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Biomedical subjects

F Severi

Publications and source records attributed to F Severi.

At least 55 records · Page 3Linked to original sources

Evolving pituitary hormone deficiency is associated with pituitary vasculopathy: dynamic MR study in children with hypopituitarism, diabetes insipidus, and Langerhans cell histiocytosis.

PURPOSE: To assess pituitary vascularization in children with hypopituitarism, central diabetes insipidus (DI), or Langerhans cell histiocytosis. MATERIALS AND METHODS: Dynamic MR images were obtained through the pituitary stalk after injection of gadopentetate dimeglumine in 21 patients (11 boys and 10 girls, aged 4-17 years) and 10 age-matched control subjects. RESULTS: Initial enhancement of the posterior pituitary lobe occurred simultaneously with that of the straight sinus in all subjects except four patients with central DI and a thick stalk. Enhancement of the entire anterior pituitary lobe was statistically significantly prolonged (P < .005) in the four patients with delayed initial posterior pituitary lobe enhancement. CONCLUSION: Fast-framing dynamic MR imaging provides new information on the blood supply of the hypothalamic pituitary area in normal and abnormal pituitary glands. Enhancement times exceeding 20 seconds for the posterior pituitary lobe and 30 seconds for the anterior pituitary lobe may suggest abnormal vascularization in the hypophyseal arteries and portal system.

Adolescent↗

Immunoactivation by pidotimod in children with recurrent respiratory infections.

The therapeutic activity and safety of pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, PGT/1A, CAS 121808-62-6), a new synthetic "biological response modifier", were examined in a double-blind, placebo-controlled, multicentre trial in 101 children, including 53 boys and 48 girls aged 2-13 years (mean +/- SD: 4.7 +/- 2.1 years) with a history of recurrent respiratory infections (RRI). Pidotimod (400 mg/day) or placebo were administered orally for 60 consecutive days, followed by a further 60-day follow-up period. The trial was completed by 89.1% of patients. The results indicate that pidotimod has a beneficial effect in children with recurrent respiratory infections: the percentage of patients presenting symptoms affecting the upper and lower airways was significantly lower after treatment with the active drug than after treatment with placebo. Relevant side effects were not reported during the trial. An evaluation of the expression of CD25 (after in vitro stimulation of circulating mononuclear cells with PHA) before and after treatment with the two products revealed a significant increase in CD25+ cells in the group treated with pidotimod but not in the group treated with placebo.

Adjuvants, Immunologic↗

Use of recombinant human erythropoietin after bone marrow transplantation in pediatric patients with acute leukemia: effect on erythroid repopulation in autologous versus allogeneic transplants.

We carried out a pilot study on the use of recombinant human erythropoietin (rHuEPO) in children undergoing allogeneic or mafosfamide-purged autologous BMT for ALL or AML. rHuEPO was administered intravenously at a dose of 75 U/kg/day for 30 days after transplant. Ten rHuEPO-treated patients receiving allogeneic BMT and 10 given autologous BMT were compared with 15 allogeneic and 10 autologous historical controls. Endogenous EPO production was appropriate for the degree of anemia after autologous BMT. In these patients, rHuEPO did not accelerate erythroid repopulation and did not modify transfusion requirements. With allogeneic BMT, erythroid marrow activity increased faster in patients given rHuEPO than in controls and resulted in higher red cell production, the mean reticulocyte count on day +30 being 187 +/- 51 x 10(9)/l in treated patients versus 107 +/- 63 x 10(9)/l in controls (p < 0.01). The total number of RBC units administered was 1.7 +/- 1.3 in the rHuEPO group versus 5.1 +/- 3.0 in the control group (p < 0.001). The total number of platelet transfusions was 4.0 +/- 2.3 for patients given allogeneic BMT and receiving rHuEPO versus 8.4 +/- 6.8 for historical controls (p < 0.05) whereas it was similar in rHuEPO-treated and control autologous BMT patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

CD5-positive B cells in type 1 (insulin-dependent) diabetic children.

