ABSTRACT
Current evidence and recent publications have led to the recognition that aerosol-borne transmission of COVID-19 is possible in indoor areas such as educational centers. A crucial measure to reduce the risk of infection in high occupancy indoors is ventilation. In this global pandemic context of SARS-CoV-2 virus infection, a study has been carried out with the main objective of analyzing the effects of natural ventilation conditions through windows on indoor air quality and thermal comfort during on-site examinations in higher education centers during the winter season, as this implies situations of unusual occupation and the impossibility in many cases of taking breaks or leaving classrooms, as well as the existence of unfavorable outdoor weather conditions in terms of low temperatures. For this purpose, in situ measurements of the environmental variables were taken during different evaluation tests. As the main results of the study, ventilation conditions were generally adequate in all the tests carried out, regardless of the ventilation strategy used, with average CO2 concentration levels of between 450 and 670 ppm. The maximum CO2 concentration value recorded in one of the tests was 808 ppm. On this basis, the limit for category IDA 2 buildings, corresponding to educational establishments, was not exceeded in any case. However, these measures affected the thermal comfort of the occupants, especially when the outside temperature was below 6 °C, with a dissatisfaction rate of between 25 and 72%. Examinations carried out with outside temperatures above 12 °C were conducted in acceptable comfort conditions regardless of outside air supply and classroom occupancy. In these cases, the dissatisfaction rate was less than 10%. The results obtained have made it possible to establish strategies for ventilation in the implementation of future exams, depending on the climatic conditions outside.
Subject(s)
Air Pollution, Indoor , COVID-19 , Air Pollution, Indoor/analysis , Carbon Dioxide/analysis , Humans , SARS-CoV-2 , Schools , VentilationSubject(s)
Facial Dermatoses/epidemiology , Patch Tests , Adult , Facial Dermatoses/diagnosis , Female , Humans , Male , Middle Aged , Retrospective Studies , Spain , Young AdultABSTRACT
In recent years, biomass market has constantly increased. Pellet industry has started looking for new products with the potential to be used as biofuels. Among them are agricultural wastes, such as corn cob waste, which presents some characteristics that make its direct use in industrial facilities possible. However, these properties are not enough for its use in domestic stoves and boilers, where higher quality of fuel is needed. For this reason, densification is used. In the present research work a technical and energy analysis of corn cob waste pelletizing was carried out in a semi-industrial pelletizer. Some relationships between variables, such as moisture, bulk density and mechanical durability, were analyzed, as well as their influence on energy use and final productivity. The results were satisfactory, as the pellets manufactured fulfilled with most specifications that were consulted, with higher values than those recorded for similar kinds of pellets. Concerning the energy study, the increase in production justified a higher energy consumption of the process in order to get a higher productivity ratio.
Subject(s)
Zea mays , Agriculture , Biofuels/analysis , Biomass , Industrial Waste/analysisABSTRACT
The release of anthropogenic compounds into the aquatic environment has been a particular concern, since some of these substances exhibit biologic activity of different types in non-target species. Among anthropogenic compounds present in the aquatic compartment, detergents are commonly found and may be responsible for physiological modifications in exposed organisms. The impairment of key physiological functions, such as neurotransmission, and tissue damage in some important organs, has been used to assess the effects of several classes of xenobiotics, including detergents, in aquatic organisms. The present study intended to assess the effect of three types of detersive compounds (sodium dodecylsulfate (SDS), benzalkonium chloride (BZC), and Triton X-100 (TX100)) in the acetylcholinesterase activity (AChE) and tissue damage (gills and liver) of Gambusia holbrooki after a chronic exposure to realistic levels of these compounds. SDS, BZC, and TX100 did not cause any significant alteration in AChE. Furthermore, no specific gross morphological changes were also observed in the gills and liver of the exposed individuals. It is possible to conclude that, under ecologically relevant conditions of exposure, both tissue damage and cholinesterasic impairment are not toxicological pathways affected by detergents in G. holbrooki.
