Preparation of a respiratory syncytial virus human reference serum for use in the quantitation of neutralization antibody.

Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infection in infants, young children and the elderly. Yet, the development of a vaccine to protect against RSV infection still remains an unmet need. At present, immune responses to experimental vaccines under investigation are usually evaluated by ELISA and/or by neutralization assays against RSV. However, both types of assays are generally performed somewhat differently at different laboratories. An important step towards standardization of serology is the use of a standard human reference serum enabling normalization of results generated within and between laboratories. To fill this need, we prepared and characterized a human reference serum against the A2 strain of respiratory syncytial virus. The serum represents a pool of more than 400 individual human sera obtained from commercial sources. The sera were screened and selected on the basis of individual RSV neutralization titers. A final neutralization titer of 973 (95% C.I., 884-1072) was assigned to the final reference serum pool after it was tested three times in the presence of 10% guinea pig complement and a titer of 286 (95% C.I., 243-337) was assigned to the serum when it was tested in the absence of an exogenous complement source. Sterilely reconstituted lyophilized aliquots of the serum exhibited a stable neutralization titer for at least 1 month at room temperature and at 4 degrees C, as well as after 5 weekly freeze-and-thaw cycles at -20 degrees C. In the lyophilized state, the neutralization titer of the lyophilized reagent was stable for at least 6 months, the last time point tested. Two additional smaller pools of serum with high and medium neutralization titers of 2692 and 575, respectively, were also produced in parallel for use as positive controls and were designated as control sera. The reference serum can be used to normalize neutralization and/or other RSV-specific assay results from different laboratories and the control sera can be used for quality control purposes or as part of a panel to test operator proficiency. Individual lyophilized aliquots of the reference and control sera may be obtained from the US National Institute of Allergy and Infectious Diseases (NIAID) Reference Reagent Repository.

Genetic and phylogenetic analysis of multi-continent human influenza A(H1N2) reassortant viruses isolated in 2001 through 2003.

Genetic analyses were performed on 228 influenza A(H1) viruses derived from clinical subjects participating in an experimental vaccine trial conducted in 20 countries on four continents between 2001 and 2003. HA1 phylogenetic analysis of these viruses showed multiple clades circulated around the world with regional prevalence patterns. Sixty-five of the A(H1) viruses were identified as A(H1N2), 40 of which were isolated from South Africa. The A(H1) sequences of these viruses cluster with published H1N2 viruses phylogenetically and share with them diagnostic signature V169A and A193T changes. The results also showed for the first time that H1N2 viruses were prominent in South Africa during the 2001-2002 influenza season, accounting for over 90% of the A(H1) cases in our study, and infecting both children (29/31) and the elderly (11/13). Phylogenetic analysis of the 65 H1N2 viruses we identified, in conjunction with the 56 recent H1N2 viruses currently available in the database, provided a comprehensive view of the circulation and evolution of distinct clades of H1N2 viruses in a temporal manner between early 2001 and mid-2003, shortly after the appearance of these recent reassortant viruses in or near year 2000.

CHARGE syndrome includes hypogonadotropic hypogonadism and abnormal olfactory bulb development.

CONTEXT: CHARGE (coloboma, heart defect, choanal atresia, retarded growth and development, genital hypoplasia, ear abnormalities, and/or hearing loss defect) syndrome consists of a combination of congenital malformations including genital hypoplasia and retarded growth. OBJECTIVE: The objective of the study was to study gonadotropic axis function and growth parameters in CHARGE syndrome. DESIGN: This was a retrospective study. PATIENTS: The study included 32 children with CHARGE syndrome. RESULTS: Nineteen of 20 affected boys had micropenis and/or cryptorchidism, consistent with hypogonadotropic hypogonadism during fetal life. None of the boys was of pubertal age. Seven of nine boys tested before the age of 5 months during the neonatal peak period had extremely low testosterone levels. LH response to GnRH stimulation was variable during the first year of life and not correlated with existing clinical abnormalities. None of the girls over the age of 12 yr (n = 7) had begun puberty spontaneously, and a lack of response to GnRH stimulation was documented in five of them. Olfactory evaluation (n = 10) and magnetic resonance imaging (n = 18) of the forebrain revealed defective sense of smell and abnormal olfactory bulbs in all cases. Cardiorespiratory and nutritional problems were corrected, but the mean height of the 25 children who had reached 5 yr of age was -2 +/- 0.2 sd score. Height was not correlated with birth length or body mass index. GH deficiency was diagnosed in only three children. CONCLUSION: These findings suggest that CHARGE syndrome includes the main features of Kallmann syndrome, which is defined by hypogonadotropic hypogonadism combined with a defective sense of smell and abnormal olfactory bulb development. This forebrain abnormality, if confirmed in a larger group of patients, could serve as a major new criterion for the diagnosis of CHARGE syndrome.

