Subpopulation treatment effect pattern plot analysis: a prognostic model for distant recurrence-free survival to estimate delayed adjuvant chemotherapy initiation effect in triple-negative breast cancer

Introduction

Triple-negative breast cancer (TNBC) is a heterogeneous disease associated with a poor prognosis. Delaying in time to start adjuvant chemotherapy (TTC) has been related to an increased risk of distant recurrence-free survival (DRFS). We aimed to develop a prognostic model to estimate the effects of delayed TTC among TNBC risk subgroups.

Materials and methods

We analyzed 687 TNBC patients who received adjuvant chemotherapy at the Instituto Nacional de Enfermedades Neoplasicas (Lima, Peru). Database was randomly divided to create a discovery set (n=344) and a validation set (n=343). Univariate and multivariate Cox regression models were performed to identify prognostic factors for DRFS. Risk stratification was implemented through two models developed based on proportional hazard ratios from significant clinicopathological characteristics. Subpopulation treatment effect pattern plot (STEPP) analysis was performed to determine the best prognostic cut-off points for stratifying TNBC subgroups according to risk scores and estimate Kaplan-Meier differences in 10-year DRFS comparing TTC (≤30 vs.>30 days).

Results

In univariate analysis, patients aged ≥70 years (HR=4.65; 95% CI: 2.32-9.34; p=<0.001), those at stages pT3-T4 (HR=3.28; 95% CI: 1.57-6.83; p=0.002), and pN2-N3 (HR=3.00; 95% CI: 1.90-4.76; p=<0.001) were notably associated with higher risk. STEPP analysis defined three risk subgroups for each model. Model N°01 categorized patients into low (score: 0-31), intermediate (score:32-64), and high-risk (score: 65-100) cohorts; meanwhile, Model N°02: low (score: 0-26), intermediate (score: 27-55), and high (score: 56-100). Kaplan-Meier plots showed that in the discovery set, patients with TTC>30 days experienced a 17.5% decrease in 10-year DRFS rate (95%CI=6.7-28.3), and the impact was more remarkable in patients who belong to the high-risk subgroup (53.3% decrease in 10 years-DRFS rate). Similar results were found in the validation set.

Conclusions

We developed two prognostic models based on age, pT, and pN to select the best one to classify TNBC. For Model N°02, delayed adjuvant chemotherapy conferred a higher risk of relapse in patients ≥70 years and who were characterized by pT3/T4 and pN2/N3. Thus, more efforts should be considered to avoid delayed TTC in TNBC patients, especially those in high-risk subgroups.

Whole-Exome Sequencing of 21 Families: Candidate Genes for Early-Onset High Myopia

High myopia is the most severe and pathological form of myopia. It occurs when the spherical refractive error exceeds -6.00 spherical diopters (SDs) or the axial length (AL) of the eye is greater than 26 mm. This article focuses on early-onset high myopia, an increasingly common condition that affects children under 10 years of age and can lead to other serious ocular pathologies. Through the genetic analysis of 21 families with early-onset high myopia, this study seeks to contribute to a better understanding of the role of genetics in this disease and to propose candidate genes. Whole-exome sequencing studies with a panel of genes known to be involved in the pathology were performed in families with inconclusive results: 3% of the variants found were classified as pathogenic, 6% were likely pathogenic and the remaining 91% were variants of uncertain significance. Most of the families in this study were found to have alterations in several of the proposed genes. This suggests a polygenic inheritance of the pathology due to the cumulative effect of the alterations. Further studies are needed to validate and confirm the role of these alterations in the development of early-onset high myopia and its polygenic inheritance.

The STOP Program: a Hybrid Smoking Prevention and Cessation Training for Cancer Care Providers in Colombia and Peru

We designed and tested the feasibility of the Smoking Cessation Training Program for Oncology Practice (STOP), a hybrid (face-to-face plus web-based) educational intervention to enhance Spanish-speaking cancer care professionals' (CCPs') ability to provide brief smoking prevention and cessation counseling to cancer patients and survivors. Changes in the CCPs' competencies (knowledge, attitude, self-efficacy, and practices toward smoking and smoking cessation services) were assessed post-training. Sixty CCPs from one major cancer center in Colombia (n = 30) and Peru (n = 30) were invited to participate in a 4-module hybrid training program on smoking prevention and cessation. Demographic and pre- and post-test evaluation data were collected. The training's acceptability was measured after each module. Bivariate analysis was conducted using Wilcoxon signed-rank test to compare the CCPs' competencies before and after the delivery of the STOP Program. Effect sizes were computed over time to assess the sustainability of the acquired competencies. Twenty-nine CCPs in Colombia and 24 CCPs in Peru completed the STOP Program (96.6% and 80.0% retention rates, respectively). In both countries, 98.2% of the CCPs reported that the overall structure and organization of the program provided an excellent learning experience. The pre-post-test evaluations indicated that the CCPs significantly improved their knowledge, attitude, self-efficacy, and practices toward smoking, smoking prevention, and cessation services. We found that the CCPs' self-efficacy and practices increased over time (1-, 3-, and 6-month assessments after completing the 4 educational modules). The STOP Program was effective and well-received, demonstrating remarkable changes in CCPs' competencies in providing smoking prevention and cessation services to cancer patients.

The relationship between tumour infiltrating lymphocytes, Epstein–Barr virus and Helicobacter pylori infection in gastric cancer

Objective

Epstein–Barr virus (EBV) and Helicobacter pylori (HP) infections have been extensively recognised as gastric cancer (GC) triggers, and recent publications suggest they could behave as predictive markers for immune-modulating therapies. Tumour-infiltrating lymphocytes (TILs) have also been identified as a predictive biomarker for immunotherapy in different malignancies. This study aimed to investigate the association between EBV and HP infection with TIL levels in GC.

Methods

TIL evaluation in haematoxylin-eosin was performed by a pathologist and density of CD3, CD8 and CD163 positive (immunohistochemistry staining) immune cells was calculated with the use of digital pathology software. EBV infection was detected by in situ hybridisation (ISH) and by quantitative polymerase chain reaction (qPCR). Methylation status of EBV-related genes was detected by PCR and a methylome analysis was performed by the Illumina Infinium MethylationEPIC BeadChip. HP status was detected by qPCR.

Results

We included 98 resected GC Peruvian cases in our evaluation. Median TIL percentage was 30. The proportion of EBV+ detected by ISH was 24.1%, of EBV+ detected by qPCR was 41.8%, while 70% showed methylation of EBV-related genes, and 58.21% of cases were HP+. Younger age (p = 0.024), early stages (p = 0.001), HP+ (p = 0.036) and low CD8 density (p = 0.046) were associated with longer overall survival (OS). High TIL level was associated with intestinal subtype (p < 0.001), with grade 2 (p < 0.001), with EBV qPCR+ (p = 0.001), and with methylation of EBV-related genes (p = 0.007). Cases with high TIL level and cases that are EBV positive share eight genes with similarly methylated status in the metabolomic analysis. High CD8 density was associated with EBV PCR+ (p = 0.012) and HP− (0.005).

