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Biomedical subjects

F Castelli

Publications and source records attributed to F Castelli.

At least 109 records · Page 6Linked to original sources
PubMed1985

Toxoplasma gondii: in vivo and in vitro immunological and ultrastructural patterns of a human low virulent strain.

The AA. analyze the ultrastructural and immunological patterns of a low virulent strain of T. gondii cultured in vitro on A-9 cells line (PV-H1C-83). The tissue culture method described here is highly recommended to study the immunological aspects of experimental toxoplasmosis. Biological tests' results and the time courses of serological tests are also similar to those obtained from mice infected with cerebral tissue containing cysts. The low virulent strain (PV-H1C-83), when cultured in vitro, is able to induce the formation of large parasitophorous vacuoles, in which the EM investigation shows a typical cyst wall enveloping numerous bradyzoites.

Animals↗
PubMed1984

An improved method for increasing the sensitivity of direct agglutination test (D.A.T.) to the detection of IgM and IgG anti-toxoplasma antibodies.

The present investigation has shown that the antibody titers obtained by IgG-IFA correlate well with 2-ME-DA (correlation coefficient 0.927, p less than 0.001). These results are obtained when the antibody titers are expressed as IU/ml. Buffer without 2-ME and purification of IgM fractions by simple gel-filtration method seem to be necessary conditions for detecting IgM antibodies by DA test in adult patients. Therefore the DA with these micromodifications has a specificity and sensitivity similar to those of IgG and IgM-IFA tests and would be convenient for laboratories that perform large scale surveys during pregnancy.

Adult↗
PubMed1979

[Physical work capacity of the patient with myocardial infarction submitted to intensive rehabilitative training (author's transl)].

The Authors have examined two homogeneous groups of patients with myocardial infarction; one underwent (61 patient) to a rehabilitating training, the other underwent (42 patient) to a domiciliary physical program. Patients have been considered by means of bicycle ergometer test at 2, 4, 12 and 24 months from myocardial infarction. They have been taken into consideration clinical and Ecg factors and also, as an index of physical work capacity was considered the complete work developed, the VO2 max/Kg per min., the product B.P. x H. R. and the pulse O2. The average value of parameters have been statistically compared by means of the t of Student, analysis of variation x2, and the test of Kolmogorov-Smirnov; moreover the correlation with linear coefficient has been studied. Afterwards the many-varied discriminating analysis and the test F di Snedelor have been carried out just for the index of functionality. From the statistical analysis of the data considered it results an increase of the functional capacity and its maintenance long after in the group that underwent to the rehabilitating training. However, two years after, this increase of capacity did not result greater than that obtained, in the same period of time, by the group of patients who underwent to a domiciliary physical rehabilitating program. These considerations point out the necessity of keeping physical exercise indefinitely or at least of repeating it periodically. In that event they suggest the right time to programme further cycles of training.

Adult↗
PubMedDate not supplied

Efficacy of artesunate plus chloroquine for uncomplicated malaria in children in Sao Tome and Principe: a double-blind, randomized, controlled trial.

We conducted a double-blind, randomized, placebo-controlled trial in Sao Tome and Principe to investigate the safety, tolerability and efficacy of chloroquine (CQ) combined with artesunate (AS) over CQ monotherapy. Four hundred children, aged 6-59 months, with acute uncomplicated Plasmodium falciparum malaria were randomized to receive a standard dose of CQ (25 mg/kg bodyweight) over 3 d or CQ + AS (4 mg/kg bodyweight) daily for 3 d. Children were followed-up for 28 d. The combined treatment was well tolerated and there were no serious drug-related adverse events. By day 2 parasite clearance was significantly faster for children treated with CQ + AS compared with CQ alone (29/194 [14.9%] vs. 168/190 [88.4%] still parasitaemic, P< 0.0001). Day 14 parasitological failure rates were 153/191 (80.1%) for CQ alone compared with 32/193 (16.6%) in the CQ + AS group (odds ratio [OR] =20.2, 95% CI 11.7-35.4, P< 0.001). Corresponding clinical failure rates were 128/161 (67.0%) and 12/193 (6.2%) (OR = 30.6, 95% CI 15.3-62.7, P< 0.001). By day 28 the parasitological failure rates (new infections excluded) were 155/191 (81.1%) in the CQ group and 63/194 (32.4%) in the CQ + AS group (OR = 8.9, 95% CI 5.4-14.7, P< 0.001). Symptoms resolved faster in children who received AS. They were also less likely to be gametocytaemic after treatment. The combination treatment was well tolerated and considerably improved treatment efficacy. However, the current levels of CQ resistance preclude its use in Sao Tome where CQ should be abandoned as first-line drug. However, CQ + AS may be an option in areas where CQ resistance is lower.

