Prevalence of antifolate drug resistance markers in Plasmodium vivax in China / 医学前沿

The dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes of Plasmodium vivax, as antifolate resistance-associated genes were used for drug resistance surveillance. A total of 375 P. vivax isolates collected from different geographical locations in China in 2009-2019 were used to sequence Pvdhfr and Pvdhps. The majority of the isolates harbored a mutant type allele for Pvdhfr (94.5%) and Pvdhps (68.2%). The most predominant point mutations were S117T/N (77.7%) in Pvdhfr and A383G (66.8%) in Pvdhps. Amino acid changes were identified at nine residues in Pvdhfr. A quadruple-mutant haplotype at 57, 58, 61, and 117 was the most frequent (57.4%) among 16 distinct Pvdhfr haplotypes. Mutations in Pvdhps were detected at six codons, and the double-mutant A383G/A553G was the most prevalent (39.3%). Pvdhfr exhibited a higher mutation prevalence and greater diversity than Pvdhps in China. Most isolates from Yunnan carried multiple mutant haplotypes, while the majority of samples from temperate regions and Hainan Island harbored the wild type or single mutant type. This study indicated that the antifolate resistance levels of P. vivax parasites were different across China and molecular markers could be used to rapidly monitor drug resistance. Results provided evidence for updating national drug policy and treatment guidelines.

Successful multiple-exchange peritoneal dialysis in a patient with severe hematological toxicity by methotrexate: case report and literature review / Diálise peritoneal com múltiplas trocas bem-sucedida em paciente com grave toxicidade hematológica por metotrexato: relato de caso e revisão de literatura

Abstract Methotrexate is an effective medication to control several diseases; however, it can be very toxic, being myelosuppression one of its main adverse effects, which increases in severity and frequency in patients with renal failure. We present the case of a 68-year-old man with chronic, end-stage renal disease associated with ANCA vasculitis, under treatment with peritoneal dialysis, who received the medication at a low dose, indicated by disease activity, which presented as a complication with severe pancytopenia with mucositis that improved with support measures and multiple-exchange peritoneal dialysis. We reviewed 20 cases published to date of pancytopenia associated with methotrexate in patients on dialysis and found high morbidity and mortality, which is why its use in this type of patient is not recommended. However, when this complication occurs, a therapeutic option could be the use of multiple-exchange peritoneal dialysis in addition to supportive therapy for drug-related toxicity, although it is recognized that studies are required to show the role of multiple-exchange peritoneal dialysis in the removal of this medication.

Resumo Apesar de sua toxicidade, o metotrexato é um medicamento eficaz no controle de várias doenças. A mielossupressão, um de seus principais efeitos adversos, aumenta em gravidade e frequência nos pacientes com insuficiência renal. Apresentamos o caso de um homem de 68 anos de idade com doença renal terminal relacionada à vasculite associada ao ANCA em diálise peritoneal, que recebeu a medicação em dose baixa em função da atividade da doença e que teve como complicação pancitopenia grave com mucosite, tratada com medidas de suporte e diálise peritoneal com múltiplas trocas. Revisamos 20 casos publicados até o presente momento sobre pancitopenia associada a metotrexato em pacientes em diálise. Foi identificada alta morbidade e mortalidade, razão pela qual seu uso nesse tipo de paciente não é recomendado. No entanto, quando esta complicação ocorre, uma opção terapêutica pode ser o uso de diálise peritoneal com múltiplas trocas, além da terapia de suporte para toxicidade medicamentosa. Maiores estudos são necessários para demonstrar o papel da diálise peritoneal com múltiplas trocas na remoção desse medicamento.

Prevalence of low folate deficiency after wheat flour supplementation - should we still measure serum folate?

