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Biomedical subjects

G Fiorelli

Publications and source records attributed to G Fiorelli.

At least 91 records · Page 5Linked to original sources
PubMed1995

Evidence for bioeffects of LY 139478 on the human pre-osteoclastic cell line FLG 29.1.

LY 139478, the hydrochloride salt of LY 117018, is a member of the nonsteroidal antiestrogens, benzothiophene derivatives, described to be full estrogen agonists in bone acting via an estrogen receptor-mediated mechanism. However, the cellular actions of these compounds on bone remodelling need to be established. To investigate the "in vitro" properties of LY 139478 on osteoclast precursors, the human pre-osteoclastic cell line FLG 29.1 was examined for evidence of bioeffects of this compound. Binding studies with tritiated 17 beta-estradiol (17 beta E2) demonstrated that the relative potency of LY 139478 in inhibiting estrogen binding to its receptor was equal to that of 17 beta E2. Significant (p < 0.05) dose-dependent inhibition of cell growth was induced by LY 139478 at 10 nM, 100 nM and 1 microM. Calcitonin-induced cAMP accumulation was significantly increased by low (1 pM) and high (1 microM) doses of both 17 beta E2 and the compound with a dose-dependent response. Differently than estrogen, LY 139478 at high dose significantly reduced IL-6 release by these cells. In addition, pharmacological doses of both 17 beta E2 and LY 139478 activated apoptotic cell death. These findings show that the benzothiophene-derived LY 139478 acts directly on the human pre-osteoclastic cell line FLG 29.1 as an estrogen agonist.

Bone Marrow Cells↗
PubMed1995

Functional estrogen receptors in a human preosteoclastic cell line.

The primary biological effect of the estrogen estradiol-17 beta (17 beta E2) on bone is to decrease bone resorption. However, whether 17 beta E2 affects osteoclast differentiation or function directly or through its action on osteoblasts is unclear. To investigate this question we examined the human preosteoclastic cell line FLG 29.1 for evidence of functional estrogen receptors (ERs). Southern blotting of reverse transcription-PCR amplification products with a 32P-labeled cDNA probe for the human ER mRNA demonstrated that FLG 29.1 cells express ER mRNA. Binding of [3H]17 beta E2 to nuclear ERs was steroid specific with approximately 400 saturable, high affinity (Kd approximately 1 nM) binding sites per cell nucleus. Nuclear ERs covalently labeled with [3H]tamoxifen aziridine showed an apparent molecular weight of 65,000 by SDS/PAGE and Western blotting with the D75 monoclonal antibody to human ER. Pretreatment of cells with 0.1, 1.0, or 10 nM 17 beta E2 induced a dose- and time-dependent specific binding of progesterone to FGL 29.1 cells, and stimulation of the cells with 10 nM and 100 nM 17 beta E2 significantly (P < 0.05) reduced cell proliferation. Transcriptional activity of the ER gene was detected by transient transfection of cells with the pERE-BLCAT plasmid containing the estrogen response element for the vitellogenin A2 gene and the bacterial chloramphenicol acetyltransferase reporter gene. Treatment of FLG 29.1 cells with 10 nM 17 beta E2 increased chloroamphenicol acetyltransferase expression from 5- to 29-fold compared to controls. These observations suggest a potential role for estrogen in osteoclastogenesis.

Adenocarcinoma↗
PubMed1995

Genetic interactions in thalassemia intermedia: analysis of beta-mutations, alpha-genotype, gamma-promoters, and beta-LCR hypersensitive sites 2 and 4 in Italian patients.

