Intestinal permeability in patients with metastatic colon cancer treated with patupilone.

BACKGROUND: Only a limited number of cytotoxic drugs have shown activity in metastatic colorectal carcinoma. Patupilone is a novel agent with promising activity in this common cancer. Diarrhea represents the dose-limiting toxicity of patupilone. Measurement of intestinal permeability is one of the potential methods of non-invasive laboratory assessment of gastrointestinal toxicity. METHODS: We have assessed intestinal permeability by measuring absorption of lactulose, mannitol and xylose in 27 previously treated patients with metastatic colorectal cancer enrolled in a phase I trial of patupilone. RESULTS: Lactulose/mannitol and lactulose/xylose ratios increased after the treatment. Significantly higher lactulose/mannitol ratio was observed in patients who had severe diarrhea. Moreover, patients who subsequently had an adverse event of grade 3 or higher had significantly higher baseline lactulose/mannitol or lactulose/xylose ratios. CONCLUSIONS: Measurement of intestinal permeability using the lactulose/mannitol test may represent a biomarker for the monitoring, or even prediction of toxicity of cytotoxic drugs, including patupilone.

Hypomagnesaemia in patients with metastatic colorectal carcinoma treated with cetuximab.

BACKGROUND/AIMS: Cetuximab is a chimeric antibody registered for the therapy of advanced colorectal carcinoma. Among the side-effects of cetuximab hypomagnesaemia has been described, but the information is still limited. METHODOLOGY: We have evaluated retrospectively serum magnesium, potassium, calcium, creatinine and albumin in 51 consecutive patients with metastatic colorectal carcinoma treated with cetuximab, mostly combined with irinotecan-based combination chemotherapy. RESULTS: A significant decrease of serum magnesium, potassium, calcium and corrected serum calcium, creatinine and albumin concentrations was already evident one week after the start of treatment. Hypomagnesaemia of any grade was detected in 56% of evaluable patients, but grade 3 or grade 4 hypomagnesaemia was observed in 6% and 4% of patients, respectively. Grade 1 hypokalemia was detected in 47%, grade 3 in 17% and grade 4 hypokalemia was detected in 6% of the patients. Among evaluable patients grade 1 hypocalcaemia was detected in (36%), grade 2 hypocalcaemia in 42%, grade 3 in 4% and grade 4 in 13% of patients. Baseline hypocalcaemia of grade 1 or higher was associated with significantly inferior survival. CONCLUSIONS: Asymptomatic hypomagnesaemia, hypokalemia and hypocalcaemia are common in metastatic colorectal carcinoma patients treated with cetuximab. Hypocalcaemia is a predictor of poor prognosis.

Pneumocystis pneumonia during medicamentous treatment of Cushing's syndrome--a description of two cases.

Only a few cases of pneumocystis pneumonia (PCP) in Cushing's syndrome have been published in the literature so far. In the majority of these patients, the pneumonia occurred after reduction of the hypercortisolism with medicamentous treatment. We report two cases of PCP during conservative treatment of hypercortisolism. We describe clinical, imaging and laboratory findings in two patients and review published cases of pneumocystits pneumonia in Cushing's syndrome. A 60-year-old woman and 20-year-old man with Cushing's syndrome due to ectopic ACTH syndrome were treated at our department. Both developed pneumocystis pneumonia early after treatment with ketoconazole and ethomidate bromide had been introduced and the levels of cortisol rapidly decreased. PCP prophylaxis in patients with high cortisolemia should be started before treatment of hypercortisolism in current practice. Gradual lowering of plasma cortisol should also reduce the risk of infection by Pneumocystis jiroveci.

Increased melibiose/rhamnose ratio in bile of rats with acute cholestasis.

BACKGROUND AND AIM: Melibiose/rhamnose permeability test is used for noninvasive intestinal mucosa barrier testing. However, the possible escape route of the absorbed saccharides through either intact or impaired blood-biliary barriers has not so far been explored. The objective of the present study was therefore two-fold: First, to describe in detail the biliary pharmacokinetics of melibiose and rhamnose in rats; second, to evaluate the changes of both sugars' pharmacokinetics upon impairment of the blood-biliary barrier by acute extrahepatic cholestasis in rats. METHODS: Bile duct obstructed (BDO), sham-operated and intact (unoperated) male Wistar rats were administered, 24 h after the appropriate intervention, with a single intravenous dose of melibiose and rhamnose, and a 4-h pharmacokinetic study was performed. RESULTS: In intact animals, the biliary excretion of melibiose and rhamnose was only 0.06% and 0.4% of the administered dose, respectively, while the urinary excretion accounted for 70.6% and 61.7%, respectively. In BDO animals, the biliary excretion rate of both saccharides, especially that of melibiose, was increased with a consequent 4.4-fold rise of the biliary melibiose/rhamnose ratio, the accepted paracellular permeability indicator. Both, the renal clearance of melibiose and the urinary melibiose/rhamnose ratio remained uninfluenced by cholestasis. CONCLUSION: The present study is the first to describe in detail pharmacokinetic parameters and the biliary excretion of melibiose and rhamnose in healthy and cholestatic rats. The altered melibiose/rhamnose biliary excretion ratio in BDO rats indicates that the test is able to detect the impairment of the blood-biliary barrier in acute extrahepatic cholestasis.

