Biomedical subjects

R Tarnawski

Publications and source records attributed to R Tarnawski.

At least 19 recordsLinked to original sources

PubMed2005

Split-course accelerated hyperfractionation (CHA-CHA) for advanced head and neck cancers -- preliminary results.

The purpose of the study was to evaluate toxicity and effectiveness of the split course, accelerated hyperfractionation with a planned gap (CHA-CHA) on a base of the pilot group treatment results. The material consisted of 27 patients with advanced (T2N2c-3, T3-4N2), oral cavity, oro- hypopharynx and larynx cancers, irradiated with a df 1.6 Gy twice a day, with 6-hour gap, up to TD 64 Gy in 28 days, with 8-day gap in a middle. Mean tumor dimensions were 4.2 and 3.9 cm in X and Y axes, respectively and mean nodes dimensions 3.9 cm in both axes. The course and intensity of the mucositis were evaluated in the Dische scale together with the degree of a tumor and nodes regression. Survival analysis and dependencies evaluation between physical/biological factors and treatment results were performed. The mucositis intensity was high from 2nd to 5th week (the highest mean - 15 Dische points in 4th week), but on acceptable level. 54.5% of CR of the tumor and 57.1% of nodes were noted. Survival analysis showed 44% of a 2-year and 35% of a 4-year OS and 44% of a 2-year and 38% of a 4-year survival excluding deaths from distant metastases. Correlation between the hemoglobin level and the nodal regression two months after the radiotherapy (p=0.01), showed the tumor diameter and TCP (p=0.047), the OS and the nodes diameter (p=0.004), the PS (p=0.02) and the hemoglobin level (p=0.04). CHA-CHA could be a valid method in advanced head and neck cancer treatment but its efficacy should be confirmed in randomized phase of trial.

Adult↗

PubMed2002

Evidence of oxidative stress in the renal cortex of diabetic rats: favourable effect of vitamin E.

The aim of this study was to determine whether there are any disturbances of red/ox balance in the renal cortex of rats during the course of experimental diabetes. In the renal cortex of rats with streptozotocin-induced diabetes, the activity of superoxide dismutase (SOD) isoenzymes, glutathione peroxidase (GSH-Pox). glutathione S-transferase (GST) and glutathione reductase (GSH-RED) was measured in the 5th, 10th and 15th weeks of diabetes. Free radical cell damage was assessed on the basis of malonyldialdehyde (MDA) concentration. The influence of lipophilic antioxidant vitamin E on these analytes was also studied. An increase in MDA concentration in the 10th and 15th weeks of diabetes correlated significantly with plasma glucose concentration (r=0.47; p<0.001). Moreover, MDA concentration was influenced by time (+); p<0.001, diabetes (+); p<0.001, vitamin E (-) p<0.001 (ANOVA). Plasma creatinine concentration in rats was elevated by diabetes (p<0.001), whereas vitamin E decreased the concentration (p<0.05). Vitamin E lowered the activity of GSHPox (p<0.001) and GST (p<0.01) (ANOVA). Our results indicate that during experimental diabetes, disturbances of red/ox balance lead to disturbance in renal function manifested as increased creatinine blood concentration. We suggest that oral supplementation of vitamin E protects the renal cortex of rats during experimental diabetes.

Animals↗

PubMed2001

Nephrotic origin hyperlipidemia, relative reduction of vitamin E level and subsequent oxidative stress may promote atherosclerosis.

