Quantitative evaluation of liver function with gadoxetic acid enhanced MRI: Comparison among signal intensity-, T1-relaxometry-, and dynamic-hepatocyte-specific-contrast-enhanced MRI- derived parameters.

AIMS: Three types of gadoxetic acid enhanced MRI parameters have been proposed to quantify liver function. However, until now there is no consensus on which one that has the greatest potential for use in clinical practice. This study was conducted to compare the efficacy of three types of gadoxetic acid enhanced MR parameters for quantitative assessment of liver function. METHODS: Imaging data of 10 patients with chronic liver disease and 20 healthy volunteers were analyzed. Parameters based on signal intensity(SI), T1 changes or dynamic-hepatocyte-specific-contrast-enhancement MR were calculated. Their mutual correlations, discriminatory capacity between cirrhotic and healthy liver and correlations with Child-Pugh score and Model for end-stage liver-disease (MELD) were estimated. RESULTS: The strongest correlations were observed between relative enhancement of the liver and T1 time at 20 min after contrast agent injection, and between liver-spleen contrast ratio at 20 min after contrast agent injection and hepatic uptake rate (|r|> 0.90, p < .05, both). All parameters but input-relative blood flow (p = 0.17) were significantly different between patient and control group (p < .05), with AUROCs of liver-to-muscle ratio (LMR), increase of LMR and hepatic extraction fraction greater than 0.90 (p < .05). Liver-to-spleen ratio, LMR and hepatic uptake index presented a strong correlation with Child-Pugh score and MELD (|r|> 0.8, p < .05). CONCLUSION: Simple SI-based parameters were as good as more complex parameters in evaluating liver function at gadoxetic acid enhanced MR. In clinical routine LMR seems to be the easiest-to-use parameter for quantitative evaluation of liver function.

Physical activity, post-traumatic stress disorder, and exposure to torture among asylum seekers in Sweden: a cross-sectional study.

BACKGROUND: Forced migrant populations have high rates of trauma-related ill health, including post-traumatic stress disorder (PTSD). Physical activity (PA) is well-established as an effective stress reliever, while insufficient PA is associated with adverse effects on both mental and physical health. The aim of this study was to examine the prevalence of different levels of PA and its association with PTSD symptom severity, controlled for exposure to torture, among asylum seekers in Sweden. METHODS: A cross-sectional survey study, with data from 455 asylum seekers, originating from Afghanistan, Eritrea, Iraq, Somalia, and Syria, residing at large housing facilities across Sweden. Level of PA was assessed by the Exercise Vital Sign and categorized as; Inactive, Insufficient PA, and Sufficient PA. Prevalence estimates for proportions of different levels of PA were calculated. Analysis of variance were conducted to determine the association between levels of PA and PTSD symptom severity, measured by the Harvard Trauma Questionnaire. Multivariable logistic regression analysis was performed to determine the contribution of PA on PTSD beyond sex, age, and exposure to torture. RESULTS: About half of the participants (53.3, 95% CI: 48.6-58.1) met the recommendations for Sufficient PA. One third of the participants (33.3, 95% CI: 28.7-37.8) were insufficiently engaged in PA, and 13.4% (95% CI: 10.1-16.7) were inactive. There was a significant difference in PTSD symptom severity between groups of asylum seekers with different levels of PA (F(2, 316) = 23.15, p < .001). When controlling for sex, age, and exposure to torture, Sufficient PA was found to be associated with less PTSD symptom severity compared to both Insufficient PA (B = 0.297, SE = 0.086, p < .001) and Inactive (B = 0.789, SE = 0.104, p < .001). CONCLUSIONS: Insufficient PA was common among the asylum seekers and our findings suggest that more PA is highly associated with lower PTSD symptom severity. An increased focus on assessment and promotion of PA is justified and discussed as particularly pertinent considering the much extended time of asylum-seeking processes. The results support previous evidence of PA as a potentially important factor in the context of PTSD and forced migrants' health.

Laparoscopic Roux-en-Y Gastric Bypass Without Division of the Mesentery Reduces the Risk of Postoperative Complications.

