Prevalence and antimicrobial resistance of Escherichia coli and Salmonella spp. in animal feed in Colombia

Objective

To determine the prevalence and antimicrobial resistance of Escherichia coli and Salmonella spp. in animal feed samples collected between 2018 and 2021 in Colombia.

Methods

This was a laboratory-based cross-sectional study using routine data from the program for inspection, surveillance, and control of animal feed at the Colombian Agriculture Institute. Samples of animal feed for swine, poultry, canine, feline, leporine, piscine, and equine species were processed for detection of E. coli and Salmonella spp. using enrichment and selective culture methods. Isolates were tested for antimicrobial susceptibility using an automated microdilution method.

Results

Of 1 748 animal feed samples analyzed, 83 (4.7%) were positive for E. coli and 66 (3.8%) for Salmonella spp. The presence of E. coli and Salmonella spp. was highest in feed for poultry (6.4% and 5.5%) and swine (6.1% and 4.3%). Antimicrobial resistance testing was performed in 27 (33%) E. coli isolates and 26 (39%) Salmonella isolates. Among E. coli, resistance was most frequently observed to ampicillin (44.5%) followed by cefazolin (33.3%), ciprofloxacin (29.6%), ampicillin/sulbactam (26%), and ceftriaxone (11.1%). The highest resistance levels in Salmonella spp. isolates were against cefazolin (7.7%) and piperacillin/tazobactam (7.7%).

Conclusions

This is the first study from Colombia reporting on the prevalence and antimicrobial resistance of E. coli and Salmonella spp. in animal feed samples. Its results establish a baseline over a wide geographical distribution in Colombia. It highlights the need to integrate antimicrobial resistance surveillance in animal feed due to the emergence of resistant bacteria in this important stage of the supply chain.

EPCT-04. RESULTS OF A PHASE 1 STUDY OF THE ONCOLYTIC ADENOVIRUS DNX-2401 WITH RADIOTHERAPY FOR NEWLY DIAGNOSED DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG)

Background

A Phase 1, single center study is ongoing to evaluate the conditionally replicative oncolytic adenovirus, DNX-2401 (tasadenoturev), followed by radiotherapy (RT) in pediatric patients with newly diagnosed diffuse intrinsic pontine glioma (DIPG).

Methods

Patients 1–18 years with newly diagnosed DIPG with no prior treatment, Lansky/Karnofsky performance score ≥ 70, and adequate organ function were enrolled. A tumor biopsy was performed followed by a single intratumoral injection of 1e10-5e10 virus particles (vp) DNX-2401. Conventional radiotherapy was initiated within 1 month of DNX-2401 administration.

Results

Enrolled subjects (n=12) had a median age of 9 (range 3–18) and performance scores of 90–100 (n=4; 33%) or 70–80 (n=8; 67%). As part of a dose escalation design, subjects were treated with 1e10 vp (n=4) or 5e10 vp DNX-2401 (n=8), which was then followed by standard RT in 11 of 12 subjects (92%). No dose-limiting toxicities were observed and the treatment regimen was well-tolerated. Adverse events (AEs) have been primarily mild to moderate and consistent with underlying disease. The most commonly reported AEs (≥ 5 subjects), regardless of study drug relationship, include headache, asthenia, vomiting, anemia, leukocytosis, and fever. Two SAEs have been reported including grade 3 lymphopenia and grade 3 abdominal pain. Tumor reductions have been observed and efficacy evaluations are ongoing. As of 09Dec2020, 12-month survival (OS-12) was 71% and 4 of 12 patients had survived > 20 months. Four subjects continue to be followed for survival. Correlative analysis of tumor biopsy and peripheral samples is ongoing.

Conclusions

DNX-2401 followed by RT can be safely administered to pediatric subjects with newly diagnosed DIPG; clinical activity and preliminary survival are encouraging.

HGG-15. THE IMIPRIDONE ONC201 IN COMBINATION WITH THE ONCOLYTIC ADENOVIRUS DELTA-24-RGD HAS A SYNERGISTIC EFFECT IN PRECLINICAL MODELS OF PHGGS AND DMGS

Pediatric High Grade Gliomas (pHGGs), including Diffuse Midline Gliomas (DMGs), are aggressive pediatric tumors with a poor overall survival. In the last years, ONC201 has emerged as a promising agent in the field of pediatric brain tumors. Another interesting approach is virotherapy; Delta-24-RGD, which is an oncolytic virus, has demonstrated safety and effectiveness in different preclinical models and in clinical trials. Therefore, in this work we set to evaluate whether the combination of ONC201 with Delta-24-RGD could result in an increased therapeutic benefit in pHGGs and DMGs. Given that ONC201 targets mitochondrial metabolism in a preclinical setting, we assessed potential negative interactions of the combination therapy. While ONC201 treatment resulted in decreased viral protein load (E1A and fiber), there was no significant negative impact on the viral replication (measured by hexon staining). ONC201 did not disrupt the activation of mTORC1 pathway by the adenovirus. Furthermore, Delta-24-RGD did not affect the decrease in basal oxygen consumption rate induced by ONC201. Our results suggested that ONC201 and Delta-24-RGD are not antagonistic. Evaluation of the in vitro cytotoxicity in different human pHGG (CHLA-03-AA and SF188) and DMG (TP-54 and SU-DIPG-IV) cell lines showed that the combination treatment was significantly better that either agent alone. In vivo, a single local injection of Delta-24-RGD followed by a weekly ONC201 of mice bearing CHLA-03-AA cell line orthotopically significantly increased the median overall survival (PBS: 48 days; ONC201: 54.5 days; Delta-24-RGD: 62 days; ONC201+Delta-24-RGD: 95 days (P=0.0008)) of these mice leading to 20% long-term survivors, free of disease. Currently, we are evaluating the effect of the combination in immunosuppressed and immunocompetent models of DMGs. In summary, our data indicate ONC201 in combination with Delta-24-RGD could be a potential therapeutic choice for patients affected by pHGGs and DMGs.