Subject(s)
Biomarkers , Cyprinodontiformes/metabolism , Detergents/toxicity , Water Pollutants, Chemical/toxicity , Animals , Biomarkers/analysis , Biomarkers/metabolism , Tissue DistributionABSTRACT
BACKGROUND: Obesity is associated with decreased iron status, possibly due to a rise in hepcidin, an inflammatory protein known to reduce iron absorption. In animals, we have shown that maternal iron deficiency is minimised in the foetus by increased expression of placental transferrin receptor (pTFR1), resulting in increased iron transfer at the expense of maternal iron stores. OBJECTIVE: This study examines the effect of obesity during pregnancy on maternal and neonatal iron status in human cohorts and whether the placenta can compensate for decreased maternal iron stores by increasing pTFR1 expression. SUBJECTS/METHODS: A total of 240 women were included in this study. One hundred and fifty-eight placentas (Normal: 90; Overweight: 37; Obese: 31) were collected at delivery. Maternal iron status was measured by determining serum transferrin receptor (sTFR) and ferritin levels at 24 and 34 weeks and at delivery. Hepcidin in maternal and cord blood was measured by ELISA and pTFR1 in placentas by western blotting and real-time RT-PCR. RESULTS: Low iron stores were more common in obese women. Hepcidin levels (ng ml(-1)) at the end of the pregnancy were higher in obese than normal women (26.03±12.95 vs 18.00±10.77, P<0.05). Maternal hepcidin levels were correlated with maternal iron status (sTFR r=0.2 P=0.025), but not with neonatal values. mRNA and protein levels of pTFR1 were both inversely related to maternal iron status. For mRNA and all women, sTFR r=0.2 P=0.044. Ferritin mRNA levels correlated only in overweight women r=-0.5 P=0.039 with hepcidin (r=0.1 P=0.349), irrespective of maternal body mass index (BMI). CONCLUSIONS: The data support the hypothesis that obese pregnant women have a greater risk of iron deficiency and that hepcidin may be a regulatory factor. Further, we show that the placenta responds to decreased maternal iron status by increasing pTFR1 expression.
Subject(s)
Antigens, CD/blood , Hepcidins/blood , Iron/blood , Mothers , Obesity, Abdominal/blood , Placenta/metabolism , Receptors, Transferrin/blood , Adult , Antimicrobial Cationic Peptides/blood , Biomarkers/blood , Body Mass Index , Dietary Carbohydrates/adverse effects , Dietary Sucrose/adverse effects , Female , Homeostasis , Humans , Infant, Newborn , Iron Deficiencies , Iron, Dietary/administration & dosage , Male , Maternal Nutritional Physiological Phenomena , Maternal-Fetal Exchange , Obesity/blood , Obesity, Abdominal/epidemiology , Obesity, Abdominal/prevention & control , Pregnancy , Transferrin/metabolismABSTRACT
BACKGROUND/OBJECTIVES: Obesity in childhood is very common in Europe. It may be linked to diet, and intakes of protein and polyunsaturated fatty acids (PUFA) have been investigated. The study aims to investigate child size and dietary differences at the age of 4 years between three European countries and to assess dietary adequacy. SUBJECTS/METHODS: A total of 161 4-year-old children from Spain, Germany and Hungary, whose mothers participated in a pregnancy micronutrient supplementation trial, were included in this analysis. Child size was assessed by standardised anthropometry and diet calculated from parent-completed food frequency questionnaires. Adequacy of the diet was evaluated using US guidelines. RESULTS: The Spanish children had a higher mean body mass index (BMI) (16.4±1.5) compared with German (15.7±1.0) and Hungarian children (14.9±1.4, P<0.01). In Spanish children, dietary intakes were higher in animal protein density, particularly from dairy foods, were little different in total protein density and slightly lower in n-6 PUFA density compared with the intakes in the other groups. Dietary intakes of most children (% contribution to energy) were higher than those recommended for protein, saturated fat and added sugar. CONCLUSIONS: Spanish children had a higher mean BMI compared with German and Hungarian children. Diets taken by Spanish children may be more obesogenic than those taken by German or Hungarian children. In the present study, many children in all three countries were consuming diets that were high in protein, saturated fat and sugar.
