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Biomedical subjects

S D Ferrara

Publications and source records attributed to S D Ferrara.

At least 37 records · Page 2Linked to original sources
PubMed1994

Drugs-of-abuse testing in urine: statistical approach and experimental comparison of immunochemical and chromatographic techniques.

This study deals with the experimental and statistical comparison of six immunochemical techniques, including noninstrumental on-site and instrumental formats (EIA-EMIT and EZ-SCREEN; FPIA-ADx; RIA-Coat-A-Count; LI-Abuscreen ONTRAK; CBI-Triage), and three chromatographic techniques (TLC-Toxi-Lab; HPLC; HPLC-REMEDi drug profiling system), using GC-MS as a reference technique for analyzing amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, methadone, and opiates in the urine of various kinds of drug users. The study reports (a) the values of sensitivity, specificity, false-positive rates, and false-negative rates of each technique; (b) the results of bayesian statistical analysis, which are based on prevalence values of the samples examined and expressed as positive and negative predictive values and cumulative predictive values for each single technique and for combinations of paired immunochemical and chromatographic techniques; and (c) the results of a rough classification of the various degrees of predictability of these techniques. Lastly, this study proposes a decision-making process for establishing the best combination of analytical techniques for the goals in question, according to the characteristics and facilities of each laboratory.

Chromatography↗
PubMed1993

Dose-dependent absorption and elimination of gamma-hydroxybutyric acid in healthy volunteers.

Gamma-hydroxybutyric acid (GHB) is effective in treatment of the alcohol and opiate withdrawal syndromes. Its absorption and disposition kinetics have been studied in 8 healthy male volunteers following oral administration of single doses of 12.5, 25 and 50 mg kg-1. The AUC increased disproportionately with the dose and so the apparent oral clearance decreased significantly as the dose was increased, whereas the terminal half-life and mean residence time increased. The peak plasma concentrations normalised to the lowest dose fell significantly with increasing doses, whilst the corresponding peak times increased. These findings suggest that both the oral absorption and the elimination of GHB are capacity-limited processes. GHB did not bind to significant extent to plasma proteins over the therapeutic concentration range. The pharmacokinetic parameters in healthy volunteers were not significantly different from those previously observed in alcohol-dependent patients with compensated alcoholic liver disease.

Absorption↗
PubMed1993

Simultaneous identification of amphetamine and its derivatives in urine using HPLC-UV.

An HPLC-UV method for the simultaneous identification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) in urine is described. It includes a rapid extraction procedure of the 4 analogs from urine using Extrelut 3 columns, derivatization with sodium 1,2-naphthoquinone-4-sulphonate (NQS) to obtain highly chromophoric UV-VIS derivatives, and a final HPLC analysis using an ion-pair reversed-phase technique with eluent monitoring at 480 nm. Structural characterization of the derivatives obtained by mass spectrometry is reported. Recoveries of the amphetamines were in the range 80-85% at concentrations of 300 ng/ml. Practical detection limits were 40-60 ng/ml (S/N ratio = 10) for all derivatives. The chromatographic peaks of the NQS derivatized amphetamines are fairly narrow and well resolved. The method is simple, rapid, quite sensitive, and specific for convenient confirmation of preliminary positive results obtained with immunoassays.

3,4-Methylenedioxyamphetamine↗
PubMed1993

Therapeutic gamma-hydroxybutyric acid monitoring in plasma and urine by gas chromatography-mass spectrometry.

A gas chromatographic-mass spectrometric (GC-MS) method for the determination of therapeutic levels of gamma-hydroxybutyric acid (GHB) in plasma and urine samples is described. GHB is converted to its lactonic form gamma-butyrolactone (GBL) which is extracted from biological fluids after the addition of the internal standard delta-valerolactone. Final GC-MS analysis is obtained under electron impact selected ion monitoring (SIM) conditions. Mean relative recoveries of GHB from plasma and urine are 75.5% (RSD% = 2.2) and 76.4% (RSD% = 2.4), respectively. The assay is linear over a plasma GHB range of 2-200 micrograms ml-1 (r = 0.999) and a urine GHB range of 2-150 micrograms ml-1 (r = 0.998). Intra- and inter-assay relative standard deviations (n = 5) determined at 10 and 100 micrograms ml-1 are below 5%. The method is simple, specific and accurate, and may be applied for analytical purposes related to pharmacokinetic studies and therapeutic drug monitoring.

4-Butyrolactone↗
PubMed1993

Gamma-hydroxybutyric acid for treatment of opiate withdrawal syndrome.

In a double-blind placebo-controlled trial, gamma-hydroxybutyric acid (GHB) (25 mg/kg orally) suppressed most of the withdrawal symptomatology in 14 heroin addicts and 13 methadone-maintained subjects. The GHB effect was prompt (within 15 minutes) and persisted for between 2 and 3 hours. Subsequently, the same patients received GHB in an open study every 2 to 4 hours for the first 2 days and 4 to 6 hours for the following 6 days: most abstinence signs and symptoms remained suppressed and patients reported felling well. Urine analysis failed to detect any presence of opiate metabolites. No withdrawal symptomatology recurred after 8 days of treatment when GHB was suspended, and patients were challenged with an intravenous injection of 0.4 mg naloxone. The results indicate that GHB may be useful in the management of opiate withdrawal.

