RESUMEN
An increase in the average herd size on Australian dairy farms has also increased the labor and animal management pressure on farmers, thus potentially encouraging the adoption of precision technologies for enhanced management control. A survey was undertaken in 2015 in Australia to identify the relationship between herd size, current precision technology adoption, and perception of the future of precision technologies. Additionally, differences between farmers and service providers in relation to perception of future precision technology adoption were also investigated. Responses from 199 dairy farmers, and 102 service providers, were collected between May and August 2015 via an anonymous Internet-based questionnaire. Of the 199 dairy farmer responses, 10.4% corresponded to farms that had fewer than 150 cows, 37.7% had 151 to 300 cows, 35.5% had 301 to 500 cows; 6.0% had 501 to 700 cows, and 10.4% had more than 701 cows. The results showed that farmers with more than 500 cows adopted between 2 and 5 times more specific precision technologies, such as automatic cup removers, automatic milk plant wash systems, electronic cow identification systems and herd management software, when compared with smaller farms. Only minor differences were detected in perception of the future of precision technologies between either herd size or farmers and service providers. In particular, service providers expected a higher adoption of automatic milking and walk over weighing systems than farmers. Currently, the adoption of precision technology has mostly been of the type that reduces labor needs; however, respondents indicated that by 2025 adoption of data capturing technology for monitoring farm system parameters would be increased.
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Bovinos , Industria Lechera/instrumentación , Industria Lechera/métodos , Animales , Australia , Agricultores , Granjas , Femenino , LecheRESUMEN
OBJECTIVE: To test the hypothesis that maternal restriction of polyphenol-rich foods (PRF), which, like non-steroidal anti-inflammatory drugs (NSAID), inhibit prostaglandin synthesis in the third trimester, reverse fetal ductal constriction (DC). STUDY DESIGN: An open clinical trial of 51 third trimester fetuses with DC with no history of NSAID intake was designed. All mothers were submitted to a food frequency questionnaire and were oriented to withdrawl PRF, being reassessed after 3 weeks. Doppler parameters were assessed before and after discontinuation of these substances. A control group of 26 third trimester normal fetuses, with no ductus arteriosus (DA) constriction, in which no dietary intervention was offered, was reviewed after 3 weeks. Student's t-test and Wilcoxon's test were used. RESULT: Mean gestational age was 32±3 weeks (28 to 37 weeks). After discontinuation of PRF (≥3 weeks), 48/51 fetuses (96%) showed complete reversal of DC, with decrease in mean ductal systolic velocity (1.74±0.20 m s(-1) to 1.31±0.34 m s(-1), P<0.001), mean diastolic velocity (0.33±0.09 m s(-1) to 0.21±0.07 m s(-1), P<0.001) and mean right to left ventricular dimension ratio (1.37±0.26 to 1.12±0.17, P<0.001) and increase in mean ductal pulsatility index (PI) (1.98±0.36 to 2.46±0.23, P<0.001). Median daily maternal consumption of PRF was 286 mg per day and decreased after orientation to 0 mg per day, P<0.001. In the control group, with GA of 32±4 w (29-37 w), there was no significant differences in median daily maternal consumption of PRF, mean ductal systolic velocitiy, diastolic velocity, PI and right ventricular to left ventricular diameter ratio (RV/LV) ratio. CONCLUSION: Reduction of maternal PRF intake during pregnancy, especially in the third trimester, is followed by complete reversal of DC (wide open DA), which may influence maternal dietary habits in late pregnancy.