BACKGROUND: The relation between nephrotic syndrome and atherosclerosis has not yet been fully clarified, although the high levels of low-density lipoprotein cholesterol usually found in this syndrome may give rise to atherosclerosis. This study was intended to test the disturbances of antioxidant/oxidant status in children with nephrotic syndrome (NS). METHODS: 8 children in the active stage (AS) of NS, 7 children during the remission stage (REM) of NS, and 14 control subjects (CTRL) were enrolled into the study. The levels of plasma total cholesterol (TC), HDL-cholesterol (HDL-chol), LDL-cholesterol (LDL-chol), triglycerides (TG), vitamin E and 7-ketocholesterol (7KCH) before and after plasma saponification were measured. RESULTS: A significant increase in the concentrations of TC, LDL-chol, vitamin E and total 7KCH in AS patients have been found. These patients had also a lower vitamin E/LDL-chol ratio. These changes have not been observed in the remission stage of nephrotic syndrome. Higher amounts of electronegatively charged-(oxidized) LDL particles as well as different oxysterols in AS patients have also been demonstrated. CONCLUSION: The study revealed significant disturbances in oxidant status during NS leading to plasma accumulation of oxidized LDL and cholesterol oxidation products that exert cytotoxicity and are known to induce atherosclerosis. We suggest that this may constitute an important link between nephrotic syndrome and atherosclerosis.

Adult↗

PubMed2000

Discriminatory power of MRI for differentiation of adrenal non-adenomas vs adenomas evaluated by means of ROC analysis: can biopsy be obviated?

The purpose of our study was to evaluate the discriminatory power of MRI in high-field magnet (1.5 T) for differentiation of adrenal non-adenomas vs adenomas assessing the following parameters separately and in combination: mean diameter of adrenal mass; previously described and new ratios as well as index calculated from signal intensity (SI) on SE T2-weighted images, chemical shift imaging (CSI), and Gd-DTPA-enhanced dynamic studies. One hundred eight adrenal masses (36 non-hyperfunctioning adenomas, 27 pheochromocytomas, 23 aldosterone-secreting adenomas, 20 malignant masses and 2 cortisol-secreting adenomas) in 95 patients were evaluated with SE sequences, CSI and Gd-DTPA dynamic studies. Indices and ratios of SI for all examined MRI methods were calculated and examined retrospectively for significance of differences between the groups with calculation of sensitivity and specificity. Receiver operating characteristics (ROC) analysis of calculated parameters in combination was performed. The multifactorial analysis of all four parameters, including size of the tumor, T2(liver) index, CSI ratio reflecting lipid content in the tumor and Wo(max/last) ratio reflecting maximal washout of contrast agent from the tumor had 100 % sensitivity and 100 % specificity in characterization of adrenal non-adenoma. The best performance of combination of mean tumor diameter with single MRI SI parameter was achieved in combination with T2(liver) index for all adrenal masses (area under ROC 0.987) and CSI ratio for non-hyperfunctioning adrenal masses (area under ROC 0.991). Magnetic resonance imaging enables sensitive and specific diagnosis of adrenal non-adenoma.

Adenoma↗

PubMed2000

Randomized clinical trial on 7-day-continuous accelerated irradiation (CAIR) of head and neck cancer - report on 3-year tumour control and normal tissue toxicity.

PURPOSE: To evaluate tumour and normal tissues 3-year response to 7-day-a-week continuous accelerated irradiation (CAIR) compared to a conventional treatment (5 days per week) in a randomized trial. MATERIALS AND METHODS: One hundred patients with squamous cell carcinoma of the head and neck in stage T(2-4)N(0-1)M(0) were entered into the trial between December 1, 1993 and June 30, 1996. Dose per fraction of 2.0 Gy (to the end of 1994), and 1.8 Gy (since January 1, 1995) was the same in both arms and delivered once a day at regular 24-h intervals to total dose in the range of 66-72 Gy (depending on tumour stage). The only difference was overall treatment time being 5 weeks in the CAIR and 7 weeks in control arm. RESULTS: Actuarial 3-year local tumour control was 82% in the CAIR and 37% in the control group (P<0.0001) with reduction in local recurrence rate of 83%. Actuarial 3-year overall survival was 78 and 32% (P<0.0001), respectively. Confluent mucositis was significantly more severe and lasted longer in the CAIR than in control arm. After 2.0 Gy fractions five of 23 patients (22%) in the CAIR developed early necroses over a period of 2-4 months of follow-up which can be considered as a consequential to severe protracted acute mucosal reactions (CLE). For this reason dose per fraction was lowered to 1. 8 Gy and the CLE was not observed again until now. Thus the overall rate of CLE decreased to 10%. CONCLUSIONS: The gain in tumour control is likely the effect of shortening of overall treatment time by 14 days and regular continuous dose delivery during the whole course of radiation therapy including weekends. A 7-day schedule produces more severe acute mucosal reactions lasting longer than in conventional fractionation, however tolerable by patients. Relatively high rate (22%) of CLE in the 7-day arm observed during the first year of the study was eliminated by decreasing dose per fraction from 2.0 Gy to 1.8 Gy.

