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Biomedical subjects

F Nieto

Publications and source records attributed to F Nieto.

At least 19 recordsLinked to original sources
PubMed2001

47,XYY karyotype and normal SRY in a patient with a female phenotype.

A rare case of a female patient with a 47,XYY karyotype is described. She had normal female external genitalia, bilateral testes, rudimentary Fallopian tubes and no uterus. Molecular analysis revealed a normal SRY encoding sequence. The possible events in the etiology of this sex reversal entity are discussed.

Adolescent↗
PubMed1999

Ambulatory blood pressure: normality and comparison with other measurements. Hypertension Working Group.

Previous studies have reported results on 24-hour ambulatory blood pressure (ABP) in Europe and Japan, but no data exists from South America. In this study, we conducted a population survey to identify reference values and to compare ambulatory blood pressure with clinic, home, and self-measured values. A random sample of 2650 adults was selected among 190 000 people covered by our prepaid healthcare institution. Clinic (physician and nurse) and home (nurse) blood pressure measurements were performed 3 times each, with semiautomatic electronic equipment. Self-measurements were performed by the subjects manually activating the ambulatory device. We analyzed 1573 individuals who were not receiving antihypertensive therapy from 1921 participants. Self-measurement was available in a subgroup of 577 participants younger than the whole sample. Normal ambulatory blood pressure limits were estimated as those that best correlated with 140/90 mm Hg at clinic. Estimated values were 125/80 mm Hg for 24-hour ambulatory (range: 122 to 128 and 77 to 83 mm Hg) and 129/84 mm Hg for daytime ambulatory (range: 127 to 132 and 81 to 86) blood pressure, depending on gender and age. Ambulatory and clinic blood pressures increased with age. The age-dependent increase in ABP was similar in women and men. Average blood pressure at clinic was 124/79 mm Hg by physician and 123/78 mm Hg by nurse. Nurse measurement at home was 125/78 mm Hg, daytime ambulatory was 121/77 mm Hg, and 24-hour ambulatory was 118/74 mm Hg. The values of the subgroup with self-measurement were physician 119/77 mm Hg; nurse at clinic 118/77 mm Hg; nurse at home 121/78 mm Hg; self-measured 115/72 mm Hg; daytime ambulatory 119/77 mm Hg; and 24-hour ambulatory 115/73 mm Hg. This study shows that a 24-hour ABP average value of 125/80 mm Hg and a daytime ABP average value of 129/84 mm Hg are suitable upper limits for normality. Higher limits would yield an artificially higher prevalence of white coat hypertension. Most subjects showed higher blood pressure levels when measurements were performed by healthcare personnel at a clinic or at home than when self-measured at home.

Adult↗
PubMed1997

Testicular and epididymal sperm in a microinjection program: methods of retrieval and results.

OBJECTIVE: To describe the methods of collection and laboratory preparation of epididymal and testicular sperm; to compare the fertilization and pregnancy rates; and to establish prognostic factors. DESIGN: Retrospective analysis. SETTING: Academic reproductive medicine clinic. PATIENT(S): One hundred twelve consecutive microinjection cycles in 80 patients using either epididymal or testicular sperm. INTERVENTION(S): Sperm were collected by microepididymal sperm aspiration, open testicular biopsy, or fine needle tissue aspiration testicular biopsy. MAIN OUTCOME MEASURE(S): Fertilization rate, implantation, and clinical pregnancy rates. RESULT(S): The fertilization rate was higher with epididymal sperm (67%) than with testicular sperm (50%). Implantation rates (fetal hearts per embryo, testicular: 11%, epididymal: 8%) and pregnancy rates (clinical pregnancy per oocyte collection procedure, testicular: 25%, epididymal: 29%) were not significantly different with epididymal and testicular sperm. Multiple regression analysis showed that normal fertilization rates were significantly lower with testicular sperm, immotile sperm, and severe spermatogenic disorders. CONCLUSION(S): Although fertilization rates are significantly lower with testicular sperm, higher implantation rates resulted in equivalent pregnancy rates. Thus, testicular aspiration of sperm for intracytoplasmic sperm injection is a simple, inexpensive method of sperm retrieval in cases of azoospermia resulting from genital tract obstruction or severe spermatogenic disorder.

