Biomedical subjects

A Perico

Publications and source records attributed to A Perico.

27 records · Page 2Linked to original sources

PubMed1991

Analysis of platelet-activating factor by gas chromatography-mass spectrometry: low-energy electron impact of the corresponding 3-acetyl-2-tert.-butyldimethylsilyl derivative.

A method for the analysis of platelet-activating factor in platelets employing gas chromatography and selected-ion monitoring mass spectrometry with low-energy electron impact and stable isotope dilution was developed. The procedure involved Bligh and Dyer extraction of the sample followed by thin-layer chromatographic purification. Platelet-activating factor is successively hydrolysed to the corresponding 2-acetyl-1-O-alkylglycerol by digestion with phospholipase C, and the product is allowed to isomerize to the more thermodynamically stable 3-acetyl-1-O-alkylglycerol before column purification and derivatization of the free OH with tert.-butyldimethylchlorosaline-imidazole. This reagent is of common use in platelet-activating factor derivatization, but is made to react with 2-acetyl instead of 3-acetyl isomer. The advantages of using the latter for the final derivatization are discussed and this method is compared with others currently available for gas chromatographic-mass spectrometric analysis of platelet-activating factor.

Blood Platelets↗

PubMed1991

Gas chromatographic-mass spectrometric determination of two new antimycotic agents, 1-[(5-chloro-2-benzofuranyl)(2-chlorophenyl)methyl]-1H-imidazole and 1-[(5-bromo-2-benzofuranyl)phenylmethyl]-1H-imidazole, in rabbit plasma following topical administration: a preliminary comparison with bifonazole.

A method for the analysis of the antimycotic drugs 1-[(5-chloro-2-benzofuranyl)(2-chlorophenyl)methyl]-1H-imidazole, 1-[(5-bromo-2-benzofuranyl)phenylmethyl]-1H-imidazole and bifonazole in rabbit plasma, employing gas chromatography-mass spectrometry with selected-ion monitoring, was developed. The procedure involved single-step purification of the biological matrix via liquid-liquid extraction on Extrelut columns and use of a carrier substance to minimize the negative effects of adsorption sites during the gas chromatographic process. The limits of detection ranged from 0.1 to 1.4 ng/ml, starting from a 200-microliter sample. The method was applied to a preliminary evaluation of percutaneous absorption of both drugs in the rabbit after a single administration, in comparison with bifonazole.

Administration, Topical↗

PubMed1989

Local dynamics in biological macromolecules.

The diffusive approach in the optimized Rouse-Zimm approximation to segment relaxation in the nanosecond time domain (ORZLD) is extended to consider chains of nonequivalent units as occurring in biological macromolecules. The correlation times for second-order time correlation functions of each virtual bond on the chain are calculated for some homopolypeptides, and random and regular copolypeptides. The expected correlation times for biological macromolecules organized in multiple domains are discussed via a simple model of the ORZLD hierarchy. Dynamic bond correlation times are compared with static local persistence lengths.

Chemical Phenomena↗

PubMedDate not supplied

Assessment of exposure to polycyclic aromatic hydrocarbons in police in Florence, Italy, through personal air sampling and biological monitoring of the urinary metabolite 1-hydroxypyrene.

In this study, the authors evaluated exposure to airborne polycyclic aromatic hydrocarbons (PAHs) in workers exposed to exhaust gas from cars, and they assessed the efficiency of urinary 1-hydroxypyrene as an indicator of exposure to pyrene and PAHs. The authors selected 2 groups of police who worked in 2 areas in the city of Florence: 1 group was highly exposed to high-density traffic emissions during the winter and summer of 1997, and the 2nd group experienced low exposure to traffic emissions during the same period. Ambient monitoring was achieved with personal sampling of airborne PAHs during each workshift. Eight hydrocarbons were used as indicators of pollution caused by PAHs (e.g., pyrene, benzo[a]pyrene, benzo[a]anthracene, dibenzo[a,h]anthracene). Biological monitoring was performed through dosing of 1-hydroxypyrene (pyrene metabolite) in urine samples taken at the end of each workshift. The ambient monitoring revealed that PAH concentrations were influenced by both season of sampling and varying intensities of traffic in the different areas. The median concentration of benzo[a]pyrene in winter was twice as high in the high-density traffic area as in the low-density traffic area (i.e., 4.1 ng/m3 versus 1.8 ng/m3). In summer, the high-density traffic area experienced benzo[a]pyrene concentrations that were 6 times higher than in the low-density traffic area (i.e., 1.2 ng/m3 versus 0.2 ng/m3). Benzo[a]pyrene was also correlated highly (r(s) = .92, p < .0001) with the mixture of total PAHs analyzed, thus confirming its function as a good indicator of exposure to PAHs in an urban environment. Levels of urinary 1-hydroxypyrene appeared to be generally influenced by the intensity of traffic, especially during the winter (i.e., median value in winter was 199.2 ng/gm creatinine in the high-density traffic area and 120.5 ng/gm creatinine in the low-density traffic area). An analysis of the general data revealed that 1-hydroxypyrene was, to some degree, related to pyrene, benzo[a]pyrene, and airborne total PAHs, whereas analysis of separate data for the area and the season revealed an emergence of a closer correlation during the winter in the high-traffic area. Therefore, 1 -hydroxypyrene can be considered a good biological indicator of exposure to airborne PAHs in the urban environment, especially in winter and in high-density traffic areas.

