bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing the role of the proximal heme ligand in cytochrome P450cam by recombinant incorporation of selenocysteine
Authors: Aldag Caroline , Gromov Igor A. , García-Rubio Inés , von Koenig Konstanze , Schlichting Ilme , Jaun Bernhard , Hilvert Donald
Published: March 2009

The unique monooxygenase activity of cytochrome P450cam has been attributed to coordination of a cysteine thiolate to the heme cofactor. To investigate this interaction, we replaced cysteine with the more electron-donating selenocysteine. Good yields of the selenoenzyme were obtained by bacterial expression of an engineered gene containing the requisite UGA codon for selenocysteine and a simplified yet functional selenocysteine insertion sequence (SECIS). The sulfur-to-selenium substitution subtly modulates the structural, electronic, and catalytic properties of the enzyme. Catalytic activity decreases only 2-fold, whereas substrate oxidation becomes partially uncoupled from electron transfer, implying a more complex role for the axial ligand than generally assumed.
Activation of critical, host-induced, metabolic and stress pathways marks neutrophil entry into cystic fibrosis lungs
Authors: Makam Megha , Diaz Daisy , Laval Julie , Gernez Yael , Conrad Carol K. , Dunn Colleen E. , Davies Zoe A. , Moss Richard B. , Herzenberg Leonore A. , Herzenberg Leonard A. , Tirouvanziam Rabindra
Published: March 2009

Cystic fibrosis (CF) patients undergo progressive airway destruction caused in part by chronic neutrophilic inflammation. While opportunistic pathogens infecting CF airways can cause inflammation, we hypothesized that host-derived metabolic and stress signals would also play a role in this process. We show that neutrophils that have entered CF airways have increased phosphorylation of the eukaryotic initiation factor 4E and its partner the 4E-binding protein 1; 2 key effectors in the growth factor- and amino acid-regulated mammalian target of rapamycin (mTOR) pathway. Furthermore CF airway neutrophils display increased phosphorylation of the cAMP response element binding protein (CREB), a major transcriptional coactivator in stress signaling cascades. These active intracellular pathways are associated with increased surface expression of critical adaptor molecules, including the growth factor receptor CD114 and the receptor for advanced glycation end-products (RAGE), a CREB inducer and sensor for host-derived damage-associated molecular patterns (DAMPs). Most CF airway fluids lack any detectable soluble RAGE, an inhibitory decoy receptor for DAMPs. Concomitantly, CF airway fluids displayed high and consequently unopposed levels of S100A12; a potent mucosa- and neutrophil-derived DAMP. CF airway neutrophils also show increased surface levels of 2 critical CREB targets, the purine-recycling enzyme CD39 and the multifunctional, mTOR-inducing CXCR4 receptor. This coordinated set of events occurs in all patients, even in the context of minimal airway inflammation and well-preserved lung function. Taken together, our data demonstrate an early and sustained activation of host-responsive metabolic and stress pathways upon neutrophil entry into CF airways, suggesting potential targets for therapeutic modulation.
Evolution of virulence in epidemic community-associated methicillin-resistant
Staphylococcus aureus
Authors: Li Min , Diep Binh An , Villaruz Amer E. , Braughton Kevin R. , Jiang Xiaofei , DeLeo Frank R. , Chambers Henry F. , Lu Yuan , Otto Michael
Published: March 2009

Community-associated methicillin-resistant
Staphylococcus aureus
(CA-MRSA) has recently emerged worldwide. The United States, in particular, is experiencing a serious epidemic of CA-MRSA that is almost entirely caused by an extraordinarily infectious strain named USA300. However, the molecular determinants underlying the pathogenic success of CA-MRSA are mostly unknown. To gain insight into the evolution of the exceptional potential of USA300 to cause disease, we compared the phylogeny and virulence of USA300 with that of closely related MRSA clones. We discovered that the sublineage from which USA300 evolved is characterized by a phenotype of high virulence that is clearly distinct from other MRSA strains. Namely, USA300 and its progenitor, USA500, had high virulence in animal infection models and the capacity to evade innate host defense mechanisms. Furthermore, our results indicate that increased virulence in the USA300/USA500 sublineage is attributable to differential expression of core genome-encoded virulence determinants, such as phenol-soluble modulins and α-toxin. Notably, the fact that the virulence phenotype of USA300 was already established in its progenitor indicates that acquisition of mobile genetic elements has played a limited role in the evolution of USA300 virulence and points to a possibly different role of those elements. Thus, our results highlight the importance of differential gene expression in the evolution of USA300 virulence. This finding calls for a profound revision of our notion about CA-MRSA pathogenesis at the molecular level and has important implications for design of therapeutics directed against CA-MRSA.
The Epstein–Barr virus Bcl-2 homolog, BHRF1, blocks apoptosis by binding to a limited amount of Bim
Authors: Desbien Anthony L. , Kappler John W. , Marrack Philippa
Published: March 2009