In order to verify the genetic factors influencing the clinical expression of beta-thalassemia we have studied 292 Italian patients, 165 with thalassemia intermedia and 127 with thalassemia major. The beta-globin gene mutations were defined in all cases. The number of alpha-globin genes and the integrity of specific control regions of the beta-globin cluster--gamma promoters and beta-Locus Control Region (beta-LCR)--were studied in selected cases. Homozygosity for mild mutations (group I) accounts for 24% of the intermedia patients and it is not represented among major patients. Forty-four percent of intermedia patients had combinations of mild/severe (group II) mutations and 32% had homozygosity or double heterozygosity for severe mutations (group III). Seventy-six percent of patients with thalassemia major were classified in group III and 24% in group II. Deletion type-alpha3.7 thalassemia, assessed in a part of the cases, was found in 5% of thalassemia major and 19.5% of intermedia patients in groups II and III. Structural analysis of gamma promoters and beta-LCR HS2 and HS4 regions, carried out in order to look for alterations associated with Hb F increase, did not reveal new mutations. Only rare polymorphic changes were observed at the HS2 and HS4 level. The -158G gamma C T change was found with an increased incidence in intermedia patients in groups II and III. A subset of 10 beta-thalassemia heterozygotes with mild intermedia phenotype resulted from coinheritance of a triplicated alpha-locus. We have been unable to find a molecular basis for the benign clinical course in approximately 20% of patients with thalassemia intermedia. Other genetic or acquired factors must be hypothesized which ameliorate the clinical condition.

Adolescent↗
PubMed1995

Molecular characterisation of the glucose-6-phosphate dehydrogenase (G6PD) Ferrara II variant.

During the last ten years, molecular biological techniques such as cloning and sequencing and, more recently, polymerase chain reaction (PCR) amplification have led to the identification of the molecular defects responsible for more than fifty glucose-6-phosphate dehydrogenase (G6PD) variants. In this paper, we report the identification of the molecular abnormality underlying the G6PD Ferrara II variant, present in the Po delta area of Northern Italy. Biochemical characterisation shows an enzymatic activity of about 15% of normal (WHO class III), slow electrophoretic mobility, low Km for G6P, high percentage substrate analogue utilisation and a biphasic pH optimum curve. After PCR amplification, non-radioisotopic single-strand conformation polymorphism analysis carried out for the entire coding region has revealed a mobility shift in exon 8. Nucleotide sequencing has demonstrated a missense 844 G > C mutation, causing an Asp > His amino-acid replacement, known as being responsible for G6PD Seattle, G6PD Modena and G6PD Lodi.

Adult↗
PubMed1995

Interactions between ipriflavone and the estrogen receptor.

Estrogen replacement therapy is effective in the prevention of postmenopausal osteoporosis, and a direct action of 17-beta-estradiol (17 beta E2) on osteoblastic and osteoclastic cells has been demonstrated. The inhibition of bone resorption by ipriflavone (IP), an isoflavone derivative devoid of estrogenic properties but active in potentiating the effects of estrogen on bone tissue, has been shown in in vitro and in vivo studies and confirmed by clinical data. To investigate the molecular mechanisms that underlie IP effect, we studied the possible interactions of IP and its four main in vivo metabolites (I, II, III, and V) with the estrogen receptor (ER) in the human preosteoclastic cell line FLG 29.1, whose growth and function are modulated by the compound. In parallel experiments, the human breast cancer cell line MCF7 was also analyzed. IP binding sites were demonstrated in the nuclear fraction of FLG 29.1 cells. 17 beta E2 and other steroid compounds failed to displace IP binding to intact FLG 29.1 cells. Similarly, IP and metabolites I, III, and V were not able to displace 17 beta E2 binding to intact MCF7 cells, whereas metabolite II showed an IC50 of 61 nM. 17 beta E2 binding to FLG 29.1 cells was increased after preincubation with metabolites I, III, and V. IP and its metabolites did not induce ER-dependent gene expression in FLG 29.1 and MCF7 cells transfected with a reporter gene and an estrogen response element (ERE).(ABSTRACT TRUNCATED AT 250 WORDS)

Binding, Competitive↗
PubMed1995

Single-tube reverse transcription and heminested polymerase chain reaction of hepatitis C virus RNA to detect viremia in serologically negative hemodialysis patients.