Subject(s)
Body Mass Index , Diet , Feeding Behavior , Pediatric Obesity/etiology , Anthropometry , Child, Preschool , Diet/adverse effects , Energy Intake , Female , Germany , Humans , Hungary , Male , Nutrition Assessment , Nutrition Policy , Spain , Surveys and QuestionnairesABSTRACT
En los deportes de equipo el conocimiento que necesita el juegador está relacionado con la lógica de juego (Grehaigne, Godbout y Bouthier, 1999). Esta lógica dará lugar a los principios de juego, siendo uno de ellos conservar el balón (Bayer, 1992). Para su cumplimiento es necesario facilitar el pase al jugador con balón (Cárdenas y Alarcón 2009). De los diferentes modelos de enseñanza en educación física que buscan la mejora de la toma de decisiones del jugador es el modelo constructivista el que mejor se adapta a las necesidades de aprendizaje que tiene el jugador de baloncesto, ya que utiliza una intervención reflexiva que ayuda al jugador a interiorizar los conocimientos relacionados con la lógica del juego (Grehaigne, Wallian y Godbout, 2005). El objetivo de este estudio fue analizar la influencia de un programa de entrenamiento basado en la presentación de los objetivos y principios de juego mediante una intervención reflexiva, sobre la toma de decisiones relacionada con la capacidad de facilitar el pase al jugador con balón durante el juego real de un equipo de baloncesto (AU)
Subject(s)
Humans , 34600/methods , Decision Making , Athletic Performance/psychology , Sensitivity Training Groups , Decision Support Techniques , Group ProcessesABSTRACT
BACKGROUND: Sitaxentan inhibits the metabolism of warfarin, resulting in a need for adjustment of warfarin dose when both drugs are coadministered. We report the long-term effects on bleeding of acenocoumarol co-administered as part of conventional therapy for pulmonary hypertension with sitaxentan in a subset of patients enrolled in the Sitaxentan To Relieve ImpaireD Exercise-3 (STRIDE-3) study. MATERIALS AND METHODS: STRIDE-3 is an ongoing, long-term, open-label trial, evaluating the safety and efficacy of sitaxentan, 100 mg once daily, in patients with pulmonary arterial hypertension. Information on bleeding events was collected prospectively, including the type of event, severity, anticoagulant use and investigator attribution of causality. Coagulation tests were performed on a monthly basis. A clinically significant interaction was defined as an international normalized ratio (INR) >/= 5.0, or any minor bleeding event plus an INR > 2.0 and < 5.0. RESULTS: Of 55 patients enrolled in STRIDE-3, 50 received acenocoumarol. Average follow-up was 158.6 +/- 57.6 weeks. The average dose of anticoagulant therapy was 3.9 +/- 1.3 mg week(-1) (range, 1.5-7.0 mg week(-1)). Following treatment, an INR >/= 5 in at least one INR determination was observed in 13 patients, although none of these patients had a clinically significant bleeding event. Dose reductions in acenocoumarol were performed to adjust target INR to 1.5-2.0. Two patients died of massive haemoptysis, but these episodes were not attributed to a drug interaction. Four patients with an INR > 2.0 and < 5.0 experienced a minor bleeding event (nosebleeds/gingivitis). CONCLUSIONS: No clinically significant bleeding events were recorded with coadministration of sitaxentan and acenocoumarol in this patient subgroup. These results suggest that coadministration of sitaxentan and acenocoumarol is clinically manageable and well tolerated.
Subject(s)
Acenocoumarol/pharmacology , Anticoagulants/pharmacology , Antihypertensive Agents/pharmacology , Hypertension, Pulmonary/drug therapy , Isoxazoles/pharmacology , Thiophenes/pharmacology , Acenocoumarol/administration & dosage , Acenocoumarol/adverse effects , Adolescent , Adult , Anticoagulants/administration & dosage , Anticoagulants/adverse effects , Drug Administration Schedule , Drug Interactions , Endothelin Receptor Antagonists , Female , Hemorrhage/chemically induced , Humans , International Normalized Ratio , Male , Prospective Studies , Survival Analysis , Young AdultABSTRACT
BACKGROUND: Of the factors identified in different studies as the possible causes of alcoholism, heredity appears to be the most important. However, environmental factors can increase or decrease the risk of an individual developing alcohol dependence. METHOD: To clarify the possible influence of heredity on alcoholism, we studied the plasma concentration of beta-endorphins in 25 families with alcoholic members: 27 children whose father was alcoholic and 7 whose father and mother were both alcoholics. The results were compared with finding in an age-matched control group of no-drinking adults and normal children in non-drinking families. RESULTS: The children of alcoholic parents had significantly lower beta-endorphin levels (p < 0.001) than control individuals, and concentrations were especially low when both parents were alcoholics. CONCLUSION: We conclude that plasma beta-endorphin concentration may have predictive value in identifying persons likely to become alcoholics.
