Comparison of energy expenditure of individuals with Duchenne muscular dystrophy in the sitting posture on the ground and in water.

Duchenne Muscular Dystrophy (DMD) is one of the most frequent childhood dystrophies, affecting cardiopulmonary functions and walking ability. One of the main symptoms is fatigue, which is caused by altered muscle metabolism related to energy expenditure (EE). Aquatic physiotherapy is a therapeutic modality that facilitates the maintenance of this posture because of immersion on the body. This cross-sectional observational study aimed to compare the EE on the ground and water of individuals with DMD through oxygen consumption in the maintenance of sitting posture. The individuals were in a sitting position on the ground and in the water for 20 min for the assessments. The variables peripheral oxygen saturation, heart rate, maximum expiratory pressure, maximum inspiratory pressure, forced vital capacity, respiratory quotient (RQ), and oxygen consumption per kilogram of body weight (VO2 /kg) were compared, adopting a significance of 5 %. No difference was found between medians and quartiles of RQ when comparing the two environments. The same was observed for VO2 /Kg values on the ground and in water. The data from this study demonstrate that the EE of individuals with DMD did not change when maintaining a sitting posture on the ground and in water.

Incidencia de síndrome de dolor postmastectomía en Colombia / Incidence of post-mastectomy pain syndrome in Colombia

Abstract Introduction: Breast cancer in Colombia is the first cause of cancer death. Post-mastectomy pain syndrome ranges from 13% to 69%; there are no regional studies evaluating its incidence among our population. Objectives: Determining the incidence of post-mastectomy pain syndrome in patients diagnosed with breast cancer undergoing therapeutic oncology surgery at Hospital Universitario de Santander. Materials and methods: Observational, prospective study of a cohort from January, 2014 through July, 2015 during the Pain Clinic follow-up evaluating the occurrence of post-mastectomy pain syndrome. Results: In all, 76 patients were followed and a 55.3% incidence of the post-mastectomy pain syndrome was identified. Among them, 54.8% were classified as mild intensity (visual analog scale [VAS] <4), 42.9% as moderate intensity (VAS 5-7), and 2.4% severe intensity (VAS >8). The most frequent type of pain identified was myofascial pain (42.1%), followed by neuropathic pain (34.2%). Among the group of patients with this type of pain, a relationship was identified between age below 49 years, and this presentation (P = 0.018). Conclusions: The incidence of post-mastectomy pain is 55.3%, higher than various world publications. We found that younger patients were more prone to develop myofascial post-mastectomy pain syndrome.

Resumen Introducción: El cáncer de mamá en Colombia es la primera causa de muerte oncológica. El síndrome de dolor post mastectomía es de 13 a 69%; no hay estudios a nivel regional que evalúen su incidencia en nuestra población. Objetivos: Determinar la incidencia de síndrome de dolor post mastectomía en pacientes con diagnóstico de cáncer de mama sometidas a cirugía oncológica terapéutica en el Hospital Universitario de Santander. Materiales y métodos: Estudio observacional prospectivo de una cohorte en el período de enero de 2014 a julio de 2015 durante el seguimiento por Clínica de Dolor que evaluó la aparición de síndrome de dolor post mastectomía. Resultados: Se realizó seguimiento a 76 pacientes, se encontró una incidencia de síndrome de dolor post mastectomía de 55.3%, de las cuales un 54.8% fueron clasificadas como intensidad leve (Escala visual análoga - EVA < 4), 42,9% como intensidad moderada (EVA 57) y 2,4% de intensidad severa (EVA > 8). La característica de dolor el más frecuentemente encontrado fue el de tipo miofascial (42,1%) seguido por el dolor neuropático (34,2%). En el grupo de pacientes con dolor de tipo miofascial se encontró una relación entre la edad menor a 49 años y la presentación de este tipo (p = 0,018). Conclusiones: La incidencia de síndrome de dolor post mastectomía es del 55,3%, siendo mayor a diferentes publicaciones a nivel mundial. Encontramos que las pacientes de menor edad, eran mas propensas a presentar síndrome de dolor postmastectomía tipo dolor miofascial.