Effects of growth hormone on growth factors after renal transplantation.

Growth retardation occurs frequently in renal transplanted children (RTx) and can be improved by growth hormone (GH) treatment. This study retrospectively examines the insulin-like growth factor-1 (IGF-1) and IGF binding protein (IGFBP) profile of ten growth-retarded children previously given renal allografts, after 1 year of GH treatment period. Ten prepubertal patients (nine boys and one girl) were investigated. They had a mean chronological age (CA) of 11.4 +/- 1.1 years and a mean bone age (BA) of 7.3 +/- 0.9 years. Mean height was -3.9 +/- 0.4 SD units below the mean for CA. The mean body mass index (BMI) was 16.9 +/- 0.6 and the mean inulin clearance was 36.5 +/- 4.9 ml/min/1.73 m2. Recombinant hGH was given at 4 IU/m2/day. Plasma GH, total and free IGF-1, IGFBP-2 and -3 were measured by specific radioimmunoassay (RIA). IGFBPs were characterized by SDS PAGE techniques and ligand and immunoblot analyses. Mean velocity was markedly increased (P < 0.01) after 1 year of GH therapy, expressed as SD score for BA. The range of growth response was wide. The total and free plasma IGF-1 increased (P < 0.01) by about 100% (mean values after GH therapy: 95.9 +/- 2.1 nM and 165 +/- 29 pM, respectively). Plasma IGFBP-3 concentrations increased by about 40% (mean value: 148 +/- 18 pM, P < 0.01), with a concomitant increase in both intact IGFBP-3 and its 30-kDa proteolytic fragment. There was no change in plasma IGFBP-2 concentration. Both mean values of inulin clearance and BMI were unchanged during the treatment. In view of the IGF-1/IGFBP concentration changes, there should have been an even better growth response to GH therapy in these patients. This strongly suggests IGF-1 insensitivity, probably as a result of corticosteroid therapy.

Absence of furrowing activity following regional cortical tension reduction in sand dollar blastomere and fertilized egg fragment surfaces.

The purpose of the present investigation was to test experimentally the possibility that division mechanism establishment at the equator of sand dollar eggs may be a consequence of cortical tension gradients between the equator and the poles. Cytochalasin has been shown to decrease tension at the sea urchin egg surface. The concave ends of cytochalasin D-containing agarose cylinders were held against regions of the surface of Echinarachnius parma blastomeres and enucleated fertilized egg fragments. The ability to interfere with normal furrowing activity was used as a biological indicator of the effectiveness of cytochalasin. When agarose containing 2 microg/mL cytochalasin contacted the equatorial region of the blastomeres resulting from the first cleavage, or the equatorial surfaces of nucleated fertilized egg halves, furrowing was blocked, stalled or delayed, indicating that the concentration of cytochalasin was effective. When the same concentration of cytochalasin was applied to the poles, the cells and nucleated fertilized egg fragments divided in the same way as the controls, indicating that the effectiveness of the cytochalasin did not spread from the poles to the equator and that bisection did not interfere with the division of nucleated fertilized egg fragments. When the same concentration of cytochalasin was applied to diametrically opposed surfaces of enucleated, spherical egg fragments, there was no evidence of furrowing activity between the areas that contacted the cytochalasin or in any other part of the surface. Because of the tension-reducing effect of cytochalasin, a tension gradient existed between the regions affected and unaffected by cytochalasin. The results strongly suggest that establishment of the division mechanism by simple gradients of tension at the surface is unlikely.

Follow up of precocious pseudopuberty associated with isolated ovarian follicular cysts.