Phase I Trial of DNX-2401 for Diffuse Intrinsic Pontine Glioma Newly Diagnosed in Pediatric Patients

BACKGROUND

There are no effective treatments for diffuse intrinsic pontine gliomas (DIPGs); these tumors cannot be surgical resected, and diagnosis is based on magnetic resonance imaging. As a result, tumor tissues for molecular studies and pathologic diagnosis are infrequent. New clinical trials are investigating novel medications and therapeutic techniques in an effort to improve treatment of patients with DIPGs.

OBJECTIVE

To determine the safety, tolerability, and toxicity of an oncolytic adenovirus, DNX-2401, injected into the cerebellar peduncle in pediatric subjects with DIPG and to collect tumor samples of this type of tumor.

METHODS

Phase I, single-center, uncontrolled trial. A tumor biopsy will be performed through the cerebellar peduncle, and DNX-2401 will be injected immediately after the biopsy. Standard therapy consisting of radiotherapy and chemotherapy will follow in 2 to 6 wk.

EXPECTED OUTCOMES

Improvement of overall survival and quality of life in patients with DIPG and collection of tumor specimens to study the molecular profiling of these tumors.

DISCUSSION

The aims of this trial are to contribute to the sample collection of DIPG and to offer treatment during the tumor tissue biopsy using the virus. If this virus works as expected, it could kill the tumor cells with no damage to healthy tissue, functioning as a targeted therapy. It is important to note that edema has not been observed with this virus in all trials performed to date. The information obtained through this and other similar studies may be useful for developing or improving new therapies in the battle against DIPG.

OS5.1 Phase I clinical trial with oncolytic virus DNX-2401 for DIPGs

BACKGROUND

Despite our increased understanding of the genetic make-up and new therapies for pediatric high grade glioma (pHGG) and Diffuse Intrinsic Pontine Glioma (DIPG) the outcome remains grim. Delta-24-RGD (DNX-2401 in the clinic) has been tested for adult glioblastoma presenting a safe profile and promising efficacy. Recently our group has showed that the virus is safe and effective in preclinical models of pHGG and DIPG. Moreover, we showed that the virus is able to trigger an antitumor immune response. These outstanding preclinical results allowed us to propel a phase I clinical trial for newly diagnosed DIPGs (NCT03178032) where the patients received an intratumoral viral injection followed by standard radiotherapy.

MATERIALS AND METHODS

A phase I clinical trial with DNX-2401 for patients with newly diagnosed DIPG to assess the MTD is taking place in our hospital (N=12). Tumor biopsy is performed through the cerebellar peduncle, followed by virus injection. The virus is injected using a cannula, MEMS cannula (Alcyone Lifesciences) that prevents the reflux. Virus will be injected starting with 1010 pv. The trial is uncontrolled, unicentric with a 3 + 3 design. The objective of this trial is to determine the safety, tolerability, and toxicity of DNX-2401 in subjects with DIPG and to collect tumor samples of this type of tumor. Secondary endpoints are overall survival at 12 months (OS12), percentage of responses and induced immune response against tumor. The follow up includes close monitoring of neurological status, blood tests and brain MRI. If this trial shows evidence of safety and efficacy will propel a multicenter clinical trial.

RESULTS

All the clinical data from the trial available until September 2019 will be presented during the congress, to date 8 patients have been treated within the trial. Three patients were treated with the D1=1x1010vp and because the lack of toxicity we escalated to the D2= 5x1010vp. The procedure was well tolerated and safe. Patients were home 3–4 days after the injection. All the patients displayed a reduced tumor volume after combined treatment. We performed molecular studies in 6 out of the 8 patients. We are currently assessing the immune responses to the virus.

CONCLUSIONS

Information acquired within this clinical study would aid to understand the response of DIPGs to viral therapies and therefore to better tailor this strategy to improve the survival and the quality of life of pediatric brain tumors.

