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Biomedical subjects

J M Fraga

Publications and source records attributed to J M Fraga.

16 recordsLinked to original sources
PubMed2004

Enzymolysis approach to compare cu availability from human milk and infant formulas.

The purpose of the present paper is to develop an easy and quick in vitro method to compare copper availability from breast milk and infant formulas. This study focuses on the differences caused by the use of pH 2.0 (adult gastric pH) or pH 5.0 (newborn gastric pH) in the first stage of the enzymolysis. pH affects Cu solubility, a possible estimator of the availability. Selection of a digestor, times of enzymolysis, centrifugation parameters, and Cu determination by ETAAS were discussed as well. Percentage of Cu solubility was larger from breast milk (gastric pH 2.0, 65.3 +/- 14.0 vs 40.0 +/- 13.9%; gastric pH 5.0, 61.2 +/- 16.5 vs 26.6 +/- 10.3%), but the soluble content was larger from infant formulas for both pHs (gastric pH 2.0, 245.3 +/- 82.1 vs 113.0 +/- 103.4 ng mL(-1); gastric pH 2.0, 169.3 +/- 76.9 vs 75.3 +/- 21.9 vs ng mL(-1)).

Biological Availability↗
PubMed2001

Copper fractionation by SEC-HPLC and ETAAS: study of breast milk and infant formulae whey used in lactation of full-term newborn infants.

This method will allow the determination of bound copper to low relative molecular mass compounds in milk. The milk whey obtained by ultracentrifugation was submitted to fractionation by size exclusion chromatography (SEC) on a TSK-Gel2000 (Toso Haas) column with a mobile phase of 0.2 M NH4NO3 + NH3, pH 6.7. Fractions of effluent corresponding to the protein peaks were collected and the copper content was determined by ETAAS. The method was sensitive (LOD 0.4 microgram l-1 and LOQ 1.5 micrograms l-1 in the fraction; LOQ 7.5-22.5 micrograms l-1 referred to the milk sample and depended on fraction volume) and precise (RSD +/- 10%). Media sample recoveries from the column were 101.2%. Cu was predominantly present in fractions corresponding to relative molecular mass 76 and 15 kDa of breast milk while copper was mostly found in fractions corresponding to 14 and 38 kDa of cow's milk-based infant formulae; moreover, copper was eluted in the relative molecular mass region < 6 kDa.

Chromatography, High Pressure Liquid↗
PubMed2000

Rehospitalization because of respiratory syncytial virus infection in premature infants younger than 33 weeks of gestation: a prospective study. IRIS Study Group.

OBJECTIVE: To collect data on hospitalization for respiratory syncytial virus (RSV) infections and presumptive risk factors for rehospitalization among premature infants in Spain. DESIGN: Observational, prospective, longitudinal, multicenter study. SETTING: Fourteen Spanish neonatal units with an annual birth cohort of 57,000 infants. PATIENTS: All children (n = 680) born < or =32 weeks of gestational age between April 1, 1998, and March 31, 1999, and discharged from the hospital before March 31, 1999, were included in the study. A total of 96 were excluded because of administration of prophylactic treatment (n = 55) or were lost to follow-up (n = 41). Five children died during the study period, but death was related to RSV in only 1 case. METHODS AND MAIN OUTCOME MEASURES: Neonatal and demographic data were recorded at the initial visit. Infants were prospectively followed at monthly intervals up to March 31, 1999. In patients rehospitalized for respiratory disorders, further data about RSV status and morbidity were collected. A comparison was made between children rehospitalized for RSV infection and those who were not. The influence of factors on the probability of rehospitalization for RSV infection was assessed by logistic regression analysis. RESULTS: Of the 584 evaluable patients 118 (20.2%) were rehospitalized for respiratory disease during the study period. The causative pathogen was identified in 89 (75.4%) hospital admissions. Of these 59 (66.3%) were a result of RSV infection in 53 children; 6 were reinfections. In a logistic regression model significant independent prognostic variables included: lower risk of RSV hospitalization with increase gestational age [odds ratio (OR), 0.85; 95% confidence interval (CI), 0.72 to 0.99; P < 0.047]; higher risk with chronic lung disease (OR = 3.1; 95% CI 1.22 to 7.91; P < 0.016); and living with school age siblings (OR = 1.86; 95% CI 1.01 to 3.4; P < 0.048). CONCLUSION: This large descriptive study has enabled us to define the influence of specific risk factors that increase the risk of rehospitalization for RSV infection in preterm infants. Such studies help to define the appropriate role of available prophylactic interventions and establish treatment guidelines.

