Biomedical subjects
Publications and source records attributed to A Mancini.
An echographic follow-up of a case of congenital retinoblastoma was performed by monitoring variations in the tumoral echostructure concomitant with the appearance of microcalcifications. A previously unreported echo-graphic aspect regarding the first phase of observation is described. The calcifications in the tumour were evidenced on the 41st day of the patient's life.
The role of ifosfamide as first-line chemotherapy treatment of non metastatic Ewing's sarcoma of the extremity is still under discussion. The purpose of this paper is to report the results achieved in a neoadjuvant protocol (REN-3) in which ifosfamide, added to the conventional VACA regimen, was employed since the induction phase. Induction chemotherapy consisted of vincristine, cyclophosphamide, doxorubicin, actinomycin-D and ifosfamide. After local treatment, patients received the drugs used in the induction phase and etoposide. Between November 1991 and November 1994, 61 patients with non metastatic Ewing's sarcoma of the extremity were treated. Forty-nine patients underwent surgery and 73.5% of them had a good histologic response. At a median follow-up of 60 months (range 32-76), 48 patients (79%) remained continuously disease-free. The 5-year event-free and overall survival were 77% and 87%, respectively. These results were significantly better both in terms of histologic response or event-free and overall survival than those obtained in 58 patients with non metastatic Ewing's sarcoma of the extremity treated in a previous protocol (REN-2) in which the same drugs were used, but ifosfamide was employed only in the maintenance phase. The present study suggests the importance of early use of ifosfamide in the treatment of patients with non metastatic Ewing's sarcoma of the extremity.
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BACKGROUND: The purpose of this work is to show the effectiveness of percutaneous embolization therapy in the treatment of visceral arterial pseudoaneurysms and to propose the method as a valid alternative to surgery. METHODS: Twenty-eight patients with visceral artery pseudoaneurysms were treated: 10 of them were hepatic; 9 renal; 7 duodenal-pancreatic; 1 splenic and 1 of the celiac trunk. Materials employed were: Gianturco metallic coils, Spongostan and Poli-Vinyl-Alcohol. RESULTS: Immediate success was obtained in all cases; recurrences occurred in 5 patients (18%) and they have all been successfully retreated with percutaneous method; complications occurred in 3 patients (10%) and they were all directly related to the pre-existing pathology and not to the percutaneous treatment. CONCLUSIONS: To obtain the best results from embolization, it is necessary to respect some conditions regarding the correct choice of embolic materials, the superselective catheterization of the injured artery and the low injection pressure of the contrast medium in order to avoid rupturing the thin pseudoaneurysmatic wall. The advantages of the percutaneous treatment are: less trauma, local anesthesia, reduction of the time between diagnosis and therapy, reduction of hospitalization stay and limitation of parenchymal destruction, Complications are relatively not frequent and in no cases the percutaneous therapy compromised the surgical intervention when it became necessary.
Tyrosine autophosphorylation of the v-Fms oncogene product results in the formation of high-affinity binding sites for cellular proteins containing Src homology 2 (SH2) domains. These proteins transduce various mitogenic and morphogenic signals. As reported previously, Y696KNI in the kinase insert domain of v-Fms binds to the growth factor receptor bound protein 2 (Grb2), a stimulator of the Ras/Raf1 pathway. Here, we mapped Y921TNL within the C-terminal domain of Fms as a novel autophosphorylation site. We demonstrate that this site constitutes a second Grb2 binding site: a recombinant fusion protein (residues 904-944) containing phosphorylated Y921 bound Grb2 from FDCP-1Mac11 cell extracts significantly more efficiently than a corresponding protein (residues 617-759) containing Y696. A yeast two-hybrid system which allowed the formation of a functional Fms tyrosine kinase was employed to quantify binding of Grb2. Fms-protein containing either one of the two phosphorylation sites bound Grb2 equally well, binding was increased for proteins carrying both sites. In contrast, the simultaneous substitution of Y696 and Y921 by phenylalanines abolished Grb2 binding. Mouse NIH3T3 cells expressing the Y921F mutant Fms-protein showed a substantially higher content of fibronectin network than wild-type transformed cells and had largely lost their serum independent growth phenotype.