Gamma irradiation of human leukaemic cells HL-60 and MOLT-4 induces decrease in Mcl-1 and Bid, release of cytochrome c, and activation of caspase-8 and caspase-9.

PURPOSE: Apoptosis is significantly controlled by proteins of Bcl-2 (B-cell lymphoma 2) family promoting cell death or maintaining cell survival. We selected two representatives of Bcl-2 family (anti-apoptotic Mcl-1 - myeloid cell line-1 and pro-apoptotic Bid - Bcl-2 homology domain 3 interacting death agonist), cytochrome c (cyt-c), and two initial caspases (-8 and -9) to evaluate their function in ionizing radiation (IR)-induced apoptosis in human leukaemic cell lines diverging in p53 (TP53 tumor suppressor gene) status. MATERIALS AND METHODS: A total of 30 microg of proteins of whole-cell lysates or 10 microg of mitochondrial protein fractions were electrophoretically separated and analyzed by Western-blotting. RESULTS: Here we show that in both HL-60 (p53 null) and MOLT-4 (p53 wild type) leukaemic cells the amount of Mcl-1 initially increased after irradiation by sublethal but not by lethal dose and later (when apoptosis occurred) it decreased in a dose-dependent manner. Caspase-8 was cleaved and afterwards the amount of Bid decreased as it was truncated. We also found cyt-c release from the inner mitochondrial membrane space into cytoplasm to be dose-dependent and it was followed by induction of apoptosis. In the p53-null cells caspase-8 was activated prior caspase-9, whereas the cells harboring p53 exhibited a simultaneous activation of both initial caspases. CONCLUSION: IR induced a decrease in Mcl-1, activation of Bid, caspase-8, and -9, and release of cyt-c. Presented data indicate that both extrinsic and intrinsic apoptosis signalling pathways were activated in HL-60 and MOLT-4 cells upon exposure to IR regardless to the p53 status.

Gamma-radiation-induced ATM-dependent signalling in human T-lymphocyte leukemic cells, MOLT-4.

ATM kinase (ATM) is essential for activation of cell cycle check points and DNA repair in response to ionizing radiation (IR). In this work we studied the molecular mechanisms regulating DNA repair and cell death in human T-lymphocyte leukemic cells, MOLT-4. Apoptosis was evaluated by flow-cytometric detection of annexin V. Early apoptotic cells were determined as sub-G1 cells and late apoptotic cells were determined as APO2.7-positive ones. Proteins involved in ATM signalling pathway were analysed by Western-blotting. We observed a rapid (0.5 h) phosphorylation of ATM declining after 6 h after irradiation by all the doses studied (1.5, 3.0, and 7.5 Gy). Checkpoint kinase-2 (Chk-2) was also phosphorylated after 0.5 h but its phosphorylated form persisted 4, 2, and 1 h after the doses of 1.5, 3.0, and 7.5 Gy, respectively. The amount of p53 protein and its form phosphorylated on Ser-392 increased 1 h after irradiation (1-10 Gy). The lethal dose of 7.5 Gy caused an immediate induction and phosphorylation of p53 after 0.5 h post-irradiation. At the time of phosphorylation of p53, we found simultaneous phosphorylation of the oncoprotein Mdm2 on Ser-166. Neither ATM nor its downstream targets showed a dose-dependent response after 1 h when irradiated by the doses of 1-10 Gy. MOLT-4 cells were very sensitive to the effect of IR. Even low doses, such as 1.5 Gy, induced apoptosis 16 h after irradiation (evaluated according to the cleavage of nuclear lamin B to a 48-kDa fragment). IR-induced molecular signalling after exposure to all the tested doses was triggered by rapid phosphorylation of ATM and Chk-2. Subsequent induction of p53 protein and its phosphorylation was accompanied by concomitant phosphorylation of its negative regulator, oncoprotein Mdm2, and followed by induction of apoptosis.