Child, Preschool↗
PubMed1999

Aluminum contents of human milk, cow's milk, and infant formulas.

BACKGROUND: Aluminum toxicity is well documented and contamination of milk formulas has been implicated as the source of accumulation in bone and brain tissues. The purpose of the current study was to evaluate the aluminum contents of human milk, cow's milk, and infant formulas. METHODS: Aluminum contents were determined by atomic absorption spectrometry in samples of human milk in the colostrum, intermediate, and mature stages; infant formulas from eight manufacturers; and various types and brands of commercially available cow's milk. RESULTS: Mean aluminum concentration was lowest in human milk (23.4 +/- 9.6 microg/l), and did not differ significantly between colostrum, intermediate-stage and mature-stage milk. Mean aluminum concentration was 70 microg/l in cow's milk, and 226 microg/l in reconstituted infant formulas. Aluminum concentrations in infant formulas differed markedly among manufacturers; concentration in milk from one of the manufacturers was particularly high (mean, 551 microg/l; range, 302-1149 microg/l). These values are for milk reconstituted with aluminum-free water under laboratory conditions; formulas prepared with tap water in the University Hospital's infant-feeding unit had even higher aluminum content. Experiments showed that aluminum concentration in the high-aluminum milk could be reduced by more than 70% at the manufacturing stage, by using low aluminum components. CONCLUSIONS: The results of the present study support the recommendations for infant formula manufacturers to strive to reduce aluminum concentration in their products.

Aluminum↗
PubMed1998

[Neonatal sepsis: epidemiologic indicators and relation to birth weight and length of hospitalization time].

OBJECTIVE: All cases of neonatal septicemia among neonates admitted to the neonatal unit in the pediatric department (CHUS) in Santiago de Compostela between 1992 and 1995 were studied. Our aims were: 1) To assess the incidence and microbial epidemiology. 2) To study the incidence of coagulase-negative staphylococci (CONS) sepsis stratified according to birth weight and gestational age. 3) To assess the incidence density of sepsis (IDS) and 4) To analyze the associated mortality. PATIENTS AND METHODS: One hundred eighteen episodes of sepsis in 103 neonates which fulfilled clinical and laboratory criteria with positive blood cultures were included in this study. Between the years of 1992 and 1995 there were 318 neonates suspect of having sepsis among the 2,083 who were admitted to the unit during this period and which came from our own maternity department, as well as other centers. RESULTS: In this period there were 10,457 live births in our maternity department. The annual incidence of sepsis was 6/1000 live births. Early onset sepsis was observed in 2.5/1000 live births (26 cases) and the occurrence of late onset increased to 3.5/1000 live births (36 cases). Neonatal sepsis was confirmed in 103 neonates (4.9%) corresponding to 118 episodes of sepsis. S. epidermidis was the most frequent agent isolated in blood cultures (38.1%). The highest incidence of sepsis caused by S. epidermidis was observed in neonates below 1500 g (12.1%) and less than 32 weeks gestational age (13.4%). The incidence was lower in those whose birth weights were more than 2500 g (1.9%) and > 37 weeks of gestational age (1.6%), p < 0.001. Overall mortality due to sepsis was 0.7% and increased to 5.0% among hospitalized newborns with birth weights below 1500 g. The average IDS stratified in three groups of birth weight and gestational age was 18 sepsis work-ups per 1000 patient-days of hospitalization, the lowest IDS 12.9/1000 was found in neonates whose birth weights were between 1501 g and 2500 g in comparison with neonates who weighted more than 2500 g (21.5/1000), p < 0.05, and very similar to the IDS found in the intermediate group of gestational age (13.1/1000). CONCLUSIONS: S. epidermidis and other CONS are the main agents causing sepsis in hospitalized neonates, although there is a decreasing trend of incidence (-71.1%) between the years 1992 and 1995 (5.0% vs 1.5%). Gram-negative organisms and S. agalactiae played a minor role as agents causing sepsis even though S. agalactiae is the most important agent in early onset sepsis. Overall mortality associated with sepsis (7/1000 live births) is in or under the average range of international statistics. Indexes of IDS are more valuable as epidemiological tools in assessing septicemia than the simple attack rate because they have taken into consideration the length of stay, number of hospitalized newborns, as well as the number of positive sepsis work-ups in the calculating process.

