bluuebunny/crossref_metadata_2025_split huggingface dataset:
DETERMINING CONSUMER VALUATION OF DIFFERENTIATED BEEF STEAK QUALITY ATTRIBUTES
Authors: FELDKAMP T.J. , SCHROEDER T.C. , LUSK J.L. 
Published: February 2005

ABSTRACT Consumer sensory analysis provides consistent and accurate consumer preference rankings for experimental meat products. However, consumer valuation of product attributes has often been overlooked. Valuations provide a monetary standard for comparison among meat products and product attributes as well as across different studies, a weakness of consumer sensory rating scales. This paper discusses the use of consumer valuation in a consumer sensory panel setting focusing on an incentive compatible method where consumers have an incentive to truthfully reveal their values for a product.
SENSORY PERCEPTION OF CURED‐SMOKED PORK LOIN FROM CARRIERS AND NONCARRIERS OF THE RN– ALLELE AND ITS RELATIONSHIP WITH TECHNOLOGICAL MEAT QUALITY
Authors: HULLBERG ANJA , JOHANSSON LISBETH , LUNDSTRÖM KERSTIN 
Published: February 2005

ABSTRACT The effects of RN genotype on the sensory perception of cured‐smoked loins were investigated in 30 female pigs crossbred with Hampshire. RN– carriers (RN–/rn+) were more tender, juicy and acidic than noncarriers (rn+/rn+). They were also more patty‐like and less salty. Further, they were more homogeneous in cured pink color and tended to have more pores than noncarriers. Despite the superior eating quality, in terms of higher tenderness and juiciness, most consumers preferred cured‐smoked loins from noncarriers. Multivariate statistical analyses showed that sensory tenderness, juiciness, acidity, number of pores and homogeneity of cured pink color were inversely related to instrumental tenderness measurements, but not well related to ultimate pH and water‐holding capacity. Instrumental tenderness measurements explained 44% of the variation in sensory tenderness, and RN genotype 41% of the variation in sensory juiciness. RN genotype best explained the variations in sensory attributes, followed by hardness.
IDENTIFICATION OF MEATS USING RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) TECHNIQUE
Authors: ARSLAN ALI , ILHAK IRFAN , CALICIOGLU MEHMET , KARAHAN MURAT 
Published: February 2005

ABSTRACT Use of a simpler, faster and reliable method for identification of species of origin in fresh and processed meat products is required to prevent unethical practices that may occur in the meat industry. The effectiveness of a random amplified polymorphic DNA (RAPD) method for identification of fresh meats from cattle, goat, sheep, camel, pork, wild swine, donkey, cat, dog, rabbit or bear origin was evaluated using a 10‐base primer (ACGACCCACG). The method was also used to determine the species in a 1 : 1 mix of raw minced meat from sheep‐pork, horse‐beef or beef‐sheep. Characteristic RAPD profiles for each species were obtained. However, efficacy of the technique in identifying species in meat mixtures varied depending on the species in the mix. These results indicate that RAPD may be useful for identification of meat samples from single species, such as intact meat samples, whereas caution should be exercised in identification of origin of species in minced meat that may consist of multiple species.
Relationship between Surface Accessibility for PpmA, PsaA, and PspA and Antibody-Mediated Immunity to Systemic Infection by
Streptococcus pneumoniae
Authors: Gor Dennis O. , Ding Xuedong , Briles David E. , Jacobs Michael R. , Greenspan Neil S. 
Published: February 2005

ABSTRACT

Antibodies to capsular polysaccharide (PS) are protective against systemic infection by
Streptococcus pneumoniae
, but the large number of pneumococcal serogroups and the age-related immunogenicity of pure PS limit the utility of PS-based vaccines. In contrast, cell wall-associated proteins from different capsular serotypes can be cross-reactive and immunogenic in all age groups. Therefore, we evaluated three pneumococcal proteins with respect to relative accessibility to antibody, in the context of intact pneumococci, and their ability to elicit protection against systemic infection by encapsulated
S. pneumoniae
. Sequences encoding pneumococcal surface adhesin A (PsaA), putative protease maturation protein A (PpmA), and the N-terminal region of pneumococcal surface protein A (PspA) from
S. pneumoniae
strain A66.1 were cloned and expressed in
Escherichia coli.
The presence of genes encoding PsaA, PpmA, and PspA in 11 clinical isolates was examined by PCR, and the expression of these proteins by each strain was examined by Western blotting with antisera raised to the respective recombinant proteins. We used flow cytometry to demonstrate that PspA was readily detectable on the surface of the pneumococcal strains analyzed, whereas PsaA and PpmA were not. Consistent with these observations, mice with passively or actively acquired antibodies to PspA or type 3 PS were equivalently protected from homologous systemic challenge with type 3 pneumococci, whereas mice with passively or actively acquired antibodies to PsaA or PpmA were not effectively protected. These experiments support the hypothesis that the extent of protection against systemic pneumococcal infection is influenced by target antigen accessibility to circulating host antibodies.
Altered Gingipain Maturation in
vimA-
and
vimE
-Defective Isogenic Mutants of
Porphyromonas gingivalis
Authors: Vanterpool Elaine , Roy Francis , Sandberg Lawrence , Fletcher Hansel M. 
Published: February 2005