Epidemiological characterization of ophidian accidents in a Colombian tertiary referral hospital. Retrospective study 2004-2014 / Caracterización epidemiológica de accidentes ofídicos en un hospital de tercer nivel en Colombia. Estudio retrospectivo 2004-2014

Abstract Introduction: In Colombia, there are 5 000 cases of ophidism per year. This is a public health issue that causes mortality in 8% of cases and disability in 10% due to inadequate clinical attention. Objective: To describe the clinical and epidemiological characteristics of patients diagnosed with ophidic accident in a tertiary hospital in Colombia. Materials and methods: A review of clinical charts that included a diagnosis of ophidism during the 2004-2014 period was made at Hospital Universitario de La Samaritana Empresa Social del Estado. The frequency of the variables associated with snake bites, previous treatment and in-hospital management was analyzed. Results: 42 medical charts were reviewed. Ophidism predominated in male farmers, who presented with bites in the lower limbs and were initially treated by medicine men/women. 90% of patients developed superinfections, 30% wound culture, 74% received antibiotics, 50% underwent fasciotomy and 95.2% were given antivenin. Conclusions: Significant variability in the management of patients, discrepancy in antivenin dose and in classification of poisoning severity were observed throughout the study, as well as a high incidence of infections despite antibiotic schemes and surgical procedures. Medical management of ophidic accidents must be continuously updated to reduce disability and mortality in patients.

Resumen Introducción. En Colombia se presentan 5 000 casos de ofidismo anuales, un problema de salud pública que por manejo inadecuado provoca mortalidad en el 8% de los casos y discapacidad en el 10%. Objetivo. Describir las características clínicoepidemiológicas de los pacientes diagnosticados con accidente ofídico en un hospital de tercer nivel en Colombia. Materiales y métodos. Se realizó una revisión de las historias clínicas con diagnóstico de ofidismo del Hospital Universitario De La Samaritana Empresa Social del Estado, en el período 2004-2014, analizando la frecuencia en las variables asociadas a la mordedura de serpiente, el tratamiento previo y el manejo intrahospitalario. Resultados. Se revisaron 42 historias clínicas. Predominó el ofidismo en hombres agricultores, con mordedura en miembros inferiores y asistidos inicialmente por curanderos. 90% de los pacientes presentó sobreinfección, 30% tuvo cultivo de la herida, 74% recibió antibiótico, al 50% se les realizó fasciotomía y al 95.2% se le suministró antiveneno. Conclusiones. Se evidenció variabilidad en el manejo de los pacientes y discrepancia en la dosis de antiveneno y la clasificación de severidad del envenenamiento, alta incidencia de infecciones a pesar del esquema antibiótico y procedimientos quirúrgicos reevaluados en ofidismo. El manejo médico del accidente ofídico debe estar en continua actualización para disminuir discapacidad y mortalidad en los pacientes.

Chagas disease immunogenetics: elusive markers of disease progression.

Introduction: Chagas disease (CD) is caused by a parasitic infection. The disease usually occurs after decades of the primary infection and can involve the myocardium or the digestive system. Of note, around 30% of T. cruzi infected patients develop CD while the other 70% may remain asymptomatic for their entire life. CD is usually observed as familial clustered phenomena. Moreover, individuals with chronic Chagas heart disease (CCHD) usually present a strong, deregulated immune response, which strongly suggests an immunogenetic effect.Areas covered: In this article we review and discuss the information currently available from the published scientific literature regarding the genetic variants of molecules of the immune system that contribute to the clinical presentation of the disease.Expert commentary: Of note, the most promissory results are found on the polymorphisms of chemokine receptors, particularly CCR5 and CCR2. Additional investigations are required, particularly with a focus on the genes that regulate the immune system.

The association between serum ß-hydroxybutyrate and milk fatty acid profile with special emphasis on conjugated linoleic acid in postpartum Holstein cows.

BACKGROUND: Ketogenesis is a secondary metabolic pathway to provide energy to dairy cows during early lactation; however when the production of ketone bodies (acetoacetate, acetone, ß- hydroxybutyrate) is above certain levels a subclinical disorder may appear. The aim of the present study was to investigate the association between serum concentrations of ß- hydroxybutyrate (BHBA) and fatty acid (FA) profile of milk with emphasis in conjugated linoleic acid (CLA) in a population of early lactation Holstein cows. Fifty cows between parity 1 and 5, ranging from 14 to 21 days in milk, were randomly selected from 3 farms of the central area of Chile for determination of serum BHBA concentrations, milk fat content, and milk FA profiles. RESULTS: Cows were divided in low (n = 26) and high (n = 24) BHBA groups considering the median value of the serum concentration of BHBA (0.7 mmol/L) (SEM = 0.094). Mean milk fat % was 3.45% and 3.60% for cows in the low and high BHBA groups, respectively (P = 0.15). Concentrations of several FA were significantly different between both groups. Specifically, mean CLA concentrations were 0.40% (4 ± 0.03 g/kg) and 0.33% (3.3 ± 0.03 g/kg) for the low and high BHBA groups, respectively (P = 0.05). CONCLUSIONS: It is concluded that early postpartum cows with serum BHBA > 0.7 mmol/L tended to have higher milk fat % and had significantly lower concentrations of CLA than early postpartum cows with BHBA ≤ 0.7 mmol/L.

