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Biomedical subjects

K L Reed

Publications and source records attributed to K L Reed.

At least 19 recordsLinked to original sources
PubMed1996

Adolescence and very low birth weight infants: a disproportionate association.

OBJECTIVE: To examine the incidence of very low birth weight (VLBW) neonates, defined as those weighing less than 1500 g, delivered by adolescents compared with the general obstetric population. METHODS: A retrospective observational study of 16,857 women delivering live-born infants from January 1, 1989, to June 30, 1993, was conducted at the University of Arizona Health Sciences Center. Adolescents were defined as those having a maternal age of 18 years or less at the time of delivery. The rate of VLBW infants delivered to adolescent mothers was compared with the general obstetric population (women at least 19 years old) using chi 2 analysis, multiple analysis of variance, and multiple linear regression. RESULTS: During the study period, 204 VLBW infants were delivered, yielding an overall VLBW delivery rate of 1.2%. Adolescents had a VLBW delivery rate that was considerably higher than the general obstetrical population: 35 of 1758 (2.0%) versus 169 of 15,099 (1.1%) (P = .002). Whereas adolescents accounted for 10.6% of the total deliveries during the study period, they delivered 17% of the VLBW neonates. The relative risk of an adolescent delivering a VLBW infant was 1.7 (95% confidence interval 1.2-2.2). CONCLUSION: Preterm birth is one of the major unresolved problems in modern obstetrics. Although the association between adolescence and preterm birth has been reported previously, specific attention has not been focused on the VLBW neonate. We conclude that adolescents deliver a disproportionate number of VLBW infants.

Adolescent↗
PubMed1996

Umbilical venous Doppler velocity pulsations and inferior vena cava pressure elevations in fetal lambs.

OBJECTIVE: To examine effects of fluid administration on inferior vena cava pressure and umbilical venous Doppler velocities in the term fetal lamb. METHODS: With the ewe given inhalation anesthetics, eight chronically instrumented intrauterine fetal lambs at 125-135 days' gestation were given normal saline fluid boluses. Inferior vena cava peak pressures and umbilical venous Doppler velocities were measured before, during, and after administration of normal saline. Pressures were obtained with fluid-filled and solid state pressure transducers. RESULTS: Umbilical venous Doppler velocity pulsations developed in six fetuses after 120 mL and all eight fetuses after 240 mL of fluid were administered. Inferior vena cava peak pressure increased from 5.15 +/- 2.7 to 10.9 +/- 3.9 mmHg (P < .001). Heart rate did not change significantly, and umbilical arterial systolic-to-diastolic velocity ratios decreased (P < .03). CONCLUSION: Umbilical venous Doppler velocity pulsations developed after fluid administration and were associated with increases in inferior vena cava peak pressure. These findings suggest that umbilical venous pulsations develop when fetal venous pressures are elevated.

Animals↗
PubMed1995

The relation between pulmonary hypoplasia and amniotic fluid volume: lessons learned from discordant urinary tract anomalies in monoamniotic twins.

BACKGROUND: Adequate amniotic fluid (AF) volume is one of several factors felt to be essential for normal lung development. Renal agenesis and urinary tract obstruction usually result in oligohydramnios and pulmonary hypoplasia. CASE: Two sets of monoamiotic twins with discordant urinary tract anomalies were seen. One twin in each set had anomalies that in a singleton or diamiotic pregnancy would likely have resulted in fetal pulmonary hypoplasia and subsequent death. However, neither of these infants had pulmonary hypoplasia. One infant is unique in being the first case reported of normal pulmonary function and survival despite the anomaly. CONCLUSION: Adequate AF provided by a monoamniotic twin environment may prevent pulmonary hypoplasia, which usually results from oligohydramnios due to certain fetal urinary tract anomalies.

Abnormalities, Multiple↗
PubMed1995

Citation analysis of faculty publication: beyond Science Citation Index and Social Science Citation Index.

