Evaluation of the inflammation-based modified Glasgow Prognostic Score (mGPS) as a prognostic and predictive biomarker in patients with metastatic colorectal cancer receiving first-line chemotherapy: a post hoc analysis of the randomized phase III XELAVIRI trial (AIO KRK0110)

BACKGROUND

The inflammation-based modified Glasgow Prognostic Score (mGPS) combines serum levels of C-reactive protein and albumin and was shown to predict survival in advanced cancer. We aimed to elucidate the prognostic impact of mGPS on survival as well as its predictive value when combined with gender in unselected metastatic colorectal cancer (mCRC) patients receiving first-line chemotherapy in the randomized phase III XELAVIRI trial.

PATIENTS AND METHODS

In XELAVIRI, mCRC patients were treated with either fluoropyrimidine/bevacizumab followed by additional irinotecan at first progression (sequential treatment arm; Arm A) or upfront combination of fluoropyrimidine/bevacizumab/irinotecan (intensive treatment arm; Arm B). In the present post hoc analysis, survival was evaluated with respect to the assorted mGPS categories 0, 1 or 2. Interaction between mGPS and gender was analyzed.

RESULTS

Out of 421 mCRC patients treated in XELAVIRI, 362 [119 women (32.9%) and 243 men (67.1%)] were assessable. For the entire study population a significant association between mGPS and overall survival (OS) was observed [mGPS = 0: median 28.9 months, 95% confidence interval (CI) 25.9-33.6 months; mGPS = 1: median 21.4 months, 95% CI 17.6-26.1 months; mGPS = 2: median 16.8 months, 95% CI 14.3-21.2 months; P < 0.00001]. Similar results were found when comparing progression-free survival between groups. The effect of mGPS on survival did not depend on the applied treatment regimen (P = 0.21). In female patients, a trend towards longer OS was observed in Arm A versus Arm B, with this effect being clearly more pronounced in the mGPS cohort 0 (41.6 versus 25.5 months; P = 0.056). By contrast, median OS was longer in male patients with an mGPS of 1-2 treated in Arm B versus Arm A (20.8 versus 17.4 months; P = 0.022).

CONCLUSION

We demonstrate the role of mGPS as an independent predictor of OS regardless of the treatment regimen in mCRC patients receiving first-line treatment. mGPS may help identify gender-specific subgroups that benefit more or less from upfront intensive therapy.

Changes over time in the course of advanced pancreatic cancer treatment with systemic chemotherapy: a pooled analysis of five clinical trials from two decades of the German AIO study group

BACKGROUND

Over the past two decades, our group has conducted five multicenter trials focusing on first-line systemic therapy for patients with advanced pancreatic cancer. The current pooled analysis was designed to evaluate prognosis over time and the impact of clinical characteristics on survival.

PATIENTS AND METHODS

Individual patient data were derived from five prospective, controlled, multicenter trials conducted by the 'Arbeitsgemeinschaft Internistische Onkologie' (AIO): 'Gem/Cis', 'Ro96', 'RC57', 'ACCEPT' and 'RASH', which recruited patients between December 1997 and January 2017.

RESULTS

Overall, 912 patients were included. The median overall survival (OS) for all assessable patients was 7.1 months. OS significantly improved over time, with a median OS of 8.6 months for patients treated from 2012 to 2017 compared with 7.0 months from 1997 to 2006 [hazard ratio (HR) 1.06; P < 0.004]. Eastern Cooperative Oncology Group performance status (HR 1.48; P < 0.001), use of second-line treatment (HR 1.51; P < 0.001), and Union for International Cancer Control (UICC) stage (III versus IV) (HR 1.34, P = 0.002) had a significant impact on OS. By contrast, no influence of age and gender on OS was detectable. Comparing combination therapy with single-agent chemotherapy did not demonstrate a survival benefit, nor did regimens containing epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) such as afatinib or erlotinib, compared with chemotherapy-only arms. Patients with early-onset pancreatic cancer (age at study entry of ≤50 years, n = 102) had a similar OS compared with those >50 years (7.1 versus 7.0 months; HR 1.13; P = 0.273). The use of a platinum-containing regimen was not associated with better outcomes in patients with early-onset pancreatic cancer.