Current knowledge suggests that the balance between life and death within a cell can be controlled by the stable engagement of Bcl-2-related proapoptotic proteins such as Bak, Bax, and Bim by survival proteins such as Bcl-2. BHRF1 is a prosurvival molecule from Epstein–Barr virus that has a high degree of homology to Bcl-2. To understand how BHRF1 blocks apoptosis, BHRF1 and mutants of BHRF1 were expressed in primary cells and an IL-2-dependent T cell line. BHRF1 bound the Executioner Bak and, when cells were cultured without cytokines, BHRF1 associated with Bim. A point mutation that lost the ability to bind Bak retained its ability to bind Bim and to protect cells. This result demonstrated that it was the capacity of BHRF1 to bind Bim, not Bak, that provided protection. Interestingly, the amount of Bim bound by BHRF1 was minimal when compared with the amount of Bim induced by apoptosis. Thus, BHRF1 does not act by simply absorbing the excess Bim produced while cells prepare for death. Rather, BHRF1 may act either by binding preferentially the most lethal form of Bim or by acting catalytically on Bim to block apoptosis.
Dispositional optimism among American and Jordanian college students: Are Westerners really more upbeat than Easterners?
Authors: Khallad Yacoub
Published: March 2009

The present study aimed at assessing some previous research conclusions, based primarily on comparisons of North Americans and East Asians, that Westerners tend to be optimistic while Easterners tend to be pessimistic. Two samples of European American and Jordanian college students were administered a questionnaire consisting of items measuring dispositional optimism along with items pertaining to risk and self‐protective behaviors (e.g., seatbelt use, vehicular speeding, smoking) and social and demographic factors (e.g., sex, socioeconomic status, religiosity). The findings uncovered dispositional optimism to be stronger for American compared to Jordanian participants. Separate analyses of optimism versus pessimism revealed that Jordanian participants were more pessimistic, but not less optimistic than their American counterparts. No significant correlations were found between dispositional optimism and sex, socioeconomic status, or religiosity. The levels of optimism displayed by Jordanians in this study are inconsistent with previous claims of an optimistic West and a pessimistic East, and suggest that self‐enhancing processes may not be confined to Western or highly individualistic groups. The findings did not uncover an association between dispositional optimism and risk or self‐protective behaviors. Multiple regression analyses showed cultural background and sex to be the best predictors of these behaviors. The implications of these findings are discussed.
1 The study of semantic alignment: retrospect and state of the art
Authors: Wichmann Søren
Published: March 2009

This introductory chapter presents the background of the book, discusses the new term ‘semantic alignment’ and related terminology, traces major developments in the study of semantic alignment, characterizes the overall achievement of the book, and summarizes the individual chapters.
4 Thematic roles, event structure, and argument encoding in semantically aligned languages
Authors: Arkadiev Peter M.
Published: March 2009

This chapter surveys the semantic motivations of ‘split’ case marking of intransitive subjects in several genetically unrelated languages in terms of Dowty's proto-role entailments. It is argued that it is not the overall balance of entailments but a single entailment grammaticalized in a given language which determines case marking.
12 The emergence of agentive systems in core argument marking
Authors: Mithun Marianne
Published: March 2009

It has been proposed that patterns of core argument categorization, sometimes termed ‘alignment’, are highly stable over time. Certain language families, however, show evidence of relatively recent shifts in these patterns. Agent/patient patterns in particular, which are considered rare, show strong areal concentrations in certain regions such as North America. This chapter examines situations that can trigger such shifts, mechanisms of diffusion, and the traces they can leave behind.
Inhibition of Anchorage‐Independent Proliferation and G0/G1 Cell‐Cycle Regulation in Human Colorectal Carcinoma Cells by 4,7‐Dimethoxy‐5‐Methyl‐l,3‐Benzodioxole Isolated from the Fruiting Body of Antrodia camphorate
Authors: Lien Hsiu-Man , Lin Hsiao-Wei , Wang Ying-Jan , Chen Li-Ching , Yang Ding-Yah , Lai Ya-Yun , Ho Yuan-Soon
Published: March 2009

In this study, 4,7‐dimethoxy‐5‐methyl‐l,3‐benzodioxole (SY‐1) was isolated from three different sources of dried fruiting bodies of Antrodia camphorate (AC). AC is a medicinal mushroom that grows on the inner heartwood wall of Cinnamomum kanehirai Hay (Lauraceae), an endemic species that is used in Chinese medicine for its anti‐tumor and immunomodulatory properties. In this study, we demonstrated that SY‐1 profoundly decreased the proliferation of human colon cancer cells (COLO 205) through G0/G1 cell‐cycle arrest (50–150 μM) and induction of apoptosis (>150 μM). Cell‐cycle arrest induced by SY‐1 was associated with a significant increase in levels of p53, p21/Cip1 and p27/Kip1, and a decrease in cyclins D1, D3 and A. In contrast, SY‐1 treatment did not induce significant changes in G0/G1 phase cell‐cycle regulatory proteins in normal human colonic epithelial cells (FHC). The cells were cultured in soft agar to evaluate anchorage‐independent colony formation, and we found that the number of transformed colonies was significantly reduced in the SY‐1‐treated COLO 205 cells. These findings demonstrate for the first time that SY‐1 inhibits human colon cancer cell proliferation through inhibition of cell growth and anchorage‐independent colony formation in soft agar. However, the detailed mechanisms of these processes remain unclear and will require further investigation.
Condensed Tannins in Traditional Wet‐Cooked and Modern Extrusion‐Cooked Sorghum Porridges
Authors: Dlamini Nomusa R. , Dykes Linda , Rooney Lloyd W. , Waniska Ralph D. , Taylor John R. N.
Published: March 2009

