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Biomedical subjects

V Ferrari

Publications and source records attributed to V Ferrari.

At least 19 recordsLinked to original sources
PubMed1992

Determination of 8-methoxypsoralen in plasma by gas chromatography-mass spectrometry using selected-ion monitoring.

A sensitive and accurate assay was developed for the measurement of 8-methoxypsoralen in plasma using electron-impact positive-ion mass fragmentography. 4,5,8-Trimethylpsoralen was used as an internal standard. Sample preparation consisted of a two-step liquid phase extraction using acetonitrile and methylene chloride. The calibration curve showed a linear relationship between the peak areas of 8-methoxypsoralen and 4,5,8-trimethylpsoralen over a wide range of 8-methoxypsoralen concentrations (1-500 ng/ml). With-in- and between-run precisions, measured at five different drug concentrations, varied from 0.82 to 1.41% and from 0.82 to 1.86%, respectively.

Gas Chromatography-Mass Spectrometry↗
PubMed1992

Allopurinol challenge test in children.

The allopurinol challenge test was performed on 44 healthy subjects (28 children and 16 adolescents) in order to establish normal values of urinary orotic acid excretion following allopurinol ingestion in the paediatric population. The subjects were divided into three groups according to their age: 6 months to 6 years; 6 years to 10 years; and 10 years to 17 years. They were given 100 mg, 200 mg, or 300 mg of allopurinol, respectively (based on age) in a single oral dose. Maximum peak urinary orotic acid levels following ingestion of allopurinol were 13.0 (n = 14), 9.3 (n = 14), and 10.2 (n = 16) mumol/mmol creatinine in the three groups, respectively. In all children tested the peak orotic acid level was 3.1 +/- 2.7 mumol/mmol creatinine (mean +/- SD, n = 44). This allopurinol challenge test was also performed in six children with urea-cycle disorders, including five females with ornithine transcarbamylase (OTC) deficiency, all of whom demonstrated abnormally elevated levels of urinary orotic acid (peak levels of 26-134 mumol/mmol creatinine) following allopurinol ingestion.

Adolescent↗
PubMed1991

Simulation of kinetic data on the influx and efflux of chloroquine by erythrocytes infected with Plasmodium falciparum. Evidence for a drug-importer in chloroquine-sensitive strains.

Literature data on influx and efflux kinetics of chloroquine (CQ) with erythrocytes infected with the malaria parasite Plasmodium falciparum were simulated using a four-compartment model with first-order exchange between the compartments. The four compartments represent (1) the buffer surrounding the infected erythrocyte; (2) the cytosol of the host erythrocyte; (3) the parasite cytosol; and (4) the food vacuole. Simulations showed that basal membrane transport of CQ, estimated from data on influx of CQ into uninfected red cells, largely accounts for uptake and release of CQ by erythrocytes infected with two different CQ-resistant (CQ-R) parasite strains. In contrast, the rate of uptake of CQ by erythrocytes infected with a CQ-sensitive (CQ-S) strain is substantially higher than predicted by uptake with membrane transfer by basal diffusion of CQ. Simulations also indicate that the difference in kinetics of CQ uptake by erythrocytes infected with the CQ-S and CQ-R strains can be explained by a net increase in the inward permeability coefficient at the host erythrocyte membrane, the composite membrane surrounding the parasite or the food vacuole membrane. The results are consistent with the presence of a drug-importer for CQ in erythrocytes infected with sensitive strains, which is absent in those infected with resistant strains. They are not consistent with the hypothesis that CQ resistance is attributable to a drug-exporter in resistant cells which is lacking in sensitive cells.

Animals↗
PubMed1991

Kinetics and thermodynamics of chloroquine and hydroxychloroquine transport across the human erythrocyte membrane.

