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Biomedical subjects

A Riccardi

Publications and source records attributed to A Riccardi.

At least 19 recordsLinked to original sources
PubMed2004

Low diversity in the major histocompatibility complex class II DRB1 gene of the Spanish ibex, Capra pyrenaica.

During the last two centuries, the Spanish ibex (Capra pyrenaica) has shown a significant demographic decline as a result of the progressive destruction of its natural habitat, disease epidemics, and uncontrolled hunting. Partial sequencing of the class II MHC DRB1 gene revealed that the Spanish ibex has remarkably low levels of genetic variation at this locus, with only six different DRB1 alleles and an observed heterozygosity of 0.429-0.579. The rates of nonsynonymous vs synonymous substitutions were significantly different in the peptide-binding region (dN/dS=5.347, P=0.002), a feature that indicates that the DRB1 gene is under positive selection. A phylogenetic analysis of the Spanish ibex and a set of domestic goat DRB1 alleles revealed that the reported sequences represent four major allelic lineages. The limited allelic repertoire of the DRB1 gene in the Spanish ibex is likely the direct result of the recent history of population bottlenecks and marked demographic decline of this species. A genetic survey of 13 microsatellite loci was consistent with this idea. The Spanish ibex subspecies C. p. hispanica and C. p. victoriae consistently showed considerably lower levels of microsatellite heterozygosity (Ho=0.184-0.231) and allelic diversity (mean number of alleles per locus=2-2.4) than those reported in other wild ruminants. This study demonstrates the significance of both natural selection and the demographic history of populations in determining patterns of genetic variation at MHC loci. In addition, our results emphasize the importance of locally adapted populations for the preservation of genetic diversity.

Amino Acid Sequence↗
PubMed2003

Response to first-line chemotherapy and long-term survival in patients with multiple myeloma: results of the MM87 prospective randomised protocol.

In this study we evaluated whether a good response to conventional chemotherapy, i.e. a significant tumour reduction, is a prerequisite for improved survival in multiple myeloma (MM). Between January 1987 and March 1990, 341 consecutive previously untreated patients with MM received chemotherapy within the prospective, multicentre, randomised Protocol MM87. Of these, 258 patients were evaluable for both response and long-term survival and 244 (94.6%) have died. The median survival of all patients was 40 months (6-162 months). The median survival did not differ between patients who had complete response (CR) (50 months (9-162 months)), partial response (PR) (46 months (8-147 months)) or stable disease (SD) (41 months (7-135 months)). The median survival was shorter (13.6 months (6-135 months)) (P<0.0001) in patients whose disease progressed while they were receiving first induction chemotherapy. Causes of death were more frequently (P=0.04) related to MM in patients who had progressive disease (PD) than in patients who had a CR or PR or SD. The main clinical and laboratory characteristics were similar in the four groups. These data indicate that patients who maintain SD during first-line chemotherapy have a prognosis similar to that of patients who attain a response. Only patients whose disease progresses have a distinctly worse outcome.

Analysis of Variance↗
PubMed2002

Sentinel lymph node identification in breast cancer patients.

PURPOSE: To evaluate the predictive value of sentinel lymph node biopsy versus axillary node dissection on lymph node status in patients with T1-T2 breast cancer. MATERIAL AND METHODS: Twenty-nine patients with T1 and 12 with T2 breast carcinoma and clinically N0 axillary lymph nodes, underwent lymphoscintigraphy following the administration of 99mTc-human albumin nanocolloids. The tracer was injected subdermally, over the tumor mass, in the 34 patients with palpable lesions and peritumorally (n=3) or intratumorally (n=4), under stereotactic or ultrasound guidance, in the 7 patients with non-palpable lesions. Anterior and lateral planar images were acquired 15 min after the injection of the tracer and repeated every 30 min up to 3 hr until identification of sentinel lymph node. At the end of the scintigraphic study, sentinel node skin projection was marked using a dermographic pen. Eighteen hours after lymphoscintigraphy, sentinel lymph node was identified and removed during surgery by hand-held gamma probe, then, the remaining axillary lymph nodes were dissected. All surgical specimens underwent histologic examination. Sentinel lymph nodes free of metastasis at histology, underwent additional examination with immunohistochemistry using monoclonal antibodies against cytokeratin and EMA to search for micrometastases. RESULTS: Sentinel lymph node was identified in the 34 patients injected subdermally and in the 3 patients injected peritumorally, while it remained undetected in the 4 patients injected intratumorally except for one case in which it was isolated by radioguided surgery but not scintigraphically. Sentinel nodes resulted free of metastases both at histology and immunohistochemistry in 32 cases and metastatic in 6. In the 32 patients with non-metastatic sentinel lymph nodes the other axillary nodes were also free of metastases. Among the 6 metastatic sentinel lymph nodes, in 3 cases they were the only metastatic nodes of the axilla while in the other 3 cases metastases were spread to other axillary nodes. CONCLUSIONS: In agreement with previous studies, our results showed that sentinel lymph node radioguided biopsy is a simple and reliable method for predicting axillary lymph nodes status and for avoiding axillary dissection in early breast cancer patients with sentinel node free of metastases.

