bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro proliferation and differentiation of human CD34+ cells from peripheral blood into mature red blood cells with two different cell culture systems
Authors: Dorn Isabel , Lazar‐Karsten Pamela , Boie Stefanie , Ribbat Julika , Hartwig Dirk , Driller Birgit , Kirchner Holger , Schlenke Peter
Published: February 2008

BACKGROUND:An in vitro erythropoiesis assay is a powerful tool for investigating red blood cell (RBC) development and diseases of the erythroid lineage. Most assays, however, failed in either proliferation or terminal differentiation. Here two liquid cultures (LCs) for in vitro generation of RBCs from peripheral blood CD34+ cells were compared.

STUDY DESIGN AND METHODS:Granulocyte–colony‐stimulating factor–mobilized CD34+ cells were cultured for 16 days in a two‐phase LC (2P‐LC; Days 1‐8, stem cell factor [SCF], erythropoietin [EPO], insulinlike growth factor [IGF]‐1, and steroids; Days 9‐16, EPO and insulin) and for 21 days in a three‐phase LC (3P‐LC; Days 1‐7, SCF, thrombopoetin, and Flt3‐ligand; Days 8‐14, SCF, EPO, and IGF‐1; Days 15‐21, EPO and IGF‐1). Maturation was analyzed by flow cytometry (CD36, CD71, glycophorin A [GPA]) and microscopy.

RESULTS:In the 2P‐LC, cell numbers increased from 0.5 × 106to 25.7 × 106 ± 15.1 × 106cells per mL. More than 95 percent were GPA+ and showed morphologic characteristics of normoblasts (52 ± 15%) and enucleated reticulocytes (43 ± 18%). In the 3P‐LC, a higher overall proliferation to 55.7 × 106 ± 37.7 × 106cells per mL was achieved (p < 0.05). This was also accompanied by a high degree of normoblasts (36 ± 16%) and reticulocytes (48 ± 24%). The amount of GPA+ cells was slightly lower (88.4 ± 16.4%), associated with a significantly higher contamination by nonerythroid cells (15.8 ± 19.3% vs. 3.9 ± 2.9%, p < 0.05).

CONCLUSION:Both LCs were able to generate fully matured RBCs and represent powerful tools for fundamental research in erythroid development and diseases targeting the erythroid lineage. A slightly higher proliferation was achieved in the 3P‐LC. This was associated with a limited homogeneity due to more nonerythroid cells, however. Therefore the 2P‐LC is favored, also saving additional culture days and growth factors.
Release of immune modulation factors from platelet concentrates during storage after photochemical pathogen inactivation treatment
Authors: Cognasse Fabrice , Osselaer Jean‐Claude , Payrat Jean Marc , Chavarin Patricia , Corash Laurence , Garraud Olivier
Published: February 2008

BACKGROUND: Blood platelets (PLTs) are critical for hemostasis, and they contain biologically active constituents with the potential to modulate inflammatory responses. This study examined the effects of photochemical pathogen inactivation treatment (PCT) on the release of cytokines and/or chemokines from PLT components.

STUDY DESIGN AND METHODS: Double‐dose apheresis PLT components were suspended in plasma–PLT additive solution mixtures and divided into paired therapeutic units. One unit served as an untreated control and the other unit was treated with PCT. PLT concentrations, pH, and levels of cytokines and/or chemokines (CD62p, platelet‐derived growth factor‐AB, interleukin [IL]‐8, soluble CD40 ligand [sCD40L], IL‐1β, and tumor necrosis factor α) were measured during 7 days of storage in PLT component supernatants and PLT lysates.

RESULTS: PLT content, pH, and cytokine and/or chemokine content and release from PLT component prepared with PCT were not different (p > 0.05) from paired control components during storage. Levels of sCD40L, however, increased significantly during storage while decreasing in parallel within PLT lysates, although no differences were detected between paired PCT and control PLT component.

CONCLUSION: PCT did not increase the release or secretion of PLT chemokines and/or cytokines over a 7‐day period compared to conventional PLT component.
The phosphate site of trehalose phosphorylase from Schizophyllum commune probed by site‐directed mutagenesis and chemical rescue studies
Authors: Goedl Christiane , Nidetzky Bernd
Published: February 2008

Schizophyllum communeα,α‐trehalose phosphorylase utilizes a glycosyltransferase‐like catalytic mechanism to convert its disaccharide substrate into α‐d‐glucose 1‐phosphate and α‐d‐glucose. Recruitment of phosphate by the free enzyme induces α,α‐trehalose binding recognition and promotes the catalytic steps. Like the structurally related glycogen phosphorylase and other retaining glycosyltransferases of fold family GT‐B, the trehalose phosphorylase contains an Arg507‐XXXX‐Lys512 consensus motif (where X is any amino acid) comprising key residues of its putative phosphate‐binding sub‐site. Loss of wild‐type catalytic efficiency for reaction with phosphate (kcat/Km = 21 000 m−1·s−1) was dramatic (≥107‐fold) in purified Arg507→Ala (R507A) and Lys512→Ala (K512A) enzymes, reflecting a corresponding change of comparable magnitude in kcat (Arg507) and Km (Lys512). External amine and guanidine derivatives selectively enhanced the activity of the K512A mutant and the R507A mutant respectively. Analysis of the pH dependence of chemical rescue of the K512A mutant by propargylamine suggested that unprotonated amine in combination with H2PO4−, the protonic form of phosphate presumably utilized in enzymatic catalysis, caused restoration of activity. Transition state‐like inhibition of the wild‐type enzyme A by vanadate in combination with α,α‐trehalose (Ki = 0.4 μm) was completely disrupted in the R507A mutant but only weakened in the K512A mutant (Ki = 300 μm). Phosphate (50 mm) enhanced the basal hydrolase activity of the K512A mutant toward α,α‐trehalose by 60% but caused its total suppression in wild‐type and R507A enzymes. The results portray differential roles for the side chains of Lys512 and Arg507 in trehalose phosphorylase catalysis, reactant state binding of phosphate and selective stabilization of the transition state respectively.
Use of molecular markers in participatory plant breeding: assessing the genetic variability in cotton populations bred by farmers
Authors: Lançon J. , Pichaut J.‐P. , Djaboutou M. , Lewicki‐Dhainaut S. , Viot C. , Lacape J.‐M.
Published: February 2008

