24 results on '"Poiesi C"'
Search Results
2. Proteolysis of αs-Casein as a Marker of Grana Padano Cheese Ripening
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Gaiaschi, A., Beretta, B., Poiesi, C., Conti, A., Maria Gabriella Giuffrida, Galli, C. L., and Restani, P.
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Time Factors ,Food Handling ,Immunoblotting ,Antibodies, Monoclonal ,Caseins ,Proteins ,Cheese ,Endopeptidases ,Genetics ,Electrophoresis, Polyacrylamide Gel ,Animal Science and Zoology ,Amino Acid Sequence ,Fibrinolysin ,Chymosin ,Food Science - Abstract
Since casein proteolysis has a critical role in defining the typical characteristics of Grana Padano cheese, we evaluated the hydrolysis of alphas-casein during the ripening process. Thanks to the high specificity of the anti-alphas((alphas1 + alphas2)-casein monoclonal antibody and amino acid sequence determination, it was possible to identify three main alphas-casein-derived polypeptides in cheese: alphaa, alphab, and alphac. Their production by the three enzymes most involved in cheese proteolysis (pepsin, chymosin, and plasmin) was evaluated by performing in vitro digestions. Data showed that alphaa was released in cheese mainly by the chymosin attack, while alphab and alphac were due to the action of plasmin. A significant correlation between the abundance of some polypeptides and ripening process was shown.
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- 2000
3. HIV p17 enhances lymphocyte proliferation and HIV-1 replication after binding to a human serum factor
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A. D. Canaris, Simona Fiorentini, Turano A, De Francesco Ma, Dima F, Poiesi C, Arnaldo Caruso, Fallacara F, S. Licenziati, F. Martinelli, and M. Corulli
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CD4-Positive T-Lymphocytes ,HIV Antigens ,viruses ,Lymphocyte ,Immunology ,Gene Products, gag ,Lymphocyte proliferation ,CD8-Positive T-Lymphocytes ,Antibodies, Viral ,Lymphocyte Activation ,Virus Replication ,gag Gene Products, Human Immunodeficiency Virus ,Peripheral blood mononuclear cell ,Epitope ,law.invention ,Viral Proteins ,immune system diseases ,law ,medicine ,Animals ,Humans ,Immunology and Allergy ,Phytohaemagglutinin ,biology ,virus diseases ,Blood Proteins ,Virology ,Molecular biology ,Recombinant Proteins ,Cross-Linking Reagents ,Infectious Diseases ,medicine.anatomical_structure ,Cell culture ,HIV-1 ,biology.protein ,Recombinant DNA ,Rabbits ,Antibody ,Protein Binding - Abstract
objective: To analyse the role of recombinant HIV-1 protein p17 in the modulation of cell activity. Methods: Peripheral blood mononuclear cells (PBMC) obtained from healthy donors were cultured in the presence or absence of p17 with mitogens such as phytohaemagglutinin or interleukin-2 and their response assayed by cell proliferation. Cross-linking experiments were employed to investigate the presence of a binding between p17 and factor(s) present in human serum. An immunoenzymatic assay for p24 antigen detection was used to analyse the effect of the addition of exogenous p17 to cultures of PBMC infected with HIV-1 in vitro. Results: Purified recombinant p17 protein at a concentration of 0.25 μg/ml significantly increased the proliferation of preactivated PBMC obtained from healthy donors. This effect was obtained by binding p17 to factor(s) present in human serum and observed on both CD4 + and CD8 + T cells. Recombinant p17 also induced an increased rate of HIV-1 replication, probably due to enhanced T-cell proliferation. The activity of p17 protein was inhibited by anti-p17 antibodies generated by injecting recombinant p17 in rabbits, but not by human antibodies generated during the natural course of HIV infection. Conclusion: Characterization of the human factor(s) and identification of the interacting p17 epitope(s) will improve our understanding of the mechanisms used by HIV to efficiently replicate in our organisms.
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- 1998
4. Effects of LY 117018, a Raloxifene analog, on 17-beta-estradiolo-induced Growth Hormone (GH) Secretion in Cultured Human GH-Secreting Pituitary Adenoma Cells
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TULIPANO G, C. BONFANTI, POIESI C, MILANI G, TURAZZI S, BARONE G, BOLLATI A, VALLE D, GIUSTINA , ANDREA, Tulipano, G, C., Bonfanti, Poiesi, C, Milani, G, Turazzi, S, Barone, G, Bollati, A, Valle, D, and Giustina, Andrea
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- 2001
5. Somatostatin analogs selective for subtyps 2 and 5 of the somatostatin receptor suppress with different patterns growth hormone (GH) secretion in human GH-secreting adenoma cells cultured in vitro
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Tulipano, Giovanni, Bonfanti, Carlo, Milani, G., Billeci, B., Bollati, Angelo, Cozzi, R., Maira, G., Marphy, C., Poiesi, C., Turazzi, S., Giustina, Andrea, Tulipano, G., C., Bonfanti, Milani, G., Billeci, B., Bollati, A., Cozzi, R., Maira, G., Marphy, C., Poiesi, C., Turazzi, S., and Giustina, Andrea
- Published
- 2001
6. Effects of LY 117018, a Raloxifene analog, on Growth Hormone GH-Secreting Pituitary Adenoma Cells
- Author
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TULIPANO G, C. BONFANTI, POIESI C, MILANI G, TURAZZI S, BARONE G, BOLLATI A, VALLE D, GIUSTINA , ANDREA, Tulipano, G, C., Bonfanti, Poiesi, C, Milani, G, Turazzi, S, Barone, G, Bollati, A, Valle, D, and Giustina, Andrea
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- 2001
7. Maturation of the regulation of growth hormone secretion in young males with hypogonadotropic hypogonadism pharmacologically exposed to progressive increments in serum testosterone
