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Biomedical subjects

F Mimouni

Publications and source records attributed to F Mimouni.

At least 55 records · Page 3Linked to original sources
PubMed1991

Effects of maternally administered epidermal growth factor on placental permeability.

Epidermal growth factor is a well-studied modulator of epithelial membrane structure and function. Mammalian placentas are a rich source of epidermal growth factor receptors, but the role of epidermal growth factor in placental pathophysiologic conditions is unclear. To determine whether epidermal growth factor could affect mechanisms of placental transfer, we used an in situ rat placental perfusion model. Fourteen Sprague-Dawley rats that were 20 days pregnant were randomized to epidermal growth factor or placebo during placental transport experiments. We chose ethylenediaminetetraacetate tagged with chromium 51 as a marker of placental permeability. Epidermal growth factor treatment led to a dramatic increase of maternofetal clearances of chromium 51-ethylenediaminetetraacetate. We conclude that maternally administered epidermal growth factor has a potent action on placental permeability.

Animals↗
PubMed1991

Umbilical cord ulceration and intestinal atresia: a new association?

In three fetuses, congenital intestinal atresia was associated with linear ulcerations of the umbilical cord. In two cases, hemorrhage was seen from the cord ulcer. Both fetuses required emergency cesarean section for fetal distress and were born anemic. The third fetus was mildly hydropic, attributed to hemorrhage, and was stillborn. The mechanism of the association could not be determined. These cases suggest a risk of prenatal umbilical cord hemorrhage in infants with intestinal atresia.

Adult↗
PubMed1991

A role for magnesium in neonatal parathyroid gland function?

Little is known of the factors regulating parathyroid function in the neonatal period. Twenty-seven term infants born after uncomplicated pregnancies, labors, and deliveries were studied to test the hypothesis that in normal newborns the amplitude of parathyroid hormone (PTH) response to decreasing serum ionized calcium (iCa) correlates with serum magnesium (Mg) concentrations. Serum iCa (ion selective electrode, Radiometer ICA 1), PTH (1-84 intact molecules, radioimmunoassay) and Mg (atomic absorption) were measured at birth (cord blood) and 24 hours of age. Repeated measures analysis of covariance showed decreasing serum iCa (p less than 0.01) and increasing serum Mg (p less than 0.01) and PTH (p less than 0.01) over time. The change in PTH over the first 24 hours was directly correlated with cord blood (r = 0.38, p less than 0.05) and 24-hr Mg concentrations (r = 0.53, p less than 0.01). We conclude that the ability of the parathyroid gland to respond to decreasing serum iCa after birth is directly related to Mg status. We speculate that neonatal hypomagnesemia may lead to a blunted PTH secretory response, thus contributing to early neonatal hypocalcemia.

Analysis of Variance↗
PubMed1991

A case-control study of hypocalcemia in high-risk neonates: racial, but no seasonal differences.

A role for vitamin D in the defense against falling serum calcium (Ca) concentrations following cord clamping has been suggested. Since race and season are known to affect vitamin D status, we theorized that black race and birth in winter are additional risk factors for neonatal hypocalcemia (NHC). We retrospectively studied 13,462 infants born at University Hospital (Cincinnati, OH) between January 1, 1984 and December 31, 1987. Serum Ca was measured at 24 hours of age routinely in infants with low birth weight (less than 2500 g), preterm delivery (less than 2500 g), preterm delivery (less than 37 weeks), neonatal asphyxia, and diabetic mothers. After exclusion of infants of diabetic mothers (to remove maternal diabetes as a major confounder) and infants with major congenital anomalies, 714 infants remained. In multiple regression analysis, low serum Ca values were significantly associated with low gestational age (p less than 0.01), low Apgar score (p less than 0.01), and white race (p less than 0.01) (R2 = 0.457). Season or month of birth was not significant. In pair-matched analysis controlling for factors other than season, season of birth did not affect serum Ca. In pair-matched analysis controlling for factors other than race, white race was once again a risk factor for hypocalcemia. Thus, low gestational age, low Apgar score, and white race, but not black race and delivery in winter, are risk factors for NHC. We speculate that in our climate and with the prevailing diet in pregnancy, vitamin D deficiency does not appear to play a role in NHC.(ABSTRACT TRUNCATED AT 250 WORDS)

Black or African American↗
PubMed1991

Effects of albumin on ionized calcium in vitro.