Conclusion

Lower CD8 density and HP+ predict longer OS. High TIL level is associated with EBV+ and methylation of EBV-related genes, while lower CD8 density is associated with HP+ GC.

MLPA followed by target-NGS to detect mutations in the dystrophin gene of Peruvian patients suspected of DMD/DMB

Background

We report the molecular analysis of the DMD gene in a group of Peruvian patients with Duchenne/Becker dystrophinopathy. This is the first study to thoroughly characterize mutations in this population.

Methods

We used the combination of multiplex ligation‐dependent probe amplification (MLPA) and sequencing analysis of the DMD gene. We recruited Peruvian patients in 2 years from reference national hospitals. We performed DNA tests in 152 patients, checking first exon deletion/duplication by MLPA, and subsequently, if negative, samples were sequenced to detect point mutations.

Results

The average age for diagnosis was 9.8 years, suggesting a delay for timely diagnosis and care. We found causal DMD mutations in 125 patients: 72 (57.6%) exon deletions/duplications (41.6% deletions, 16.0% duplications), and 53 (42.4%) point mutations (27.2% nonsense, 9.6% small indels, and 5.6% splice site).

Conclusion

Due to our genetic background, we expected a higher number of novel and recurrent causal mutations in our sample. Results showed 16% of novel mutations, similar to other well‐studied populations.

Alternative Strategies for the Estimation of a Disease's Basic Reproduction Number: A Model-Agnostic Study

This work presents a model-agnostic evaluation of four different models that estimate a disease’s basic reproduction number. The evaluation presented is twofold: first, the theory behind each of the models is reviewed and compared; then, each model is tested with eight impartial simulations. All scenarios were constructed in an experimental framework that allows each model to fulfill its assumptions and hence, obtain unbiased results for each case. Among these models is the one proposed by Thompson et al. (Epidemics 29:100356, 2019), i.e., a Bayesian estimation method well established in epidemiological practice. The other three models include a novel state-space method and two simulation-based approaches based on a Poisson infection process. The advantages and flaws of each model are discussed from both theoretical and practical standpoints. Finally, we present the evolution of Covid-19 outbreak in Colombia as a case study for computing the basic reproduction number with each one of the reviewed methods.

ABC4 Consensus: First Latin American Meeting-Assessment, Comments, and Application of Its Recommendations

Breast cancer accounts for a high burden among all the neoplasms in Latin America, with more-advanced stages at presentation, which could result in high mortality rates. The 4th International Consensus Conference for Advanced Breast Cancer (ABC4) is focused on standardizing therapy for advanced breast cancer (ABC) and has held 5 meetings so far. ABC4 took place in Lisbon, Portugal, from November 2 to 4, 2017; however, the first Latin American ABC conference was held in Lima, Peru, from 18 to 19 May, 2018, chaired by Fatima Cardoso, MD, PhD. During these 2 days, the ABC4 consensus recommendations for advanced and locally advanced breast cancer were presented. Local treatment and systemic therapy were discussed with local experts, mainly focusing on anti-human epidermal growth factor receptor 2 therapy and newly approved drugs for hormone receptor-positive breast cancer, such as as CDK4/6, mammalian target of rapamycin, and poly (ADP-ribose) polymerase inhibitors for triple-negative breast cancer. The discussion focused additionally on access to drugs and ABC4 consensus recommendations as regards Latin American patients.

Abstract B080: Assessment of the molecular mechanisms of a protective variant for breast cancer in Latinas

The incidence of breast cancer is lower in women of Latin American origin in the U.S. compared to European American and African American women. Among Latinas, the rs140068132A&gt;G variant, which is common in women with IAA, has been associated to a lower risk of breast cancer. The frequency of the G allele is 0% for non-Latinos while 12% in Latinos, being highest in the Peruvian population (23%). This variant is located on chromosome 6 near the Estrogen Receptor 1 gene (ESR1) and even though experimental evidence suggests that this variant might be functional, the molecular mechanisms that explain its protective effect are unknown. We hypothesize that the rs140068132-G variant decreases ESR1 expression, which affects the expression or function of genes involved in associated pathways. We aim to test the association of the rs140068132 variant and gene expression in breast cancer tumors from patients with high IAA. We collected 47 breast tumors and blood samples from the Instituto Nacional de Enfermedades Neoplásicas in Lima, Peru. These patients were genotyped for IAA estimation and determination of the rs140068132 genotype. Total RNA was extracted from tumor samples and used for a paired-end sequencing (2 × 75bp paired-end,100 million reads per sample) in the Illumina NextSeq500. Differential gene expression between genotypes was performed by DEseq2 R package and statistical significance was determined using FDR&lt;0.05 for samples with at least log2 1.5-fold change. Differentially expressed isoforms were detected by EBseq R package using FDR&lt;0.05. Tumor intrinsic subtypes were obtained using PAM50 as implemented in the genefu R package. The average IAA for the 47 Peruvian patients was 77% (SD=0.17). Twenty-seven patients were homozygous AA, 19 heterozygous AG and 1 GG for the rs140068132 variant. According to PAM50 classification, 10 tumors were Luminal A, 12 Luminal B, 15 HER2+ and 10 Basal. Among luminal tumors there was a suggestive trend towards lower expression of the ESR1 gene in patients carrying the protective allele (p=0.16). Including all subtypes, 27 genes were differentially expressed according to the rs140068132 genotype. Four of these genes are ER dependent or associated with ER status. The expression of the top gene, which is a transcriptional target of ER, is lost in patients with the protective allele. This association is mainly driven by its expression in luminal tumors and remained significant after adjusting for IAA. ESR1 isoforms were not differentially expressed by genotype, however significant differences were detected in the expression of isoforms for 115 genes, of which 18% have been reported to be transcriptional targets of ER or functionally related. Our preliminary results suggest that the rs140068132 variant decreases ER expression and affects the expression of functionally associated genes in luminal tumors. Further allele-specific expression analysis will elucidate if this variant is part of a cis-regulatory module.

Note: This abstract was not presented at the conference.

Citation Format: Valentina A. Zavala, Tatiana Vidaurre, Katie Marker, Sandro Casavilca, Lizeth Tamayo, Carlos Castañeda, Jeannie Vásquez, Fernando Valencia, Zaida Morante, M. Calderon, J. Abugattas, H. Gomez, H. Fuentes, C. Monge-Pimentel, Silvia Neciosup, Jovanny Zabaleta, Laura Fejerman. Assessment of the molecular mechanisms of a protective variant for breast cancer in Latinas [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B080.