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Giustina, Andrea, Scalvini, T, Tassi, C, Desenzani, P, Poiesi, C, Wehrenberg, Wb, Rogol, Ad, Veldhuis, Jd, Giustina, Andrea, Scalvini, T, Tassi, C, Desenzani, P, Poiesi, C, Wehrenberg, Wb, Rogol, Ad, and Veldhuis, Jd
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Male ,Adolescent ,Human Growth Hormone ,Entropy ,Hypogonadism ,Arginine ,Growth Hormone-Releasing Hormone ,Circadian Rhythm ,Drug Combinations ,Insulin-Like Growth Factor Binding Protein 3 ,Pulsatile Flow ,Humans ,Testosterone ,Longitudinal Studies ,Insulin-Like Growth Factor I ,Gonadal Steroid Hormones - Abstract
To study the onset of the action of gonadal sex steroids on the GH axis in spontaneous puberty, which is prolonged and sparingly predictable, we present a clinical investigative paradigm in which six previously untreated boys with isolated hypogonadotropic hypogonadism were exposed to progressively higher testosterone levels designed to mimic the androgen environment recognized during the early stages of puberty. We administered three incremental doses of testosterone (25-, 50-, and 100-mg im injections), each over a period of 4 weeks. Studies of overnight pulsatile GH secretion and GH responses to GHRH alone or combined with L-arginine (a functional somatostatin antagonist) were performed before testosterone administration and after each dose of testosterone. Serum testosterone, but not estrogen, levels increased progressively in all subjects during therapy. Deconvolution analysis of GH release profiles disclosed that GH secretory burst mass was stimulated significantly even by 25 mg testosterone. This parameter was not altered further by higher doses of testosterone. Spontaneous GH secretory burst number and amplitude increased significantly only after the 50- and 100-mg testosterone treatments, after which the serum GH response to GHRH and arginine also rose significantly. In contrast, the GH response to GHRH alone was not significantly affected by any dose of testosterone. Serum testosterone levels correlated significantly with the primary parameters of nocturnal GH secretion. In summary, our experimental model suggests that in males even very small increases in circulating testosterone occurring during the earliest stages of puberty are able to amplify pulsatile GH secretion. Our concomitant secretagogue data further suggest that testosterone exerts its action at different sites in the hypothalamo-somatotropic axis, i.e. directly at the pituitary level, and also at hypothalamic loci, possibly increasing both GHRH and somatostatin release.
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- 1997
8. Proteolysis of β-Casein as a Marker of Grana Padano Cheese Ripening
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Gaiaschi, A., primary, Beretta, B., additional, Poiesi, C., additional, Conti, A., additional, Giuffrida, M.G., additional, Galli, C.L., additional, and Restani, P., additional
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- 2001
- Full Text
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9. Antigenic mimicry between Helicobacter pylori and gastric mucosa in the pathogenesis of body atrophic gastritis
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Negrini, R, primary, Savio, A, additional, Poiesi, C, additional, Appelmelk, BJ, additional, Buffoli, F, additional, Paterlini, A, additional, Cesari, P, additional, Graffeo, M, additional, Vaira, D, additional, and Franzin, G, additional
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- 1996
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10. Effects of the selective estrogen receptor modulator LY117018 on growth hormone secretion: in vitro studies
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Sergio Turazzi, A. Burattin, Domenico Valle, Andrea Giustina, Angelo Bollati, Renato Cozzi, Carlo Bonfanti, Giovanni Tulipano, Claudio Poiesi, G Barone, Tulipano, G, Bonfanti, C, Poiesi, C, Burattin, A, Turazzi, S, Barone, G, Cozzi, R, Bollati, A, Valle, D, and Giustina, Andrea
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Adenoma ,Adult ,Male ,Selective Estrogen Receptor Modulators ,medicine.medical_specialty ,Pyrrolidines ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,LY117018 ,pituitary adenoma ,Endogeny ,Thiophenes ,Growth Hormone-Releasing Hormone ,Rats, Sprague-Dawley ,Endocrinology ,Internal medicine ,medicine ,Animals ,Humans ,Raloxifene ,Secretion ,Cells, Cultured ,Estrogen receptor beta ,Aged ,pituitary adenomas ,growth hormone ,tamoxifen ,Dose-Response Relationship, Drug ,Estradiol ,Chemistry ,Middle Aged ,In vitro ,Growth hormone secretion ,Rats ,Tamoxifen ,Selective estrogen receptor modulator ,Estrogen ,Growth Hormone ,Pituitary Gland ,Raloxifene Hydrochloride ,Female ,Secretory Rate ,Cell Division ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
Sex steroids play an important role in modulating pulsatile growth hormone (GH) release, acting at both hypothalamic and pituitary level in both humans and experimental animals. Selective estrogen receptor modulators (SERMs) act as either estrogen receptor agonists or antagonists in a tissue-selective manner. In postmenopausal women, serum GH levels correlate positively with endogenous estradiol levels and insulin-like grwoth factor-I (IGF-I) is positively related to bone mineral density (BMD) at the spine and hip. The aim of the present study was to evaluate, for the first time, the direct effect of LY117018, an analog of raloxifene, on GH secretion from both human and rodent pituitary cells in vitro. Our results demonstrated that pharmacological concentrations of the raloxifene analog LY117018 can stimulate GH secretion through a direct action on the pituitary. LY117018 also showed an estrogen-like activity, inducing the proliferation of rat pituitary GH-secreting adenomatous cells (GH1).