Successful management of infusion reaction accompanying the start of cetuximab therapy.

INTRODUCTION: Cetuximab is a chimeric antibody registered for the therapy of advanced colorectal carcinoma after failure of standard chemotherapy. Rare infusion reactions that resulted in the cessation of therapy have been described after cetuximab administration. CASE DESCRIPTION: We have observed severe infusion reactions accompanied by a loss of consciousness in two patients. The patients were transferred to intensive care unit, and the treatment was continued after administration of corticosteroids under careful monitoring of vital signs without any further serious reactions. In both cases, benefit of therapy with cetuximab could be demonstrated. CONCLUSION: This experience indicates that cetuximab can be continued in patients who experience infusion reactions. Surveillance in the intensive care unit is mandatory during readministration of the drug.

Survival of patients with colorectal cancer liver metastases treated by regional chemotherapy.

BACKGROUND/AIMS: Liver is the most common site of metastatic disease in colorectal cancer. Superior response rate was demonstrated in trials comparing hepatic arterial administration of cytotoxic agents with systemic chemotherapy. METHODOLOGY: Records of 109 consecutive patients with colorectal carcinoma metastatic to the liver treated by regional chemotherapy, who underwent implantation of a port system into hepatic artery or portal vein tributaries between 1991 and 1999, were reviewed and survival was evaluated using the log-rank test and multivariate analysis (Cox's proportional hazard regression). RESULTS: The median survival from diagnosis was 24 months. Survival was significantly longer for patients treated by radical resection, and patients treated in 1997-1999. On multivariate analysis, treatment by 6 or more chemotherapy cycles, stage 1 liver metastases, treatment with irinotecan and radical resection were associated with better survival, while the presence of extrahepatic disease had an adverse effect on the risk of death. Extrahepatic spread was subsequently detected in almost half of the patients who had originally isolated liver metastases. CONCLUSIONS: Patients treated by liver resection had the best outcome, while patients with extrahepatic diseases had poor prognosis. The prognosis of patients treated by regional chemotherapy improved significantly with the advent of irinotecan and better selection.

Regional chemotherapy in patients with breast carcinoma liver metastases.

BACKGROUND/AIMS: Although liver is a common site of metastases in breast cancer, isolated liver metastases in patients with disseminated breast cancer are rare. The role of liver-directed therapies in these patients is based on data derived from retrospective analysis of case series. METHODOLOGY: We have reviewed the records of 8 patients with liver metastases and a history of breast cancer treated at our institution over a period of 11 years with regional chemotherapy administered through surgically implanted port systems. RESULTS: Three of the patients also had a history of second primary colorectal carcinoma. One patient had evidence of extrahepatic spread. All patients were treated by regimens based on the combination of 5-fluorouracil and folinic acid. Three patients were also treated by cytoreductive procedures. The median survival times from the diagnosis and port systems implantation were 34 months and 31 months, respectively. CONCLUSIONS: Our data support the use of regional intraarterial chemotherapy in patients with metastatic breast cancer limited to the liver.

Detection of Aspergillus spp. in biological samples by real-time PCR.

BACKGROUND: Recently, the proportion of invasive infections caused by the filamentous fungi of the Aspergillus genus are growing in immunocompromised persons particularly in transplant recipients and neutropenic patients. Unfortunately, laboratory diagnostics of invasive aspergillosis remains extremely difficult, mainly with regard to the sensitivity of the methods and to the correct interpretation of the results in particular. AIM: The aim of this work was to design a standard and reproducible Aspergillus DNA detection method and its validation. The second aim was to practically use this method for diagnosis of Aspergillus DNA in various samples in patients. METHOD: Real-time PCR with two hybridization probes. Amplification and on-line quantification was carried out on a LightCycler 1.5 Instrument. RESULTS: Specificity of the reaction was tested for A. fumigatus, A. flavus, A. niger and A. terreus, and its sensitivity was determined at 5 copies per ml. The reproducibility of the results was comparable to other methods, reported in the literature. Applicability of the real-time PCR was assessed for detection of Aspergillus DNA in 354 various clinical samples taken from 179 patients at risk of invasive aspergillosis over the period of 33 months. Of 354 samples 103 (29.10 %) taken from 65 patients (36.31 %) were evaluated as positive. Over one year, the percentage of positive samples was mostly about 30 % or less per month. CONCLUSIONS: Our results demonstrate the high sensitivity, specificity and reproducibility of this technique, and its usefulness for rapid laboratory diagnosis of invasive aspergillosis.