Abstract 3117: Delta-24-RGD/DNX-2401: Oncolytic virotherapy for pediatric high grade glioma and DIPG

Pediatric High Grade Glioma (pHGG), including Diffuse Intrinsic Pontine Glioma (DIPG) are the most common and aggressive pediatric brain tumor. Despite great strides in the knowledge of their genetic make-up and new therapies, the outcome for children affected with these malignancies remains dismal. Therefore, it is critical to implement new therapeutic approaches that improve the survival and quality of life of these kids. Delta-24-RGD (DNX-2401 in the clinic), is a tumor specific oncolytic adenovirus that has been tested in preclinical and clinical studies in adult high grade glioma, demonstrating its safe profile and certain degree of efficacy. The objective of this work was to evaluate the safety and the antitumor effect of DNX-2401 in pHGG and DIPGs. Delta-24-RGD showed a potent antitumor effect in a battery of pHGG (N=5) and DIPGs (N=6) cell lines (IC50 ranging from 1 to 50 MOIs) that was mediated by an effective replication. Moreover, Delta-24-RGD administration to mice bearing pHGG and DIPG tumors resulted in a significantly increase in the overall survival, and in some cases leading to 50% of long-term survivors. Clinical trials with DNX-2401 have shown that the immune response triggered in a subset of glioma patients is the responsible for the durable responses observed. Therefore, we assessed viral efficacy in two immunocompetent models bearing mice DIPG tumors. Delta-24-RGD, administered in mice brainstem, was well tolerated and no signs of toxicity were observed. Importantly, Delta-24-RGD treatment resulted in a significant survival benefit in immunocompent DIPG orthotopic models. Tumor examination showed that Delta-24-RGD also promoted an increase in T-cell infiltration (CD3+, CD4+ and CD8+; p<0.001) within the tumor. mRNA expression levels of IFNg, CD8a and CD4 were also increased in treated tumors (p<0.001). In addition, esplenocytes from Delta-24-RGD treated mice significantly increase the IFNg production (p<0.0001) when were co-cultured with DIPG tumor cells. In summary, Delta-24-RGD administration triggers an immune response against DIPG tumors These encouraging preclinical results allowed us to propose a phase 1 clinical trial for naïve DIPGs to evaluate the safety and feasibility of injecting this virus into the pons (NCT03178032). DIPG patients undergo a tumor biopsy and immediately after DNX-2401 is infused intratumorally, using the same biopsy route. Up to date 6 patients have been treated with the virus (with up to 3x1010 viral particles in 1mL). The biopsy and the virus injection were well tolerated by the patients and they were home 3 to 4 days after the surgery. In the next months will have more information regarding the possible effect of the virus. We believe that the information acquired through this study could serve to develop or improve new therapies in the battle against DIPG and constitute a paradigm change in the treatment of this devastating tumor.

Citation Format: Naiara Martinez-Velez, Marc Garcia-Moure, Virginia Laspidea, Maider Varela, Oren Becher, Candelaria Gomez-Manzano, Juan Fueyo, Ana Patiño, Ricardo Diez-Valle, Sonia Tejada-Solis, Marta M. Alonso. Delta-24-RGD/DNX-2401: Oncolytic virotherapy for pediatric high grade glioma and DIPG [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3117.

Liquid Biopsy: From Basic Research to Clinical Practice

Liquid biopsy refers to the molecular analysis in biological fluids of nucleic acids, subcellular structures, especially exosomes, and, in the context of cancer, circulating tumor cells. In the last 10 years, there has been an intensive research in liquid biopsy to achieve a less invasive and more precise personalized medicine. Molecular assessment of these circulating biomarkers can complement or even surrogate tissue biopsy. Because of this research, liquid biopsy has been introduced in clinical practice, especially in oncology, prenatal screening, and transplantation. Here we review the biology, methodological approaches, and clinical applications of the main biomarkers involved in liquid biopsy.

A cumulative effect involving malfunction of the PTH1R and ATP4A genes explains a familial gastric neuroendocrine tumor with hypothyroidism and arthritis

BACKGROUND

Type I gastric neuroendocrine tumors (gNETs) classically arise because of hypergastrinemia and involve destruction of parietal cells, which are responsible for gastric acid secretion through the ATP4A proton pump and for intrinsic factor production.

METHODS

By whole exome sequencing, we studied a family with three members with gNETs plus hypothyroidism and rheumatoid arthritis to uncover their genetic origin.

RESULTS

A heterozygous missense mutation in the ATP4A gene was identified. Carriers of this variant had low ferritin and vitamin B₁₂ levels but did not develop gNETs. A second heterozygous mutation was also uncovered (PTH1R p.E546K). Carriers exhibited hypothyroidism and one of them had rheumatoid arthritis. Gastrin activates parathyroid hormone like hormone/parathyroid hormone 1 receptor (PTH1R) signaling, which is involved in gastric cell homeostasis. Activation of parathyroid hormone/PTH1R, which is upregulated by thyrotropin in the thyroid, is also involved in RANKL expression, which regulates bone homeostasis. Thyrotropin and RANKL expression were deregulated in PTH1R mutation carriers, suggesting a link between the PTH1R gene, hypothyroidism, rheumatoid arthritis, and gastric disease. Only patients with both mutations developed gNETs plus hypothyroidism and rheumatoid arthritis.

CONCLUSION

Both mutations suggest that a collaborative mechanism is operative in this family, in which mutations in these genes affect the function and viability of parietal cells and lead to the achlorhydria that drives hypergastrinemia and the formation of gNETs.