Adult↗
PubMed2001

A phase II study of sequential 5-fluorouracil, epirubicin and cyclophosphamide (FEC) and paclitaxel in advanced breast cancer (Protocol PV BC 97/01).

Sequential administration of the association of 5-fluorouracil, epirubicin and cyclophosphamide (FEC) and paclitaxel could be better tolerated than the association of an anthracycline and paclitaxel while having a similar antitumour effect. 69 patients with advanced breast cancer previously untreated with anthracyclines or paclitaxel entered a phase II multicentre study in which FEC was followed by paclitaxel. Both regimens were administered 4 times every 21 days. The median follow-up is 20 months and 38/69 patients have died. Grade III-IV toxicity was acceptable. Leukopenia occurred in 26% of patients, thrombocytopenia in 2% and anaemia in 4%. One patient had reversible heart failure during FEC therapy. Peripheral neuropathy and arthralgia-myalgia occurred in 9% and 4% of patients, respectively and one patient had respiratory hypersensitivity during paclitaxel treatment. 9 patients did not complete therapy because of: treatment refusal (n = 1), cardiac toxicity (n = 1), early death during FEC chemotherapy (n = 1), major protocol violations (n = 4), hypersensitivity reaction (n = 1) and early death during paclitaxel chemotherapy (n = 1). The overall response rate was 65% (95% CI = 53-76), and 7% of patients had stable disease. Therapy was defined as having failed in 28% of patients because they were not evaluable (13%) or had progressive disease (15%). The median time to progression and survival are 13.2 and 23.5 months, respectively. Sequential FEC-paclitaxel is a suitable strategy for patients with metastatic breast cancer who have not been previously treated with anthracyclines and/or taxanes. In fact, it avoids major haematologic toxicity and has a good antitumour effect.

Adult↗
PubMed2001

Scintimammography with 99mTc-MIBI versus dynamic MRI for non-invasive characterization of breast masses.

Although mammography remains the technique of choice for the early detection of breast cancer, several imaging techniques, including scintimammography and magnetic resonance imaging (MRI), have recently been proposed as adjuncts for this purpose and included in many diagnostic protocols. This study was undertaken to assess the clinical accuracy of scintimammography with technetium-99m methoxyisobutylisonitrile (MIBI) and contrast-enhanced MRI in the detection of primary breast carcinoma in patients with equivocal mammographic findings. Forty-nine patients with a suspicious breast mass detected either by physical examination or by mammography and ultrasound (US) were studied. All patients underwent scintimammography and dynamic contrast-enhanced MRI 1 week apart. The results of the two techniques were compared and correlated to the final diagnoses. Two independent readers reported the scans using a four-point confidence scale. The areas under the receiver operator characteristic (ROC) curves were obtained. Scintimammography showed an accuracy for tumour detection of 84%, with a sensitivity of 80% and a specificity of 88%. MRI showed an accuracy of 86%, with a sensitivity and specificity of 96% and 75%, respectively. Comparison of the two areas under the ROC curves showed no significant differences between MRI, 0.91+/-0.05 (mean+/-SD), and scintimammography, 0.88+/-0.05 (P=0.9). It is concluded that dynamic MRI and scintimammography possess comparable accuracy in the diagnosis of primary breast carcinoma in patients with equivocal mammographic or US findings.

Biopsy↗
PubMed2001

Sequential intrahepatic and systemic fluoropyrimidine-based chemotherapy for metastatic colorectal cancer confined to the liver. A phase II study.

