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Biomedical subjects

F Buzi

Publications and source records attributed to F Buzi.

At least 19 recordsLinked to original sources
PubMed2006

Common polymorphisms of the growth hormone (GH) receptor do not correlate with the growth response to exogenous recombinant human GH in GH-deficient children.

CONTEXT: GH acts through the GH receptor (GHR), whose polymorphisms might affect the growth response to recombinant human GH (rhGH). OBJECTIVE: The objective of this study was to investigate possible influences of GHR polymorphisms on the growth response to rhGH in GH-deficient (GHD) children. DESIGN: This was a 2-yr study (first year, spontaneous growth; second year, growth during rhGH treatment). SETTING: This study was performed at a referral center. PATIENTS: Fifty-four prepubertal GHD children (11 females; mean age, 7.8 yr; sd, 3.96) were studied. INTERVENTION: Patients were treated with rhGH (0.2 mg/kg.wk) for at least 1 yr after diagnosis. Growth velocity (GV) was measured 1 yr before treatment and during the first treatment year. GHR exons were amplified by PCR using pairs of intronic primers. The presence of single or multiple mismatches in the PCR products was revealed by denaturing high-pressure liquid chromatography. For exons in which mismatches were found by denaturing high-pressure liquid chromatography, direct sequencing was performed by automatic sequencer. MAIN OUTCOME MEASURES: Before the start of treatment, the mean height (Ht) sd score was -1.93 (sd, 0.70), and the mean GV sd score was -1.49 (sd, 1.26). RESULTS: The posttreatment (first 12 months) mean GV sd score was 3.55 (sd, 3.27). Molecular analysis revealed a high frequency of GHR polymorphisms; in particular: exon 3 deletion (Del 3) in 26 subjects (48%), polymorphism 504 A>G at codon 168 of exon 6 in 44 (82%), and polymorphism 1576 A>C at codon 526 of exon 10 in 35 (65%). In most patients, these different polymorphisms recurred in association. We found no significant differences in GV between the groups of subjects defined by the polymorphic genotypes. CONCLUSION: The most common GHR polymorphisms, alone or in association, do not appear to affect the growth response to rhGH in GHD children.

Child↗
PubMed2006

Menstrual disorders in adolescence.

Altered frequency of the menstrual cycle accompanied by pain are manifestations of functional anomalies of the female reproductive system. These symptoms require prompt and accurate diagnosis and therapy to prevent a chronic condition that can seriously disturb the adolescent's psychic well being. The most common anomalies of the menstrual cycle and the causes of altered cycle frequency are outlined, as are useful criteria for diagnosing premenstrual syndrome dysmenorrhea and for distinguishing the causes and alterations in frequency and amount of menstrual discharge from other disturbances, including amenorrhea and abnormal uterine bleeding. The treatment of dysmenorrhea and quantitative alterations of the menstrual cycle is the focus of this article.

Adolescent↗
PubMed2006

Geometry and bone density.

Bone development is a key process in the growing child. It is, therefore, of paramount importance to survey this process, which is characterized by increasing length and size of the bone together with its progressive mineralization. The bone status can be evaluated by different techniques, each of them having its pros and cons. Furthermore, it should be underlined that the results of bone assessment depend not only from the employed technique but also from the auxological characteristics of the subjects. It is, therefore, the aim of this review to examine the characteristics of the various methods of bone evaluation, such as dual energy X-ray absorptiometry (DEXA), peripheral quantitative computed tomography (pQCT), ultrasound and metacarpal index and to explain how changes in bone structure and geometry may influence the results.

Absorptiometry, Photon↗
PubMed2004

Growth hormone (GH) isoforms following acute 22-kDa GH injection: is it useful to detect GH abuse?

The aim of the study was to investigate the influence of an acute administration of 22-kDa hGH (22-kDa GH) on 22-kDa GH and 20-kDa GH serum levels, biological activity of GH (Nb2-GH) and on 22-kDa/20-kDa GH ratio, in order to verify whether the assessment of the GH isoforms could be a potential tool for diagnosing GH abuse. Twenty-eight children (21 M, 7 F), age 10.4 +/- 0.8 y, affected by idiopathic isolated GH deficiency and 10 children (8 M, 2 F), age 9.2 +/- 2.3 y affected by constitutional growth delay, were evaluated. After an overnight fast, a basal blood sample was obtained between 8 a.m. and 9 a.m. and a dose of 22-kDa GH was then administered subcutaneously (0.1 U/Kg). Blood was drawn after 2, 4 and 6 h, for the evaluation of 22-kDa GH, Nb2-GH and 20-kDa GH serum levels. Similar results were obtained in patients and controls: a significant rise, although of variable amplitude, of 22-kDa GH and Nb2-GH was found (p < 0.001) and the maximum peak was detected after 4 h in the majority of subjects. No acute changes in 20-kDa GH serum levels were observed. The 22-kDa/20-kDa GH ratio increased progressively, due to the rising levels of 22-kDa GH. A positive correlation was seen between 22-kDa GH and Nb2-GH levels at baseline and at 2, 4 and 6 h (p < 0.014, r = 0.99). Since in normal subjects the ratio of endogenous 22-kDa GH and 20-kDa GH is constant, an altered ratio of 22-kDa/20-kDa GH is highly suggestive of GH abuse. The short period of time available for the evaluation however (within 3 h from GH injection), severely limits this investigational tool in athletes.

