Search Results

1 - 9 of 9 items

  • Author: Daniela Serban x
Clear All Modify Search
Antibacterial activity of some saturated polyoxotungstates

Abstract

Polyoxometalates are important inorganic compounds with a broad range of pharmacological properties, including antiviral, antibacterial, antiprotozoal or antitumoral activities, even that their molecular mechanism of action is poorly understood. Purpose: In this paper we evaluated the antibacterial activity of some saturated polyoxotungstates (POW) compounds, since nowadays, the increasing resistance of bacteria to drugs represents a major health problem. Materials and methods: The antibacterial activity was studied by disk diffusion method as a possible screening method and by successive micro-dilutions method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) have been calculated for each compound by successive dilutions. We also compared the reliability of each testing method for this particular POW evaluation. Results: The best antibacterial activity was expressed by H4[SiW12O40]*nH2O and the lowest by Na3[PW12O40]*nH2O, but with very good activity on Staphylococcus spp., especially on MRSA. The POW activity occurs only at relatively high concentrations, and it is dependent on bacterial strain, with very good activity on Staphylococcus spp. The most reliable method for assessing the antibacterial effects of POW is micro-dilutions. POWs could be practically applied in hospital decontamination and could have a possible in vivo antibacterial application.

Open access
Snake Venom Metalloproteinases

Abstract

As more data are generated from proteome and transcriptome analysis revealing that metalloproteinases represent most of the Viperid and Colubrid venom components authors decided to describe in a short review a classification and some of the multiple activities of snake venom metalloproteinases. SVMPs are classified in three major classes (P-I, P-II and P-III classes) based on the presence of various domain structures and according to their domain organization. Furthermore, P-II and P-III classes were separated in subclasses based on distinctive post-translational modifications. SVMPs are synthesized in a latent form, being activated through a Cys-switch mechanism similar to matrix metalloproteinases. Most of the metalloproteinases of the snake venom are responsible for the hemorrhagic events but also have fibrinogenolytic activity, poses apoptotic activity, activate blood coagulation factor II and X, inhibit platelet aggregation, demonstrating that SVMPs have multiple functions in addition to well-known hemorrhagic function.

Open access
Rapid liquid chromatography tandem mass spectrometry determination of rivaroxaban levels in human plasma for therapeutic drug monitoring

Abstract

A rapid, sensitive, high-throughput liquid chromatography coupled with tandem mass spectrometry method for the quantification of rivaroxaban from human plasma has been developed and validated. For the analytical separation a Zorbax SB-C18 column with isocratic flow of mobile phase composed of 0.2% formic acid in water and acetonitril (65:35, V/V) with a flow rate of 1 mL/min at a temperature of 45ºC was used. Detection of rivaroxaban was performed using positive electrospray ionization and MS/MS mode (sum of m/z 231.1; 289.2 and 318.2 from m/z 436.3). Plasma samples were prepared using single-step protein precipitation with methanol. Method validation was performed with regards to selectivity, linearity (r >0.9927), within-run and between-run precision (CV< 13.1 %) and accuracy (bias< 9.4 %) over a concentration range of 24.00 - 960.00 ng/mL plasma. Recovery was between 96.5 - 108.5% and the lower limit of quantification of rivaroxaban was 24.00 ng/mL. The developed method is simple, rapid, and selective, requires small plasma sample volumes, and was successfully applied for therapeutic drug monitoring of rivaroxaban in treated patients.

Open access
The influence of personality types on the impulsive buying behavior of a consumer

Abstract

The relation between the personality of consumers and their buying behavior has been a very much debated topic in the field of marketing researches. Several studies have shown that personality has a significant influence on the way consumer behave in their social and economic environment, in the way they approach and accept innovations and new developed products or even in their shopping behavior. This paper presents the influence of the Myers-Briggs personality dichotomies on the impulsive consumer behavior and the openness to buy newly launched products. Discriminant analysis was used to evaluate primary collected data and the core results show that extroverted, feeling-based decision-makers and perception oriented persons have more frequently an impulsive buying behavior at shopping sessions. Extroverts and intuition based consumers are more open to new products. The temptation to buy attractive unplanned products is higher for extroverts, feeling based decision makers and perceiving persons. Despite of this, none of the personality dichotomies influences the amount and care for spending in stores, this being influenced by other independent factors, mainly economic ones.

Open access
Multiple Intracerebral Hemorrhages in an Old Patient with Rheumatoid Arthritis

Abstract

A 78-year-old Caucasian man was admitted in the Department of Neurology for visual disturbances, started two days before. The next day the patient experienced headache, fever and gait disturbances. He had hypertension, diabetes mellitus, an ischemic stroke 13 years ago, longstanding seronegative rheumatoid arthritis (17 years), polynodular goiter, right ischio-pubian fracture and right femoral vein thrombosis a year ago due to a car accident, since he is treated with oral anticoagulants associated to antiaggregant, hypotensors, statin and oral antidiabetics. The neurologic examination had evidenced nuchal rigidity, left homonymous hemianopsia, left central facial palsy, ataxia of the inferior limbs with wide-based gait, achilean reflexes abolished bilaterally, bilaterally abolished plantar reflexes, ideomotor apraxia, dysarthria, hypoprosexia, and preserved consciousness patient. A non-contrast cerebral CT scan had shown right temporal and parieto-occipital intraparenchymatous hemorrhages, a right frontal sequelar lesion, multiple old lacunar infarcts, cortical atrophy. Laboratory findings included an inflammatory syndrome, absence of rheumatoid arthritis positive serology, normal coagulogram, an elevated proteinuria. The cerebral IRM performed on the seventh day of hospitalisation was suggestive for subacute right parietal hemorrhage, old cerebral infarction in the right anterior cerebral artery area, old lacunar infarcts and cerebral atrophy. The anticoagulant and antiaggregant treatment was stopped after a generalized tonic-clonic seizure occurred. Antiedematous, hypotensor, anticonvulsivant, beta-blocker, and symptomatic treatment was started, while the antidiabetic treatment was continued. All symptoms remitted. Arguments for amyloid angiopathy in our patient are previous non-cardioembolic ischemic stroke and a chronic inflammatory disease-rheumatoid arthritis in his personal medical history.