CONCLUSIONS

Within this selected group of patients treated within prospective clinical trials, survival has shown improvement over two decades. This effect is likely attributable to the availability of more effective combination therapies and treatment lines, rather than to any specific regimen, such as those containing EGFR-TKIs. In addition, concerning age and sex subgroups, the dataset did not provide evidence for distinct clinical behavior.

P-141 The good, the bad and the ugly – The fate of collapsed blastocysts in frozen embryo transfer

Study question

What is the clinical outcome of collapsed blastocysts without signals of re-expansion in frozen embryo transfers (FET)?

Summary answer

FET of non-re-expanded blastocysts after thawing showed a live-birth rate in 11.5% of the cases. Embryos vitrified on day 5 revealed the best results.

What is known already

Embryo viability is crucial for FET to be successful. Since the introduction of vitrification techniques, outcomes have improved substantially and are even comparable to fresh transfers. Nevertheless, some indicators may help predict the outcome of frozen-thawed blastocysts. Blastocoele re-expansion after thawing has been widely studied and is a strong predictor of clinical pregnancy outcome. However, accurate data on non-re-expanded blastocysts after FET is still not available. Hence, this study aims to evaluate the clinical outcome of non-re-expanded blastocyst after FET.

Study design, size, duration

The retrospective study was designed and conducted at the Kinderwunsch Institut Schenk GmbH (Dobl, Austria). Data was collected from FET performed between 2017 and 2021. In total, 104 FET cycles of collapsed blastocysts were analysed. All the transfers performed were single embryo transfers (SET). Patient’s average age was of 33.6 years at the time of embryo vitrification. Embryos were excluded if they showed more fragmentation than before vitrification.

Participants/materials, setting, methods

Patients were divided into two groups following the time of blastocyst cryopreservation: day 5 (44 SET) and day 6 (60 SET); which was dependant on the time of blastocoel expansion. They were further divided according to the trophectoderm quality: good (42 SET) and poor (62 SET) and the overall embryo quality, considering trophectoderm and inner cell mass (ICM): good (37 SET) and poor (67 SET). In both cases quality was assessed before vitrification.

Main results and the role of chance

A total of 104 collapsed blastocysts were transferred (SET). 16.3% of the patients had a positive biochemical pregnancy. 11.5% of the pregnancies resulted in a live birth and 4.8% of the pregnancies ended in abortion. FET with day 5 non-re-expanded blastocysts after thawing showed better results than day 6 thawed blastocysts regarding biochemical pregnancy (29.5% vs 6.6%, p = 0.02) and live birth rate (20.4% vs 5%, p = 0.017). Good embryo quality before vitrification showed a trend for better clinical outcome, however, results were not significant. A good trophectoderm quality before vitrification revealed a live birth rate of 16.7% compared to 8.1% in poor trophectoderm quality. Regarding overall embryo quality (trophectoderm and ICM quality) the results were 14.3% deliveries for good quality blastocysts vs 7.6% for poor quality blastocysts.

Limitations, reasons for caution

The sample size may be seen as a study limitation. However, statistically significant results were obtained. Nonetheless, results should be confirmed with a bigger sample size.

Wider implications of the findings

The present study revealed a lower chance of live birth for non-re-expanded blastocysts after thawing, which should nevertheless not be overlooked; specially in cases with good quality embryos frozen and thawed on day 5. Transfer of collapsed embryos after thawing would be recommended taking into consideration the study results.

Trial registration number

Not Applicable

P–196 Bacterial influence on oocyte quality - the secret of a successful fertilization

Study question

Is there a difference in bacterial composition of follicular fluid between oocytes developing a good quality blastocyst and oocytes that fail fertilization?

Summary answer

Follicular fluids of oocytes failing fertilization show a different bacterial profile compared to follicular fluids of oocytes that were successfully fertilized.