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Antiinflamatorios no Esteroideos/farmacología , Conducto Arterial/efectos de los fármacos , Corazón Fetal/efectos de los fármacos , Polifenoles/farmacología , Adolescente , Adulto , Velocidad del Flujo Sanguíneo , Constricción Patológica , Conducto Arterial/diagnóstico por imagen , Conducto Arterial/patología , Femenino , Corazón Fetal/diagnóstico por imagen , Humanos , Embarazo , Complicaciones del Embarazo , Tercer Trimestre del Embarazo , Encuestas y Cuestionarios , Ultrasonografía Prenatal , Adulto JovenRESUMEN
Procaine is a local anesthetic used by dentists for decades. Nowadays it is being used to treat depression, increase the libido and act on inflammatory conditions and also to induce weight loss, among other uses. However, there has been criticism of such treatments with this substance, alone or in combination. The lack of a scientific basis makes its use subjective and unfounded and often potentially harmful to the individual. Therefore, the aim of this review is to find scientific evidence of systemic actions of procaine that demonstrate its efficacy for such purposes. From a review of the scientific literature, it was concluded that, except for a possible antidepressant effect, so far there are no data proving the alleged effects of procaine. In view of this, the current use of this substance in the treatment of chronic diseases or as an anti-aging drug would not be justified. Moreover, this review emphasizes the need for pharmacological and toxicological studies on procaine and the need to carry out in vivo and in vitro safety trials on pharmaceutical preparations containing this substance, in order to prove or disqualify the indications for its use.
A procaína é um anestésico local utilizado há décadas por dentistas. Atualmente, tem sido utilizada para tratar a depressão, aumentar a libido e agir em processos inflamatórios e no emagrecimento, entre outras utilidades. Porém, existem críticas acerca do tratamento com essa substância isolada ou associada. A falta de embasamento científico para sua utilização torna seu uso infundado e subjetivo, podendo ser muitas vezes nocivo ao indivíduo. Portanto, este artigo tem como objetivo buscar evidências científicas das ações sistêmicas da procaína que comprovem seus efeitos para tais finalidades. Foi realizado um levantamento na literatura científica e concluiu-se que, exceto por um possível efeito antidepressivo, até o momento não existem dados que comprovem os efeitos alegados para a procaína. Devido a isso, os usos atuais não se justificariam no tratamento de doenças crônicas ou no combate ao envelhecimento. Além disso, esta revisão enfatiza a necessidade da realização de estudos para avaliação farmacológica e toxicológica da procaína, bem como a necessidade de aplicar-se ensaios in vivo e in vitro na avaliação da segurança de preparações farmacêuticas que contenham essa substância, a fim de comprovar as inúmeras indicações de uso.
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Antidepresivos , Anestésicos Locales/administración & dosificación , Anestésicos Locales/farmacología , Procaína/farmacología , Procaína/toxicidadRESUMEN
It is well established that the involvement of reactive species in the pathophysiology of several neurological diseases, including phenylketonuria (PKU), a metabolic genetic disorder biochemically characterized by elevated levels of phenylalanine (Phe). In previous studies, we verified that PKU patients (treated with a protein-restricted diet supplemented with a special formula not containing L-carnitine and selenium) presented high lipid and protein oxidative damage as well as a reduction of antioxidants when compared to the healthy individuals. Our goal in the present study was to evaluate the effect of Phe-restricted diet supplemented with L-carnitine and selenium, two well-known antioxidant compounds, on oxidative damage in PKU patients. We investigated various oxidative stress parameters in blood of 18 treated PKU patients before and after 6 months of supplementation with a special formula containing L-carnitine and selenium. It was verified that treatment with L-carnitine and selenium was capable of reverting the lipid peroxidation, measured by thiobarbituric acid-reactive species, and the protein oxidative damage, measured by sulfhydryl oxidation, to the levels of controls. Additionally, the reduced activity of glutathione peroxidase was normalized by the antioxidant supplementation. It was also verified a significant inverse correlation between lipid peroxidation and L-carnitine blood levels as well as a significant positive correlation between glutathione peroxidase activity and blood selenium concentration. In conclusion, our results suggest that supplementation of L-carnitine and selenium is important for PKU patients since it could help to correct the oxidative stress process which possibly contributes, at least in part, to the neurological symptoms found in phenylketonuric patients.