Abstract 704: Therapeutic potential of Delta24-ACT, a novel immunostimulatory oncolytic adenovirus, for the treatment of pediatric solid tumors: Initial study in pHGG, DIPG and osteosarcoma

Pediatric High Grade Glioma (pHGG), including Diffuse Intrinsic Pontine Glioma (DIPG), and osteosarcoma are amongst the most common and lethal pediatric solid tumors. Despite improvements in surgery, radiotherapy and chemotherapy, the outcome for children affected with these malignancies remains dismal since the current treatments are ineffective and inflict severe side effects. Thus, it is critical to implement novel and radically different therapeutic approaches to improve the survival and quality of life of these children. Delta24 is a modified adenovirus with a tumor dependent replication, and its antitumor effect has been tested in preclinical and clinical models of both high grade glioma and osteosarcoma. The adenovirus destroys the tumor mass as it replicates within the tumor. Additionally, the adenovirus infection triggers the recruitment of lymphocytes to the tumor. However, tumors are often characterized by an immunosuppressive environment that hampers the synergistic effect mediated by the virus and the immune system. Here we describe the generation of a new oncolytic adenovirus Delta24-ACT, based on the Delta24 platform, encoding an immunostimulatory protein. For this project we used relevant immunocompetent pediatric solid models. The toxicity of the virus was assessed by dose-escalation experiments. Delta24-ACT was well tolerated and did not lead to important adverse effects. The antitumor effect of Delta24-ACT was evaluated in immunocompetent mice bearing orthotopic supratentorial glioma, DIPG or local osteosarcoma that spontaneously metastasize to lungs, obtaining significant tumor shrinkage or complete elimination in some of them. Delta24-ACT also promoted an increased T-cell infiltration within the tumor and an enhanced antitumor immune response. Of importance, treatment with Delta24-ACT led to a significant increase in median survival in all the tumor models tested and resulted in long-term survivors free of disease. Furthermore, in our osteosarcoma model local treatment of primary tumors led to the regression of spontaneous lung metastases, which are usually the leading cause of death in most of the patients affected by osteosarcoma. Currently, we are performing re-challenge experiments to evaluate a possible memory effect mediated by the virus and mechanistic studies to elucidate the mechanism of action. Altogether, these results demonstrate the potential therapeutic benefit of Delta24-ACT adenovirus in the treatment of pediatric solid tumors such as pHGG, DIPG and osteosarcoma, representing an important milestone in the fight against cancer.

Citation Format: Marc Garcia Moure, Naiara Martínez-Vélez, Enric Xipell, Marisol González-Huarriz, Ana Patiño, Oren J. Becher, Cande Gómez-Manzano, Juan Fueyo, Marta M. Alonso. Therapeutic potential of Delta24-ACT, a novel immunostimulatory oncolytic adenovirus, for the treatment of pediatric solid tumors: Initial study in pHGG, DIPG and osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 704. doi:10.1158/1538-7445.AM2017-704

The Oncolytic Adenovirus VCN-01 as Therapeutic Approach Against Pediatric Osteosarcoma

PURPOSE

Osteosarcoma is the most common malignant bone tumor in children and adolescents. Despite aggressive chemotherapy, more than 30% of patients do not respond and develop bone or lung metastasis. Oncolytic adenoviruses engineered to specifically destroy cancer cells are a feasible option for osteosarcoma treatment. VCN-01 is a replication-competent adenovirus specifically engineered to replicate in tumors with a defective RB pathway, presents an enhanced infectivity through a modified fiber and an improved distribution through the expression of a soluble hyaluronidase. The aim of this study is to elucidate whether the use of VCN-01 would be an effective therapeutic strategy for pediatric osteosarcoma.

EXPERIMENTAL DESIGN

We used osteosarcoma cell lines established from patients with metastatic disease (531MII, 678R, 588M, and 595M) and a commercial cell line (143B). MTT assays were carried out to evaluate the cytotoxicity of VCN-01. Hexon assays were used to evaluate the replication of the virus. Western blot analysis was performed to assess the expression levels of viral proteins and autophagic markers. The antitumor effect of VCN-01 was evaluated in orthotopic and metastatic osteosarcoma murine animal models.

RESULTS

This study found that VCN-01, a new generation genetically modified oncolytic adenovirus, administered locally or systemically, had a potent antisarcoma effect in vitro and in vivo in mouse models of intratibial and lung metastatic osteosarcoma. Moreover, VCN-01 administration showed a safe toxicity profile.

CONCLUSIONS

These results uncover VCN-01 as a promising strategy for osteosarcoma, setting the bases to propel a phase I/II trial for kids with this disease. Clin Cancer Res; 22(9); 2217-25. ©2015 AACR.

[Association between feeding behavior, and genetic polymorphism of leptin and its receptor in obese Chilean children]

INTRODUCTION

Leptin (LEP) is mainly produced in adipose tissue and acts in the hypothalamus to regulate energy intake. Mutations in the LEP gene or its receptor (LEPR) that produce monogenic obesity are infrequent. However, LEP and LEPR polymorphisms have been associated with obesity multifactorial, due to the association found with body weight and eating behavior.

AIM

Measure the association between LEP and LEPR polymorphisms with childhood obesity and eating behavior.

METHODS

221 Chilean obese children (BMI above the 95th percentile) were recruited. Parents of 134 of these children were also recruited to determine the association between LEP and LEPR polymorphisms with obesity in a case study-parent trio. Eating behavior was measured through the questionnaire of three factors progenitors' version (TFEQ-P19) and eating behavior in children (CEBQ).

RESULTS

No significant difference between the studied polymorphisms and childhood obesity, after correction for multiple comparisons, was observed. The dimensions; "Slow eating", "emotional eating", "enjoyment of food" and "uncontrolling eating" were significant associated with certain polymorphisms of LEP and LEPR.