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- 2004
11. Kinetic analysis of TNF-α oligomer-monomer transition by surface plasmon resonance and immunochemical methods
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Angelo Corti, Giovanni Cassani, Claudio Poiesi, Alberto Albertini, S. Ghielmi, Poiesi, C, Albertini, A, Ghielmi, S, Cassani, G, and Corti, Angelo
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Protein Conformation ,Immunology ,Kinetics ,Enzyme-Linked Immunosorbent Assay ,Biosensing Techniques ,In Vitro Techniques ,Biochemistry ,Oligomer ,Dissociation (chemistry) ,chemistry.chemical_compound ,Animals ,Humans ,Immunology and Allergy ,Bovine serum albumin ,Surface plasmon resonance ,Molecular Biology ,Chromatography ,biology ,Tumor Necrosis Factor-alpha ,Immunochemistry ,Serum Albumin, Bovine ,Hematology ,Recombinant Proteins ,Monomer ,chemistry ,Covalent bond ,biology.protein ,Protein quaternary structure - Abstract
In this work we have studied the kinetic parameters of oligomeric tumour necrosis factor alpha (TNF-alpha) dissociation using biospecific interaction analysis (BIA), based on surface plasmon resonance (SPR) of TNF-alpha immobilized on a sensor chip, and by an ELISA technique able to detect TNF-alpha oligomers in solution. Validation studies, carried out with sensor chips bearing TNF-alpha oligomers or bovine albumin monomers, verified that: (a) TNF-alpha can be immobilized in the oligomeric form onto sensor chips; (b) the covalent linkage between TNF-alpha and sensor chips is stable under the experimental conditions; (c) TNF-alpha monomers are present on the sensor chips after dissociation; (d) immobilization and dissociation rate constant (kdiss) measurements are reproducible. The kdiss of recombinant TNF-alpha, measured under non denaturing conditions at pH 7.4 by BIA and ELISA were in good agreement, being 0.92 x 10(-5)/s and 1.1 x 10(-5)/s respectively (corresponding to a half life of about 20.9 h and 17.5 h, respectively). The dissociation rate was found to be significantly affected by the presence of detergents and by the pH of the solution, suggesting that TNF-alpha, at low concentrations, exists in solution with different molecular forms depending on the time of storage and buffer composition. Real-time BIA is rapid and does not require particular antibodies or reagents. Thus, the stability of the quaternary structure of natural or recombinant TNF-alpha from human or animal species as well as that of other oligomeric cytokines can probably be studied using this method.
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- 1993
12. Endocrine predictors of acute hemodynamic effects of growth hormone in congestive heart failure
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Andrea Giustina, Filippo Manelli, P. Desenzani, Roberto Lorusso, Amerigo Giordano, Maurizio Volterrani, Claudio Poiesi, Giustina, Andrea, Volterrani, M, Manelli, F, Desenzani, P, Poiesi, C, Lorusso, R, and Giordano, A.
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Male ,Cardiac Catheterization ,medicine.medical_specialty ,Time Factors ,Heart disease ,Cardiac index ,Hemodynamics ,medicine.artery ,Internal medicine ,Humans ,Medicine ,Insulin-Like Growth Factor I ,Infusions, Intravenous ,Aged ,Heart Failure ,Analysis of Variance ,Human Growth Hormone ,business.industry ,Dilated cardiomyopathy ,Middle Aged ,Prognosis ,medicine.disease ,Endocrinology ,Blood pressure ,Echocardiography ,Heart failure ,Pulmonary artery ,Exercise Test ,Linear Models ,Cardiology ,Liver function ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background The aim of our study was to assess whether there could be any clinical and/or endocrine (spontaneous growth hormone [GH] secretion rate, baseline insulin-like growth factor-1 [IGF-1]) predictors and/or determinants of the acute effects of continuous intravenous infusion of recombinant human GH on hemodynamic parameters in 12 patients with dilated cardiomyopathy and congestive heart failure (CHF). Methods And Results The study involved 12 male patients with chronic CHF (ischemic in 8 patients and idiopathic in 4). Ten patients were in New York Heart Association functional class III or IV and 2 in class II. The first 24 hours were considered the control period; in fact, during the following 24 hours, all the patients underwent intravenous constant pump infusion of recombinant human GH. Blood samples for GH assay were taken every 20 minutes during the first night of the study (from 10 PM to 6 AM). Moreover, blood samples for GH assay were also taken during exogenous GH infusion. Blood samples for IGF-1 assays were taken at 8 AM of each of the 3 days of the study. Pulmonary artery pressure (PAP) and capillary wedge (PCWP) pressure, cardiac index, and arterial blood pressure were measured 30 minutes after right heart catheterization (baseline 1), at the end of the control period (baseline 2), and every 4 hours during GH infusion. A negative correlation has been found between mean nocturnal GH levels and baseline IGF-1 levels (r = –0.47, P = .124) and between mean nocturnal GH levels and both postinfusion absolute (r = –0.67, P < .05) and delta (postinfusion–preinfusion) (r = –0.58; P < 005) IGF-1 levels. No significant correlations have been found between several parameters of liver function (albumin, bilirubin, and pseudocholinesterase) and mean nocturnal GH. However, baseline IGF-1 levels showed a negative significant correlation (r = –0.76, P < .01) with total bilirubin and a positive correlation (r = 0.72, P < .01) with pseudocholinesterase. Baseline IGF-1 levels showed a significant negative correlation with baseline mean PAP (r = –0.68, P < .05) and PCWP (r = –0.70, P < .05) and a positive correlation with baseline cardiac index (r = 0.71, P < .05). Baseline IGF-1 levels also showed a significant negative correlation with absolute mean PAP (r = –0.63, P < .05) and mean PCWP (r = –0.67, P < .05) after GH infusion. After GH infusion, IGF-1 levels also negatively correlated with post–GH infusion mean PAP (r = –0.50, P = .09) and mean PCWP (r = –0.66, P < .05). The positive correlation between either baseline or postinfusion IGF-1 and the postinfusion cardiac index (r = 0.40 and 0.43, respectively) did not reach statistical significance. Conclusions GH has acute functional effects on the heart in patients with CHF, including both an increase in myocardial contractility and a decrease in vascular resistances, and among patients with CHF, those with low baseline IGF-1 are likely to have fewer beneficial effects from GH infusion. (Am Heart J 1999;137:1035-43.)
