bluuebunny/crossref_metadata_2025 huggingface dataset:
A histopathological score on baseline biopsies from elderly donors predicts outcome 1 year after renal transplantation
Authors: TOFT BIRGITTE G. , FEDERSPIEL BIRGITTE H. , SØRENSEN SØREN S. , BAGI PER , NIELSEN HENNING B. , ANDERSEN CLAUS B.
Published: November 2011

Toft BG, Federspiel BH, Sørensen SS, Bagi P, Nielsen HB, Andersen CB. A histopathological score on baseline biopsies from elderly donors predicts outcome 1 year after renal transplantation. APMIS 2012; 120: 182–6.

Kidneys from elderly deceased patients and otherwise marginal donors may be considered for transplantation and a pretransplantation histopathological score for prediction of postoperative outcome is warranted. In a retrospective design, 29 baseline renal needle biopsies from elderly deceased donors (age: 63 ± 4 years; mean ± SD) were evaluated independently by three pathologists and with ten or more glomeruli and one artery present the biopsy was histopathologically scored (numeric score: 0–12) according to the presence of glomerulosclerosis, tubular atrophy, interstitial fibrosis and increased wall thickness of arteries and/or arterioles. Nineteen renal baseline biopsies from 15 donors (age: 64 ± 10 years) were included and following consensus the histopathological score was 4.3 ± 2.1 (intraclass correlation coefficient: 0.81; confidence interval: 0.66–0.92). The donor organs were used for single renal transplantation (recipient age: 47 ± 3 years). Two grafts were lost after the transplantation. In the remaining 17 recipients the 1‐year creatinine clearance (54 ± 6 mL/min) correlated to the baseline histopathological score (r2 = 0.59; p < 0.01). This study demonstrates that in elderly Danish donors a histopathological score on baseline renal needle biopsies, with at least ten glomeruli and one artery present, predicts graft function 1 year after transplantation.
Nuclear expression of S‐phase kinase–associated protein 2 predicts poor prognosis of hepatocellular carcinoma
Authors: SHIN EUN , KIM SOO‐HEE , JEONG HAE‐YEON , JANG JA‐JUNE , LEE KYUNGBUN
Published: November 2011

Shin E, Kim S‐H, Jeong H‐Y, Jang J‐J, Lee K. Nuclear expression of S‐phase kinase–associated protein 2 predicts poor prognosis of hepatocellular carcinoma. APMIS 2012; 120: 349–57.

The S‐phase kinase–associated protein 2 (Skp2), which ubiquitinates the cell cycle inhibitor p27Kip1 and targets it for degradation, is commonly overexpressed in human cancers and is associated with poor prognosis in several cancers. The aim of this study was to investigate Skp2 expression and its clinicopathologic significance in surgically resected hepatocellular carcinomas. We collected 359 hepatocellular carcinoma samples and evaluated Skp2 protein expression in cytoplasmic and nuclear fractions by immunohistochemistry using a tissue microarray method. Among the 359 patients, nuclear expression of Skp2 was observed in 41 (10.38%), and cytoplasmic expression of Skp2 was observed in 195 (49.37%). Of the several clinicopathologic variables examined, high Edmonson‐Steiner grade and early recurrence correlated with nuclear expression of Skp2 (p = 0.000 and 0.022, respectively). Cytoplasmic expression of Skp2 correlated negatively with microvascular and macrovascular invasion, tumor size, histologic grade, and overall survival. Multivariate analysis revealed that nuclear expression of Skp2 correlated with short disease‐free survival. Our findings suggest that nuclear expression of Skp2 may be used as an independent predictor of poor prognosis for hepatocellular carcinoma, whereas cytoplasmic expression of Skp2 may indicate less aggressive disease.
Sebaceous hyperplasia within epidermis after scald
Authors: Yin ZhiQiang , Xu JiaLi , Luo Dan , Zhang MeiHua
Published: November 2011

A 16‐year‐old girl with polycystic ovarian syndrome presented with numerous rufous papules arising within a large depigmented macule that developed following a severe scald injury on the back. Histopathology revealed that many mature sebaceous glands were growing in the middle and bottom of the epidermis with slight acanthosis. On the basis of patient history, clinical manifestation and histopathology, we suggested that this patient's skin lesion be diagnosed as ‘sebaceous hyperplasia within epidermis after scald’.

Yin Z, Xu J, Luo D, Zhang M. Sebaceous hyperplasia within epidermis after scald.
Actinic granuloma occurring in an unusual association with cutaneous B‐cell chronic lymphocytic leukemia
Authors: Kauffman Julia A. , Ivan Doina , Cutlan Jonathan E. , Hymes Sharon R.
Published: November 2011

Granulomatous cutaneous reactions are well described in association with T‐cell non‐Hodgkin lymphoma and Hodgkin lymphoma, but are rarely seen in association with B‐cell non‐Hodgkin lymphoma or leukemia. We report a case of a 65‐year‐old woman with B‐cell chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) who presented with multiple, tender, firm pink papules on the face, upper trunk and upper extremities 6 years after diagnosis of CLL. Biopsy revealed both palisading granulomatous dermatitis consistent with actinic granuloma and a dense perivascular lymphocytic infiltrate consistent with the patient's known history of leukemia. This is an unusual manifestation of cutaneous B‐cell CLL that is rarely seen.