Human serum albumin is used to treat hypoproteinemia in neonates or used as a volume expander. We tested the hypothesis that the addition of human serum albumin to neonatal serum decreases the serum ionized calcium (iCa) concentration. Concentrated human serum albumin was added to 12 placental and cord serum samples to reach seven incremental concentrations from 0 to 20.0 g/L. Serum iCa concentration decreased significantly with the addition of serum albumin. From multiple regression analysis, the effect of albumin addition on serum iCa concentration had more marked effects at high baseline albumin or low baseline Ca concentrations. From this in vitro study, we speculate that fast infusion of albumin in human neonates has the potential for acutely lowering serum iCa concentration.

Blood Proteins↗
PubMed1991

Perinatal magnesium metabolism: personal data and challenges for the 1990s.

This review addresses recent developments in the field of perinatal magnesium (Mg) metabolism. After a brief review of perinatal Mg physiology, it critically addresses the issue of possible teratogenicity of Mg deficiency; maternal hypermagnesaemia and its effects on pregnancy, the fetus, and the newborn; the role of Mg in neonatal calcium homeostasis; and the possible relationship between Mg deficiency, apnoea of prematurity, and sudden infant death syndrome.

Calcium↗
PubMed1991

Patient experience in a diabetic program project improves subsequent pregnancy outcome.

There has been a notable improvement in the outcome of the pregnancies of insulin-dependent diabetics. This improvement has resulted from intensive health care programs and increased awareness among patients and health providers of the need for specialized prenatal care. We hypothesized that participation in a specialized program providing early glycemic control would benefit the patient's subsequent pregnancy, despite progression of the diabetic disease process. We prospectively studied 55 insulin-dependent diabetic patients enrolled before 9 weeks' gestation through two consecutive pregnancies: sequence 1 and sequence 2. A control group of 55 insulin-dependent diabetic patients, entering the program for the first time, were matched with the sequence 2 pregnancies of the study group by maternal age and year of pregnancy. Specific outcomes related to glycemic control in early gestation were significantly improved from sequence 1 to sequence 2 pregnancies: earlier week of entry (P = .0001), lower glycohemoglobin at 9 weeks (P = .005) and at 14 weeks (P = .02), and improved fetal outcome (decreased rate of spontaneous abortions or major malformations; P less than .01). Week of entry and glycohemoglobin at 9 and 14 weeks were also significantly improved compared with the control group. Seventy-three percent of the patients entered the program earlier in their sequence 2 pregnancies (P = .001) and had lower glycohemoglobin concentrations at 9 weeks (P = .005) compared with their sequence 1 pregnancies. Sixty-five percent of the patients in sequence 2 had advanced diabetic disease (White class D-RF), compared with 46% in sequence 1 (P less than .05) and 44% of the controls (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Spontaneous↗
PubMed1991

Hypertension during pregnancy in insulin-dependent diabetic women.

Insulin-dependent diabetic patients are at increased risk for hypertensive disorders of pregnancy. This study was designed to study prospectively the rate of pregnancy-induced hypertension (PIH) in 175 insulin-dependent diabetic pregnancies (88 White classes B-C, 87 classes D-RT). Pregnancy-induced hypertension was defined as two or more occurrences after 20 weeks' gestation of a mean arterial pressure (MAP) of 105 mmHg or greater or an increase of 20 mmHg or greater from the baseline MAP. The rate of PIH in the diabetic population was 15.4% and was significantly associated with nulliparity, poor glycemic control in the first and second trimesters, and advanced White class. Neonatal outcome was not significantly altered in the presence of PIH. We speculate that improved glycemic control throughout pregnancy might reduce the rate of this complication in diabetic patients.