PRESENCE OF MYCOBACTERIUM AVIUM SUBSP. PARATUBERCULOSIS IN ALPACAS (LAMA PACOS) INHABITING THE CHILEAN ALTIPLANO.

Mycobacterium avium subsp. paratuberculosis (MAP) is the etiologic agent of paratuberculosis. The organism causes disease in both domestically managed and wild ruminant species. South American camelids have a long, shared history with indigenous people in the Andes. Over the last few decades, increasing numbers of alpacas were exported to numerous countries outside South America. No paratuberculosis surveillance has been reported for these source herds. In this study, individual fecal samples from 85 adult alpacas were collected from six separate herds in the Chilean Altiplano. A ParaTB mycobacterial growth indicator tube (MGIT) liquid culture of each individual fecal sample, followed by real-time polymerase chain reaction (PCR) protocol was used for confirmation. DNA extracts from a subset of confirmed MAP isolates were subjected to mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing. Fifteen alpaca were fecal culture test-positive. Five false-positive culture samples were negative on PCR analysis for Mycobacterium avium subsp. avium (MAA), Mycobacterium bovis (M. bovis), and the 16 S rDNA gene. Three MAP isolates subset-tested belonged to the same MIRU-VNTR type, showing four repeats for TR292 (locus 1) in contrast to the three repeats typical of the MAP reference strain K10. The number of repeats found in the remaining loci was identical to that of the K10 strain. It is not known how nor when MAP was introduced into the alpaca population in the Chilean Altiplano. The most plausible hypothesis to explain the presence of MAP in these indigenous populations is transmission by contact with infected domestic small ruminant species that may on occasion share pastures or range with alpacas. Isolation of this mycobacterial pathogen from such a remote region suggests that MAP has found its way beyond the confines of intensively managed domestic agriculture premises.

Genetic Variants of Cytochrome CYP2D6 in Two Mixed Chilean Populations.

OBJECTIVES: It is known that the interindividual and interethnic variability of the genetic polymorphisms of CYP2D6 plays an important role in the presentation of adverse drug reactions and concerning lack of therapeutic effects in humans. However, there are few data available from mixed populations of Latin America, including the Chilean. The aim of this study was therefore to estimate the frequencies of CYP2D6 variants in two samples of hospitals from the northern (Hospital San José, HSJ) and eastern (Clínica Las Condes, CLC) parts of Santiago, Chile, with different degrees of Amerindian admixture (HSJ: 34.5%; CLC: 15.9%). METHODS: We used polymerase chain reaction followed by restriction endonuclease digestion (PCR-RFLP) to genotype 7 CYP2D6 alleles in 250 healthy unrelated individuals of Chilean Mestizo background. The detection of allele CYP2D6*5 and the duplication of this gene was performed by long-PCR. RESULTS: The degrees of Amerindian admixture are reflected in the observed frequencies of the CYP2D6*1 (HSJ: 58.26%; CLC: 41.06%), CYP2D6*2 (HSJ: 28.10%; CLC: 40.65%), and CYP2D6*4 (HSJ: 8.26%; CLC: 12.60%) alleles; the frequencies of CYP2D6*1 (p = 0.0002) and CYP2D6*2 (p = 0.0036) are significantly different between the samples. Four individuals (CLC: 0.41%; HSJ: 1.24%) could not be assigned to a genotype. We identified 3.25% of the genotypes which predict a poor metabolizer phenotype in CLC and 1.65% in HSJ. CONCLUSION: Our data indicate ethnic group-dependent genetic differences in the vulnerability to treatment with the large variety of drugs metabolized by the enzyme CYP2D6.

Muir-Torre syndrome: case report and molecular characterization.

