Experiments were conducted to establish whether B-haplotype genes that determine resistance to RSV-induced tumors would also influence resistance to Marek's disease and lymphoid leukosis. Matings of line 6(3) x 15(1) F3 or F4 breeders segregating for the Ea-B locus antigens that are markers for B2 and B5 haplotypes of the B major histocompatibility complex were made to produce B2B2, B2B5, and B5B5 chicks. The chicks were infected with a standard inoculum of one of the three tumor viruses in separate experiments. The B2 haplotype from 6(3) conveyed greater resistance to tumors induced by all three viruses than the B5 from 15(1) chickens. This finding suggests that some gene(s) in the B-haplotype may determine a general ability to resist tumor formation or cause tumor regression.

Imatinib mesylate (IM) is a tyrosine kinase inhibitor, which inhibits phosphorylation of downstream proteins involved in BCR-ABL signal transduction. It has proved beneficial in treating patients with chronic myeloid leukaemia (CML). In addition, IM demonstrates activity against malignant cells expressing c-kit and platelet-derived growth factor receptor (PDGF-R). The activity of IM in the blastic crisis of CML and against various myeloma cell lines suggests that this drug may also target other cellular components. In the light of the important role of telomerase in malignant transformation, we evaluated the effect of IM on telomerase activity (TA) and regulation in various malignant cell lines. Imatinib mesylate caused a dose-dependent inhibition of TA (up to 90% at a concentration of 15 microM IM) in c-kit-expressing SK-N-MC (Ewing sarcoma), SK-MEL-28 (melanoma), RPMI 8226 (myeloma), MCF-7 (breast cancer) and HSC 536/N (Fanconi anaemia) cells as well as in ba/F3 (murine pro-B cells), which do not express c-kit, BCR-ABL or PDGF-R. Imatinib mesylate did not affect the activity of other DNA polymerases. Inhibition of TA was associated with 50% inhibition of proliferation. The inhibition of proliferation was associated with a decrease in the S-phase of the cell cycle and an accumulation of cells in the G2/M phase. No apoptosis was observed. Inhibition of TA was caused mainly by post-translational modifications: dephosphorylation of AKT and, to a smaller extent, by early downregulation of hTERT (the catalytic subunit of the enzyme) transcription. Other steps of telomerase regulation were not affected by IM. This study demonstrates an additional cellular target of IM, not necessarily mediated via known tyrosine kinases, that causes inhibition of TA and cell proliferation.

The role of hematopoietic cytokines in lineage commitment remains uncertain. To gain insight into the contribution of cytokine signaling to myeloid lineage specification, we compared granulocyte colony-stimulating factor (G-CSF) and macrophage colony-stimulating factor (M-CSF) signaling in Ba/F3 cells expressing both the G-CSF and M-CSF receptors and in lineage-negative murine marrow cells. G-CSF and M-CSF serve as prototypes for additional cytokines that also influence immature myeloid cells. G-CSF specifically activated signal transducer and activator of transcription 3 and induced Src homology region 2 domain-containing phosphatase 2 (SHP2) phosphorylation, whereas M-CSF preferentially activated phospholipase Cgamma2, and thereby extracellular signal-regulated kinase (ERK), to stabilize c-Fos and stimulate CCAAT/enhancer-binding protein (C/EBP)alpha(S21) phosphorylation. In contrast, activation of Jun kinase or c-Jun was similar in response to either cytokine. Inhibition of ERK prevented induction of c-Fos by M-CSF and reduced C/EBPalpha phosphorylation and formation of colony-forming unit-monocytes. SHP2 inhibition reduced ERK activation in G-CSF, but not M-CSF, and reduced colony-forming unit-granulocytes, underscoring divergent pathways to ERK activation. Phorbol ester mimicked the effect of M-CSF, activating ERK independent of SHP2. In summary, M-CSF activates ERK more potently than G-CSF, and thereby induces higher levels of c-Fos and phospho-C/EBPalpha(S21), which may directly interact to favor monopoiesis, whereas G-CSF activates signal transducer and activator of transcription 3 and SHP2, potentially shifting the balance to granulopoiesis via gene induction by C/EBPalpha homodimers and via effects of SHP2 on regulators besides ERK.