PURPOSE: Several trials have suggested that intrahepatic chemotherapy increases the likelihood of response in advanced colon cancer patients, but has no significant impact on survival due to the development of extrahepatic metastases. We report our experience of combined hepatic intraarterial and systemic chemotherapy in advanced colorectal cancer patients. METHODS: A group of 35 patients received intrahepatic FUDR (0.3 mg/kg per day for 14 days by continuous infusion), followed, after 1 week's rest, by systemic 5-FU and L-leucovorin (370 and 100 mg/m2 per day, respectively, both for 5 consecutive days). After another week off therapy, the combined intrahepatic and systemic regimen was repeated and cycles continued until disease progression. RESULTS: Of 32 assessable patients, 17 (53.1%) had an objective response, while 8 (25%) had disease stabilization. Median time to progression (TTP) was 32 weeks (range 8-104 weeks), while the median overall survival was only 39 weeks (range 9-109 weeks). Incomplete liver perfusion was the only variable that showed a significant correlation with a poorer survival (P = 0.046, log-rank test). CONCLUSIONS: Our results are in agreement with previous data suggesting a relative efficacy of such a treatment approach for advanced colon cancer patients. More thorough investigations are warranted, especially as an adjuvant treatment for selected high-risk patients.

Adult↗
PubMed2001

In vitro and in vivo antitumor activity of the novel trinuclear platinum complex BBR 3464 in neuroblastoma.

PURPOSE: BBR 3464 is a promising new trinuclear platinum complex that has been shown to circumvent the resistance to cisplatin in a panel of tumor cell lines and xenografts with acquired or intrinsic resistance to cisplatin. The in vitro and in vivo antitumor activity of BBR 3464 was evaluated and compared with that of cisplatin in neuroblastoma. METHODS: In in vitro studies, the short- and long-term cytotoxicities, cell cycle perturbations, the ability to induce apoptosis, the intracellular platinum accumulation and DNA platination were evaluated in three neuroblastoma cell lines exposed to appropriate drug concentrations for 1 h. In in vivo studies, BBR 3464 was administered i.v. at doses of 0.30 and 0.35 mg/kg three times at intervals of 4 days (q4dx3), and cisplatin was administered i.v. according to two different schedules (at 2 and 4 mg/kg three times at intervals of 4 days and at 6 and 12 mg/kg as single doses). RESULTS: In a short-term growth inhibition assay, BBR 3464 was shown to be up to 100-fold more potent than cisplatin and it was even more potent in a clonogenic assay. The difference in the antitumor effect of BBR 3464 on the different cell lines was evident in both assays, while cisplatin exerted a comparable antitumor activity in all lines tested. Cell cycle analysis demonstrated a longer-lasting block in G2/M phase induced by BBR 3464 without the early S phase accumulation induced by cisplatin. The higher potency of BBR 3464 appeared to be unrelated to the induction of apoptosis, that was lower or at most comparable to cisplatin. Cellular platinum accumulation and platinum-DNA adduct formation following BBR 3464 exposure was higher than following cisplatin exposure. These differences may have resulted from a different mechanism of action and may explain the lack of cross-resistance with cisplatin. In xenografts of neuroblastoma, BBR 3464 was confirmed to be very potent as compared to cisplatin (MTD 0.35 mg/kg and 4 mg/kg for BBR 3464 and cisplatin, respectively). The efficacy of BBR 3464 was superior to that of cisplatin when both drugs were administered on a fractionated schedule (q4dx3), while BBR 3464 appeared equally active to 12 mg/kg cisplatin administered as a single dose. CONCLUSIONS: Our findings indicate that BBR 3464 has a definite antitumor effect in neuroblastoma lines and may be a candidate for early clinical trials in children with neuroblastoma.

Animals↗
PubMed2001

The novel trinuclear platinum complex BBR3464 induces a cellular response different from cisplatin.