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Antioxidantes/farmacología , Carnitina/farmacología , Estrés Oxidativo/efectos de los fármacos , Fenilcetonurias/fisiopatología , Selenio/farmacología , Adolescente , Antioxidantes/administración & dosificación , Antioxidantes/uso terapéutico , Carnitina/administración & dosificación , Carnitina/uso terapéutico , Suplementos Dietéticos , Humanos , Fenilcetonurias/sangre , Fenilcetonurias/dietoterapia , Especies Reactivas de Oxígeno/metabolismo , Selenio/administración & dosificación , Selenio/uso terapéutico , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Adulto JovenRESUMEN
In this study, oil-in-water formulations were optimized to determine sodium, potassium, calcium, magnesium, zinc, and iron in emulsified egg samples by flame atomic absorption spectrometry (FAAS). This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures and allows the calibration to be carried out using aqueous standards. Different oily phases such as corn oil, decyl oleate and octyl stearate were tested, as well as Tween 80, Triton X-100 and Triton 114 were analyzed as surfactants. The optimum type and proportion of formulations were determined and their use depended on the element studied. The emulsion preparation was performed by a conventional method that involves mixing both phases at 60 degrees C by magnetic stirring and phase inversion to change the water-to-oil ratio by increasing the volume of the surfactant-water external phase and correspondingly decreasing the volume of internal phase. The accuracy of the method was further confirmed by determining the metals in a whole egg powder CRM and recoveries ranged from 97.5% for Mg to 102.2% for Na, with relative standard deviations lower than 2.3%. The precision of the procedures was determined through repeatability (intra-day precision) and intermediate precision (inter-day). The repeatability presented RSD values lower than 4.2%. The intermediate precision was evaluated using the RSD and F-test. The RSD values to intermediate precision was lower than 5.3% and the computed F-values were lower than tabulated F-values, indicating no significant difference between the results obtained on different days. The proposed method including, sample emulsification for subsequent metal determination for FAAS, has proved to be sensitive, reproducible, simple and economical.
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Huevos/análisis , Análisis de los Alimentos/métodos , Metales/análisis , Metales/química , Métodos Analíticos de la Preparación de la Muestra , Animales , Calcio/análisis , Calcio/química , Calibración , Pollos , Emulsiones , Análisis de los Alimentos/normas , Hierro/análisis , Hierro/química , Magnesio/análisis , Magnesio/química , Potasio/análisis , Potasio/química , Estándares de Referencia , Reproducibilidad de los Resultados , Sodio/análisis , Sodio/química , Espectrofotometría Atómica , Zinc/análisis , Zinc/químicaRESUMEN
This work has investigated the effects of prolonged exposure of young rats to nicotine on some physiological and biochemical parameters. Wistar male rats (30 days old) were treated (s.c.) with saline or nicotine 5mg/kg/day for 28 or 56 days. They received five injections (1mg/kg) per day (8, 10, 12:00 a.m., 2 and 4:00 p.m.) on the dark period of the cycle. Nicotine exposure for 56 days reduced body and liver weights. Moreover, nicotine exposure for 28 or 56 days decreased the hepatic glycogen but not blood glucose levels. The activities of blood and hepatic PBG-synthase, and blood and cerebral acetylcholinesterase were not affected by in vivo exposure. However, these activities were inhibited by nicotine in vitro. Results show that although high levels of plasma cotinine were found in both intervals of exposures, the parameters here analyzed were not affected by prolonged nicotine exposure except the storage of glucose, and body and liver weights.
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Envejecimiento/efectos de los fármacos , Nicotina/toxicidad , Acetilcolinesterasa/metabolismo , Animales , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Peso Corporal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Cotinina/sangre , Exposición a Riesgos Ambientales , Inyecciones Subcutáneas , Hígado/anatomía & histología , Hígado/efectos de los fármacos , Masculino , Nicotina/administración & dosificación , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas WistarRESUMEN
Dietary supplements containing bitter orange unripe fruit extract/p-synephrine are consumed worldwide for lose weight. This study were conducted to determine the concentration of p-synephrine in unripe fruits and leaves from Citrus aurantium Lin, C. sinensis Osbeck, C. deliciosa Ten, C. limon Burm and C. limonia Osbeck, collected in Southern Brazil, and to evaluate the acute toxicity of C. aurantium extract and p-synephrine. A high performance liquid chromatographic method with diode array detector (HPLC-DAD) was optimized and validated for determination of p-synephrine. The results indicate that all of analyzed samples present p-synephrine in amounts that range from 0.012% to 0.099% in the unripe fruits and 0.029 to 0.438% in the leaves. Acute oral administration of C. aurantium extracts (2.5% p-synephrine, 300-5,000 mg/kg) in mice produced reduction of locomotor activity, p-synephrine (150-2,000 mg/kg) produced piloerection, gasping, salivation, exophtalmia and reduction in locomotor activity, which was confirmed in spontaneous locomotor activity test. All the effects were reversible and persisted for 3-4h. The toxic effects observed seem to be related with adrenergic stimulation and should alert for possible side effects of p-synephrine and C. aurantium.