Liver stiffness measurement (LSM) frequently overestimates the severity of liver fibrosis in nonalcoholic fatty liver disease (NAFLD). Controlled attenuation parameter (CAP) is a new parameter provided by the same machine used for LSM and associated with both steatosis and body mass index, the two factors mostly affecting LSM performance in NAFLD. We aimed to determine whether prediction of liver fibrosis by LSM in NAFLD patients is affected by CAP values. Patients (n = 324) were assessed by clinical and histological (Kleiner score) features. LSM and CAP were performed using the M probe. CAP values were grouped by tertiles (lower 132-298, middle 299-338, higher 339-400 dB/m). Among patients with F0-F2 fibrosis, mean LSM values, expressed in kilopascals, increased according to CAP tertiles (6.8 versus 8.6 versus 9.4, P = 0.001), and along this line the area under the curve of LSM for the diagnosis of F3-F4 fibrosis was progressively reduced from lower to middle and further to higher CAP tertiles (0.915, 0.848-0.982; 0.830, 0.753-0.908; 0.806, 0.723-0.890). As a consequence, in subjects with F0-F2 fibrosis, the rates of false-positive LSM results for F3-F4 fibrosis increased according to CAP tertiles (7.2% in lower versus 16.6% in middle versus 18.1% in higher). Consistent with this, a decisional flowchart for predicting fibrosis was suggested by combining both LSM and CAP values.

In patients with NAFLD, CAP values should always be taken into account in order to avoid overestimations of liver fibrosis assessed by transient elastography. (Hepatology 2017;65:1145-1155).

KRIT1 is a disease gene responsible for Cerebral Cavernous Malformations (CCM). It encodes for a protein containing distinct protein-protein interaction domains, including three NPXY/F motifs and a FERM domain. Previously, we isolated KRIT1B, an isoform characterized by the alternative splicing of the 15th coding exon and suspected to cause CCM when abnormally expressed. Combining homology modeling and docking methods of protein-structure and ligand binding prediction with the yeast two-hybrid assay of in vivo protein-protein interaction and cellular biology analyses we identified both structural and functional differences between KRIT1A and KRIT1B isoforms. We found that the 15th exon encodes for the distal beta-sheet of the F3/PTB-like subdomain of KRIT1A FERM domain, demonstrating that KRIT1B is devoid of a functional PTB binding pocket. As major functional consequence, KRIT1B is unable to bind Rap1A, while the FERM domain of KRIT1A is even sufficient for this function. Furthermore, we found that a functional PTB subdomain enables the nucleocytoplasmic shuttling of KRIT1A, while its alteration confers a restricted cytoplasmic localization and a dominant negative role to KRIT1B. Importantly, we also demonstrated that KRIT1A, but not KRIT1B, may adopt a closed conformation through an intramolecular interaction involving the third NPXY/F motif at the N-terminus and the PTB subdomain of the FERM domain, and proposed a mechanism whereby an open/closed conformation switch regulates KRIT1A nuclear translocation and interaction with Rap1A in a mutually exclusive manner. As most mutations found in CCM patients affect the KRIT1 FERM domain, the new insights into the structure-function relationship of this domain may constitute a useful framework for understanding molecular mechanisms underlying CCM pathogenesis.

Sprouty/Spred family proteins have been identified as negative regulators of growth factor-induced ERK/mitogen-activated protein (MAP) kinase activation. However, it has not been clarified whether these proteins regulate cytokine-induced ERK activity. We found that Spred-1 is highly expressed in interleukin-3 (IL-3)-dependent hematopoietic cell lines and bone marrow-derived mast cells. To investigate the roles of Spred-1 in hematopoiesis, we expressed wild-type Spred-1 and a dominant negative form of Spred-1, DeltaC-Spred, in IL-3- and stem cell factor (SCF)-dependent cell lines as well as hematopoietic progenitor cells from mouse bone marrow by retrovirus gene transfer. In IL-3-dependent Ba/F3 cells expressing c-kit, forced expression of Spred-1 resulted in a reduced proliferation rate and ERK activation in response to not only SCF but also IL-3. In contrast, DeltaC-Spred augmented IL-3-induced cell proliferation and ERK activation. Wild-type Spred-1 inhibited colony formation of bone marrow cells in the presence of cytokines, whereas DeltaC-Spred-1 expression enhanced colony formation. Augmentation of ERK activation and proliferation in response to IL-3 was also observed in Spred-1-deficient bone marrow-derived mast cells. These data suggest that Spred-1 negatively regulates hematopoiesis by suppressing not only SCF-induced but also IL-3-induced ERK activation.

OBJECTIVE

The proposed cut-off values for the degree of fibrosis as assessed by liver stiffness measurement (LSM) might not be applicable in severe acute exacerbation of chronic hepatitis B (CHB). We aimed to assess the effect of necroinflammatory activity on LSM in this condition.