BACKGROUND: Anastomotic complications after laparoscopic Roux-en-Y gastric bypass (LRYGB) including leaks, ulceration, and stenosis remain a significant cause of post-operative morbidity and mortality. Our objective was to compare two different surgical techniques regarding short-term anastomotic complications. METHODS: A retrospective analysis of all patients operated with a primary LRYGB from 2006 to June 2015 in one institution, where prospectively collected data from an internal quality registry and medical journals were analyzed. RESULTS: In total, 2420 patients were included in the analysis. 1016 were operated with a technique where the mesentery was divided during the creation of the Roux-limb (DM-LRYGB) and 1404 were operated with a method where the mesentery was left intact (IM-LRYGB). Leakage in the first 30 days [2.6% vs. 1.1% (p < 0.05)], and ulceration or stenosis occurring during the first 6 months after surgery [5.6% vs. 0.1% (p < 0.05)] was significantly higher in the DM-LRYGB group. Adjusted odds ratio for anastomotic leak was 0.46 (95% CI 0.24-0.87) and for stenosis/ulceration 0.01 (95% CI 0.002-0.09). CONCLUSION: IM-LRYGB seems to reduce the risk of complications at the anastomosis. A plausible explanation for this is that the blood supply to the anastomosis is compromised when the mesentery is divided.

Synchronous and metachronous liver metastases in patients with colorectal cancer-towards a clinically relevant definition.

BACKGROUND: Approximately 25% of patients with colorectal cancer (CRC) will have liver metastases classified as synchronous or metachronous. There is no consensus on the defining time point for synchronous/metachronous, and the prognostic implications thereof remain unclear. The aim of the study was to assess the prognostic value of differential detection at various defining time points in a population-based patient cohort and conduct a literature review of the topic. METHODS: All patients diagnosed with CRC in the counties of Stockholm and Gotland, Sweden, during 2008 were included in the study and followed for 5 years or until death to identify patients diagnosed with liver metastases. Patients with liver metastases were followed from time of diagnosis of liver metastases for at least 5 years or until death. Different time points defining synchronous/metachronous detection, as reported in the literature and identified in a literature search of databases (PubMed, Embase, Cochrane library), were applied to the cohort, and overall survival was calculated using Kaplan-Meier curves and compared with log-rank test. The influence of synchronously or metachronously detected liver metastases on disease-free and overall survival as reported in articles forthcoming from the literature search was also assessed. RESULTS: Liver metastases were diagnosed in 272/1026 patients with CRC (26.5%). No statistically significant difference in overall survival for synchronous vs. metachronous detection at any of the defining time points (CRC diagnosis/surgery and 3, 6 and 12 months post-diagnosis/surgery) was demonstrated for operated or non-operated patients. In the literature search, 41 publications met the inclusion criteria. No clear pattern emerged regarding the prognostic significance of synchronous vs. metachronous detection. CONCLUSION: Synchronous vs. metachronous detection of CRC liver metastases lacks prognostic value. Using primary tumour diagnosis/operation as standardized cut-off point to define synchronous/metachronous detection is semantically correct. In synchronous detection, it defines a clinically relevant group of patients where individualized multimodality treatment protocols will apply.

Colorectal cancer liver metastases - a population-based study on incidence, management and survival.

BACKGROUND: Colorectal cancer (CRC) is a leading cause of cancer-associated deaths with liver metastases developing in 25-30% of those affected. Previous data suggest a survival difference between right- and left-sided liver metastatic CRC, even though left-sided cancer has a higher incidence of liver metastases. The aim of the study was to describe the liver metastatic patterns and survival as a function of the characteristics of the primary tumour and different combinations of metastatic disease. METHODS: A retrospective population-based study was performed on a cohort of patients diagnosed with CRC in the region of Stockholm, Sweden during 2008. Patients were identified through the Swedish National Quality Registry for Colorectal Cancer Treatment (SCRCR) and additional information on intra- and extra-hepatic metastatic pattern and treatment were retrieved from electronic patient records. Patients were followed for 5 years or until death. Factors influencing overall survival (OS) were investigated by means of Cox regression. OS was compared using Kaplan-Meier estimations and the log-rank test. RESULTS: Liver metastases were diagnosed in 272/1026 (26.5%) patients within five years of diagnosis of the primary. Liver and lung metastases were more often diagnosed in left-sided colon cancer compared to right-sided cancer (28.4% versus 22.1%, p = 0.029 and 19.7% versus 13.2%, p = 0.010, respectively) but the extent of liver metastases were more extensive for right-sided cancer as compared to left-sided (p = 0.001). Liver metastatic left-sided cancer, including rectal cancer, was associated with a 44% decreased mortality risk compared to right-sided cancer (HR = 0.56, 95% CI: 0.39-0.79) with a 5-year OS of 16.6% versus 4.3% (p < 0.001). In liver metastatic CRC, the presence of lung metastases did not significantly influence OS as assessed by multivariate analysis (HR = 1.11, 95% CI: 0.80-1.53). CONCLUSION: The worse survival in liver metastatic right-sided colon cancer could possibly be explained by the higher number of metastases, as well as more extensive segmental involvement compared with left-sided colon and rectal cancer, even though the latter had a higher incidence of liver metastases. Detailed population-based data on the metastatic pattern of CRC and survival could assist in more structured and individualized guidelines for follow-up of patients with CRC.