CONTEXT: Muir-Torre syndrome is a rare autosomal dominant genodermatosis caused by mutations in the mismatch repair genes. It is characterized by the presence of sebaceous skin tumors and internal malignancies, affecting mainly the colon, rectum and urogenital tract. Awareness of this syndrome among physicians can lead to early diagnosis of these malignancies and a better prognosis. CASE REPORT: We report the case of a Chilean patient who, over the course of several years, had multiple skin lesions, endometrial cancer and colon cancer. The syndrome was diagnosed using molecular techniques such as microsatellite instability analysis, immunohistochemistry and DNA sequencing, which allowed us to find the causative mutation. CONCLUSION: Molecular diagnostics is a highly useful tool, since it allows clinicians to confirm the presence of mutations causing Muir-Torre syndrome. It is complementary to the analysis of the clinical data, such as dermatological presentation, presence of visceral malignancies and family history of colorectal tumors, and it provides important knowledge to help physicians and patients choose between treatment options.

Muir-Torre Syndrome: case report and molecular characterization / Sindrome de Muir-Torre: relato de caso e caracterizacao molecular

CONTEXT: Muir-Torre syndrome is a rare autosomal dominant genodermatosis caused by mutations in the mismatch repair genes. It is characterized by the presence of sebaceous skin tumors and internal malignancies, affecting mainly the colon, rectum and urogenital tract. Awareness of this syndrome among physicians can lead to early diagnosis of these malignancies and a better prognosis. CASE REPORT: We report the case of a Chilean patient who, over the course of several years, had multiple skin lesions, endometrial cancer and colon cancer. The syndrome was diagnosed using molecular techniques such as microsatellite instability analysis, immunohistochemistry and DNA sequencing, which allowed us to find the causative mutation. CONCLUSION: Molecular diagnostics is a highly useful tool, since it allows clinicians to confirm the presence of mutations causing Muir-Torre syndrome. It is complementary to the analysis of the clinical data, such as dermatological presentation, presence of visceral malignancies and family history of colorectal tumors, and it provides important knowledge to help physicians and patients choose between treatment options. .

CONTEXTO: A síndrome de Muir-Torre é uma genodermatose autossômica dominante rara causada por mutações nos genes de reparo de incorreções. Caracteriza-se pela presença de tumores sebáceos da pele e doenças malignas internas, afetando principalmente cólon, reto e trato urogenital. A consciência desta síndrome pelos médicos pode levar ao diagnóstico precoce dessas doenças malignas e a um melhor prognóstico. RELATO DE CASO: Relatamos o caso de uma paciente chilena que, ao longo de vários anos, teve lesões cutâneas múltiplas, câncer de endométrio e câncer de cólon. A síndrome foi diagnosticada com técnicas moleculares, como a análise de instabilidade de microssatélites, imunoistoquímica e sequenciamento de DNA, o que nos permitiu encontrar a mutação causadora. CONCLUSÃO: Diagnóstico molecular é uma ferramenta muito útil, uma vez que permite que os clínicos confirmem a presença de mutações causadoras de síndrome de Muir-Torre. É complementar para a análise dos dados clínicos, tais como a apresentação dermatológica, a presença de doenças malignas viscerais e história familiar de tumores colorrectais, e fornece conhecimentos importantes para ajudar os médicos e os pacientes a escolher entre opções de tratamento. .

Prevalence of the 35delG mutation in the GJB2 gene in two samples of non-syndromic deaf subjects from Chile.

Hearing loss is the most common inherited sensorial deficiency in humans; about 1 in 1000 children suffer from severe or profound hearing loss at birth. Mutations in the GJB2 gene are the most common cause of prelingual, non-syndromic autosomal recessive deafness in many populations; the c.35delG mutation is the most common in Caucasian populations. The frequency of the c.35delG mutation was estimated in two samples of deaf patients from Santiago, Chile. Unrelated non-syndromic sensorioneural deaf patients were examined: Group 1 consisted of 47 unrelated individuals with neurosensory deafness referred to the Chilean Cochlear Implant Program; Group 2 included 66 school children with prelingual deafness attending special education institutions for deaf people. Individuals with profound to moderate isolated neurosensory hearing loss with unknown etiology were included. The presence of the c.35delG mutation was evaluated by the allele-specific polymerase chain reaction method (PCR), and in some cases it was confirmed by direct DNA sequencing of the coding region of the GJB2 gene. Deaf relatives were present in 20.3% of the cases. We found 19.5% (22/113) patients with the c.35delG mutation, 6 of them homozygous; these rates are similar to frequencies found in other Latin American countries.

