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Biomedical subjects

J R Barton

Publications and source records attributed to J R Barton.

At least 73 records · Page 4Linked to original sources

Nonimmune hydrops fetalis associated with maternal infection with syphilis.

Intrauterine infection with syphilis was diagnosed by reactive maternal serologic studies, ultrasonographic findings, and exclusion of other causes in three hydropic fetuses at 31, 34, and 35 weeks' gestation. With penicillin therapy and preterm delivery all infants survived through the perinatal period. Intrauterine infection that follows syphilis is a potentially treatable cause of nonimmune hydrops.

Adolescent↗

Baking powder pica mimicking preeclampsia.

We report a case of baking powder pica during pregnancy that was associated with maternal hypertension, hypokalemia, and elevated liver function tests. After discontinuation of baking powder ingestion and correction of electrolyte abnormalities, the blood pressure and the liver function tests normalized.

Adult↗

A randomized prospective comparison of nifedipine and bed rest versus bed rest alone in the management of preeclampsia remote from term.

OBJECTIVE: The objective of our study was to test the hypothesis that treatment with nifedipine for mild preeclampsia remote from term reduces the number of days of maternal hospitalization and improves pregnancy outcome. STUDY DESIGN: A total of 200 patients at 26 to 36 weeks' gestation were randomly allocated to treatment with either bed rest alone (n = 100) or bed rest in combination with nifedipine (n = 100). RESULTS: Patients receiving nifedipine had significantly lower systolic (p < 0.0001) and diastolic (p < 0.0001) blood pressures during therapy. Severe hypertension as an indication for delivery was significantly (p < 0.05) more frequent in the bed-rest-alone group. The two study groups had similar average days of maternal hospitalization (12.6 +/- 7.9 vs 12.3 +/- 10.3) and pregnancy prolongation (22.3 +/- 13.5 vs 22.5 +/- 15.7). There were no differences between groups with respect to birth weight, incidences of small-for-gestational-age infants and preterm birth, number of days spent in special care unit, or cord blood gas measurement. CONCLUSION: Nifedipine therapy for preeclampsia reduces maternal blood pressure but does not reduce number of days of maternal hospitalization or improve perinatal outcome.

Bed Rest↗

Magnesium sulfate therapy in preeclampsia is associated with increased urinary cyclic guanosine monophosphate excretion.

OBJECTIVE: Our objective was to determine if maternal urinary cyclic guanosine monophosphate levels are altered in preeclampsia. STUDY DESIGN: Aliquots from 24-hour urine samples collected from 57 women with preeclampsia and 14 normotensive pregnant women in the third trimester of pregnancy were assayed for urinary cyclic guanosine monophosphate. Urinary cyclic guanosine monophosphate values were expressed per milligram of urinary creatinine to standardize for renal function. RESULTS: There was no difference in gestational age at time of urine collection between the two groups. Urinary cyclic guanosine monophosphate levels (mean +/- SD) were similar between normotensive and preeclamptic pregnant women (751 +/- 498 vs 632 +/- 363 pmol/mg urinary creatinine, respectively, p = 0.12). Preeclamptic women receiving magnesium sulfate had significantly higher levels of urinary cyclic guanosine monophosphate than those not receiving magnesium sulfate (786 +/- 360 vs 555 +/- 344 pmol/mg urinary creatinine, respectively, p = 0.02). CONCLUSIONS: These preliminary results indicated that cyclic guanosine monophosphate excretion increases in patients with preeclampsia during magnesium sulfate infusion. The vascular smooth muscle relaxation effects of magnesium sulfate may be mediated by directly increasing cyclic guanosine monophosphate production or indirectly through endothelium-derived relaxing factor.

Cyclic GMP↗

Cerebral imaging in eclampsia: magnetic resonance imaging versus computed tomography.

OBJECTIVES: Our objectives were to study the cerebral pathophysiology of eclampsia with the noninvasive technique of magnetic resonance imaging to compare the ability of magnetic resonance imaging to detect cerebral abnormalities in eclampsia with that of computed tomography. STUDY DESIGN: Twenty-four patients with eclampsia received both magnetic resonance imaging and computed tomographic scanning. RESULTS: Forty-six percent of the magnetic resonance imaging was abnormal and 33% of the computed tomography was abnormal. This higher incidence of abnormal magnetic resonance imaging scans was present in spite of the fact that they were obtained significantly longer after the patient's seizure activity. The most common abnormalities were cortisol, subcortical, and white matter edema. CONCLUSION: Magnetic resonance imaging and computed tomographic scan abnormalities in eclampsia are usually similar. Cerebral imaging is not necessary in patients with uncomplicated eclampsia.