[Programa de detección del alelo APOE-E4 en adultos mayores mexicanos con deterioro cognitivo]

Introduction

In Mexico, the prevalence of neurocognitive disorders (NCDs) has increased in parallel with the increase in life expectancy. The E4 allele of the gene that encodes apolipoprotein E (APOE) is the main genetic risk factor for cognitive impairment.

Objective

To replicate the association of APOE-E4 allele with neurocognitive impairment in a Mexican population, as well as to implement a genetic risk-detection program with the APOE-E4 allele.

Method

A program was structured for the detection of APOE-E4 allele risk in different recruiting centers from the central zone of the Mexican Republic, with three stages: recruitment and selection of candidates for the detection of the risk-allele, genetic risk analysis and delivery of results.

Results

In the genetic-association study to replicate the association with neurocognitive disorders by means of multivariate logistic models, the APOE-E4 allele increased the risk for cognitive impairment in the Mexican populations by approximately 6 % (OR: 5.83, p = 0.0025). In addition, 367 genetic risk results were delivered.

Conclusions

The present program is the first one to be implemented in Mexico with the purpose to inform on a genetic risk factor for neurocognitive disorders in several centers of the country.

Abstract P2-14-12: Impact of the time interval between neoadjuvant chemotherapy and surgery in Latin-Americans breast cancer patients

Background: Few studies have evaluated the impact of the time interval between neoadjuvant chemotherapy (NAC) and surgery in breast cancer. In Latin America, where the vast majority of hospitals are oversaturated, it is important to define which patients to give priority and to be clear about ideal time or maximum to schedule surgery after NAC without altering the prognosis. The objective of this work is to establish the ideal time interval for post-neoadjuvant surgery and evaluate the impact on patient survival.

Methods: We reviewed the clinical histories of breast cancer with clinical stage II and III who received NAC between 2005 and 2014. Patients were divided into 3 groups according to the time interval to surgery: &lt;4, 4-8 and &gt;8 weeks. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method, and comparisons of survival curves using the logrank or Breslow test, both globally and by molecular subtypes. The optimal time to surgery has been determined by the Cox model.

Results: During the study period, 583 patients who had post NA surgery before six months were registered. The median age was 49 years (range: 24-85), 82% had clinical stage III, 53% histological grade III, 32.7% were luminal A, 15.6% luminal B, 24.4% Her2 and 27.3% TN. According to the time interval to surgery, 67 (11.5%) patients had surgery before 4 weeks, 204 (35.0%) between 4 to 8 weeks, and 312 (53.5%) after 8 weeks. The groups do not present differences in relation to the clinical characteristics (p&gt; 0.05). The median follow-up time was 4.8 years. The 5-year OS rate according to the time interval was 57.9, 61.5, and 62.7% (p = 0.581) and the RFS rate was 40.6, 52.3, and 51.1% (p = 0.411). No differences were found in the survival curves by molecular subtypes , except for luminal b like . In the multivariate analysis, the effect of the time interval to surgery was not significant in OS and RFS; however, the HR curve suggests that the appropriate cut-off point for surgical time would be 8 weeks.

Table 1:Time Interval :OS - RFS  RFS  OS  MEDIAN5 - yearsPMEDIAN5 - yearsPWeeks for NAC to Surgery      &lt;4 weeks3.240.6 6.157.9 4-8 weeks6.352.3 9.161.5 &gt;8 weeks5.151.10.416.762.70.581       Weeks for NAC to Surgery      &lt;8 weeks549.5 9.160.7 &gt;8 weeks5.151.10.5856.762.70.414

Table 2 :Time Interval - Molecular Subtype  RFS  OS  MEDIAN5 - yearsPMEDIAN5 - yearsPLUMINAL A LIKE      &lt; 8 weeks----74.1 ----84 &gt;8 weeks7.163.80.719.973.90.236       *LUMINAL B LIKE      &lt; 8 weeks2.336.8 5.460.5 &gt;8 weeks5.857.60.46----820.08       HER2      &lt;8 weeks2.228.7 3.938.4 &gt;8weeks3.645.90.57.26.261.30.616       TRIPLE NEGATIVE      &lt;8 weeks3.144.2 3.448.4 &gt;8 weeks2.041.80.9143.743.90.516* ER + PR &gt;20% KI67&gt;14% , HER2 NEGATIVE

Conclusion: The time interval between the end of neoadjuvant period and surgery has no impact on recurrence-free survival or on overall survival, despite this we suggest that the period of time between neoadjuvant and surgery not be greater than 8 weeks. More studies will be required to determine the ideal time interval and which cases should be prioritized according to the characteristics of our patients.

Citation Format: Rebaza LP, Galarreta JA, Castañeda C, Cotrina JM, Vilchez S, de la Cruz M, Ponce J, Aguilar A, Flores C, Castillo M, Galvez M, Vigil C. Impact of the time interval between neoadjuvant chemotherapy and surgery in Latin-Americans breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-12.

Evaluación y manejo del riesgo cardiovascular en infección por VIH. Consenso de expertos ACIN

Los pacientes con infección por VIH tienen una mayor incidencia de eventos cardiovasculares en comparación con la población general; los factores que contribuyen al incremento del riesgo de eventos cardiovasculares son la prevalencia de factores de riesgo cardiovascular tradicionales (FRCV), la infección por VIH que condiciona tanto un proceso de inflamación crónica como alteración de la función endotelial y la exposición a los antirretrovirales. Los factores que deben ser objeto de intervención son los FRCV tradicionales, en especial la alta tasa de fumadores entre este grupo de pacientes, la tamización y tratamiento de HTA, el síndrome metabólico y el acceso temprano a la terapia antirretroviral con medicamentos con mayor perfil de seguridad. Esta guía pretende proveer información y recomendaciones en el ámbito nacional acerca de la relación entre la infección por VIH/SIDA (Síndrome de Inmunodeficiencia Adquirida), uso de antirretrovirales y riesgo cardiovascular.

