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Biomedical subjects

K L Reed

Publications and source records attributed to K L Reed.

At least 37 records · Page 2Linked to original sources
PubMed1997

Umbilical venous velocity pulsations are related to atrial contraction pressure waveforms in fetal lambs.

OBJECTIVE: To identify the source of umbilical venous velocity pulsations, times of transmission from the atrial contraction pressure waveform to velocity waves in the inferior vena cava, ductus venosus, intra-abdominal umbilical vein, and intra-amniotic umbilical vein were examined. METHODS: Five lamb fetuses at 125-135 days' gestation were instrumented with solid state pressure transducers in the inferior vena cava, fluid-filled catheters in the inferior vena cava and descending aorta, and epicardial pacemakers. Three to 5 days postoperatively, inferior vena cava, ductus venosus, and umbilical vein velocities were examined with Doppler ultrasound. Normal saline was administered and umbilical vein velocity pulsations developed (180 +/- 60 mL). In three fetuses, premature atrial contractions were induced under baseline conditions and after umbilical vein velocity pulsations developed. RESULTS: Times of transmission from the atrial contraction pressure waveform until velocity decreases in the fetal venous system were significantly different in the inferior vena cava, ductus venosus, intra-abdominal umbilical vein, and intra-amniotic umbilical vein (P < .001). Times increased with the distance from the atrium. Inferior vena cava pressure increased with fluid administration from 3.7 +/- 4.7 mmHg to 9.3 +/- 2.3 mmHg (P < .01). Time from increased pressure waveforms with induced premature atrial contractions to the nadir of subsequent umbilical vein velocity waves decreased from 0.123 +/- 0.047 seconds before saline administration to 0.072 +/- 0.039 seconds after saline administration (P < .001). CONCLUSION: Transmission time of atrial pressure into the venous circulation increases with distance from the atrium and decreases with volume loading. Umbilical venous velocity pulsations derive from atrial pressure changes transmitted in a retrograde fashion.

Animals↗
PubMed1997

Doppler--the fetal circulation.

Intrauterine growth restriction is associated with abnormalities in the fetal circulation. These abnormalities are currently best understood in the umbilical arterial and venous systems. Changes in intracardiac velocities are more variable as well as more difficult to detect. Doppler ultrasound, particularly of the umbilical circulation, has been useful in the fetus at risk for growth restriction, particularly in serial studies of a fetus identified as requiring increased surveillance. Doppler ultrasound also can add to the general understanding of the physiologic changes that occur in growth-restricted fetuses.

Adult↗
PubMed1997

A pilot study comparing ketoprofen and acetaminophen with hydrocodone for the relief of postoperative periodontal discomfort.

The aim of this study was to compare ketoprofen to acetaminophen with hydrocodone (A/H) in a postoperative periodontal pain model. A double-blind protocol was used. Thirty minutes prior to each procedure, subjects were given orally either 100 mg ketoprofen or a placebo tablet. Four hours later, the subjects took either 50 mg ketoprofen (ketoprofen group) or 1000 mg acetaminophen with 10 mg hydrocodone (placebo group). Subjects reported levels of overall discomfort and pain using visual analog scales at eight hourly intervals following the first dose of ketoprofen or placebo. Information about adverse side effects was requested from the patients in the form of a checklist. The results revealed only small differences between the two drug regimens with respect to levels of pain or overall discomfort. A/H provided significantly better pain relief at Hours 5 and 6, while overall discomfort levels were significantly higher with ketoprofen than with placebo at Hours 3 and 4. Pain levels were low for both groups. It is recommended that additional analgesics for mild to moderate pain should be tested.

Acetaminophen↗
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↗
PubMed1996

Porcine endometrial glandular epithelial cells in vitro: transcriptional activities of the pregnancy-associated genes encoding antileukoproteinase and uteroferrin.