ABSTRACT

We have previously shown that gingipain activity in
Porphyromonas gingivalis
is modulated by the unique
vimA
and
vimE
genes. To determine if these genes had a similar phenotypic effect on protease maturation and activation, isogenic mutants defective in those genes were further characterized. Western blot analyses with antigingipain antibodies showed RgpA-, RgpB-, and Kgp-immunoreactive bands in membrane fractions as well as the culture supernatant of both
P. gingivalis
W83 and FLL93, the
vimE-
defective mutant. In contrast, the membrane of
P. gingivalis
FLL92, the
vimA
-defective mutant, demonstrated immunoreactivity only with RgpB antibodies. With mass spectrometry or Western blots, full-length RgpA and RgpB were identified from extracellular fractions. In similar extracellular fractions from
P. gingivalis
FLL92 and FLL93, purified RgpB activated only arginine-specific activity. In addition, the lipopolysaccharide profiles of the
vimA
and
vimE
mutants were truncated in comparison to that of W83. While glycosylated proteins were detected in the membrane and extracellular fractions from the
vimA-
and
vimE
-defective mutants, a monoclonal antibody (1B5) that reacts with specific sugar moieties of the
P. gingivalis
cell surface polysaccharide and membrane-associated Rgp gingipain showed no immunoreactivity with these fractions. Taken together, these results indicate a possible defect in sugar biogenesis in both the
vimA
- and
vimE
-defective mutants. These modulating genes play a role in the secretion, processing, and/or anchorage of gingipains on the cell surface.
Recombinant Guinea Pig Tumor Necrosis Factor Alpha Stimulates the Expression of Interleukin-12 and the Inhibition ofMycobacterium tuberculosisGrowth in Macrophages
Authors: Cho Hyosun , Lasco Todd M. , Allen Shannon Sedberry , Yoshimura Teizo , McMurray David N. 
Published: February 2005

ABSTRACTTumor necrosis factor alpha (TNF-α) plays an important role in the host immune response to infection with the intracellular pathogenMycobacterium tuberculosis. It is essential for the formation of protective tuberculous granulomas and regulates the expression of other cytokines which contribute to a protective immune response. Interleukin-12 (IL-12) is known to promote a Th1 response, which is essential for antimycobacterial resistance. Recombinant guinea pig TNF-α (rgpTNF-α) protein (17 kDa) was purified, and its bioactivity was confirmed by its cytotoxicity for L929 fibroblasts. High titers of polyclonal anti-gpTNF-α antibody were obtained by immunization of rabbits. Resident alveolar and peritoneal macrophages were isolated from guinea pigs and infected with either the H37Ra or H37Rv strain ofM. tuberculosis. The mRNA levels for TNF-α and IL-12 p40 were measured using real-time PCR. IL-12 p40 mRNA was up-regulated in a dose-dependent manner by rgpTNF-α alone. In infected macrophages, a lower dose of rgpTNF-α intensified the mRNA levels of TNF-α and IL-12 p40. However, higher doses of rgpTNF-α suppressed TNF-α and IL-12 p40 mRNA. The antimycobacterial activity of macrophages was assessed by metabolic labeling ofM. tuberculosiswith [3H]uracil. Resident alveolar and peritoneal macrophages treated with anti-gpTNF-α antibody to block endogenous TNF-α exhibited increased intracellular mycobacterial growth. These data suggest that the dose of TNF-α is crucial to the stimulation of optimal expression of protective cytokines and that TNF-α contributes to the control of mycobacterial replication to promote host resistance againstM. tuberculosis.
Role of the Pst System in Plaque Formation by the Intracellular Pathogen
Shigella flexneri
Authors: Runyen-Janecky L. J. , Boyle A. M. , Kizzee A. , Liefer L. , Payne S. M. 
Published: February 2005

