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Biomedical subjects

J G Quirk

Publications and source records attributed to J G Quirk.

At least 19 recordsLinked to original sources

MR imaging in high-risk obstetric patients: a valuable complement to US.

The accuracy of prenatal diagnosis has become increasingly critical in the field of high-risk obstetrics. Although ultrasound (US) provides adequate information in most cases and continues to be the initial prenatal examination of choice, there are instances in which the results of the US study may be equivocal. The role of magnetic resonance (MR) imaging was explored in 27 selected patients with various indications to determine its effectiveness as a complement to US. MR imaging was most helpful in the diagnosis of extrauterine gestation, evaluation of placental position, determination of extent or nature of masses associated with pregnancy, and differentiation between diaphragmatic hernia and a thoracic mass. Although MR imaging did not add information that affected the accuracy of the diagnosis of oligohydramnios, in all other cases it provided an extra dimension in diagnosis by showing clearer anatomic relationships in the pelvis. It has proved to be a valuable complement to an equivocal US study.

Diagnosis, Differential

Alteration in age-specific risks for chromosomal trisomy by maternal serum alpha-fetoprotein and human chorionic gonadotropin screening.

Maternal serum screening for alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) increases the detection rate of Down's syndrome (DS) pregnancies. To estimate the risk of a DS pregnancy for a particular woman, Wald et al. combine a trivariate function of AFP, hCG, and unconjugated oestriol with age-specific risk. Calculation of independent likelihood ratios (LRs) for AFP and hCG has allowed us to examine the predictive value of each test alone and the combination. AFP and hCG were measured in stored serum samples from 672 normal, 8 trisomy 21 (DS), 9 trisomy 18, and 2 trisomy 13 pregnancies. AFP and hCG multiples of the median (MOM) were calculated for each sample. The LRs for AFP MOM and hCG MOM were calculated and combined with age-specific risk. Of eight DS pregnancies, six had increased risk based on age and AFP. Addition of hCG detected two additional DS pregnancies. Of nine trisomy 18 pregnancies, four (44 per cent) had hCG MOM under 0.25. Three out of nine would have been classified as high risk by AFP, but none by combined AFP and hCG. Amniocentesis would have been recommended in 74 per cent of aneuploid pregnancies if both age and serum screening were used. Abandonment of amniocentesis based on age alone would have excluded two abnormal pregnancies from detection. Screening programmes should note that combined risk figures are specific for DS and do not include other trisomies. Detection of other trisomies requires inclusion of low hCG level as a discriminator and continuation of age-based testing.

Age Factors

New monoclonal antibodies identify the glycoprotein carrying the CA 125 epitope.

CA 125 is an antigenic determinant located on the surface of ovarian carcinoma cells and elevated in the serum of greater than 90% of patients with carcinoma. The antigen, derived from the ovarian epithelium, has been described as a mucinlike glycoprotein greater than 200 kd. To date little is known of the metabolic regulation or expression of this antigen in either normal or neoplastic tissues. New monoclonal antibodies that we describe here recognize both unique and similar epitopes to OC 125. These reagents may allow for a more complete definition of the structure and expression of the CA 125 complex. These antibodies recognize high-molecular weight (greater than 200 kd) subspecies and a lower-molecular-weight (68 kd) subspecies of the antigen and identify it in the cytoplasm and the extracellular matrix of CA 125-producing cells.

Animals

The N-terminal and C-terminal portions of the atrial natriuretic factor prohormone increase during preeclampsia.

The influence of preeclampsia on the circulating concentrations of the 28-amino-acid carboxy terminus (C-terminus) (i.e., atrial natriuretic factor) and the amino terminus (N-terminus) of the 126-amino-acid atrial natriuretic factor prohormone (pro ANF) was studied in the third trimester with the use of three specific radioimmunoassays that recognize: (1) atrial natriuretic factor (i.e., amino acids 99 to 126), (2) the whole 98-amino-acid N-terminus, and (3) amino acids 31 to 67 from the midportion of the N-terminus of the prohormone. The C-terminus was significantly increased (p less than 0.001) in the third trimester in women with preeclampsia, the mean +/- SEM of 15 subjects was 150 +/- 7 pg/ml versus 89 +/- 7 pg/ml in the third trimester in 12 women during normal pregnancies and 65 +/- 2 pg/ml in 19 healthy nonpregnant women. The whole 98-amino-acid N-terminus, likewise, was significantly increased (p less than 0.001) in women with preeclampsia to 4706 +/- 629 pg/ml versus 2160 +/- 79 pg/ml in women in the third trimester of normal pregnancies and versus the circulating concentration of 1847 +/- 127 pg/ml in healthy nonpregnant women. ProANF 31 to 67 mean circulating concentration in preeclampsia was 4638 +/- 725 pg/ml, which was also significantly (p less than 0.001) increased compared with its mean circulating concentration in the third trimester of normal pregnancy of 1758 +/- 83 pg/ml or that in healthy nonpregnant women (1400 +/- 105 pg/ml). The circulating concentrations of both the N-terminus and C-terminus of the atrial natriuretic factor prohormone decreased within 24 hours after delivery in contrast to a normal pregnancy in which they both increase post partum. These results indicate a marked difference in the metabolism of both the N-terminus and the C-terminus of the atrial natriuretic factor prohormone in women with preeclampsia versus that in women with normal pregnancies or that in healthy nonpregnant women.

