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Biomedical subjects

M Kamiński

Publications and source records attributed to M Kamiński.

At least 19 recordsLinked to original sources

Techniques of preparing plant material for chromatographic separation and analysis.

This paper discusses preparation techniques of samples of plant material for chromatographic analysis. Individual steps of the procedures used in sample preparation, including sample collection from the environment or from tissue cultures, drying, comminution, homogenization, leaching, extraction, distillation and condensation, analyte enrichment, and obtaining the final extracts for chromatographic analysis are discussed. The techniques most often used for isolation of analytes from homogenized plant material, i.e., Soxhlet extraction, ultrasonic solvent extraction (sonication), accelerated solvent extraction, microwave-assisted extraction, supercritical-fluid extraction, steam distillation, as well as membrane processes are emphasized. Sorptive methods of sample enrichment and removal of interferences, i.e., solid-phase extraction, and solid-phase micro-extraction are also discussed.

Chromatography↗

Procedure for and results of simultaneous determination of aromatic hydrocarbons and fatty acid methyl esters in diesel fuels by high performance liquid chromatography.

The content of aromatic hydrocarbons in diesel fuels is regulated by appropriate standards, and a further reduction in the allowed concentration of these hazardous substances in these fuels is expected. The content of aromatic hydrocarbons in diesel fuels is most often determined using standard methods EN-12916 or ASTM D-6591. The content of polycyclic aromatic hydrocarbons (PAHs) is determined from a single peak obtained using normal phase high-performance liquid chromatography (NP-HPLC), a column of the NH2 type, n-heptane as the eluent, refractive index detector (RID) and backflushing of the eluent. However, the methods mentioned above cannot be applied when the fuel contains fatty acid methyl esters (FAME), which lately has become more common. The content of FAME in diesel oils is determined using mid-IR spectrophotometry based on the absorption of carbonyl group. However, no standard procedure for the determination of classes of aromatic hydrocarbons in diesel fuels containing FAME is yet available. The present work describes such a modification of methods EN-12916/ASTM D-6591 that provides a simultaneous determination of individual groups of aromatic hydrocarbons, total content of polycyclic aromatic hydrocarbons and the FAME content in diesel fuels. The refractive index detector (RID) and n-heptane as the mobile phase are still used, but backflushing of the eluent is applied after the elution of all polycyclic aromatic hydrocarbons. Additionally, ultraviolet diode array detection is used for the exact determination of low contents of polycyclic aromatic hydrocarbons and to confirm the presence of FAME in the analyzed fuel.

Calibration↗

Experiences in kidney transplantation with duplicated ureters.

INTRODUCTION: The purpose of this study was to evaluate the complications of duplicated ureters in renal transplant recipients. METHODS: Between 1983 and 2004, 12 patients (median age 34 years) received renal transplants from donors with duplicated ureters. In four patients the ureter to bladder anastomoses were performed separately according to the method described by MacKinnon, including two cases transplanted with ureteral catheters because of narrow widths. In the following cases of eight duplicated ureters an anastomosis was performed between the distal part of each ureter to form a common ureteral ostium, which was connected to the urinary bladder. A ureteral catheter was used to the splint ureterovesical anastomosis. RESULTS: No graft loss to ureteral complications was observed. There was no ureteral necrosis in the postoperative period. No clinical symptoms of ureteral junction obstruction were revealed after removing the ureteral catheter. By ultrasound examination four patients showed a slight temporary pyelocaliectasis was observed and four patients developed temporary urinary fistulas. CONCLUSION: Our ureterocystoneostomy procedures with duplicated ureters were safe and useful in kidney transplantation.

Adult↗

Propagation of EEG activity in the beta and gamma band during movement imagery in humans.

OBJECTIVES: The objective of the paper was the determination of electrical brain activity propagation in sensorimotor areas during hand movement imagery. METHODS: Right-hand and left-hand movement imagination was studied in three subjects. The 10-channel Multivariate Autoregressive Model (MVAR) was fitted to EEG signals recorded from subsets of electrodes overlying central and related brain areas. By means of the Short-time Directed Transfer Function (SDTF) the propagation of brain activity as a function of frequency and time was found. RESULTS: During imagery the relation between propagations in gamma and beta bands changed significantly for electrodes overlying sensorimotor areas, namely the increase in gamma was accompanied by the decrease in the beta band. CONCLUSIONS: The hypothesis was put forward that these kinds of changes in flow of electrical brain activity are connected with the specific information processing.

