bluuebunny/crossref_metadata_2025 huggingface dataset:
The Notch coactivator, MAML1, functions as a novel coactivator for MEF2C-mediated transcription and is required for normal myogenesis
Authors: Shen Huangxuan , McElhinny Abigail S. , Cao Yang , Gao Ping , Liu Jingxuan , Bronson Roderick , Griffin James D. , Wu Lizi
Published: March 2006

The MAML (mastermind-like) proteins are a family of three cotranscriptional regulators that are essential for Notch signaling, a pathway critical for cell fate determination. Though the functions of MAML proteins in normal development remain unresolved, their distinct tissue distributions and differential activities in cooperating with various Notch receptors suggest that they have unique roles. Here we show that mice with a targeted disruption of the Maml1 gene have severe muscular dystrophy. In vitro, Maml1-null embryonic fibroblasts failed to undergo MyoD-induced myogenic differentiation, further suggesting that Maml1 is required for muscle development. Interestingly, overexpression of MAML1 in C2C12 cells dramatically enhanced myotube formation and increased the expression of muscle-specific genes, while RNA interference (RNAi)-mediated MAML1 knockdown abrogated differentiation. Moreover, we determined that MAML1 interacts with MEF2C (myocyte enhancer factor 2C), functioning as its potent cotranscriptional regulator. Surprisingly, however, MAML1’s promyogenic effects were completely blocked upon activation of Notch signaling, which was associated with recruitment of MAML1 away from MEF2C to the Notch transcriptional complex. Our study thus reveals novel and nonredundant functions for MAML1: It acts as a coactivator for MEF2C transcription and is essential for proper muscle development. Mechanistically, MAML1 appears to mediate cross-talk between Notch and MEF2 to influence myogenic differentiation.
Identification of phosphatases for Smad in the BMP/DPP pathway
Authors: Chen Hong B. , Shen Jiali , Ip Y. Tony , Xu Lan
Published: March 2006

Phosphorylation of the SSXS motif of Smads is critical in activating the transforming growth factor β (TGF-β) and bone morphogenetic protein (BMP) pathways. However, the phosphatase(s) involved in dephosphorylating and hence inactivating Smads remained elusive. Through RNA interference (RNAi)-based screening of serine/threonine phosphatases in Drosophila S2 cells, we identified pyruvate dehydrogenase phosphatase (PDP) to be required for dephosphorylation of Mothers against Decapentaplegic (MAD), a Drosophila Smad. Biochemical and genetic evidence suggest that PDP directly dephosphorylates MAD and inhibits signal transduction of Decapentaplegic (DPP). We show that the mammalian PDPs are important in dephosphorylation of BMP-activated Smad1 but not TGF-β-activated Smad2 or Smad3. Thus, PDPs specifically inactivate Smads in the BMP/DPP pathway.
Functional genomics of genes with small open reading frames (sORFs) in S. cerevisiae
Authors: Kastenmayer James P. , Ni Li , Chu Angela , Kitchen Lauren E. , Au Wei-Chun , Yang Hui , Carter Carole D. , Wheeler David , Davis Ronald W. , Boeke Jef D. , Snyder Michael A. , Basrai Munira A.
Published: March 2006

Genes with small open reading frames (sORFs; <100 amino acids) represent an untapped source of important biology. sORFs largely escaped analysis because they were difficult to predict computationally and less likely to be targeted by genetic screens. Thus, the substantial number of sORFs and their potential importance have only recently become clear. To investigate sORF function, we undertook the first functional studies of sORFs in any system, using the model eukaryote Saccharomyces cerevisiae. Based on independent experimental approaches and computational analyses, evidence exists for 299 sORFs in the S. cerevisiae genome, representing ∼5% of the annotated ORFs. We determined that a similar percentage of sORFs are annotated in other eukaryotes, including humans, and 184 of the S. cerevisiae sORFs exhibit similarity with ORFs in other organisms. To investigate sORF function, we constructed a collection of gene-deletion mutants of 140 newly identified sORFs, each of which contains a strain-specific “molecular barcode,” bringing the total number of sORF deletion strains to 247. Phenotypic analyses of the new gene-deletion strains identified 22 sORFs required for haploid growth, growth at high temperature, growth in the presence of a nonfermentable carbon source, or growth in the presence of DNA damage and replication-arrest agents. We provide a collection of sORF deletion strains that can be integrated into the existing deletion collection as a resource for the yeast community for elucidating gene function. Moreover, our analyses of the S. cerevisiae sORFs establish that sORFs are conserved across eukaryotes and have important biological functions.
Systematic identification of functional orthologs based on protein network comparison
Authors: Bandyopadhyay Sourav , Sharan Roded , Ideker Trey
Published: March 2006

Annotating protein function across species is an important task that is often complicated by the presence of large paralogous gene families. Here, we report a novel strategy for identifying functionally related proteins that supplements sequence-based comparisons with information on conserved protein–protein interactions. First, the protein interaction networks of two species are aligned by assigning proteins to sequence homology clusters using the Inparanoid algorithm. Next, probabilistic inference is performed on the aligned networks to identify pairs of proteins, one from each species, that are likely to retain the same function based on conservation of their interacting partners. Applying this method to Drosophila melanogaster and Saccharomyces cerevisiae, we analyze 121 cases for which functional orthology assignment is ambiguous when sequence similarity is used alone. In 61 of these cases, the network supports a different protein pair than that favored by sequence comparisons. These results suggest that network analysis can be used to provide a key source of information for refining sequence-based homology searches.
Interferon‐γ down‐regulates expression of the 230‐kDa bullous pemphigoid antigen gene (BPAG1) in epidermal keratinocytes via novel chimeric sequences of ISRE and GAS
Authors: Kaneko Takahide , Tamai Katsuto , Matsuzaki Yasushi , Yamazaki Takehiko , Nakano Hajime , Kon Atsushi , Hashimoto Isao , Hanada Katsumi , Kaneda Yasuhumi , Uitto Jouni
Published: March 2006