The implementation of the Plan Esperanza and response to the imPACT Review

Following the implementation of the National Cancer Prevention and Control Results-based Budget Programme (PpR Cancer-024) in 2011, the Peruvian Government approved the Plan Esperanza-a population-based national cancer control plan-in 2012. Legislation that ensured full government-supported funding for people who were otherwise unable to access or afford care and treatment accompanied the Plan. In 2013, the Ministry of Health requested an integrated mission of the Programme of Action for Cancer Therapy (imPACT) report to strengthen cancer control in Peru. The imPACT Review, which was executed in 2014, assessed Peru's achievements in cancer control, and areas for improvement, including cancer control planning, further development of population-based cancer registration, increased prevention, early diagnosis, treatment and palliative care, and the engagement and participation of civil society in the health-care system. This Series paper gives a brief history of the development of the Plan Esperanza, describes the innovative funding model that supports it, and summarises how funds are disseminated on the basis of disease, geography, and demographics. An overview of the imPACT Review, and the government's response in the context of the Plan Esperanza, is provided. The development and execution of the Plan Esperanza and the execution of and response to the imPACT Review demonstrates the Peruvian Government's commitment to fighting cancer across the country, including in remote and urban areas.

Abstract P5-09-08: Molecular evaluation of Peruvian patients with hereditary breast cancer reveals a novel germline mutation in BRCA1

Background

Breast cancer is the leading cancer in women worldwide, while in Peru is the second most frequent cancer with a high incidence of triple negative breast cancers (21%). There is no previous information about BRCA1/BRCA2 mutations in Peruvian high-risk breast cancer patients. Prior studies from International diagnostic laboratories only presented results of our population as a pooled Hispanic data. Our aim was to characterize mutations in BRCA1/BRCA2 genes in Peruvian patients with breast cancer with hereditary patterns.

Methods

We evaluated mutations in BRCA1/BRCA2 genes by Sanger sequencing and large genomic rearrangements by multiplex ligation-dependent probe amplification (MLPA) in 18 families with hereditary breast cancer criteria identified at the Breast Unit of Oncosalud-AUNA (Lima-Peru). Molecular analysis was done in the facilities of Genetics and Molecular Biology Center at the San Martin de Porres University (Lima-Peru).

Results

Sequencing identified 4 pathogenic mutations in 4/18 families, three previously detected (BRCA1: c.302-1G&gt;C y c.815_824dup10; BRCA2: c.5946delT) and a novel germline mutation in exon 15 of BRCA1 (c.4647_4648dupAA, ClinVar SCV000256598.1) producing a frameshift variant. MLPA revealed 2 amplifications in exon 7 (duplication and triplication) in BRCA1 in unrelated patients with potential pathogenic effects, one of this co-existed with the BRCA2: c.5946delT mutation. In addition, three variants of uncertain significance were found (c.140G&gt;T, in exon 5 of BRCA1 and c.464G&gt;A and c.938C&gt;T in exon 5 and 10 of BRCA2, respectively).

Conclusions

After a comprehensive evaluation we found an alteration rate of 27.8% (5/18) in BRCA1/BRCA2 in families with criteria for hereditary breast cancer. We reported BRCA1 c.4647_4648dupAA as a novel mutation. Further studies including a larger sample size of Peruvian patients should evaluate the prevalence or founder effect of this mutation in our population.

Citation Format: Ponce J, Vigil C, Araujo JM, Castañeda C, Calderon G, Buleje JL, Acosta O, Danos P, Huaman F, Guevara-Fujita ML, Aguilar A, Pinto JA, Gomez HL, Fujita R. Molecular evaluation of Peruvian patients with hereditary breast cancer reveals a novel germline mutation in BRCA1 [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-09-08.

Sentinel lymph node biopsy and axillary dissection in breast cancer: results in a Latina population

Aim: we aim to evaluate accuracy of sentinel node (SN) in biopsy breast cancer (BC). Patients & methods: We reviewed 1259 early cases who underwent SN biopsy between 1996 and 2010. Results: Median age was 52 years; and 48.9, 39.7, 68.4 and 12.1% had T2, HG-III, ER+ and HER2+++, respectively. Median SN was two nodes, 34.3% had SN+ and 41.6% went to axillary dissection (AD). SN-positive is associated with AD-positive nodes (p < 0.001). Number of SN-positive were related to number of AD-positive nodes (p < 0.001). Factors predicting AD-positive nodes in the SN-positive group were lymphovascular invasion (p = 0.016) and HG III (p = 0.041). Axillary recurrence was similar in those with or without AD nodes (0.0136 vs 0.0153, p = 0.8023). Conclusion: The SN predicts AD involvement and offers a low rate of axillary recurrence in our Latina population.

[Parametrial involvement in cervical cancer IB1 patients treated with radical hysterectomy in Peru]

OBJECTIVES

To assess the frequency and factors associated with parametrial involvement (PI) in patients with cervical cancer IB1 who underwent radical hysterectomy (RH) at the National Institute of Neoplastic Diseases in Peru.

MATERIALS AND METHODS

Cross-sectional study of 214 patients with cervical cancer IB1 undergoing RH with pelvic lymphadenectomy between 2007 and 2012. The population was compared with and without clinicopathological variables associated with PI such as age, tumor size, depth of infi histological grade and pelvic lymph node involvement.

RESULTS

Ten patients (4.6%) had PI. Multivariate analysis showed that the depth of invasion (OR 8.37, 95% CI 1.24- 56.41, p=0.029) and pelvic node involvement (OR 18.03; 95% CI 3.30-98.44, p=0.001) were all independent predictors of PI. The presence of tumor size = 2 cm, invasion = 10 mm, absence of lymphovascular permeation and absence of nodal involvement identifi 97 patients at low risk of PI, none of whom had PI pathology.

CONCLUSIONS

We confi the low frequency of PI in the cervical cancer IB1 subgroup and its association with the depth of invasion and lymph node involvement suggested in previous studies. This information will allow the identifi of a subgroup of patients at low risk of PI for less radical surgery in our institution.

Carbapenem resistance and mortality in patients with Acinetobacter baumannii infection: systematic review and meta-analysis

Acinetobacter baumannii has emerged as a major cause of healthcare-associated infections. Controversy exists as to whether antimicrobial resistance increases the risk of mortality. We conducted a systematic review and meta-analysis to examine this association. We searched MEDLINE and EMBASE databases up to May 2013 to identify studies comparing mortality in patients with carbapenem-resistant A. baumannii (CRAB) vs. carbapenem-susceptible A. baumannii (CSAB). A random-effects model was used to pool Odds Ratios (OR). Heterogeneity was examined using I(2). We included 16 observational studies. There were 850 reported deaths (33%) among the 2546 patients. Patients with CRAB had a significantly higher risk of mortality than patients with CSAB in the pooled analysis of crude effect estimates (crude OR = 2.22; 95% CI = 1.66, 2.98), although substantial heterogeneity was evident (heterogeneity I(2) = 55%). The association remained significant in the pooled adjusted OR of 10 studies. Studies reported that patients with CRAB compared to patients with CSAB were more likely to have severe underlying illness and also to receive inappropriate empirical antimicrobial treatment, which increases the risk of mortality. Our study suggests that carbapenem resistance may increase the risk of mortality in patients with A. baumannii infection. However, cautious interpretation is required because of the residual confounding factors and inadequate sample size in most studies.