When evaluated for promotion or tenure, faculty members are increasingly judged more on the quality than on the quantity of their scholarly publications. As a result, they want help from librarians in locating all citations to their published works for documentation in their curriculum vitae. Citation analysis using Science Citation Index and Social Science Citation Index provides a logical starting point in measuring quality, but the limitations of these sources leave a void in coverage of citations to an author's work. This article discusses alternative and additional methods of locating citations to published works.

Abstracting and Indexing↗
PubMed1994

Smoking and pregnancy: a comparison of Mexican-American and non-Hispanic white women.

OBJECTIVE: To describe ethnic differences in tobacco use during pregnancy in a clinical population of Mexican-American and non-Hispanic white women. METHODS: Subjects were randomly selected from all patients attending a university-based obstetrics clinic in Tucson, Arizona. Of 555 subjects selected, 367 were interviewed and had their urinary cotinine levels measured. The 37 subjects who refused an interview and the 136 who were selected but not interviewed did not differ from other subjects regarding ethnicity, education, obstetric history, or smoking status. The interviewer gathered standard demographic and obstetric information as well as data on smoking behavior. Subjects were interviewed in Spanish or English by a bilingual interviewer using a standardized questionnaire. Statistical techniques included chi 2 test, t test, and logistic regression. RESULTS: The odds for Mexican-American women to have been smokers were 3.39 times lower than for non-Hispanic white women. The odds of quitting during pregnancy were 4.71 times higher for Mexican-Americans (95% confidence interval 1.66-13.38). Urinary cotinine values verified the latter rates. Mexican-American smokers reported smoking significantly fewer cigarettes than non-Hispanic white women (t = 2.34, P < .05). CONCLUSIONS: In comparing Mexican-American and non-Hispanic white women, we found marked differences in smoking behavior during pregnancy. Mexican-Americans were nearly three times more likely to quit than non-Hispanic whites, and those who continued to smoke showed greater reductions in cigarettes per day. These results show behavioral changes in Mexican-Americans during pregnancy that meaningfully alter the risk profile for the fetus. Understanding the basis for this behavioral change may facilitate the development of preventive measures for other ethnic groups.

Adult↗
PubMed1994

Changes in umbilical arterial and venous blood flow velocity waveforms during late decelerations of the fetal heart rate.

OBJECTIVE: To compare umbilical arterial and venous Doppler velocity waveforms during labor in fetuses with normal heart rate tracings and fetuses with late decelerations. METHODS: During labor, umbilical arterial and venous Doppler flow velocity waveforms were obtained between and during contractions in 20 fetuses (ten with normal heart rate tracings and ten with late decelerations). The umbilical arterial systolic-diastolic (S/D) velocity ratios were compared, and umbilical venous velocities were examined for the presence or absence of venous pulsations. RESULTS: Fetuses with late decelerations had a significant increase in the umbilical arterial S/D ratio between contractions compared to normal fetuses (2.43 +/- 0.74 versus 1.56 +/- 0.27, P = .003). There was no significant difference in S/D ratios obtained between contractions compared with those obtained during contractions in either the normal or late deceleration group. Umbilical venous pulsations were significantly more common (90 versus 0%, P < .00001) during contractions in fetuses with late decelerations; umbilical venous pulsations were not seen in these fetuses between contractions and were not present at any time in fetuses with normal heart rate tracings. CONCLUSIONS: Increased umbilical arterial velocity ratios and the presence of umbilical venous pulsations during contractions in fetuses with late decelerations suggest that the cardiovascular pathophysiology of late decelerations involves changes in placental resistance as well as cardiac performance. The presence of umbilical venous pulsations during late decelerations is consistent with the hypoxic fetal cardiovascular changes (hypertension and myocardial depression) previously reported from animal studies.

Apgar Score↗
PubMed1993

Basic technique of fetal echocardiography.

The fetal heart is the organ system most commonly affected with congenital disease. Though risk factors exist for congenital heart disease (eg, family history, toxin exposure, maternal illness, abnormal karyotype, and other fetal anomalies), the fetal heart is most often examined as part of a routine evaluation of the fetal anatomy in the fetus with no identifiable risk factors. The importance of a systematic, complete assessment of the cardiac axis cannot be overemphasized. All aspects of sonography (ie, real time, M-mode, pulsed, and color Doppler) can provide unique and integral information in evaluating the fetal heart and thorax.