The profile and quantities of condensed tannins (CT) in foods are affected by processing due to their highly reactive nature, which may affect their antioxidant activity and the nutritional value of the foods. The objective was to compare the quantity and profile of condensed tannins in traditional wet‐cooked and modern ready‐to‐eat extrusion‐cooked sorghum porridges. CT were analyzed using normal‐phase HPLC with fluorescence detection and their content was compared to CT and total phenols determined with standard colorimetric assays. Both the traditionally prepared and instant porridges had significantly reduced CT polymers (DP > 8), with retentions of 38 and 9%, respectively, of the CT present in the whole grain. Oligomer (DP 2–8) and monomer (DP 1) contents in traditional porridges were not significantly different from those of grain. In extruded porridges, the oligomers were reduced and the monomer content was increased. The extractable CT oligomers and monomers in the extrusion‐cooked sorghum porridges may be more biologically available because extrusion appears to increase their availability.
Relationships of Quality Characteristics with Size‐Exclusion HPLC Chromatogram of Protein Extract in Soft White Winter Wheats
Authors: Ohm J. B. , Ross A. S. , Peterson C. J. , Morris C. F.
Published: March 2009

This study investigated relationships between molecular weight distributions of unreduced grain proteins and grain, flour, and end‐use quality characteristics of soft white winter wheats grown in Oregon. Absorbance area and area percentage values of protein fractions separated by size‐exclusion HPLC (SE‐HPLC) showed significant correlations with quality characteristics, indicating associations of molecular weight distributions of proteins with quality characteristics. Specifically, high molecular weight polymeric protein fractions appeared to have a detrimental effect on soft wheat quality. This was shown by significant positive correlations with single kernel hardness index, and mixograph water absorption and tolerance, and negative correlations with break flour yield, cookie diameter, and cake volume. Higher proportions of soluble monomeric protein fraction eluted after the main gliadin peak, were associated with soft wheat quality due to negative associations with single kernel hardness index and mixograph water absorption and tolerance, and positive associations with break flour yield, cookie diameter, and cake volume. Calibration models were developed by the application of multivariate analyses to the SE‐HPLC data. These models explained >90% of the variation in mixograph water absorption and cookie diameter and thickness.
White Pan Bread and Sugar‐Snap Cookies Containing Wheat Starch Phosphate, A Cross‐Linked Resistant Starch
Authors: Lee Yeo Lee , Seib Paul A.
Published: March 2009

Pup‐loaf bread was made with 10, 30, and 50% substitution of flour with wheat starch phosphate, a cross‐linked resistant starch (XL‐RS4), while maintaining flour protein level at 11.0% (14% mb) by adding vital wheat gluten. Bread with 30% replacement of flour with laboratory‐prepared XL‐RS4 gave a specific volume of 5.9 cm3/g compared with 6.3 g/cm3 for negative control bread (no added wheat starch), and its crumb was 53% more firm than the control bread after 1 day at 25°C, but 13% more firm after 7 days. Total dietary fiber (TDF) in one‐day‐old bread made with commercial XL‐RS4 at 30% flour substitution increased 3–4% (db) in the control to 19.2% (db) in the test bread, while the sum of slowly digestible starch (SDS) plus resistant starch (RS), determined by a modified Englyst method, increased from 24.3 to 41.8% (db). The reference amount (50 g, as‐is) of that test bread would provide 5.5 g of dietary fiber with 10% fewer calories than control bread. Sugar‐snap cookies were made at 30 and 50% flour replacement with laboratory‐prepared XL‐RS4, potato starch, high‐amylose (70%) corn starch, and commercial heat‐moisture‐treated high‐amylose (70%) corn starch. The shape of cookies was affected by the added starches except for XL‐RS4. The reference amount (30 g, as‐is) of cookies made with commercial XL‐RS4 at 30% flour replacement contained 4.3 g (db) TDF and 3.4 g (db) RS, whereas the negative control contained 0.4 g TDF and 0.6 g RS. The retention of TDF in the baked foods containing added XL‐RS4 was calculated to be >80% for bread and 100% for cookies, while the retention of RS was 35–54% for bread and 106–113% for cookies.
Morphological, Physical, and Chemical Properties of Grain and Flour from Chalky Rice Mutants
Authors: Ashida Kanae , Iida Shuichi , Yasui Takeshi
Published: March 2009

Morphological, physical, and chemical properties of grain and flour of 20 chalky rice mutants were compared with those of a translucent parental cultivar, Koshihikari. Compound starch granules were loosely packed and single starch granules were observed in chalky parts of mutant endosperm. Chalky mutant lines were classified into milky‐white and white‐core lines based on the degree of endosperm chalkiness. Physical and chemical characteristics also suggest a division of chalky mutant lines into two groups, consistent with the classification made based on morphological characteristics. Milky‐white mutant lines showed significantly lower grain weight, decreased starch content, and lower grain hardness than white‐core mutants and Koshihikari. Rice flour prepared from milky‐white mutants by dry milling showed less starch damage and finer mean particle size than white‐core mutants and the parent. These results indicated that a loosely packed structure in chalky endosperm was responsible for fragile grain and that it yielded fine flour with lower damaged starch contents. Decreased starch contents of chalky mutant lines correlated to lower RVA viscosities. Milky‐white mutant lines were expected to be useful to produce fine flour, which undergoes less starch damage during dry milling processing.
Uridine-Ribohydrolase Is a Key Regulator in the Uridine Degradation Pathway of Arabidopsis
Authors: Jung Benjamin , Flörchinger Martin , Kunz Hans-Henning , Traub Michaela , Wartenberg Ruth , Jeblick Wolfgang , Neuhaus H. Ekkehard , Möhlmann Torsten
Published: March 2009