- Published
- 1999
13. Inhibitory effects of galanin on growth hormone (GH) release in cultured GH-secreting adenoma cells: comparative study with octreotide, GH-releasing hormone, and thyrotropin-releasing hormone
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Sergio Turazzi, Giorgio Ragni, Angelo Bollati, Carlo Bonfanti, Massimo Licini, Claudio Poiesi, Renato Cozzi, Andrea Giustina, Giustina, Andrea, Ragni, G, Bollati, A, Cozzi, R, Licini, M, Poiesi, C, Turazzi, S, and Bonfanti, C.
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Adenoma ,endocrine system ,Pituitary gland ,medicine.medical_specialty ,endocrine system diseases ,Somatotropic cell ,Endocrinology, Diabetes and Metabolism ,Octreotide ,Thyrotropin-releasing hormone ,Neuropeptide ,Thyrotropin ,Galanin ,Peptide hormone ,Biology ,Gonadotropin-Releasing Hormone ,Endocrinology ,Pituitary Hormones, Anterior ,Internal medicine ,medicine ,Tumor Cells, Cultured ,Humans ,Human Growth Hormone ,medicine.disease ,medicine.anatomical_structure ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
The aim of the present study was to characterize in a large series (N = 12) of cultured somatotrope adenomas the in vitro effects of the neuropeptide galanin on growth hormone (GH) secretion. This was contrasted with two peptides known to be GH secretagogues (GH-releasing hormone [GHRH] and thyrotropin-releasing hormone [TRH]) and a peptide with a known GH-inhibitory effect (the somatostatin analog octreotide). Groups of three wells were incubated for 4 hours with growth medium alone (control incubation), galanin, GHRH(1–29)NH 2 , TRH, or octreotide. Galanin and octreotide were applied at concentrations of 0.1, 1, and 10 μmol/L, and GHRH and TRH at concentrations of 0.01, 0.1, and 1 μmol/L. Galanin was able to inhibit GH release in nine of 12 cultured somatotrope adenoma cells. This inhibitory effect was clearly dose-dependent in five adenomas. Overall, the mean GH nadir after galanin was −36.1% in nine responder adenoma cultures versus control wells. Octreotide inhibited GH release in five of eight cultured somatotrope adenoma cells. The mean GH nadir after octreotide was −32.7% in five responder adenoma cultures compared with control wells. GHRH and TRH were able to stimulate GH release, respectively, in seven of 11 and in six of seven cultured somatotrope adenoma cells. The mean GH peaks after either GHRH or TRH in responder adenoma cultures were, respectively, +71.5% and +143.7% compared with levels in the control wells. In conclusion, the consistency and potency of the in vitro GH-inhibitory effect of galanin in a large series of somatotrope adenomas are at least similar to those of the most effective available GH-lowering agent, the somatostatin analog octreotide.
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- 1997
14. Comparison of the effects of growth hormone-releasing hormone and hexarelin, a novel growth hormone-releasing peptide-6 analog, on growth hormone secretion in humans with or without glucocorticoid excess
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C. Poiesi, M. Licini, A R Bussi, Andrea Giustina, B. P. Imbimbo, Romano Deghenghi, William B. Wehrenberg, Giustina, Andrea, Bussi, Ar, Deghenghi, R, Imbimbo, B, Licini, M, Poiesi, C, and Wehrenberg, Wb
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Adult ,Male ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Growth Hormone-Releasing Hormone ,Endocrinology ,Bolus (medicine) ,Internal medicine ,medicine ,Humans ,Single-Blind Method ,Growth Substances ,Glucocorticoids ,Saline ,Aged ,Cross-Over Studies ,business.industry ,Drug Synergism ,Middle Aged ,Growth hormone–releasing hormone ,Crossover study ,Stimulation, Chemical ,Growth hormone secretion ,Kinetics ,Somatostatin ,Growth Hormone ,Female ,business ,Oligopeptides ,Glucocorticoid ,medicine.drug ,Hormone - Abstract
The aim of our study was to investigate the effect of hexarelin, a novel GH-releasing peptide-6 analog, and GH-releasing hormone (GHRH) (alone or in combination) on GH secretion in adult patients with increased somatostatin tone due to chronic glucocorticoid excess. We studied seven adult patients undergoing long-term (no less than 6 months) immunosuppressive glucocorticoid treatment for non-endocrine diseases (six females and one male, age range 42–68 years) and one subject (female, age 31 years) with endogenous hypercortisolism due to adrenal adenoma. Six normal subjects (four females and two males) matched for sex and age with the patients and not undergoing any therapy served as controls. All the subjects underwent the following three tests in random order: (1) human GHRH (1–29)NH2 (100 μg in 1 ml saline) injected as an i.v. bolus at 0 min, (2) hexarelin (100 μg in 1 ml saline) injected as an i.v. bolus at 0 min and (3) hexarelin (100 μg in 1 ml of saline) plus GHRH (100 μg in 1 ml saline) injected as an i.v. bolus at 0 min. After GHRH alone the patients with glucocorticoid excess showed a blunted GH response as compared with normal subjects (median delta GH: 0·9, range 0–5·6 μg/l vs 7·1, range 0·3–14·9 μg/l). No significant differences were observed in the steroid-treated group with respect to normal subjects after hexarelin alone (median delta GH: 15·5, range 1·9–45·2 μg/l vs 17·9, range 5·5–53·9 μg/l). The GH responses after the combined stimuli were significantly decreased in the patients with glucocorticoid excess as compared with normal subjects (median delta GH: 43·5, range 21–56·9 μg/l vs 73·7, range 19·6-116·8 μg/l). The two stimuli acted in a synergistic fashion in both groups of subjects. It may be hypothesized that hexarelin influences the GH inhibitory effect of glucocorticoids in humans, acting at the hypothalamic somatostatin level. Journal of Endocrinology (1995) 146, 227–232
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- 1995
15. Tumor-necrosis-factor (TNF)-alpha quantification by ELISA and bioassay - effects of TNF-alpha-soluble TNF-receptor (p55) complex dissociation during assay incubations
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Giovanni Cassani, Silvia Merli, Claudio Poiesi, Angelo Corti, Corti, Angelo, Poiesi, C, Merli, S, and Cassani, G.