Echocardiography↗
PubMed1993

Comparison of Doppler with two-dimensional sonography and CA 125 for prediction of malignancy of pelvic masses.

OBJECTIVE: To assess the validity of Doppler flow sonography for the prediction of malignancy in adnexal masses and to compare the results with two-dimensional ultrasonographic examination and CA 125 levels. METHODS: In a cross-sectional study, 55 patients with adnexal masses were examined using Doppler sonography to measure the resistance index of tumor-associated blood flow profiles. In addition, abdominal and transvaginal ultrasound examinations were performed and preoperative CA 125 serum levels were assessed. RESULTS: Sixteen patients had malignant tumors and 39 had benign tumors. A resistance index cutoff of less than or equal to 0.8 showed the highest sensitivity (93.8%), with a specificity of 56.4%, a positive predictive value of 46.8%, and a negative predictive value of 95.7%. Compared with two-dimensional sonographic evaluation using either a scoring system or subjective assessment, and with CA 125 levels, the resistance index showed higher sensitivity and negative predictive value but lower specificity and positive predictive value. False-positive resistance index values were prevalent with endometriosis, leiomyomata, and mucinous cystadenoma. The combination of the resistance index with either the sonographic features or CA 125 increased the sensitivity and negative predictive value to 100%, with only a slight decrease in specificity and positive predictive value, but was not superior to the combination of two-dimensional sonography and CA 125. CONCLUSION: Doppler sonographic evaluation of resistance indexes in the vessels of adnexal masses increased the sensitivity of two-dimensional sonography and CA 125. However, 46% of positive Doppler results were false and 37.5% of the benign tumors had low resistance indexes, thus limiting the validity of this technique for screening programs.

Adnexal Diseases↗
PubMed1992

Isolation and characterization of Chinese hamster ovary cells defective in the intracellular metabolism of low density lipoprotein-derived cholesterol.

We have isolated clones of an established cell line which express defects in intracellular cholesterol metabolism. Chinese hamster ovary cells were mutagenized, and clones unable to mobilize low density lipoprotein (LDL)-derived cholesterol to the plasma membrane were selected. Biochemical analysis of two mutant clones revealed a phenotype characteristic of the lysosomal storage disease, Niemann-Pick type C. The mutant cell lines were found to be defective in the regulatory responses elicited by LDL-derived cholesterol. LDL-mediated stimulation of cholesterol esterification was grossly defective, and LDL suppression of 3-hydroxy-3-methylglutaryl-CoA reductase was impaired. However, the mutants modulated these activities normally in response to 25-hydroxycholesterol or mevalonate. The LDL-specific defects were predicated by the inability of these mutants to mobilize LDL-derived cholesterol from lysosomes. Cell fractionation studies showed that LDL-derived, unesterified cholesterol accumulated in the lysosomes of mutant cells to significantly higher levels than normal, commensurate with defective movement of cholesterol to other cellular membranes. Characterization of cell lines defective in intracellular cholesterol transport will facilitate identification of the gene(s) required for intracellular cholesterol movement and regulation.

Amphotericin B↗
PubMed1992

History of federal legislation for persons with disabilities.

This paper discusses federal legislation relating to persons with disabilities and it divides into 13 areas. Several areas of legislation, such as education and basic education, have a long history beginning with World War I. Laws related to other areas, such as federal support for developing technology, have been adopted only within the past 5 years. The Americans With Disabilities Act of 1990 (ADA) (Public Law 101-336), which guarantees civil rights to Americans with disabilities, has five titles, and each is summarized. Although the ADA provides for Americans with disabilities to be included in American society, it has some major limitations, including the lack of an affirmative action requirement and of provisions for the education and training of persons with disabilities so that they can qualify for employment. Several of the federal laws related to persons with disabilities have affected the field of occupational therapy either favorably or adversely. The conclusion is drawn that occupational therapists need to be alert to pending legislation to promote the role of occupational therapy in serving persons with disabilities.

Civil Rights↗
PubMed1991

The dimension of chaos in the fetal heart rate.