Subject(s)
Alcoholism/genetics , beta-Endorphin/blood , Adolescent , Adult , Biomarkers , Case-Control Studies , Child , Child, Preschool , Family Health , Fathers , Genetic Predisposition to Disease , Humans , Infant , Middle Aged , Mothers , beta-Endorphin/deficiencyABSTRACT
Introducción: En los últimos años son numerosos los trabajos acerca de las posibles causas del alcoholismo, donde parece intervenir varios factores, siendo la herencia uno de los más implicados, aunque se han destacado otros, como factores ambientales, que contribuirían a aumentar o disminuir el riesgo individual para desarrollar una dependencia alcohólica. Método: Para intentar aclarar la posible influencia de la herencia en el alcoholismo, hemos estudiado los niveles de beta-endorfinas (β-E) en 25 familias de alcohólicos, en las cuales había 27 hijos con un padre alcohólico y 7 hijos con los dos, así como en dichos padres alcohólicos, y comparado los resultados con unos grupos control: uno de adultos no bebedores y otro de niños normales en familias de no-bebedores, con edades similares. Resultados: Se ha encontrado que los hijos de alcohólicos tienen unos niveles de Beta-E significativamente más bajos (p < 0,001) que los controles, y estos niveles eran aún más bajos en los hijos cuyos dos padres eran alcohólicos. Conclusión: Se concluye que la determinación de β-E podía tener un valor predictivo a la hora de determinar quién es más propenso a ser alcohólico en el futuro
Background: Of the factors identified in different studies as the possible causes of alcoholism, heredity appears to be the most important. However, environmental factors can increase or decrease the risk of an individual developing alcohol dependence. Method: To clarify the possible influence of heredity on alcoholism, we studied the plasma concentration of beta-endorphins in 25 families with alcoholic members: 27 children whose father was alcoholic and 7 whose father and mother were both alcoholics. The results were compared with finding in an age-matched control group of no-drinking adults and normal children in non-drinking families. Results: The children of alcoholic parents had significantly lower beta-endorphin levels (p < 0.001) than control individuals, and concentrations were especially low when both parents were alcoholics. Conclusion: We conclude that plasma beta-endorphin concentration may have predictive value in identifying persons likely to become alcoholics
Subject(s)
Male , Female , Infant , Child, Preschool , Child , Adolescent , Humans , beta-Endorphin/metabolism , Alcoholism/etiology , Genetic Markers/genetics , Case-Control Studies , Parents , Predictive Value of TestsABSTRACT
OBJECTIVE: To evaluate the effects of the metabolic control of the insulin-dependent diabetes mellitus (IDDM) on the nutritional status of vitamin E. METHODS: A total of 47 children with IDDM and a mean age of 11.91+/-1.60 (mean+/-SD) years were studied, matched for age and sex with 16 healthy children (11.75+/-1.83 years). Following the American and British Associations for IDDM, we used a classification of "good", "moderate" or "poor" control of the illness: (a) good control [glycosilated haemoglobin (HbAlc) < or =7%]; (b) moderate control (7%< HbAlc < or =8%); and (c) poor control (HbAlc>8%). Serum concentrations of total cholesterol (CHOL), triglycerides (TG), high-density lipoproteins-cholesterol (HDLc), very low- and low-density lipoproteins cholesterol (VLDLc and LDLc), plasma and erythrocyte vitamin E (Vit Ep and Vit Ee) and plasma vitamin A (Vit Ap) were measured in all children. RESULTS: The children with "poor" metabolic control of the illness presented significantly higher plasma concentrations of CHOL, LDLc, VLDLc, LDLc/HDLc, (VLDL+LDL)c/HDLc, TG and Vit Ep; higher indices Vit Ep/Vit Ee and Vit Ep/Vit Ap relative to those with a "good" control of the illness. Direct-linear correlations were found between Vit Ep and the percentage of HbAlc and with the markers of atherogenic risk in the IDDM children. CONCLUSION: There is a significant rise in Vit Ep concentrations as metabolic control of the illness worsens, whereas Vit Ee remained unchanged. These results suggest that vitamin E maintains its nutritional status despite a poor control of the IDDM during childhood.