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Receptor complex ,medicine.drug_class ,medicine.medical_treatment ,Immunology ,Enzyme-Linked Immunosorbent Assay ,In Vitro Techniques ,Monoclonal antibody ,Binding, Competitive ,Receptors, Tumor Necrosis Factor ,Epitope ,medicine ,Humans ,Immunology and Allergy ,Bioassay ,Receptor ,Tumor Necrosis Factor-alpha ,Chemistry ,Cytotoxicity Tests, Immunologic ,Molecular biology ,Recombinant Proteins ,Dissociation constant ,Cytokine ,Solubility ,Biological Assay ,Tumor necrosis factor alpha ,Protein Binding - Abstract
It has been previously reported that different quantitative results can be obtained when TNF alpha is measured in biological fluids by bioassay and immunoassay. This is thought to be related to the presence of antigenic forms of TNF alpha that cannot be detected by bioassay, such as complexes with soluble receptors (sTNF-R) or TNF alpha monomers. In this work we have observed discrepancies between antigenic and bioactive TNF alpha even when we used a sandwich-ELISA, unable to detect TNF alpha monomers, based on antibodies that bind epitopes overlapping with the soluble-receptor binding site of TNF alpha. Moreover, we found that antigenic TNF alpha levels in the presence of p55-sTNF-R (sTNF-R1) measured by different immunoassays were variable, depending on the immunoreagents and incubation time. To investigate whether TNF alpha-soluble receptor complex dissociation occurring during assay incubations contributes to the variability of results, we studied the kinetics of TNF alpha-soluble receptor interactions and examined the effect of complex dissociation using different analytical systems. TNF alpha association (k(on)) and dissociation (k(off)) rate constants with sTNF-R1, measured by real-time biospecific interaction analysis, were 5.01 x 10(5) s(-1) M(-1) and 2.8 x 10(-4) s(-1), corresponding to an equilibrium constant (K-d) of 0.59 nM and to a half life for these complexes of 38 min. Complex dissociation and differential changes in the TNF alpha-sTNF-R1 bound:free ratio, in different analytical systems, markedly affects TNF alpha quantification.
- Published
- 1994
16. Anti-Glycan Autoantibodies Induced by Helicobacter pylori as a Potential Risk Factor for Myocardial Infarction.
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Negrini R, Villanacci V, Poiesi C, and Savio A
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- Animals, Autoantigens immunology, Cross Reactions, Helicobacter Infections immunology, Humans, Mice, Molecular Mimicry immunology, Polysaccharides immunology, Rabbits, Risk Factors, Antibodies, Bacterial immunology, Autoantibodies immunology, Helicobacter pylori immunology, Lewis Blood Group Antigens immunology, Myocardial Infarction immunology
- Abstract
A number of epidemiological studies have evaluated the potential association between H. pylori and cardiovascular disease, but with contrasting results. We have previously shown that Helicobacter pylori infection is able to induce in mice and humans autoantibodies cross-reacting with histo-blood group Lewis antigens, expressed in different organs and in plasma glycoproteins and glycolipids. The aim of this study was to assess whether immunization of animals with H. pylori might induce myocardial histopathological changes. We have retrospectively examined, in detail, the histology of archived organs from mice and rabbits immunized with H. pylori in our previous studies. Human sera and cross-reacting monoclonal antibodies were also tested against bacterial preparations and tissue sections. Areas of myocardial necrosis, associated with coronary thrombotic occlusion, were found in 5 of 20 mice and 2 of 5 rabbits previously immunized with suspensions of H. pylori . No similar lesions were found in control animals, suggesting a causal link with H. pylori immunization. The animals bearing myocardial lesions had not been infected but only immunized months earlier with parenteral injections of dead H. pylori cells. This strongly suggests that immunization, by itself, might play a causative role. We propose that the cross-reactive autoimmune response induced by H. pylori could promote thrombotic occlusion through direct endothelial damage or by perturbing the coagulation process., (Copyright © 2020 Negrini, Villanacci, Poiesi and Savio.)
