Validating a Four-gene Set for H-ARS Severity Prediction in Peripheral Blood Samples of Irradiated Rhesus Macaques

Increased radiological and nuclear threats require preparedness. Our earlier work identified a set of four genes (DDB2, FDXR, POU2AF1 and WNT3), which predicts severity of the hematological acute radiation syndrome (H-ARS) within the first three days postirradiation In this study of 41 Rhesus macaques (Macaca mulatta, 27 males, 14 females) irradiated with 5.8-7.2 Gy (LD29-50/60), including some treated with gamma-tocotrienol (GT3, a radiation countermeasure) we independently validated these genes as predictors in both sexes and examined them after three days. At the Armed Forces Radiobiology Research Institute/Uniformed Services University of the Health Sciences, peripheral whole blood (1 ml) of Rhesus macaques was collected into PAXgene® Blood RNA tubes pre-irradiation after 1, 2, 3, 35 and 60 days postirradiation, stored at -80°C for internal experimental analyses. Leftover tubes from these already ongoing studies were kindly provided to Bundeswehr Institute of Radiobiology. RNA was isolated (QIAsymphony), converted into cDNA, and for further gene expression (GE) studies quantitative RT-PCR was performed. Differential gene expression (DGE) was measured relative to the pre-irradiation Rhesus macaques samples. Within the first three days postirradiation, we found similar results to human data: 1. FDXR and DDB2 were up-regulated, FDXR up to 3.5-fold, and DDB2 up to 13.5-fold in the median; 2. POU2AF1 appeared down regulated around tenfold in nearly all Rhesus macaques; 3. Contrary to human data, DDB2 was more up-regulated than FDXR, and the difference of the fold change (FC) ranged between 2.4 and 10, while the median fold changes of WNT3, except days 1 and 35, were close to 1. Nevertheless, 46% of the Rhesus macaques showed down-regulated WNT3 on day one postirradiation, which decreased to 12.2% on day 3 postirradiation. Considering the extended phase, there was a trend towards decreased fold changes at day 35, with median-fold changes ranging from 0.7 for DDB2 to 0.1 for POU2AF1, and on day 60 postirradiation, DGE in surviving animals was close to pre-exposure values for all four genes. In conclusion, the diagnostic significance for radiation-induced H-ARS severity prediction of FDXR, DDB2, and POU2AF1 was confirmed in this Rhesus macaques model. However, DDB2 showed higher GE values than FDXR. As shown in previous studies, the diagnostic significance of WNT3 could not be reproduced in Rhesus macaques; this could be due to the choice of animal model and methodological challenges.

Validating Radiosensitivity with Pre-Exposure Differential Gene Expression in Peripheral Blood Predicting Survival and Non-Survival in a Second Irradiated Rhesus Macaque Cohort

Radiosensitivity differs in humans and possibly in closely related nonhuman primates. The reasons for variation in radiosensitivity are not well known. In an earlier study, we examined gene expression (GE) pre-radiation in peripheral blood among male (n = 62) and female (n = 60) rhesus macaques (n = 122), which did or did not survive (up to 60 days) after whole-body exposure of 7.0 Gy (LD66/60). Eight genes (CHD5, CHI3L1, DYSF, EPX, IGF2BP1, LCN2, MBOAT4, SLC22A4) revealed significant associations with survival. Access to a second rhesus macaque cohort (males = 40, females = 23, total n = 63) irradiated with 5.8-7.2 Gy (LD29-50/60) and some treated with gamma-tocotrienol (GT3, a radiation countermeasure) allowed us to validate these gene expression changes independently. Total RNA was isolated from whole blood samples and examined by quantitative RT-PCR on a 96-well format. cycle threshold (Ct)-values normalized to 18S rRNA were analyzed for their association with survival. Regardless of the species-specific TaqMan assay, similar results were obtained. Two genes (CHD5 and CHI3L1) out of eight revealed a significant association with survival in the second cohort, while only CHD5 (involved in DNA damage response and proliferation control) showed mean gene expression changes in the same direction for both cohorts. No expected association of CHD5 GE with dose, treatment, or sex could be established. Instead, we observed significant associations for those comparisons comprising pre-exposure samples with CHD5 Ct values ≤ 11 (total n = 17). CHD5 Ct values ≤ 11 in these comparisons were mainly associated with increased frequencies (61-100%) of non-survivors, a trend which depending on the sample numbers, reached significance (P = 0.03) in males and, accordingly, in females. This was also reflected by a logistic regression model including all available samples from both cohorts comprising CHD5 measurements (n = 104, odds ratio 1.38, 95% CI 1.07-1.79, P = 0.01). However, this association was driven by males (odds ratio 1.62, 95% CI 1.10-2.38, P = 0.01) and CHD5 Ct values ≤ 11 since removing low CHD5 Ct values from this model, converted to insignificance (P = 0.19). A second male subcohort comprising high CHD5 Ct values ≥ 14.4 in both cohorts (n = 5) appeared associated with survival. Removing these high CHD5 Ct values converted the model borderline significant (P = 0.051). Based on the probability function of the receiver operating characteristics (ROC) curves, 8 (12.3%) and 5 (7.7%) from 65 pre-exposure RNA measurements in males, death and survival could be predicted with a negative and positive predictive value ranging between 85-100%. An associated odds ratio reflected a 62% elevated risk for dying or surviving per unit change (Ct-value) in gene expression, considering the before-mentioned CHD5 thresholds in RNA copy numbers. In conclusion, we identified two subsets of male animals characterized by increased (Ct values ≤ 11) and decreased (Ct values ≥ 14.4) CHD5 GE copy numbers before radiation exposure, which independently of the cohort, radiation exposure or treatment appeared to predict the death or survival in males.

