bluuebunny/crossref_metadata_2025 huggingface dataset:
Rituximab in recalcitrant thrombotic thrombocytopenic purpura secondary to systemic lupus erythematosus
Authors: HALIM A. G. , SOEHARDY Z. , SHAHRIR M. S. , ROZITA M. , LOO C. Y. , RASHIDI S. , NORELLA KONG C. T.
Published: April 2008

Systemic lupus erythematosus (SLE) is a typical autoimmune disease with manifestations due to unopposed production of autoantibodies against the patient's own cells. The clinical features are diverse, ranging from musculoskeletal involvement, lupus nephritis to cerebral and even haematological involvement. We report a case of a young woman with known SLE who developed thrombotic thrombocytopenic purpura (TTP) secondary to SLE resistant to conventional treatment with plasma exchange. She was then treated with rituximab (MabThera®), a CD20 monoclonal antibody, and showed remarkable improvement. To our best knowledge this is the first case reporting the use of rituximab in acute resistant TTP secondary to SLE.
Influence of Water Stress on Endogenous Hormone Contents and Cell Damage of Maize Seedlings
Authors: Wang Chunrong , Yang Aifang , Yin Haiying , Zhang Juren
Published: April 2008

Phytohormones play critical roles in regulating plant responses to stress. We investigated the effects of water stress induced by adding 12% (w/v) polyethylene glycol to the root medium on the levels of abscisic acid (ABA), indole‐3‐acid (IAA), zeatin (ZT), and gibberellin3 (GA3) in maize leaves. The results suggested that water stress had significant effects on the four hormone levels. There was a transient increase in the IAA content during the initial stage of adaptation to water stress in maize leaves, but it dropped sharply thereafter in response to water stress. ABA content increased dramatically in maize leaves after 24 h of exposure to water stress, and then the high levels of ABA were maintained to the end. The contents of ZT and GA3 rapidly declined in maize leaves subjected to water stress. The effects of water stress on chlorophyll content, electrolyte leakage and malondialdehyde levels in maize leaves were also studied. The variation of cell damage was negatively correlated with ZT and GA3 levels in maize leaves under water stress. Thus, we explored the roles of ZT and GA3 on the growth of maize seedlings under water stress by exogenous application. It is possible that both ZT and GA3 were effective in protecting maize seedlings from water stress, which would be of great importance for the improvement of drought tolerance in maize by genetic manipulation.
In Vivo Efficacy of β-Cyclodextrin Derivatives against Anthrax Lethal Toxin
Authors: Moayeri Mahtab , Robinson Tanisha M. , Leppla Stephen H. , Karginov Vladimir A.
Published: April 2008

We evaluated the in vivo efficacy of three β-cyclodextrin derivatives that block the anthrax protective antigen pore. These compounds were at least 15-fold more potent than previously described β-cyclodextrins in protecting against anthrax lethal toxin in a rat model. One of the drugs was shown to protect mice from bacterial infection.
Cerebrospinal Fluid Compartmental Pharmacokinetics of Amikacin in Neonates
Authors: Allegaert K. , Scheers I. , Adams E. , Brajanoski G. , Cossey V. , Anderson B. J.
Published: April 2008

To describe and investigate the covariate effects of cerebrospinal fluid (CSF) amikacin pharmacokinetics in neonates, CSF samples were prospectively collected from neonates in whom amikacin had been initiated before a diagnostic lumbar puncture was performed. CSF analysis (amikacin concentration, white blood count [WBC], glucose content, and protein concentration) and amikacin therapeutic drug monitoring results (peak and trough concentrations) in serum were recorded. Correlations (Spearman rank) between the CSF amikacin concentration and the CSF WBC and glucose and protein concentration were investigated. There were 44 CSF amikacin concentrations and 83 serum samples available from 43 neonates (mean postmenstrual age, 36 weeks [range, 26 to 41 weeks]; mean weight, 2.43 kg [range, 0.87 to 3.86 kg]). The median time interval between initiation of amikacin administration and CSF sampling was 25 h (range, 2.5 to 93.7 h). The median amikacin concentration in the CSF was 1.08 mg/liter (range, 0.34 to 2.65 mg/liter), and the mean trough and peak amikacin concentrations in serum were 3.8 ± 2.5 mg/liter and 35.7 ± 5.9 mg/liter, respectively. A correlation between CSF amikacin and CSF protein contents (
P
< 0.01,
r
= 0.41, 95% confidence interval = 0.13 to 0.63) but not between CSF WBC and CSF glucose was documented. A two-compartment (central and CSF) linear disposition model was used to estimate population pharmacokinetics. The half time for equilibration (
T
eq
) between serum and CSF compartments was used as a measure of blood-brain barrier permeability. The
T
eq
was 7.58 h (coefficient of variation [CV] = 49.1%) with a partition coefficient of 0.103 (CV = 26.4%). There was no relationship between the
T
eq
and CSF WBC, CSF glucose content, or CSF protein content.
Enrichment of Fluoroquinolone-Resistant
Staphylococcus aureus
: Oscillating Ciprofloxacin Concentrations Simulated at the Upper and Lower Portions of the Mutant Selection Window
Authors: Firsov Alexander A. , Lubenko Irene Y. , Smirnova Maria V. , Strukova Elena N. , Zinner Stephen H.
Published: April 2008