We have measured CD5+ B cell levels in the peripheral blood of 35 type 1 (insulin-dependent) diabetic children, aged 1.1-21.2 years (10.7 +/- 4.6 years). Patients were divided into two groups according to disease duration (group I < 6 months and group II > 1.5 years). Group I included 18 patients and group II 17 patients. Thirty-nine healthy subjects, comparable for age and sex, served as controls. CD5+ B cells were identified by double immunofluorescence staining with rhodamine-conjugated rabbit anti-human immunoglobulin and with a mouse anti-CD5 monoclonal antibody revealed by a fluorescein-conjugated goat anti-mouse immunoglobulin. We found that CD5+ B cell levels (expressed as percentages of peripheral blood B lymphocytes) were significantly higher in group I (median 24; range 4-48) than in controls (median 14; range 0-36, P < 0.001) and in group II (median 4; range 0-20, P < 0.001). A follow-up study of 12 group I patients showed a significant decline in CD5+ B cell levels. The data obtained in our diabetic patients suggest that CD5+ B cells are expanded in the early phase of type 1 diabetes mellitus and may play a role in the autoimmune process of the disease.

Adolescent↗

Growth in children after bone marrow transplantation.

Growth velocity pattern and growth hormone (GH) secretion were evaluated in 18 prepubertal patients (13 males, 5 females), receiving an allogeneic (7 patients) or autologous (11 patients) bone marrow transplantation (BMT). Children were affected by oncological or hematological malignancies and the age range was between 2 and 11 years. Nine patients received a conditioning regimen consisting of chemotherapy and fractionated total body irradiation (TBI) (12 Gy in 6 fractions over 3 days), whereas 9 children also received previous prophylactic cranial irradiation during first-line chemotherapy. GH secretion in response to pharmacological stimuli (insulin, arginine and/or L-Dopa) was evaluated when growth failure occurred. The 9 prepubertal patients who had received previous prophylactic cranial irradiation during first-line chemotherapy, showed a significant decrease in growth rate already 1 year after BMT and this reduced growth rate presented a progressive further decrease in the 2nd and 3rd year after BMT. On the contrary, in the 9 prepubertal children treated with TBI and chemotherapy alone, growth rate presented an impressive decrease only during the 3rd year. In the two groups of patients, pretransplantation growth rates were comparable, while, due to the earlier growth failure in children receiving TBI and previous prophylactic cranial irradiation, mean standard deviation score (SDS) significantly differed at 1 and 2 years following BMT. Such a difference disappeared at 3 years after BMT, because of the late decrease in growth rate in patients given TBI and chemotherapy alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Determination by Skeleton↗

Diagnosing growth hormone deficiency: the value of short-term hypocaloric diet.

In the attempt to define possible causes of false positive GH deficiency, the role of caloric intake on GH determination was explored. The serum GH responses to insulin-induced hypoglycemia or arginine were assessed before and after 3 days of a hypocaloric diet in 23 prepubertal children of normal weight, aged 6.7-11.9 yr. Seventeen had short stature and a GH response to insulin and arginine below 10 micrograms/L, and 6 controls had normal stature and a GH peak above 10 micrograms/L in response to arginine. After diet, the serum peak GH and the area under the curve increased in both the patients (P < 0.0005 and P < 0.0005) and the controls (P < 0.005 and P < 0.025) with a GH peak greater than 10 micrograms/L in 11 of 17 patients. The patients with a persistent GH response below 10 micrograms/L also had lower mean 12-h overnight GH levels (P < 0.0005), whereas those with a normal GH response after diet had an overnight GH level greater than 3 micrograms/L. In the patients, the mean nighttime GH concentrations correlated with the serum GH peak (r = 0.85; P < 0.005) and with the area under the curve after the diet (r = 0.65; P < 0.025). The diet induced changes in plasma insulin-like growth factor-I, GH-releasing hormone levels, basal blood sugar and the nadir level obtained during insulin stimulation, total T3, and rT3. Height increased significantly during 1 and 2 yr (P < 0.005) of GH treatment only in patients with a GH response below 10 micrograms/L after the diet. These data are consistent with the hypothesis that the GH response to stimulation is strongly calorie dependent and that 3 days of a hypocaloric diet can increase the number and height of GH peaks and the total GH responses to insulin and arginine. The clear correlation of the GH response to stimulation after a hypocaloric diet with the mean nighttime GH and also with the growth response to GH treatment indicates that GH deficiency may be overdiagnosed in many children with short stature.

