Microwave-assisted extraction and content determination of astilbin in Lysiphyllum strychnifolium stems

Abstract Lysiphyllum strychnifolium (Craib) A. Schmitz. (in Thai name, Ya nang daeng) has been traditionally used to treat fever, alcohol intoxication, cancer, allergies, and blood toxins. It can be used as a health-promoting herbal tea and contains hydroalcoholic extracts. The purpose of the present study was to develop a microwave-assisted extraction method for astilbin in L. strychnifolium stems. HPLC was used to determine astilbin content. Three extraction conditions were optimized: types of solvent, microwave power levels, and the number of extraction cycles. Water:methanol (40:60) was the best solvent for astilbin extraction from L. strychnifolium stems using 450 watts and six microwave-assisted extraction cycles. This technique offers important advantages over conventional methods, such as shorter extraction times, substantial energy savings, and a reduced environmental burden.

Determinação de protocolo para descristalização de mel em micro-ondas / Standard to melt honey with microwaves

O presente estudo teve como objetivo obter um protocolo para descristalização do mel de forma a não alterar os parâmetros físico-químicos. Para o estudo, foram utilizadas amostras de mel que estavam cristalizadas nos locais de compra, sendo estas submetidas em micro-ondas a diferentes níveis de potência (Mínima, Média e Alta) e tempos (5, 10, 15 e 20 segundos). As amostras de mel apresentaram valores de 2,57 a 3,58 mg.kg de hidroximetilfurfural (HMF). Além da análise de HMF, foram avaliados também o teor de umidade, Teste de Fiehe, Prova de Lugol e Lund, sendo obtidos resultados dentro do preconizado na legislação brasileira. Um protocolo adequado para descristalizaçao de mel em micro-ondas foi obtido com uso de potência média e com tempo de 15 segundos.

Efeito da forma de aquecimento em parâmetros de qualidade e identidade de óleos vegetais / Effect of the heating means in quality and identity parameters of vegetable oils

Objetivou-se com este trabalho avaliar parâmetros de identidade e qualidade de óleo de abacate produzido nacionalmente, comparativamente a azeite de oliva e óleo de arroz, após aquecimento em bloco digestor ou micro-ondas. Avaliaram-se amostras sem aquecimento (controle) e aquecidas por 1:30 h em bloco digestor ou 3 min em micro-ondas. Determinaram-se a acidez e os índices iodo e refração. Os resultados indicaram que houve aumento de acidez, redução no índice de iodo e índice de refração após o aquecimento. Apesar do maior valor de acidez após o aquecimento, o óleo de abacate sofreu menor elevação em relação ao controle (cerca de 4 vezes) do que as demais amostras. O impacto do aquecimento foi maior no óleo de arroz, seguido do azeite de oliva. O aquecimento por micro-ondas afetou mais a qualidade das amostras que o aquecimento em bloco digestor.

Prevalence of fatigue reported by physiotherapists operating diathermy equipment for microwave / Prevalência de fadiga referida por fisioterapeutas que operam equipamentos de diatermia por micro-ondas

Objective: To Analyze the association between prevalence of fatigue referred by physical therapists and their occupational exposure to radiation emitted by therapeutic microwave diathermy equipment. Methods: A Cross-sectional study conducted in 193 physical therapists from four cities of the west of Paraná State, Brazil. A specified structured web questionnaire was applied for collecting data about microwave diathermy exposition and potential confounders, plus the Multidimensional Assessment of Fatigue (MAF). Statistical analysis included logistic regression and Student's t-test. Results: The prevalence of fatigue in the category exposed to microwave diathermy was higher (15.0%) than in non-exposed (2.9%). On multivariate logistic regression, a significant independent association between exposure to microwave diathermy and prevalence of fatigue was observed (odds ratio 4.93; 95% confidence interval 1.04 - 23.25; p = 0.04). The Student's t-test showed significant difference between the number of hours exposed to diathermy microwave, being 3,839.1 within physical therapists who referred fatigue and 497.6 within others (p = 0.004). Conclusion: The results demonstrate a significant and independent association between occupational exposure of physical therapists to radiation of microwave diathermy and prevalence of fatigue. Therefore, occupational safety guidelines aimed at these professionals as a prevention of possible adverse effects, as well as the replication of this study are suggested. .