In participatory plant breeding, farmers are involved in simple selection schemes that are not suitable for assessing genetic variability in the segregating populations. We propose to use information derived from molecular marker analyses to help monitoring such populations. In this study, we used three indicators to compare genetic variability in eight genetic structures, that is three plant populations selected by farmers over five generations, three nonselected populations and two commercial varieties. The three indicators were the polymorphic locus rate, heterozygosity rate and dissimilarity index. The results highlighted that the genetic variability decreased more with farmers’ selection than with environmental factors. The breeding process was not complete because genetic variability in the selected populations was midway between that of the nonselected populations and that of the commercial varieties monitored. The three proposed indicators were relevant for describing the studied populations. They could be interpreted according to a grid drawn up on the basis of the results of the present study.
Seed Dispersal and Ingestion of Insect‐Infested Seeds by Black Howler Monkeys in Flooded Forests of the Parana River, Argentina
Authors: Bravo Susana Patricia
Published: February 2008

All howler monkey species (Alouatta spp.) have a folivorous–frugivorous diet. Howler monkeys are reported to be seed dispersers in several areas, including black howlers (Alouatta caraya), which are important seed dispersers in northern Argentinean forests. The goal of this work was to study the three‐way interaction between insects, seeds, and black howlers, and assess the functional significance of this tri‐trophic interaction for seed dispersal. I determined through direct observation that fruits of species with a high proportion of insect infestation were important components of howler monkey diet. Ocotea diospyrifolia seeds from fresh faeces of black howlers contained dead larvae, but seeds were still able to germinate. Seeds in which larvae had reached an advanced stage of development did not germinate. Larvae of infested Eugenia punicifolia fruits were killed by digestion when they occurred in the pulp early in the fruiting season, but were dispersed alive with seeds later in the season. Banara arguta fruits contained both healthy and infested seeds; infested seeds were destroyed during digestion, while healthy seeds were dispersed. Black howlers' ingestion of infested fruits could result in the: (1) killing of larvae and dispersion of healthy seeds; (2) spread of larvae; or (3) destruction of infested seeds. This will depend on the relationship between the time at which fruit is consumed by black howlers, the time at which insect infestation occurs, and also probably on the hardness of the seed coat and the seed–insect size ratio.
No Pain, No Strain: Impact of Health on the Financial Security of Older Americans
Authors: KIM HYUNGSOO , LYONS ANGELA C.
Published: February 2008

This study uses data from the 2002 and 2004 Health and Retirement Study to investigate the impact that new and existing health problems have on the financial strain of older Americans. Two‐period models are estimated for a series of financial ratio guidelines that take into account household solvency, liquidity, and investment asset accumulation. We test our models using a subjective measure of self‐reported health status and two objective measures of health that control for the severity of specific health conditions. The results show that health problems significantly increase the likelihood of financial strain for older individuals, but the effects vary by the measure of financial strain used and how health status is defined. Specifically, existing health conditions were more likely to affect solvency and investment asset accumulation than liquidity, while new health events were more likely to affect solvency. The severity of the condition did not seem to matter as much as whether the condition was chronic. These results provide insight into the future financial security of older Americans and have important implications for health policy and research.
Recognizing Consumer Issues in DTC Pharmaceutical Advertising
Authors: ROYNE MARLA B. , MYERS SUSAN D.
Published: February 2008

As one of the most controversial modern business practices in history, direct‐to‐consumer advertising of prescription medications is a critical topic for consumer advocates, but the current body of literature falls short of providing practical guidance for the eminent policy change. The current article reviews the existing perspectives on direct‐to‐consumer advertising and offers directions for answering important questions that focus on the consumer’s interests.
Green fluorescent protein incorporation by mouse myoblasts may yield false evidence of myogenic differentiation of human haematopoietic stem cells
Authors: Di Castro A. , Bonci D. , Musumeci M. , Grassi F.
Published: February 2008

Aims:  Haematopoietic CD34+ stem cells are able to differentiate into skeletal muscle, a potentially invaluable tool for treating degenerative diseases such as muscular dystrophy. However, some studies argue that the differentiative potential of these cells might have been overestimated. In vitro studies provide a controlled environment in which to investigate this point.

Methods:  CD34+ stem cells from human peripheral blood, labelled with green fluorescent protein (GFP), were co‐cultured with mouse myogenic C2C12 cells. The functional properties of mononucleated GFP+ cells were determined using electrophysiological techniques and were related to protein profiling determined by immunofluorescence staining and single‐cell RT‐PCR. Mouse mesoangioblasts co‐cultured with human myotubes provided methodological controls.

