bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Hemin and Carbon Monoxide Releasing Molecule (CORM-3) on cGMP in Rat Penile Tissue
Authors: Abdel Aziz M. Talaat , El-Asmar M. Farid , Mostafa Taymour , Atta Hazem , Fouad Hanan H. , Roshdy Nagwa K. , Rashed Laila A. , Obaia Eman A. , Sabry Dina A. , Abdel Aziz Ahmed T. , Drummond George , Olszanecki Rafal
Published: August 2010

Introduction

Cyclic guanosine monophosphate (cGMP) levels can be regulated by heme oxygenase-1 and 2 (HO-1 and HO-2)-derived carbon monoxide (CO).

Aims

Assessment of the effect of upregulating CO in rat corpora cavernosa (CC) on cavernous cGMP.

Methods

Three experimental groups were studied: first group (N=40), short-term HO induction over 2 weeks by injection of intraperitoneal increasing doses of hemin; the second group (N=40) was subjected to intracavernosal injection of CO donor, CORM-3, or its inactive form (iCORM-3) over 2 weeks; the third group (N=60) was subdivided into three subgroups: the first one received a combined hemin and CORM-3, the second one received hemin and its inhibitor stannus mesoporphyrin (SnMP), and third one received a combined hemin, CORM-3, and SnMP.

Main Outcome Measures

In CC, HO-1 and HO-2 gene expression, Northern blot and Western blot, cGMP levels, and HO enzyme activity.

Results

In the first group, maximum induction of HO-1 gene expression, HO enzyme activity, and cGMP occurred with 4-mg hemin dose with a successive increase over 2 weeks. In the second group, CORM-3 increased cGMP by twofold compared with iCORM-3, and also increased HO-1 protein. In the third group, SnMP inhibited the enhancing effect of CORM-3 and HO on erectile signaling molecules; i.e., HO-1 gene, enzyme activity, and cGMP.

Conclusions

CORM-3- or hemin-mediated CO release could increase cavernous tissue cGMP.
Interrelations between the Microbiotas in the Litter and in the Intestines of Commercial Broiler Chickens
Authors: Cressman Michael D. , Yu Zhongtang , Nelson Michael C. , Moeller Steven J. , Lilburn Michael S. , Zerby Henry N.
Published: August 2010

The intestinal microbiota of broiler chickens and the microbiota in the litter have been well studied, but the interactions between these two microbiotas remain to be determined. Therefore, we examined their reciprocal effects by analyzing the intestinal microbiotas of broilers reared on fresh pine shavings versus reused litter, as well as the litter microbiota over a 6-week cycle. Composite ileal mucosal and cecal luminal samples from birds (
n
= 10) reared with both litter conditions (fresh versus reused) were collected at 7, 14, 21, and 42 days of age. Litter samples were also collected at days 7, 14, 21, and 42. The microbiotas were profiled and compared within sample types based on litter condition using PCR and denaturing gradient gel electrophoresis (PCR-DGGE). The microbiotas were further analyzed using 16S rRNA gene clone libraries constructed from microbiota DNA extracted from both chick intestinal and litter samples collected at day 7. Results showed significant reciprocal effects between the microbiotas present in the litter and those in the intestines of broilers. Fresh litter had more environmental bacteria, while reused litter contained more bacteria of intestinal origin.
Lactobacillus
spp. dominated the ileal mucosal microbiota of fresh-litter chicks, while a group of bacteria yet to be classified within
Clostridiales
dominated in the ileal mucosal microbiota in the reused-litter chicks. The Litter condition (fresh versus reused) seemed to have a more profound impact on the ileal microbiota than on the cecal microbiota. The data suggest that the influence of fresh litter on ileal microbiota decreased as broilers grew, compared with temporal changes observed under reused-litter rearing conditions.
Glutamate Decarboxylase-Mediated Nisin Resistance in
Listeria monocytogenes
Authors: Begley Máire , Cotter Paul D. , Hill Colin , Ross R. Paul
Published: August 2010

Analysis of a complete set of glutamate decarboxylase (
gad
) mutants of
Listeria monocytogenes
strain LO28 (Δ
gadD1
, Δ
gadDT1
, Δ
gadD2
, Δ
gadT2
, and Δ
gadD3
mutants) revealed that the Δ
gadD1
mutant is impaired in its ability to tolerate exposure to both sublethal and lethal levels of the lantibiotic nisin.
gadD1
is strain variable and is found only in approximately 50% of
L. monocytogenes
strains. Growth and survival experiments revealed that possession of
gadD1
correlates with a higher degree of tolerance to nisin. Significantly, a similar finding using a
gadB
mutant of
L. lactis
IL1403 implies that this may be a general phenomenon in Gram-positive bacteria. Our findings thus suggest that the specific inhibition of GAD activity or a reduction in the levels of free glutamate may prevent the growth of otherwise resistant GAD
+
bacteria in foods where low pH and/or nisin is used as a preservative.
Heterologous Expression and Extracellular Secretion of Cellulolytic Enzymes byZymomonas mobilis
Authors: Linger Jeffrey G. , Adney William S. , Darzins Al
Published: August 2010