The time inside the mutant selection window (MSW),
T
MSW
, appears to be less predictive of the selection of fluoroquinolone-resistant
Staphylococcus aureus
than is the ratio of the area under the concentration-time curve (AUC) to the MIC. This observation might be attributed to the fact that
T
MSW
does not consider the actual position of simulated antibiotic concentrations inside the MSW, which also might influence the amplification of resistant mutants. To test this hypothesis, the enrichment of ciprofloxacin-resistant
S. aureus
was studied at ciprofloxacin (CIP) concentrations that oscillate near the mutant prevention concentration (MPC), i.e., closer to the top of the MSW (“upper case”), and closer to the MIC, i.e., at the lower limit of the MSW (“lower case”) at the same
T
MSW
. Two methicillin-resistant strains of
S. aureus
, ATCC 6538 and ATCC 43300 (MICs of 0.25 and 0.5 mg/liter, respectively, and MPCs of 4 and 2 mg/liter, respectively), were exposed to twice-daily CIP treatments for three consecutive days. With
S. aureus
ATCC 6538, the simulated ratios of the AUC at 24 h (AUC
24
) to the MIC were 50 and 260 h (
T
MSW
75% of the dosing interval). With
S. aureus
ATCC 43300, the simulated AUC
24
/MICs were 30 and 100 h (
T
MSW
56%). With each organism, mutants resistant to CIP were enriched in an AUC
24
/MIC-dependent manner: the higher the AUC
24
/MIC ratio, the lower the growth on CIP-containing plates. For example, the area under the time-kill curve of mutants resistant to 4× MIC of CIP in the upper case was three times smaller than that in the lower case for both
S. aureus
strains. Similar differences were seen at the higher (8× MIC) and lower (2× MIC) CIP concentrations. These data highlight differences in the selection of resistant
S. aureus
, depending on the position of simulated concentrations inside the MSW at a given
T
MSW
. This explains why
T
MSW
-based predictions of resistance are less accurate than those based on AUC/MIC and AUC/MPC.
Daptomycin Exerts Bactericidal Activity without Lysis of
Staphylococcus aureus
Authors: Cotroneo Nicole , Harris Robert , Perlmutter Nancy , Beveridge Terry , Silverman Jared A.
Published: April 2008

The ability of daptomycin to produce bactericidal activity against
Staphylococcus aureus
while causing negligible cell lysis has been demonstrated using electron microscopy and the membrane integrity probes calcein and ToPro3. The formation of aberrant septa on the cell wall, suggestive of impairment of the cell division machinery, was also observed.
Relation between Genetic Markers of Drug Resistance and Susceptibility Profile of Clinical
Neisseria gonorrhoeae
Strains
Authors: Ilina Elena N. , Vereshchagin Vladimir A. , Borovskaya Alexandra D. , Malakhova Maja V. , Sidorenko Sergei V. , Al-Khafaji Nazar C. , Kubanova Anna A. , Govorun Vadim M.
Published: April 2008

The main goal of this work is to clarify the predictive value of known genetic markers of
Neisseria gonorrhoeae
resistance to penicillin, tetracycline, and fluoroquinolones. The correlation between the presence of certain genetic markers and susceptibility of
N. gonorrhoeae
isolates to penicillin, tetracycline, and fluoroquinolones has been analyzed by means of statistical methods. Susceptibility testing with penicillin, tetracycline, and fluoroquinolones was performed by the agar dilution method.
N. gonorrhoeae
genomic DNA was isolated. The presence of
bla
TEM-1
and
tet
(
M
) genes was analyzed by PCR. A novel method of polymorphism discovery based on a minisequencing reaction followed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry was applied for the analysis of chromosomal
N. gonorrhoeae
genes involved in antimicrobial resistance development. Clinical
N. gonorrhoeae
isolates (
n
= 464) were collected. Susceptibility levels to penicillin, tetracycline, and fluoroquinolones were found to be 25.9%, 35.9%, and 54.1%, respectively. Among the 19
N. gonorrhoeae
isolates with penicillin MICs of ≥4 μg/ml, the
bla
TEM-1
gene was detected in 12. The Tet(M) determinant was found in 4 of 12
N. gonorrhoeae
isolates with tetracycline MICs of ≥16 μg/ml. The chromosomal genetic markers of penicillin and tetracycline resistance were detected especially in isolates with penicillin MICs of 0.25 to 2.0 μg/ml and tetracycline MICs of 0.5 to 4 μg/ml. Mutations in GyrA and ParC were found in 208 of 211 quinolone-resistant
N. gonorrhoeae
isolates. This work is the first representative molecular research of the
N. gonorrhoeae
population in Russia. Information about the prevalence of antibiotic resistance mechanisms and the positive predictive value of certain genetic determinants is given. The positive predictive values of the analyzed genetic markers were found to be different for fluoroquinolones (90.3%), penicillin (91.1%), and tetracycline (81.9%).
Induction and Resuscitation of Viable Nonculturable
Arcobacter butzleri
Cells
Authors: Fera M. T. , Maugeri T. L. , Gugliandolo C. , La Camera E. , Lentini V. , Favaloro A. , Bonanno D. , Carbone M.
Published: April 2008

Two strains of
Arcobacter butzleri
, ATCC 49616 and an environmental isolate, became nonculturable in seawater microcosms at 4°C by 20 days and at room temperature by 14 days. Nonculturable cells were viable for up to 270 days of incubation in microcosms. Resuscitation of
A. butzleri
cells from microcosms at both temperatures was achieved 9 days after nutrient addition.
Shewanella
and
Photobacterium
spp. in Oysters and Seawater from the Delaware Bay
Authors: Richards Gary P. , Watson Michael A. , Crane Edward J. , Burt Iris G. , Bushek David
Published: April 2008