Results:  After 2–4 days, mononucleated adherent GFP+ cells showed acetylcholine‐evoked current responses, typical of myogenic cells, as if stem cells had integrated into the host environment. In contrast to this hypothesis, human nuclei could not be detected in adherent GFP+ cells by immunofluorescence. Moreover, single‐cell RT‐PCR showed that adherent GFP+ cells responsive to acetylcholine expressed mouse markers while loose unresponsive GFP+ cells were of human origin. The transcripts of the human α1 subunit of the acetylcholine muscle receptor were not amplified in co‐cultures.

Conclusion:  Single‐cell analysis of functional properties combined with other markers revealed that, under the co‐culture conditions used, GFP was transferred from human CD34+ stem cells to C2C12 myoblasts by mechanisms unrelated to myogenic stem cell differentiation. Our results emphasize the need for careful controls using several markers when investigating the myogenic differentiation of circulating stem cells.
Preparation of Low‐Fat Uptake Doughnut by Dry Particle Coating Technique
Authors: Lee J.‐S. , Kim B.‐K. , Kim K.‐H. , Park D.‐J.
Published: February 2008

ABSTRACT:  Soybean hull–wheat flour composites were prepared and used a doughnut formulation in order to decrease fat uptake during deep‐fat frying. Soybean hulls were microparticulated by jet milling, and wheat flour was air‐classified into coarse and fine fraction by an air classifying system. The coarse fraction of wheat flour was dry‐coated with the microparticulated soybean hulls by a hybridization system. To investigate the effect on fat uptake, 4 different types of composites were prepared, which contained 0%, 1%, 5%, and 10% of soybean hulls. Doughnuts containing 1%, 5%, and 10% of microparticulated hulls decreased fat contents of 11.5%, 13.6%, and 35.8%, respectively. As soybean hulls content increased, hardness and crispiness increased. However, sensory evaluations demonstrated that there were no significant differences in appearance, flavor, crispiness, taste, and general liking (P < 0.05). Inner crust structures of doughnut showed slight reductions in cell size and improved cellular integrity with shrinkage in the cell membrane as the content of soybean hulls increased. These results show that microparticulated soybean hulls may form a protective layer during frying process, and this process could be used by the food industry for preparing doughnuts with reduced fat uptake.
Detergent and Sanitizer Stresses Decrease the Thermal Resistance of Enterobacter sakazakii in Infant Milk Formula
Authors: Osaili T.M. , Shaker R.R. , Olaimat A.N. , Al‐Nabulsi A.A. , Al‐Holy M.A. , Forsythe S.J.
Published: February 2008

ABSTRACT:  This study determined the effect of acid, alkaline, chlorine, and ethanol stresses on the thermal inactivation of Enterobacter sakazakii in infant milk formula. Unstressed or stressed cells were mixed with reconstituted powdered infant milk formula (PIMF) at temperatures between 52 and 58 °C for various time periods or mixed with PIMF prior to reconstitution with hot water between 50 and 100 °C. D‐ and z‐values were determined using liner regression analysis. In general, detergent and sanitizer stresses decreased the thermal resistance of E. sakazakii in infant milk formula. The results of this study may be of use to regulatory agencies, manufacturers, and infant caregivers to design heating processes to eliminate E. sakazakii.
Statistical simulation of flood variables: incorporating short‐term sequencing
Authors: Cai Y. , Gouldby B. , Hawkes P. , Dunning P.
Published: February 2008

The pluvial and fluvial flooding in the United Kingdom over the summer of 2007 arose as a result of anomalous climatic conditions that persisted for over a month. Gaining an understanding of the sequencing of storm events and representing their characteristics within flood risk analysis is therefore of importance. This paper provides a general method for simulating univariate time series data, with a given marginal extreme value distribution and required autocorrelation structure, together with a demonstration of the method with synthetic data. The method is then extended to the multivariate case, where cross‐variable correlations are also represented. The multivariate method is shown to work well for a two‐variable simulation of wave heights and sea surges at Lerwick. This work was prompted by an engineering need for long time series data for use in continuous simulation studies where gradual deterioration is a contributory factor to flood risk and potential structural failure.
Overnight variability in transcutaneous carbon dioxide predicts vascular impairment in women
Authors: Aittokallio Jenni , Polo Olli , Hiissa Jukka , Virkki Arho , Toikka Jyri , Raitakari Olli , Saaresranta Tarja , Aittokallio Tero
Published: February 2008

While there are a number of studies demonstrating association between arterial oxyhaemoglobin saturation events during sleep and markers of vascular impairment, the contribution of peripheral carbon dioxide to the development of atherosclerosis is poorly understood. We used ultrasound imaging to measure carotid artery intima–media thickness (IMT), as well as flow‐mediated dilatation (FMD) and nitroglycerin‐mediated dilatation (NMD) of brachial artery, in 103 generally healthy 46‐year‐old (±2 years) women. Characteristic event patterns were extracted from their overnight recordings of arterial oxyhaemoglobin saturation
, end‐tidal partial pressure of carbon dioxide
and transcutaneous partial pressure of carbon dioxide
. Importance of the event patterns was evaluated through predictive modelling of classes of the ultrasound measurements while controlling for potential confounders. Prediction accuracy was assessed with cross‐validation and reported as the area under the receiver operating characteristic curve (AUC). Overnight
patterns predicted each of the ultrasound measurements with high accuracy (IMT, AUC = 0.70; FMD, AUC = 0.75; and NMD, AUC = 0.81; all with P < 0.001). Adding the
or
patterns into the models did not significantly increase their predictive powers (AUC = 0.72, AUC = 0.77 and AUC = 0.83, respectively). The most important patterns reflected overnight variability in
. These results suggest a novel link between overnight carbon dioxide events and early signs of vascular impairment in middle‐aged women. Non‐invasive
measurements combined with non‐linear modelling techniques could be used to reveal potential markers of vascular impairment present in relatively healthy subjects.
Role of angiotensin‐converting enzyme 2 and angiotensin(1–7) in 17β‐oestradiol regulation of renal pathology in renal wrap hypertension in rats
Authors: Ji Hong , Menini Stefano , Zheng Wei , Pesce Carlo , Wu Xie , Sandberg Kathryn
Published: February 2008

