This report describes the development and the biology of Sch 55700, a humanized monoclonal antibody to human IL-5 (hIL-5). Sch 55700 was synthesized using CDR (complementarity determining regions) grafting technology by incorporating the antigen recognition sites for hIL-5 onto consensus regions of a human IgG4 framework. In vitro, Sch 55700 displays high affinity (Kd = 20 pmol/l) binding to hIL-5, inhibits the binding of hIL-5 to Ba/F3 cells (IC50 = 0.5 nmol/l) and blocks IL-5 mediated proliferation of human erythroleukemic TF-1 cells. In allergic mice, Sch 55700 (0.1-10 mg/kg, i.p. or i.m.) inhibits the influx of eosinophils in the lungs, demonstrates long duration of activity and the anti-inflammatory activity of this compound is additive with oral prednisolone. In allergic guinea pigs, Sch 55700 (0.03-30 mg/kg i.p.) inhibits both the pulmonary eosinophilia and airway hyperresponsiveness and at 30 mg/kg, i.p. inhibited allergic, but not histamine-induced bronchoconstriction. In allergic rabbits, Sch 55700 blocks cutaneous eosinophilia. Sch 55700 (0.1-1 mg/kg i.p.) also blocks the pulmonary eosinophilia and neutrophilia caused by tracheal injection of hIL-5 in guinea pigs. In allergic cynomolgus monkeys, a single dose of Sch 55700 (0.3 mg/kg i.v.) blocks the pulmonary eosinophilia caused by antigen challenge for up to six months. Sch 55700 is, therefore, a potent antibody against IL-5 in vitro and in a variety of species in vivo that could be used to establish the role of IL-5 in human eosinophilic diseases such as asthma.

Bcr-Abl oncoproteins are responsible for the pathogenesis of human leukemias with a reciprocal chromosome translocation t(9;22). The amino-terminal Bcr sequence has a potential to form a homotetramer (tetramer domain), and destructions of the tetramer domain cause a complete loss of biological activities in Bcr-Abl. Here we show that Bcr-Abl in which the tetramer domain is replaced with glutathione S-transferase (GST) with a dimerizing ability (GST/Bcr-Abl-(Delta1-160)) can no longer induce an interleukin-3 (IL-3) independence in Ba/F3 cells or transform mouse bone marrow cells but still retains by 30-40% the ability to transform Rat1 cells. Compared with the wild type Bcr-Abl, autophosphorylation of GST/Bcr-Abl-(Delta1-160) in vivo was reduced by more than 50%. The Grb-2 binding to GST/Bcr-Abl-(Delta1-160) was 50% reduced in Rat1 cells and undetectable in Ba/F3 cells. In Rat1 cells expressing GST/Bcr-Abl-(Delta1-160), phosphotyrosine contents of p62 and Shc were 70% decreased.

A mutation that fails to complement certain alleles of the testis-specific beta 2-tubulin gene (B2t) of Drosophila melanogaster maps to a separate locus, haywire, located at 3-34.4 map units in polytene region 67E3-F3. Second-site non-complementing mutations such as haync2 and B2t alleles could identify genes that encode products that participate in the same functions or that interact in the same structure. Consistent with a structural interaction between the hay gene product and beta 2-tubulin, the genetic interaction between haync2 and B2t requires the presence of the mutant hay gene product; a deficiency for the hay region complements the same alleles of B2t that haync2 fails to complement. haync2 is a recessive male sterile mutation in a genetic background that is wild type at the B2t locus. Homozygous males have defects in meiosis, flagellar elongation and nuclear shaping, the three major microtubule-based processes in which the testis-specific beta 2-tubulin participates. The haync2 allele also has effects outside of spermatogenesis. It is a temperature-sensitive semilethal mutation, and homozygous haync2 females have reduced fertility. These phenotypes are consistent with a role for the haywire gene product in general microtubule function. Analysis of second-site non-complementing mutations such as haync2 offers a genetic tool for analysis of interacting proteins in complex assemblies.

