Effects of radiation therapy on myocardial cell integrity and pump function: which role for cardiac biomarkers?

BACKGROUND

Radiation therapy to the mediastinum and breast can be associated with cardiac complications. Cardiac damage may manifest early during radiation therapy or occur late, years after radiation therapy has been finished.

HYPOTHESIS

Myocardial damage is associated with the release of both troponin I (TnI) and brain natriuretic peptide (BNP). The current study sought to determine whether radiation treatment to the mediastinum and breast leads to the release of cardiac biomarkers.

METHODS

The study comprised 23 patients: 18 with lung cancer and 5 with breast cancer. Radiation therapy was performed for up to 6 weeks. Total radiation dose was >45 Gy in each patient with a dose of 1.8 Gy per fraction. Blood samples to determine TnI and BNP were taken before and once a week during radiation therapy. Echocardiography was done before and after radiation had been finished.

RESULTS

Two patients died during the study. Both TnI and BNP levels increased significantly during the study (log(10) scale); however, absolute and mean values remained on a relatively low level (mean preradiation and postradiation TnI: 0.007 +/- 0.008, 0.014 +/- 0.01 ng/ml; mean preradiation and postradiation BNP: 123 +/- 147, 159 +/- 184 pg/ml).

CONCLUSION

Radiation therapy leads to cardiac cell damage and changes in the left ventricular loading conditions as suggested by a significant increase of the cardiac biomarkers TnI and BNP. Determination of serum levels seems to be superior to echocardiography in detecting radiation-induced cardiac damage. Serial measurements of cardiac biomarkers may facilitate the management of patients undergoing radiation therapy and may help to define subgroups at high risk of developing heart failure.

Computer-aided classification of colorectal polyps based on vascular patterns: a pilot study

BACKGROUND AND STUDY AIMS

Recent studies have shown that narrow-band imaging (NBI) is a powerful diagnostic tool for differentiating between neoplastic and nonneoplastic colorectal polyps. The aim of the present study was to develop and evaluate a computer-based method for automated classification of colorectal polyps on the basis of vascularization features.

PATIENTS AND METHODS

In a prospective pilot study with 128 patients who were undergoing zoom NBI colonoscopy, 209 detected polyps were visualized and subsequently removed for histological analysis. The proposed computer-based method consists of image preprocessing, vessel segmentation, feature extraction, and classification. The results of the automated classification were compared to those of human observers blinded to the histological gold standard.

RESULTS

Consensus decision between the human observers resulted in a sensitivity of 93.8 % and a specificity of 85.7 %. A "safe" decision, i. e., classifying polyps as neoplastic in cases when there was interobserver discrepancy, yielded a sensitivity of 96.9 % and a specificity of 71.4 %. The overall correct classification rates were 91.9 % for the consensus decision and 90.9 % for the safe decision. With ideal settings the computer-based approach achieved a sensitivity of approximately 90 % and a specificity of approximately 70 %, while the overall correct classification rate was 85.3 %. The computer-based classification showed a specificity of 61.2 % when a sensitivity of 93.8 % was selected, and a 53.1 % specificity with a sensitivity of 96.9 %.

CONCLUSIONS

Automated classification of colonic polyps on the basis of NBI vascularization features is feasible, but classification by observers is still superior. Further research is needed to clarify whether the performance of the automated classification system can be improved.

Angiopoietin-2 in patients requiring renal replacement therapy in the ICU: relation to acute kidney injury, multiple organ dysfunction syndrome and outcome

PURPOSE

Endothelial activation has emerged as an early event in the pathogenesis of microcirculatory dysfunction, capillary leakage and multi-organ dysfunction syndrome (MODS). Angiopoietin-2 (Ang-2), a circulating antagonistic ligand of the endothelial-specific Tie2 receptor, has been identified as a non-redundant gatekeeper of endothelial activation. On the basis of our previous report demonstrating release of Ang-2 in endotoxemia and sepsis, we aimed to study the utility of Ang-2 to serve as an outcome-specific biomarker in patients requiring renal replacement therapy (RRT) in the intensive care unit (ICU).