17β‐Oestradiol (E2)‐mediated inhibition of angiotensin‐converting enzyme (ACE) protects the E2‐replete kidney from the progression of hypertensive renal disease. Angiotensin‐converting enzyme 2 (ACE2), a homologue of ACE, counters the actions of ACE by catalysing the conversion of angiotensin II (Ang II) to angiotensin(1–7) [Ang(1–7)]. We investigated E2 regulation of ACE2 in the renal wrap (RW) model of hypertension in rats. After 6 weeks on a high‐sodium diet (4% NaCl), the activity of ACE2 was reduced in the renal cortex by 31%, which was mirrored by similar decreases in ACE2 protein (30%) and mRNA expression (36%) in the ovariectomized RW rat (RW‐OVX); E2 replacement prevented these effects. The RW‐OVX rats exhibited greater renal injury, including 1.7‐fold more tubulointerstitial fibrosis and 1.6‐fold more glomerulosclerosis than E2‐replete females (RW‐Intact and RW‐OVX+E2). Angiotensin(1–7) infusion prevented these exacerbating effects of ovariectomy on renal pathology; no differences in indicators of renal injury were observed between RW‐OVX‐Ang(1–7) and RW‐Intact rats. These renal protective effects of Ang(1–7) infusion were not attributable to increased ACE2 activity or to changes in heart rate or body weight, since these parameters were unchanged by Ang(1–7) infusion. Furthermore, Ang(1–7) infusion did not attenuate renal injury by reducing mean arterial pressure (MAP), since infusion of the peptide did not lower MAP but rather caused a slight increase during a 6 week chronic treatment for Ang(1–7). These results suggest that E2‐mediated upregulation of renal ACE2 and the consequent increased Ang(1–7) production contribute to E2‐mediated protection from hypertensive renal disease. These findings have implications for E2‐deficient women with hypertensive renal disease and suggest that therapeutics targeted towards increasing ACE2 activity and Ang(1–7) levels will be renal protective.
Interplay of angiotensin II and angiotensin(1–7) in the regulation of matrix metalloproteinases of human cardiocytes
Authors: Pan Chun‐Hsu , Wen Cheng‐Hao , Lin Chih‐Sheng
Published: February 2008

Angiotensin II (Ang II) is a critical effector in the renin–angiotensin system (RAS), which modulates cardiovascular homeostasis, and the matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) related metabolism of extracellular matrix (ECM). Angiotensin(1–7) [Ang(1–7)] is another bioactive peptide in the RAS and is considered to have opposite effects to Ang II. However, the modulation of MMPs and TIMPs by Ang(1–7) is largely unclear in cardiocytes, and the antagonistic effects of Ang(1–7) on Ang II‐mediated expression of MMPs and TIMPs have yet to be identified. In the present study, we examined the transcript expression of MMPs and TIMPs in human cardiac fibroblasts (HCF) and myocytes (HCM) after Ang II or Ang(1–7) stimulation, and analysed the antagonistic effects of Ang(1–7) to Ang II. The results show that Ang II decreased transcript expression of MMP‐1, MMP‐2, TIMP‐1, TIMP‐2 and TIMP‐3, but upregulated MMP‐9 expression in the HCF cells. Transcript expression of MMP‐9 and TIMP‐2 was downregulated by Ang(1–7) in the same cells. In the HCM cells, Ang II induced MMP‐1 and MMP‐9 overexpression but MMP‐2 was downregulated. All of the examined MMPs and TIMPs, except MMP‐9, were markedly decreased by Ang(1–7). In the studies of antagonistic effects of Ang(1–7) to Ang II, Ang(1–7) counteracted the effects of Ang II‐mediated regulation on MMP‐9 and TIMP‐1 in the HCF cells compared with the control group. The regulations of all examined MMPs by Ang II were reversed to basal expression by Ang(1–7) in the HCM cells. Our results suggest that Ang(1–7) and Ang II have opposite and antagonistic effects on regulation of transcription of MMPs and TIMPs in primary cultures of human cardiocytes. These effects lead to increased ratios of MMPs to TIMPs after Ang II stimulation and decreased ratios of MMPs to TIMPs after Ang(1–7) stimulation; effects which may partly depend of the type of cardiac cells. These results suggest a potential role for Ang(1–7) in attenuatating cardiac damage in Ang II‐induced ECM remodelling.
Local renal aldosterone production induces inflammation and matrix formation in kidneys of diabetic rats
Authors: Siragy Helmy M. , Xue Chun
Published: February 2008