Development of the strategy known as consolidated bioprocessing (CBP) involves the use of a single microorganism to convert pretreated lignocellulosic biomass to ethanol through the simultaneous production of saccharolytic enzymes and fermentation of the liberated monomeric sugars. In this report, the initial steps toward achieving this goal in the fermentation hostZymomonas mobiliswere investigated by expressing heterologous cellulases and subsequently examining the potential to secrete these cellulases extracellularly. Numerous strains ofZ. mobiliswere found to possess endogenous extracellular activities against carboxymethyl cellulose, suggesting that this microorganism may harbor a favorable environment for the production of additional cellulolytic enzymes. The heterologous expression of two cellulolytic enzymes, E1 and GH12 fromAcidothermus cellulolyticus, was examined. Both proteins were successfully expressed as soluble, active enzymes inZ. mobilisalthough to different levels. While the E1 enzyme was less abundantly expressed, the GH12 enzyme comprised as much as 4.6% of the total cell protein. Additionally, fusing predicted secretion signals native toZ. mobilisto the N termini of E1 and GH12 was found to direct the extracellular secretion of significant levels of active E1 and GH12 enzymes. The subcellular localization of the intracellular pools of cellulases revealed that a significant portion of both the E1 and GH12 secretion constructs resided in the periplasmic space. Our results strongly suggest thatZ. mobilisis capable of supporting the expression and secretion of high levels of cellulases relevant to biofuel production, thereby serving as a foundation for developingZ. mobilisinto a CBP platform organism.
Endopeptidase Activities of Botulinum Neurotoxin Type B Complex, Holotoxin, and Light Chain
Authors: Wang Hai-Hong , Riding Stephen , Lindo Paul , Singh Bal Ram
Published: August 2010

Botulinum neurotoxin (BoNT) serotype B (BoNT/B) is one of the serotypes of BoNT that causes deadly human botulism, though it is used clinically for treatment of many neuromuscular diseases. BoNT/B is produced by
Clostridium botulinum
, and it is secreted along with a group of neurotoxin-associated proteins (NAPs) in the form of a BoNT/B complex. The complex dissociates into a 150-kDa holotoxin and NAPs at alkaline pHs. The 150-kDa BoNT/B holotoxin can be nicked to produce a 50-kDa domain referred to as the light chain (LC) and a 100-kDa heavy chain, with the former possessing a unique endopeptidase activity. The two chains remain linked through a disulfide bond that can be reduced to separate the two chains. The endopeptidase activity is present in all three forms of the toxin (complex, purified BoNT/B holotoxin, and separated light chain), which are used by different researchers to develop detection methods and screen for inhibitors. In this research, the endopeptidase activities of the three forms, for the first time, were compared under the same conditions. The results show that enzyme activities of the three forms differ significantly and are largely dependent on nicking and disulfide reduction conditions. Under the conditions used, LC had the highest level of activity, and the complex had the lowest. The activity was enhanced by nicking of BoNT/B holotoxin and was enhanced even more by dithiothreitol (DTT) reduction after nicking. This information is useful for understanding the properties of BoNT endopeptidases and for comparing the efficacies of different inhibitors when they are tested with different forms of BoNT endopeptidase.
Evaluating the Growth Potential of Pathogenic Bacteria in Water
Authors: Vital Marius , Stucki David , Egli Thomas , Hammes Frederik
Published: August 2010

The degree to which a water sample can potentially support the growth of human pathogens was evaluated. For this purpose, a pathogen growth potential (PGP) bioassay was developed based on the principles of conventional assimilable organic carbon (AOC) determination, but using pure cultures of selected pathogenic bacteria (
Escherichia coli
O157,
Vibrio cholerae
, or
Pseudomonas aeruginosa
) as the inoculum. We evaluated 19 water samples collected after different treatment steps from two drinking water production plants and a wastewater treatment plant and from ozone-treated river water. Each pathogen was batch grown to stationary phase in sterile water samples, and the concentration of cells produced was measured using flow cytometry. In addition, the fraction of AOC consumed by each pathogen was estimated. Pathogen growth did not correlate with dissolved organic carbon (DOC) concentration and correlated only weakly with the concentration of AOC. Furthermore, the three pathogens never grew to the same final concentration in any water sample, and the relative ratio of the cultures to each other was unique in each sample. These results suggest that the extent of pathogen growth is affected not only by the concentration but also by the composition of AOC. Through this bioassay, PGP can be included as a parameter in water treatment system design, control, and operation. Additionally, a multilevel concept that integrates the results from the bioassay into the bigger framework of pathogen growth in water is discussed. The proposed approach provides a first step for including pathogen growth into microbial risk assessment.
Influence of the Diversity of Bacterial Isolates from Drinking Water on Resistance of Biofilms to Disinfection
Authors: Simões Lúcia Chaves , Simões Manuel , Vieira Maria João
Published: August 2010

Single- and multispecies biofilms formed by six drinking water-isolated bacterial species were used to assess their susceptibilities to sodium hypochlorite (SHC). In general, multispecies biofilms were more resistant to inactivation and removal than single biofilms. Total biofilm inactivation was achieved only for
Acinetobacter calcoaceticus
single-species biofilms and for those multispecies biofilms without
A. calcoaceticus
. Biofilms with all bacteria had the highest resistance to SHC, while those without
A. calcoaceticus
were the most susceptible.
A. calcoaceticus
formed single biofilms susceptible to SHC; however, its presence in multispecies biofilms increased their resistance to disinfection.
Mutation of High-Affinity Methionine Permease Contributes to Selenomethionyl Protein Production in
Saccharomyces cerevisiae
Authors: Kitajima Toshihiko , Chiba Yasunori , Jigami Yoshifumi
Published: August 2010