BBR3464 is a new platinum-based drug non cross-resistant with cisplatin. To characterise the cellular basis of BBR3464 cytotoxicity as opposed to cisplatin, we performed a comparative study of the two drugs in cisplatin-resistant neuroblastoma and astrocytoma cells. In both model systems, BBR3464 proved to be more potent than cisplatin and was able to overcome cisplatin resistance. The higher potency exhibited by BBR3464 correlated with an increased cellular platinum accumulation and DNA-adduct formation. At equitoxic doses, BBR3464 induced apoptosis to a lesser extent than cisplatin and failed to overcome the decreased susceptibility to cisplatin-induced apoptosis in cisplatin-resistant cells. Cell cycle analysis showed a dose-dependent G2/M arrest by BBR3464. In astrocytoma cells, cisplatin treatment resulted in the upregulation of p53, p21 and bax, while only p21 induction was observed after BBR3464 treatment. In cisplatin-resistant cells, the reduced sensitivity to cisplatin paralleled a resistance to the induction of p53/p21 pathway by cisplatin, while the same doses of BBR3464 induced p21 to a similar extent in the resistant cells as in the parental cells. In conclusion, BBR3464 induces a cellular response that is different from cisplatin, supporting the view that the two drugs act through different mechanisms. Our data indicate that BBR3464 may be a promising agent in the treatment of tumours unresponsive to cisplatin and with a non-functional p53.

Antineoplastic Agents↗
PubMed2001

An SVM classifier to separate false signals from microcalcifications in digital mammograms.

In this paper we investigate the feasibility of using an SVM (support vector machine) classifier in our automatic system for the detection of clustered microcalcifications in digital mammograms. SVM is a technique for pattern recognition which relies on the statistical learning theory. It minimizes a function of two terms: the number of misclassified vectors of the training set and a term regarding the generalization classifier capability. We compare the SVM classifier with an MLP (multi-layer perceptron) in the false-positive reduction phase of our detection scheme: a detected signal is considered either microcalcification or false signal, according to the value of a set of its features. The SVM classifier gets slightly better results than the MLP one (Az value of 0.963 against 0.958) in the presence of a high number of training data; the improvement becomes much more evident (Az value of 0.952 against 0.918) in training sets of reduced size. Finally, the setting of the SVM classifier is much easier than the MLP one.

Algorithms↗
PubMed2001

Strategies of medical treatment for metastatic breast cancer (Review).

Presently, metastatic breast cancer cannot be cured and therefore good palliation of symptoms and longer overall survival make the most important targets, always considering quality of life. In addition to the established hormonal therapies or chemotherapy regimens, several recent advances have accelerated progress in metastatic breast cancer treatment. As demonstrated in recent studies, the third-generation aromatase inhibitors are playing a significant role in the improvement of the therapeutic approach. The development of new drugs with novel mechanisms of action, such as taxanes, used alone in innovative schedules or in association with other drugs (mainly the anthracyclines), vinorelbine and gemcitabine, or capecitabine, which is administered orally, has broadened the scope of metastatic breast cancer chemotherapy. A new investigation field is represented by high-dose chemotherapy with stem cell support, which has provided controversial preliminary results but is also acknowledged to deserve larger and randomized trials. Finally, the emergence of biological therapies such as the anti-HER2 monoclonal antibody Trastuzumab opens new and exciting prospects for the treatment of this disease. Moreover, the present trend is to try to rationalize the therapeutic approach on the basis of biological parameters which are prognostic and predictive of treatment response.

Antibodies, Monoclonal↗
PubMed2000

Long-term survival of stage I multiple myeloma given chemotherapy just after diagnosis or at progression of the disease: a multicentre randomized study. Cooperative Group of Study and Treatment of Multiple Myeloma.

We conducted a randomized trial to evaluate whether melphalan-prednisone (MPH-P) treatment administered just after diagnosis improves survival of stage I multiple myeloma (MM). Between January 1987 and March 1993, 145 consecutive previously untreated patients with stage I MM were randomized between treatment with MPH-P (administered for 4 days every 6 weeks) just after diagnosis and treatment only at disease progression. Survival was not influenced by MPH-P treatment either administered just after diagnosis or at disease progression (64 vs 71 months respectively). Comparing the first with the second group the odds ratio of death is 1.17 (95% confidence interval 0.57-2.42; P = 0.64). Disease progression occurred within a year in about 50% of patients who were initially untreated. Response rate was similar in both groups, but duration of response was shorter in patients who were treated at disease progression (48 vs 79 months, P = 0.044). Patients actually treated at disease progression (34/70) survived shorter than those who had neither disease progression nor treatment (56 vs > 92 months; P = 0.005). Starting MPH-P just after diagnosis does not improve survival and response rate in stage I MM, with respect to deferring therapy until disease progression. However, patients with stage I MM randomized to have treatment delayed and who actually progressed and were treated had shorter survival than those with stable disease and no treatment. Biologic or other disease features could identify these subgroups of patients.