ABSTRACT Objectives: To determine the frequency of folic acid deficiency in consecutive serum folate determinations and to determine whether there was a significant decrease in serum folate deficiency after folate was added to wheat flour. Methods: A retrospective descriptive observational study was performed of consecutive folate measurements at the Hospital Privado Universitario, Cordoba, Argentina. Results: Two cohorts were analyzed: 1197 folate measurements between 2001 and 2008 (before supplementation) and 3335 folate measurements from 2009 to 2014 (after supplementation). Folate deficiency was found in 84/1197 (7%) subjects in the pre-supplementation group and in 58/3335 (1.73%) after supplementation. The prevalence of folate deficiency was 12% between 2001 and 2003 when folate was not added to flour compared to 4% in 2004-2007 (p-value < 0.0001) when folate was added to the flour but no widespread use was documented. Conclusions: In the studied population, the prevalence of serum folic acid deficiency after folate supplementation was low at 1.73%. There was a significant decrease in folate deficiency after folate was added to wheat flour. Given the low prevalence of folic acid deficiency observed in this and similar studies, and the observed change with supplementation, we conclude that routine measurement of serum folate is of limited clinical use.

The effect of hippophae rhamnoides extract on oral mucositis induced in rats with methotrexate

ABSTRACT Objective: To investigate the effect of HRE (Hippophae rhamnoides extract) on oral mucositis induced in rats with MTX. Material and Methods: Experimental animals were divided into groups as healthy (HG), HRE+MTX (HMTX), and control group, which received MTX (MTXC). HMTX group received 50 mg/kg HRE while MTXC and HG groups received equivolume distilled water with gavage once a day. After one hour of HRE and distilled water administration, HMTX and MTXC groups received a single dose of oral MTX 5 mg/ kg. This procedure was repeated for one month. Results: The levels of MDA, IL-1β, and TNF-α were found to be significantly higher in the cheek, lower lip, and tongue tissue of the animals receiving MTX, compared with HG and HMTX groups; however, these parameters were lower in the cheek and low lip tissue, and a milder damage ocurred in these tissues, compared with the tongue tissue in MTXC group. No histopathologic damage was observed in the cheek, lower lip, and tongue tissues of the rats treated with HRE. Conclusion: This findings indicate that HRE as a natural product is an important advantage compared with synthetic drugs for prophylaxis of oral mucositis developed due to MTX.

Ulcerations due to methotrexate toxicity in a psoriasis patient

Abstract: Methotrexate is one of the most used drugs in the treatment of psoriasis with indication of systemic therapy. Cutaneous and mucous side effects are described by pharmacological characteristics of the drug itself or due to overdose. We report the case of a patient with ulcerations in oral mucosa and psoriatic plaques after incorrect use of Methotrexate. Prescribed in a weekly dose, it was used continuously for 10 days and without simultaneous intake of folic acid. It is important to ensure correct comprehension of the prescription.

Dapsone in the treatment of pemphigus vulgaris: adverse effects and its importance as a corticosteroid sparing agent

Pemphigus vulgaris is an autoimmune disease characterized by suprabasal blisters with acantholysis, which has a fatal course in a large number of untreated patients. Systemic corticosteroid therapy is considered first-line therapy. Adjuvant treatment with the goal of sparing corticosteroids include, among others, dapsone. This drug is not without side effects and its use requires clinical and laboratory control. We present a patient with PV initially managed with suboptimal dose of prednisone, evolving into drug-induced hepatitis after introduction of dapsone.

Dermatitis herpetiformis: pathophysiology, clinical presentation, diagnosis and treatment

Researches on DH have shown that it is not just a bullous skin disease, but a cutaneous-intestinal disorder caused by hypersensitivity to gluten. Exposure to gluten is the starting point of an inflammatory cascade capable of forming autoantibodies that are brought to the skin, where they are deposited, culminating in the formation of skin lesions. These lesions are vesico-bullous, pruritic, and localized especially on elbows, knees and buttocks, although atypical presentations can occur. Immunofluorescence of perilesional area is considered the gold standard for diagnosis, but serological tests help in cases where it is negative. Patients who follow glutenfree diets have better control of symptoms on the skin and intestine, as well as lower risks of progression to lymphoma. Dapsone remains the main drug for treatment, but it requires monitoring of possible side effects, some potentially lethal.