Objetivo: Analisar a associação entre a prevalência de fadiga referida por fisioterapeutas e a exposição desses profissionais à radiação emitida por equipamentos terapêuticos de diatermia por micro-ondas. Metodologia: Foi realizado estudo de corte transversal com 193 fisioterapeutas de quatro municípios da região Oeste do Estado do Paraná, Brasil. Foi aplicado, via eletrônica, questionário estruturado especialmente para a coleta de dados sobre a exposição ocupacional à radiação emitida por equipamentos de diatermia por micro-ondas e potenciais fatores de confusão, acrescido do questionário de Avaliação Multidimensional de Fadiga. A análise estatística incluiu regressão logística e teste t de Student. Resultados: A prevalência de fadiga na categoria expostos a micro-ondas foi maior (15,0%) do que em não expostos (2,9%). Na regressão logística multivariada foi observada associação independente significante entre a exposição ocupacional de fisioterapeutas à radiação de diatermia por micro-ondas e a prevalência de fadiga (odds ratio 4,93; intervalo de confiança de 95% 1,04 - 23,25; p = 0,04). O teste t de Student mostrou diferença significante entre o número total de horas de exposição à radiação de diatermia por micro-ondas, sendo de 3.891,1 entre os fisioterapeutas que referiram fadiga e de 497,6 entre os que não referiram (p = 0,004). Conclusão: Os resultados demonstraram associação significante entre a exposição ocupacional de fisioterapeutas à radiação emitida por equipamentos de diatermia por micro-ondas e fadiga, portanto, são sugeridas orientações de segurança ocupacional, dirigidas a esses profissionais, como medida preventiva ...

The therapeutic effect of a pulsed electromagnetic field on the reproductive patterns of male Wistar rats exposed to a 2.45-GHz microwave field

INTRODUCTION: Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields. OBJECTIVES: This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz) on the reproductive systems of male Wistar rats (70 days old). METHODS: The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz), pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz) exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays. RESULTS: The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer) are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents. CONCLUSIONS: Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.

Spatial memory perfomance of wistar rats exposed to mobile phone

INTRODUCTION: With the tremendous increase in number of mobile phone users world wide, the possible risks of this technology have become a serious concern. OBJECTIVE: We tested the effects of mobile phone exposure on spatial memory performance. MATERIALS AND METHODS: Male Wistar rats (10-12 weeks old) were exposed to 50 missed calls/day for 4 weeks from a GSM (900/1800MHz) mobile phone in vibratory mode (no ring tone). After the experimental period, the animals were tested for spatial memory performance using the Morris water maze test. RESULTS: Both phone exposed and control animals showed a significant decrease in escape time with training. Phone exposed animals had significantly (~3 times) higher mean latency to reach the target quadrant and spent significantly (~2 times) less time in the target quadrant than age- and sex-matched controls. CONCLUSION: Mobile phone exposure affected the acquisition of learned responses in Wistar rats. This in turn points to the poor spatial navigation and the object place configurations of the phone-exposed animals.

Effect of mobile phone microwaves on fetal period of BALB/ c mice in histological characteristics of hippocampus and learning behaviors

The possible risks of radio-frequency electromagnetic fields [EMF] for the living organisms and human body are a growing concern for our society. In this study, we examined the possibility of changes in working memory and hippocampal histological characteristics effects in mice brain following whole body exposure to microwave radiation. During gestation period, we exposed mice for 4 hr to Global system for mobile communications [GSM], Specific Absorption Rate [SAR] of 200 mW/kg. Pregnant control mice were sham-exposed or free in a cage without further restraining. Three month after exposure, animals were prepared for behavioral [Radial Arm Maze [RAM] and Morris Water Maze [MWM]] and histological studies. The showed that microwave exposed mice were slower than sham, and control in finding the platform. Analyses of error rates in RAM and MWM performance revealed significant differences which emphasize the effect of acute exposure to pulsed microwaves in deficit of spatial reference memory in the mice. However in this study exposed group didn't show any statistically significant loss of hippocampal CA1, CA3 neurons versus controls or sham. We conclude that there is evidence from the current study that exposure to MW radiation under parameters examined caused decrements in the ability of mice to learn the spatial memory task