Birth Weight↗
PubMed1997

Anonymous testing of newborn infants for HIV antibodies as a basis for estimating prevalence of HIV in childbearing women: the 1991-1994 study in Spain.

During 1991-1994, anonymous screening of newborn infants for maternal antibody to human immunodeficiency virus (HIV) was carried out in three regions of Spain: Valencia, Galicia and Sevilla. The newborn infants whose heel-stick blood eluates were satisfactory for HIV antibody tests were a consecutive series of 104 876, representing 99.3% of all newborn infants undergoing routine metabolic screening and estimated as comprising at least 98% of all births in the three regions. Enzyme immunoassay (EIA) positives were confirmed by immunoblot, yielding 246 confirmations: a rate of 2.3 per 1000. Seropositivity rates ranged from 1.4 per 1000 in Galicia to 2.1 in Sevilla and 3.1 in Valencia, and remained relatively stable in each region during the years of the study. Within socioeconomically defined subgroups of birth hospitals in Valencia and Galicia, all subgroups contained seropositives, even though there was a twofold to fivefold over-representation in the "inner city" public hospitals. To estimate the proportion of HIV-1-seropositive newborn infants who were positive for HIV-1 DNA, polymerase chain reaction (PCR) assays were performed on 165 dried blood spots that had been retained following positive immunoblot assays. Fifteen (9%) were PCR positive, and when this proportion is adjusted for the age-specific sensitivity of the method, it translates into an estimated HIV-1 transmission rate of 24% (range 18-36%). For 94,906 of the 104,876 newborn infants screened, the EIA used could detect antibodies that react with epitopes of HIV-1 and HIV-2. There were 30 newborn infants whose blood eluate was positive by this combined HIV-1/HIV-2 antibody screen and whose secondary screening with monovalent HIV-2 and HIV-1 EIA indicated that the HIV-2 reactivity was above the cut-off whereas the HIV-1 was not. Ranking these 30 results according to absolute HIV-2 reactivity and relative reactivity with respect to HIV-1 indicated that four infants were probable true HIV-2 seropositives and a total of 12 were possible HIV-2 seropositives, a prevalence of the order of 1:10000 to 1:20000 newborn infants. These anonymous population-based serological studies provide "leading-indicator" data to complement traditional AIDS surveillance for epidemiological and planning purposes.

AIDS Serodiagnosis↗
PubMed1996

[Rotavirus: clinical and epidemiological study in hospitalized children under two years of age].