The production of selenomethionine (SeMet) derivatives of recombinant proteins allows phase determination by single-wavelength or multiwavelength anomalous dispersion phasing in X-ray crystallography, and this popular approach has permitted the crystal structures of numerous proteins to be determined. Although yeast is an ideal host for the production of large amounts of eukaryotic proteins that require posttranslational modification, the toxic effects of SeMet often interfere with the preparation of protein derivatives containing this compound. We previously isolated a mutant strain (SMR-94) of the methylotrophic yeast
Pichia pastoris
that is resistant to both SeMet and selenate and demonstrated its applicability for the production of proteins suitable for X-ray crystallographic analysis. However, the molecular basis for resistance to SeMet by the SMR-94 strain remains unclear. Here, we report the characterization of SeMet-resistant mutants of
Saccharomyces cerevisiae
and the identification of a mutant allele of the
MUP1
gene encoding high-affinity methionine permease, which confers SeMet resistance. Although the total methionine uptake by the
mup1
mutant (the SRY5-7 strain) decreased to 47% of the wild-type level, it was able to incorporate SeMet into the overexpressed epidermal growth factor peptide with 73% occupancy, indicating the importance of the moderate uptake of SeMet by amino acid permeases other than Mup1p for the alleviation of SeMet toxicity. In addition, under standard culture conditions, the
mup1
mutant showed higher productivity of the SeMet derivative relative to other SeMet-resistant mutants. Based on these results, we conclude that the
mup1
mutant would be useful for the preparation of selenomethionyl proteins for X-ray crystallography.
Anaerobic Biotransformation of High Concentrations of Chloroform by an Enrichment Culture and Two Bacterial Isolates
Authors: Shan Huifeng , Kurtz Harry D. , Mykytczuk Nadia , Trevors Jack T. , Freedman David L.
Published: August 2010

A fermentative enrichment culture (designated DHM-1) was developed that is capable of cometabolically biotransforming high concentrations of chloroform (CF) to nontoxic end products. Two
Pantoea
spp. were isolated from DHM-1 that also possess this dechlorination capability. Following acclimation to increasing levels of CF, corn syrup-grown DHM-1 was able to transform over 500 mg/liter CF in the presence of vitamin B
12
(approximately 3% of CF on a molar basis) at a rate as high as 22 mg/liter/day in a mineral salts medium. CO, CO
2
, and organic acids were the predominant biodegradation products, suggesting that hydrolytic reactions predominate during CF transformation. DHM-1 was capable of growing on corn syrup in the presence of high concentrations of CF (as may be present near contaminant source zones in groundwater), which makes it a promising culture for bioaugmentation. Strains DHM-1B and DHM-1T transform CF at rates similar to that of the DHM-1 enrichment culture. The ability of these strains to grow in the presence of high concentrations of CF appears to be related to alteration of membrane fluidity or homeoviscous and homeophasic adaptation.
Development of
pyrF-
Based Genetic System for Targeted Gene Deletion in
Clostridium thermocellum
and Creation of a
pta
Mutant
Authors: Tripathi Shital A. , Olson Daniel G. , Argyros D. Aaron , Miller Bethany B. , Barrett Trisha F. , Murphy Daniel M. , McCool Jesse D. , Warner Anne K. , Rajgarhia Vineet B. , Lynd Lee R. , Hogsett David A. , Caiazza Nicky C.
Published: August 2010

We report development of a genetic system for making targeted gene knockouts in
Clostridium thermocellum
, a thermophilic anaerobic bacterium that rapidly solubilizes cellulose. A toxic uracil analog, 5-fluoroorotic acid (5-FOA), was used to select for deletion of the
pyrF
gene. The Δ
pyrF
strain is a uracil auxotroph that could be restored to a prototroph via ectopic expression of
pyrF
from a plasmid, providing a positive genetic selection. Furthermore, 5-FOA was used to select against plasmid-expressed
pyrF
, creating a negative selection for plasmid loss. This technology was used to delete a gene involved in organic acid production, namely
pta
, which encodes the enzyme phosphotransacetylase. The
C. thermocellum
Δ
pta
strain did not produce acetate. These results are the first examples of targeted homologous recombination and metabolic engineering in
C. thermocellum
, a microbe that holds an exciting and promising future in the biofuel industry and development of sustainable energy resources.
Quantification of Enteric Viruses, Pathogen Indicators, and
Salmonella
Bacteria in Class B Anaerobically Digested Biosolids by Culture and Molecular Methods
Authors: Wong Kelvin , Onan Brandon M. , Xagoraraki Irene
Published: August 2010

The most common class B biosolids in the United States are generated by mesophilic anaerobic digestion (MAD), and MAD biosolids have been used for land application. However, the pathogen levels in MAD biosolids are still unclear, especially with respect to enteric viruses. In this study, we determined the occurrence and the quantitative levels of enteric viruses and indicators in 12 MAD biosolid samples and of
Salmonella enterica
in 6 MAD biosolid samples. Three dewatered biosolid samples were also included in this study for purposes of comparison. Human adenoviruses (HAdV) had the highest gene levels and were detected more frequently than other enteric viruses. The gene levels of noroviruses (NV) reported were comparable to those of enteroviruses (EV) and human polyomaviruses (HPyV). The occurrence percentages of HAdV, HAdV species F, EV, NV GI, NV GII, and HPyV in MAD samples were 83, 83, 42, 50, 75, and 58%, respectively. No hepatitis A virus was detected. Infectious HAdV was detected more frequently than infectious EV, and all infectious HAdV were detected when samples were propagated in A549 cells. Based on most-probable-number (MPN) analysis, A549 cells were more susceptible to biosolid-associated viruses than BGM cells. All indicator levels in MAD biosolids were approximately 10
4
MPN or PFU per gram (dry), and the dewatered biosolids had significantly higher indicator levels than the MAD biosolids. Only two MAD samples tested positive for
Salmonella enterica
, where the concentration was below 1.0 MPN/4 g. This study provides a broad comparison of the prevalence of different enteric viruses in MAD biosolids and reports the first detection of noroviruses in class B biosolids. The observed high quantitative and infectivity levels of adenoviruses in MAD biosolids indicate that adenovirus is a good indicator for the evaluation of sludge treatment efficiency.
The N Terminus of Phosphodiesterase TbrPDEB1 of Trypanosoma brucei Contains the Signal for Integration into the Flagellar Skeleton
Authors: Luginbuehl Edith , Ryter Damaris , Schranz-Zumkehr Judith , Oberholzer Michael , Kunz Stefan , Seebeck Thomas
Published: August 2010