Shewanella algae
,
S. putrefaciens
, and
Photobacterium damselae
subsp.
damselae
are indigenous marine bacteria and human pathogens causing cellulitis, necrotizing fasciitis, abscesses, septicemia, and death. Infections are rare and are most often associated with the immunocompromised host. A study was performed on the microbiological flora of oysters and seawater from commercial oyster harvesting sites in the Delaware Bay, New Jersey. From 276 water and shellfish samples tested, 1,421 bacterial isolates were picked for biochemical identification and 170 (12.0%) of the isolates were presumptively identified as
S. putrefaciens
, 26 (1.8%) were presumptively identified as
P. damselae
subsp.
damselae
, and 665 (46.8%) could not be identified using the API 20E identification database. Sequencing of the 16S rRNA genes of 22
S. putrefaciens
-like isolates identified them as
S. abalonesis
,
S. algae
,
S. baltica
,
S. hafniensis
,
S. marisflavi
,
S. putrefaciens
,
Listonella anguillarum
, and
P. damselae
. Beta-hemolysis was produced by some
S. algae
and
P. damselae
isolates, while isolates of
S. baltica
and
L. anguillarum
, species perceived as nonpathogenic, also exhibited β-hemolysis and growth at 37°C. To our knowledge, this is the first time these beta-hemolytic strains were reported from shellfish or seawater from the Delaware Bay. Pathogenic
Shewanella
and
Photobacterium
species could pose a health threat through the ingestion of contaminated seafood, by cuts or abrasions acquired in the marine environment, or by swimming and other recreational activities.
Shuttle Vector Expression in
Thermococcus kodakaraensis
: Contributions of
cis
Elements to Protein Synthesis in a Hyperthermophilic Archaeon
Authors: Santangelo Thomas J. , Čuboňová L'ubomíra , Reeve John N.
Published: April 2008

Shuttle vectors that replicate stably and express selectable phenotypes in both
Thermococcus kodakaraensis
and
Escherichia coli
have been constructed. Plasmid pTN1 from
Thermococcus nautilis
was ligated to the commercial vector pCR2.1-TOPO, and selectable markers were added so that
T. kodakaraensis
transformants could be selected by Δ
trpE
complementation and/or mevinolin resistance. Based on Western blot measurements, shuttle vector expression of RpoL-HA, a hemagglutinin (HA) epitope-tagged subunit of
T. kodakaraensis
RNA polymerase (RNAP), was ∼8-fold higher than chromosome expression. An idealized ribosome binding sequence (5′-AGGTGG) was incorporated for RpoL-HA expression, and changes to this sequence reduced expression. Changing the translation initiation codon from AUG to GUG did not reduce RpoL-HA expression, but replacing AUG with UUG dramatically reduced RpoL-HA synthesis. When functioning as translation initiation codons, AUG, GUG, and UUG all directed the incorporation of methionine as the N-terminal residue of RpoL-HA synthesized in
T. kodakaraensis
. Affinity purification confirmed that an HA- plus six-histidine-tagged RpoL subunit (RpoL-HA-his
6
) synthesized ectopically from a shuttle vector was assembled in vivo into RNAP holoenzymes that were active and could be purified directly from
T. kodakaraensis
cell lysates by Ni
2+
binding and imidazole elution.
Biogeochemistry and Community Composition of Iron- and Sulfur-Precipitating Microbial Mats at the Chefren Mud Volcano (Nile Deep Sea Fan, Eastern Mediterranean)
Authors: Omoregie Enoma O. , Mastalerz Vincent , de Lange Gert , Straub Kristina L. , Kappler Andreas , Røy Hans , Stadnitskaia Alina , Foucher Jean-Paul , Boetius Antje
Published: April 2008

In this study we determined the composition and biogeochemistry of novel, brightly colored, white and orange microbial mats at the surface of a brine seep at the outer rim of the Chefren mud volcano. These mats were interspersed with one another, but their underlying sediment biogeochemistries differed considerably. Microscopy revealed that the white mats were granules composed of elemental S filaments, similar to those produced by the sulfide-oxidizing epsilonproteobacterium “
Candidatus
Arcobacter sulfidicus.” Fluorescence in situ hybridization indicated that microorganisms targeted by a “
Ca
. Arcobacter sulfidicus”-specific oligonucleotide probe constituted up to 24% of the total the cells within these mats. Several 16S rRNA gene sequences from organisms closely related to “
Ca
. Arcobacter sulfidicus” were identified. In contrast, the orange mat consisted mostly of bright orange flakes composed of empty Fe(III) (hydr)oxide-coated microbial sheaths, similar to those produced by the neutrophilic Fe(II)-oxidizing betaproteobacterium
Leptothrix ochracea
. None of the 16S rRNA gene sequences obtained from these samples were closely related to sequences of known neutrophilic aerobic Fe(II)-oxidizing bacteria. The sediments below both types of mats showed relatively high sulfate reduction rates (300 nmol·cm
−3
·day
−1
) partially fueled by the anaerobic oxidation of methane (10 to 20 nmol·cm
−3
·day
−1
). Free sulfide produced below the white mat was depleted by sulfide oxidation within the mat itself. Below the orange mat free Fe(II) reached the surface layer and was depleted in part by microbial Fe(II) oxidation. Both mats and the sediments underneath them hosted very diverse microbial communities and contained mineral precipitates, most likely due to differences in fluid flow patterns.
Biome-Level Biogeography of Streambed Microbiota
Authors: Findlay Robert H. , Yeates Christine , Hullar Meredith A. J. , Stahl David A. , Kaplan Louis A.
Published: April 2008

