Unique structures in a tumor herpesvirus revealed by cryo-electron tomography and microscopy.

Gammaherpesviruses, including the human pathogens Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, are causative agents of lymphomas and other malignancies. The structural characterization of these viruses has been limited due to difficulties in obtaining adequate amount of virion particles. Here we report the first three-dimensional structural characterization of a whole gammaherpesvirus virion by an emerging integrated approach of cryo-electron tomography combined with single-particle cryo-electron microscopy, using murine gammaherpesvirus-68 (MHV-68) as a model system. We found that the MHV-68 virion consists of distinctive envelope and tegument compartments, and a highly conserved nucleocapsid. Two layers of tegument are identified: an inner tegument layer tethered to the underlying capsid and an outer, flexible tegument layer conforming to the overlying, pleomorphic envelope, consistent with the sequential viral tegumentation process inside host cells. Surprisingly, comparison of the MHV-68 virion and capsid reconstructions shows that the interactions between the capsid and inner tegument proteins are completely different from those observed in alpha and betaherpesviruses. These observations support the notion that the inner layer tegument across different subfamilies of herpesviruses has evolved significantly to confer specific characteristics related to viral-host interactions, in contrast to a highly conserved capsid for genome encapsidation and protection.

NOVEL MECHANISMS OF ANTIGEN PROCESSING THAT ENHANCE BCG VACCINE EFFICACY

Mycobacterium tuberculosis, the causative agent of tuberculosis, is the most lethal single infectious agent afflicting man today causing 2 million deaths per year. The World Health Organization recommends a vaccine as the best option to prevent this disease. The current vaccine, BCG, has a variable efficacy and does not protect adults. It is known that BCG vaccine becomes sequestered in special phagosome compartments of macrophages that do not fuse with lysosomes. Since lysosome fusion is necessary for peptide production and T cell priming leading to protective TH1 immunity, we hypothesized that vaccine efficacy is reduced and occurs perhaps due to non-lysosome dependent mechanisms. We therefore proposed an in depth analysis of phagosome environment, and its proteome to unravel mechanisms of antigen processing and presentation. We initially discovered that three mechanisms of pH regulation including vacuolar proton ATPase, phagocyte oxidase and superoxide dismutase (SOD) secretion from BCG vaccine affect antigen processing within phagosomes. These studies led to the discovery that a mutant of BCG vaccine which lacked SOD was a better vaccine. Subsequently, the proteomic analysis of vaccine phagosomes led to the discovery of novel protease (γ-secretase) enriched on BCG vaccine phagosomes. We then demonstrated that these proteases generated a peptide from the BCG vaccine which was presented through the MHC-II pathway to T cells and induced a TH1 response. The specificity of antigen production from γ-secretase was confirmed through siRNA knockdown of the components of the protease namely, nicastrin, presenilin and APH, which led to a decrease in antigen presentation. We therefore conclude that, even though BCG phagosomes are sequestered and do not fuse with lysosomes to generate peptide antigens, there are complex and novel in situ mechanisms within phagosomes that are capable of generating an immune response. We conclude that TH1 immunity to BCG vaccine arises mostly due to non-lysosome dependent immune mechanisms of macrophages and dendritic cells.

THE EFFECTS OF CURCUMIN ON BODY COMPOSITION OF PATIENTS WITH ADVANCED PANCREATIC CANCER

Cachexia is very common among patients with advanced pancreatic cancer and is a marker of poor prognosis. Weight loss in cachexia is due to both adipose and muscle compartments, and sarcopenia (severe muscle depletion) is associated with worse outcomes. Curcumin has shown a myriad of biological effects, including anti-cancer and anti-inflammatory. The ability of curcumin to attenuate cachexia and muscle loss has been tested in animal models, with conflicting results so far. The hypothesis of this study was that patients with advanced pancreatic cancer treated with curcumin for two months have less fat and muscle loss as compared to matched controls not treated with this compound. A matched 1:2 case-control retrospective study was conducted with 22 patients with pancreatic cancer who were treated with curcumin on a previous protocol and 44 untreated controls with the same diagnosis matched by age, gender, time from advanced cancer, body mass index, and number of prior therapies. Data was collected regarding oncologic treatment, medication use, weights, heights, and survival. Body composition was determined by computerized tomography analyses at two timepoints separated by 60±20 days. For treated patients, the first image was at the beginning of treatment and for controls it was determined by the matching time from advanced cancer. The evolution of body composition over time was quantitatively analyzed comparing both groups. All patients lost weight both due to fat and muscle losses, and patients treated with curcumin presented greater losses both in lean adipose body mass. Use of medications, chemotherapy, age, time from advanced cancer, baseline albumin, performance status, and number of prior therapies were not independently correlated with changes in body composition variables. Patients treated with curcumin had borderline shorter survival when compared with untreated patients. Sarcopenic treated patients had significantly shorter survival than non-sarcopenic counterparts, and sarcopenia status was not associated with survival among the controls. Treated patients with shorter survival showed a tendency to lose more lean and especially fat body mass as compared to untreated patients, maybe suggesting an effect of curcumin on shifting weight loss towards the end of life by impacting its mechanisms.