Abstract:  The 230‐kDa bullous pemphigoid antigen (BPAG1) is an integral component of hemidesmosomes. We have previously reported that interferon‐γ (IFNγ) inhibits the transcription of the BPAG1 gene (1). Here we investigated the target sequences of IFNγ‐signal transduction pathway in the BPAG1 promoter in epidermal keratinocytes. Transient transfections with 5′‐deletion constructs of BPAG1 promoter‐luciferase reporter gene plasmids in cultured normal human epidermal keratinocytes (NHEK) allowed us to narrow the DNA region containing IFNγ inhibitory element (IGIE) to between −1 and −89, upstream from the transcription initiation site (+1). Homology search in this region identified a chimeric sequence, consisting of IFN‐stimulated responsive element (ISRE) with a partial 7‐bp sequence of IFNγ activation site (GAS), as identified in the guanylate‐binding protein (GBP) gene, inserted at its center. Functional analysis of IGIE, inserted in front of the heterologous thymidine kinase promoter, indicated that IGIE acts as a down‐regulatory element of the promoter through IFNγ‐dependent signal pathway. Transient transfection studies with BPAG1 promoter‐reporter gene constructs containing mutated IGIE (with TT to GG transversions in the region of 5′ISRE, GAS, and 3′ISRE) demonstrated that disruption of the ISRE sequences, but not GAS, markedly suppressed the BPAG1 basal promoter activity and resulted in attenuated IFNγ response in keratinocytes. Our findings provide novel insight into the mechanism of IFNγ regulation in keratinocyte differentiation and proliferation.
Cholinergic control of epidermal cohesion
Authors: Grando Sergei A.
Published: March 2006

Abstract: The non‐neuronal cholinergic system of human epidermis includes the keratinocyte (KC) acetylcholine (ACh) axis composed of the enzymes mediating ACh synthesis and degradation, and two classes of ACh receptors, the nicotinic and muscarinic ACh receptors, mediating biological effects of the cutaneous cytotransmitter ACh. Regulation of KC cell–cell and cell–matrix adhesion is one of the important biological functions of cutaneous ACh. The downstream targets of ACh effects mediated by distinct ACh receptor subtypes include both the intercellular adhesion molecules, such as classical and desmosomal cadherins, and integrins mediating KC adhesion to a substrate. The signaling pathways include activation or inhibition of kinase cascades resulting in either up‐ or down‐regulation of the expression of cell adhesion molecules or changes in their phosphorylation status, or both. The components of the KC ACh axis are involved in cutaneous blistering in patients with autoimmune pemphigus, junctional and dystrophic forms of epidermolysis bullosa, thermal burns, and mustard‐induced vesication. Recent progress with the development of antiacantholytic therapies of patients with pemphigus using cholinomimetics indicates that cholinergic drugs may be a promising approach for other cutaneous blistering disorders.
E‐cadherin and its downstream catenins are proteolytically cleaved in human HaCaT keratinocytes exposed to UVB
Authors: Hung Chi‐Feng , Chiang Han‐Sun , Lo Huey‐Ming , Jian Jr‐Shian , Wu Wen‐Bin
Published: March 2006

Abstract:  It has been reported that ultraviolet B (UVB) irradiation causes the loss of E‐cadherin of melanocytes, leading them to escape from neighboring keratinocytes during melanoma development. However, little has been paid on its effect on E‐cadherin of keratinocytes. In the present study we therefore focus on whether UVB affects expression of E‐cadherin‐catenin complex in human HaCaT keratinocytes. We found that E‐cadherin, β‐, and γ‐catenin but not α‐catenin were proteolytically cleaved in UVB‐irradiated HaCaT keratinocytes. The effect was only observed in keratinocyte undergoing apoptosis. Cleavage of β‐ and γ‐catenin was fully abolished by caspase‐3 and caspase‐8 inhibitors, whereas cleavage of E‐cadherin was inhibited by neither caspase nor metalloproteinase inhibitors. Functional analysis showed that the cleavage resulted in the disruption of the physical association between E‐cadherin and catenins, indicating that E‐cadherin signaling was compromised in UVB‐irradiated HaCaT keratinocytes. Because E‐cadherin in keratinocytes plays important roles in mediating cell–cell adhesion in epidermis of skin, the loss of E‐cadherin and signaling components in keratinocytes may lead to the disruption of skin integrity after UVB exposure.
Non‐steroidal and steroidal anti‐inflammatory drugs vary in their modulation of dendritic cell function in the elicitation phase of allergic contact dermatitis
Authors: Bäumer W. , Krekeler S. , DeVries V. C. , Niedorf F. , Tschernig T. , Kietzmann M.
Published: March 2006