Paraparesia espástica tropical asociada a HTL-1. Comunicación de un caso

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Molecular biomarkers as predictive factors of pCR for early triple-negative breast cancer

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Background: Early triple-negative breast cancer (TNBC) patients (p) without pathologic complete response (pCR) after neoadjuvant chemotherapy (NCT) have unsuccessful prognosis. Predictive factors for pCR are necessary in order to improve the treatment choice. The aims of the study are to determine the expression of different biomarkers (BM) in the initial biopsy (IB) of TNBC, to analyze the relationship between the BM expression and pCR, and to determine the expression changes of BM after NCT. Methods: We reviewed retrospectively the medical records of 49 TNBC p treated with NCT between 2001 and 2011 at two institutions. Expression of 14 BM in the IB and after NCT was independently analyzed by inmunohistochemistry by two pathology specialists. Staining intensity 0-1 + was considered as negative expression, and 2-3-4 + as positive. Ki 67>13% was interpreted as positive. Results: Forty-nine p with a median age of 47 years (27-79) were evaluated. Twenty-seven p (55%) had grade 3. Tumor stages were T1(2%), T2(26%), T3(39%), and T4(33%). 38p (77%) were node positive. Five p (10%) received anthracyclines and 42p (86%) anthracyclines plus taxanes. Fourteen p (29%) presented pCR, 27p (55%) partial response, 4p (8%) stable disease, 2p (4%) progressive disease, and 2p (4%) were not evaluable. The BM expression in the IB was: CD44 (88%), CK 5/6 (27%), EGFR ( 0%), Ki 67 (73%), Wt-1 (10%), p-Akt (24%), HER2 (19%), NY-ESO-1 (11%), MAGE A1 (0%), HER3 (14%), BRCA1 (84%), PTEN (12%), IGFR1 (12%) and AR (14%). Diferentially expressed BM in IB for p with and without pCR, respectively, were p-Akt 0/8(0%) vs 5/13(38%) p=0.11, CK 5/6: 4/9 (44%) vs 2/15 (13%) p=0.15 and Ki 67: 7/7(100%) vs 10/17(59%) p=0.06. The Table shows the BM expression before and after NCT for p without pCR. Conclusions: Tumor samples of TNBC show high expression of CD44, ki67, and BRCA1. Most of BM has a decrease in expression after NCT. CK 5/6, Ki 67, and p-Akt could be predictive factor for pCR, although larger prospective studies are needed. [Table: see text]

Mammographic findings in locally advanced breast carcinoma treated with neoadjuvant chemotherapy

e12538

Background: Breast Cancer (BC) is a heterogeneous disease. Mammograpy images of BC has been associated with tumor features. We evaluated relationship between radiologic features of pre-neoadjuvant chemotherapy (NAC) lesions and clinico pathological tumor features. Methods: We evaluated mammography films and clinicopathological information of BC patient who received NAC followed by tumor resection at Instituto Nacional de Enfermedades Neoplásicas from 2000 to 2011. Results: 495 BC cases were selected. Most cases were staged in clinical Tumor size stage 4 (48.2%) and node stage 1 (58.7%); and had a GIII histological grade (51.2%). Breast density (BD) was classified as BIRADS grade 1 in 17%, grade 2 in 22%, grade 3 in 35% and grade 4 in 25.3%. High BD has been associated to younger age (p<0.001) and obesity (p=0.012). An association between mammographic rounded shape and triple-negative (TN) phenotype was found (p=0.002). An association between the dusty microcalcification and HER2 group as well as between the casting and the TN BC group (p=0.001) is found. NAC included anthracyclines and taxanes in 422 (85.4%) cases. Four and 5 Miller Payne pathologic response (pR) in the primary lesion and absence of axilary lymph nodes involvement were found in14.8% of the whole population, and in 10.5% of luminal cases, 17.7% of HER2- enriched and 23% of TN BC. pCR was associated to patient age (p<0.001), tumor grade (p<0.001) and high breast density (p=0.001), as well as better DFS (p=0.05). Conclusions: Radiographic images are related to tumor features in pre-NAC BC cases. pCR is associated to high density breast as well as previously described clinicopathological features.

Impact of carbapenem resistance on clinical and economic outcomes among patients with Acinetobacter baumannii infection in Colombia

Acinetobacter baumannii is a major cause of healthcare-associated infection, often affecting critically ill patients. The purpose of the study was to examine the associations of carbapenem resistance with mortality, length of hospital stay and hospital costs among patients infected with A. baumannii in intensive-care units (ICUs) in Colombia. A prospective, multicentre cohort study was conducted among 165 patients with A. baumannii infection admitted to ICUs between April 2006 and April 2010. Patients with carbapenem-resistant A. baumannii had higher risk of 30-day mortality than patients with carbapenem-susceptible A. baumannii in the univariate analysis (unadjusted hazard ratio = 2.12; 95% CI 1.14-3.95; p 0.018). However, carbapenem resistance was not significantly associated with risk of mortality (adjusted hazard ratio = 1.45; 95% CI 0.74-2.87; p 0.28) after adjusting for APACHE II score and other confounding factors. We did not find a significant difference in length of stay in ICU after the onset of infection between the two groups in the multivariate analysis (adjusted mean = 13.1 days versus 10.5 days; p 0.14). The average total cost of hospitalization among patients with carbapenem-resistant A. baumannii was significantly higher than that among patients with carbapenem-susceptible A. baumannii in the multivariate analysis (adjusted cost; US$ 11 359 versus US$ 7049; p <0.001). Carbapenem resistance was not significantly associated with mortality, though we are unable to rule out an increased risk due to the limited sample size. Carbapenem resistance was associated with an additional cost of hospitalization.

Estrogen receptor in HER2-positive early breast cancer: Two different diseases?