Adolescent

How do perinatologists manage preeclampsia?

The members of the Society of Perinatal Obstetricians were surveyed regarding management of preeclampsia, with focus on drug therapy, use of invasive monitors, and both general policies and treatment of hypothetical cases of preterm severe preeclampsia. There was agreement that magnesium sulfate should be given to all patients with preeclampsia during labor and postpartum and that blood pressure should be held to about 160/105 mmHg. The drugs of choice for control of blood pressure were hydralazine, alpha-methyldopamine, and cardioselective beta-blockers. Most perinatologists use invasive monitors only for specific indications, but a substantial minority use either arterial lines or central venous pressure monitors routinely in severe preeclampsia. There was no consensus with respect to management of preterm, severe preeclampsia, but even among the 49% of respondents who volunteered an unequivocal policy of "deliver regardless of gestational age," over three fourths would hospitalize and observe in selected cases meeting American College of Obstetrics and Gynecology criteria for severe preeclampsia.

Adrenergic beta-Antagonists

Landry Guillain-Barré Strohl syndrome in pregnancy: report of three cases treated with plasmapheresis.

Landry Guillain-Barré Strohl syndrome complicating pregnancy is a rare occurrence, with only 31 cases previously reported in the obstetric literature. Cytomegalovirus as a potential etiologic agent has been documented in only two of these cases. In the past, symptomatic treatment of pregnant patients with severe and progressive symptoms has been associated with an unacceptably high rate of maternal morbidity and mortality. Recent studies have shown convincingly that plasmapheresis is the treatment of choice for nonpregnant patients acutely ill with Guillain-Barré syndrome, but data regarding its use in pregnancy are limited. We report three patients, two of whom had positive cytomegalovirus titers, in whom aggressive plasmapheresis prevented the need for ventilatory support and its inherent increase in maternal morbidity and mortality.

Adult

Second-trimester ultrasonography: determinants of visualization of fetal anatomic structures.

Little information has been published regarding rates of visualization of fetal anatomic structures or factors affecting visualization in unselected patients. We prospectively studied these points by scoring visualization of intracranial, spinal, cardiac, ventral wall, umbilical cord, stomach, bladder, and genital anatomy in 573 consecutive midtrimester scans in which no fetal anomalies were seen. Each feature was scored 0, 1, or 2, corresponding to poor, adequate, or optimal visualization, and these eight numbers were summed for an overall visualization score. Overall visualization fell abruptly beyond maternal weight 165 pounds (p less than 0.001) and rose with advancing gestational age (p less than 0.001). Placental location did not significantly influence visualization. Overall, an adequate screening scan, defined as adequate visualization of central nervous system, heart, stomach, ventral wall, bladder, and cord was obtained in 51% of scans, and optimal visualization of each of these in only 9% of cases. Factors that might improve anatomic visualization and the implications of these results for the use of ultrasonography in screening for congenital anomalies are discussed.

Amniocentesis

Distribution of CA 125 in embryonic tissues and adult derivatives of the fetal periderm.

New murine monoclonal antibodies to a partially purified CA 125 antigen were developed and identified as M 2 and M 11. With immunohistochemical techniques, these new antibodies and OC 125 antibody were used to search for CA 125 in embryonic tissues and adult apocrine sweat glands and mammary glands. The embryonic skin, the periderm, expressed CA 125 antigen and its adult derivatives, the mammary glands and apocrine sweat glands, expressed CA 125 while in the active state of secretion. In a 6-week-old formalin-fixed and paraffin-embedded ectopic embryo specimen, antibodies M 2 and M 11 recognized CA 125 in the periderm, the notochord, the myocardium, the pericardium, the gastroenteric tract, enteric duct remnants in the umbilical cord (vitelline and allantoic ducts), the mesonephric duct, and the amnion. OC 125 staining of these formalin-fixed specimens was either very faint or absent. In a formalin-fixed and paraffin-embedded specimen of apocrine sweat glands from the axilla, antibodies M 2 and M 11 detected CA 125 antigen intracellularly in the secretory cells. Again no staining was observed with OC 125 antibody. In a frozen and acetone-fixed specimen of lactating mammary glands, antibodies M 2 and OC 125 detected CA 125 antigen intraductally. Colostrum and milk collected from 25 mothers at various stages post partum had mean CA 125 levels of 34,213 U/ml in colostrum, 1469 U/ml at 3 to 7 days, and 105 U/ml at 5 to 26 weeks.

