bluuebunny/crossref_metadata_2025 huggingface dataset:
Exposure to retinoic acid at the onset of hindbrain segmentation induces episodic breathing in mice
Authors: Guimarães Laura , Domínguez‐del‐Toro Eduardo , Chatonnet Fabrice , Wrobel Ludovic , Pujades Cristina , Monteiro Luís S. , Champagnat Jean
Published: June 2007

Hyperpnoeic episodic breathing (HEB), a cyclic waxing and waning of breathing, has been widely reported in pre‐term neonates, patients with Joubert syndrome and adults (Cheyne‐Stokes respiration) with congestive heart failure and brainstem infarction. We now provide a developmental mouse model of neonatal HEB. We used retinoic acid (RA) (0.5–10 mg/kg of maternal weight) to alter embryonic development of the respiratory neuronal network at the onset of hindbrain segmentation (7.5 days post‐coitum). HEB was observed in vivo after RA treatment during post‐natal days 1–7 but not in control animals. HEB persisted after reduction of the chemoafferent input by hypocapnic hyperoxia (100% O2). A large increase and decrease of the rhythm resembling an HEB episode was induced in vitro by stimulating the parafacial respiratory oscillator in treated but not in control neonates. Post‐natal localization of the superior cerebellar peduncle and adjacent dorsal tegmentum was found to be abnormal in the pons of RA‐treated juvenile mice. Thus, early developmental specifications in the rostral hindbrain are required for the development of neurones that stabilize the function of the respiratory rhythm generator, thereby preventing HEB during post‐natal maturation.
Evoked response amplitudes from somatosensory cortices do not determine reaction times to tactile stimuli
Authors: Ploner Markus , Platzen Jens , Pollok Bettina , Gross Joachim , Schnitzler Alfons
Published: June 2007

Sensory events cause changes in brain activity, which underlie the perception of and behavioural responses to sensory stimuli. Evoked cortical responses are an important measure of these stimulus‐evoked changes in brain activity. However, evidence on the relationship between behavioural responses and evoked responses is inconsistent. Therefore, we used magnetoencephalography to reinvestigate the relationship between evoked responses from somatosensory cortices and behavioural responses to somatosensory stimuli. We characterized modulations of somatosensory‐evoked responses exerted by preceding painful and tactile conditioning stimuli (CS), and related these modulations of evoked responses to modulations of reaction times. Our results show that painful CS yield a long‐lasting (> 4 s) facilitation of evoked responses, whereas tactile CS result in a shorter lasting (1–2 s) suppression of evoked responses to tactile stimuli. These contrary physiological effects were both associated with a significant shortening of reaction times. These findings indicate that the conditioning effects of painful and tactile stimuli represent essentially different modulatory mechanisms. Moreover, our results show that amplitudes of evoked responses from somatosensory cortices do not determine reaction times to tactile stimuli.
Multi‐directional differentiation of doublecortin‐ and NG2‐immunopositive progenitor cells in the adult rat neocortex in vivo
Authors: Tamura Yasuhisa , Kataoka Yosky , Cui Yilong , Takamori Yasuharu , Watanabe Yasuyoshi , Yamada Hisao
Published: June 2007

