Amniotic fluid volume assessment: oligohydramnios.
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Amniotic Fluid↗
Biomedical subjects
C V Smith
Publications and source records attributed to C V Smith.
Analysis of pentoxifylline in rabbit plasma using a Hisep high-performance liquid chromatography column.
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Animals↗
Double-blind comparison of intravaginal prostaglandin E2 gel and "chip" for preinduction cervical ripening.
The intravaginal application of prostaglandin E2 for preinduction cervical ripening has proved to be advantageous in the management of patients with an unfavorable cervix. The purpose of this double-blind randomized investigation was to compare the efficacy and safety of two methods of prostaglandin E2 delivery. Patients who were to have preinduction cervical ripening because of an unfavorable cervix (Bishop score less than or equal to 4) were randomly assigned to be given a single dose of prostaglandin E2 as either 2.5 mg of gel or a 3.0 mg "chip" intravaginally in a placebo-controlled manner. Sixty-nine patients received the active prostaglandin E2, 34 in the gel group and 35 in the "chip" group. The groups were similar in maternal age, race, parity, gestational age, and initial Bishop score. Both forms of prostaglandin E2 were easy to administer and helpful in priming an unfavorable cervix. The need for, duration of, and maximum dose of oxytocin were similar in both groups. Cesarean delivery because of failed induction occurred in 5 of 35 (14.3%) patients receiving a "chip" and 4 of 34 (11.8%) receiving the gel. However, patients receiving a "chip" experienced a 20% (7/35) incidence of hyperstimulation, compared with 2.9% (1/36) in those receiving the gel (p less than 0.05). The only case requiring immediate cesarean delivery because of intractable uterine hyperstimulation received a "chip." We conclude that both methods were effective for cervical ripening, but the lower incidence of uterine hyperstimulation seen with the gel would suggest that it is preferable to the "chip."
Administration, Intravaginal↗
Intrauterine sound levels: intrapartum assessment with an intrauterine microphone.
The complex mechanisms responsible for fetal hearing are in place and functional by 26 weeks of gestation, but little is known about the acoustic milieu of the amniotic cavity. We placed an electrically isolated microphone in the uterus of nine term gravid volunteers after amniorrhexis. Baseline levels of intrauterine sound were 72 to 88 db. Transabdominal vibroacoustic stimulation with an artificial larynx produced peak mixed frequency sound levels of 91 to 111 db. We conclude that the term fetus in labor is exposed to physiologic sound levels higher than we had anticipated; the application of a quantifiable sound stimulus to the maternal abdominal wall results in a small increment in intrauterine sound; and within the limits specified, experimental fetal acoustic stimulation should pose no major risks.
Acoustic Stimulation↗
Effect of a single dose of oral pseudoephedrine on uterine and fetal Doppler blood flow.
Pseudoephedrine, a stereoisomer of ephedrine with alpha- and beta-adrenergic properties, is the active ingredient in over-the-counter oral decongestants. Its safety during pregnancy has not been studied adequately. The purpose of this investigation was to evaluate the effects of pseudoephedrine on uterine and fetal Doppler blood flows. Twelve healthy pregnant women between 26-40 weeks' gestation ingested a standard 60-mg dose of pseudoephedrine. A pulsed Doppler system was used to perform blood flow measurements of the uterine arcuate artery, fetal aorta, and umbilical artery before dosing, immediately thereafter, and at 15-minute intervals during the first 3 hours after drug ingestion. Blood flow velocities were not altered significantly after dosing in either the maternal or fetal circulation. In no case did absolute fetal or uterine blood flow velocities decrease significantly or systolic/diastolic ratios persistently elevate to abnormal values. We conclude that no significant alterations in the uterine or fetal circulations occur after the ingestion of a single dose of oral pseudoephedrine by healthy pregnant patients in the third trimester.
Administration, Oral↗
Biochemical manifestations of oxygen toxicity in the newborn lamb.