The Impact of a Hepatobiliary Multidisciplinary Team Assessment in Patients with Colorectal Cancer Liver Metastases: A Population-Based Study.

BACKGROUND: Assessing patients with colorectal cancer liver metastases (CRCLM) by a liver multidisciplinary team (MDT) results in higher resection rates and improved survival. The aim of this study was to evaluate the potentially improved resection rate in a defined cohort if all patients with CRCLM were evaluated by a liver MDT. PATIENTS AND METHODS: A retrospective analysis of patients diagnosed with colorectal cancer during 2008 in the greater Stockholm region was conducted. All patients with liver metastases (LM), detected during 5-year follow-up, were re-evaluated at a fictive liver MDT in which previous imaging studies, tumor characteristics, medical history, and patients' own treatment preferences were presented. Treatment decisions for each patient were compared to the original management. Odds ratios (ORs) and 95% confidence intervals were estimated for factors associated with referral to the liver MDT. RESULTS: Of 272 patients diagnosed with LM, 102 patients were discussed at an original liver MDT and 69 patients were eventually resected. At the fictive liver MDT, a further 22 patients were considered as resectable/potentially resectable, none previously assessed by a hepatobiliary surgeon. Factors influencing referral to liver MDT were age (OR 3.12, 1.72-5.65), American Society of Anaesthesiologists (ASA) score (OR 0.34, 0.18-0.63; ASA 2 vs. ASA 3), and number of LM (OR 0.10, 0.04-0.22; 1-5 LM vs. >10 LM), while gender (p = .194) and treatment at a teaching hospital (p = .838) were not. CONCLUSION: A meaningful number of patients with liver metastases are not managed according to best available evidence and the potential for higher resection rates is substantial. IMPLICATIONS FOR PRACTICE: Patients with liver metastatic colorectal cancer who are assessed at a hepatobiliary multidisciplinary meeting achieve higher resection rates and improved survival. Unfortunately, patients who may benefit from resection are not always properly referred. In this study, the potential improved resection rate was assessed by re-evaluating all patients with liver metastases from a population-based cohort, including patients with extrahepatic metastases and accounting for comorbidity and patients' own preferences towards treatment. An additional 12.9% of the patients were found to be potentially resectable. The results highlight the importance of all patients being evaluated in the setting of a hepatobiliary multidisciplinary meeting.

Stereotactic CT-Guided Percutaneous Microwave Ablation of Liver Tumors With the Use of High-Frequency Jet Ventilation: An Accuracy and Procedural Safety Study.

