Search PubMed⌕ Search

Biomedical subjects

M Venturini

Publications and source records attributed to M Venturini.

133 records · Page 8Linked to original sources
PubMedDate not supplied

[Automated blood cell measurements: a comparison between the Bayer H2 and the Abbott Cell-Dyn 3500].

INTRODUCTION: We have compared two hematologic analyzers, H2 (Bayer) and CELL DYN 3500 (Abbott). The protocol we used was able to evaluate the overall analytical quality, the effect of aging of the sample on the measured parameters, the quality of leucocytes differential count. Number and quality of information supplied for each sample by both analyzers were then taken in account. RESULTS: Excellent correlation for all measured parameters was found: only monocytes were, albeit modestly, overestimated by CELL DYN 3500 compared to H2. Ageing of sample and temperature of storage had a marked effect on CELL DYN's measurements, resulting in impaired recognition and classification of leucocytes, while the results for the other parameters were acceptable. Comparative evaluation of the differential count of leucocytes was made between the results of both analyzers and microscopic examination. While specificity, predictive value of negative results and quantity of false negative results were practically the same, sensitivity, predictive value of positive results and quantity of false positive results were better for H2 as compared to CELL DYN (87.1% vs 78.1%, 79.4% vs 65.8, 7 vs 13, respectively). The clinical utility of supplementary informations (alarms, flags, cytograms, etc.) yielded by the analyzers was relevant for H2 regarding the erythrocytes cytograms, for CELL-DYN 3500 regarding the application of the extended lyse program for lytic resistant RBCs and of the Vet Package. CONCLUSIONS: CELL DYN 3500 performance have on the whole confirmed the producer's claims, being of reliable use in the haematological screening on account of its simplicity and more than good overall analytical quality.

Autoanalysis↗
PubMedDate not supplied

[Ocular color Doppler echography: the examination technic, identification and flowmetry of the orbital vessels].

We studied the main ocular and retrobulbar vessels with color-Doppler US and report on examination technique, detectability of the vessels and their flow characteristics to define the normal ranges of Doppler spectra for each artery and vein. We comparatively examined both eyes of 20 healthy subjects. Of each eye we studied the ophthalmic artery, the central retinal artery, the ciliary artery, the central retinal vein and the superior ophthalmic vein. The following flow parameters were considered: peak systolic velocity, end-diastolic velocity and resistive index for arteries; maximum and minimum velocity for veins. The examination lasted about 10 minutes per eye--20 minutes for each subject. In all subjects the five investigated vessels were identified in both eyes, and adequate Doppler spectra were obtained. The average peak systolic velocities of ophthalmic, central retinal and ciliary arteries were respectively about 35, 12 and 10 cm/s, with low resistance patterns (resistive index: 0.75, 0.72 and 0.68, respectively). The venous flow, which is usually continuous, may be sometimes influenced by cardiac and respiratory activities: the maximum velocities of superior ophthalmic and central retinal veins were about 6 and 5 cm/s, respectively. Color-Doppler US noninvasively visualizes both ocular and retrobulbar vessels, providing major hemodynamic information from different flow parameters; the knowledge of these parameters in normal conditions can be the basis of hemodynamic studies in many abnormal orbital conditions.

Blood Flow Velocity↗
PubMedDate not supplied

[Mobilization of peripheral blood stem cells with conventional chemotherapy].

Autologous peripheral blood progenitor cells (PBPC) rescue after high-dose chemotherapy has been used progressively as a form of treatment in some solid and hematologic tumors. This increasing use can be explained by both advantages of PBPC rescue over bone marrow rescue (decrease in the duration of marrow aplasia, reduction of platelet transfusions, earlier discharge from hospital, potential use in patients with inadequate bone marrow reserve) and the low number of aphereses (one or two) needed to collect a sufficient number of progenitor cells for autografting. High-dose chemotherapy is likely to be increasingly used after the results of two recently reported studies in which treatment with high-dose compared with standard-dose chemotherapy increases overall survival in metastatic breast cancer patients and relapsed lymphoma patients. After the initial use of unselected mobilizing regimens regardless of the patient characteristics and the tumor type, now it seems more useful to optimize this approach. Mobilization of PBPC can be obtained by several approaches. Moderate or high doses of single agent alone (e.g. cyclophosphamide 4-7 g/m2) or some hematopoietic growth factors alone (e.g. G-CSF, GM-CSF) have been proven to be adequate mobilizing agents. However, the use of hematopoietic growth factors alone may disadvantageously delay the start of an effective chemotherapy. An efficient mobilizing regimen requires the use of both chemotherapy and hematopoietic growth factors: the efficiency of mobilization was greater and with less side effects than chemotherapy alone. It was postulated that PBPC mobilization could be achieved only at hematopoietic recovery following myeloablative chemotherapy. Recently, it has been demonstrated that some standard-dose chemotherapy regimens associated with hematopoietic growth factors are efficient priming agents. We reported that standard-dose CEF chemotherapy plus filgrastim is a disease specific regimen (breast cancer) allowing PBPC mobilization without any relevant toxicity. The maximum release of PBPC has been observed at day 11. The optimal time for PBPC collection is predictable and aphereses can be guided by WBC counts. In conclusion, both standard and high dose chemotherapy are effective priming regimens. So presently a mobilizing regimen should be an effective disease specific chemotherapy program and should contain a hematopoletic growth factor. The choice between standard and high-dose chemotherapy can be based on patients characteristic and disease status.