Biopsy↗
PubMed1996

Testicular aspiration of sperm for intracytoplasmic sperm injection: a novel treatment for ejaculatory failure on the day of oocyte retrieval.

OBJECTIVE: To present a successful outcome of an IVF cycle complicated by failure to produce a sperm sample on the morning of oocyte retrieval. DESIGN: Case report. SETTING: Hospital-based IVF clinic. PATIENT: A couple suffering secondary infertility undergoing their first IVF and intracytoplasmic sperm injection (ICSI) cycle. INTERVENTION: Fine-needle testicular biopsy for sperm retrieval. MAIN OUTCOME MEASURES: Sperm retrieval, fertilization, pregnancy. RESULTS: Sufficient spermatozoa were obtained for ICSI. Ten metaphase II oocytes were injected with two embryos being transferred fresh and four cryopreserved. A single fetal heart was confirmed at 6-week sonar. CONCLUSION: Testicular aspiration of sperm for ICSI is a simple, inexpensive, and effective means of rescuing an IVF cycle in which the male partner unexpectedly has been unable to produce a sperm sample on the morning of oocyte collection.

Adult↗
PubMed1994

[The "arrhythmic pattern": a new method with prognostic significance in myocardial infarct].

OBJECTIVES: To establish a score or arrhythmic pattern for the prediction of long-term cardiac deaths on patients who have survived to the first acute myocardial infarction. PATIENTS AND METHODS: We studied prospectively 200 patients that survived at a first myocardial infarction and in whom ambulatory ECG monitoring during 24 hours between days 7th and 18th (mean 12th) from the infarction was performed. The mean follow-up time was 51 +/- 18 months. The number and type of ventricular arrhythmias were analyzed and a score was measured, accordingly with Castellanos and Lown's classifications. An "arrhythmic pattern" or "total punctuation" was defined and compared among two groups: group 1 > 65 points and group 2 < 65 points. RESULTS: The differential characteristics of both groups were: age (60 +/- 9 versus 56 +/- 10 years old; p = 0.004); hypertension (63% versus 29%; p < 0.001); clinic stage II-III (23% versus 11%; p = 0.02); echocardiographic ejection fraction (45 +/- 11% versus 50 +/- 10%; p = 0.04); positive exercise testing (73% versus 56%; p = 0.01); arrhythmias on the exercise test (15% versus 25%; p = 0.006). The long-term cardiac mortality was 25% versus 6% (p = 0.01), with an incidence of sudden death of 11% versus 3% (p < 0.05). Specificity, sensibility, positive predictive value and negative predictive value (reference cut point of 100) were 94, 65, 71 and 91%, respectively. CONCLUSIONS: The use of a score of arrhythmic pattern may identify 2 groups of patients with different clinic profiles that probably justify a different long-term prognosis after a first acute myocardial infarction.

Cardiac Complexes, Premature↗
PubMed1991

Cesarean section and maternal age in low-risk nulliparas.

The relationship between maternal age and cesarean section in low-risk nulliparas was analysed in 7454 perinatal clinical records selected from eleven databases of Latin American institutions obtained with a comprehensive perinatal information system. The risk of cesarean section in nulliparas between 29 and 49 years of age was found to be three times higher than that corresponding to pregnant women of lesser age. This clearly more aggressive obstetrical conduct could not be explained by the main indications for cesarean section.

Adolescent↗
PubMed1991

Oxygen transport in newborns at different gestational ages.