OBJECTIVE: The purpose of the present study is to evaluate the accuracy and safety of antenna placement performed with the use of a CT-guided stereotactic navigation system for percutaneous ablation of liver tumors and to assess the safety of high-frequency jet ventilation for target motion control. MATERIALS AND METHODS: Twenty consecutive patients with malignant liver lesions for which surgical resection was contraindicated or that were not readily visible on ultrasound or not accessible by ultrasound guidance were included in the study. Patients were treated with percutaneous microwave ablation performed using a CT-guided stereotactic navigation system. High-frequency jet ventilation was used to reduce liver motion during all interventions. The accuracy of antenna placement, the number of needle readjustments required, overall safety, and the radiation doses were assessed. RESULTS: Microwave ablation was completed for 20 patients (28 lesions). Performance data could be evaluated for 17 patients with 25 lesions (mean [± SD] lesion diameter, 14.9 ± 5.9 mm; mean lesion location depth, 87.5 ± 27.3 mm). The antennae were placed with a mean lateral error of 4.0 ± 2.5 mm, a depth error of 3.4 ± 3.2 mm, and a total error of 5.8 ± 3.2 mm in relation to the intended target. The median number of antenna readjustments required was zero (range, 0-1 adjustment). No major complications were related to either the procedure or the use of high-frequency jet ventilation. The mean total patient radiation dose was 957.5 ± 556.5 mGy × cm, but medical personnel were not exposed to irradiation. CONCLUSION: Percutaneous microwave ablation performed with CT-guided stereotactic navigation provides sufficient accuracy and requires almost no repositioning of the needle. Therefore, it is technically feasible and applicable for safe treatments.

A new technique for minimally invasive irreversible electroporation of tumors in the head and body of the pancreas.

BACKGROUND: Palliative irreversible electroporation of pancreatic adenocarcinomas is rapidly gaining in interest since a large proportion of these patients cannot be radically resected. METHODS: This is a description of a minimally invasive approach to irreversible electroporation of pancreatic tumors using computer-assisted navigation, laparoscopy and laparoscopic ultrasound to correctly guide electrodes into the tissue. RESULTS: The procedure is presented. CONCLUSION: Minimally invasive irreversible electroporation of pancreatic tumors through computer-assisted navigation of needles during laparoscopy is a feasible and accurate approach.

Laparoscopic image-based navigation for microwave ablation of liver tumors-A multi-center study.

BACKGROUND: Stereotactic navigation technology has been proposed to augment accuracy in targeting intrahepatic lesions for local ablation therapy. This retrospective study evaluated accuracy, efficacy, and safety when using laparoscopic image-guided microwave ablation (LIMA) for malignant liver tumors. METHODS: All patients treated for malignant liver lesions using LIMA at two European centers between 2013 and 2015 were included for analysis. A landmark-based registration technique was applied for intraoperative tumor localization and positioning of ablation probes. Intraoperative efficiency of the procedure was measured as number of registration attempts and time needed to achieve sufficient registration accuracy. Technical accuracy was assessed as Fiducial Registration Error (FRE). Outcome at 90 days including mortality, postoperative morbidity, rates of incomplete ablations, and early intrahepatic recurrences were reported. RESULTS: In 34 months, 54 interventions were performed comprising a total of 346 lesions (median lesions per patient 3 (1-25)). Eleven patients had concomitant laparoscopic resections of the liver or the colorectal primary tumor. Median time for registration was 4:38 min (0:26-19:34). Average FRE was 8.1 ± 2.8 mm. Follow-up at 90 days showed one death, 24% grade I/II, and 4% grade IIIa complications. Median length of hospital stay was 2 days (1-11). Early local recurrence was 9% per lesion and 32% per patient. Of these, 63% were successfully re-ablated within 6 months. CONCLUSIONS: LIMA does not interfere with the intraoperative workflow and results in low complication and early local recurrence rates, even when simultaneously targeting multiple lesions. LIMA may represent a valid therapy option for patients with extensive hepatic disease within a multimodal treatment approach.

The inhomogeneous distribution of liver function: possible impact on the prediction of post-operative remnant liver function.

BACKGROUND: Previous studies have shown that liver function is inhomogeneously distributed in diseased livers, and this uneven distribution cannot be compensated for if a global liver function test is used for the prediction of post-operative remnant liver function. Dynamic Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) can assess segmental liver function, thus offering the possibility to overcome this problem. METHODS: In 10 patients with liver cirrhosis and 10 normal volunteers, the contribution of individual liver segments to total liver function and volume was calculated using dynamic Gd-EOB-DTPA-enhanced MRI. Remnant liver function predictions using a segmental method and global assessment were compared for a simulated left hemihepatectomy. For the prediction based on segmental functional MRI assessment, the estimated function of the remnant liver segments was added. RESULTS: Global liver function assessment overestimated the remnant liver function in 9 out of 10 patients by as much as 9.3% [median -3.5% (-9.3-3.5%)]. In the normal volunteers there was a slight underestimation of remnant function in 9 out of 10 cases [median 1.07% (-0.7-2.5%)]. DISCUSSION: The present study underlines the necessity of a segmental liver function test able to compensate for the non-homogeneous nature of liver function, if the prediction of post-operative remnant liver function is to be improved.

