Biomedical subjects

R Caporale

Publications and source records attributed to R Caporale.

At least 19 recordsLinked to original sources

PubMed1998

Erythropoietin upregulates the expression of its own receptor in TF-1 cell line.

In the erythroleukemia cell line TF-1, recombinant human erythropoietin (rHEpo), but not c-kit ligand, enhanced the number of cells expressing the erythropoietin receptor (EpoR), as measured by flow-cytometric analysis of binding of the biotin-labeled Epo. Moreover, 125I-Epo binding and Scatchard analyses, indicated that TF-1 cells, maintained in standard conditions with IL-3, and those stimulated with c-kit ligand, bear a single class of EpoR. On the other hand, cells cultured in the presence of rHEpo had a higher number of receptors than IL-3 or c-kit ligand-stimulated cells, and had two binding sites with different affinities for the ligand. EpoR mRNA expression was higher in cells exposed to rHEpo than in IL-3 or c-kit-stimulated cells. This difference may have been dependent on either a higher level of transcription or an increased stability of mRNA. The observed changes of EpoR in rHEpo-stimulated TF-1 cell line could cooperate, together with the alteration of the gene (3' end deletion), in the occurrence of the erythroleukemic process. Changes induced in EpoR by rHEpo were not accompanied by an increase in the expression of glycophorin A or globin chain mRNAs. This may suggest that rHEpo is unable to induce erythroid differentiation in TF-1 cells. The results also indicate that this cell line could be a model for the investigation of the role of transcription factor(s) in the expression of EpoR, and for the study of the mechanism(s) underlying the changes in the number and affinity of the cell receptors.

Erythropoietin↗

PubMed1998

Coexpression of erythroid and megakaryocytic genes in acute erythroblastic (FAB M6) and megakaryoblastic (FAB M7) leukaemias.

There is evidence to suggest a close relationship between the erythroid and megakaryocytic lineages. Using RT-PCR, we evaluated the coexpression of erythroid and megakaryocytic genes in blasts from 25 acute myeloid leukaemia (AML) cases (FAB M1-M7) and three unclassifiable leukaemias with trilineage dysplasia (trilineal AML). All FAB M6 and M7 and trilineal leukaemias expressed mRNAs for alpha-globin, glycoprotein IIb (GpIIb), erythropoietin receptor (Epo-R) and thrombopoietin receptor (c-mpl), but not for myeloperoxidase (MPO) which in contrast was expressed in the other FAB-subtype leukaemias. These data support the hypothesis that blasts from M7 and M6 leukaemias may derive from (or represent) a common progenitor cell with resident bipotentiality towards the megakaryocytic and erythrocytic lineages.

Base Sequence↗

PubMed1998

[The prevalence and clinical characteristics of heart failure in a population sample of Calabria].

Two-hundred and fourteen patients with congestive heart failure were identified over a six-month period in the general practice of 29 GPs covering an adult population of 29,959 subjects residing in the region of Calabria, in southern Italy, with an overall prevalence of 7 per 1000. Males represented 52% of the cases and females 48%, with a median age of 75 years. On average, the condition was first diagnosed 41 months before the present examination. Patients generally had a high body mass index (28 kg/m2). Patients were classified as follows in the NYHA classification: 9.4% in class I, 45.3% in class II, 39.2% in class III, 6.1% in class IV. Hypertension, either alone or associated with ischemic heart disease (totally about 75% of cases), was the most common etiology, while COPD was the most commonly associated chronic condition. Clinical symptoms and signs were used to classify patients in a simplified version of the Boston score which was reported in 48% of cases as definite, 12% as possible, 6% as improbable and 34% as absent. A specific treatment was already ongoing in 97% of patients. The most commonly administered drugs were diuretics (83%), ACE-inhibitors (77%), and digitalis (67%). This three-drug combination (alone or with other drugs) covered 46% of patients. A comparison of four predefined typologies of treatment against the Boston score suggested that at least part of the outcome in classifying patients using this procedure was due to pathomorphosis of the syndrome induced by early pharmacological treatment.

Aged↗

PubMed1997

Severe hypoxia enhances the formation of erythroid bursts from human cord blood cells and the maintenance of BFU-E in vitro.