The purpose of this project was to study the role of lipid peroxidation in oxygen-induced lung injury in the newborn lamb. It was our hypothesis that injury to the microvascular bed of the lung by oxygen would coincide with a burst of peroxidative activity and would be accompanied by an increased rate of excretion of ethane and pentane in expired gas. We measured vascular pressures, the rate of lung lymph flow and concentrations of ethane and pentane in exhaled gas in 10 newborn lambs that breathed greater than 95% oxygen continuously. Our marker for oxygen-induced lung injury was an increase in the permeability of the microvascular bed of the lung to protein (an increase in the rate of lung lymph flow accompanied by an increase in the protein concentration in lymph). Although all 10 lambs demonstrated an abrupt increase in microvascular permeability to protein within 48 to 96 h of exposure to greater than 95% oxygen, the rates of ethane and pentane excretion remained unchanged throughout the entire experimental period. Lung tissue concentrations of glutathione decreased by 40% in the oxygen-exposed lambs and the concentrations of glutathione disulfide increased 85% relative to air-breathing controls. Activities of glutathione reductase and superoxide dismutase were lower in the lungs of the oxygen-exposed lambs than in controls, whereas the activities of glutathione peroxidase and catalase were not changed. We conclude that, in the lamb, changes in the rates of excretion of ethane and pentane do not correlate with the timing of injury to the microvascular bed of the lung.
Animals↗
The role of transvaginal ultrasound in a referral military hospital.
In an attempt to overcome some of the difficulties encountered with transabdominal ultrasonography we report on 55 patients who underwent 88 transvaginally directed sonograms. In 24 patients in whom a diagnosis of an early intrauterine pregnancy was made, the mean crow-rump length (CRL) was 10.7 mm (range, 3 to 27). In six patients (25%) the CRL was 5 mm or less. These data suggest that the use of transvaginally directed sonography may permit an earlier diagnosis of pregnancy than the abdominal approach does. This earlier diagnosis should allow the exclusion of ectopic pregnancy in many of the patients at risk for this disorder.
Female↗
Amniotic fluid assessment.
The mysterious environment surrounding the fetus for much of his or her life is now being explored with increasing fervor. Assessment of amniotic fluid in the early portion of pregnancy is now possible for fetal karyotype determination. This may permit early diagnosis of abnormal fetuses, increasing the options for patients. As pregnancy progresses, high-resolution ultrasound assessment of amniotic fluid volume is integral to the management of pregnancies at risk for oligohydramnios. Such pregnancies include those who are postdate and those with suspected intrauterine growth retardation. Additional evaluation and ultrasonography are recommended for evaluation of the fetus in this clinical situation. With either hydramnios or oligohydramnios, careful ultrasound assessment of the fetus is essential to rule out significant congenital malformations. Finally, the use of ultrasound-directed amniocentesis in later pregnancy permits an assessment of fetal lung maturity and of the fetus at risk for Rhesus immunization. Attention to detail should increase chances of a successful pregnancy outcome while decreasing neonatal morbidity and mortality.
Amniocentesis↗
Uterine and fetal Doppler flow changes from a single dose of a long-acting intranasal decongestant.
Oxymetazoline, an alpha-adrenergic agent, is the active vasoconstrictor in long-acting intranasal decongestants. This investigation studied the effects of oxymetazoline on the maternal and fetal circulations. Twelve healthy gravid patients in the third trimester (27-39 weeks) underwent flow velocity measurements by the same sonographer using a pulsed Doppler system (ATL Ultramark 4 machine). Maternal and fetal indices were recorded 15 minutes before dosing, immediately thereafter, and at 15-minute intervals during the first 2 hours after the drug was given. No significant changes were found in either the maternal blood pressures or pulse rates. Blood flow velocities did not change significantly from baseline for the uterine arcuate artery, fetal aorta, or umbilical artery circulations. In no case did absolute blood flow velocity decrease significantly or systolic/diastolic ratios elevate to worrisome values. For uncomplicated pregnancies, we conclude there are no significant acute changes in the maternal and fetal circulations after a single dose of intranasal oxymetazoline.
Administration, Intranasal↗
Perinatal outcome after a prolonged second stage of labor.
It is commonly held that the second stage of labor should last no more than two hours because of an apparently increased risk of morbidity. The purpose of this investigation was to determine whether this commonly held notion is true in this era of close fetal monitoring and umbilical blood gas determination. Between May 1987 and October 1988, 50 (3.5%) of 1,432 uncomplicated term pregnancies ended in delivery after a second stage of labor lasting greater than 120 minutes. A prolonged second stage was associated more commonly with nulliparity, occiput posterior positioning, epidural anesthesia and a need for operative delivery but not birth weight greater than 4,000 g or a short umbilical cord. Infants born after a prolonged second stage did not have an increased incidence of umbilical artery pH less than 7.20 or of five-minute Apgar scores less than 7, nor did they need intensive care nursery admission. A prolonged second stage of labor appears not to impose an increased hazard on the fetus but does require close fetal monitoring and increases the possibility of operative delivery.