Abstract:  The role of dendritic cells (DCs) in allergic contact dermatitis has been clearly demonstrated for the induction phase. However, the situation during the elicitation phase is very complex within a distinct inflammatory response. This study was performed to exploit DC migration in the elicitation phase in a mouse model of allergic contact dermatitis and to evaluate the effects of steroidal and non‐steroidal anti‐inflammatory drugs (NSAIDs) on DC migration through skin in the elicitation phase of allergic contact dermatitis. Topically and systemically administered acetylsalicylic acid (ASA) did not reduce the inflammatory response. However, systemically administered ASA significantly reduced the DC migration to the draining lymph node. In contrast, topically administered indomethacin reduced the inflammatory response, but had only minor effects on DC migration, whereas diflorasone diacetate reduced both inflammatory reaction and DC migration. Thus, NSAIDs may differ in their inhibitory action in immunological inflammation.
Skin carotenoid concentration correlates with male hunting skill and territory quality in the kestrel Falco tinnunculus
Authors: Casagrande Stefania , Csermely Davide , Pini Elena , Bertacche Vittorio , Tagliavini James
Published: March 2006

In the context of sexual selection carotenoid based signals are candidates for indicator traits: they have to be taken up in the diet by animals, they can indicate the ability of the bearer to accumulate a limited resource, and they help in maintaining the health status. We investigated the yellow‐orange colouration of the tarsi of the kestrel Falco tinnunculus in relation to sex, diet and to different aspects of male reproductive behaviour. The colouration of the tarsi (estimated as hue) was more intense in males than in females. Among males, the tarsi hue was associated with the intake of invertebrates; this was true also if the population diet was based mainly on voles. Carotenoid based colouration was positively associated with the number of vertebrate preys delivered to the nest per time unit and with territory quality (calculated on the basis of home‐range size, habitat extension and prey availability). These results are consistent with predictions derived from good‐parent models of sexual selection, suggesting that in the common kestrel carotenoid based colouration is important as an indicator of male quality.
A case of diffuse plane normolipemic xanthomatosis associated with pancytopenia and monoclonal gammopathy
Authors: KOUROU Kazuhiro , SUGA Yasushi , MURAMATSU Shigenori , YAGUCHI Hitoshi , OGAWA Hideoki
Published: March 2006

We report a case of diffuse plane normolipemic xanthomatosis (DPNX) which showed poorly demarcated, uncommon, yellow macules symmetrically distributed on the nape, axillae and inguinal folds accompanied by severe, persistent itching. Histopathological and ultrastructural studies of skin biopsy specimens revealed the existence of some foamy cells and the deposition of neutral fat in the upper papillary dermis. Laboratory investigations and bone marrow aspirate smears showed that our patient had myelodysplastic syndrome (MDS) associated with pancytopenia and monoclonal gammopathy of undetermined significance. Because our patient had neither a malignant hematological disorder nor a severe systemic disease, monoclonal gammopathy might explain the pathogenesis of DPNX in the present case.
The implications of a growing evidence base for drug use in elderly patients. Part 3. β‐adrenoceptor blockers in heart failure and thrombolytics in acute myocardial infarction
Authors: Mangoni A. A. , Jackson S. H. D.
Published: March 2006

β‐adrenoceptor blockers and thrombolytic agents are of established value in the pharmacological management of heart failure and ST‐elevation myocardial infarction, respectively. However, there is uncertainty as to whether these therapeutic strategies can be safely and effectively adopted in elderly patients with comorbidities, particularly in old‐old individuals. This review focuses on these trials and the age‐related efficacy and safety of these drugs.
Investigation on pharmacokinetics of mycophenolic acid in Chinese adult renal transplant patients
Authors: Zicheng Yu , Peijun Zhou , Da Xu , Xianghui Wang , Hongzhuan Chen
Published: March 2006

Aims

To characterize the pharmacokinetics of mycophenolic acid (MPA) in Chinese renal transplant patients.

Methods

Thirty‐one renal transplant patients (17 male, 14 female) receiving mycophenolate mofetil (MMF) 1.0 g twice daily were included in this study. A pharmacokinetic study was performed during an interval in dosing after steady state had been reached within 2 months after transplantation. The plasma MPA concentration were measured by high‐performance liquid chromatography (HPLC) at 0.5, 1, 1.5, 2, 4, 6, 8, 10 and 12 h after the administration of a single dose. Pharmacokinetic parameters were calculated with 3P97 software. SAS® software was used for statistical analysis. Multiple linear regression analysis was used to determine limited sampling approaches.

Results

The mean peak plasma concentration (Cmax) and area under the concentration–time curve (AUC0−12) were 19.67 ± 8.21 µg ml−1 and 52.16 ± 12.50 µg h ml−1, but there was large variability in these pharmacokinetic parameters. Regression analysis between each plasma concentration and AUC for the limited sampling strategy of MMF therapeutic drug monitoring demonstrated that each of the concentrations at 0.5, 1, 4 and 10 h was positively correlated with AUC (r = 0.60, P = 0.0004; r = 0.60, P = 0.0003; r = 0.61, P = 0.0003; r = 0.64, P = 0.0001, respectively). The combined use of these four samples explained over 90% of the variance in the total (nine‐point) AUC0−12. A formula was obtained for the assessment of MPA AUC based on four samples: MPA AUC = 12.61 + 0.37 × C0.5 + 0.49 × C1 + 3.22 × C4 + 8.17 × C10.

Conclusions

Chinese renal transplant patients had higher median AUCs than caucasians and African‐Americans. As in other studies, there was large interindividual variability. A limited four‐point AUC was in good agreement with the 12‐h AUC and provided the basis of a predictive formula.
Platelet activation in allergic asthma patients during allergen challenge with Dermatophagoides pteronyssinus
Authors: Kowal K. , Pampuch A. , Kowal‐Bielecka O. , DuBuske L. M. , Bodzenta‐Łukaszyk A.
Published: March 2006

Background
Animal models of allergic asthma indicate that intravascular platelet activation is necessary for the development of allergen‐induced chronic airway inflammation.