Adolescent↗

Adult respiratory distress syndrome in pregnancy.

OBJECTIVE: Our objective was to determine the causes of adult respiratory distress syndrome in pregnancy, the treatment required, and maternal and perinatal outcomes. STUDY DESIGN: We examined a case series of 16 patients with adult respiratory distress syndrome initially treated in an obstetric intensive care unit. Criteria for the diagnosis were respiratory distress requiring mechanical ventilation and a lung injury score > 2.5. RESULTS: The incidence of adult respiratory distress syndrome in pregnancy was 1 per 2893 deliveries, occurring primarily in the third trimester. The causes were infection (n = 8), preeclampsia/eclampsia (n = 4), hemorrhage (n = 2), thrombotic thrombocytopenic purpura (n = 1), and smoke inhalation (n = 1). Most patients (69%) were delivered before or soon after admission to our hospital. Multiple organ failure developed in 12 patients (75%). Complications of mechanical ventilation occurred in 81% of cases. Other complications of intensive care unit support were endocarditis, superior vena cava thrombosis, line sepsis, and bacteremia. Maternal mortality was 44%; perinatal mortality was 20%. CONCLUSIONS: Adult respiratory distress syndrome in pregnancy is associated with a maternal mortality similar to that of studies in the nonpregnant patient. The main causes in pregnancy are hemorrhage, infection, and toxemia. All maternal deaths occurred in patients with multiorgan failure.

Critical Care↗

Immunosenescence and mucosal immunity: significant effects of old age on secretory IgA concentrations and intraepithelial lymphocyte counts.

Concentrations of immunoglobulins (Ig) and levels of isotype specific antibodies to three dietary antigens in serum, pure parotid saliva, and in intestinal secretions obtained by whole gut lavage from groups of healthy elderly subjects (aged greater than 70 years) and of younger adult controls (aged 25-50 years) were measured. In addition, counts of lamina propria and intra-epithelial lymphoid cells were performed in histologically normal jejunal biopsy specimens from elderly and younger subjects. Elderly subjects had significantly higher concentrations of serum and salivary IgA and of salivary IgM (both, p less than 0.01), and of salivary IgA antibodies than did the younger subjects, but the amount of immunoglobulin and antibody in whole gut lavage fluid was similar in the two age groups. Jejunal biopsy specimen cell counts showed higher IgA plasma cell counts and lower intraepithelial lymphocyte counts in the elderly group (p less than 0.01), with similar counts of IgM and IgG plasma cells, eosinophils, and mast cells in the two groups. There is evidence of significant effects of old age on the mucosal immune system.

Adult↗

Care of the pregnancy complicated by HELLP syndrome.

Pregnancies complicated by HELLP syndrome require a well-formulated management plan. The development of this syndrome after 34 weeks' gestation or with documentation of fetal lung maturity is an indication for delivery. Vaginal delivery can be accomplished in most cases; however, if cesarean section is required, the use of general anesthesia, subfascial drains, and preoperative platelet transfusion for platelet counts less than 50,000/mm3 can reduce the incidence of complications. It is advisable that patients with complications of HELLP syndrome such as pulmonary edema, acute renal failure, liver rupture, or extreme prematurity be referred to a tertiary care center where maternal and neonatal intensive care facilities are available.

Acute Disease↗

Acute life-threatening emergencies in preeclampsia--eclampsia.

Severe dysfunction of the pulmonary, renal, hepatic, and central nervous systems as a consequence of preeclampsia--eclampsia warrant aggressive multidisciplinary management and treatment. Preventive therapy, when possible or early recognition and therapy are clearly associated with improved maternal and neonatal outcome. Should cardiopulmonary arrest occur as a function of the disease process or management, then perimortem cesarean delivery initiated within 4 minutes of maternal cardiac arrest is associated with the highest rates of maternal and neonatal survival.

Acute Disease↗

Population-based study of surgery in juvenile onset Crohn's disease.

