unexpected variability in outcomes is unknown. We sought to determine whether there was an association between IL-6, IL-10 and IL-17 polymorphisms with cytokine production and development of sepsis. We evaluated 71 patients with burns ≥15% TBSA and 109 healthy subjects. The genotypes of IL-6 (-174C/G), IL-10 (-819C/T and -1082A/G) and IL-17 (7488T/C) polymorphisms were identified applying polymerase chain reaction protocols. The cytokine levels in serum were determined with enzyme-linked immunoabsorbent assays. Our results demonstrated no significant differences in the genotype frequencies studied between burn patients and healthy subjects. No significant associations were found among IL-6 and IL-17F genotypes and the related cytokine serum levels. Only IL-10 promoter -1082GG genotype was related to an increased IL-10 production in burned patients. In addition, septic subjects bearing -1082G/G genotype have shown the highest and non-septic bearing -1082A/* genotypes the lowest IL-10 serum levels. All together these data seem to indicate that genetically determined individual difference in IL-10 production might influence the susceptibility to septic complications in burned patients and suggest that these markers might be useful in burned patient management.

Risk profiles in type 2 diabetes (metabolic syndrome): integration of IL-10 polymorphisms and laboratory parameters to identify vascular damages related complications.

Recently it has been reported that low serum IL-10 levels are associated with an increased susceptibility for metabolic syndrome and type 2 diabetes mellitus (T2DM). We investigated whether the -1087G/A (rs1800896), -824C/T (rs1800871), -597C/A (rs1800872) IL-10 polymorphisms were associated with type 2 diabetes in a study on a cohort of Italian Caucasians comprising 490 type 2 diabetic and 349 control subjects. Stratifying the data according to IL-10 genotypes, trends for the progressive increase of glucose and neutrophil levels were observed in -1087GG vs. -1087GA vs. -1087AA positive diabetic patients (-1087GG<-1087GA<-1087AA). In addition, evaluating the laboratory parameters according to the -597/-824/-1087 derived haplotypes a significant increase of neutrophils was found in diabetic vs. non-diabetic -597A/ -824T/-1087A positive subjects (Student t test = 3.707, p<0.01). In an attempt to integrate clinical laboratory and immunogenetic data to determine whether these factors taken together define sufficient risk sets for type 2 diabetes we performed the grade-of-membership analysis (GoM). GoM allowed to identify a population of subjects negative for IL-10 -824T allele, 74.4% of which were diabetic patients characterised by vascular damages (Chronic kidney failure and/or Myocardial Infarction), reduction of haematocrit, increase of blood urea nitrogen, creatinin and monocyte levels. These data seem to suggest that -597A/-824T/-1087A negative subjects are more prone to the major type 2 diabetic vascular damages and allow to hypothesise that the contemporary evaluation of some simple hematochemical parameters and IL-10 SNPs may allow identifying diabetic patients with the worse prognostic profile, needing both better complication prevention planning and therapeutic strategies.

Evaluation of cytokine polymorphisms (TNFalpha, IFNgamma and IL-10) in Down patients with coeliac disease.

BACKGROUND: In Down syndrome there is an increased prevalence of coeliac disease, but the reasons for this association are yet unknown. AIMS: To evaluate a possible correlation between TNFalpha, IFNgamma and IL-10 genotype polymorphisms with the susceptibility to coeliac disease in Down syndrome patients. METHODS: Single nucleotide polymorphisms of TNFalpha (-308G-->A promoter region), IFNgamma (+874T-->A promoter region) and IL-10 (-1082G-->A promoter region) have been studied in 10 Down patients with coeliac disease, in 40 Down patients without coeliac disease and in 220 healthy controls. Clinical features were also studied in coeliac disease-Down syndrome patients. RESULTS: The 10 coeliac disease-Down syndrome patients had a biopsy proven coeliac disease afterward a serological testing positive to antigliadin, antiendomysium and antitransglutaminase antibodies. Intestinal biopsy showed total atrophy in 6/10 and partial villous atrophy in 4/10 of them. All coeliac disease-Down syndrome patients had silent forms of coeliac disease and classical trisomy 21. No significant differences were observed for the IFNgamma and IL-10 polymorphisms in the studied groups. A significant trend for increase of TNFalpha -308A positive frequency was observed in coeliac disease-Down syndrome patients compared to healthy controls (p=0.043). CONCLUSIONS: Single nucleotide polymorphisms of IFNgamma and IL-10 do not play a role in predisposing Down syndrome patients to coeliac disease, while the TNFalpha -308 allele could be an additional genetic risk factor for coeliac disease in trisomy 21.