Open access
Antibiotic susceptibility and resistance profiles of Romanian Clostridioides difficile isolates

Abstract

This study investigated the antibiotic susceptibility patterns and genetic resistance markers of 35 C. difficile strains isolated from patients with C. difficile infection. Vancomycin, metronidazole, tigecycline, teicoplanin, rifampicin, moxifloxacin, cefotaxime, tetracycline, erythromycin, clindamycin, chloramphenicol, linezolid and imipenem MICs were determined for toxigenic strains belonging to PCR ribotypes (PR) 012 (2), 014 (4), 017 (3), 018 (2), 027 (17), 046 (2), 087 (3) and 115 (2). Results showed vancomycin, metronidazole, tigecycline and teicoplanin to be active against all isolates. High resistance rates were noticed against cefotaxime (n = 35), clindamycin (n = 33), imipenem (n = 31), moxifloxacin (n = 25), erythromycin (n = 25) and rifampicin (n = 22). Linezolid-resistance was found in three isolates (PR 017/2, PR 012/1), showing complex resistance (7-9 antibiotics). PR 012, 017, 018, 027 and 046 isolates (n = 26) were resistant to 5-9 antibiotics. Twelve resistance profiles (2-9 antibiotics) were detected. Rifampicin-moxifloxacin-cefotaxime-erythromycin-clindamycin-imipenem-resistance was predominant, being expressed by 18 strains (PR 027/17, PR 018/1). PCR results suggested tetracycline-resistance to be induced by the gene tetM. Three tetM-positive isolates (PRs 012, 046), were also tndX-positive, suggesting the presence of a Tn5397-like element. Only two MLSB-resistant strains (PR 012) had the ermB gene and chloramphenicol-resistance determinant catD was not detected, leaving room for further investigating resistance mechanisms. Multidrug resistance could be attributed to most analysed strains, underlining, once more, the impact of wide-spectrum antimicrobial over prescription, still a tendency in our country, on transmission of antimicrobial resistance and emergence of epidemic C. difficile strains generating outbreaks.

Open access
Calculation of the differences of attitude and behavior of two generations with the Euclidian-metric

Abstract

This paper presents the results of a research about the differences of behavior between two generations. Pairs of consumers consisting of a young consumer and one of his/her parents were questioned about different aspects of life. By applying the Euclidian Metric, the similarities and differences were determined for the examined issues. The results of the research show that for traditional product groups like medical services, education system, the consumers of the two generations have a similar behavior. For product groups related to the online environment such as social networks, mobile/smart phones, the consumers of the two generations show higher differences. Higher differences can be also observed for social groups, as the young generation has an inclination for doing spare time activities with their friends, such as going out, going on holiday. The results of the research have an impact on the way in which consumer’s reference groups are going to be used in marketing communication campaigns.

Open access
Anaesthesiology trainees and their needs: a Romanian perspective. Results from a European survey

Abstract

Anaesthesiology training is going through continuous transformations worldwide. Recent data from a European Survey on anaesthesiology postgraduate trainees and their concerns have been published for the first time, following an initiative by the European Society of Anaesthesiology. Among the responders of this survey, 10.8% were represented by Romanian trainees. The main needs of the Romanian anaesthesiology trainees who completed the questionnaire were, in descending order educational contents/EDAIC, technical skills, exchange programmes, residency workload, residency costs and autonomy transition. Another observation coming from the analysed data is that Romanian anaesthesiologists in training are highly concerned and interested in the field of intensive care medicine. The results also pinpoint to the high costs associated with continuous medical education, leading to a high incentive for workforce migration.

Open access
New RP-HPLC Method for Separation of Naja haje haje Venom and Studies of its Bactericidal Effect

Abstract

Background: Snake venom is a complex mixture of biologically active substances. Some peptides and proteins from snake have already demonstrated their therapeutically potential. The venom of Naja haje, an Elapidae member, has been analyzed from this point of view. Understanding the fully biochemical role of its enzymes has determined the scientists to find new separation and identification methods.

Objective: Our goal was to develop an optimal HPLC analytical method for separation and identification of Naja haje snake venom components, known for its neurotoxic activity. In addition, we wanted to find out if crude snake venom could inhibit the development of both Gram-positive and Gram-negative bacterial cultures. Materials and Method: Analysis of venom was performed on a HPLC system using a C16 column with UV detection at 210 nm. The analysis was done using two mobile phases, containing different concentrations of acetonitrile and trifluoroacetic acid aqueous solution at different pH values. An elution gradient was set at a flow of 0.60 mL/min. Bactericidal activity was quantified by measuring inhibition diameter around an aseptically disk filled with crude venom using Staphylococcus aureus and Escherichia coli. Results: An optimal HPLC analytical method has been developed by changing different parameters such as the pH value of mobile phase A or the elution gradient. The best resolution were obtained at a pH value of 7.4, in gradient varying from 5% to 45% in mobile phase B. Microbiological studies of the venom showed that Gram-positive bacteria growth was inhibited by crude venom, while on Gram-negative bacteria growth no effect was observed. Inhibition zone is dose-dependent and fresh crude venom is with 30% more potent than venom freeze and kept at -55°C. Conclusions: A comprehensive catalog of venom composition may serve as a starting point for studying structurefunction correlations of individual toxins for the development of new research tools and drugs of potential clinical use.

Open access