Variability in the fetal heart rate is known to be a sign of fetal well-being, and yet the origins of the variations remain unclear. This study incorporated the nonlinear analytic techniques of phase-space reconstruction and dimensional analysis to 12 normal heart rate tracings obtained from fetal scalp electrodes of fetuses in labor. Phase-space attractors were constructed with the method of time delays and showed characteristics consistent with those of nonlinear chaotic systems. Dimensional analysis resulted in three distinct groups being identified. Results indicate that control of the fetal heart rate may be modeled as a nonlinear or chaotic system, and analytic techniques borrowed from the physical sciences are useful in exploring heart rate variability. That different groups could be distinguished among qualitatively similar heart rate tracings may lead to understanding of discrepancies between evaluation of the monitor tracing and neonatal outcome.

Cardiotocography↗
PubMed1991

Doppler flow velocities in single umbilical arteries.

Fetal compromise has been associated with an umbilical artery waveform pattern of low or absent diastolic velocity relative to systolic velocity. Fetuses with single umbilical arteries have an increased risk of major malformations, mortality, retarded fetal growth, and prematurity. In this study Doppler flow velocities were obtained in 13 fetuses (four twin fetuses and nine singletons) with a single umbilical artery. Five (38%) fetuses, consisting of four singletons and one twin, had anomalies. Six (46%) fetuses were small for gestational age, including two twin fetuses and three singleton fetuses with anomalies. Three (23%) of the 13 systolic-to-diastolic velocity ratios were abnormally high. Whereas this is a higher rate of abnormal ratios than the reported 2% to 3% in control populations, it is interesting to note that 77% of fetuses with single umbilical arteries had normal systolic-to-diastolic ratios.

Abnormalities, Multiple↗
PubMed1991

Significance of oligohydramnios complicating pregnancy.

Oligohydramnios is a serious complication of pregnancy that is associated with a poor perinatal outcome. Eighty pregnancies complicated by oligohydramnios constitute the basis for this retrospective study. Forty patients had premature rupture of the membranes; of these, outcomes were good in 25. Twelve of 14 fetuses with oligohydramnios and intrauterine growth retardation survived. None of the nine fetuses with severe renal anomalies lived. None of the twins with twin-twin transfusion and oligohydramnios survived. Six pregnancies with oligohydramnios and premature separation of the placenta were identified; all of these resulted in fetal or neonatal death during the second trimester.

Blood Flow Velocity↗
PubMed1991

Tricuspid valve disease with significant tricuspid insufficiency in the fetus: diagnosis and outcome.

The echocardiographic studies and clinical course of 27 fetuses (mean gestational age 26.9 weeks) diagnosed in utero with tricuspid valve disease and significant tricuspid regurgitation were reviewed. The diagnosis of Ebstein's anomaly was made in 17 of the fetuses, 7 had tricuspid valve dysplasia with poorly developed but normally attached leaflets and 2 had an unguarded tricuspid valve orifice with little or no identifiable tricuspid tissue. One fetus was excluded from data analysis because a more complex heart lesion was documented at autopsy. All fetuses had massive right atrial dilation and most who were serially studied had progressive right-sided cardiomegaly. Hydrops fetalis was found in six cases and atrial flutter in five. Associated cardiac lesions included pulmonary stenosis in five cases and pulmonary atresia in six. Four fetuses with normal forward pulmonary artery flow at the initial examination were found at subsequent study to have retrograde pulmonary artery and ductal flow in association with the development of pulmonary stenosis (n = 1) and pulmonary atresia (n = 3). On review of the clinical course of the 23 fetuses (excluding 3 with elective abortion), 48% of the fetuses died in utero and 35% who were liveborn died despite vigorous medical and, when necessary, surgical management, many of whom had severe congestive heart failure. Of the four infants who survived the neonatal period, three had a benign neonatal course, all of whom were diagnosed with mild to moderate Ebstein's anomaly; only one had pulmonary outflow obstruction. An additional finding at autopsy was significant lung hypoplasia documented in 10 of 19 autopsy reports.(ABSTRACT TRUNCATED AT 250 WORDS)

Ebstein Anomaly↗