Adult↗

PubMedDate not supplied

[Acute dimethylformamide (DMF) poisoning: a case report].

This paper describes a case of acute occupational intoxication by dimethylformamide in a worker assigned to polyurethanic resin preparation in a simulated leather factory. The peculiarity of this case is constituted by the association of a dimethylformamide classic clinical syndrome, frequently described in the scientific literature (alcohol intolerance, gastroenteric manifestations with liver injury), with coagulation alterations and thrombocytopenia. Measurement of environmental concentrations of the solvents and biological monitoring revealed high levels of exposure to dimethylformamide at the workplace. Our observations confirm the effects of dimethylformamide on hemostasis reported by other authors in previous studies. It is possible to speculate that the effects of dimethylformamide on coagulation and platelets strictly depend on the amount of solvent accumulated in the body.

Acute Disease↗

PubMedDate not supplied

[Reference values of solvents and metabolites in biological samples].

This article presents a review of reference values for organic solvent biomarkers. Some of these results were obtained in the research activities of the Italian Society Reference Values (SIVR). Most experiences show data obtained from control groups during occupational exposures assessment investigations. We considered only data related to the following biomarkers: immodified solvents in blood and urine, their main urinary metabolites. The reference values of the following solvents are reported: benzene, toluene, xylene, nhexane, cyclohexane, trichloroethylene, perchloroethylene, methanol, acetone, N,N-dimethylformamide, carbon disulphide. In the text also the influence of some confounding factors is discussed.

Blood↗

PubMedDate not supplied

Simultaneous quantitative determination of calcium leucovorin and parabens in lyophilized ampoules by derivative spectroscopy.

A simple and rapid procedure for quantitation of Calcium Leucovorin and parabens simultaneously in lyophilized ampoules formulation by "zero crossing" first-order derivative spectroscopy was developed. The ampoules content was dissolved in a mixture water/ethanol (50/50) and first-derivative spectra were recorded. The absolute values of the derivative at 312 nm for the determination of Calcium Leucovorin and between 244 and 246 nm for the determination of parabens were measured. The method is linear, quantitative and reproducible.

Chromatography, High Pressure Liquid↗

PubMedDate not supplied

[Evaluation of professional exposure to antiblastic chemotherapeutic agents in a Tuscan hospital environment].

The aim of this study, carried out from 1997 to 2000, was to evaluate the exposure to antiblastic drugs of hospital staff (38 nurses of 7 oncological Day Hospital care in Tuscany). To evaluate the internal exposure was used biological monitoring, in particular was determined the concentration of urinary cyclophosfamide (CF); pad was made to evaluate the skin contamination. The contamination of working surfaces was determinate, by wipe-test, to verify the decontamination procedures; were used, as markers, CF and 5-fluorouracil (5-FU). We assessed the permeability thorough gloves usually used by the staff and the degradative activity to these drugs by agents used to decontaminate the working surfaces. The results shows, in urine, value lower than the detection limits, although was found a diffused contamination of the working environment. The results confirmed that NaClO is the best product to decontaminate working surfaces and nitrile gloves the ones with less permeability.

Adult↗

PubMedDate not supplied

[Occupational exposure and individual factors influencing urinary elimination of hippuric acid].

The influence of not occupational factors (smoking, alcohol, coffee, drugs, sport, sex, age and body weight) on hippuric acid excretion was analyzed in two groups of healthy male subjects. A group was constituted of 710 painters occupied in wood and coach workings and the other one of 109 not occupational. The 5 degrees, 50 degrees, 95 degrees percentiles of the two distribution were 208, 605, 1784 and 153, 538, 1700 mg/g creatinine respectively. The analysis of variance undertaken on exposed subjects showed that there was a significative difference between urinary hippuric acid levels of subjects consuming alcohol and the not ones. Multiple regression analysis on hippuric acid excretion values distribution in not exposed group showed that only the variable "coffee consumption" resulted statistically significative (Ln hippuric acid = 5.0287 + 0.8062; R2 = 01221). Coffee consumption increase excretion rate (mg/hour) of hippuric acid likely an exposure to a toluene air concentration of 50 mg/m3. The authors suggest an action of caffeine on endogenous amount of benzoic acid.

Adolescent↗