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Biomedical subjects

G Cavalli

Publications and source records attributed to G Cavalli.

At least 55 records · Page 3Linked to original sources
PubMed1992

Cerebrospinal fluid beta 2-microglobulin in AIDS related central nervous system involvement.

We measured cerebrospinal fluid (CSF) and serum beta 2-microglobulin (beta 2-M) in Acquired Immunodeficiency Syndrome (AIDS) patients with or without clinical evidence of central nervous system (CNS) involvement. The CSF beta 2-M level was significantly higher than the serum level in AIDS patients with neurological symptoms, but not in AIDS without neurological symptoms, suggesting an increased shedding of this protein in CSF, as a result of rapid cellular turnover within CNS. CSF beta 2-M level increases both in Human Immunodeficiency Virus type 1 (HIV-1) related and in opportunistic CNS syndromes, confirming that beta 2-M is a non specific marker of CNS involvement in AIDS. Nevertheless, the highest CSF beta 2-M values were observed in patients with severe dementia and autoptic diagnosis of multifocal giant cells encephalitis (MGCE) without other opportunistic diseases. This observation could have important implications for monitoring AIDS dementia complex in AIDS patients. Finally, 5 out of 7 (71%) AIDS patients with cryptococcal meningitis showed a decline in CSF beta 2-M level well related to the decrease of cryptococcal antigen (Crypto-Ag) titres and the clinical remission. This data suggests that CSF beta 2-M determination could be used as a useful test in monitoring efficacy of therapy of CNS pathologies in AIDS patients.

AIDS Dementia Complex↗
PubMed1991

Maternal predictors of HIV vertical transmission.

We performed a retrospective study of 57 HIV-positive pregnant women and their children to look for maternal parameters related to rates of vertical transmission of HIV. Sixteen (28%) infants were HIV-infected. There was no positive correlation between maternal risk factors for HIV and vertical transmission of HIV. Multiparity seemed to be related to a higher prevalence of vertical transmission, whereas neither preterm delivery nor cesarean section resulted in different rates of vertical transmission, although they tended to have some protective effect. Maternal beta 2-microglobulin and serum neopterin levels were not related to different rates of vertical transmission of HIV. CD4+ cell counts did so only when cut-off values of 400/mm3 were taken. All the women in CDC group IV and all the HIV p24 antigen-positive transmitted the infection to their infants, whereas only 7/48 women in CDC groups II and III (P = 0.000006) and 9/48 HIV p24 antigen negative women (P = 0.00006) gave birth to infected infants. No other maternal characteristics were associated with different rates of vertical transmission in a multivariate analysis restricted to women in CDC groups II and III and with HIV p24 antigen negativity.

Adult↗
PubMed1991

Identification of the peroxidation product hydroxystearic acid in Lewis lung carcinoma cells.

Whole cell lipids were extracted from the Lewis lung carcinoma in vitro line C108. The fatty acids were derivatized to methylesters in order to identify endogenous oxidized derivatives by gasmass spectroscopy. The presence of 9-hydroxystearic acid and 10-hydroxystearic acid was thus evidenced for the first time in cultured mammalian cells. Moreover a linear correlation was found between the concentration of these products expressed as percentage of total fatty acid methylesters and the cell density in tissue culture flasks. This finding suggests an involvement of hydroxystearic acid in cellular functions related to the cell density in monolayer cultures.

Animals↗
PubMed1991

Induction of differentiation in human HL-60 cells by 4-hydroxynonenal, a product of lipid peroxidation.

4-Hydroxynonenal (HNE) is the major diffusible toxic product generated by lipid peroxidation of cellular membranes. The level of lipid peroxidation and, consequently, the concentration of its products are inversely related to the rate of cell proliferation and directly related to the level of cell differentiation. In the present paper the effects of HNE on the proliferation and differentiation of the HL-60 human promyelocytic cell line have been investigated. Repeated treatment at 45-min intervals with HNE (1 microM) was performed to maintain the cells in the presence of the aldehyde for 7 1/2 or 9 h. The effect of HNE on cell proliferation and differentiation was compared with dimethyl sulfoxide (DMSO)-treated cells. HNE causes a strong inhibition of cell growth without affecting cell viability. Moreover, HL-60 cells acquire the capability to produce chemiluminescence after soluble (phorbol myristate acetate) or corpuscolate (zymosan) stimulation. The phagocytic ability has also been calculated by counting the number of cells that phagocytize opsonized zymosan. Values were 43 and 55% after 10 or 12 HNE treatments, respectively, and 88% in DMSO-treated cells. Myeloperoxidase activity, 5 days after treatment, decreased by 85% in either HNE- or DMSO-treated cells while acid phosphatase activity increased with respect to untreated cells. Results obtained indicate that HNE at concentrations close to those found in the normal tissues can induce inhibition of proliferation and induction of differentiation in the HL-60 cell line.

