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Biomedical subjects

R A Castillo

Publications and source records attributed to R A Castillo.

At least 19 recordsLinked to original sources
PubMed2006

The genetic structure of the gynodioecious Kallstroemia grandiflora (Zygophyllaceae): the role of male sterility and colonization history.

In gynodioecious populations, the frequency of females is expected to have a strong influence on the contemporary genetic structure of populations. Historical patterns of range contraction and expansion are also known to influence the genetic diversity of plant populations. We explore the influence of male sterility and colonization history on the genetic diversity in populations of Kallstroemia grandiflora along the Pacific of México. Both the overall population Fis and Fis values of hermaphrodites showed a negative association with female frequency. Genetic diversity declined with latitude. Our results provide evidence that females have a significant effect on the genetic structure as predicted by theoretical models and provide support for the hypothesis that historical processes have modified the genetic structure of K. grandiflora.

Desert Climate↗
PubMed1994

Fetal biophysical activities in third-trimester pregnancies complicated by diabetes mellitus.

OBJECTIVE: Our purpose was to compare third-trimester fetal biophysical activities in normal and well-controlled insulin-dependent diabetic pregnancies. STUDY DESIGN: We performed serial bimonthly fetal biophysical studies from 30 to 38 weeks in 18 normal and 18 well-controlled insulin-dependent diabetic pregnancies (White classes B through D). Each study contained 60 minutes of simultaneous ultrasonographic recordings of fetal breathing movements and rates, baseline heart rate, and body movements. Mean daily blood glucose levels of diabetic patients were determined from home monitors; HbA1c was determined every 6 weeks and ultrasonographic fetal growth rates every 3 weeks. Data were compared with t tests, analysis of variance with repeated measures, and chi 2 tests. RESULTS: Women in the diabetic group maintained good glycemic control and were delivered of normal infants of weights similar to those of nondiabetic gravidas. Their fetuses had higher mean incidences of fetal breathing movement, fetal heart rates, and fetal breathing rates but lower fetal movements and fetal heart rate acceleration counts than did controls throughout the study. Neither short- nor long-term maternal glycemic levels correlated well with fetal biophysical performance. CONCLUSIONS: In spite of good maternal glycemic control fetuses of diabetic women behaved differently from those of nondiabetic women. Modulation of their biophysical activities may be affected by maternal glycemic status before the last trimester. Different standards might need to be applied to interpret their tests.

Adult↗
PubMed1990

The diagnostic values of concurrent nonstress testing, amniotic fluid measurement, and Doppler velocimetry in screening a general high-risk population.

To determine the values of individual and combined biophysical fetal surveillance tests in a general high-risk population, we examined 1000 consecutive pregnancies complicated by either postdatism, hypertension, intrauterine growth retardation, or diabetes mellitus. Nonstress tests, amniotic fluid pocket measurements, and umbilical artery Doppler velocimetry were performed on each patient; each test was rated against gestational age-adjusted standards. Clinical end points included perinatal mortality, intrapartum fetal distress, 5-minute Apgar score less than 7, and neonatal acidosis in pregnancies without major anomalies or extreme prematurity (age at birth greater than 32 weeks), delivered within 72 hours of final tests. Each testing method had specificity greater than 90%. Sensitivities ranged from 69% (nonstress test) to 21% (Doppler velocimetry). Negative predictive values of each method exceeded 85%; positive predictive values ranged from 81% (nonstress test) to 42% (amniotic fluid measurements). The positive predictive value for any abnormal test was 54% and increased to 100% when all tests were abnormal; this latter condition occurred in only 2% of the total population. Amniotic fluid measurements or Doppler velocimetry, when compared with the nonstress test, appeared to be less powerful "stand-alone" screening tests. The performance of all tests in a single session confers little improvement in detection of fetal compromise if the nonstress test is normal; however, this approach may aid decision-making in the management of pregnancies when fetal maturity is not established.

Amniotic Fluid↗
PubMed1989

The preterm nonstress test: effects of gestational age and length of study.