Incubation in severe hypoxia (1% oxygen) increased the number of erythroid bursts generated from full-term CD34+, or premature mononucleated, human cord blood (CB) cells, in semisolid cultures containing stem cell factor (SCF), interleukin (IL)-3 and erythropoietin (EPO). Severe hypoxia also enhanced the maintenance of erythroid burst-forming units (BFU-E) in CB cell liquid cultures. These positive effects of hypoxia on the maintenance and cloning efficiency of BFU-E did not extend to the other progenitors assayed. Hypoxia, on the other hand, markedly reduced the size and level of hemoglobinization of bursts and, in liquid cultures, suppressed the growth factor-stimulated numerical increase in BFU-E and inhibited the expression of CD36, a marker of erythroid colony-forming units and maturing erythroid precursors. However, when transferred to clonal assays incubated in air, cells from liquid cultures incubated in hypoxia or in air generated fully expanded and hemoglobinized bursts, suggesting that in hypoxia the clonogenic potential of BFU-E was maintained and the development of erythroid clones reversibly inhibited. These results indicate that hypoxia inversely regulates two subsequent phases of erythropoiesis, i.e., it enhances the maintenance of BFU-E and the early development of erythroid clones but inhibits the terminal expansion and maturation of these clones. The cloning of CB cells selected for CD34 positivity, when compared with that of the total population of mononucleated CB cells, revealed that the early development of erythroid bursts was either hypoxia-enhanced or hypoxia-insensitive, reflecting the existence of two different types of BFU-E. Hypoxia-enhanced BFU-E are relatively immature, are maintained in hypoxia but not in air, and account for a large part of CD34+ BFU-E and for a high percentage of the BFU-E in premature CB. Hypoxia-insensitive BFU-E are mostly CD34- and are largely predominant in full-term CB, and most probably correspond to a more mature type of BFU-E.

Antigens, CD↗

PubMed1997

[Long-term captopril therapy in asymptomatic patients with severe chronic aortic insufficiency].

BACKGROUND: Clinical history of patients with severe chronic aortic regurgitation is characterized by a long period without any symptom, although the left ventricle enlarges progressively. The administration of oral vasodilators could reduce ventricular enlargement or its progression, delaying the development of myocardial dysfunction and/or the need for valvular surgery. OBJECTIVES: To verify the efficacy of long-term captopril therapy to reduce left ventricular mass and dimensions in patients with severe chronic aortic regurgitation. METHODS: This is a prospective echocardiographic study in which each individual patient is considered his own control case. Eleven asymptomatic patients with severe chronic aortic regurgitation in sinus rhythm, who had an ejection fraction greater than 50% and were not taking cardiovascular drugs, were orally administered captopril at the maximum tolerated dosage (127 +/- 13 mg/day). Follow-up lasted for 24 +/- 3 months. RESULTS: Left ventricular telediastolic diameter decreased from 69 +/- 5 to 61 +/- 3 mm (p < 0.01), telesystolic diameter decreased from 48 +/- 5 to 41 +/- 4 mm (p < 0.01); ejection fraction increased from 56 +/- 4 to 61 +/- 3% (p < 0.001); myocardial mass decreased from 208 +/- 32 to 174 +/- 27 g/m2 (p < 0.01), and mean wall stress from 264 +/- 35 to 203 +/- 25 mmHg (p < 0.001). All variations were still significant at 6 months. CONCLUSIONS: These results suggest that captopril has a favourable effect on left ventricular mass, dimensions and load conditions, and could favourably influence the natural history of chronic aortic regurgitation. The efficacy of medical treatment can be verified through serial echocardiographic study.

Adult↗

PubMed1996

Medical treatment of end-stage heart failure.