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Citrus/química , Sinefrina/análisis , Sinefrina/toxicidad , Animales , Temperatura Corporal/efectos de los fármacos , Brasil , Calibración , Cromatografía Líquida de Alta Presión , Citrus/crecimiento & desarrollo , Frutas/química , Frutas/crecimiento & desarrollo , Indicadores y Reactivos , Masculino , Ratones , Actividad Motora/efectos de los fármacos , Hojas de la Planta/química , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrofotometría UltravioletaRESUMEN
Reactive oxygen species are implicated as mediators of tissue damage in the acute renal failure induced by inorganic mercury. Astaxanthin (ASX), a carotenoid with potent antioxidant properties, exists naturally in various plants, algae, and seafoods. This paper evaluated the ability of ASX to prevent HgCl(2) nephrotoxicity. Rats were injected with HgCl(2) (0 or 5 mg/kg b.w., sc) 6h after ASX had been administered (0, 10, 25, or 50mg/kg, by gavage) and were killed 12h after HgCl(2) exposure. Although ASX prevented the increase of lipid and protein oxidation and attenuated histopathological changes caused by HgCl(2) in kidney, it did not prevent creatinine increase in plasma and delta-aminolevulinic acid dehydratase inhibition induced by HgCl(2). Glutathione peroxidase and catalase activities were enhanced, while superoxide dismutase activity was depressed in HgCl(2)-treated rats when compared to control and these effects were prevented by ASX. Our results indicate that ASX could have a beneficial role against HgCl(2) toxicity by preventing lipid and protein oxidation, changes in the activity of antioxidant enzymes and histopathological changes.
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Antioxidantes/farmacología , Enfermedades Renales/inducido químicamente , Enfermedades Renales/prevención & control , Cloruro de Mercurio/antagonistas & inhibidores , Cloruro de Mercurio/toxicidad , Estrés Oxidativo/efectos de los fármacos , Animales , Biomarcadores , Glutatión Transferasa/metabolismo , Riñón/efectos de los fármacos , Riñón/enzimología , Pruebas de Función Renal , Peroxidación de Lípido/efectos de los fármacos , Masculino , Necrosis/inducido químicamente , Necrosis/patología , Porfobilinógeno Sintasa/metabolismo , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Compuestos de Sulfhidrilo/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Xantófilas/farmacologíaRESUMEN
AIMS: Isolation and antimicrobial evaluation of aquatic bacterial strains from two cenotes. METHODS AND RESULTS: A total of 258 bacterial strains were isolated from the water and sediment of two cenotes in the Yucatan peninsula, all of which were screened against six pathogenic micro-organisms. Antimicrobial activity was detected in 46 of the isolated strains against at least one of the target strains tested. Antimicrobially active isolates were identified as: Aeromonas, Bacillus, Burkholderia, Photobacterium, Pseudomonas, Serratia, Shewanella, Stenotrophomonas genera, and 13 remained unidentified. All antimicrobially active strains were able to grow in salt medium at a concentration of 75 g l(-1), thus classifying as moderately halotolerant bacteria. Most of the antimicrobially active strains exhibited a broad action spectrum, where 61% was because of uncharacterized antimicrobial substances, 25% because of bacteriocins and 13% because of siderophores. Ten strains were able to biosynthesize biosurfactant metabolites. CONCLUSIONS: Native bacteria from the Yucatan peninsula showed an interesting antimicrobial activity, diverse mode of action and moderate halotolerance to salt. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on bacterial isolates from cenotes of the Yucatan peninsula and their antimicrobial characterization, with great potential for future biotechnological applications.