Alterations in TSH and thyroid hormones following mobile phone use

In recent years, the widespread use of mobile phones has lead to a public debate about possible detrimental effects on human health. In spite of years of research, there is still a great controversy regarding the possibility of induction of any significant physiological effects in humans by microwave radiations emitted by mobile phones. This study aims to investigate the effects of electromagnetic fields induced by the Global System for Mobile communications [GSM] mobile phones on the Thyroid Stimulating Hormone [TSH] and thyroid hormones in humans. 77 healthy university students participated in this study. The levels of T3, T4 and TSH were measured by using appropriate enzyme-linked immunosorbent assay [ELISA] kits [Human, Germany]. The average levels of T3,T4 and TSH in students who moderately used mobile phones were 1.25 +/- 0.27 ng/ ml, 7.76 +/- 1.73 micro g/dl and 4.25 +/- 2.12 micro u/l respectively. The levels in the students who severely used mobile phones were 1.18 +/- 0.30, 7.75 +/- 1.14 and 3.75 +/- 2.05 respectively. In non-users, the levels were 1.15 +/- 0.27, 8.42 +/- 2.72 and 2.70 +/- 1.75, respectively. The difference among the levels of TSH in these 3 groups was statistically significant [P<0.05]. As far as the study is concerned, this is the first human study to assess the association between mobile phone use and alterations in the levels of TSH and thyroid hormones. Based on the findings, a higher than normal TSH level, low mean T4 and normal T3 concentrations in mobile users were observed. It seems that minor degrees of thyroid dysfunction with a compensatory rise in TSH may occur following excessive use of mobile phones. It may be concluded that possible deleterious effects of mobile microwaves on hypothalamic-pituitary-thyroid axis affects the levels of these hormones

[Effect of radiation leakage of microwave oven on rat's serum testosterone]

Since discovery of high frequency waves and their application in different industries, their adverse biological effects have been of great attention. Increased male fertility problems have suggested the possible role of microwaves in producing this disorder. Testes are active body tissues, which can be affected by these waves. Age of the patients at the time of the exposure can have important influence on the effect of these waves. Therefore, the aim of this study was to evaluate the effect of radiation leakage of microwave oven on rat serum testosterone at pre and post pubertal stages. In this study we used 18 mature [two months old] and 18 immature [one months old] rats. Mature and immature rats each were divided into control and experimental groups. Experimental groups were exposed to 2450 MHZ microwaves produced by a microwave oven, three times a day, each time for 30 minutes and control groups were kept in the laboratory under identical conditions in view of temperature and light. At the end of experiment blood was collected via heart puncture and serum testosterone was measured by RIA method. Collected data were analyzed by means of t-test. The result of this study showed that the level of serum testosterone in experimental group was less than that of control group in immature rats [P>0.05]. But in the mature rats, the serum testosterone level of experimental group was less than that of control group significantly [P<0.05]. Exposure to microwaves leakage of microwave oven resulted in decreased testosterone production by testes in mature rats which may be due to the direct effect of microwave on leydig cells or its indirect effect on pituitary and hypothalamus

[ effects of mobile phone waves [940MHz] on embryonic development of hematopoiesis system in Balb/C mouse]

Today, increasing usage of microwaves generator sets such as cell phones, have been caused much worry related to their waves effects on human health. In this research, simulated waves effects of cell phones with frequency of 940MHz have been studied on hematopoiesis system of Balb/C mouse embryo. In an experimental study pregnant mice [Balb/C] were used as a laboratory model. The mice were divided into control, sham-exposed and experimental groups. The experimental groups were exposed to the waves on the 8[th] day of embryonic development for 4 or 10 days [everyday for 4 hours]. At the end of treatment period, the experimental samples, sham-exposed and control related to morphology and histology studies of hematopoiesis organs were done by light microscope. Using t-test and Mann-Whitney test, the quantitative data were analyzed. Morphologic study of embryos which were 18 days old didn't show any abnormality but the weight of experimental embryos [1.263 +/- 0.017 gr] compared with sham-exposed [1.268 +/- 0.006 gr] showed significant increase [P<0.05]. The study of tissue sections in embryos which were 12 days old didn't show significant change in tissue and cellular position of yolk sac of experimental samples as compared with control group. Also, tissue studies of embryos which were 18 days old didn't show any changes in general structure of liver, spleen, marrow bone but the number of Megakaryocytes of spleen and erythrocytes which had not nucleus in bone marrow of experimental samples showed significant increase as compared with the sham-exposed. The number of erythrocytes in liver which had not nucleus also showed significant increase as compared with the sham-exposed [P<0.05]. Waves of cell phones with frequency of 940MHz don't affect on general structure of liver, spleen, bone marrow of Balb/C embryos but it causes significant changes in the number of cells of these tissues

Biomarkers of induced electromagnetic field and cancer.

