Urinary neopterin concentration and toxicity of radiotherapy in patients with head and neck carcinoma during external beam radiation.

AIM: Increased serum or urinary concentrations of neopterin are predictive of poor prognosis in patients with tumors across a spectrum of primary locations. Less information is available about the significance of changes of urinary neopterin concentrations during therapy. The aim of the present study was to examine the association between urinary neopterin and toxicity of radiotherapy. PATIENTS AND METHODS: We analyzed changes of urinary neopterin and toxicity of therapy in 12 patients with head and neck carcinoma during external-beam radiation. Urinary neopterin was determined daily by high-performance liquid chromatography. RESULTS: In addition to a trend for increased neopterin concentrations during radiation therapy, a significant association between changes of neopterin and toxicity and vice versa was observed with a rise of neopterin predicting a later manifestation of toxicity as well as manifestion of toxicity predicting a later rise of neopterin. CONCLUSION: Urinary neopterin is predictive of toxicity in patients with head and neck carcinoma. An association between toxicity and subsequent rise of urinary neopterin concentrations was also observed.

Application of core-shell technology for determination of retinol and alpha-tocopherol in breast milk.

Breast milk is a main source of fat-soluble vitamins for newborns and it is needful to monitor the nutritional status prior to its application. In this work a novel, high-throughput and low-cost method for monitoring of retinol and alpha-tocopherol in breast milk was developed, validated and compared with reference method using monolithic column. For this purpose five various porous shell and monolithic columns were tested on the basis of relationship between HETP and linear mobile phase velocity, analysis time and consumption of solvents. Finally the core-shell analytical column Kinetex C18 (2.6 µm, 100 Å, 100×4.6 mm) was chosen as the best and optimal values of flow rate, injection volume and temperature of analysis were established. The detection of retinol and alpha-tocopherol was carried out at 325 and 295 nm, respectively by diode array detector. The LOD 0.004 µmol/L and 0.078 µmol/L, the LOQ 0.012 µmol/L and 0.182 µmol/L for retinol and alpha-tocopherol, respectively were calculated. The validation data showed good linearity, repeatability of retention time with RSD 0.22% and 0.12%, repeatability of peak area with RSD 6.94% and 1.75%, recovery 114.1-116.3% and 99.0-108.6% for retinol and alpha-tocopherol, respectively. Moreover, the newly developed method substantially decreased the solvent consumption by about 263 mL per 100 samples with the total time of analysis 1.75 min in comparison with analysis time 1.80 of the reference method.

Prognostic significance of serum retinol, serum alpha-tocopherol, and urinary neopterin in patients with head and neck carcinoma treated with external beam radiation.

High serum or urinary neopterin concentrations are associated with poor prognosis in patients with tumors of different primary locations, but reports on neopterin in patients with head and neck carcinoma are relatively less numerous. It has been established that decreased circulating concentrations of retinol and alpha-tocopherol are common in this population. We have evaluated the prognostic significance of urinary neopterin, serum retinol, and alpha-tocopherol in 44 patients with head and neck carcinoma. Urinary neopterin, serum retinol, and alpha-tocopherol were determined with high-performance liquid chromatography. High urinary neopterin and low serum retinol were predictive of poor prognosis, while the prognostic significance of low alpha-tocopherol was of borderline significance. Serum retinol significantly decreased during external beam radiation, but a less marked decrease of alpha-tocopherol during therapy did not reach statistical significance. An increase of urinary neopterin was evident late during the course of treatment. In conclusion, high urinary neopterin and low serum retinol are predictive of poor prognosis in patients with head and neck carcinoma.

Carotid intima-media thickness and laboratory parameters of atherosclerosis risk in patients with breast cancer.

AIM: To investigate the relation between intima-media thickness (IMT) and laboratory parameters of atherosclerosis risk in patients with breast carcinoma. PATIENTS AND METHODS: IMT and a panel of laboratory parameters associated with the risk of atherosclerosis were studied in 192 patients with histologically-verified breast carcinoma. RESULTS: Patients with metastatic disease had significantly higher fibrinogen, C-reactive protein (CRP), urinary neopterin and mean IMT, and significantly lower serum albumin and hemoglobin concentrations. Significant correlations were observed between CRP, urinary neopterin, mean IMT and other parameters of cardiovascular risk. Age was an independent predictor of the presence of sonographic signs of atherosclerosis using logistic regression, and age, glucose, time from start of chemotherapy, high-density lipoprotein cholesterol, D-dimers were independently associated with IMT in stepwise regression models. CONCLUSION: In addition to the associations between IMT and laboratory or clinical parameters of the risk of atherosclerosis, IMT may also be associated with the time from chemotherapy.

Rapid sample preparation procedure for determination of retinol and α-tocopherol in human breast milk.