Kauffman JA, Ivan DS, Cutlan JE, Hymes SR. Actinic granuloma occurring in an unusual association with cutaneous B‐cell chronic lymphocytic leukemia.
Herpes simplex virus‐induced plasmacytic atypia
Authors: Boyd Alan S. , Zwerner Jeffrey P. , Miller Jami L.
Published: November 2011

The clinical and histopathological features of cutaneous herpes simplex virus (HSV) infection have been well described. Genital herpetic infections are largely induced by HSV type 2, but 30% of cases can be caused by HSV type 1. Immunocompromised patients are known to exhibit atypical patterns of clinical presentation with variable lesion morphology and anatomic location. A subset of patients may show morphology such as nodules or verrucous lesions. Analogously, some biopsy specimens may show unusual microscopical features, such as a lack of keratinocyte cytopathology, lymphocyte infiltration or vasculopathic changes that are expected irrespective of the patient's immune status. We present the case of a patient carrying a previous diagnosis of pemphigus vulgaris, status posttreatment with methotrexate and prednisone, who developed a perineal ulcer exhibiting significant numbers of plasma cells, many of which were cytologically atypical. This morphology was suggestive of a hematopoietic malignancy. Immunoperoxidase staining for HSV decorated a focal collection of keratinocytes that lacked appreciable viral changes expected of HSV infection.

Boyd AS, Zwerner JP, Miller JL. Herpes simplex virus‐induced plasmacytic atypia.
Exploitation of Fallen Diaspores by Ants: Are there Ant–Plant Partner Choices?
Authors: Christianini Alexander V. , Mayhé‐Nunes Antônio J. , Oliveira Paulo S.
Published: November 2011

Ants frequently interact with fleshy fallen diaspores (fruits or seeds) not adapted for ant‐dispersal. Such interactions are usually considered as opportunistic, but recent evidence has indicated that these ants may differ in their effects on diaspore survival and plant recruitment. We investigated if partner choices are recognizable among genera of ants and plants, and if ant and plant traits may influence such preferences in cerrado (savanna‐like vegetation) from southeast Brazil. During a 2‐yr period, 521 ant–diaspore interactions were recorded through various methods, yielding 71 ant species and 38 plant species. Exploitation of fallen diaspores was common among several ant genera, and included carnivorous, omnivorous, and fungivorous ants. Contrary to others areas around the world, where true myrmecochory (seed dispersal by ants) is common among shrubs, ants also exploited diaspores from several cerrado trees. Plant life form, diaspore size, and ant body size did not seem to explain the pattern of interactions observed. Two subsets of preferential interactions, however, segregated fungivorous ants from another group composed of carnivorous and omnivorous ants, probably influenced by the chemical composition of the plant diaspores. Omnivorous ants usually remove the fleshy portion of diaspores on spot and probably provide limited benefits to plants. Carnivorous and fungivorous ants usually remove the whole diaspore to the nest. As each of these ant groups may influence the fitness of diaspores in different ways, there are possible subtle pathways for the evolution of partner choices between ants and these non‐myrmecochorous diaspores.
Nitrogen Addition Shapes Soil Phosphorus Availability in Two Reforested Tropical Forests in Southern China
Authors: Lu Xiankai , Mo Jiangming , Gilliam Frank S. , Fang Hua , Zhu Feifei , Fang Yunting , Zhang Wei , Huang Juan
Published: November 2011

Scant information is available on how soil phosphorus (P) availability responds to atmospheric nitrogen (N) deposition, especially in the tropical zones. This study examined the effect of N addition on soil P availability, and compared this effect between forest sites of contrasting land‐use history. Effects of N addition on soil properties, litterfall production, P release from decomposing litter, and soil P availability were studied in a disturbed (reforested pine forest with previous understory vegetation and litter harvesting) and a rehabilitated (reforested mixed pine/broadleaf forest with no understory vegetation and litter harvesting) tropical forest in southern China. Experimental N‐treatments (above ambient) were the following: Control (no N addition), N50 (50 kg N ha−1 yr−1), and N100 (100 kg N ha−1 yr−1). Results indicated that N addition significantly decreased soil P availability in the disturbed forest. In the rehabilitated forest, however, soil P availability was significantly increased by N addition. Decreases in soil P availability may be correlated with decreases in rates of P release from decomposing litter in the N‐treated plots, whereas the increase in soil P availability was correlated with an increase in litterfall production. Our results suggest that response of soil P availability to N deposition in the reforested tropical forests in southern China may vary greatly with temporal changes in tree species composition and soil nutrient status, caused by different land‐use practices.
Photocatalytic Synthesis of Urea from in situ Generated Ammonia and Carbon Dioxide
Authors: Srinivas Basavaraju , Kumari Valluri Durga , Sadanandam Gullapelli , Hymavathi Chilumula , Subrahmanyam Machiraju , De Bhudev Ranjan
Published: November 2011

TiO2 and Fe‐titanate (different wt%) supported on zeolite were prepared by sol‐gel and solid‐state dispersion methods. The photocatalysts prepared were characterized by X‐ray diffraction, scanning electron microscopy and ultraviolet (UV)–visible diffuse reflectance spectroscopy techniques. Photocatalytic reduction of nitrate in water and isopropanol/oxalic acid as hole scavengers are investigated in a batch reactor under UV illumination. The yield of urea increased notably when the catalysts were supported on zeolite. The Fe‐titanate supported catalyst promotes the charge separation that contributes to an increase in selective formation of urea. The product formation is because of the high adsorption of in situ generated CO2 and NH3 over shape‐selective property of the zeolite in the composite photocatalyst. The maximum yield of urea is found to be 18 ppm while 1% isopropanol containing solution over 10 wt% Fe‐titanate/HZSM‐5 photocatalyst was used.
Levosimendan Produces an Additional Clinical and Hemodynamic Benefit in Patients With Decompensated Heart Failure Successfully Submitted to a Fluid Removal Treatment
Authors: Giglioli Cristina , Cecchi Emanuele , Landi Daniele , Chiostri Marco , Spini Valentina , Valente Serafina , Gensini Gian F. , Romano Salvatore M.
Published: November 2011