Complementary data on four methods for sampling free-living ticks in the Brazilian Pantanal / Dados complementares de quatro métodos para amostragem de carrapatos em vida livre no Pantanal brasileiro

In this study, four methods for sampling free-living ticks that are used in ecological and human tick-bite risk studies were evaluated. Cloth dragging, carbon dioxide traps and visual searches and inspection of plant litter on the ground were used in field and forest areas within the Brazilian Pantanal. Among the three tick species collected, Amblyomma sculptum predominated, followed by Amblyomma parvum and Amblyomma ovale. Dragging, a cheap and simple technique, yielded the highest numbers of ticks, particularly nymphs. The visual search detected a high number of adult ticks and provided information on tick questing height. Even though laborious, plant litter examination showed that large numbers of ticks may use this stratum. Carbon dioxide (CO2) traps are expensive and difficult to handle, but they are highly efficient for adult ticks, especially A. parvum. These data indicate that one method alone is incapable of providing a representative sample of the tick fauna in a particular area and that multiple techniques should be used for tick population studies.

Neste estudo, foram avaliados quatro métodos de amostragem de carrapatos em vida livre, usados em estudos ecológicos e avaliação do risco de picadas em humanos. Arraste de flanela, armadilhas de gás carbônico (CO2), busca visual e inspeção de serrapilheira foram aplicados em áreas campestres e florestais no Pantanal brasileiro. Dentre três espécies coletadas, a predominância foi de Amblyomma sculptum, seguida por Amblyomma parvum e Amblyomma ovale. O arraste, técnica simples e de baixo custo, resultou em maior número de carrapatos, particularmente de ninfas. A busca visual detectou alto número de carrapatos adultos e forneceu informações sobre altura de espera por hospedeiros. Apesar de trabalhoso, o exame da serrapilheira demonstrou que grande número de carrapatos pode utilizar esse estrato. Armadilhas de CO2 têm custo elevado e são difíceis de manusear, entretanto, são altamente eficientes para carrapatos adultos, em especial para A. parvum. Esses dados indicam que somente um método é incapaz de fornecer amostra representativa da ixodofauna em uma área particular e que, para estudos populacionais, técnicas múltiplas devem ser usadas.

Cuidar da saúde do vizinho: atuação do antropólogo Charles Wagley no Serviço Especial de Saúde Pública* / Caring for the health of your neighbor: the work of anthropologist Charles Wagley with the Serviço Especial de Saúde Pública

Recupera a atuação do antropólogo Charles Wagley como alto funcionário do Serviço Especial de Saúde Pública, programa de cooperação estabelecido entre EUA e Brasil na Segunda Guerra Mundial. Convocado a colaborar nos esforços de guerra, atuou na política de migração do Programa da Borracha. À luz dessa experiência de intervenção, do contexto marcado pela promoção do desenvolvimento e por questões então prementes no campo da antropologia, este estudo propõe-se retomar a obra Uma comunidade amazônica. Trata-se de discutir o estudo de comunidade conduzido na localidade amazônica que Wagley conheceu ainda durante as missões do Serviço e cuja realidade considerou ilustrativa de uma região subdesenvolvida, levando-o a refletir sobre mudança social e o papel das ciências.

The article focuses on the work of Charles Wagley as a top staff member with Serviço Especial de Saúde Pública (Special Public Health Service), a US-Brazil cooperation program established during World War II. Taking into consideration Wagley’s experience with migration policy under Brazil’s Rubber Program, as well as the context of development promotion and the issues then on the anthropological agenda, the article explores Wagley’s community study of the Amazon town he visited while on SESP missions, published in the book Uma comunidade amazônica (Amazon Town). Encountering a reality that he believed emblematic of underdevelopment, Wagley was led to reflect on social change and the role of science.