The precise subcellular localization of the components of the cyclic AMP (cAMP) signaling pathways is a crucial aspect of eukaryotic intracellular signaling. In the human pathogen
Trypanosoma brucei
, the strict control of cAMP levels by cAMP-specific phosphodiesterases is essential for parasite survival, both in cell culture and in the infected host. Among the five cyclic nucleotide phosphodiesterases identified in this organism, two closely related isoenzymes,
T. brucei
PDEB1 (TbrPDEB1) (PDEB1) and TbrPDEB2 (PDEB2) are predominantly responsible for the maintenance of cAMP levels. Despite their close sequence similarity, they are distinctly localized in the cell. PDEB1 is mostly located in the flagellum, where it forms an integral part of the flagellar skeleton. PDEB2 is mainly located in the cell body, and only a minor part of the protein localizes to the flagellum. The current study, using transfection of procyclic trypanosomes with green fluorescent protein (GFP) reporters, demonstrates that the N termini of the two enzymes are essential for determining their final subcellular localization. The first 70 amino acids of PDEB1 are sufficient to specifically direct a GFP reporter to the flagellum and to lead to its detergent-resistant integration into the flagellar skeleton. In contrast, the analogous region of PDEB2 causes the GFP reporter to reside predominantly in the cell body. Mutagenesis of selected residues in the N-terminal region of PDEB2 demonstrated that single amino acid changes are sufficient to redirect the reporter from a cell body location to stable integration into the flagellar skeleton.
Endocytic Machinery Protein SlaB Is Dispensable for Polarity Establishment but Necessary for Polarity Maintenance in Hyphal Tip Cells of Aspergillus nidulans
Authors: Hervás-Aguilar América , Peñalva Miguel A.
Published: August 2010

TheAspergillus nidulansendocytic internalization protein SlaB is essential, in agreement with the key role in apical extension attributed to endocytosis. We constructed, by gene replacement, a nitrate-inducible, ammonium-repressibleslaB1allele for conditional SlaB expression. Video microscopy showed that repressedslaB1cells are able to establish but unable to maintain a stable polarity axis, arresting growth with budding-yeast-like morphology shortly after initially normal germ tube emergence. Using green fluorescent protein (GFP)-tagged secretory v-SNARE SynA, which continuously recycles to the plasma membrane after being efficiently endocytosed, we establish that SlaB is crucial for endocytosis, although it is dispensable for the anterograde traffic of SynA and of the t-SNARE Pep12 to the plasma and vacuolar membrane, respectively. By confocal microscopy, repressedslaB1germlings show deep plasma membrane invaginations. Ammonium-to-nitrate medium shift experiments demonstrated reversibility of the null polarity maintenance phenotype and correlation of normal apical extension with resumption of SynA endocytosis. In contrast, SlaB downregulation in hyphae that had progressed far beyond germ tube emergence led to marked polarity maintenance defects correlating with deficient SynA endocytosis. Thus, the strict correlation between abolishment of endocytosis and disability of polarity maintenance that we report here supports the view that hyphal growth requires coupling of secretion and endocytosis. However, downregulatedslaB1cells form F-actin clumps containing the actin-binding protein AbpA, and thus F-actin misregulation cannot be completely disregarded as a possible contributor to defective apical extension. Latrunculin B treatment of SlaB-downregulated tips reduced the formation of AbpA clumps without promoting growth and revealed the formation of cortical “comets” of AbpA.
Conserved Motifs Involved in ATP Hydrolysis by MalT, a Signal Transduction ATPase with Numerous Domains fromEscherichia coli
Authors: Marquenet Emélie , Richet Evelyne
Published: August 2010

The signal transduction ATPases with numerous domains (STAND) are sophisticated signaling proteins that are related to AAA+proteins and control various biological processes, including apoptosis, gene expression, and innate immunity. They function as tightly regulated switches, with the off and on positions corresponding to an ADP-bound, monomeric form and an ATP-bound, multimeric form, respectively. Protein activation is triggered by inducer binding to the sensor domain. ATP hydrolysis by the nucleotide-binding oligomerization domain (NOD) ensures the generation of the ADP-bound form. Here, we use MalT, anEscherichia colitranscription activator, as a model system to identify STAND conserved motifs involved in ATP hydrolysis besides the catalytic acidic residue. Alanine substitution of the conserved polar residue (H131) that is located two residues downstream from the catalytic residue (D129) blocks ATP hydrolysis and traps MalT in an active, ATP-bound, multimeric form. This polar residue is also conserved in AAA+. Based on AAA+X-ray structures, we proposed that it is responsible for the proper positioning of the catalytic and the sensor I residues for the hydrolytic attack. Alanine substitution of the putative STAND sensor I (R160) abolished MalT activity. Substitutions of R171 impaired both ATP hydrolysis and multimerization, which is consistent with an arginine finger function and provides further evidence that ATP hydrolysis is primarily catalyzed by MalT multimers.
Actin-Based Motility of
Burkholderia thailandensis
Requires a Central Acidic Domain of BimA That Recruits and Activates the Cellular Arp2/3 Complex
Authors: Sitthidet Chayada , Stevens Joanne M. , Field Terence R. , Layton Abigail N. , Korbsrisate Sunee , Stevens Mark P.
Published: August 2010