The clinical outcomes of seven girls presenting with pseudosexual precocity caused by isolated autonomous ovarian follicular cysts are presented. Six of the seven girls, aged 11 months to 6.9 years, had a unilateral ovarian cyst detected by ultrasound at the first acute episode. Plasma oestradiol was raised in only five of the cases, but all had a low response to luteinising hormone releasing hormone stimulation. Follow up lasted for up to eight years with recurrent episodes of variable frequency and severity in all seven patients. Evidence of McCune-Albright syndrome appeared later in only three patients. It could not be predicted from the initial symptoms or the clinical course. Mutations of the G(s)alpha protein leading to activation were investigated in the lymphocytes and ovarian and bone tissues of four patients. Only one patient showed a mutation in bone tissue. Close follow up with repeated searches for skeletal lesions remains necessary since the distribution of somatic mutations cannot be assessed by molecular studies. Most patients with recurrent ovarian cysts require a conservative approach.

Growth response to rhIGF-I 80 microg/kg twice daily in children with growth hormone insensitivity syndrome: relationship to severity of clinical phenotype.

BACKGROUND: rhIGF-I has been used effectively to promote growth in growth hormone insensitivity syndrome (GHIS) in doses ranging from 40 microg/kg twice daily to 150-200 microg/kg once daily. It appears that the dose of 80 microg/kg twice daily s.c. may induce an equivalent response to higher doses with less side-effects. OBJECTIVE: To study the efficacy and safety of rhIGF-I, 80 microg/kg twice daily s.c., in children with GHIS and to analyse the relationship of growth response to severity of phenotype. PATIENTS AND DESIGN: Eleven prepubertal children (3 females, 8 males) with GHIS; basal GH > 2.5 microg/l, IGF-I < 50 microg/l, IGFBP-3 < - 2SD; were treated with IGF-I 80 microg/kg twice daily in a multi-centre study. The baseline characteristics of these patients were as follows (mean +/- SD): age, 7.5 +/- 2.5 years (range, 2.5-11.7 years), bone age (Tanner-Whitehouse - 2 RUS), 5.2 +/- 2.4 years (range, 2.3-9.1 years), mean height SDS, - 5.6 +/- 1.6 (range, - 3.1 to - 8.1), height velocity (HV), 3.1 +/- 1.1 cm/year (range, 1.9-4.9 cm/year). Height, HV, weight, skinfold thickness, puberty stage and bone age were measured at baseline and 6 monthly for 2 years. RESULTS: During the first 12 months of IGF-I therapy, the mean +/- SD HV was 7.7 +/- 1.6 cm/year (range, 6.1-11.2 cm/year), the mean +/- SD increase in HV was 4.7 +/- 2.1 cm/year (range, 1.7-8.8 cm/year) and the mean +/- SD progression of bone age was 1.9 +/- 1.0 years (range, 0.8-3.8 years). Pre-treatment height SDS at the start of IGF-I therapy correlated positively with pretreatment serum IGFBP-3 SDS levels (r = 0.85; P < 0.01). There was a significant inverse correlation between gain in height SDS and pre-treatment height SDS (r = - 0.76; P < 0.01). During the 2nd 12 months of therapy, mean HV was 7.0 +/- 3.4 cm/year (range 3.8-12.4) change in height SDS from 12 to 24 months was not significantly correlated with pre-treatment height SDS. Subscapular skinfold SDS decreased significantly (P < 0.05) during the study period, whereas there was no significant change in body mass index and triceps skinfold thickness SDS. Adverse events reported in the patient group included headache (2 patients), hypoglycaemia (2 patients), papilloedema (transient, 1 patient), lipohypertrophy (5 patients) and tonsillectomy/adenoidectomy (2 patients). CONCLUSION: This study reveals that IGF-I treatment at a dose of 80 microg/kg twice daily is effective in patients with growth hormone insensitivity syndrome. During the first 12 months of therapy, there was a significant inverse relationship between growth response to IGF-I therapy and the severity of the phenotype of growth hormone insensitivity syndrome, as measured by height SDS, at the start of therapy. Patients with a more severe clinical phenotype of growth hormone insensitivity syndrome, who also had most severe IGFBP-3 deficiency, responded better than those who were more mildly affected. An analogous situation has been shown to be the case in GH-deficient patients treated with hGH.

Development of a fluorescent focus identification assay using serotype-specific monoclonal antibodies for detection and quantitation of rotaviruses in a tetravalent rotavirus vaccine.