Cleansing the world of the germ of laziness: hygiene, sanitation, and the Javanese population in Suriname / Limpando o mundo do germe da preguiça: higiene, saneamento e população javanesa no Suriname

In 1915 the Rockefeller Foundation took its hookworm eradication campaign to Suriname, but was soon disappointed because of opposition from its main target group: the Javanese. Moreover, authorities and planters objected to the construction of latrines because of the costs and their belief that the Javanese were “unhygienic”. In describing the labor migration from Java to Suriname, I show that this “lack of hygiene” was closely related to the system’s organization. I argue that uncleanliness was the consequence of harmful socio-economic and ecological conditions. Secondly I suggest that even though the Foundation did not manage to cleanse Suriname of hookworm, its educational efforts, its emphasis on prevention, and its training of local health workers probably had more impact than Rockefeller officials thought.

Em 1915, a Fundação Rockefeller levou sua campanha de erradicação da ancilostomíase ao Suriname, logo sofrendo a oposição de seu principal alvo, os javaneses. Autoridades e proprietários rurais também reagiram à instalação de latrinas devido aos custos implicados e à crença de que os javaneses eram “anti-higiênicos”. Ao descrever a migração de trabalhadores de Java para o Suriname, mostro que a “falta de higiene” ligava-se à organização do sistema. Argumento que a sujeira era consequência de condições ecológicas e socioeconômicas danosas. Sugiro ainda que, embora a Fundação não tenha livrado o Suriname da anciolostomíase, seus esforços educacionais, sua ênfase na prevenção e o treinamento de profissionais de saúde locais tiveram maior impacto do que o imaginado pelos funcionários da agência norte-americana.

Percepção de enfermeiros sobre o uso do computador no trabalho / Perception of nurses on the use of computer at the work / Resumen percepción de enfermeros sobre el uso de la computadora en el trabajo

Estudo que teve como objetivo apreender a percepção de enfermeiros sobre o uso do computador no ambiente de trabalho hospitalar. Participaram 14 enfermeiros de um hospital público. A coleta de dados realizou-se por meio de entrevista gravada e Diário de Campo. Os dados foram analisados de acordo com a técnica Análise de Conteúdo. Das entrevistas emergiram seis categorias temáticas abordando aspectos positivos tais como: rapidez, legibilidade e exatidão das informações; maior segurança do paciente e melhorias na qualidade do cuidado. Dentre os aspectos negativos se destacaram a conduta de copiar e colar as Prescrições Médicas e de Enfermagem; falta de computadores e distanciamento do enfermeiro do paciente. Apesar das fragilidades relatadas, os enfermeiros manifestaram-se favoráveis ao uso da tecnologia computacional no trabalho e indicaramna como recurso indispensável à qualidade do cuidado.

The objective of this study was to apprehend the perception nurses have on the use of computer in the hospital environment. Took part in the study 14 nurses of a public hospital. Collection of data took place through recorded interview and Field Diary. Data was analyzed according to Content Analysis technique. Six thematic categories emerged from the interviews such as the one that approached the positive aspects: speed, legibility and accuracy of the information; patients' safety and; improvements in the quality of care. Among the negative aspects copy and paste the Medical Prescriptions and Nursing; lack of computers and the nurse distancing to the patient were highlighted. In spite of the fragilities, they were all in favor of the use of computer technology at the work and they pointed it as indispensable resource to the quality of care.

Estudio que tuvo como objetivo aprehender la percepción de enfermeros sobre el uso de la computadora en el ambiente de trabajo hospitalario. Participaron 14 enfermeros de un hospital público. La recolección de datos fue realizado por medio de entrevista grabada y Diario de Campo. Los datos fueron analizados de acuerdo con la técnica Análisis de Contenido. De las entrevistas emergieron seis categorías temáticas como aquella que abarcó los aspectos positivos tales como: rapidez, legibilidad y exactitud de las informaciones; mayor seguridad del paciente y; mejorías en la calidad del cuidado. Entre los aspectos negativos se destacaron la conducta de copiar y pegar las Prescripciones Médicas y de Enfermería; falta de computadoras y alejamiento del enfermero con el paciente. A pesar de las fragilidades, todos se manifestaron favorables al uso de la tecnología computacional en el trabajo y la señalaron como recurso indispensable a la calidad del cuidado.