Analysis of Variance↗
PubMed2004

Serum osteoprotegerin and receptor activator of nuclear factors kB (RANKL) concentrations in normal children and in children with pubertal precocity, Turner's syndrome and rheumatoid arthritis.

BACKGROUND: Osteoprotegerin (OPG) is a secreted member of the TNF receptor superfamily. OPG is made by osteoblastic cells and is expressed in a wide variety of cell and tissue types. It acts as a decoy receptor by binding the receptor activator of nuclear factors kB (RANKL) and preventing RANKL-induced osteoclast formation and differentiation. Numerous cytokines and hormones (TGF-beta, PTH, vitamin D, glucocorticoids and oestrogens) exert their effects on osteoclastogenesis by regulating the production of OPG. PATIENTS AND METHODS: In the present study we compared serum OPG and RANKL concentrations in a group of normal children (1-14 years old) with those of pair-aged children affected by different diseases [Turner's syndrome (TS), early/precocious puberty (PP) and rheumatoid arthritis (RA)]. OPG and RANKL concentrations were measured by an enzyme immunoassay method using a commercial kit. RESULTS: Mean (+/- SD) OPG level in normal children was 4.05 +/- 1.63 pmol/l with no difference between males and females. OPG values in children 1-4 years old (5.87 +/- 2.22 pmol/l) were significantly higher than in children 4-14 years old (3.55 +/- 0.97 pmol/l). OPG levels in children with RA were significantly higher than in controls (6.33 +/- 2.57 pmol/l vs. 4.05 +/- 1.63 pmol/l, P < 0.01); patients with TS or PP had OPG levels superimposable to those of controls (2.61 +/- 0.67 pmol/l and 3.99 +/- 0.85 pmol/l, respectively), but in TS OPG levels were significantly lower than in age-matched females. Mean RANKL concentration in normal subjects was 0.81 +/- 1.55 pmol/l; there was a slight decline in RANKL levels with age. RANKL concentrations in subjects with TS, PP, RA and controls did not differ significantly, and did not differ from those published in adult normal subjects. CONCLUSIONS: It appears from our data that OPG serum levels in healthy children aged > 4 years are similar to those present in young adult men, with higher levels in the first 4 years of life. Although the meaning of the alterations of OPG levels observed in pathological conditions is still obscure, they appear potentially interesting in view of a key role played by this protein in bone homeostasis.

Aging↗
PubMed2004

Hyperparathyroidism.

Hyperparathyroidism is a disease characterized by hypercalcemia with hypophosphoremia resulting from increased secretion of parathyroid hormone (PTH). The disease may be divided into 3 forms: a) primary, b) secondary, c) tertiary (secondary refractory form). Primary hyperparathyroidism is rare in children; hyperplasia is more frequent during the early years of life (neonates and infants) and is difficult to distinguish from adenoma in children. The disease may be asymptomatic; elevated calcemia levels (>12 <13.5 mg/dl) are accompanied by anorexia, asthenia and persistent stipsis; severely elevated concentrations (>13.5 mg/dl) are accompanied by nausea, vomiting, polyuria due to osmosis, with dehydration and progressive onset of lethargy, stupor and coma. Osteopenia or osteitis fibrosa cystica may be present due to augmented bone resorption. Height and weight increases are altered due to anorexia and dehydration. Differential diagnosis includes iatrogenic causes of hypercalcemia (excessive vitamin D intake, prolonged immobilization, etc.) and idiopathic familial hypercalcemia. Emergency treatment is required in cases of extremely elevated hypercalcemia (Ca >13.5-14 mg/dl), due to risk of injury to the heart, the central nervous system, the gastrointestinal tract and the kidneys. The 4 cardinal points of treatment are: hydration, calciuresis, inhibition of bone calcium resorption, treatment of the cause underlying hyperparathyroidism. Secondary hyperparathyroidism is found in cases where chronic hypocalcemia is present, particularly in chronic renal failure, untreated deficiency rickets, chronic intestinal malabsorption, hepatobiliary disease, types I and II vitamin D-dependent rickets, tubular acidosis or Fanconi's syndrome. The tertiary form is distinguished by the autonomous nature of the parathyroid glands which have become hypertrophic/hyperplastic due to uncontrollable, chronic severe renal failure. It can also be of iatrogenic origin due to excessive intake of inorganic phosphates in familial hypophosphatemic rickets or chronic vitamin D deficiency.

