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Biomedical subjects

Piotr Kowalski

Publications and source records attributed to Piotr Kowalski.

17 recordsLinked to original sources
PubMed2006

Minor betalains in fruits of Hylocereus species.

Betacyanins in peel and flesh of fruits of different Hylocereus species were identified by means of GC/MS, electrospray MS/MS, HPLC as well as (1)H and (13)C NMR techniques. As hitherto unknown pigments: betanidin 5-O-(2'-O-beta-D-apiofuranosyl)-beta-D-glucopyranoside, betanidin 5-O-(4'-O-malonyl)-beta-D-glucopyranoside and betanidin 5-O-[(5''-O-E-sinapoyl)-2'-O-beta-D-apiofuranosyl]-beta-D-glucopyranoside were elucidated. The sinapoyl moiety attachment position in the structure of betacyanins was established for the first time. The peel contained a more complex pattern of betacyanins with apiofuranosyl moiety. Other recently identified pigments were also present in the samples and their (1)H or (13)C NMR spectra were recorded. In the case of phyllocactin and its 4'-isomer the migration of the malonyl group was noticed.

Betalains↗
PubMed2006

Fatality involving vinblastine overdose as a result of a complex medical error.

The purpose of the study is a presentation of a fatal case involving an 83-year-old woman, who died due to an overdose of vinblastine-a cytostatic agent of a vinca alkaloid employed in cancer chemotherapy. The postmortem investigation included an autopsy and histological examination, as well as a toxicological analysis of post-mortem specimens collected in the course of autopsy. The authors performed a toxicological assessment of vinblastine employing liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (LC-MS-MS-APCI). The determined vinblastine concentration levels amounting to 29 ng/g in blood and 52.5 ng/g in liver were in a considerable excess of values encountered in patients on chemotherapy using the drug. The fatality was investigated in the context of medical error. In the described case, the erroneous and medically unjustified administration of vinblastine was identified by a series of unfortunate events involving as many as three acting consecutively individuals: a physician, a pharmacist and a nurse. The report may thus document the clinical course of vinblastine poisoning along with postmortem changes resulting from the drug action.

Accidents, Traffic↗
PubMed2005

Comparative evaluation between capillary electrophoresis and high-performance liquid chromatography for the analysis of florfenicol in plasma.

A capillary electrophoresis (CE) and a reversed phase high-performance liquid chromatography (RP-HPLC) method with UV detection have been developed for florfenicol analysis in plasma samples. The suitabilities of both methods for quantitative determination of florfenicol were approved through validation specification, such as linearity, precision, selectivity, accuracy, limit of detection and quantification. The capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) assay were compared by analyzing a series of plasma samples containing florfenicol in different concentrations using the two methods. The extraction procedure is simple and no gradient elution or derivatization is required. Furthermore, the analysis time of the CE method is two times shorter than the respective parameter in HPLC and solvent consumptions is considerably lower. The calibration curve were linear to at least 0.05-10 microg/ml (r = 0.9998) and 0.1-10 microg/ml (r = 0.9998) for CE and HPLC, respectively. The separation efficiency are good for both methods. The detection limits for florfenicol were 0.015 microg/ml with CE and 0.03 microg/ml with HPLC and CE method gave lower value, even though UV detector was applied in the both cases. The both methods were selective, robust and reliable quantification of florfenicol and can be useful for clinical and biomedical investigations.

Anti-Bacterial Agents↗
PubMed2004

The impact of spacer structure on 5-HT7 and 5-HT1A receptor affinity in the group of long-chain arylpiperazine ligands.

New cis-, trans-2-butene and 1,2-bismethylbenzene analogues of MM77 and NAN-190 (1-[4-[4-(2-methoxyphenyl)-piperazin-1-yl]-butyl]-pyrrolidine-2,5-dione and isoindole-1,3-dione, respectively) were synthesized. The differences in their in vitro affinity for serotonin 5-HT(7) and 5-HT(1A) receptors were explained using a conformational analysis. A bioactive conformation of those compounds for the 5-HT(7) receptor, different from that established for 5-HT(1A), was proposed.

Ligands↗
PubMed2004

Validated capillary electrophoretic method for the analysis of ivermectin in plasma after intragastric administration in pigs and horses.

