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C Porta

Publications and source records attributed to C Porta.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Influence of three-dimensional structure on the immunogenicity of a peptide expressed on the surface of a plant virus.

The influence of peptide structure on immunogenicity has been investigated by constructing a series of cowpea mosaic virus (CPMV) chimaeras expressing the 14 amino acid NIm-1A epitope from human rhinovirus 14 (HRV-14) at different positions on the capsid surface. Biochemical and crystallographic analysis of a CPMV/HRV chimaera expressing the NIm-1A epitope inserted into the betaC'-betaC" loop of the S protein revealed that, although the inserted peptide was free at its C-terminus, it adopted a conformation distinct from that previously found when a similarly cleaved peptide was expressed in the betaB-betaC loop of the S protein. Adjustment of the site of insertion within the betaB-betaC loop resulted in the isolation of a chimaera in which cleavage at the C-terminus of the epitope was much reduced. Crystallographic analysis confirmed that in this case the epitope was presented as a closed loop. Polyclonal antisera raised against the CPMV/ HRV chimaera presenting the NIm-1A epitope as a closed loop had a significantly enhanced ability to bind to intact HRV-14 particles compared with antisera raised against chimaeras presenting the same sequence as peptides with free C-termini. These results demonstrate that the mode of presentation of an epitope on a heterologous carrier can dramatically affect its immunological properties.

Amino Acid Sequence↗
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5-Fluorouracil and d,l-leucovorin calcium are active to treat unresectable hepatocellular carcinoma patients: preliminary results of a phase II study.

Twenty-five patients affected with unresectable hepatocellular carcinomas (HCCs) were treated with 370 mg/m2 5-fluorouracil (5-FU) plus 200 mg/m2 racemic leucovorin both for 5 consecutive days. The chemotherapy cycle was repeated every 4 weeks until disease progression. One complete remission (4%) and 6 partial responses (24%) were obtained, that is 7 objective responses in all (28%, ninety-five confidence interval: 10.1-45.9%). All responders had a good PS and only 1 of them presented with bulky disease. Five patients (20%) exhibited stable disease, while the remaining 13 patients (52%) progressed. Toxicity was mild: 11 patients (44%) had grade II/III mucositis, 10 patients (40%) grade II diarrhea, 7 patients (28%) grade II nausea, 2 patients grade III granulocytopenia and 1 patient only (4%) grade I skin toxicity. This regimen made it possible to obtain a high rate of objective responses even in inoperable HCCs which are commonly considered as chemoresistant lesions.

Aged↗
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Colon cancer in pregnancy: report of a case and review of the literature.

Most colon cancer cases occur in patients over 50 years of age, although about 3% of colorectal cancer patients are younger than 40. During pregnancy the incidence of this neoplasm is estimated to be 0.002%. To date only 32 cases of colonic cancer arising above the peritoneal reflection during pregnancy have been described in the literature. We report another such case, stressing the need for constant alertness on the part of physicians in the presence of abdominal pain and/or distension, a palpable abdominal mass, rectal bleeding and/or weight loss during pregnancy. In fact, the reportedly poorer prognosis of this cancer in pregnant patients is mainly due to the fact that the initial symptoms of the malignancy are usually attributed by the patient, but also by physicians, to normal pregnancy.

Adult↗
PubMedDate not supplied

Cell cycle status and apoptosis of hematopoietic progenitor cells released into the peripheral blood after taxanes and granulocyte colony-stimulating factor in breast cancer patients.