Zinc has ambiguous effects on chromium (VI)-induced oxidative stress and apoptosis.

Zinc is an important cellular antioxidant. We investigated its role in chromium-induced oxidative stress and apoptosis in human tumor cell line Hep-2. The measured parameters included intracellular labile zinc content (Zinquin-E fluorescence), cell viability (WST-1 assay), oxidative stress (spectrophotometry), mitochondrial potential (flow cytometry), caspase-3 activity, and PARP cleavage (immunofluorescence). We found that Hep-2 cells contain abundant labile zinc stores that may be depleted by the ionophore TPEN or increased by external zinc supplementation. Chromium (VI)-induced cytotoxicity and apoptosis were enhanced in zinc-depleted cells after 24 h, in particular at chromium (VI) concentrations of 50 and 150 micromol/l. On the other hand, elevated levels of labile zinc were able to protect against apoptosis induced by 10 micromol/l chromium (VI) but at higher chromium (VI) concentrations (50 and 150 micromol/l) acted synergistically, significantly enhancing oxidative stress and the course of apoptosis, possibly through oxidative stress and mitochondrial damage.

Hexavalent chromium disrupts the actin cytoskeleton and induces mitochondria-dependent apoptosis in human dermal fibroblasts.

Exposure to hexavalent chromium causes various adverse effects including deep skin ulcerations and allergic dermatitis. Because of many potential intracellular targets for hexavalent chromium toxicity, its mechanisms of action are not entirely understood. To investigate the role of the cytoskeleton and mitochondria in this process, primary human dermal fibroblasts were exposed to various concentrations of potassium chromate for 24 h. The followed markers included cell motility, cytoskeletal organization, oxidative stress, mitochondrial activity and activation of the apoptotic cascade. Potassium chromate (1.5-45 microM) induced time- and concentration-dependent cell shrinkage, reorganization of cytoskeleton and loss of motile activity in fibroblasts. In some cells this was followed by membrane blebbing. Dynamic changes in cell morphology were accompanied with the loss of mitochondrial membrane potential, increased oxidative stress and release of cytochrome c. Apoptosis was confirmed by detection of activated caspase-3 and nuclear fragmentation. The results indicate that in fibroblasts hexavalent chromium-induced damage to cytoskeleton and mitochondria might occur concurrently at relatively early stages of exposure. Furthermore, alterations of these targets seem to activate mitochondria-dependent and- independent apoptosis.

Hepatic arterial infusion chemotherapy in sarcoma liver metastases: a report of 6 cases.

AIMS AND BACKGROUND: Liver metastases in patients with sarcoma are rare and associated with a poor prognosis. The experience with liver-directed therapies, eg hepatic arterial infusion, in these patients is limited. METHODS: Six patients with sarcoma metastatic to the liver (4 patients with gastrointestinal stromal tumors and 2 patients with leiomyosarcoma) were treated by hepatic arterial infusion in our center over a 12-year period. Since the experience was limited, a pooled analysis of reports with data on survival of 22 individual patients was performed. RESULTS: None of the 5 assessable patients responded to the therapy, and liver metastases progressed in all patients. The median survival was 20 months. In the pooled analysis, partial response was observed in 10 of 21 assessable patients (48%) and median survival was 20 months. The survival was significantly longer in responding patients compared to nonresponders (35 vs 14 months; logrank test, P = 0.009). CONCLUSIONS: Hepatic arterial infusion has little efficacy in the treatment of sarcoma metastatic to the liver. More promising results have been reported for chemoembolization. The survival of responding patients seems to be better compared to non-responders.

The changes of peripheral nerve microstructure after surgical manipulation--experiment on rat model.

The aim of our study was to describe histopathology of the peripheral nerve after its circular release followed by embedding in different environs. We operated on 18 male rats divided into 3 groups. In the first group right femoral nerve was surgically released. In the second group the nerve was enveloped by the subcutaneous fat flap. In the third one the nerve was wrapped up by the skeletal muscle. Six weeks later the animals were killed by exsanguination. The femoral nerve, in the first group, did not show any pathological changes. In the second group 3 animals appeared normal or nearly normal, nevertheless in 3 of them perineural fibrosis and axonal degeneration were observed. Histological reaction in the third group disclosed dispersed axonal injury. Our experiments using rat model imitate situation in humans. The results obtained will help us in making meaningful decision when performing peripheral nerve injury.

Hepatic arterial infusion chemotherapy in gastric cancer: a report of four cases and analysis of the literature.

