Luiz. Lacerda

O tumor do córtex adrenal (TCA) na infância é raro. Entretanto, no Paraná sua incidência é 15 vezes maior do que a observada em outros países. Descrevemos as características clínicas, laboratoriais, tratamento e evolução de 125 pacientes atendidos em uma única instituição no Paraná. A média de idade ao diagnóstico foi de 4,3 anos, com uma relação feminino:masculino de 2,6:1. As formas clínicas mais comuns foram virilização isolada (51,2%) e virilização e síndrome de Cushing (42%). Em 4,8% dos casos, os tumores foram não-funcionantes. Dois pacientes (1,6%) apresentaram síndrome de Cushing isolado e 1 (0,8%) síndrome de Conn. Hipertensão arterial ocorreu em 56% dos pacientes. O único tratamento curativo é a cirurgia. Os dados da nossa casuística mostram que estádio clínico 1 do TCA, ausência de trombo intra-venoso e ausência de spillage durante a cirurgia estão associados a uma maior sobrevida.

Purpose We created a registry for pediatric adrenocortical tumors (ACTs), which are rare and are not well characterized. We provide a descriptive analysis of 254 patients registered on the International Pediatric Adrenocortical Tumor Registry. Patients and Methods Between January 1990 and December 2001, 254 patients younger than 20 years of age with newly diagnosed or previously treated ACTs were registered. A histologic diagnosis of ACT was required, although central review was not mandatory. Follow-up information was periodically requested from the referring physician. Treatment was chosen by the primary physician. Results The overall female-male ratio was 1.6:1, but it varied widely among age groups. The most common presenting sign (84.2%) was virilization. Cushing's syndrome without virilization was uncommon (5.5%). Tumors were completely resected in 83% of patients. Patients with disseminated or residual disease received mitotane, cisplatin, etoposide, and/or doxorubicin, a...

Tumores tireoideanos são raros na infância e adolescência. Foram revisados os prontuários de quinze pacientes (8 do sexo feminino) com idades entre 5,8 e 15,2 anos, atendidos na Unidade de Endocrinologia Pediátrica (UEP) do HC-UFPR entre fevereiro de 1988 e março de 2003. Nódulo cervical anterior foi a queixa inicial mais freqüente. Dez pacientes eram portadores de carcinoma papilífero (CP), quatro apresentavam carcinoma medular (CMT; dos quais, três com NEM-2B) e um, carcinoma folicular. Dois pacientes com NEM-2B apresentam mutação de novo (Met918Thr) do proto-oncogene RET. PAAF, efetuada em dez pacientes, foi positiva para neoplasia em cinco deles. Todos os pacientes foram submetidos a tireoidectomia total. Terapia adjuvante com 131I foi realizada em dez pacientes. Dois pacientes faleceram por doença não relacionada ao tumor. Nove pacientes não apresentam evidência clínica ou laboratorial do tumor; um (CP) apresentou recidiva 5 anos após o tratamento inicial e três (1 CP, 2 CMT) a...

O tumor do córtex adrenal (TCA) na infância é raro. Entretanto, no Paraná sua incidência é 15 vezes maior do que a observada em outros países. A mutação germinativa R337H TP53, presente em mais de 95% dos nossos pacientes, provavelmente está relacionada à maior incidência. Cento e vinte e cinco pacientes foram tratados no período de 1966 a 2003. A cirurgia é o único tratamento curativo. Em nossa experiência, tumores no estádio I, ausência de spillage durante a cirurgia e ausência de trombo são parâmetros relacionados à maior sobrevida. Dados preliminares mostram que a associação de etoposídeo, doxorrubicina, cisplatina e mitotano produziu remissão completa do tumor e/ou das metástases em alguns pacientes. Os efeitos colaterais destas drogas são comuns e pode ocorrer insuficiência adrenocortical. As doses de reposição de glicocorticóides e mineralocorticóides devem ser 2 a 3 vezes maiores que as doses fisiológicas.