Paclitaxel and its analogue docetaxel show a significant antitumor activity, particularly evident in breast cancer. Paclitaxel has also been proved to be effective as a peripheral blood progenitor cell (CPC) mobilizing agent. To optimize the use of active, disease-specific drugs as CPC priming, we have evaluated the effects of either paclitaxel or docetaxel both at standard dosages and followed by granulocyte colony-stimulating factor (G-CSF), on circulating CPC release and function in 18 patients with advanced breast cancer who had failed previous anthracycline-based regimens. The reported differences in biological behaviour between bone marrow and blood-derived hematopoietic progenitor cells and the ability of both paclitaxel and docetaxel to induce apoptosis, prompted us to simultaneously evaluate the cell cycle perturbations induced on CD34+ cells. Median CD34+ peaks were 24 microl (range: 10-58) in the paclitaxel-treated patients and 39 microl (range: 17-91), respectively, in the patients who received docetaxel. After paclitaxel, the percentage of CD34+ cells in S-phase was low (bromodeoxyuridine, BrdU, labelling index = 3.4+/-2%) with a concomitant presence of early apoptotic cells (8.1+/-3%). On the contrary, after docetaxel, the percentage of CD34+ cells in S-phase was higher (BrdU labelling index = 14.5+/-4%, p<0.05 vs. paclitaxel), while early apoptotic cells were detected at a similar rate (8. 6+/-3%, p = n.s. vs. paclitaxel). In conclusion, when used at standard dosages, with respect to paclitaxel + G-CSF, docetaxel + G-CSF is a more satisfactory tool to mobilize CPC and to induce them into the cell cycle. These data should be taken into account when combinations of docetaxel with other agents are explored as CPC mobilizing regimens for autografting.

Adult↗
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Left ventricular function in colon cancer patients receiving adjuvant fluoro-folate chemotherapy: an echocardiographic study.

Cardiotoxicity has been reported with increasing frequency after 5-FU administration. Since 5-FU-based regimens are increasingly used as adjuvant treatment for resected colon cancer patients, this carries a potential increased risk of cardiotoxicity. In the present study, we evaluated if fluoro-folate chemotherapy has any effect on left ventricular (LV) diastolic function in resected colon cancer. Twenty-five resected colon cancer patients receiving adjuvant fluoro-folate chemotherapy, were prospectively studied. Both digitized M-mode and Doppler echocardiography were performed, in order to investigate different aspects of LV diastolic function. None of the studied parameters was influenced by chemotherapy administration. Indeed, values recorded at the end of the 6-month treatment and 6 months later were not statistically different from baseline values. This study suggests that the use of fluoro-folate chemotherapy in otherwise normal subjects carries a very low risk of severe cardiotoxicity.

Aged↗
PubMedDate not supplied

Cisplatin, mitomycin-C, 5-fluorouracil and leucovorin combination chemotherapy (l-FCM) in locally advanced unresectable or metastatic gastric carcinoma: a phase-II study.

Despite relevant progress, the impact of chemotherapy on advanced gastric cancer patients' survival is still unsatisfactory. Thus, the key objective of our efforts should be palliation of the symptoms and the maintenance of an adequate quality of life. In this phase-II study, we evaluated toxicity and efficacy of the combination of cisplatin, fluorofolates and mitomycin C. Thirty-one advanced gastric cancer patients received cisplatin (15 mg/m2) and 5-fluorouracil (350 mg/m2), both for 5 consecutive days every 4 weeks; 5-fluorouracil infusion was preceded by a rapid i.v. injection of 100 mg/m2 leucovorin, while mitomycin-C (10 mg/m2) was administered on day 1 of odd cycles. Cycles were repeated every 4 weeks until disease progression. We recorded 16 objective responses (51.6%, 95% confidence interval: 42.63-60.57); furthermore, such a response rate was coupled with a moderate degree of toxicity and an extremely good tolerance. In particular, alopecia, a frequent and distressing side-effect in patients, especially women, in our series occurred only in two patients. This treatment appears to be an active and tolerable therapeutic option for patients with advanced gastric carcinoma.

Adult↗
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[Functions and changes of chemoreflex in physiological and pathological conditions].

Chemoreceptors are known to respond to changes in composition of the gases in the inspired air by changing pulmonary ventilation. Whereas, less known it is the role that they play in many both physiologic and pathologic conditions. In this review we do not only consider the anatomic and physiologic chemoreceptor features but also we analyse the relationship between chemoreflex and baroreflex in the cardiovascular control, their role in the pathogenesis of essential hypertension and in the increase of blood pressure in subjects affected by obstructive sleep apnea, their implication in the genesis of dyspnea in chronic heart failure and their role in pulmonary disease. In this review we also analyse the chemoreflex changes with relation to physiologic situations such as aging, obesity, exercise, training and high altitude. Three methods are described for the study of the chemoreflex function, but more attention is paid to the new rebreathing technic. The aim of this paper is to underline the interactions between chemoreceptors and cardiovascular system and to analyse their functional changes in both physiologic and pathologic conditions.