Congestive heart failure is a lethal condition that affects an increasing number of patients. In recent years a great amount of data have accumulated on the pathophysiology and medical and surgical therapy of this condition. In spite of the advances in its management and the great number of patients affected, common errors are still made by internists and cardiologists in the use of drugs and therapeutic strategies. Digitalis has only recently been shown to affect hemodynamics, exercise capacity, and clinical symptoms, but the effects on survival still have to be demonstrated. Loop diuretics, eventually combined with thiazides and antialdosterone drugs in patients with clinical signs and symptoms of fluid retention, are the mainstays of therapy of congestive heart failure. In order to make diuretic therapy efficacious, moderate salt and water intake restriction is mandatory. Angiotensin-converting enzyme (ACE) inhibitors are now considered unavoidable drugs in the management of heart failure, and an attempt to reach the doses that have been shown to be efficacious for survival in the large trials has to be made in every patient with this condition. Other vasodilators, such as hydralazine and nitrates, which show a less pronounced effect on survival but more effective hemodynamic actions than ACE inhibitors, may be used to control mitral insufficiency or to improve hemodynamics in very sick patients. Hemodynamic instability refractory to increasing doses of vasodilators and diuretics is a severe condition that requires hospital admission to administer drugs parenterally. These patients are usually treated with the combination of catecholamines and phosphodiesterase inhibitors associated with intravenous diuretics until clinical stability is again achieved and oral therapy is resumed and restructured. The use of aggressive pharmacological therapy and phosphodiesterase inhibitors has reduced the need for assisted circulatory support in these patients. Beta-blockers have shown promising results when administered to patients with heart failure, although a definitive demonstration of their effects on survival is still lacking. Other additional measures that need to be considered in patients with end-stage congestive heart failure are the use of antiarrhythmic drugs and anticoagulation.

Adrenergic beta-Antagonists↗

PubMed1996

Defective aggregation in cirrhosis is independent of in vivo platelet activation.

BACKGROUND/AIMS: Platelet function abnormalities contribute to the hemostatic defect in patients with cirrhosis. In this study we evaluated the occurrence of in vivo platelet activation as a possible mechanism of defective platelet aggregation in patients with cirrhosis. METHODS: Nine patients with severe (Child B-C) cirrhosis and defective platelet aggregation were studied in comparison with age- and sex-matched healthy controls. The presence of activated platelets in the bloodstream was evaluated by fluorescence-activated flow cytometry using antibodies directed against activation-dependent platelet proteins and by measuring plasma levels of beta-thromboglobulin and platelet factor 4. Urinary levels of 11-dehydro-TXB2 and of 2,3-dinor-TXB2 were assayed by radioimmunoassay following chromatographic separation. RESULTS: In unstimulated platelets, the expression of both GMP 140 and GP 53 was not significantly different in patients with cirrhosis and in controls. After stimulation with ADP and epinephrine, expression of activation-dependent antigens was lower in platelets from patients (GMP 140: 0.64 +/- 0.09 vs 0.73 +/- 0.04, p = 0.02; GP 53: 0.41 +/- 0.13 vs 0.54 +/- 0.14). Plasma levels of beta-thromboglobulin and platelet factor 4, as indexes of in vivo platelet activation, were also comparable in the two groups of subjects. Urinary levels of 11-dehydro-TXB2 and of 2,3-dinor-TXB2, the major systemic metabolites of TXA2, were significantly higher in patients with cirrhosis (1807 +/- 518 vs 341 +/- 121 ng/pg creatinine and 693 +/- 512 vs 205 (93 ng/pg creatinine, respectively, p < 0.001). However, increased excretion of TXB2 metabolites was also observed in three patients with chronic autoimmune thrombocytopenia. CONCLUSIONS: These data indicate that circulating platelets are not activated in cirrhosis, and that defective aggregation is most likely dependent on the alteration of the transmembrane signaling pathways. The increased urinary excretion of systemic TXA2 metabolites may be related to increased intrasplenic platelet destruction.

Aged↗

PubMed1996

Megakaryocyte-like increase in ploidy of Friend's erythroleukemia cells induced to endoreplication by colcemid.