Dynamic gadoxetate-enhanced MRI for the assessment of total and segmental liver function and volume in primary sclerosing cholangitis.

PURPOSE: To evaluate dynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) for the assessment of global and segmental liver volume and function in patients with primary sclerosing cholangitis (PSC), and to explore the heterogeneous distribution of liver function in this patient group. MATERIALS AND METHODS: Twelve patients with primary sclerosing cholangitis (PSC) and 20 healthy volunteers were examined using DHCE-MRI with Gd-EOB-DTPA. Segmental and total liver volume were calculated, and functional parameters (hepatic extraction fraction [HEF], input relative blood-flow [irBF], and mean transit time [MTT]) were calculated in each liver voxel using deconvolutional analysis. In each study subject, and incongruence score (IS) was constructed to describe the mismatch between segmental function and volume. Among patients, the liver function parameters were correlated to bile duct obstruction and to established scoring models for liver disease. RESULTS: Liver function was significantly more heterogeneously distributed in the patient group (IS 1.0 versus 0.4). There were significant correlations between biliary obstruction and segmental functional parameters (HEF rho -0.24; irBF rho -0.45), and the Mayo risk score correlated significantly with the total liver extraction capacity of Gd-EOB-DTPA (rho -0.85). CONCLUSION: The study demonstrates a new method to quantify total and segmental liver function using DHCE-MRI in patients with PSC.

Quantized conductance and its correlation to the supercurrent in a nanowire connected to superconductors.

We report conductance and supercurrent of InAs nanowires coupled to Al-superconducting electrodes with short channel lengths and good Ohmic contacts. The nanowires are suspended 15 nm above a local gate electrode. The charge density in the nanowires can be controlled by a small change in the gate voltage. For large negative gate voltages, the number of conducting channels is reduced gradually, and we observe a stepwise decrease of both conductance and critical current before the conductance vanishes completely.

Exploring tumor heterogeneity in colorectal liver metastases by imaging: Unsupervised machine learning of preoperative CT radiomics features for prognostic stratification.

OBJECTIVES: This study aimed to investigate tumor heterogeneity of colorectal liver metastases (CRLM) and stratify the patients into different risk groups of prognoses following liver resection by applying an unsupervised radiomics machine-learning approach to preoperative CT images. METHODS: This retrospective study retrieved clinical information and CT images of 197 patients with CRLM from The Cancer Imaging Archive (TCIA) database. Radiomics features were extracted from a segmented liver lesion identified at the portal venous phase. Those features which showed high stability, non-redundancy, and indicative information were selected. An unsupervised consensus clustering analysis on these features was adopted to identify subgroups of CRLM patients. Overall survival (OS), disease-free survival (DFS), and liver-specific DFS were compared between the identified subgroups. Cox regression analysis was applied to evaluate prognostic risk factors. RESULTS: A total of 851 radiomics features were extracted, and 56 robust features were finally selected for unsupervised clustering analysis which identified two distinct subgroups (96 and 101 patients respectively). There were significant differences in the OS, DFS, and liver-specific DFS between the subgroups (all log-rank p < 0.05). The subgroup with worse outcome using the proposed radiomics model was consistently associated with shorter OS, DFS, and liver-specific DFS, with hazard ratios of 1.78 (95 %CI: 1.12-2.83), 1.72 (95 %CI: 1.16-2.54), and 1.59 (95 %CI: 1.10-2.31), respectively. The general performance of this radiomics model outperformed the traditional Clinical Risk Score and Tumor Burden Score in the prognosis prediction after surgery for CRLM. CONCLUSION: Radiomics features derived from preoperative CT images can reveal the heterogeneity of CRLM and stratify the patients with CRLM into subgroups with significantly different clinical outcomes.

High critical-current superconductor-InAs nanowire-superconductor junctions.

We report on the fabrication of InAs nanowires coupled to superconducting leads with high critical current and widely tunable conductance. We implemented a double lift-off nanofabrication method to get very short nanowire devices with Ohmic contacts. We observe very high critical currents of up to 800 nA in a wire with a diameter of 80 nm. The current-voltage characteristics of longer and suspended nanowires display either Coulomb blockade or supercurrent depending on a local gate voltage, combining different regimes of transport in a single device.