PUM1 and PGK1 are Favorable Housekeeping Genes over Established Biodosimetry-related Housekeeping Genes such as HPRT1, ITFG1, DPM1, MRPS5, 18S rRNA and Others after Radiation Exposure

In gene expression (GE) studies, housekeeping genes (HKGs) are required for normalization purposes. In large-scale inter-laboratory comparison studies, significant differences in dose estimates are reported and divergent HKGs are employed by the teams. Among them, the 18S rRNA HKG is known for its robustness. However, the high abundance of 18S rRNA copy numbers requires dilution, which is time-consuming and a possible source of errors. This study was conducted to identify the most promising HKGs showing the least radiation-induced GE variance after radiation exposure. In the screening stage of this study, 35 HKGs were analyzed. This included selected HKGs (ITFG1, MRPS5, and DPM1) used in large-scale biodosimetry studies which were not covered on an additionally employed pre-designed 96-well platform comprising another 32 HKGs used for different exposures. Altogether 41 samples were examined, including 27 ex vivo X-ray irradiated blood samples (0, 0.5, 4 Gy), six X-irradiated samples (0, 0.5, 5 Gy) from two cell lines (U118, A549), as well as eight non-irradiated tissue samples to encompass multiple biological entities. In the independent validation stage, the most suitable candidate genes were examined from another 257 blood samples, taking advantage of already stored material originating from three studies. These comprise 100 blood samples from ex vivo X-ray irradiated (0-4 Gy) healthy donors, 68 blood samples from 5.8 Gy irradiated (cobalt-60) Rhesus macaques (RM) (LD29/60) collected 0-60 days postirradiation, and 89 blood samples from chemotherapy-(CTx) treated breast tumor patients. CTx and radiation-induced GE changes in previous studies appeared comparable. RNA was isolated, converted into cDNA, and GE was quantified employing TaqMan assays and quantitative RT-PCR. We calculated the standard deviation (SD) and the interquartile range (IQR) as measures of GE variance using raw cycle threshold (Ct) values and ranked the HKGs accordingly. Dose, time, age, and sex-dependent GE changes were examined employing the parametrical t-test and non-parametrical Kruskal Wallis test, as well as linear regression analysis. Generally, similar ranking results evolved using either SD or IQR GE measures of variance, indicating a tight distribution of GE values. PUM1 and PGK1 showed the lowest variance among the first ten most suitable genes in the screening phase. MRPL19 revealed low variance among the first ten most suitable genes in the screening phase only for blood and cells, but certain comparisons indicated a weak association of MRPL19 with dose (P = 0.02-0.09). In the validation phase, these results could be confirmed. Here, IQR Ct values from, e.g., X-irradiated blood samples were 0.6 raw Ct values for PUM1 and PGK1, which is considered to represent GE differences as expected due to methodological variance. Overall, when compared, the GE variance of both genes was either comparable or lower compared to 18S rRNA. Compared with the IQR GE values of PUM1 and PGKI, twofold-fivefold increased values were calculated for the biodosimetry HKG HPRT1, and comparable values were calculated for biodosimetry HKGs ITFG1, MRPS5, and DPM1. Significant dose-dependent associations were found for ITFG1 and MRPS5 (P = 0.001-0.07) and widely absent or weak (P = 0.02-0.07) for HPRT1 and DPM1. In summary, PUM1 and PGK1 appeared most promising for radiation exposure studies among the 35 HKGs examined, considering GE variance and adverse associations of GE with dose.

RENEB Inter-Laboratory Comparison 2021: Inter-Assay Comparison of Eight Dosimetry Assays