A field study was conducted to determine the microbial community structures of streambed sediments across diverse geographic and climatic areas. Sediment samples were collected from three adjacent headwater forest streams within three biomes, eastern deciduous (Pennsylvania), southeastern coniferous (New Jersey), and tropical evergreen (Guanacaste, Costa Rica), to assess whether there is biome control of stream microbial community structure. Bacterial abundance, microbial biomass, and bacterial and microbial community structures were determined using classical, biochemical, and molecular methods. Microbial biomass, determined using phospholipid phosphate, was significantly greater in the southeastern coniferous biome, likely due to the smaller grain size, higher organic content, and lower levels of physical disturbance of these sediments. Microbial community structure was determined using phospholipid fatty acid (PLFA) profiles and bacterial community structure from terminal restriction fragment length polymorphism and edited (microeukaryotic PLFAs removed) PLFA profiles. Principal component analysis (PCA) was used to investigate patterns in total microbial community structure. The first principal component separated streams based on the importance of phototrophic microeukaryotes within the community, while the second separated southeastern coniferous streams from all others based on increased abundance of fungal PLFAs. PCA also indicated that within- and among-stream variations were small for tropical evergreen streams and large for southeastern coniferous streams. A similar analysis of bacterial community structure indicated that streams within biomes had similar community structures, while each biome possessed a unique streambed community, indicating strong within-biome control of stream bacterial community structure.
Use of Murine Norovirus as a Surrogate To Evaluate Resistance of Human Norovirus to Disinfectants
Authors: Belliot Gaël , Lavaux Amandine , Souihel Donya , Agnello Davide , Pothier Pierre
Published: April 2008

Murine norovirus (MNV) was used as a surrogate to study resistance of human norovirus to disinfectants used in hospitals. MNV was sensitive to alcohol, alcohol hand rubs, bleach, and povidone iodine-based disinfectant. Real-time reverse transcription-PCR results indicated that the presence of viral RNA did not correlate with the presence of infectious virus.
Development of a Cell Surface Display System in a Magnetotactic Bacterium, “
Magnetospirillum magneticum
” AMB-1
Authors: Tanaka Masayoshi , Nakata Yuko , Mori Tetsushi , Okamura Yoshiko , Miyasaka Hitoshi , Takeyama Haruko , Matsunaga Tadashi
Published: April 2008

Bacterial cell surface display is a widely used technology for bioadsorption and for the development of a variety of screening systems. Magnetotactic bacteria are unique species of bacteria due to the presence of magnetic nanoparticles within them. These intracellular, nanosized (50 to 100 nm) magnetic nanoparticles enable the cells to migrate and be manipulated by magnetic force. In this work, using this unique characteristic and based on whole-genomic and comprehensive proteomic analyses of these bacteria, a cell surface display system has been developed by expressing hexahistidine residues within the outer coiled loop of the membrane-specific protein (Msp1) of the “
Magnetospirillum magneticum
” (proposed name) AMB-1 bacterium. The optimal display site of the hexahistidine residues was successfully identified via secondary structure prediction, immunofluorescence microscopy, and heavy metal binding assay. The established AMB-1 transformant showed high immunofluorescence response, high Cd
2+
binding, and high recovery efficiency in comparison to those of the negative control when manipulated by magnetic force.
Aspergillus nidulans
Natural Product Biosynthesis Is Regulated by MpkB, a Putative Pheromone Response Mitogen-Activated Protein Kinase
Authors: Atoui Ali , Bao Dapeng , Kaur Navgeet , Grayburn W. Scott , Calvo Ana M.
Published: April 2008

The
Aspergillus nidulans
putative mitogen-activated protein kinase encoded by
mpkB
has a role in natural product biosynthesis. An
mpkB
mutant exhibited a decrease in sterigmatocystin gene expression and low mycotoxin levels. The mutation also affected the expression of genes involved in penicillin and terrequinone A synthesis.
mpkB
was necessary for normal expression of
laeA
, which has been found to regulate secondary metabolism gene clusters.
Evaluation of the Persistence of Infectious Human Noroviruses on Food Surfaces by Using Real-Time Nucleic Acid Sequence-Based Amplification
Authors: Lamhoujeb Safaa , Fliss Ismail , Ngazoa Solange E. , Jean Julie
Published: April 2008

Noroviruses (NoV) are the major cause of nonbacterial gastroenteritis. However, there is no published study to ascertain their survival on foodstuffs which are directly related to human health risk. In the present study, we developed a rapid, simple, and sensitive real-time nucleic acid sequence-based amplification (NASBA) combined with an enzymatic treatment for distinguishing infectious from noninfectious human NoV. The developed method was validated using spiked ready-to-eat food samples. When feline calicivirus (FCV) was used as a NoV surrogate in the preliminary assays, it appeared more sensitive to heat inactivation and enzymatic pretreatment than the human NoV. This suggests that FCV may not be an ideal model for studying NoV. Our results reveal clearly that the developed enzymatic pretreatment/real-time NASBA combination successfully distinguished the infectious from heat-inactivated NoV. Moreover, we demonstrate that NoV survived for at least 10 days on refrigerated ready-to-eat foods, such as lettuce and turkey. However, the survival rate was higher on turkey than on lettuce, probably because of their different surface natures. The approach developed in this study may be suitable for more in-depth studies of the persistence and inactivation of human NoV and may be applied to other nonculturable RNA viruses. Moreover, the evaluation of infectious NoV survival provided valuable information concerning its persistence on ready-to-eat food.
Identification and Characterization of a Repeat-in-Toxin Gene Cluster in
Vibrio anguillarum
Authors: Li Ling , Rock Jessica L. , Nelson David R.
Published: April 2008