A fluorescent focus identification assay (FFIDA) was developed for use in experimental studies and for quantitation of the components in a tetravalent live oral rotavirus vaccine. The assay utilizes four serotype-specific neutralizing monoclonal antibodies (MAb) to detect and quantify individual rotaviruses by immunofluorescence staining of fixed virus-infected monkey kidney cells. In mixed virus infections, all four MAb, W1 (serotype 1), 1C10 (serotype 2), R1 (serotype 3), and S4 (serotype 4), specifically stain the relevant homologous serotype without exhibiting any cross-reactivity against the other serotypes. Furthermore, the test is sensitive enough to differentiate at least twofold (0.3 log) differences in virus titer. The results of testing four individual experimental vaccine lots three or more consecutive times showed that all four lots contained similar proportions of the four vaccine strains as detected by the classical plaque neutralization identification test. The rapidity and efficiency of the FFIDA are desirable attributes that make it suitable for use in studies requiring identification and quantitation of one or more of the four major rotavirus serotypes.

Effects of growth hormone in short children after renal transplantation. French Society of Pediatric Nephrology.

From 1991 to 1993, 90 children having received a kidney graft with a post-transplantation period of at least 12 months were included in a prospective study carried out in 18 French pediatric centers. After informed consent and randomization, children received recombinant human growth hormone (rhGH) (Genotonorm, Pharmacia peptide hormones) 30 U/m2 per week, either immediately on enrollment, for the treated group, or after 1 year of follow-up for the group serving as a control. After 1 year both groups were treated and we analyzed data during the subsequent years. Eighty-five children completed the 1-year study. Growth velocity was significantly increased by rhGH: 7.7 cm with a gain of +0.3 standard deviation score in the treated group versus 4.6 cm in the control group (P<0.0001) during the 1st year. Four factors predicted response to therapy: growth velocity prior to GH therapy, glomerular filtration rate (GFR) at the start, mode of corticosteroid administration, and degree of insulin resistance. After 1 year we observed a moderate, significant decrease in GFR in both groups. Biopsy-proven acute rejection episodes were not significantly more frequent during the 1st year in the group of patients who received rhGH: 9 in 44 versus 4 in 46 patients. The patients who rejected did not differ in terms of age, renal function at the start, and type of immunosuppression, but history of rejection before GH treatment was discriminatory: 6 of 17 children with two or more episodes had a new rejection versus 1 of 22 who had no or only one episode (P=0.01). Glucose tolerance was not modified after 1 year of GH therapy. During the subsequent years of treatment a decrease in growth velocity was noted: 5.9 cm at 2 years, 5.5 at 3 years, and 5.2 cm at 4 years. In conclusion, GH is efficient for improving growth velocity in short transplanted children, inducing clear-cut but limited catch-up growth. The risk of rejection was shown only in patients with a prior history of more than one rejection episode.

Three-year data from a comparative study with recombinant human growth hormone in the treatment of short stature in young children with intrauterine growth retardation.

Growth acceleration and bone maturation were studied for 3 y in 69 children with severe short stature and a history of intrauterine growth retardation (IUGR), to determine the effect of treatment with recombinant human growth hormone (r-hGH). The patients were enrolled in an open, multicentre trial and were randomly allocated to either the treated group (Group 1) or the control group (Group 2). The children in Group 1 were treated daily with 0.2 IU/kg/body weight (0.067 mg/kg) s.c., during 3 y and the children in Group 2 started the study with a 1-y observation period followed by a 3-y treatment period. At birth, their mean weight standard deviation score (SDS) was -2.5 and their mean length SDS -3.5. At baseline, the patients were prepubertal, non-GH deficient, with no known dysmorphic features. Mean age was 4.5 y, bone age was 3.3 y, height SDS was -3.4, height velocity (HV) SDS was -1.6, and body mass index SDS was -1.4. After 1 y of treatment, linear HV in Group 1 increased in comparison with the pre-treatment period (from 5.7 +/- 2.0 to 10.1 +/- 1.7 cm/y; p < 0.001) and with the first year of observation in Group 2 (p < 0.001). Increased HV was sustained during the second and third year of treatment and was significantly higher than at baseline. A similar growth pattern was seen during the 3 y of GH treatment in Group 2. Mean height SDS for chronological age increased by 2.0 +/- 0.7 in the two groups after 3 y of treatment. HV after 1 y of treatment was negatively correlated with growth velocity at baseline. Bone age remained retarded but increased with a mean of almost 4 y after 3 y of treatment in both groups. Even at a dose that is three times the replacement dose treatment with r-hGH was well tolerated. From these results, we conclude that r-hGH treatment over 3 y can induce sustained catch-up growth in young children with severe short stature and a history of IUGR. Long-term studies are needed to assess ultimate effects on final height.