Oxygen (O2) transport was assessed through the affinity between O2 and hemoglobin (Hb) in 123 newborns of 28 to 40 week gestational ge, with a minimum of 9 newborns for each gestational age group (see table). In order to assess the O2-Hb affinity, we studied the correlation between the pO2 and the Hb saturation for each gestational age, obtaining estimates of the oxy-hemoglobin dissociation curves corresponding to each gestational age (see fig. 3). The pO2 levels corresponding to the 50% saturation (P50) for each gestational age were estimated from there. All newborns were from single vaginal deliveries with no fetal distress before birth and with an adequate weight for gestational age. The latter was calculated according to the date of the last menstrual period (78% of the cases), echography (10.6% of the cases) or neonatal physical exam (11.4% of the cases). A P50 vs. gestational age linear regression showed a high determination rate (r2 = 0.957, p less than 0.00001) (see fig. 2) which supports the hypothesis of the P50 linear growth; decrease in the Hb-O2 affinity with increasive gestational age (Hb-O2 affinity is different in newborns of different gestational ages). With these results one may conclude that the Hb-O2 uptake varies according to gestational age (P50 changes linearly as gestational age increases) and that a single measurement of pO2 in a newborns, blood does not accurately evaluate the amount of O2 that is transported to the tissues, because the transport capacity depends, among other factors, upon gestational age. The Hb saturation better represents the amount of O2 that can get to the cell level.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbon Dioxide↗
PubMed1989

[Asymptomatic common truncus arteriosus in a 25-year-old patient with paroxysmal tachycardia and truncal valve insufficiency].

We present an adult patient (25-years old), free of symptoms with a congenital heart disease very infrequent and survival to adulthood is exceptional, the truncus arteriosus. Who entered to the Emergency Care Unit because of paroxysmal tachycardia. We describe the case with special reference to echocardiographic findings and we detached the rarity of this congenital heart disease in adulthood.

Adult↗
PubMed1988

Assessment of pulmonary dynamics in normal newborns: a pneumotachographic method.

A pneumotachographic method for assessment of pulmonary dynamics in critically ill newborns in an intensive care setting was developed in our laboratory. Before the results obtained with this method could be applied, the normal range of values were determined in 48 normal term and preterm newborns. Their body weight ranged between 1200 and 4100 g, and postnatal ages between 24 hours and 21 days. In three infants, two determinations were performed after an interval of 7 days. The studies were performed with a pneumotachograph applied to the upper airway by means of an inflatable face mask or latex nasal prongs. The air flow signal was electronically integrated to time to produce a volume signal. Airway pressure was determined proximal to the pneumotachograph. Esophageal pressure was determined with a water filled catheter placed in the lower third of the esophague. Tidal volume (VT), minute ventilation (V), Dynamic compliance (Cdyn), total pulmonary resistance (R), total pulmonary work (Wt), Elastic work (We), and flow resistive work (Wv), were determined. A significant linear correlation was found between Cdyn and body weight (r = 0.50, p less than 0.01) whereas no significative correlation was found between body weight and VT, V or R. Values for VT, V and Cdyn were corrected for body weight and means (X), standard deviation (SD) so as 10th and 90th percentiles are shown in table III. X, SD and percentiles for R were shown in table III. Wt, We and Wv were corrected for V, and X, SD and percentiles shown in table III. Values of VT/Kg, Cdyn/Kg and R are similar to those found by other authors with pneumotachography and plethysmography. The V/Kg values obtained by us were higher than those reported by other authors, which together with the lack of correlation of VT and V with body weight, question the reliability of V values in our study. This could be explained by: 1) excessive increase in dead space in cases in which a face mask was used; 2) nocioceptive stimulus produced by face mask or nasal prongs; 3) inadequate selection of the moment at which the record was obtained. Whichever the explanation, our values of V cannot be considered as basal, and should be interpreted with caution. The results obtained allow us to continue with our program and apply this method to the study of newborn infants with RDS.