Prevalence of the 35delG mutation in the GJB2 gene in two samples of non-syndromic deaf subjects from Chile

Hearing loss is the most common inherited sensorial deficiency in humans; about 1 in 1000 children suffer from severe or profound hearing loss at birth. Mutations in the GJB2 gene are the most common cause of prelingual, non-syndromic autosomal recessive deafness in many populations; the c.35delG mutation is the most common in Caucasian populations. The frequency of the c.35delG mutation was estimated in two samples of deaf patients from Santiago, Chile. Unrelated non-syndromic sensorioneural deaf patients were examined: Group 1 consisted of 47 unrelated individuals with neurosensory deafness referred to the Chilean Cochlear Implant Program; Group 2 included 66 school children with prelingual deafness attending special education institutions for deaf people. Individuals with profound to moderate isolated neurosensory hearing loss with unknown etiology were included. The presence of the c.35delG mutation was evaluated by the allele-specific polymerase chain reaction method (PCR), and in some cases it was confirmed by direct DNA sequencing of the coding region of the GJB2 gene. Deaf relatives were present in 20.3% of the cases. We found 19.5% (22/113) patients with the c.35delG mutation, 6 of them homozygous; these rates are similar to frequencies found in other Latin American countries.

Cutaneous leishmaniasis in the dorsal skin of hamsters: a useful model for the screening of antileishmanial drugs.

Traditionally, hamsters are experimentally inoculated in the snout or the footpad. However in these sites an ulcer not always occurs, measurement of lesion size is a hard procedure and animals show difficulty to eat, breathe and move because of the lesion. In order to optimize the hamster model for cutaneous leishmaniasis, young adult male and female golden hamsters (Mesocricetus auratus) were injected intradermally at the dorsal skin with 1 to 1.5 x l0(7) promastigotes of Leishmania species and progression of subsequent lesions were evaluated for up to 16 weeks post infection. The golden hamster was selected because it is considered the adequate bio-model to evaluate drugs against Leishmania as they are susceptible to infection by different species. Cutaneous infection of hamsters results in chronic but controlled lesions, and a clinical evolution with signs similar to those observed in humans. Therefore, the establishment of the extent of infection by measuring the size of the lesion according to the area of indurations and ulcers is feasible. This approach has proven its versatility and easy management during inoculation, follow up and characterization of typical lesions (ulcers), application of treatments through different ways and obtaining of clinical samples after different treatments. By using this method the quality of animal life regarding locomotion, search for food and water, play and social activities is also preserved.

DNA extraction from formalin-fixed laryngeal biopsies: Comparison of techniques.

CONCLUSION: PCR-quality DNA could be extracted from formalin-fixed paraffin-embedded (FFPE) samples with amplicons of at least 390 bp. Paraffin removal was not a necessary step. Proteinase K digestion was as efficient as the commercial kit for DNA extraction with a lower cost. OBJECTIVES: To compare different DNA extraction protocols for FFPE samples and to describe the suitability of the extracted DNA for PCR reactions. METHODS: For deparaffinization the following techniques were compared: alkaline heat, xylene, and no removal. For DNA extraction, proteinase K digestion and organic extraction were compared. A commercial extraction kit was included as standard. DNA quality was assessed by PCR amplification of the HFE gene, for amplicons of 208 and 390 bp. RESULTS: Extraction with the commercial kit and proteinase K digestion were more efficient than other techniques, with no statistical difference between them for both amplicons. The proteinase K digestion buffer had a cost of U$ 0.2 per sample and the commercial kit of U$7 per sample.

O vírus da hepatite C como causa de miocardiopatia dilatada idiopática: uma revisão de literatura / Hepatitis C virus as cause of idiopathic dilated cardiomyopathy: a literature review

O vírus da hepatite C (VHC) é hepatotróico de transmissão parenteral. Apesar do hepatotropismo, o VHC também é capaz de infectar outros tecidos e está implicado em diversas doenças, principalmente de natureza auto-imune. Recentes estudos sugerem uma alta prevalência da infecção pelo vírus C em pacientes portadores de cardiomiopatia dilatada idiopática. Sabe-se que a miocardite é comumente causada por diversas viroses e que a progressão para cardiomiopatia dilatada e conseqüente disfunção sistólica, em pacientes previamente hígidos, que tiveram um quadro de miocardite, é uma complicação esperada. Neste trabalho, focalizaremos uma ampla revisão de literatura sobre as inter-relações entre a infecção pelo VHC e a cardiomiopatia dilatada.