A Doença de Graves (DG) é responsável por mais de 90% dos casos de hipertireoidismo em crianças. Na DG, o hipertireoidismo é causado por anticorpos estimuladores dirigidos contra o receptor do TSH, conhecidos como TRAb (TRAb, Thyrotropin Receptor Antibody), que mimetizam os efeitos do TSH. O hipertireoidismo pode, ainda, ser devido a mutações nos genes do receptor do TSH ou da sub-unidade alfa da proteína G e secreção inadequada de TSH, ao passo que tireotoxicose pode ser causada por tireoidite de Hashimoto ou tireoidite sub-aguda. O tratamento inicial da DG é feito com drogas antitireoidianas (DAT) e o tratamento definitivo com DAT, tireoidectomia ou 131I. Nenhum oferece segurança, efetividade e eutireoidismo permanente. beta-bloqueadores podem ser usados para diminuir os sinais adrenérgicos. As DAT inibem a síntese de T3 e T4 e agem sobre o sistema imune; o propiltiouracil (PTU) diminui a conversão periférica de T4 a T3. Recomenda-se PTU, 5-10mg/kg/dia, em três tomadas; ou metimaz...

A 14-year-old female presented to the Pediatric Endocrine Clinic, Universidade Federal o Parana Curitiba, Brazil, for obesity. A few years later, despite normal breast development, the patient had failed to menstruate and lacked pubic and axillary hair. Laboratory analyses revealed high levels of testosterone. Karyotype analysis was XY. Direct sequencing of her genomic DNA showed a G to T transition at nucleotide 2089 at exon 2 in the androgen receptor gene, resulting in a substitution of Phe for Cys at position 576. This mutation disrupts the first Zn finger critical to DNA binding and transcriptional activity and results in complete androgen-insensitivity syndrome (CAIS). This individual was part of 700-member multigenerational kindred of German origin living in small villages in Southern Brazil. Family members who gave informed consent were screened using a polymerase chain reaction-based method. Nineteen CAIS-affected individuals and carriers were identified. All presented with infertility and lack of or sparse pubic hair. The prevalence of common AIS within the kindred greatly exceeds that of the general population and is due in part to their isolated familial and community structures. All individuals are genuinely feminine in their appearance, sex behavior, gender identity, and integration within their communities. We conclude that CAIS leads to complete feminization of XY individuals and results in individuals who are psychologically and socially established and integrated as women within the familial and cultural contexts of their communities.

ObjectivesAdequate treatment of congenital hypothyroidism (CH) is required for normal growth and sexual development. To evaluate pubertal development in patients with permanent CH detected by a statewide Neonatal Screening Program of Paraná and, secondly, to evaluate adult height (AH) in a subgroup of patients.MethodsClinical, laboratory, and auxological data obtained from medical records of 174 patients (123 girls).ResultsMedian chronological age (CA) at treatment initiation was 24 days, and mean initial levothyroxine dose was 11.7 ± 1.9 μg/kg/day; mean CA at puberty onset was 11.5 ± 1.3 years (boys) and 9.7 ± 1.2 years (girls); mean CA in girls who underwent menarche (n=81) was 12.1 ± 1.1 years. Thyroid-stimulating hormone (TSH) values above the normal range were observed in 36.4% of the boys and 32.7% of the girls on puberty onset, and in 44.6% around menarche. Among 15 boys and 66 girls who had reached the AH, the median height z-score value was significantly greater than the ta...

Experimental and clinical studies suggest that GH and IGF-I may be involved in neovascularization of the retina in diabetes and retinopathy of prematurity. However, the role of GH and IGF-I has not been well established in normal retinal vessel development in humans. Therefore, we examined retinal vessel morphology by digital image analysis of ocular fundus photographs in 13 patients with genetic defects of the GH/IGF-I axis and low levels of IGF-I during and after normal retinal vessel growth. Eleven patients (four females and seven males aged 10–49 yr) had defects of the GH receptor (Laron syndrome). One male (20 yr) had a partial deletion of the IGF-I THERE HAS BEEN great interest in the mechanism of retinal neovascularization because it plays a critical role in retinopathy of prematurity (ROP), diabetic retinopathy, and age-related macular degeneration. Several decades