Objective
To evaluate whether the development of a late asthmatic response (LAR) in allergic asthma patients challenged with a relevant allergen is consequent to platelet activation.

Methods
Thirty‐three house dust mite sensitive asthmatic patients were challenged intrabronchially with Dermatophagoides pteronyssinus (Dp) extract. Twelve non‐atopic healthy subjects (HC) were used as controls. Platelet count and plasma levels of β‐thromboglobulin (β‐TG), platelet factor‐4 (PF‐4) and soluble P‐selectin (sP‐selectin) were assessed before the challenge (T0) and 30 min (TEAR), 6 h (TLAR) and 24 h (T24) after the challenge.

Results
Eleven patients responded to allergen challenge with an isolated early asthmatic response (single responders, SR). In 22 patients dual asthmatic response was demonstrated (dual responders, DR). At T0 neither the platelet count nor the mean plasma level of β‐TG in DR or SR were different from HC, the mean plasma level of PF‐4 in SR was significantly greater than in HC (P=0.01) or DR (P=0.001), the mean plasma level of sP‐selectin was significantly greater in DR than in HC (0.0002) but not statistically different from SR (P=0.055). A significant decrease in the platelet count and increase in the plasma level of all the studied markers was seen at TEAR, which was followed by a gradual return to the baseline values in the SR. Elevated plasma levels of platelet activation markers and decreased platelet count were seen in the DR even at T24. Strong correlation was found between the increase in plasma concentration of β‐TG at TEAR and the maximum fall in forced expiratory volume in 1 s at TLAR (r=−0.57; P=0.0006).

Conclusion
In allergic asthma patients development of prolonged airway inflammation after allergen challenge is associated with intravascular platelet activation.
Inverse association between periodontitis and respiratory allergies
Authors: Friedrich N. , Völzke H. , Schwahn C. , Kramer A. , Jünger M. , Schäfer T. , John U. , Kocher T.
Published: March 2006

BackgroundPeriodontitis is an infection with systemic effects and a high prevalence among adults. In the aetiology of allergic diseases the hygiene hypothesis claims that infections in early infancy may protect against allergic diseases.

ObjectiveThe aim of the present analyses was to investigate the independent relation between periodontitis and respiratory allergies such as hayfever, house dust mite (HDM) allergy and asthma.

MethodsFrom the Study of Health in Pomerania (SHIP) a total number of 2837 subjects aged 20 to 59 years were included in the analysis. In our study population 326, 111 and 114 subjects were classified as suffering from hayfever, HDM allergy or asthma, respectively. The attachment loss (AL) were measured. Periodontitis was defined according to the percentage of surfaces which exceeded 3 mm AL [healthy: 0–7.7%, mild: 7.8–28.6%, moderate: 28.7–63.9%, severe: >63.9%]. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression.

ResultsAfter adjustment for confounding factors these analyses revealed inverse associations between periodontitis and hayfever as well as periodontitis and HDM allergy. For increasing AL, a trend of decreasing risk could be observed for hayfever (healthy: reference; mild AL: OR 0.87 [95%‐CI 0.6–1.2]; moderate AL: OR 0.80 [95% CI 0.6–1.2]; server AL: OR 0.53 [95% CI 0.3–0.9];Ptrend=0.01) and for HDM allergy (healthy: reference; mild AL: OR 0.80 [95% CI 0.5–1.3]; moderate AL: OR 0.64 [95% CI 0.3–1.2]; server AL: OR 0.39 [95% CI 0.2–0.9];Ptrend=0.02). Furthermore, for asthma were observed a slightly inverse association in the full‐adjusted model (healthy: reference; mild AL: OR 1.10 [95% CI 0.6–2.0]; moderate AL: OR 0.96 [95% CI 0.5–1.8]; server AL: OR 0.48 [95% CI 0.2–1.0];Ptrend=0.11).

ConclusionThere is an inverse association between periodontitis and respiratory allergies. Our results might support the hygiene hypothesis.
Polymorphisms in manganese superoxide dismutase and catalase genes: functional study in Hong Kong Chinese asthma patients
Authors: Mak J. C. W. , Leung H. C. M. , Ho S. P. , Ko F. W. S. , Cheung A. H. K. , Ip M. S. M. , Chan‐Yeung M. M. W.
Published: March 2006

Background
Reactive oxygen species may contribute to the pathogenesis of asthma. Functional genetic polymorphisms of antioxidant enzymes, superoxide dismutase (SOD) and catalase are good candidates for asthma susceptibility.

Objective
To investigate the association of the manganese‐containing form of SOD (MnSOD) gene at amino acid position 16 (Val16Ala) and catalase gene in the promoter at A‐21T and C‐262T polymorphisms and asthma in a Hong Kong Chinese population.

Methods
The association study was conducted in a case–control design in asthma patients (n=251) and healthy controls (n=316) by genotyping. The functional significance was assessed by determining erythrocyte SOD and catalase activity.

Results
The Val allele of MnSOD at Val16Ala and the A allele of catalase gene at A‐21T were not different between patients and controls, while the C allele of catalase gene at C‐262T was found to be significantly different between patients and controls (P=0.033). The less frequent variant of catalase gene (−262T) was found to be protective from the development of asthma in a Hong Kong Chinese non‐smoking population (adjusted odds ratio=0.35, 0.15–0.85; P=0.017). Asthma patients had elevated erythrocyte SOD and catalase activities in comparison with healthy controls (P<0.01). However, their activities were not associated with different genotypes within healthy controls or asthma patients.