Burkholderia
species use BimA for intracellular actin-based motility. Uniquely,
Burkholderia thailandensis
BimA harbors a central and acidic (CA) domain. The CA domain was required for actin-based motility, binding to the cellular Arp2/3 complex, and Arp2/3-dependent polymerization of actin monomers. Our data reveal distinct strategies for actin-based motility among
Burkholderia
species.
Postconditioning effect of granulocyte colony-stimulating factor is mediated through activation of risk pathway and opening of the mitochondrial KATP channels
Authors: Sumi Shohei , Kobayashi Hiroyuki , Yasuda Shinji , Iwasa Masamitsu , Yamaki Takahiko , Yamada Yoshihisa , Ushikoshi Hiroaki , Hattori Arihiro , Aoyama Takuma , Nishigaki Kazuhiko , Takemura Genzou , Minatoguchi Shinya
Published: August 2010

Granulocyte colony-stimulating factor (G-CSF) has been reported to improve cardiac function after myocardial infarction. However, whether postinfarct acute effect of G-CSF is mediated through the same signaling pathways as those of ischemic postconditioning is still unclear. We examined the postinfarct acute effect of G-CSF on myocardial infarct size and its precise molecular mechanism. Japanese white rabbits underwent 30 min of ischemia and 48 h of reperfusion. Rabbits were intravenously injected 10 μg/kg of G-CSF (G-CSF group) or saline (control group) immediately after reperfusion. The wortmannin + G-CSF, PD-98059 + G-CSF, Nω-nitro-l-arginine methyl ester (l-NAME) + G-CSF, and 5-hydroxydecanoic acid sodium salt (5-HD) + G-CSF groups were respectively injected with wortmannin (0.6 mg/kg), PD-98059 (0.3 mg/kg), l-NAME (10 mg/kg), and 5-HD (5 mg/kg) 5 min before G-CSF administration. Myocardial infarct size was calculated as a percentage of the risk area of the left ventricle. Western blot analysis was performed to examine the signals such as protein kinase B (Akt), extracellular signal-regulated protein kinase (ERK), eNOS, p70S6 kinase (p70S6K), and glycogen synthase kinase-3β (GSK3β) in the ischemic myocardium after 48 h of reperfusion. The infarct size was significantly smaller in the G-CSF group (26.7 ± 2.7%) than in the control group (42.3 ± 4.6%). The infarct size-reducing effect of G-CSF was completely blocked by wortmannin (44.7 ± 4.8%), PD-98059 (38.3 ± 3.9%), l-NAME (42.1 ± 4.2%), and 5-HD (42.5 ± 1.7%). Wortmannin, PD-98059, l-NAME, or 5-HD alone did not affect the infarct size. Western blotting showed higher myocardial expression of phospho-Akt, phospho-ERK, phosho-eNOS, phosho-p70S6K, and phosho-GSK3β at 10 min and 48 h after reperfusion in the G-CSF group than in the control group. In conclusion, postreperfusion G-CSF administration reduces myocardial infarct size via activation of phosphatidylinositol 3-kinase-Akt and ERK prosurvival signaling pathways and their downstream targets eNOS, p70S6 kinase, GSK3β, and mitochondrial ATP-dependent K+ channel.
Insufficient cutaneous vasoconstriction leading up to and during syncopal symptoms in the heat stressed human
Authors: Crandall C. G. , Shibasaki M. , Wilson T. E.
Published: August 2010

As much as 50% of cardiac output can be distributed to the skin in the hyperthermic human, and therefore the control of cutaneous vascular conductance (CVC) becomes critical for the maintenance of blood pressure. Little is known regarding the magnitude of cutaneous vasoconstriction in profoundly hypotensive individuals while heat stressed. This project investigated the hypothesis that leading up to and during syncopal symptoms associated with combined heat and orthostatic stress, reductions in CVC are inadequate to prevent syncope. Using a retrospective study design, we evaluated data from subjects who experienced syncopal symptoms during lower body negative pressure ( N = 41) and head-up tilt ( N = 5). Subjects were instrumented for measures of internal temperature, forearm skin blood flow, arterial pressure, and heart rate. CVC was calculated as skin blood flow/mean arterial pressure × 100. Data were obtained while subjects were normothermic, immediately before an orthostatic challenge while heat stressed, and at 5-s averages for the 2 min preceding the cessation of the orthostatic challenge due to syncopal symptoms. Whole body heat stress increased internal temperature (1.25 ± 0.3°C; P < 0.001) and CVC (29 ± 20 to 160 ± 58 CVC units; P < 0.001) without altering mean arterial pressure (83 ± 7 to 82 ± 6 mmHg). Mean arterial pressure was reduced to 57 ± 9 mmHg ( P < 0.001) immediately before the termination of the orthostatic challenge. At test termination, CVC decreased to 138 ± 61 CVC units ( P < 0.001) relative to before the orthostatic challenge but remained approximately fourfold greater than when subjects were normothermic. This negligible reduction in CVC during pronounced hypotension likely contributes to reduced orthostatic tolerance in heat-stressed humans. Given that lower body negative pressure and head-up tilt are models of acute hemorrhage, these findings have important implications with respect to mechanisms of compromised blood pressure control in the hemorrhagic individual who is also hyperthermic (e.g., military personnel, firefighters, etc.).
Sildenafil added to sitaxsentan in overcirculation-induced pulmonary arterial hypertension
Authors: Rondelet Benoit , Dewachter Laurence , Kerbaul François , Dewachter Céline , Hubloue Ives , Fesler Pierre , Franck Stephane , Remmelink Myriam , Brimioulle Serge , Naeije Robert
Published: August 2010

