bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel energy mapping approach for CT‐based attenuation correction in PET
Authors: Teimourian B. , Ay M. R. , Zafarghandi M. Shamsaie , Ghafarian P. , Ghadiri H. , Zaidi H. 
Published: March 2012

Purpose:Dual‐energy CT (DECT) is arguably the most accurate energy mapping technique in CT‐based attenuation correction (CTAC) implemented on hybrid PET/CT systems. However, this approach is not attractive for clinical use owing to increased patient dose. The authors propose a novel energy mapping approach referred to as virtual DECT (VDECT) taking advantage of the DECT formulation but using CT data acquired at a single energy (kVP). For this purpose, the CT image acquired at one energy is used to generate the CT image at a second energy using calculated kVP conversion curves derived from phantom studies.Methods:The attenuation map (μ‐map) at 511 keV was generated for the XCAT phantom and clinical studies using the bilinear, DECT, and VDECT techniques. The generated μ‐maps at 511 keV are compared to the reference derived from the XCAT phantom serving as ground truth. PET data generated from a predefined activity map for the XCAT phantom were then corrected for attenuation using μ‐maps generated using the different energy mapping approaches. In addition, the generated μ‐maps using the above described methods for a cylindrical polyethylene phantom containing different concentrations of K2HPO4 in water were compared to actual attenuation coefficients. Likewise, CT images of five clinical whole‐body studies were used to generate μ‐maps using the various energy‐mapping approaches were compared with μ‐maps acquired at 511 keV using 68Ge/68Ga rod sources for the clinical studies.Results:The results of phantom studies demonstrate that the proposed method is more accurate than the bilinear technique. All three μ‐maps yielded almost similar results for soft and lung tissues whereas for bone tissues, the DECT and the VDECT methods produced a much smaller mean relative difference (3.0% and 2.8%, respectively) than the bilinear approach (11.8%). Likewise, the comparison of PET images corrected for attenuation using the various methods showed that the proposed method provides better accuracy (6.5%) than the bilinear method (13.4%). Clinical studies further demonstrated that, compared to the bilinear method, the VDECT approach has better agreement for bony structures with the DECT technique (1.5% versus 8.9%) and transmission scanning (8.8% versus 17.7%).Conclusions:It was concluded that the proposed method outperforms the bilinear method especially in bony structures. Further evaluation using a large clinical PET/CT database is underway to evaluate the potential of the technique in a clinical setting.
Listeria monocytogenes Grown at 7°C Shows Reduced Acid Survival and an Altered Transcriptional Response to Acid Shock Compared to L. monocytogenes Grown at 37°C
Authors: Ivy R. A. , Wiedmann M. , Boor K. J. 
Published: March 2012

ABSTRACTSurvival of the food-borne pathogenListeria monocytogenesin acidic environments (e.g., in the human stomach) is vital to its transmission. Refrigerated, ready-to-eat foods have been sources of listeriosis outbreaks. The purpose of this study was to determine whether growth at a low temperature (i.e., 7°C) affectsL. monocytogenessurvival or gene transcription after exposure to a simulated gastric environment (i.e., acid shock at 37°C).L. monocytogenescells grown at 7°C were less resistant to artificial gastric fluid (AGF) or acidified brain heart infusion broth (ABHI) than bacteria grown at higher temperatures (i.e., 30°C or 37°C). ForL. monocytogenesgrown at 7°C, stationary-phase cells were more resistant to ABHI than log-phase cells, indicating that both temperature and growth phase affect acid survival. Microarray transcriptomic analysis revealed that the number and functional categories of genes differentially expressed after acid shock differed according to both growth temperature and growth phase. The acid response ofL. monocytogenesgrown to log phase at 37°C involved stress-related transcriptional regulators (i.e., σB, σH, CtsR, and HrcA), some of which have been implicated in adaptation to the intracellular environment. In contrast, for bacteria grown at 7°C to stationary phase, acid exposure did not result in differential expression of the stress regulons examined. However, two large operons encoding bacteriophage-like proteins were induced, suggesting lysogenic prophage induction. The adaptive transcriptional response observed in 37°C-grown cells was largely absent in 7°C-grown cells, suggesting that temperatures commonly encountered during food storage and distribution affect the ability ofL. monocytogenesto survive gastric passage and ultimately cause disease.
Phospholipase A
2
Inhibitors Synthesized by Two Entomopathogenic Bacteria, Xenorhabdus nematophila and Photorhabdus temperata subsp. temperata
Authors: Seo Samyeol , Lee Sunghong , Hong Yongpyo , Kim Yonggyun 
Published: March 2012