Conclusion
This is the first report showing that SOD and catalase functional activities are not associated with their respective genetic polymorphisms but related to the presence of asthma in a Hong Kong Chinese population.
The prognosis of occupational asthma due to detergent enzymes: clinical, immunological and employment outcomes
Authors: Brant A. , Zekveld C. , Welch J. , Jones M. , Taylor A. Newman , Cullinan P.
Published: March 2006

Background Little is known about the prognosis of occupational asthma induced by high molecular weight proteins. Objective Our objective was to measure the clinical, immunological and employment outcomes of individuals with occupational asthma induced by detergent enzymes. Methods We undertook a workforce‐based follow‐up study in 35 (78%) of the 45 ex‐employees from a single factory with occupational asthma. In each case the diagnosis was supported by evidence of specific sensitization and characteristic changes in peak flow or a positive response to specific bronchial provocation testing. Results This group had left the factory on average 37 months before study. On review 25 (71%) reported chest symptoms during the last month. Compared with when working at the factory, most (86%) reported that their symptoms had improved. Twenty continued to attend their general practitioner for respiratory symptoms and 19 still used asthma medications. Since leaving the factory 16 (46%) and four (11%) had found full‐time or part‐time employment, respectively; of these 16 found they were paid less than when they worked at the factory. The remaining 15 subjects had not had any paid employment. All but two had positive skin prick tests to one or more three detergent enzymes. The estimated half‐life of serum‐specific IgE antibodies was 20 months for protease, and 21 months for cellulase and amylase. Conclusions Population‐based follow‐up studies of the prognosis of occupational asthma are rare but probably avoid the bias in clinic‐derived surveys. This study demonstrates that 3 years after the avoidance of exposure with detergent enzymes most patients continue to be troubled by, albeit improved, symptoms and experience difficulty in re‐employment.
Peripheral T lymphocytes from patients with early systemic sclerosis co-cultured with autologous fibroblasts undergo an oligoclonal expansion similar to that occurring in the skin
Authors: De Palma Raffaele , Del Galdo Francesco , Lupoli Salvatore , Altucci Paolo , Abbate GianFranco , Valentini Gabriele
Published: March 2006

In recent years several reports have suggested that T cells may have a role in systemic sclerosis (SSc). The aim of our study was to investigate the dynamics of T cell repertoire in early SSc disease analysing a target organ, the skin, and the peripheral blood. To date, indeed, it is not clear if T cell expansions found in SSc reflect a general activation or result from specific antigen stimulation in the target organs. This is an important point to assess in order to characterize the role of T cells in the development of SSc. To address these questions we studied T cell repertoire by CDR3 length analysis in skin biopsies and peripheral blood obtained from patients affected by SSc and we found that a skewed T cell repertoire was present only in the biopsies. In order to characterize more effectively the meaning of these data, we performed co-cultures using fibroblasts and peripheral blood mononuclear cells (PBMCs) obtained from SSc patients. These experiments showed that same T cell expansions were detectable in the skin of SSc patients and in the cultures of PBMCs and autologous fibroblasts of the patients but not in their peripheral blood. Taken together, these data suggest that fibroblasts trigger specific T cell expansions in the early phase of SSc.
Anti-PCNA autoantibodies preferentially recognize C-terminal of PCNA in patients with chronic hepatitis B virus infection
Authors: Hsu T-C , Tsay G J , Chen T-Y , Liu Y-C , Tzang B-S
Published: March 2006

We previously reported anti-PCNA autoantibodies in sera from patients with chronic HBV and HCV infection. To analyse the antigenic regions on proliferating cell nuclear antigen (PCNA) that confer autoantibody binding in patients with chronic hepatitis B (HBV) and C (HCV) infection, eight constructs including one wild type PCNA, one mutant type Y114A_PCNA and six C- or N-terminal PCNA truncations were generated. Sera from 185 patients with systemic lupus erythematosus (SLE), 178 with chronic HBV and 163 with chronic HCV infection, and 68 healthy individuals were examined for the presentation of anti-PCNA antibodies by enzyme linked immunosorbent assay (ELISA). By ELISA, anti-PCNA positive sera from patients with SLE, chronic HBV and HCV infection preferentially recognized the wild type PCNA more than the mutant type Y114A_PCNA (P < 0·05). The inhibition of binding by purified full-length rPCNA proteins with anti-PCNA positive sera was shown to exceed 70%. The inhibition of binding by purified truncated rPCNA proteins with sera from patients with chronic HBV and HCV infection and SLE was shown to confer dominant binding in TL2 and TL3. Moreover, the higher frequency of inhibition by using TL3 was found in patients with chronic HBV infection. These data indicate that anti-PCNA autoantibodies preferentially recognize C-terminal of PCNA in patients with chronic HBV infection and may also provide advanced understanding between viral infection and autoimmunity for further study.
Pneumococcal 6-phosphogluconate-dehydrogenase, a putative adhesin, induces protective immune response in mice
Authors: Daniely D , Portnoi M , Shagan M , Porgador A , Givon-Lavi N , Ling E , Dagan R , Nebenzahl Y Mizrachi
Published: March 2006