Adult↗

PubMed2000

[Prognostic factors in radiotherapy for hypopharyngeal cancer].

This paper presents influence of selected prognostic factors on results of hypopharyngeal cancer radiotherapy used as only treatment in 97 patients irradiated in Centre of Oncology-Institute in Gliwice between 1980-1987. One-variant analysis showed statistically significant influence of gender, decrease of haemoglobin level during radiotherapy and higher T and N stages. Multivariant analysis demonstrated, that only locoregional status and treatment time has decisive importance on radiotherapy results. Thus, better results of treatment depend on lower T and N stages and correct radiotherapy time.

Adult↗

PubMed2000

The impact of delivered dose errors on local control of irradiated advanced laryngeal cancer.

On the basis of 1,015 entrance and 863 exit dose in vivo measurements, 863 calculations of midline dose were done, and the average deviation and ranges of its value were estimated. Data of 710 advanced larynx cancers were reviewed in order to achieve dose-response relationship. Patients data were fitted directly to L-Q model using maximum likelihood estimation. In 16.5% of measurements the deviation of midline dose was larger than -5.2%. A steep dose response relationship for TCP was found. Considering -5.2% deviation of 2 Gy fraction and 72 Gy of total dose, the 17% (from 48 to 31%) decrease of TCP was found. It shows that deviations of delivered dose influence the tumor control probability and that after systematic error finding during fractionated radiotherapy the value of remaining fraction size and total dose should be modified to compensate the change of TCP.

Dose-Response Relationship, Radiation↗

PubMed1999

Clinical radiobiology of glottic T1 squamous cell carcinoma.

PURPOSE: Radiation therapy is the treatment of choice for early glottic squamous cell cancer in many institutions over the world. Despite a relatively homogenous clinical model of T1 glottic tumors for the fractionation studies, the relationships between dose-time parameters remain unclear. To analyze the influence of fractionation parameters and hemoglobin level on tumor cure, this study has been performed. MATERIALS AND METHODS: This is a retrospective review of 235 patients with T1N0M0 glottic cancer treated by radiation therapy alone given in a conventional schedule with 5 fractions each week. The individual total dose, dose per fraction, and overall treatment time (OTT) ranged from 51-70 Gy, 1.5-3.0 Gy, and 24-79 days, respectively. The median follow-up was 48 months. Patient data--total dose, dose per fraction, OTT, and hemoglobin level (Hb) measured before the radiation treatment--were fitted by the mixed LQ/log-logistic model. RESULTS: The 5-year local relapse-free survival rate was 84%. All parameters included in the mixed LQ/log-logistic model improved the fit significantly. The dose-response curve for 235 patients with T1 glottic cancer was well defined and steep, and showed significant decrease in tumor control probability (TCP) when total doses were below 61 Gy. The 10-day prolongation of OTT, from 45 to 55 days, decreased the TCP by 13%. The dose of 0.35 Gy/day, compensated repopulation during the 1 day of prolongation, which indicates a potential doubling time (Tpot) for glottic T1 tumor clonogens of 5.5 days. The drop of Hb level of 1 g/dl (from 13.8 g/dl to 12.8 g/dl) gave a 6% decrease of TCP, provided that OTT was 45 days. CONCLUSION: The significant correlation between the total dose, overall treatment time, hemoglobin concentration, and tumor control probability has been found for T1 glottic cancer.