Chloroquine (CQ) and hydroxychloroquine (HCQ) have almost identical molecular volumes but showed very different permeability characteristics. The permeability coefficient for the unionised species of CQ (2.0 cm/sec at 25 degrees) was about fifty times that of HCQ (0.039 cm/sec at 25 degrees), but the apparent activation energy for transport (85 kJ/mol for CQ, 81 kJ/mol for HCQ) was almost identical for the two drugs. The partition coefficient of CQ into various organic solvents was much higher than for HCQ, but the different permeability behaviour cannot be quantitatively explained by partitioning behaviour into hexane or octanol, two solvents commonly used to mimic the membrane interior. A comparison of permeability and partitioning characteristics suggests that the barrier phase for these drugs within the membrane can be modelled by a mixed solvent of 5% octanol in hexane. The results suggest that interactions with hydrogen bonding groups within the membrane are important in the membrane transport of these drugs, and that the membrane does not behave functionally as a simple hydrocarbon barrier.

Biological Transport↗
PubMed1991

[Wernicke-Korsakoff syndrome caused by prolonged infusion therapy during the postoperative period].

Wernicke-Korsakoff's syndrome (W.K.S.) is a complication of alcoholism and malnutrition and usually presents acutely and is characterized by disturbances of consciousness, paralysis of the external ocular muscles, ataxia and disorder of retentive memory. The disease results from deficiency of vitamin B1, or thiamine, an essential coenzyme in intermediate carbohydrate metabolism. We report a seriously ill, nonalcoholic surgical patient, who developed W.K.S. in the postoperative period as a result of thiamine deficiency, during prolonged intravenous therapy. It is recommended that malnourished patients receive 100 mg parenteral thiamine especially when glucose infusions are administered.

Aged↗
PubMed1991

Safety of ibopamine therapy in congestive heart failure. Ibopamine cohort study: baseline and 1-year results.

The study was designed to evaluate the safety of ibopamine (3,4-diisobutyryl ester of N-methyldopamine. SB(-)-505. Inopamil; CAS 66195-31-1) for the chronic treatment of congestive heart failure. It was conducted as a comparative cohort survey, versus digitalis. A third cohort was made with patients who received both drugs in association. Any differences between cohorts at baseline were dealt with by identifying explanatory variables with linear discriminant analysis and by performing multivariate statistical analysis by Cox's proportional hazard model. During 16 months, 3.330 patients were enrolled and then followed-up for a median time of 1 year. Baseline characteristics are reported as well as follow-up results on mortality, disease progression, anginal episodes, arrhythmias, need for cointervention and other undesired on-therapy events. Results pointing to efficacy are consistent with the favourable results from controlled randomized double blind medium--long term clinical trials. In addition, data from the present study do indeed provide strong evidence on the safety of long-term treatment with ibopamine. At variance with inotropic agents ibopamine did not increase mortality. The results rather suggest that long-term treatment with ibopamine affords an increase in survival and a delay in the progression of the disease, without adverse effects on cardiac rhythm and myocardial oxygen balance, and with a general improvement in the patients' quality of life.

Adolescent↗
PubMed1990

Uptake of chloroquine by human erythrocytes.

Analysis of studies of the pH dependence of the kinetics of chloroquine (CQ) uptake by human erythrocytes indicates that the unionised CQ species is the major membrane permeant at physiological pH even though the concentration of this species as a fraction of the total CQ concentration in solution is extremely small (0.01% at pH 7.4). CQ concentration-dependence studies and studies performed in the presence of various substrates and inhibitors of erythrocyte membrane transport failed to provide evidence of saturation or inhibition of CQ transport, which suggests that the likely mechanism of CQ transport across human erythrocyte membranes is by passive diffusion. Results of equilibrium binding studies of CQ to intact and lysed human erythrocytes indicated that the mechanism of CQ accumulation in intact human erythrocytes appears to be by a combination of ion trapping (a consequence of the basic nature of the drug and the pH gradient across the human erythrocyte membrane) and binding of CQ to cell components.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1989

Cyclophosphamide, epirubicin, high-dose folinic acid and 5-fluorouracil (super-FEC) as first-line chemotherapy for advanced breast cancer: preliminary results.