Objective: This study aimed to determine the frequency of diabetic ketoacidosis (DKA) as initial presentation among patients with type-1 Diabetes Mellitus (DM-1) following in Aseer Diabetes Center of Aseer Region, Southwestern of Saudi Arabia. Patients and Methods: Retrospectively we reviewed and analyzed medical records of type-1 DM children who were less than 15 years and diagnosed with DKA at initial presentation, over period of 7 years from February 2006 till January 2013. Results: Out of 508 diabetic patients, 244 (48%) patients had DKA at the initial presentation. The mean age was 8.5 years. 120 (49.1%) with DKA were males and 124 (50.9%) females. Six patients with type-1 DM were less than one year and 5 (83.3%) of them were in DKA, compared with the 239 patients (47.6%) of the remaining 502 patients beyond this age. Generally, frequency of DKA among patients from (1-5) year was 51.7% (N=176) and more than 5 years was 46.9% (N=153). No death, renal failure or permanent neurolo...

Objective: To analyze the variables associated with the presence of diabetic ketoacidosis in type 1 diabetes mellitus (T1DM) diagnosis and its impact on the progression of the disease. Methods: We reviewed the records of 274 children and adolescents under 15 years, followed in a Pediatric Endocrinology clinic of a university hospital in Curitiba-PR. They had their first appointment between January 2005 and April 2015. Results: Most patients received their T1DM diagnosis during a diabetic ketoacidosis episode. The associated factors were: lower age and greater number of visits to a physician’s office prior to diagnosis; diabetic ketoacidosis was less frequent in patients who had siblings with T1DM and those diagnosed at the first appointment. Nausea and vomiting, abdominal pain, tachydyspnea, and altered level of consciousness were more common in the diabetic ketoacidosis group. There was no association with socioeconomic status, duration of symptoms before diagnosis, and length of t...

Purpose To evaluate the phonological characteristics of children with congenital hypothyroidism (CH). Methods Observational, analytical, cross-sectional, ambispective study including prepubertal children with CH (n=100; study group, SG) and controls without CH ( n=100; control group, CG). Assessments included a speech language pathology interview, the phonological evaluation of the ABFW Child Language Test, medical data, and neuropsychological tests in the first three years of life. Results On treatment onset of the SG, the median chronological age of the participants was 18.0 days and 48.4% had total T4 <2.5 µg/dL (31.75 nmol/L). At the age of 7 years, children in the SG had higher rates of consonant cluster simplification and lower rates of complete phonological system compared to those in the CG. On analysis of combined age groups (4+5 and 6+7 years), the CG had a higher frequency of complete acquisition versus the SG. On multivariate analysis, thyroid agenesis, abnormal score...

Background During the transition phase (TP), patients with growth hormone deficiency (GHD) exhibit decreased muscle strength. Studies assessing the effects of resistance exercise alone on muscle strength in these individuals are scarce. The objective of this study was to evaluate the effects of a program of resistance exercise (PRE) on parameters of muscle strength in subjects in the TP and with childhood-onset GHD treated with recombinant GH (rGH). Methods Sixteen male patients were enrolled and divided into two groups: GHD (n=9) and GH sufficiency (GHS, n=7). Patients with GHD underwent a 12-week PRE followed by another 12-week PRE plus rGH, while GHS patients underwent a 12-week PRE alone. Dynamic knee muscle strength was evaluated using an isokinetic dynamometer. Results Before PRE, there were significant differences between the groups regarding the results of flexor peak torque (FPT) normalized to body weight (BW-FPT) in the dominant (DO, p=0.008) and non-dominant (ND, p=0.01) ...

To evaluate the vocal characteristics of a group of children with congenital hypothyroidism (CH) and the association of these characteristics with the children's clinical, laboratory, and therapeutic profiles. Observational, analytical, cross-sectional study including 200 prepubertal children, of whom 100 had CH (study group [SG]) and 100 had no CH (control group [CG]). The following parameters were evaluated: 1) history (identification, complaints, and interfering variables), 2) auditory-perceptual and acoustic evaluation (samples analyzed by a group of specialists, and objectively by a computer program), 3) self-assessment scores in the Pediatric Voice-Related Quality-of-Life (PVRQoL) survey, 4) laryngological evaluation (presence or absence of laryngeal lesions and data regarding glottal closure), and 5) medical records (CH etiology, age at treatment initiation, disease severity at diagnosis, treatment quality, and thyroid function tests on the day of the examination). In the...