Tools for radiation exposure reconstruction are required to support the medical management of radiation victims in radiological or nuclear incidents. Different biological and physical dosimetry assays can be used for various exposure scenarios to estimate the dose of ionizing radiation a person has absorbed. Regular validation of the techniques through inter-laboratory comparisons (ILC) is essential to guarantee high quality results. In the current RENEB inter-laboratory comparison, the performance quality of established cytogenetic assays [dicentric chromosome assay (DCA), cytokinesis-block micronucleus assay (CBMN), stable chromosomal translocation assay (FISH) and premature chromosome condensation assay (PCC)] was tested in comparison to molecular biological assays [gamma-H2AX foci (gH2AX), gene expression (GE)] and physical dosimetry-based assays [electron paramagnetic resonance (EPR), optically or thermally stimulated luminescence (LUM)]. Three blinded coded samples (e.g., blood, enamel or mobiles) were exposed to 0, 1.2 or 3.5 Gy X-ray reference doses (240 kVp, 1 Gy/min). These doses roughly correspond to clinically relevant groups of unexposed to low exposed (0-1 Gy), moderately exposed (1-2 Gy, no severe acute health effects expected) and highly exposed individuals (>2 Gy, requiring early intensive medical care). In the frame of the current RENEB inter-laboratory comparison, samples were sent to 86 specialized teams in 46 organizations from 27 nations for dose estimation and identification of three clinically relevant groups. The time for sending early crude reports and more precise reports was documented for each laboratory and assay where possible. The quality of dose estimates was analyzed with three different levels of granularity, 1. by calculating the frequency of correctly reported clinically relevant dose categories, 2. by determining the number of dose estimates within the uncertainty intervals recommended for triage dosimetry (±0.5 Gy or ±1.0 Gy for doses <2.5 Gy or >2.5 Gy), and 3. by calculating the absolute difference (AD) of estimated doses relative to the reference doses. In total, 554 dose estimates were submitted within the 6-week period given before the exercise was closed. For samples processed with the highest priority, earliest dose estimates/categories were reported within 5-10 h of receipt for GE, gH2AX, LUM, EPR, 2-3 days for DCA, CBMN and within 6-7 days for the FISH assay. For the unirradiated control sample, the categorization in the correct clinically relevant group (0-1 Gy) as well as the allocation to the triage uncertainty interval was, with the exception of a few outliers, successfully performed for all assays. For the 3.5 Gy sample the percentage of correct classifications to the clinically relevant group (≥2 Gy) was between 89-100% for all assays, with the exception of gH2AX. For the 1.2 Gy sample, an exact allocation to the clinically relevant group was more difficult and 0-50% or 0-48% of the estimates were wrongly classified into the lowest or highest dose categories, respectively. For the irradiated samples, the correct allocation to the triage uncertainty intervals varied considerably between assays for the 1.2 Gy (29-76%) and 3.5 Gy (17-100%) samples. While a systematic shift towards higher doses was observed for the cytogenetic-based assays, extreme outliers exceeding the reference doses 2-6 fold were observed for EPR, FISH and GE assays. These outliers were related to a particular material examined (tooth enamel for EPR assay, reported as kerma in enamel, but when converted into the proper quantity, i.e. to kerma in air, expected dose estimates could be recalculated in most cases), the level of experience of the teams (FISH) and methodological uncertainties (GE). This was the first RENEB ILC where everything, from blood sampling to irradiation and shipment of the samples, was organized and realized at the same institution, for several biological and physical retrospective dosimetry assays. Almost all assays appeared comparably applicable for the identification of unexposed and highly exposed individuals and the allocation of medical relevant groups, with the latter requiring medical support for the acute radiation scenario simulated in this exercise. However, extreme outliers or a systematic shift of dose estimates have been observed for some assays. Possible reasons will be discussed in the assay specific papers of this special issue. In summary, this ILC clearly demonstrates the need to conduct regular exercises to identify research needs, but also to identify technical problems and to optimize the design of future ILCs.