What is known already

The presence of pathogens in the female reproductive tract has been intensively investigated. Lactobacillus species are mainly associated with a healthy genital tract and good prognosis for a successful pregnancy. Studies of the bacterial composition of follicular fluids have been mainly undertaken in women participating in reproductive medicine treatment because of the nature to obtain the specimen. In most studies follicular fluids have been pooled for analysis. Information on separately collected follicular fluids is still rare. We hypothesized that the composition of bacteria within follicular fluids is responsible for the success of the fertilization process.

Study design, size, duration

The study was designed and conducted at the Kinderwunsch Institut Schenk GmbH (Dobl, Austria) together with DNA-Technology. Follicular fluids from 46 patients undergoing IVF (in vitro fertilization) and ICSI (intracytoplasmic sperm injection) treatment were included and analyzed.

Participants/materials, setting, methods

Follicular fluids from 46 patients were collected separately. 2 follicular fluids from each patient were screened for common bacteria of the genital tract. One from an oocyte developing a good quality blastocyst and one displaying fertilization failures. Samples were analyzed for bacterial composition using the Femoflor16 (DNA-Technology).

Main results and the role of chance

Quantitative analysis revealed a higher total bacteria mass in follicles from oocytes that failed fertilization. Furthermore, Lactobacillus were not present in those follicles compared to good blastocyst follicles. In addition, Chlamydia trachomatis was found mainly in follicular fluid of not fertilized oocytes together with Eubacterium, Gardnarella and Trichomonas species. Interestingly, a trend of elevated levels of Ureaplasma species in follicular fluids of oocytes developing good quality blastocysts was observed.

Limitations, reasons for caution

Contamination of follicular fluids due to the procedure of oocyte pick up and follicular fluid retrieval cannot be completely excluded. Results should be confirmed with a higher sample size.

Wider implications of the findings: We assume that different bacterial compositions in follicular fluids are responsible for the destiny of the oocyte. It is tempting to speculate that bacterial analysis of follicular fluids may be beneficial to select to best oocytes in future IVF/ICSI treatments.

Trial registration number

Not applicable

Clinical and molecular insights into BCG immunotherapy for melanoma

The incidence of cutaneous melanoma and the mortality rate of advanced melanoma patients continue to rise globally. Despite the recent success of immunotherapy including ipilimumab and pembrolizumab checkpoint inhibitors, a large proportion of patients are refractory to such treatment modalities. The application of mycobacteria such as Bacillus Calmette-Guérin (BCG) in the treatment of various malignancies, including cutaneous melanoma, has been clearly demonstrated after almost a century of observations and experimentation. Intralesional BCG (IL-BCG) immunotherapy is a highly efficient and cost-effective treatment option for inoperable stage III in-transit melanoma, as recommended in the National Comprehensive Cancer Network Guidelines. IL-BCG has shown great efficacy in the regression of directly injected metastatic melanoma lesions, as well as distal noninjected nodules in immunocompetent patients. Clinical and preclinical studies have shown that BCG serves as a strong immune modulator, inducing the recruitment of various immune cells that contribute to antitumour immunity. However, the specific mechanism of BCG-mediated tumour immunity remains poorly understood. Comparative genome analyses have revealed that different BCG strains exhibit distinct immunological activity and virulence, which might impact the therapeutic response and clinical outcome of patients. In this review, we discuss the immunostimulatory potential of different BCG substrains and highlight clinical studies utilizing BCG immunotherapy for the treatment of cutaneous melanoma. Furthermore, the review focuses on the cellular and molecular mechanisms of the BCG-induced immune responses of both the innate and adaptive arms of the immune system. Furthermore, the review discussed the administration of BCG as a monotherapy or in combination with other immunotherapeutic or chemotherapeutic agents.