Recently, we reported the presence of a local renal aldosterone production. In the present study, we tested the hypothesis that local aldosterone production in the kidney contributes to renal inflammation, matrix formation and albuminuria associated with diabetes. We evaluated changes in renal aldosterone content (RAC), aldosterone synthase expression, nuclear factor κB (NFκB), tumour necrosis factor α (TNFα), interleukin‐6 (IL‐6), transforming growth factor β (TGFβ), glomerular fibronectin, collagen type IV and urinary albumin extraction (UAE) in response to the aldosterone synthase inhibitor FAD286. Studies were conducted in adrenalectomized, normoglycaemic (control) or diabetic rats for 14 weeks. The FAD286 was administered during the last 10 weeks of the study. Plasma aldosterone levels were not detectable in any of the study groups. Compared with control rats, diabetic rats had higher levels of RAC by 488% (P < 0.01), NFκB by 293% (P < 0.01), TNFα by 356% (P < 0.01), IL‐6 by 378% (P < 0.01), TGFβ by 337% (P < 0.01) and UAE by 1122% (P < 0.01), and increased glomerular fibronectin and collagen type IV immunostaining. In diabetic rats, FAD286 reduced RAC (P < 0.01), UAE (P < 0.05), NFκB mRNA, TNFα mRNA, IL‐6 mRNA and TGFβ mRNA by 51, 41, 41 and 52% and also their proteins and decreased glomerular fibronectin and collagen type IV immunostaining. In conclusion, diabetes increases local aldosterone production in the kidney, which contributes to development of renal inflammation, matrix formation and albuminuria. Inhibition of aldosterone production in the kidney could be helpful in management of diabetic nephropathy.
Molecular Characterization of New Natural Hybrids of
Saccharomyces cerevisiae
and
S
.
kudriavzevii
in Brewing
Authors: González Sara S. , Barrio Eladio , Querol Amparo
Published: February 2008

We analyzed 24 beer strains from different origins by using PCR-restriction fragment length polymorphism analysis of different gene regions, and six new
Saccharomyces cerevisiae
×
Saccharomyces kudriavzevii
hybrid strains were found. This is the first time that the presence in brewing of this new type of hybrid has been demonstrated. From the comparative molecular analysis of these natural hybrids with respect to those described in wines, it can be concluded that these originated from at least two hybridization events and that some brewing hybrids share a common origin with wine hybrids. Finally, a reduction of the
S. kudriavzevii
fraction of the hybrid genomes was observed, but this reduction was found to vary among hybrids regardless of the source of isolation. The fact that 25% of the strains analyzed were discovered to be
S. cerevisiae
×
S. kudriavzevii
hybrids suggests that an important fraction of brewing strains classified as
S. cerevisiae
may correspond to hybrids, contributing to the complexity of
Saccharomyces
diversity in brewing environments. The present study raises new questions about the prevalence of these new hybrids in brewing as well as their contribution to the properties of the final product.
Modeling the Aminogenic Potential of
Enterococcus faecalis
EF37 in Dry Fermented Sausages through Chemical and Molecular Approaches
Authors: Gardini Fausto , Bover-Cid Sara , Tofalo Rosanna , Belletti Nicoletta , Gatto Veronica , Suzzi Giovanna , Torriani Sandra
Published: February 2008

Amino acid decarboxylase activity of the
Enterococcus faecalis
strain EF37 was monitored during fermentation and ripening of a traditional dry fermented sausage from Northern Italy (Salame Veronese) by means of microbiological, chemical, and molecular approaches in relation to three technological factors: fermentation temperature, sodium chloride concentration, and amount of glucose added to the meat mixture. Besides the analytical determination of tyramine and phenylethylamine accumulation and the counts of enterococci, the presence and quantification of the tyrosine decarboxylase gene (
tdc
) and its mRNA transcript were also investigated by using real-time PCR. According to the mathematical models obtained, all of the three factors studied were statistically significant and microbiologically relevant for the early development of enterococci, although the fermentation temperature had a more relevant influence on the enterococcal viable cells of the ripened product. Sodium chloride concentration was the most determinant factor of the final tyramine and 2-phenylethylamine accumulation and also of the levels of
tdc
present in the final product. In contrast, an effect of glucose concentration on
tdc
expression was observed in the last period of ripening. Moreover, increasing amounts of sodium chloride and decreasing fermentation temperature resulted in a reduced
tdc
expression. This is the first time that bacterial tyrosine decarboxylase potential is directly examined through a molecular approach in a fermented meat. The quantification of
tdc
and its transcript can help to elucidate the critical steps and factors during food manufacturing at which bacterial aminogenesis is possible, thus allowing researchers to propose technological measures to control decarboxylase activities.
Impaired Ribosome Biogenesis Disrupts the Integration between Morphogenesis and Nuclear Duplication during the Germination of
Aspergillus fumigatus
Authors: Bhabhra Ruchi , Richie Daryl L. , Kim H. Stanley , Nierman William C. , Fortwendel Jarrod , Aris John P. , Rhodes Judith C. , Askew David S.
Published: February 2008