Apgar Score↗
Cervical ripening. A retrospective experience with prostaglandin E2 "chips".
To improve the unfavorable cervix we instituted a policy of cervical ripening with "chips" of prostaglandin E2 suppositories. A standard, 20-mg suppository was cut into six equal parts, and one of the chips was inserted just inside the vaginal introitus every four to six hours. Repeat doses were utilized if no cervical change was evident and uterine activity was minimal. All the patients underwent continuous monitoring in the labor-and-delivery unit. Fifty patients with Bishop's scores of less than 4 underwent cervical ripening for a variety of obstetric indications. Forty-two patients (84%) achieved vaginal delivery. Three patients underwent cesarean delivery for fetal distress unrelated to hyperstimulation. Two additional patients experienced hyperstimulation; one of them required subcutaneous terbutaline. No other neonatal or maternal complications were encountered. Cervical ripening with prostaglandin chips may be a reasonable clinical alternative when one is faced with an obstetric indication for delivery in a patient with an unfavorable cervix.
Adult↗
Reliability of compact electronic blood pressure monitors for hypertensive pregnant women.
Self-monitoring of blood pressure is an asset to managing hypertensive pregnant women on an outpatient basis. Many brands of electronic blood pressure devices are now available for use during pregnancy. An investigation was undertaken to compare the relative accuracy and acceptability of four of the least expensive and most compact units (Sunbeam III, Norelco, Lumiscope and Marshall). The reliability of the devices was compared with simultaneous measurements using a Dinamap 845A monitor on 22 pregnant hypertensive women. All measurements were performed without difficulty by a skilled observer and the patients. The accuracy varied, but each electronic device was considered as accurate as a mechanical aneroid unit available at the same retail stores. The advantages of these electronic units were ease of application and readability of the measurements without the need for a stethoscope or an assistant.
Adult↗
Lipid hydroperoxy and hydroxy derivatives in copper-catalyzed oxidation of low density lipoprotein.
Oxidation of low density lipoprotein (LDL) causes changes in the biological properties of LDL that may be important in atherogenesis. That LDL oxidation is accompanied by lipid peroxidation has been demonstrated, but previous analyses of the products of LDL oxidation have not included measurement of specific lipid hydroperoxy and hydroxy derivatives. In this study, LDL was isolated from plasma of normal volunteers and exposed to oxygenated buffer and 5 microM CuSO4 for 24 h. Oxidized LDL showed decreased linoleate (18:2) and arachidonate (20:4) content with increased concentrations of thiobarbituric acid reactive substances (TBARS) and hydroxy and hydroperoxy 18:2 and 20:4. The electrophoretic mobility of the LDL protein also was increased by oxidation. After reduction, the hydroxy fatty acids were characterized by gas chromatography-mass spectrometric analysis of the trimethylsilyl ether methyl ester derivatives. The hydroperoxy and hydroxy derivatives accounted for approximately 70% of the linoleate consumed during LDL oxidation and represented 45-fold more product than was measured by TBARS analysis. Numerous biological properties, including cytotoxic and chemoattractant activities of hydroperoxy and hydroxy fatty acids, have been reported, but the manner in which they may contribute to atherogenesis requires further study.
Arachidonic Acids↗
Glutathione disulfide formation and lipid peroxidation during cardiac ischemia and reflow in the dog in vivo.
The content of glutathione disulfide (GSSG) in tissue, coronary sinus blood plasma, and in cardiac lymph was measured in a well-characterized model of regional cardiac ischemia and reflow in dogs in vivo in order to assess the magnitude of the oxidant stress produced. No increase in GSSG content was observed during 60 min of occlusion of the circumflex or left anterior descending arteries, or during up to 70 min of reflow. The contents of 11-, 12-, and 15-hydroxyeicosatetraenoates (HETEs) in total lipids also were not increased following 60 min of regional ischemia and up to 60 min of reflow. In addition, global ischemia produced by aortic crossclamping and cardiopulmonary bypass did not increase HETE content. In contrast, infusion of tertiary butyl hydroperoxide (tBHP) into the left atrium produced readily measurable increases in GSSG content with or without prior induction of myocardial ischemia. Infusion of tBHP also increased tissue contents of the HETEs. These findings indicate that the canine myocardium subjected to ischemia-reflow conditions does not generate large amounts of reactive oxygen and does not form significant amounts lipid peroxidation products.