RENEB Inter-Laboratory Comparison 2021: The Gene Expression Assay

Early and high-throughput individual dose estimates are essential following large-scale radiation exposure events. In the context of the Running the European Network for Biodosimetry and Physical Dosimetry (RENEB) 2021 exercise, gene expression assays were conducted and their corresponding performance for dose-assessment is presented in this publication. Three blinded, coded whole blood samples from healthy donors were exposed to 0, 1.2 and 3.5 Gy X-ray doses (240 kVp, 1 Gy/min) using the X-ray source Yxlon. These exposures correspond to clinically relevant groups of unexposed, low dose (no severe acute health effects expected) and high dose exposed individuals (requiring early intensive medical health care). Samples were sent to eight teams for dose estimation and identification of clinically relevant groups. For quantitative reverse transcription polymerase chain reaction (qRT-PCR) and microarray analyses, samples were lysed, stored at 20°C and shipped on wet ice. RNA isolations and assays were run in each laboratory according to locally established protocols. The time-to-result for both rough early and more precise later reports has been documented where possible. Accuracy of dose estimates was calculated as the difference between estimated and reference doses for all doses (summed absolute difference, SAD) and by determining the number of correctly reported dose estimates that were defined as ±0.5 Gy for reference doses <2.5 Gy and ±1.0 Gy for reference doses >3 Gy, as recommended for triage dosimetry. We also examined the allocation of dose estimates to clinically/diagnostically relevant exposure groups. Altogether, 105 dose estimates were reported by the eight teams, and the earliest report times on dose categories and estimates were 5 h and 9 h, respectively. The coefficient of variation for 85% of all 436 qRT-PCR measurements did not exceed 10%. One team reported dose estimates that systematically deviated several-fold from reported dose estimates, and these outliers were excluded from further analysis. Teams employing a combination of several genes generated about two-times lower median SADs (0.8 Gy) compared to dose estimates based on single genes only (1.7 Gy). When considering the uncertainty intervals for triage dosimetry, dose estimates of all teams together were correctly reported in 100% of the 0 Gy, 50% of the 1.2 Gy and 50% of the 3.5 Gy exposed samples. The order of dose estimates (from lowest to highest) corresponding to three dose categories (unexposed, low dose and highest exposure) were correctly reported by all teams and all chosen genes or gene combinations. Furthermore, if teams reported no exposure or an exposure >3.5 Gy, it was always correctly allocated to the unexposed and the highly exposed group, while low exposed (1.2 Gy) samples sometimes could not be discriminated from highly (3.5 Gy) exposed samples. All teams used FDXR and 78.1% of correct dose estimates used FDXR as one of the predictors. Still, the accuracy of reported dose estimates based on FDXR differed considerably among teams with one team's SAD (0.5 Gy) being comparable to the dose accuracy employing a combination of genes. Using the workflow of this reference team, we performed additional experiments after the exercise on residual RNA and cDNA sent by six teams to the reference team. All samples were processed similarly with the intention to improve the accuracy of dose estimates when employing the same workflow. Re-evaluated dose estimates improved for half of the samples and worsened for the others. In conclusion, this inter-laboratory comparison exercise enabled (1) identification of technical problems and corrections in preparations for future events, (2) confirmed the early and high-throughput capabilities of gene expression, (3) emphasized different biodosimetry approaches using either only FDXR or a gene combination, (4) indicated some improvements in dose estimation with FDXR when employing a similar methodology, which requires further research for the final conclusion and (5) underlined the applicability of gene expression for identification of unexposed and highly exposed samples, supporting medical management in radiological or nuclear scenarios.

Gene Expression Changes in a Prefinal Health Stage of Lethally Irradiated Male and Female Rhesus Macaques

Radiation-induced gene expression (GE) changes can be used for early and high-throughput biodosimetry within the first three days postirradiation. However, is the method applicable in situations such as the Alexander Litvinenko case or the Goiania accident, where diagnosis occurred in a prefinal health stage? We aimed to characterize gene expression changes in a prefinal health stage of lethally irradiated male and female rhesus macaques. Peripheral blood was drawn pre-exposure and at the prefinal stage of male and female animals, which did not survive whole-body exposure with 700 cGy (LD66/60). RNA samples originated from a blinded randomized Good Laboratory Practice study comprising altogether 142 irradiated rhesus macaques of whom 60 animals and blood samples (15 samples for both time points and sexes) were used for this analysis. We evaluated GE on 34 genes widely used in biodosimetry and prediction of the hematological acute radiation syndrome severity (H-ARS) employing quantitative real-time polymerase chain reaction (qRT-PCR). These genes were run in duplicate and triplicate and altogether 96 measurements per time point and sex could be performed. In addition, 18S ribosomal RNA (rRNA) was measured to depict the ribosome/transcriptome status as well as for normalization purposes and 16S rRNA was evaluated as a surrogate for bacteremia. Mean differential gene expression (DGE) was calculated for each gene and sex including all replicate measurements and using pre-exposure samples as the reference. From 34 genes, altogether 27 genes appeared expressed. Pre-exposure samples revealed no signs of bacteremia and 18S rRNA GE was in the normal range in all 30 samples. Regarding prefinal samples, 46.7% and 40% of animals appeared infected in females and males, respectively, and for almost all males this was associated with out of normal range 18S rRNA values. The total number of detectable GE measurements was sixfold (females) and 15-fold (males) reduced in prefinal relative to pre-exposure samples and about tenfold lower in 80% of prefinal compared to pre-exposure samples (P < 0.0001). An overall 11-fold (median) downregulation in prefinal compared to pre-exposure samples was identified for most of the 27 genes and even FDXR appeared 4-14-fold downregulated in contrast to a pronounced up-regulation according to cited work. This pattern of overall downregulation of almost all genes and the rapid reduction of detectable genes at a prefinal stage was found in uninfected animals with normal range 18S rRNA as well. In conclusion, in a prefinal stage after lethal radiation exposure, the ribosome/transcriptome status remains present (based on normal range 18S rRNA values) in 60-67% of animals, but the whole transcriptome activity in general appears silenced and cannot be used for biodosimetry purposes, but probably as an indicator for an emerging prefinal health stage.