OBJECTIVE: Rotavirus (RV) remains as the leading cause of acute diarrheal disease in early infancy; nevertheless, there are few epidemiological studies in our geographical area. In order to better understand the clinical epidemiology of RV, we have carried out a revision of acute diarrheal illnesses in the area of Santiago de Compostela (Spain) in children younger than 2 years of age who needed hospitalization during a 12 month period. PATIENTS AND METHODS: In 155 children with suspected gastroenteritis, 339 stool samples were collected and separated into two groups depending upon the presence or not of RV antigen. RESULTS: In the group of RV-positive stool patients, the occurrence of vomiting, fever, need of intravenous fluid rehydration (p = 0.01), respiratory symptoms (p < 0.01), the incidence during winter, as well as the development of disaccharidase depression (p < 0.001), were more frequent as compared with the group of children of similar age who did not present RV in faeces. There was no difference between the two groups regarding the presence of other potential enteropathogen agents (p > 0.05). The incidence of RV-positive faeces per 100 hospitalized infants/year was 10.5 and that of infants with RV diarrhea who needed hospitalization was 5.5%/ year. CONCLUSIONS: There was no mortality related with gastroenteritis, but RV-infection remains an important cause of morbidity and socioeconomic burden. Nosocomially acquired hospital infections add to morbidity and the cost of hospitalization.

Female↗
PubMed1993

Neonatal cardiovascular dynamics in relation to matroclinous and patroclinous history of high blood pressure.

Genetic risk is a primary contributing factor to the predisposition of a newborn child to elevated blood pressure later in life. An index of this factor is needed to assess in the neonate the success or failure of preventive interventions instituted for the pregnant women. This index could be based on characteristics of blood pressure and heart rate variability measured during the first 2 days after birth. In the search for such an index, the systolic and diastolic blood pressures and heart rates of 127 newborn babies were automatically monitored at about 30-min intervals for 48 h with a Nippon Colin device, starting early after birth. Circadian parameters (obtained by the linear least-squares fit of a 24-h cosine curve to each individual series) and descriptive statistics for the three circulatory variables were used in a multiple regression analysis to compute a linear prediction function for the cardiovascular risk score. This score was obtained for each neonate on the basis of the presence or absence of overt cardiovascular disease, elevated blood pressure, or obesity across two generations, those of the newborn's parents and grandparents. Results from regression indicate that the best model includes the circadian amplitudes of systolic and diastolic blood pressure and the circadian ranges of systolic blood pressure and heart rate. The contributions from patroclinous versus matroclinous family history were then compared. Results show that linear prediction models include the same variables for both paternal and maternal cardiovascular risk score. These results provide a neonatal index of cardiovascular risk, to be used later for the evaluation of the effects on the newborn of intervention for the pregnant women.

Blood Pressure↗
PubMed1987

Cord serum gamma glutamyltransferase in newborns.

This article reports correlations among gamma-glutamyltransferase (GGT), fetal haemoglobin (fH), alpha-fetoprotein, 5'-nucleotidase, ceruloplasmin, and direct, indirect, and total bilirubin in the serum of blood taken from the umbilical cords of 128 newborns delivered after 37-42 weeks of gestation. GGT was significantly correlated with alpha-fetoprotein, but not with direct bilirubin, indirect bilirubin, total bilirubin, fH, or %fH. Neither fH nor %fH were correlated with alpha-fetoprotein, but there was highly significant negative correlation between both fH and %fH on the one hand, and gestational age and weight at birth on the other. The %fH was also correlated negatively with ceruloplasmin, which in turn exhibited negative correlation with alpha-fetoprotein. The predominant forms of GGT in umbilical cord and adult sera were, respectively, those with alpha 1 and alpha 2 mobility. In cord sera, delipidation with n-butanol brought about loss of GGT activity and a shift from an alpha 1 to an alpha 2 position, whereas no significant effect of this kind was observed in adult sera. Affinity chromatography through Concanavalin A-Sepharose showed cord sera to contain a proportion of bound-GGT (68.5 +/- 5.5%) that was significantly greater (p less than 0.001) than that found in adult sera (59.8 +/- 10.2%). It is concluded that the high GGT activity of cord sera is probably due to hepatic immaturity rather than maternal sources, enzymatic induction or microsomal lesions; that the predominant form of GGT in cord serum may be a complex with HDL and less sialized than the adult enzyme; and that, of the factors examined, the best indicator of neonatal maturity is fetal haemoglobin.

5'-Nucleotidase↗
PubMed1981

Continuous thin-layer chromatography of sugars of clinical interest in samples of urine impregnated on paper.