An examination of the characteristics, concentration and distribution of androgen receptor in rat testis during sexual maturation

Previously reported androgen receptor concentrations in rat testis and testicular cell types have varied widely. In the studies reported here a nuclear exchange assay was established in rat testis in which exchange after 86 hours at 4$\sp\circ$C was greater than 85% complete and receptor was stable. Receptor concentration per DNA measured by exchange declined between 15 and 25 days of age in the rat testis, then increased 4-fold during sexual maturation. Proliferation of germ cells which had low receptor concentration appeared to account for the early decline in testicular receptor concentration, whereas increase in receptor number per Sertoli cell between 25 and 35 days of age contributed to the later increase. Increase in Leydig cell number during maturation appeared to account for the remainder of the increase due to the high receptor concentration in these cells. Detailed studies showed that other possible explanations for changes in receptor number (e.g. shifts in receptor concentration between the cytosol and nuclear subcellular compartments or changes in the affinity of the receptor for its ligands) were not likely.^ Androgen receptor dynamics in testicular cells showed rapid, specific uptake of ($\sp3$H) -testosterone that was easily blocked by unlabeled testosterone (RA of 7 nM in both cell types), and medroxyprogesterone acetate (RA of 28 and 16 nM in Sertoli and peritubular cells, respectively), but not as well by the anti-androgens cyproterone acetate (RA of 116 and 68 nM) and hydroxyflutamide (RA of 300 and 180 nM). The affinity of the receptor for the ligand dimethylnortestosterone was similar in the two cell types (K$\rm\sb{d}$ values of 0.78 and 0.71 nM for Sertoli and peritubular cells) and was virtually identical with the affinity of the whole testis receptor (0.89 nM). Medroxyprogesterone acetate and testosterone significantly increased nuclear androgen receptor concentration relative to untreated controls in Sertoli and peritubular cells, whereas hydroxyflutamide and cyproterone acetate did not. Despite the different embryological origins of peritubular and Sertoli cells, their responses to both androgens and anti-androgens were similar. In addition, these studies suggest that peritubular cells are as likely as Sertoli cells to be primary androgen targets. ^

Molecular analysis of $\beta$1,4-galactosyl-transferase localization to the cell surface and participation in cell adhesion

$\beta$1,4-Galactosyltransferase (GalTase) is unusual among the glycosyltransferases in that it is found in two subcellular compartments where it performs different functions. In the trans-Golgi complex, GalTase participates in oligosaccharide biosynthesis as do other glycosyltransferases. GalTase is also found on the cell surface, where it associates with the cytoskeleton and functions as a receptor for extracellular oligosaccharide ligands. Although we know much regarding GalTase function on the cell surface, little is known about the mechanisms underlying its transport to the plasma membrane. Cloning of the GalTase gene revealed that there are two GalTase proteins (i.e., long and short) with different size cytoplasmic tails. This raises the possibility that differences in the cytoplasmic domain of GalTase may influence its subcellular distribution. The object of this study was to examine this hypothesis directly through the use of molecular, immunological, and biochemical approaches.^ To examine whether the two GalTase proteins are targeted to different subcellular compartments, F9 embryonal carcinoma cells were transfected with either long or short GalTase cDNAs and intracellular and cell surface enzyme levels measured. Cell surface GalTase activity was enriched in cells overexpressing the long, but not the form of short GalTase. Furthermore, a dominant negative mutation in cell surface GalTase was created by transfecting cells with GalTase cDNAs encoding a truncated version of long GalTase devoid of the extracellular catalytic domain. Overexpressing the complete cytoplasmic and transmembrane domains of long GalTase led to a loss of GalTase-dependent cellular adhesion by specifically displacing surface GalTase from its cytoskeletal associations. In contrast, overexpressing the analogous truncated protein of short GalTase had no effect on cell adhesion. Finally, chloramphenicol acetyltransferase (CAT) reporter proteins were used to determine directly whether the cytoplasmic domains of long and short GalTase were responsible for differential subcellular distribution. The cytoplasmic and transmembrane domains of long GalTase led to CAT expression on the ceil surface and its association with the detergent-insoluble cytoskeleton; the analogous fusion protein containing short GalTase was restricted to the Golgi compartment. These results suggest that the cytoplasmic domain unique to long GalTase is responsible for targeting a portion of this protein to the cell surface and associating it with the cytoskeleton, enabling it to function as a cell adhesion molecule. ^