Studies performed in animals and humans have suggested a functional interaction between opioid and cholinergic systems in the control of growth hormone (GH) secretion. Moreover, the sex-dependent modulation of GH secretion in humans is well established. To investigate the role of sex and food intake in the regulation of the reciprocal influences of opioids and acetylcholine in the modulation of GH secretion, we studied the GH response to pyridostigmine (PYR) alone and during a naloxone (NAL) infusion in a group of normal men and women before a meal (at 1:00 PM) and postprandially. In women, the response of GH to PYR alone before the meal was significantly lower than in the men (area under the curve [AUC], mean +/- SEM, 320.18 +/- 87.16 v 1,031.06 +/- 333.21 micrograms/L/90 min, P < .01). Before the meal, NAL completely abolished the response of GH to PYR in men (AUC, 1,031.06 +/- 333.21 v 16.50 +/- 7.50 micrograms/L/90 min, P < .01), whereas infusion of NAL did not significantly modify the GH response to PYR in women. Consumption of the meal significantly decreased PYR-induced GH release in both women (AUC, 21.75 +/- 12.75 v 320.18 +/- 87.16 micrograms/L/90 min, P < .05) and men (AUC, 45.75 +/- 18.75 v 1,031.06 +/- 333.21 micrograms/L/90 min, P < .01). Conversely, food intake did not change the effects of NAL infusion on the GH response to PYR either in women or in men. We conclude that the sex-dependent opioid modulation of PYR-induced GH secretion is observed before a meal but not in the postprandial state. Food intake may be hypothesized to influence the cholinergic regulation of GH secretion and the sex-dependent opioid modulation of central cholinergic tone.
The growth hormone (GH) response to stimulation tests is impaired in obesity. Moreover, obese patients exhibit a "paradoxical" increase of GH to GH-releasing hormone (GHRH) stimulation after food ingestion; this paradoxical response is reversed by naloxone infusion. On the other hand, beta-endorphin seems to exert profound effects on insulin release. Recent studies also demonstrated an impairment of GH response to several stimuli in polycystic ovary syndrome (PCOS), a condition associated with obesity, hyperinsulinism, and insulin resistance. Chronic inhibition of opioid tone by the opioid antagonist naltrexone (NTX) is able to reduce the insulin response to an oral glucose tolerance test (OGTT) in hyperinsulinemic PCOS patients. Since insulin and GH may reciprocally influence their secretion and the opioid system may have a role in the pathogenesis of hyperinsulinemia and reduced GH secretion, we have explored the involvement of these neuroendocrine mechanisms in essential obesity and in obesity associated with hyperandrogenism by a long-term treatment with an opiate antagonist. We tested seven obese patients affected by PCOS, seven matched women with essential obesity (EO), and five non-obese control subjects. All patients, in the follicular phase, underwent an OGTT (75 g) and basal hormone assay. Two days later, patients were subjected to a GHRH test. The patients then had 4 weeks of treatment with NTX 50 mg/d. Following continuation of the treatment, OGTT and GHRH tests were repeated. Insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 (IGFBP-3) plasma concentrations were also determined in the basal condition before and after NTX treatment. NTX treatment reduced fasting insulin levels in patients with EO (P < .05) and restored a normal GH response to GHRH without affecting IGF-1 and IGFBP-3 levels. In PCOS subjects, NTX reduced the insulin response to a glucose load and failed to modify the blunted GH response to GHRH. Our data suggest a significant difference in opioid system function in PCOS and EO subjects, indicating a particular form of obesity in PCOS. The opiate antagonist treatment in EO may act through the reduction of negative insulin feedback on GH secretion. In PCOS patients, the failure to improve GH secretion in obese hyperandrogenized patients may be related to a high opioidergic tone or to the inhibitory predominance of other neurotransmitters.