Amnion

Increase in the plasma levels of the N-terminal and C-terminal portions of the prohormone of atrial natriuretic factor during normal pregnancy.

The influence of pregnancy on the circulating concentrations of atrial natriuretic factor, the 28 amino acid carboxy (C)-terminal end of the 126 amino acid atrial natriuretic factor prohormone, and the amino (N)-terminus of the prohormone was studied with three specific radioimmunoassays recognizing: (1) atrial natriuretic factor (i.e., amino acids 99 through 126), (2) the 98 amino acid N-terminus, and (3) amino acids 31 through 67 from the midportion of the N-terminus of the prohormone. Plasma atrial natriuretic factor in normal pregnant women gradually increased as pregnancy progressed, with the mean +/- SEM being 58 +/- 4 pg/ml in the first trimester, 74 +/- 5 pg/ml in the second trimester, and 89 +/- 7 pg/ml in the third trimester. Likewise, proatrial natriuretic factor 31 through 67 increased from 1421 +/- 76 pg/ml (first trimester) to 1509 +/- 84 pg/ml (second trimester) to 1758 +/- 83 pg/ml in the third trimester, whereas the whole N-terminus of the prohormone increased from 1804 +/- 98 pg/ml (first trimester) to 1909 +/- 111 pg/ml (second trimester) to 2160 +/- 79 pg/ml in the third trimester. These results suggest that release of the N-terminus of the prohormone, as well as atrial natriuretic factor, increases with the rise in blood volume associated with a normal pregnancy. The circulating concentrations of both the C-terminus and N-terminus of the atrial natriuretic factor prohormone increased further in the 48 hours after delivery. Because both the C-terminus and N-terminus of the atrial natriuretic factor prohormone contain diuresis-producing peptides, these results suggest that postpartum diuresis may be mediated by these peptides.

Analysis of Variance

Amniotic and thromboembolism.

Embolic phenomena in pregnancy demand rapid investigation and treatment. Regardless, some patients will not survive due to the enormity of the insult. Optimally, such patients should be treated in tertiary care centers, but this is not always possible.

Embolism, Amniotic Fluid

Expression of the ras oncogene in gynecologic tumors.

Control of oncogene expression has been shown to be a coordinated regulatory mechanism in normal growth and development. Overt expression of these genes also has been noted in transformed or neoplastic cell types. The ras family of oncogenes has been shown to be particularly evident among genes expressed in malignant tissues. We provide evidence, using ribonucleic acid dot analysis and Western blot analysis of gynecologic tumor extracts, that ras expression may be a common occurrence in these malignancies. Furthermore, the ras-related peptides can be detected in sera of some patients with tumors.

Electrophoresis, Polyacrylamide Gel

Fetal teratomas: antenatal diagnosis and clinical management.

Four cases of fetal teratomas arising from the sacrococcygeal and oropharyngeal areas are reported. The diagnosis, method of management, and grade of tumor are compared with previous experience in the literature. Pharyngeal lesions carry a worse prognosis for survival compared to the more common sacrococcygeal type (SCT). Atraumatic delivery and early repair of the lesion contribute to prolonged survival and lack of complications in cases of sacrococcygeal teratomas.

Adult

Prenatal diagnosis of abdominal cystic hygroma.

We present a case of fetal abdominal cystic hygroma that presented at 19 weeks of gestation. Ultrasonographic evaluation of the fetus revealed soft tissue enlargement of the left leg and a retroperitoneal mass in the left pelvis and abdomen. This represents the first reported case of prenatal diagnosis of abdominal cystic hygroma.

Abdominal Neoplasms

ras oncogene is expressed in adenocarcinoma of the endometrium.

Activation of c-ras oncogenes has been implicated in human carcinomas of the colorectum, prostate, bladder and breast. The major peptide product of c-ras is a 21 kilodalton peptide (p21), but other larger "ras-related" peptides have been described in urine obtained from patients with several types of cancers. In the present investigation immunohistochemical methods were used to assess c-ras expression in tissues obtained from patients with endometrial adenocarcinoma. Formalin-fixed, paraffin-embedded tissues were processed in routine fashion, then incubated with a monoclonal antibody raised against a v-H-ras synthetic peptide. ras Peptides were not detected in proliferative or secretory endometrium or in benign adenomatous hyperplasia. One of four specimens of atypical adenomatous hyperplasia and two of 11 specimens of grade 1 (international Federation of Gynecology and Obstetrics) adenocarcinoma stained positive for ras peptides. A total of 95% of the grade 2 and 3 adenocarcinoma studied contained detectable ras peptides within neoplastic cells. In contrast to previous immunohistochemical studies that identified ras peptides only in neoplastic cells of bladder, prostate, colon, and breast cancers, we routinely found ras peptides within stromal cells of high-grade endometrial carcinomas. When stained with hematoxylin and eosin, these cells have the appearance of foamy macrophages.

Adenocarcinoma