A pivotal role in treating decompensated heart failure (HF) is played by inotropes and calcium sensitizers such as levosimendan. In this study, the authors evaluated whether levosimendan could determine further clinical and hemodynamic benefits in 31 HF patients (New York Heart Association [NYHA] class III or IV), after successful treatment with diuretics (n=15) or ultrafiltration (n=16). Systolic, diastolic, dicrotic, and mean arterial pressures; systemic vascular resistance (SVR); some classic hemodynamic variables (cardiac output [CO], stroke volume [SV], dP/dtmax); and indices of cardiovascular system performance (cardiac cycle efficiency [CCE], cardiac power output) have been assessed by the pressure recording analytical method (PRAM), a minimally invasive monitoring system, before levosimendan infusion, at the end of treatment (EoT), and 36 hours after EoT (post‐36). A significant increase in CCE, CO, SV, and dP/dtmax and a significant decrease in diastolic and dicrotic arterial pressures and in SVR have been observed at EoT and at post‐36. After the addition of levosimendan, a further reduction in signs and symptoms of HF and NYHA class was observed. Five patients showed an opposite trend of several hemodynamic parameters without any significant clinical improvement (nonresponders). In conclusion, most HF patients treated with diuretics or ultrafiltration receive additional clinical and hemodynamic benefits from levosimendan. The characterization of nonresponders could help in optimizing its use. Congest Heart Fail. 2012;18:47–53. ©2011 Wiley Periodicals, Inc.
Spatial analysis by distance indices: an alternative local clustering index for studying spatial patterns
Authors: Li Baohua , Madden Laurence V. , Xu Xiangming
Published: November 2011

1. The spatial analysis by distance indices (SADIE) methodology for data analysis is valuable for quantifying spatial patterns of organisms in terms of patches and gaps. Previous research showed that the calculation of the local clustering indices, key SADIE statistics, does not adequately adjust for the absolute location or the magnitude of the counts.

2. We present a new definition of a local clustering index, which overcomes the problem associated with the original cluster indices related to sampling position and count size. The new index is calculated without breaking the link between the observed count and its original position and quantifies the contribution of an observed count at this particular position to the local gaps or patches for the observed pattern relative to the expected under the assumption of spatial independence amongst observed counts. Randomisation‐based testing for statistical significance of an individual local clustering index follows naturally from the definition of the new index.

3. New indices, calculated for several simulated and observed data sets, showed that the original indices overestimated the number of points (sites, locations) contributing to the gaps/patches in a spatial grid. Results indicate that the significance (or interpretation) of individual local clustering indices cannot be made based on its magnitude only and needs to be supported by statistical testing.

4. The newly developed index will provide a valuable tool for quantifying the local pattern and testing for its significance and enhance the value of SADIE methodology in analysing spatial patterns. It can also be used in conjunction with other approaches that test for global clustering.
Effect of changes in intrathoracic pressure on cardiac function at rest and during moderate exercise in health and heart failure
Authors: Lalande Sophie , Luoma Charles E. , Miller Andrew D. , Johnson Bruce D.
Published: November 2011

This study investigated the effect of changes in inspiratory intrathoracic pressure on stroke volume at rest and during moderate exercise in patients with heart failure and reduced ejection fraction (HFREF) as well as healthy individuals. Stroke volume was obtained by echocardiography during 2 min of spontaneous breathing (S), two progressive levels of inspiratory unloading (UL1 and UL2) using a ventilator, and two progressive levels of inspiratory loading using resistors in 11 patients with HFREF (61 ± 9 years old; ejection fraction 32 ± 4%; NYHA class I–II) and 11 age‐matched healthy individuals at rest and during exercise at 60% of maximal aerobic capacity on a semi‐recumbent cycle ergometer. At rest, inspiratory unloading progressively decreased stroke volume index (SVI; S, 35.2 ± 5.4 ml m−2; UL1, 33.3 ± 5.1 ml m−2; and UL2, 32.2 ± 4.4 ml m−2) in healthy individuals, while it increased SVI (S, 31.4 ± 4.6 ml m−2; UL1, 32.0 ± 5.9 ml m−2; and UL2, 34.0 ± 7.2 ml m−2) in patients with HFREF (P = 0.04). During moderate exercise, inspiratory unloading decreased SVI in a similar manner (S, 43.9 ± 7.1 ml m−2; UL1, 40.7 ± 4.7 ml m−2; and UL2, 39.9 ± 3.7 ml m−1) in healthy individuals, while it increased SVI (S, 40.8 ± 6.5 ml m−2; UL1, 42.8 ± 6.9 ml m−2; and UL2, 44.1 ± 4. ml m−2) in patients with HFREF (P = 0.02). Inspiratory loading did not significantly change SVI at rest or during moderate exercise in both groups. It is concluded that inspiratory unloading improved SVI at rest and during moderate exercise in patients with HFREF, possibly due to a reduction in left ventricular afterload.
Community Composition, Toxigenicity, and Environmental Conditions during a Cyanobacterial Bloom Occurring along 1,100 Kilometers of the Murray River
Authors: Al-Tebrineh Jamal , Merrick Chester , Ryan David , Humpage Andrew , Bowling Lee , Neilan Brett A.
Published: November 2011