The application of the nonstress test between 24 and 32 weeks' gestation has been limited by high rates of "false" nonreactivity in normal fetuses, by use of term criteria, and the lack of age-appropriate interpretative standards. To establish such standards, we studied 30 normal fetuses undergoing 90-minute fetal heart rate recordings at 2-week intervals from 24 to 32 weeks' gestational age. Using a specially programmed computer we quantified (1) baseline fetal heart rate, (2) incidence of 10- and 15-beat accelerations, and (3) incidence of fetal heart rate decelerations. With a criterion of three 15-beat accelerations per 30 minutes 91% of tests were reactive within 90 minutes. A criterion of three 10-beat accelerations per 30 minutes was associated with 100% reactivity within 60 minutes. Suitable interpretative criteria may be established for nonstress tests before 32 weeks' gestation by extending the testing time or by decreasing the minimum amplitude required of fetal heart rate accelerations.

Adult↗
PubMed1989

The effects of vibroacoustic stimulation on baseline heart rate, breathing activity, and body movements of normal term fetuses.

To determine the fetal biophysical effects of vibroacoustic stimulation produced by an electronic artificial larynx we studied 20 normal term pregnancies assigned either to control (no stimulus) or experimental (stimulus) groups. Each fetus was observed for 3 hours; either no stimulus or a 3-second stimulus was delivered after the first hour. Fetal heart rate baseline and variation, breathing movement incidence, rate, and variation, and body movement incidence data were acquired concurrently and analyzed at 15-minute intervals. Intergroup comparisons showed that, after stimulation, fetal heart rate baseline and variation increased significantly, whereas breathing incidence fell during the first 15 minutes. Within-group analyses showed that poststimulus elevation of fetal heart rate baseline was the only significant time interaction over the 3 hours. Vibroacoustic stimulation appears to be primarily associated with transient alterations in fetal heart rate baseline; concomitant changes in breathing activity probably reflect normal biologic cycles.

Acoustic Stimulation↗
PubMed1989

The effects of acute alcohol intoxication on biophysical activities: a case report.

A computer-assisted biophysical assessment was performed in a woman with chronic alcoholism at 37 weeks' gestation. She was first seen in a state of acute alcohol intoxication (322 mg/dl). Although fetal breathing movement incidence was normal (30%), fetal tachypnea (67 breaths per minute) and decreased fetal body movements (0.11%) were seen. Because these findings differ from those previously reported with regard to normal pregnancies exposed to lower levels of alcohol, their implications are discussed.

Adult↗
PubMed1989

Central pontine myelinolysis and pregnancy.

Central pontine myelinolysis, also known as osmotic demyelination syndrome, is an uncommon disorder associated with rapid correction of severe hyponatremia. We present the case of a healthy young pregnant woman with hyperemesis gravidarum who developed severe hyponatremia (serum sodium 103 mEq/L). After rapid correction of her serum sodium within 12-15 hours with a 0.9% saline solution, the patient became comatose and died of sepsis and respiratory failure. Examination of the brain showed extensive demyelination in both pontine and extrapontine areas.

Adult↗
PubMed1988

Prognostic components of computerized fetal biophysical testing.

Fetal biophysical testing with arbitrary scores for fetal heart rate (FHR), breathing movements, body movements, tone, and amniotic fluid volume has not proved to be highly sensitive or significantly better than FHR testing alone. Using a computerized analysis system for simultaneously acquired biophysical variables, we studied 200 high-risk fetuses near term. The dynamic parameters obtained for each fetus were compared with established nomograms, and overall test results correlated with the presence or absence of perinatal mortality, fetal distress, a 5-minute Apgar score less than 7, and intrauterine growth retardation for those delivered within 7 days of the last test. A test was considered abnormal if two or more parameters fell more than 2 standard deviations from the population mean. A decreased incidence of fetal body movements, amniotic fluid volume, and frequency of FHR acceleration were the most common individual test abnormalities. Test sensitivity (86%), specificity (89%), positive predictive value (75%), and negative predictive value (93%) exceeded those of the "standard" scoring approach and correctly identified all fetuses with malformation, perinatal death, and 19 of 22 fetuses with intrauterine growth retardation.