The liposoluble vitamins (retinol and α-tocopherol) concentration in human breast milk is of a cardinal knowledge especially for nutrition of prematurely born. It enables the feeding optimization of these important micronutrients for preterm infants. The novel rapid liquid-liquid extraction procedure for human breast milk investigation was developed and validated according to FDA guidelines. The recovery of retinol was 82-90% measured at three concentration levels 1.0, 2.5 and 5.0 µmol/L, for α-tocopherol 92-109% at concentration levels 2.5, 5.0 and 10.0 µmol/L. The repeatability of extraction procedure expressed as relative standard deviation was 3.26% for retinol and 4.79% for α-tocopherol. Developed extraction procedure was applied on 120 human breast milk samples. The separation of vitamins was completed using advantages of a monolithic column which accomplished demands of acceleration made by modern bio-analytical HPLC methodology. The analytes of interest were detected by diode-array detector at wavelengths 325 nm for retinol and 290 nm for α-tocopherol.

Determination of neopterin, kynurenine, tryptophan and creatinine in human serum by high throuput HPLC.

A new HPLC method for simultaneous determination of neopterin, creatinine, kynurenine and tryptophan in human serum was developed and validated. Monolithic stationary phase's technology (two monolithic columns RP-18e were connected with guard monolithic cartridge 4.6 mm × 50 mm+3.0 mm × 100 mm and 4.6 × 10 mm) and special auto sampler for micro titration plates (samples are storage in dark cooled place protected against evaporation) were combined with easy sample preparation step. As mobile phase 15 mmol/L phosphate buffer at pH 4.50 was used. Neopterin and tryptophan were detected using fluorescent detection and kynurenine and creatinine were detected by diode-array detection. This method may be suitable for large sequences of samples in clinical research and routine practice.

Intima-media thickness, myocardial perfusion and laboratory risk factors of atherosclerosis in patients with breast cancer treated with anthracycline-based chemotherapy.

An increased incidence of complications of atherosclerosis has been noted in cancer survivors. The aim of the present study was to evaluate, in patients with breast carcinoma, the effect of antracycline-based chemotherapy on carotid intima-media thickness (IMT), myocardial perfusion, assessed by single-photon emission tomography (SPECT) and laboratory parameters associated with the risk of atherosclerosis. Thirty-six patients with breast cancer were evaluated before and after anthracycline-based chemotherapy. Retinol, alpha-tocopherol, glycosylated hemoglobin and urinary neopterin were measured by high-performance liquid chromatography. Peripheral blood cell count, D-dimers, fibrinogen, antithrombin, glucose, magnesium, creatinine, uric acid, albumin, C-reactive protein, lipoprotein (a), cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, homocysteine, urinary albumin and N-acetyl-beta-D-glucosaminidase (NAG) were determined with routine methods. No significant differences were observed between patients and 16 controls. Compared to the measurement before the start of therapy, peripheral blood leukocyte and platelet count, hemoglobin, creatinine, HDL cholesterol, retinol, albumin, urinary albumin and NAG decreased, and total cholesterol, LDL cholesterol, triglycerides, neopterin and mean IMT increased significantly after the treatment. Of the 36 patients who had SPECT after treatment, perfusion defects were noted only in two cases, including the patient who had perfusion defects at baseline examination and a patient who did not have a baseline SPECT. In conclusion, a significant increase in carotid IMT, total cholesterol, LDL cholesterol, triglycerides and urinary neopterin and a decrease of peripheral blood leukocyte and platelet counts, hemoglobin, creatinine, HDL cholesterol, retinol, albumin and NAG were observed after the treatment.

Serum retinol, alpha-tocopherol and systemic inflammatory response in metastatic colorectal carcinoma patients treated with combination chemotherapy and cetuximab.

Cetuximab is a chimeric antibody registered for the therapy of advanced colorectal carcinoma. Cancer and anticancer therapy are associated with oxidative stress, and disorders of antioxidant balance may be involved in the toxicity associated with anticancer treatment. The aim of the present study was to investigate the changes of serum retinol, alpha-tocopherol and C-reactive protein during the first month of treatment with cetuximab and chemotherapy. Twenty-five consecutive patients with metastatic colorectal carcinoma treated with a combination of chemotherapy and cetuximab were included in the present study. Serum retinol and alpha-tocopherol were determined by high-performance liquid chromatography and serum C-reactive protein was determined using commercial kits. Significant correlation was observed between baseline concentrations of retinol and C-reactive protein (r(s)=-0.54, p<0.01). Median survival of patients who had baseline serum retinol below 1.25 µmol/L was 10 mo compared to 18 mo for patients who had serum retinol equal or above 1.25 µmol/L (p<0.05); median survival of patients who had serum C-reactive protein below 24 mg/L was significantly longer compared to patients with C-reactive protein levels equal or above 24 mg/L (18 vs. 7 mo, p<0.05), but no difference in survival was observed based on alpha-tocopherol levels. Twenty-two patients had evaluation of retinol, alpha-tocopherol and C-reactive protein at least once during the follow up. Serum concentration of alpha-tocopherol decreased significantly during the therapy, but retinol and C-reactive protein concentrations remained unchanged. In conclusion, a significant correlation was observed between serum retinol and C-reactive protein. Serum alpha-tocopherol decreased significantly during the first month of combination therapy with cetuximab. Low retinol and high C-reactive protein concentrations were predictive of poor prognosis in this patient population.