Adult↗
PubMed1990

Transplacental passage of insulin in pregnant women with insulin-dependent diabetes mellitus. Its role in fetal macrosomia.

BACKGROUND AND METHODS: Fetal macrosomia occurs despite nearly normal maternal blood glucose levels in women with diabetes treated with insulin. We examined the hypothesis that it may be caused by insulin transferred as an insulin-antibody complex from the mother to her fetus. We adapted and validated a method based on high-performance liquid chromatography and used it to quantitate insulin in small volumes (0.5 to 1.0 ml) of cord serum from 51 infants born to mothers with insulin-dependent diabetes mellitus. RESULTS: In mothers receiving only human insulin (n = 6), only human insulin was detected in cord serum. Of the remaining 45 infants, whose mothers received animal insulin during pregnancy, 28 (group 1) had levels of animal (bovine or porcine) insulin (mean [+/- SE], 707 +/- 163 pmol per liter) that constituted 27.4 +/- 2.5 percent of the total insulin concentration (2393 +/- 500 pmol per liter) measured in the cord serum. The cord-serum insulin concentration in the remaining 17 infants (group 2), in whom only human insulin was detected (381 +/- 56 pmol per liter), was only 15 percent of that in group 1 (P less than 0.001). There was a significant correlation between the maternal and the cord-serum concentrations of anti-insulin antibody and the concentration of animal insulin in the baby (r = 0.77, P less than 0.01, and r = 0.76, P less than 0.001, respectively), suggesting that the animal insulin was transferred as an insulin-antibody complex. In group 1 the mean concentration of animal insulin in cord serum was higher in the 12 infants with macrosomia than in the 16 infants without the condition (1113 +/- 321 vs. 402 +/- 110 pmol per liter; P less than 0.05), and the concentration of animal insulin in cord serum correlated with birth weight (r = 0.39, P less than 0.05). The maternal glycosylated hemoglobin values and the incidence of respiratory distress syndrome were similar in groups 1 and 2. CONCLUSIONS: Considerable amounts of antibody-bound insulin are transferred from mother to fetus during pregnancy in some women with insulin-dependent diabetes mellitus; the extent of transfer correlates with the maternal concentration of anti-insulin antibody. The correlation between macrosomia and the concentrations of animal insulin in cord serum indicates that the transferred insulin has biologic activity and suggests that the formation of antibody to insulin in the mother is a determinant of fetal outcome independent of maternal blood glucose levels.

Adult↗
PubMed1990

High infectious morbidity in pregnant women with insulin-dependent diabetes: an understated complication.

Patients with insulin-dependent diabetes are prone to infection, possibly related to poor metabolic control. Relative immune deficiency exists in pregnancy. We hypothesized that pregnant patients with insulin-dependent diabetes are at an increased risk for infection and that infection is related to poor glycemic control. We matched 65 pregnant women with insulin-dependent diabetes to 65 nondiabetic pregnant controls. At least one episode of infection before delivery occurred in 83% of the women with insulin-dependent diabetes (26% in control group). The rate of postpartum infection was five times higher in the group with insulin-dependent diabetes and they were susceptible to more kinds of infections. Although there was no overall difference among the indices of glycemic control, hemoglobin A1 obtained before the infection was higher than during infection. We conclude that a high rate of infection exists in pregnant women with diabetes; infection and poor glycemic control may be associated, but it is unclear whether improvement in metabolic control will reduce this high infection rate.

Adult↗
PubMed1990

Early neonatal predictors of neonatal hypocalcemia in infants of diabetic mothers: an epidemiologic study.