ABSTRACT

The entomopathogenic bacteria
Xenorhabdus nematophila
and
Photorhabdus temperata
subsp.
temperata
suppress insect immune responses by inhibiting the catalytic activity of phospholipase A
2
(PLA
2
), which results in preventing biosynthesis of immune-mediating eicosanoids. This study identified PLA
2
inhibitors derived from culture broths of these two bacteria. Both
X. nematophila
and
P. temperata
subsp.
temperata
culture broths possessed significant PLA
2
-inhibitory activities. Fractionation of these bacterial metabolites in the culture broths using organic solvent and subsequent chromatography purified seven potent PLA
2
inhibitors, three of which (benzylideneacetone [BZA], proline-tyrosine [PY], and acetylated phenylalanine-glycine-valine [FGV]) were reported in a previous study. Four other compounds (indole, oxindole,
cis
-cyclo-PY, and
p
-hydroxyphenyl propionic acid) were identified and shown to significantly inhibit PLA
2
.
X. nematophila
culture broth contained these seven compounds, while
P. temperata
subsp.
temperata
culture broth contained three compounds (BZA, acetylated FGV, and
cis
-cyclo-PY). BZA was detected in the largest amount among these PLA
2
compounds in both bacterial culture broths. All seven bacterial metabolites also showed significant inhibitory activities against immune responses, such as phenoloxidase activity and hemocytic nodulation; BZA was the most potent. Finally, this study characterized these seven compounds for their insecticidal activities against the diamondback moth,
Plutella xylostella
. Even though these compounds showed relatively low toxicities to larvae, they significantly enhanced the pathogenicity of
Bacillus thuringiensis
. This study reports bacterial-origin PLA
2
inhibitors, which would be applicable for developing novel insecticides.
Conserved Terminal Organelle Morphology and Function in Mycoplasma penetrans and Mycoplasma iowae
Authors: Jurkovic Dominika A. , Newman Jaime T. , Balish Mitchell F. 
Published: March 2012

ABSTRACT

Within the genus
Mycoplasma
are species whose cells have terminal organelles, polarized structures associated with cytadherence and gliding motility.
Mycoplasma penetrans
, found mostly in HIV-infected patients, and
Mycoplasma iowae
, an economically significant poultry pathogen, are members of the
Mycoplasma muris
phylogenetic cluster. Both species have terminal organelles that interact with host cells, yet the structures in these species, or any in the
M. muris
cluster, remain uncharacterized. Time-lapse microcinematography of two strains of
M. penetrans
, GTU-54-6A1 and HF-2, and two serovars of
M. iowae
, K and N, show that the terminal organelles of both species play a role in gliding motility, with differences in speed within and between the two species. The strains and serovars also differed in their hemadsorption abilities that positively correlated with differences in motility speeds. No morphological differences were observed between
M. penetrans
and
M. iowae
by scanning electron microscopy (SEM). SEM and light microscopy of
M. penetrans
and
M. iowae
showed the presence of membranous filaments connecting pairs of dividing cells. Breaking of this filament during cell division was observed for
M. penetrans
by microcinematography, and this suggests a role for motility during division. The Triton X-100-insoluble fractions of
M. penetrans
and
M. iowae
consisted of similar structures that were unique compared to those identified in other mycoplasma species. Like other polarized mycoplasmas,
M. penetrans
and
M. iowae
have terminal organelles with cytadherence and gliding functions. The difference in function and morphology of the terminal organelles suggests that mycoplasmas have evolved terminal organelles independently of one another.
Molecular Structure of Isolated MvspI, a Variable Surface Protein of the Fish Pathogen Mycoplasma mobile
Authors: Adan-Kubo Jun , Yoshii Shu-hei , Kono Hidetoshi , Miyata Makoto 
Published: March 2012

ABSTRACT

Mycoplasma mobile
is a parasitic bacterium that causes necrosis in the gills of freshwater fishes. This study examines the molecular structure of its variable surface protein, MvspI, whose open reading frame encodes 2,002 amino acids. MvspI was isolated from mycoplasma cells by a biochemical procedure to 92% homogeneity. Gel filtration and analytical ultracentrifugation suggested that this protein is a cylinder-shaped monomer with axes of 66 and 2.7 nm. Rotary shadowing transmission electron microscopy of MvspI showed that the molecule is composed of two rods 30 and 45 nm long; the latter rod occasionally features a bulge. Immuno-electron microscopy and epitope mapping showed that the bulge end of the molecular image corresponds to the C terminus of the amino acid sequence. Partial digestion by various proteases suggested that the N-terminal part, comprised of 697 amino acids, is flexible. Analysis of the predicted amino acid sequence showed that the molecule features a lipoprotein and 16 repeats of about 90 residues; 15 positions exist between residues 88 and 1479, and the other position is between residues 1725 and 1807. The amino acid sequence of MvspI was mapped onto a molecular image obtained by electron microscopy. The present study is the first to elucidate the molecular shape of a variable surface protein of mycoplasma.
The prognostic value of Ki-67 expression in penile squamous cell carcinoma
Authors: Stankiewicz Elzbieta , Ng Mansum , Cuzick Jack , Mesher David , Watkin Nick , Lam Wayne , Corbishley Cathy , Berney Daniel M 
Published: March 2012