AIMS AND BACKGROUND: Gastric cancer is associated with high mortality. Although the liver is a common site of metastases in this tumor, the experience with liver-directed therapies is limited. METHODS: We report a single-center experience involving four patients with liver metastases from gastric cancer treated by hepatic arterial infusion (HAI). In addition, we performed a search for reports on HAI in gastric cancer metastatic to the liver and used the studies with data on survival of individual patients for a pooled analysis. RESULTS: Among three valuable patients, one had a complete response, one had stable disease and one had progressive disease. The patient with complete response is still alive 41 months after the diagnosis of liver metastases, while the other patients died 6, 22 and 31 months after the diagnosis. Objective responses were observed in 48% of the 25 patients in the pooled analysis. Objective response and limited hepatic involvement were independent predictors of survival in these patients. CONCLUSIONS: Although isolated liver involvement in metastatic gastric cancer is rare, HAI seems to be similarly effective in these patients as in patients with liver metastases from colorectal cancer. The prognosis is significantly better in gastric cancer patients who have limited hepatic involvement and attain an objective response after HAI.

Apoptosis in Hep2 cells treated with etoposide and colchicine.

When malignant cells undergo apoptosis, they exhibit many distinct patterns of behavior, with blebbing being one of the most spectacular and mysterious features. Despite huge advancements in our understanding of cell death, the mechanisms of apoptosis associated blebbing have not been elucidated. In order to verify the putative involvement of actin and tubulin in this process, Hep2 cells were treated with a combination of etoposide (10 microg/ml) and colchicine (0.2 microg/ml) for 24 h. Blebbing was analyzed using immunofluorescence staining of actin and tubulin, and the course of apoptosis was followed by time-lapse videomicroscopy, immunofluorescence detection of caspase-3 and cytokeratin fragment 18. The results indicate that microfilaments (actin) and not microtubules (tubulin) are involved in blebbing of Hep2 cells. Furthermore, despite the different mechanisms by which both chemicals act, their combined effects are not additive, but rather eliminate each other.

[Proliferation and differentiation of neural stem cells within the subependymal layer of lateral brain ventricles in response to the neurodegenerative process in the striatum]. / Proliferace a diferenciace neurálních kmenových bunek v subependymové vrstve postranních mozkových komor v reakci na neurodegenerativní proces ve striatu.

It is known that the subependymal layer (SEL) of the lateral brain ventricles' wall is a source of neural stem cells (NSCs) of adult mammalian brain including the human brain. The NSCs in relation to the striatum differentiate only into glial phenotype. Therefore we focused on proliferative activity of NSCs and precursors in the SEL and on the course of their differentiation into the astrocytes in reaction to the neurodegenerative process in the striatum like in Huntington's disease. Increased gliogenesis, differentiation of newly generated cells and their ability to migrate into the striatum were evaluated in two groups of the rats surviving 1 and 3 months after the application of the neurotoxic (ibotenic) acid into the striatum. For evaluation of the proliferative activity we compared the results obtained using two proliferative markers--Bromodeoxyuridine (BrdU) and Ki-67. Characterization of newly generated cells and of their differentiation was based on the detection using the following antibodies: Nestin (a marker for NSCs and precursors), GFAP (detection of astrocytes), also the double-staining method with BrdU and GFAP.

Effect of therapeutic doses of ionising radiation on the somatomammotroph pituitary cell line, GH3.

Ionising radiation is used for the treatment of pituitary tumours as fractionated radiotherapy, where the total dose reaching the tumour area is in the range of 40-50 Gy, or during stereotactic radiosurgery, where the total dose reaching the tumour area during one session is in the range of 20-90 Gy. In this study, we investigated the effect of ionising radiation of (60)Co (dose rate of 3 Gy/min, similar to that used during gamma knife procedure) on the mode of cell death of the somatomammotroph pituitary cell line, GH3, an immortalized cell line derived from a rat pituitary adenoma. We found that the basic mechanism of cell death induced by irradiation of this GH3 cell line by gamma-rays was programmed cell death-apoptosis. Doses of 20-50 Gy were shown to inhibit proliferation in these cells. 24 hours after irradiation with a dose of 20 and 50 Gy, cells were shown to accumulate in the G(2)/M phase of cell cycle. This cell cycle arrest lasted for at least ten days. Apoptosis was detected 72 hours towards until the end of the study (10 days). However, a significant number of cells were still alive ten days following irradiation. We conclude that ionising radiation doses of 20 and 50 Gy induce pituitary GH3 cell apoptosis following cell cycle arrest in the G(2)/M phase.