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Biomedical subjects

R C Cefalo

Publications and source records attributed to R C Cefalo.

At least 73 records · Page 4Linked to original sources
PubMed1987

Single-probe spectrophotometry in the assessment of fetal oxygenation.

Six sheep fetuses were monitored with a single-probe tissue spectrophotometer. This spectrophotometer provides continuous digital output of the index of hemoglobin that is saturated with oxygen. To vary the fetal pO2, each maternal ewe was given room air, 100% oxygen, 12% oxygen, and 100% nitrogen via rebreathing bag. Fetal venous (N = 4) or arterial (N = 2) blood was analyzed for pO2. There was excellent correlation between the index of hemoglobin saturated with oxygen and the fetal pO2. The single-probe spectrophotometer overcomes two of the technical problems encountered when a double-probe spectrophotometer is used.

Animals↗
PubMed1986

Detection of smoking-related covalent DNA adducts in human placenta.

The presence of covalent DNA chemical addition products (adducts) in human term placentas was investigated by recently developed immunologic and 32P-postlabeling assays. DNA from placental specimens of smokers showed a small but not statistically significant increase in adduct levels when tested by antibodies to DNA modified with a benzo[a]pyrene dihydrodiol epoxide (BPDE-I), the ultimate carcinogenic derivative of benzo[a]pyrene. The postlabeling assay detected several modified nucleotides, one of which (adduct 1) strongly related to maternal smoking during pregnancy. This adduct was present in placental tissue from 16 of 17 smokers, but only 3 of 14 nonsmokers. Among smokers, levels of adduct 1 in general were only weakly related to questionnaire and biochemical measures of the intensity of smoking exposures, which suggests modulation by individual susceptibility factors. The adduct seemed to be derived from an aromatic carcinogen, but it may not result from several of the most intensely studied polycyclic aromatic hydrocarbons or aromatic amines in tobacco smoke. The data show the association of cigarette smoking with covalent damage to human DNA in vivo.

Carcinogens↗
PubMed1986

The cardiorespiratory effects of perfluorochemicals on acute carbon monoxide poisoning in the pregnant ewe.

Studies in nonpregnant animal models of carbon monoxide poisoning have demonstrated the protective effect of perfluorochemicals. Anesthetized pregnant ewes were exposed to carbon monoxide. After symptoms of toxicity were demonstrated, group 1 animals were respired with room air. Group 2 animals respired room air and were given intravenous perfluorochemicals. Group 3 animals were administered 100% oxygen. Group 4 animals were given intravenous perfluorochemicals and respired 100% oxygen. In all ewes exposure to carbon monoxide resulted in increased cardiac output, heart rate, and carboxyhemoglobin level without a significant change in arterial oxygen tension. After carbon monoxide exposure, there was no significant difference in the carboxyhemoglobin to oxyhemoglobin conversion between groups 1 and 2 although the conversion rates were more rapid in groups 3 and 4. Fetal oxygenation was improved in groups 3 and 4. All fetal lambs exhibited a progressive increase in carboxyhemoglobin and a decrease in venous pH regardless of the maternal postexposure treatment. There was no significant increase in the fetal venous oxygen content of group 4 as compared with that of group 3, suggesting that the adjunctive administration of limited quantities of perfluorochemicals to the mother offers no apparent advantage over 100% oxygen alone for acute fetal resuscitation.

Animals↗
PubMed1986

The effects of fetal exchange transfusion with a red blood cell substitute.

Isovolemic exchange transfusion in the fetal lamb in utero was performed with the use of Fluosol-DA (20%), a perfluorochemical erythrocyte substitute. With maternal hyperoxygenation, a physiologic PO2 was maintained in the fetal lambs, although the total fetal oxygen content decreased as the hematocrit dropped. Because of the oxygen-carrying properties of the perfluorochemical emulsion, the fraction of fetal oxygen carried in the dissolved state increased significantly when compared with that in controls that received saline solution.

Animals↗
PubMed1986

Femur length versus biparietal diameter for estimating gestational age in the third trimester.

It is well established that ultrasound measurement of femur length and biparietal diameter are comparably accurate estimators of gestational age when obtained in the first half of pregnancy. Both estimators, however, become less accurate later in pregnancy. The present study compares the relative accuracy of these estimators when obtained in the third trimester. It is concluded from linear regression analysis that the correlation between gestational age estimated from femur length and the actual gestational age is stronger than that between gestational age estimated from biparietal diameter and actual gestational age. Furthermore, gestational age calculated from femur length is significantly more likely to be within 2 weeks (P less than or equal to .01) and 3 weeks (P less than or equal to .05) of actual gestational age than is gestational age calculated from biparietal diameter. Estimating gestational age from the mean of the gestational age based on biparietal diameter and that based on femur length is less accurate than estimating gestational age from femur length alone.