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Background: HER2+ breast cancer (BC) is a well characterized subtype of BC, due to the predictive value of HER2 overexpression for anti-HER2 targeted therapies. Nevertheless, around 50% of HER2+ BC are ER+ and clasiffied as luminal B/HER2+, but their biological and clinical behaviour may be different from HER2+/ER- tumors. Methods: We retrospectively reviewed 347 HER2+ (Herceptest +++ or FISH+) early BC patients (see Table) diagnosed at our institution in 1997-2007, and were divided into two study groups: HER2+/ER+ (group A) and HER2+/ER- (group B). ER+ was defined if expressed in > 10% tumor cells. Results: See table below. Mean age: 54.7 y (44.6 – 65). Mean Ki 67 was higher in B (37,2 vs 22,4%, p<0.0001). At the current FU, n¼ of events were insufficient to reach median DFS/OS. Mean DFS was 6.9 y (3.5 – 10.2); recurrent disease was higher (p 0.003) for B (54 pts, 43%) vs A (62 pts, 28%). 5-year DFS estimates: 78.4 % (95% CI 72.3 – 83.3) and 62.3 % (95% CI 53 – 70.27) for A and B, and 10-year DFS was 73.4% (95% CI 66.6 – 79) and 52.5% (95% CI 42.4 – 61.6) for A and B, respectively (p 0.0006). Most common recurrent sites were local (18) and bone (9) for HER2+/ER+ and liver (8) and lung (8) for HER2+/ER-. Mean OS was 8.03y (5.4 – 10.8); 28 (12,6%) pts died in A, vs 26 (21%) in B (p 0.043). 5-year OS estimates: 93.9 % (95% CI 89.7 – 96.4) and 87.6 % (95% CI 80.3 – 92.3) for A and B, and 10-year DFS was 84.2% (95% CI 77.5 – 89.0) and 74.1% (95% CI 63.4 – 82.2) for A and B, respectively (p 0.01). Conclusions: ER expression in HER2+ early BC defines two clinically distinct diseases with different long-term prognosis. These data may help to better individualize adjuvant therapies and future clinical trial designs. [Table: see text]

Evidence for cooperative and domain-specific binding of the signal transducing adaptor molecule 2 (STAM2) to Lys63-linked diubiquitin

As the upstream component of the ESCRT (endosomal sorting complexes required for transport) machinery, the ESCRT-0 complex is responsible for directing ubiquitinated membrane proteins to the multivesicular body pathway. ESCRT-0 is formed by two subunits known as Hrs (hepatocyte growth factor-regulated substrate) and STAM (signal transducing adaptor molecule), both of which harbor multiple ubiquitin-binding domains (UBDs). In particular, STAM2 possesses two UBDs, the VHS (Vps27/Hrs/Stam) and UIM (ubiquitin interacting motif) domains, connected by a 20-amino acid flexible linker. In the present study, we report the interactions of the UIM domain and VHS-UIM construct of STAM2 with monoubiquitin (Ub), Lys(48)- and Lys(63)-linked diubiquitins. Our results demonstrate that the UIM domain alone binds monoubiquitin, Lys(48)- and Lys(63)-linked diubiquitins with the same affinity and in the same binding mode. Interestingly, binding of VHS-UIM to Lys(63)-linked diubiquitin is not only avid, but also cooperative. We also show that the distal domain of Lys(63)-linked diubiquitin stabilizes the helical structure of the UIM domain and that the corresponding complex adopts a specific structural organization responsible for its greater affinity. In contrast, binding of VHS-UIM to Lys(48)-linked diubiquitin and monoubiquitin is not cooperative and does not show any avidity. These results may explain the better sorting efficiency of some cargoes polyubiquitinated with Lys(63)-linked chains over monoubiquitinated cargoes or those tagged with Lys(48)-linked chains.

Nonenzymatic assembly of natural polyubiquitin chains of any linkage composition and isotopic labeling scheme

Polymeric chains made of a small protein ubiquitin act as molecular signals regulating a variety of cellular processes controlling essentially all aspects of eukaryotic biology. Uncovering the mechanisms that allow differently linked polyubiquitin chains to serve as distinct molecular signals requires the ability to make these chains with the native connectivity, defined length, linkage composition, and in sufficient quantities. This, however, has been a major impediment in the ubiquitin field. Here, we present a robust, efficient, and widely accessible method for controlled iterative nonenzymatic assembly of polyubiquitin chains using recombinant ubiquitin monomers as the primary building blocks. This method uses silver-mediated condensation reaction between the C-terminal thioester of one ubiquitin and the ε-amine of a specific lysine on the other ubiquitin. We augment the nonenzymatic approaches developed recently by using removable orthogonal amine-protecting groups, Alloc and Boc. The use of bacterially expressed ubiquitins allows cost-effective isotopic enrichment of any individual monomer in the chain. We demonstrate that our method yields completely natural polyubiquitin chains (free of mutations and linked through native isopeptide bonds) of essentially any desired length, linkage composition, and isotopic labeling scheme, and in milligram quantities. Specifically, we successfully made Lys11-linked di-, tri-, and tetra-ubiquitins, Lys33-linked diubiquitin, and a mixed-linkage Lys33,Lys11-linked triubiquitin. We also demonstrate the ability to obtain, by high-resolution NMR, residue-specific information on ubiquitin units at any desired position in such chains. This method opens up essentially endless possibilities for rigorous structural and functional studies of polyubiquitin signals.

Delineation and functional status monitoring in small saline wetlands of NE Spain

The small playa-lakes and other saline wetlands of Monegros, scattered over a dry area with winter cereal monoculture, are threatened by the settlement of new irrigation districts and other kinds of human pressure. Enforcing the protection rules of European Union in these valuable habitats requires, first, their delimitation and monitoring. This article shows how these tasks can be undertaken using remote sensing in conjunction with field observations. A series of Landsat images covering different seasons provided a comprehensive view of these wetlands encompassing their changing facies, hydrologic regime, state of conservation, and functional status. Remotely-sensed data were the primary, and in most cases the only available, source of consistent information. Our approach can help planning and surveying for the implementation of saline wetland protection measures in harmony with the conterminous agricultural areas.

Land cover mapping of wetland areas in an agricultural landscape using SAR and Landsat imagery

Saline wetlands in the Monegros Desert, NE Spain, are situated in an agricultural landscape which is undergoing significant changes. Agricultural intensification in recent decades and current installation of new irrigation systems threaten these valuable habitats, set to be included in the Natura2000 network. Their preservation and successful management depend on the information available regarding the transformation of surrounding areas. When soil and vegetation maps at adequate scale are not available, remote sensing is an alternative means to obtain needed data. We have used SAR data, taking advantage of the soil surface characteristics perceived in SAR images. The objective of this work is to explore the capability of multitemporal SAR data to characterize the land covers of these wetlands and their environment. We have developed specific contextual classifications which take into account the statistical properties of the radar distribution. Moreover, we tested the contribution of radar in Landsat classification.