Experimental left-to-right shunt-induced pulmonary arterial hypertension (PAH) can be partially prevented by the endothelin-A receptor blocker sitaxsentan or by the phosphodiesterase-5 inhibitor sildenafil. We hypothesized that the combined administration of these drugs would completely prevent shunt-induced PAH, arguing in favor of a major role of endothelial dysfunction in the initiation of the disease. Twenty-four 3-wk-old piglets were randomized to a sham operation or to placebo, sitaxsentan therapy, or sitaxsentan combined with sildenafil after the anastomosis of the left subclavian artery to the pulmonary arterial trunk. Three months later, the animals underwent a hemodynamic evaluation, followed by pulmonary tissue sampling for morphometry and quantitative real-time PCR for endothelin-1, angiopoietin-1, and bone morphogenetic protein receptor (BMPR) signaling molecules. Three months of left-to-right shunting induced an increase in pulmonary vascular resistance (PVR) and medial thickness, an overexpression of endothelin-1, and angiopoietin-1 and decreased expressions of BMPR-2 and BMPR-1A. Sitaxsentan partially prevented a shunt-induced increase in PVR, medial thickness, and associated biological disturbances. Sildenafil combined with sitaxsentan normalized PVR, medial thickness, and the expression of endothelin-1. However, the expression of angiopoietin-1 remained increased, and the expressions of BMPR-1A and BMPR-2 were incompletely returned to normal. The coupling of right ventricular end-systolic to arterial elastances was maintained in all circumstances. Sitaxsentan combined with sildenafil prevents shunt-induced PAH more effectively than sitaxsentan alone, suggesting a major role for the targeted signaling pathways in the initiation of the disease. Sitaxsentan alone or combined with sildenafil did not affect right ventricular function.
Interleukin-18 induces EMMPRIN expression in primary cardiomyocytes via JNK/Sp1 signaling and MMP-9 in part via EMMPRIN and through AP-1 and NF-κB activation
Authors: Reddy Venkatapuram Seenu , Prabhu Sumanth D. , Mummidi Srinivas , Valente Anthony J. , Venkatesan Balachandar , Shanmugam Prakashsrinivasan , Delafontaine Patrice , Chandrasekar Bysani
Published: August 2010

IL-18 and the extracellular matrix metalloproteinase (MMP) inducer (EMMPRIN) stimulate the expression of proinflammatory cytokines and MMPs and are elevated in myocardial hypertrophy, remodeling, and failure. Here, we report several novel findings in primary cardiomyocytes treated with IL-18. First, IL-18 activated multiple transcription factors, including NF-κB (p50 and p65), activator protein (AP)-1 (cFos, cJun, and JunD), GATA, CCAAT/enhancer-binding protein, myocyte-specific enhancer-binding factor, interferon regulatory factor-1, p53, and specific protein (Sp)-1. Second, IL-18 induced EMMPRIN expression via myeloid differentiation primary response gene 88/IL-1 receptor-associated kinase/TNF receptor-associated factor-6/JNK-dependent Sp1 activation. Third, IL-18 induced a number of MMP genes, particularly MMP-9, at a rapid rate as well as tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-3 at a slower rate. Finally, the IL-18 induction of MMP-9 was mediated in part via EMMPRIN and through JNK- and ERK-dependent AP-1 activation and p38 MAPK-dependent NF-κB activation. These results suggest that the elevated expression of IL-18 during myocardial injury and inflammation may favor EMMPRIN and MMP induction and extracellular matrix degradation. Therefore, targeting IL-18 or its signaling pathways may be of potential therapeutic benefit in adverse remodeling.
Expression of store-operated Ca2+entry and transient receptor potential canonical and vanilloid-related proteins in rat distal pulmonary venous smooth muscle
Authors: Peng Gongyong , Lu Wenju , Li Xiaoyan , Chen Yuqin , Zhong Nanshan , Ran Pixin , Wang Jian
Published: August 2010

Chronic hypoxia causes remodeling and alters contractile responses in both pulmonary arteries and pulmonary veins. Although pulmonary arteries have been studied extensively in these disorders, the mechanisms by which pulmonary veins respond to hypoxia and whether these responses contribute to chronic hypoxic pulmonary hypertension remain poorly understood. In pulmonary arterial smooth muscle, we have previously demonstrated that influx of Ca2+through store-operated calcium channels (SOCC) thought to be composed of transient receptor potential (TRP) proteins is likely to play an important role in development of chronic hypoxic pulmonary hypertension. To determine whether this mechanism could also be operative in pulmonary venous smooth muscle, we measured intracellular Ca2+concentration ([Ca2+]i) by fura-2 fluorescence microscopy in primary cultures of pulmonary venous smooth muscle cells (PVSMC) isolated from rat distal pulmonary veins. In cells perfused with Ca2+-free media containing cyclopiazonic acid (10 μM) and nifedipine (5 μM) to deplete sarcoplasmic reticulum Ca2+stores and block voltage-dependent Ca2+channels, restoration of extracellular Ca2+(2.5 mM) caused marked increases in [Ca2+]i, whereas MnCl2(200 μM) quenched fura-2 fluorescence, indicating store-operated Ca2+entry (SOCE). SKF-96365 and NiCl2, antagonists of SOCC, blocked SOCE at concentrations that did not alter Ca2+responses to 60 mM KCl. Of the seven known canonical TRP (TRPC1–7) and six vanilloid-related TRP channels (TRPV1–6), real-time PCR revealed mRNA expression of TRPC1 > TRPC6 > TRPC4 > TRPC2 ≈ TRPC5 > TRPC3, TRPV2 > TRPV4 > TRPV1 in distal PVSMC, and TRPC1 > TRPC6 > TRPC3 > TRPC4 ≈ TRPC5, TRPV2 ≈ TRPV4 > TRPV1 in rat distal pulmonary vein (PV) smooth muscle. Western blotting confirmed protein expression of TRPC1, TRPC6, TRPV2, and TRPV4 in both PVSMC and PV. Our results suggest that SOCE through Ca2+channels composed of TRP proteins may contribute to Ca2+signaling in rat distal PV smooth muscle.
A new role for bicarbonate in mucus formation
Authors: Chen Eric Y. T. , Yang Ning , Quinton Paul M. , Chin Wei-Chun
Published: August 2010