Predicting the Radiation Sensitivity of Male and Female Rhesus Macaques Using Gene Expression

Radiosensitivity differs in humans and likely among closely-related primates. Reasons for variation in radiosensitivity are not well known. We examined preirradiation gene expression in peripheral blood among male and female rhesus macaques which did or did not survive (up to 60 days) after whole-body irradiation with 700 cGy (LD66/60). RNA samples originated from a blinded randomized Good Laboratory Practice study in 142 irradiated rhesus macaques. Animals were untreated (placebo), or treated using recombinant human IL-12, G-CSF or combination of the two. We evaluated gene expression in a two-phase study design where phase I was a whole genome screen [next generation sequencing (NGS)] for mRNAs (RNA-seq) using five RNA samples from untreated male and female animals per group of survivor and non-survivor (total n = 20). Differential gene expression (DGE) was defined as a statistically significant and ≥2-fold up- or downregulation of mRNA species and was calculated between groups of survivors and non-survivors (reference) and by gender. Altogether 659 genes were identified, but the overlapping number of differentially expressed genes (DGE) observed in both genders was small (n = 36). Fifty-eight candidate mRNAs were chosen for independent validation in phase II using the remaining samples (n = 122) evaluated with qRT-PCR. Among the 58 candidates, 16 were of significance or borderline significance (t test) by DGE. Univariate and multivariate logistic regression analysis and receiver operating characteristic (ROC) curve analysis further refined and identified the most outstanding validated genes and gene combinations. For untreated male macaques, we identified EPX (P = 0.005, ROC=1.0), IGF2BP1 (P = 0.05, ROC=0.74) and the combination of EPX with SLC22A4 (P = 0.03, ROC=0.85) which appeared most predictive for the clinical outcome for treated and combined (untreated and treated) male macaque groups, respectively. For untreated, treated and both combined female macaque groups the same gene (MBOAT4, P = 0.0004, ROC = 0.81) was most predictive. Based on the probability function of the ROC curves, up to 74% of preirradiation RNA measurements predicted survival with a positive and negative predictive value ranging between 85-100% and associated odds ratios reflecting a 2-3-fold elevated risk for surviving per unit change (cycle threshold value) in gene expression. In conclusion, we identified gender-dependent genes and gene combinations in preirradiation blood samples for survival prediction after irradiation in rhesus macaques.

[A glimpse into the future: smart technologies and enhanced recovery after surgery (ERAS)]

Smart technologies facilitate our daily life in many respects, e.g. by rendering travel safer. In medicine, however, they have so far hardly been used, even though the demographic changes with an aging population in small or single households warrant an urgent change of our traditional care structures. Furthermore, patients are more demanding and better informed than they were a few decades ago. Enhanced recovery after surgery (ERAS) focusses on good prehabilitation as well as fast rehabilitation and therefore represents, even almost 20 years after the first publication, a modern and evidence-based treatment concept. Nevertheless, it is still not comprehensively implemented nationwide. The reasons for this may be concerns regarding an early discharge. In addition, there is often a gap in care care between discharge from hospital and start of the follow-up rehabilitation. In order to improve acceptance of the ERAS concept, to fulfil the patients' needs for better information while decreasing the workload of the medical staff and to close the gap in care after discharge from hospital, integrating ERAS into the concept of a smart hospital with subsequent transition into a temporary smart home is an appealing idea. With the use of an individually configurated online learning platform, a large part of the information flow can be transferred from the outpatient clinic to the pre-outpatient area (i.e. the patient's home). Consequently, patients will be better prepared for their first contact with the hospital. After a short stay in hospital the patient is then discharged into the serviced apartments of the smart quarter, where a stress-free recovery in a home-like environment is possible. The further rehabilitation is undertaken there under virtual guidance, following individualized schedules on demand.

[Intraoperative completion diagnostics in open vascular surgery]

Intraoperative imaging diagnostics during open vascular surgical procedures aim to enhance diagnostic certainty during the operation, ensure quality control documentation and reduce avoidable complications; however, the evidence for the various diagnostic imaging procedures with respect to improvement of perioperative outcome is not confirmed for carotid endarterectomy or for infrainguinal bypass surgery. Nevertheless, an intraoperative diagnostic control is principally recommended. The advantage of intraoperative imaging is confirmed and essential for the surgical reconstruction of bypass occlusions and acute thromboembolic occlusions.

[From Axial Spondyloarthritis to Osteoporosis - Spectrum of Skeletal Involvement in Inflammatory Bowel Diseases]

From Axial Spondyloarthritis to Osteoporosis - Spectrum of Skeletal Involvement in Inflammatory Bowel Diseases Abstract. Inflammatory bowel diseases (IBD) are frequently accompanied by non-inflammatory joint pain and inflammatory spondyloarthritides. Spondyloarthritides can restrict joint function and typically manifest with inflammatory back pain with nightly pain and morning stiffness that improves upon exercising. In other patients, small or large peripheral joints are predominantly involved. Treatment comprises pain medication including COX-II selective non-steroidal anti-inflammatory drugs (NSAID), since non-selective NSAID can aggravate IBD. For axial manifestations, physiotherapy and tumor necrosis factor (TNF) inhibitors are effective, while for peripheral manifestations steroid injections, sulfasalazine and TNF inhibitors are useful. Osteopenia and osteoporosis may result from inflammation, malabsorption and/or steroids. Long-lasting disease activity or steroid treatment should prompt osteoporosis screening. Adequate calcium and vitamin D intake must be ensured and treatment with bisphosphonates evaluated.