Carcinoma, Squamous Cell↗

PubMed1999

Role of short TE 1H-MR spectroscopy in monitoring of post-operation irradiated patients.

Post-surgical radiation therapy is a routine procedure in the treatment of primary malignant brain tumors. Along with modest therapeutic effects conventional fractionated radiotherapy, in spite of any modifications, produces damage to non-malignant brain tissues lying within the treatment volume, the extent of which depends on radiation dose. Serial 1H-MRS allows non-invasive investigation of tissue metabolic profiles. In the present study the ratios of resonance signals assigned to the major 1H-MRS-visible metabolites (N-acetylaspartate, choline, creatine, inositol, lactate and lipid methylene group) were evaluated before, during and after post-surgical fractionated radiotherapy in brain regions close to and more distant from the tumor bed, receiving different radiation exposures (60 and < 40 Gy, respectively). The study group consisted of ten patients (aged 28-51). A MRI/MRS system (Elscint 2T Prestige) operating at the field strength of 2 T and the proton resonance frequency of 81.3 MHz has been used and the 1H-MR spectra were acquired using single voxel double-spin-echo PRESS sequence with a short TE. The spectra were post-processed with automatic fitting in the frequency domain. It was found that although the metabolite profiles depend on the dose obtained, but other stress factors (like surgery) seem to contribute to the overall picture of the metabolic status of the brain as well. In studies of early irradiation injuries, an increase of choline related ratios may serve rather as cell proliferation indictors than as cell injury ones, whereas the mI/Cr ratio appears as one of the first indicators of local irradiation injury. In order to establish the prognostic marker for early radiation damage, however, it seems necessary to analyze all visible metabolites as well. None of the metabolites separately may serve as such an indicator due to the complexity of tissue metabolism. Interestingly, MRI reveals no changes during the therapy process, whereas the metabolite ratios are being affected in the course of time, thus supporting the presumption that the 1H-MRS is a valuable method of radiation therapy monitoring.

Adult↗

PubMed1999

[Troponin T--is it a marker of restenosis after transluminal percutaneous angioplasty in unstable angina patients?].

Troponin T (TpT) is a protein implicated in skeletal muscle contractions, including myocardium. It was shown that the presence of troponin TpT in unstable angina patients' blood is associated with poor prognosis. In the present study amongst 25 patients with unstable angina 12 were found to have TpT present in their blood. TpT concentration was higher in patients with III and IVo CCS symptoms in comparison with class I and IIo CCS symptoms: 0.207 +/- 0.275 and 0.144 +/- 0.186 ng/mL respectively (p = 0.053; nonparametric Kolmogorow-Smirnov test). Patients were subjected to percutaneous transluminal coronary angioplasty (PTCA). After 3 months of follow up 17 patients (the rest of them dropped out) were assigned to two groups: A (n = 8)--without and B (n = 9)--with clinical and electrocardiographic signs of restenosis. Retrospective analysis revealed the presence of TpT before PTCA in 6 group B patients and 2 group A patients. Relative risk of stenocardia recurrence was calculated as 2.25. TpT was present in the blood of 20 patients in the first 24 hours after PTCA, and group B patients had higher mean TpT concentration; that could result from reperfusion of more ischaemic myocardium. It seems that the presence of TpT in unstable angina patients' blood may be an important factor characterizing patients with more serious prognosis.

Angina, Unstable↗

PubMed1998

The radiosensitivity of recurrent clones of an irradiated murine squamous cell carcinoma in the in vitro megacolony system.