Detection of hepatitis C virus genome is the only method currently available for detecting viremia in infected individuals. We describe a substantial simplification of current methods for viral RNA reverse transcription and polymerase chain reaction amplification, which allows cDNA synthesis and nested amplification in a single tube; this is achieved through compartmentalization of the reagents for the two reactions with a wax barrier. This procedure retains a high sensitivity: analysis of serum samples from hemodialysis patients, a high-risk group for hepatitis C virus infection, confirmed the presence of the virus in 88% of antibody-positive patients and detected viremia in patients without serological or biochemical evidence of hepatitis C virus infection.

Adult↗
PubMed1995

High prevalence of a rare hepatitis C virus in patients treated in the same hemodialysis unit: evidence for nosocomial transmission of HCV.

Hepatitis C virus (HCV) is a major cause of hepatitis among patients treated with maintenance hemodialysis. Blood transfusion appears to be the primary risk factor, but nosocomial transmission of HCV in the dialytic environment has been hypothesized. We addressed this issue by analyzing the individual variation of genomic sequences of HCV in 28 patients on chronic hemodialysis (HD) from the same department and 25 environmentally unrelated patients with HCV-related liver disease. Genome variations of HCV were studied by single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction products obtained from the 5'-untranslated region of the viral genome and by sequence analysis. Six different SSCP patterns were identified in HD patients versus 16 in control patients. Among HD patients the three more frequent SSCP patterns accounted for 85% of observations, while in the control group each pattern was found in 4 to 12% of patients. The ability of SSCP to discriminate sequence variation was proven by sequence analysis which confirmed identity/diversity of sequences selected by SSCP. Moreover, sequence analysis permitted a recognition of the most frequent genome observed in HD patients as a type 4 HCV, which is considered to be rare in the Italian population. The relative homogeneity of HCV variants in HD patients treated in the same HD and the high prevalence in this unit of a rare viral variant support the possibility of a nosocomial transmission of HCV in the dialytic environment.

Adult↗
PubMed1995

Liver iron concentration in chronic viral hepatitis: a study of 98 patients.

OBJECTIVE: To compare the liver iron concentration (LIC) of Italian patients with chronic hepatitis B and C with those of controls, to evaluate increased LIC frequency in patients and to investigate the influence of the haemochromatosis gene in the development of liver iron overload. DESIGN AND SETTING: Prospective controlled trial in two northern Italian hospitals. PATIENTS: Ninety-eight patients (61 men and 37 women), 85 with chronic hepatitis C and 13 with chronic hepatitis B, and 38 control individuals (20 men and 18 women). METHODS: Atomic absorption spectrophotometry was used to determine LIC; standard lymphocytotoxicity test was used for HLA typing in patients with increased LIC; and family studies were performed for patients with major iron overload. RESULTS: Mean LIC was significantly higher in both patient groups than in the controls. Thirty-five patients (36%) had an increased LIC. Twenty-six of these patients had a minor iron overload, whereas nine (9.2%) had a major overload. HLA-A3 antigen was present in five out of the 26 and in four out of the nine patients, respectively. Family studies revealed two siblings HLA-identical to their own proband without evidence of iron overload and chronic hepatitis. CONCLUSION: Increased LIC is frequent in Italian patients with chronic hepatitis. The mechanism by which the hepatitis virus promotes liver iron accumulation is not known, but it can favour the development of major iron overload in some cases. HLA-A3 antigen prevalence and family studies suggest that in these cases a single haemochromatosis gene probably coexists with the viral infection. LIC should be determined as part of the screening evaluation in patients with suspected chronic hepatitis B or C.

Aged↗
PubMed1995

Carbohydrate-deficient transferrin in alcohol and nonalcohol abusers with liver disease.