Nucleoside degradation and salvage are important metabolic pathways but hardly understood in plants. Recent work on human pathogenic protozoans like Leishmania and Trypanosoma substantiates an essential function of nucleosidase activity. Plant nucleosidases are related to those from protozoans and connect the pathways of nucleoside degradation and salvage. Here, we describe the cloning of such an enzyme from Arabidopsis thaliana, Uridine-Ribohydrolase 1 (URH1) and the characterization by complementation of a yeast mutant. Furthermore, URH1 was synthesized as a recombinant protein in Escherichia coli. The pure recombinant protein exhibited highest hydrolase activity for uridine, followed by inosine and adenosine, the corresponding K  m values were 0.8, 1.4, and 0.7 mM, respectively. In addition, URH1 was able to cleave the cytokinin derivative isopentenyladenine-riboside. Promoter β-glucuronidase fusion studies revealed that URH1 is mainly transcribed in the vascular cells of roots and in root tips, guard cells, and pollen. Mutants expressing the Arabidopsis enzyme or the homolog from rice (Oryza sativa) exhibit resistance toward toxic fluorouridine, fluorouracil, and fluoroorotic acid, providing clear evidence for a pivotal function of URH1 as regulative in pyrimidine degradation. Moreover, mutants with increased and decreased nucleosidase activity are delayed in germination, indicating that this enzyme activity must be well balanced in the early phase of plant development.
A functional genomics approach to evaluate candidate genes located in a QTL interval for milk production traits on BTA6
Authors: Sheehy P. A. , Riley L. G. , Raadsma H. W. , Williamson P. , Wynn P. C.
Published: March 2009

The potential genetic and economic advantage of marker‐assisted selection for enhanced production in dairy cattle has provided an impetus to conduct numerous genome scans in order to identify associations between DNA markers and future productive potential. One area of focus has been a quantitative trait locus on bovine chromosome 6 (BTA6) found to be associated with milk yield, milk protein and fat percentage, which has been subsequently fine‐mapped to six positional candidate genes. Subsequent investigations have yet to resolve which of the potential positional candidate genes is responsible for the observed associations with productive performance. In this study, we analysed candidate gene expression and the effects of gene knockdown on expression of β‐ and κ‐casein mRNA in a small interfering RNA transfected bovine in vitro mammosphere model. From our expression studies in vivo, we observed that four of the six candidates (ABCG2, SPP1, PKD2 and LAP3) exhibited differential expression in bovine mammary tissue over the lactation cycle, but in vitro functional studies indicate that inhibition of only one gene, SPP1, had a significant impact on milk protein gene expression. These data suggest that the gene product of SPP1 (also known as osteopontin) has a significant role in the modulation of milk protein gene expression. While these findings do not exclude other positional candidates from influencing lactation, they support the hypothesis that the gene product of SPP1 is a significant lactational regulatory molecule.
Endogenous nitric oxide synthase inhibitors in sickle cell disease: abnormal levels and correlations with pulmonary hypertension, desaturation, haemolysis, organ dysfunction and death
Authors: Kato Gregory J. , Wang Zeneng , Machado Roberto F. , Blackwelder William C. , Taylor 6th James G. , Hazen Stanley L.
Published: March 2009

Pulmonary hypertension (PH) in patients with sickle cell disease (SCD) is linked to intravascular haemolysis, impaired nitric oxide bioavailability, renal dysfunction, and early mortality. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthases (NOS), is associated with vascular disease in other populations. We determined the plasma concentrations for several key arginine metabolites and their relationships to clinical variables in 177 patients with SCD and 29 control subjects: ADMA, symmetric dimethylarginine (SDMA), NG‐monomethyl L‐arginine (L‐NMMA), N‐omega‐hydroxy‐L‐arginine (NOHA), arginine and citrulline. The median ADMA was significantly higher in SCD than controls (0·94  μmol/l vs. 0·31 μmol/l, P < 0·001). Patients with homozygous SCD had a remarkably lower ratio of arginine to ADMA (50 μmol/l vs. 237, P < 0·001). ADMA correlated with markers of haemolysis, low oxygen saturation and soluble adhesion molecules. PH was associated with high levels of ADMA and related metabolites. Higher ADMA level was associated with early mortality, remaining significant in a multivariate analysis. Subjects with homozygous SCD have high systemic levels of ADMA, associated with PH and early death, implicating ADMA as a functional NOS inhibitor in these patients. These defects and others converge on the nitric oxide pathway in homozygous SCD with vasculopathy.
Haemoglobin concentration and the risk of death in older adults: differences by race/ethnicity in the NHANES III follow‐up
Authors: Patel Kushang V. , Longo Dan L. , Ershler William B. , Yu Binbing , Semba Richard D. , Ferrucci Luigi , Guralnik Jack M.
Published: March 2009

Mildly low haemoglobin concentration is associated with increased mortality in older adults. However, this relationship has not been well characterized in racial/ethnic minorities. Therefore, this study determined the haemoglobin threshold below which risk of death is significantly increased in older non‐Hispanic whites, non‐Hispanic blacks, and Mexican Americans. Data on 4089 participants of the 1988–94 US National Health and Nutrition Examination Survey who were ≥65 years of age were analyzed with mortality follow‐up through December 31, 2000. Mean haemoglobin in non‐Hispanic whites (n = 2686) and Mexican Americans (n = 663) was 140 g/l, while in non‐Hispanic blacks (n = 740) the mean was 10 g/l lower. A total of 1944 (47·5%) participants died. Among non‐Hispanic whites and Mexican Americans, age‐ and sex‐adjusted models showed that the haemoglobin thresholds below which mortality risk was significantly increased were 4 and 2 g/l respectively, above the World Health Organization (WHO) cut‐off points for anaemia. In contrast, the threshold for non‐Hispanic blacks was 7 g/l below the WHO criteria. Similar threshold effects were observed when analyzing haemoglobin in categories and adjusting for multiple confounders. In conclusion, the haemoglobin threshold below which mortality rises significantly is a full g/dl lower in non‐Hispanic blacks than in non‐Hispanic whites and Mexican Americans.
Naturally acquired inhibitory antibodies toPlasmodium vivaxDuffy binding protein are short-lived and allele-specific following a single malaria infection
Authors: Ceravolo I P , Sanchez B A M , Sousa T N , Guerra B M , Soares I S , Braga E M , McHenry A M , Adams J H , Brito C F A , Carvalho L H
Published: March 2009