The aim of this investigation was to establish a homologous culture system for study of the transcriptional mechanisms underlying endometrial expression of the pregnancy-associated genes encoding antileukoproteinase (ALP), an elastase/cathepsin G protease inhibitor, and uteroferrin (Uf), a transplacental iron transport protein. Glandular epithelial (GE), Luminal epithelial (LE), and stromal (ST) cells were isolated from pig endometrium at Day 12 of pregnancy by differential enzymatic digestion and sieve filtration. The three cell populations differed with respect to their morphology in culture and with respect to their expression of ALP and Uf. Expression of the ALP gene was much higher in GE than in LE cells and was undetectable in ST cells. Similarly, GE had the highest expression of the Uf gene, and expression in ST was lower but distinct. Western blot analysis of conditioned media (72 h) from GE, LE, and ST, using antiporcine Uf antiserum, detected significant levels of secreted Uf only in GE. The steroid hormone responsiveness of GE cells was monitored by changes in steady-state levels of ALP mRNA after 24-h exposure to estradiol 17 beta (E2; 10 nM) and/or progesterone (P; 10 nM). Glandular epithelial cells treated with E2, P, and E2 + P had increased (p < 0.05) ALP mRNA levels relative to those in control cultures. Glandular epithelial cells were transiently transfected with reporter constructs containing the 5'-flanking genomic regions of each gene. For ALP, the 1266-nucleotide (nt) region of the ALP 5'-flanking genomic DNA, and progressive 5' deletions within this region, were coupled to a luciferase reporter gene (LUCE). The most proximal 119-bp fragment (-119ALP LUCE), which contains the TATAA box (-21 to -26 nt) and a GC-rich sequence (-66 to -74 nt), was sufficient to confer transcriptional activity to the reporter vector. Progressively longer 5'-genomic fragments had promoter activities higher than or similar to those of the 119-nt fragment. Estrogen had no effect on the transcriptional activities of any of the ALP constructs. Uteroferrin 5'-flanking and promoter DNA constructs containing the chloramphenicol acetyl transferase (CAT) reporter gene also exhibited transcriptional activity in GE cells. The presence of multiple interacting cis-regulatory sequences within this region was demonstrated by increased promoter activity, relative to that of the smallest construct (-182 UFCAT-E; basal activity), with the inclusion of sequences between -182 and -484 nf, and drastic reduction to basal activity with the inclusion of sequences between -484 and -831 nt. In summary, primary cultures of GE from early-pregnant porcine endometrium express ALP and Uf, are steroid hormone-responsive, and support the transcriptional activity of endometrial-associated gene promoter and regulatory sequences. The use of primary GE cells thus provides a convenient in vitro system for further study of the endocrine, paracrine, and autocrine factors regulating endometrial gene expression during pregnancy.

Acid Phosphatase↗
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

Correlations in umbilical blood flow Doppler velocities in the human fetus during breathing.

We hypothesized that changes in intrathoracic pressure during fetal breathing episodes result in quantifiable variations in umbilical arterial and venous blood flow velocities, and that these variations are related to compliance properties of each system. We further hypothesized that these variations in velocities are different in fetuses with normal and abnormal umbilical arterial Doppler velocities. Umbilical arterial and venous Doppler velocities were measured simultaneously during breathing episodes in 15 normal fetuses and 14 fetuses with elevated systolic-to-diastolic (S/D) umbilical arterial Doppler velocity ratios. Umbilical arterial end-diastolic velocity changes were less than umbilical venous velocity changes in normal fetuses, but were significantly greater in four fetuses with elevated S/D ratios (p < 0.004). Furthermore, umbilical arterial diastolic velocity minima preceded umbilical venous velocity minima by a time lag that was greater in fetuses with elevated S/D ratios (p < 0.002). These results suggest that differences in umbilical arterial and venous velocity variation during fetal breathing episodes may be related in part to vascular compliance, which may be altered in fetuses with abnormal umbilical arterial Doppler velocity.

Journal Article↗
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↗