Vibrio anguillarum
is the causative agent of vibriosis in fish. Hemolysins of
V. anguillarum
have been considered virulence factors during infection. One hemolysin gene,
vah1
, has been previously identified but does not account for all hemolytic activity. The mini-Tn
10
Km mutagenesis performed with a
vah1
mutant resulted in a hemolysin-negative mutant. The region surrounding the mutation was cloned and sequenced, revealing a putative
rtx
operon with six genes (
rtxACHBDE
), where
rtxA
encodes an exotoxin,
rtxC
encodes an RtxA activator,
rtxH
encodes a conserved hypothetical protein, and
rtxBDE
encode the ABC transporters. Single mutations in
rtx
genes did not result in a hemolysin-negative phenotype. However, strains containing a mutation in
vah1
and a mutation in an
rtx
gene resulted in a hemolysin-negative mutant, demonstrating that the
rtx
operon is a second hemolysin gene cluster in
V. anguillarum
M93Sm. Reverse transcription-PCR analysis revealed that the
rtxC
and
rtxA
genes are cotranscribed, as are the
rtxBDE
genes. Additionally, Vah1 and RtxA each have cytotoxic activity against Atlantic salmon kidney (ASK) cells. Single mutations in
vah1
or
rtxA
attenuate the cytotoxicity of
V. anguillarum
M93Sm. A
vah1 rtxA
double mutant is no longer cytotoxic. Moreover, Vah1 and RtxA each have a distinct cytotoxic effect on ASK cells, Vah1 causes cell vacuolation, and RtxA causes cell rounding. Finally, wild-type and mutant strains were tested for virulence in juvenile Atlantic salmon. Only strains containing an
rtxA
mutation had reduced virulence, suggesting that RtxA is a major virulence factor for
V. anguillarum
.
Distinct Roles for MyD88 and Toll-Like Receptors 2, 5, and 9 in Phagocytosis ofBorrelia burgdorferiand Cytokine Induction
Authors: Shin Ok S. , Isberg Ralph R. , Akira Shizuo , Uematsu Satoshi , Behera Aruna K. , Hu Linden T.
Published: April 2008

The contribution of Toll-like receptors (TLRs) to phagocytosis ofBorrelia burgdorferihas not been extensively studied. We show that bone marrow-derived macrophages (BMDM) from MyD88−/−mice or Raw cells transfected with a dominant-negative MyD88 were unable to efficiently internalizeB. burgdorferi.Knockouts of TLR2 and TLR9 or knockdown of TLR5 by small interfering RNA produced no defects in phagocytosis ofB. burgdorferi. Production of inflammatory cytokines was greatly diminished in MyD88−/−BMDM but only partially affected in TLR2−/−BMDM or knockdown of TLR5 and unaffected in TLR9−/−BMDM. Cytochalasin D reduced cytokine induction, but not to the level of the MyD88−/−BMDM. Addition of cytochalasin D to TLR2−/−BMDM inhibited inflammatory responses toB. burgdorferito the level of MyD88−/−BMDM, consistent with a role for TLR2 in both recognition of extracellular products and lysosomal sampling by TLR2 after processing of the organism. Cytochalasin D had no impact on cytokine production in cells undergoing TLR5 knockdown. These results suggest that MyD88, but not TLR2, TLR5, and TLR9, is important for the uptake ofB. burgdorferiand that MyD88 affects inflammatory responses through both its effects on phagocytosis and its role in transducing signals from TLR2 and TLR5.
EUROPHIUM, A NEW GENUS OF THE ASCOMYCETES WITH A LEPTOGRAPHIUM IMPERFECT STATE
Authors: Parker A. K.
Published: April 2008

The perfect state of a species of Leptographium Lag. & Melin has been placed in the new genus Europhium of the Eurotiaceae and described as Europhium trinacriforme sp. nov. Perithecia were found on the trunks of dead or dying Pinus monticola Dougl. and a method was developed for their production in culture.
The Plasmodiophoromycete parasitic on Heteranthera dubia
Authors: Braselton James P.
Published: April 2008

Light and transmission electron microscopy were used to characterize representative stages of sporogenic plasmodia and resting spores of the plasmodiophorid parasite in roots of Heteranthera dubia (Jacq.) MacM. (water-stargrass). Cruciform nuclear divisions occurred in young plasmodia and noncruciform divisions occurred in more mature, transitional plasmodia. Prophase nuclei in transitional plasmodia contained synaptonemal complexes; noncruciform divisions were interpreted, therefore, as meiosis. Host–parasite interfaces were single unit membranes. Centrioles were paired end-to-end in plasmodia, but unpaired, single centrioles were in resting spores. Resting spores also contained crystalline bodies. Sporosori were disklike, consisted predominantly of single layers of resting spores, and were located at the periphery of host cells. Membranosorus heterantherae Ostenfeld and Peterson was considered the appropriate genus–species for the parasite, not Sorodiscus heterantherae Wernham.
A biometrie and taxonomic study of pollen character variation in Berendtiella and Hemichaena (Scrophulariaceae)
Authors: Argue Charles L.
Published: April 2008

The pollen grains of Berendtiella and Hemichaena are single, isopolar, and tricolporate with a microreticulate to reticulate sexine 2. Intra- and inter-specific variability in pollen characters are assessed statistically, and preliminary evaluation of the taxonomic utility of these data is presented. The bearing of the pollen evidence on proposed intratribal categories and the transfer of the genera from the tribe Scrophularieae (Cheloneae) to the tribe Mimuleae are discussed. The proposed close relationship between the genera and the transfer of Diplacus rugosa to Berendtiella are consistent with the pollen data, but suggested affinities between Berendtiella and Diplacus clearly are not. The grains of Berendtiella and Hemichaena resemble the type II pollen of Mimulus, and the uniformity of pollen morphology in members of the Mimuleae other than Mimulus lends support to the recognition of segregate genera in the latter palynologically diverse genus.
Uptake and accumulation of heavy metals by Typha latifolia in wetlands of the Sudbury, Ontario region
Authors: Taylor Gregory J. , Crowder A. A.
Published: April 2008