CONCLUSIONS

There would be an association between polymorphisms of the LEP and LEPR genes with eating behavior in Chilean obese children.

No evidence of association between the serotonin 2A receptor −1438G/A promoter polymorphism and childhood obesity in a Spanish population: A case-parent study and a matched case-control study

Serotonin has been related to feeding behaviour and body weight control through its suppressive effect on appetite. Conflicting results have been published in the literature regarding the association between the - 1438 G/A promoter polymorphism of the 5HT2A gene with obesity-related variables. The aim of this study was to assess the association between the--1438 G/A polymorphism of the 5HT2A gene with childhood obesity in a Spanish population. A total of 136 cases aged 6-16 years with BMI above the 97th percentile of the Spanish BMI reference data for age and gender were matched by gender and age (+/- 6 months) with 136 controls. Additionally, 43 obese children and their parents were selected for a family-based association study (case-parent study). Genotyping was carried out by polymerase chain reaction and restriction enzyme analysis. Conditional logistic regression and transmission/disequilibrium test were used to assess genotype-obesity association. In the matched case-control study, the crude and adjusted odds ratios for the association between 5HT2A--1438 G/A genotypes were nonsignificant. Likewise, no association is suggested by the case-parent study. In conclusion, it is unlikely that the--1438 G/A polymorphism of 5HT2A gene may influence obesity in a Spanish children population.

A novel mutation Thr162Arg of the melanocortin 4 receptor gene in a Spanish children and adolescent population

OBJECTIVE

The melanocortin 4 receptor gene (MC4R) is involved in body weight regulation. While many studies associated MC4R mutations with childhood obesity, information on MC4R mutations in Spanish children and adolescents is lacking. Our objective was to screen a population of children and adolescents from the north of Spain (Navarra) for MC4R mutations and to study the phenotypes of carriers and their families. In addition, functional assays were performed for a novel MC4R mutation.

METHODS

The study was composed of 451 Spanish children and adolescents (49% boys), aged 5-18 year. According to the International Obesity Task Force (IOTF) criteria, the groups included 160 obese, 132 overweight and 159 normal-weight control subjects.

RESULTS

One novel (Thr162Arg) and three known nonsynonymous mutations in the MC4R gene (Ser30Phe, Thr150Ile, Ala244Glu) were detected heterozygously. The MC4R mutations were found in three male (one obese and two overweight) and two female subjects (one obese and one overweight). The novel mutation did not appear to lead to an impaired receptor function. An unequivocal relationship of MC4R mutations with obesity in pedigrees together with an impaired function of the encoded receptor could not be established for any of the mutations.

CONCLUSIONS

The presence of heterozygous MC4R mutations in obese and overweight subjects indicates that these mutations may be a susceptibility factor for obesity development, but lifestyle factors, such as exercise or sedentary activities, may modify their effect.

The child and adolescent first-episode psychosis study (CAFEPS): design and baseline results

OBJECTIVE

The child and adolescent first-episode psychosis study (CAFEPS) is a multicenter, two-year, longitudinal project aiming to evaluate different clinical, neuropsychological, neuroimaging, biochemical, immunological, and genetic variables and treatment and prognostic factors in these patients. This paper describes the methods and rationale behind the study and the general characteristics of the sample.

METHOD

At six different centers, from March 2003 through November 2005, we consecutively recruited 110 patients, ages 9-17 years, who presented with a first psychotic episode. Controls were recruited from the same geographic areas and were matched for gender and age.

RESULTS

Patients had lower socioeconomic status (SES) (p=0.018) and parental years of education (p<0.001) than controls. The percentage of patients recruited increased with age (p<0.001) and there was a higher percentage of males (p<0.001). The total mean PANSS score was 89.03+/-20.1, the positive score 23.8+/-6.5 and the negative score 20.02+/-8.8. There were no significant differences between the genders with respect to age, parental years of education, SES, or scores in premorbid adjustment or general functioning. There were statistically significant positive correlations between age and positive symptoms and between all PANSS subscales and the Disability Assessment Schedule, and negative correlations between positive symptoms and global functioning. Diagnoses after the baseline evaluation were: psychotic disorder not otherwise specified (NOS) 35.5%, schizophreniform disorder 24.5%, mood disorder with psychotic symptoms 22.7%, schizophrenia 10%, schizoaffective disorder 2.7%, and other psychotic disorders 4.5%. Patients had worse premorbid adjustment (p<0.001) and global functioning (p<0.001) than controls after controlling for SES.

CONCLUSIONS

Infancy and adolescence adjustment and global functioning are lower in children and adolescents with psychotic disorders than in controls, severity of symptoms are related to general disability, and the most frequent diagnoses are psychotic disorders NOS.