Previous work from this laboratory has shown that Friend's murine erythroleukemia cells (MELCs) express some bio-chemical traits of the megakaryocytic lineage. The supposed mixed erythroid/megakaryocytic nature of these cells has been investigated further by challenging MELCs with the antimicrotubule agent colcemid. This compound, at the concentration of 40 nM, was found to induce a striking arrest of cell growth without significant effects on viability. At the same time, the bulk of treated MELCs underwent a large increase in size to contain, after 3 days, as much as 4 times more proteins and 5 times more DNA than controls. As shown by high rates of 3H-thymidine incorporation, increase in DNA content was the result of active synthesis without completion of intervening mitosis according to a process that closely resembled endoreplication. Eventually, colcemidinduced MELCs presented multilobed nuclei and were arranged into discrete ploidy groups containing up to 16 N levels of DNA. Moreover, upon colcemid addition, MELCs initiated a polyploid response that was shown to continue, even in the absence of the inducer, to yield cells that became strongly positive for acetylcholinesterase (AChE) in the late stages of culture. These effects were compatible with a colcemid-induced commitment of MELCs to megakaryocyte differentiation, for which these cells seemed to be definitely programmed. The expression of megakaryocyte features in MELCs provided further evidence for the bipotentiality (erythroid/megakaryocytic) of this model.

Animals↗

PubMed1995

Identification and conditions for selective expression of megakaryocytic markers in Friend erythroleukemia cells.

Friend murine erythroleukemia cells (MELCs) have been reevaluated in terms of their nature and potential pathways of differentiation. MELC induced with 5 mmol/L hexamethylene bisacetamide (HMBA), in addition to expression of known markers of the erythroid phenotype, were also found to exhibit traits of the megakaryocytic lineage. Erythroid differentiation was shown by the typical synthesis and accumulation of hemoglobin (Hb); megakaryoblastoid differentiation of MELCs upon induction was shown by increased specific activity of acetylcholinesterase (AChE). Incubation of MELCs with 5 mmol/L HMBA in RPMI supplemented with 1% fetal calf serum (FCS) (instead of the usual 5%), induced cells to selectively express high levels of AChE (up to approximately 170 mU/mg protein) with little activation of Hb synthesis (less than 5% B+ cells). The increase in AChE levels was a general phenomenon affecting the whole cell population and approached its maximum within 3 days of incubation with the inducer. Subsequently, MELCs become committed to terminal division, undergoing growth arrest and expression of the megakaryocytic phenotype even after the removal of HMBA. There were no appreciable changes of basal AChE levels in MELCs that were either made resistant to HMBA or treated with 0.1 mmol/L hemin that activated differentiated erythroid function without commitment. Phorbol 12-myristate 13-acetate (PMA), known to repress induced Hb synthesis in these cells, did not prevent the full increase in AChE when incubated with MELCs 2 days before HMBA addition. HMBA-induced MELCs always underwent AChE increase that was more or less pronounced depending on the low or high serum content in culture, respectively. Conversely, Hb expression was permitted only when MELCs were transferred in the late phase or at the end of commitment from low to high serum media. Variations of FCS content in culture media proved to be a simple and reliable approach to change the MELC response to inducers and to modulate expression of either megakaryocytic or mixed erythromegakaryocytic phenotype. These findings suggested that MELC might be considered, at least, as a bipotential model of differentiation to be used for studies on regulation of either megakaryocytic or erythroid markers and on competition between the two hematopoietic lineages. In this regard, it was intriguing that AChE levels attained under selective induction (low serum) were always higher than under conditions allowing coexpression of both AChE and Hb (high serum). Moreover, MELCs were also found to bind the specific rat-antimouse platelet monoclonal antibody 4A5.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetamides↗

PubMed1995

Natural fluorescence of white blood cells: spectroscopic and imaging study.

Autofluorescence has been proved to be an intrinsic parameter of biological substrates that may aid in both the characterization of the physiological state and the discrimination of pathological from normal conditions of cells, tissues and organs. In this work, the fluorescence properties of human white blood cells have been studied in suspension and on single cells at microscopy. The results indicate that suspensions of agranulocytes and granulocytes differ in the amplitude of the fluorescence signal on excitation at wavelengths in the range 250-370 nm. The differences are particularly enhanced when excitation is performed in the 250-265 nm range. Microspectrofluorometric analysis, performed on single cells, allows several leukocyte families to be characterized. Lymphocytes, monocytes, neutrophils and eosinophils can be distinguished according to the intensity and spectral shape of the autofluorescence emission in the visible range from 440 to 580 nm. Both the nature and extent of the differences change when the excitation wavelength is moved from 366 to 436 nm. Differences in the intrinsic metabolic engagement, rather than in the cell dimensions, seem to be responsible for the differences observed between the leukocyte populations. The results identify interesting perspectives for autofluorescence as a discriminating parameter in the differential counting of human white blood cells.

