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Biomedical subjects

A Tenore

Publications and source records attributed to A Tenore.

At least 37 records · Page 2Linked to original sources

Prognostic signs in the evolution of premature thelarche by discriminant analysis.

Since premature thelarche (PT) can be a first sign of precocious puberty (PP), the aim of our study was to identify simple items in the course of the first 6 months of follow-up that could help predict if PT would evolve to PP. Thirty-two girls with PT were studied. First evaluation included bone age (BA), basal estradiol, FSH, LH and prolactin. GnRH was performed in 15 subjects and BA was checked at 6 month intervals in 30. Based on clinical outcome after a mean follow-up of 33.4 +/- 16.5 (SD) months, patients were divided into 2 groups: Group I (G-I) included subjects whose breast development either remained unchanged, increased or regressed; Group II (G-II) included subjects who progressed to PP. The multivariate combination of the items which was able to best discriminate between the two groups was chosen in predicting the evolution of PT. The items considered included four variables available at the time of diagnosis [chronological (CA) at onset less than 3 years, basal FSH, basal LH and BA/CA ratio] and two additional variables after a 6-month follow-up (delta BA/delta CA and growth velocity); 88% of G-I and 14% of G-II had CA less than 3 yr. Basal FSH levels were elevated in both G-I (7.6 +/- 3.0 mIU/ml) and G-II (12.1 +/- 4.1) with respect to controls (2.6 +/- 1.2); however, approximately 20% of G-I had low FSH levels. Basal LH levels were consistently higher in G-II (8.0 +/- 1.3 mIU/ml) than in G-I (2.9 +/- 1.5) or controls (2.8 +/- 1.2). Although initial BA was advanced (greater than 2SD) in 21% of G-I and in all of G-II, an acceleration of BA was seen only in G-II. The mean growth velocity of G-I (44.1 +/- 31.5%) was significantly less than G-II (92 +/- 32%; p less than 0.0025). With the help of the discriminant equations derived from data obtained at diagnosis and during the first 6 months of follow-up, all subjects with isolated premature thelarche could be sharply distinguished from those who subsequently progressed to precocious puberty.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

X-linked ichthyosis, due to steroid sulphatase deficiency, associated with Kallmann syndrome (hypogonadotropic hypogonadism and anosmia): linkage relationships with Xg and cloned DNA sequences from the distal short arm of the X chromosome.

We report a large Italian pedigree in which five out of six males are affected by a syndrome, following an X-linked inheritance pattern, characterized by ichthyosis, hypogonadotropic hypogonadism, and anosmia. The concurrence of features of X-linked ichthyosis (XLI) with those of Kallmann syndrome, another disease often inherited as an X-linked trait, prompted us to perform biochemical, cytogenetic, and molecular studies in relation to the short arm of the X chromosome (Xp). Steroid sulphatase (STS) activity was found to be completely deficient in all affected members of the family. Prometaphase chromosome analyses of two obligate heterozygous women and one affected male showed normal karyotypes. Xg blood group antigen analysis and molecular studies employing cloned DNA sequences from the distal segment of the Xp (probes RC8, 782, dic56, and M1A), did not provide evidence for deletions or rearrangements of the X chromosome. The linkage analysis showed no crossovers between the disease, Xg, and DXS143, the locus defined by probe dic56, thus suggesting the possibility of a linkage between these two markers of the distal segment of Xp and the X-linked ichthyosis, hypogonadism, and anosmia syndrome.

Adolescent

Congenital giant diverticulum of the posterior urethra in a 4-year-old boy.

A congenital giant diverticulum of the posterior urethra in a 4-year-old boy is reported. The theories on development of congenital urethral diverticula are considered and the importance of the clinical, radiological, endoscopical and histological examination for the differential diagnosis of the acquired diverticula and enlarged utricle is emphasised. In the majority of diverticula transurethral unroofing is most appropriate. The larger and symptomatic diverticula require open excision and eventually urethral reconstruction. Small asymptomatic diverticula may not require any treatment.

Child, Preschool

Vasculitis, pulmonary cavitation, and anemia during antithyroid drug therapy.