Adult↗
PubMed2000

Doubling of the epirubicin dosage within the 5-fluorouracil, epirubicin and cyclophosphamide regimen: a prospective, randomized, multicentric study on antitumor effect and quality of life in advanced breast cancer.

In metastatic breast cancer (MBC) doubling the epirubicin (EPI) dose intensity (DI) within the FEC (5-fluorouracil, EPI, cyclophosphamide) regimen could increase the response rate (RR) and ameliorate the quality of life (QoL) over standard FEC. From May, 1995, 74 consecutive patients with MBC were randomly treated with 6 courses of two FEC regimens containing 60 (60FEC) or 120 (120FEC, supported by primary G-CSF) mg/m2 of EPI. Drugs were administered every 21 days. The QoL was assessed over and after treatment by the EORTC QLQ-C30 (VER 2.0) and QLQ-BR23 questionnaires, compiled by the patient, and the Spitzer's QL-index, compiled by the physician. The study was prematurely closed in May, 1997, due to RR and QoL data of 4th interim analysis. The delivered EPI DI was 20.0 and 37.9 mg/m2/week in 60- and in 120FEC, respectively. Among the two regimens, there was no statistically significant difference in RR or in improvement of baseline overall QoL. With respect to 60FEC patients, the 120FEC patients had longer time to progression (19.2 vs 13.1 mos, p=0.04). Over baseline, the 120- but not the 60FEC patients had significantly greater pain decrease and lower deterioration of body image. In MBC, both 60- and 120FEC regimens furnished the same RR and improvement in overall baseline QoL. With respect to 60FEC patients, the 120FEC patients experienced longer time to progression. Over baseline, pain decrease and preservation of body image were also greater in these patients.

Adult↗
PubMed1999

Antitumour activity of oxaliplatin in neuroblastoma cell lines.

Oxaliplatin appears non cross-resistant with cisplatin and has a comparable antitumour effect both in preclinical and clinical studies. We compared the antitumour effect of oxaliplatin with that of cisplatin in human neuroblastoma cell lines SK-N-DZ, LAN-1 and BE(2)M17 following 24 h exposure at concentrations ranging from 0.5 to 5 microM. Oxaliplatin was less potent with IC50 values 1.08-3.4-fold higher than cisplatin. Like cisplatin, oxaliplatin induced a cell cycle block in the G2/M phase although to a lesser extent than that caused by cisplatin. The concomitant increase of DNA fragmentation and decrease of G2/G1 ratio at 72 h indicated that a fraction of blocked cells underwent apoptosis. Morphological analysis confirmed these data, although oxaliplatin appeared to be 2-3 times less potent than cisplatin in inducing apoptosis. Our results indicate that oxaliplatin is active in neuroblastoma in vitro and this finding warrants in vivo preclinical studies.

Antineoplastic Agents↗
PubMed1999

Influence of cisplatin and doxorubicin on 125I-meta-iodobenzylguanidine uptake in human neuroblastoma cell lines.

The combination of 131I-meta-iodobenzylguanidine (MIBG) with chemotherapy has recently been employed in the treatment of advanced stage neuroblastoma with encouraging results. However, the mechanisms underlying the interaction between these two different modalities of treatment have not yet been explored. In this study, human neuroblastoma cell lines pretreatment with cisplatin and doxorubicin increased cellular 125I-MIBG accumulation in a dose-dependent manner. Cell cycle analysis showed that increased 125I-MIBG accumulation correlated with the drug-induced G2/M phase block. Northern blot analysis demonstrated an increase in gene expression of the noradrenaline transporter induced by doxorubicin, but not by cisplatin treatment. Increased 125I-MIBG accumulation was also observed in murine xenografts of the human neuroblastoma cell line SK-N-DZ or BE(2)M17 treated intraperitoneally (i.p.) with cisplatin or doxorubicin, respectively. These results suggest that the combination of 131I-MIBG and these drugs could selectively increase radiation doses delivered to neuroblastomas.

3-Iodobenzylguanidine↗