Arginine↗

Partial response after intensive chemotherapy for adrenal cortical carcinoma in a child.

Adrenocortical carcinoma (ACC) in childhood is a rare tumor with high fatality rate. Available reports provide event free survival rates ranging between 10 to 50%. Optimal treatment has not yet been established; surgery plays a major role, and the value of adjuvant chemotherapy needs to be evaluated further, especially in children who develop recurrent disease and those with metastases at diagnosis. Optimal therapy of ACC has not been established. Surgery has been curative after complete tumor resection. Children with inoperable, recurrent and metastatic ACC have been treated with O,P'DDD, with response rates ranging from 10 to 60% in different series [7,11-20]. Radiotherapy [21] and other anti-cancer drugs have been used [4-22] but their efficacy has not been established. Combination chemotherapy containing oncovin, cisPlatinum, epipodophyllotoxin and cyclophosphamide (OPEC) produced regression of metastatic ACC in a 5-year-old male [23]. We report one girl with relapsed disseminated ACC who showed good, even if temporary, control of the disease, with disappearance of lung, liver and spleen metastases, and marked reduction of the adrenal mass, following combined chemotherapy according to the "eight-drugs-in-one-day" protocol.

Adrenal Gland Neoplasms↗

Influence of HLA genotype on birth weight of patients with Turner syndrome.

Growth failure starting before birth is a common characteristic in Turner syndrome, and its pathogenesis is still not completely explained. Experiments performed in mice and rats to test whether a genetic disparity between mothers and offspring and maternal immunological status have any influence on litter size have demonstrated that allogenic litters are significantly larger in size than genetically compatible ones. Studies in humans have given contrasting results, but some authors have found that heterozygosity at enzyme loci and in blood groups is positively correlated with intrauterine growth. HLA class I and II polymorphisms were defined in 53 patients with Turner syndrome and in their parents, and lymphocytotoxic antibody detection was performed in 36 mothers. These data were related to the patients' birth weight. The frequency of the HLA-B16 allele in patients with a birth weight greater than 10th centile was significantly higher in comparison with those less than 10th centile. HLA antigen sharing was present in 43 couples (81.1%). Mean birth weight was 2934 +/- 472 g in patients without HLA antigen parental sharing and 2721 +/- 529 g in those whose parents shared HLA antigens. The mean birth weight of the 10 patients whose parents do not share HLA antigens was significantly higher than that of the patients with parental HLA-B+ DR sharing (P less than 0.05) and not significantly highe than in those patients with parental HLA sharing at other HLA loci. Patients whose parents shared B+DR antigens also had significantly smaller birth weights than those with B and A+B+DR sharing (P less than 0.025 and P less than 0.025). No significant difference in mean birth weight was found in relation to other parameters, such as mother-child histocompatibility, HLA homozygosity and lymphocytotoxic production in the mothers.

Antibody Formation↗

CYP21/C4 gene organisation in Italian 21-hydroxylase deficiency families.