In the adult mammalian brain, multipotent stem or progenitor cells involved in reproduction of neurons and glial cells have been well investigated only in very restricted regions; the subventricular zone of the lateral ventricle and the dentate gyrus in the hippocampal formation. In the neocortex, a series of in vitro studies has suggested the possible existence of neural progenitor cells possessing neurogenic and/or gliogenic potential in adult mammals. However, the cellular properties of the cortical progenitor cells in vivo have not been fully elucidated. Using 5′‐bromodeoxyuridine labeling and immunohistochemical analysis of cell differentiation markers, we found that a subpopulation of NG2‐immunopositive cells co‐expressing doublecortin (DCX), an immature neuron marker, ubiquitously reside in the adult rat neocortex. Furthermore, these cells are the major population of proliferating cells in the region. The DCX(+)/NG2(+) cells reproduced the same daughter cells, or differentiated into DCX(+)/NG2(–) (approximately 1%) or DCX(–)/NG2(+) (approximately 10%) cells within 2 weeks after cell division. The DCX(+)/NG2(–) cells were also immunopositive for TUC‐4, a neuronal linage marker, suggesting that these cells were committed to neuronal cell differentiation, whereas the DCX(–)/NG2(+) cells showed faint immunoreactivity for glutathione S‐transferase (GST)‐pi, an oligodendrocyte lineage marker, in the cytoplasm, suggesting glial cell lineage, and thereafter the cells differentiated into NG2(–)/GST‐pi(+) mature oligodendrocytes after a further 2 weeks. These findings indicate that DCX(+)/NG2(+) cells ubiquitously exist as ‘multipotent progenitor cells’ in the neocortex of adult rats.
Circadian and photic regulation of clock and clock‐controlled proteins in the suprachiasmatic nuclei of calorie‐restricted mice
Authors: Mendoza Jorge , Pévet Paul , Challet Etienne
Published: June 2007

In mammals, behavioural and physiological rhythms as well as clock gene expression in the central suprachiasmatic clock (SCN) are phase‐shifted by a timed calorie restriction (T‐CR; animals receiving at midday 66% of their daily food intake). The molecular mechanism of SCN depends on feedback loops involving clock genes and their protein products. To understand how T‐CR mediates its synchronizing effects, we examined the rhythmic expression of three clock proteins, PERIOD (PER) 1, 2 and CLOCK, and one clock‐controlled protein (i.e. vasopressin; AVP) in the SCN of mice either fed ad libitum (AL) or with T‐CR. Moreover, we evaluated expression of these proteins in the SCN of AL and T‐CR mice following a 1‐h light pulse. The results indicate that, while PER1 and AVP rhythms were phase‐advanced in T‐CR mice, the PER2 rhythm showed an increased amplitude. CLOCK was expressed constitutively in AL mice while in T‐CR it was significantly reduced, especially after feeding time. A light pulse produced a delayed increase in PER1 and a larger increase in PER2 expression in the SCN of T‐CR mice than in AL animals. In addition, light exposure triggered an increase in AVP‐ir cells in both AL and T‐CR mice, and also of CLOCK expression but in T‐CR mice only. The circadian changes in clock and clock‐controlled proteins and their acute responses to light in the SCN of T‐CR mice demonstrate that metabolic cues induced by a calorie restriction modulate the translational regulation of the SCN clock.
The New Medicare Part D Prescription Drug Benefit: An Estimation of Its Effect on Prescription Drug Costs in a Medicare Population with Atrial Fibrillation
Authors: Evans‐Molina Carmella , Regan Susan , Henault Lori E. , Hylek Elaine M. , Schwartz Gregory R.
Published: June 2007

OBJECTIVES: To compare prescription drug cost savings under the most commonly selected Medicare Part D prescription plan in 2006 with savings under the Medicare standard benefit and with drug costs assuming no coverage in an elderly cohort of patients.

DESIGN: Inception cohort study.

SETTING: An academic medical center.

PARTICIPANTS: Four hundred seventy‐two patients aged 65 and older who were followed as part of a larger study assessing stroke prevention in patients with atrial fibrillation.

MEASUREMENTS: Prescription drug expenditures were calculated for each patient in the cohort under three conditions: the 2006 AARP‐endorsed prescription drug plan, the Medicare standard benefit, and no prescription drug coverage.

RESULTS: Total prescriptions drug costs were lower under the AARP plan, yet patients paid a similar percentage of total costs under the AARP plan and the Medicare standard benefit. Using different cost assessments, 27% to 46% of patients entered the “doughnut hole” in the AARP plan, and 3% to 11% emerged to receive catastrophic coverage.