The present article delineates the epidemiological and experimental studies of electromagnetic field which affects various tissues of human body. These affects lead to cell proliferation, which may lead to cancer formation. Certain biomarkers have been identified which are one way or the other responsible for tumor promotion or co-promotion. These are (i) melatonin, a hormone secreted by pineal gland, (ii) Ca2+, which is essential in the regulation of the resting membrane potential and in the sequence of events in synaptic excitation and neurotransmitter, release are affected by electromagnetic field, (iii) ornithine decarboxylase (ODC), a rate-limiting enzyme in the biosynthesis of polyamines, considered as a useful biological marker; over expression of ODC can cause cell transformation and enhancement of tumor promotion. (iv) protein kinase is an enzyme, which transfers phosphate groups from ATP to hydroxyl groups in the amino acid chains of acceptor proteins, and (v) Na+-K+ ATPase, which transports sodium and potassium ions across the membrane has a critical role in living cells. The various possible mechanisms depending upon non equilibrium thermodynamics, co-operativism, stochastic and resonance are discussed as possible models of signal transduction in cytosol, thereby controlling the transcription phenomena. Finally a mechanism comprising the extremely low frequency and radio frequency (RF)/microwave (MW) modulated field is compared.

Use of mobile phones in ICU--why not ban?

Due to the rapid growth of mobile telecommunications it is predicted that by 2005 there will be 1.6 billion mobile phone users worldwide. The usage of cellphones in Intensive Care Units carries with it a high incidence of interference with a number of medical devices like implantable defibrillators, cardioverters, pacemakers, monitors and other important devices like ventilators. It is in this context that this article will throw a light on complications of cellphones use in the Intensive Care Units and various strategies that can be taken to restrict their use in the Intensive Care Units.

Establishment and analytical quality control of laboratories for Hg determination in biological and geological samples in the Amazon, Brazil

During the past 20 years significant amounts of HG have been released in the Amazonian environment due to goldmining activities. Several Brazilian and foreign research groups have been studying the region, always facing difficulties regarding preservation and transfer of the collected samples from the field to the analytical laboratories. Aiming to solve these problems two high quality Hg analytical laboratories were established in the region. One is located at Fundação Esperança (FE, Santarém, PA), a medical assitance foundation and the other at the Universidade Federal de Rondônia (UNIR), Porto Velho, RO. Their main equipament is: Atomic absorption spectrophotometers for Hg analysis (Klow Injection Mercury System-FIAS 400 with automatic samples-AS90-Perkin Elmer) and a microwave oven digestion system (MDS-2000-CEM). Technicians and researchers were trained in several aspects like environmental and human sampling, digestion methods and Hg analysis for biotic and abiotic materials. This training as well as the installation of the mentioned laboratories were the responsibility of the Universidade Federal do Rio de Janeiro (UFRJ). Intercalibration exercices were performed between several laboratories: Environmental Medicine of Odense University (Denmark), Centre de Toxicologie du Québec, Canada and Occupational Health Sciences (Health-Canada). In the last 18 months the FE laboratory joined the Hg urine analysis intercalibration program of the Laboratory of the Centre of Toxicology in Québec, Canada, reaching accurate results. To date both Amazonian laboratories are able to analyze several different materials: Sediment, soil, fish, urine, hair and blood. The FE laboratory is becoming more specialized in human samples such as urine, blood and hair, wile UNIR laboratory deals with environmental samples such as fish, sediment and soil.