Shedding of rotavirus after administration of the tetravalent rhesus rotavirus vaccine.

BACKGROUND: The tetravalent rhesus rotavirus vaccine (RV-TV) has been administered to several thousand children in multiple settings throughout the world. It has been proved safe and efficacious, resulting in an application for licensure in 1997. However, only limited information has been reported on viral shedding after RV-TV vaccination. METHODS: Stool specimens were collected between Days 3 and 5 after administration of each of 3 doses of RV-TV to 248 subjects 6 to 12 weeks of age in 8 centers across the United States. Rotavirus antigen was measured by an enzyme-linked immunosorbent assay to determine the number of subjects who shed after each dose. The relative quantities of vaccine strains shed were then determined by plaque purification and serotype analysis. RESULTS: Rotavirus shedding was detected in 125 (50.4%) subjects, and 19 shed after more than 1 dose. Although fewer subjects shed rotavirus after Dose 2 (14.5%), shedding after Doses 1 (26.0%) and 3 (22.5%) were comparable. After plaque purification and serotyping, most viruses shed (76.2%) were identified as G3 after Dose 1, but a major shift to G2 strains was found after Doses 2 (61.3%) and 3 (69.0%). CONCLUSIONS: Sequential RV-TV administrations caused no overall significant decrease in the number of vaccinees who experienced detectable shedding. A major shift in shedding was found from the serotype G3 vaccine strain (RRV) after the first dose of vaccine to the serotype G2 reassortant after Doses 2 and 3.

Serologic correlates of immunity in a tetravalent reassortant rotavirus vaccine trial. US Rotavirus Vaccine Efficacy Group.

The correlation of antibody responses (serum rotavirus IgA and neutralizing antibody to serotype G1-G4 human rotaviruses and rhesus rotavirus [RRV]) in a reassortant rotavirus vaccine trial with protection against rotavirus infection or disease was investigated. Most subjects administered 4 x 10(5) pfu of either the serotype G1 monovalent or serotype G1-G4 tetravalent vaccine seroconverted for at least one of the six antibodies (85% and 91%, respectively). However, fewer than one-third seroconverted to any prototype G1-G4 human rotavirus. Analyses of covariance indicated that higher prevaccination neutralizing antibody titers negatively affected postvaccination titers. Significant relationships were found between several postvaccination rotavirus antibody titers and protection, and serotype-specific correlates of protection were identified between anti-Wa titers and G1 illnesses (P = .03) and between anti-RRV titers and G3 illnesses (P < .001). Overall, however, serotype-specific immunity was no more significant than heterotypic immunity, and no specific titer of any antibody analyzed was a reliable indicator of protection.

Attenuation of a human rotavirus vaccine candidate did not correlate with mutations in the NSP4 protein gene.

The NSP4 protein of a simian rotavirus was reported to induce diarrhea following inoculation of mice. If NSP4 is responsible for rotavirus diarrhea in humans, attenuation of a human rotavirus may be reflected in concomitant mutations in the NSP4 gene. After 33 passages in cultured monkey kidney cells, a virulent human rotavirus (strain 89-12) was found to be attenuated in adults, children, and infants. Nucleotide sequence analysis of the NSP4 protein gene revealed only one base pair change between the virulent (unpassaged) and attenuated 89-12 viruses, which resulted from a substitution of alanine for threonine at amino acid 45 of the encoded NSP4 protein. Because both threonine and alanine have been found at position 45 of NSP4 in symptomatic and asymptomatic human rotaviruses, neither amino acid in this position could be established as a marker of virulence. Therefore, attenuation of rotavirus strain 89-12 appears to be unrelated to mutations in the NSP4 gene.

Comparison of immunocytochemical and molecular features with the phenotype in a case of incomplete male pseudohermaphroditism associated with a mutation of the luteinizing hormone receptor.