The Duffy binding protein of Plasmodium vivax (DBP) is a critical adhesion ligand that participates in merozoite invasion of human Duffy-positive erythrocytes. A small outbreak of P. vivax malaria, in a village located in a non-malarious area of Brazil, offered us an opportunity to investigate the DBP immune responses among individuals who had their first and brief exposure to malaria. Thirty-three individuals participated in the five cross-sectional surveys, 15 with confirmed P. vivax infection while residing in the outbreak area (cases) and 18 who had not experienced malaria (non-cases). In the present study, we found that only 20% (three of 15) of the individuals who experienced their first P. vivax infection developed an antibody response to DBP; a secondary boosting can be achieved with a recurrent P. vivax infection. DNA sequences from primary/recurrent P. vivax samples identified a single dbp allele among the samples from the outbreak area. To investigate inhibitory antibodies to the ligand domain of the DBP (cysteine-rich region II, DBPII), we performed in vitro assays with mammalian cells expressing DBPII sequences which were homologous or not to those from the outbreak isolate. In non-immune individuals, the results of a 12-month follow-up period provided evidence that naturally acquired inhibitory antibodies to DBPII are short-lived and biased towards a specific allele.
Human peripheral blood leucocyte non-obese diabetic-severe combined immunodeficiency interleukin-2 receptor gamma chain gene mouse model of xenogeneic graft-versus-host-like disease and the role of host major histocompatibility complex
Authors: King M A , Covassin L , Brehm M A , Racki W , Pearson T , Leif J , Laning J , Fodor W , Foreman O , Burzenski L , Chase T H , Gott B , Rossini A A , Bortell R , Shultz L D , Greiner D L
Published: March 2009

Immunodeficient non-obese diabetic (NOD)-severe combined immune-deficient (scid) mice bearing a targeted mutation in the gene encoding the interleukin (IL)-2 receptor gamma chain gene (IL2rγnull) engraft readily with human peripheral blood mononuclear cells (PBMC). Here, we report a robust model of xenogeneic graft-versus-host-like disease (GVHD) based on intravenous injection of human PBMC into 2 Gy conditioned NOD-scid IL2rγnull mice. These mice develop xenogeneic GVHD consistently (100%) following injection of as few as 5 × 106 PBMC, regardless of the PBMC donor used. As in human disease, the development of xenogeneic GVHD is highly dependent on expression of host major histocompatibility complex class I and class II molecules and is associated with severely depressed haematopoiesis. Interrupting the tumour necrosis factor-α signalling cascade with etanercept, a therapeutic drug in clinical trials for the treatment of human GVHD, delays the onset and progression of disease. This model now provides the opportunity to investigate in vivo mechanisms of xenogeneic GVHD as well as to assess the efficacy of therapeutic agents rapidly.
Reduced expression of IL‐3 mediates intestinal mast cell depletion in diabetic rats: role of insulin and glucocorticoid hormones
Authors: De Frias Carvalho Vinicius , De Oliveira Barreto Emiliano , Farias‐Filho Francisco Alves , Gomes Leonardo Henrique Ferreira , De Lima Mendonça Leila , Cordeiro Renato Sérgio Balão , Martins Marco Aurélio , Silva Patrícia Machado Rodrigues e
Published: March 2009

Rats turned diabetic by alloxan treatment are refractory to systemic anaphylactic shock, in a direct association with reduced intestinal haemorrhage and tissue response to antigen challenge. As diabetic rats show reduction in mast cell numbers in different body compartments, this study was undertaken to investigate the influence of alloxan diabetes on mast cell population as well as the expression of the mast cell growth factor interleukin (IL)‐3 in the small intestine of rats. We also analysed the putative involvement of endogenous insulin and glucocorticoid hormones in this phenomenon. There was a significant decrease in the number of mast cells present in the small intestine (ileum segment) of diabetic rats. Likewise, the immunohistochemical analysis revealed that IL‐3 labelling was markedly attenuated in diabetic rats, as compared with normal animals, a phenomenon which paralleled with a decreased mRNA expression as attested by Reverse transcriptase‐polymerase chain reaction technique. Treatment with insulin and with the steroid receptor antagonist RU 486 restored basal mast cell numbers, normal levels of IL‐3 labelling and mRNA expression for IL‐3 in the ileum of diabetic rats. In conclusion, our findings show that there is a causative relationship between down‐regulation of mast cell numbers and the expression of IL‐3 associated with diabetic state. In addition, as both parameters were suppressed by administration of insulin and RU 486, it indicates that an imbalance between the systemic levels of insulin and glucocorticoid hormones seems to be implicated in the reduction in intestinal mast cell population and refractoriness to antigen provocation in alloxan diabetes.
Dystroglycan patterns on the prostate of non‐obese diabetic mice submitted to glycaemic control
Authors: Cagnon Quitete Valéria Helena Alves , Fávaro Wagner José
Published: March 2009