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OBJECTIVE: Recent studies have demonstrated the restoration of a normal 24 h GH profile induced by a reduction of insulinaemia after weight loss, suggesting a reciprocal relationship between plasma insulin and GH concentrations. We aimed to clarify if an opiate-induced reduction in plasma insulin could affect GH secretion in obesity. DESIGN: We have studied the insulin response to an oral glucose tolerance test (OGTT) and the GH response to GHRH before and after prolonged treatment with Naltrexone (NTX). C-peptide, IGF-I, IGFBP-3 plasma levels and the IGF-I/IGFBP-3 molar ratio were also determined. SUBJECTS: Twelve obese women (aged 25-41 y; Body mass index (BMI): 31-39 kg/m2) and six lean normal women (aged 25-38; BMI: 19.8-23.1 kg/m2). MEASUREMENT: GH was determined by the IRMA method; insulin, C-peptide, IGF-I and IGFBP-3 were assayed by the RIA method. For molar comparison between IGF-I and IGFBP-3 we have considered 30.5 kDa the molar weight of IGFBP-3. Results are expressed as mean +/- s.e.m. RESULTS: We observed a significant decrease in basal concentration of both insulin (230.1 +/- 34.9 vs 133.2 +/- 16.9 pmol/L; P < 0.005) and C-peptide (3.7 +/- 0.3 vs 2.4 +/- 0.1 micrograms/L; P < 0.02). No modifications in the insulin secretory response to the OGTT were observed. A significant increase of the GHRH-induced GH peak response (7.7 +/- 1.4 vs 19.7 +/- 3.1 micrograms/L; P < 0.01) and GH-AUC (533 +/- 151 vs 1415 +/- 339 micrograms/L/120 min; P < 0.01) was found after NTX treatment. A negative correlation was found between basal insulin and GH peak values, both before (r = -0.641, P = 0.027) and after NTX (r = -0.714, P = 0.013). No modifications were found in IGF-I, IGFBP-3 and IGF-I/IGFBP-3 molar ratio. Moreover, NTX affected neither the insulin response to OGTT or IGF-I, IGFBP-3 and IGF-I/IGFBP-3 molar ratio in a group of six lean controls. Conversely, NTX significantly reduced the GH response to GHRH, when expressed as both peak and AUC values. CONCLUSIONS: The opiate antagonist significantly reduced basal insulin concentrations and augmented the GH response to GHRH in obese subjects. In the absence of modifications in IGF-I and IGFBP-3 plasma levels and their molar ratio, we propose that insulin may exert a negative feedback on GH secretion.
OBJECTIVE: To verify if a chronic opioid blockade could affect the GH/IGF-I axis. DESIGN: We have investigated the effects of naltrexone (NTX) treatment on GH response to GHRH in normal women. METHODS: GHRH test (50 micrograms i.v.) performed in seven normal female volunteers (age 25-38 years, with a body mass index ranging from 19.8 to 23.1 kg/m2) before and after 4-weeks NTX treatment (50 mg p.o. daily). RESULTS: Basal GH, IGF-I, insulin-like growth factor binding protein-3 (IGFBP-3) plasma levels and the IGF-I/IGFBP-3 molar ratio remained unaffected by NTX. NTX significantly reduced the GH peak values (15.52 +/- 3.59 vs 4.78 +/- 0.49 micrograms/l; P < 0.01), and GH area under curve (918.93 +/- 253.96 vs 401.09 +/- 79.63 micrograms/l; P < 0.01). CONCLUSIONS: This finding suggests that the long-term opioid receptor blockade has an inhibitory role on GHRH-induced GH secretion. A central influence on neurotransmitter control of GH might be hypothesised. The inhibition of stimulated GH release, without interference with the basal level, could indicate an enhanced somatostatin secretion and/or activity. Opioids could be involved only in the regulation of GH dynamics and not in basal secretion. Nevertheless, a direct involvement of opioids at the pituitary level, which could be modified by NTX, cannot be excluded.