CNS tissues are protected from circulating cells and factors by the blood-brain barrier (BBB), a specialization of the neurovasculature. Outcomes of the loss of BBB integrity and cell infiltration into CNS tissues can differ vastly. For example, elevated BBB permeability is closely associated with the development of neurological disease in experimental allergic encephalomyelitis (EAE) but not during clearance of the attenuated rabies virus CVS-F3 from the CNS tissues. To probe whether differences in the nature of BBB permeability changes may contribute to the pathogenesis of acute neuroinflammatory disease, we compared the characteristics of BBB permeability changes in mice with EAE and in mice clearing CVS-F3. BBB permeability changes are largely restricted to the cerebellum and spinal cord in both models but differ in the extent of leakage of markers of different size and in the nature of cell accumulation in the CNS tissues. The accumulation in the CNS tissues of CD4 T cells expressing mRNAs specific for IFN-gamma and IL-17 is common to both, but iNOS-positive cells invade into the CNS parenchyma only in EAE. Mice that have been immunized with myelin basic protein (MBP) and infected exhibit the features of EAE. Treatment with the peroxynitrite-dependent radical scavenger urate inhibits the invasion of iNOS-positive cells into the CNS tissues and the development of clinical signs of EAE without preventing the loss of BBB integrity in immunized/infected animals. These findings indicate that BBB permeability changes can occur in the absence of neuropathology provided that cell invasion is restricted.

c-Mpl, a receptor for thrombopoietin (TPO), belongs to the haemopoietin/cytokine receptor superfamily, a group of cell surface molecules characterized by conserved sequence motifs within their ligand binding domains. A recurring mechanism for the activation of haemopoietin receptors is the formation of functional complexes by receptor subunit oligomerization. Within the growth hormone receptor, a cluster of extracellular amino acids forms a dimer interface domain that stabilizes ligand-induced homodimers. This domain appears to be functionally conserved in the erythropoietin (EPO) receptor because substitution of cysteines for residues in the analogous region causes EPO-independent receptor activation via disulfide-linked homodimerization. This report identifies an homologous domain within the c-Mpl receptor. The substitution of cysteine residues for specific amino acids in the dimer interface homology regions of c-Mpl induced constitutive receptor activity. Factor-dependent FDC-P1 and Ba/F3 cells expressing the active receptor mutants no longer required exogenous factors and proliferated autonomously. The results imply that the normal process of TPO-stimulated Mpl activation occurs through receptor homodimerization and is mediated by a conserved haemopoietin receptor dimer interface domain. Moreover, cells expressing activated mutant Mpl receptors were tumorigenic in transplanted mice. Thus, like v-mpl, its viral counterpart, mutated forms of the cellular mpl gene also have oncogenic potential.

OBJECTIVE

Signal transducers and activators of transcription (STAT) factors are critical mediators in the signal transduction of cytokine receptors. In hematopoietic and epithelial cells, activation of STAT 1 induces apoptosis and growth arrest, whereas activation of STAT3 and STAT5 transduces growth-promoting signals. We and others have previously described a high expression and constitutive activation of STAT1, 3, and 5 in AML blasts. In this report we focused on the mechanisms and also the biologic relevance of STAT activation in AML.Results.

RESULTS

We report here that a constitutive STAT activation can be detected in up to 95% of primary AML blasts. In vitro, neither induction of the leukemic fusion protein PML-RAR alpha in U937 cells nor expression of transforming ras-mutants, but several leukemic protein tyrosine kinase (PTK), strongly induced activation of STAT3 and 5. Stable transfection of BA/F3 cells with TEL-JAK2, TEL-ABL, and BCR-ABL resulted in IL-3 independent growth and strong activation of STAT3 and STAT5 by TEL-JAK2 and TEL-ABL, but not by BCR-ABL. In addition, expression of constitutive active mutants of STAT3 and STAT5 alone were sufficient to transform BA/F3 cells.

CONCLUSIONS

These results show that STAT3 and STAT5 are activated in the majority of primary AML blasts and are major targets of leukemic fusion proteins with PTK activity. However, the STAT activation pattern by leukemic PTKs differed significantly and might reflect their transforming potential in acute (TEL-JAK2 and TEL-ABL) and chronic leukemias (p210BCR-ABL). The transforming capacity of constitutively activated STAT3 and STAT5 mutants strongly supports their fundamental role in the process of malignant transformation in hematopoietic cells.