Acute Disease↗
PubMedDate not supplied

A calorimetric study on diflunisal release from poly(lactide-co-glycolide) microspheres by monitoring the drug effect on dipalmitoylphosphatidylcholine liposomes: temperature and drug loading influence.

Diflunisal release from poly-Lactide-co-Glycolide (50:50, 34,000 MW) microspheres loaded with two different amounts of drug (2.5 +/- 0.5% and 10 +/- 0.5% w/w) was monitored by following the effects exerted by the drug on the thermotropic behavior of dipalmitoylphosphatidylcholine unilamellar vesicles at different temperatures. The effects of the drug released from the microspheres on the thermotropic behavior of lipid aqueous dispersion containing different molar ratios of drug was detected by differential scanning calorimetry and was compared with the effects exerted by the free Diflunisal. Diflunisal affects mainly the temperature (Tm) of the transition characteristic of phospholipid vesicles as model biomembrane, causing a shift toward lower values. This shift was modulated by the drug molar fraction with respect to the lipid concentration in the aqueous dispersion. Afterward, calorimetric measurements were performed on suspensions of blank liposomes added to weighed amounts of unloaded and differently Diflunisal-loaded microspheres as well as free powdered Diflunisal after incubation for increasing times at three different temperatures (25, 37, and 50 degrees C). The Tm shifts of the lipid bilayer, caused by the drug released from polymeric system as well as by the free drug during incubation periods, were compared with that caused by free drug increasing molar fractions dispersed directly on the membrane, employed as a calibration curve to obtain the fraction of drug released. This in vitro study suggests that the kinetic process involved in drug release is influenced by the amount of drug loaded in the microspheres as well as by the temperature acting on drug solubility and membrane disorder. This drug release model, monitored by the calorimetric technique shows that a) the poly-Lactide-co-Glycolide microspheres are a good delivery system able to sustain the drug release; b) the differential scanning calorimetry technique applied on the drug interaction with biomembranes constitutes a good tool to follow the drug release; 3) this model, representing an innovative alternative in vitro model, should be used to determine the different kinetics involved in the drug transfer from a drug delivery system to a membrane as uptake site.

1,2-Dipalmitoylphosphatidylcholine↗
PubMedDate not supplied

Effect of pH on diclofenac release from Eudragit RS100 microparticles. A kinetic study by DSC.

The present work is aimed at investigating the release of Diclofenac (DCF) from Eudragit RS100 (RS) microparticles to a biological model membrane consisting of dimyristoylphosphatidylcholine (DMPC) multilamellar vesicles (MLV). The microparticles were prepared by the Quasi-Emulsion Solvent Diffusion method (QESD). The drug release was monitored by Differential Scanning Calorimetry (DSC) technique, following the effects exerted by DCF on the thermotropic behaviour of DMPC multilamellar vesicles at different temperatures. DCF affects the transition temperature (Tm) of phospholipid vesicles, causing a shift towards lower values, which is modulated by the drug fraction entering into the lipid bilayer. Calorimetric measurements were performed at two different pH (4.0 and 7.4) on suspensions of blank liposomes added to weighed amounts of unloaded and DCF-loaded microspheres, as well as to the powdered free drug, after incubation at 37 degrees C. The Tm shifts, caused by the drug released from the polymeric system or by the free drug during incubation cycles, were compared to those caused by a chosen molar fractions of the free drug dispersed directly in the membrane. This in vitro study suggests as the kinetic process involved in drug release is influenced by the amount of drug loaded in the microspheres as well as by the pH value, acting on drug solubility and membrane disorder.

Acrylic Resins↗
PubMedDate not supplied

Evaluation of the interaction and drug release from alpha,beta-polyaspartamide derivatives to a biomembrane model.

This article reports on a comparative study on the ability of various polymers, containing hydrophilic and/or hydrophobic groups, to interact with a biomembrane model using the differential scanning calorimetry (DSC) technique. Multilamellar vesicles of mixed dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidic acid (DMPA) were chosen as a model of cell membranes. The investigated samples were a water soluble polymer, the alpha,beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) and its derivatives partially functionalized with polyethylene glycol (PEG2000) to obtain PHEA-PEG2000, with hexadecylamine (C16) to obtain PHEA-C16, and with both compounds to obtain PHEA-PEG2000-C16. These polymers are potential candidates to prepare drug delivery systems. In particular, some samples give rise to polymeric micelles able to entrap hydrophobic drugs in an aqueous medium. The migration of drug molecules from these micelles to DMPC/DMPA vesicles also has been evaluated by DSC analysis, by using ketoprofen as a model drug.