Erythrocyte alpha-tocopherol in breast cancer patients treated with letrozol.

In an earlier study, we have observed an increase of alpha-tocopherol in breast cancer patients treated with third-generation aromatase inhibitors that was related to tamoxifen withdrawal. We report here the results of measurement of alpha-tocopherol in erythrocytes and alpha-tocopherol/cholesterol ratios in patients treated with letrozol. Alpha-tocopherol in lipoprotein fractions and erythrocytes was determined by high-performance liquid chromatography in 124 post-menopausal women with breast cancer treated with letrozol immediately before the start of treatment as well as 2 and 4 mo later. After a transient decrease after 2 mo of letrozol therapy, erythrocyte alpha-tocopherol concentrations returned to pre-treatment levels 4 mo after the start of treatment. Apart from lower cholesterol in patients pre-treated with tamoxifen, no significant differences were observed at baseline between patients previously treated with tamoxifen and patients who had no prior tamoxifen in any of the other parameters investigated, but the transient decrease of erythrocyte alpha-tocopherol was observed only in patients previously treated with tamoxifen. Alpha-tocopherol content of lipoprotein fractions was significantly increased 4 mo after the start of therapy, but this increase was evident mostly in patients not treated earlier with tamoxifen. In conclusion, only minor changes of alpha-tocopherol, including a transient decrease of alpha-tocopherol in erythrocyte membranes, and an increase of alpha-tocopherol in lipoprotein fractions were observed during the first 4 mo of letrozol therapy.

Intestinal permeability, vitamin A absorption and serum alpha-tocopherol during therapy with gefitinib.

Measurement of intestinal permeability represents one of the potential methods of noninvasive laboratory assessment of gastrointestinal toxicity of anticancer therapy. We have assessed intestinal permeability (by measuring absorption of lactulose, mannitol, and xylose), vitamin A absorption and serum alpha-tocopherol in patients with non-small cell lung carcinoma or head and neck carcinomas treated with gefitinib. Lactulose, mannitol and xylose were determined by capillary gas chromatography, and retinol, alpha-tocopherol, retinyl stearate and retinyl palmitate were determined by high-performance liquid chromatography. Compared to healthy controls, patients had significantly increased lactulose/mannitol ratio and lower postprandial retinyl palmitate and retinyl stearate concentrations. Compared with pre-treatment values, xylose absorption was decreased and lactulose/mannitol and lactulose/xylose ratios were increased during the therapy. A significant decrease of serum alpha-tocopherol was evident throughout the course of therapy. In contrast, only minor alterations of vitamin A absorption were observed. In conclusion, an alteration in intestinal permeability reflected in increased lactulose/mannitol and lactulose/xylose ratios was observed during gefitinib therapy. Potential association between decreased serum alpha-tocopherol concentrations and the toxicity of gefitinib therapy should be further investigated.

Intestinal permeability, vitamin A absorption and serum alpha-tocopherol in gastrointestinal stromal tumor patients treated with imatinib.

Administration of imatinib is the therapy of choice in patients with advanced (inoperable) or metastatic gastrointestinal stromal tumors (GIST). Gastrointestinal toxicity is one of the most common side effects of anticancer therapy, including imatinib. Measurement of intestinal permeability represents a method of noninvasive laboratory assessment of gastrointestinal toxicity. We have measured intestinal permeability (by determining absorption of lactulose, mannitol and xylose), vitamin A absorption and serum alpha-tocopherol in 16 patients with advanced/metastatic GIST treated with imatinib. Lactulose/mannitol and lactulose/xylose ratios as well as parameters of vitamin A absorption did not change significantly during the treatment, but a significant decrease of alpha-tocopherol was observed. We conclude that, in contrast to most other anticancer agents studied so far, imatinib does not have an effect on intestinal permeability. No effect on vitamin A absorption was observed, but serum alpha-tocopherol decreased significantly during the treatment.

Intestinal permeability, vitamin A absorption, alpha-tocopherol, and neopterin in patients with rectal carcinoma treated with chemoradiation.