OBJECTIVE

YKL-40 is a chitinase-like protein involved in matrix remodelling and a non-invasive fibrosis marker. We assessed whether a functional promoter polymorphism in CHI3L1, encoding YKL-40, is associated with HCV-induced liver fibrosis and influences YKL-40 serum concentrations.

METHODS

The CHI3L1 -131G->>C promoter polymorphism was genotyped in two cohorts of HCV infected patients (n=440) by 5'-endonuclease assays. Histological fibrosis scores and YKL-40 serum levels (ELISA) were associated with CHI3L1 -131G->>C by quantitative and qualitative genetic analyses and corrected by multivariate analysis.

RESULTS

CHI3L1 -131G->>C genotype was strongly associated with the stage of liver fibrosis in the screening (n=265, P=0.001) and validation cohort (n=175, P=0.009). Homozygous carriers of the G allele were protected from severe fibrosis (F3/F4). This association was confirmed after correction for age and gender. Functionally, the G allele was associated with reduced serum levels of YKL-40 in HCV infected patients (P=0.002).

CONCLUSIONS

The CHI3L1 promoter polymorphism -131G->>C determines YKL-40 serum levels and is associated with the severity of HCV-induced liver fibrosis. These results suggest a functional role of YKL-40 in liver fibrogenesis and should be taken into account when using YKL-40 as a non-invasive fibrosis marker.

We report 2 ALK-positive large B-cell lymphoma cases showing granular cytoplasmic and cytoplasmic/nuclear ALK immunostaining in which cryptic ALK rearrangements were identified by fluorescent in situ hybridization and molecular analysis. In the first case, the ALK-involving t(2;3)(p23;q27) masked the cryptic SEC31A-ALK fusion generated by an insertion of the 5' end of SEC31A (4q21) upstream of the 3' end of ALK. This rearrangement was associated with loss of the 5' end of ALK and duplication of SEC31A-ALK on der(20). In the second case with complex rearrangements of both chromosomes 2, a submicroscopic NPM1-ALK fusion created by insertion of the 3' end of ALK into the NPM1 locus was evidenced. Further studies of SEC31A-ALK showed that this variant fusion transforms IL3-dependent Ba/F3 cells to growth factor independence, and that the ALK inhibitor TAE-684 reduces cell proliferation and kinase activity of SEC31A-ALK and its downstream effectors ERK1/2, AKT, STAT3 and STAT5.

Low frequency (< 1 Hz) delta EEG in sleep is of increasing interest as it indicates cortical reorganization, especially in the prefrontal cortex (PFC). Other research shows that delta power in sleep is positively linked to waking cerebral metabolic rate. Such findings suggest that < 1 Hz activity may reflect waking performance at neuropsychological tests specific to the PFC. We investigated this unexplored area. Sleep EEGs (Fp1-F3, Fp2-F4, O1-P3, O2-P4) were recorded in 24 healthy 61-75-year-olds. We found significant associations between 0.5-1.0 Hz power from the left frontal EEG channel, in the first non-REM period, and performance at tasks more specific to the left PFC (e.g., nonverbal planning and verbal fluency). This association was absent from the posterior channels. Neither age nor response times were confounding factors. This potential sleep EEG marker for PFC neuropsychological function in healthy, older people also points to further uses of the sleep EEG in understanding the role of sleep.