A total of 33 Italian 21-hydroxylase (21-OH) deficiency families were investigated using a combination of short and long range restriction mapping of the CYP21/C4 gene cluster. The analyses revealed that large-scale length polymorphism in this gene cluster strictly conformed to a compound variable number of tandem repeats (VNTR) plus insertion system with between one and four CYP21 + C4 units and seven BssHII restriction fragment length polymorphisms (RFLPs) (75 kb, 80 kb, 105 kb, 110 kb, 135 kb, 140 kb and 180 kb). A total of 9/66 disease haplotypes, but only 1/61 non-disease haplotypes, showed evidence of gene addition by exhibiting three or more CYP21 + C4 repeat units. Of these, two were identified in one 21-OH deficiency patient who has a total of eight CYP21 + C4 units, being homozygous for the HLA haplotype DR2 DQ2 B5 A28. This haplotype carries four CYP21 + C4 units, three of which contain CYP21A-like genes and one of which contains a CYP21B-like gene that presumably carries a pathological point mutation. Of the other gene addition haplotypes associated with 21-OH deficiency, four show three CYP21 + C4 units flanked by HLA-DR1 and HLA-B14 markers. Although such haplotypes have commonly been associated with non-classical 21-OH deficiency, three examples in the present study are unexpectedly found in two salt-wasting patients, who are respectively homozygous or heterozygous for this haplotype. Only 7/66 disease haplotypes showed evidence of a CYP21B gene deletion.

Adrenal Hyperplasia, Congenital↗

IgG subclasses compared in maternal and cord serum and breast milk.

Total and specific IgG subclass antibodies against 14 pneumococcal capsular polysaccharide antigens on the cord serum from 11 healthy term infants at birth and on serum from their mothers at delivery were evaluated. The same evaluation was performed five days after delivery on the serum and the milk obtained from the six mothers who were breast feeding their infants. Mean neonatal: maternal serum ratio of total IgG1 was significantly higher than the ratios of total IgG2, IgG3, and IgG4 and higher than the ratios of pneumococcal IgG subclass antibodies. Total IgG3 and IgG4 ratios were higher than the specific antibody ratios of the same IgG subclass. Type 1 and type 14 IgG1 antibodies were the highest antipneumococcal ratios. Although the maternal milk:serum ratios of total IgG subclasses were very low, significant amounts of specific antibodies were found in the milk, at about half the concentration observed in mother's serum.

Adolescent↗

Testicular masses in association with adrenogenital syndrome: US findings.

Adrenogenital syndrome (AGS) is the result of inborn enzymatic defects in the synthesis of steroid hormones. The production of cortisol is deficient and that of adrenocorticotropic hormone is increased. Sometimes male patients have clinically detectable testicular lesions, known as testicular tumors of AGS (TTAGS). From 1985 to 1991, scrotal ultrasonography (US) was performed in 30 consecutive pubertal and postpubertal patients with AGS to investigate the prevalence and US characteristics of TTAGS. Eight of 30 patients had a testicular lesion (27%); six of the eight lesions were clinically undetected. The mean diameter of the lesions was 16.44 mm (range, 2-28 mm). The lesions were hypoechoic in all cases, with well-defined margins in six cases. The nodules were multifocal in all patients and bilateral in six (75%). If testicular lesions are present in a patient with AGS, TTAGS are likely, and frequent US monitoring is adequate for diagnostic evaluation.

Adolescent↗

Final height attainment and gonadal function in girls with precocious puberty treated with cyproterone acetate.

Thirty-four girls with precocious puberty (27 idiopathic, 6 cerebral, 1 McCune-Albright syndrome) were treated with cyproterone acetate (CPA) for 1.2-8.4 years (3.71 +/- 0.31; mean +/- SEM) at a daily dosage of 66-150 mg/m2 (103.7 +/- 6.2). The mean chronological age (CA) and bone age at the beginning of treatment were 5.99 +/- 0.31 and 8.6 +/- 0.39 years, respectively, and 9.78 +/- 0.19 and 12.44 +/- 0.22 years, respectively, at the end of therapy. At the last evaluation, mean CA was 14.23 +/- 0.4 years, and 32 girls had reached final height. The control group consisted of 10 girls with idiopathic precocious puberty who, at their parents' request, were not treated. Mean CA at the onset of pubertal signs was 6.05 +/- 0.25 years. All patients had reached final height at the time of the last observation. There was no significant difference between final height of treated (152.43 +/- 1.36 cm) and untreated (149.55 +/- 1.99 cm) girls. Final height was significantly lower than target height in both treated (155.08 +/- 0.92 cm; p < 0.025) and untreated (156.45 +/- 1.29 cm; p < 0.0005) patients, but the mean height of treated patients is nearer to target height than that of untreated ones. A positive correlation was found between final height and target height both in treated (p < 0.005) and untreated (p < 0.05) patients. After the discontinuation of CPA treatment all girls resumed the progressive course of puberty.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Height↗

Correlation between magnetic resonance imaging of posterior pituitary and neurohypophyseal function in children with diabetes insipidus.