Biochemical characterization of the bifunctional enzyme dihydrofolate reductase-thymidylate synthase from Leishmania ( Viannia ) and its evaluation as a drug target / Caracterización bioquímica de la enzima bifuncional dihidrofolato reductasa-timidilato sintasa de Leishmania ( Viannia ) y su evaluación como blanco molecular

Introduction. Dihydrofolate reductase (DHFR) has been used successfully as a drug target in the area of anti-bacterial, anti-cancer and anti-malarial therapy. Although this bifunctional enzyme is also a potential drug target for treatment of leishmaniasis, there have been no reports on its efficacy against Leishmania ( Viannia ) species . Materials and methods. The gene encoding the bifunctional DHFR and thymidylate synthase (TS) of Le. (V.) braziliensis was isolated and expressed in E. coli. The enzyme was purified and characterized. The inhibitory effects of antifolates and four aporphine alkaloids on its activity were evaluated. Results. The full-length gene consists of a 1560-bp open reading frame encoding a 58 kDa translated peptide containing DHFR and TS domains linked together in a single polypeptide chain. The recombinant DHFR-TS enzyme revealed K m and V max values of 55.35 ± 4.02 µ M (mean ± SE) and 0.02 ± 5.34 x 10 -4 µ M/min respectively for dihydrofolic acid (H 2 F). The Le. braziliensis rDHFR-TS have Ki values for antimicrobial antifolates in the µM range. Methotrexate (MTX) was a more-potent inhibitor of enzymatic activity ( Ki = 22.0 µM) than trimethoprim ( Ki = 33 µM) and pyrimethamine ( Ki = 68 µM). These Ki values are significantly lower than those obtained for the aporphine alkaloids. Conclusion. The results of the study show the inhibitory effect of antifolate drugs on enzymatic activity, indicating that Le. braziliensis rDHFR-TS could be a model to studying antifolate compounds as potential antiprotozoal drugs.

Introducción. La dihidrofolato reductasa (DHFR) se ha utilizado como blanco molecular en tratamientos antibacterianos, anticancerígenos y antipalúdicos. También, actúa como blanco molecular en Leishmania ; sin embargo, no existen reportes de la enzima bifuncional en especies de Leishmania ( Viannia ). Materiales y métodos. Se ha aislado y expresado en Escherichia coli el gen que codifica para la enzima bifuncional DHFR y la timidilato-sintasa (TS) de Leishmania braziliensis . La enzima recombinante se purificó y caracterizó, y se evaluó el efecto inhibitorio de algunos antifolatos, así como de cuatro alcaloides aporfínicos. Resultados. El gen se compone de aproximadamente 1.560 pb y codifica un péptido de 58 kDa que contiene los dominios DHFR y TS ligados en una sola cadena polipeptídica. La enzima recombinante DHFR-TS, utilizando el dihidrofolato (H2F) como sustrato, presentó valores de K m y V max de 55,35 ± 4,02 (media ± el error estándar de la media) y de 0,02 ± 5,34 x 10 -4 , respectivamente. La enzima rDHFR-TS de L. braziliensis presentó valores de Ki para los antifolatos en el rango de micras. El metotrexato fue el inhibidor más potente de la actividad enzimática ( Ki =22,0 mM) en comparación del trimetoprim ( Ki =33 mM) y la pirimetamina ( Ki =68 mM). Estos valores de Ki son significativamente más bajos en comparación con los obtenidos para los alcaloides aporfínicos. Conclusión. Los resultados muestran el efecto inhibitorio de los antifolatos sobre la actividad enzimática, lo cual indica que la rDHFR-TS de L. braziliensis podría ser un modelo para estudiar moléculas antiprotozoarias potenciales.