INTRODUCTION: We report our personal technique and the preliminary results of percutaneous implantation of intraarterial catheters connected to a subcutaneous infusion reservoir (Port-a-cath) for the regional chemotherapy of hepatic and extrahepatic tumors. January, 1996, to February, 1997 fifty patients underwent the procedure: 44 had liver cancers (42 had metastases and 2 hepatocellular carcinomas), 4 pelvic tumors (2 bladder carcinomas, one uterine cancer and one vaginal cancer), one had inoperable pancreatic tumor and one breast cancer. MATERIALS AND METHODS: The access was the left axillary artery in 45 cases, the femoral artery in 4 and both the femoral and the axillary artery in one case. The infusion catheter was placed in the hepatic artery in 44 cases, in the splenic artery in one case of pancreatic cancer, in the hypogastric artery in 4 cases and in the internal mammary artery in one case. When the catheter was positioned in the hepatic artery, embolization of the gastroduodenal or accessory hepatic arteries was performed using metallic coils; when the catheter was positioned in the hypogastric artery, the contralateral hypogastric artery and the ipsilateral gluteal branches were embolized. The catheter was then tunnelled and connected to a subcutaneous reservoir, sutured to the pectoral fascia or to the inguinal ligament. After the injection of heparinated solution, infusion chemotherapy was started the day after the procedure. RESULTS: We obtained immediate technical success in all cases. Four major complications occurred: a pseudoaneurysm of the left axillary artery (percutaneously treated by placement of a covered stent), 2 thromboses of the hepatic artery and one case of gastritis. Among minor complications, the catheter was displaced in 9 cases and 7 catheters were percutaneously replaced. Side-effects, not related to the procedure, were pain, nausea, vomiting and mucositis. During the follow-up, 7 patients died (6 for tumor progression); median catheter patency was 5.14 months. Though the aim of this work is to present the technical aspects of the procedure, we report the preliminary clinical data: radiological examinations showed partial tumor regression in 15 of 33 patients with 3-month follow-up; no change was shown in 2 patients and disease progression was found in 4; the response could not be assessed in the other cases. CONCLUSIONS: In conclusion, the percutaneous placement of intraarterial catheters for continuous regional chemotherapy is a feasible, safe and tolerable procedure and can represent an alternative to the surgical implantation of catheters in the hepatic artery for the treatment of liver metastases from colorectal cancer. The technique opens new therapeutic possibilities for the local treatment of extrahepatic tumors (such as gynecologic, vesical, pancreatic and breast cancers), even though its clinical efficacy must be assessed in selected trials.
A method for quantitating glycerophosphorylcholine by flow injection analysis is reported in the present paper. Glycerophosphorylcholine phosphodiesterase and choline oxidase, immobilized on controlled porosity glass beads, are packed in a small reactor inserted in a flow injection manifold. When samples containing glycerophosphorylcholine are injected, glycerophosphorylcholine is hydrolyzed into choline and sn-glycerol-3-phosphate. The free choline produced in this reaction is oxidized to betain and hydrogen peroxide. Hydrogen peroxide is detected amperometrically. Quantitation of glycerophosphorylcholine in samples containing choline and phosphorylcholine is obtained inserting ahead of the reactor a small column packed with a mixed bed ion exchange resin. The time needed for each determination does not exceed one minute. The present method, applied to quantitate glycerophosphorylcholine in samples of seminal plasma, gave results comparable with those obtained using the standard enzymatic-spectrophotometric procedure. An alternative procedure, making use of co-immobilized glycerophosphorylcholine phosphodiesterase and glycerol-3-phosphate oxidase for quantitating glycerophosphorylcholine, glycerophosphorylethanolamine and glycerophosphorylserine is also described.