The impact of small anions on the physical properties of gel-forming mucin has been almost overlooked relative to that of cations. Recently, based on the coincident abnormalities in HCO3−secretion and abnormal mucus formed in the hereditary disease cystic fibrosis (CF), HCO3−was hypothesized to be critical in the formation of normal mucus by virtue of its ability to sequester Ca2+from condensed mucins being discharged from cells. However, direct evidence of the impact of HCO3−on mucus properties is lacking. Herein, we demonstrate for the first time that mucin diffusivity (∼1/viscosity) increases as a function of [HCO3−]. Direct measurements of exocytosed mucin-swelling kinetics from airway cells showed that mucin diffusivity increases by ∼300% with 20 mM extracellular HCO3−concentration. Supporting data indicate that HCO3−reduces free Ca2+concentration and decreases the amount of Ca2+that remains associated with mucins. The results demonstrate that HCO3−enhances mucin swelling and hydration by reducing Ca2+cross-linking in mucins, thereby decreasing its viscosity and likely increasing its transportability. In addition, HCO3−can function as a Ca2+chelator like EGTA to disperse mucin aggregates. This study indicates that poor HCO3−availability in CF may explain why secreted mucus remains aggregated and more viscous in affected organs. These insights bear on not only the fundamental pathogenesis in CF, but also on the process of gel mucus formation and release in general.
MicroRNA-21 plays a role in hypoxia-mediated pulmonary artery smooth muscle cell proliferation and migration
Authors: Sarkar Joy , Gou Deming , Turaka Prasanna , Viktorova Ekaterina , Ramchandran Ramaswamy , Raj J. Usha
Published: August 2010

Hypoxia stimulates pulmonary artery smooth muscle cell (PASMC) proliferation. Recent studies have implicated an important role for microRNAs (miRNAs) in hypoxia-mediated responses in various cellular processes, including cell proliferation. In this study, we investigated the role of microRNA-21 (miR-21) in hypoxia-induced PASMC proliferation and migration. We first demonstrated that miR-21 expression increased by ∼3-fold in human PASMC after 6 h of hypoxia (3% O2) and remained high (∼2-fold) after 24 h of hypoxia. Knockdown of miR-21 with anti-miR-21 inhibitors significantly reduced hypoxia-induced cell proliferation, whereas miR-21 overexpression in normoxia enhanced cell proliferation. We also found that miR-21 is essential for hypoxia-induced cell migration. Protein expression of miR-21 target genes, specifically programmed cell death protein 4 (PDCD4), Sprouty 2 (SPRY2), and peroxisome proliferator-activated receptor-α (PPARα), was decreased in hypoxia and in PASMC overexpressing miR-21 in normoxia and increased in hypoxic cells in which miR-21 was knocked down. In addition, PPARα 3′-untranslated region (UTR) luciferase-based reporter gene assays demonstrated that PPARα is a direct target of miR-21. Taken together, our findings indicate that miR-21 plays a significant role in hypoxia-induced pulmonary vascular smooth muscle cell proliferation and migration by regulating multiple gene targets.
Personalized Medicine: Marking a New Epoch in Cancer Patient Management
Authors: Diamandis Maria , White Nicole M.A. , Yousef George M.
Published: August 2010

Personalized medicine (PM) is defined as “a form of medicine that uses information about a person's genes, proteins, and environment to prevent, diagnose, and treat disease.” The promise of PM has been on us for years. The suite of clinical applications of PM in cancer is broad, encompassing screening, diagnosis, prognosis, prediction of treatment efficacy, patient follow-up after surgery for early detection of recurrence, and the stratification of patients into cancer subgroup categories, allowing for individualized therapy. PM aims to eliminate the “one size fits all” model of medicine, which has centered on reaction to disease based on average responses to care. By dividing patients into unique cancer subgroups, treatment and follow-up can be tailored for each individual according to disease aggressiveness and the ability to respond to a certain treatment. PM is also shifting the emphasis of patient management from primary patient care to prevention and early intervention for high-risk individuals. In addition to classic single molecular markers, high-throughput approaches can be used for PM including whole genome sequencing, single-nucleotide polymorphism analysis, microarray analysis, and mass spectrometry. A common trend among these tools is their ability to analyze many targets simultaneously, thus increasing the sensitivity, specificity, and accuracy of biomarker discovery. Certain challenges need to be addressed in our transition to PM including assessment of cost, test standardization, and ethical issues. It is clear that PM will gradually continue to be incorporated into cancer patient management and will have a significant impact on our health care in the future. Mol Cancer Res; 8(9); 1175–87. ©2010 AACR.
CLOSE-IN FALLOUT
Authors: Kellogg W. W. , Rapp R. R. , Greenfield S. M.
Published: August 2010