Widely differing screening and treatment practice for osteoporosis in patients with inflammatory bowel diseases in the Swiss IBD cohort study

Low bone mineral density (BMD) and osteoporosis remain frequent problems in patients with inflammatory bowel diseases (IBDs). Several guidelines with nonidentical recommendations exist and there is no general agreement regarding the optimal approach for osteoporosis screening in IBD patients. Clinical practice of osteoporosis screening and treatment remains insufficiently investigated.In the year 2014, a chart review of 877 patients included in the Swiss IBD Cohort study was performed to assess details of osteoporosis diagnostics and treatment. BMD measurements, osteoporosis treatment, and IBD medication were recorded.Our chart review revealed 253 dual-energy x-ray absorptiometry (DXA) scans in 877 IBD patients; osteoporosis was prevalent in 20% of tested patients. We identified widely differing osteoporosis screening rates among centers (11%-62%). A multivariate logistic regression analysis identified predictive factors for screening including steroid usage, long disease duration, and perianal disease; even after correction for all risk factors, the study center remained a strong independent predictor (odds ratio 2.3-21 compared to the center with the lowest screening rate). Treatment rates for patients with osteoporosis were suboptimal (55% for calcium, 65% for vitamin D) at the time of chart review. Similarly, a significant fraction of patients with current steroid medication were not treated with vitamin D or calcium (treatment rates 53% for calcium, 58% for vitamin D). For only 29% of patients with osteoporosis bisphosphonate treatment was started. Treatment rates also differed among centers, generally following screening rates. In patients with longitudinal DXA scans, calcium and vitamin D usage was significantly associated with improvement of BMD over time.Our analysis identified inconsistent usage of osteoporosis screening and underuse of osteoporosis treatment in IBD patients. Increasing awareness of osteoporosis as a significant clinical problem in IBD patients might improve patient care.

Which factors affect the long-term survival of patients with hepatocellular carcinoma UICC stage IV?

AIM

In the 7th edition of the TNM classification, not only HCC with distant metastases but also those with regional lymph node metastases are classified as stage IV.

MATERIALS AND METHODS, RESULTS

From our prospectively recorded tumor registry, 138 patients (17 %) with HCC were in stage IV. Among those were 68 and 70, respectively, in stage IVA (regional lymph node metastases) and IVB (distant metastases). The tumors were less frequently treated with resection or local ablative treatment (chemoembolization, RFA, SIRT, percutaneous radiation) than patients in stage I-III. Ten HCCs were resected. Five of the resected patients were in stage IVA and five in stage IVB. After tumor resection, patients lived longer than those who underwent local or systemic treatment only (p = 0.003 or p = 0.001, respectively). In the univariate survival analysis, the stage IV patients' long-term survival was decreased statistically significantly through elevated bilirubin, low albumin, Okuda stage III and BCLC stage D. Patients' age and sex, pre-treatment AFP level, Child stage and the presence of venous invasion did not influence survival. In the multivariate analysis (Cox regression), tumor resection and BCLC stage were independent prognostic factors.

CONCLUSION

Patients with HCC in TNM stage IV have a very poor prognosis. Only few patients are eligible for resection because of the extent of tumor growth, comorbidities and general condition. These, however, benefit markedly from tumor resection with lymph node dissection and possibly resection of distant metastases.

Prediction of low bone mineral density in patients with inflammatory bowel diseases

BACKGROUND

Low bone mineral density (BMD) remains a frequent problem in patients with inflammatory bowel diseases (IBD). There is no general agreement regarding osteoporosis screening in IBD patients.

METHODS

Cases of low BMD and disease characteristics were retrieved from 3172 patients of the Swiss IBD cohort study. Multivariate logistic regression analysis was conducted for predictive modeling. In a subgroup of 877 patients, 253 dual-energy X-ray absorptiometry (DXA) scans were available for validation.

RESULTS

Low BMD was prevalent in 19% of patients. We identified seven predictive factors: type of IBD, age, recent steroid usage, low body mass index, perianal disease, recent high disease activity and malabsorption syndrome. Low BMD could be predicted with a sensitivity of 79% and a specificity of 64%, a positive predictive value (PPV) of 35% and a negative predictive value (NPV) of 93%. The area under the curve of the receiver operating characteristics was 0.78. In the validation cohort we calculated a PPV of 26% and an NPV of 88%.

CONCLUSION

We provide a comprehensive analysis of risk factors for low BMD and propose a predictive model with seven clinical variables. The high NPV of models such as ours might help in excluding low BMD to prevent futile investigations.

[Incidence of non-metastatic liver lesions in tumor patients: consequences for chemotherapy and local ablative procedures]

INTRODUCTION

Even in patients with a history of solid malignant tumors, especially of gastrointestinal origin, newly diagnosed solid liver lesions do not necessarily correspond to metastases of the respective primary tumor. A reliable diagnosis can only be made by definitive histological examination.

