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Biomedical subjects

B Bernard

Publications and source records attributed to B Bernard.

At least 109 records · Page 6Linked to original sources
PubMed1979

Comparison of T4, T3, rT3 and TSH concentrations in cord blood and serum of infants up to 3 months of age.

T4, T3, TSH and rT3 concentrations were measured by radioimmunoassay in cord and postnatal (8--94 days of age) serum samples from randomly selected normal newborn infants (Group I). T4 and TSH levels also were determined in cord and postnatal sera from an additional group of apparently healthy infants 8--260 days of age, whose cord serum T4 levels were in the upper or lower 10% of the normal range of values (Group II). Postnatal T4, T3 and TSH concentrations were stable over this age range; there were no significant differences between male and female infant samples. However, there was a significant decrease in serum rT3 concentrations from 8 to 50 days of age. For the Group I infants, there were significant positive correlations between cord serum T4 and postnatal serum T4 levels, cord serum TSH and postnatal serum TSH levels, and cord serum rT3 and postnatal serum rT3 concentrations. For Group II infants, a significant positive correlation was found for cord T4--postnatal T4 serum concentrations.

Age Factors↗
PubMed1979

Oscillations in reverse triiodothyronine levels in serum of healthy infants aged 0 to 130 hours.

rT3 was measured by RIA in sera from 273 normal healthy infants between 0--130 h of age. The curve for the mean rT3 level plotted against age was polyexponential in shape and showed superimposed oscillations with a period of about 16 h, similar to the curves for T4, T3, and TSH previously found for the same group of subjects (J Clin Endocrinol Metab 47: 61, 1978). The ratio of concentrations of rT3 to T4 remained approximately constant, with a mean value of 0.016 over the age range of 3--130 h. These observations suggest that the variations in rT3 levels in newborn serum during the first few days of life are largely accountable by variations in T4 substrate concentrations.

Humans↗
PubMed1979

Concanavalin A binding to amphibian embryo and effect on morphogenesis.

The effect of Concanavalin A (Con A) on morphogenesis in Pleurodeles waltlii has been studied. Embryos were incubated with various concentrations of the lectin for a period of 6 days. Three stages of development were examined, late blastula, young gastrula and late gastrula. In the presence of the lectin at a concentration of 200, 150 or 100 micrograms/ml morphogenic movements were delayed, altered and finally blocked. At lower concentrations, 50 or 25 microgram/ml, there was a slight delay in gastrulation, but in some cases development was normal. These findings indicate that Con A exerted an inhibitory effect on amphibian morphogenesis and there is evidence that the lectin effect was concentration dependent. The effects of Con A were specific since they were totally inhibited by alpha-methyl-D-mannopyranoside (0.05 M). The viability of the 24 h lectin-treated embryos was demonstrated by washing experiments. Labelled Con A binding to the embryos was investigated before and after discarding the vitelline membrane. The results suggest a direct interaction between Con A and the cell surface and this was confirmed by using fluorescein isothiocyanate Con A.

Animals↗
PubMed1978

Cord blood reverse T3 in congenital hypothyroidism.

Reverse triiodothyronine (rT3) was measured in cord serum from 5 infants with congenital hypothyroidism and compared with normal values in 70 euthyroid control infants. The mean (and SEM) value in the affected infants (135 +/- 12 ng/dl) was significantly lower than that in the control population (270 +/- 9 ng/dl). However, the large overlap in range of concentrations in affected and control infants indicates that newborn screening based on the determination of rT3 in cord blood specimens offers no advantage over present screening methods.

Congenital Hypothyroidism↗
PubMed1978

Damped oscillations in serum thyroid hormone levels of normal newborn infants.

Exposure to the extrauterine environment is associated with marked stimulation of the hypothalamic-pituitary-thyroid system after which, pituitary-thyroid equilibrium must be reestablished. This marked endogenous perturbation offers the opportunity to study the manner in which the pituitary-thyroid axis is reequilibrated. T4, T3 and TSH concentrations have been measured by RIA in sera from 440 healthy newborn infants, whose ages ranged from birth to 236 h. Results were analyzed by nonlinear curve-fitting procedures to assess the changes in mean hormone concentrations with age (t). Equations have been derived by Danziger and Elmergreen to allow assessment of oscillatory behavior during hormone equilibration. Applying these equations to the present data, we observed the presence of an oscillatory cosine term in the equation for each hormone. This indicates significant oscillations in serum T4, T3, and TSH concentrations during the first 5 days of life. The period of the oscillations approximates 16 h. The oscillations in T4, lag 1/2 to 3/4 cycle behind TSH; T3 lags behind T4. Thus, disturbances in hypothalamic-pituitary-thyroid equilibrium seem to be followed by periodic oscillations in hormone concentrations; these oscillations decrease in amplitude as the negative feedback system establishes new equilibrium conditions.

Aging↗
PubMed1977

Correlation between gestational age, weight, or ponderosity and serum thyroxine concentration at birth.