METHODS

We prospectively recruited consecutive patients with severe acute exacerbation of CHB (alanine aminotransferase or ALT>> 10x upper limit of normal). The relationship of ALT levels and LSM were serially assessed and liver biopsy was carried out after ALT normalization.

RESULTS

Eleven patients (10 male, median age 43 years) were followed up for 25 weeks; nine patients received antiviral therapy. Overall, LSM was positively correlated with ALT levels (r = 0.67, P < 0.001). At initial presentation, the median serum ALT and LSM was 1136 (581-2210) IU/L and 26.3 (11.1-33.3) kPa. A progressive reduction in LSM was observed during subsequent visits in parallel with the reduction of ALT levels. At the last visit, the median ALT was 27 (11-52) IU/L and LSM was 7.7 (4.7-10.8) kPa. Among the five patients who had liver biopsy carried out at week 25, four patients had F2 fibrosis (LSM 5.7-8.1 kPa) and one patient had F3 fibrosis (LSM 8.6 kPa).

CONCLUSIONS

LSM using transient elastography with the current proposed cut-off values might misdiagnose liver cirrhosis in patients suffering from severe acute exacerbation of CHB. LSM should be assessed after normalization of ALT levels in order to accurately assess the degree of fibrosis.

OBJECTIVE

Liver stiffness measurement (LSM) by transient elastography (TE) is widely used for the noninvasive assessment of fibrosis. Our objectives were to examine the prevalence, risk factors and causes of discordance between fibrosis estimated by TE and liver biopsy.

METHODS

Two hundred and fifty-one patients with hepatitis B, C and nonalcoholic fatty liver disease underwent LSM by TE and liver biopsy. Predictors of discordance (≥2 fibrosis stages) between measures, which occurred in 14% of patients (n=35), were identified by comparing patient, TE and biopsy characteristics of discordant and nondiscordant cases.

RESULTS

According to predefined criteria, 40% of discordances were attributed to TE error and 23% to biopsy error; 37% were indeterminate. In multivariate analysis, mild fibrosis (F0-2 vs. F3-4), and higher body mass index (BMI), ALT and LSM variability [assessed by the ratio of the interquartile range to median LSM (IQR/M)] were independently associated with discordance. Discordance was three-fold more common in patients with obesity (28 vs. 9%), ALT ≥60 U/L (20 vs. 7%) and IQR/M ≥0.17 (22 vs. 7%; all P<0.005). Based on these variables, a discordance risk score assigning 1 point to each factor was developed. The prevalence of discordance in patients with 0, 1, 2 and 3 factors were 2, 7, 20, and 55% respectively (P<0.0005).

CONCLUSIONS

Discordance between liver fibrosis estimated by TE and biopsy occurs in one in seven patients. In assessing the validity of TE results, clinicians must recognize risk factors for discordance and in at-risk patients, consider alternative measures including biomarkers and possibly biopsy.

Individual differences in resting asymmetrical frontal brain activity have been found to predict subsequent emotional responses. The question of whether frontal brain asymmetry can cause emotional responses has yet to be addressed. Biofeedback training designed to alter the asymmetry of frontal brain activity was therefore examined. Eighteen right-handed female participants were randomly assigned to receive biofeedback training designed to increase right frontal alpha relative to left frontal alpha (n = 9) or to receive training in the opposite direction (n = 9). Five consecutive days of biofeedback training provided signals of reward or nonreward depending on whether the difference between right (F4) and left (F3) frontal alpha exceeded a criterion value in the specified direction. Systematic alterations of frontal EEG asymmetry were observed as a function of biofeedback training. Moreover, subsequent self-reported affect and facial muscle activity in response to emotionally evocative film clips were influenced by the direction of biofeedback training.

OBJECTIVE

Direct-acting antiviral agents (DAAs) are safe and effective in patients with hepatitis C. Conflicting data were reported on the risk of hepatocellular carcinoma (HCC) during/after therapy with DAAs. The aim of this study was to evaluate the incidence of newly diagnosed HCC and associated risk factors in patients with advanced hepatitis C treated with DAAs.

METHODS

The study is based on the NAVIGATORE platform, a prospectively recording database of all patients with hepatitis C receiving DAAs in the Veneto region of Italy. The inclusion criteria were: fibrosis stage ≥F3. The exclusion criteria were: Child-Turcotte-Pugh (CTP)-C, liver transplantation before DAAs, history or presence of HCC, follow-up <4 weeks after starting DAAs. A total of 3,917 out of 4,234 consecutive patients were included, with a mean follow-up of 536.2 ± 197.6 days.