Aspergillus fumigatus
is an important opportunistic fungal pathogen that is responsible for high mortality rates in the immunosuppressed population. CgrA, the
A. fumigatus
ortholog of a
Saccharomyces cerevisiae
nucleolar protein involved in ribosome biogenesis, contributes to the virulence of this fungus by supporting rapid growth at 37°C. To determine how CgrA affects ribosome biogenesis in
A. fumigatus
, polysome profile and ribosomal subunit analyses were performed on both wild-type
A. fumigatus
and a Δ
cgrA
mutant. The loss of CgrA was associated with a reduction in the level of 80S monosomes as well as an imbalance in the 60S:40S subunit ratio and the appearance of half-mer ribosomes. The gene expression profile in the Δ
cgrA
mutant revealed increased abundance of a subset of translational machinery mRNAs relative to the wild type, suggesting a potential compensatory response to CgrA deficiency. Although Δ
cgrA
conidia germinated normally at 22°C, they swelled excessively when incubated at 37°C and accumulated abnormally high numbers of nuclei. This hypernucleated phenotype could be replicated pharmacologically by germinating wild-type conidia under conditions of reductive stress. These findings indicate that the germination process is particularly vulnerable to global disruption of protein synthesis and suggest that CgrA is involved in both ribosome biogenesis and polarized cell growth in
A. fumigatus
.
High-Frequency Intragenomic Heterogeneity of the Ribosomal DNA Intergenic Spacer Region in
Trichophyton violaceum
Authors: Chang Jen-Chyi , Hsu Mark Ming-Long , Barton Richard C. , Jackson Colin J.
Published: February 2008

The intergenic spacer (IGS) of the rRNA genes was analyzed from the dermatophyte
Trichophyton violaceum
isolated from cases of tinea capitis in Taiwan and Iran.
T. violaceum
strains were cultured from different colonies, from single conidial colonies derived by dilution plating, and from micromanipulation of single conidia from clinical samples. A ribosomal DNA probe hybridizing to multiple EcoRI fragments was used to compare restriction fragment length polymorphisms in different
T. violaceum
isolates. The arthroconidia of
T. violaceum
that form in vivo during infection were shown to contain a single nucleus by 4′,6′-diamidino-2-phenylindole staining. IGS regions from an isolate cultured from a single conidium were amplified, cloned, and sequenced. The results identified that heterogeneity exists between IGS regions within a single
T. violaceum
genome due to different copy numbers of a 171-bp tandem repeat. This suggests that the IGS of
T. violaceum
is partially excluded from the concerted evolution of the rRNA gene locus. The heterogeneous character of the IGS regions in
T. violaceum
contrasts with the closely related dermatophyte
Trichophyton rubrum
, posing further questions on the phylogeny and the evolution of dermatophyte fungi.
Effects of SecE Depletion on the Inner and Outer Membrane Proteomes of
Escherichia coli
Authors: Baars Louise , Wagner Samuel , Wickström David , Klepsch Mirjam , Ytterberg A. Jimmy , van Wijk Klaas J. , de Gier Jan-Willem
Published: February 2008

The Sec translocon is a protein-conducting channel that allows polypeptides to be transferred across or integrated into a membrane. Although protein translocation and insertion in
Escherichia coli
have been studied using only a small set of specific model substrates, it is generally assumed that most secretory proteins and inner membrane proteins use the Sec translocon. Therefore, we have studied the role of the Sec translocon using subproteome analysis of cells depleted of the essential translocon component SecE. The steady-state proteomes and the proteome dynamics were evaluated using one- and two-dimensional gel analysis, followed by mass spectrometry-based protein identification and extensive immunoblotting. The analysis showed that upon SecE depletion (i) secretory proteins aggregated in the cytoplasm and the cytoplasmic σ
32
stress response was induced, (ii) the accumulation of outer membrane proteins was reduced, with the exception of OmpA, Pal, and FadL, and (iii) the accumulation of a surprisingly large number of inner membrane proteins appeared to be unaffected or increased. These proteins lacked large translocated domains and/or consisted of only one or two transmembrane segments. Our study suggests that several secretory and inner membrane proteins can use Sec translocon-independent pathways or have superior access to the remaining Sec translocons present in SecE-depleted cells.
Evidence of In Vivo Cross Talk between the Nitrogen-Related and Fructose-Related Branches of the Carbohydrate Phosphotransferase System of
Pseudomonas putida
Authors: Pflüger Katharina , de Lorenzo Víctor
Published: February 2008

The genome of
Pseudomonas putida
KT2440 encodes only five recognizable proteins belonging to the phosphoenolpyruvate (PEP)-carbohydrate phosphotransferase system (PTS). Two of these PTS constituents (FruA and FruB) form a complete system for fructose intake. The other three products, encoded by
ptsP
(EI
Ntr
),
ptsO
(NPr), and
ptsN
(EIIA
Ntr
), comprise a branch of the system unrelated to sugar traffic but thought to have an influence on coordination of N and C metabolism. We used a genetic approach to clarify the course of high-energy phosphate through this reduced set of PTS proteins. To this end, we monitored the phosphorylation state in vivo of the EIIA
Ntr
enzyme in various genetic backgrounds and growth conditions. Our results show that the source of phosphate available to the system is PEP and that the primary flow of phosphate through the N/C-sensing PTS proceeds from PEP to EI
Ntr
to NPr to EIIA
Ntr
. We also found that in the presence of fructose, unlike in the presence of succinate, EIIA
Ntr
can be phosphorylated in a
ptsP
strain but not in a
ptsP fruB
double mutant. This result revealed that the fructose transport system has the ability to cross talk in vivo with the N-related PTS branch. The data reported here thus document an unexpected connection in vivo between the sugar-dependent and sugar-independent PTSs.
Enhanced rooting of Picea mariana cuttings by ectomycorrhizal fungi
Authors: Stein Anne , Fortin J. André , Vallée Gilles
Published: February 2008