Cephalometry↗
PubMed1986

Fatal influenza A pneumonia in pregnancy.

Today, influenza A infections are an uncommon cause of maternal morbidity and mortality. This is a report of a 20-year-old pregnant woman who died from pneumonia caused by influenza A/Philippines/1982. The decreased immune system and respiratory functions of pregnancy make pregnant women especially susceptible to having a complicated influenza infection, though such infections probably do not directly threaten the fetus. The use of influenza immunizations and antiviral medication during pregnancy is discussed.

Adult↗
PubMed1986

The relationship between mean abdominal diameter and femur length in normal and impaired fetal growth.

The relationship of fetal mean abdominal diameter (MAD) to fetal femur length (FL) in clinically normal pregnancies and 37 cases of intrauterine growth retardation (IUGR) was studied. The normal relationship of FL to MAD is closely described by the equation: log (MAD) = 3.326 + (0.185 X FL). r = .953, P less than .001. In the growth retarded infants, 59% of the abdominal measurements fell below the lower 75% confidence limit. Of the abdominal measurements derived from infants with birthweight greater than 2 SD below the mean for gestational age, 86% fell below the lower 75% confidence limit. These data show the MAD is selectively depressed in many, but not all cases of IUGR and particularly in the more severely affected infant, but the technique is not sufficiently discriminant to be used by itself for the detection of IUGR. Detection of an anomaly of this relationship would be strong supportive evidence of IUGR independent of gestational age and possibly identifies infants growth retarded specifically due to chronic deprivation.

Abdomen↗
PubMed1986

Elevated second trimester maternal serum alpha-fetoprotein and cytomegalovirus infection.

A case is presented of intrauterine cytomegalovirus infection. Initially, the infection was most probably manifested by elevated second trimester maternal serum alpha-fetoprotein levels. Placental involvement by the infectious agent may have produced the elevations in maternal serum. Alpha-fetoprotein elevation unrelated to fetal anatomic abnormalities, twins, or incorrect dates may represent a potential marker of placental pathology.

Adolescent↗
PubMed1986

Absence of estrogenic activity in some drugs commonly used during pregnancy.

Treatment of pregnant women with estrogenic compounds such as diethylstilbestrol (DES) has been associated with genital tract abnormalities in their male and female offspring. Since these data suggest the developing fetus is highly susceptible to the tumorigenic and dysmorphogenic effects of estrogenic substances, knowledge of the estrogenic activity of some drugs commonly used during pregnancy is important. Based on structural similarities to other known estrogenic compounds and to the frequency of use among pregnant women, phenobarbital, saccharin and acetaminophen were assayed for estrogenic activity; DES was used as a positive control. Using a competitive receptor binding assay, these compounds did not show appreciable binding to a soluble uterine receptor preparation while DES showed strong binding interactions. Analysis of the compounds in an in vivo uterotropic bioassay using immature female mice showed that, over the dose range used (5 micrograms/kg-50 micrograms/kg), only DES had any estrogenic activity while the other compounds were negative. Therefore, phenobarbital, saccharin and acetaminophen did not display estrogenic activity under the conditions of test.

Acetaminophen↗
PubMed1985

Effect of maternal intravenous infusions on fetal extracellular fluid composition in pregnant ewes.

Infusion of intravenous solutions to women in labor is common clinical practice. Since these infusions may change the volume and electrolyte balance between the mother and fetus, we investigated the influence of acute maternal volume expansion upon fetal and maternal fluid and electrolyte equilibrium in the chronically catheterized fetal lamb. Paired measurements of maternal and fetal plasma sodium and potassium concentrations, osmolality, and colloid osmotic pressure (COP), plus measurements in the fetal-placental plasma volume were obtained following rapid maternal infusions with saline, dextrose, and dextran solutions. Maternal infusions resulted in changes in fetal electrolyte concentrations as well as alterations in transplacental COP differences. Despite these changes, however, no changes in fetal plasma volume were noted.

Animals↗
PubMed1985

Amniotic fluid embolism. Three case reports with a review of the literature.