METHODS

We measured circulating Ang-2 by ELISA in 117 critically ill patients with AKI at inception of RRT in the ICU. Mortality, length of stay and renal recovery were prospectively assessed during a study period of 28 days after the inception of RRT.

RESULTS

Circulating Ang-2 levels were significantly higher in AKI patients with RIFLE category-Injury or -Failure, compared to patients with RIFLE category-Risk. Elevated levels of circulating Ang-2 correlated with impaired oxygenation, low mean arterial pressure, vasopressor dose and the sequential organ failure assessment (SOFA) score. Ang-2 concentrations were significantly higher in non-survivors than in survivors at day 0 and day 14 after initiation of RRT. Multivariate Cox regression and decision tree analyses confirmed a strong independent prognostic impact of elevated Ang-2 as a predictor of 28-day survival.

CONCLUSIONS

The results from this study indicate that circulating Ang-2 is as a strong and independent predictor of mortality in ICU patients with dialysis-dependent AKI.

High-affinity blockade of voltage-operated skeletal muscle and neuronal sodium channels by halogenated propofol analogues

BACKGROUND AND PURPOSE

Voltage-operated sodium channels constitute major target sites for local anaesthetic-like action. The clinical use of local anaesthetics is still limited by severe side effects, in particular, arrhythmias and convulsions. These side effects render the search for new local anaesthetics a matter of high interest.

EXPERIMENTAL APPROACH

We have investigated the effects of three halogenated structural analogues of propofol on voltage-operated human skeletal muscle sodium channels (Na(V)1.4) and the effect of one compound (4-chloropropofol) on neuronal sodium channels (Na(V)1.2) heterologously expressed in human embryonic kidney cell line 293.

KEY RESULTS

4-Iodo-, 4-bromo- and 4-chloropropofol reversibly suppressed depolarization-induced whole-cell sodium inward currents with high potency. The IC(50) for block of resting channels at -150 mV was 2.3, 3.9 and 11.3 microM in Na(V)1.4, respectively, and 29.2 microM for 4-chloropropofol in Na(V)1.2. Membrane depolarization inducing inactivation strongly increased the blocking potency of all compounds. Estimated affinities for the fast-inactivated channel state were 81 nM, 312 nM and 227 nM for 4-iodopropofol, 4-bromopropofol and 4-chloropropofol in Na(V)1.4, and 450 nM for 4-chloropropofol in Na(V)1.2. Recovery from fast inactivation was prolonged in the presence of drug leading to an accumulation of block during repetitive stimulation at high frequencies (100 Hz).

CONCLUSIONS AND IMPLICATIONS

Halogenated propofol analogues constitute a novel class of sodium channel-blocking drugs possessing almost 100-fold higher potency compared with the local anaesthetic and anti-arrhythmic drug lidocaine. Preferential drug binding to inactivated channel states suggests that halogenated propofol analogues might be especially effective in suppressing ectopic discharges in a variety of pathological conditions.

Irinotecan/fluorouracil combination in first-line therapy of older and younger patients with metastatic colorectal cancer: combined analysis of 2,691 patients in randomized controlled trials

PURPOSE

Uncertainty exists about whether elderly patients benefit to the same extent as younger patients from combination therapy with irinotecan in the first-line treatment of metastatic colorectal cancer (CRC).

PATIENTS AND METHODS

Combined analysis was carried out with source data from the fluorouracil (FU)/folinic acid (FA) and the irinotecan/FU/FA arms of four first-line, phase III trials of CRC to investigate the efficacy and safety of combination and monotherapy in elderly (age > or = 70 years; n = 599) compared with younger (age < 70 years; n = 2,092) patients.