Adolescent↗

Factors that impact on immediate graft function in patients after renal transplantation.

Kidney transplantation has become therapy of choice for patients with end-stage renal failure. However, many factors may cause graft rejection or delayed graft function, both of which decrease the prognosis for graft survival. For transplantologists the most important endeavor is to eliminate factors responsible for shortening graft function and to find those predictive of immediate graft function. The aim of the study was to investigate which factors influence early graft function. We retrospectively reviewed 442 renal transplant patients performed between 1990 and 1995 in two Szezecin units. All patients received an identical immunosuppressive drug schedule. Three hundred twelve patients who displayed immediate graft function were included in the study group to analyze donor and recipient age and sex, etiology of ESRD, HLA compatibility AB0 and Rh compatibility cold ischemia time, warm ischemia time, antileukocytes antibodies (PRA), and period of dialysis therapy before transplantation. We observed statistical significance for HLA and AB0 compatibility, younger donor age, and shorter cold ischemia time as the most important factors predictive of early graft function and an improved prognosis for graft survival.

ABO Blood-Group System↗

Variations in temperature of the donor kidney during cold ischemia time and subsequent assessment of reperfusion using the application of thermovision camera.

Cold ischemia time (CIT) and graft reperfusion events are important nonimmunological factors that influence kidney graft function. The optimal temperature for the organs during CIT ranges from 4 degrees C to 8 degrees C. However, preservation of the designated temperature is usually not controlled during standard storage procedures. Aspects of initial graft reperfusion are usually assessed indirectly. Better evaluation of the effectiveness of the early blood supply may improve the surgical outcome. The aim of the study was to monitor the temperature during CIT in the kidney and surrounding area and subsequently to assess graft reperfusion using thermography. Temperature values of the area surrounding the kidney were registered during 8 organ procurements. We observed that the area surrounding the kidney displayed the optimal temperature range only during the first 5 minutes of CIT; later the temperature oscillated between 1 degrees C and 3.5 degrees C. The study proved that the temperature of the preservation fluid is frequently below prescribed. Analysis of the thermograms of 40 transplanted kidneys with the use of a thermovision camera ThermaCAM SC500 showed usefulness of this method to assess reperfusion and blood distribution in the transplanted kidney.

Cold Temperature↗

Impact of selected factors on early graft function in patients after renal transplantation.

Transplantation is the best treatment for end-stage renal diseases. For transplantologists, it is most important to know the factors that worsen graft survival prognosis. The aim of the study was to investigate factors predictive of graft loss and shortened graft survival. We retrospectively reviewed 442 renal transplant patients between 1990 and 1995 in two Szczecin units, all of whom received a triple-drug immunosuppressive regimen. One hundred thirty patients showed graft disorders such as delayed graft function or primary nonfunction. The occurrence of these disorders was examined as a function of donor and recipient age and sex, cause of ESRD, HLA compatibility, ABO and Rh compatibility, cold ischemia time, warm ischemia time, antileukocyte antibody level (PRA), and period of dialysis therapy before transplantation. The study showed that a high maximal PRA level, incompatibility for ABO group, and a longer warm ischemia time increase the probability of early graft function disorders.

ABO Blood-Group System↗

Morphological changes in lungs, placenta, liver and kidneys of pregnant rats exposed to cigarette smoke.