Impact of adult attention deficit hyperactivity disorder and medication status on sleep/wake behavior and molecular circadian rhythms

Attention deficit hyperactivity disorder (ADHD) is a common neuropsychiatric condition that has been strongly associated with changes in sleep and circadian rhythms. Circadian rhythms are near 24-h cycles that are primarily generated by an endogenous circadian timekeeping system, encoded at the molecular level by a panel of clock genes. Stimulant and non-stimulant medication used in the management of ADHD has been shown to potentially impact on circadian processes and their behavioral outputs. In the current study, we have analyzed circadian rhythms in daily activity and sleep, and the circadian gene expression in a cohort of healthy controls (N = 22), ADHD participants not using ADHD-medication (N = 17), and participants with ADHD and current use of ADHD medication (N = 17). Rhythms of sleep/wake behavior were assessed via wrist-worn actigraphy, whilst rhythms of circadian gene expression were assessed ex-vivo in primary human-derived dermal fibroblast cultures. Behavioral data indicate that patients with ADHD using ADHD-medication have lower relative amplitudes of diurnal activity rhythms, lower sleep efficiency, more nocturnal activity but not more nocturnal wakenings than both controls and ADHD participants without medication. At the molecular level, there were alterations in the expression of PER2 and CRY1 between ADHD individuals with no medication compared to medicated ADHD patients or controls, whilst CLOCK expression was altered in patients with ADHD and current medication. Analysis of fibroblasts transfected with a BMAL1:luc reporter showed changes in the timing of the peak expression across the three groups. Taken together, these data support the contention that both ADHD and medication status impact on circadian processes.

Development and quality assessment of a turbid carrot-orange juice blend processed by UV-C light assisted by mild heat and addition of Yerba Mate (Ilex paraguariensis) extract

Carrot-orange juice processed by UV-C (10.6 kJ/m²) assisted with mild heat (H, 50 °C) and yerba mate addition (E) was obtained. UV-C/H + E treated juice was examined for native flora, polyphenol content (PC), total antioxidant activity (TAA), colour, turbidity, °Brix and pH along storage (4 °C). Consumer profiling studies were performed. UV-C/H + E provoked 2.6-5.7 native flora log reductions, preventing from recovery during 24 day-storage. The UV-C/H + E juice exhibited a significant increase in PC (720.2 µg/mL) and TAA (5.5 mg/mL) compared to untreated (PC = 205.0 µg/mL/TAA = 0.7 mg/mL) and single treated juices (PC = 302.1-408.0 µg/mL/TAA = 0.7-2.4 mg/mL), remaining constant throughout storage. UV-C/H + E juice exhibited scarce changes in colour. Nevertheless, increases in °Brix and turbidity were observed compared to single treatments. A cluster sensory analysis revealed that one group showed a marked interest in UVC/H + E beverages with herbal taste and strong aroma. CATA question revealed that some improvements should be introduced in order to satisfy the consumers' ideally beverage.

Efficacy of gemcitabine plus erlotinib in rash-positive patients with metastatic pancreatic cancer selected according to eligibility for FOLFIRINOX: A prospective phase II study of the 'Arbeitsgemeinschaft Internistische Onkologie'

INTRODUCTION

In metastatic pancreatic ductal adenocarcinoma (mPDAC) treatment, erlotinib is known to be more effective in patients developing skin rash. Treatment with the FOLFIRINOX regimen is only performed in fit patients following defined inclusion criteria. The present study investigates the efficacy of gemcitabine plus erlotinib (gem/erlotinib) in rash-positive patients fit for FOLFIRINOX.

PATIENTS AND METHODS

For this prospective phase II study, 150 patients were recruited in 20 centres. All patients received gem/erlotinib for 4 weeks (run-in phase); the subsequent treatment was determined by the development of skin rash: patients with rash grades 1-4 continued with gem/erlotinib, rash-negative patients were switched to FOLFIRINOX. Primary study end-point was to achieve a 1-year survival rate in rash-positive patients ≥40%.