A cyanobacterial bloom impacted over 1,100 km of the Murray River, Australia, and its tributaries in 2009. Physicochemical conditions in the river were optimal to support a bloom at the time. The data suggest that at least three blooms occurred concurrently in different sections of the river, with each having a different community composition and associated cyanotoxin profile. Microscopic and genetic analyses suggested the presence of potentially toxicAnabaena circinalis,Microcystis flos-aquae, andCylindrospermopsis raciborskiiat many locations. Low concentrations of saxitoxins and cylindrospermopsin were detected inAnabaenaandCylindrospermopsispopulations. A multiplex quantitative PCR was used, employing novel oligonucleotide primers and fluorescent TaqMan probes, to examine bloom toxigenicity. This single reaction method identified the presence of the major cyanotoxin-producing species present in these environmental samples and also quantified the various toxin biosynthesis genes. A large number of cells present throughout the bloom were not potential toxin producers or were present in numbers below the limit of detection of the assay and therefore not an immediate health risk. Potential toxin-producing cells, possessing the cylindrospermopsin biosynthesis gene (cyrA), predominated early in the bloom, while those possessing the saxitoxin biosynthesis gene (sxtA) were more common toward its decline. In this study, the concentrations of cyanotoxins measured via enzyme-linked immunosorbent assay (ELISA) correlated positively with the respective toxin gene copy numbers, indicating that the molecular method may be used as a proxy for bloom risk assessment.
Methicillin-Resistant Coagulase-Negative Staphylococci on Pig Farms as a Reservoir of Heterogeneous Staphylococcal Cassette Chromosome
mec
Elements
Authors: Tulinski Pawel , Fluit Ad C. , Wagenaar Jaap A. , Mevius Dik , van de Vijver Lucy , Duim Birgitta
Published: November 2011

Methicillin-resistant
Staphylococcus aureus
(MRSA) likely originated by acquisition of the staphylococcal cassette chromosome
mec
(SCC
mec
) from coagulase-negative staphylococci (CNS). However, it is unknown whether the same SCC
mec
types are present in MRSA and CNS that reside in the same niche. Here we describe a study to determine the presence of a potential
mecA
reservoir among CNS recovered from 10 pig farms. The 44 strains belonged to 10 different
Staphylococcus
species. All
S. aureus
strains belonged to sequence type 398 (ST398), with SCC
mec
types V and IVa. Type IVc, as well as types III and VI, novel subtypes of type IV, and not-typeable types, were found in CNS.
S. aureus
,
S. epidermidis
, and
S. haemolyticus
shared SCC
mec
type V. The presence of SCC
mec
type IVc in several staphylococcal species isolated from one pig farm is noteworthy, suggesting exchange of this SCC
mec
type in CNS, but the general distribution of this SCC
mec
type still has to be established. In conclusion, this study shows that SCC
mec
types among staphylococcal species on pig farms are heterogeneous. On two farms, more than one recovered staphylococcal species harbored the same SCC
mec
type. We conclude that staphylococci on pig farms act as a reservoir of heterogeneous SCC
mec
elements. These staphylococci may act as a source for transfer of SCC
mec
to
S. aureus
.
Characterization of Phascolarctobacterium succinatutens sp. nov., an Asaccharolytic, Succinate-Utilizing Bacterium Isolated from Human Feces
Authors: Watanabe Yohei , Nagai Fumiko , Morotomi Masami
Published: November 2011

Isolation, cultivation, and characterization of the intestinal microorganisms are important for understanding the comprehensive physiology of the human gastrointestinal (GI) tract microbiota. Here, we isolated two novel bacterial strains, YIT 12067
T
and YIT 12068, from the feces of healthy human adults. Phylogenetic analysis indicated that they belonged to the same species and were most closely related to
Phascolarctobacterium faecium
ACM 3679
T
, with 91.4% to 91.5% 16S rRNA gene sequence similarities, respectively. Substrate availability tests revealed that the isolates used only succinate; they did not ferment any other short-chain fatty acids or carbohydrates tested. When these strains were cocultured with the xylan-utilizing and succinate-producing bacterium
Paraprevotella xylaniphila
YIT 11841
T
, in medium supplemented with xylan but not succinate, their cell numbers became 2 to 3 orders of magnitude higher than those of the monoculture; succinate became undetectable, and propionate was formed. Database analysis revealed that over 200 uncultured bacterial clones from the feces of humans and other mammals showed high sequence identity (>98.7%) to YIT 12067
T
. Real-time PCR analysis also revealed that YIT 12067
T
-like bacteria were present in 21% of human fecal samples, at an average level of 3.34 × 10
8
cells/g feces. These results indicate that YIT 12067
T
-like bacteria are distributed broadly in the GI tract as subdominant members that may adapt to the intestinal environment by specializing to utilize the succinate generated by other bacterial species. The phylogenetic and physiological properties of YIT 12067
T
and YIT 12068 suggest that these strains represent a novel species, which we have designated
Phascolarctobacterium succinatutens
sp. nov.
Isolation of Bacteria Capable of Growth with 2-Methylisoborneol and Geosmin as the Sole Carbon and Energy Sources
Authors: Guttman Lior , van Rijn Jaap
Published: November 2011

Using a relatively simple enrichment technique, geosmin and 2-methylisoborneol (MIB)-biodegrading bacteria were isolated from a digestion basin in an aquaculture unit. Comparison of 16S rRNA gene sequences affiliated one of the three isolates with the Gram-positive genus
Rhodococcus
, while the other two isolates were found to be closely related to the Gram-negative family
Comamonadaceae
(
Variovorax
and
Comamonas
). Growth rates and geosmin and MIB removal rates by the isolates were determined under aerated and nonaerated conditions in mineral medium containing either of the two compounds as the sole carbon and energy source. All isolates exhibited their fastest growth under aerobic conditions, with generation times ranging from 3.1 to 5.7 h, compared to generation times of up to 19.1 h in the nonaerated flasks. Incubation of the isolates with additional carbon sources caused a significant increase in their growth rates, while removal rates of geosmin and MIB were significantly lower than those for incubation with only geosmin or MIB. By fluorescence
in situ
hybridization, members of the genera
Rhodococcus
and
Comamonas
were detected in geosmin- and MIB-enriched sludge from the digestion basin.
Characterization and Functional Analyses of
R
-Specific Enoyl Coenzyme A Hydratases in Polyhydroxyalkanoate-Producing Ralstonia eutropha
Authors: Kawashima Yui , Cheng Wen , Mifune Jun , Orita Izumi , Nakamura Satoshi , Fukui Toshiaki
Published: November 2011

