Jacek Szeliga

Identification of volatile organic compounds secreted from cancer tissues and bacterial cultures

The early cancer diagnosis increases the possibility of total recovery. The infection of Helicobacter pylori is associated with gastric cancer, the second most common cancer in the world. The determination of volatile organic compounds (VOCs) excreted by stomach tissue and bacteria culture has been investigated. Solid-phase microextraction (SPME) was used for preconcentration and the determination was accomplished by gas chromatography coupled with mass spectrometry (GC/MS). The samples of tissue were taken from five patients (ten samples) with stomach cancer and normal (non-cancerous) segments from other parts of the stomach were used as a control. Eighteen compounds were identified in stomach tissue and seven of them were present both in healthy and cancer tissue. These compounds assumed to be endogenous and acetone ratio (AR) was calculated for ethanol, butane, carbon disulfide, 1-propanol, 2-butanone and 2-pentanone. The data shows that amount of 1-propanol and carbon disulfide in the gaseous composition is higher in cancer tissue than in normal tissue. Eight compounds were identified both in bacteria and tissue. These data suggest that bacteria present in the stomach might cause the increase in the concentration of 1-propanol and carbon disulfide in emission from cancer tissue.

Preliminary study of volatile organic compounds from breath and stomach tissue by means of solid phase microextraction and gas chromatography-mass spectrometry.

The determination of volatile organic compounds (VOCs) in exhaled air and stomach tissue emission for the detection of cancer has been investigated. Solid phase microextraction (SPME) was used for sample preconcentration. The method presented in this paper showed satisfactory precision (RSD below 11%), linearity in the range of 2.8-136 ppb and limit of detection ranging from 0.6 to 2.1 ppb. The breath and emission from cancer tissue were collected from three patients with stomach cancer. Acetone, carbon disulfide, 2-propanol, ethyl alcohol and ethyl acetate were identified in breath and tissue samples. These compounds have been assumed as endogenous. Acetone ratio (AR) was calculated for carbon disulfide, 2-propanol and n-butane. The AR for carbon disulfide was found to be higher for normal tissue (20.64-44.95) than for emission from cancer tissue (2.01-18.20). A limitation of this study is that only a few clinical samples were investigated. These results should be evaluated as preliminary because of the small number of patients examined.

Development of novel molecularly imprinted solid-phase microextraction fibers and their application for the determination of antibiotic drugs in biological samples by SPME-LC/MSn

Novel molecularly imprinted polymer (MIP)-coated fibers for solid-phase microextraction (SPME) fibers were prepared by using linezolid as the template molecule. The characteristics and application of these fibers were investigated. The polypyrrole, polythiophene, and poly(3-methylthiophene) coatings were prepared in the electrochemical polymerization way. The molecularly imprinted SPME coatings display a high selectivity toward linezolid. Molecularly imprinted coatings showed a stable and reproducible response without any influence of interferents commonly existing in biological samples. High-performance liquid chromatography with spectroscopic UV and mass spectrometry (MS) detectors were used for the determination of selected antibiotic drugs (linezolid, daptomycin, amoxicillin). The isolation and preconcentration of selected antibiotic drugs from new types of biological samples (acellular and protein-free simulated body fluid) and human plasma samples were performed. The SPME MIP-coated fibers are suitable for the selective extraction of antibiotic drugs in biological samples.

A new approach for antibiotic drugs determination in human plasma by liquid chromatography–mass spectrometry

Sensitive and selective analytical procedures based on high performance liquid chromatography with mass spectrometric detection were developed for the determination of linezolid (LIN) and amoxicillin (AMOX) in human plasma samples. Samples were prepared by applying protein precipitation (PP), solid phase extraction (SPE), and microextraction in packed syringe (MEPS). The analytical separation was carried out using reversed phase liquid chromatography in isocratic mode. All analytes were monitored by mass spectrometry (MS) detection in the product ion mode and the method was validated covering the corresponding therapeutic range of 1-30 μg/mL and 1-50 μg/mL for LIN and AMOX respectively. The assay was linear over AMOX and LIN concentration ranges. The method provided good validation data: accuracy (102.9% (LIN), 100.9% (AMOX)), limit of detection (0.1407 ng/mL (LIN); 0.1341 ng/mL (AMOX); quantification (0.3814 ng/mL (LIN), 0.4249 ng/mL (AMOX)) and acceptable stability within 24h in the auto-sampler. Three different methods were compared as regards precision, accuracy, recovery and matrix effects. The proposed methods offer a fast and simple way to determine selected antibiotic drugs in human plasma that could be applied in pharmacokinetic studies.

Combination of capillary electrophoresis, PCR and physiological assays in differentiation of clinical strains of Staphylococcus aureus.

Fast, sensitive and cheap determination of pathogenic bacteria is extremely important in many branches, for example biotechnology, quality control, analysis of samples and antimicrobial therapy. The development and application of analytical techniques in practice could provide new possibilities in this regard. The bacterial pathogen Staphylococcus aureus is responsible for a significant amount of human morbidity and mortality. Rapid and sensitive determination is therefore very important. In the present study, novel methods, based on capillary zone electrophoresis and (as confirmation of these results) molecular analysis of a part of the coag gene, were developed for identification and differentiation of three S. aureus strains. The electrophoretic measurements rely on the differential mobility of bacteria in the fused silica capillary under the direct current electric field. To perform coagulase gene typing, the repeated units encoding hypervariable regions of the S. aureus gene were amplified using the PCR technique followed by restriction enzyme digestion and analysis of restriction fragment length polymorphism patterns as well as sequencing. Finally, the results of electrophoretic measurements with molecular analysis were compared.