Aldehydes↗
PubMed1991

[Pseudonecrosis waves: simulation of myocardial necrosis by retrograde P wave].

The Authors describe a case of a patient showing, during an episode of chest pain, an ecg-pattern of wide and tall "Q" wave simulating inferior myocardial infarction. In fact, a further ecg recorded during sinus rhythm denotes that the "Q" wave was a retrograde P wave generated by a nodal rhythm. The other known causes of "pseudonecrosis" are discussed.

Aged↗
PubMed1991

[Evaluation of the kinetics of MB creatine kinase in patients undergoing systemic thrombolytic therapy].

This study was aimed to evaluate if the time-course of creatinkinase MB in acute myocardial infarction (AMI) is influenced by therapy and which index, derived from the enzymatic curve, is the most reliable marker of successful coronary artery recanalization. We studied the enzymatic curves in 38 patients with transmural myocardial infarction, 19 treated with streptokinase (SK) and 19 with tissue plasminogen activator (rtPA). Blood samples were obtained every 2 hours for the first 12 hours and every 6 hours until the level of serum CK returned to baseline. Three indexes were calculated: peak serum enzyme level, time to peak enzyme level and maximal enzyme rise velocity. Time to peak did not differ significantly between SK and rtPA groups. Peak levels were significantly higher (414 +/- 40 vs 249 +/- 33; p = 0.004) in rtPA groups, as well as maximal enzyme rise velocity (1.7 +/- 0.4 vs 0.8 +/- 0.1; p = 0.02). However, infarct size evaluated by the total release of CK-MB in 28 patients was greater in rtPA group (10949 +/- 1097 vs 6346 +/- 869; p = 0.002). These findings suggest that differences in peak level and in maximal velocity of rise observed between SK and rtPA are due to differences in infarct size and not to a different recanalization rate. Thus, enzymatic estimate of infarct size significantly correlates to peak enzyme (r = 0.894, p less than 0.001), and to maximal rise velocity (r = 0.518, p = 0.007) but not to time to peak (r = 0.208, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Creatine Kinase↗
PubMed1991

Effect and pharmacokinetics of netilmicin given as bolus intramuscular administration: an open comparative trial versus amikacin and fosfomycin in elderly patients affected by urinary tract infections.

A randomized comparative open clinical trial was performed on 96 hospitalized patients of both sexes, most of whom (84.4%) over 60 years of age, affected by simple and complicated urinary tract infections. Patients were divided in three unequal sized groups and treated with a single administration of netilmicin (5 mg/kg intramuscularly), of amikacin (15 mg/kg i.m.) or of fosfomycin (3 g per os). Patients were evaluated clinically and microbiologically before the beginning of the therapy, 1, 7, 15, 30 days thereafter and at monthly intervals, up to the 18th month, after the drug administration. The pharmacokinetic study was performed in six elderly patients of both sexes, apparently in good general health, except for their urinary tract infections. Symptoms of urinary tract infection disappeared in 50 out of 53 (94.3%) patients treated with netilmicin 14.48 +/- 9.6 hours after the drug administration, in 22 out of 23 (95.6%) of those treated with amikacin after 31.9 +/- 14.3 hours and in 16 (84.2%) out of 19 of symptomatic patients treated with fosfomycin after 37.5 +/- 10.6 hours. The disappearance of symptoms in netilmicin-treated patients is significantly (p less than 0.01) faster than in the other two groups. Twenty-four hours after the administration, netilmicin and amikacin produced sterilization of the cultures in more than 95% of cases, fosfomycin in 90%. Of those patients in which sterilization of cultures was achieved about 70%, in the netilmicin group, and 50% in the other two treatment groups had sterile urine cultures after one month. At the end of the study, 18 months later, more than 60% of the patients treated with netilmicin, the infection had not recurred in comparison with 39.1% and 50% in the amikacin and fosfomycin groups respectively. If only the patients with uncomplicated infections were considered, 88.9% and 83.3% had sterile cultures after 1 and 18 months respectively in the netilmicin group. The corresponding figures in other two groups were: 66.7% for both time intervals in the case of amikacin and 60% both for 1 and 18 months in the case of fosfomycin. The pharmacokinetic results indicate that netilmicin is rapidly absorbed and distributed from the injection site, possesses a beta half-life of about two hours and is mainly excreted by the kidneys. The single dose administration produces very high urinary concentrations of the drug in the first 24 hours and concentrations above 4 micrograms/ml, the 90% minimum inhibitory concentration cut-off point for netilmicin sensitive strains, for four days(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed1991

Immune material processing by phagocyte cell system in cryoglobulinemia.