A genome survey of polyhydroxyalkanoate (PHA)-producing
Ralstonia eutropha
H16 detected the presence of 16 orthologs of
R
-specific enoyl coenzyme A (enoyl-CoA) hydratase, among which three proteins shared high homologies with the enzyme specific to enoyl-CoAs of medium chain length encoded by
phaJ4
from
Pseudomonas aeruginosa
(

phaJ4
Pa

). The recombinant forms of the three proteins, termed PhaJ4a

Re

to PhaJ4c

Re

, actually showed enoyl-CoA hydratase activity with
R
specificity, and the catalytic efficiencies were elevated as the substrate chain length increased from C
4
to C
8
. PhaJ4a

Re

and PhaJ4b

Re

showed >10-fold-higher catalytic efficiency than PhaJ4c

Re

. The functions of the new PhaJ4 proteins were investigated using previously engineered
R. eutropha
strains as host strains; these strains are capable of synthesizing poly((
R
)-3-hydroxybutyrate-
co
-(
R
)-3-hydroxyhexanoate) [P(3HB-
co
-3HHx)] from soybean oil. Deletion of

phaJ4a
Re

from the chromosome resulted in significant decrease of 3HHx composition in the accumulated copolyester, whereas no change was observed with deletion of

phaJ4b
Re

or

phaJ4c
Re

, indicating that only PhaJ4a

Re

was one of the major enzymes supplying the (
R
)-3HHx-CoA monomer through β-oxidation. Introduction of

phaJ4a
Re

or

phaJ4b
Re

into the
R. eutropha
strains using a broad-host-range vector enhanced the 3HHx composition of the copolyesters, but the introduction of

phaJ4c
Re

did not. The two genes were then inserted into the
pha
operon on chromosome 1 of the engineered
R. eutropha
by homologous recombination. These modifications enabled the biosynthesis of P(3HB-
co
-3HHx) composed of a larger 3HHx fraction without a negative impact on cell growth and PHA production on soybean oil, especially when

phaJ4a
Re

or

phaJ4b
Re

was tandemly introduced with

phaJ
Ac

from
Aeromonas caviae
.
Cj1386 Is an Ankyrin-Containing Protein Involved in Heme Trafficking to Catalase in Campylobacter jejuni
Authors: Flint Annika , Sun Yi-Qian , Stintzi Alain
Published: November 2011

Campylobacter jejuni
, a microaerophilic bacterium, is the most frequent cause of human bacterial gastroenteritis.
C. jejuni
is exposed to harmful reactive oxygen species (ROS) produced during its own normal metabolic processes and during infection from the host immune system and from host intestinal microbiota. These ROS will damage DNA and proteins and cause peroxidation of lipids. Consequently, identifying ROS defense mechanisms is important for understanding how
Campylobacter
survives this environmental stress during infection. Construction of a ΔCj1386 isogenic deletion mutant and phenotypic assays led to its discovery as a novel oxidative stress defense gene. The ΔCj1386 mutant has an increased sensitivity toward hydrogen peroxide. The Cj1386 gene is located directly downstream from
katA
(catalase) in the
C. jejuni
genome. A Δ
katA
Δ Cj1386 double deletion mutant was constructed and exhibited a sensitivity to hydrogen peroxide similar to that seen in the ΔCj1386 and Δ
katA
single deletion mutants. This observation suggests that Cj1386 may be involved in the same detoxification pathway as catalase. Despite identical KatA abundances, catalase activity assays showed that the
Δ
Cj1386 mutant had a reduced catalase activity relative to that of wild-type
C. jejuni
. Heme quantification of KatA protein from the ΔCj1386 mutant revealed a significant decrease in heme concentration. This indicates an important role for Cj1386 in heme trafficking to KatA within
C. jejuni
. Interestingly, the ΔCj1386 mutant had a reduced ability to colonize the ceca of chicks and was outcompeted by the wild-type strain for colonization of the gastrointestinal tract of neonate piglets. These results indicate an important role for Cj1386 in
Campylobacter
colonization and pathogenesis.
Structural Insights into the Catalytic Mechanism of Escherichia coli Selenophosphate Synthetase
Authors: Noinaj Nicholas , Wattanasak Rut , Lee Duck-Yeon , Wally Jeremy L. , Piszczek Grzegorz , Chock P. Boon , Stadtman Thressa C. , Buchanan Susan K.
Published: November 2011

Selenophosphate synthetase (SPS) catalyzes the synthesis of selenophosphate, the selenium donor for the biosynthesis of selenocysteine and 2-selenouridine residues in seleno-tRNA. Selenocysteine, known as the 21st amino acid, is then incorporated into proteins during translation to form selenoproteins which serve a variety of cellular processes. SPS activity is dependent on both Mg
2+
and K
+
and uses ATP, selenide, and water to catalyze the formation of AMP, orthophosphate, and selenophosphate. In this reaction, the gamma phosphate of ATP is transferred to the selenide to form selenophosphate, while ADP is hydrolyzed to form orthophosphate and AMP. Most of what is known about the function of SPS has derived from studies investigating
Escherichia coli
SPS (EcSPS) as a model system. Here we report the crystal structure of the C17S mutant of SPS from
E. coli
(EcSPS
C17S
) in apo form (without ATP bound). EcSPS
C17S
crystallizes as a homodimer, which was further characterized by analytical ultracentrifugation experiments. The glycine-rich N-terminal region (residues 1 through 47) was found in the open conformation and was mostly ordered in both structures, with a magnesium cofactor bound at the active site of each monomer involving conserved aspartate residues. Mutating these conserved residues (D51, D68, D91, and D227) along with N87, also found at the active site, to alanine completely abolished AMP production in our activity assays, highlighting their essential role for catalysis in EcSPS. Based on the structural and biochemical analysis of EcSPS reported here and using information obtained from similar studies done with SPS orthologs from
Aquifex aeolicus
and humans, we propose a catalytic mechanism for EcSPS-mediated selenophosphate synthesis.
In the NadR Regulon, Adhesins and Diverse Meningococcal Functions Are Regulated in Response to Signals in Human Saliva
Authors: Fagnocchi Luca , Pigozzi Eva , Scarlato Vincenzo , Delany Isabel
Published: November 2011