Cuttings of Picea mariana (Mill.) B.S.P. and Larix decidua Mill, were rooted in a peat moss – vermiculite substrate inoculated with vegetative mycelium of two ectomycorrhizal fungi. The fungal influence on rooting was compared with auxin-treated cuttings. The symbionts stimulated rhizogenesis of P. mariana, resulting in significantly increased rooting percentage, number of roots per cutting, and average root length as compared with controls. The best rooting percentage and the highest number of roots formed per cutting was reached under the hormonal treatment. No stimulating effect by ectomycorrhizal fungi was observed on L. decidua cuttings. With L. decidua, no significant differences in rooting percentage between the four treatments were obtained. The use of indolebutyric acid significantly increased the number of roots per cutting and decreased mean root length.
Large disparity in recombination fractions reported in Picea mariana for the Aat-1/Pgi-2 linkage group
Authors: Ringius Gordon S. , Innes David J.
Published: February 2008

A survey of 84 trees in a natural population of Picea mariana located near St. John's, Newfoundland, yielded 3 trees heterozygous for the Aat-1/Pgi-2 linked locus pair. Segregation analysis of this linkage group in 330 megagametophytes resulted in an estimated pooled recombination fraction of 0.015. This is the lowest known recombination fraction for this linkage group in the Pinaceae. It is in contrast with earlier reports of recombination fractions of 0.155 and 0.250 from other populations of P. mariana in eastern Canada. The presence of substantial variation in recombination fractions in populations from eastern Canada precludes a regional selection–adaptation explanation. The cause of this variation is unknown. Substantial variation, both temporal and spatial, in other linkage groups suggests that the basis of linkage variation is complex and in need of further investigation in the Pinaceae.
Scanning electron microscopy examination of soybean hilum development
Authors: Baker Daniel M. , Mebrahtu Tadesse
Published: February 2008

Seeds of the soybean (Glycine max (L.) Merr.) cultivar Tracy-M were harvested from field-grown plants, and fractures of the hilum were examined with a scanning electron microscope. Macrosclereid and hilar fissure differentiation were observed at approximately 1% maximum seed size. The tracheid bar, stellate cells, sclerenchyma, and rim aril began differentiation near 5% maximum seed size. Outer integument differentiation was nearly completed by 35% maximum seed size, when articulated parenchyma, aerenchyma, and pits in the developing tracheids were observed. Hilum development was completed when the aleurone differentiated from the inner integument prior to seed maturity. Partial seed abscission was observed during hilum development.
La torsion de contrainte et le modèle phyllotaxique de Jean
Authors: Barabé Denis , Vieth Joachim
Published: February 2008

The phyllotactic model of Jean is used to analyse the phenomena of biastrepsis in Dipsacus silvestris. The interpretation deduced from Jean's model is compared with those of De Vries and of Plantefol. From the mean values of the divergence angle of seedling rosettes (75.4°) and twisted stems (151.3°), we can determine the phyllotactic series of the system. These results show that the phyllotaxy of Dipsacus silvestris is controlled by the series J(2,5,7,12,19,… ), with J = 1 orJ = 2. By comparing our results with those of De Vries, we can also deduce that in other cases the phyllotaxy of twisted stems is controlled by the series (1,2,3,5,8,… ). This interpretation agrees with other observations and allows us to analyse known facts in a more coherent framework than other studies.
Influence, chez le Manihot esculenta, du développement de la lame du limbe sur celui du pétiole et de l'entre-noeud sous-jacent
Authors: Médard R. , Walter J. M. N. , Barnola P.
Published: February 2008

Within each internode and about four plastochrons after its formation, an intercalary growth area appears, leading to a continued lengthening due essentially to anticline mitoses. It temporarily looks like a cambium. The blade of the leaf which is directly above the internode is absolutely necessary for the formation of this growth area. Xylem integrity of the cauline vascular bundle connected with this leaf is also required. Within each leaf, the presence of the blade and the integrity of vascular bundles are also indispensable for the lengthening of the petiole, whose mitotic system resembles the internode's. The hypothesis of a blade influence on the mitotic lengthening system through mechanical pressure due to the vascular development is discussed. Key words: internode, petiole, blade, vascular tissues, Manihot esculenta, intercalary growth.
Morphology of the outer integument in three primitive angiosperm families
Authors: Imaichi Ryoko , Kato Masahiro , Okada Hiroshi
Published: February 2008

Scanning electron microscope examinations were performed to characterize the developmental morphology of the outer integument in several species of the three families Annonaceae (Cananga odorata var. fruticosa, Goniothalamus macrophyllus, and Stelechocarpus burahol), Eupomatiaceae (Eupomatia laurina), and Winteraceae (four Tasmannia species). In all species examined, the inner integument arises as an annular ring, but the outer integument initiates as a semiannular outgrowth interrupted on the concave side of the funiculus; the outer integument then becomes hood-shaped. The inner integument overtops the outer one at maturity, and the micropyle consists only of an endostome. Data from the present and previous studies support the hypothesis that the outer integument is hood-shaped in magnolialean angiosperms and that the bilaterally symmetrical, bladelike outer integument is homologous with the ovuliferous sporophyll of the glossopterids. The micropyle consisting of an endostome might be in a primitive state, compared with a bistomic one. Key words: developmental morphology, integument, micropyle, phylogenesis, primitive angiosperms, scanning electron microscopy.
Effect of fertilization of balsam fir trees on spruce budworm nutrition and development
Authors: Shaw G. G. , Little C. H. A. , Durzan D. J.
Published: February 2008