El ensayo de micronúcleos como medida de inestabilidad genética inducida por agentes genotóxicos

Human genetic integrity is compromised by the intense industrial activity, which emphasizes the importance to determine an "acceptable" genetic damage level and to carry out routine genotoxicity assays in the populations at risk. Micronuclei are cytoplasmatic bodies of nuclear origin which correspond to genetic material that is not correctly incorporated in the daughter cells in the cellular division; they reflect the existence of chromosomal aberrations and are originated by chromosomal breaks, replication errors followed by cellular division of the DNA and/or exposure to genotoxic agents. There are several factors able to modify the number of micronuclei present in a given cell, among them are age, gender, vitamins, medical treatments, daily exposure to genotoxic agents, etc. The cytogenetic assay for the detection of micronuclei (CBMN: cytokinesis-block micronucleus) is based on the use of a chemical agent, cytochalasin-B, which is able to block cytocinesis but allowing the nuclear division, therefore yielding binucleated and monodivided cells. The micronuclei scoring is performed on 1000 binucleated cells and the starting sample may vary, although most studies are performed on peripheral blood lymphocytes. The micronuclei assay is considered a practical, universally validated and technically feasible protocol which is useful to evaluate the genetic instability induced by genotoxic agents.

Gene-gene interaction between PPAR gamma 2 and ADR beta 3 increases obesity risk in children and adolescents

AIMS

Multiple genes are likely to be involved in obesity and these genes may interact with environmental factors to influence obesity risk. Our aim was to explore the synergistic contribution of the two polymorphisms: Pro12Ala of the PPAR gamma 2 gene and Trp64Arg of the ADR beta 3 gene to obesity risk in a Spanish children and adolescent population.

METHODS

We designed a sex- and age-matched case-control study. Participants were 185 obese and 185 control children (aged 5-18 y) from the Navarra region, recruited through Departments of Pediatrics (Hospital Virgen del Camino, Navarra University Clinic and several Primary Health Centers). The obesity criterion (case definition) was BMI above the 97th percentile according to Spanish BMI reference data for age and gender. Anthropometric parameters were measured by standard protocols. The genotype was assessed by PCR-RFLP after digestion with BstUI for PPAR gamma 2 mutation and BstNI for ADR beta 3 variants. Face-to-face interviews were conducted to assess the physical activity. Using a validated physical activity questionnaire, we computed an activity metabolic equivalent index (METs h/week), which represents the physical exercise during the week for each participant. Statistical analysis was performed by conditional logistic regression, taking into account the matching between cases and controls.

RESULTS

Carriers of the polymorphism Pro12Ala of the PPAR gamma 2 gene had a significantly higher obesity risk than noncarriers (odds ratio (OR)=2.18, 95% CI=1.09-4.36) when we adjusted for sex, age and physical activity. Moreover, the risk of obesity was higher (OR=2.59, 95% CI=1.17-5.34) when family history of obesity was also taken into account in the model. The OR for obesity linked to both polymorphisms (PPAR gamma 2 and ADR beta 3) was 5.30 (95% CI=1.08-25.97) when we adjusted for sex, age and physical activity. After adjustment for family history of obesity, the OR for carriers of both polymorphisms was 19.5 (95% CI=2.43-146.8).

CONCLUSIONS

A synergistic effect between polymorphism Pro12Ala of the PPAR gamma 2 gene and Trp64Arg of the ADR beta 3 gene for obesity risk was found in a case-control study including children and adolescents.

Epigenetic loss of the familial tumor-suppressor gene exostosin-1 (EXT1) disrupts heparan sulfate synthesis in cancer cells

Germline mutations in the Exostoses-1 gene (EXT1) are found in hereditary multiple exostoses syndrome, which is characterized by the formation of osteochondromas and an increased risk of chondrosarcomas and osteosarcomas. However, despite its putative tumor-suppressor function, little is known of the contribution of EXT1 to human sporadic malignancies. Here, we report that EXT1 function is abrogated in human cancer cells by transcriptional silencing associated with CpG island promoter hypermethylation. We also show that, at the biochemical and cellular levels, the epigenetic inactivation of EXT1, a glycosyltransferase, leads to the loss of heparan sulfate (HS) synthesis. Reduced HS production can be reversed by the use of a DNA demethylating agent. Furthermore, the re-introduction of EXT1 into cancer cell lines displaying methylation-dependent silencing of EXT1 induces tumor-suppressor-like features, e.g. reduced colony formation density and tumor growth in nude mouse xenograft models. Screening a large collection of human cancer cell lines (n=79) and primary tumors (n=454) from different cell types, we found that EXT1 CpG island hypermethylation was common in leukemia, especially acute promyelocytic leukemia and acute lymphoblastic leukemia, and non-melanoma skin cancer. These findings highlight the importance of EXT1 epigenetic inactivation, leading to an abrogation of HS biosynthesis, in the processes of tumor onset and progression.

Serotonergic polymorphisms and psychotic disorders in populations from North Spain

There is strong biological evidence relating alterations in the serotonergic system with mental disorders. These alterations may be originated at the DNA level by sequence mutations that alter the functioning of serotonin receptors and transporter. To test this hypothesis we investigated three genetic variants of the 5-HT2A receptor (-1438G/A, 102T/C and His452Tyr) and two variants of the serotonin transporter (a VNTR in the second intron and a 44 bp insertion/delition in the promoter region of the gene) in a clinical sample recruited in a human isolate and in surrounding areas in Northern Spain (N = 257) and in ethnically matched controls (N = 334). No clear association was found between 5-HT2A variants and psychosis. However, marginal associations were observed between the 5-HTT LPR and VNTR variants and psychosis (P < or = 0.05) indicating a minor contribution to psychosis of genetic alterations in this gene.