PURPOSE: To measure changes in spontaneous growth rate and radiation response in the progeny of irradiated squamous cell carcinoma cells. MATERIALS AND METHODS: Murine SCC cells of the line AT478 were grown as epithelial megacolonies in vitro, using both the original line and two subsequent passages derived from a clone that had recurred after a high radiation dose. Radiosensitivity was evaluated in terms of local control following single dose irradiation of standard size megacolonies (0.8 cm2). In addition, original megacolonies were given a priming dose of 20 Gy and the recurrent clones arising in situ were retreated at three dose levels for analysis of curability. RESULTS: A marked increase in radiosensitivity was observed in the megacolonies grown from irradiated progeny as compared to original megacolonies, reflected in a shift of the TCD50 from 24.5 to 16.5 Gy. Direct parameter estimation from the cure data suggested that the underlying change was a lowered number of clonogenic 'stem' cells rather than increased cellular sensitivity. A similar decrease in clonogen density was also apparent for the recurrent clones in situ. The change in megacolony curability was paralleled by a substantial growth retardation. CONCLUSION: The data demonstrate persistent changes in the progeny of irradiated SCC tumour cells that affect both growth and radiosensitivity and are compatible with the expression of delayed reproductive death.

Animals↗

PubMed1998

[The effectiveness of radiotherapy and the prognostic value of Hb level for patients with early glottic cancer (T1N0, T2N0)].

Effectiveness of radiotherapy as a sole treatment modality was analysed in a group of 225 patients with glottic cancer in stage T1 (153 patients) or T2 (72 patients) without metastases in regional neck lymph nodes. All patients were irradiated with gamma 60Co or 10 MeV photons 5 times per week conventional treatment with the dose of 2.0-2.5 Gy per fraction. The total dose was in the range of 60-70 Gy given in overall treatment time of 30-61 days. 3-year local control rate was 88% for T1 patients and 54% for T2. In group T1 total dose of 65-70 Gy correlated with a high, 94-100%, local rate whereas in group T2 for the same range of total dose, extension of overall treatment time beyond 45 days caused significant decrease in local tumour control of about 3% for each one day of treatment protraction. Moreover, the Hb level was found to be a significant prognostic factor and its value below 12 g/dl correlated with remarkably lower local control of glottic cancer of about 30% comparing with patients with Hb level above 12 g/dl.

Aged↗

PubMed1997

Prognostic value of hemoglobin concentration in radiotherapy for cancer of supraglottic larynx.

PURPOSE: The aim of this work is the estimation of correlations between hemoglobin concentration either before or after radiotherapy and local tumor control probability for laryngeal cancer. METHODS AND MATERIALS: Retrospective analysis of 847 cases of laryngeal supraglottic squamous cell carcinoma treated with radiation alone was performed using maximum likelihood estimations, and step-wise logistic regression. All patients were in good initial performance status (Karnofsky index >70). The minimum follow-up time was 3 years. RESULTS: Logistic regression showed that the hemoglobin concentration after radiotherapy is an important prognostic factor. There was a very strong correlation between hemoglobin concentration and tumor local control probability. Hemoglobin concentration at the beginning of radiotherapy does not correlate with treatment outcome, but any decrease of hemoglobin during therapy is a strong prognostic factor for treatment failure. CONCLUSIONS: Although regression models with many variables may be instable, the present results suggest that hemoglobin concentration after treatment is at least as important as overall treatment time. It was not possible to find out whether the low concentration of hemoglobin is an independent cause of low TCP or whether it reflects other mechanisms that may influence both hemoglobin level and the TCP.

Carcinoma, Squamous Cell↗

PubMed1996

Sequential combination of radio-chemotherapy (5-fluorouracil, cis-platinum and irradiation) in the management of locally advanced head and neck cancers.