We report the case of an infant who presented at birth with a hypoplastic phallus associated with hypospadias. Low testosterone production, normal serum levels of steroid precursors, and increased LH in response to LH-releasing hormone supported a defect in Leydig cell differentiation or function. Conventional microscopic study of the testes showed fibroblastic cells in the interstitium. However immunocytochemical analysis using anti-LH receptor and anti-P450c17 antibodies demonstrated that about one third of these cells were Leydig cells or precursors of Leydig cells. No histological feature could distinguish the latter cells from fibroblasts. A homozygous substitution of cysteine 133 for arginine was found in the extracellular domain of the receptor. This is the first naturally occurring missense mutation found in the extracellular domain of the LH receptor. COS-7 cells transfected with the mutant receptor exhibited a marked impairment of hCG binding, whereas some cAMP production could be observed at high hCG concentrations. We propose that the partial impairment of LH receptor function, as reflected by the presence of Leydig cells, was responsible for the incomplete male pseudohermaphroditism observed in our patient.

Cleavage furrow establishment by the moving mitotic apparatus.

The midpoint of the mitotic apparatus is fixed in the future division plane long before the division mechanism develops, and this static relationship has been considered essential in speculations concerning division mechanism establishment. The purpose of the present investigation was to determine whether prevention of the static relationship affects the establishment process. Sand dollar eggs were reshaped into cylinders by confinement in an elastic capillary tube and, beginning about 20 min before cleavage, the mitotic apparatus was kept in reciprocal motion by alternately compressing the poles. When the movement was continuous and the excursions were 25, 50 or 75 microm, furrow activity developed near the midpoint of the region underlain by the mitotic apparatus. The acuteness of the furrow decreased as the distance the mitotic apparatus was moved increased. When the movement was made discontinuous by allowing the mitotic apparatus to pause at the end of each excursion, the results depended upon the duration of the pause. Pauses 30 s long resulted in a single furrow formed in the midpoint of the entire region underlain by the mitotic apparatus. When the pauses were 45 s long, furrowing activity developed in both regions where the mitotic apparatus was allowed to pause. The results indicated that the normal static relation between the mitotic apparatus midpoint and the division plane is unnecessary for division mechanism establishment. They also demonstrate that a restricted region of contractile activity can be established in the cortex despite experimentally induced spreading and dilution of mitotic apparatus effect.

A 5-year prospective study of growth hormone (GH)-deficient children treated with GH before the age of 3 years. French Serono Study Group.

The aim of the study was to assess the efficacy of GH therapy in GH-deficient children treated before the age of 3 yr. A noncomparative multicenter prospective study included 49 children (22 girls and 27 boys) with isolated GH deficiency (n = 19) or multiple pituitary hormone deficiency (n = 30) treated with daily s.c. injections (0.6 U/kg.week) for 3-5 yr. They were divided into two groups according to their height SD score for chronological age (CA) at the initiation of therapy: group A consisted of 8 patients presenting an initial height within the normal range (< 2 SD below the mean) followed for 2-5 yr, and group B consisted of 25 children followed for 5 yr among 41 patients with initial growth retardation. In group A, the mean height SD score increased from -1.1 +/- 0.6 to 0.35 +/- 1.0 SD (P < 0.001) in the first year and remained in the normal range throughout the following 4 yr. In group B after 4 yr of treatment, the mean height SD score for age had increased from -3.6 +/- 1.0 SD (time zero) to -0.9 +/- 1.2 SD. During the fourth year of therapy, the mean height gain of 0.2 +/- 0.2 SD was significant (P < 0.001). After 5 yr of treatment, a plateau was reached with a corresponding height SD score (CA) of -0.8 +/- 1.2 SD (95% confidence interval between -1.3 and -0.2 SD). This value remained significantly below normal for age (P < 0.001), indicating that catch-up growth was incomplete. Only four patients (16%) remained below -2SD for CA. The 5-yr height gain was negatively correlated with the height SD score at the start of treatment (r = -0.6; P < 0.005) and the first year height gain was the most predictive parameter. There was no significant influence of intrauterine growth retardation, body mass index and age at the start of treatment, or parental target height. Bone maturation was significantly retarded over CA by a mean value of 1.1 +/- 0.9 yr (P < 0.0001), with a mean bone age/CA ratio of 0.8 +/- 0.2 after a mean treatment duration of 5.1 +/- 1.1 yr. In conclusion, the rapid and almost complete return to normal height obtained in this study supports the need for GH treatment in early diagnosed GH-deficient children. The present dosage may be considered the minimum to obtain satisfactory catch-up growth ensuring a favorable outcome for these children. In addition, it allowed growth at a rate normal for age in patients diagnosed before growth retardation.