For most bacteria, adherence to human cells is achieved by bacterial lectins binding to mammalian surface glyconjugates. 6-Phosphogluconate dehydrogenase (6PGD) was identified by us as one of Streptococcus pneumoniae cell wall lectin proteins, which elicits an age-dependent immune response in humans. This study assesses the role of 6PGD in S. pneumoniae pathogenesis as an adhesin and its ability to elicit a protective immune response in mice. Recombinant 6PGD (r6PGD) was cloned from S. pneumoniae serotype 3 (strain WU2). r6PGD interference in adhesion of three genetically unrelated unencapsulated pneumococcal strains (3·8, 14·8 and R6) and two genetically unrelated encapsulated pneumococcal strains (WU2 and D39) to A549 type II lung carcinoma cell was tested. BALB/c mice were immunized with r6PGD and boosted after 3 weeks. Immunized mice were challenged intranasally with a lethal dose of S. pneumoniae. r6PGD inhibited 90% and 80% of pneumococcal adhesion to the A549 cells of three unencapsulated S. pneumoniae strains and two encapsulated S. pneumoniae strains, respectively, in a concentration-dependent manner (P < 0·05). Antibodies to r6PGD produced in mice significantly inhibited bacterial adhesion to A549 cell (P < 0·05). Immunization of mice with r6PGD protected 60% (P < 0·001) of mice for 5 days and 40% (P < 0·05) of the mice for 21 days following intranasal lethal challenge. We have identified 6PGD as a surface-located immunogenic lectin protein capable of acting as an adhesin. 6PGD importance to bacterial pathogenesis was demonstrated by the ability of r6PGD to elicit a protective immune response in mice.
Increased hepatitis C virus (HCV)-specific CD4+CD25 + regulatory T lymphocytes and reduced HCV-specific CD4+ T cell response in HCV-infected patients with normalversusabnormal alanine aminotransferase levels
Authors: Bolacchi F , Sinistro A , Ciaprini C , Demin F , Capozzi M , Carducci F C , Drapeau C M J , Rocchi G , Bergamini A
Published: March 2006

CD4+CD25+ T regulatory cells may play a role in the different clinical presentations of chronic hepatitis C virus (HCV) infection by suppressing CD4+ T cell responses. Peripheral CD4+CD25+ T cells from chronic HCV carriers with normal and abnormal alanine aminotransferase (ALT) were analysed for specificity and effect on HCV-specific CD4+ T cell reactivity by flow cytometry for intracellular cytokine production and proliferation assay. HCV-specific CD4+CD25+high T cells consistently produced transforming growth factor (TGF)-β but only limited amounts of interleukin (IL)-10 and no IL-2 and interferon (IFN)-γ. The HCV-specific TGF-β response by CD4+CD25+high T cells was significantly greater in patients with normal ALT compared to patients with elevated ALT. In addition, a significant inverse correlation was found between the HCV-specific TGF-β response by CD4+CD25+high T cells and liver inflammation. In peripheral blood mononuclear cells (PBMC), both HCV antigen-induced IFN-γ production and proliferation of CD4+ T cells were greater in patients with elevated ALT compared with patients with normal ALT. Depletion of CD4+CD25+ cells from PBMC resulted in an increase of both IFN-γ production and proliferation of HCV-specific CD4+ T cells that was significantly greater in patients with normal ALT levels compared with patients with elevated ALT. In addition, CD4+CD25+ T cells from patients with normal ALT levels proved to be significantly more potent to suppress CD4+ T cell reactivity with respect to those from patients with elevated ALT. In conclusion, these data support the hypothesis that CD4+CD25+ cells may play a role in controlling chronic inflammatory response and hepatic damage in chronic HCV carriers.
Immunohistochemical analysis of coeliac mucosa following ingestion of oats
Authors: Srinivasan U , Jones E , Carolan J , Feighery C
Published: March 2006

There is now considerable clinical evidence that oats do not activate coeliac disease. Nonetheless, a reluctance to include oats in the gluten-free diet remains. Because gluten-induced damage is accompanied by activation of the gastrointestinal immune system, the purpose of this study was to investigate if similar changes were induced by oats ingestion. Small intestinal histological sections from 10 patients who ingested 50 g of oats daily for 3 months were investigated for possible evidence of immune activation. Tissue obtained before and after oats challenge was stained with a series of antibodies directed against the following molecules: human leucocyte antigen D-related (HLA-DR), Ki-67, CD25, CD54 [intercellular adhesion molecule 1 (ICAM-1)] and mast cell tryptase. None of the patients developed clinical or laboratory evidence of adverse effects. The distribution of intestinal HLA-DR expression was not affected by oats ingestion and the crypt epithelium remained unstained. In the pre-oats biopsies, the percentage of Ki-67 positive enterocytes, 29·5 ± 6·9 [95% confidence interval (CI) 13·9–45·0] did not differ significantly from that found in postoats biopsies, 41·2 ± 3·7 (95% CI, 32·8–49·6), P = 0·19, not significant. Furthermore, oats ingestion did not alter the number of CD25 positive and tryptase positive cells. Finally, the distribution and intensity of ICAM-1 staining was unchanged by dietary oats. In summary, detailed immunohistological studies of biopsies from patients ingesting oats for 3 months did not reveal evidence of immune activation. Together with other reported findings, this study strengthens the view that oats can be included safely in the diet of gluten sensitive patients.
Acid hydrolysis of easily dispersed and microaggregate‐derived silt‐ and clay‐sized fractions to isolate resistant soil organic matter
Authors: Plante A. F. , Conant R. T. , Paul E. A. , Paustian K. , Six J.
Published: March 2006