Thirty-seven previously untreated patients with advanced, inoperable head and neck were treated with a sequential courses combining hypofractionated irradiation with chemotherapy (5-fluorouracil and cis-platinum). Each course was repeated every 4 weeks. Tumor response was evaluated and for 15 patients (41%) with a partial or complete regression after 3 radio-chemotherapy courses conventional radiotherapy was added. Eleven percent of all patients were in complete remission at the end of a treatment. This tumor response rate and the 50% rate of pain subside after first course for symptomatic patients contributed for a good palliative effect in the present study. However, the median survival of 7.2 months was considered unsatisfactory.

Adult↗

PubMed1995

Changes in elastin in human atherosclerotic aorta: carbon-13 magic angle sample-spinning NMR studies.

The dipolar-decoupled, natural abundance Fourier transform and cross polarization [13C] NMR spectra of human elastin isolated from atherosclerotic aorta and aortas free of atherosclerotic lesions, bovine insoluble elastin and bovine kappa-elastin were obtained at 75 MHz, with 5-7 kHz magic angle sample spinning. Spin-lattice rotating frame relaxation parameters were measured for protons (T1pH) and for carbons (T1pC) at room temperature. Proton relaxation times were shorter for bovine kappa-elastin (T1pH = 1.7 ms) than for bovine elastin (T1pH) = 3.5 ms). Calculation of T1pH showed no differences between human normal and atherosclerotic elastins. T1pC were shorter for bovine kappa-elastin than for bovine elastin. While alpha-carbons of human atherosclerotic elastin had shorter T1pC than normal elastin alpha carbons, carbons from hydrophobic amino acid side chains had longer T1pC for atherosclerotic then for normal elastin. Biochemical studies of aortic wall and purified elastin showed significantly increased content of lipids (atherosclerotic 67.7 mmol/g elastin, control 54.7 mmol/g elastin) and calcium (atherosclerotic 38.3 mmol/g elastin, control 19.6 mmol/g elastin). Changes in relaxation parameter values may be caused by the structural and biochemical changes in human elastin. Increased mobility of polypeptide chains as based on the model kappa-elastin studies is caused by the action of elastase. Restriction of mobility is expected to be caused by the accumulation of lipids and calcium.

Analysis of Variance↗

PubMed1995

[Lymph--biochemical composition, importance of its circulation in the physiology and pathology of the organism].

The lymph plasma contains various chemical constituents filtered out from the blood capillaries and metabolic or secretory products of tissue itself, and differs from tissue fluid. The various organs of the body contribute in very distinct manners to flow and composition of this main lymph. The paper presents review of the literature concerning the data on the role of lymph flow and lymph biochemistry.

Animals↗

PubMed1994

Changes of the activities of urea cycle enzymes extracted from rat liver after surgical reduction of stomach capacity and after feeding a high-fat diet.

Fourty-two Wistar FL tribe rats were divided into control groups, fed a high-fat diet or subjected to surgical reduction of stomach capacity by 75%. After 60 days of experiment we observed decrease of animal body weight gain, as well as decrease of ornithine transcarbamylase and arginase activity. As indicated by the activity of these enzymes high-fat diet leads to an increase in urea cycle activity probably due to metabolic and hormonal imbalance. The utilisation of carbamoylphosphate for the pyrimidine biosynthesis pathway did not seem to change the ATC-ase activity.

Animals↗

PubMed1994

[Measurements of amylase isoenzymes in sera and saliva of patients after radiotherapy because of larynx carcinoma].

Serum and salivary alpha-amylase were measured for controls and patients with laryngeal carcinoma before, and after localised irradiation including salivary glands. Additionally amylase isoenzymes in sera were measured using mini-column method. A significant increase in amylasemia was observed after irradiation. Alpha-amylase activity in saliva was decreased after irradiation but differences were not statistically significant due to the significant decrease of protein in saliva of irradiated group. An increase of salivary isoenzyme S activity was observed while pancreatic isoenzyme activity was not altered. This method allows easy differentiation of hyperamylasemia due to irradiation of parotid gland and disorders of the pancreas. Alpha-amylase activity measurements may detect metabolic changes in salivary glands after irradiation.

Adult↗