RESULTS

Response rates were improved with irinotecan-based combination therapy compared with FU/FA in patients both younger than 70 years and > or = 70 years (46.6% v 29.0% P < .0001; and 50.5% v 30.3%, P < .0001, respectively). With irinotecan/FU/FA, progression-free survival was better for both younger (hazard ratio [HR], 0.77; 95% CI, 0.70 to 0.85; P < .0001) and elderly patients (HR, 0.75; 95% CI, 0.61 to 0.90; P = .0026). In younger patients, overall survival was improved with combination therapy (HR, 0.83; 95% CI, 0.75 to 0.92; P = .0003). The same trend was observed in elderly patients (HR, 0.87; 95% CI, 0.72 to 1.05; P = .15). There was no significant interaction between treatment arm and age in the regression analysis. The expected differences in toxicity between combination and monotherapy in elderly and younger patients were observed. A significant interaction between treatment and age (cutoff, 70 years) for vomiting and hepatotoxicity was not confirmed by analysis that used age as a continuous variable.

CONCLUSION

Patients older than 70 years of age who were selected for inclusion in phase III trials derived similar benefits as younger patients from irinotecan-containing chemotherapy, and the risk of toxicity was similar.

Irinotecan/Fluorouracil Combination in First-Line Therapy of Older and Younger Patients With Metastatic Colorectal Cancer: Combined Analysis of 2,691 Patients in Randomized Controlled Trials

Purpose

Uncertainty exists about whether elderly patients benefit to the same extent as younger patients from combination therapy with irinotecan in the first-line treatment of metastatic colorectal cancer (CRC).

Patients and Methods

Combined analysis was carried out with source data from the fluorouracil (FU)/folinic acid (FA) and the irinotecan/FU/FA arms of four first-line, phase III trials of CRC to investigate the efficacy and safety of combination and monotherapy in elderly (age ≥ 70 years; n = 599) compared with younger (age < 70 years; n = 2,092) patients.

Results

Response rates were improved with irinotecan-based combination therapy compared with FU/FA in patients both younger than 70 years and ≥ 70 years (46.6% v 29.0% P < .0001; and 50.5% v 30.3%, P < .0001, respectively). With irinotecan/FU/FA, progression-free survival was better for both younger (hazard ratio [HR], 0.77; 95% CI, 0.70 to 0.85; P < .0001) and elderly patients (HR, 0.75; 95% CI, 0.61 to 0.90; P = .0026). In younger patients, overall survival was improved with combination therapy (HR, 0.83; 95% CI, 0.75 to 0.92; P = .0003). The same trend was observed in elderly patients (HR, 0.87; 95% CI, 0.72 to 1.05; P = .15). There was no significant interaction between treatment arm and age in the regression analysis. The expected differences in toxicity between combination and monotherapy in elderly and younger patients were observed. A significant interaction between treatment and age (cutoff, 70 years) for vomiting and hepatotoxicity was not confirmed by analysis that used age as a continuous variable.

Conclusion

Patients older than 70 years of age who were selected for inclusion in phase III trials derived similar benefits as younger patients from irinotecan-containing chemotherapy, and the risk of toxicity was similar.

Role of endotoxin in the pathogenesis of critical illness polyneuropathy

Critical illness polyneuropathy (CIP) occurs in association with sepsis and multiple organ failure; however, little is known about the pathomechanisms of CIP and its therapy. In order to determine the parameters which interfere with development of CIP, electrophysiological investigations of peripheral nerves and biochemical measures were correlated to each other. The present study includes 20 consecutive patients in an intensive care unit developing severe sepsis or septic shock. Nerve conduction studies and electromyography were performed with occurring sepsis (day 1, 7, 14) and neurophysiological parameters were correlated with biochemical measures, especially indicators of infection and inflammation. It was found that all patients developed neurophysiological signs of axonal motor polyneuropathy. There was a significant correlation between serum concentrations of endotoxin and interleukin-2 receptors (IL2-R) and reduction of the amplitude of the compound motor action potentials. Other clinical and biochemical parameters showed no significant correlations with neurophysiological data. This finding apparently indicates that endotoxin damages nerve axons directly or indirectly, e.g. by activation of inflammatory cascades (IL2-R). Endotoxin appears to be an essential factor in the pathogenesis of CIP in sepsis, and therapeutic options neutralizing endotoxin may prevent development of CIP.