Treg phenotype in T-cell lymphomas

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Background: Foxp3 is a key regulatory gene required for the development and function of: regulatory CD4+CD25high T cells (Treg) specialized in maintaining the balance between immunity and tolerance and activated conventional CD4+CD25low T cells without suppressive activity. Previous studies had reported the origin of Adult T-cell Leukemia/Lymphoma cells (ATLL) in Foxp3 T cells and in other lymphomas types the FOXP3 expression was only detected in the reactive T-cell background. Our objetive was to determine the presence of Treg phenotype cells by the FOXP3 expression in T-cell lymphomas. Methods: A retrospective study was performed on 48 samples collected from diverse T-cell lymphomas in our institution. A highly sensitive immunohistochemical method was used to demonstrate Treg phenotype by FOXP3 protein expression with a mouse monoclonal antibody (clone 236A/E7ABCAM) in most formalin-fixed paraffin-embedded tissue sections from lymph nodes, skin, bone marrow and extranodal sites samples as cavum and stomach. We did not co-stained with CD25 and considered a FOXP3+ tissue when positivity was > 20% of tumor cells. The statistical method was descriptive and survival was calculated using the Kaplan-Meier method. Results: Among the 48 evaluable T-cell lymphomas collected, 33 were ATLL, 8 unspecified peripheral T-cell lymphomas (U-PTCL), 6 mycosis fungoides (MF) and 1 cutaneous aggressive epidermotropic CD8(+) cytotoxic T-cell lymphoma. Among the 33 ATLL: lymphomatous=17, acute=11, smoldering=1, chronic=1, cutaneous=1 and undefined=2. FOXP3 expression in tumour cells was detected in 24% (8/33) of ATLL cases and in 37% (3/8) of U-PTCL. It was negative in MF tumour cells and aggressive epidermotropic CD8(+) cytotoxic T-cell lymphoma Among the ATLL cases FOXP3 positivity were obtained in 35% (6/17) of lymphomatous type; 18% (2/11) of acute ones and none in others ATLL types studied. Interestingly 3 U-PTCL had Treg phenotype and were related to EBV (LMP1 positive); two had extranodal primary ( parotide and cavum) and one was nodal. We failed to demonstrate any correlation between FOXP3 status and survival. Conclusions: Some ATLL and U-PTCL had Treg phenotype. In our work Foxp3 expression was not found to be a prognostic factor.

No significant financial relationships to disclose.

Dyed-polyvinyl alcohol films: molecular weight and hydrolysis degree influence on optical recording

An analysis of different polyvinyl alcohol films dyed with Malachite Green is presented. Absorbance and diffraction efficiency of holographic gratings are compared, taking as a parameter the molecular weight and hydrolysis degree of the polymer. It is observed that, using the same dye concentration, the absorption coefficient of the films increases as the molecular weight increases. The absorbance of these plates can be modified when exposed to UV light. In addition, it is found that for holographic recording there is an optimal dye-polymer system film.

HLA DQA1*0501 and DQB1*02 in Cuban celiac patients

Celiac disease (CD) susceptibility has been strongly associated with HLA-DQ2 and HLA-DQ8. The main objective of this study was to assess the distribution of HLA DQA1*0501 and DQB1*02 alleles (DQ2) for the first time in a group of Cuban celiac patients. We evaluated 22 patients, 54 first-degree relatives, and 60 controls for detection of antitissue transglutaminase (tTG)-specific antibodies in serum. We found that 100% of the probands and 19% of the first-degree relatives were positive for the antibodies in serum. We did not detect any specific response for the healthy control individuals. We observed a significant over-representation of DQ2 heterodimer, both in patients and relatives. In the group of patients, 86.3% were positive for DQA1*0501, 90.2% were positive for DQB1*02, and 86.3% were positive for both alleles. The frequencies in relatives and controls were as follows: 70%, 90%, and 70%; and 56.6%, 45%, and 20%, respectively. In conclusion, we found that the proportion of our celiac patients carrying DQ2 was similar to the proportion of CD patients reported in populations with different genetic backgrounds. These results underline the primary importance of HLA-DQ alleles in susceptibility to celiac disease.

Biological modifiers as cytoreductive therapy before stem cell transplant in previously untreated patients with multiple myeloma

BACKGROUND

High dose chemotherapy with supporting autologous stem cell transplantation is now considered the treatment of choice in patients with multiple myeloma <65 years old. The best regimen appears to be VAD (vincristine, doxorubicin and dexamethasone), but acute and late toxicity can limit the use of this combination. The use of biological modifiers has not been considered in this situation. We developed a new cytoreductive regimen, in an attempt to retain clinical efficacy but reduce toxicity.

PATIENTS AND METHODS

Thirty-six patients, previously untreated with diagnosis of multiple myeloma were enrolled to received the DAI regimen (dexamethasone 30 mg/m(2), i.v., days 1-4, all-trans-retinoic acid 45 mg/m(2), p.o., days 5-14 and interferon alpha 2a, 4.5 MU s.c., days 5-14) administered every 28 days for six cycles before high-dose chemotherapy (melphalan 200 g/m(2)) and autologous stem cell transplantation.

RESULTS

Overall response was observed in 29 cases (80%), complete response in 19 and partial response in 10 patients. Five patients were >65 years old and were treated with dexamethasone/thalidomide. Twenty-four patients underwent transplants. At a median follow-up of 31.6 months, no relapse or disease progression was observed, thus actuarial curves at 3-years showed that event-free survival was 86% and overall survival was 94%. Toxicity was mild.

CONCLUSIONS

This regimen appears to be an excellent alternative as cytoreductive treatment before high-dose chemotherapy and autologous stem cell transplantation with excellent overall response and minimal toxicity. Controlled clinical trials are warranted to define the role of this new therapeutic approach.

Peripheral neuropathy associated with treatment for multidrug-resistant tuberculosis

OBJECTIVE

To review the incidence and management of peripheral neuropathy in patients receiving therapy for MDR-TB.

METHODS

A case series with retrospective chart review of 75 patients who initiated individualized therapy for multidrug-resistant tuberculosis (MDR-TB) in Lima, Peru, between 1 August 1996 and 31 January 1999.

RESULTS

All patients had confirmed MDR-TB and were receiving individualized therapy, comprised of an average of six drugs. Ten (13%) of these patients presented with symptoms of peripheral neuropathy, confirmed by electromyography. All symptoms were reported in the lower extremities, and all were sensory in nature. Median time to presentation from initiation of MDR-TB therapy was 9.1 months. No significant risk factors associated with development of peripheral neuropathy were identified. Management strategies depended on the severity of symptoms and included the treatment of contributing co-morbidities, medications for neuropathic pain, and adjustment of doses of possible offending agents. All patients responded to management; three patients were left with mild residual symptoms. Patients whose neuropathy resolved had symptoms for a median of 7 months.

CONCLUSIONS

Peripheral neuropathy was encountered in 13% of our cohort of MDR-TB patients. The diagnosis of peripheral neuropathy can be based on clinical presentation alone, and effective management of this side-effect is possible without sacrificing MDR-TB treatment efficacy.