The phenomenon of radioactive fallout from an atomic explosion is described, and a quantitative technique for determining the distribution of radioactive material on the ground is developed. The primary factors which must be considered are wind field, yield and height of burst, and particle-size distribution. Certain parameters which enter directly into a fallout determination are given quantitatively, such as the altitude and size of the atomic cloud (as a function of explosion yield and atmospheric stability) and particle fall-rates (as a function of altitude and particle size). Two hypothetical fallout patterns for a one-megaton explosion, computed on a high-speed digital computer are presented, showing the large effect which the wind has in determining the character of the fallout. The meteorological problems associated with a fallout prediction are discussed.
A STUDY OF THE RAINFALL PATTERNS AND SOME RELATED FEATURES IN A DISSIPATING HURRICANE
Authors: Gilbert Sterling C. , LaSeur N. E.
Published: August 2010

A detailed investigation of the hourly rainfall patterns accompanying a dissipating hurricane over the southeastern United States demonstrates the pronounced asymmetry in the decay of release of latent heat, the primary energy source of the storm. This appears to be associated with the incorporation into the storm circulation of dry air in the layer from 800 to 400 millibars. This air is first drawn in from the outer portions of the left-front quadrant, then sweeps rapidly around thestorm into the right-rearand right-front quadrants.
ON THE STANDARD VECTOR-DEVIATION WIND ROSE
Authors: Crutcher Harold L.
Published: August 2010

Wind-data presentations are varied. Some serve one purpose better than another. A relatively new type of wind rose is presented in order that its potential may be exploited. This is the standard vector-deviation wind rose. It is an easily reproduced rose and may be constructed from values of the vector mean wind, standard deviations of the latitudinal and meridional wind components, and the correlation between the components. If the distribution is circular, rather than elliptical, only the vector mean and the standard vector deviation are needed. Methods to test for ellipticity and to construct the roses are given.
A PRELIMINARY ANALYSIS OF ATMOSPHERIC DENSITIES FROM METEOR DECELERATIONS FOR SOLAR, LUNAR AND YEARLY OSCILLATIONS
Authors: Jacchia Luigi G.
Published: August 2010

Upper-atmosphere densities derived from photographic meteor decelerations were analyzed to probe the existence of detectable oscillations with periods corresponding to solar and lunar tides (and half-periods) and seasonal variations. Extensive fragmentation in meteors adds considerable difficulty to the analysis and makes empirical corrections necessary. The mean height of the analyzed meteors is 91.8 kilometers. A seasonal variation with an amplitude of 15 per cent of the mean density barely emerges from its probable error by a factor of two; tidal oscillations, if present, are masked by observational scatter and could not exceed 10 per cent of the mean density.
AN APPROACH TO QUANTITATIVE PRECIPITATION FORECASTING
Authors: Estoque M. A.
Published: August 2010

A quantitative method of predicting precipitation due to large-scale vertical motions is described. A two-level prediction model is applied at the 1000- and 500-millibar pressure levels. Solutions are obtained by graphical procedure which enables one to obtain a 24-hour forecast in about two hours for an area comparable to the size of the North American continent. Tests on ten cases of major cyclone developments show some success.
MEASUREMENTS OF CLOUD DROP-SIZE DISTRIBUTIONS
Authors: Eldridge Ralph G.
Published: August 2010

Through the analysis of infrared transmittance of a natural cloud, its drop-size distribution can be inferred. This technique has been used to measure and analyze ten cloud situations on Mount Washington. These clouds show drop-size distributions that are bimodal in character. In all the distributions, a large number of small droplets is inferred. To test the synthesized distributions in another region of the spectrum, the visual range was computed. This determination of the visual range is in agreement with the observed visibilities.
THE ANNUAL MERIDIONAL TIDE IN THE ATMOSPHERE
Authors: Spar Jerome
Published: August 2010

No Abstract Available.
CALCIUM CARBONATE AS AN ICE NUCLEUS
Authors: Manson James E.
Published: August 2010

No Abstract Available.
ACTIVATED SALT SURFACES IN ICE NUCLEATION AND GROWTH, AND THE FORMATION OF DROPLETS
Authors: PAPÉE HENRY M.
Published: August 2010

No Abstract Available.
The Numerical Simulation of Airflow and Dispersion in Three-Dimensional Atmospheric Recirculation Zones
Authors: Dawson Paul , Stock David E. , Lamb Brian
Published: August 2010

A three-dimensional, nonhydrostatic numerical code using the two-equation turbulence closure was developed to model the atmospheric transport and diffusion of pollutants over buildings and a three-dimensional hill. The standard engineering two-equation, first-order turbulence closure was modified to account for surface layer effects and the reduced production of dissipation in the region above the surface layer found in an atmospheric boundary layer.

The computations for the dispersion of a building rooftop release showed good agreement with wind tunnel measurements, except when very close to the ground. The transport and dispersion of a plume over a 300-m conical hill, Steptoe Butte, was also simulated. The computations are compared with near ground-level field measurements.
Comment on “Persistence and Recurrence Probabilities of Cloud-Free and Cloudy Lines of Sight through the Atmosphere”
Authors: Medler Charles L. , MacNichol Kenneth B.
Published: August 2010

Although published some time ago, the subject paper represents a well-known resource for modeling and assessing cloud impacts on land-based and air-based electro-optical systems. The Lund dataset, derived from whole-sky photographs taken during the summer months at Columbia, Missouri, remains unique and valuable and has been used in assembling critical cloud-free line-of-sight models. In Lund's paper, cloud-free and cloudy persistence and recurrence probabilities, plotted versus elapsed time interval for each of 11 categories of fractional sky cover, are provided. The purpose of this comment is to provide an expression that properly combines these probabilities to produce persistence and recurrence probabilities irrespective of sky cover category (i.e., probabilities that are valid when the sky cover is not known a priori). Lund presented a “matrix model” for representing these probabilities. Lund's matrix model does not represent the average recurrence or persistence probability over all sky cover conditions, as is shown in the Appendix.