Value of magnifying chromoendoscopy and narrow band imaging (NBI) in classifying colorectal polyps: a prospective controlled study

BACKGROUND AND STUDY AIMS

Chromoendoscopy in combination with magnifying endoscopy is useful in distinguishing neoplastic from non-neoplastic colorectal polyps. Narrow band imaging (NBI) has been developed as a new technique to differentiate tissue patterns in vivo. The aim of the present study was to directly compare the diagnostic values of chromoendoscopy and NBI for the differentiation of neoplastic from non-neoplastic colorectal polyps.

PATIENTS AND METHODS

In total, 200 colorectal polyps from 99 patients were distributed in a 1 : 1 ratio in order to analyze the surface according to the pit pattern classification and vascular patterns by either magnifying chromoendoscopy or NBI magnification. Histologic analysis was performed on all lesions.

RESULTS

Using the Kudo classification of mucosal patterns, NBI with magnification resulted in a sensitivity of 90.5 % and a specificity of 89.2 % for the differentiation of neoplastic vs. non-neoplastic lesions. This performance was comparable to magnifying chromoendoscopy with a sensitivity of 91.7 % and a specificity of 90 %, respectively. Using vascular patterns for differentiation, NBI with magnification correctly identified 93.7 % of neoplastic polyps and 89.2 % of non-neoplastic colorectal lesions, whereas magnifying chromoendoscopy had a specificity of 95 % but a sensitivity of only 66.7 %.

CONCLUSION

NBI in combination with magnifying endoscopy is a promising tool for the differentiation of neoplastic from non-neoplastic colorectal polyps in vivo without the necessity of using dye. The detection of capillary vessels with NBI allows the evaluation of colorectal lesions based on the vascular patterns with high diagnostic accuracy.

Correlations between magnetic resonance spectroscopy alterations and cerebral ammonia and glucose metabolism in cirrhotic patients with and without hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is considered to be mainly caused by increased ammonia metabolism of the brain. If this hypothesis is true, cerebral glucose utilisation, which is considered to represent brain function, should be closely related to cerebral ammonia metabolism. The aim of the present study was to analyse whether cerebral ammonia and glucose metabolism in cirrhotic patients with early grades of hepatic encephalopathy are as closely related as could be expected from current hypotheses on hepatic encephalopathy.

METHODS

(13)N-ammonia and (18)F-fluorodesoxyglucose positron emission tomography, magnetic resonance imaging and magnetic resonance spectroscopy (MRS) were performed in 21 cirrhotic patients with grade 0-1 hepatic encephalopathy. Quantitative values of cerebral ammonia uptake and retention rate and glucose utilisation were derived for several regions of interest and were correlated with the MRS data of the basal ganglia, white matter and frontal cortex.

RESULTS

A significant correlation between plasma ammonia levels and cerebral ammonia metabolism, respectively, and MRS alterations could be shown only for white matter. In contrast, MRS alterations in all three regions studied were significantly correlated with the glucose utilisation of several brain regions. Cerebral ammonia and glucose metabolism were not correlated.

CONCLUSION

Increase of cerebral ammonia metabolism is an important but not exclusive causal factor for the development of hepatic encephalopathy.

The type of arterial anastomosis influences hepatic hemodynamics and overall survival in liver graft recipients

AIM

Evaluation of the influence of arterial anastomoses on hepatic hemodynamics and overall survival in liver graft recipients using color Doppler ultrasound.