Regulation of the gastrin-releasing peptide/bombesin receptor

Gastrin-releasing peptide (GRP) and other bombesin-like peptides stimulate hormone secretion and cell proliferation by binding to specific G-protein-coupled receptors. Three studies were performed to identify potential mechanisms involved in GRP/bombesin receptor regulation.^ Although bombesin receptors are localized throughout the gastrointestinal tract, few gastrointestinal cell lines are available to study bombesin action. In the first study, the binding and function of bombesin receptors in the human HuTu-80 duodenal cancer cell line were characterized. ($\sp{125}$I-Tyr$\sp4$) bombesin bound with high affinity to a GRP-preferring receptor. Bombesin treatment increased IP$\sb3$ production, but had no effect on cell proliferation. Similar processing of ($\sp{125}$I-Tyr$\sp4$) bombesin and of GRP-receptors was observed in HuTu-80 cells and Swiss 3T3 fibroblasts, a cell line which mitogenically responds to bombesin. Therefore, the lack of a bombesin mitogenic effect in HuTu-80 cells is not due to unusual processing of ($\sp{125}$I-Tyr$\sp4$) bombesin or rapid GRP-receptor down-regulation.^ In the second study, a bombesin antagonist was developed to study the processing and regulatory events after antagonist binding. As previously shown, receptor bound agonist, ($\sp{125}$I-Tyr$\sp4$) bombesin, was rapidly internalized and degraded in chloroquine-sensitive compartments. Interestingly, receptor-bound antagonist, ($\sp{125}$I-D-Tyr$\sp6$) bombesin(6-13)PA was not internalized, but degraded at the cell-surface. In contrast to bombesin, (D-Tyr$\sp6$) bombesin(6-13)PA treatment did not cause receptor internalization. Together these results demonstrate that receptor regulation and receptor-mediated processing of antagonist is different from that of agonist.^ Bombesin receptors undergo acute desensitization. By analogy to other G-protein-coupled receptors, a potential desensitization mechanism may involve receptor phosphorylation. In the final study, $\sp{32}$P-labelled Swiss 3T3 fibroblasts and CHO-mBR1 cells were treated with bombesin and the GRP-receptor was immunoprecipitated. In both cell lines, bombesin treatment markedly stimulated GRP-receptor phosphorylation. Furthermore, bombesin-stimulated GRP-receptor phosphorylation occurred within the same time period as bombesin-stimulated desensitization, demonstrating that these two processes are correlated.^ In conclusion, these studies of GRP-receptor regulation further our understanding of bombesin action and provide insight into G-protein-coupled receptor regulation in general. ^

Modular organization of the cortical connections linking visual areas V1, V2 and V4 in Macaque monkeys

The macaque cortical visual system is hierarchically organized into two streams, the ventral stream for recognizing objects and the dorsal stream for analyzing spatial relationships. The ventral stream extends from striate cortex or area V1 to inferior temporal cortex (IT) through extra-striate areas V2 and V4. Between V1 and V2, the ventral stream consists of two roughly parallel sub-streams, one extending from the cytochrome oxidase (CO) rich blobs in V1 to the CO rich thin stripes in V2, the other extending from the interblobs in V1 to interstripes, in V2. The blob-dominated sub-stream is thought to analyze the surface features such as color, whereas the interblob-dominated one is thought to analyze the contour features such as shape. ^ In the current study, the organization of cortical pathways linking V2 thin stripe and interstripe compartments with area V4 was investigated using a combination of physiological and anatomical techniques. Different compartments of V2 were first characterized, in vivo, using optical recording of intrinsic cortical signals. These functionally derived maps of V2 stripe compartments were then used to guide iontophoretic injections of multiple, distinguishable, anterograde tracers into specific V2 compartments. The distribution of labeled axons was analyzed either in horizontal sections through the prelunate gyrus, or in tangentially sectioned portions of physically unfolded cortex containing the lunate sulcus, prelunate gyrus and superior temporal sulcus. When a V2 thin stripe and adjacent interstripe were injected with distinguishable tracers, a large primary and several secondary foci were observed in V4. The primary focus from the thin stripe injection was spatially segregated from the primary focus from the V2 interstripe injection, suggesting a retention of the pattern of compartmentation. ^ We examined the distribution of retrogradely labeled cells in V1 following the injections of tracers into V2 different compartments, in order to quantitate just how parallel the two sub-streams are from V1 to V2. Our results suggest that both blobs and interblobs project to thin stripes in V2, whereas only interblobs project to interstripes. This asymmetrical segregation argues against the original proposal of strict parallelism. (Abstract shortened by UMI.) ^