ABSTRACT

In response to the host cell environment, the intracellular pathogen
Shigella flexneri
induces the expression of numerous genes, including those in the
pst
operon which is predicted to encode a high-affinity phosphate acquisition system that is expressed under reduced phosphate conditions. An
S. flexneri pst
mutant forms smaller plaques in Henle cell monolayers than does the parental strain. This mutant exhibited normal production and localization of the
S. flexneri
IcsA protein. The
pst
mutant had the same growth rate as the parental strain in both phosphate-reduced and phosphate-replete media in vitro and during the first 3 h of growth in Henle cells in vivo. During growth in phosphate-replete media, the PhoB regulon was constitutively expressed in the
pst
mutant but not the parental strain. This suggested that the inability of the
S. flexneri pst
mutant to form wild-type plaques in Henle cell monolayers may be due to aberrant expression of the PhoB regulon. A mutation in
phoB
was constructed in the
S. flexneri pst
mutant, and the
phoB
mutation suppressed the small plaque phenotype of the
pst
mutant. Additionally, a specific mutation (R220Q) was constructed in the
pstA
gene of the
pst
operon that was predicted to eliminate Pst-mediated phosphate transport but allow normal PhoB-regulated gene expression, based on the phenotype of an
Escherichia coli
strain harboring the same mutation. Addition of this
pstA
R220Q
mutation to a
S. flexneri pst
mutant, as part of the
pst
operon, restored normal plaque formation and regulation of
phoA
expression.
Rat/MgrA, a Regulator of Autolysis, Is a Regulator of Virulence Genes in
Staphylococcus aureus
Authors: Ingavale Susham , van Wamel Willem , Luong Thanh T. , Lee Chia Y. , Cheung Ambrose L. 
Published: February 2005

ABSTRACT

We have previously identified
mgrA
(
rat
) as a regulator of autolysis in
Staphylococcus aureus
. Besides its effect on autolytic activity, we recently found alterations in the expression of regulator and target virulence genes in the
mgrA
mutant. Northern analysis and transcription fusion assays showed that inactivation of
mgrA
has led to the downregulation of RNAIII of
agr
and
hla
and upregulation of
sarS
and
spa
. Although both SarA and
agr
are activators of α-hemolysin and a repressors of protein A synthesis, we found that the transcription of
sarA
was not affected in the
mgrA
mutant and vice versa, indicating that MgrA likely regulates
hla
and
spa
in a SarA-independent manner. Previously we have shown that SarT, a SarA homolog, is a repressor of
hla
and an activator of
spa
, presumably by activating SarS, however, analysis of the double
sarT mgrA
mutant for
hla
and
spa
transcription indicated that the
mgrA-
mediated effect is not mediated via
sarT
. Our results further demonstrated that the
mgrA
gene product regulates
hla
and
spa
expression in a dual fashion, with the first being
agr
dependent and the second
agr
independent. In the
agr
-independent pathway, MgrA binds directly to
hla
and the
sarS
promoter to modulate α-hemolysin and protein A expression. Thus, our studies here have defined the nature of interaction of
mgrA
with other regulators such as
agr
,
sarS
, and
sarT
and its role in regulating
hla
and
spa
transcription within the virulence regulatory network of
S. aureus.
IpaD of
Shigella flexneri
Is Independently Required for Regulation of Ipa Protein Secretion and Efficient Insertion of IpaB and IpaC into Host Membranes
Authors: Picking Wendy L. , Nishioka Hiroaki , Hearn Patricia D. , Baxter M. Aaron , Harrington Amanda T. , Blocker Ariel , Picking William D. 
Published: February 2005

ABSTRACT

Shigella flexneri
causes human dysentery after invading the cells of the colonic epithelium. The best-studied effectors of
Shigella
entry into colonocytes are the invasion plasmid antigens IpaC and IpaB. These proteins are exported via a type III secretion system (TTSS) to form a pore in the host membrane that may allow the translocation of other effectors into the host cytoplasm. TTSS-mediated secretion of IpaD is also required for translocation pore formation, bacterial invasion, and virulence, but the mechanistic role of this protein is unclear. IpaD is also known to be involved in controlling Ipa protein secretion, but here it is shown that this activity can be separated from its requirement for cellular invasion. Amino acids 40 to 120 of IpaD are not essential for IpaD-dependent invasion; however, deletions in this region still lead to constitutive IpaB/IpaC secretion. Meanwhile, a central deletion causes only a partial loss of control of Ipa secretion but completely eliminates IpaD's invasion function, indicating that IpaD's role in invasion is not a direct outcome of its ability to control Ipa secretion. As shigellae expressing
ipaD
N-terminal deletion mutations have reduced contact-mediated hemolysis activity and are less efficient at introducing IpaB and IpaC into erythrocyte membranes, it is possible that IpaD is responsible for insertion of IpaB/IpaC pores into target cell membranes. While efficient insertion of IpaB/IpaC pores is needed for optimal invasion efficiency, it may be especially important for Ipa-dependent membrane disruption and thus for efficient vacuolar escape and intercellular spread.
The Locus of Enterocyte Effacement-Encoded Effector Proteins All Promote Enterohemorrhagic
Escherichia coli
Pathogenicity in Infant Rabbits
Authors: Ritchie Jennifer M. , Waldor Matthew K. 
Published: February 2005