This study investigated the organization of the callosal connections of the two subdivisions of the monkey dorsal premotor cortex (PMd), dorso-rostral (F7) and dorso-caudal (F2). In one animal, Fast blue and Diamidino yellow were injected in F7 and F2, respectively; in a second animal, the pattern of injections was reversed. F7 and F2 receive a major callosal input from their homotopic counterpart. The heterotopic connections of F7 originate mainly from F2, with smaller contingent from pre-supplementary motor area (pre-SMA, F6), area 8 (frontal eye fields), and prefrontal cortex (area 46), while those of F2 originate from F7, with smaller contributions from ventral premotor areas (F5, F4), SMA-proper (F3), and primary motor cortex (M1). Callosal cells projecting homotopically are mostly located in layers II-III, those projecting heterotopically occupy layers II-III and V-VI. A spectral analysis was used to characterize the spatial fluctuations of the distribution of callosal neurons, in both F7 and F2, as well as in adjacent cortical areas. The results revealed two main periodic components. The first, in the domain of the low spatial frequencies, corresponds to periodicities of cell density with peak-to-peak distances of approximately 10 mm, and suggests an arrangement of callosal cells in the form of 5-mm wide bands. The second corresponds to periodicities of approximately 2 mm, and probably reflects a 1-mm columnar-like arrangement. Coherency and phase analyses showed that, although similar in their spatial arrangements, callosal cells projecting to dorsal premotor areas are segregated in the tangential cortical domain.

RUNX1/AML1 regulates lineage-specific genes during hematopoiesis and stimulates G1 cell-cycle progression. Within RUNX1, S48, S303, and S424 fit the cyclin-dependent kinase (cdk) phosphorylation consensus, (S/T)PX(R/K). Phosphorylation of RUNX1 by cdks on serine 303 was shown to mediate destabilization of RUNX1 in G2/M. We now use an in vitro kinase assay, phosphopeptide-specific antiserum, and the cdk inhibitor roscovitine to demonstrate that S48 and S424 are also phosphorylated by cdk1 or cdk6 in hematopoietic cells. S48 phosphorylation of RUNX1 paralleled total RUNX1 levels during cell-cycle progression, S303 was more effectively phosphorylated in G2/M, and S424 in G1. Single, double, and triple mutation of the cdk sites to the partially phosphomimetic aspartic acid mildly reduced DNA affinity while progressively increasing transactivation of a model reporter. Mutation to alanine increased DNA affinity, suggesting that in other gene or cellular contexts phosphorylation of RUNX1 by cdks may reduce transactivation. The tripleD RUNX1 mutant rescued Ba/F3 cells from inhibition of proliferation by CBFbeta-SMMHC more effectively than the tripleA mutant. Together these findings indicate that cdk phosphorylation of RUNX1 potentially couples stem/progenitor proliferation and lineage progression.

BACKGROUND

Liver stiffness measurement (LSM) using transient elastography (TE) is a promising tool for the noninvasive assessment of hepatic fibrosis.

OBJECTIVE

To determine the feasibility and performance of TE in a North American cohort of patients with chronic liver disease.

METHODS

LSMs were obtained using TE in 260 patients with chronic hepatitis B or C, or nonalcoholic fatty liver disease from four Canadian hepatology centres. The accuracy of TE compared with liver biopsy for the prediction of significant fibrosis (Metavir fibrosis score of F2 or greater), bridging fibrosis (Metavir fibrosis score of F3 or greater) and cirrhosis (Metavir fibrosis score of F4 ) was assessed using area under ROC curves (AUROCs), and compared with the aspartate aminotransferase-to-platelet ratio index. The influence of alanine aminotransferase (ALT) levels and other factors on liver stiffness was determined using linear regression analyses.

RESULTS

failure of TE occurred in 2.7% of patients, while liver biopsies were inadequate for staging in 0.8%. Among the remaining 251 patients, the AUROCs of TE for Metavir fibrosis scores of F2 and F3 or greater, and F4 were 0.74 (95% CI 0.68 to 0.80), 0.89 (95% CI 0.84 to 0.94), and 0.94 (95% CI 0.90 to 0.97), respectively. LSM was more accurate than the aminotransferase-to-platelet ratio index for bridging fibrosis (AUROC 0.78) and cirrhosis (AUROC 0.88), but not significant fibrosis (AUROC 0.76). At a cut-off of 11.1 kPa, the sensitivity, specificity, and positive and negative predictive values for cirrhosis (prevalence 11%) were 96%, 81%, 39% and 99%, respectively. For significant fibrosis (prevalence 53%), a cut-off of 7.7 kPa was 68% sensitive and 69% specific, and had a positive predictive value of 70% and a negative predictive value of 65%. Liver stiffness was independently associated with ALT, body mass index and steatosis. The optimal LSM cut-offs for cirrhosis were 11.1 kPa and 11.5 kPa in patients with ALT levels lower than 100 U⁄L and 100 U⁄L or greater, respectively. For fibrosis scores of F2 or greater, these figures were 7.0 kPa and 8.6 kPa, respectively.