CONCLUSION: Both the AARP‐sponsored and standard Medicare Part D prescription drug benefit programs offer significant savings to enrollees. A greater savings is achieved under the private AARP drug insurance plan, largely due to greater discounts reflected in the negotiated drug prices. A substantial portion of enrollees enter but do not emerge from the coverage gap.
Cor Triatriatum Dexter Assessed by Three‐Dimensional Echocardiography Reconstruction in Two Adult Patients
Authors: Lee Young‐Soo , Kim Kee‐Sik , Lee Jin‐Bae , Kean‐Ryu Jae , Choi Ji‐Yong , Chang Sung‐Gug
Published: June 2007

Cor triatriatum dexter is a rare congenital anomaly caused by persistence of the right valve of the embryonic sinus venosus, and this results in septation of the right atrium. Three‐dimensional echocardiography is a novel technique that can be used to identify and characterize this entity. Here, we report two women with cor triatriatum dexter.
Effects of Composition on the Reaction Kinetics of Hydrothermally Derived Barium Strontium Titanate
Authors: Xu Huiwen , Karadibhave Sreedhar , Slamovich Elliott B.
Published: June 2007

Barium strontium titanate (BST, BaxSr1−xTiO3) powders were fabricated by reacting nanocrystalline TiO2 with aqueous alkaline solutions containing Ba and Sr at 80°C. Measurements of reaction kinetics showed that Ba‐rich BST compositions exhibited more rapid reaction rates compared with Sr‐rich BST compositions, and the reaction rate increased monotonically with increasing Ba content. The average particle size also increased with increasing Ba content, with the particle growth rate of BaTiO3 being approximately a factor of 10 greater than SrTiO3. The increase in growth rate from Sr‐rich to Ba‐rich BST corresponded to a morphological transition from 20 to 30 nm cuboidal particles to 80 nm raspberry‐like particles, respectively.
Feasibility, efficacy and safety of CHOP‐14 in elderly patients with very high‐risk diffuse large B‐cell lymphoma
Authors: Tholstrup Dorte , De Nully Brown Peter , Jurlander Jesper , Hansen Mads
Published: June 2007

Objectives:  The dose‐dense CHOP‐14 regimen is efficient and safe in elderly patients with diffuse large B‐cell lymphoma (DLBCL). However, no clinical data regarding very high‐risk patients [age >75 yr and/or performance status (PS) >3] are available. The objective of this study was to evaluate the feasibility, efficacy and safety of CHOP‐14 in these patients not eligible for clinical trials.

Methods:  We analyzed 65 patients treated with CHOP‐14. Patients were stratified into two cohorts; A: very high‐risk (age 60–75 with PS = 4 or age >75; n = 24) and B: standard risk (age 60–75 with PS ≤3 or age <60; n = 41).

Results:  Fifty eight percent in cohort A achieved complete response (CR) compared with 80% in cohort B (P = 0.054). The 3‐yr event free survival (EFS) was 40% vs. 52% (ns), 3‐yr overall survival (OAS) 44% vs. 68% (P = 0.017). Median schedule‐erosion was 14 (0–67) (A) vs. 8 (0–44) (B) days (ns) and dose‐erosion was confined to vincristine‐reduction in both cohorts. Therapy‐associated deaths did not differ. However, a significant increase in hospital admission was found in cohort A, where 88% required hospitalization (median 47 d) compared with 68% (median 9 d) in cohort B (P = 0.003). The patients presented with a combination of opportunistic infections, malnutrition and decreasing PS.