Two thyrotoxic girls, aged 12 and 16 years, had a clinical picture consisting of purpuric skin rash, nephritis, pulmonary cavitation, hemoptysis, and profound anemia during antithyroid drug therapy. These major toxic manifestations prompted discontinuation of antithyroid drugs and institution of antibiotic and glucocorticoid therapy before the resolution of the severe illness. The girls eventually required ablative doses of radioactive iodine, and one of them had a thyroidectomy for the treatment of thyrotoxicosis. The skin biopsy specimen in one patient was indicative of mononuclear cell cutaneous vasculitis. After recovery, the patients had no evidence Of persistent anemia, nephritis, or pulmonary parenchymal disease.

Adolescent

Separation and radioimmunoassay of T3 and T4 in human breast milk.

There is little agreement among published reports of the radioimmunoassayable thyroid hormone content of breast milk, likely due to wide variations in methodology applied. In order to achieve a higher degree of specificity in the determination of T3 and T4 concentrations in breast milk, samples were ethanol-extracted and then chromatographed on an LH-20 column. Using this method, all T3 and T4 RIA activity eluted with the void volume. Following pancreatin digestion and subsequent extraction of whole milk samples, void volume T3 RIA activity decreased, and T3 co-eluted primarily with a standard preparation of T3 or 125I-T3, at a concentration of 275 +/- 132 ng/dl (mean +/- SD) (n = 9). In contrast, the elution volume of T4 RIA activity appeared unaffected by pancreatin. These data indicate that immunoreactive T3 and T4 are differentially bound to a thyroid hormone 'binding' substance present in breast milk. They further support the hypothesis that thyroid hormone sufficient to supplement the thyroid economy of the thyroid-deficient suckling infant is present in human breast milk.

Adult

A thyroxine-binding protein in human breast milk similar to serum thyroxine-binding globulin.

A thyroid hormone-binding substance (TBGw) similar to serum T4-binding globulin (TBG) has been identified in the whey fraction of human breast milk. TBGw coeluted with serum TBG, as determined by Bio-Gel P-100 chromatography, and has an isoelectric point of 4.2-4.8, similar to that of serum TBG. The affinity constant of TBGw for T4 was similar to that of serum TBG(Ka, 1.54 +/- 0.38 X 10(9) M-1). Marked inhibition of TBGw binding of [125I]T4 was achieved by the addition of 1.5 X 10(-3) M 8-anilino-1-naphthalene-sulfonic acid. An albumin-like low affinity site (Ka, greater than 10(7) M-1) was also found. RIA of whey concentrates serially diluted in TBG-depleted serum indicated nearly identical binding curves for TBGw and TBG, with slopes of 2.33 (n = 15; r = 0.947) and 2.54 (n = 7; r = 0.996), respectively. Using a specific TBG RIA, a TBGw concentration of 0.29 +/- 0.08 microgram/ml (mean +/- SD) in breast milk (n = 26) was determined. Paired serum and whey specimens from individuals between 6 and 20 weeks of lactation were analyzed by TBG RIA; in these individuals, mean serum TBG concentrations were 25.0 +/- 3.4 micrograms/ml (n = 7); corresponding TBGw levels were 0.26 +/- 0.08 micrograms/ml (n = 7), i.e. approximately 1% of serum levels. Nonetheless, linear regression analysis of the data revealed no significant correlation between serum and whey TBG concentrations in these individuals.

Albumins

n-acetyl-beta-hexosaminidase activity in human breast milk.

1. The lysosomal enzyme, N-acetyl-beta-hexosaminidase (HEX) is present in human breast milk. It is composed predominantly of "A" (heat-labile) and "B" (heat-stable) isozymes which coelute with the corresponding major serum isozymes on DE-52 ion-exchange chromatography. 2. Total HEX activity in "early" milk obtained at 2.8 +/- 1.4 weeks post partum, is approx. 2.5-fold higher (87 +/- 29 nmol/60'/mg protein. n = 10) than that of pregnancy serum (35.7 nmol/60'/mg protein) prior to delivery. 3. These levels increase to greater than 3-fold (110 +/- 20 nmol/60'/mg protein, n = 13) as the milk matures (10.3 +/- 4.2 weeks). 4. The specific activity of HEX A in the milk changes little with time post partum, because absolute 5. In contrast, HEX B specific activity is increased, as absolute levels (per volume) remain constant in the face of decreasing milk protein content, 5. These changes result in a high degree of correlation (r = 0.81) between time of lactation and % HEX A observed.

