Neonatal screening for cystic fibrosis

Cerebral atrophy often coexists with other brain disorders and by itself may alter the pattern of cerebral perfusion. If unrecognized, it may confound diagnoses based on brain single-photon emission tomography (SPET). In this retrospective study, we describe and evaluate criteria for the diagnosis of cerebral atrophy on technetium-99m hexamethylpropylene amine oxime brain SPET studies. The SPET scans of 11 patients with cerebral atrophy and ten controls were evaluated for the presence of a prominent interhemispheric fissure, presence of prominent cerebral sulci, separation of thalamic nuclei, and pronounced separation of caudate nuclei. The SPET studies were interpreted by two independent observers blind to the findings of magnetic resonance imaging, which provided the final diagnosis of cerebral atrophy. The combination of the four scintigraphic signs was accurate in the diagnosis of cerebral atrophy in 95% of the cases and had a sensitivity of 91% and a specificity of 100%.     

Screening for congenital hypothyroidism in cognitively delayed children

BACKGROUND: Estrogen replacement therapy (ERT) in postmenopausal women decreases cardiac mortality and improves endothelial function. The endothelium regulates vascular tone and growth by releasing such factors as nitric oxide and endothelin-1. OBJECTIVE: To determine whether ERT alters the balance between the total oxidized products of nitric oxide and endothelin-1. DESIGN: Single-arm, before-after clinical trial. SETTING: Outpatient clinical research center of an academic medical center. PATIENTS: 15 postmenopausal women. INTERVENTION: Treatment with 17 beta-estradiol for 6 months and a 10-day course of methoxyprogesterone every 3 months. MEASUREMENTS: Plasma nitric oxide and endothelin-1 levels were measured at baseline and after 6 months of ERT. RESULTS: The mean baseline nitric oxide level was 27.5 nmol/mL (range, 20.3 to 34.8 nmol/mL) and increased by a mean of 7.2 nmol/mL (range, 0.2 to 14.1 nmol/mL) (P = 0.04). The mean baseline plasma endothelin-1 level was 16.4 pg/mL (range, 12.0 to 20.8 pg/mL) and decreased by a mean of 3.9 pg/mL (range, 0.4 to 7.8 pg/mL) (P = 0.04). The mean baseline ratio of nitric oxide to endothelin-1 was 2.0 (range, 1.3 to 2.8) and increased by 1.2 (range, 0.1 to 2.2) (P = 0.03). CONCLUSION: ERT results in an increased ratio of nitric oxide to endothelin-1. This may be one mechanism by which ERT provides cardiovascular benefit.     

Ultrasound screening for congenital uterine anomalies

The aim of this study was to investigate the prevalence of congenital uterine anomalies in 1046 women attending gynaecological ultrasound clinics for a variety of indications. Using three-dimensional ultrasound, anomalies were found in 55 women (5.4%), including 32 (3.1%) with an arcuate uterus and 23 (2.3%) with major anomalies. The prevalence of uterine anomalies was similar to the findings in women undergoing elective sterilisation, but lower than in studies of women with recurrent miscarriage.     

Outcome of lower L-thyroxine dose for treatment of congenital hypothyroidism

The appropriateness of the recommended L-thyroxine dose (10-15 micrograms/kg/day) for the treatment of congenital hypothyroidism has been questioned because of the risk of iatrogenic hyperthyroidism. We report the outcome of 23 newborns with congenital primary hypothyroidism treated with 25 micrograms L-thyroxine per day (5.3-9.2 micrograms/kg/day) and followed for an average of 59 months. Serum thyroxine (T4) values increased (X = 11.4 +/- 2.7 micrograms/dL) within 4 weeks posttherapy; eight infants had T4 levels > or = 13 micrograms/dL on only half the currently recommended dose. Thyroid-stimulating hormone (TSH) values remained elevated in 18 of 21 patients for 2-21 months despite a high-normal T4. Psychometric tests were performed in 19 of the 23 patients. The mean Full Scale IQ for the congenital hypothyroid group (n = 16) was 101.4 +/- 13.2 with comparable Verbal and Performance IQ scores. Patients with a bone age (BA) of < or = 32 weeks or T4 < 2 micrograms/dL at initial evaluation had significantly Lower Verbal IQ scores. A standardized parent-report assessment of behavioral and emotional functioning revealed subgroup scale scores that were indistinguishable from nonclinical norms. We conclude that (1) average range IQ scores and positive behavioral adaptation are observed in congenitally hypothyroid children treated with L-thyroxine doses lower than currently recommended; (2) the L-thyroxine dose should be individualized to prevent iatrogenic hyperthyroidism; (3) TSH normalization should not be a primary objective of treatment, and (4) a prospective study comparing the advantages and risks of different doses of L-thyroxine is needed.     