Fluorescence↗

PubMed1995

Attenuated-dose idarubicin in acute myeloid leukaemia of the elderly: pharmacokinetic study and clinical results.

AML in the elderly is characterized by intrinsic biological features implying an enhanced chemoresistance. Intensive chemotherapy should be the treatment of choice, but the standard doses could induce unacceptable rates of aplastic deaths. We evaluated the efficacy of an induction protocol with attenuated-dose idarubicin (IDA) 8 mg/m2 for 3 d plus cytarabine and etoposide in 26 AML patients aged > 60. 18 patients (69%) achieved CR, five (19%) were non-responders and three (12%) died during induction. To compare the pharmacokinetics of IDA between elderly and young patients, we assayed daily the serum level of the drug and of its metabolite (idarubicinol, IDAol) in a group of eight elderly patients who received a dose of 8 mg/m2 (group A) and in a group of nine younger AML patients treated with 12 mg/m2 (group B). The apparent terminal half-life of IDAol was significantly longer in the elderly than in the younger patients (mean half-life 59.7 h versus 41.4 h, P < 0.05). The values of the area under the serum concentration curve of IDAol indicated that the two patient groups received a very similar exposure to the drug despite the different doses. In conclusion, this protocol, based on attenuated doses of IDA, compares well with the results obtained previously in similar age-matched patient series.

Adult↗

PubMed1995

Low-dose cytosine arabinoside in patients with acute myeloid leukemia not eligible for standard chemotherapy.

The results of treatment with low dose cytosine arabinoside (LDARA-C) in 131 AML patients ineligible for standard regimens were analyzed retrospectively. Eighty-seven were previously untreated, 25 were refractory to conventional chemotherapy and 19 were relapsed patients. The median age was 66 years (15-84). An antecedent hematological disorder (AHD) was documented in half of the patients. Overall, 22 (17%) achieved complete remission, 14 (11%) partial remission, 77 (59%) had resistant leukemia and 18 died during induction. Median disease free survival was 57 weeks and median survival, for the 87 previously untreated patients, was 22.5 weeks. The prognostic value of initial parameters was analyzed for response. Bone marrow cellularity was the only significant factor. We observed 33% vs 81% (p < 0.01) of responses in patients with normo-hypercellular and hypocellular marrow, respectively. Accordingly, there was a trend to more responses in patients with leukocyte counts of less than 10 x 10(9)/L. M4-M5 FAB subtypes were frequently resistant to LDARA-C, resulting in a lower response rate compared to M0-M2 (18% vs 32%). Other parameters, including age, sex, hemoglobin, platelet count, AHD and fever at diagnosis, had no prognostic value. Our findings suggest that LDARA-C may be an effective treatment for some patients who are not eligible for first line conventional chemotherapy. However, this schedule is not advised in patients with monocytic leukemia or those with an hypercellular marrow.

Acute Disease↗

PubMed1993

[Restrictive cardiomyopathies].

The restrictive cardiomyopathies are the least common of the 3 major categories of cardiomyopathic disorders seen in Western countries. According to the report of the WHO/ISFC Task Force the term restrictive cardiomyopathy applies to only 2 conditions: endomyocardial fibrosis and Loeffler endocarditis while many specific myocardial diseases can develop a restrictive pathophysiologic profile along their natural history. During the last decade this topic has received 2 main contributions: the identification of a common pathophysiologic ground linking Loeffler endocarditis and endomyocardial fibrosis and the identification of the so-called idiopathic restrictive cardiomyopathy. This condition, defined as a myocardial disease with restrictive physiology, unknown etiology and without histological evidence of infiltrative or storage diseases, appears to be the single most frequent type of restrictive cardiomyopathy in Western countries. A revision of the current classification of cardiomyopathies and particularly of restrictive myocardial disease is necessary.

Cardiomyopathy, Restrictive↗

PubMed1993

Mixed acute leukemia with genotypic lineage switch: a case report.