Adolescent

Cytogenetic and endocrine findings in a female with 45,X,t(y;18) (p11;p11).

A 23-year-old phenotypic female with congenital heart disease, mental retardation and mild virilization was referred for evaluation of short stature and delayed sexual development. Endocrine studies revealed a markedly elevated serum testosterone, which was within the adult range. At laparotomy, a small uterus, normal fallopian tubes and bilateral gonadal tumors, consisting of a left gonadoblastoma and right dysgerminoma were found. Trypsin G banding of peripheral blood revealed a 45,XO, 18p+ karyotype. Q banding demonstrated intense fluorescence of the distal portion of the extra material on chromosome 18, consistent with fluorescence of Y chromosomal heterochromatin. A combination of banding techniques enabled us to determine a 45,X,t(Y;18) (p11;p11) karyotype in peripheral blood. Cultures of gonadal tissue revealed 45,X,t(Y;18)/46,XY mosaicism.

Adult

Thyrotropin in human breast milk.

The thyrotropin (TSH) content of human breast milk was investigated, using both direct 125I-TSH radioimmunoassay and radioimmunoassay preceded by a partial purification step of elution from concanavalin A-Sepharose 4B. 15 samples of human milk between 1 and 13 weeks post-partum were found to contain 2.0 +/- (SD) 0.9 microU TSH/ml when assayed after Con A-extraction and adjusted for recovery by interpolation of a standard curve of Con A-extracted TSH standards. Recovery of 125I-hTSH tracer from both serum standards (58.6 +/- 5.5%; n = 10) and milk (53.6 +/- 6.7%; n = 15) were comparable. TSH levels obtained post-extraction were not significantly different from those that TSH is present in human breast milk in low concentrations, comparable to those normally found in the serum of euthyroid adults.

Adult

Diagnosis of ectopic thyroid: value of pretracheal soft-tissue measurements.

Thyroid ectopia, dysgenesis, or agenesis has been conventionally diagnosed with the use of radioisotope scanning procedures. This report proposes the use of a conventional lateral radiograph of the neck to determine the presence or absence of the thyroid gland in its normal anatomic position. The thyroid gland is ensheathed by the pretracheal layer of the deep cervical fascia anterior to the trachea. The gland's presence or absence can be determined by calculating the ratio of the soft-tissue measurements between the anterior wall of the trachea and both the outer margin of the skin and the margin of the subcutaneous fat as determined from a lateral radiograph of the neck. This "pretracheal ratio" may be used to accurately differentiate between a lingual thyroid and other masses at the base of the tongue.

Adolescent

Changes in serum N-acetyl-beta-hexosaminidase levels after treatment of hypothyroid and hyperthyroid individuals with L-thyroxine and propylthiouracil.