Previous studies have shown that food ingestion is not capable of inhibiting the GHRH-induced GH release in anorexia nervosa, at variance with what is observed in normal subjects. Moreover, a cholinergic alteration has been hypothesized in this disorder. In a group of 24 anorectic patients in a stabilized phase of the illness, we tested, before and after a standard meal, the GH response to GHRH alone and after pre-treatment with pyridostigmine, an inhibitor of acetylcholinesterase, and, on a different day, with oxiracetam, which stimulates the central cholinergic neurones. The GH response to GHRH was significantly increased by both drugs in a fasting state. The postprandial response was not significantly modified by pyridostigmine nor by oxiracetam. Neither of these compounds was able to enhance the postprandial GH 'paradoxical' response to GHRH in anorectic patients. The lack of effect of both groups postprandially also suggests a suppression of somatostatinergic activity.
In order to gain insight into the neuroendocrine mechanism underlying the paradoxical GH response to TRH in acromegalic patients, we have investigated the effect of an infusion of Naloxone (Nal, 1.6 mg/hr for two hours), on a TRH test performed both in responder (n = 9) and non-responder (n = 5) acromegalic patients. The response of GH, PRL and TSH to TRH injection were evaluated. NAL did not exert significant variations in the GH response, even if different patterns of GH response during NAL were observed in the group of TRH-responder patients. Similarly, TRH-induced PRL response was not significantly affected by the infusion of an opiate antagonist. On the contrary, a significant inhibition of the TSH response was observed in the group of TRH-responder patients (delta TSH after TRH 4.76 +/- 1.11 microU/ml, after NAL + TRH 2.81 +/- 0.99 microU/ml, p < 0.05). No significant effects were observed in the TRH non-responder patients (delta TSH after TRH 4.58 +/- 1.44 microU/ml, after NAL + TRH 6.26 +/- 3.27 microU/ml). The differences observed in the two groups of patients could be ascribed to a different endogenous somatostatinergic tone and could furnish a prognostic indication in acromegalic patients.
The tumour necrosis factor alpha (TNF), has been implicated in the pathogenesis of non-steroidal anti-inflammatory drug (NSAID) induced gastropathy and Helicobacter pylori induced gastritis. Both conditions are characterised by high plasma pepsinogen concentrations, which are thought to reflect an increased rate of enzyme release by the pepsinogen secreting (chief) cells. The mechanisms responsible for this cell dysfunction are unknown. This study investigates whether chief cells express TNF receptors and, if so, whether their activation results in cell death. Immunohistochemical studies conducted with monoclonal antibodies (mAbs) directed against two TNF receptor associated proteins of 55 kDa (TNF-R1) and 75 kDa (TNF-R2) showed that TNF binding sites were expressed in approximately 100% gastric chief cells. Western blot analysis of whole chief cell lysates probed with the TNF-R1 and TNF-R2 mAbs gave two distinct bands of 55 and 75 kDa in the immunoprecipitate. Incubating chief cells with TNF caused concentration and time dependent cell death, which was prevented by pretreating the cells with anti-TNF receptor mAbs. Exposing the cells to TNF reduced sphingomyelin content by 25%. Sphingomyelinase (10(-6) to 10(-2) IU/ml) mimicked the effect of TNF in that it provoked a concentration and time dependent reduction in chief cell viability and increased pepsinogen release. In conclusion, gastric chief cells express two TNF receptors partially linked to the sphingomyelin pathway. TNF induced chief cell dysfunction might be responsible for the high plasma pepsinogen concentrations seen in patients with NSAID gastropathy or H pylori induced gastritis.