Splicing CYP19 gene variants causing aromatase deficiency in 46,XX disorder of sexual development (DSD) patients have been reported in a few cases. A misbalance between normal and aberrant splicing variants was proposed to explain spontaneous pubertal breast development but an incomplete sex maturation progress. The aim of this study was to functionally characterize a novel CYP19A1 intronic homozygote mutation (IVS9+5G>A) in a 46,XX DSD girl presenting spontaneous breast development and primary amenorrhea, and to evaluate similar splicing variant expression in normal steroidogenic tissues. Genomic DNA analysis, splicing prediction programs, splicing assays, and in vitro protein expression and enzyme activity analyses were carried out. CYP19A1 mRNA expression in human steroidogenic tissues was also studied. A novel IVS9+5G>A homozygote mutation was found. In silico analysis predicts the disappearance of the splicing donor site in intron 9, confirmed by patient peripheral leukocyte cP450arom and in vitro studies. Protein analysis showed a shorter and inactive protein. The intron 9 transcript variant was also found in human steroidogenic tissues. The mutation IVS9+5G>A generates a splicing variant that includes intron 9 which is also present in normal human steroidogenic tissues, suggesting that a misbalance between normal and aberrant splicing variants might occur in target tissues, explaining the clinical phenotype in the affected patient. © 2015 S. Karger AG, Basel.

Adrenocortical carcinoma (ACC), a very rare tumor in children in the United States, is apparently more common among Brazilian children. We reviewed the medical records of 40 children whose disease was diagnosed between 1966 and 1987. There were 12 boys and 28 girls; their median age was 3.9 years (range, 1 day to 15.7 years). Virilization was the most common clinical sign (37 of 40); other signs included abdominal mass, deepened voice, plethora, hypertension, seizures (seven patients) and, rarely, weight loss (two patients). The median time between first signs or symptoms and diagnosis was 1.4 years (range, 3 days to 5 years). Four of 33 tumors were classified as benign according to the Weiss, van Slooten, or Hough systems (tumor tissue was unavailable for seven patients). Tumors were completely resected in 26 of 38 patients; of those, 17 are in continuous complete remission, five relapsed, and four have been lost to follow-up. One patient, who had local recurrence, has been in a th...

OBJETIVO: associar os índices de autoavaliação vocal aos dados da avaliação clínica de indivíduos disfônicos. MÉTODOS: estudo observacional, analítico, retrospectivo. Foram analisados os prontuários de pacientes disfônicos atendidos em uma Clínica-Escola de Fonoaudiologia no período de 2007 a 2011. Foram levantados os dados referentes à autoavaliação vocal (índices de qualidade de vida em voz, desvantagem vocal e atribuição de nota referente ao impacto vocal), à anamnese (sexo, idade, profissão, tipo de queixa, tempo de queixa, tratamentos anteriores para a disfonia), à avaliação perceptivo-auditiva (qualidade vocal, grau de alteração, pitch, loudness, ressonância, articulação e coordenação pneumofonoarticulatória) e aos dados objetivos (tempos máximos fonatórios e relação s/z). Os dados foram tabulados e analisados estatisticamente. RESULTADOS: não houve diferença na comparação dos escores do protocolo de qualidade de vida em voz e índice de desvantagem vocal com as variáveis refer...