Phenotype of capillaries in skeletal muscle of nNOS-knockout mice

Because neuronal nitric oxide synthase (nNOS) has a well-known impact on arteriolar blood flow in skeletal muscle, we compared the ultrastructure and the hemodynamics of/in the ensuing capillaries in the extensor digitorum longus (EDL) muscle of male nNOS-knockout (KO) mice and wild-type (WT) littermates. The capillary-to-fiber (C/F) ratio (-9.1%) was lower (P ≤ 0.05) in the nNOS-KO mice than in the WT mice, whereas the mean cross-sectional fiber area (-7.8%) and the capillary density (-3.1%) varied only nonsignificantly (P > 0.05). Morphometrical estimation of the area occupied by the capillaries as well as the volume and surface densities of the subcellular compartments differed nonsignificantly (P > 0.05) between the two strains. Intravital microscopy revealed neither the capillary diameter (+3% in nNOS-KO mice vs. WT mice) nor the mean velocity of red blood cells in EDL muscle (+25% in nNOS-KO mice vs. WT mice) to significantly vary (P > 0.05) between the two strains. The calculated shear stress in the capillaries was likewise nonsignificantly different (3.8 ± 2.2 dyn/cm² in nNOS-KO mice and 2.1 ± 2.2 dyn/cm² in WT mice; P > 0.05). The mRNA levels of vascular endothelial growth factor (VEGF)-A were lower in the EDL muscle of nNOS-KO mice than in the WT littermates (-37%; P ≤ 0.05), whereas mRNA levels of VEGF receptor-2 (VEGFR-2) (-11%), hypoxia inducible factor-1α (+9%), fibroblast growth factor-2 (-14%), and thrombospondin-1 (-10%) differed nonsignificantly (P > 0.05). Our findings support the contention that VEGF-A mRNA expression and C/F-ratio but not the ultrastructure or the hemodynamics of/in capillaries in skeletal muscle at basal conditions depend on the expression of nNOS.

Surface Deformations as Indicators of Deep Ebullition Fluxes in a Large Northern Peatland

Peatlands deform elastically during precipitation cycles by small (+/- 3 cm) oscillations in surface elevation. In contrast, we used a Global Positioning System network to measure larger oscillations that exceeded 20 cm over periods of 4 - 12 hours during two seasonal droughts at a bog and fen site in northern Minnesota. The second summer drought also triggered 19 depressuring cycles in an overpressured stratum under the bog site. The synchronicity between the largest surface deformations and the depressuring cycles indicates that both phenomena are produced by the episodic release of large volumes of gas from deep semi-elastic compartments confined by dense wood layers. We calculate that the three largest surface deformations were associated with the release of 136 g CH4 m(-2), which exceeds by an order of magnitude the annual average chamber fluxes measured at this site. Ebullition of gas from the deep peat may therefore be a large and previously unrecognized source of radiocarbon depleted methane emissions from northern peatlands.

Decadal Variability in the Northeast Pacific in a Physical-Ecosystem Model: Role of Mixed Layer Depth and Trophic Interactions