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Antibacterianos/metabolismo , Bacterias/metabolismo , Agua Dulce/microbiología , Aeromonas/metabolismo , Bacillus/metabolismo , Bacteriocinas/biosíntesis , Burkholderia/metabolismo , Bacterias Gramnegativas/metabolismo , México , Photobacterium/metabolismo , Pseudomonas/metabolismo , Serratia/metabolismo , Shewanella/metabolismo , Sideróforos/biosíntesis , Cloruro de Sodio/metabolismo , Stenotrophomonas/metabolismoRESUMEN
BACKGROUND: Malondialdehyde (MDA) is one of the better-known secondary products of lipid peroxidation, and it is widely used as an indicator of cellular injury. The employment of the thiobarbituric acid reactive substances (TBARS) technique to measure MDA has received criticism over the years because of its lack of specificity. Thus, a specific and reliable method for MDA determination in plasma by high performance liquid chromatographic (HPLC)-VIS was validated; alkaline hydrolysis, n-butanol extraction steps and MDA stability were established. METHODS: The plasma underwent alkaline hydrolysis, acid deproteinization, derivatization with TBA and n-butanol extraction. After this, MDA was determined at 532 nm by HPLC-VIS. The method was applied to 65-year-old subjects from a retirement home. RESULTS: The assay was linear from 0.28 to 6.6 microM. The reproducibility of intra-run was obtained with CV%<4% and the inter run with CV%<11%. The accuracy (bias) ranged from 2 to -4.1%, and the recovery was greater than 95%. The limit of detection (LOD) and limit of quantification (LOQ) were 0.05 and 0.17 microM, respectively. For the stability test, every sample was stored at -20 degrees C. The plasma MDA was not stable when stored after the alkaline hydrolysis step, remained stable for 30 days after TBA derivatization storage and was stable for 3 days when stored after n-butanol extraction. The elderly subjects had MDA plasma levels of 4.45+/-0.81 microM for women and 4.60+/-0.95 microM for men. CONCLUSION: The method is reproducible, accurate, stable, sensitive, and can be used in the routines in clinical laboratories. Besides, this technique presents advantages such as the complete release of protein bound MDA with the alkaline hydrolysis step, the removal of interferents with n-butanol extraction, mobile phase without phosphate buffer and rapid analytical processes and run times.
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Cromatografía Líquida de Alta Presión/métodos , Malondialdehído/sangre , Espectrofotometría/métodos , 1-Butanol/química , Anciano , Brasil , Femenino , Humanos , Hidrólisis , Modelos Lineales , Masculino , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Hidróxido de Sodio/química , Solventes/química , Tiobarbitúricos/química , Factores de TiempoRESUMEN
BACKGROUND AND AIMS: biological processes in all organisms are controlled by environmental conditions, however, information concerning the molecular responses to external pH is scarce. In this work we studied the pH response of UGA4 gene encoding delta-aminolevulinic acid and gamma-aminobutyric acid permease in Saccharomyces cerevisiae. METHODS: we analyzed the effect of pH on the expression of UGA4 gene measuring beta-galactosidase activity in cells carrying a UGA4::lacZ fusion gene. RESULTS: results indicate that UGA4 expression is higher at acidic pH. The expression of UGA3 and UGA35 genes, which encode two positive transcription factors, is not regulated by external pH, while the expression of UGA43 gene encoding a repressor of UGA4 transcription is dependent on pH. Using a strain lacking Uga43p we clearly showed that the effect of ambient pH on UGA4 expression is not a secondary effect of the pH regulation on UGA43. We have also demonstrated that the effect of pH can only be detected when UGA4 gene is not subject to a strong repression by Uga43p nor to GABA induction. CONCLUSION: here, we demonstrate that UGA4 is an acid-expressed gene. This regulation is probably mediated by Rim101p through the consensus site 5'-GCCARG-3' at 237 bp preceding the UGA4 coding sequence (201).