A capillary electrophoretic (CE) method has been developed for the determination of ivermectin (CAS 70288-86-7), a new generation drug with antiparasitic activity, in pig and horse plasma. The method was statistically validated for its linearity, accuracy, precision and selectivity. The linear range was from 1 to 30 ng mL(-1) with correlation coefficients greater than 0.999. The limit of detection was 0.3 ng mL(-1), while the quantitative limit was 1 ng mL(-1), using a 0.5 mL sample size. The validated procedure was used to determination of pharmacokinetic parameters of ivermectin after ingestion of 0.1 mg for pigs and 0.2 mg dose per kg body weight for horses, respectively. Studies were performed on a group of eight pigs and six horses. There were no significant differences between pigs and horses in any of the estimated pharmacokinetic parameters.

Animals↗
PubMed2004

The bioequivalence study of baclofen and lioresal tablets using capillary electrophoresis.

A simple and robust analytical method for rapid separation and sensitive quantification of baclofen in human plasma by capillary electrophoresis technique was developed. Electrophoretic separation was optimized and successfully performed using simple sodium tetraborate aqueous solution. Observed detection limit in biological material was 10 ng. Using UV detection at 200 nm excellent linearity (r = 0.999) was observed over the concentration range from 0.025 to 1.0 microg mL(-1). The described method has been validated and applied to the quantitative determination of baclofen in human plasma. The bioavailability of Baclofen (Polpharma) and Lioresal (Novartis) in 18 healthy volunteers was investigated. The results indicate bioequivalence of the reference and Baclofen preparations.

Adult↗
PubMed2004

[Oxygen transfer and consumption in human placenta exposed to variable magnetic fields in vitro].

The initial investigations concerning the influence of variable magnetic fields (MF) on transfer and oxygen consumption in isolated human cotyledon in vitro were performed. Ten dual closed perfusion of the human cotyledon were conducted in each group. The control group was not exposed to magnetic fields. In studied groups cotyledons were exposed to magnetic field: in the group B1 (B = 2 mT, f = 50 Hz), and in the group B2 (B = 5 mT, f = 50 Hz) for 180 min. Obtained results may suggest that variable magnetic field (B = 5 mT, f = 50 Hz) cause decrease of oxygen consumption in human placenta in 120 and 150 min of experiment.

Active Transport, Cell Nucleus↗
PubMed2003

Electrospray mass spectrometric studies of noncovalent complexes of buspirone hydrochloride and other serotonin 5-HT(1A) receptor ligands containing arylpiperazine moieties.

Noncovalent complexes consisting of two protonated amines and a chloride anion were observed under electrospray ionization mass spectrometry (ESI-MS) conditions. The observed phenomenon was investigated for the hydrochlorides of buspirone, a well-known anxiolytic drug, and 23 other arylpiperazine derivatives that had been developed as serotonin 5-HT(1A) receptor ligands. Due to the major role of ionic interactions in a vacuum, it was proposed that the detected complexes were formed by NH(+)---Cl(-)---NH(+) bridges. It was found that complexation depended on structural features of the analyzed compounds. For derivatives with a shorter linker (three methylene groups) containing a terminal cyclic amide fragment, complex ions were not observed. It was postulated that, in the latter case, steric hindrance due to a terminal group could disturb ionic bridge formation. Since both the observed complexation and ligand-binding processes are driven by noncovalent forces, and a qualitative relationship between them was found (compounds with a 4-carbon chain always display higher affinity for 5-HT(1A) receptors than do their 3-carbon analogues), such ESI-MS studies may yield valuable information on ligand-receptor interactions.

Buspirone↗
PubMed2002

Synthesis and pharmacological evaluation of new arylpiperazines. 3-[4-[4-(3-chlorophenyl)-1-piperazinyl]butyl]-quinazolidin-4-one - a dual serotonin 5-HT(1A)/5-HT(2A) receptor ligand with an anxiolytic-like activity.

On the basis of systematic studies on the structure-activity relationships in arylpiperazine group of serotonin ligands, 12 new derivatives containing quinazolidin-4(3H)-one (1-4), 2-phenyl-2,3-dihydrophthalazine-1,4-dione (5-8) or 1-phenyl-1,2-dihydropyridazine-3,6-dione (9-12) fragments were synthesized. The majority of the tested compounds (2, 4, 7, 8 and 10-12) showed a high affinity for 5-HT(1A) receptors (K(i)=11-54 nM) and two (1, 2) were found active at 5-HT(2A) sites (16 and 68 nM, respectively). All the new 5-HT(1A) ligands tested in vivo revealed an antagonistic activity at postsynaptic 5-HT(1A) receptors, and three of them behaved as agonists at presynaptic ones. Additionally, both the meta-chlorophenylpiperazine derivatives containing quinazolidin-4-one fragment showed features of 5-HT(2A) receptor antagonists. The dual 5-HT(1A)/5-HT(2A) receptor ligand (2) was further tested for its potential psychotropic activity. It showed a distinct anxiolytic-like activity in a conflict drinking test in rats and the observed effect was more potent in terms of the active dose, than that produced by diazepam (used as a reference drug).