Morphologically well classifiable leukemias can reveal a mixed phenotype. A case of acute myeloid leukemia (CD13, CD33, CD14, CD11b) which at presentation showed a co-expression of B-lymphoid markers (CD19, CD10, CD20), at the time of the first relapse revealed a morphologic, phenotypic and genotypic switch of the blasts to a purely lymphoid form. Analysis of the immunoglobulin (Ig) H chain locus and of the T-cell receptor (TCR) genes showed at diagnosis a germline configuration of the IgH, TCR beta and tau genes, and a deletion of the TCR delta gene at the second chromosome. At relapse, monoclonal rearrangements of the IgH, TCR tau, and TCR delta were detected. At a subsequent relapse, the blasts re-expressed myeloid morphologic features and myeloid-associated antigens, while they retained the same rearranged configuration of the IgH and TCR beta and delta genes. The TCR delta gene configuration, which links each phase of the disease, may represent an early pathogenetic event and makes the emergence of a second malignancy unlikely. Each phenotypic change occurred after anti-myeloid and anti-lymphoid oriented chemotherapy. The close correlation between the progressive acquisition of different phenotypes and the switch at the genomic level represent the peculiar features of this unusual case.

Adult↗

PubMed1993

[Aortic dissection without intimal laceration: a case report and review of the problem].

A 43-year-old hypertensive woman with symptoms of aortic dissection was referred to our hospital 3 days after the initial episode. Transesophageal echocardiography and magnetic resonance showed a large intramural hematoma of the ascending and descending aorta without intimal flap and tears. Aortography confirmed the absence of intimal disruption. Medical therapy with beta and alpha blocking agents was established. After 5 months the patient was asymptomatic. On transesophageal echocardiogram and magnetic resonance, complete reabsorption of the hematoma of descending aorta was evident while a clearly identifiable false lumen and intimal flap (without tear) were present at the aortic arch level. The diagnostic criteria and therapeutic options are discussed and the literature on this topic is reviewed.

Adult↗

PubMed1992

Continuous-infusion cyclophosphamide in combination with teniposide and dexamethasone in refractory myeloma.

Forty-three consecutive patients with refractory myeloma, median age 60, received monthly courses of teniposide 30 mg/m2 i.v. on days 1-2, dexamethasone 40 mg i.v. on days 1-7 and cyclophosphamide 200 mg/m2 by continuous i.v. infusion for seven days. Major response (decrease > 50% of M-protein) was achieved in 18 of 37 evaluable patients and minor response in 9, with an overall response rate of 73%. Response was irrespective of disease status, time from diagnosis and previous treatments, while beta 2 microglobulin > 6 mg/l was a powerful prognostic factor. All patients experienced transient granulocytopenia but extramedullary toxicity was negligible. Median survival of the whole group is 20 months, with 74% of responding patients projected to be alive at 30 months. In refractory myeloma cyclophosphamide appears to be more active when given by continuous infusion.

Adult↗

PubMed1989

[Stroop's color-word test as a mental stressor in the functional evaluation of recent myocardial infarction: comparison with arithmetic calculation].

To assess the power of Stroop's color-word test to induce cardiovascular arousal in cardiac patients, 10 postinfarct patients underwent Stroop's test, as well as the mental arithmetic test, which was assumed to be the gold standard. Both stressors induced significant increases in heart rate and blood pressure; the differences between these increases were not statistically significant. Stroop's test is a useful alternative to the mental arithmetic test in the study of cardiovascular responses to mental stress.

Adult↗

PubMed1989

[The association of arithmetic calculation and noise as a mental stressor in the functional evaluation of recent myocardial infarction].

To evaluate the possible augmented power of mental arithmetic when given to the subjects during noise, 12 postinfarct patients underwent mental arithmetic in the standard way and then the same stressor with a white noise: mental arithmetic significantly increased (p less than 0.05) the heart rate, while mental arithmetic and white noise significantly increased (p less than 0.05) heart rate, systolic and mean blood pressure, as well as skin conductance. Nevertheless, the increments in heart rate, blood pressure and skin conductance induced by the two different ways of stressing did not significantly differ. Thus, adding white noise to mental arithmetic does not seem to be useful to increase the power of mental arithmetic in order to elicit cardiovascular responses.

Blood Pressure↗