Subject(s)
Diabetes Mellitus, Type 1/metabolism , Nutritional Status/physiology , Vitamin E/blood , Adolescent , Analysis of Variance , Biomarkers , Child , Cholesterol/blood , Female , Glycated Hemoglobin/analysis , Humans , Lipoproteins/blood , Male , Risk Factors , Triglycerides/blood , Vitamin A/bloodABSTRACT
- The effects of acute alcohol intoxication (AAI) on the pituitary-gonadal axis hormones, and the possible contribution of pituitary-adrenal axis hormones, beta-endorphin and prolactin to alcohol-induced dysfunction of pituitary-gonadal axis hormones were studied in adult men and women. Blood samples were drawn from adults of both sexes who arrived at the emergency department with evident behavioural symptoms of drunkenness (AAI) or from adult volunteers with nil consumption of alcohol (controls). Our results demonstrated that AAI produces a high increase in plasma prolactin, corticotropin (adrenocorticotropic hormone, ACTH), and cortisol in adults of both sexes, a decrease in luteinizing hormone levels only in men, an increase in dehydroepiandrosterone-sulphate (DHEAS) and a contradictory behaviour of testosterone according to gender, with increased plasma testosterone in women and a decrease in men. ACTH and prolactin correlated positively with cortisol, DHEAS and testosterone in women, which suggests that prolactin and ACTH could contribute to stimulated adrenal androgen production. In contrast, the decrease in testosterone and increase in beta-endorphin in men suggests that AAI could have an inhibitory effect on testicular testosterone, perhaps mediated by beta-endorphin. Our results suggest that the effect of alcohol on pituitary-gonadal axis hormones in humans could depend on the gender and degree of sexual maturity of the individual.
Subject(s)
Alcoholic Intoxication/blood , Gonadal Steroid Hormones/blood , Pituitary-Adrenal System/metabolism , Prolactin/blood , beta-Endorphin/blood , Acute Disease , Adrenocorticotropic Hormone/blood , Adult , Age Factors , Cross-Sectional Studies , Female , Humans , Hydrocortisone/blood , Linear Models , Male , Pituitary Hormones/blood , Sex FactorsABSTRACT
OBJECTIVE: The present study was designed to identify patterns of alcohol consumption among Spanish high school students and describe the relationship between alcohol intake and school performance. METHOD: The sample population consisted of students, aged 14 to 19 years, who were attending high school during the academic year 1994-95 in the city of Granada in southern Spain. We studied 1,602 (861 female) students (alpha error - 0.05, sampling error = 5%), using a self-administered questionnaire that contained items about individual and family demographics, quantity and frequency of alcohol consumption, and school performance. Total alcohol consumption was recorded as grams (g) of alcohol per week and per day for three categories of alcoholic drinks: wine, beer and distilled spirits. RESULTS: The percentage of nondrinkers was 21.05% for male adolescents and 28.56% for female adolescents. The mean amount of alcohol consumed per week was larger in male than in female students (F= 18.36, l/l,594 df, p < .001) and distilled spirits accounted for the largest proportion of alcohol consumed. No significant differences in drinking patterns were found between students at public and private schools. The risk of academic failure increased considerably when more than 150 g of alcohol were consumed per week (OR: 2.91; 95% CI: 1.94-4.43). CONCLUSIONS: Although we cannot draw any conclusions about the causes of the association between academic failure and teenage drinking, our results do show that the risk of failing increases together with alcohol intake. However, it should be noted that academic achievement is also influenced by many factors other than alcohol consumption.