Dystroglycan (DG) is an adhesion protein which plays a crucial role in the maintenance of tissue integrity. Diabetes has been pointed out as a disease which causes harmful effects on prostate function. Therefore, the main objective of this work was to verify DG distribution and structure features in diabetic mice with and without glycaemic control and to relate these parameters to prostate pathogenesis. Thirty mice (Nod and BALB/c) were divided into three groups after 20 days of diabetic state: the control group received a 5 ml/kg dose of physiological saline daily for 20 days; the diabetic group had the same treatment as the control group; the diabetic‐insulin group received 4–5 IU doses of Neutral Protamine Hagedorn (NPH) insulin daily for 20 days. After 20 days of treatment, all animals were killed and samples from the ventral prostate were processed for immunological and light microscopy analyses. The results showed diminished β‐ and α‐DG receptors in the diabetic group. However, there was a recovery of both β‐and α‐DG receptor immunolocalization after insulin administration. Epithelial and stromal morphological changes were verified in the diabetic group, which also presented recovery after insulin treatment. Thus, it could be concluded that diabetes disturbed prostate structure integrity and altered the occurrence of α and β‐DG receptors, indicating decreased cell‐matrix extracellular and cell‐basal membrane attachment. However, insulin treatment could partially restore glandular homeostasis. The decrease in epithelial–stromal interaction certainly predisposes this gland in diabetic mice to be a prostate disease target.
Megaoesophagus in Rassf1a‐null mice
Authors: Van Der Weyden Louise , Happerfield Lisa , Arends Mark J. , Adams David J.
Published: March 2009

Megaoesophagus, or oesophageal achalasia, is a neuromuscular disorder characterized by an absence of peristalsis and flaccid dilatation of the oesophagus, resulting in the retention of ingesta in the dilated segment. The aetiology and pathogenesis of idiopathic (or primary) megaoesophagus are still poorly understood and very little is known about the genetic causes of megaoesophagus in humans. Attempts to develop animal models of this condition have been largely unsuccessful and although the ICRC/HiCri strain of mice spontaneously develop megaoesophagus, the underlying genetic cause remains unknown. In this report, we show that aged Rassf1a‐null mice have an enhanced susceptibility to megaoesophagus compared with wild‐type littermates (∼20%vs. ∼2% incidence respectively; P = 0.01). Histological examination of the dilated oesophaguses shows a reduction in the numbers of nerve cells (both ganglia and nerve fibres) in the myenteric plexus of the dilated mid and lower oesophagus that was confirmed by S100 immunohistochemistry. There was also a chronic inflammatory infiltrate and subsequent fibrosis of the myenteric plexus and the muscle layers. These appearances closely mimic the gross and histopathological findings in human cases of megaoesophagus/achalasia, thus demonstrating that this is a representative mouse model of the disease. Thus, we have identified a genetic cause of the development of megaoesophagus/achalasia that could be screened for in patients, and may eventually facilitate the development of therapies that could prevent further progression of the disease once it is diagnosed at an early stage.
Histological characteristics of human papilloma‐virus‐positive and ‐negative invasive and in situ squamous cell tumours of the penis
Authors: Krustrup Dorrit , Jensen Helle Lone , Van Den Brule Adriaan J.C. , Frisch Morten
Published: March 2009

A high prevalence of cervical cancer associated high‐risk types of human papillomavirus (hrHPV) has been demonstrated in premalignant and invasive squamous cell lesions of the penis, but large studies correlating histological characteristics with HPV status are few in number. Tumour tissues from 145 patients with invasive (n = 116) or in situ (n = 29) penile squamous cell carcinoma were subjected to systematic histological evaluation and were PCR‐tested for 14 hrHPV types and 23 low‐risk HPV types. Around half (52%) of invasive and nine‐tenths (90%) of in situ lesions were positive for an hrHPV type, of which HPV 16 was by far the predominant type (91% of hrHPV‐positive lesions). In relation to histological characteristics, hrHPV positivity was statistically significantly more common in high‐grade tumours, lesions dominated by small tumour cells, lesions with a high number of multinucleated cells and mitoses, and lesions with a small amount of parakeratosis. In conclusion, about half of invasive penile squamous carcinomas in this study were hrHPV‐positive, most notably to HPV 16, and probably arose through in situ lesions whereas the other half of invasive penile lesions appeared to be unrelated to hrHPV. A number of histological characteristics differed significantly between hrHPV‐positive and ‐negative invasive penile carcinomas.
The effects of colonization, extinction and competition on co‐existence in metacommunities
Authors: Hunt Julia J.F.G. , Bonsall Michael B.
Published: March 2009

The co‐existence of competitors in heterogeneous landscapes depends on the processes of colonization, extinction and spatial scale. In this study, we explore the metapopulation dynamics of competitive interactions.

Rather than simply evaluating the outcome of interspecific competition in the traditional manner, we focus on both the local population dynamic effects and the regional metapopulation processes affecting species co‐existence.

We develop a theoretical model of regional co‐existence to generate a set of predictions on the patterns of colonization necessary for co‐existence and the regional processes that can lead to competitive exclusion. We empirically test these predictions using metacommunity microcosms of the interaction between two bruchid beetles (Callosobruchus chinensis,Callosobruchus maculatus).

Using well‐replicated time series of the interaction between the bruchids and statistical methods of model fitting, we show how the qualitative and quantitative pattern of interspecific competition between the bruchid beetles is shaped by the structure of the metacommunity.