The pituitary-specific transcription factor Pit-1/GHF-1 is responsible for pituitary development and expression of somatotrophs and lactotrophs as well as hormonal regulation of the prolactin (PRL) and thyrotropin (TSH) beta genes by thyrotropin-releasing hormone (TRH) and cyclic adenosine monophosphate (cAMP). Pit-1 gene mutations result in complete growth hormone (GH) and PRL deficiencies and variable degrees of TSH deficiency, producing the clinical syndrome of combined pituitary hormone deficiency (CPHD). Several cases of mutations in the Pit-1 gene have been reported; the most common one is a sporadic mutation altering an arginine (R) to a tryptophan (W) in codon 271, in one allele of the Pit-1 gene. We describe a case of a 38-year-old woman, born to consanguineous parents, presenting with growth failure and hypothyroidism. Growth failure was noted from early infancy, whereas hypothyroidism was only apparent from adolescence. She had almost undetectable GH and PRL levels and an inappropriate low TSH for very low triiodothyronine (T3) and thyroxine (T4) levels, while the remaining pituitary evaluation was normal. The pituitary gland was hypoplastic by magnetic resonance imaging. A point mutation in exon 6, monoallelic, causing a C to T substitution that changes amino acid 271 from Arg (R) to Trp (W) was identified. Children with Pit 1 mutations and delayed onset of hypothyroidism may be initially diagnosed as isolated GH deficiency.

We assessed body composition and muscle strength during the transition phase in 18 growth hormone (GH) deficient males treated with recombinant GH to final height and 18 controls. According to peak-stimulated GH and basal insulin-like growth factor-1 (IGF-1) during the transition phase, patients were subdivided into GH deficient (GHD-TP, n=9) and GH sufficient (GHS-TP, n=9) groups. Assessments included lean and fat body mass and bone mineral density (BMD), all measured by dual-energy X-ray absorptiometry, and dynamic knee muscle strength, assessed by isokinetic dynamometer. Total body and lumbar spine BMD and muscle strength were lower in GHD-TP patients when compared with GHS-TP and controls (all p<0.05), whereas lean and fat body mass were lower in both GHD-TP and GHS-TP patients when compared with controls (p<0.05). These findings suggest that administration of recombinant GH to final height is not sufficient to provide normal body composition and muscle strength in young male patients with GH deficiency.

Congenital hypothyroidism (CH) is mainly due to developmental abnormalities leading to thyroid dysgenesis (TD). TD encompasses very distinct morphologic subtypes of disease. This study examined and compared the phenotype in TD variants and searched for genetic alterations in sporadic thyroid hypoplasia (TH), the most misdiagnosed form of CH. This was a longitudinal study over a 14-year period (1990-2004). A continuous series of 353 children with TD was identified using thyroid function tests [thyroxine (T4) and TSH], scintigraphy, and ultrasound as diagnostic tools. Individual phenotypes were analyzed in 253 children with TD. Mutations in the most likely candidate genes were studied in 35 cases of TH. The overall birth prevalence of permanent CH was 1:4795. Ectopy represented 37% of all cases of permanent primary CH, dyshormonogenesis 28%, agenesis 24%, hypoplasia 10%, and hemiagenesis 1%. The lowest screening T4 level and the highest TSH level were in the agenetic group, followed by TH. The TH group had an improvement in the thyroid function showing less-severe phenotype with aging. In the molecular analysis, one patient was identified with a mutation in the PAX8 gene (155G>C; R52P); four patients had a heterozygous G>C substitution in position -569; two patients showed a (234C>A; P52T) or (2181C>G; D727E) polymorphic variants of the TSH-R gene; and one patient presented a novel heterozygous nonsynonymous substitution, 293G>A; S98N, in the NKX2.5 gene. The prevalence of CH was within the previously reported range of 1:3000-4000. Ectopy was the most common etiology. Clinical analysis revealed distinct hormonal patterns in TH subgroup when compared with other variants of TD, with genetic abnormalities identified only in few cases in the TSH-R, PAX8, and NKX2.5 genes.