The accumulation of Cu, Ni, Zn, Fe, Mn, Mg, and Ca in tissues of Typha latifolia along a 76-km transect extending northwest from Sudbury, Ont., was investigated. Despite high levels of Cu and Ni in the soil–sediment material, these metals were largely excluded from aboveground tissues of T. latifolia. Concentrations of Fe in tissues of T. latifolia were unusually low and may reflect induced iron deficiency. The patterns of uptake of all the metals (except Ca) were similar. Roots showed higher concentrations than the rhizomes and aboveground parts and young leaf tissue (leaf bases) showed lower concentrations than older leaf tissue (leaf tips). Concentrations of Zn, Mg, and Ca accumulated in tissues of T. latifolia were not correlated with soil–sediment metal concentrations. Concentrations of Cu and Ni in belowground and reproductive tissues were correlated with soil–sediment concentrations; however, concentrations in the leaves were not. Accumulation of Fe and Mn in all plant tissues was correlated with concentrations in the soil–sediment material. Soil–sediment pH, Eh, and organic carbon content may have affected the uptake of metals by T. latifolia. However, the effects of any of these factors in isolation may have been obscured by the variation in other physical or biotic factors.
Étude biométrique du développement des folioles de Parkinsonia aculeata (Leguminosae)
Authors: Jeune B.
Published: April 2008

There are three successive phases to foliolar development in Parkinsonia aculeata: (i) an initial phase during which primordium formation occurs; (ii) a morphogenic phase, with foliole formation; (iii) a histogenic and differentiation phase, with foliole development. Foliolar shape is determined during the basic morphogenic phase; a longer phase in which a zoning effect analogous to that seen in branches has been observed: (i) a zone of distal organ formation where folioles appear in constant succession, in a specific location, and in close proximity of each other along each border (these are the three criteria which define intrafoliolar generation centres); (ii) a histogenic median zone; and if the foliole is old enough (iii) a subproximal differentiation zone; (iv) an adult proximal zone.
Contribution à l'étude écologique du complexe orophile Carex sempervirens (Cyperaceae) : étude expérimentale de la germination de populations pyrénéennes
Authors: Georges François , Lazare Jean-Jacques
Published: April 2008

Within the framework of the ecological study of the orophilous complex Carex sempervirens Vill., the germination of achenes of two Pyrenean populations are compared as references. One of them belongs to the subspecies sempervirens with 2n = 30 chromosomes and the other one to the subspecies granitica (Br.-Bl.) C. Vicioso with 2n = 34 chromosomes. Twenty-nine experimental treatments including various pretreatments (stratification, scarification) and temperature and light conditions were examined. The achenes did not exhibit any dormancy. The behaviour of the two populations was different; the population of the subspecies granitica showed a very important positive photosensibility and, in general, a lower speed and percentage of germination than the population of the subspecies sempervirens. The optimum experimental conditions for germination seem to be realized with stratification of achenes, followed by 16 h photoperiods and a constant temperature of 20 °C.
Emergence of seedlings of aquatic macrophytes from lake sediments
Authors: Haag Richard W.
Published: April 2008

Sediment samples were collected in May 1980 from 11 stations at five sites in Lake Wabamun. Emergence of seedlings was recorded in a greenhouse at 19 °C for 120 days. The sediments were then chilled at 4 °C for 120 days and reexposed to greenhouse conditions for a further 90 days. Total seedling densities varied from 0 to 2335 m−2. Depth and sediment texture each accounted for 20% of the variance in seedling numbers. Discharge of thermal effluent from the Wabamun generating station also caused substantial variation in seedling number; seedling numbers at the shallowest Wabamun Outlet station were over four times those at any other site. Chilling of the sediment samples in the laboratory caused further emergence of seedlings from the four sites with the highest seedling densities in the initial treatment. Total numbers were up to 50% of those for seedlings that emerged during the initial exposure to greenhouse conditions. Potamogeton pectinatus and P. pusillus were most common among the seedlings of six species. Two of the three most common macrophytes in the lake were rare as seedlings, while no seedlings were recorded for the most common angiosperm, Myriophyllum exalbescens. Reproduction by seed makes a secondary contribution to the dynamics of the vegetation of Lake Wabamun.
Localization of 14C-labeled assimilates in sieve elements of Macrocystis integrifolia by histoautoradiography
Authors: Shih M. L. , Floch J.-Y. , Srivastava L. M.
Published: April 2008

Macrocystis integrifolia fronds are known to translocate photoassimilates at velocities of 35–72 cm/h. By means of 14C-labeled histoautoradiography it is shown that this translocation occurs in sieve elements, and, further, that it is the mature, fully differentiated sieve elements that have undergone selective hydrolysis of cell contents, including nucleus, and have wide open pores that are involved in this translocation. Cortical cells, young differentiating and old callosed sieve elements, and hyphal cells show no label above background. Sieve elements immediately below the 14C-fed blade are the ones that show the label which indicates that only specific sieve elements are involved in translocation of photoassimilate from a blade. Since the sieve elements form a three-dimensional longitudinal system and since label is seen in the cross-connecting sieve elements, it is probable that at increasing distances from the fed blade the label will be distributed in many more sieve elements. The cytology of sieve elements that are shown here to be conducting is supportive of an osmotically driven pressure flow movement of assimilates in Macrocystis.
The mass propagation of Lilium in vitro by stimulation of multiple adventitious bulb-scale formation and by shake culture
Authors: Takayama Shinsaku , Misawa Masanaru
Published: April 2008

Multiple adventitious bulb scales of Lilium were investigated as a source for bulblet production. Addition of kinetin to the medium markedly increased the number of adventitious bulb scales differentiated from bulblets grown in vitro. The segments with numerous bulb scales were too small to separate into individual bulb scales, but the use of a shake culture technique markedly stimulated their growth. Such bulb scales were severed and each individual scale was transferred to fresh medium without kinetin to induce bulblet formation. The use of multiple adventitious bulb scales grown by shake culture seems to be advantageous for the mass propagation of Lilium bulblets.
Microenvironment of Lake Huron sand dunes
Authors: Baldwin K. A. , Maun M. A.
Published: April 2008