In unlimited dispersal metacommunities, the global exclusion of the inferior competitor is shown to be influenced more by the processes associated with extinction rather than low colonization ability. In restricted dispersal metacommunities, we show how the co‐existence of competitors in a spatially heterogeneous habitat (patches connected through limited dispersal) is affected by Allee effects and life‐history [colonization (dispersal) – competition] trade‐offs.
Putting a break on protein translocation: metabolic regulation of mitochondrial protein import
Authors: Herrmann Johannes M.
Published: March 2009

Sequence‐inherent targeting information directs polypeptides synthesized in the cytosol to their respective cellular compartment. Some proteins use ambiguous sorting signals or specific folding properties to be dually distributed between the cytosol and mitochondria. A study published in this issue of Molecular Microbiology shows that in the case of fumarase this distribution is controlled by the metabolic state of yeast cells. The metabolite‐dependent distribution of fumarase represents an exciting example of regulated protein import into mitochondria that shows that eukaryotes can adapt the intracellular protein distribution to their physiological conditions.
Proven germline mosaicism in a father of two children with CHARGE syndrome
Authors: Pauli S , Pieper L , Häberle J , Grzmil P , Burfeind P , Steckel M , Lenz U , Michelmann HW
Published: March 2009

CHARGE syndrome is an autosomal dominant malformation syndrome caused by mutations in the CHD7 gene. The majority of cases are sporadic and only few familial cases have been reported. In these families, mosaicism in one parent, as well as parent‐ to‐child transmission of a CHD7 mutation, has been described. In some further cases, germline mosaicism has been suggested. Here, we report the first case in which germline mosaicism could be demonstrated in a father of two affected children with CHARGE syndrome. The truncating mutation c.7302dupA in exon 34 of the CHD7 gene was found in both affected children but was not detected in parental lymphocytes. However, in DNA extracted from the father’s spermatozoa, the c.7302dupA mutation could be identified. Furthermore, mutation analysis of DNA isolated from 59 single spermatozoa revealed that the c.7302dupA mutation occurs in 16 spermatozoa, confirming germline mosaicism in the father of the affected children. This result has a high impact for genetic counselling of the family and for their recurrence risk in further pregnancies.
Voriconazole pharmacokinetic variability in cystic fibrosis lung transplant patients
Authors: Berge M. , Guillemain R. , Boussaud V. , Pham M.‐H. , Chevalier P. , Batisse A. , Amrein C. , Dannaoui E. , Loriot M.‐A. , Lillo‐Le Louet A. , Billaud E.M.
Published: March 2009

Background. Aspergillosis is a high‐risk complication in cystic fibrosis (CF) lung transplant patients. Azole antifungal drugs inhibit CYP3A4, resulting in significant metabolic drug–drug interactions. Voriconazole (VRZ) was marketed without therapeutic drug monitoring (TDM) recommendations, consistent with favorable pharmacokinetics, but regular determinations of plasma VRZ concentration were introduced in our center to manage interactions with calcineurin inhibitors and to document the achievement of therapeutic levels.

Methods. VRZ TDM data analysis for trough concentration (C0) and peak concentration (C2) was carried out, using validated liquid chromatography assay with ultraviolet detection, for 35 CF lung transplant patients (mean age 25 years, mean weight 47 kg, balanced sex ratio) since 2003. Therapeutic range (C0: 1.5 ± 0.5 – C2 : 4.0 ± 1.0 mg/L) was expressed relative to pivotal pharmacokinetic trial data.

Results. The duration of VRZ treatment ranged from 9 days to 22 months. The recommended standard dose of VRZ (200 mg twice a day, following the loading dose) resulted in significant plasma concentrations (>0.5 mg/L) in 20% of CF lung transplant patients. Therapeutic concentrations were obtained using higher doses (average 570 ± 160 mg/day, +43%, P<0.01). Despite adaptation, C0 remained <0.5 mg/L (11%), even when the drug was administered intravenously, highlighting the variability of VRZ pharmacokinetics, possibly enhanced by CYP2C19 polymorphism. The risk of inefficacy during periods of underdosage was overcome by treatment with antifungal drug combinations (caspofungin, n=10). The therapeutic index was limited by neurologic effects (14%) and hepatic abnormalities (30%). VRZ concentrations correlated significantly (P<0.01) with aspartate aminotransferase levels but not with bilirubin levels. VRZ acted as a metabolic inhibitor of tacrolimus (C0 to dose ratio 5.8 ± 2.6, n=31/VRZ versus 1.7 ± 0.9 alone, P<0.001). Large changes in azole concentration affected the magnitude of the drug–drug interactions and adjustment requirements.

Conclusions. TDM is required because VRZ levels are often undetectable in treated CF lung transplant patients, supporting the use of antifungal drug combinations until achievement of VRZ C0 at a steady state between 1 and 2 mg/L. Plasma VRZ concentrations should be determined for the quantitative, individualized management of drug–drug interactions in lung transplant patients, in particular immunosuppressant such as tacrolimus, considering VRZ to be both a target and an inhibitor of CYP3A4.
Population density of Diabrotica virgifera virgifera LeConte beetles in Serbian first year and continuous maize fields
Authors: Sivcev I. , Stankovic S. , Kostic M. , Lakic N. , Popovic Z.
Published: March 2009