An impaired function of splenic macrophages, measured as the clearance rate of erythrocytes coated with IgG (E-IgG), was observed in 7 out of 8 cryoglobulinemic patients with severe urinary abnormalities and systemic symptoms, and in 0 out of 6 patients without urinary symptoms and only mild systemic signs of disease. The E-IgG clearance rate was not related to HLA or Rh phenotype, patients' age or disease duration. Moreover, longitudinal studies showed this parameter to be strictly related to disease activity. To investigate the nature of the defect, five series of analyses were planned using peripheral blood phagocytes (PBP) from 8 patients: a) detection of cell-bound immune material by using the antibody CE59 directed to the Fc fragment of IgG modified by the antibody-antigen reaction; b) cytofluorometric and/or radiometric analyses of the cell surface expression of HLA II, CR1 and FcR structures by means of specific monoclonal antibodies (MoAbs); c) electron microscopy (EM) examination of diverse combinations of cryoglobulins incubated with PBP from patients and normals; d) analysis of cryoglobulin-induced inhibition of E-IgG phagocytosis; e) measurement of the generation of chemiluminescence (CL) in response to Zymosan, Phorbol Myristate Acetate and n-Formyl-Methyonine-Leucine-Phenilalanine (n-FMLP). Patients' PBP were found to have a higher amount of cell-bound immune material as compared to normals (p less than 0.01). CR1 and FcR expression was not different from controls, whereas a slight increase in percentage of monocytes bearing HLA II structures was found in patients (p less than 0.05). Upon EM examination no obvious differences were found in the internalization capacity of cryoglobulins between patients and controls. The CL production was lower than normal (p less than 0.02), whatever stimulus used, with a maximal impairment for n-FLMP (p less than 0.005), the most specific test probe for cytoskeleton integrity. Finally, a remarkable cryoglobulin-induced inhibition of E-IgG phagocytosis was shown. A combination of saturation mechanisms and intracellular abnormalities could underlie the apparent discrepancy between E-IgG clearance defect and preserved potential of cryoglobulin internalization in cryoglobulinemia.

Adult↗
PubMed1990

Influence of 4-hydroxynonenal on chemiluminescence production by unstimulated and opsonized zymosan-stimulated human neutrophils.

The lipid peroxidation product 4-hydroxy-2, 3-trans-nonenal (HNE) has a spectrum of biological effects on different cell types depending on the concentrations tested. In particular micromolar HNE concentrations stimulate neutrophil migration and polarization whereas higher doses inhibit. In our experimental conditions, fMet-Leu-Phe (fMLP) increased CL production of both unstimulated and zymosan-stimulated neutrophils, whereas cell stimulation with low HNE concentrations as well as zymosan addition to HNE incubated cells did not enhance light emission. In contrast 10(-4) M HNE reduced CL emission by unstimulated cells nearly to background values, completely depressed CL production by zymosan-stimulated cells and reduced phagocytosis. Cysteine was found to be able to counteract the HNE effect by about 70 per cent. The possibility that this aldehyde could exert its inhibitory effect through the alkylation of NADPH-oxidase SH-groups is postulated. Moreover, our present data on differences observed between fMLP and HNE indicate a different chemotactic mechanism induced by these two classes of compounds and lead to the conclusion that the local functional features of the attracted cells may be different.

Aldehydes↗
PubMed1990

Changes in neutrophil oxidative potential in patients undergoing cardiopulmonary bypass with polypropylene hollow fiber oxygenators.

Neutrophil oxidative metabolism, C3d and beta 2 microglobulin levels, were assessed in nine consecutive patients undergoing cardiopulmonary bypass surgery with polypropylene hollow fiber oxygenators for open cardiac operations. Generation of oxygen free radicals by neutrophils was measured as luminol-enhanced chemiluminescence after stimulation with opsonized Zymosan and phorbol myristate acetate. A significant increase in light emission was detected by using both of the chemiluminescence stimulators. Moreover, a remarkable and significant increase in C3d levels was found already at 10 min. Conversely minimal changes in levels of beta 2 microglobulin were detected during cardiopulmonary bypass surgery. These data suggest that the impact of the patient blood with the foreign surface of cardiopulmonary bypass results in activation of phagocyte cells with increased potential in oxygen consumption. These effects could be partially complement-mediated.

Cardiopulmonary Bypass↗
PubMed1990

Wheat protein antigens and effector cells of aspecific immunity.

The effects of gliadin and glyc-gli on leukocyte chemiluminescence response, cytotoxic activity and locomotion were assessed in vitro. A dose-dependent increase in chemiluminescence response of neutrophils stimulated by Zymosan was observed by using gliadin at concentrations ranging between 1 and 20 micrograms. By increasing glyc-gli concentrations, a bimodal response was observed with an enhancement up to 50 micrograms/ml, followed by dose-dependent suppressive effects. The cytotoxic activity of a suspension of peripheral blood mononuclear cells on the human myeloid line K562 was assessed in a Chromium release assay. By pretreating effector cells with optimal doses of gliadin (5 micrograms/ml) or glyc-gli (50 micrograms/ml), an enhancement of cytotoxic activity, similar to that of the gamma-Interferon, could be achieved. Finally glyc-gli was found to elicit neutrophil chemokinesis. The possible implications of these findings in diseases characterized by gluten intolerance are discussed.