Thyroxine levels were measured in cord blood sera from 2,1800 healthy infants born of "low-risk" mothers in Los Angeles. Variations of T4 with gestational age, birth weight, ponderosity (size related to weight), sex, and race were studied, as well as the variation of W and P with GA. Over the range of GA 30 to 47 weeks, serum T4 concentrations, W, and P each increase with GA, leveling off to approximately constant values from 42 to 47 weeks; the increases are 12, 66, and 20%, respectively. For a fixed GA, T4 increases with increasing W but is not correlated with P; W, GA, and their product are useful measurements for predicting T4, but P is not. Formulas for predicting cord T4 are given for possible use in improving computer-assisted screening programs for congenital hypothyroidism; mean T4 values (+/- I SD) are tabulated against W and GA.

Birth Weight↗
PubMed1977

Thyroid function at birth in infants of 30 to 45 weeks' gestation.

Serum T4 was measured in cord blood of 2,683 infants of gestational ages 30 to 45 weeks and birth weights of 1,460 to 5,250 gm. In addition, serum TBG was measured in 180, and serum TSH in 125 of these infants. Mean serum T4 increased with gestational age from 9.4 microng/dl at 30 weeks to 11.7 at 45 weeks. TBG varied from 3.1 to 11.4 mg/dl but showed no correlation with gestational age. There was a positive correlation between T4 and TBG. Serum TSH levels showed a significant negative correlation with gestational age, decreasing from 15 micronU/ml at 30 weeks to 7 micronU/ml at 45 weeks, while the serum T4/TSH ratio increased from 0.6 to 1.6. The results indicate that cord, T4 varies mainly with TBG, and to a lesser extent with gestational age.

Fetal Blood↗
PubMed1977

Maternal-fetal pharmacological activity of amikacin.

Thirty healthy gravid patients of six to 20 weeks' gestation each received a single dose of 7.5 mg of amikacin/kg within 24 hr prior to elective hysterectomy. The half-life (t1/2) of amikacin in maternal serum was 2.07 hr. The mean peak concentration of amikacin in the sera of these patients was slightly lower than that in nonpregnant adults. Two-thirds of the placental samples had amikacin concentrations of greater than or equal to 8 microng/g during the 20-hr interval between drug injection and delivery time. In fetal kidney the concentration of amikacin peaked at a level of 22.4 microng/g at 12 hr after administration. The peak concentration of amikacin in fetal urine was 24 microng/ml, and the t1/2 was 3.2 hr. High levels of the drug in fetal urine and low levels in fetal serum (less than 4 microng/ml) and amniotic fluid (less than 3 microng/ml) were unrelated to high levels found in fetal kidney. Levels of amikacin in fetal lung were 1.4-8.0 microng/g during intervals of 1-16 hr between administration of the drug and time of delivery. With the increasing number of drugs available for use, both potential benefits and risks for the fetus must be considered when prescribing an antibiotic to treat the infected gravid patient, and it should be kept in mind that low levels in body fluid may not be equated with safety.

Amikacin↗
PubMed1977

Maternal-fetal transfer of cefazolin in the first twenty weeks of pregnancy.

Maternal-fetal transfer of cefazolin was investigated with use of a single 14-mg/kg intramuscular dose administered to 40 gravidas before elective hysterectomy. The half-life of cefazolin in maternal serum was 1.5 hr with mean concentrations at 2 and 4 hr of 39 and 16 microgram/ml, respectively. By microbiological assay, cefazolin was not detected in brain, cerebrospinal fluid, lung, liver, or kidney of the fetus but was present in concentrations of 1-11 microgram/ml in 12 of 27 individual samples of fetal serum from 0.75 to 10.66 hr. Cefazolin appeared in fetal urine from 2.17 to 19.5 hr at levels of less than 5 microgram/ml with a half-life of 5.4 hr. Cefazolin was present in the amniotic fluid of fetuses older than 14 weeks in concentrations of less than 1 microgram/ml from 9 to 21.75 hr. After administration of a single dose to the mother early in pregnancy, the fetal distribution of cefazolin is limited to the body fluids.

Amniotic Fluid↗
PubMed1977

Tobramycin: maternal-fetal pharmacology.

To investigate the maternal-fetal transfer of tobramycin (TBM) and its distribution in the fetus, a single dose of 2 mg/kg was administered intramuscularly to 35 pregnant patients (13 first trimester, 22 second trimester) 0.5 to 34 h before hysterectomy. TBM concentration was assayed microbiologically in maternal serum, fetal tissues (placenta, brain, lung, liver, and kidney), and fluids (amniotic, cerebrospinal fluid [CSF], urine, and serum). Mean maternal serum half-life (1.54 h) and mean peak serum concentration of TBM were within ranges reported for nonpregnant adults. In fetal serum, half-life was 5.2 h, and TBM levels did not exceed 0.58 mug/ml. For intervals up to 34 h, the mean TBM concentration in placental tissues was 1.4 mug/g. Concentration differences related to fetal maturation were found for fetal CSF, amniotic fluid, and fetal kidney. No antimicrobial activity was found in the fetal CSF of >16 weeks' gestation. TBM was present predominantly in the second trimester amniotic fluid specimens. Fetal kidney concentrations reached 7.2 mug/g at 34 h after maternal drug administration. Higher TBM concentrations were related to advanced maturation of the fetal kidney. Second trimester fetal urine concentrations for TBM ranged from 0.1 to 3.4 mug/ml, and the fetal urinary half-life was 3.7 h. Knowledge of fetal pharmacology is essential for weighing the fetal benefits or risks of antimicrobial therapy for the infected gravid patient.