Carbohydrate-deficient transferrin (CDT) has been demonstrated to be a marker of prolonged heavy alcohol consumption. We compared this marker with gamma-glutamyltranspeptidase (GGT) and mean corpuscular volume (MCV) in alcohol and nonalcohol abusers with liver disease. Our results confirm that the sensitivity of CDT in alcoholics is high, although lower than that of GGT and MCV; however, the specificity of CDT was higher than that of the other two markers. This finding supports the notion that CDT is only partially influenced by the presence of liver damage, whereas increases of GGT and MCV are greatly affected by several factors, including liver damage and drugs. Moreover, we observed that the sensitivity and the specificity of CDT were greater than those of GGT and MCV in younger drinkers.

Adult↗
PubMed1995

Stroke and alcohol intake in a hospital population. A case-control study.

BACKGROUND AND PURPOSE: The aim of the study was to assess whether excessive alcohol intake is an independent risk factor for stroke. METHODS: A case-control study was undertaken in 200 consecutive ischemic and hemorrhagic stroke patients and 372 age- and sex-matched control subjects (170 hospital-based and 202 community-based individuals). Data were collected through direct interview regarding demographics, risk factors for stroke, current daily alcohol consumption, and diagnosis of alcoholism. Blood was also taken to test the common biological markers of alcohol intake (erythrocyte mean cell volume, uric acid, aspartate aminotransferase, and gamma-glutamyl transferase). RESULTS: After controlling for the most significant risk factors (antecedent strokes, hypertension, diabetes, smoking) and using hospital control subjects for reference, we determined the risk of stroke to be 2.2 (95% confidence interval [CI], 1.2 to 4.0) in moderate drinkers (men, < or = 60 g/d; women, < or = 40 g/d) and 2.9 (95% CI, 1.4 to 6.1) in heavy drinkers (men, > 60 g/d; women, > 40 g/d). The corresponding risk values obtained when we compared case subjects and external control subjects were 1.4 (95% CI, 0.8 to 2.7) and 3.0 (95% CI, 1.3 to 7.0). Even with some fluctuations across groups, the risk did not change significantly after subgroup analysis in men, patients with first-ever stroke, patients with ischemic stroke, and after exclusion of subjects with risk factors for stroke. Compared with hospital and external control subjects, stroke patients included a higher proportion of heavy drinkers (26.6% versus 20.6% versus 10.8%), alcoholics (14.6% versus 7.7% versus 2.5%), and cases with abnormal erythrocyte mean cell volume (63.0% versus 47.6% versus 34.2%) or gamma-glutamyl transferase (35.5% versus 32.4% versus 12.9%). Mean alcohol consumption was 42.2 g/d in the case subjects, 30.8 g/d in the hospital control subjects, and 23.2 g/d in the external control subjects. CONCLUSIONS: The study indicates that alcohol can be considered an independent risk factor for stroke in Italy.

Adult↗
PubMed1994

Binding and bioeffects of Ipriflavone on a human preosteoclastic cell line.

Ipriflavone, a synthetic isoflavone derivative, reduces bone resorption by inhibiting osteoclasts activity. In order to evaluate the role of Ipriflavone on osteoclast growth and differentiation, we tested Ipriflavone and its four "in vivo" main metabolites (Metabolites I, II, III, and V) on a clonal population of human osteoclast precursor cells (FLG 29.1). Pharmacological doses of Ipriflavone and Metabolite III were able to inhibit cell proliferation and interleukin 6 release. In co-cultures of FLG 29.1 cells and osteoblastic (Saos-2) cells Ipriflavone at 1 microM dose inhibited the adhesion of FLG 29.1 cells to the osteoblastic monolayer and reduced the immunocytochemical reaction of the vitronectin receptor. Binding studies with tritiated Ipriflavone showed the presence of a single specific binding site, wtih a Kd of about 70 nM and a binding capacity of 8 fmol/10(6) cells. These results demonstrate a direct effect of Ipriflavone and of Metabolite III on the human osteoclast precursor cell line FLG 29.1.