The
Neisseria meningitidis
regulator NadR was shown to repress expression of the NadA adhesin and play a major role in NadA phase-variable expression. In this study, we identified through microarray analysis over 30 genes coregulated with
nadA
in the NadR mutant and defined members of the NadR regulon through
in vitro
DNA-binding assays. Two distinct types of promoter architectures (I and II) were identified for NadR targets, differing in both the number and position of NadR-binding sites. All NadR-regulated genes investigated were found to respond to 4-hydroxyphenylacetic acid (4HPA), a small molecule secreted in human saliva, which was previously demonstrated to induce
nadA
expression by alleviating NadR-dependent repression. Interestingly, two types of NadR 4HPA responsive activities were found on different NadR targets corresponding to the two types of genes identified by different promoter architectures: while NadA and the majority of NadR targets (type I) are induced, only the MafA adhesins (type II) are corepressed in response to the same 4HPA signal. This alternate behavior of NadR was confirmed in a panel of strains in response to 4HPA and after incubation in saliva. The
in vitro
NadR binding activity at type I and type II promoter regions is differentially affected by 4HPA, suggesting that the nature of the NadR binding sites may define the regulation to which they will be subjected. We conclude that NadR coordinates a broad transcriptional response to signals present in human saliva, mimicked
in vitro
by 4HPA, enabling the meningococcus to adapt to the relevant host niche.
The Major Autolysin Acm2 from Lactobacillus plantarum Undergoes Cytoplasmic O-Glycosylation
Authors: Fredriksen Lasse , Mathiesen Geir , Moen Anders , Bron Peter A. , Kleerebezem Michiel , Eijsink Vincent G. H. , Egge-Jacobsen Wolfgang
Published: November 2011

The major autolysin Acm2 from the probiotic strain
Lactobacillus plantarum
WCFS1 contains high proportions of alanine, serine, and threonine in its N-terminal so-called AST domain. It has been suggested that this extracellular protein might be glycosylated, but this has not been experimentally verified. We used high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) to study the possible occurrence of glycans on peptides generated from lactobacillary surface proteins by protease treatment. This approach yielded five glycopeptides in various glycoforms, all derived from the AST domain of Acm2. All five glycopeptides contained the hydroxy-amino acids serine and threonine, suggesting that Acm2 is O-glycosylated. By using lectin blotting with succinylated wheat germ agglutinin, and by comparing the wild-type strain with an Acm2-negative derivative (NZ3557), we found that the attached
N
-acetylhexosamines are most likely
N
-acetylglucosamines (GlcNAc). NZ3557 was further used as a genetic background to express an Acm2 variant lacking its secretion signal, resulting in intracellular expression of Acm2. We show that this intracellular version of Acm2 is also glycosylated, indicating that the GlcNAc modification is an intracellular process.
Additional-Body Effects in a Self-Aligned Deca-Nanometer Ultrathin-Body and Buried Oxide Silicon-on-Insulator Metal–Oxide–Semiconductor Field-Effect Transistor: A Three-Dimensional Simulation Study
Authors: Lin Jyi-Tsong , Eng Yi-Chuen , Chen Cheng-Hsin , Fan Yi-Hsuan
Published: November 2011

In this paper, we numerically investigate the additional-body effects (ABEs) created by the isolation-last fabrication process of a self-aligned deca-nanometer ultrathin-body and buried oxide (UTBB) silicon-on-insulator (SOI) metal–oxide–semiconductor field-effect transistor (MOSFET). The reasons for the device's new electrical characteristics are also explained in detail. The additional silicon body volumes of the UTBB SOI MOSFET are found to improve the subthreshold swing and the on/off current ratio. The additional body has a negative effect, however, upon both the gate leakage current and the total gate capacitance, when compared with a standard UTBB SOI MOSFET.
Large Angle Silicon-on-Insulator Tilting Actuator with Kinematic Excitation and Simple Integrated Parallel-Plate Electrostatic Transducer
Authors: Ya'akobovitz Assaf , Krylov Slava
Published: November 2011

We report on the novel architecture and operational principle of an electrostatically actuated large angle tilting microelectromechanical (MEMS) actuator with kinematic excitation. The device transforms and amplifies small linear out-of-plane motion of a parallel-plate transducer into a large angular motion of a tilting element attached to the transducer with a certain offset using an elastic torsion axis. The actuator, which is distinguished by the single layer robust architecture and incorporating the simple integrated electrostatic transducer, was fabricated from a silicon-on-insulator (SOI) substrate using a common deep reactive ion etching (DRIE) based process. Detailed modeling of the device was followed by the experimental characterization of the actuator. Large tilting angles were observed in experiments, consistenty with the theoretical prediction. An optical peak to peak angle of 37.5° was measured under relatively low actuation voltages. Our theoretical and experimental results collectively demonstate the feasibility of the suggested apporach and show that simple electrostatic actuation combined with the dynamic amplification results in efficient large amplitude operation of tilting devices.
InGaAs Nano-Photodiode Enhanced Using Polarization-Insensitive Surface-Plasmon Antennas
Authors: Okamoto Daisuke , Fujikata Junichi , Ohashi Keishi
Published: November 2011