A 5‐year field survey examined western corn rootworm (WCR) (Diabrotica virgifera virgifera LeConte) beetle density in Serbia from 2002 to 2006. First‐, second‐, third‐, fourth‐ and fifth‐year maize fields were sampled; they represented 64.61%, 21.66%, 9.45%, 3.53% and 0.75% of all sampled fields respectively. Results showed that the mean WCR beetle population density from 794 maize fields differed depending on cropping history. Minimum mean WCR/trap/day was 0.0 in the first‐year maize fields in 2002 and 2006. Maximum mean WCR/trap/day was registered in the fourth‐year and the fifth‐year maize fields (27.8 and 21.2 respectively). Mean population density of WCR adults increased with the number of years of continuous maize from 1.17, 4.61, 6.41, 10.30 up to 13.53 WCR/trap/day for first‐fifth‐year maize fields respectively. Mean WCR/trap/day ± SE exceeded the economic population threshold of >6 WCR/trap/day in third‐year continuous maize fields. Out of 794 maize fields, 697 (87.78%) registered a mean population density below the <6 beetles/trap/day threshold. In only 97 fields was WCR population density >6 beetles/trap/day, a finding that predicts a risk of economic damage to a subsequent maize planting. These data are representative of the Serbian situation from 2002 to 2006; they indicate that WCR are well dispersed across commercial maize fields in Serbia. These results provide new insight into the current low WCR population densities in maize fields managed by crop rotation, a finding that can help in creating long‐term management strategy.
Prepenetration Stages of Guignardia psidii in Guava: Effects of Temperature, Wetness Duration and Fruit Age
Authors: Escanferla Maria Eugenia , Moraes Sylvia Raquel Gomes , Salaroli Renato Barbosa , Massola Jr Nelson Sidnei
Published: March 2009

This study examined the effects of temperature and wetness duration in vitro and in vivo as well as the effects of fruit age on germination and appressoria formation by conidia of Guignardia psidii, the causal agent of black spot disease in guava fruit. The temperatures tested for in vitro and in vivo experiments were 10, 15, 20, 25, 30, 35 and 40°C. The wetness periods studied were 6, 12, 24, 36 and 48 h in vitro and 6, 12 and 24 h in vivo. Fruit 10, 35, 60, 85 and 110‐days old were inoculated and maintained at 25°C, with a wetness period of 24 h. Temperature and wetness duration affected the variables evaluated in vitro and in vivo. All variables reached their maximum values at between 25 and 30°C with a wetness duration of 24 h in vivo and 48 h in vitro. These conditions resulted in 31.3% conidia germination, 33.6% appressoria formation and 32.5% appressoria melanization in vitro, and 50.4% conidia germination and 9.5% appressoria formation in vivo. Fruit age also influenced these factors. As fruit age increased, conidia germination and appressoria formation gradually increased. Conidia germination and appressoria formation were 10.8% and 2.3%, respectively, in 10‐day‐old fruits. In 110‐day‐old fruits, conidia germination and appressoria formation were 42.5% and 23.2% respectively.
Strain E26 of Agrobacterium vitis, a Biological Control Agent of Grapevine Crown Gall, Does Not Contain virA and virG Pathogenic Determinants
Authors: Wei Qing , Li Jin‐Yun , Wang Jian‐Hui , Wang Hui‐Min
Published: March 2009

Risk assessment of biological control agents (BCAs) for the control of plant diseases in the field and/or laboratories has now become a necessary procedure before developing and producing novel BCAs. Agrobacterium vitis strain E26 is a promising potential biocontrol agent of grapevine crown gall disease. However, much less is understood about its safety or environmental risks. In this study, polymerase chain reaction (PCR) and Southern blot analyses were used to determine whether five essential virulence genes (virA, virG, iaaH, iaaM and ipt) were present in strain E26. Primers and probes were designed based on the conserved regions of each gene. The overall results obtained indicated that A. vitis strain E26 does not contain the virA and virG determinants, suggesting that this strain would be unlikely to elicit crown gall symptoms in either host or non‐host plants. It seems that the iaaH, iaaM, or ipt gene were not present in strain E26 either. An applicable new approach combining PCR and Southern blot analyses to examine the pathogenicity of potential BCAs, particularly BCAs from the genus of Agrobacterium spp. was described.
Apatite fission track constraints on the Neogene tectono‐thermal history of Nimu area, southern Gangdese terrane, Tibet Plateau
Authors: Yuan Wanming , Deng Jun , Zheng Qiugen , Dong Jinquan , Bao Zengkuan , Eizenhoefer Paul R. , Xu Xiaotong , Huang Zhixin
Published: March 2009

Apatite fission track dating of five samples from Cenozoic volcanic strata in the Nimu District in the southern Gangdese Terrane exhibits single population grain ages with a single mean age and associated central ages ranging from 6.8 ± 0.6 Ma to 9.7 ± 1.2 Ma. Mean track lengths are between 12.9 ± 1.7 µm and 14.2 ± 2.3 µm with a single peak characteristic of a single thermal event. The newly documented ages coincide well with the age of high sedimentation rates in the North Tibet Basin that resulted from a 9–5 Ma compressional event. Track length modeling allows three stages to be identified in the sample cooling. The first stage (12–8 Ma) records a period of relative stability with little, if any, cooling at temperatures of 120–110°C suggesting this region had low relief. The second stage (8–2 Ma) reflects rapid cooling with temperatures decreasing from ∼110°C to surface temperatures of ∼15°C. This stage can be related to far‐field effects of the Himalayan collision, which probably generated the surface uplift and relief that defines the present‐day Gangdese Mountains. The mean uplift rate of this period is estimated to be 1.41–0.95 mm/y with total uplift reaching ∼5900 m. The final stage is related to surface evolution since the Pliocene.