The posterior pituitary lobe and stalk were studied by magnetic resonance imaging in 20 children with diabetes insipidus of different origins: primary familial autosomal dominant (n = 2) or idiopathic (n = 2), and secondary to craniopharyngioma (n = 6, resected in 5), to Langerhans cell histiocytosis (n = 5), to excessive water intake (dipsogenic; n = 3), to renal vasopressin insensitivity (n = 1), and to osmoreceptor dysfunction (n = 1). Of the four children with primary diabetes insipidus, the posterior bright signal was recognizable in two with the familial autosomal dominant form and one with the idiopathic form; in the latter, the pituitary stalk was thin, while it was normal in the first two patients; no posterior hyperintense signal with enlarged and gadolinium-enhanced pituitary stalk was observed in the fourth. The posterior hyperintense signal was absent without evidence of ectopic posterior pituitary tissue regeneration in five children with surgically removed craniopharyngioma and was doubtful in the child with unresected craniopharyngioma; the stalk was unrecognizable in all patients. In the five children with Langherans cell histiocytosis, the posterior bright signal was absent, while the stalk was normal in two and unexpectedly enlarged in three (uniformly in two and mainly at the level of median eminence and hypothalamus in one). All five patients with dipsogenic or nephrogenic diabetes insipidus or osmoreceptor dysfunction had normal images of posterior pituitary lobe and stalk. Normal posterior pituitary bright signal and stalk were found in all 25 healthy control children. Plasma vasopressin was undetectable in all patients except in nephrogenic one, in the child with osmoreceptor dysfunction, and in two of three dipsogenic children, the third mimicking partial neurogenic diabetes insipidus.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

Immunodeficiency, growth hormone deficiency and central nervous system involvement in a girl.

We describe a mentally retarded 12-year-old girl with ataxia in whom diagnostic evaluation for short stature revealed isolated growth hormone (GH) deficiency and multiple central nervous system (CNS) lesions. Assessment of immunologic status, performed because of the persistence of recurrent respiratory tract infections, showed associated deficiencies of IgG2-IgG4 and specific antibody response; in addition, in vitro lymphocyte response to mitogens was low, in vitro production of interleukin-2 and of IgM was absent, and natural killer activity was decreased. The possibility that association of the CNS lesions, GH deficiency and immune defects could be due to alterations of the neuro-immuno-endocrine network secondary to a disturbance of neurotransmitters induced by precocious CNS damage of a viral or ischemic nature is discussed.

Brain Diseases↗

Effects of short-term administration of human chorionic gonadotropin on immune functions in cryptorchid children.

To delineate the effects of human chorionic gonadotropin (hCG) administration on immune responsiveness, immunological parameters including serum immunoglobulins, total and differential white blood cell count T and B lymphocyte membrane phenotype, in vitro, proliferative response to phytohaemagglutinin, Concanavalin A (ConA) and pokeweed mitogen were studied in 13 prepubertal cryptorchid boys before, during, and 3 months after hCG therapy. Before treatment, all the immunological parameters were normal except for an unexpected high percentage of T suppressor-cytotoxic cells (CD8+). During therapy, the absolute number of total peripheral blood lymphocytes, and that of total T-cells, T helper-inducer cells and of CD8+ subsets were diminished. The percentage of CD8+ cells and lymphocyte response to ConA decreased significantly and returned to normal after hCG withdrawal. The possible effects of long-term hCG treatment remain to be determined.

Child↗