Amines↗
PubMedDate not supplied

Antiviral potency of HAART regimens and clinical success are not strictly coupled in real life conditions: evidence from the MASTER-1 study.

PURPOSE: To compare in a real clinical setting the largely unknown midterm clinical effectiveness of two protease inhibitor (PI)-based highly active antiretroviral therapy (HAART) regimens with different potency and tolerability profiles in naïve patients. METHOD: This study was a multicenter, open-label, randomized trial in naïve patients with less than 400 CD4+ cell count/microL, regardless of viral load. Treatment arms were hard gel capsule saquinavir (HGC-SQV)-based HAART (Arm A), with an expected more favorable tolerability profile, and indinavir (IDV)-based HAART (Arm B), with more potent virologic activity. While viro-immunological surrogate markers and World Health Organization (WHO) grade III toxicity (secondary endpoints) were regularly monitored, primary endpoints of the study were clinical and defined as any AIDS-defining event, AIDS-related death, WHO grade IV toxicity, drop outs, and protocol violations. RESULTS: 262 consecutive patients were enrolled in the study from March 1, 1997 to December 31, 1997, in 24 different Italian clinical centers (132, Arm A; 130, Arm B). After 24 months of follow-up, patients who were enrolled in Arm B showed a significantly higher rate of virological success (75% had viremia below 500 copies/mL, CI = 12.9%, in the on-treatment analysis) and immunological gain (mean CD4+ cell count increase of 274 CD4+ cells/microL, SD = 234) when compared to patients enrolled in arm A (57%, CI = 15.5% and 223 CD4+ cells/microL, SD = 192; p =.0353 and.026, respectively). Despite the significant difference observed in surrogate markers, the number of total primary endpoints did not differ in the two groups (55 out of 132 in Arm A vs. 58 out of 130 person-years in Arm B; p =.86). CONCLUSION: Our results suggest that, after 24 months of follow-up in a real clinical setting, a PI-based HAART induces significant clinical benefits in naïve patients even in the absence of a complete suppression of viral replication. However, the long-term clinical impact of the possible accumulation of viral mutations in the presence of low-grade viral replication remains to be elucidated.

Adult↗
PubMedDate not supplied

Predictors of long-term immunological outcome in rebounding patients on protease inhibitor-based HAART after initial successful virologic suppression: implications for timing to switch.

OBJECTIVE: To assess predictive factors of long-term immune restoration in patients who started protease inhibitor (PI)-based HAART and experienced virological rebound after initial complete success. METHOD: A retrospective longitudinal analysis of all HIV-infected patients who started their first PI-based HAART and reached viral load below 500 copies/mL was carried out in a large academic center in Italy. Patients were classified either as complete virologic responder (CR) or rebounders (REB) when confirmed plasma viremia was detected thereafter. Immunological outcome was the area under the curve (AUC) of the absolute CD4+ cell count change since the 8th month after treatment initiation (CD4+ T-cell AUC). Association between baseline characteristics, virological outcome, and CD4+ T-cell AUC was assessed by univariate and multivariate analysis. RESULTS: There were 374 patients who were included in the study. Mean follow-up was 30.2 months. There were 226/374 patients (60.4%) who remained CR while 148/374 (39.6%) presented at least one rebound (REB). Among REB patients, complete viral suppression was regained in 15/42 (35.7%) and 50/106 (47.1%) patients who underwent therapy changes or not, respectively. When multiple linear regression was carried out, previous nucleoside reverse transcriptase inhibitor (NRTI) experience and baseline CD4+ cell count below 350 cells/muL did not impair long-term immune restoration. The occurrence of rebound, its duration (> 18 months), and its magnitude (peak of viral load > 10,000 copies/mL) were independent negative prognostic factors. CONCLUSION: The occurrence of viral rebound is independently associated with significantly impaired long-term immunological restoration. The magnitude of viral rebound (< 10,000 copies/mL) and its duration (< 18 months) may be useful to identify those rebounding patients who may still profit from maintaining the current failing therapy if a more aggressive approach may be expected to be deleterious for tolerability reasons or lack of options.

Adolescent↗
PubMedDate not supplied

Malaria in illegal Chinese immigrants, Italy.

A cluster of 22 imported malaria cases, 21 caused by Plasmodium falciparum, was observed among illegal Chinese immigrants in northern Italy in the summer of 2000. The rate of severe disease was high because the patients were not immune and they sought health-care services late in their illness because of their clandestine status. Recognition of the outbreak was delayed because no regional alert system among infectious diseases hospitals was in place.

Adolescent↗