A procedure for the analysis of sugars of clinical interest in samples of urine impregnated on Whatman 3MM paper is described. The sugars are eluted from the sample and spotted directly on to the application zone of concentration-zone silica gel plates. followed by continuous development. The optimal composition of the eluent and developing solvent and the optimal development distance were established, together with the development time and its influence of the RF values. The locating reaction is based on the reduction of vanadium (V) to vanadium (IV) in acidic medium.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1981

[Prophylaxis and treatment of streptococcus infections (author's transl)].

Authors review and bring up to date problems related to prophylaxis and treatment of streptococcus infections in children. In those caused by the Group A streptococcus, the problem is rather one of medical education and practical application of techniques, and medicines. Active vaccination is still a remote possibility. In the case of streptococcus B and its perinatological incidence, there is still no standard therapeutic prophylaxis covering both the mother and child. With reference to streptococcus D plans proposed are somewhat discordant since it is difficult to carry out studies with sufficiently large groups but there are also proposals which can be carried out perfectly well and are reasonably safe. As far as the infectious, and to a great extent contagious, processes are concerned, measures of individual and collective hygiene are particularly important.

Anti-Bacterial Agents↗
PubMedDate not supplied

Chromium content in human milk, cow's milk, and infant formulas.

Chromium was measured by Electrothermal Atomic Absorption Spectrometry in human milk, cow's milk, and infant formulas. The mean levels found were 1.56, 0.83, and 4.84 (13%) micrograms/L, respectively. According to our data, the daily intake for the Spanish neonates is lower than the Recommended Dietary Allowances (RDAs) (10-40 micrograms/d) for this element.

Animals↗
PubMedDate not supplied

Speciation of zinc in low molecular weight proteins of breast milk and infant formulas by size exclusion chromatography/flame atomic absorption spectroscopy.

Size exclusion chromatography (SEC) and flame atomic absorption spectroscopy (FAAS) were used for the separation of metal-containing species in milk whey. After milk ultracentrifugation, the sample was injected into a TSK-Gel G2000 glass column and eluted with 0.2M NH4NO3-NH3, pH 6.7. Low molecular weight proteins were fractionated, and the fractions were characterized by molecular weight. Zinc distributions were obtained by FAAS using a high performance nebulizer. The method was very sensitive (limit of detection = 2.6 x 10(-3) microg/mL; limit of quantitation = 8.9 x 10(-3) microg/mL) and precise (RSDs < or =10%). This method was applied to the determination of Zn in binding compounds in breast milk whey and in commercial cow's milk-based formulas. Distribution patterns were different. The presence of Zn in most fractions in breast milk was most significant, whereas in infant formulas Zn was detected only in fractions of molecular weight <5 kDa and in the highest molecular weight peak.

Calibration↗
PubMedDate not supplied

Hardware-software approach for neonatal cardiovascular risk estimation.

Genetic risk is a primary contributing factor to the predisposition of a newborn child to elevated blood pressure later in life. To determine whether there is a correlation between potential genetic risk as established by family history and measured physiologic variables in the neonate, the systolic and diastolic blood pressures and heart rates of 150 newborn babies were automatically monitored at about 30-minute intervals for 48 hours with a Nippon Colin device, starting early after birth. Circadian parameters (obtained by the linear least-squares fit of a 24-hour cosine curve to each individual series) and descriptive statistics for the three circulatory variables were used in a multiple-regression analysis to compute a linear prediction function for a neonatal cardiovascular risk score. This score was obtained for each neonate on the basis of the presence or absence of overt cardiovascular disease, elevated blood pressure, or obesity across two generations, those of the newborn's parents and grandparents. Results from multiple regression indicate that the best model for prediction of the risk score includes the circadian amplitudes of systolic and diastolic blood pressure, the circadian range of heart rate, and the 90% range and standard deviation of diastolic blood pressure. The multiple correlation coefficient between the predicted and the computed risk scales is 0.666, a value that, although statistically significant (p < 0.001), is still low for a generalized practical use of the model in predicting risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular Diseases↗