CONCLUSIONS

the major role of TE is the exclusion of bridging fibrosis and cirrhosis. However, TE cannot replace biopsy for the diagnosis of significant fibrosis. Because liver stiffness may be influenced by significant ALT elevation, body mass index and⁄or steatosis, tailored liver stiffness cut-offs may be necessary to account for these factors.

OBJECTIVE

Subclinical inflammation represents a risk factor of type 2 diabetes and several diabetes complications, but data on diabetic neuropathies are scarce. Therefore, we investigated whether circulating concentrations of acute-phase proteins, cytokines, and chemokines differ among diabetic patients with or without diabetic polyneuropathy.

METHODS

We measured 10 markers of subclinical inflammation in 227 type 2 diabetic patients with diabetic polyneuropathy who participated in the population-based MONICA/KORA Survey F3 (2004-2005; Augsburg, Germany). Diabetic polyneuropathy was diagnosed using the Michigan Neuropathy Screening Instrument (MNSI).

RESULTS

After adjustment for multiple confounders, high levels of C-reactive protein and interleukin (IL)-6 were most consistently associated with diabetic polyneuropathy, high MNSI score, and specific neuropathic deficits, whereas some inverse associations were seen for IL-18.

CONCLUSIONS

This study shows that subclinical inflammation is associated with diabetic polyneuropathy and neuropathic impairments. This association appears rather specific because only certain immune mediators and impairments are involved.

Mycoplasma hyopneumoniae induces respiratory disease in swine by colonizing cilia causing ciliostasis, cilial loss and epithelial cell death. Heparin binds to M. hyopneumoniae cells in a dose-dependent manner and blocks its ability to adhere to porcine cilia. We show here that Mhp493 (P216), a paralogue of the cilium adhesin P97 (Mhp183), is cleaved between amino acids 1040 and 1089 generating surface-accessible, heparin-binding proteins P120 and P85. Antiphosphoserine antibodies recognized P85 in 2-D immunoblotting studies and TiO(2) chromatography of trypsin digests of P85 isolated a single peptide with an m/z of 917.3. A phosphoserine residue in the tryptic peptide (90)VSELpSFR(96) (position 94 in P85) was identified by MALDI-MS/MS. Polyhistidine fusion proteins (F1(P216), F2(P216), F3(P216)) spanning Mhp493 bound heparin with biologically significant Kd values, and heparin, fucoidan and mucin inhibited this interaction. Latex beads coated with F1(P216), F2(P216) and F3(P216) adhered to and entered porcine kidney epithelial-like (PK15) cell monolayers. Microtitre plate-based assays showed that sequences within P120 and P85 bind to porcine cilia and are recognized by serum antibodies elicited during infection by M. hyopneumoniae. Mhp493 contributes significantly to the surface architecture of M. hyopneumoniae and is the first cilium adhesin to be described that lacks an R1 cilium-binding domain.

Cytokines exert biological functions by activating Janus tyrosine kinases (JAKs), and JAK inhibitors JAB (also referred to as SOCS1 and SSI1) and CIS3 (SOCS3) play an essential role in the negative regulation of cytokine signaling. We have found that transgenic (Tg) mice expressing a mutant JAB (F59D-JAB) exhibited a more potent STAT3 activation and a more severe colitis than did wild-type littermates after treatment with dextran sulfate sodium. We now find that there is a prolonged activation of JAKs and STATs in response to a number of cytokines in T cells from Tg mice with lck promoter-driven F59D-JAB. Overexpression of F59D-JAB also sustained activation of JAK2 in Ba/F3 cells. These data suggested that F59D-JAB up-regulated STAT activity by sustaining JAK activation. To elucidate molecular mechanisms related to F59D-JAB, we analyzed the effects of F59D-JAB on the JAK/STAT pathway using the 293 cell transient expression system. We found that the C-terminal SOCS-box played an essential role in augmenting cytokine signaling by F59D-JAB. The SOCS-box interacted with the Elongin BC complex, and this interaction stabilized JAB. F59D-JAB induced destabilization of wild-type JAB, whereas overexpression of Elongin BC canceled this effect. Levels of endogenous JAB and CIS3 in T cells from F59D-JAB Tg-mouse were lower than in wild-type mice. We propose that F59D-JAB destabilizes wild-type, endogenous JAB and CIS3 by chelating the Elongin BC complex, thereby sustaining JAK activation.