Conclusions:  Although the 3‐yr OAS in very high‐risk DLBCL is encouraging, the high frequency of severe toxicity with infections and malnutrition responsible for increased morbidity during treatment, warrants for careful attention to these very high‐risk patients.
A Chemical Basis for Sour Taste Perception of Acid Solutions and Fresh‐Pack Dill Pickles
Authors: Da Conceicao Neta E.R. , Johanningsmeier S.D. , Drake M.A. , McFeeters R.F.
Published: June 2007

ABSTRACT:  Sour taste is influenced by pH and acids present in foods. It is not currently possible, however, to accurately predict and modify sour taste intensity in foods containing organic acids. The objective of this study was to investigate the roles of protonated (undissociated) organic acid species and hydrogen ions in evoking sour taste. Sour taste intensity increased linearly with hydrogen ion concentration (R2= 0.995), and with the concentration of protonated organic acid species at pH 3.5 (R2= 0.884), 4.0 (R2= 0.929), and 4.5 (R2= 0.975). The structures of organic acid molecules did not affect sour taste after adjusting for the effects of protonated organic acid species and hydrogen ions. Sour taste intensity was also linearly related to the total concentration of protonated organic acid species in fresh‐pack dill pickles (R2= 0.957). This study showed that the sour taste of organic acids was directly related to the number of molecules with at least 1 protonated carboxyl group plus the hydrogen ions in solution. Conclusions from these results are that all protonated organic acids are equally sour on a molar basis, that all protonated species of a given organic acid are equally sour, and that hydrogen ions and protonated organic acids are approximately equal in sour taste on a molar basis. This study provides a new understanding of the chemical species that are able to elicit sour taste and reveals a basis for predicting sour taste intensity in the formulation of acidified foods.
Nonisothermal Kinetics of Acrylamide Elimination and Its Acceleration by Table Salt—A Model Study
Authors: Kolek E. , Šimon P. , Šimko P.
Published: June 2007

ABSTRACT:  Acrylamide was applied onto table salt and heated in a glass reaction vessel within the temperature range 50 to 210 °C with a heating rate of 2 °C/min in order to study the influence of temperature and table salt on acrylamide elimination. For comparison purposes, pure acrylamide was also heated at the same conditions to 190 °C. Both systems were analyzed for acrylamide amount by GC‐MS. During heating, the amount of acrylamide in contact with table salt decreased from 99.9 to 67.7 μg while the amount of acrylamide without table salt decreased from 99.9 to 81.3 μg, obviously due to polymerization reactions taking place in both studied systems. Comparing the results it was found that table salt has substantial catalytic effects on the polymerization reactions. Based on the treatment of experimental results, the parameters characterizing the kinetics of acrylamide polymerization, for example, the rate of its elimination at nonisothermal conditions, have been obtained, also making possible the calculation of rate constant values for any temperature in isothermal regime. As concluded, the polymerization may represent one of conceivable pathways of acrylamide elimination in a real food matrix.
Effects of Varying Levels of Vegetable Juice Powder and Incubation Time on Color, Residual Nitrate and Nitrite, Pigment, pH, and Trained Sensory Attributes of Ready‐to‐Eat Uncured Ham
Authors: Sindelar J.J. , Cordray J.C. , Sebranek J.G. , Love J.A. , Ahn D.U.
Published: June 2007

ABSTRACT:  Vegetable juice powder (VJP) and a starter culture containing Staphylococcus carnosus have been identified as necessary ingredients for the manufacture of uncured, no‐nitrate/nitrite‐added meat products with quality and sensory attributes similar to traditional cured products. The objectives of this study were to determine the effects of varying concentrations of VJP and incubation time (MIN‐HOLD) on quality characteristics, including lipid oxidation, color, and cured meat pigment concentrations, of ham over a 90‐d storage period, compare residual nitrate and nitrite content, and determine if differences exist in sensory properties of finished products. Four ham treatments (TRT) (TRT 1: 0.20% VJP, 0 MIN‐HOLD; TRT 2: 0.20% VJP, 120 MIN‐HOLD; TRT 3: 0.35% VJP, 0 MIN‐HOLD; TRT 4: 0.35% VJP, 120 MIN‐HOLD) and a sodium nitrite‐added control (C) were used for this study. No differences (P > 0.05) were observed between TRTs and C for CIE L*, a*, b*, and cured color measured by reflectance ratio. Lipid oxidation (TBARS) for combined TRTs and C revealed little change over time while the C had less (P < 0.05) lipid oxidation than TRTs 2 and 4 for combined days. No differences (P > 0.05) were reported for cured pigment concentration between TRTs and C. Trained sensory panel intensity ratings for ham and vegetable aroma, and flavor, color, and firmness showed that a high concentration (0.35%) of VJP resulted in the highest scores for undesirable vegetable aroma and flavor. Treatment combinations with a low concentration (0.20%) of VJP were comparable to the C for all sensory attributes.
Pilot Plant Scale Production of Protein from Catfish Treated by Acid Solubilization/Isoelectric Precipitation
Authors: Mireles DeWitt C.A. , Nabors R.L. , Kleinholz C.W.
Published: June 2007