The clinical use of a fast screening test based on technology of capillary zone electrophoresis (CZE) for identification of Escherichia coli infection in biological material

Summary Background Escherichia coli is a Gram-negative bacterium which is a basic, symbiotic element of the physiological flora of the large intestine of humans and warm-blooded animals. However, in specific cases it may become a very dangerous pathogen (eg, diarrhoea, infection of the urinary tract, lungs, and generalized infections). Its early detection, as a cause of infectious disease, helps to achieve optimal treatment results; however, classical microbiological tests require at least 24 hours from sample taking to diagnosis. Material/Methods We present a unique solution based on CZE technologies enabling identification of E. coli presence in studied sample within half an hour. Altogether, 30 E. coli-infected wounds and ulcerations were examined, comparing the results obtained by classical culture method with the result of capillary zone electrophoresis (CZE) electropherogram. Results The method, which does not require any preparation of the sample, achieved 86.7% sensitivity and 85%specificity in the examined clinical material (infections of surgical wounds). Conclusions The obtained results enable reliable, very fast testing for E. coli as a pathogen.

Minimally invasive procedures in severe acute pancreatitis treatment – assessment of benefits and possibilities of use

Introduction Acute pancreatitis (AP) consists of an extremely varied complex of pathological symptoms and clinical conditions, ranging from mild gastric complaints to multi-organ failure resulting in death. Aim To present the authors’ own experience regarding surgical treatment for pancreatic necrosis complicated by infection using different methods, including classic and laparoscopic methods as well as those combined with percutaneous techniques. Material and methods In the period 2007–2010, 34 patients with the diagnosis of severe AP were treated at the Department of General, Gastroenterological and Oncological Surgery, Collegium Medicum, Nicolaus Copernicus University. In 7 patients classic necrosectomy with repeated peritoneal flushing was performed (type 1), in 5 patients laparotomy with active drainage (type 2), in 12 video-assisted retroperitoneal debridement (type 3), and in 10 only percutaneous drainage methods (type 4). Results Total duration of hospitalisation was from 10 to 192 days. The highest death rate was observed for type 1 procedures. Significant differences with regard to the absolute number of postoperative complications between different groups were not observed; however, their quality varied. Classic methods were used in patients whose general and local condition was more severe. Conclusions When AP and its complications are diagnosed, a suitable method of surgical treatment has to be selected extremely precisely and in an individualised way. Minimally invasive methods used in selected patients provide better outcomes and higher safety superseding classic, open techniques of surgical treatment.

Laparoscopic surgery of esophageal hiatus hernia - single center experience.

Introduction Esophageal hiatal hernias are the most frequent types of internal hernias. This condition involves disturbance of normal functioning of the stomach cardiac mechanism and reflux of the gastric contents to the esophagus. Aim: To evaluate postoperative results in our Clinic and the comparison of these results to data from the literature. Material and methods One hundred and seventy-eight patients underwent surgery due to esophageal hiatal hernia at the Clinic of General, Gastroenterological and Oncological Surgery, Collegium Medicum, Bydgoszcz, Nicolaus Copernicus University, Torun, Poland, from 2006 to 2011. All operations were performed using laparoscopy. Fundoplication by means of the Nissen-Rossetti method was carried out in 172 patients while Toupets and Dors methods were applied in 4 and 2 patients, respectively. Results Average time of the surgery was 82 min (55–140 min). Conversion was performed in 4 cases. No serious intraoperative complications were noted. In the postoperative period, dysphagia was reported in 20 patients (11.2%). Postoperative wound infection was observed in 1 patient (0.56%). Hernias in the trocar insertion area were reported in 3 patients (1.68%). Ailments recurred in 6 patients. The recurrence of esophageal hiatal hernia was confirmed in 2 patients. Patients with recurrent hernia were re-operated using a laparoscopic approach. Conclusions Laparoscopic surgery is a simple and effective approach for patients with gastroesophageal reflux symptoms due to diaphragmatic esophageal hiatus hernia. The number of complications is lower after laparoscopic procedures than after “open” operations.

Clinical application of a rapid microbiological test based on capillary zone electrophoresis to assess local skin infection

BackgroundThe basic clinical problem associated with infection treatment is the fact that classic, commonly and routinely used isolation and identification methods are based on long-term processes of a phenotypic analysis of microorganisms. Consequently sometimes, especially in small centres, rapid implementation of antibacterial treatment becomes delayed.The work presents the initial results of rapid microbiological identification based on an original method of capillary zone electrophoresis (CZE). The study involved the analysis of 78 biological samples from post-operative wounds and trophic ulcers.ResultsThe attempt was made to identify individual bacterial species based on characteristic features of electropherograms achieved. Finally, G(+) cocci type bacteria and different G(-) rods were identified with sensitivity of 88.1% and specificity of 100%.ConclusionsBased on the clinical trials using an electrophoretic technique in the field of microbiological diagnostics of infected exudate from a post-operative wound it can be concluded that it is a rapid and relatively sensitive method for initial identification of infectious pathogens.

Transanal total mesorectal excision (TATME) – preliminary findings

Fifteen years ago, laparoscopic surgery of rectal cancer was considered as radical in terms of oncology as open surgery. A trend to reduce surgical injury may be observed in surgery in recent years. In this paper the first experience in the new minimally invasive method of anterior rectal resection is described – through the transanal way. The procedure duration was 130 min. The use of transanal access in rectal cancer surgery is undoubtedly an alternative method to standard laparoscopic surgery. In patients with a large tumour in the lower rectum, the technique allows a longer rectal stump to be left below the resection border.