We propose InGaAs nano-photodiodes incorporated with a ring-type polarization-insensitive surface-plasmon (SP) antenna, which consists of gold concentric-ring gratings. This ring antenna induces SP resonance for any polarization of incident light and enhances light absorption in a thin InGaAs layer owing to its symmetric structure. Finite-difference time-domain simulations suggest that the carefully designed ring SP antenna can achieve a quantum efficiency of more than 70% for a wide wavelength range and a maximum efficiency of about 80%. A 3 dB bandwidth of 21 GHz and an external responsivity of 0.39 A/W were experimentally demonstrated at a 1.55 µm wavelength.
Investigation of the Resistance Dependence on Temperature of Single Carbon Nanotube in Different Environments
Authors: Inomata Naoki , Arai Fumihito
Published: November 2011

We investigated the electrical resistance dependence on temperature of a single carbon nanotube (CNT) in vacuum, air, and water by heating the end of the CNT locally. The device used for investigation consisted of a microheater for local heating, four electrodes for measuring resistance on a silicon-on-insulator wafer, and a trench for further heat insulation. Then, the resistance of a single CNT assembled on the device was measured as a function of added heat quantity. The temperature coefficients of resistance of the CNT were 0.214×10-3, 0.422×10-3, and 0.735×10-3/°C in vacuum, air, and water, respectively. Moreover, the heat quantities required to raise the temperature of a CNT in air and water are 1.2- and 1.3-fold that in vacuum, respectively. Thus, CNTs, mainly used as thermal sensors in vacuum, may also be suitable for use in air and water.
Mathematical modeling mechanisms of arrhythmias in transgenic mouse heart overexpressing TNF-α
Authors: Petkova-Kirova Polina S. , London Barry , Salama Guy , Rasmusson Randall L. , Bondarenko Vladimir E.
Published: November 2011

Transgenic mice overexpressing tumor necrosis factor-α (TNF-α mice) possess many of the features of human heart failure, such as dilated cardiomyopathy, impaired Ca2+ handling, arrhythmias, and decreased survival. Although TNF-α mice have been studied extensively with a number of experimental methods, the mechanisms of heart failure are not completely understood. We created a mathematical model that reproduced experimentally observed changes in the action potential (AP) and Ca2+ handling of isolated TNF-α mice ventricular myocytes. To study the contribution of the differences in ion currents, AP, Ca2+ handling, and intercellular coupling to the development of arrhythmias in TNF-α mice, we further created several multicellular model tissues with combinations of wild-type (WT)/reduced gap junction conductance, WT/prolonged AP, and WT/decreased Na+ current ( INa) amplitude. All model tissues were examined for susceptibility to Ca2+ alternans, AP propagation block, and reentry. Our modeling results demonstrated that, similar to experimental data in TNF-α mice, Ca2+ alternans in TNF-α tissues developed at longer basic cycle lengths. The greater susceptibility to Ca2+ alternans was attributed to the prolonged AP, resulting in larger inactivation of INa, and to the decreased SR Ca2+ uptake and corresponding smaller SR Ca2+ load. Simulations demonstrated that AP prolongation induces an increased susceptibility to AP propagation block. Programmed stimulation of the model tissues with a premature impulse showed that reduced gap junction conduction increased the vulnerable window for initiation reentry, supporting the idea that reduced intercellular coupling is the major factor for reentrant arrhythmias in TNF-α mice.
Constitutive overexpression of phosphomimetic phospholemman S68E mutant results in arrhythmias, early mortality, and heart failure: potential involvement of Na+/Ca2+ exchanger
Authors: Song Jianliang , Gao Erhe , Wang JuFang , Zhang Xue-Qian , Chan Tung O. , Koch Walter J. , Shang Xiying , Joseph Jeffrey I. , Peterson Blaise Z. , Feldman Arthur M. , Cheung Joseph Y.
Published: November 2011

Expression and activity of cardiac Na+/Ca2+ exchanger (NCX1) are altered in many disease states. We engineered mice in which the phosphomimetic phospholemman S68E mutant (inhibits NCX1 but not Na+-K+-ATPase) was constitutively overexpressed in a cardiac-specific manner (conS68E). At 4–6 wk, conS68E mice exhibited severe bradycardia, ventricular arrhythmias, increased left ventricular (LV) mass, decreased cardiac output (CO), and ∼50% mortality compared with wild-type (WT) littermates. Protein levels of NCX1, calsequestrin, ryanodine receptor, and α1- and α2-subunits of Na+-K+-ATPase were similar, but sarco(endo)plasmic reticulum Ca2+-ATPase was lower, whereas L-type Ca2+ channels were higher in conS68E hearts. Resting membrane potential and action potential amplitude were similar, but action potential duration was dramatically prolonged in conS68E myocytes. Diastolic intracellular Ca2+ ([Ca2+]i) was higher, [Ca2+]i transient and maximal contraction amplitudes were lower, and half-time of [Ca2+]i transient decline was longer in conS68E myocytes. Intracellular Na+ reached maximum within 3 min after isoproterenol addition, followed by decline in WT but not in conS68E myocytes. Na+/Ca2+ exchange, L-type Ca2+, Na+-K+-ATPase, and depolarization-activated K+ currents were decreased in conS68E myocytes. At 22 wk, bradycardia and increased LV mass persisted in conS68E survivors. Despite comparable baseline CO, conS68E survivors at 22 wk exhibited decreased chronotropic, inotropic, and lusitropic responses to isoproterenol. We conclude that constitutive overexpression of S68E mutant was detrimental, both in terms of depressed cardiac function and increased arrhythmogenesis.
Pim Kinase Inhibitors Sensitize Prostate Cancer Cells to Apoptosis Triggered by Bcl-2 Family Inhibitor ABT-737
Authors: Song Jin H. , Kraft Andrew S.
Published: November 2011