Adult↗
PubMedDate not supplied

Malignant mesothelioma in 2004: How advanced technology and new drugs are changing the perspectives of mesothelioma patients. Highlights from the VIIth Meeting of the International Mesothelioma Interest Group.

Malignant mesothelioma (MMe) is a seemingly uncommon tumour whose incidence has in fact increased steadily and progressively over the last 30 years. Indeed, an actual "epidemic" is expected in the next 20 years, with over 1300 new cases a year till 2020 at least. Despite unquestionable improvement in the diagnostic methods at our disposal and the availability of new treatment strategies, the prognosis of MMe patients remains dramatically poor. For all the above reasons, translational research is the key to success; indeed, ever increasing knowledge of the molecular mechanisms underlying MMe pathogenesis could lead (and is actually leading) to new, hopefully more active, treatment options. To foster discussion among investigators working in this field, and to exchange different viewpoints concerning the newest advances in MMe pathogenesis and treatment, the VII International Mesothelioma Interest Group (IMIG) meeting was held in Brescia (Italy) between 24 and 26 June 2004 in cooperation with the Italian Group for the Study and Therapy of MMe (GIMe). The aim of this report is to summarize the most significant advances in the different disciplines applied to MMe presented and discussed during the IMIG meeting and how these advances will be changing the perspective of patients with MMe.

Angiogenesis Inhibitors↗
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Spasm of arm arteries due to ergotamine tartrate. A case report.

Ergotamine tartrate and caffeine has been widely prescribed for the prevention and treatment of migraine headaches. Rarely the ergotamine can cause symptoms of peripheral vascular insufficiency, often concerning the lower extremities. A case report of bilateral severe ischemia to the upper limbs, caused by a chronic assumption of ergotamine tartrate is presented.

Arm↗
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[Eosinophilic infiltration of the gastrointestinal system: description of a clinical case simulating a lymphoproliferative process].

A case of diffuse eosinophilic infiltration of the gastroenteric tract which involved a large portion of the small intestine is discussed. It arose in a patient not previously affected with allergic traits and without eosinophilia in peripheral blood. Problems of differential diagnosis and clinical-therapeutic implications are reported.

Adult↗
PubMedDate not supplied

Treatment of thrombotic thrombocytopenic purpura with high-dose immunoglobulins. Results in 17 patients. Italian Cooperative Group for TTP.

BACKGROUND: The experimental observation that plasma from TTP patients sometimes exhibits a protein which can cause platelet agglutination, and that such agglutination can be inhibited in vitro by the use of IgG led some authors to treat plasma exchange-resistant TTP patients with high-dose IgG (HDIgG). METHODS: We report the results obtained with HDIgG treatment in 17 patients retrospectively examined by the Italian Cooperative Group for the study of TTP: 6 males and 11 females, mean age was 31.7 years for the women (range: 20-65) and 44.6 for the men (range: 26-66). In all cases HDIgG administration was combined with other treatment modalities. RESULTS: Of the 17 patients, 7 died from disease progression (41.1%), 2 achieved partial remission (11.7%) and the remaining 8 achieved complete remission (47%). Of the 10 cases (58.8%) with a positive response, only in 4 did the addition of HDIgG seem to produce significant improvement. All efforts made to characterize the subgroup of patients who responded to HDIgG and compare them with the non responders failed. CONCLUSIONS: Although our results do not unquestionably demonstrate the role of HDIgG in the treatment of TTP, they suggest a possible role for HDIgG in the treatment of those rare plasma exchange-resistant TTP cases.

Adult↗
PubMedDate not supplied

[Hypokalemic rhabdomyolysis and thiazide diuretics. 3 clinical cases].

Rhabdomyolysis is an acute skeletal muscle disorder characterized by altered integrity of the cell membranes of muscle fiber cells and can be caused by a variety of factors whose nature is not necessarily traumatic. Hypokalemia is one of the most common metabolic causes, accounting for about 14-28% of rhabdomyolytic syndromes. We report and discuss three cases of hypokalemia caused by diuretic treatment with hydrochlorothiazide: the main clinical features were muscle symptoms following massive rhabdomyolysis.

Adult↗