[Interferon alfa 2b treatment decreases histological activity in children with chronic hepatitis B]

Interferon alfa (IFN-alpha) is the only approved treatment for chronic hepatitis B (HBV) infection. In a non-controlled study 33 pediatric patients infected with HBV and in chronic phase of the disease were included and treated with 3 to 5 x 10(6) IU/m2 body surface of Interferon alpha 2b, 3 times per week, during 4 months. The objective was to evaluate the efficacy of the treatment in terms of the histological, biochemical and viral markers evolution of the patients. The patients were evaluated carrying out determinations of alanine aminotransferase (ALAT), HBsAg and HBeAg before treatment, at the end of the treatment and every 4 months during one year of follow-up. Liver biopsy and Knodell index determination were carried out at the beginning and upon concluding the follow-up. 39.3% of the patients concluded the treatment with normal ALAT values; 7% became HBsAg negative and 14.3% became HBsAg negative. These values ascended after follow-up to 51.5%, 11% and 37.5% respectively. The histological analysis evidenced a decrease of the Knodell index in 69% of the patients, an increase in 14.2%, and 13.8% did not show variation. Correlating the biochemical and histological responses, a favorable outcome was obtained in 36.4% of the patients, evidencing a remarkable reduction of the hepatic cytolysis. The treatment was well tolerated, being the fever the most frequent adverse events. The results confirm that interferon alfa seems to be an effective treatment for children with chronic hepatitis B.

Nutritional status indicators and their interactions in rural Guatemalan elderly: a study in San Pedro Ayampuc

Anthropometry and body-composition measures, hematologic and biochemical measures of nutritional status, and helminthic infection were studied in the population of elderly persons (> or = 60 y of age) in a rural village in Guatemala that was 65% Mayan (indigenous) and 35% ladino (European). The population had low levels of literacy and formal education. The elderly persons were much shorter and lighter than reference populations. Anemia was present in 18% of the population, and riboflavin and vitamin B-12 deficiencies were detected in 70% and 38%, respectively. Both anthropometric and biochemical-hematologic variables were lower, on average, in the Mayan descendants than in the ladinos. When grouped by body mass index (BMI; in kg/m2), greater BMI signified higher values for almost all biochemical-hematologic measures. Sixty-five percent of the sampled population had mild-to-moderate Ascaris lumbricoides and Trichuris trichiura infections. The lifestyle in rural Guatemala is evolving, and the present findings provide insights into the evolution of nutritional status in the growing number of elderly in the countryside.

Tropical spastic paraparesis and HTLV-I infection: clinical and epidemiological study in Lima, Peru

A descriptive study was performed to investigate the epidemiology and clinical features of 50 patients with tropical spastic paraparesis (TSP) associated with HTLV-I infection acquired in Peru. Cases seen at two reference centers in Lima (Alexander von Humboldt Tropical Medicine Institute and Guillermo Almenara National Hospital) between August 1989 and December 1995 are reviewed. All patients had serologic evidence of infection with reactive ELISA tests for HTLV-I, confirmed by positive Western blot assays. The male-female ratio of cases was 1.0:1.78. The mean age at the time of diagnosis was 52.4 years (range: 29 to 73, SD:11.3). A considerable proportion of patients (68%) had lived in Andean regions: this basically due to their native places (48%) because only 8% of cases were referred from these regions. The mean duration of symptoms prior to diagnosis was 4.95 years (range 0.5-22 years). The clinical features at diagnosis included progressive spastic paraparesis (100%) associated with sphincter disturbances (77.7%), paresthesia (61.1%) or lumbar pain (44%). The functional status of all patients was impaired at the time of evaluation: 44.1% walked unaided with a 'scissors-like' gait, 38% used assist devices for walking, 10% used wheelchairs and 8% were bedridden.

[Immunological detection of aflatoxin-albumin adducts in children with chronic hepatitis B infection]

The value of aflatoxins is well known as a carcinogenic, mutagenic and teratogenic, likewise its association with the hepatitis B virus. In addition, it is known the incidence of hepatocellular carcinoma in such viral infection. A study was performed on the albumin adducts-aflatoxins levels in sera determined by ELISA method of children within 3-15 years old at the Service of Pediatric Gastroenterology from the National Institute of Gastroenterology. Samples consisted of 40 patients with chronic active hepatitis (CAH) B, 10 HBsAg+ carriers and 20 controls. The CAH group, showed a 32.5% of positiveness with a maximum levels of 25pg aflatoxin lysine/mg albumin while 20% of HBsAg positive carriers showed levels of un 12.3 pg aflatoxin lysine/mg albumin and 15% of the control group 5pg AF lysine/mg albumin. It can be observed that aflatoxin levels in patients of CAH presented values up to 5 times over the control group. This study suggest the validity of aflatoxin-albumin adducts as a marker of chronic exposure to this carcinogen and its importance in relation with the virus of hepatitis B.

Electroencephalography in congenital malformations of the central nervous system

We studied clinical and EEG features of 36 cases with congenital malformations of the CNS. Patients were followed at the outpatient clinic of Hospital Cayetano Heredia and of Hogar Clinica San Juan de Dios in Lima-Peru, from January 1984 to June 1992. Eighty percent of the patients had convulsive syndromes and mental retardation. The most frequent malformation was agenesis of corpus callosum, and it was not possible to find a "typical" EEG pattern. The second were porencephalic cysts, with a good clinical-EEG correlation. There were two typical cases of schizencephaly, one of hemimegalencephaly with good prognosis, and one of holoprosencephaly. The results are compared to those obtained for a series we previously reported. Data discussed take into account reports on the subject registered in the literature. It is concluded that EEG is an useful method to evaluate possible CNS malformations in developing countries.

Prevalence of riboflavin deficiency among Guatemalan elderly people and its relationship to milk intake

Six groups of elderly subjects from central Guatemala were assessed for riboflavin status by using the erythrocyte glutathione reductase activity coefficient (EGRAC). The prevalence of riboflavin deficiency ranged from 50% to 76% among the free-living rural elderly subjects. Milk intake data that were collected from some of the subjects showed a significant correlation (P < 0.0001) between frequency of milk intake and riboflavin status. In a short-term riboflavin supplementation experiment in which nine riboflavin-deficient subjects were given 10 mg riboflavin/d for 3 d, all the subjects' EGRACs were normalized by the supplementation. However, they returned to a state of deficiency within 2 wk while consuming their usual diets without supplementation. It appears that the high prevalence of riboflavin deficiency in elderly Guatemalan people is caused by inadequate intake of riboflavin-rich foods such as dairy products, and that sufficient amounts of riboflavin need to be ingested regularly to maintain satisfactory riboflavin status.