ABSTRACT:  Catfish fillets were minced and acid (pH 3.0) solubilized in dilute conditions (1:9). Insolubles were removed by centrifugal force (3000 ×g) and the soluble protein was recovered by isoelectric precipitation (pI approximately 5.4). Moisture and NaCl of the batters were equilibrated to 78% and 2%, respectively. Samples were stuffed into casings, cooked, and chilled. Proximate composition, color, cook yield, water holding ability (WHA), and texture profile analysis (TPA) were determined. Treatment of catfish protein by the solubilization process removed 74% of the fat. In addition, gels from treated protein were less red (−1.61 compared with −1.06) and yellow (6.58 compared with 7.09). There was no difference in whiteness (72.0 compared with 71.8) of gels or in percent cook yield (94.6% compared with 95.0%) between treated protein and the control, respectively. The WHA of gels made from control protein was 0.73 g/g protein higher than treated. The texture analysis indicated that treated proteins had significantly higher hardness (1193 g compared with 1046 g), springiness (0.919 compared with 0.897), chewiness (0.701 compared with 0.584), and cohesiveness (0.637 mJ compared with 0.619 mJ). The resilience was equivalent for both treated and control gels. The results indicated the protein solubilization process produced a low fat protein product with good gel strength properties.
Effect of Hydrogen Ion Concentration and Electrostatic Polarity on Food Powder Coating Transfer Efficiency and Adhesion
Authors: Setyo D. , Barringer S.
Published: June 2007

ABSTRACT:  Two kinds of soy protein isolate, rice protein, whey protein isolate, albumen, bovine collagen hydrolysate, NaCl, and corn starch were used in this study. Solutions were prepared by mixing the powder and distilled water (1:8 ratio) and either H2SO4 or NH4OH to obtain pH 3, 5, 7, 9, and 11. The solutions were dried to produce powders with different hydrogen ion concentrations and the powders were ground. Powders were coated nonelectrostatically and using negative and positive polarity corona electrostatically. There was no solution pH effect on transfer efficiency or adhesion for most powders. However, transfer efficiency and density of both of the soy protein isolates and corn starch changed with solution pH. Solution pH may have affected the density, which affected the transfer efficiency for these powders. Adhesion and cohesiveness of one of the soy protein isolates and corn starch also changed with solution pH. Solution pH may have affected the cohesiveness, which affected the adhesion for these powders. Negative and positive coronas produced the same results for most powders, with no solution pH effect, except for one of the soy protein isolates, rice protein, and corn starch. These powders accumulated on the electrode wires during negative corona electrostatic coating, reducing transfer efficiency and adhesion. This polarity effect was intermittent, implying it is due to tribocharging.
Stakeholder Willingness to Pay for Watershed Restoration in Rural Bolivia1
Authors: Shultz Steven , Soliz Bruno
Published: June 2007