TNFalpha, IFNgamma and IL-10 gene polymorphisms in a sample of Sicilian patients with coeliac disease.

BACKGROUND: Coeliac disease is associated with DQ2 and DQ8 alleles, but other genes also confer an additional genetic risk. AIMS: Defining whether the genetic profiles of interleukin-10, tumour necrosis factor alpha and interferon gamma are associated with an increased coeliac disease risk. PATIENTS AND METHODS: The functionally gene polymorphisms of tumour necrosis factor alpha (-308G/A), interferon gamma (+874T/A) and interleukin-10 (-1082G/A) were typed using sequence specific primer-polymerase chain reaction in 110 Sicilian coeliac disease patients and in 220 Sicilian healthy controls. RESULTS: No differences in genotype frequencies of interleukin-10 polymorphisms were found between coeliac disease patients and healthy controls. A significant increase of -308A (p<0.033; OR: 1.72; CI: 1.27-2.33) and of +874T (p: 0.0045; OR: 3.02; CI: 1.47-6.21) allele frequencies, both in hetero- and homozygosis, was observed in coeliac patients in comparison with healthy controls. In addition, simultaneous significant higher percentages of -308A and +874T alleles (p: 0.0066; OR: 2.33; CI: 1.42-3.82) as well as simultaneous significant lower percentages of -308A and +874T alleles (p: 0.003; OR: 0.23; CI: 0.10-0.60) were observed in coeliac patients compared with healthy controls. CONCLUSIONS: Genetically determined higher frequencies of -308A tumour necrosis factor alpha and +874T interferon gamma alleles, both in hetero and in homozygosis and mostly whether simultaneous, may play a role in predisposing to gluten intolerance. Subjects positive for -308A tumour necrosis factor alpha and +874T interferon gamma alleles have an increased risk for coeliac disease.

Genotype frequencies of the +874T-->A single nucleotide polymorphism in the first intron of the interferon-gamma gene in a sample of Sicilian patients affected by tuberculosis.

In the light of the key role played by interferon (IFN)-gamma in the control of tuberculosis, in the present paper we have evaluated the distribution of the functional +874T --> A IFN-gamma single nucleotide polymorphism (SNP) in Sicilian patients affected by tuberculosis. Our aim was to determine whether there is an association between the TT genotype, which has been suggested to be linked to an increased production of IFN-gamma, and resistance to chronic tuberculosis. DNA samples were obtained from 45 patients and 97 healthy controls. Polymorphism at +874 was identified using amplification refractory mutational system methodology. The +874T SNP was less frequent in patients than in controls (0.42 vs. 0.50) but the difference was not significant. The +874TT genotype, which has been suggested to be associated with high IFN-gamma production, was significantly decreased in the patients. Thus, resistance to chronic lung tuberculosis might be associated with a genetically determined high IFN-gamma production capacity. In conclusion, the present data add another piece of evidence to the complex puzzle of genetic and environmental factors involved in control of infectious diseases. Studies on cytokine gene polymorphisms may elucidate the complex network of trans-interactive genes influencing the type and strength of responses to environmental stressors and may help to identify the genetic factors that affect survival in humans.

Use of voltage gradient gel electrophoresis in apoptotic DNA analysis.

In this paper the use of voltage gradient gel electrophoresis (VGGE) in the electrophoretic analysis of apoptotic DNAs is described. The peculiarity of VGGE fractionation in enhancing DNA bands in the gel by reducing their thickness was used to obtain a rapid, more selective and higher-quality electrophoretic fractionation of apoptotic DNA with respect to conventional electrophoresis. The use of VGGE fractionations also allowed a reduced amount of DNA to be used to detect a characteristic apoptotic DNA ladder pattern, in a lower agarose gel concentration, with respect to conventional electrophoretic fractionation