Twenty of 67 children registered on the International Registry of Childhood Adrenocortical Tumors between May 1988 and December 1994 had small adrenocortical tumors (defined for this study as measuring < or = 200 cm3 and/or weighing < or = 100 g). We reviewed the records of these 20 patients to characterize the clinical and pathologic findings and outcomes of children with small adrenocortical tumors. Median patient age was 2 years (range, 4 months to 5 years). There was only one boy. All had clinical signs of virilization, and seven had signs or symptoms of Cushing syndrome. A median 5.5 months (range, 1-40 months) had elapsed between the first signs of endocrine dysfunction and diagnosis. All tumors were surgically resected. Tumor volume was 3.3-195 cm3 (median, -8.7 cm3), and weight was 3.7-100 g (median, 36 gm Tumor samples were histologically reviewed in 18 cases. Eight were adenomas, and 10 were carcinomas (6 low grade and 4 high grade). Pathology records described tumor with diagnostic features of adrenocortical carcinoma in two patients. One patient received mitotane for 8 months after surgery. Only one patient had recurrent disease, which was detected 6 months after diagnosis and proved rapidly fatal. Another has been lost to follow-up. The remaining 18 patients are alive with no evidence of disease at a median 2.3 years (range, 6 months to 6.1 years) after diagnosis. Our data suggest that children with small adrenocortical tumors have an excellent prognosis with surgery as the sole therapy, regardless of tumor histiotype.

Four male pseudohermaphrodites from two families have been described. Although reared as females, at puberty, the timing, pattern, and degree of masculinization was similar to that of a normal male. No feminization occurred. They had normal testicular testosterone synthesis as judged by plasma testosterone, LH and FSH concentrations, as well as incubations of testicular minces with labeled precursors. Studies on cultured skin fibroblasts indicated adequate peripheral 5 alpha-reductase and normal receptor affinity and capacity for dihydrotestosterone. The histology of the testis was suggestive of a primary testicular defect. A mosaic pattern was seen: some areas contained tubules with active spermiogenesis; other areas, only Sertoli cells. These male pseudohermaphrodites appear to have a defect in fetal testicular maturation in which inadequate fetal testosterone synthesis and defective differentiation of germinal elements occurred.

The discriminatory power of three clinical tests for adrenal activity are compared by measuring the variability of the results obtained in 40 normal control subjects, 35 patients with mild essential hypertension, and 13 patients with Cushing syndrome. The variance of the 24-h integrated plasma concentration of cortisol was significantly (P < 0.0001) smaller than the variance of the 24-h urinary excretion of 17-hydroxycorticosteroids and free cortisol. While the 24-h urinary excretion of 17-hydroxycorticosteroids and free cortisol of the patients with Cushing syndrome overlapped with the corresponding values of the normal and hypertensive subjects, their integrated cortisol concentration did not exhibit any overlap.

A portable constant withdrawal pump was used to determine consecutive 30-min integrated concentrations of growth hormone (ICGH) for a 24-h period in 18 normal subjects, ages 5 to 28 yr. Seven prepubertal, 5 pubertal and 6 young adult subjects were studied under conditions of normal activity. Pubertal, prepubertal, and adult subjects had peaks during waking hours as well as during sleep, but peaks in the adults were usually lower than in the children. Using an analysis of variance, a significant (P smaller than 0.01) downward trend of ICGH was observed to occur during sleep. During waking hours a significant variation (P smaller than 0.01 by analysis of variance) was found with low levels in the first few hours after awakening and an upward trend as the evening approached. Food intake had no significant effect on ICGH nor did the introduction of the indwelling catheter. The mean apparent half-life values of growth hormone calculated on the basis of 87 episodes with 3 or more points on the downslope was 40.1 min. This is significantly higher than the known true half-life of the hormone, suggesting that complete secretory inactivity after a secretory episode is an infrequent event.

The integrated concentration (I. C.) of plasma aldosterone and cortisol was determined every 30 min during a 24-h period, using a blood collection system composed of a nonthrombogenic catheter and a small, portable withdrawal pump. The experiments were carried out in 8 normal adult men during daily routine life, and repeated in 2 of the subjects while recumbent in bed most of the day. The following conclusions were made: a) The 30-min I. C. of aldosterone fluctuated widely throughout the day. b) Although peaks of increased concentration occurred after a change in posture from supine to erect, there were many peaks of concentration that occurred during the supine posture. The 24-h I.C. of aldosterone in 2 subjects that were studied a second time while staying in bed most of the day was lower than the I. C. observed during normal activity. Furthermore, there was a significant correlation between 24-h I. C. and percentage of time spent in supine position. c) A weak, but significant correlation was found between the 30-min I. C. of aldosterone and cortisol in 4 out of the 7 subjects tested. The overall correlation for all experiments was also significant (R = 0.3. p smaller than 0.001). D) The 4-h I. C. of aldosterone and cortisol showed that the lowest mean values were between 4 PM and 4 AM and the highest values between 4 AM and 4 PM for both steroids.