Translocation of membrane-impermeant molecules to the interior of living cells is a necessity for many biochemical investigations. Myristoylation was studied as a means to introduce peptides into living cells. Uptake of a myristoylated, fluorescent peptide was efficient in the B lymphocyte cell line BA/F3. In contrast, this cell line was resistant to uptake of a cell-penetrating peptide derived from the TAT protein. In BA/F3 cells, membrane association was shown to be rapid, reaching a maximum within 30 min. Cellular uptake of the peptide lagged the membrane association but occurred within a similar time frame. Experiments performed at 37 versus 4 degrees C demonstrated profound temperature dependence in the cellular uptake of myristoylated cargo. Myristoylated peptides with either positive or negative charge were shown to load efficiently. In contrast to TAT-conjugated cargo, pyrenebutyrate did not enhance cellular uptake of the myristoylated peptide. The myristoylated peptide did not adversely affect cell viability at concentrations up to 100 muM. This assessment of myristoyl-based transport provides fundamental data needed in understanding the intracellular delivery of myristoylated peptide cargoes for cell-based biochemical studies.

Log-transformed EEG power spectral estimates (6-7, 9,10-11,18-22, and 36-44 Hz), obtained from skilled marksmen and novice shooters at sites F3, F4, C3, C4,T3, T4, P3, P4, O1, and O2 during the aiming period (6 s) of a target shooting task for each of 40 trials up to the moment of trigger pull, were contrasted to determine regional differences in cortical activation. The EEG power obtained from both groups during the preparatory aiming period was also compared to that observed for a similar time period during the processing of standard verbal and spatial tasks. The marksmen exhibited less activation than the novice shooters at all sites during the aiming period with a pronounced difference in the left central-temporal-parietal area. Fewer group differences in cortical activation were observed during the comparative verbal and spatial tasks with which the groups held equal experience. Additionally, the novice shooters exhibited a cortical activation pattern during target shooting that was similar to that observed during the processing of the comparative verbal and spatial tasks. In contrast, marksmen generally exhibited less cortical activation during the aiming period when contrasted to that during the novel comparative tasks. These results are consistent with the notion of relative economy in the cortical processes of marksmen, relative to controls, during the specific challenge with which they are highly practiced.

OBJECTIVE

Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease that leads to extensive liver fibrosis and cirrhosis, which are associated with poor outcome. However, there are no validated noninvasive markers of liver fibrosis in patients with PSC. We assessed the diagnostic performance, reproducibility, longitudinal changes, and prognostic value of liver stiffness measurement (LSM) using vibration-controlled transient elastography (VCTE).

METHODS

In a prospective study, we analyzed percutaneous liver biopsy specimens from 73 consecutive patients with PSC from January 2005 to December 2010. Patients underwent VCTE no more than 6 months after the biopsy specimens were collected. The biopsy specimens were analyzed by a pathologist blinded to the results of VCTE for the stage of fibrosis, and LSM was associated with the stage of fibrosis and other variables using the Kruskal-Wallis and Spearman correlation tests. The cutoff values of LSM were selected based on the accuracy with which they identified the stage of fibrosis on receiver-operating characteristic analysis. The rates of LSM progression were assessed using a linear mixed model, and the association between LSM values and clinical outcomes were evaluated using Cox regression analysis in 168 patients with PSC treated with ursodeoxycholic acid and followed up from November 2004 to July 2013 (mean follow-up period, 4 years).