Cell Adhesion↗
PubMed1994

Prognostic factors for hepatocellular carcinoma in genetic hemochromatosis.

To identify factors that might be useful as prognostic indexes for the risk of hepatocellular carcinoma in Italian patients with genetic hemochromatosis, 152 homozygotes were studied prospectively for 1 to 229 mo. Factors that were considered in estimating the risk of developing hepatocellular carcinoma were age, sex, cirrhosis (Child class), HBsAg, antibodies to HBsAg, antibodies to HBcAg, hepatitis C antibodies, alcohol abuse and the amount of iron removed during therapeutic phlebotomy to produce iron depletion. At diagnosis, cirrhosis was present in 97 patients and absent in 55. During follow-up, hepatocellular carcinoma developed in 28 of the 97 patients with cirrhosis but in none of those without. Among patients with cirrhosis, the cumulative probability of being free of hepatocellular carcinoma at 10 yr was 70%. For patients with and without HBsAg the probabilities of being free of liver cancer at 10 yr were, respectively, 54% and 75%; for those with and without history of alcoholism, 58% and 78%; and for those younger and older than 55 yr, 90% and 54%. In patients with cirrhosis, multivariate analysis using proportional-hazards (Cox) regression found that the only factors contributing significantly to the estimation of a prognostic index were age, presence of HBsAg and alcohol abuse. Age over 55 yr increased the relative risk of hepatocellular carcinoma 13.3-fold (p < 0.001), the presence of HBsAg increased it 4.9-fold (p < 0.02) and alcohol abuse increased it 2.3-fold (p < 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Characterization, regulation, and function of specific cell membrane receptors for insulin-like growth factor I on bone endothelial cells.

It is now widely accepted that insulin-like growth factor-I (IGF-I) has a local regulatory role in bone remodeling. IGF-I has also been demonstrated to regulate proliferation of bone-derived endothelial cells. Such studies suggest a role of IGF-I in skeletal angiogenesis. Using BBE cells, a bovine bone endothelial cell line, we characterized the kinetics and chemical properties of IGF-I receptors and examined the effect of IGF-I on bone endothelium migration. Two classes of binding sites with high affinity for IGF-I were detected by binding experiments on bone endothelial cells. Both competition analyses and cross-linking studies revealed the presence of type I IGF receptor in bone endothelial cells. Moreover, these cells produced and released authentic IGF-I into the medium, as evidenced by radioimmunoassay analyses of gel-filtered conditioned media. Both IGF-I binding capacity and release decreased either with increases in cell number or after treatment with 17 beta-estradiol (17 beta E2) and parathyroid hormone (PTH). Both hormones also inhibited chemotactic responses of bone endothelial cells to IGF-I. Taken together, these results strongly suggest that IGF-I, a growth factor that promotes the proliferation of various bone cell types, also induces growth and chemotactic responses in bone endothelium acting through the type I IGF receptor. This may be part of a generalized response of bone cells to IGF-I that facilitates cell migration.

Analysis of Variance↗
PubMed1994

Role for autocrine TGF-beta 1 in regulating differentiation of a human leukemic cell line toward osteoclast-like cells.