The current paradigm in soil organic matter (SOM) dynamics is that the proportion of biologically resistant SOM will increase when total SOM decreases. Recently, several studies have focused on identifying functional pools of resistant SOM consistent with expected behaviours. Our objective was to combine physical and chemical approaches to isolate and quantify biologically resistant SOM by applying acid hydrolysis treatments to physically isolated silt‐ and clay‐sized soil fractions. Microaggegrate‐derived and easily dispersed silt‐ and clay‐sized fractions were isolated from surface soil samples collected from six long‐term agricultural experiment sites across North America. These fractions were hydrolysed to quantify the non‐hydrolysable fraction, which was hypothesized to represent a functional pool of resistant SOM. Organic C and total N concentrations in the four isolated fractions decreased in the order: native > no‐till > conventional‐till at all sites. Concentrations of non‐hydrolysable C (NHC) and N (NHN) were strongly correlated with initial concentrations, and C hydrolysability was found to be invariant with management treatment. Organic C was less hydrolysable than N, and overall, resistance to acid hydrolysis was greater in the silt‐sized fractions compared with the clay‐sized fractions. The acid hydrolysis results are inconsistent with the current behaviour of increasing recalcitrance with decreasing SOM content: while %NHN was greater in cultivated soils compared with their native analogues, %NHC did not increase with decreasing total organic C concentrations. The analyses revealed an interaction between biochemical and physical protection mechanisms that acts to preserve SOM in fine mineral fractions, but the inconsistency of the pool size with expected behaviour remains to be fully explained.
Large HIV‐specific CD8+ cytotoxic T‐lymphocyte (CTL) clones reduce their overall size but maintain high frequencies of memory CTL following highly active antiretroviral therapy
Authors: Weekes Michael P. , Wills Mark R. , Sissons J. G. Patrick , Carmichael Andrew J.
Published: March 2006

Cytotoxic T‐lymphocytes (CTL) play an important role in the control of human immunodeficiency virus (HIV) and of human cytomegalovirus (HCMV) infection. Following highly active antiretroviral therapy (HAART), most studies have demonstrated a decline in the frequency of HIV‐specific CTL. We analysed the effect of HAART on the size, phenotype and function of individual HIV‐ and HCMV‐specific CTL clones, using clonotypic oligonucleotide probing specific for the T‐cell receptor (TCR) β‐chain hypervariable sequence of defined immunodominant CTL clones specific for peptides of HIV or HCMV, and quantified the limiting dilution analysis frequencies of CTL precursors (CTLp) specific for the same viral peptides. We found that the clonal composition of CD8+ T cells specific for HIV gag and env epitopes was highly focused and did not change after HAART. Following HAART, there was progressive contraction of HIV‐specific CD8+ clones, especially in the CD28– CD27– subpopulation – the remaining cells of contracting HIV‐specific clones were predominantly CD28– CD27+ CD45ROhi. We observed maintenance of strong functional HIV‐specific CD8+ T‐cell responses in limiting dilution analysis following HAART, indicating preferential loss of HIV‐specific cells that have reduced cloning efficiency in vitro. Following HAART, we also observed selective expansion of HCMV‐specific CD8+ clones. Most HCMV‐specific CD8+ clones were predominantly CD28– CD27+/– CD45RAhi following HAART. In one subject, a Vβ6.4+ clone specific for HCMV pp65 selectively expanded following HAART, without expansion of two other Vβ6.4+ clones, indicating that individual clonotypes specific for the same peptide can show different kinetics and phenotypes in response to antiretroviral therapy.
Is that authentic or artificial? Understanding consumer perceptions of risk in e‐service encounters
Authors: Featherman Mauricio S. , Valacich Joseph S. , Wells John D.
Published: March 2006

Abstract. As companies race to digitize physical‐based service processes repackaging them as online e‐services, it becomes increasingly important to understand how consumers perceive the digitized e‐service alternative. We theorize that consumers often perceive e‐services as being artificial and non‐authentic, and that consumers must perform this assessment when deciding whether new e‐services are viable alternatives to traditional service methods. This research investigates whether consumer perceptions of artificiality increase perceptions of e‐service risk, which has been shown to hamper consumer acceptance in a variety of online settings. An empirical study operationalized perceived artificiality (PA) within a controlled laboratory experiment that manipulated the risk of a specific e‐service class (e‐payments). For a specific e‐service brand, PA is reduced when the web interface is viewed as easy to use; alternatively, PA is increased when consumers have relatively high risk perceptions about the overall e‐service class. Furthermore, consumers who were rated as information technology innovators had lower overall artificiality perceptions, however, exposure to negatively framed e‐service efficacy information removed this artificiality reducing effect. The theoretical linkages between PA and perceived risk, and the two antecedents – ease of use and e‐service class risk – were confirmed by survey results. The implications of these results for future research as well as the design and marketing of e‐services are examined.
Predicting consumer intention to use mobile service
Authors: Wang Yi‐Shun , Lin Hsin‐Hui , Luarn Pin
Published: March 2006

Abstract. Advances in wireless technology have increased the number of people using mobile devices and accelerated the rapid development of mobile service (m‐service) conducted with these devices. However, although many companies are today making considerable investments to take advantage of the new business possibilities offered by wireless technology, research on mobile commerce suggests potential consumers may not adopt these m‐services in spite of their availability. Thus, there is a need for research to identify the factors that affect consumer intention to use m‐services. Based on the technology acceptance model (TAM), theory of planned behaviour (TPB) and Luarn & Lin's 2005 mobile banking acceptance model, the current research respecifies and validates an integrated model for predicting consumer intention to use m‐service by adding one trust‐related construct (‘perceived credibility’) and two resource‐related constructs (‘self‐efficacy’ and ‘perceived financial resources’) to the TAM's nomological structure and re‐examining the relationships between the proposed constructs. Data collected from 258 users in Taiwan were tested against the research model using the structural equation modelling approach. The results strongly support the proposed model in predicting consumer intention to use m‐service. Several implications for information technology/information system acceptance research and m‐service management practices are discussed.
Mechanisms of cytotoxicity of eugenol in human osteoblastic cells in vitro
Authors: Ho Y.‐C. , Huang F.‐M. , Chang Y.‐C.
Published: March 2006

Aim  To evaluate the mechanisms of cytotoxicity of eugenol in human osteoblastic cells in vitro.