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- 2020
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17. HIV-1 p17 matrix protein interacts with heparan sulfate side chain of CD44v3, syndecan-2, and syndecan-4 proteoglycans expressed on human activated CD4+ T cells affecting tumor necrosis factor alpha and interleukin 2 production.
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De Francesco MA, Baronio M, and Poiesi C
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- CD4-Positive T-Lymphocytes immunology, Female, HIV Antigens genetics, HIV Antigens immunology, HIV-1 genetics, HIV-1 immunology, HeLa Cells, Heparitin Sulfate genetics, Heparitin Sulfate immunology, Humans, Hyaluronan Receptors genetics, Hyaluronan Receptors immunology, Interleukin-2 genetics, Interleukin-2 immunology, Lymphocyte Activation, Male, Protein Binding, Syndecan-2 genetics, Syndecan-2 immunology, Syndecan-4 genetics, Syndecan-4 immunology, Tumor Necrosis Factor-alpha genetics, Tumor Necrosis Factor-alpha immunology, gag Gene Products, Human Immunodeficiency Virus genetics, gag Gene Products, Human Immunodeficiency Virus immunology, CD4-Positive T-Lymphocytes metabolism, HIV Antigens metabolism, HIV-1 metabolism, Heparitin Sulfate metabolism, Hyaluronan Receptors metabolism, Interleukin-2 biosynthesis, Syndecan-2 metabolism, Syndecan-4 metabolism, Tumor Necrosis Factor-alpha biosynthesis, gag Gene Products, Human Immunodeficiency Virus metabolism
- Abstract
HIV-1 p17 contains C- and N-terminal sequences with positively charged residues and a consensus cluster for heparin binding. We have previously demonstrated by affinity chromatography that HIV-1 p17 binds strongly to heparin-agarose at physiological pH and to human activated CD4(+) T cells. In this study we demonstrated that the viral protein binds to heparan sulfate side chains of syndecan-2, syndecan-4, and CD44v3 purified from HeLa cells and that these heparan sulfate proteoglycans (HSPGs) co-localize with HIV-1 p17 on activated human CD4(+) T cells by confocal fluorescence analysis. Moreover, we observed a stimulatory or inhibitory activity when CD4(+) T cells were activated with mitogens together with nanomolar or micromolar concentrations of the matrix protein.
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- 2011
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18. HIV-1 matrix protein p17 increases the production of proinflammatory cytokines and counteracts IL-4 activity by binding to a cellular receptor.
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De Francesco MA, Baronio M, Fiorentini S, Signorini C, Bonfanti C, Poiesi C, Popovic M, Grassi M, Garrafa E, Bozzo L, Lewis GK, Licenziati S, Gallo RC, and Caruso A
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- Amino Acid Sequence, Animals, Cells, Cultured, Gene Expression Regulation immunology, Humans, Interferon-gamma metabolism, Interleukin-2 pharmacology, Kinetics, Lymphocyte Activation, Lymphocytes drug effects, Lymphocytes virology, Mice, Molecular Sequence Data, Peptide Fragments chemistry, Receptors, Cell Surface immunology, Reference Values, Virus Replication, gag Gene Products, Human Immunodeficiency Virus, Cytokines genetics, Gene Products, gag pharmacology, HIV Antigens pharmacology, HIV-1 physiology, Interleukin-4 antagonists & inhibitors, Lymphocytes immunology, Viral Proteins
- Abstract
Purified recombinant HIV-1 p17 matrix protein significantly increased HIV-1 replication in preactivated peripheral blood mononuclear cell cultures obtained from healthy donors. Because HIV-1 infection and replication is related to cell activation and differentiation status, in the present study, we investigated the role played by p17 during the process of T cell stimulation. Using freshly isolated peripheral blood mononuclear cells, we demonstrate that p17 was able to enhance levels of tumor necrosis factor alpha and IFN-gamma released from cells stimulated by IL-2. IL-4 was found to down-regulate IFN-gamma and tumor necrosis factor alpha, and p17 restored the ability of cells to produce both cytokines. The property of p17 to increase production of proinflammatory cytokines could be a mechanism exploited by the virus to create a more suitable environment for HIV-1 infection and replication. Our data show that p17 exerts its biological activity after binding to a specific cellular receptor expressed on activated T lymphocytes. The functional p17 epitope involved in receptor binding was found to be located at the NH(2)-terminal region of viral protein. Immunization of BALB/c mice with a 14-aa synthetic peptide representative of the HIV-1 p17 functional region (SGGELDRWEKIRLR) resulted in the development of p17 neutralizing antibodies capable of blocking the interaction between p17 and its cellular receptor. Our results define a role for p17 in HIV-1 pathogenesis and contribute to our understanding of the molecular mechanism of HIV-1 infection and the development of additional antiviral therapeutic strategies.
- Published
- 2002
- Full Text
- View/download PDF
19. Proteolysis of beta-casein as a marker of Grana Padano cheese ripening.
- Author
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Gaiaschi A, Beretta B, Poiesi C, Conti A, Giuffrida MG, Galli CL, and Restani P
- Subjects
- Amino Acid Sequence, Antibodies, Monoclonal analysis, Caseins analysis, Chymosin metabolism, Electrophoresis, Polyacrylamide Gel, Fibrinolysin metabolism, Pepsin A metabolism, Peptide Fragments chemistry, Time Factors, Caseins metabolism, Cheese analysis, Food Handling, Peptide Fragments analysis
- Abstract
Proteolysis has a critical role in defining the typical organoleptic characteristics of Grana Padano, a well-known Italian cheese. During the ripening process, hydrolysis of beta-casein produces different fragments, the most abundant and widely studied of which are gamma-caseins, three polypeptides containing the HOOC-terminal portion of beta-casein. By sodium dodecyl sulfate-PAGE and a specific anti-beta-casein monoclonal antibody, two beta-casein-derived bands were identified in Grana Padano cheese: betaa and betab. Thanks to the identification of the amino acid sequences, it was shown that: a) betaa contains gamma1-casein [beta-casein (29-209)] and the correlated peptide [beta-casein (30-209)]; b) betab contains gamma2-casein [beta-casein (106-209)] and gamma3-casein [beta-casein (108-209)]. The production of betaa and betab by the three enzymes most involved in cheese proteolysis (pepsin, chymosin, and plasmin) was evaluated by performing in vitro digestions. A significant correlation between abundance of some polypeptides and ripening process was shown.