Prevalence of Drug Resistance-Associated Gene Mutations in Plasmodium vivax in Central China

Resistance of Plasmodium spp. to anti-malarial drugs is the primary obstacle in the fight against malaria, and molecular markers for the drug resistance have been applied as an adjunct in the surveillance of the resistance. In this study, we investigated the prevalence of mutations in pvmdr1, pvcrt-o, pvdhfr, and pvdhps genes in temperate-zone P. vivax parasites from central China. A total of 26 isolates were selected, including 8 which were previously shown to have a lower susceptibility to chloroquine in vitro. For pvmdr1, pvcrt-o, and pvdhps genes, no resistance-conferring mutations were discovered. However, a highly prevalent (69.2%), single-point mutation (S117N) was found in pvdhfr gene. In addition, tandem repeat polymorphisms existed in pvdhfr and pvdhps genes, which warranted further studies in relation to the parasite resistance to antifolate drugs. The study further suggests that P. vivax populations in central China may still be relatively susceptible to chloroquine and sulfadoxine-pyrimethamine.

Leishmaniasis: current status of available drugs and new potential drug targets

The control of Leishmania infection relies primarily on chemotherapy till date. Resistance to pentavalent antimonials, which have been the recommended drugs to treat cutaneous and visceral leishmaniasis, is now widespread in Indian subcontinents. New drug formulations like amphotericin B, its lipid formulations, and miltefosine have shown great efficacy to treat leishmaniasis but their high cost and therapeutic complications limit their usefulness. In addition, irregular and inappropriate uses of these second line drugs in endemic regions like state of Bihar, India threaten resistance development in the parasite. In context to the limited drug options and unavailability of either preventive or prophylactic candidates, there is a pressing need to develop true antileishmanial drugs to reduce the disease burden of this debilitating endemic disease. Notwithstanding significant progress of leishmanial research during last few decades, identification and characterization of novel drugs and drug targets are far from satisfactory. This review will initially describe current drug regimens and later will provide an overview on few important biochemical and enzymatic machineries that could be utilized as putative drug targets for generation of true antileishmanial drugs.

Purification and activity evaluation of methionine synthase / 药学学报

Methionine synthase (MS, EC2.1.1.13), a key enzyme in the folate metabolism area catalyzing methyl transfer from N5-methyltetrahydrofolate to homocysteine to give tetrahydrofolate and methionine, takes a core position in folate cycle, one-carbon-unit transfer and sculpture amino acid pathways. Cobalamin-dependent methionine synthase was purified from rat liver. The enzyme was purified 609-fold to near homogeneity by batch chromatography on DE-52, anion-exchange chromatography on Q Sepharose Fast Flow and CHT-I hydroxyapatite column and was identified by SDS-PAGE and Western blotting. The enzyme activity was determined by spectrophotometric assay. In addition, the influencing factor and optimal reaction condition were performed. The steady state kinetic of rat liver methionine synthase was similar to that of other mammalian cobalamin-dependent methionine synthase which employed a Ping-Pong mechanism. The result indicated that cobalamin-dependent methionine synthase purified from rat liver is suitable for screening and studying methionine synthase specific inhibitors.

Research advances in antitumor activities of pyrimidine derivatives / 药学学报

Pyrimidine derivatives have been the subject of much attention in pesticide and medicine fields owing to their unique biological properties. Particularly, a large number of these compounds have recently been reported to show substantial antitumor activities, and some of them have been investigated in clinical trials. Although these structurally novel compounds have a common chemical moiety of a pyrimidine ring, there are a variety of mechanisms of their antitumor action, such as, inhibition of cyclin-dependent-kinases, inhibition of protein tyrosine kinase, inhibition of carbonic anhydrases, inhibition of dihydrofolate reductase and disruption of microtubule assembly. In this paper, we described the latest advances in the research of such pyrimidine derivatives as antitumor drug according to their action on targets.