MATERIAL AND METHODS

Data of all patients who underwent liver resection under the preoperative diagnosis of liver metastases between 1997 and 2011 and for whom liver specimens were examined histologically, were extracted from the prospectively maintained cancer registry.

RESULTS

An unexpected histological result occurred in 47 out of 770 patients (6.1 %). Primary tumors in these patients included renal cell (n=12), colorectal (n=11), breast (n=8), gastric (n=4), pancreatic (n=3), skin (n=3) and other cancers (n=6). Liver lesions were diagnosed synchronously in 15 cases or metachronously after a median of 17 months following primary therapy in 32 patients. Histology revealed a benign tumor in 38 cases (81 %) as well as 6 cases of HCC, 2 cases of CCC and in 1 case metastasis of a previously unknown colorectal cancer in a patient with known esophageal carcinoma. Suspicion of metastatic disease was based on four different imaging modalities in two cases and on three different imaging modalities in nine cases. Either computed tomography (CT) or magnetic resonance imaging (MRI) was combined with ultrasound in another 23 patients and with positron emission tomography (PET) CT in 6 more cases. In two patients CT plus MRI and CT only, respectively, was performed. In the remaining three patients, suspicion of metastases occurred intraoperatively after macroscopic examination of the liver. Preoperative percutaneous biopsy was attempted in four patients with indeterminate results.

CONCLUSION

Even with modern diagnostics the risk of treating a benign or other form of malignant tumor with neoadjuvant or palliative chemotherapy persists. The same holds true for local ablative procedures. Prior to local ablation or definitive palliative chemotherapy histological confirmation of metastases should be attempted.

[Portal vein embolisation prior to extended liver resection - current and future aspects]

Extended liver resections are associated with the risk of postoperative liver dysfunction up to liver failure. For this reason, prior to extended liver resections patients are conditioned in multi-modal therapy regimes. Portal vein embolisation is an essential part of such a multi-modal therapy. The aim of this intervention is an induction of hypertrophy of the future remnant liver volume. Thereby, the risk of postoperative liver failure is decreased. This article summarises the actual aspects of portal vein embolisation prior to extended liver resections.

[Living Donor Liver Transplantation - Past and Present]

Since the first living donor liver transplantations at the end of the 1980s, this transplantation technique has developed as an established tool within the modern transplantation medicine. Especially in Asia, the majority of liver transplantation is performed through living donation, mainly for religious reasons. Liver grafts for adult recipients are mainly the right liver lobe of the donor, for paediatric recipients mainly the left lateral lobe. In some cases, the living donor liver transplantation is realised from two different donors for one recipient, the so-called "dual graft" transplantation. This article summarises the history of living donor liver transplantation up to the current status of this transplantation procedure worldwide.

[Liver transplantation for hilar cholangiocarcinoma]

Local non-resectable, hilar cholangiocarcinoma can be cured by performing a liver transplantation. The initially poor results after transplantation have significantly improved since neoadjuvant therapy protocols have been established. Therefore, hilar cholangiocarcinoma is now an accepted indication for liver transplantation in selected patients. This article summarizes the current state, recommendations and results of liver transplantation for these patients.

Emergency surgery for complications related to percutaneous endoscopic gastrostomy

Percutaneous endoscopic gastrostomy (PEG) is used to restore enteral nutrition in patients with inadequate oral intake. Because of its minimally invasive nature complications are thought to be rare. We analyzed data on all patients treated for PEG-related complications at the Department of General, Visceral, and Oncologic Surgery at the Klinikum Bremen-Mitte, Germany, between 2005 and 2008. A total of 38 patients with complications required surgical evaluation. Emergency laparotomy was performed for leakage in 16 patients, for a misplaced or dislodged PEG tube in nine patients, for buried bumper with accompanying signs of peritonitis in four patients and for gastrocutaneous fistula in one patient. Eight complications were managed conservatively. Early complications within 10 days (60 %) were related to leakage or mispositioning of the PEG, while PEG device migration and fistula formation represented late complications. Hospital mortality was 17 % with the underlying disease contributing significantly to the fatal outcome. Most PEG-associated major complications were related to technical errors and carried a high mortality.

Regulatory requirements for clinical trial and marketing authorisation application for gene therapy medicinal products

Over the last two decades, clinical trials using gene therapy medicinal products (GTMPs) have been carried out for a large number of rare, inherited monogeneic disorders as well as common multigeneic diseases such as cancer, cardiovascular and infectious diseases including AIDS. Despite some early difficulties and setbacks, the gene therapy field has slowly progressed and, nowadays, offers the promise of novel treatments for a growing number of diseases. On the other hand, gene therapy approaches are often associated with additional risks due to limited clinical experience with a given gene transfer system, long-lasting effects of the therapeutic gene, and/or a complex mode of action. As a result, specific regulations and guidelines have been introduced within the EU to help address these uncertainties. This article summarises the legislative framework and will provide an overview on the regulatory requirements for clinical trials and marketing authorisation applications.