Amniotic Fluid↗
PubMed1987

Pleural effusions and pulmonary hypoplasia.

Nine cases of fetuses with pleural effusions are presented in which the diagnosis was made by ultrasound before the thirtieth week of gestation. A ratio of lung span to hemithorax diameter was calculated and ranged from 0.44 to 0.77 (mean 0.60). At autopsy, pulmonary hypoplasia was confirmed in all cases by criteria based on the ratio of lung weight to total body weight. Because pleural effusions occurring in the midtrimester can be detected and may lead to pulmonary hypoplasia, consideration should be given to definitive in utero therapy when no other major fetal abnormality is detected.

Adult↗
PubMed1987

Fetal biophysical testing. The effects of prolonged maternal fasting and the oral glucose tolerance test.

Fetal biophysical testing incorporates observations of the fetal heart rate (FHR), fetal breathing movements (FBMs) and fetal trunkal movements (FTMs). These parameters were examined during maternal fasting and glucose loading. Thirty normal term gravidas were studied during a 210-minute session, of which the first 30 minutes served as a fasting control period, following which 20 (group G) received 100 g oral glucose, while 10 (group F) continued fasting. Serum glucose levels in both groups were determined every 30 minutes. FHR, FBMs and FTMs were recorded concurrently using abdominal electrocardiography and real-time ultrasonography and entered on line into a microcomputer. Offline data analysis provided mean 30-minute baseline FHRs, acceleration counts, FBM incidences, FBM rates and FTM incidences. Both groups were similar for gestational age, birth weight and perinatal outcomes. Mean 30-minute FHR baseline was unchanged and similar in both groups. Mean 30-minute FHR acceleration counts and FTM incidences were significantly higher in group F, while FBM incidences and rates were significantly higher in group G. While biophysical testing can be conducted under either set of maternal conditions, different normal standards must be employed, test length must be sufficient to account for normal biologic variations, and biophysical parameters must be monitored concurrently.

Electrocardiography↗
PubMed1987

Clinical significance of fetal tachypnea during antepartum biophysical testing.

Fetal tachypnea has been regarded as a rare finding with a poor perinatal prognosis. Eighteen cases of fetal tachypnea were noted during the biophysical tests of 200 patients. Biophysical testing consisted of concurrent ultrasound observations of fetal breathing and body movements and electronic monitoring of fetal heart rate, coupled with determinations of fetal tone and amniotic fluid volume. Fetal breathing movement frequency and rate, fetal trunkal movement frequency, and baseline fetal heart rate were analyzed on a programmed microcomputer. The mean (+/- SD) breathing rate was 68.2 +/- 6.4 breaths per minute; mean breathing frequency, 55 +/- 22.6%; mean baseline heart rate, 141 +/- 8 beats per minute; mean trunkal movement incidence, 5.5 +/- 2.6%; and mean acceleration frequency, 14.6 +/- 9.8 per hour. No fetus was apneic for more than eight minutes, and there were no significant correlations between fetal breath rates and the other biophysical parameters. There were no perinatal deaths. Seven fetuses experienced perinatal morbidity, of whom five had other abnormalities on biophysical testing. This study indicates that fetal tachypnea occurs more often than previously believed and does not generally signify fetal compromise unless other biophysical abnormalities are also present.

Female↗
PubMed1987

Ruptured chordae tendineae complicating pregnancy. A case report.

A 29-year-old women at 30 weeks' gestation had acute mitral insufficiency secondary to bacterial endocarditis and ruptured chordae tendineae. Although this complication has been reported on previously, recent advances in technology have led to significant improvements in its diagnosis and treatment.

Adult↗
PubMed1986

Maternal dietary substrates and human fetal biophysical activity. I. The effects of tryptophan and glucose on fetal breathing movements.