Forty patients with metastatic breast cancer were treated with a new combination regimen consisting of cyclophosphamide, epirubicin, high-dose folinic acid and 5-fluorouracil (super-FEC). A major objective response was observed in 32 patients (80%). Among these, 11 patients (27%) experienced a complete remission. The median duration of response was 10+ and 12+ months for CR and PR, respectively. The most common side-effect was oral mucositis (Grade III = nine patients; grade IV = two patients), while haematological toxicity was virtually absent. Considering the high-risk characteristics of the vast majority of the enrolled patients (75% had dominant visceral disease), these preliminary results suggest that super-FEC has a powerful activity in poor-prognosis metastatic breast cancer with an acceptable degree of toxicity.

Adult↗
PubMed1989

Phase II trial of 5-fluorouracil and high-dose folinic acid in advanced renal cell cancer.

Fourteen patients with metastatic renal cell carcinoma (RCC) were treated with high-dose folinic acid (HDFA): 200 mg/m2 i.v. and 5-fluorouracil (5-FU): 370 mg/m2 i.v. for 5 consecutive days every 28 days. Severe oral mucositis (WHO grade III-IV) was experienced by two patients, whereas hematological toxicity was mild. No complete or partial remission was observed. Short-lasting stable disease occurred in 8 patients (median = 5 months, range 2-11). This combination does not need further evaluation in patients with RCC.

Adult↗
PubMed1988

Premarin priming before prednimustine, high-dose folinic acid and 5-fluorouracil as salvage chemotherapy for advanced breast cancer.

Thirty patients with advanced and mainly pretreated breast cancer were treated with a combination of premarin, prednimustine, high-dose folinic acid and 5-fluorouracil. Among the 30 evaluable patients, 9 (30%) achieved an objective response (median duration: 9 months). Oral mucositis was the limiting toxicity, while myelosuppression was quite mild. In spite of considerable activity as salvage regimen, these results do not seem better than those achieved in our Institute with high-dose folinic acid and 5-fluorouracil alone.

Breast Neoplasms↗
PubMed1988

Complete estrogen blockade with buserelin and aminoglutethimide for advanced breast cancer: a phase I-II study with long-term hormonal correlations.

We treated 21 patients with advanced breast cancer with buserelin, aminoglutethimide and cortisone acetate in an attempt to obtain a complete estrogen blockade both in premenopausal and postmenopausal patients. Ten patients (47%) obtained an objective response without any relevant side-effects. Dealing with hormonal data, it must be outlined that serum testosterone levels decreased significantly in postmenopausal patients, suggesting a possible explanation for the activity of luteinizing hormone-releasing hormone analogue in this group of patients.

Adult↗
PubMed1988

[Update on paraneoplastic hypercalcemia. Our experience in the treatment of hypercalcemic states of patients with advanced breast carcinoma].

The treatment of hypercalcemia of malignancy is troublesome. Personal experience with breast cancer associated hypercalcemia is presented. Eight patients were hydrated with intravenous administration of saline solution containing high doses of salmon calcitonin and subsequently six were treated with antiblastic polychemotherapy. Calcium level fell to normal in all patients. Hypercalcemia, with or without evidence of metastatic bone disease, may be caused by the production of humoral substance by tumoral tissue. In our experience the first therapeutic stage is the infusion of saline solution containing high doses of calcitonin, while the elective treatment is antiblastic polychemotherapy which, acting on tumour growth, may inhibit the release of humoral mediators of hypercalcemia causing a slower but stable reduction in serum calcium level.

Adult↗
PubMed1987

Temperature dependence of the acid dissociation constants of chloroquine.

The pKa values of the conjugate acids of the antimalarial drug chloroquine were determined at various temperatures using fluorescence spectrophotometry and nonlinear regression in the data analysis. Both pKa values decreased by approximately one unit with increasing temperature over the range 0-37 degrees C with enthalpy changes of 46 and 49 kJ X mol-1. The ionization of chloroquine was found to be mainly controlled by the change in enthalpy. The chloroquine monocation was shown to be almost exclusively in the alkylamino protonated form at all temperatures studied.

Chloroquine↗