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Transportadores de Anión Orgánico/biosíntesis , Transportadores de Anión Orgánico/genética , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/genética , Ácido Aminolevulínico/metabolismo , Sitios de Unión , Proteínas Transportadoras de GABA en la Membrana Plasmática , Concentración de Iones de Hidrógeno , Operón Lac , Regiones Promotoras Genéticas , Proteínas de Saccharomyces cerevisiae , beta-Galactosidasa/metabolismoRESUMEN
In Saccharomyces cerevisiae, as in all eukaryotic organisms, delta-aminolevulinic acid (ALA) is a precursor of porphyrin biosynthesis, a very finely regulated pathway. ALA enters yeast cells through the gamma-aminobutyric acid (GABA) permease Uga4. The incorporation of a metabolite into the cells may be a limiting step for its intracellular metabolization. To determine the relationship between ALA transport and ALA metabolization, ALA incorporation was measured in yeast mutant strains deficient in the delta-aminolevulinic acid-synthase, uroporphyrinogen III decarboxylase, and ferrochelatase, three enzymes involved in porphyrin biosynthesis. Results presented here showed that neither intracellular ALA nor uroporphyrin or protoporphyrin regulates ALA incorporation, indicating that ALA uptake and its subsequent metabolization are not related to each other. Thus a key metabolite as it is, ALA does not have a transport system regulated according to its role.
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Ácido Aminolevulínico/metabolismo , Transportadores de Anión Orgánico , Porfirinas/biosíntesis , Porfirinas/metabolismo , Saccharomyces cerevisiae/metabolismo , 5-Aminolevulinato Sintetasa/deficiencia , 5-Aminolevulinato Sintetasa/genética , 5-Aminolevulinato Sintetasa/metabolismo , Ácido Aminolevulínico/farmacología , Transporte Biológico , Ferroquelatasa/genética , Ferroquelatasa/metabolismo , Proteínas Transportadoras de GABA en la Membrana Plasmática , Genes Fúngicos/genética , Cinética , Proteínas de Transporte de Membrana/metabolismo , Mutación/genética , Porfobilinógeno/metabolismo , Porfobilinógeno Sintasa/metabolismo , Protoporfiria Eritropoyética , Protoporfirinas/metabolismo , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae , Uroporfirinógeno Descarboxilasa/deficiencia , Uroporfirinógeno Descarboxilasa/genética , Uroporfirinógeno Descarboxilasa/metabolismo , Uroporfirinas/metabolismoRESUMEN
Six Holstein-Friesian heifers fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 3x3 Latin square to study the effects of partial replacement [1:1 dry matter (DM) basis] of fresh winter oats (WO) by ground corn (C) or barley (B) on digestion and bacterial protein synthesis. Supplemented diets contained 24% starch, and all diets were fed indoors at 2.5% of body weight (DM basis). Ruminal and total tract digestibilities of organic matter and neutral detergent fiber were similar for all treatments. Ruminal and total tract starch digestibility was similar for C and B diets. Nitrogen intake was greater for WO than for supplemented diets. However, duodenal flows of nonammonia N and bacterial N did not differ among treatments. The efficiency of bacterial protein synthesis was similar for the three diets, suggesting that the fermentation of high quality fresh forage DM provided sufficient energy for the microorganisms in the rumen. Ruminal ammonia-N concentration was greater for WO than for supplemented diets, and for C than for B diet. Ruminal fluid pH and concentrations of total volatile fatty acid were not different among diets, but concentration of acetate was higher and that of propionate was lower for WO than for supplemented diets and for C than for B diet. Supplementation of WO with barley rather than with corn decreased C2:C3 ratio without affecting fiber digestion. Supplements increased N utilization relative to N intake but did not increase duodenal nonammonia N flow.