Multiple serum samples were obtained from six hypothyroid and six hyperthyroid females, 11--17 years of age, over the course of their corrective treatment with L-thyroxine (LT4) and propylthiouracil (PTU), respectively. Sera were assayed for total N-acetyl-beta-hexosaminidase (HEX), the A (heat-labile) and B (heat-stable) isozymes, and total T4. HEX activity (total HEX A) in sera from hypothyroid (< 4 micrograms/dl T4) patients (total HEX: 518 +/- 66 nmol/60 min/ml, mean +/- S.D.; HEX A: 325 +/- 55; n = 5) was significantly lower than that of the euthyroid control group (total HEX: 638 +/- 77 (p < 0.005); HEX A: 420 +/- 76 ( p < 0.01); n = 23); no difference in HEX B levels was noted. Serum samples from patients successfully treated for hypothyroidism via oral administration of LT4 (n = 12) displayed levels of total HEX (722 +/- 113) and HEX A (491 +/- 91) significantly higher than those of the control group (p < 0.01 in both cases); again, no change in levels of HEX B was observed. HEX activity in sera from hyperthyroid (> 13 micrograms/dl T4) individuals (total HEX: 839 +/- 96; HEX A: 540 +/- 74; HEX B: 299 +/- 52; n =20) was significantly higher than that of the control group (p < 0.005 in all cases). The depression of hormone activity to the euthyroid range by PTU was accompanied ay a decrease in enzyme activity to control levels (total HEX: 632 +/- 92; HEX A: 400 +/- 55; HEX B: 232 +/- 52; n = 16). Non-parametric analysis of the data shows highly significance differences between pre- and post-treatment enzyme levels (alpha < 0.001) in both hyper- and hypothyroid groups. Alteration of thyroid status, and specifically T4 level is, therefore, indicated to be a contributing factor in the regulation of serum HEX activity in humans, as evidenced by individual responsiveness to oral administration of this hormone, or inhibitors of its peripheral metabolism.

Adolescent

Sex differences in serum levels of N-acetyl-beta-hexosaminidase in infancy: correlation of enzyme activity with testosterone levels.

Serum levels of N-acetyl-beta-hexosaminidase (HEX) (EC 3.2.1.30) activity in infants display a sexual dimorphism. Total HEX activity in males between 1 and 3 months of age is significantly elevated over female levels (male (M), 1535 +/- 300 nmol/60 min/ml; female (F), 1150 +/- 203, P < 0.0005), and the A (labile) isozyme constitutes a significantly lower proportion of the total activity present (M, 56.0 +/- 4.2, N = 24; F, 64.3 +/- 4.6, N = 21, P < 0.0005). These findings led us to investigate the relationship between testosterone concentration and HEX activity in serum. Samples from male (N = 36) and female (N = 33) infants between 1 and 6 months of age were included. In both sexes, a high degree of correlation (P < 0.0005) was observed between testosterone and total HEX (M, r = 0.71; F, r = 0.73), HEX A (M, r = 0.68; F, r = 0.56) and HEX B (M, r = 0.68; F, r = 0.72). An inverse relationship exists between testosterone levels and % A: M, r = -0.56; F, r = -0.38 (P < 0.0025 and 0.025, respectively). In contrast, no correlation between HEX levels and testosterone was evident in either male or female adults (r = 0.20 and 0.18, respectively). These data implicate testosterone in the regulation of HEX activity during the early months of human development.

Adult

Thyroidal response to peroral TSH in suckling and weaned rats.

The biological activity of perorally administered bovine thyroid-stimulating hormone (bTSH) was investigated in suckling (14-day-old) and weaned (30-day-old) rats. Animals were treated with water or bTSH given either by subcutaneous injection or by the oral route. Both suckling and weaned animals responded to subcutaneous administration of bTSH by an increase in serum thyroxine (T4) and triiodothyronine (T3) concentrations. Bovine TSH administered orally to weaned animals had no effect on thyroid hormone levels. In contrast, suckling pups responded to perorally administered bTSH with increases of T4 and T3 levels comparable to those achieved in animals that received bTSH subcutaneously. The characteristics of the gastric secretion and intestinal epithelium of the weaned animal, therefore, appear to play a role in preventing absorption of a polypeptide hormone. However, protein hormones contained in maternal milk can be transferred to the suckling in which their full biological functions can be expressed.

Administration, Oral

Effect of triiodothyronine injection on levels of triiodothyronine and thyroid-stimulating hormone in sera and milk of lactating rats and in sera of their sucklings; precocious development of jejunal alpha-disaccharidases in the sucklings.

Administration of high doses of triiodothyronine (T3) for 4 days to lactating rats evokes an increase in T3 levels in their sera and milk, as well as in the sera of pups suckled by them. Thyroid-stimulating hormone levels in sera of mothers and sucklings are decreased. Suckling rats of T3-treated mothers exhibit a precocious increase in the activity of jejunal sucrase and maltase as well as in activity of several liver acid beta-glycosidases.

Acetylglucosaminidase