The hourly integrated concentrations of testosterone and LH in the plasma of 6 young adult, normal men were determined during 24 hr of normal activity and sleep. A portable non-thrombogenic pump system was used for the constant blood withdrawal. Although no distinct rhythm of ...

The diagnostic value of the 24-h integrated concentration (IC) test of cortisol (IC-24-F) was found to be superior to the value of both urinary 17OHCS and urinary free-cortisol tests. The IC-24-F test is too cumbersome for widespread clinical use. The purpose of the present study was to evaluate the diagnostic value of an abbreviated and practical 6-h IC of cortisol (IC-6-F) test. The IC of cortisol (IC-F) was measured in 68 normal subjects and 13 patients with surgically proven Cushing's syndrome. A portable nonthrombogenic constant blood withdrawal system was used over a 24-h period. The IC-F was measured in plasma withdrawn during each 1/2-h period (IC-1/2-F). The mean of 12 consecutive measurements of IC-1/2-F yielded the IC-6-F. The mean of all the IC-1/2-F collected over a 24-h period constituted the IC-24-F. The IC-1/2-F of the patients and their IC-6-F from 0800-1400 h, 1400-2000 h, and 2000-0200 h overlapped the corresponding levels in the control subjects. There was no overlap between the IC-24-F and the IC-6-F (from 2000-0200 h) of the patients and the control subjects. It was concluded that the diagnostic value of a 6-h IC-F test conducted during the afternoon and early part of the might is equal to the diagnostic value of the 24-h IC-F test.

Patients with single allele defects in the gene encoding the type 1 IGF receptor have been reported to have growth failure, but fibroblasts from affected patients have not exhibited insensitivity to the effects of IGF-I in vitro. The in vitro and in vivo responses to short-term recombinant human IGF-I (rhIGF-I) in a severely growth-retarded girl with ring chromosome 15 and deletion of a single allele for the type 1 IGF receptor gene have been investigated. The child exhibited prenatal and severe post-natal growth failure, and delayed psychomotor development. Southern blotting revealed a 50% reduction in IGF-I receptor DNA, and in an RNase protection assay (RPA), a quantitatively similar reduction in steady-state mRNA for type 1 IGF receptor. rhIGF-I was administered in graded doses of 40, 60 and 80 microg/kg twice daily by subcutaneous injection for periods of 2-2.5 days each. During rhIGF-I treatment, mean urinary nitrogen excretion was unchanged and urinary calcium rose to 60% greater than in the pre-treatment period. rhIGF-I injections produced only a modest decrease in indices of GH secretion, assessed by frequent (every 20 min) sampling over periods of 12 h. There was no significant difference between the mean GH concentrations during rhIGF-I treatment (5.32 +/- 6.2 mU/l) compared with that before rhIGF-I treatment (8.46 +/- 10.2 mU/l). Mean IGFBP-3-values were increased (4.5 mg/l before vs. 5.4 mg/l during rhIGF-I). TSH values after injection of TRH were not significantly reduced by IGF-I (mean of all values, 18.6 mU/l vs. 15.5 mU/l during rhIGF-I treatment). In vitro binding of radiolabelled IGF-I to the patient's fibroblasts was less than that bound by control fibroblasts (patient, 0.69% binding by 248 000 cells, vs. 1.41% binding by 260 000 fibroblasts from an age-matched control). However, the patient's fibroblasts exhibited a growth response in vitro to the addition of IGF-I in a fashion similar to that of control fibroblasts. These studies show evidence in each of the indices examined of in vivo resistance to IGF-I and suggest that the growth retardation observed in such patients may be the direct result of the absence of one of the alleles encoding the type 1 IGF receptor.