Anti-Bacterial Agents↗
PubMed1977

Maternal-fetal pharmacology of cefatrizine in the first 20 weeks of pregnancy.

To evaluate maternal-fetal pharmacology of cefatrizine (BL-S 640), a new oral cephalosporin, a single oral 1,000-mg dose was administered to 33 gravidas (8 to 20 weeks' gestation) at varying intervals within 46 h of an elective therapeutic abortion by hysterectomy or intra-amniotic prostaglandin F(2a) induction. Mean maternal serum concentrations at 1, 2, 4, and 8 h were 3.7, 7.9, 6.5, and 1.6 mug/ml; beyond a 3-h peak, a half-life of 2.4 h was determined. Cefatrizine placental half-life was 4.4 h. None of the 11 fetuses from a prostaglandin F(2a) abortion revealed cefatrizine activity; in contrast, 17 of 22 fetuses from a surgical abortion demonstrated cefatrizine concentrations in two or more samples. Fetal cefatrizine levels were less than 3 mug/g or mug/ml in kidney and urine, less than 2 mug/ml in serum and bile, and less than 2.5 mug/g in lung. After a single maternal dose, cefatrizine has a wide distribution in the fetus in the first half of gestation.

Amniotic Fluid↗
PubMed1977

Multiple forms of thymidine kinase during human development.

The developmental progression of thymidine kinase from the electrophoretically slow-migrating 'fetal' forms to the fast-migrating 'adult' form was examined in human serum and fetal liver. In fetal liver, only the fetal forms of the enzyme were present at 17 weeks' gestation. A transitional period followed in that both enzyme forms were identified and by 24 weeks only the adult form was detected in fetal liver. This same enzyme changeover pattern--fetal to transitional to adult--occurred at a later time in human serum as it took place between 30 and 40 weeks' gestation.

Adult↗
PubMed1975

Serum thyrotrophin concentration: an unreliable test for detection of early hypothyroidism after thyroidectomy.

Three groups of patients who had undergone subtotal thyroidectomy for Graves's disease, toxic multinodular goitre, or euthyroid multinodular goitre 12 to 15 years before and in whom a normal serum thyroxine (T-4) level was found were each divided into two subgroups on the basis of a normal or a raised serum thyrotrophin concentration. There was no difference in mean serum T-4 concentration between patients with normal and those with raised serum thyrotrophin concentrations, and the values were similar to the mean T-4 values of the normal population. The mean serum triiodothyronine values of all groups were higher than normal, but the mean values of the groups with a normal and a raised serum thyrotrophin were similar. After thyroidectomy a mildly raised serum thyrotrophin does not in itself indicate the presence of hypothyroidism.

Humans↗
PubMedDate not supplied

Cognitive and motor function in patients with Parkinson's disease with and without depression.

The objective of this study was to define risk factors for depression in patients with idiopathic Parkinson's disease (PD) and to evaluate the correlation of depression with cognitive function and the primary domains of parkinsonian motor dysfunction tremor, bradykinesia, rigidity, gait and balance impairment. The risk factors for depression in patients with PD remain controversial. Several investigators have demonstrated a significant association between cognitive dysfunction and depression, but motoric and disease variables can confound this evaluation and have shown an inconsistent relation to depression. A consecutive series of 88 patients with PD were examined using the motor subscale of the Unified Parkinson's Disease Rating Scale (UPDRSm), Hoehn-Yahr stage (HY), and Hamilton Rating Scale for Depression (HRSD). Major depression was diagnosed according to the criteria in the Diagnostic and Statistic Manual of Mental Disorders, 4th edition. Gender, age, handedness, PD duration, side of PD onset, motor fluctuations, UPDRSm total score, daily Levodopa dose, and Mini-Mental State Examination score (MMSE) were analyzed using multivariate and univariate logistic regression, Fisher's Exact test, and Pearson correlations. Major depression was diagnosed in 12 patients (7.3%). Low MMSE score, axial bradykinesia, gait and balance impairment were strongly significant predictors of depression. In conclusion, depression and physical function are important factors impairing the quality of life for patients with PD, and regular depression screening and treatment should focus on patients with PD who have cognitive impairment, high axial bradykinesia, gait and balance impairment.

Aged↗