Abstract:  Two CVM surveys were administered to 211 urban households and 188 rural farmer‐irrigators in the Comarapa watershed in Bolivia, South America, to estimate stakeholder willingness to pay (WTP) for a proposed upper watershed restoration program. Mean monthly household WTP to improve drinking water was $1.95 (65% of current charges), while mean annual WTP among farmer‐irrigators to improve irrigation water was $17 per hectare (34% of current costs). Aggregated to the entire population of households and farmer‐irrigators total WTP is $77,400 per year, which is 77% of the minimum cost to implement a watershed restoration program.
Ranch Ownership Change and New Approaches to Water Resource Management in Southwestern Montana: Implications for Fisheries1
Authors: Gosnell Hannah , Haggerty Julia H. , Byorth Patrick A.
Published: June 2007

Abstract:  This article reports on a survey of ranch owners in high amenity areas in southwestern Montana that have experienced marked ownership change over the last two decades. Specifically, we focus on findings from a set of questions targeting water resource and riparian area management. After reviewing the results, we consider how new owners may be managing water resources differently than longtime owners and what the ecological implications of this shift in management might be for Montana’s prized wild fisheries. Uses more closely associated with new owners than with longtime owners include water reallocation to instream uses, aquatic and riparian ecosystem restoration, and fish pond construction. These uses have both positive and negative impacts on the region’s fisheries. Our findings suggest that current laws and institutions guiding the management of water resources and the aquatic and riparian ecosystems they support may not be adequate to address emerging conservation opportunities and challenges.
Characterization and Use of Mammalian-Expressed Vaccinia Virus Extracellular Membrane Proteins for Quantification of the Humoral Immune Response to Smallpox Vaccines
Authors: García Alonzo D. , Meseda Clement A. , Mayer Anne E. , Kumar Arunima , Merchlinsky Michael , Weir Jerry P.
Published: June 2007

The licensed smallpox vaccine Dryvax is used as the standard in comparative immunogenicity and protection studies of new smallpox vaccine candidates. Although the correlates of protection against smallpox are unknown, recent studies have shown that a humoral response against the intracellular mature virion and extracellular enveloped virion (EV) forms of vaccinia virus is crucial for protection. Using a recombinant Semliki Forest virus (rSFV) vector system, we expressed a set of full-length EV proteins for the development of EV antigen-specific enzyme-linked immunosorbent assays (ELISAs) and the production of monospecific antisera. The EV-specific ELISAs were used to evaluate the EV humoral response elicited by Dryvax and the nonreplicating modified vaccinia virus Ankara (MVA) in mouse vaccination experiments comparing doses and routes of vaccination. Quantitatively similar titers of antibodies against EV antigens A33R, A56R, and B5R were measured in mice vaccinated with Dryvax and MVA when MVA was administered at a dose of 108plaque-forming units. Further, a substantial increase in the EV-specific antibody response was induced in mice inoculated with MVA by using a prime-boost schedule. Finally, we investigated the abilities of the EV-expressing rSFV vectors to elicit the production of polyclonal monospecific antisera against the corresponding EV proteins in mice. The monospecific serum antibody levels against A33R, A56R, and B5R were measurably higher than the antibody levels induced by Dryvax. The resulting polyclonal antisera were used in Western blot analysis and immunofluorescence assays, indicating that rSFV particles are useful vectors for generating monospecific antisera.
Epitope-Blocking Enzyme-Linked Immunosorbent Assay To Differentiate West Nile Virus from Japanese Encephalitis Virus Infections in Equine Sera
Authors: Kitai Yoko , Shoda Mizue , Kondo Takashi , Konishi Eiji
Published: June 2007