Subject(s)
Achievement , Alcohol Drinking/epidemiology , Educational Status , Students , Adolescent , Adult , Analysis of Variance , Female , Humans , Logistic Models , Male , Odds Ratio , Sex Factors , Spain/epidemiology , Students/statistics & numerical data , Surveys and QuestionnairesABSTRACT
SUMMARY: The presence of development disorders in neonates attended in a Neonatal Intensive Care Unit (NICU) is highly variable; the aim of this study, therefore, was to determine the evolution of somatic and neurosensory development in a group of neonates requiring treatment in the NICU and to analyse the perinatal and developmental aspects of children presenting abnormalities. PATIENTS AND METHODS: A total of 492 neonates (275 premature, 106 with birthweight < or =1500 g), who were treated in the NICU between January 1994 and December 1997, were followed-up until the age of 2 years. Data were obtained concerning birthweight, body length, head circumference, gestational age, normality of weight for gestational age, single/multiple birth, duration of stay in the NICU and the hospital, duration of mechanically assisted respiration and evolutive somatometry, neurological examination and the Brunet-Lezine development test, adjusted for the gestational age of the neonates, at 6, 12, 18 and 24 months. When abnormal results were detected, Early Attention (EA) programmes were applied. RESULTS: Somatometry at birth in relation to gestational age revealed a weekly weight gain of 8.6%, an increase in body length of 1% and in head circumference of 1% (p<0.001). The evolution of somatic development to the age of 2 years showed that neonates with a birthweight < or =1500 g did not reach the values of neonates with a greater birthweight. The prevalence of cerebral palsy among all neonates was 6.8%, 14.6% among those weighing < or =1500 g, 4% among those weighing 1501-2500 g and 5% among those weighing >2500 g. The overall rate of neurosensory injury was 10.5%. These neonates presented less somatic development than those did with no neurologic disorder. To sum up, most of the neonates attended in the NICU during the 1990s presented a normal pattern of development. Nevertheless, they should be the object of special attention during the first years of life, particularly those neonates with a birthweight < or =1500 g and those presenting neurosensory risk.
Subject(s)
Growth , Intensive Care, Neonatal , Nervous System/growth & development , Birth Weight , Body Height , Cephalometry , Cerebral Palsy/epidemiology , Follow-Up Studies , Gestational Age , Humans , Infant, Newborn , Neurologic Examination , Spain , Weight GainABSTRACT
The harmful effects of smoking on health have been widely documented, although it is as yet unclear whether tobacco dependence is only psychological in nature, or both psychological and physical. We studied plasma concentrations of beta-endorphin, cortisol, and adrenocorticotropic hormone (ACTH) in healthy persons who consumed different numbers of cigarettes per day, and compared the findings with those in a control group of nonsmokers. Beta-endorphin levels were significantly higher than in controls only in persons who smoked fewer than 10 cigarettes per day. Cortisol levels were significantly higher in smokers who consumed more than 20 cigarettes per day. There were no significant differences between any of the groups in plasma ACTH concentrations.