Calcium↗
PubMed2003

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome: time to review diagnostic criteria?

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an autosomal-recessive syndrome defined by two of the following conditions: chronic mucocutaneous candidiasis, hypoparathyroidism, or Addison's disease. Other autoimmune conditions may be associated, such as hypothyroidism, hypogonadism, insulin-dependent diabetes mellitus, chronic active hepatitis, pernicious anemia, vitiligo, alopecia, biliary cirrhosis, and ectodermal dysplasia. APECED is caused by mutations in the autoimmune regulator gene, mapping to 21q22.3. We report on three patients whose clinical and molecular features challenge the currently used diagnostic criteria for APECED. AR presented at 15 yr of age with a history of recurrent infections and mucocutaneous candidiasis. He is now 21 yr old, and no other signs or symptoms of APECED have appeared to date. DR presented at 7 yr of age with hypocalcemia and a prolonged Q-T interval on the electrocardiogram. He also had minor facial dysmorphisms and mild mental retardation. Serum calcium levels were low, PTH levels were undetectable, and hypoparathyroidism was therefore diagnosed. All other biochemical, immunological, and endocrinological tests were normal. DR is now 8 yr old with no other signs or symptoms of APECED. ST presented at 14 yr of age for alopecia aerata and pitted nail dystrophy and goiter. Thyroid function was normal in the presence of thyroid-specific antibodies. No other signs or symptoms of APECED have appeared to date. Genetic analysis revealed a typical mutation (R257X) on a single allele in both AP and DR; in ST, heterozygosity for a novel mutation (V484M) involving one of the zinc fingers of the plant homeodomain of the protein was found. The finding of a typical APECED mutation in two patients presenting with one isolated major clinical APECED feature and of a novel mutation in a patient presenting with atypical features of APECED onset suggests that the time might have come for updating the diagnostic criteria of this syndrome.

Adolescent↗
PubMed2002

Thyroid nodules.

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Biopsy, Needle↗
PubMed2002

Hypothyroidism.

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Humans↗
PubMed2001

Frasier syndrome with childhood-onset renal failure.

BACKGROUND: The Wilms' tumour 1 (WT1) gene encodes a protein which is believed to exert transcriptional and tumour-suppressor activities. Mutations of this gene have occasionally been associated with Wilms' tumour (<15% of cases) and, more consistently, with three syndromes characterized by urogenital abnormalities (WAGR, Denys-Drash and Frasier syndrome). SUBJECT/METHOD: A 25-year-old phenotypic female with a 46,XY karyotype presented with amenorrhoea. An ultrasound scan showed streak gonads and a rudimentary uterus. The patient had a history of post-streptococcal glomerulonephrosis, when aged 4 years, which had rapidly progressed to kidney failure, requiring transplantation at age 8. RESULT: Frasier syndrome was suspected and confirmed by genetic analysis. In fact, direct sequencing of the PCR product of the intron 9 donor splice site revealed a substitution of guanine for adenine in position +5. CONCLUSION: Besides being one of the few Frasier syndrome cases to be genetically characterized, this case is interesting because of the unusually early-onset renal failure.

Adult↗
PubMed2001

Idiopathic short stature.

Idiopathic short stature (ISS) is a term used to describe the status of children with short stature that cannot be attributed to a specific cause. Many children diagnosed as having ISS have partial GH insensitivity, which can result from disturbances at various points of the GH-IGF-I axis. Several clinical studies on spontaneous growth in ISS showed that adult height was almost in the range of target height. GH treatment led to adult height not significantly higher than the pretreatment predicted adult height in most reports. No metabolic side effects have been observed, even when the dose was higher than in GH deficiency. Manipulation of puberty with gonadotrophin releasing hormone analogues reported by a few authors in a small number of children has shown conflicting results. Long-term psychological benefits of GH therapy for short normal children have not been demonstrated to date.

Adolescent↗
PubMed2001

Optimal therapy of pubertal disorders in precocious/early puberty.

GnRHa have been used in the treatment of central precocious puberty (CPP) for a decade and some final results of this therapy are now available. Treatment preserves height potential in younger patients and a complete recovery of the hypothalamic-pituitary-gonadal axis occurs at the end of treatment. However, some aspects of the management of CPP are still debated. Probably the age limits between normal and precocious puberty have to be lowered, and new diagnostic tools will modify and simplify diagnostic criteria. The possibility of progression of premature thelarche into precocious puberty, the pathogenesis of organic and idiopathic precocious puberty, the criteria for decision to treat and to stop treatment and the utility of an association with GH treatment will be better understood in the future. Follow-up of patients after stopping therapy includes frequency and characteristics of menses, the possible higher incidence of polycystic ovary-like syndrome and the correct achievement of a normal peak bone mass and body composition. In this review we discuss some of these points, with particular attention to precocious puberty in girls.

Adolescent↗