West Nile virus (WNV) is now widely distributed worldwide, except in most areas of Asia where Japanese encephalitis virus (JEV) is distributed. Considering the movement and migration of reservoir birds, there is concern that WNV may be introduced in Asian countries. Although manuals and guidelines for serological tests have been created in Japan in preparedness for the introduction of WNV, differential diagnosis between WNV and JEV may be complicated by antigenic cross-reactivities between these flaviviruses. Here, we generated a monoclonal antibody specific for the nonstructural protein 1 (NS1) of WNV and established an epitope-blocking enzyme-linked immunosorbent assay that can differentiate WNV from JEV infections in horse sera. Under conditions well suited for our assay system, samples collected from 95 horses in Japan (regarded as negative for WNV antibodies), including those collected from horses naturally infected with JEV, showed a mean inhibition value of 8.2% and a standard deviation (SD) of 6.5%. However, inhibition values obtained with serum used as a positive control (obtained after 28 days from a horse experimentally infected with WNV) in nine separate experiments showed a mean of 54.4% and an SD of 7.1%. We tentatively determined 27.6% (mean + 3 × SD obtained with 95 negative samples) as the cutoff value to differentiate positive from negative samples. Under this criterion, two horses experimentally infected with WNV were diagnosed as positive at 12 and 14 days, respectively, after infection.
Seroprevalence of Neutralizing Antibodies to Adenovirus Type 5 among Children in India: Implications for Recombinant Adenovirus-Based Vaccines
Authors: Appaiahgari Mohan Babu , Pandey Ravindra Mohan , Vrati Sudhanshu
Published: June 2007

We determined the levels of adenovirus 5 (Ad5) neutralizing antibodies in children in India less than 2 years of age. The results clearly show an age-dependent increase in Ad5-specific immunity, with 7- to 12-month-old children having the lowest levels of Ad5 immunity. This opens up the scope for the use of recombinant Ad5-based vaccines in this age group.
Quinolone Resistance of
Salmonella enterica
Serovar Virchow Isolates from Humans and Poultry in Israel: Evidence for Clonal Expansion
Authors: Solnik-Isaac Hadas , Weinberger Miriam , Tabak Mina , Ben-David Alon , Shachar Dina , Yaron Sima
Published: June 2007

Salmonella enterica
serovar Virchow is highly prevalent in humans and farm animals in Israel. In addition to high rates of resistance to multiple antibiotics, this serovar exhibits a high incidence of resistance to nalidixic acid. More than 90% of
Salmonella
serovar Virchow isolates of human and poultry origin obtained from 1997 to 2004 were resistant to nalidixic acid (MIC ≥ 128 μg/ml), with reduced susceptibility to ciprofloxacin (MIC between 0.125 and 0.250 μg/ml). Most isolates belonged to two predominant, closely related pulsed-field gel electrophoresis image types. Investigation of the mechanisms of quinolone resistance revealed that this pathogen probably emerged from a parental clone that overproduced the AcrAB efflux pump and had a single point mutation in
gyrA
leading to the Asp87Tyr substitution. The close resemblance between human and poultry isolates points to poultry as a likely source of
Salmonella
serovar Virchow in the food chain.
Development and Evaluation of a Line Probe Assay for Rapid Identification of
pncA
Mutations in Pyrazinamide-Resistant
Mycobacterium tuberculosis
Strains
Authors: Sekiguchi Jun-Ichiro , Nakamura Tomohiko , Miyoshi-Akiyama Tohru , Kirikae Fumiko , Kobayashi Intetsu , Augustynowicz-Kopeć Ewa , Zwolska Zofia , Morita Koji , Suetake Toshinori , Yoshida Hiroshi , Kato Seiya , Mori Toru , Kirikae Teruo
Published: June 2007

Resistance of
Mycobacterium tuberculosis
to pyrazinamide (PZA) derives mainly from mutations in the
pncA
gene. We developed a reverse hybridization-based line probe assay with oligonucleotide probes designed to detect mutations in
pncA
. The detection of PZA resistance was evaluated in 258 clinical isolates of
M. tuberculosis
. The sensitivity and specificity of PZA resistance obtained by this new assay were both 100%, consistent with the results of conventional PZA susceptibility testing. This assay can be used with sputa from tuberculosis patients. It appears to be reliable and widely applicable and, given its simplicity and rapid performance, will be a valuable tool for diagnostic use.
Field Evaluation of a Rota- and Adenovirus Immunochromatographic Assay Using Stool Samples from Children with Acute Diarrhea in Ghana
Authors: Weitzel Thomas , Reither Klaus , Mockenhaupt Frank P. , Stark Klaus , Ignatius Ralf , Saad Eiman , Seidu-Korkor Andrew , Bienzle Ulrich , Schreier Eckart
Published: June 2007