Measurements were obtained of relative abundance of vegetation, edaphic properties, and microclimate characteristics of some initial stages of the Lake Huron sand-dune sequence at Pinery Provincial Park, Ont. Of the five dune habitats sampled, the oldest (transition zone) was distinguishable from the rest on the basis of greater diversity and abundance of vegetation, higher organic matter content, higher moisture-retaining capacity, enhanced concentrations of available K+ and Mg2+, depleted levels of Ca2+ in the surface soil, reduced air turbulence, and slightly higher air temperatures. The midsummer microclimate of the open dune habitat was characterized by extremely high day temperatures at the soil surface (5 cm) with large diurnal temperature fluctuations. Soil moisture content was generally low in the surface layers of the soil, but at depths greater than 10 cm, it was always plentiful (> 2.5% of soil by weight). Canonical variates analysis showed that the transition zone habitat (800 years old) was separated from younger ones (first dune ridge, slack, high beach) on the first canonical variate (V1), which accounted for about 50% of the total dispersion in the data. The discrimination of the transition zone microclimate on V1 was best characterized by difference in soil moisture content at shallow depths (5 and 10 cm) and wind velocity at 50 and 150 cm above the soil surface.
The taxonomy of Vaccinium § Cyanococcus: a summation
Authors: Kloet S. P. Vander
Published: April 2008

Vaccinium § Cyanococcus is defined by having verrucose twigs, dimorphic perennating buds, corymbose inflorescences, pedicels that are articulated with the calices, and berries that are pseudo-10-loculed. The section is endemic to North America and contains nine species, four of which have a hybrid origin. The ancestral group had a probable South American origin and migrated through the Caribbean to Florida, where the group underwent radiation. It is also shown that the lowbush diploid species in the section do not interbreed freely in all combinations and that the F1 hybrids may have a selective disadvantage.
A colorimetric method for assay of glutamate synthase in leaf tissue of Vigna mungo
Authors: Singh V. K. , Mathur M. , Mukerji D. , Mathur S. N.
Published: April 2008

Glutamine-2-oxo-glutarate aminotransferase (GOGAT) or glutamate synthase is generally assayed in terms of the disappearance of NAD(P)H from the assay medium. We describe a new technique which allows colorimetric measurement of the enzyme activity in cell-free extracts and whole tissue of Vigna mungo leaves in terms of disappearance of the substrate (α-ketoglutarate). The technique is offered as an alternative, more convenient method for assay of GOGAT. This also eliminates the use of more sophisticated ultraviolet range instrumentation required for measurement of NAD(P)H.
Assignment of the rumen anaerobe Neocallimastix frontalis to the Spizellomycetales (Chytridiomycetes) on the basis of its polyflagellate zoospore ultrastructure
Authors: Heath I. Brent , Bauchop Tom , Skipp Robert A.
Published: April 2008

Neocallimastix frontalis is an anaerobic herbivore gut inhabitant which occupies an uncertain taxonomic position, probably among zoospore fungi. It produces uninucleate zoospores which are bipartite with an organelle-free anterior portion and a posterior half bearing about 10 flagella and all organelles. The flagella are arranged primarily in two rows and beat as a unit. The flagellar roots are composed of two arrays of single microtubules, all of which emanate, in groups of about 14, from single kinetosome-associated spurs. The main array forms a divergent cone with which the microbodies (hydrogenosomes?) are intimately associated. The second group (the posterior fan) forms a fan-shaped array lying close to the posterior plasmalemma. Zoospores encyst, develop rhizoids, and can produce new zoospores at any stage in their subsequent development from a uninucleate to a multinucleate eucarpic thallus. Zoospore production involves intracytoplasmic flagellar vesicles, organelle clustering, and loss of the sporangium plasmalemma. Zoospore release follows nonlocalized dissolution of the entire sporangium wall. On these data, we assign the genus to a new family, the Neocallimasticaceae, in the Spizellomycetales of the Chytridiomycetes and thereby redefine these taxa to accommodate organisms producing polyflagellate zoospores.
Studies in Gentianaceae. Microsporangium and pollen
Authors: Rao K. Sankara , Chinnappa C. C.
Published: April 2008

The development and structure of the microsporangium and pollen in 22 taxa from the Gentianaceae have been studied and literature on the subject reviewed. Formation of the microsporangial wall follows the dicotyledonous sequence. In Exacum and Cotylanthera, the anthers dehisce by pores, and the endothecium is nonfibrous. The other genera have longitudinal anther dehiscence, and the endothecium is fibrous. Although a single middle layer is usual in the family, Exacum, Cotylanthera, Voyria and Swertia carolinensis show one to four middle layers. The tapetum is derived partly from the primary parietal layer and partly from the ground tissue on the connective side. A tapetum of sporogenous origin occurs in some Gentianinae and Erythraeinae where partitions of tapetal tissue (sterile trabeculae) subdivide the microsporangium. Ubisch granules are present in Exacum. Cytokinesis in the microsporocytes is simultaneous. Microspore tetrads are tetrahedral, isobilateral, or decussate. Pollen grains are two or three celled at the time of anther dehiscence. They occur as single grains or are held in tetrads or polyads. Single grains are tri-, tetra-, or penta-colporate or pericolporate or one to six porate with smooth, scabrous, striate, striato-reticulate or reticulate surface pattern. Variation among tribes and subtribes and lack of information on the microsporangium in Chironiinae, Tachiinae, Rusbyantheae, Helieae, Voyrieae, and Leiphaimeae are pointed out.
The taxonomy and distribution of Festuca idahoensis in British Columbia and northwestern Washington
Authors: Pavlick Leon E.
Published: April 2008