Prematurity, neonatal asphyxia, hypomagnesemia, and advanced maternal diabetes are traditional risk factors for hypocalcemia in infants of diabetic mothers (IDMs). The aim of this study was to determine the relative contribution of these factors separately and combined in a cohort of diabetic pregnancies managed prospectively in the recent 9 years and to find accurate predictors of neonatal hypocalcemia in infants of diabetic mothers. We hypothesized that these factors plus low cord blood calcium (Ca) concentration allow prediction of IDMs who develop neonatal hypocalcemia. We studied 186 IDMs (White class B-RT); gestational age (GA, weeks) was by last menstrual period, confirmed +/- 2 weeks by Ballard score. The goals of glycemic control were: preprandial blood glucose less than 100 mg/dl and 90-minute postprandial blood glucose less than 140 mg/dl. Apgar scores, and cord, 24-, 48- and 72-hour serum calcium (Ca) (mg/dl) and magnesium (Mg; mg/dl) were determined. In univariate analysis, lowest serum Ca correlated with cord blood Ca (r = 0.48, p less than 0.001), GA (r = 0.37, p less than 0.001), and 1-minute Apgar score (r = 0.18, p = 0.09), but did not correlate with cord Mg or with advanced White class. In multiple regression, cord Ca and GA were dominant effects and other variables became insignificant. Lowest Ca (mg/dl) was predicted as follows: lowest Ca = 34.05 - 3.22 (Ca cord) - 0.84 (GA) + 0.10 (GA) (Ca cord). This equation predicts neonatal hypocalcemia (lowest Ca less than 8 mg/dl) with a sensitivity of 72% and a specificity of 75%. Thus, GA and cord Ca allow determination of IDMs at risk for neonatal hypocalcemia.

Asphyxia Neonatorum↗
PubMed1990

Histopathology of spontaneous abortion in diabetic pregnancies.

This study reviewed the histopathology of endometrial curettings following spontaneous abortion in diabetics and controls. The two groups did not differ significantly for an array of histologic features. The relationships between histopathology and diabetic White class, diabetic nephropathy or retinopathy, first trimester hemoglobin A1 percentage, and first trimester serum magnesium level were studied. The only significant correlation found was between diabetic retinopathy and decidual congestion with the presence of venous fibrin.

Abortion, Spontaneous↗
PubMed1990

Spectrum and natural history of congenital hyperparathyroidism secondary to maternal hypocalcemia.

Fourteen cases of congenital hyperparathyroidism secondary to maternal hypocalcemia have been reported. We report two additional cases that highlight the wide spectrum of the disease. We extensively studied the parathyroid function of these infants to test the hypothesis that the biochemical hyperparathyroidism found in these infants would be transient in nature, since the presumed etiology (maternal and subsequent fetal hypocalcemia) should disappear soon after birth with establishment of enteral feedings. Infant 1 was born to a mother with idiopathic hypoparathyroidism with poor compliance to therapy and documented hypocalcemia in pregnancy. Severe congenital demineralization and intrauterine fractures with clinical and radiologic bowing of the long bones were obvious. Bone mineral content and bone mineral content/bone width ratio, measured by photon absorptiometry, were both markedly below normal. Infant 2 was born to a mother with postsurgical hypoparathyroidism with excellent compliance. The mother was normocalcemic. The infant was clinically and radiologically asymptomatic. The bone mineral content was just at the lower limit of normal, but bone mineral content/bone width ratio was below the normal limits. Biochemical features include elevation of cord serum parathyroid hormone (1-84, radioimmunoassay) in both cases, coexisting with serum calcium, phosphorus concentrations within normal limits. Serum parathyroid hormone fell to within normal ranges by 9 days of age in both infants. With no treatment, bone mineral content at 1 month of age was normal in both infants.

Adult↗
PubMed1990

Postnatal changes in serum osteocalcin and parathyroid hormone concentrations.