METHOD

224 patients recruited retrospectively were divided into five groups according to arterial anastomoses: (1) common hepatic (CHA)/gastro duodenal, (2) CHA/CHA, (3) aorta/celiac trunc, (4) aorta/aorta, (5) more than one anastomosis. We compared maximum portal [(P)Vmax], systolic [(A)Vmax] and end diastolic [(A)Vmin] arterial velocities, resistance indexes(RI), spleen and liver size between the groups. We analyzed further in a multivariate analysis the influence of time elapsed since orthotopic liver transplantation, age of recipient and donor on significant parameters as well as the overall survival of the patients between the groups.

RESULTS

Significant differences were found for: (A) Vmax between groups 2/4 (p<0.007) and 2/5 (p<0.010), (A) Vmin between groups 1/3 (p<0.029) and 2/3 (p<0.015) and RI between the groups 1/3 (p<0.018) and 3/4 (p<0.006). (A)Vmax and RI were only dependent on the type of arterial anastomosis (p<0.008 and p<0.014). The overall survival of the patients between the groups was significantly different (p<0.047).

CONCLUSION

In this study we report the natural course of the mean values of portal and arterial velocities in different arterial reconstructions for the first time. (A) Vmax of the hepatic artery is identified as the most promising candidate prognostic parameter for the assessment of hemodynamic alterations after liver transplantation originating in the type of arterial anastomosis performed. The group of patients with more than one anastomosis had the lowest arterial (A) Vmax and simultaneously the lowest overall survival.

Marrow fibrosis and its relevance during imatinib treatment of chronic myeloid leukemia

In chronic myeloid leukemia (CML), imatinib may reverse bone marrow fibrosis (MF). Whether the unfavorable prognosis of MF is also reversed and whether imatinib guarantees against evolution of MF are unclear as yet. Fifty-nine patients with Ph+ CML treated with > or = 400 mg imatinib/day were examined for MF in 6- to 12-month intervals. Imatinib effectively reversed initial MF (P<0.0005). However, during a follow-up period of up to 4.8 years, small foci with abnormal fiber increase (FFI) emerged in 8 of 30 pretreated and 6 of 29 non-pretreated patients. Patients with FFI showed a significantly lower probability of achieving a complete cytogenetic or major molecular response (36 versus 81%; P<0.007). During the further follow up, 57% of patients with FFI but none of the other patients suffered from full-blown MF (P=0.00005). None of the patients with FFI or MF showed a Janus kinase-2 mutation (V617F). Evolutions of FFI and MF were independent significant predictors of imatinib failure (P=0.0031), accelerated phase and death of patients (P=0.0001; multivariate analyses). Imatinib effectively reverses initial MF in CML, but neither eliminates its unfavorable prognosis nor guarantees completely against new evolution of MF.

The influence of blood alcohol concentrations of around 0.03% on neuropsychological functions--a double-blind, placebo-controlled investigation

There is a general agreement that blood alcohol concentrations (BACs) of about 0.05% result in impairment of the ability to drive. This fact has been supported by means of experiments. In addition, there are only a few studies to date investigating low BACs. The present study aims to investigate the extent and quality of cognitive changes in low BACs of around 0.03%. Sixteen healthy male subjects were examined in a double-blind, placebo-controlled study. During the trials the BAC was regulated to about 0.03%. As part of the study a record was made of the general level of intelligence, subjective impairments, possible depressive symptoms, general ability to perform, vigilance, divided attention, response times and performance of memory. Statistical analysis took place using the two-period crossover design. Verbal intelligence, general performance, vigilance (optical stimuli), divided attention, vigilance towards acoustic stimuli and the general response time to acoustic and visual-acoustic sequential stimuli, and memory were not impaired significantly by a BAC of around 0.03%. The total response and motor response time to optical stimuli as well as decision time about sequential optical stimuli were, however, significantly changed for BACs of around 0.03%. In conclusion, the present results show that already in BACs of around 0.03%, particular cognitive functions which rely on perception and processing of visual information, are significantly impaired. This was evident in the more complex and urgent tasks.