Timing variability in children with early-treated congenital hypothyroidism

Hypertonic acetate solution in small volumes greatly improves cardiac output and corrects acid-base disturbances in hemorrhaged animals. We hypothesized that the combination of alpha alpha-crosslinked human hemoglobin (alpha alpha Hb), an oxygen carrier and vasoconstrictor, with hypertonic sodium acetate (HAHb), a vasodilator, may be effective for small volume resuscitation of hemorrhagic shock. Six pigs hemorrhaged to a mean arterial pressure of 40 mmHg for 60 min (bled volume: 23.6 +/- 2.5 ml.kg-1) received a single bolus of 4 ml.kg-1 of HAHb infused over two min. HAHb restored arterial pressure, increased systemic vascular resistance and caused a modest increase in cardiac output and SvO2, while pulmonary arterial pressure and vascular resistance were markedly increased. In two animals, transient severe hypotension and low cardiac output may have been due to acute pulmonary hypertension during injection. Compared to our previous study, in which animals received 4 ml-kg-1 of alpha alpha Hb alone, HAHb produced higher cardiac output and a smaller increase in systemic and pulmonary vascular resistance. However, slower, titrated infusions may be needed when hemoglobin solutions are combined with drugs or solutions that cause vasodilation in order to decrease the likelihood of acute hemodynamic instability.     

The instrumental and clinical laboratory follow-up of congenital hypothyroidism

Early diagnosis, L-tiroxine therapy and adequate follow-up are determinant to remove the damages resulting from hormone deficiency in congenital hypothyroidism (CH). In order to achieve a better intellectual development, the authors suggest some guidelines for a correct follow-up on the basis of their personal experience on a population of 160 children with CH. These guidelines include monitored therapy, biochemical controls, instrumental investigations, clinical and auxological serial examinations. To better predict the mental outcome of these patients as adults, the authors propose a longer follow-up till adolescents, especially in the children with more severe hypothyroidism at diagnosis.     

Incidence of febrile convulsions in children with congenital hypothyroidism

Brain excitability has been inconsistently reported to be increased both in hypo- and hyperthyroidism, but there have been few studies on the effects of thyroid hormones on brain excitability in children. With this in mind, we investigated the incidence of febrile convulsions (FCs) among patients with congenital hypothyroidism, who have been taking L-thyroxine since the age of 1 month. The incidence of FCs among congenital hypothyroid patients was 1.6% (1/63) which was significantly low (p < 0.05) compared with that of normal control children who visited our hospitals as outpatients (28/341, 8.2%) and that of others (322/3301, 9.8%) investigated 33 years ago in the same area. The incidence of FC among siblings of the 63 patients (7/74, 9.5%) was not statistically different from the controls. At least 8 of the 126 parents (6.4%) had experienced FC, however, only one child was affected in the 8 families. In conclusion, it seems likely that patients with congenital hypothyroidism on regular L-T4 replacement are less prone to experience FC. More studies on the incidence of convulsive disorders in children with thyroid diseases are needed to clarify the effects of thyroid hormones on brain excitability.     