ABSTRACT

The genes encoding the enterohemorrhagic
Escherichia coli
(EHEC) type III secretion system (TTSS) and five effector proteins secreted by the TTSS are located on the locus of enterocyte effacement (LEE) pathogenicity island. Deletion of
tir
, which encodes one of these effector proteins, results in a profound reduction (∼10,000-fold) in EHEC colonization of the infant rabbit intestine, but the in vivo phenotypes of other LEE genes are unknown. Here, we constructed in-frame deletions in
escN
, the putative ATPase component of the TTSS, and the genes encoding the four other LEE-encoded effector proteins, EspH, Map, EspF, and EspG, to investigate the contributions of the TTSS and the translocated effector proteins to EHEC pathogenicity in infant rabbits. We found that the TTSS is required for EHEC colonization and attaching and effacing (A/E) lesion formation in the rabbit intestine. Deletion of
escN
reduced EHEC recovery from the rabbit intestine by ∼10,000-fold. Although EspH, Map, EspF, and EspG were not required for A/E lesion formation in the rabbit intestine or in HeLa cells, these effector proteins promote EHEC colonization. Colonization by the
espH
and
espF
mutants was reduced throughout the intestine. In contrast, colonization by the
map
and
espG
mutants was reduced only in the small intestine, indicating that Map and EspG have organ-specific effects. EspF appears to down-regulate the host response to EHEC, since we observed increased accumulation of polymorphonuclear leukocytes in the colonic mucosa of rabbits infected with the EHEC
espF
mutant. Thus, all the known LEE-encoded effector proteins influence EHEC pathogenicity.
Translocation and Surface Expression of Lipidated Serogroup B Capsular Polysaccharide in
Neisseria meningitidis
Authors: Tzeng Yih-Ling , Datta Anup K. , Strole Cristy A. , Lobritz Michael A. , Carlson Russell W. , Stephens David S. 
Published: February 2005

ABSTRACT

The capsule of
N. meningitidis
serogroup B, (α2→8)-linked polysialic acid and the capsules of other meningococcal serogroups and of other gram-negative bacterial pathogens are anchored in the outer membrane through a 1,2-diacylglycerol moiety. Previous work on the meningococcal
cps
complex in
Escherichia coli
K-12 indicated that deletion of genes designated
lipA
and
lipB
caused intracellular accumulation of hyperelongated capsule polymers lacking the phospholipid substitution. To better understand the role of
lip
and
lipB
in capsule expression in a meningococcal background, the location, sequence, and relationship to related bacterial capsule genes were defined and specific mutations in
lipA
and
lipB
were generated in the serogroup B meningococcal strain NMB. The
lipA
and
lipB
genes are located on the 3′ end of the
ctr
operon and are most likely transcribed independently. Inactivation of
lipA
,
lipB
, and both resulted in the same total levels of capsular polymer production as in the parental controls; however, these mutants were as sensitive as an unencapsulated mutant to killing by normal human serum. Immunogold electron microscopy and flow cytometric analyses revealed intracellular inclusions of capsular polymers in
lipA
,
lipB
, and
lipA lipB
mutants. Capsular polymers purified from
lipA
,
lipB
, and
lipA lipB
mutants were lipidated. The phospholipid anchor was shown by gas chromatography-mass spectroscopy analysis to be a phosphodiester-linked 1,2-dipalmitoyl (C16:0) glycerol moiety and was identical in structure to that found on the wild-type meningococcal capsule polymers. Thus,
lipA
and
lipB
do not encode proteins responsible for diacylglycerophosphatidic acid substitution of the meningococcal capsule polymer; rather, they are required for proper translocation and surface expression of the lipidated polymer.
Inactivation of Membrane Tumor Necrosis Factor Alpha by Gingipains fromPorphyromonas gingivalis
Authors: Mężyk-Kopeć Renata , Bzowska Małgorzata , Potempa Jan , Bzowska Monika , Jura Natalia , Sroka Aneta , Black Roy A. , Bereta Joanna 
Published: February 2005