AimsTo determine whether Ki-67 immunoexpression in penile squamous cell carcinoma (PSCC) has a prognostic value and correlates with lymph node metastasis, human papillomavirus (HPV) infection and patient survival.Methods148 formalin-fixed paraffin-embedded PSCC samples were tissue-microarrayed, including 97 usual-type SCCs, 17 basaloid, 15 pure verrucous carcinomas, 2 warty and 17 mixed-type tumours. All samples were immunostained for Ki-67 protein. HPV DNA was detected with INNO-LiPA assay. Follow-up data were available for 134 patients.ResultsKi-67 was strongly expressed in 57/148 (38.5%) of PSCCs. Different cancer subtypes showed significant difference in Ki-67 expression (p<0.0001) with highest positivity in basaloid, 16/17 (94%), followed by usual type, 38/97 (39%) and lack of Ki-67 positive cases within verrucous tumours, 0/15. Ki-67 positively correlated with high-risk HPV (p<0.0001) and showed good specificity (84%) but low sensitivity (61%) for high-risk HPV detection. Ki-67 protein strongly positively correlated with tumour grade (p<0.0001) but not with stage (p=0.2193), or lymph node status (p=0.7366). Ki-67 showed no prognostic value for cancer-specific survival (HR=1.00, 95%, CI 0.99 to 1.02, p=0.54) or overall survival (HR=1.00, 95%, CI 0.99 to 1.02, p=0.45). High tumour stage, lymph node metastasis, high tumour grade and age at diagnosis were all independent prognostic factors for cancer-specific survival and overall survival.ConclusionsKi-67 is only a moderate surrogate marker for HPV infection in PSCC. It does not show prognostic value for cancer-specific survival and overall survival in PSCC.
Comparison of the RNA-based EndoPredict multigene test between core biopsies and corresponding surgical breast cancer sections
Authors: Müller Berit Maria , Brase Jan C , Haufe Franziska , Weber Karsten E , Budzies Jan , Petry Christoph , Prinzler Judith , Kronenwett Ralf , Dietel Manfred , Denkert Carsten 
Published: March 2012

AimThis study compared the perfomance of the RNA-based EndoPredict multigene test on core biopsies and surgical breast cancer specimens and analysed the influence of biopsy-induced tissue injuries on the test result.Methods80 formalin-fixed paraffin-embedded samples comprising paired biopsies and surgical specimens from 40 ER-positive, HER2-negative patients were evaluated. Total RNA was extracted and the EndoPredict score was determined.ResultsRNA yield was considerably lower in core biopsies, but sufficient to measure the assay in all samples. The EndoPredict score was highly correlated between paired samples (Pearson r=0.92), with an excellent concordance of classification into a low or high risk of metastasis (overall agreement 95%).ConclusionsThe measurements are comparable between core biopsies and surgical sections, which suggest that the EndoPredict assay can be performed on core biopsy tissue. Inflammatory changes induced by presurgical biopsies had no significant effect on the RNA-based risk assessment in surgical specimens.
Risk Factors for Vagal Palsy following Cerebellopontine Angle Surgery
Authors: Best Simon R. , Starmer Heather M. , Agrawal Yuri , Ward Bryan K. , Hillel Alexander T. , Chien Wade W. , Francis Howard W. , Tamargo Rafael J. , Akst Lee M. 
Published: March 2012