Low growth hormone-binding protein in infants with congenital hypothyroidism

We evaluated the circulating levels of GH, insulin-like growth factor I (IGF-I), GH-binding protein (GHBP), and IGF-binding protein-3 (IGFBP-3) before L-T4 therapy in 19 infants with congenital hypothyroidism (CH), aged 12-29 days, diagnosed by neonatal screening and in a group of age- and sex-matched control infants. The same parameters were reevaluated after several months of treatment. Serum GHBP was measured by the high performance liquid chromatography-gel filtration method; serum GH, IGF-I, and IGFBP-3 levels were determined by commercial kits. The hypothyroid patients, before beginning therapy, presented significantly lower GHBP values than controls (P < 0.0001); during treatment, these values increased significantly; however, after 6 months they were still significantly lower than control values (P < 0.01). The pretreatment levels of GH were not significantly different from control values; after 1 month of treatment, GH did not show the decrease observed in controls and, therefore, was significantly higher (P < 0.01). The pretreatment levels of IGF-I were not significantly different from control values, but were lower in patients with severe than in those with mild hypothyroidism. They decreased at about 4 months of life and became significantly lower than control values at about 7 months of age (P < 0.05). In conclusion, it may be hypothesized that the condition of CH induces a change in GHBP expression, perhaps beginning in fetal life. The intrauterine production of IGF-I seems to be independent of the levels of GHBP and partially affected by fetal thyroid function.     

Current status of neonatal screening for congenital adrenal hyperplasia

Randomized trials are the optimal approach for evaluations of treatment efficacy but may not always be feasible. We study the adequacy of the case-control design in evaluating efficacy in a situation where the investigated therapy, namely the administration of magnesium sulfate for the prevention of eclampsia in patients with preeclampsia, has a suspected strong protective effect. A total of 66 cases of eclampsia were ascertained from among deliveries occurring between 1977 and 1992 at two hospitals in Houston, Texas. Randomly selected preeclamptic controls were matched to cases based on hospital and month of delivery. Magnesium sulfate administration prior to seizure occurrence had a strong protective effect against eclampsia in patients with preeclampsia (OR, 0.02; 95% CI, 0.01-0.05). This protective effect remained when controls were stratified by the degree of severity of preeclampsia (mild-to-moderate OR, 0.03, 95% CI, 0.01-0.09 and severe OR, 0.005; 95% CI, 0.0005-0.04) and when cases were stratified by the timing of the first seizure (antepartum and intrapartum seizures OR, 0.01; 95% CI, 0.003-0.05 and postpartum seizures OR, 0.03; 95% CI, 0.005-0.15). The effect also remained after adjustment for other important predictors in a multivariate logistic regression model (OR, 0.11; 95% CI, 0.03-0.38). The results of this study are in support of a recent randomized trial on the efficacy of magnesium sulfate as a prophylactic agent against eclampsia. Although there are serious potential sources of bias in this study, the magnitude of the protective effect of magnesium sulfate minimizes the likelihood that this effect can be explained by bias. Observational studies could be appropriate complements or alternatives to randomized trials in situations where a strong treatment effect is expected.     

Congenital hypothyroidism screening in Oklahoma: a change in follow-up recommendations for 1999

The new century brings unique challenges--especially Y2K compliance. This article presents nurse managers and executives with an overview of the issues and action steps to keep their organizations on track.     

Semiautomated enzyme immunoassay of thyrotropin as a mass screening test for neonatal hypothyroidism

A sensitive, simple, and rapid semiautomated sandwich enzyme immunoassay (EIA) was developed for measuring thyrotropin in dried blood samples on filter paper for use in screening for neonatal hypothyroidism. Good correlation was found between values for thyrotropin determined by this method and those determined by radioimmunoassay (RIA) (r=0.94). In pilot tests on 17,160 newborn infants in the general population, five cases of primary hypothyroidism were detected by both EIA and RIA. The recall rate was slightly highter in EIA than in RIA.     

Neonatal transient hypothyroidism: aetiological study. Italian Collaborative Study on Transient Hypothyroidism

AIMS: To define the aetiology of neonatal transient hypothyroidism (NTH) and recommend preventive measures. METHODS: Maternal and perinatal clinical data on the use of antiseptics, drugs, and contrast agents containing iodine were collected from 40 subjects. Thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), thyroglobulin (TG), TSH receptor antibodies, thyroid peroxidase antibodies and urinary iodine were measured in random neonatal samples. In the mothers with known or suspected thyroid disorders, TSH, FT4, TSH receptor antibodies and thyroid peroxidase antibodies were also measured. RESULTS: The NTH aetiology was identified in 85% of cases. More than 50% of the babies with transient hypothyroidism had been exposed to iodine; maternal transfer of antibodies had occurred in a third of them. CONCLUSIONS: It is suggested that the practice of using iodine containing disinfectants should be withdrawn, and chlorhexidine substituted instead; that pregnant women should be advised of the adverse effects of using iodine products; and that thyroid function should be monitored whenever iodine is used.