Methodology  Cytotoxicity and cell proliferation assays were performed to elucidate the toxic effects of eugenol on the human osteoblastic cell line U2OS. Furthermore, the effects of antioxidants catalase (scavenger of H2O2), superoxide dismutase (SOD, an extracellular superoxide free radical scavenger) and N‐acetyl‐L‐cysteine (NAC, a cell‐permeable glutathione precursor) were added to discover the possible mechanisms of eugenol‐induced cytotoxicity. Paired Student's t‐test was applied for the statistical analysis of the results.

Results  Eugenol demonstrated a cytotoxic effect to U2OS cells in a dose‐dependent manner (P < 0.05). The 50% inhibition concentration of eugenol was approximately 0.75 mmol L−1. Eugenol also inhibited cell proliferation during a 4‐day culture period (P < 0.05). Addition of NAC extracellularly protected the cells from eugenol‐induced cytotoxicity (P < 0.05). Neither, SOD nor catalase provided any protective effects on eugenol‐induced cytotoxicity (P > 0.05).

Conclusions  The levels of eugenol tested inhibited growth and proliferation of U2OS cells. Eugenol has significant potential for periapical toxicity. These inhibitory effects were associated with glutathione levels.
RNase R affects gene expression in stationary phase: regulation of ompA
Authors: Andrade José Marques , Cairrão Fátima , Arraiano Cecília Maria
Published: March 2006

In nature, bacteria remain mostly in the stationary phase of the life cycle. Although mRNA is a major determinant of gene expression, little is known about mRNA decay in the stationary phase. The results presented herein demonstrate that RNase R is induced in stationary phase and is involved in the post‐transcriptional regulation of ompA mRNA. This work is the first report of RNase R activity on a full length mRNA. In the absence of RNase R in a single rnr mutant, higher levels of ompA mRNA are found as a consequence of the stabilization of ompA full transcript. This effect is growth‐phase‐specific and not a growth‐rate‐dependent event. These higher levels of ompA mRNA were correlated with increases in the amounts of OmpA protein. We have also analysed the role of other factors that could affect ompA mRNA stability in stationary phase. RNase E was found to have the most important role, followed by polyadenylation. PNPase also affected the decay of the ompA transcript but RNase II did not seem to contribute much to this degradation process. The participation of RNase R in poly(A)‐dependent pathways of decay in stationary phase of growth is discussed. The results show that RNase R can be a modulator of gene expression in stationary phase cells.
A novel homozygous MMP2 mutation in a family with Winchester syndrome
Authors: Rouzier C , Vanatka R , Bannwarth S , Philip N , Coussement A , Paquis‐Flucklinger V , Lambert J‐C
Published: March 2006

The 2001 International Classification of Constitutional Disorders of Bone has included in the group of multicentric hands and feet osteolysis syndromes three autosomal recessive inherited disorders: Winchester, Torg and nodulosis–arthropathy–osteolysis (NAO) syndromes. Nosographic delineations of these rare syndromes are difficult to define, and there is no consensus. In 2001, two mutations in the matrix metalloproteinase 2 gene (MMP2) have been identified in two families with a NAO phenotype. In a recent study, a homozygous MMP2 mutation has also been identified in a patient presenting with Winchester syndrome. We report the clinical evolution of two sisters with a Winchester phenotype. Clinical review over 23 years provides information on the general evolution of osteolysis and points to an intrafamilial variation with clinical and radiological changes during the patients' life. In both sisters, we identified a new homozygous mutation in the catalytic domain of the MMP2 gene. Our study results are consistent with the involvement of MMP2 in Winchester syndrome and with the hypothesis that Winchester and NAO syndromes are allelic disorders that form a continuous clinical spectrum. At last, our observation emphasizes the interest of molecular analysis in genetic counselling of this consanguineous family.
A measure of the within‐chromosome synergistic epistasis for Drosophila viability
Authors: ROSA J. M. , CAMACHO S. , GARCÍA‐DORADO A.
Published: March 2006

In order to detect possible synergistic epistasis for viability in Drosophila melanogaster we assayed the relative viability of chromosomes II in: (i) panmixia, (ii) forced total homozygosity, and (iii) homozygosity for, on the average, half of their loci. As these genotypes were constructed using exactly the same set of chromosomes in the three cases, the design allows us to estimate the inbreeding depression rate at two different inbreeding levels in the absence of purging natural selection. Overall, no consistent synergistic epistasis was found. However, there was a small fraction of chromosomes whose severely deleterious effect when homozygous was almost significantly larger than expected from their viability when homozygous for half of their loci. This suggests occasional but important synergistic epistasis, which might confer evolutionary advantage to recombination in tightly linked genomes. Nevertheless, such epistasis is unlikely to be an evolutionary advantage driving the evolution of sexual anisogamous reproduction, as its contribution to overall viability is small when compared with the two‐fold cost of anisogamy.