Amniotic fluid embolism is a catastrophic event of the intra- and early postpartum period which may also be seen with cesarean delivery and during abortions. Presenting symptomatology includes respiratory distress with cyanosis, shock, and possibly tonic-clonic seizures. DIC frequently occurs. The pathogenesis may include entry of amniotic fluid through lacerations or ruptures of the uterus or cervix, through endocervical veins and through abnormal uteroplacental sites, such as with placental abruption, placenta previa, or placenta accreta. Amniotic fluid probably causes cardiovascular-respiratory symptoms by pulmonary vascular obstruction and through a vasoactive substance causing pulmonary vascular constriction. The lethality of amniotic fluid may be enhanced by a high particulate content or meconium staining. The diagnosis of amniotic fluid embolism may be made ante mortem by demonstrating amniotic fluid debris in central blood samples or expectorated sputum. Postmortem diagnosis often requires meticulous examination of the pulmonary microvasculature with the utilization of special stains. Treatment is directed towards symptoms of shock, arterial hypoxemia, and DIC. Acute renal failure may complicate the picture after shock. If the patient survives the embolic and coagulative problems, recovery is usually complete without long-term sequelae.

Abortion, Missed↗
PubMed1985

Prenatal detection of intraamniotic bands: implications and management.

The prenatal diagnosis of intraamniotic bands with confirmation at delivery is presented, and the pertinent literature is reviewed. The significance of intrauterine membranes or bands detected during pregnancy is not known. Direct fetal involvement by these structures has been reported in only one instance, but malformations apparently unrelated to amniotic bands have been common among reported cases. Serial ultrasound examinations are recommended both to exclude pseudosac, extrachorionic hemorrhage, blighted twin, and other possible causes of membranous structures and to search for fetal abnormalities.

Adult↗
PubMed1985

Thrombotic thrombocytopenic purpura in early pregnancy.

Thrombotic thrombocytopenic purpura during pregnancy in which both mother and fetus have survived has been an exceedingly rare occurrence, due at least in part to the difficulty in distinguishing this uncommon disease from hematologic complications of preeclampsia. In the nonpregnant patient, the use of plasma infusion or exchange plasmapheresis as therapy of choice has resulted in a dramatic increase in survival. By using more specific criteria than the classical clinical pentad, the diagnosis of thrombotic thrombocytopenic purpura during pregnancy can be made with greater accuracy. The first known instance of the successful use of exchange plasmapheresis leading to the survival of both mother and fetus in thrombotic thrombocytopenic purpura clearly not secondary to preeclampsia is reported.

Adult↗
PubMed1984

The relationship of intracranial infrared light absorbance to fetal oxygenation. I: Methodology.

Current clinical methods for assessing fetal oxygenation in labor are indirect and remain somewhat imperfect. Since infrared light passes through the cranium and infrared light absorbance by tissues has been shown in adult animals to vary with oxygenation, monitoring of infrared light absorbance may serve as the basis for a new, more direct technique for the assessment of fetal condition. Described here is the application of infrared reflectance spectrophotometry to a fetal sheep model and the precision of the relationship between fetal arterial or venous PO2 and infrared light absorbance at selected wavelengths. A very strong, linear correlation (r = 0.915) was found between fetal arterial PO2 and intracranial infrared light absorbance according to an algorithm developed for selective monitoring of the state of hemoglobin oxygenation in tissue. With further development, this method holds promise for a more direct, noninvasive assessment of fetal condition in labor than is currently available.

Absorption↗
PubMed1984

Maternal and fetal effects of exchange transfusion with a red blood cell substitute.

Recent reports have demonstrated the efficacy of Fluosol-DA (20%) as a temporary erythrocyte substitute. We investigated two groups of pregnant ewes that underwent exchange transfusion. In group 1, the animals underwent a nearly total isovolemic exchange of Fluosol-DA (20%) for maternal whole blood; in group 2, the red blood cells were removed and the plasma along with Ringer's lactate was replaced isovolumetrically. Although group 1 animals received 100% oxygen and Fluosol-DA (20%), the maternal arterial P02 increased to 350 to 400 torr. However, the maternal blood oxygen content decreased during the exchange, with no change in fetal pH, Pco2, or hematocrit. Maternal blood pressure remained stable and there was a 40% to 50% increase in cardiac output and mean pulmonary arterial pressure. During the exchange, the maternal hematocrit decreased from a mean of 32% to 5.5%; the maternal fluorocrit at the end of the exchange was 9%. Throughout the Fluosol-DA (20%) exchange, the proportion of fetal brain oxyhemoglobin as estimated from infrared transcranial transmittance increased, as did the fetal blood P02 and oxygen content. In group 2, the maternal mean blood pressure decreased, and the hematocrit decreased from a mean of 32% to 8%. Despite an increase in the maternal P02 to 250 torr, the fetal P02 and oxygen content decreased in group 2. This investigation demonstrated that Fluosol-DA (20%) exchange of the mother does not impair delivery of oxygen to the fetus under the conditions of the study.

Animals↗