RESULTS

LSM was independently linked to the stage of fibrosis. Cutoff values for fibrosis stages ≥F1, ≥F2, ≥F3, and F4 were 7.4 kPa, 8.6 kPa, 9.6 kPa, and 14.4 kPa, respectively. The adjusted diagnostic accuracy values for severe fibrosis and cirrhosis were 0.83 and 0.88, respectively. The diagnostic performance of LSM was comparable to that of hyaluronic acid measurement but superior to the aspartate aminotransferase/platelet ratio index, FIB-4 score, and Mayo risk score in differentiating patients with significant or severe fibrosis from those without. LSM had a high level of reproducibility between operators for the same measurement site and for the same operator between 2 adjacent sites. LSM increased significantly and exponentially over time. Baseline measurements and rate of LSM progression were strongly and independently linked with patients' outcomes.

CONCLUSIONS

VCTE is able to differentiate severe from nonsevere liver fibrosis with high levels of confidence in patients with PSC. Baseline measurements of LSM and longitudinal changes are prognostic factors for PSC.

OBJECTIVE

To evaluate the effects of minimal to moderate alcohol consumption on the severity of histological lesions in patients with chronic hepatitis C.

METHODS

Daily alcohol intake (none, 1-20, 21-30, 31-50 g/day) and histological activity and fibrosis were recorded in 260 patients with chronic hepatitis C.

RESULTS

The proportion of patients with moderate (A2) or marked (A3) activity increased gradually from 53.8% in abstinent patients to 86.5% for an intake between 31 and 50 g/day (P = 0.003). In multivariate analysis, age>> 40 years, alcohol intake between 31 and 50 g/day and moderate or severe steatosis were independently related to histological activity. The proportion of patients with moderate (F2) or marked (F3) fibrosis or cirrhosis (F4) gradually increased from 29.0% in abstinent patients to 67.6% for an intake between 31 and 50 g/day (P < 0.001). Multivariate analysis also showed that alcohol intake between 31 and 50 g/day, moderate or severe steatosis and histological activity were independently related to fibrosis. The deleterious effect of alcohol intake on histological lesions differed according to gender.

CONCLUSIONS

This study demonstrates that both activity and fibrosis gradually increase according to the amount of alcohol ingested, and that even moderate alcohol consumption, as low as 31-50 g/day in men and 21-50 g/day in women, may aggravate histological lesions in patients with chronic hepatitis C.

The majority of anaplastic large cell lymphomas (ALCLs) express the nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) fusion protein, which is oncogenic due to its constitutive tyrosine kinase activity. Transformation by NPM-ALK not only increases proliferation, but also modifies cell shape and motility in both lymphoid and fibroblastic cells. We report that the Rac1 GTPase, a known cytoskeletal regulator, is activated by NPM-ALK in ALCL cell lines (Karpas 299 and Cost) and transfected cells (lymphoid Ba/F3 cells, NIH-3T3 fibroblasts). We have identified Vav3 as one of the exchange factors involved in Rac1 activation. Stimulation of Vav3 and Rac1 by NPM-ALK is under the control of Src kinases. It involves formation of a signaling complex between NPM-ALK, pp60(c-src), Lyn and Vav3, in which Vav3 associates with tyrosine 343 of NPM-ALK via its SH2 domain. Moreover, Vav3 is phosphorylated in NPM-ALK positive biopsies from patients suffering from ALCL, demonstrating the pathological relevance of this observation. The use of Vav3-specific shRNA and a dominant negative Rac1 mutant demonstrates the central role of GTPases in NPM-ALK elicited motility and invasion.

Resistance to submergence stress is an important breeding objective in areas where rice cultivars are subjected to complete inundation for a week or more. The present study was conducted to develop a high-resolution map of the region surrounding the submergence tolerance gene Sub1 in rice, which derives from the Indian cultivar FR13A. Submergence screening of 8-day-old plants of F3 families kept for 14 days submerged in 60 cm of water allowed an accurate classification of Sub1 phenotypes. Bulked segregant analysis was used to identify AFLP markers linked to Sub1. A population of 2950 F2 plants segregating for Sub1 was screened with two RFLP markers flanking the Sub1 locus, 2.4 and 4.9 cM away. Submergence tolerance was measured in the recombinant plants, and AFLP markers closely linked to Sub1 were mapped. Two AFLP markers cosegregated with Sub1 in this large population, and other markers were localized within 0.2 cM of Sub1. The high-resolution map should serve as the basis for map-based cloning of this important locus, as it will permit the identification of BAC clones spanning the region.