RESULTS

Overall, HCC was diagnosed in 55 patients. During the first year, HCC incidence was 0.46% (95% CI 0.12-1.17) in F3, 1.49% (1.03-2.08) in CTP-A and 3.61% (1.86-6.31) in CTP-B cirrhotics; in the second year, HCC incidences were 0%, 0.2%, and 0.69%, respectively. By multivariate analysis, HCC was significantly associated with an aspartate aminotransferase to platelet ratio ≥2.5 (hazard ratio [HR] 2.03; 95% CI 1.14-3.61; p = 0.016) and hepatitis B virus infection (HR 3.99; 1.24-12.91; p = 0.021). Failure to achieve a sustained virological response was strongly associated with development of HCC (HR 9.09; 5.2-16.1; p = 0.0001). A total of 29% of patients with HCC had an aggressive tumor, often seen in the early phase of treatment.

CONCLUSIONS

These data, obtained in a large, prospective, population-based study, indicate that in patients with advanced hepatitis C receiving DAAs, the risk of "de novo" hepatocarcinoma during the first year is not higher, and might be lower, than that of untreated patients. The risk further declines thereafter. Early hepatocarcinoma appearance may reflect pre-existing, microscopic, undetectable tumors.

UNASSIGNED

Hepatocellular carcinoma is one of the complications of hepatitis C related cirrhosis. Treating patients with advanced hepatitis C with the new interferon-free direct-acting antiviral agents has been associated with improvement in liver function and survival, while more conflicting data have been reported regarding the risk of hepatocellular carcinoma. We report the results of a prospective population study on the incidence of newly diagnosed hepatocellular carcinoma in patients with advanced hepatitis C treated with direct-acting antiviral agents, clearly indicating that the residual hepatocellular carcinoma risk is reduced and declines progressively with time after a sustained virological response. Development of a liver tumor during/after therapy was associated with known risk factors and with virological failure.

OBJECTIVE

The noninvasive serum markers, FibroTest-ActiTest (FT-AT), are an alternative to liver biopsy in patients with chronic hepatitis C and B. The aim was to use these markers in a prospective study of patients treated with lamivudine in order to assess the impact of treatment, as well as the factors associated with fibrosis progression.

METHODS

Two hundred and ninety-eight patients were included in a prospective longitudinal study in 50 hospitals across France. FT-AT were measured at baseline, and then after 6, 12, and 24 months of lamivudine 100-mg treatment. Epidemiological, clinical, and virologic characteristics were analyzed by univariate and multivariate analysis.

RESULTS

Two hundred and eighty-three patients were included for analysis. The accuracy of FT-AT versus biopsy was validated with the area under the ROC curve, 0.77 (SE = 0.03) for bridging fibrosis and 0.75 (SE = 0.06) for severe activity (A3). At baseline, bridging fibrosis (METAVIR stages F2-F3-F4) was highly associated (p < 0.001) in multivariate analysis with male gender and age and marginally associated with anti-HBe presence (p= 0.05) and non-Asian ethnic origin (p= 0.046). Lamivudine treatment had a very significant impact overall. FT decreased significantly from 0.51 at baseline to 0.37 at 24 months (p < 0.001), and 85% of patients had improvement at 24 months. AT also decreased significantly from 0.56 to 0.13 (p < 0.0001), and 91% of patients had improvement at 24 months. A three-phase kinetics was observed for both fibrosis and activity; there was a marked improvement during the first 6 months, followed by a plateau between 6 and 12 months, and another improvement between 12 and 24 months. The occurrence of a YMDD variant does not entirely explain these three-phase variations. The first phase impact on fibrosis rates was higher in Asian patients (p= 0.01) and in patients younger than 40 yr (p < 0.001).

CONCLUSIONS

In patients with chronic hepatitis B, a 24-month course of lamivudine treatment leads to a significant decrease in necroinflammatory grades and fibrosis stages as assessed by noninvasive markers, with the occurrence of a three-phase kinetics. FT-AT should be useful in the noninvasive follow-up of lamivudine treatment.