ObjectiveDescribe the incidence, risk factors, and outcomes of postoperative vagal palsy in patients undergoing surgical excision of cerebellopontine angle (CPA) tumors.Study DesignCase series with chart review.SettingAcademic tertiary care center.Subjects and MethodsOne hundred eighty‐one consecutive patients undergoing surgical excision of CPA pathology from January 1, 2008, to December 31, 2010, at Johns Hopkins Hospital. Postoperative unilateral vagal palsy was identified by laryngoscopy or videofluoroscopy, and clinical variables were collected from medical records.ResultsPostoperative unilateral vagal palsy was identified in 19 of 181 (10%) patients. Vocal fold motion impairment (VFMI) in combination with pharyngeal palsy was more common than VFMI or pharyngeal palsy alone. Those with vagal palsy had a larger mean tumor size (30 mm) than those without vagal palsy (20 mm, P =. 0002) and a significantly longer mean hospital stay (9 vs 5 days, P <. 0001). Vagal palsy was not associated with tumor pathology, prior treatment (stereotactic radiation or prior surgery), or surgical approach (suboccipital craniotomy vs translabyrinthine approach). Significant rates of aspiration were observed in patients with vagal palsy (67%).ConclusionVoice and swallowing function can be affected by surgical excision of pathology of the CPA. Tumor size is an independent risk factor for postoperative vagal palsy, which in turn has important consequences for prolonged hospital stay, aspiration, and voice and swallowing impairment.
Inhibition of Bcl-2 antiapoptotic members by obatoclax potently enhances sorafenib-induced apoptosis in human myeloid leukemia cells through a Bim-dependent process
Authors: Rahmani Mohamed , Aust Mandy Mayo , Attkisson Elisa , Williams David C. , Ferreira-Gonzalez Andrea , Grant Steven 
Published: March 2012

Abstract
Interactions between the multikinase inhibitor sorafenib and the BH3-mimetic obatoclax (GX15-070) were examined in human acute myeloid leukemia (AML) cells. Treatment with sorafenib/obatoclax induced pronounced apoptosis in and reduced the clonogenic growth of multiple AML lines and primary AML cells but not normal CD34+ cells. Sorafenib triggered rapid and pronounced Mcl-1 down-regulation accompanied by enhanced binding of Bim to Bcl-2 and Bcl-xL, effects that were abolished by obatoclax coadministration. Notably, shRNA knockdown of Bim, Bak, or Bax, but not Noxa, significantly attenuated obatoclax/sorafenib lethality, whereas ectopic expression of Mcl-1 exerted a protective effect. Furthermore, exposure of leukemia cells to sorafenib and obatoclax markedly induced autophagy, reflected by rapid and pronounced LC3 processing and LC3–green fluorescent protein (GFP) punctate formation. Multiple autophagy inhibitors or VPS34 knockdown, significantly potentiated sorafenib/obatoclax lethality, indicating a cytoprotective role for autophagy in this setting. Finally, studies in a xenograft mouse model revealed that combined sorafenib/obatoclax treatment markedly reduced tumor growth and significantly prolonged survival in association with Mcl-1 down-regulation and apoptosis induction, whereas agents administered individually had only modest effects. These findings suggest that combining sorafenib with agents that inhibit Mcl-1 and Bcl-2/Bcl-xL such as obatoclax may represent a novel and potentially effective strategy in AML.
Cyclic intensive light exposure induces retinal lesions similar to age-related macular degeneration in APPswe/PS1 bigenic mice
Authors: Dong Zhizhang , Li Juan , Leng Yunxia , Sun Xuerong , Hu Huiling , He Yuan , Tan Zhiqun , Ge Jian 
Published: March 2012

Abstract

Background
Intensive light exposure and beta-amyloid (Aβ) aggregates have been known as a risk factor for macular degeneration and an important component in the pathologic drusen structure involved in this disorder, respectively. However, it is unknown whether Aβ deposition mediates or exacerbates light exposure-induced pathogenesis of macular degeneration. Several studies including the one from us already showed accumulation of Aβ deposits in the retina in Alzheimer's transgenic mice. Using histopathological analysis combined with electroretinographic functional assessment, we investigated the effects of cyclic intensive light exposure (CILE) on the architecture of retina and related function in the APPswe/PS1bigenic mouse.

Results
Histopathological analysis has found significant loss of outer nuclear layer/photoreceptor outer segment and outer plexiform layer along with abnormal hypo- and hyper-pigmentation in the retinal pigment epithelium (RPE), remarkable choroidal neovascularization (CNV), and exaggerated neuroinflammatory responses in the outer retina of APPswe/PS1 bigenic mice following cyclic intensive light exposure (CILE), whereas controls remained little change contrasted with age-matched non-transgenic littermates. CILE-induced degenerative changes in RPE are further confirmed by transmission electron microcopy and manifest as formation of basal laminar deposits, irregular thickening of Bruch's membrane (BrM), deposition of outer collagenous layer (OCL) in the subretinal space, and vacuolation in the RPE. Immunofluorescence microscopy reveals drusenoid Aβ deposits in RPE as well as neovessels attached which are associated with disruption of RPE integrity and provoked neuroinflammatory response as indicated by markedly increased retinal infiltration of microglia. Moreover, both immunohistochemistry and Western blots detect an induction of vascular endothelial growth factor (VEGF) in RPE, which corroborates increased CNV in the outer retina in the bigenic mice challenged by CILE.