Increasing evidence suggests that transforming growth factor-beta (TGF-beta) is involved in bone formation during remodeling. Using a recently cloned human leukemic cell line (FLG 29.1 cells) we demonstrate that these cells synthesize and secrete TGF-beta 1 and that exogenous or autocrine TGF-beta 1 can induce the same features of osteoclastic-like cells, exerting its effects through the binding to TGF-beta specific receptors. Scatchard analysis of 125I-labeled TGF-beta 1 to FLG 29.1 cells revealed the presence of a single high affinity binding site with a Kd value of approximately 25 pM and a binding capacity of approximately 900 sites/cell. Affinity labeling experiments showed that FLG 29.1 cells express type I and type II TGF-beta receptors. Stimulation of FLG 29.1 cells with low TGF-beta 1 doses reduced cell proliferation and increased cell adhesion and tartrate resistant acid phosphatase (TRAcP) activity. Pretreatment of FLG 29.1 cells with TGF-beta 1 caused a significant and dose-dependent response to calcitonin. Northern blot of total mRNA and analysis of the conditioned media (CM) showed that TGF-beta 1 was synthesized by FLG 29.1 cells. TPA treatment, which induces partial differentiation of these cells, markedly increased TGF-beta 1 mRNA expression and growth factor release. The majority of TGF-beta 1 secreted by TPA-treated cells was in its latent form. However, anti-TGF-beta antibodies inhibited TGF-beta 1 and TPA-induced growth inhibition, calcitonin responsiveness, and TRAcP activity, suggesting that the TPA effect is mediated in part by autocrine TGF-beta 1 and indicating that the cells can activate and respond to the TGF-beta that they secrete. These findings support a potential autocrine role for TGF-beta 1 in osteoclast differentiation.

Acid Phosphatase↗
PubMed1994

G6PD Ferrara I has the same two mutations as G6PD A(-) but a distinct biochemical phenotype.

The cloning and sequencing of the normal glucose-6-phosphate dehydrogenase (G6PD) gene has led to the study of the molecular defects that determine enzymatic variants. In this paper, we describe the mutations responsible for the Ferrara I variant in an Italian man with a family history of favism, from the Po delta. Nucleotide sequencing of this variant showed a G-->A mutation at nucleotide 202 in exon IV causing a Val-->Met amino acid exchange, and a second A-->G mutation at nucleotide 376 in exon V causing an Asn-->Asp amino acid substitution. Although on the basis of its biochemical properties this variant was classified as G6PD Ferrara I, it has the same two mutations as G6PD A(-), which is common in American and African blacks, and as the sporadic Italian G6PD Matera. The mutation at nucleotide 202 was confirmed by NlaIII digestion of a polymerase chain reaction amplified DNA fragment spanning 109 bp of exon IV. The 109-bp mutated amplified sequence is not distinguishable from the normal sequence in single strand conformation polymorphism analysis.

Cloning, Molecular↗
PubMed1994

Glucose 6-phosphate dehydrogenase deficiency and red cell membrane defects: additive or synergistic interaction in producing chronic haemolytic anaemia.

We have investigated two unrelated patients with congenital haemolytic anaemia in both of whom we found a combination of hereditary spherocytosis (HS) and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Segregation of the two defects was documented in both families, who had different molecular abnormalities for both HS and G6PD deficiency. In one family the propositus had a reduced level of spectrin and G6PD Seattle (282Asp-->His). In the other family the propositus had a band 3 abnormality and was heterozygous for G6PD Mediterranean (188Ser-->Phe). From a comparison of clinical and haematological findings in family members with either or both abnormalities we conclude that in one case the two defects exhibited a synergistic effect, resulting in a severe chronic haemolytic anaemia; whereas in the other the association was simply additive.

Anemia, Hemolytic, Congenital↗
PubMed1994

Biochemical and molecular characterization of a new sporadic glucose-6-phosphate dehydrogenase variant described in Italy: G6PD Modena.

A new glucose-6-phosphate dehydrogenase variant detected in an Italian man from the Po delta is described and designated as G6PD Modena. Biochemical characterization of the variant enzyme revealed an activity 21% of normal, a slow electrophoretic mobility, increased Km value for NADP, decreased Km value for G6P and a complete absence of NADPH inhibition, which could account for the apparently nonhaemolytic feature of this variant. The cloning and sequencing of the G6PD Modena allele showed a G-->C transition at nucleotide 844 in exon VIII causing a Asp-->His amino acid substitution. On the basis of biochemical characterization, G6PD Modena is classified as a genuine variant but it has the same mutation as G6PD Seattle-like.

Adult↗