Maturation of human hypothalamic-pituitary-thyroid function and control.

Measurements of serum thyrotropin (TSH) and free thyroxine (T4) concentrations were conducted in infants, children, and adults to assess maturation of the hypothalamic-pituitary-thyroid (HPT) feedback control axis. Serum free T4 and TSH concentration data were collated for cord blood of the midgestation fetus, for premature and term infants, and for peripheral blood from newborn infants, children, and adults. Mean values were plotted on a nomogram developed to characterize the reference ranges of the normal axis quantitatively based on data from 522 healthy subjects, 2 weeks to 54 years of age; 83 untreated hypothyroid patients; and 116 untreated hyperthyroid patients.

Midbrain periaqueductal lesions do not degrade medial forebrain bundle stimulation reward.

To investigate the possible role of the midbrain central grey and dorsal raphe in medial forebrain bundle (MFB) self-stimulation, 12 rats received monopolar stimulation electrodes in both the lateral hypothalamic and ventral tegmental MFB and an ipsilateral lesioning electrode in either the central grey or dorsal raphe. Baseline rate-frequency data were collected at several currents at each stimulation site until the frequency required to maintain half-maximal responding stabilized and then an electrolytic lesion was made by passing either 20 or 60 s of anodal constant current through the lesioning electrode. Post-lesion rate-frequency data indicated that lesions of the central grey and dorsal raphe had little appreciable effect on the rewarding nature of MFB stimulation.

Thyroid function in very low birth weight infants.

Objectives: The purpose of this study was to test the hypothesis that low circulating thyroxine concentrations characteristic of very low birth weight (VLBW) neonates (< 1500 g) are the result of decreased protein binding of thyroid hormones and to elucidate the mechanism(s) responsible and possible significance thereof.

Design: Cross-sectional comparison of thyroid related measurements in cord blood specimens from VLBW infants and from full term infants. Longitudinal comparison in cord and 2- and 4-week blood specimens from VLBW infants.

Association between flow cytometric S-phase fraction and apoptotic rate in breast cancer.

Tumor heterogeneity may adversely affect the flow cytometric measurement of S-phase fraction (SPF) in breast cancer specimens, and 10-20% of breast cancer specimens are not evaluable by flow cytometry due to technical factors such as debris, high coefficients of variation, poor specimen quality, or small sample size. Therefore, we performed this study on 207 specimens of breast cancer in order to determine if the apoptotic rate (AR) could serve as a useful adjunct to flow cytometric SPF measurements in breast cancers. The average AR in each specimen was determined by microscopic examination of tumor tissue that was specifically stained for apoptotic bodies by a commercially available TUNEL (Tdt-mediated dUTP digoxigenin nick end labelling) assay kit.

Neural network prediction of nonstress test results: how often should we perform nonstress tests?

Objective: Our purpose was to predict outcomes and optimal intervals for nonstress tests of term gravid women with neural networks.

Study Design: We studied 100 normal term patients whose 30-minute nonstress tests, performed on 5 consecutive days, were computer analyzed for the following elements: fetal heart rate baseline, variability, signal loss, accelerations (> 15 beats/min), and decelerations. The training set used 65 patients; the testing, 35 patients.

Reference ranges for newer thyroid function tests in premature infants.

Objective: To establish reference ranges for recently developed assays of thyroid function in premature infants.

Methods: We measured serum free thyroxine (T4) by direct equilibrium dialysis and serum thyrotropin by a sensitive immunometric method in 104 preterm infants (25 to 36 weeks of gestational age) during the first week of life.

Results: The free T4 level correlated positively with gestational age (p < 0.

Skeletal response to recombinant human growth hormone (rhGH) in children treated with long-term corticosteroids.

Corticosteroid therapy causes osteopenia and growth retardation in children; such changes are associated with diminished rates of bone formation and turnover. Since growth hormone activates bone remodeling, the biochemical and skeletal responses to rhGH were evaluated in four pediatric patients, aged 12.8 +/- 3 years, with long-term corticosteroid use (5 +/- 2 years).

Age-related changes in serum free thyroxine during childhood and adolescence.

The purposes of this study were to reevaluate age-related changes in the concentration of serum free thyroxine (T4) between early infancy and adulthood, and to study the relationship of serum thyrotropin to these changes in free T4. Five hundred thirty-six healthy infants, children, adolescents, and adults between 1 day and 45 years of age were studied. Serum free T4 was determined by direct equilibrium dialysis, thyrotropin by a sensitive immunoassay, and total T4 by radioimmunoassay.

Development of third-generation immunochemiluminometric assays of follitropin and lutropin and clinical application in determining pediatric reference ranges.

We developed dioxatane-based immunochemiluminometric assays (ICMAs) for lutropin (LH) and follitropin (FSH), using monoclonal antibodies. These ICMAs have a minimal detectable dose (analytical sensitivity) of 0.01 IU/L, extending the lower limit of sensitivity 10-fold (from 0.

Modified immunoradiometric assay of parathyroid hormone-related protein: clinical application in the differential diagnosis of hypercalcemia.

We have developed a sensitive, specific solid-phase immunoradiometric assay (IRMA) of parathyroid hormone-related protein (PTH-RP) with use of affinity-purified polyclonal immunoglobulins. Antibodies recognizing PTH-RP(37-74) are immobilized to a polystyrene bead to "capture" analytes from the sample; antibodies to epitopes within the 1-36 amino acid region of PTH-RP are labeled with 125I. This IRMA recognizes PTH-RP(1-74) and PTH-RP(1-86) equivalently, but does not detect N-terminal or C-terminal fragments of PTH-RP, intact human parathyrin (PTH), or fragments of PTH.

Rapid radioimmunoassay of circulating chromogranin A: in vitro stability, exploration of the neuroendocrine character of neoplasia, and assessment of the effects of organ failure.

Chromogranin A is a useful probe of neuroendocrine neoplasia in humans. Here we optimize a rapid, sensitive radioimmunoassay modification for detecting chromogranin A in humans and other species. The site of chromogranin A circulation is the acellular plasma; platelets contain no chromogranin A immunoreactivity.

Connection between internal representation of rigid transformation and cortical activity paths.

A canonical unitary representation of the Euclidean group on the range space of the Gabor transform is constructed from mathematical properties of the Euclidean group and the quaternions. The visual cortical activity pattern corresponding to a given retinal image is represented by a point in the range space of the Gabor transform. Paths experienced in apparent motion and mental rotation are represented by paths in the Euclidean group.

Autoimmune thyroid disease: an expanding spectrum.

Autoimmune thyroid disease classically has included Hashimoto's thyroiditis and Graves' disease. Hashimoto's thyroiditis probably also includes focal thyroiditis, fibrous thyroiditis, primary myxedema, and Hashitoxicosis as variants. Graves' disease is associated with ophthalmopathy and dermopathy, and recent evidence suggests that these manifestations are autoimmune phenomena as well.

Behavioral modification in a weight-reduction program.

Previous surveys have shown a high prevalence of obesity in women of low socioeconomic status. This study confirmed the relationship in the Medical Appointment Clinic at Grady Memorial Hospital, Atlanta. Behavioral modification therapy for obesity had not been carefully tested in this type of population.

A computer program for Wiener filtering of evoked potential data.

We have developed a computer program for Wiener filtering of evoked potential data. The basic algorithm involves computation of the difference berween the power spectrum of the sweep sum and the sum of power spectra of individual sweeps. Power spectra are computed by means of the discrete Fourier transform.