A geographically based cohort of 68 children with Crohn's disease was derived by sampling from Scottish Hospital In-patient Statistics. Surgical histories were examined and analysed by actuarial methods, and the nature of major operations performed was compared with operations for Crohn's disease in the Lothians' Surgical Audit. Fifty-four of the 68 patients were treated surgically, with a total of 135 operations (71 major, 64 minor). Fifty per cent of the cohort had a major operation within 5 years of onset of symptoms; median time to a second operation was 4 years. The types of major operation performed in juvenile onset patients differed significantly from those recorded in the Lothians' audit, with a high rate of exploratory laparotomy in younger patients (12 cases). With a mean follow-up of 7 years, 12 patients (18 per cent) have a permanent stoma. There were five deaths, three postoperative. This study highlights the frequency of surgical intervention in young people with Crohn's disease.

Adolescent↗

Population-based study of surgery in juvenile onset ulcerative colitis.

A geographically based cohort of 37 children with ulcerative colitis has been derived by sampling from Scottish Hospital In-patient Statistics. Surgical histories were examined and analysed by actuarial methods, and the major operations performed were compared with operations for ulcerative colitis in the Lothians' Surgical Audit. Fourteen of the 37 patients had a total of 26 operations (15 major, 11 minor). Sixteen per cent had major surgery within 5 years of onset of symptoms, and the types of operation were similar to those recorded in Lothians' Surgical Audit. Operation rate was significantly lower than that for a parallel cohort of patients with Crohn's disease. With a mean follow-up of 7.4 years, seven (19 per cent) patients have a permanent stoma and there has been one death.

Adolescent↗

Endomyocardial ultrastructural findings in preeclampsia.

Ultrastructural findings in endomyocardial biopsy specimens obtained during cardiac catheterization in a patient with severe preeclampsia are described. Intramyocardial vessels revealed prominent swelling of the endothelial cell cytoplasm. In addition, cardiac myocyte mitochondria showed swelling and clearing within the matrix. Endomyocardial ultrastructural injury occurs in severe preeclampsia.

Adult↗

Maternal plasma level of endothelin is increased in preeclampsia.

Endothelin is a potent vasoconstrictor that is reportedly increased in conditions characterized by endothelial damage. Maternal plasma endothelin levels were compared between 27 women with preeclampsia (23 without and 4 with the hemolysis, elevated liver enzymes, and low platelet count syndrome) and 14 women with normotensive pregnancies. The mean +/- SEM plasma endothelin values were significantly higher in patients with preeclampsia uncomplicated by the hemolysis, elevated liver enzymes, and low platelet count syndrome (5.48 +/- 0.30 fmol/ml vs 3.86 +/- 0.28, p less than 0.001). In addition, the preeclamptic group with the hemolysis, elevated liver enzymes, and low platelet count syndrome had significantly higher endothelin levels than those without the syndrome (8.30 +/- 1.62 fmol/ml vs 5.48 +/- 0.30, p less than 0.05). There was no correlation between plasma endothelin values and either systolic or diastolic blood pressure. We conclude that plasma endothelin levels are significantly increased in women with preeclampsia and particularly in those with the hemolysis, elevated liver enzymes, and low platelet count syndrome, suggesting an association with widespread endothelial damage.

Adult↗

Nifedipine pharmacokinetics and pharmacodynamics during the immediate postpartum period in patients with preeclampsia.

Pharmacokinetic and pharmacodynamic parameters of oral nifedipine were studied in the immediate postpartum period in eight women with preeclampsia. Peak serum concentrations of 18 +/- 2.1 micrograms/L occurred 40 minutes after ingestion of nifedipine (10 mg). The terminal elimination half-life (mean = 1.35 +/- 0.3 hours) was found to be shorter than that reported for normotensive volunteers or nonpregnant hypertensive women (mean, 3.4 +/- 0.4 hours). A mean apparent oral elimination clearance of 3.3 +/- 1.3 L/hr/kg was more rapid than that found in normal volunteers (mean, 0.49 +/- 0.09 L/hr/kg) or in women with pregnancy-induced hypertension in the third trimester (mean, 2.0 +/- 0.8 L/hr/kg). Initial nadirs in mean arterial pressure were noted at 50 minutes after ingestion of nifedipine, with an average reduction in mean arterial pressure of 13.8 mm Hg. A dosing interval of every 3 to 4 hours is suggested when rapid-release nifedipine is used in the postpartum patient with preeclampsia.

Administration, Oral↗

Fetal blood sampling in patients undergoing elective cesarean section: a correlation with cord blood gas values obtained at delivery.