- Published
- 2001
- Full Text
- View/download PDF
20. Proteolysis of alphas-casein as a marker of Grana Padano cheese ripening.
- Author
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Gaiaschi A, Beretta B, Poiesi C, Conti A, Giuffrida MG, Galli CL, and Restani P
- Subjects
- Amino Acid Sequence, Antibodies, Monoclonal, Caseins analysis, Chymosin metabolism, Electrophoresis, Polyacrylamide Gel, Fibrinolysin metabolism, Immunoblotting, Proteins metabolism, Time Factors, Caseins metabolism, Cheese analysis, Endopeptidases metabolism, Food Handling
- Abstract
Since casein proteolysis has a critical role in defining the typical characteristics of Grana Padano cheese, we evaluated the hydrolysis of alphas-casein during the ripening process. Thanks to the high specificity of the anti-alphas((alphas1 + alphas2)-casein monoclonal antibody and amino acid sequence determination, it was possible to identify three main alphas-casein-derived polypeptides in cheese: alphaa, alphab, and alphac. Their production by the three enzymes most involved in cheese proteolysis (pepsin, chymosin, and plasmin) was evaluated by performing in vitro digestions. Data showed that alphaa was released in cheese mainly by the chymosin attack, while alphab and alphac were due to the action of plasmin. A significant correlation between the abundance of some polypeptides and ripening process was shown.
- Published
- 2000
- Full Text
- View/download PDF
21. HIV p17 enhances lymphocyte proliferation and HIV-1 replication after binding to a human serum factor.
- Author
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De Francesco MA, Caruso A, Fallacara F, Canaris AD, Dima F, Poiesi C, Licenziati S, Corulli M, Martinelli F, Fiorentini S, and Turano A
- Subjects
- Animals, Antibodies, Viral, Cross-Linking Reagents, Gene Products, gag metabolism, HIV Antigens metabolism, Humans, Protein Binding, Rabbits, Recombinant Proteins metabolism, Recombinant Proteins pharmacology, gag Gene Products, Human Immunodeficiency Virus, Blood Proteins metabolism, CD4-Positive T-Lymphocytes virology, CD8-Positive T-Lymphocytes virology, Gene Products, gag pharmacology, HIV Antigens pharmacology, HIV-1 physiology, Lymphocyte Activation drug effects, Viral Proteins, Virus Replication drug effects
- Abstract
Objective: To analyse the role of recombinant HIV-1 protein p17 in the modulation of cell activity., Methods: Peripheral blood mononuclear cells (PBMC) obtained from healthy donors were cultured in the presence or absence of p17 with mitogens such as phytohaemagglutinin or interleukin-2 and their response assayed by cell proliferation. Cross-linking experiments were employed to investigate the presence of a binding between p17 and factor(s) present in human serum. An immunoenzymatic assay for p24 antigen detection was used to analyse the effect of the addition of exogenous p17 to cultures of PBMC infected with HIV-1 in vitro., Results: Purified recombinant p17 protein at a concentration of 0.25 microg/ml significantly increased the proliferation of preactivated PBMC obtained from healthy donors. This effect was obtained by binding p17 to factor(s) present in human serum and observed on both CD4+ and CD8+ T cells. Recombinant p17 also induced an increased rate of HIV-1 replication, probably due to enhanced T-cell proliferation. The activity of p17 protein was inhibited by anti-p17 antibodies generated by injecting recombinant p17 in rabbits, but not by human antibodies generated during the natural course of HIV infection., Conclusion: Characterization of the human factor(s) and identification of the interacting p17 epitope(s) will improve our understanding of the mechanisms used by HIV to efficiently replicate in our organisms.
- Published
- 1998
- Full Text
- View/download PDF
22. Maturation of the regulation of growth hormone secretion in young males with hypogonadotropic hypogonadism pharmacologically exposed to progressive increments in serum testosterone.