The amino acid composition and antioxidant activities of peptide fractions obtained from HPLC separation of a pea protein hydrolysate (PPH) were studied. Thermolysin hydrolysis of pea protein isolate and ultrafiltration (3 kDa molecular weight cutoff membrane) yielded a PPH that was separated into five fractions (F1-F5) on a C(18) reverse phase HPLC column. The fractions that eluted later from the column (F3-F5) contained higher contents hydrophobic and aromatic amino acids when compared to fractions that eluted early or the original PPH. Fractions F3-F5 also exhibited the strongest radical scavenging and metal chelating activities; however, hydrophobic character did not seem to contribute to reducing power of the peptides. In comparison to glutathione, the peptide fractions had significantly higher (p < 0.05) ability to inhibit linoleic acid oxidation and chelate metals. In contrast, glutathione had significantly higher (p < 0.05) free radical scavenging properties than the peptide fractions.

BACKGROUND

Liver stiffness measurement (LSM) using transient elastography (TE) is used to stage fibrosis in patients with liver disease, diagnostic reliability and the factors affecting its performance in patients with non-alcoholic fatty liver disease (NAFLD) are incompletely understood.

OBJECTIVE

To assess LSM.

METHODS

Consecutive NAFLD patients (n = 169), assessed by liver biopsy (Kleiner score), anthropometrical, biochemical and metabolic features, underwent LSM using TE with standard M probe.

RESULTS

Liver stiffness measurement was not reliable in 23 patients (14%) due to obesity. Among patients with a reliable TE, a LSM value >7.25 kPa was the best cut-off for predicting significant fibrosis at biopsy (AUC 0.794); however, this cut-off still failed to rule out F2-F4 fibrosis in 31% (false-negative rate) or rule in F3-F4 in 29% (false-positive rate). Similarly a LSM value >8.75 kPa was the best cut-off for severe fibrosis (F3-F4) (AUC 0.870), with a rate of false-negatives 24% and of false-positives 2%. Body mass index was the major determinant of these diagnostic errors in predicting significant and severe fibrosis both by overestimating or underestimating the stage of fibrosis.

CONCLUSIONS

In NAFLD patients, even when liver stiffness measurement is feasible, high BMI values negatively affect the diagnostic reliability. Improved performance of transient elastography could be obtained using specifically designed probes.

Endogenous circadian rhythms are almost ubiquitous among organisms from cyanobacteria to mammals and regulate diverse physiological processes. It has been suggested that having an endogenous circadian system enables an organism to anticipate periodic environmental changes and adapt its physiological and developmental states accordingly, thus conferring a fitness advantage. However, it is hard to measure fitness directly and there is, to date, only limited evidence supporting the assumption that having a circadian system can increase fitness and therefore be adaptive. In this article, we report an evolutionary approach to examine the adaptive significance of a circadian system. By crossing Arabidopsis thaliana plants containing mutations that cause changes in circadian rhythms, we have created heterozygous 'Mother' (F1) plants with genetic variance for circadian rhythmicity. The segregating F2 offspring present a range of circadian rhythm periods. We have applied a selection to the F2 plants of short and long T-cycles under different competition strengths and found that the average phenotype of circadian period of the resulting F3 plants show a strong positive correlation with the T-cycle growth conditions for the competing F2 plants. Consistent with their circadian phenotypes, the frequency of long-period alleles was altered in the F3 plants. Our results show that F2 plants with endogenous rhythms that more closely match the environmental T-cycle are fitter, producing relatively more viable offspring in the F3 population. Thus, having a circadian clock that matches with the environment is adaptive in Arabidopsis.

Assessment of liver fibrosis is critical for successful individualized disease management in persons with chronic hepatitis B (CHB) or chronic hepatitis C (CHC). We expanded and validated serum marker indices to provide accurate, reproducible and easily applied methods of fibrosis assessment. Liver biopsy results from over 284 CHB and 2304 CHC patients in the Chronic Hepatitis Cohort Study ('CHeCS') were mapped to a F0-F4 equivalent scale. APRI and FIB-4 scores within a 6-month window of biopsy were mapped to the same scale. A novel algorithm was applied to derive and validate optimal cut-offs for differentiating fibrosis levels. For the prediction of advanced fibrosis and cirrhosis, the FIB-4 score outperformed the other serum marker indices in the CHC cohort and was similar to APRI in the CHB cohort. The area under the receiver operating characteristic curves (AUROC) for FIB-4 in differentiating F3-F4 from F0-F2 was 0.86 (95% CI: 0.80-0.92) for CHB and 0.83 (95% CI: 0.81-0.85) for CHC. The suggested cut-offs based on FIB-4 model produced high positive predictive values [CHB: 90.0% for F0-F2, 100.0% for cirrhosis (F4); CHC: 89.7% for F0-F2; 82.9% for cirrhosis (F4)]. In this large observational cohort, FIB-4 predicted the upper and lower end of liver fibrosis stage (cirrhosis and F0-F2, respectively) with a high degree of accuracy in both CHB and CHC patients.