OBJECTIVE: Histopathological examination of changes in foetal and newborn rats, and histopathological and morphometric assessments of changes in lungs, placenta, liver and kidneys of adult rats exposed to cigarette smoke were performed. METHODS: Non-pregnant and pregnant Wistar female rats were exposed to cigarette smoke at a carbon monoxide concentration of 1500 mg/m(3) for 6 h per day, 5 days per week, for 3 weeks. Levels of urine nicotine and cotinine were used as measures of exposure. Paraffin-embedded, haematoxylin and eosin (HE)-stained sections were used for examination. Morphometry of studied organs was performed using a computer image analyser. RESULTS: Applied smoke dose and exposure time produced dramatic histopathological changes in lungs of exposed rats (emphysema, emphysematous, inflammatory, metaplastic changes) and reduction in height of respiratory-bronchiole epithelium, and considerably less-marked morphological changes in hepatic (number of apoptotic hepatocytes) and renal (height of proximal convoluted tubule epithelium) cells as well as in the placenta (for example, size of giant cells in labyrinth, height of epithelium covering yolk sac ). Exposure to cigarette smoke did not result in histopathological changes in lungs and liver of surviving foetuses. The duration of pregnancy was not changed but a tendency for a decrease in the mothers' fertility indices as well as some changes in foetal and newborn parameters was observed. CONCLUSION: Taking into account the morphological changes observed in adult rat tissues and placentae which can result in definite hormonal and trophic effects on the foetus, the possibility of early or late physiological effects in progeny under the influence of cigarette smoke must be taken into consideration.

Animals↗

Wealth condensation in pareto macroeconomies.

We discuss a Pareto macroeconomy (a) in a closed system with fixed total wealth and (b) in an open system with average mean wealth, and compare our results to a similar analysis in a super-open system (c) with unbounded wealth [J.-P. Bouchaud and M. Mézard, Physica A 282, 536 (2000)]. Wealth condensation takes place in the social phase for closed and open economies, while it occurs in the liberal phase for super-open economies. In the first two cases, the condensation is related to a mechanism known from the balls-in-boxes model, while in the last case, to the nonintegrable tails of the Pareto distribution. For a closed macroeconomy in the social phase, we point to the emergence of a "corruption" phenomenon: a sizeable fraction of the total wealth is always amassed by a single individual.

Journal Article↗

Factors influencing low incidence of living donors for renal transplantation in Poland.

PURPOSE OF THE STUDY: To answer the question: "Why are only 3.8% of kidney transplantations in Poland from living donors?" MATERIAL AND METHODS: The research was conducted using data from anonymous polls addressed to family members of dialyzed patients (potential donors). RESULTS: Almost everybody (98%) had heard about the possibility of treating renal insufficiency by kidney transplantation, but only 77% knew about the possibility of giving their own kidney to a related person. Merely 36% had been informed about this treatment method by a doctor. The most common fears within respondents were those of: health worsening after donating a kidney--45%, and the operation itself (taking an organ)--39%.

Adult↗

Organ procurements in West Pomerania in years 2000-2001.

Year by year the actual number of transplanted organs has been growing in Poland. In the event of the Województwo Zachodniopomorskie (Western Pomeranian Province) the primary activities were focused on informing medical personnel at hospital departments about approaching donors through trainings for such medical personnel. Such activities resulted in both acceptance and support, especially by medical personnel of medium as well as lower ranks. Since 1983 two transplant units have been functioning in the Province: SPSK-2 and S. P. W. S. Z. in Szczecin, and since 2000 two co-ordination offices, too. Main result of our activities can be seen in the number of organs procured for transplantation. In 2000 we had 27.7 procurements per million (ppm), in 2001 there were 39.9 ppm.

Humans↗

Phase and amplitude analysis in time-frequency space--application to voluntary finger movement.

Two methods operating in time-frequency space were applied to analysis of EEG activity accompanying voluntary finger movements. The first one, based on matching pursuit approach provided high-resolution distributions of power in time-frequency space. The phenomena of event related desynchronization (ERD) and synchronization (ERS) were investigated without the need of band-pass filtering. Time evolution of mu- and beta-components was observed in a detailed way. The second method was based on a multichannel autoregressive model (MVAR) adapted for investigation of short-time changes in EEG signal. The direction and spectral content of the EEG activity propagation was estimated by means of short-time directed transfer function (SDTF). The evidence of 'cross-talk' between different areas of motor and sensory cortex was found. The earlier known phenomena, connected with voluntary movements, were confirmed and a new evidence concerning focal ERD/surround ERS and beta activity post-movement synchronization was found.

Algorithms↗

Evaluating causal relations in neural systems: granger causality, directed transfer function and statistical assessment of significance.