ABSTRACTGingipains are cysteine proteinases produced byPorphyromonas gingivalis, a major causative bacterium of adult periodontitis. They consist of arginine-specific (HRgpA and RgpB) and lysine-specific (Kgp) proteinases. Gingipains strongly affect the host defense system by degrading some cytokines, components of the complement system, and several immune cell receptors. In an in vitro model, gingipains were shown to degrade soluble tumor necrosis factor alpha (TNF-α). However, since membrane TNF-α shows strong biological activity, especially in local inflammatory lesions, it was worth investigating whether gingipains might also destroy membrane TNF-α and limit its biological activities. To avoid a possible influence of gingipains on ADAM17, the secretase of TNF-α, the majority of experiments were performed using ADAM17−/−fibroblasts stably transfected with cDNA of human pro-TNF-α (ADAM17−/−TNF+). Arginine-specific gingipains (Rgp's) strongly diminished the level of TNF-α on the cell surface as measured by flow cytometry, and this process was not accompanied by an increased concentration of soluble TNF-α in the culture medium. Degradation of membrane TNF-α by Rgp's correlated with a strong decrease in TNF-α-mediated biological activities of ADAM17−/−TNF+cells. First, the activation state of transcription factor NF-κB was suppressed; second, the cells were no longer able to induce apoptosis in HL-60 cells. Kgp was also able to cleave membrane TNF-α, but its effect was much weaker than that of Rgp's. Gingipains also limited the binding of native TNF-α to the target cells. Thus, gingipains are able not only to cleave soluble TNF-α but also to destroy the membrane form of the cytokine, which may additionally dysregulate the cytokine network.
Rapid Method for the Construction of
Salmonella enterica
Serovar Typhimurium Vaccine Carrier Strains
Authors: Husseiny Mohamed I. , Hensel Michael 
Published: February 2005

ABSTRACT

Salmonella enterica
serovar Typhimurium is a versatile organism for the generation of live recombinant vaccines for mucosal immunization. Various strategies have been devised for the stable and efficient expression of heterologous antigens by attenuated
S. enterica
strains, but these methods often require complex manipulations. Use of phage λ Red recombinase has recently been devised for gene replacements in
Escherichia coli
and
S. enterica
after introduction of PCR products. Based on this method, we have developed an approach that allows the integration of recombinant expression cassettes for heterologous antigens in a single step. The recombinant construct is integrated into the chromosome and is devoid of any selective marker such as antibiotic resistance. We observed the stable expression of model antigens without selective pressure. In addition, the method allows the simultaneous generation of attenuating mutations by gene deletions. The novel “knock-in” approach allows the rapid and efficient construction of recombinant
Salmonella
strains as vaccine carriers.
Gelatinase Is Important for Translocation of
Enterococcus faecalis
across Polarized Human Enterocyte-Like T84 Cells
Authors: Zeng Jing , Teng Fang , Murray Barbara E. 
Published: February 2005

ABSTRACT

Previously, in our laboratory, we established a two-chamber system to study translocation of
Enterococcus faecalis
across monolayers of polarized human colon carcinoma-derived T84 cells. By using the same system in the present study, we now show that disruption of
gelE
of strain OG1RF, which also has a polar effect on the cotranscribed
sprE
, as well as disruption of its regulatory system (
fsrA
,
fsrB
, and
fsrC
) resulted in a loss of detectable translocation by
E. faecalis
OG1RF; these mutants lost gelatinase (GelE) and serine protease (SprE) production by standard assay. A
gelE
deletion mutant of OG1RF (GelE
−
SprE
+
) also showed that significantly reduced translocation and complementation with the
gelE
gene (pTEX5438) in
trans
restored gelatinase and translocation, demonstrating that gelatinase is important for
E. faecalis
translocation. Complementation of
fsrA
,
fsrB
, and
fsrC
mutants with all three
fsr
genes also resulted in production of gelatinase and translocation. Furthermore, introduction of
fsr
genes into two non-gelatinase-producing
E. faecalis
isolates, the well-characterized laboratory strain JH2-2 and a human-derived fecal isolate, TX1322 (both of which have
gelE
but not
fsrA
or
fsrB
, are gelatinase negative, and do not translocate), resulted in gelatinase production by these strains and restored translocation across T84 monolayers, while transformation with pTEX5438 (
gelE
) showed little or no translocation and no detectable gelatinase, confirming the importance of both
fsr
and gelatinase for
E. faecalis
translocation. The importance of gelatinase production was also corroborated among 20
E. faecalis
human isolates (7 fecal, 7 endocarditis, and 6 urine isolates), which showed translocation by all gelatinase-positive isolates but little to no translocation for gelatinase nonproducers. These results indicate that gelatinase is important for the successful in vitro translocation of
E. faecalis
across human enterocyte-like T84 cells.