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Avena , Proteínas Bacterianas/biosíntesis , Bovinos/fisiología , Digestión , Hordeum , Zea mays , Amoníaco/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta , Fibras de la Dieta/administración & dosificación , Fibras de la Dieta/metabolismo , Duodeno/fisiología , Ácidos Grasos Volátiles/metabolismo , Femenino , Fermentación , Nitrógeno/administración & dosificación , Nitrógeno/metabolismo , Rumen/metabolismo , Rumen/microbiología , Almidón/administración & dosificaciónRESUMEN
The first specific precursor of porphyrin biosynthesis is delta-aminolevulinic acid. delta-Aminolevulinic acid enters Saccharomyces cerevisiae cells through the gamma-aminobutyric acid specific permease Uga4p. It was described that this permease is inducible by gamma-aminobutyric acid and its regulation involves several specific and pleiotropic transcriptional factors. However, some studies showed that under certain growth conditions the synthesis of Uga4p was not dependent on the presence of gamma-aminobutyric acid. To study the effect of the trans-acting factors Uga43p, Uga3p, Uga35p, Ure2p and Gln3p on the expression of UGA4, we measured gamma-aminobutyric acid and delta-aminolevulinic acid uptake in yeast mutant cells, lacking one of these regulatory factors, grown under different conditions. Experiments analyzing the UGA4 promoter using a fusion construction UGA4::lacZ were also carried out. The results show that the constitutive expression of the UGA4 gene found in cells under certain growth conditions depends on the presence of Uga3p and Uga35p. In contrast, Gln3p and Ure2p do not seem to have any effect on this constitutive mechanism.
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Proteínas de Unión al ADN/metabolismo , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica , Proteínas de Transporte de Membrana/genética , Transportadores de Anión Orgánico , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Factores de Transcripción/metabolismo , Alanina/metabolismo , Ácido Aminolevulínico/metabolismo , Proteínas Transportadoras de GABA en la Membrana Plasmática , Proteínas de Transporte de Membrana/metabolismo , Regiones Promotoras Genéticas , Proteínas Recombinantes de Fusión/metabolismo , Saccharomyces cerevisiae/metabolismo , beta-Galactosidasa/genética , beta-Galactosidasa/metabolismo , Ácido gamma-Aminobutírico/metabolismoRESUMEN
1. Delta-aminolevulinic acid (ALA) and gamma-aminobutyric acid (GABA) transport through the rat blood-brain barrier (BBB) was studied. 2. GABA transport (Km=3.2+/-0.1 microM and Vmax=0.299+/-0.045 micromol/mg protein min) is probably mediated by a permease similar to Saccharomyces cerevisiae PUT4; this result also indicates that the isolated capillaries are metabolically active. 3. ALA incorporation into rat brain endothelial cells is not detected even in capillaries treated to expose the luminal surface. 4. Previous evidence indicates that ALA can cross the BBB from blood to brain; so we conclude that, with the methodology used here, transport in the luminal membrane of the capillaries cannot be investigated.
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Ácido Aminolevulínico/farmacocinética , Barrera Hematoencefálica/fisiología , Animales , Permeabilidad Capilar , Técnicas In Vitro , Masculino , Ratas , Ratas Sprague-Dawley , Ácido gamma-Aminobutírico/farmacocinéticaRESUMEN
Ninety-eight females with congenital adrenal hyperplasia due to a defect in either the 21-hydroxylase or the 11 beta-hydroxylase enzyme were evaluated to determine the effects of glucocorticoid treatment on growth, pubertal development, and fertility. When treatment was begun prior to one year of age, mean final height was 157.4 +/- 7.3 com, well within the normal adult female range, and significantly (p less than 0.001) greater than the mean final height of 150.9 +/- 4.3 cm found in untreated patients. The mean age of menarche in patients treated prior to the age of six years was 13.8 +/- 3.7 years which is significantly (p less than 0.01) delayed compared to that in the normal population of the United States. However, 92% of patients with menstrual delay had inadequate suppression of adrenal androgens and urinary excretion of 17 ketosteroids larger than 7.0 mg/24hours. The increased production of adrenal androgens was the result of poor compliance or an insufficient prescribed dose of glucocorticoids. The fertility rate in patients first treated between six and 20 years of age was 64%. The excretion of urinary 17 KS at the time of pregnancy was 2.5 to 5.3 mg/24 hours. All of the patients who delivered term infants required delivery by cesarean section because of cephalopelvic disproportion. The major problems encountered in the management of adolescent patients were patient noncompliance and physician failure to increase the glucocorticoid dose as the patient's body size increased.