Variaciones en las concentraciones de IgA, complemento y aglutininas en la leche humana, posterior al calentamiento en horno de microondas / IgA, complement and agglutinin levels variations in human milk, after rapidly heated using microwave oven

Intoducción. Objetivo: evaluar las modificaciones en los niveles de IgA y la fracción 3 y 4 del complemento (C3 y C4) y las algutininas en la leche humana al ser sometida a calentamiento rápido empleando el horno de microondas. Material y métodos. Mediante un ensayo clínico (antes, después) en muestras de leche humana elegidas al azar, se estudiaron 46 muestas de leche, recolectadas en los primeros 5 días del puerperio, proveniente de madres con embarazo y parto sin complicaciones. Se fraccionaron las muestras para formar 2 grupos, la muestra de leche del primer grupo se mantuvo en temperatura ambiente (grupo 1) y la segunda se incluyó para ser calentada durante 30 segundos a temperatura máxima en un horno de microondas de marca comercial (grupo 2). En ambas muestras se determinaron las concentraciones de IgA total, y la aglutinación contra Candida albicans. Resultados. La temperatura a la que fueron sometidas las muestras del grupo 2 fue de 55.5 ºC (límite de 32 a 72 ºC). Al comparar los resultados entre ambos grupos se observaron que los valores de IgA fueron de 0.95 y 0.63 g/L (P< 0.001), C3 de 2.22 y 0.49 g/L (P< 0.01), C4 de 3.7 y 1.21 g/L (P< 0.0003) y las aglutininas con dilución de 1467 y 1156 (P< 0.04), para los grupos 1 y 2 respectivamente. La temperaturar crítica fue diferente para cada variable. Para la IgA y C3 fue de 50 ºC; para C4 y las aglutininas fue de 56 ºC. Conclusiones. Se documentó el efecto negativo en la concentración de IgA, C3 C4 y aglutininas por efecto del calentamiento en el horno de microondas. La temperatura generada por este medio es alta y difícilmente controlada. Por lo que no se recomienda el clentamiento de la leche humana en el horno de microondas

O uso de microondas para descalcificaçäo de tecidos mineralizados da mandíbula de ratos / Using microwaves for the decalcification of mineralized tissues of the rat mandible

Neste trabalho, compararam-se a preservaçäo tecidual e o tempo de descalcificaçäo através de E.D.T.A. a 7 por cento, pH 7,3, hemimandíbulas de ratos fixadas em etanol 70 por cento, associado ou näo às microondas. Houve o mesmo grau de preservaçäo histológica em ambos os grupos estudados, com uma acentuada reduçäo do tempo de desmineralizaçäo na ordem de 83 por cento quando se associou o microondas

Poly ADP ribosylation as a possible mechanism of microwave--biointeraction.

Electromagnetic fields (EMFs) affect the metabolism of the body including the nervous, endocrine, cardiovascular, hematological as well as the reproductive system. EMFs are environmental pollutants, thus posing a health hazard which can cause steric changes in the molecule located at the cell surface. Microwaves are known to cause chromosomal abberations and act as tumor promoters. The process involves a stream of signals from cell membrane to nucleus and other organelles. The present investigations aim to understand the mechanism of biological effects of microwaves (2.45 GHz). The effect was studied on poly ADP-ribosylation, which is a post translational modification of chromatin protein catalysed by the enzyme poly ADPR polymerase using NAD+ as the substrate. Poly ADP-ribosylation has been shown to be involved in several aspects of chromatin structure and function. Twenty-three days old rats weighing 42-48 gms were exposed at a microwave dose level of 1.0 mW/cm2. After exposure for sixty days the animals were sacrificed and an estimation of poly ADPR polymerase activity was undertaken in different organs of these animals. There was an increase of 20% in its activity in liver, 35% in testis, whereas brain showed a 53% decrease in diencephalon and 20% decrease in the cortex in the exposed animals as compared to their respective controls. There was no change in enzyme activity in spleen and kidney. This was accompanied by concomitant changes in NAD+ levels. The above results may be cited as important events in carcinogenesis and tumor promotion related to microwave exposure and the signal transduction mechanism involved. The goal is to shed light on complex ecogenetic interactions leading to cancer modulation of gene expression by epigenetic mechanism.

2§ relatório técnico de visita às instalaçöes do GICLA em Säo Luís e Alcântara / 2§ technical report of survey at the GICLA facilities in Säo Luís e Alcântara

A avaliaçäo realizada apresenta caráter quantitativo, viabilizando a comparaçäo entre os níveis de exposiçäo ocupacional a radiaçöes näo ionizantes (microondas) e os padröes recomendados nas normas ACGIH; para avaliar a exposiçäo ocupacional dos trabalhadores do Grupo de Implantaçäo do Centro de Lançamento de Alcântara durante as operaçöes de lançamento e recomendar medidas de controle