Thymidylate synthase expression and therapeutic effect analysis of pemetrexed in advanced lung adenocarcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of thymidylate synthase (TS) in patients with advanced lung adenocarcinoma and its relation with the therapeutic effect of pemetrexed.</p><p><b>METHODS</b>The clinicopathological data of 38 patients with stage IIIIB/IV lung adenocarcinoma receiving pemetrexed treatment were retrospectively analyzed. The tumor samples of the patients were collected for detecting TS expression using RT-PCR, and the therapeutic effect of the treatment was analyzed.</p><p><b>RESULTS</b>TS positivity was found in 26.32 (10/38) of the patients. TS positivity was not correlated to gender, TNM stage or PS score. The total response rate of pemetrexed treatment (CR+PR) was 34.21 (13/38) in these patients, and the rate was 39.29% (11/28) in TS-negative patients, as compared to 20.00% (2/10) in the positive patients (P=0.087). Patients with low TS expression had significantly higher control rate by pemetrexed treatment than those with TS overexpression [89.29% (25/28) vs 40.00% (4/10), P=0.002].</p><p><b>CONCLUSION</b>TS expression may serve as a potential indicator of chemosensitivity to pemetrexed in patients with advanced lung adenocarcinoma.</p>

clinical significance of methylenetetrahydrofolate reductase [MTHFR] polymorphisms in acute lymphoblastic leukaemia

Acute lymphoblastic leukemia [ALL] is lie most common pediatric cancer. Genetic polymorphisms in the folate metabolic pathway may contribote to the susceptibility to childhood ALL because they affect the DNA synthesis, methylation and repair. The most common two polymorphisms are methylenetetrahydrofolate reductase [MTHFR] C677T and A1298C. We studied their effect on 30 ALL patients and 30 healthy controls regarding the incidence, toxicity and response to treatment using polymerase chain reaction-restriction fragment length polymorphism [PCR-RFLP]. MTHFR 1298 AC showed a decrease in incidence of ALL [OR=0.5; 95% CI=0.28-0.8; p=0.01] .Treatment toxicity with MTHFR C677T polymorphism was seen in the form of a decreased platelet Count [p=0.03] and with A 1298C in the form of liver toxicity [p=0.03]. No significant association could be found between the polymorphisms and the response to treatment

Folic acid antagonist methotrexate causes the development malformation of heart and down-regulates the BMP2b and HAS2 expressions in zebrafish / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effect of methotrexate (MTX), a folic acid antagonist which can lead to folic acid deficient, on the cardiac development and on the expressions of BMP2b and HAS2 in zebrafish.</p><p><b>METHODS</b>The zebrafish embryos at 6-48 hrs post fertilization (hpf) were treated with various concentrations of MTX (0.5 x 10(-3), 1.0 x 10(-3) and 2.0 x 10(-3) M). At 48 hpf, the percentage of cardiac malformation and heart rate were recorded. The zebrafish embryos at 6-10 hpf treated with 1.5 x 10(-3) M MTX were used as the MTX treatment group. At 24 and 48 hpf the cardiac morphology was observed under a microscope. The expressions of BMP2b and HAS2 in zebrafish were detected by in situ antisense RNA hybridization and real-time PCR.</p><p><b>RESULTS</b>6-12 hpf, the early embryonic developmental stage, was a sensitive period that MTX affected cardiac formation of zebrafish. The retardant cardiac development and the evidently abnormal cardiac morphology was found in the MTX treatment group. The results of in situ antisense RNA hybridization showed that the expressions of BMP2b and HAS2 in the zebrafish heart were reduced in the MTX treatment group at 36 and 48 hpf. The real-time PCR results demonstrated that the BMP2b expression decreased at 12, 24, 36 and 48 hpf, and that the HAS2 expression decreased at 24, 36 and 48 hpf in the treatment group compared with the control group without MTX treatment.</p><p><b>CONCLUSIONS</b>The inhibition of folic acid function may affect cardiac development of early embryos, resulting in a retardant development and a morphological abnormality of the heart in zebrafish, possibly by down-regulating the expressions of BMP2b and HAS2.</p>