Animals↗
PubMed2002

Proposal for an indexical method of evaluating risk of hand tool operators' exposure to mechanical vibrations.

The article presents proposals for an indexical evaluation of exposure of hand tool operators to vibrations. The presented indices have been developed on the basis of the results of laboratory tests. The examinations studied the effect of pressure force and grip force exerted by an operator on a hand tool as well as the amplitudes and frequencies of an exciting signal on vibrations transmitted in the hand-tool handle system.

Biomechanical Phenomena↗
PubMed2002

[Hand skin blood flow measurement in assessing protective efficacy of antivibration gloves].

The literature data show that a long exposure to local vibration leads to neuro-vessels, and less frequently to osteoarticular or mixed disorders within upper extremities. In five healthy males, not occupationally exposed to vibration, skin blood flow was examined during a 5-min exposure of the right hand to local vibration (filtered off white noise 2-2000 Hz, weighted vibration acceleration of 9 m/s-2), and the cold provocation test with water at 14 degrees C in two variants: with and without antivibration glove, was performed. Immediately after local vibration, evident changes in the skin blood flow on the right and left hands were registered in the experiment without antivibration glove. There were no changes in the experiment with antivibration glove The cold provocation test, in none of its variants (with and without antivibration glove) showed any changes. It seems that the skin blood flow measurements taken immediately after the hand exposure to local vibration may be a useful method for assessing protective efficiency of antivibration gloves, however further studies are required to support this observation.

Adult↗
PubMedDate not supplied

[Crimes against life in the material of Cracow's Institute of Forensic Medicine--comparative analysis in the years 1986-2000 and 1996-2000].

The authors presented a comparative analysis of crimes against life in five year periods of the past and present political systems based on autopsy material of Cracow's Institute of Forensic Medicine. Investigation of these types of crime confirmed sociological observations of arising the criminal trends in the last years. The incident of these types of crimes arose in the last period by about 40% in a relation of male to female victims 3.7:1. Probable motives of these crimes were: drinking 8%, decline in family relationships 12%, fight and revenge 9% robbery 8%, sexual offenses only in 1%. In 61% of analyzed cases the motives were unknown. Among the weapons of crime the most often used were blunt objects and death due to stabbings and cuts. A very high incidence of fire arm crimes in comparison to previous period was observed--from 2 cases in 1986-1990 to 25 in the five year period of 1996-2000. 78% of victims were in a state of insobriety at the moment of crime.

Autopsy↗
PubMedDate not supplied

Studies on the syntheses of 1-substituted benzimidazole derivatives.

Several novel 1-heteroarylalkyl substituted benzimidazoles were synthesized in the reaction of various halogenoalkylheterocycles with benzimidazoles. The structures of the products were confirmed by their spectral and analytical data. The potential biological properties of the new compounds were evaluated using the PASS programme.

Benzimidazoles↗
PubMedDate not supplied

[Instability of the health care system and concomitant meaning of the notion of partial incapacity to work as an element determining dysfunctionality of the pension system].

Opinioning for the State Insurance Court, which is of fundamental interest to the authors of this paper, leads them to investigate certain factors contributing to the dysfunctionality of opinion within the pension system. We have attempted to find out to what degree changes in the functioning of the health care system, restricting access to specialist diagnosis are reflected in the construction of an opinion relating to incapability to work. On the basis of our analysis, it can be concluded that the basis of the majority of arguable opinions constitutes the legal notion of "partial incapability to work", which should be understood as "partial capability to work". In the case of the suggested change of view of this problem, the majority of controversial opinions lose their validity.

Disability Evaluation↗
PubMedDate not supplied

[Opinioning on the ability to conduct activities concerned with law suit, participation in court trials, temporary imprisonment and police station arrest].

Opinioning on the ability to conduct law procedures mentioned in the title is one of the important aspects of the experts task. It seems that one of the causes of this situation is lack of consideration of this problem in the available medical texts. The aim of this paper is the attempt to find an answer to the question: what does the incapability to participate in legal procedures mean in practice and which functional elements of the state of health should be the subject of assessment. Based on their own practice, the authors try to create a systematic approach for opinions issued for the purpose expressed in the title. This problem, as we think, is not exclusively the domain of forensic medicine specialists since the ability to make a reliable assessment of health condition is required from every licensed physician.

Criminal Law↗