Cord clamping at birth leads to interruption of calcium (Ca) supply to the fetus. After birth, neonatal parathyroid hormone (PTH) secretion appears stimulated by hypocalcemia, with serum PTH increasing after birth and peaking at 24 hours of age. This rise in PTH presumably leads to bone resorption and Ca release. We theorize that bone formation may also be affected and that a serum marker of bone formation, serum osteocalcin (OC) concentrations, will decrease postnatally. OC is synthesized by osteoblasts and its serum concentrations are believed to reflect bone formation. We measured serum ionized Ca (iCa), PTH, and OC in cord blood and at 2 and 24 hours in 26 neonates born after uncomplicated pregnancies, labors, and deliveries. Serum iCa (mg/dl) decreased from 5.79 +/- 0.06 (cord, means +/- SEM) to 5.31 +/- 0.05 (2 hr), then to 4.89 +/- 0.05 (24 hr) (p less than 0.05). Serum PTH (microliter Eq/ml) increased from 35.9 +/- 4.3 (cord) to 41.7 +/- 4.0 (2 hr) (p = 0.1), and to 50.3 +/- 4.6 (24 hr) (p less than 0.01). Serum OC (ng/ml) decreased from 55.1 +/- 10.6 (cord), to 12.4 +/- 4.3 (2 hr) (p less than 0.01), then remained stable at 12.7 +/- 1.9 (24 hr). The change (cord minus 24 hr) in OC correlated inversely with the change in PTH over the first 24 hours of age (r = -0.42. p = 0.03). Therefore, there is a sudden decrease in an index of bone formation (i.e., serum OC) in the first 24 hours of life in which rising serum PTH may have had an impact.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Development↗
PubMed1990

Minor congenital malformations in infants of insulin-dependent diabetic women: association with poor glycemic control.

A prospective study of 171 insulin-dependent diabetic pregnant women was undertaken to establish the relationship of glycemic control with minor congenital malformations. Each live-born infant was assessed systematically by two independent examiners using a standardized checklist. There were 32 infants with minor congenital malformations (18.7%). There were significant differences in mean glycohemoglobin A1 between the group with minor congenital malformations and the group without congenital malformations at 12, 16, and 20 weeks, but not at 8 or 24 weeks. Logistic regression analysis showed that maternal age, race, gravidity, White class, duration of diabetes, maternal vasculopathy, and cigarette smoking were not significant variables correlated with minor congenital malformations. Because glycohemoglobin levels from 12-20 weeks are believed to reflect glycemic control from approximately 6-20 weeks, we conclude that poor glycemic control during late embryogenesis and early fetal development is associated with an increased risk of minor congenital malformations. We speculate that improvement of glycemic control during this period should decrease the risk of minor congenital malformations.

Blood Glucose↗
PubMed1990

Postnatal surge in serum calcitonin concentrations: no contribution to neonatal hypocalcemia in infants of diabetic mothers.

It has been suggested that hypercalcitoninemia may contribute to neonatal hypocalcemia in infants of diabetic mothers (IDM). Because the role of calcitonin (CT) in Ca metabolism in humans is questionable, we hypothesized that serum CT peaks similarly after birth in IDM and controls and that serum Ca concentrations do not correlate with serum CT. Forty-seven term IDM (White classes B-RT) were compared with 31 controls. Controls were born after normal pregnancies, labors, and deliveries. Blood samples (cord and 24 h) were analyzed for Ca, Mg, parathyroid hormone (PTH), and CT. Repeated measures analysis showed increasing serum Mg, PTH, and CT, and decreasing Ca over time. The incidence of hypocalcemia was significantly higher in the diabetic group (p less than 0.01) and the incidence of hypomagnesemia was borderline significantly higher (p less than 0.06). There were no differences in cord or 24-h serum concentrations of CT between groups. In multiple regression analysis, serum Ca and PTH were correlated (p less than 0.02, R2 = 0.33), but not serum Ca and CT; the increase in serum PTH in relation to serum Ca at the nadir (24 h) correlated directly with serum Mg concentrations (R2 = 0.31, p less than 0.05). Thus, serum CT increases after birth irrespective of the rate of decrease of serum Ca in both IDM and controls; high CT concentrations observed after birth (as compared with adult norms) do not seem to play a role in the pathogenesis of neonatal hypocalcemia in IDM; and responsiveness of parathyroid gland at birth is adversely affected by hypomagnesemia, which supports the theory of functional hypoparathyroidism in Mg deficiency.

Calcitonin↗