Subject(s)
Smoking/blood , beta-Endorphin/blood , Adolescent , Adrenocorticotropic Hormone/blood , Adult , Humans , Hydrocortisone/blood , Male , Middle Aged , Nicotine/bloodABSTRACT
BACKGROUND: The studies on hepatitis C virus (HCV) vertical transmission, the effect of potential risk factors and the role of breast-feeding have reported conflicting results. PATIENTS AND METHODS: Seventy-three infants of 63 anti-HCV-positive and anti-HIV-negative mothers were studied from 1993 to 1999 in the south of Spain. The mean period of follow-up in children was 29.2 +/- 19 months (range, 8 to 76 months); 6 (8%) children were lost to follow-up. Breast milk was studied for HCV-RNA in 68 samples of 35 mothers. RESULTS: Alanine aminotransferase was high in 19 (26%) and HCV-RNA was positive in 46 (63%) pregnant woman. Breast milk HCV-RNA was negative in nonviremic mothers and positive in 20% of the viremic mothers. The overall rate of vertical HCV transmission was 11.9% (n = 8) (95% confidence interval, 6 to 23%) if HCV-RNA was positive one or more times, but only 1.5% (n = 1) (95% confidence interval, 0.1 to 9%) if HCV-RNA was permanently positive. Seven HCV-infected children did not develop antibodies to HCV, and they had a spontaneous clearance of the virus. A 10-month-old baby was HCV-RNA-positive from birth to the end of the follow-up. The genotype in each of the infants was consistent with that of their mother. The rate of HCV transmission was higher for infants of mothers with higher HCV viremia (P < 0.01) and also for infants whose mothers were HCV-RNA-positive in breast milk (P < 0.05). There were no statistically significant differences between other risk factors. CONCLUSION: The presence of transitory viremia without seroconversion indicates that the vertical transmission of HCV is not important. This could be related to the viral charge and ingestion of milk of HCV-RNA-positive mothers. However, to advise avoidance of maternal breast feeding, it would be necessary to conduct larger studies.
Subject(s)
Breast Feeding , HIV Seronegativity , Hepatitis C/transmission , Infectious Disease Transmission, Vertical , Adult , Birth Weight , Child, Preschool , Female , Follow-Up Studies , Humans , Infant , Infant, Newborn , Milk, Human/virology , Pregnancy , RNA, Viral/analysis , Risk FactorsABSTRACT
Ca2+ and Eu3+ were able to assist solvolysis on peptidyl-Kaiser oxime resins generating alpha-methyl and -ethyl esters of protected peptides. The methanolysis assistance was at least twice as effective as that of acetic acid, the common catalyst used in aminolysis of the ester oxime linkage. No molar excess of Ca2+ or Eu3+ was needed to enhance this reaction efficiency. Ca2+ also assisted aminolysis on peptidyl-Kaiser oxime resins. Solvolysis and aminolysis rates depended on the nature of the C-terminal residue attached to the resin and on the alcohol used. Both reactions were selective to the ester oxime linkage since no significant amount of secondary products, resulting from rearrangements or simultaneous transesterification of the beta-benzyl or cyclohexyl esters, was detected in the reaction media. The alpha-methyl and -ethyl esters of Ac-Ala-Gly-X [where, X = Gly, Ala, Phe or Lys (2-Cl-Z)] and of Ac-Ile-Ser (Bzl)-Asp(OZ) (where, Z = Bzl or cHex) were essentially the only products formed in the solvolyses performed. Ac-Ile-Ser(Bzl)-Asp(OcHex)Arg(HCl)-OMe and Ac-Ile-Ser(Bzl)-Asp(OcHex)Arg (HCl)-OEt were the major products formed in the aminolysis reactions. In the presence of the metal ions, the resin-cleavage yields were > 50%. In their absence, they were < 15%.
Subject(s)
Peptides/chemistry , Calcium , Chemical Phenomena , Chemistry, Physical , Chromatography, High Pressure Liquid , Esters/chemical synthesis , Ethanol/chemistry , Europium , Hydrolysis , Methanol/chemistry , Oximes/chemistry , Resins, Plant/chemistryABSTRACT
Antifungal and antibacterial activities were detected in the hemolymph and gut contents of the cattle tick, Boophilus microplus. A peptide with antibacterial activity from the tick gut contents was purified to homogeneity by reversed-phase chromatography. The molecular mass of the purified peptide was 3,205.7 Da, measured by matrix-assisted laser desorption/ionization mass spectrometry. The amino acid sequence was obtained by Edman degradation and showed that the peptide was identical to a fragment of the bovine alpha-hemoglobin. A synthetic peptide based on the sequence obtained showed characterization data identical to those of the isolated material, confirming its structure. The synthetic peptide was active in micromolar concentrations against Gram-positive bacteria and fungi. These data led us to conclude that the antibacterial activity detected in tick gut contents is the result of enzymatic processing of a host protein, hemoglobin. This activity may be used by ticks as a defense against microorganisms.