Conclusions
Our findings demonstrate that degenerative changes in the outer retina in the APPswe/PS1 bigenic mouse induced by CILE are consistent with these in AMD. These results suggest that an Alzheimer's transgenic animal model with accumulation of Aβ deposits might be an alternative animal model for AMD, if combined with other confounding factors such as intensive light exposure for AMD.
Factors associated with discharge destination from acute care after acquired brain injury in Ontario, Canada
Authors: Chen Amy Y , Zagorski Brandon , Parsons Daria , Vander Laan Rika , Chan Vincy , Colantonio Angela 
Published: March 2012

Abstract

Background
The aim of this paper is to examine factors associated with discharge destination after acquired brain injury in a publicly insured population using the Anderson Behavioral Model as a framework.

Methods
We utilized a retrospective cohort design. Inpatient data from provincial acute care records from fiscal years 2003/4 to 2006/7 with a diagnostic code of traumatic brain injury (TBI) and non-traumatic brain injury (nTBI) in Ontario, Canada were obtained for the study. Using multinomial logistic regression models, we examined predisposing, need and enabling factors from inpatient records in relation to major discharge outcomes such as discharge to home, inpatient rehabilitation and other institutionalized care.

Results
Multinomial logistic regression revealed that need factors were strongly correlated with discharge destinations overall. Higher scores on the Charlson Comorbidity Index were associated with discharge to other institutionalized care in the nTBI population. Length of stay and special care days were identified as markers for severity and were both strongly positively correlated with discharge to other institutionalized care and inpatient rehabilitation, compared to discharge home, in both nTBI and TBI populations. Injury by motor vehicle collisions was found to be positively correlated with discharge to inpatient rehabilitation and other institutionalized care for patients with TBI. Controlling for need factors, rural location was associated with discharge to home versus inpatient rehabilitation.

Conclusions
These findings show that need factors (Charlson Comorbidity Index, length of stay, and number of special care days) are most significant in terms of discharge destination. However, there is evidence that other factors such as rural location and access to supplemental insurance (e.g., through motor vehicle insurance) may influence discharge destination outcomes as well. These findings should be considered in creating more equitable access to healthcare services across the continuum of care.
Human Neutrophil Defensins and Their Effect on Epithelial Cells
Authors: Gursoy Ulvi K. , Könönen Eija , Luukkonen Noora , Uitto Veli‐Jukka 
Published: March 2012

Background: The aims of the present study include: 1) to localize human neutrophil defensin‐1 (HNP‐1) through HNP‐3 in gingiva and in neutrophil extract‐treated epithelial cell monolayers; 2) to determine the effects of HNP‐1 on the epithelial cell viability, attachment, and spreading; and 3) to analyze the effect of HNP‐1 on the bacterial adherence to epithelial cells.Methods: For localization of HNP‐1 through HNP‐3 in gingival tissue and in preincubated cell monolayers, immunohistochemical and immunocytochemical methods were used. Viability and proliferation of epithelial cells were determined with commercial kits after incubating the keratinocytes with different HNP‐1 concentrations (low, 1 to 5 μg/mL; moderate, 10 μg/mL; high, 20 to 50 μg/mL). Attachment and spreading of keratinocytes on fibronectin‐coated surfaces in the presence of HNP‐1 were evaluated under microscope. Attachment of Fusobacterium nucleatum ATCC25586 and Prevotella intermedia ATCC25611 on keratinocytes preincubated with HNP‐1 were determined with a standard antibiotic test.Results: HNP‐1 through HNP‐3 localized in the junctional epithelium of clinically healthy gingiva and in the pocket epithelium of gingiva with periodontitis. When keratinocyte monolayers were incubated with neutrophil extracts, HNP‐1 through HNP‐3 were bound to the periphery of the growing cell colonies. In low HNP‐1 concentrations, the keratinocyte proliferation enhanced. Moderate and high concentrations of HNP‐1 increased the cellular death significantly. HNP‐1 increased the attachment and spreading of keratinocytes on fibronectin‐coated surfaces and bacterial attachment to keratinocytes in a concentration‐dependent manner.Conclusion: HNP‐1 plays a role in the integrity of keratinocytes by stimulating their proliferation, attachment, and spreading, whereas higher doses increase the bacterial attachment and keratinocyte death.