RFLP mapping of chromosome 5R in the F3 generation of a rye (Secale cereale L.) cross segregating for gibberellic acid (GA3)-insensitive dwarfness (Ct2/ct2) and spring growth habit (Sp1/sp1) identified RFLP loci close to each of these agronomically important genes. The level of RFLP in the segregating population was high, and thus allowed more than half of the RFLP loci to be mapped, despite partial homozygosity in the parental F2 plant. Eight further loci were mapped in an unrelated F2 rye population, and a further two were placed by inference from equivalent genetic maps of related wheat chromosomes, allowing a consensus map of rye chromosome 5R, consisting of 29 points and spanning 129 cM, to be constructed. The location of the ct2 dwarfing gene was shown to be separated from the segment of the primitive 4RL translocated to 5RL, and thus the gene is probably genetically unrelated to the major GA-insensitive Rht genes of wheat located on chromosome arms 4BS and 4DS. The map position of Sp1 is consistent both with those of wheat Vrn1 and Vrn3, present on chromosome arms 5AL and 5DL, respectively, and with barley Sh2 which is distally located on chromosome arm 7L (= 5HL).

Flavonoid 3'-hydroxylase (F3'H) and flavonoid 3',5'-hydroxylase (F3'5'H) are cytochrome P450 enzymes and determine the B-ring hydroxylation pattern of flavonoids by introducing hydroxyl groups at the 3'- or the 3'- and 5'-position, respectively. Sequence identity between F3'H and F3'5'H is generally low since their divergence took place early in the evolution of higher plants. However, in the Asteraceae the family-specific evolution of an F3'5'H from an F3'H precursor occurred, and consequently sequence identity is substantially higher. We used this phenomenon for alignment studies, in order to identify regions which could be involved in determining substrate specificity and functionality. Subsequent construction and expression of chimeric genes indicated that substrate specificity of F3'H and F3'5'H is determined near the N-terminal end and the functional difference between these two enzymes near the C-terminal end. The impact on function of individual amino acids located in substrate recognition site 6 (SRS6) was further tested by site-directed mutagenesis. Most interestingly, a conservative Thr to Ser exchange at position 487 conferred additional 5'-hydroxylation activity to recombinant Gerbera hybrida F3'H, whereas the reverse substitution transformed recombinant Osteospermum hybrida F3'5'H into an F3'H with low remaining 5'-hydroxylation activity. Since the physicochemical properties of Thr and Ser are highly similar, the difference in size appears to be the main factor contributing to functional difference. The results further suggest that relatively few amino acids exchanges were required for the evolutionary extension of 3'- to 3',5'-hydroxylation activity.

Orange- to red-colored flowers are difficult to produce by conventional breeding techniques in some floricultural plants. This is due to the deficiency in the formation of pelargonidin, which confers orange to red colors, in their flowers. Previous researchers have reported that brick-red colored flowers can be produced by introducing a foreign dihydroflavonol 4-reductase (DFR) with different substrate specificity in Petunia hybrida, which does not accumulate pelargonidin pigments naturally. However, because these experiments used dihydrokaempferol (DHK)-accumulated mutants as transformation hosts, this strategy cannot be applied directly to other floricultural plants. Thus in this study, we attempted to produce red-flowered plants by suppressing two endogenous genes and expressing one foreign gene using tobacco as a model plant. We used a chimeric RNAi construct for suppression of two genes (flavonol synthase [FLS] and flavonoid 3'-hydroxylase [F3'H]) and expression of the gerbera DFR gene in order to accumulate pelargonidin pigments in tobacco flowers. We successfully produced red-flowered tobacco plants containing high amounts of additional pelargonidin as confirmed by HPLC analysis. The flavonol content was reduced in the transgenic plants as expected, although complete inhibition was not achieved. Expression analysis also showed that reduction of the two-targeted genes and expression of the foreign gene occurred simultaneously. These results demonstrate that flower color modification can be achieved by multiple gene regulation without use of mutants if the vector constructs are designed resourcefully.