The FLT3 receptor is activated by juxtamembrane insertion mutations and by activation loop point mutations in patients with acute myeloid leukemia (AML). In a systematic tyrosine kinase gene exon resequencing study, 21 of 24 FLT3 exons were sequenced in samples from 53 patients with AML, 9 patients with acute lymphoblastic leukemia (ALL), and 3 patients with myelodysplasia samples. Three patients had novel point mutations at residue N841 that resulted in a change to isoleucine in 2 samples and to tyrosine in 1 sample. Introduction of FLT3-N841I cDNA into Ba/F3 cells led to interleukin-3 (IL-3)-independent proliferation, receptor phosphorylation, and constitutive activation of signal transducer and activator of transcription 5 (STAT5) and extracellular regulatory kinase (ERK), suggesting that the N841I mutation confers constitutive activity to the receptor. An FLT3 inhibitor (PKC412) inhibited the growth of Ba/F3-FLT3N841I cells (IC(50) 10 nM), but not of wild-type Ba/F3 cells cultured with IL-3. PKC412 also reduced tyrosine phosphorylation of the mutant receptor and inhibited STAT5 phosphorylation. Examination of the FLT3 autoinhibited structure showed that N841 is the key residue in a hydrogen-bonding network that likely stabilizes the activation loop. These results suggest that mutations at N841 represent a significant new activating mutation in patients with AML and that patients with such mutations may respond to small-molecule FLT3 inhibitors such as PKC412.

OBJECTIVE

Hepatitis C virus (HCV)-infected patients who responded to interferon (IFN) treatment with clearance of serum HCV RNA may rarely develop hepatocellular carcinoma (HCC). The aim of the present study was to elucidate the risk factors for liver carcinogenesis among such patients.

METHODS

In total, 126 patients with chronic hepatitis C (CHC) who achieved a sustained virological response (SVR) to IFN monotherapy, which was defined as the absence of detectable HCV RNA in the serum at 6 months after completion of treatment, were enrolled and possible risk factors for HCC were analyzed.

RESULTS

During the observation period of 66 +/- 36 months after cessation of IFN treatment, five (4.0%) of the 126 patients developed HCC. The cumulative incidence of HCC at 3, 5 and 10 years was estimated to be 0.9, 4.7 and 7.5%, respectively. The cumulative incidence of HCC was significantly higher among patients with severe fibrosis (F3 or F4) than among patients with no or mild fibrosis (F0 to F2) in the liver before treatment (P = 0.007); among patients with alcohol intake of>> or = 27 g/day than among patients with that of < 27 g/day (P = 0.015); and among patients who were>> or = 65 years old than among patients who were < 65 years old at the start of treatment (P = 0.026).

CONCLUSIONS

Patients with CHC who had severe fibrosis, who had regularly taken moderate amounts of alcohol, or who were>> or = 65 years at the start of IFN treatment should be carefully followed to detect small and controllable HCC, even after eradication of HCV.

A monoclonal antibody, IV-IA8, generated against chicken type IV collagen has been characterized and shown to bind specifically to a conformational-dependent site within a major, triple helical domain of the type IV molecule. Immunohistochemical localization of the antigenic determinant with IV-IA8 revealed that the basement membranes of a variety of chick tissues were stained but that the basement membrane of the corneal epithelium showed little, if any, staining. Thus, basement membranes may differ in their content of type IV collagen, or in the way in which it is assembled. The specificity of the antibody was determined by inhibition ELISA using purified collagen types I-V and three purified molecular domains of chick type IV collagen ([F1]2F2, F3, and 7S) as inhibitors. Only unfractionated type IV collagen and the (F1)2F2 domain bound the antibody. Antibody binding was destroyed by thermal denaturation of the collagen, the loss occurring at a temperature similar to that at which previous optical rotatory dispersion studies had shown melting of the triple helical structure of (F1)2F2. Such domain-specific monoclonal antibodies should prove to be useful probes in studies involving immunological dissection of the type IV collagen molecule, its assembly within basement membranes, and changes in its distribution during normal development and in disease.

BACKGROUND

Interquartile range/median value (IQR/M) of liver stiffness measurement (LSM) is a factor in chronic hepatitis C (CHC) leading to over estimation of fibrosis by Fibroscan.