Subject(s)
Anti-Infective Agents/isolation & purification , Hemoglobins/isolation & purification , Peptide Fragments/isolation & purification , Ticks/metabolism , Amino Acid Sequence , Animals , Anti-Bacterial Agents , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Cattle , Fungi/drug effects , Gram-Positive Bacteria/drug effects , Hemoglobins/chemistry , Hemoglobins/pharmacology , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/pharmacology , Ticks/microbiologyABSTRACT
Mixtures of a good hydrogen bond donor, 2,2,2-trifluoroethanol (TFE) or 1,1,1,3,3,3-hexafluroisopropanol, and an acceptor, dimethylformamide (DMF) (1:1, v/v), containing 4% buffer have been described as adequate solvent systems for trypsin-catalyzed peptide fragment condensations [Mihara et al. (1993) Int. J. Pept. Protein Res. 41, 405]. Thus, we decided to study the behaviour of trypsin in such solvent systems. We investigated whether this protease would efficiently catalyze condensations between fragments derived from an analogue of the gp-41 capsid protein of HIV virus or from cholecystokinin-22. None of the reactions carried out yielded the desired condensation products. However, when Fmoc-NLQNLDPSHR-OH and cholecystokinin-12 (H-ISDRDYMGWMDF-NH2) were used as substrates, the last had its R-D peptide bond hydrolyzed producing cholecystokinin-8. The proteolytic activity of this enzyme measured against a fluorogenic peptide derivative was 50 times lower in DMF/TFE containing 5% of aqueous phase than in buffer. Steady-state fluorescence studies in DMF/TFE buffer were performed to examine the structure of this protease in these media. Steady-state spectra obtained with increasing proportions of these two organic solvents in buffer showed that the emission intensities built up. Quenching studies with iodide revealed that the Io/I ratio (where Io and I are the fluorescence emission intensities in the absence and presence of quencher, respectively) changed from 1.2 in aqueous media to 2.2 in DMF/TFE (1:1, v/v) containing 11% 0.2 M Tris-HCl buffer, pH 8.0, for 0.5 M iodide. The complete data indicated a higher exposure of tryptophan residues to the quencher in organic media, probably because of the partial unfolding of the enzyme.
Subject(s)
Dimethylformamide/chemistry , Propanols/chemistry , Trifluoroethanol/chemistry , Trypsin/metabolism , Amino Acid Sequence , Catalysis , Hydrolysis , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/metabolismABSTRACT
OBJECTIVES: To study personal and familial antecedents of risk and prevalence of infection by HCV in pregnant women in the south area of Granada. PATIENTS AND METHODS: We included in the study 3003 pregnant women of the south area of Granada during the period from January 1993 to December 1995. Anti-HCV was detected in the third trimester of pregnancy by second and third generation ELISA, and positive results were confirmed by RIBA 3. We also determined HCV-RNA and genotype. Finally, we analyzed ALT levels in 1171 (39%) pregnant women. We carried out an epidemiological survey of all pregnant women, which included the following personal antecedents: transfusion, intravenous drug use, liver diseases, risk profession and sexually transmitted diseases. We studied the same antecedents in the parents, husbands and other relatives. RESULTS: Prevalence of anti-HCV was 0.63% (19 cases) with ELISA and 0.53% with RIBA. HCV-RNA was positive in 14 (74%) genotype 1b (57%) being the most frequent. ALT was increased in 52 (4.4%) pregnant women, 7 (13.5%) of whom were anti-HCV positive, versus 12 women (1%) in the normal ALT group (p < 0.001). In the epidemiological study we observed statistically significant differences in: a) housing characteristics [2125 (71%) anti-HCV negative pregnant women living in occupant-owned housing versus 7 (36%) in anti-HCV-positive group, p < 0.001]; b) personal antecedents of transfusion, chronic or acute hepatitis, or intravenous drug use (p < 0.001) (these factors were confirmed in the multivariable analysis), and c) familial antecedents of the husband (p < 0.05). CONCLUSIONS: In this study we demonstrated that 0.53% of the pregnant women were infected by HCV; most of them were HCV-RNA positive and was genotype 1b was the most frequent. The risk factors most frequently associated with infection were antecedents of transfusion, intravenous drug use and acute or chronic hepatitis.