The purpose of this study was to compare blood gas parameters obtained after delivery and cord clamping with those obtained in the intact fetal circulation. Eighteen patients undergoing elective cesarean section at term were studied. Before the induction of epidural anesthesia, cordocentesis was performed under ultrasonographic guidance. Subsequently, a second sample was obtained for cord blood gas analysis after delivery. Umbilical venous blood was analyzed for pH, PO2, PCO2, and base excess. When comparing samples obtained from the intact fetal circulation with those obtained after delivery, there was a significant difference in pH (7.36 +/- 0.03 vs 7.31 +/- 0.04; p less than 0.0001), PCO2 (41.15 +/- 3.66 vs 46.29 +/- 5.71; p less than 0.018), PO2 (32.92 +/- 8.54 vs 26.97 +/- 4.43, p less than 0.02), and base excess (-0.79 +/- 1.19 vs -2.36 +/- 1.48; p less than 0.0003). These results should be considered when cord blood gas values obtained at delivery are correlated with those from the prenatal fetal state. Blood gas values obtained at delivery may not reflect the true prenatal fetal acid-base status.

Blood Gas Analysis↗

Low-dose aspirin to improve perinatal outcome.

The list of clinical conditions for which aspirin may produce abatement or reversal of pathologic processes continues to be expanded. There are, however, definite risks reported from the use of aspirin during pregnancy, even though some of the findings have been contradictory. Some of the potential adverse effects on the infant also remain unclear. Potential benefits from the use of low doses of aspirin during pregnancy (although promising) are still experimental. Large clinical trials in the United States and overseas are currently assessing the effectiveness of low-dose aspirin in preventing preeclampsia and fetal growth retardation. A review of the world's literature to date describes over 300 pregnancies in which low-dose aspirin has been used with no evidence of major adverse effects. Until more conclusive evidence emerges, however, caution against the indiscriminate use of aspirin in any dose during pregnancy is urged. Clinicians who decide to manage complicated or potentially complicated patients with chronic administration of aspirin must continue to study these mothers, fetuses, and neonates intensively and to document their results. Because of the fear of teratogenic effects in the first trimester, initiation of aspirin therapy should be withheld until the 13th week of gestation. However, current data indicates it can be continued until delivery without complication. Monitoring of these patients should include: warning signs and symptoms of bleeding, serial ultrasonography for fetal growth and fluid, serial fetal echocardiography, and neonatal evaluation for bleeding complications. Such clinical experience will add immensely to our understanding of the safety and efficacy of aspirin during pregnancy.

Antibodies↗

Dissociation between systemic and mucosal humoral immune responses in coeliac disease.

We examined humoral immunity in coeliac disease as expressed in serum (systemic immunity), and in saliva, jejunal aspirate, and whole gut lavage fluid (mucosal immunity). The aims were to define features of the secretory immune response (IgA and IgM concentrations and antibody values to gliadin and other food proteins measured by enzyme linked immunosorbent assay (ELISA)) in active disease and remission, and to establish whether secretions obtained by relatively non-invasive techniques (saliva and gut lavage fluid) can be used for indirect measurements of events in the jejunum. Serum, saliva, and jejunal aspirate from 26 adults with untreated coeliac disease, 22 treated patients, and 28 immunologically normal control subjects were studied, together with intestinal secretions obtained by gut lavage from 15 untreated and 19 treated patients with coeliac disease and 25 control subjects. Jejunal aspirate IgA and IgM and gut lavage fluid IgM concentrations were significantly raised in patients with untreated coeliac disease; the lavage fluid IgM concentration remained higher in patients with treated coeliac disease than in controls. Serum and salivary immunoglobulin concentrations were similar in the three groups. Patients with untreated coeliac disease had higher values of antibodies to gliadin compared with treated patients and control subjects in all body fluids tested; these were predominantly of IgA and IgG classes in serum, and of IgA and IgM classes in jejunal aspirate and gut lavage fluid. Values of salivary IgA antibodies to gliadin were significantly higher in untreated coeliacs, though antibody values were generally low, with a large overlap between coeliac disease patients and control subjects. In treated patients, with proved histological recovery on gluten free diet, serum IgA antigliadin antibody values fell to control values, though serum IgG antigliadin antibody values remained moderately raised. In contrast, there was persistence of secretory antigliadin antibodies in treated patients (particularly IgM antibody) in both jejunal aspirate and gut lavage fluid. Antibody responses to betalactoglobulin and ovalbumin were similar to those for gliadin, including persistence of high intestinal antibody values in patients with treated coeliac disease. There was a positive correlation between antibody values in jejunal aspirate and gut lavage fluid, but not between saliva and jejunal aspirate; thus salivary antibodies do not reflect intestinal humoral immunity.

Adolescent↗