Although gastrointestinal toxicity is one of the most common side effects of anticancer therapy, the diagnosis and assessment of this toxicity still depend mostly on anamnestic data. Measurement of intestinal permeability is one of potential methods of non-invasive laboratory evaluation of gastrointestinal toxicity. The aim of the present study was to investigate intestinal permeability, vitamin A absorption, serum alpha-tocopherol, and urinary neopterin in patients with rectal carcinoma treated with chemoradiation. We have studied intestinal permeability, vitamin A absorption, serum alpha-tocopherol, and urinary neopterin in 17 patients with rectal carcinoma treated with chemoradiation. Urinary lactulose, mannitol, and xylose were measured by capillary gas chromatography, and serum alpha-tocopherol, retinol, retinyl esters, and urinary neopterin were determined by high-performance liquid chromatography. Lactulose/mannitol ratio was increased 5 and 6 weeks after the start of the treatment. Serum alpha-tocopherol was decreased significantly throughout the course of treatment, but no significant changes were observed in postprandial serum concentrations of retinyl esters or in the concentrations of urinary neopterin. A correlation was observed between baseline parameters of intestinal permeability and urinary neopterin. The measurement of intestinal permeability using the lactulose/mannitol test may represent a sensitive tool in the detection of changes associated with chemoradiation in patients with rectal carcinoma. The therapy is also associated with a decrease of alpha-tocopherol.

Serum homocysteine, cholesterol, retinol, alpha-tocopherol, glycosylated hemoglobin and inflammatory response during therapy with bevacizumab, oxaliplatin, 5-fluorouracil and leucovorin.

BACKGROUND: Targeted agents present with a new spectrum of side-effects, including toxicities that negatively impact the risk of atherosclerosis. The aim of the present study was to evaluate the effect of the combination of targeted therapy and chemotherapy on serum homocysteine and other laboratory parameters of cardiovascular risk in patients with metastatic colorectal carcinoma. PATIENTS AND METHODS: Thirty-one patients with metastatic colorectal carcinoma treated with the combination of bevacizumab, oxaliplatin, 5-fluorouracil and leucovorin were studied before and during the therapy. RESULTS: Serum homocysteine decreased significantly throughout the course of treatment. Total cholesterol and low-density lipoprotein cholesterol also decreased significantly during the first month of therapy. In contrast, serum retinol significantly increased during the second and third months of treatment. A significant increase in glycosylated hemoglobin was also observed. After an initial rise, serum C-reactive protein (CRP) and carcinoembryonic antigen (CEA) were significantly lower compared to baseline throughout the course of treatment. Serum ferritin increased throughout most of the course of treatment. A significant correlation was observed between CRP and high-density lipoprotein cholesterol, retinol, ferritin, and CEA. CEA correlated with hemoglobin, retinol, and ferritin. Retinol correlated significantly with hemoglobin. CONCLUSION: Tumor control, reflected in lower CEA, resulted in suppression of the acute phase response and generally in favorable effects on laboratory parameters indicative of risk factors of atherosclerosis, including lower homocysteine concentrations, and lower total and LDL cholesterol.

HPLC method for simultaneous determination of retinoids and tocopherols in human serum for monitoring of anticancer therapy.

A simple and rapid HPLC method requiring small volumes (250 microL) of human serum after C18 SPE sample preparation was developed using monolithic technology for simultaneous determination of all-trans-retinoic acid, 13-cis-retinoic acid, retinol, gamma- and alpha-tocopherol. The monolithic column, Chromolith Performance RP-18e (100x4.6 mm), was operated at ambient temperature. The mobile phase consisted of a mixture of acetonitrile (ACN) and 1% ammonium acetate in water (AMC) at pH 7.0. The mobile phase started at 98:2 (v/v) ACN/AMC (column pre-treatment) at a flow rate of 2 mL/min, then changed to 95:5 (v/v) ACN/AMC for 4 min at a flow rate of 1.5 mL/min and a further 3 min at a flow rate of 3.2 mL/min. Detection and identification were performed using a photodiode array detector. Retinol, 13-cis- and all-trans-retinoic acid were monitored at 325 nm. Both alpha- and gamma-tocopherol were detected at 295 nm. The total analysis time was 7.2 min. Tocol (synthesized tocopherol, not occurring in humans) was used as internal standard. The method was linear in the range of 0.125-10.00 micromol/L for all-trans-retinoic acid, 0.125-5.00 micromol/L for 13-cis-retinoic acid, 0.25-10.00 micromol/L for retinol, 0.5-50.00 micromol/L for gamma-tocopherol, and 0.5-50.00 micromol/L for alpha-tocopherol. The present method may be useful for monitoring of retinoids and tocopherols in clinical studies.