Influence of two polymorphisms of the tumoral necrosis factor-alpha gene on the obesity phenotype

Several populational-based studies have suggested an association between tumoral necrosis factor-alpha (TNF-alpha) polymorphisms and obesity-related phenotypes. Therefore, this study aimed at assessing the situation (frequency and associated phenotype) of two TNF-alpha common polymorphisms in a Spanish population. In a case-control design study, a group of Spanish subjects (n=313) were genotyped for the TNF-alpha G/A -308 and -238 polymorphisms. Obese subjects (cases) were compared with lean individuals (controls) according to body mass index (BMI; cases: BMI >30 kg/m2, controls: BMI <25 kg/m2). Waist-to-hip ratio, body composition and some metabolic indicators were assessed. The frequency of the -308A allele (0.14) and -238A allele (0.09) was similar to those previously reported in other Caucasian populations. Interestingly, cases with the -308A allele of the TNF-alpha gene have significantly higher hip and waist circumferences (p<0.05), BMI (p<0.01) and body fat mass (p<0.05) values than obese individuals carrying the -308G allele, but not the waist-to-hip ratio. No apparent influence of the -308A polymorphism on other metabolic indicators (insulin and leptin levels) was found. We could not detect any association between the substitution at position -238 polymorphism of the TNF-alpha gene and obesity anthropometrical phenotypes in this Spanish population, despite some differences in plasma leptin. These results support the hypothesis that the G/A -308 polymorphism of the TNF-alpha gene is associated with a higher BMI as well as hip ad waist circumferences, particularly on female bearers, while no influence on such measurements was found for the G/A -238 TNF-alpha gene polymorphism, but only an effect on leptinaemia.

Secondary myelodysplastic syndrome after treatment for promyelocytic leukemia: clinical and genetic features of two cases

Acute promyelocytic leukemia (APL) represents a biologic and clinically well-defined subtype of acute nonlymphocytic leukemia with specific morphologic and karyotypic characteristics. Although secondary leukemia and myelodysplastic syndromes (MDS) are the most frequent secondary neoplasms following chemotherapy for acute leukemia, their development after complete remission in patients with APL is uncommon. We describe the clinical and genetic features of two APL patients who achieved CR after chemotherapy and all-trans retinoid acid treatment and subsequently developed a MDS. Therapy-related MDS karyotype changes such as abnormalities of chromosomes 5 and 7 were found in the cytogenetic analysis. Since TP53 alteration was detected in one case, possible implications of these findings in the onset of MDS are discussed.

[Genetic studies in communication disorders]

OBJECTIVES

To review current literature on population, cytogenetic and molecular studies of specific language disorders (SLD) and pervasive developmental disorders (PDD).

DEVELOPMENT

Clinical concordance studies in twins and in vertical familial groups suggest polygenic multifactorial modes of inheritance, but in some families an autosomal dominant model may be present. The data favour not a modular, but rather a molar model of the relationship between genes and neural abilities for communicative behaviors. Several extensive genome screenings have demonstrated linkage to specific markers on 7q for SLD, and on 7q and 2q for PDD. The strong evidence of linkage on 7q for both disorders has led to the hypothesis that this region contains several separate quantitative trait loci (QTL) related to different communicative abilities. Mutations in different QTL would facilitate the different disabilities and stereotyped behaviors associated with the phenotypic spectrum of PDD. There are other candidate regions for QTLs but the linkage is weaker and there is little agreement between studies; due, in part, to over extensive inclusion criteria and small sizes of familial groups.

CONCLUSIONS

To enhance linkage research in further molecular genetic studies, clinicians must refine behavioral target traits when selecting familial groups and enlarge the size of familial groups by including non handicapped members with related behavioral traits. At present, a chromosome region in 7q shows the strongest evidence for communication related QTL, but other QTL need to be identified elsewhere in the genome in order to explain the genetic contribution to the large spectrum of language and autistic disorders.

[Obesity in children]

Obesity during childhood and adolescence is an increasingly common complaint in our daily clinical practice. The increase in its prevalence makes paediatrician worry about this disease, which is now considered an epidemic by the World Health Organisation. Obesity is a complex disease. Its aetiology is not yet clear, due to the multiple factors involved: environment, genetics, behaviour, life style, neuroendocrinology and metabolism. Persistent obesity increases the risk of suffering from diabetes, cardiovascular disease, hypertension, and gallbladder disease. The treatment of obesity is problematic and there are few patients who persist on a long term weight reduction programme. A multidisciplinary approach is therefore required. Paediatricians, dieticians, nurses, psychologists and psychiatrist should intervene in the treatment programme. Dietary changes must combine a decrease in energy intake and an increase in energy expenditure, inculcating both healthy eating habits and lifestyle without interfering in the child's growth and development.

[Analysis of the involvement of the tumour suppressor genes TP53, p16INK4, p21WAF1, RB1 and the drugs metabolizing enzymes in the development of bone tumours in children]

BACKGROUND

Several tumor suppressor genes such as p16INK4, TP53, RB1 y p21WAF1 are involved in cell cycle regulation in response to DNA damage and belong to the complex pathway that regulates cell proliferation and/or differentiation. We have investigated the presence of mutations in those genes and polymorphisms of Drug Metabolizing Enzymes that could be involved in the development of pediatric bone tumors or in their outcome.