OBJECTIVE

To investigate factors that affect the accuracy of LSM in chronic hepatitis B (CHB).

METHODS

One hundred and ninety-nine patients were enrolled. Only procedures yielding>> or =10 valid measurements were considered reliable. Liver fibrosis was evaluated using the Batts and Ludwig system. Liver biopsy (LB) specimens <15 mm were considered ineligible.

RESULTS

The mean age (142 men and 57 women) was 40.1 years. A significant discordance (discordance of at least two stages between LB and LSM) was identified in 38 (19.1%) and 47 (23.6%) patients respectively, according to Marcellin et al. and Chan et al.'s cutoff values. In multivariate analyses, BMI and fibrosis stage (F0-2 vs. F3-4) were identified as independent predictors for significant discordance (P = 0.040; hazard ratio [HR], 1.126; 95% confidence interval [CI], 1.005-1.261 and P = 0.036; HR, 0.450; 95% CI, 0.213-0.949 respectively) with Marcellin et al.'s cutoffs, whereas fibrosis stage was the only independent predictor (P = 0.004; HR, 0.300; 95% CI, 0.131-0.685) with Chan's cutoffs.

CONCLUSIONS

Success rate and IQR/M were not predictive factors of the accuracy for diagnosing liver fibrosis by Fibroscan in CHB. Fibrosis stage (F0-2) was the only factor to predict significant discordance between LB and LSM.

OBJECTIVE

Diagnostic values of FibroTest (FT) for hepatic fibrosis have rarely been assessed in Asian chronic hepatitis B (CHB) patients. We aimed to validate its diagnostic performances in comparison with liver stiffness (LS).

METHODS

From 2008 to 2010, 194 CHB patients who underwent liver biopsies along with FT and transient elastography were prospectively enrolled. Fibrosis stage was assessed according to the Batts and Ludwig system.

RESULTS

To predict significant fibrosis (F≥2), advanced fibrosis (F≥3), and cirrhosis (F = 4), areas under receiver operating characteristic curves (AUROCs) of FT were 0.903, 0.907, and 0.866, comparable to those of LS (0.873, 0.897, and 0.910, respectively). Optimized cutoffs of FT to maximize sum of sensitivity and specificity were 0.32, 0.52, and 0.68 for F≥2, F≥3, and F = 4, while those of LS were 8.8, 10.2, and 14.1 kPa, respectively. According to FT and LS cutoffs, 123 (63.4%) and 124 (63.9%) patients were correctly classified consistent with histological fibrosis (F1, F2, F3, and F4), respectively. Overall concordance between each fibrosis stage estimated by FT and LS was observed in 111 patients, where 88 were correctly classified with histological results. A combination formula adding LS to FT (LS+FT) showed similar AUROC levels (0.885, 0.905, and 0.915), while another multiplying LS by FT (LS×FT) showed the best AUROCs (0.941, 0.931, and 0.929 for F≥2, F≥3, and F4, respectively).

CONCLUSIONS

FT provides good fibrosis prediction, with comparable outcomes to LS in Asian CHB patients. FT substantially reduces need for liver biopsy, especially when used in combination with LS.

The Yr9 gene, which confers resistance to stripe rust caused by Puccinia striiformis f.sp. tritici (P. s. tritici) and originated from rye, is present in many wheat cultivars. To develop molecular markers for Yr9, a Yr9 near-isogenic line, near-isogenic lines with nine other Yr genes, and the recurrent wheat parent 'Avocet Susceptible' were evaluated for resistance in the seedling stage to North American P s. tritici races under controlled temperature in the greenhouse. The resistance gene analog polymorphism (RGAP) technique was used to identify molecular markers for Yr9. The BC7:F, and BC7:F3 progeny, which were developed by backcrossing the Yr9 donor wheat cultivar Clement with 'Avocet Susceptible', were evaluated for resistance to stripe rust races. Genomic DNA was extracted from 203 BC7:F2 plants and used for cosegregation analysis. Of 16 RGAP markers confirmed by cosegregation analysis, 4 were coincident with Yr9 and 12 were closely linked to Yr9 with a genetic distance ranging from 1 to 18 cM. Analyses of nullitetrasomic 'Chinese Spring' lines with the codominant RGAP marker Xwgp13 confirmed that the markers and Yr9 were located on chromosome 1B. Six wheat cultivars reported to have 1B/1R wheat-rye translocations and, presumably, Yr9, and two rye cultivars were inoculated with four races of P. s. tritici and tested with 9 of the 16 RGAP markers. Results of these tests indicate that 'Clement', 'Aurora', 'Lovrin 10', 'Lovrin 13', and 'Riebesel 47/51' have Yr9 and that 'Weique' does not have Yr9. The genetic information and molecular markers obtained from this study should be useful in cloning Yr9, in identifying germplasm that may have Yr9, and in using marker-assisted selection for combining Yr9 with other stripe rust resistance genes.