Stabilization of IgG1 in spray-dried powders for inhalation

The protein stabilizing capabilities of spray-dried IgG1/mannitol formulations were evaluated. The storage stability was tested at different residual moisture levels prepared by vacuum-drying or equilibration prior to storage. Vacuum-drying at 32 degrees C/0.1mbar for 24h reduced the moisture level below 1%, constituting an optimal basis for improved storage stability. The crystalline IgG1/mannitol powders with a weight ratio of 20/80 up to 40/60 failed to prevent the antibody aggregation as assessed by size exclusion chromatography during storage. Ratios of 60/40 up to 80/20 IgG1/mannitol provided superior stability of the antibody and the powders could be produced with high yields. The lower the residual moisture, the better was the stabilizing capability. An amount of 20% mannitol provided the best stabilization. Storage stability of 60/40, 70/30, and 80/20 IgG1/mannitol formulations over one year was adequate at 2-8 degrees C and 25 degrees C. Closed storage (sealed in vials) at 40 degrees C/75% RH and open storage at 25 degrees C/60% RH revealed that the stability still required optimization. The lower the protein content, the better was the powder flowability. The aerodynamic properties of powders spray-dried with 10% solids content were inadequate, as the particle size ranged between 5.1 and 7.2 microm and the fine particle fraction accounted for only 4-11%. Reduction of the solids content to 2.5% did improve the aerodynamic properties as the mass mean aerodynamic diameter was reduced to 3.6 microm and the fine particle fraction was increased to about 14%. The reduction of the solids content did not influence the storage stability significantly. Also spray-drying at higher temperatures had no significant impact on the storage stability, despite a higher tendency to form amorphous systems. In order to improve the storage stability and to maintain the good flowability of 70/30 IgG1/mannitol powder or to keep the storage stability but to improve the flowability of the 80/20 IgG1/mannitol powder, mannitol was partially substituted by a second excipient such as trehalose, sucrose, glycine, lactose, lactosucrose, or dextran 1. Differences in the stabilizing capability were noticeable upon closed storage at 40 degrees C/75% RH and open powder storage. Protein stabilization was improved by the addition of glycine but trehalose and sucrose were most effective in preventing aggregation, which can be primarily attributed to the water replacement properties of the sugars. The addition of another excipient, isoleucine had positive effects on both flowability and protein stability.

Efficient gene transfer into the CNS by lentiviral vectors purified by anion exchange chromatography

Lentiviral vectors have been shown to stably transduce dividing and non-dividing target cells in vitro and in vivo. However, in vivo gene transfer applications with viral vectors in the central nervous system require highly efficient vector preparations, because only very small volumes can be injected stereotactically without damage to the brain tissue. Since lentiviral vectors are generated in transient co-transfection systems, viral preparations need to be purified and efficiently concentrated before injection into the brain. We describe an alternative procedure to concentrate lentiviral preparations by binding viral particles to an anion exchange column. Viral particles are eluted with sodium chloride, desalted and further concentrated by ultrafiltration. These vector preparations allowed high levels of gene transfer into terminally differentiated neuronal and glial cells and long-term transgene expression without any signs of acute and long-term toxicity or inflammation. The purification of lentiviral vectors from large-scale preparations by anion exchange chromatography allowed us to concentrate the virus to small volumes and to use these preparations to genetically modified target cells in vivo without signs of acute inflammatory responses.

[Toxicologic evaluation of pyrethroids in indoor air: demonstrated with the example of cyfluthrin and permethrin]

Pyrethroids have varying activities depending on vehicle or route of administration (oral, dermal, inhalational). Specific features like the sensory irritation potential of the alpha-cyano-pyrethroids on the respiratory tract can only be quantified adequately by inhalation testing. Thus equitoxic dosages can vary between inhalative and oral application, especially for alpha-cyano-pyrethrolds. The no-effect values for chronic exposures derived for permethrin (type I pyrethroid) and cyfluthrin (type II pyrethroid) show clearly, that each pyrethroid has to be considered as an individual substance toxicologically, and that any extrapolation from the oral to the inhalative route should only be done after a thorough assessment of the specific toxicological profile. The study of simulated pest control measures on carpets pretreated with permethrin showed, that no significant enrichment of permethrin in total dust could be seen from a carpet additionally treated with pyrethroids. The missing correlation between absolute (mg pyrethroid/m3 air) and relative (mg pyrethroid/kg dust) concentrations in air-borne dust as well as the low degree of translocation of pyrethroids from carpets (only about 0.044% x m(-2) x h(-1) of the cyfluthrin applied to the carpet can be regarded as possibly respirable) prove, that analyses of pyrethroids in household sedimented dust ("vacuum cleaner bag analyses") without knowing the absolute surface concentration and respective air concentrations are of little value for risk assessment. The data allow the conclusion, that a scientific assessment of health risks is only possible based on absolute concentrations of pyrethroids in indoor air.