Pim serine/threonine kinases contribute to prostate tumorigenesis and therapeutic resistance, yet Pim kinase inhibitors seem to have only limited effects on prostate cancer cell survival. Because overexpression of Bcl-2 family members are implicated in chemotherapeutic resistance in prostate cancer, we investigated the cooperative effects of Pim kinase inhibition with ABT-737, a small molecule antagonist of Bcl-2 family members. Strikingly, the addition of ABT-737 to Pim inhibitors triggered a robust apoptosis of prostate cancer cells in vitro and in vivo. Pim inhibitors decreased levels of the Bcl-2 family member Mcl-1, both by blocking 5′-cap dependent translation and decreasing protein half life. In addition, Pim inhibition transcriptionally increased levels of the BH3 protein Noxa by activating the unfolded protein response (UPR), lead to eIF-2α phosphorylation and increased expression of CHOP. Increased levels of Noxa also inactivated the remaining levels of Mcl-1 protein activity. Notably, these specific protein changes were essential to the apoptotic process because ABT-737 did not inhibit Mcl-1 protein activity and Mcl-1 overexpression blocked the apoptotic activity of ABT-737. Our results therefore suggest that this combination treatment could be developed as a potential therapy for human prostate cancer where overexpression of Pim kinases and antiapoptotic Bcl-2 family members drives tumor cell resistance to current anticancer therapies. Cancer Res; 72(1); 294–303. ©2011 AACR.
STEAP1 Is Associated with the Invasive and Oxidative Stress Phenotype of Ewing Tumors
Authors: Grunewald Thomas G.P. , Diebold Isabel , Esposito Irene , Plehm Stephanie , Hauer Kristina , Thiel Uwe , da Silva-Buttkus Patricia , Neff Frauke , Unland Rebekka , Müller-Tidow Carsten , Zobywalski Colette , Lohrig Katharina , Lewandrowski Urs , Sickmann Albert , da Costa Olivia Prazeres , Görlach Agnes , Cossarizza Andrea , Butt Elke , Richter Günther H.S. , Burdach Stefan
Published: November 2011

Ewing tumors comprise the second most common type of bone-associated cancer in children and are characterized by oncogenic EWS/FLI1 fusion proteins and early metastasis. Compelling evidence suggests that elevated levels of intracellular oxidative stress contribute to enhanced aggressiveness of numerous cancers, possibly including Ewing tumors. Using comprehensive microarray analyses and RNA interference, we identified the six-transmembrane epithelial antigen of the prostate 1 (STEAP1)—a membrane-bound mesenchymal stem cell marker of unknown function—as a highly expressed protein in Ewing tumors compared with benign tissues and show its regulation by EWS/FLI1. In addition, we show that STEAP1 knockdown reduces Ewing tumor proliferation, anchorage-independent colony formation as well as invasion in vitro and decreases growth and metastasis of Ewing tumor xenografts in vivo. Moreover, transcriptome and proteome analyses as well as functional studies revealed that STEAP1 expression correlates with oxidative stress responses and elevated levels of reactive oxygen species that in turn are able to regulate redox-sensitive and proinvasive genes. In synopsis, our data suggest that STEAP1 is associated with the invasive behavior and oxidative stress phenotype of Ewing tumors and point to a hitherto unanticipated oncogenic function of STEAP1. Mol Cancer Res; 10(1); 52–65. ©2011 AACR.
Reduced Ventricular Proarrhythmic Potential of the Novel Combined Ion-Channel Blocker AZD1305 Versus Dofetilide in Dogs With Remodeled Hearts
Authors: Johnson Daniel M. , de Jong Monique M.J. , Crijns Harry J.G.M. , Carlsson Leif G. , Volders Paul G.A.
Published: November 2011

Background—

AZD1305 is an investigational antiarrhythmic agent for management of atrial fibrillation. It blocks various cardiac ion currents at different potencies and has atrial-predominant electrophysiological effects. We investigated the electrophysiological and proarrhythmic effects of AZD1305 versus dofetilide in dogs with chronic complete atrioventricular block and myocardial hypertrophic remodeling.

Methods and Results—

AZD1305 was administered to anesthetized mongrel dogs before and >2 weeks after the induction of atrioventricular block and ventricular and atrial electrophysiological parameters were assessed. In all dogs, the selective I
Kr
blocker dofetilide was used to examine susceptibility to acquired torsades de pointes in chronic atrioventricular block and for comparison. At normal sinus rhythm, AZD1305 increased QT and RR intervals from 290±7 to 397±15 ms (+37%,
P
<0.0001) and from 603±22 to 778±32 ms (+29%,
P
=0.002), respectively. In the same animals at chronic atrioventricular block, AZD1305 increased the QT interval from 535±28 to 747±36 ms (+40%,
P
<0.0001), similar to the QT prolongation by dofetilide (511±22 to 703±45 ms [+38%,
P
<0.0001]). AZD1305 slightly slowed the idioventricular rhythm. Whereas all (n=14) chronic atrioventricular block animals exhibited torsades de pointes on dofetilide, the arrhythmia was induced in only 4 of 11 dogs after AZD1305. Beat-to-beat variability of left-ventricular monophasic-action-potential duration increased after dofetilide (2.3±0.2 to 6.3±0.7 ms;
P
<0.0001) but not after AZD1305 (2.8±0.3 to 3.7±0.3 ms;
P
=0.20) despite similar left-ventricular monophasic-action-potential duration prolongations.

Conclusions—

Despite causing similar degrees of repolarization delay as the selective I
Kr
blocker dofetilide, the combined ion-channel blocker AZD1305 induces less repolarization instability and has a lower ventricular proarrhythmic potential in the remodeled dog heart.