Adult↗
PubMed1992

Frequency of HLA DQA1 alleles in an Italian population.

A sample of 103 Italians was tested for HLA-DQA1 polymorphism using the polymerase chain reaction (PCR) and dot blot hybridization. Results were in Hardy-Weinberg equilibrium. The power of discrimination was 0.91 and the rate of exclusion 56.7. The frequencies of the DQA1*0201 and DQA1*0301 alleles were found to be significantly different from other Caucasian populations.

Discriminant Analysis↗
PubMed1992

Pharmacokinetics of gamma-hydroxybutyric acid in alcohol dependent patients after single and repeated oral doses.

1. The pharmacokinetics of gamma-hydroxybutyric acid (GHB) were studied in 10 alcohol dependent subjects after single and repeated therapeutic oral doses (25 mg kg-1 every 12 h for 7 days). 2. GHB was readily absorbed and rapidly eliminated (tmax = 20-45 min; mean t1/2z 27 +/- 5 s.d. min). Urinary recovery of unchanged GHB was negligible (less than 1% of the dose). gamma-butyrolactone was not detected in either plasma or urine, indicating that lactonization of GHB does not occur in vivo. 3. The multiple-dose regimen resulted neither in accumulation of GHB nor in time-dependent modification of its pharmacokinetics. 4. In five subjects, the data were consistent with nonlinear elimination kinetics of GHB. Administration of a 50 mg kg-1 dose to these subjects resulted in significant increases in dose-normalized AUC, t1/2z and mean residence time. 5. Doubling of the dose also resulted in a significant increase in tmax with little change in Cmax. 6. At the administered doses, GHB did not accumulate in the plasma and caused no serious side effects.

Administration, Oral↗
PubMed1992

gamma-Hydroxybutyric acid in the treatment of alcohol dependence: a double-blind study.

The effect of gamma-hydroxybutyric acid on alcohol consumption and alcohol craving in alcoholics was investigated in a randomized double-blind study versus placebo. Patients were treated as outpatients during a three month period either with gamma-hydroxybutyric acid (50 mg/kg/day, divided into three daily doses) or with placebo. Of the 82 alcoholics that entered the study, 71 completed it, 36 in the gamma-hydroxybutyric acid and 35 in the placebo group. Alcohol consumption was assessed by the subject's self report. At the 3rd month of treatment, 11 patients in the gamma-hydroxybutyric acid group referred to be abstinent and 15 referred controlled drinking; while in the placebo group only two and six patients referred abstinence and controlled drinking, respectively. Serum-gammaglutamyl-transferase activity correlated with the admitted alcohol consumption. Gamma-hydroxybutyric acid treatment decreased alcohol craving during the 3 months of treatment. Transient side effects were noted by six patients on gamma-hydroxybutyric acid and two on placebo. The results suggest that gamma-hydroxybutyric acid may be useful in the treatment of alcohol dependence.

Adult↗
PubMed1991

Suitability of PCR methods for forensic investigation. Analysis of the 3'apoB VNTR system in an Italian population sample.

The PCR method has been applied to amplify a Variable Number Tandem Repeat (VNTR) sequence located at the 3' end of the apolipoprotein B (ApoB) gene. The study was conducted on an Italian population sample and in a 3-generation family of 13 members, whose relationships were previously established using conventional blood systems. The allele frequencies found were compared with those reported in the literature. The results also confirmed the Mendelian inheritance of the alleles and the suitability of the PCR method for forensic purposes.

Amino Acid Sequence↗
PubMed1991

[Use of DNA amplification by PCR in the study of the hypervariable region (VNTR) in a forensic medicine setting. Experience with 2 systems: Apo B and YNZ 22].

The PCR method has been applied to amplify two Variable-number-Tandem-Repeat (VNTR) sequences. The high polymorphism of these VNTR systems can be usefully applied in medical legal fields such as paternity testing and individual identification. The VNTR systems utilized were: ApoB and YNZ 22. The study was conducted on a three-generation family of thirteen members, whose relationship was previously established using conventional blood systems. The results confirm the Mendelian inheritance of the alleles found and the suitability of the PCR method for forensic purposes.

Alleles↗
PubMed1989

Gamma-hydroxybutyric acid for treatment of alcohol withdrawal syndrome.

The effect of gamma-hydroxybutyric acid (GHB) on ethanol withdrawal syndrome in alcoholics was investigated in a randomised double-blind study. Patients with withdrawal symptoms were treated either with GHB (orally in a syrup preparation) (11 patients) or with the syrup alone (12). GHB treatment (50 mg/kg) led to a prompt reduction in withdrawal symptoms, such as tremors, sweating, nausea, depression, anxiety, and restlessness. The only side-effect was dizziness. GHB may be useful in the management of alcohol withdrawal syndrome in man.

Administration, Oral↗
PubMed1981

Enzyme studies with human and hen autopsy tissue suggest omethoate does not cause delayed neuropathy in man.

Levels of acetylcholinesterase and neurotoxic esterase were measured in brain autopsy material. In tissue from a fatal human poisoning and from hens given 4-8 x unprotected LD50 AChE was highly inhibited and neurotoxic esterase uninhibited. The findings correlate with the inhibitory power of omethoate against these enzymes in vitro. It is concluded that omethoate has negligible potential to cause delayed neuropathy and a published report of human neuropathy due to omethoate is criticised.

Acetylcholinesterase↗