Spruce budworm (Choristoneurafumiferana Clem.) larvae were reared on field-grown balsam fir (Abiesbalsamea (L.) Mill.) trees variously treated with nitrogen, potassium, and phosphorous fertilizers. Treatment with high nitrogen had a significant effect on terminal shoot growth, the caloric value, the concentrations of total sugar, starch, crude fat, nitrogen, chlorophyll, and moisture, and the calories per milligram protein in maturing current-year needles, the budworm's food. Concomitantly, high nitrogen increased male and female pupal weight. Ammonium acetate had less effect than urea or calcium nitrate on both tree and budworm responses, and low urea had less effect than high urea. High potassium, particularly in the presence of low urea, negatively affected some tree and budworm responses. Larval survival was increased only by calcium nitrate application. Of all the foliar parameters, the calories per milligram protein and the nitrogen concentration were best correlated with pupal weight. Female pupal weight was positively correlated with number of F1 larvae per female moth. The results support the hypothesis that food quality can significantly affect budworm population dynamics.
Estimation of net radiation for a coniferous forest, and the effects of logging on net radiation and the reflection coefficient
Authors: McCaughey J. H.
Published: February 2008

The results of field studies on the radiation climate at Montmorency, Quebec, are presented. These studies were conducted in the summers of 1975 and 1976, and two sites were used. The first site, used in both years, was forested with 50- to 60-year-old balsam fir (Abiesbalsamea L. Mill.). The second site, originally forested with balsam fir, was clear-cut in the fall of 1975. The daily mean reflection coefficient for solar radiation of the forest is 7% (sample of 264 hourly values). In contrast, the clear-cut site has a daily mean reflection coefficient of 18% (sample of 171 hourly values). There is no evidence of a systematic variation of hourly reflection coefficients with solar zenith angle for either site. The effect of logging on net radiation is characterized by a sample of 21 days in 1976 when hourly values of net radiation were available for both sites. Typically, during the night, the magnitude of net radiation on the forested site is less than that on the clear-cut site, and during the day, the net radiation on the clear-cut site is less than that on the forested site. In terms of daily totals, the effect of logging is to reduce net radiation by 10%.A simple linear regression equation for the calculation of net radiation for the forested site is presented. Global solar radiation (hourly values) is used as the predictor. The parameters of the model are similar to other equations for similar surfaces.
A comparison of the growth basal area stocking level curve to a number of curves developed from south central Oregon tree data
Authors: Hopkins William E.
Published: February 2008

A single regression supporting the growth basal area concept was compared with regressions developed from various south central Oregon coniferous trees. Growth basal area is the basal area at which dominant trees grow 1 in. (25 mm) in diameter per decade referenced at age 100 years. Regressions developed from ponderosa pine (Pinusponderosa Laws.) and lodgepole pine (Pinuscontorta Dougl.) data were significantly different from the single published regression. White fir (Abiesconcolor Gord. & Glend.) and Shasta red fir (Abiesmagnifica var. shastensis Lemm.) data also proved to be significantly different. Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) data indicated no significant difference when compared with the published growth basal area curve. Therefore, application of the published growth basal area curve to stands found in south central Oregon would be considerably less precise than those curves developed from tree data collected in south central Oregon. Since tree stockability and diameter growth react to both edaphic and climatic conditions, caution is extended to users in other parts of the west.
Effects of site preparation on ponderosa pine (Pinusponderosa), associated vegetation, and soil properties in south central Oregon
Authors: Ross Darrell W. , Scott William , Heninger Ronald L. , Walstad John D.
Published: February 2008

Eight years after installation, six site preparation treatments were compared for effects on soil chemical and physical properties, nonconiferous vegetation, and the survival and growth of planted ponderosa pine (Pinusponderosa Laws.). Treatments included a logged-only control, ripping, brush blading, disking, chemical spraying (herbicide), and chemical spraying followed by disking. The brush-blade and chemical–disk treatments showed the greatest reduction in nutrient levels (total N, S, and C, and extractable P) compared with the control within the lower zone of soil sampled (15–25 cm depth). The chemical-only and disk-only treatments resulted in smaller decreases in nutrient levels, while ripping appeared to have only minor effects on soil chemical properties. Similar trends were noted in the upper soil zone (0–10 cm), although the differences were not statistically significant. Brush blading and both disking operations increased soil bulk density in the upper soil zone, but not in the lower soil zone. Aboveground biomass of shrubs was highest on the control treatment, followed by the rip, disk, brush-blade, chemical, and chemical–disk treatments. Pine survival was 78% or better for all treatments except the rip and control. The chemical–disk and chemical treatments resulted in the best height growth, followed by the disk, brush-blade, rip, and control treatments. A strong negative correlation existed between the amount of brush and pine biomass after 8 years. This study illustrates the importance of weed control to achieve maximum survival and early growth of planted pines in south central Oregon.
Detection of seed-borne Sirococcusstrobilinus with monoclonal antibodies in an enzyme-linked immunosorbent assay
Authors: Mitchell Leslie Ann , Sutherland Jack R.
Published: February 2008

A quantitative indirect enzyme-linked immunosorbent assay (ELISA) employing Sirococcusstrobilinus specific monoclonal antibodies has been developed for use in screening spruce (Picea spp.) seed extracts for this seed-bome fungal pathogen. The ELISA, which is one of the first applications of monoclonal antibodies in immunodetection of conifer fungi, offers several advantages over the currently used "detection by plating" technique for seed-bome pathogens. It is sensitive, detecting less than 25 ng of fungal protein, specific, and is not subject to interference from saprobes. The ELISA is also rapid, giving results within 24 h, and is relatively easy to perform, allowing simultaneous screening of up to 96 seed lots in a single microassay plate.