OBJECTIVE

Steatosis and insulin resistance (IR) are the major disease modifying in patients with chronic hepatitis C (CHC). Only few studies evaluated these features in patients with chronic hepatitis B (CHB). We aimed to assess the prevalence and the factors related to steatosis and IR in CHB patients, compared with CHC subjects, and to evaluate the potential association between these features and fibrosis severity.

METHODS

One hundred and seventy consecutive patients with CHB (28 HBeAg positive, 142 HBeAg negative), were evaluated using liver biopsy and metabolic measurements and matched for sex, age and body mass index with 170 genotype 1 CHC patients. IR was defined if HOMA-IR>2.7. All biopsies were scored for grading and staging by Scheuer's score, and the steatosis was considered significant if ≥ 10%.

RESULTS

The prevalence of significant steatosis was similar in both CHB and CHC patients (31 vs. 38%; P=0.14). IR rate was significantly higher in CHC than in CHB patients (42 vs. 26%; P=0.002). Severe fibrosis (F3-F4), at multivariate analysis, was independently associated with older age (OR 1.050, 95% CI 1.009-1.093), steatosis >10% (OR 4.375, 95% CI 1.749-10.943), and moderate-severe necroinflammatory activity (OR 8.187, 95% CI 2.103-31.875), regardless of HBeAg status, in CHB patients, and with older age (OR 1.080, 95% CI 1.028-1.136), IR (OR 2.640, 95% CI 1.110-6.281), steatosis >10% (OR 3.375, 95% CI 1.394-8.171), and moderate-severe necroinflammatory activity (OR 8.988, 95% CI 1.853-43.593) in CHC patients.

CONCLUSIONS

CHB patients had high steatosis prevalence, similar to CHC controls, but lower IR rate. Both steatosis and IR in CHC, and only steatosis in CHB, are independently associated with fibrosis severity.

Genome-wide association studies (GWASs) have uncovered susceptibility loci for a large number of complex traits. Functional interpretation of candidate genes identified by GWAS and confident assignment of the causal variant still remains a major challenge. Expression quantitative trait (eQTL) mapping has facilitated identification of risk loci for quantitative traits and might allow prioritization of GWAS candidate genes. One major challenge of eQTL studies is the need for larger sample numbers and replication. The aim of this study was to evaluate the robustness and reproducibility of whole-blood eQTLs in humans and test their value in the identification of putative functional variants involved in the etiology of complex traits. In the current study, we performed comphrehensive eQTL mapping from whole blood. The discovery sample included 322 Caucasians from a general population sample (KORA F3). We identified 363 cis and 8 trans eQTLs after stringent Bonferroni correction for multiple testing. Of these, 98.6% and 50% of cis and trans eQTLs, respectively, could be replicated in two independent populations (KORA F4 (n=740) and SHIP-TREND (n=653)). Furthermore, we identified evidence of regulatory variation for SNPs previously reported to be associated with disease loci (n=59) or quantitative trait loci (n=20), indicating a possible functional mechanism for these eSNPs. Our data demonstrate that eQTLs in whole blood are highly robust and reproducible across studies and highlight the relevance of whole-blood eQTL mapping in prioritization of GWAS candidate genes in humans.

Tsetse fly-transmitted trypanosomes (Trypanosoma spp.) cause "sleeping sickness' in man and have a serious impact on livestock-based agriculture in large areas of Africa. Multigene control of variation in susceptibility to trypanosomiasis is known to occur in mice, where the C57BI/6 (B6) strain is relatively resistant and the A/J (A) and Balb/c (B) strains are susceptible. Such resistance is also well described among several types of west African cattle. We report here the results of genome-wide scans for genes controlling this trait in the B6 mouse using crosses with two different susceptible strains. Regions on mouse chromosomes 5 and 17 were found to be important in determining resistance in both crosses while an additional region on chromosome 1 showed evidence of involvement in only one cross. We confirmed the size of the effect due to chromosome 17 in F3 intercross populations fixed for alternative parental chromosomes. The three loci are of large effect and account for most of the genetic variation in both F2 populations. We propose that they be designated Tir1, Tir2 and Tir3.