Plants of Festuca idahoensis from west of the Cascade Mountains in British Columbia and northwestern Washington differ in their leaf morphology and panicle size from those east of the Cascade Mountains. The western plants are recognized as F. idahoensis var. roemeri. The geographic and ecological distribution of the species and a key for distinguishing the two varieties are given.
Floral-specific polypeptides in Silene coeli-rosa
Authors: Rembur Jacques , Nougarède Arlette , Rondet Pierre , Francis Dennis
Published: April 2008

In Silene coeli-rosa (L.) Godron given a 7-long-day inductive treatment, scanning electron microscopy and two-dimensional minigel electrophoreses of total proteins were used to characterize the polypeptide pattern of each type of floral organ through early differentiation and to research the changes that occurred in the reproductive apex that initiated each new floral whorl. During early differentiation of each whorl, some polypeptides no longer expressed in the subsequent whorls were distinguished as unique to sepals (24), petals (7), and stamens (4). Newly expressed polypeptides were also observed that occasionally persisted in the subsequent whorl. However, qualitative changes were only between 1.2 and 3.8% of all the detected spots, and common spots remained the most numerous, even if a modulation of their expression in the various types of floral organs was observed. Comparison between leaves and differentiating floral organs showed that sepals shared 57% of their polypeptide spots with leaves, whereas petals, stamens, or carpels shared only 14.6, 10.5, and 7.7%, respectively. In the reproductive apex, polypeptides newly detected or unique to a particular whorl were expressed at the time of initiation of this whorl. However, some of these spots were also detected before, in the apex that initiated the preceding whorl, or they persisted later, in the apex that initiated the following whorl. Key words: floral organs, polypeptides, reproductive apex, Silene coeli-rosa.
Phylogeny of North American Festuca (Poaceae) and related genera using chloroplast DNA restriction site variation
Authors: Darbyshire S. J. , Warwick S. I.
Published: April 2008

Phylogenetic relationships in the genus Festuca, as expressed in recent classification systems, were tested using chloroplast DNA restriction endonuclease site variation data. Species native or introduced to North America were used as exemplars for taxa related to Festuca that have been recognized variously as genera, subgenera, and (or) sections. Cladistic analysis of 67 shared chloroplast DNA restriction site mutations indicated that Festuca and some related taxa, as circumscribed in morphologically based classifications, appear to be non-monophyletic. Cluster analysis of 108 polymorphic sites was largely congruent with the results of the cladistic analysis. Two main evolutionary lines were indicated. One contained the majority of the genus Festuca exemplars, including the subgenera Drymanthele, Subulatae, Subuliflorae, Obtusae, and Festuca, as well as Vulpia, Argillochloa, and subg. Leucopoa sect. Breviaristatae. The other lineage included subgenus Schedonorus, subg. Leucopoa sect. Leucopoa, and the genus Lolium. Analyses supported the recognition of two genera in each lineage: Vulpia and Festuca in one, and Leucopoa sensu stricto (including only sect. Leucopoa) and Lolium (including Festuca subg. Schedonorus) in the other. The recognition of the monotypic generic segregate Argillochloa (= F. dasyclada) was not supported by the analyses. Key words: Festuca, Leucopoa, Lolium, Vulpia, phylogeny, chloroplast DNA.
The South American species of Desmarestia (Phaeophyceae)
Authors: Ramírez María Eliana , Peters Akira F.
Published: April 2008

The South American species of Desmarestia are revised using morphological features of field sporophytes and reproductive and ontogenetic characters obtained from laboratory culture of gametophytes and young sporophytes. Ten entities including a new species are recognized: D. chordalis, D. confervoides comb.nov., D. distans, D. firma, D. gayana, D. ligulata, D. muelleri sp.nov., D. patagonica, D. peruviana, and D. tropica. Although the taxa were distinguished in part using features of the life history in culture, most field thalli can be identified using morphological characters. A key to the South American species of Desmarestia is provided. Key words: culture study, Desmarestia, Desmarestia confervoides comb.nov., Desmarestia muelleri sp.nov., Phaeophyceae, South America, taxonomy.
Molecular evidence supports the separation of Lentinula edodes from Lentinus and related genera
Authors: Molina Francis I. , Shen Peng , Jong Shung-Chang , Orikono Kazuhiko
Published: April 2008

Restriction polymorphisms in two regions of the ribosomal DNA (rDNA) repeat unit were examined in 18 strains of Lentinus, Neolentinus, Pleurotus, and the shiitake mushroom Lentinula edodes. The polymerase chain reaction was used to separately amplify the 18S rDNA and the region spanning the two internal transcribed spacers and the 5.8S ribosomal RNA gene. Amplified products were digested with a battery of 10 restriction endonucleases and the two data sets were subjected to cluster analysis. All strains of Lentinula edodes consistently exhibited identical restriction profiles that were distinct from those of the genera Lentinus, Neolentinus, and Pleurotus. The internal transcribed spacer region exhibited more variability than the 18S rDNA, giving distinctive profiles for two strains of Lentinus tigrinus and for one strain of Neolentinus lepideus. Similarity coefficients were clustered with the unweighted pair group method with arithmetic average, single-linkage method, and complete-linkage method. Results from cluster analysis of the two data sets were highly congruent and tree topologies were consistent irrespective of the clustering method used. The distinctiveness of the groups was further confirmed by computing for consensus trees and cophenetic correlation coefficients. Ribosomal DNA restriction polymorphisms support the placement of the strains examined in separate taxa. Key words: Lentinula, Lentinus, Neolentinus, Pleurotus, ribosomal DNA.