A prospective multicentre trial on survival after Microwave Ablation VErsus Resection for Resectable Colorectal liver metastases (MAVERRIC).

AIM: This multi-centre prospective cohort study aimed to investigate non-inferiority in patients' overall survival when treating potentially resectable colorectal cancer liver metastasis (CRLM) with stereotactic microwave ablation (SMWA) as opposed to hepatic resection (HR). METHODS: Patients with no more than 5 CRLM no larger than 30 mm, deemed eligible for both SMWA and hepatic resection at the local multidisciplinary team meetings, were deliberately treated with SMWA (study group). The contemporary control group consisted of patients with no more than 5 CRLM, none larger than 30 mm, treated with HR, extracted from a prospectively maintained nationwide Swedish database. After propensity-score matching, 3-year overall survival (OS) was compared as the primary outcome using Kaplan-Meier and Cox regression analyses. RESULTS: All patients in the study group (n = 98) were matched to 158 patients from the control group (mean standardised difference in baseline covariates = 0.077). OS rates at 3 years were 78% (Confidence interval [CI] 68-85%) after SMWA versus 76% (CI 69-82%) after HR (stratified Log-rank test p = 0.861). Estimated 5-year OS rates were 56% (CI 45-66%) versus 58% (CI 50-66%). The adjusted hazard ratio for treatment type was 1.020 (CI 0.689-1.510). Overall and major complications were lower after SMWA (percentage decrease 67% and 80%, p < 0.01). Hepatic retreatments were more frequent after SMWA (percentage increase 78%, p < 0.01). CONCLUSION: SMWA is a valid curative-intent treatment alternative to surgical resection for small resectable CRLM. It represents an attractive option in terms of treatment-related morbidity with potentially wider options regarding hepatic retreatments over the future course of disease.

EORTC 1409 GITCG/ESSO 01 - A prospective colorectal liver metastasis database for borderline or initially unresectable diseases (CLIMB): Lessons learnt from real life. From paradigm to unmet need.

AIM: Multidisciplinary management of metastatic colorectal liver metastases (CRLM) is still challenging. To assess postoperative complications in initially unresectable or borderline resectable CRLM, the prospective EORTC-1409 ESSO 01-CLIMB trial capturing 'real-life data' of European centres specialized in liver surgery was initiated. MATERIAL AND METHODS: A total of 219 patients were registered between May 2015 and January 2019 from 15 centres in nine countries. Eligible patients had borderline or initially unresectable CRLM assessed by pre-operative multidisciplinary team discussion (MDT). Primary endpoints were postoperative complications, 30-day and 90-days mortality post-surgery, and quality indicators. We report the final results of the 151 eligible patients that underwent at least one liver surgery. RESULTS: Perioperative chemotherapy with or without targeted treatment were administered in 100 patients (69.4%). One stage resection (OSR) was performed in 119 patients (78.8%). Two stage resections (TSR, incl. Associating Liver Partition and Portal Vein Ligation for Staged hepatectomy (ALPPS)) were completed in 24 out of 32 patients (75%). Postoperative complications were reported in 55.5% (95% CI: 46.1-64.6%), 64.0% (95% CI: 42.5-82%), and 100% (95% CI: 59-100%) of the patients in OSR, TSR and ALPPS, respectively. Post-hepatectomy liver failure occurred in 6.7%, 20.0%, and 28.6% in OSR, TSR, and ALPPS, respectively. In total, four patients (2.6%) died after surgery. CONCLUSION: Across nine countries, OSR was more often performed than TSR and tended to result in less postoperative complications. Despite many efforts to register patients across Europe, it is still challenging to set up a prospective CRLM database.

Connecting the multiple dimensions of global soil fungal diversity.