Antineoplastic Agents↗
PubMedDate not supplied

[Use of erythropoietin in oncology].

UNLABELLED: Anemia is a common complication observed in cancer patients. Its etiology is multifactorial and its severity depends on patient characteristics, type and stage of neoplasia, type of used chemotherapy. Erythropoietin can be effective by counteracting two of the main causes of anemia in cancer patients undergoing chemotherapy: 1. Myelosuppression induced by chemotherapy. Almost all cytotoxic drugs induce this effect. In this circumstance erythropoietin can be effective by accelerating the recovery of the erythroid compartment spared by chemotherapy. For this effect, higher than physiologically normal levels of erythropoietin are required. 2. Endogenous erythropoietin deficiency secondary to renal impairment. Renal impairment is primarily induced by cisplatin and leads to a deficient renal production of erythropoietin. In this case, erythropoietin administration can be considered as a hormone replacement therapy. Possible indications for the use of erythropoietin in cancer patients are the following: 1. Prevention of anemia; 2. Treatment of anemia induced by either high dose chemotherapy and bone marrow transplantation (BMT) or standard dose chemotherapy. The preventive use of erythropoietin is still under investigation. Two randomized studies reported the erythropoietin ability to prevent the anemia development. Further trials are required to identify subsets of patients in which the preventive use of the drug could be cost-effective. One of the causes of anemia after allogeneic BMT is the endogenous production of erythropoietin inappropriately low for the degree of anemia. On the contrary, after autologous BMT the erythropoietin response to anemia is appropriate. Phase III randomized studies showed the efficacy of erythropoietin in the treatment of anemia after allogeneic but not after autologous BMT. After standard dose chemotherapy, phase III randomized studies showed that erythropoietin is able to correct anemia in 60-80% of patients receiving platinum-based chemotherapy and in nearly 40% of patients receiving chemotherapy without platinum. The correction of anemia leads to a significant reduction in transfusion requirement. In solid tumors erythropoietin is commonly administered at the schedule of 150 U/Kg subcutaneously three times per week. Normal levels of current iron supply should be guaranteed by oral iron support during erythropoietin treatment. Because the response to erythropoietin occurs after a median time of 5 weeks, it is necessary to start erythropoietin therapy at an hemoglobin level higher that that triggering transfusion. Various parameters, at baseline or after 2-4 weeks of erythropoietin therapy, have been evaluated as predictors of response. However, other parameters should be studied to identify stronger predictors. CONCLUSIONS: Erythropoietin treatment is recommended after allogeneic BMT. Erythropoietin is effective in 60-80% of anemic patients receiving platinum-containing chemotherapy and in approximately 40% of patients receiving chemotherapy without platinum. The preventive use of erythropoietin is still under investigation. Further studies should identify subsets of patients and types of chemotherapy in which the prevention of anemia could be cost/effective.

Anemia↗
PubMedDate not supplied

Pre-operative chemoembolization of hepatocellular carcinoma in cirrhotic patients.

BACKGROUND/AIMS: The aim of the study was to evaluate clinical and pathological effects of transcatheter arterial chemoembolization (TACE) before surgical resection for hepatocellular carcinoma (HCC) in cirrhosis (55 patients); results were compared with a group of 45 patients undergoing surgical resection without TACE. METHODOLOGY: From March 1989 to December 1997, 55 cirrhotic patients, affected by surgically resectable HCC not larger than 5 cm with unifocal or bifocal tumor lesions, underwent TACE pre-operatively. RESULTS: Massive necrosis was observed in 26%, necrosis > 50% in 38% of lesions. Neoplastic cells were found in 47% of cases within the capsule or in the pericapsular tissue. Satellite nodules showed a low rate of necrosis. Mortality and morbidity in the pre-operative TACE group were 1.8% and 29%, respectively, and 4.4% and 33%, respectively, in the control group. One-, 3- and 5-year patient survival rates were 87%, 70% and 39%, respectively, versus 79%, 38% and 19%, respectively (p<0.02), in the control group. Disease-free survival was 40% and 28% at 3 years and 5 years with pre-operative TACE versus 20% and 11% (p<0.05). CONCLUSIONS: Pre-operative TACE can be performed with low morbidity. TACE can necrotize the main lesion and temporarily arrest portal diffusion of neoplastic cells by acting on microvascular infiltration. No evident effect on satellites and pericapsular neoplastic foci was observed. The long-term patients and disease-free survival rates were improved upon.

Aged↗