- Author
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Giustina A, Scalvini T, Tassi C, Desenzani P, Poiesi C, Wehrenberg WB, Rogol AD, and Veldhuis JD
- Subjects
- Adolescent, Circadian Rhythm, Drug Combinations, Entropy, Gonadal Steroid Hormones blood, Human Growth Hormone blood, Human Growth Hormone urine, Humans, Hypogonadism drug therapy, Insulin-Like Growth Factor Binding Protein 3 blood, Insulin-Like Growth Factor I metabolism, Longitudinal Studies, Male, Pulsatile Flow, Arginine therapeutic use, Growth Hormone-Releasing Hormone therapeutic use, Human Growth Hormone metabolism, Hypogonadism metabolism, Testosterone blood
- Abstract
To study the onset of the action of gonadal sex steroids on the GH axis in spontaneous puberty, which is prolonged and sparingly predictable, we present a clinical investigative paradigm in which six previously untreated boys with isolated hypogonadotropic hypogonadism were exposed to progressively higher testosterone levels designed to mimic the androgen environment recognized during the early stages of puberty. We administered three incremental doses of testosterone (25-, 50-, and 100-mg im injections), each over a period of 4 weeks. Studies of overnight pulsatile GH secretion and GH responses to GHRH alone or combined with L-arginine (a functional somatostatin antagonist) were performed before testosterone administration and after each dose of testosterone. Serum testosterone, but not estrogen, levels increased progressively in all subjects during therapy. Deconvolution analysis of GH release profiles disclosed that GH secretory burst mass was stimulated significantly even by 25 mg testosterone. This parameter was not altered further by higher doses of testosterone. Spontaneous GH secretory burst number and amplitude increased significantly only after the 50- and 100-mg testosterone treatments, after which the serum GH response to GHRH and arginine also rose significantly. In contrast, the GH response to GHRH alone was not significantly affected by any dose of testosterone. Serum testosterone levels correlated significantly with the primary parameters of nocturnal GH secretion. In summary, our experimental model suggests that in males even very small increases in circulating testosterone occurring during the earliest stages of puberty are able to amplify pulsatile GH secretion. Our concomitant secretagogue data further suggest that testosterone exerts its action at different sites in the hypothalamo-somatotropic axis, i.e. directly at the pituitary level, and also at hypothalamic loci, possibly increasing both GHRH and somatostatin release.
- Published
- 1997
- Full Text
- View/download PDF
23. Kinetic analysis of TNF-alpha oligomer-monomer transition by surface plasmon resonance and immunochemical methods.
- Author
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Poiesi C, Albertini A, Ghielmi S, Cassani G, and Corti A
- Subjects
- Animals, Biosensing Techniques, Enzyme-Linked Immunosorbent Assay, Humans, Immunochemistry, In Vitro Techniques, Kinetics, Protein Conformation, Recombinant Proteins chemistry, Serum Albumin, Bovine, Tumor Necrosis Factor-alpha chemistry
- Abstract
In this work we have studied the kinetic parameters of oligomeric tumour necrosis factor alpha (TNF-alpha) dissociation using biospecific interaction analysis (BIA), based on surface plasmon resonance (SPR) of TNF-alpha immobilized on a sensor chip, and by an ELISA technique able to detect TNF-alpha oligomers in solution. Validation studies, carried out with sensor chips bearing TNF-alpha oligomers or bovine albumin monomers, verified that: (a) TNF-alpha can be immobilized in the oligomeric form onto sensor chips; (b) the covalent linkage between TNF-alpha and sensor chips is stable under the experimental conditions; (c) TNF-alpha monomers are present on the sensor chips after dissociation; (d) immobilization and dissociation rate constant (kdiss) measurements are reproducible. The kdiss of recombinant TNF-alpha, measured under non denaturing conditions at pH 7.4 by BIA and ELISA were in good agreement, being 0.92 x 10(-5)/s and 1.1 x 10(-5)/s respectively (corresponding to a half life of about 20.9 h and 17.5 h, respectively). The dissociation rate was found to be significantly affected by the presence of detergents and by the pH of the solution, suggesting that TNF-alpha, at low concentrations, exists in solution with different molecular forms depending on the time of storage and buffer composition. Real-time BIA is rapid and does not require particular antibodies or reagents. Thus, the stability of the quaternary structure of natural or recombinant TNF-alpha from human or animal species as well as that of other oligomeric cytokines can probably be studied using this method.
- Published
- 1993
- Full Text
- View/download PDF
24. Helicobacter pylori infection induces antibodies cross-reacting with human gastric mucosa.
- Author
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Negrini R, Lisato L, Zanella I, Cavazzini L, Gullini S, Villanacci V, Poiesi C, Albertini A, and Ghielmi S
- Subjects
- Animals, Antibodies, Monoclonal, Autoantibodies immunology, Campylobacter jejuni immunology, Cross Reactions, Gastric Mucosa immunology, Gastric Mucosa pathology, Gastritis pathology, Helicobacter Infections pathology, Humans, Immunoglobulin G immunology, Immunohistochemistry, Mice, Mice, Inbred BALB C, Streptococcus mutans immunology, Antibodies, Bacterial analysis, Gastritis immunology, Helicobacter Infections immunology, Helicobacter pylori immunology
- Abstract
The authors' previous observation that many of the monoclonal antibodies against Helicobacter pylori cross-react with the cells of the human gastric mucosa prompted them to investigate the possibility that gastric self-antigens cross-reacting with H. pylori could be involved in the immune response against this organism. It was found that three antibodies against H. pylori, CB-4, CB-10, and CB-14, that cross-react with the human gastric mucosa also intensely cross-reacted with murine gastric epithelial cells. A strong reaction against autologous mucosa was also evident in the sera of mice immunized with H. pylori but not with other bacteria. A serological study performed in a group of 82 patients undergoing gastroscopy showed that the presence of seropositivity against H. pylori was strongly correlated with the presence of autoantibodies against human antral gastric mucosa. This activity was neutralized after absorption of the sera with H. pylori but not with other gram-negative bacteria. The antibodies in the mouse and in the human did not react with other segments of the gastrointestinal tract or with most of the other organs. Mice bearing hybridomas secreting a cross-reacting antibody (CB-4) had histopathologic abnormalities in their stomachs. These lesions were absent in the stomachs of mice bearing hybridomas secreting a non-cross-reacting antibody (CB-26). It was concluded that H. pylori infection can stimulate antibodies cross-reacting with gastric autoantigens and that this immunologic mechanism may represent a pathogenic link between H. pylori and gastritis.
- Published
- 1991
- Full Text
- View/download PDF
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