RESULTS

Ninety patients were deemed positive for skin rash by the end of the run-in phase, showing a 1-year survival rate of 40.0% (95% confidence interval [CI] 29.8-50.9). Median overall survival (OS) was 10.1 months, progression-free survival (PFS) was 3.8 months and overall response rate (ORR) was 23.3%. Patients switched to FOLFIRINOX (n = 27) had a 1-year survival rate of 48.1% (95% CI 28.7-68.1), a median OS of 10.9 months, a median PFS of 6.6 months and an ORR of 33.3%. Rash-negative patients had a lower quality of life at baseline but seemed to experience an improved control of pain during FOLFIRINOX.

CONCLUSIONS

First-line treatment with gem/erlotinib was effective in fit, rash-positive mPDAC patients achieving a 1-year survival rate comparable to previous reports for FOLFIRINOX. The study was registered at clinicaltrials.gov (NCT0172948) and Eudra-CT (2011-005471-17).

Assessment of imatinib as first-line treatment of chronic myeloid leukemia: 10-year survival results of the randomized CML study IV and impact of non-CML determinants

Chronic myeloid leukemia (CML)-study IV was designed to explore whether treatment with imatinib (IM) at 400 mg/day (n=400) could be optimized by doubling the dose (n=420), adding interferon (IFN) (n=430) or cytarabine (n=158) or using IM after IFN-failure (n=128). From July 2002 to March 2012, 1551 newly diagnosed patients in chronic phase were randomized into a 5-arm study. The study was powered to detect a survival difference of 5% at 5 years. After a median observation time of 9.5 years, 10-year overall survival was 82%, 10-year progression-free survival was 80% and 10-year relative survival was 92%. Survival between IM400 mg and any experimental arm was not different. In a multivariate analysis, risk group, major-route chromosomal aberrations, comorbidities, smoking and treatment center (academic vs other) influenced survival significantly, but not any form of treatment optimization. Patients reaching the molecular response milestones at 3, 6 and 12 months had a significant survival advantage. For responders, monotherapy with IM400 mg provides a close to normal life expectancy independent of the time to response. Survival is more determined by patients' and disease factors than by initial treatment selection. Although improvements are also needed for refractory disease, more life-time can currently be gained by carefully addressing non-CML determinants of survival.

Finite-element-modeling of egg white as a substitute for tissue coagulation during bipolar radiofrequency-induced thermofusion

Radiofrequency-induced thermofusion is a frequently used electrosurgical procedure for the sealing of blood vessels. A disadvantage of vessel sealing instruments is that the generated thermal energy spreads to the surrounding tissue and may irreversibly damage it. This is particularly problematic when operating close to sensitive structures such as nerves. Given their advantages, there is nonetheless a lot of interest in using bipolar vessel sealing for surgical procedures. To select instruments that may be safely used in such cases, it is important to reliably quantify the thermal spread to the surrounding tissue. Mathematical models can help to evaluate the transient behavior, that is the evolution of the thermal spread over time, more precisely. A finite element model allows for a detailed analysis of inhomogeneities in the spatial temperature distribution. As a first step towards a finite model of the bipolar vessel sealing process, a model of the coagulation of chicken egg white is presented here. Egg white has thermal and electrical properties that are very similar to tissue, making it suitable as a substitute for the analysis of the coagulation process. It has the additional advantage, that the spatial and temporal evolution of the thermal spread can be visually gauged. The presented model describes the experimentally observed spatial temperature distribution, the shape of the coagulated egg white, and the formation of hotspots. Furthermore, it is shown that the model can correctly predict the shape of the coagulated egg white in further experiments.

A mathematical model of bipolar radiofrequency-induced thermofusion

Bipolar radiofrequency-induced thermofusion has become a widely accepted method successfully used in open and particularly in minimally-invasive surgery for the sealing of blood vessels and tissue of up to several millimeters diameter. Despite its wide-spread application, the thermofusion process itself is not well understood on a quantitative and dynamic level, and manufacturers largely rely on trial-and-error methods to improve existing instruments. To predict the effect of alternative generator control strategies and to allow for a more systematic approach to improve thermofusion instruments, a mathematical model of the thermofusion process is developed. The system equations describe the spatial and temporal evolution of the tissue temperature due to Joule heating and heat transfer, and the loss of tissue water due to vaporization. The resulting effects on the tissue properties, most importantly the electrical resistivity, heat capacity and thermal conductivity, are considered as well. Experimental results indicate that the extent of the lateral thermal damage is directly affected by Joule heating of the lateral tissue. The experimental findings are supported by simulation results using the proposed mathematical model of thermofusion.