Dust mite species and allergen concentrations in beds of individuals belonging to different urban socioeconomic groups in Brazil.

BACKGROUND: Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis dust mites are among the most important agents of hypersensitivity reactions in human beings. However, a role of other mites in the etiology of these reactions has not yet been excluded. OBJECTIVES: To investigate the nature of the dust mite fauna and the presence of Der p 1 (allergen 1 of Dermatophagoides pteronyssinus) and Blo t 5 (allergen 5 of Blomia tropicalis) on beds used by individuals with different socioeconomic backgrounds in Salvador, a major Brazilian city and to investigate possible associations of mite frequencies and allergen levels with (a) season of the year, (b) housing characteristics, (c) bed cleaning behaviors that could affect mite densities, and (d) allergy history. METHODS: Dust samples were collected from 459 beds of 101 residences from two groups with different socioeconomic levels (hereafter called wealthy and poor groups) in the city of Salvador, Brazil, for the identification of mite species and determination of Der p 1 and Blo t 5 levels. History of allergy was collected using the ISAAC phase I questionnaire. RESULTS: Eighty nine percent of the beds analyzed harbored at least one mite species. B. tropicalis was found in 71.8%, D. pteronyssinus in 39.9%, Cheyletus sp. in 33.9%, and Gohieria fusca in 21.1% of the beds. B. tropicalis was found with a similar frequency in beds of the two socioeconomic groups; D. pteronyssinus was found more frequently in the beds of the wealthy than of the poor group, whereas the reverse was observed with G. fusca. The concentrations of Der p 1 and Blo t 5 allergens exceeded the cut-off for sensitization of 2 microg/g of dust in 94.0% and 69.3% of the wealthy and poor group beds, respectively. No associations were found between history of allergy and mite species or between history of allergy and the concentrations of mite allergens. CONCLUSIONS: The observation of B. tropicalis and D. pteronyssinus as the most frequently found mites is consistent with previous reports from tropical regions. The higher frequency of G. fusca in beds of individuals from the poor group than those from the wealthy group could be a consequence of different bed cleaning behaviors between the two groups.

Preconcentration of the herbicide glyphosate and its metabolite AMPA by immobilised metal ion affinity chromatography (IMAC).

A method based on Immobilised Metal Ion Affinity Chromatography (IMAC) using a chelating resin (Spheron Oxine 1000) loaded with Pd(II) is evaluated for the extraction and preconcentration of glyphosate and AMPA from natural water samples. The efficiency of the metal-loaded resin in retaining glyphosate and AMPA and the ability of different reagents to recover them is investigated. The most effective elution solution for the recovery of both analytes from the resin is found to be a mixture of 0.1 M HCI and 1 M NaCl. The effect of flow rate, analyte concentration, and sample volume is evaluated. The optimised experimental conditions are then used in the extraction of the analytes from spiked natural waters. The use of the Pd loaded resin led to recoveries ranging from 80-90% for glyphosate and 60-80% for AMPA.

Improved coupled-column liquid chromatographic method for the determination of glyphosate and aminomethylphosphonic acid residues in environmental waters.

An existing method for the determination of glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) in water has been improved. It is based on precolumn derivatization with the fluorescent reagent 9-fluorenylmethylcloroformate (FMOC) followed by large-volume injection in a coupled-column LC system using fluorescence detection (LC-LC-FD). The derivatization step was slightly modified by changing parameters such as volume and/or concentration of sample and reagents to decrease the limits of quantification (LOQ) of glyphosate and AMPA to 0.1 microg/l. Additionally, the use of Amberlite IRA-900 for preconcentration of glyphosate, prior to the derivatization step, was investigated; the LOQ of glyphosate was lowered to 0.02 microg/l. Drinking, surface and ground water spiked with glyphosate and AMPA at 0.1-10 microg/l concentrations were analysed by the improved LC-LC-FD method. Recoveries were 87-106% with relative standard deviations lower than 8%. Drinking and ground water spiked with glyphosate at 0.02 and 0.1 microg/l were analysed after preconcentration on the anion-exchange resin with satisfactory recoveries (94-105%) and precision (better than 8%).