MATERIALS AND METHODS

By means of PCR-based techniques, we have analyzed the presence of variations in the coding sequence of p16INK4, TP53, RB1 y p21WAF1 and of the Drug Metabolizing Enzymes in a group of 82 osteosarcomas and 47 Ewing's sarcomas as well as in a control group of 115 healthy children.

RESULTS

We detected mutations of the TP53 gene in about 25% of the samples analyzed, most frequently in association with tumors of poor prognosis or reduced survival. The p16INK4 gene was homozygously deleted in 18% of the osteosarcomas, also associated with poor prognosis and unfavourable histologic subtypes; RB1 was altered in 21% of the osteosarcomas. We did not detect relevant associations between polymorphisms of the Drug Metabolizing Enzymes or mutation of the p21WAF1 and development of pediatric bone tumors.

CONCLUSIONS

Alteration of TP53, p16INK4 and p21WAF1 seems to be involved in the development of pediatric bone tumors and to be an unfavourable prognostic factor in this type of tumors.

[Characteristics and value of chromosome aberrations induced by antitumor treatments in pediatric patients with cancer]

Cytogenetic studies were performed on 80 pediatric cancer patients to test the chromosomal damage induced by the chemotherapy treatments. G-banded karyotypes were performed on peripheral blood lymphocytes (PBL) (n = 127) obtained at diagnosis, during treatment, at remission and at relapse. We detected a significant increase in the number of altered karyotypes in the samples during treatment, lowering to similar values to those at diagnosis at two-year remission. Most of the chromosomal aberrations (CA) detected during chemotherapy were unbalanced (75%) and affected most frequently chromosomes 1, 3, 5, 6, 11, 12, 16 and 17. There was also a marked increase of CA in samples at relapse, with similar features (type and distribution) to those detected during treatment. There was an outstanding correlation between the chromosomal breakpoints in our series and fragile sites (58%), oncogene (75%) and tumour suppressor gene (33%) loci described in the literature. The results obtained suggest that the cytostatic drugs induce a transient increase in chromosome fragility that focuses to several cancer-associated breakpoints.

Ewing family tumors: potential prognostic value of reverse-transcriptase polymerase chain reaction detection of minimal residual disease in peripheral blood samples

In more than 95% of patients, the Ewing family of tumors (ET) has chimeric transcripts caused by fusion of the EWS gene to either FLI1 or ERG. The presence of specific EWS-FLI1 or EWS-ERG transcripts in peripheral blood (PB) samples of patients being treated for ET was prospectively evaluated, and these data were correlated to their clinical status. The authors studied 113 PB samples from 28 patients with ET. Treatment included chemotherapy, radiotherapy, and surgical excision of tumor after induction therapy. PB samples were taken prospectively at least 2 weeks after resection of tumor. Nested reverse-transcriptase polymerase chain reaction (RT-PCR) followed by Southern blot was performed in all samples. Resected tumors were reviewed for the degree of response to chemotherapy and volume. Seventy-seven PB samples from 28 patients had EWS-FLI1/ERG transcripts. In 11 patients, PB samples became negative with treatment, and, in 5 of them, the samples remained negative throughout the study. Samples taken during progression were always positive and, in 4 patients, became positive before progression was clinically evident. All patients with transcripts other than EWS-FLI1 type 1 (n = 3) died from tumor progression. This is a sensitive assay to monitor circulating tumor cells in Ewing tumors. The preliminary data suggest that progression is preceded by positive samples and may be related to specific transcript types.

Emergence of secondary acute leukemia in a patient treated for osteosarcoma: implications of germline TP53 mutations

BACKGROUND

Secondary leukemia and myelodysplastic syndromes have been reported in patients following treatment for a wide range of neoplastic disorders. However second malignancies after chemotherapy and/or irradiation for osteosarcoma are unusual.

PROCEDURE

We report the case of a 15-year-old girl who developed a myelodysplastic syndrome with evolution to acute nonlymphocytic leukemia after treatment for osteosarcoma. Therapy-related acute leukemia karyotype findings such as abnormalities of chromosomes 5, 7, and 17 were found in the cytogenetic analysis. Moreover, using denaturing gradient gel electrophoresis and DNA sequencing, we detected the presence of a double germline mutation in exon 7 of the TP53 gene.

CONCLUSION

This observation supports the possibility of a causal relationship between germline TP53 mutations and the development of secondary leukemia and myelodysplasia.

Molecular analysis of the Duchenne muscular dystrophy gene in Spanish individuals: deletion detection and familial diagnosis

Deletion studies were performed in 26 Duchenne muscular dystrophy (DMD) patients through amplification of nine different exons by multiplex polymerase chain reaction (PCR). DNA from paraffin-embedded muscle biopsies was analyzed in 12 of the 26 patients studied. Optimization of this technique is of great utility because it enables analysis of material stored in pathology archives. PCR deletion detection, useful in DMD-affected boys, is problematic in determining the carrier state in female relatives. For this reason, to perform familial linkage diagnosis, we made use of a dinucleotide repeat polymorphism (STRP, or short tandem repeat polymorphism) located in intron 49 of the gene. We designed a new pair of primers that enabled the detection of 22 different alleles in relatives in the 14 DMD families studied. The use of this marker allowed familial diagnosis in 11 of the 14 DMD families and detection of de novo deletions in 3 of the probands.