Airway Resistance↗
PubMed1985

[In vivo evaluation of the effect of antacids and H2 receptor blockaders on the intragastric pH in gastric and duodenal ulcer].

The aim of this work is to establish the best treatment for patients with gastric and duodenal ulcer, by measuring the effects of antiacids and H2-receptor antagonists on gastric pH. 16 patients were studied: 9 of them had a duodenal ulcer, 2 a gastric ulcer and 5 had both. All the patients remained fasting and receiving no drug for 24 hrs. During this 24 hrs., a nasogastric tube was inserted into the stomach and the gastric content was obtained by aspiration each hour from 8 A.M. to 8 P.M. Three days after, each patient received a daily dose of 1 g of Cimetidine, and the whole procedure was repeated. The same was done with 300 mg of Ranitidine daily, 150 ml of Al-Mg antiacids daily, and at last, the same procedure was performed with the association of Ranitidine and Al-Mg antiacids at the mentioned dosage. For the statistical analysis of the data, the mean ordinate of the pH was used as a representative value of each individual's pH. Individual differences (pH with treatment minus pH without treatment) were obtained. The mean effect of each treatment was obtained averaging that differences. For comparison among different drugs, the same procedure was used. Student's paired t tests were performed in a signification level. The buffering capacity was measured in the following way: The percentage of the gastric secretion samples with pH equal or higher than 4 in each treatment and in the total number of patients was confronted with the results obtained in the same patients with no treatment. All the drugs were useful for buffering the gastric acidity, but in different intensity. The association of Ranitidine and Al-Mg antiacids showed to be the most efficient statistically when compared with Cimetidine and Al-Mg antiacids; no statistical difference appeared in the comparison with Ranitidine.

Adult↗
PubMed1982

Ultrasonic patterns of intrauterine fetal growth in a Latin American country.

Head circumference and its cross-sectional area, biparietal and fronto-occipital diameters, abdominal circumference and its cross-sectional area, and the transverse and anteroposterior diameters were measured in 30 healthy single fetuses from normal pregnancies by means of ultrasound. The 5th, 50th and 95th percentiles of distance and velocity curves are described. The comparison of the values of a perimeter (abdominal or cephalic) measured directly from the photograph or calculated by the ellipse formula, showed a straight correlation. The use of the ellipse formula in current practice may simplify and reduce the cost of this technology.

Abdomen↗
PubMed1979

HCS, estriol and oxytocinase in maternal serum and neonatal condition in high risk pregnancies.

In order to find a reliable index of fetal wellbeing, maternal estriol, hCS and oxytocinase levels were related with condition of the neonate. Fifty six high risk pregnancies were studied. Estriol and hCS were determined by specific radioimmunoassay and oxytocinase with a colorimetric method. The condition of the newborn was evaluated by the APGAR score. Neonates were divided into two groups, depressed (APGAR score 0-6) and vigorous (APGAR score 7-10). When the mean birthweights of both groups were statistically different, maternal estriol levels were corrected to avoid the influencing factor of newborn weight. Mean maternal estriol level corresponding to vigorous newborns was 46.73 ng/ml. This value was statistically higher than that corresponding to the group of depressed newborns, which was 26.25 ng/ml (Fig. 1). The mean birthweight of depressed infants (2,382.75 g) was statistically lower than that of the vigorous group (3,044.75 g). The corrected mean maternal estriol values of vigorous neonates (45.44 ng/ml) was different from that of depressed ones (25.14 ng/ml) (Fig. 2). When patients were divided according to maternal diseases (diabetes, vascular pathology, Rh sensitization) serum estriol levels of the mother were statistically different according to the Apgar score of the newborns. There was no significant difference between serum hCS and oxytocinase levels of mothers with depressed and vigorous newborns. Discarding fetal weight as an influencing factor in maternal hormone level, our results indicate the suitability of maternal serum estriol determinations to predict condition of the newborns in high risk pregnancies.

Aminopeptidases↗