To study the effects of L-tryptophan and glucose on fetal breathing activity, we examined 40 women with normal term pregnancies, randomly assigned to four equal groups who either continued fasting (group C), received 1 gm of oral tryptophan (group T), received 100 gm of oral glucose (group G), or received both substrates (group T + G). Studies lasted 210 minutes, during which fetal breathing movements were observed with real-time ultrasonography and entered and analyzed for incidence, rate, and variability on a microcomputer. Plasma glucose and tryptophan levels were determined every 30 minutes. The incidence of fetal breathing movements declined in group C and rose significantly in the other groups. Breathing rates were unchanged in groups C and T but rose significantly in groups G and T + G during peak breathing intervals. Breath interval variability did not change significantly in any study group. Maternal administration of tryptophan is associated with an alteration in fetal breathing activity but to a lesser degree than that observed after maternal glucose loading.

Administration, Oral↗
PubMed1986

Nonimmune hydrops fetalis: clinical experience and factors related to a poor outcome.

Twenty-one cases of nonimmune hydrops fetalis diagnosed at the Medical College of Georgia during a 2-year period are presented. All fetuses satisfied strict diagnostic criteria and were evaluated according to a standard protocol. The corrected mortality rate was 95% with pulmonary hypoplasia being the most common cause of perinatal death. The mean gestational age at diagnosis was 24.8 weeks; in 57% of the cases the cause of nonimmune hydrops fetalis was identified. Fifteen fetuses had serial ultrasound assessment and in 19 cases postnatal evaluation was performed. Two factors that consistently conveyed a poor perinatal outcome were ultrasonographic evidence of malformation and/or the presence of persistent pleural effusions. A method for the quantification of fetal pleural effusions is presented and its clinical relevance is discussed.

Adolescent↗
PubMed1986

Metastatic pheochromocytoma in pregnancy and fetal biophysical assessment after maternal administration of alpha-adrenergic, beta-adrenergic, and dopamine antagonists.

Metastatic pheochromocytoma, a rare complication of pregnancy, was managed from 30 weeks' gestation until delivery three weeks later with a combination of alpha-adrenergic blockade (Minipres) beta-adrenergic blockade (Timolol), and dopamine synthesis inhibition (Demser). The biophysical parameters of fetal heart rate (FHR) baseline, variability, and reactivity, as well as fetal breathing movements, body movements, tone, and amniotic fluid volume were followed sequentially during this period. A 1450-g growth-retarded infant, who subsequently did well, was delivered by cesarean section; the mother received combined surgical and medical therapy for her metastatic disease in the postpartum period. The initial fetal biophysical alteration observed was a reduction in mean FHR baseline rate; further biophysical test abnormalities appeared only after overt fetal compromise was evident. Sequential multiple parameter biophysical testing in such circumstances appears to be a valid and valuable approach to antepartum management.

Adult↗
PubMed1985

Computer-assisted assessment of the fetal biophysical profile.

The biophysical profile assesses fetal heart rate, breathing movements, fetal body movements, amniotic fluid volume, and fetal tone. In the past, these data have been scored by an arbitrary, unweighted system. While this approach is useful in detecting major anomalies and oligohydramnios, both static observations, the dynamic variables (fetal heart rate, fetal breathing movements, and fetal body movements) have added little information beyond that of an extended nonstress test alone. We have evaluated an alternative biophysical assessment system, modeled after extended physiologic studies, which not only acquires dynamic fetal variables simultaneously but, with computer assistance, quantifies the biophysical information. With an ADR 4000/L scanner, a Hewlett-Packard 8040 A monitor, and a specially programmed IBM microcomputer, we studied 100 normal term fetuses during 60-minute epochs. Each gestation had normal amniotic fluid volume and fetal tone. Normative values for the dynamic variables, expressed as means +/- SD were: fetal heart rate, 137 +/- 6.3 bpm; incidence of fetal breathing movements, 25.0% +/- 17.3%; rate of fetal breathing movements, 46.0 +/- 9.4 breaths/min; total fetal breathing movements, 823 +/- 61; incidence of fetal body movements, 8.5% +/- 3.9%; accelerations (greater than 15 bpm, 15 seconds), 14.1 +/- 6.3. We conclude that this approach is practicable, respects the biologic cycles of fetal behavior, and provides a basis for population standards and sequential study of the same fetus.

Amniotic Fluid↗