We consider the question of evaluating causal relations among neurobiological signals. In particular, we study the relation between the directed transfer function (DTF) and the well-accepted Granger causality, and show that DTF can be interpreted within the framework of Granger causality. In addition, we propose a method to assess the significance of causality measures. Finally, we demonstrate the applications of these measures to simulated data and actual neurobiological recordings.

Action Potentials↗

[Widened resection in locally advanced carcinomas of the right half of the colon].

We describe two cases of locally advanced carcinomas of the right half of colon. In spite of big tumour size and infiltration of adjacent organs we decided to perform widened "en block" resection. Microscopically no neoplastic cells were found in lymph nodes. During a year observation we did not ascertain any features of neoplasm relapse what is consistent with data published by other authors. They indicate that radical resection of big-sized tumours infiltrating adjacent organs in the case of absence of metastases into lymph nodes gives the patient a chance for long-term survival.

Adenocarcinoma↗

[Tick-borne encephalitis versus multiple sclerosis: clinical and immunological aspects].

The condition of making the diagnosis of tick-borne encephalitis is the performance of serological investigation, quite apart from careful evaluation of medical history and clinical status of patient. Contemporary diagnostics of tick-borne encephalitis uses immuno-enzymatic test (ELISA), which enables detection of specific IgM antibodies (in initial phase of disease) or IgM and IgG antibodies (in the phase of the disease with neurological symptoms). The highest diagnostic value in the infection phase of disease has the demonstration of at least fourfold increase of viral antibodies level, measured in acute phase and 2 to 6 weeks after that. In case of multiple sclerosis, a laboratory test, specific for the illness, has not been established as yet. The basis for establishing the diagnosis is the clinical picture. Results of auxiliary examinations are used for the completion of clinical evaluation and for differential diagnosis. Seroepidemiological investigations were carried out in multiple sclerosis patients to estimate the level of antibodies against tick-borne encephalitis. The investigations indicated low level of IgG antibodies in patients' serum.

Diagnosis, Differential↗

Glucose-6-phosphatase and age: biochemical and histochemical studies.

Glucose-6-phosphatase catalyzes the final reactions in both gluconeogenesis and glycolysis. It occurs mainly in glycogenic tissues, such as the liver, where it plays an important role in the synthesis of glucose, a carbohydrate essential for tissue functioning. The effect of age on liver glucose-6-phosphatase activity was evaluated in male Wistar rats treated with mixed function oxidase system (MFO) inducers. The rats were divided into the following age groups: 0.5, 1, 2, 4, 8, 12, 20 and 28 months of age. Glucose-6-phosphatase activity was evaluated biochemically and histochemically. Biochemical glucose-6-phosphatase activity increased up to the 20th month of rat life and then decreased rapidly. A similar tendency was observed in inducer-treated groups, though only dexamethasone stimulated this enzyme activity in all age groups studied. Histochemical glucose-6-phosphatase activity was strongest in the periportal zones. Glucose-6-phosphatase activity decreased significantly at month 8 and then it increased significantly until month 20. In the oldest age group, glucose-6-phosphatase activity decreased again. On histochemical analysis, the inducers used variably affected glucose-6-phosphatase activity.

Aging↗

[Merkel cell carcinoma in otolaryngology].

The authors presented two cases of Merkel cell carcinoma, a rare malignant neoplasm of neuroendocrine origin located in parabasal layer of epithelium. The first described case was 67 year old woman, after resection of primary tumor of eyelid, with metastases in lymph nodes of parotid gland. The second case was 44 year old woman with the primary tumor in retroauricular region. The patient underwent radiotherapy 23 years earlier due to malignant lymphoma. Basing on the available literature the authors discussed clinical and histological features of this malignancy, they stressed the important role of immunohistochemical tests in the diagnosis.

Adult↗

[Extracapsular spread of lymph nodes as a prognostic factor in laryngeal carcinoma].

The authors analysed clinical and morphological data of 105 patients with laryngeal carcinoma metastases in cervical lymph nodes treated in Department of Otolaryngology Medical University of Gdańsk in the years 1976-1985. The incidence of extracapsular spread and its relation to certain features of primary tumor and regional lymph nodes were estimated. The authors presented treatment results in two group of patients--with and without presence of extracapsular spread and stated prognostic value of extracapsular spread in patients with laryngeal carcinoma.

Carcinoma↗