How the multiple facets of soil fungal diversity vary worldwide remains virtually unknown, hindering the management of this essential species-rich group. By sequencing high-resolution DNA markers in over 4000 topsoil samples from natural and human-altered ecosystems across all continents, we illustrate the distributions and drivers of different levels of taxonomic and phylogenetic diversity of fungi and their ecological groups. We show the impact of precipitation and temperature interactions on local fungal species richness (alpha diversity) across different climates. Our findings reveal how temperature drives fungal compositional turnover (beta diversity) and phylogenetic diversity, linking them with regional species richness (gamma diversity). We integrate fungi into the principles of global biodiversity distribution and present detailed maps for biodiversity conservation and modeling of global ecological processes.

Pyrosequencing-derived bacterial, archaeal, and fungal diversity of spacecraft hardware destined for Mars.

Spacecraft hardware and assembly cleanroom surfaces (233 m(2) in total) were sampled, total genomic DNA was extracted, hypervariable regions of the 16S rRNA gene (bacteria and archaea) and ribosomal internal transcribed spacer (ITS) region (fungi) were subjected to 454 tag-encoded pyrosequencing PCR amplification, and 203,852 resulting high-quality sequences were analyzed. Bioinformatic analyses revealed correlations between operational taxonomic unit (OTU) abundance and certain sample characteristics, such as source (cleanroom floor, ground support equipment [GSE], or spacecraft hardware), cleaning regimen applied, and location about the facility or spacecraft. National Aeronautics and Space Administration (NASA) cleanroom floor and GSE surfaces gave rise to a larger number of diverse bacterial communities (619 OTU; 20 m(2)) than colocated spacecraft hardware (187 OTU; 162 m(2)). In contrast to the results of bacterial pyrosequencing, where at least some sequences were generated from each of the 31 sample sets examined, only 13 and 18 of these sample sets gave rise to archaeal and fungal sequences, respectively. As was the case for bacteria, the abundance of fungal OTU in the GSE surface samples dramatically diminished (9× less) once cleaning protocols had been applied. The presence of OTU representative of actinobacteria, deinococci, acidobacteria, firmicutes, and proteobacteria on spacecraft surfaces suggests that certain bacterial lineages persist even following rigorous quality control and cleaning practices. The majority of bacterial OTU observed as being recurrent belonged to actinobacteria and alphaproteobacteria, supporting the hypothesis that the measures of cleanliness exerted in spacecraft assembly cleanrooms (SAC) inadvertently select for the organisms which are the most fit to survive long journeys in space.

Multimodal perioperative assessment of liver function and volume in patients undergoing hepatectomy for colorectal liver metastasis: a comparison of the indocyanine green retention test, 99mTc mebrofenin hepatobiliary scintigraphy and gadoxetic acid enhanced MRI.

OBJECTIVES: To compare the dynamic changes in future liver remnant (FLR) function and volume after hepatectomy and to evaluate the associations between three modalities in assessment of liver function. METHODS: Liver function and volume were quantified pre-operatively, at post-operative day (POD) 7 and POD 28 in 10 patients with colorectal liver metastases undergoing hemihepatectomy using the indocyanine green retention (ICG) test, hepatobiliary scintigraphy (HBS) and gadoxetic acid-enhanced MRI. The 99mTc mebrofenin uptake rate in the FLR was applied as a reference of liver function. MRI-derived parameters including liver-to-muscle ratio (LMR), liver-to-spleen ratio (LSR) and hepatocellular uptake index (HUI) were used for liver function assessment. Spearman's correlation analysis was used to evaluate the associations. RESULTS: Increase in liver function ranged from 13 to 152% (median 92%) and in volume from 37 to 134% (median 79%). There was no significant discrepancy in increase between FLR function and volume during the first month following hepatectomy. LMR showed a significant correlation to ICG test (r = -0.66, p < 0.05) while LSR had an association with standardized FLR function obtained by HBS (r = -0.71, p < 0.05). During the first week after hepatectomy, pre-operative HUI and LMR showed the strongest correlation to the FLR growth in function and volume respectively (p < 0.05). CONCLUSION: The observed growth in FLR volume is closely related to the functional increase within 1 month after hepatectomy. Gadoxetic acid-enhanced MRI might substitute HBS for regional liver function assessment and provide an imaging tool for liver growth prediction. ADVANCES IN KNOWLEDGE: Liver function growth was parallel with liver volume increase during the perioperative period. Liver function assessment with gadoxetic acid-enhanced MRI was comparable with that of HBS indicating that gadoxetic acid-enhanced MRI could substitute HBS for regional liver function evaluation.