Infrastructure and clinical practice for the detection and management of trauma-associated haemorrhage and coagulopathy

PURPOSE

Early detection and management of post-traumatic haemorrhage and coagulopathy have been associated with improved outcomes, but local infrastructures, logistics and clinical strategies may differ.

METHODS

To assess local differences in infrastructure, logistics and clinical management of trauma-associated haemorrhage and coagulopathy, we have conducted a web-based survey amongst the delegates to the 15th European Congress of Trauma and Emergency Surgery (ECTES) and the 2nd World Trauma (WT) Congress held in Frankfurt, Germany, 25-27 May 2014.

RESULTS

446/1,540 delegates completed the questionnaire yielding a response rate of 29%. The majority specified to work as consultants/senior physicians (47.3%) in general (36.1%) or trauma/orthopaedic surgery (44.5%) of level I (70%) or level II (19%) trauma centres. Clinical assessment (>80%) and standard coagulation assays (74.6%) are the most frequently used strategies for early detection and monitoring of bleeding trauma patients with coagulopathy. Only 30% of the respondents declared to use extended coagulation assays to better characterise the bleeding and coagulopathy prompted by more individualised treatment concepts. Most trauma centres (69%) have implemented local protocols based on international and national guidelines using conventional blood products, e.g. packed red blood cell concentrates (93.3%), fresh frozen plasma concentrates (93.3%) and platelet concentrates (83%), and antifibrinolytics (100%). 89% considered the continuous intake of anticoagulants including "new oral anticoagulants" and platelet inhibitors as an increasing threat to bleeding trauma patients.

CONCLUSIONS

This study confirms differences in infrastructure, logistics and clinical practice for the detection and management of trauma-haemorrhage and trauma-associated coagulopathy amongst international centres. Ongoing work will focus on geographical differences.

Serum vitamin D levels and hypogonadism in men

There is inconsistent evidence on a possible association of vitamin D and androgen levels in men. We therefore aim to investigate the association of 25-hydroxyvitamin D (25(OH)D) with androgen levels in a cohort of middle-aged men. This cross-sectional study included 225 men with a median (interquartile range) age of 35 (30-41) years. We measured 25(OH)D, total testosterone (TT) and SHBG concentrations. Hypogonadism was defined as TT <10.4 nmol/L. We found no significant correlation of 25(OH)D and androgen levels. Furthermore, androgen levels were not significantly different across 25(OH)D quintiles. The overall prevalence of hypogonadism was 21.5% and lowest in men within 25(OH)D quintile 4 (82-102 nmol/L). We found a significantly increased risk of hypogonadism in men within the highest 25(OH)D quintile (>102 nmol/L) compared to men in quintile 4 (reference) in crude (OR 5.10, 1.51-17.24, p = 0.009) as well as in multivariate adjusted analysis (OR 9.21, 2.27-37.35, p = 0.002). We found a trend towards increased risk of hypogonadism in men within the lowest 25(OH)D quintile (≤43.9 nmol/L). In conclusion, our data suggest that men with very high 25(OH)D levels (>102 nmol/L) might be at an increased risk of hypogonadism. Furthermore, we observed a trend towards increased risk of hypogonadism in men with very low vitamin D levels indicating a U-shaped association of vitamin D levels and hypogonadism. With respect to risk of male hypogonadism, our results suggest optimal serum 25(OH)D concentrations of 82-102 nmol/L.