Cyclosporine A (CyA), a well established treatment of psoriasis, is a highly lipophilic cyclic undecapeptide mainly used for its immunosuppressive properties and exerting a wide spectrum of biological activities including fungicidal antiproliferative and anti-inflammatory effects. Plasminogen activators (PA), urokinase (UK, M(r) 55,000) and tissue type plasminogen activators (tPA, M(r) 74,000), physiologically catalyze the conversion of the plasminogen to the wide spectrum proteinase plasmin. UK and tPA are involved in cell growth, differentiation and migration. It has recently been shown that psoriatic epidermis is provided with abnormal tPA-dependent PA activity and that in lesional epidermis elevated tPA mRNA levels are present. It has been suggested that the tPA-dependent PA activity is a marker of disease activity and is reversible with different topical and systemic treatments. In this preliminary study we investigate the effect of CyA on the tPA mRNA transcription on A431 keratinocytes cell line. Subconfluent A431 cell cultures have been treated with CyA at in vivo relevant concentrations (10, 7.5, 5 micrograms/ml) for 48 h. Northern blot analysis of total RNA extracted from cultured A431 cell line has been performed for detecting tPA mRNA. mRNA for tPA has been detected in the control samples whereas an evident decrease of tPA mRNA expression has been detected in the CyA-treated samples. These data suggest that CyA could have an effect in clearing psoriatic lesions also modulating the abnormal plasminogen activation i.e. tPA-dependent serinoproteinase activity.
An increased risk of colorectal cancer has been reported in first-degree relatives of affected patients, and following cholecystectomy or partial gastrectomy for benign peptic ulcer disease. The aim of this study was to examine the incidence of these potential risk factors in 197 patients (127 males, 70 females, mean age 70 years +/- 10.9, range 22-94 years) with cancer of the large bowel and 202 controls (91 males, 111 females, mean age 68 years +/- 14.06, range 17-93 years) who underwent a total colonoscopy, that revealed no colorectal neoplasms. No significant differences were found between the case and control group for a past history of cholecystectomy or gastric surgery, respectively reported by 14 and 12 patients of group 1 and 18 and 8 patients of group 2. Patients with large bowel cancer show a significant excess of both colorectal (21.31% vs 11.9%) and extracolonic malignancies (46.19% vs 26.73) in first degree relatives (p < 0.05). In approximately 7% of them the aggregation of two or more colorectal cancers among relatives is suggestive for a hereditary form of large bowel cancer.
5'-Deoxy-5'methylthioadenosine phosphorylase (MTA-Pase) gene is localized at the 9p21 region linked to the recently identified putative tumor suppressor gene, p16INK4, which appears implicated in the control of cell division cycle. The phosphorylase is a housekeeping enzyme involved in the purine and amino acid metabolism whose activity is evidentiable in all the normal tissues. Chromosomal deletions encompassing both MTAPase and p16INK4 genes cause the total absence of the enzymatic activity only in malignant cells, thus resulting in defined metabolic differences between malignant and normal cells. MTAPase deficiency was investigated by direct radiochemical assay method and by immunochemical techniques in 35 different human malignant cell lines established from several tumor types. The enzyme-deficient cells derived from breast, lung, ovary and liver cancer, malignant melanomas, malignant gliomas and liposarcomas. Two of the MTAPase-deficient cell preparations (from a liver carcinoma and from a melanoma) are primary cultures thus directly representing the original cancer genotypes. Several of the MTAPase-negative cells were studied for p16INK4 gene deletions and for p16INK4 protein deficiency. In all the examined samples a full correlation exists between the lack of MTAPase and that of p16INK4. A similar result was obtained analysing extracts of Vero cell line, which is a fibroblast MTAPase-negative cell line established from the kidney of a normal adult monkey. Conversely, Cos cells, which also are fibroblasts derived from monkey kidney, show both MTAPase and p16INK4 protein. These results: (i) demonstrate that the phosphorylase deficiency is distributed among almost all the most important human cancers; (ii) confirm and extend the tumor types were p16INK4 gene inactivation is observable and (iii) suggest that deletions at 9p21 (in humans) or at syntenic chromosomes (in other species) might represent a general mechanism of p16INK4 gene loss of function and possibly, in turn, of cancer development and/or progression.