Animals↗
Formation of pentane versus 1-pentanol in the ferrous sulfate-initiated decomposition of 15-hydroperoxyeicosatetraenoic acid in hypoxic and hyperoxic conditions.
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Chemical Phenomena↗
Effect of acetaminophen on hepatic content and biliary efflux of glutathione disulfide in mice.
The increased expiration of ethane and pentane by mice treated with hepatotoxic doses of acetaminophen suggests the possibility of oxidant mechanisms associated with the necrosis. However, studies in rats are not consistent with oxidant stress mechanisms causing the damage, because acetaminophen given to rats does not increase GSSG efflux, a sensitive index of intrahepatic oxidant stress. To compare the extent of oxidant stress generated by acetaminophen in mice versus rats, hepatic content and biliary efflux of GSSG and GSH in mice have been examined. Bile was collected from anesthetized male ICR mice before and after intraperitoneal administration of acetaminophen (325 mg/kg, 2.15 mmol/kg), t-butyl hydroperoxide (TBHP) (1.5 mmol/kg), diethyl maleate (400 mg/kg, 2.33 mmol/kg, in corn oil) or saline (control) and GSH and GSSG were measured by the enzymatic recycling method of Tietze. An increase in biliary GSSG efflux was produced by t-butyl hydroperoxide, but not by the other agents. Biliary GSH/GSSG ratios decreased in acetaminophen-treated animals, presumably reflecting the marked depletion of hepatic GSH, since a similar decrease was observed with non-hepatotoxic doses of diethyl maleate. The failure of acetaminophen to increase the hepatic content or biliary efflux of GSSG in ICR mice is not consistent with the view that oxidant stress mechanisms cause the damage, despite the increases in alkanes expired after acetaminophen administration in this specific animal model.
Acetaminophen↗
Diquat hepatotoxicity in the Fischer-344 rat: the role of covalent binding to tissue proteins and lipids.
Diquat produces hepatic necrosis in the Fischer-344 rat, and although reactive oxygen species generated by redox cycling are thought to mediate the damage, the possibility that covalent binding of diquat or diquat metabolites to tissue macromolecules contributes to the observed hepatotoxicity of diquat needed to be examined experimentally. Intraperitoneal administration of [ethylene-14C]diquat (0.1 mmol/kg) results in distribution of radioactivity to all organs examined. Measurable radioactivity remains associated with hepatic and renal protein even after extensive solvent extraction, but the amount (12-16 pmol/mg protein) is 100-fold less than the extent of covalent binding observed with comparably hepatotoxic doses of other hepatotoxins such as acetaminophen and bromobenzene. Similarly, although small amounts of radioactivity remain in Folch lipid extracts of liver and kidney (56-179 pmol/mg lipid), this is virtually completely removed by transesterification of the lipid (less than 5 pmol/mg lipid), indicating that the radioactivity does not represent an alkylation of electroneutral alkyl residues of the lipid. The diquat-induced increase in biliary excretion of glutathione disulfide temporally parallels the biliary excretion of radioactivity. Although the present results do not prove the absence of a contribution by alkylation mechanisms to diquat hepatotoxicity, the extremely low upper limits placed on possible covalent interactions reinforce the confidence with which the diquat-treated Fischer-344 rat can be employed as an animal model for mechanisms of cell death mediated by reactive oxygen species.
Animals↗
Schistosomiasis associated with rupture of the appendix in pregnancy.
Acute appendicitis is among the most common indications for exploratory laparotomy during pregnancy. Although usually pyogenic in origin, parasitic infections account for a small percentage of cases. We report here the association of pregnancy and appendicitis caused by Schistosoma japonicum. Schistosomiasis is a very common complication of pregnancy, with 250,000,000 persons infected worldwide, including 20% of pregnant women living in hyperendemic areas. Schistosome egg masses can lodge throughout the body and cause acute inflammation of the appendix, fallopian tube, liver, and spleen. Congestion of pelvic vessels during pregnancy facilitates passage of eggs into the villi and intervillous spaces, causing an inflammatory reaction. Fetal anoxia and subsequent death has been attributed to heavy infestation of the placenta. Tourism, far-ranging military actions, and immigration make this disease a potential challenge for practitioners everywhere.
Adult↗