Adult↗
PubMed1989

Functional changes of monocytes due to dialysis membranes.

The functional effects directly induced by dialysis membranes on peripheral monocytes were analyzed in a plasma-free model of simulated dialysis using Cuprophan, cuprammonium rayon, polyacrylonitrile, polymethylmetacrilate and polysulphone membranes. A severe reduction of monocyte phagocytosis of IgG-coated erythrocytes was found by using Cuprophan and cuproammonium rayon. The cytofluorimetric analysis of several cell surface receptors, involved in the immune phagocytosis and recognizable by five quoted monoclonal antibodies, did not reveal any significant change. The defective phagocytosis of the IgG-coated erythrocytes by monocytes, due to the exposure to cellulose-derived membranes, was paralleled by an impaired interiorization of heat-aggregated human immunoglobulins, as analyzed by electron microscopy. The cell membrane binding of aggregated immunoglobulins was found to be unaffected. The defect was associated to a remarkably depressed generation of reactive oxygen species after Zymosan stimulation. Therefore, the defective immune phagocytosis induced by exposure of monocytes to cellulosic membranes was not due to a receptor rearrangement or an impaired binding of ingestible particles, but to a reduced internalization capacity probably related to an energy source exhaustion (as shown by the lack of response to stimuli able to induce oxidizing species production). These features are similar to those described in monocytes from acute systemic lupus erythematosus patients.

Cell Survival↗
PubMed1989

Phenotypic and functional analysis of circulating phagocytic cells in IgA nephropathy patients.

We analysed the possible mechanisms responsible for the functional abnormalities reported on phagocyte cell function in IgA nephropathy patients. The oxidative metabolism by the superoxide anion ferricytochrome C reduction test on monocytes and the chemiluminescence response on neutrophils was examined in 32 patients. Moreover the expression of cell membrane structures involved in immune response and phagocytosis (i.e. Fc receptors and HLA class II antigens) was evaluated cytofluorimetrically using specific monoclonal antibodies. Our own results did not show striking differences in oxidative potential and phenotype of patients' phagocyte cells as compared with healthy controls. However a HLA class II-associated structure was found to be quantitatively more expressed in patients' monocytes than in normal controls (P less than 0.005). These findings suggest that the defective phagocyte system function reported in IgA nephropathy patients is not simply due to a loss of cell surface receptors, nor to abnormalities in intracellular metabolic pathways implying oxygen consumption. The increase in expression of some HLA class II structures, often associated with the presence of circulating IgA immune complexes, probably reflects a protracted immunological stimulation.

Adolescent↗
PubMed1989

[Correlation between the sites of mitral annular calcification and conduction disturbances: echocardiographic evaluation].

A clinical, electrocardiographic and echocardiographic (M-Mode, 2D) study was performed to explain the causal relationship between mitral annular calcification and cardiac conduction disturbances. Forty-seven patients, 28 women and 19 men (mean age 69) with mitral annular calcification were studied. In 18 patients A-V and/or intraventricular conduction disturbances were present. In this study we have found: a greater incidence of posterior than anterior mitral annular calcification; the anterior mitral annular calcification is often associated with aortic valve calcification and ultimately the common association between anterior mitral annular calcification and conduction disturbances.

Aged↗
PubMed1989

Omental autoimplantation of splenic tissue and intravenous pneumococcal challenge. A comparative study in rats.

Splenectomized subjects show a higher incidence of myocardial ischemia and of Overwhelming Post-Splenectomy Infection (OPSI). It is doubtful that implanted splenic tissue guarantees an adequate protection from OPSI. The histological characteristics and the capacity of protection from OPSI of two models of omental autoimplantation of splenic tissue in rats were examined. The implanted splenic tissue offers a significant protection from pneumococcal sepsis, even though there is no relation between implant architecture and survival rate.

Animals↗
PubMed1989

[Treatment of recent atrial fibrillation with intravenous propafenone].

Intravenous propafenone (1 mg/Kg in 3 min) has been administered to 14 patients with recent atrial fibrillation. The sinus rhythm was restored in 7 patients within 30 min after the injection. The left atrial size, evaluated by M-mode echocardiography, was no different in the group of responders, with respect to the non-responders. No adverse effect has been observed. One single patient manifested a long asystolic pause (3860 ms), at the restoration of sinus rhythm. Propafenone appears to be useful in the treatment of recent atrial fibrillation.

Atrial Fibrillation↗