A basin-wide interdecadal change in both the physical state and the ecology of the North Pacific occurred near the end of 1976. Here we use a physical-ecosystem model to examine whether changes in the physical environment associated with the 1976-1977 transition influenced the lower trophic levels of the food web and if so by what means. The physical component is an ocean general circulation model, while the biological component contains 10 compartments: two phytoplankton, two zooplankton, two detritus pools, nitrate, ammonium, silicate, and carbon dioxide. The model is forced with observed atmospheric fields during 1960-1999. During spring, there is a similar to 40% reduction in plankton biomass in all four plankton groups during 1977-1988 relative to 1970-1976 in the central Gulf of Alaska (GOA). The epoch difference in plankton appears to be controlled by the mixed layer depth. Enhanced Ekman pumping after 1976 caused the halocline to shoal, and thus the mixed layer depth, which extends to the top of the halocline in late winter, did not penetrate as deep in the central GOA. As a result, more phytoplankton remained in the euphotic zone, and phytoplankton biomass began to increase earlier in the year after the 1976 transition. Zooplankton biomass also increased, but then grazing pressure led to a strong decrease in phytoplankton by April followed by a drop in zooplankton by May: Essentially, the mean seasonal cycle of plankton biomass was shifted earlier in the year. As the seasonal cycle progressed, the difference in plankton concentrations between epochs reversed sign again, leading to slightly greater zooplankton biomass during summer in the later epoch.

Assessment of Skill and Portability in Regional Marine Biogeochemical Models: Role of Multiple Planktonic Groups

Application of biogeochemical models to the study of marine ecosystems is pervasive, yet objective quantification of these models' performance is rare. Here, 12 lower trophic level models of varying complexity are objectively assessed in two distinct regions (equatorial Pacific and Arabian Sea). Each model was run within an identical one-dimensional physical framework. A consistent variational adjoint implementation assimilating chlorophyll-a, nitrate, export, and primary productivity was applied and the same metrics were used to assess model skill. Experiments were performed in which data were assimilated from each site individually and from both sites simultaneously. A cross-validation experiment was also conducted whereby data were assimilated from one site and the resulting optimal parameters were used to generate a simulation for the second site. When a single pelagic regime is considered, the simplest models fit the data as well as those with multiple phytoplankton functional groups. However, those with multiple phytoplankton functional groups produced lower misfits when the models are required to simulate both regimes using identical parameter values. The cross-validation experiments revealed that as long as only a few key biogeochemical parameters were optimized, the models with greater phytoplankton complexity were generally more portable. Furthermore, models with multiple zooplankton compartments did not necessarily outperform models with single zooplankton compartments, even when zooplankton biomass data are assimilated. Finally, even when different models produced similar least squares model-data misfits, they often did so via very different element flow pathways, highlighting the need for more comprehensive data sets that uniquely constrain these pathways.

Validation of stress magnetic resonance imaging of the canine stifle joint with and without an intact cranial cruciate ligament.

OBJECTIVE To validate use of stress MRI for evaluation of stifle joints of dogs with an intact or deficient cranial cruciate ligament (CrCL). SAMPLE 10 cadaveric stifle joints from 10 dogs. PROCEDURES A custom-made limb-holding device and a pulley system linked to a paw plate were used to apply axial compression across the stifle joint and induce cranial tibial translation with the joint in various degrees of flexion. By use of sagittal proton density-weighted MRI, CrCL-intact and deficient stifle joints were evaluated under conditions of loading stress simulating the tibial compression test or the cranial drawer test. Medial and lateral femorotibial subluxation following CrCL transection measured under a simulated tibial compression test and a cranial drawer test were compared. RESULTS By use of tibial compression test MRI, the mean ± SD cranial tibial translations in the medial and lateral compartments were 9.6 ± 3.7 mm and 10 ± 4.1 mm, respectively. By use of cranial drawer test MRI, the mean ± SD cranial tibial translations in the medial and lateral compartments were 8.3 ± 3.3 mm and 9.5 ± 3.5 mm, respectively. No significant difference in femorotibial subluxation was found between stress MRI techniques. Femorotibial subluxation elicited by use of the cranial drawer test was greater in the lateral than in the medial compartment. CONCLUSIONS AND CLINICAL RELEVANCE Both stress techniques induced stifle joint subluxation following CrCL transection that was measurable by use of MRI, suggesting that both methods may be further evaluated for clinical use.

Stress parameters and behaviour of horses in walkers with and without the use of electricity

In order to investigate stress responses of horses in walkers with and without electricity, 12 horses were trained during 3 weeks in a horse walker with and without the use of electricity (3.7 kV). To evaluate the stress response, cortisol levels in the blood were measured, the heart rate was monitored using the Polar® system and the behaviour was evaluated. Neither the cortisol levels nor the heart rates showed any relevant statistically significant difference between horses moved in the horse walker with or without the use of electricity. The highest cortisol levels and heart rates were recorded during the first week (habituation period). A significant difference could be observed regarding spontaneous compartment changes: while this happened mainly during the first week and before the first use of electricity, no horses changed compartments in the periods when electricity was used and thereafter. The results of this study indicate that the use of electricity in the horse walker does not seem to cause significant detectable stress in the horses.