From Precursors to Pollutants: Some Advances in Combustion Chemistry Diagnostics

The present assessment and prediction of potential pollutant emissions from combustion systems often rely on dedicated combustion models. Their validation depends on the critical examination of the relevant chemical reaction pathways. To this end, a number of combustion diagnostic techniques are available<br />which can probe important chemical constituents in situ, thus providing direct information on the progress of the combustion reactions. Here, some recent experimental advances for the investigation of a suite of targets from molecular intermediates and soot precursors to nascent particles will be presented. Examples include the application of quantum cascade laser absorption spectroscopy (QCLAS), molecular-beam mass<br />spectrometry (MBMS) with different ionization schemes, photoelectron–photoion coincidence (PEPICO) spectroscopy, helium ion microscopy (HIM), and polarization-modulated infrared reflection–absorption spectroscopy (PM-IRRAS).<br /><br />

[Rapid release fentanyl administration forms. Comments of the Working Group on Tumor Pain of the German Pain Society]

The spectrum of indications for rapid release fentanyl preparations is controversial. For this reason the Working Group on Tumor Pain will formulate comments on how to deal with these substances. Breakthrough pain should receive individualized therapy; therefore, the use of opioids of various galenic formulations seems to be advisable. New rapid release fentanyl preparations are suitable for alleviating spontaneous breakthrough pain in tumor patients due to a rapid but short-acting effect. However, a prior optimization of the analgesic basis medication is absolutely necessary. Uncontrolled prescription for non-cancer pain must be criticized due to the problem of addiction. The medical profession should be informed about the benefits of rapid release fentanyl preparations but must also be made aware of the risk of a rapid development of addiction and tolerance. A self-commitment of the pharmaceutical industry to waive advertising for the dangerous off-label use would be desirable. In the opinion of the Working Group on Tumor Pain the use of fentanyl should be openly discussed and further scientific investigations are imperative with the aim of formulating clear recommendations.

How much oxidative stress exists without the liver?

BACKGROUND

Oxidative stress (OS) represents an important pathogenetic factor of acute liver failure and chronic liver diseases. To elucidate whether the liver itself is a major source of OS, the present study was performed to assess OS and antioxidant status in an anhepatic porcine model.

METHODS

Six pigs underwent a total hepatectomy, five pigs were sham operated. OS and antioxidant status were evaluated by measuring plasma concentrations of malondialdehyde (MDA), xanthine oxidase (XO), superoxide dismutase (SOD) and the ferric reducing ability of plasma (FRAP). They were sampled at the start of the experiment, immediately after surgery, and then at 8 and 16 hours post hepatectomy.

RESULTS

Increased concentrations of MDA were observed in anhepatic pigs postoperatively (p < 0.02) and 8 hours after hepatectomy (p < 0.003) compared to controls. XO activity increased soon after hepatectomy (22.6 ± 5.4 mU/L versus 3.3 ± 2.1 mU/L in sham animals, p < 0.03) but returned to normal values in the further course. SOD levels did not change during the observational period in both groups. FRAP values rose significantly in the anhepatic animals compared to control (p < 0.015). A significant positive correlation was observed between MDA levels and FRAP levels (Spearman's ρ = 0.62; p < 0.0001).

CONCLUSIONS

These findings show that hepatectomy does not completely prevent the occurrence of OS because the production and regulation of OS are also located outside the liver.

Imaging nanocarbon materials: soot particles in flames are not structurally homogeneous

For the first time, nascent soot particles are probed by using helium-ion microscopy (HIM). HIM is a technique that is similar to scanning electron microscopy (SEM) but it can achieve higher contrast and improved surface sensitivity, especially for carbonaceous materials. The HIM microscope yields images with a high contrast, which allows for the unambiguous recognition of smaller nascent soot particles than those observed in previous transmission electron microscopy studies. The results indicate that HIM is ideal for rapid and reliable probing of the morphology of nascent soot, with surface details visible down to approximately 5 nm, and particles as small as 2 nm are detectable. The results also show that nascent soot is structurally and chemically inhomogeneous, and even the smallest particles can have shapes that deviate from a perfect sphere.