Taxon-specific δ13C analysis of chitinous invertebrate remains in sediments from Strandsjön, Sweden

Taxon-specific stable carbon isotope (δ13C) analysis of chitinous remains of invertebrates can provide valuable information about the carbon sources used by invertebrates living in specific habitats of lake ecosystems (for example, sediments, water column, or aquatic vegetation). This is complementary to δ13C of sedimentary organic matter (SOM), which provides an integrated signal of organic matter produced in a lake and its catchment, and of diagenetic processes within sediments. In a sediment record from Strandsjön (Sweden) covering the past circa 140 years, we analyzed SOM geochemistry (δ13C, C:Natomic, organic carbon content) and δ13C of chitinous invertebrate remains in order to examine whether taxon-specific δ13C records could be developed for different invertebrate groups and whether these analyses provide insights into past changes of organic carbon sources for lacustrine invertebrates available in benthic and planktonic compartments of the lake. Invertebrate taxa included benthic chironomids (Chironomus, Chironomini excluding Chironomus, Tanytarsini, and Tanypodinae), filter-feeders on suspended particulate organic matter (Daphnia, Plumatella and Cristatella mucedo), and Rhabdocoela. δ13C of chironomid remains indicated periodic availability of 13C-depleted carbon sources in the benthic environment of the lake as δ13C values of the different chironomid taxa fluctuated simultaneously between -34.7 and -30.5‰ (VPDB). Daphnia and Bryozoa showed parallel changes in their δ13C values which did not coincide with variations in δ13C of chironomids, though, and a 2-3‰ decrease since circa AD 1960. The decrease in δ13C of Daphnia and Bryozoa could indicate a decrease in phytoplankton δ13C as a result of lower lake productivity, which is in accordance with historical information about the lake that suggests a shift to less eutrophic conditions after AD 1960. In contrast, Rhabdocoela cocoons were characterized by relatively high δ13C values (-30.4 to -28.2‰) that did not show a strong temporal trend, which could be related to the predatory feeding mode and wide prey spectrum of this organism group. The taxon-specific δ13C analyses of invertebrate remains indicated that different carbon sources were available for the benthic chironomid larvae than for the filter-feeding Daphnia and bryozoans. Our results therefore demonstrate that taxon-specific analysis of δ13C of organic invertebrate remains can provide complementary information to measurements on bulk SOM and that δ13C of invertebrate remains may allow the reconstruction of past changes in carbon sources and their δ13C in different habitats of lake ecosystems.

Multi-modal glioblastoma segmentation: man versus machine

BACKGROUND AND PURPOSE Reproducible segmentation of brain tumors on magnetic resonance images is an important clinical need. This study was designed to evaluate the reliability of a novel fully automated segmentation tool for brain tumor image analysis in comparison to manually defined tumor segmentations. METHODS We prospectively evaluated preoperative MR Images from 25 glioblastoma patients. Two independent expert raters performed manual segmentations. Automatic segmentations were performed using the Brain Tumor Image Analysis software (BraTumIA). In order to study the different tumor compartments, the complete tumor volume TV (enhancing part plus non-enhancing part plus necrotic core of the tumor), the TV+ (TV plus edema) and the contrast enhancing tumor volume CETV were identified. We quantified the overlap between manual and automated segmentation by calculation of diameter measurements as well as the Dice coefficients, the positive predictive values, sensitivity, relative volume error and absolute volume error. RESULTS Comparison of automated versus manual extraction of 2-dimensional diameter measurements showed no significant difference (p = 0.29). Comparison of automated versus manual segmentation of volumetric segmentations showed significant differences for TV+ and TV (p<0.05) but no significant differences for CETV (p>0.05) with regard to the Dice overlap coefficients. Spearman's rank correlation coefficients (ρ) of TV+, TV and CETV showed highly significant correlations between automatic and manual segmentations. Tumor localization did not influence the accuracy of segmentation. CONCLUSIONS In summary, we demonstrated that BraTumIA supports radiologists and clinicians by providing accurate measures of cross-sectional diameter-based tumor extensions. The automated volume measurements were comparable to manual tumor delineation for CETV tumor volumes, and outperformed inter-rater variability for overlap and sensitivity.