We evaluated the Rida Quick rotavirus/adenovirus Combi rapid immunochromatographic test (ICT) under field conditions with Ghanaian children with acute diarrhea. Compared to PCR results, sensitivities and specificities were 75% and 95% for rotavirus and 22% and 84% for adenovirus. In resource-poor settings, ICTs may help to overcome difficulties in the diagnosis of rotavirus infection.
Comparison of Phoenix and VITEK 2 Extended-Spectrum-β-Lactamase Detection Tests for Analysis of
Escherichia coli
and
Klebsiella
Isolates with Well-Characterized β-Lactamases
Authors: Thomson Kenneth S. , Cornish Nancy E. , Hong Seong G. , Hemrick Kim , Herdt Christian , Moland Ellen S.
Published: June 2007

The VITEK 2 and Phoenix extended-spectrum β-lactamase (ESBL) detection systems, which comprise confirmatory tests and expert systems, were evaluated for their ability to discriminate between 102 well-characterized strains of ESBL-positive or -negative
Escherichia coli
,
Klebsiella pneumoniae
, and
Klebsiella oxytoca
. At least 38 distinct ESBLs were included. The strains were chosen to include some known to cause false-positive and false-negative CLSI ESBL confirmatory test results. Therefore, enzyme characterizations, rather than CLSI tests, were the reference methods for the Phoenix and VITEK 2 evaluations. A third arm of the study was conducted with the Phoenix test using two normally inactive expert rules intended to enhance ESBL detection, in addition to using the currently available software. The Phoenix ESBL confirmatory test and unmodified expert system exhibited 96% sensitivity and 81% specificity for ESBL detection. Activation of the two additional rules increased sensitivity to 99% but reduced the specificity to 58%. The VITEK 2 ESBL confirmatory test exhibited 91% sensitivity, which was reduced to 89% sensitivity by its expert system, while its specificity was 85%. Many of the expert system interpretations of both instruments were helpful, but some were suboptimal. The VITEK 2 expert system was potentially more frustrating because it provided more inconclusive interpretations of the results. Considering the high degree of diagnostic difficulty posed by the strains, both ESBL confirmatory tests were highly sensitive. The expert systems of both instruments require modification to update and enhance their utility.
Development of a Respiratory Virus Panel Test for Detection of Twenty Human Respiratory Viruses by Use of Multiplex PCR and a Fluid Microbead-Based Assay
Authors: Mahony J. , Chong S. , Merante F. , Yaghoubian S. , Sinha T. , Lisle C. , Janeczko R.
Published: June 2007

Virology laboratories historically have used direct fluorescent-antibody assay (DFA) and culture to detect six or seven respiratory viruses. Following the discovery of five new human respiratory viruses since 2000, there is an increasing need for diagnostic tests to detect these emerging viruses. We have developed a new test that can detect 20 different respiratory virus types/subtypes in a single 5-h test. The assay employs multiplex PCR using 14 virus-specific primer pairs, followed by a multiplexed target-specific primer extension (TSPE) reaction using 21 primers for specific respiratory virus types and subtypes. TSPE products were sorted and identified by using a fluid microsphere-based array (Universal Array; TmBioscience Corporation, Toronto, Canada) and the Luminex x-MAP system. The assay detected influenza A and B viruses; influenza A virus subtypes H1, H3, and H5 (including subtype H5N1 of the Asian lineage); parainfluenza virus types 1, 2, 3, and 4; respiratory syncytial virus types A and B; adenovirus; metapneumovirus; rhinovirus; enterovirus; and coronaviruses OC43, 229E, severe acute respiratory syndrome coronavirus, NL63, and HKU1. In a prospective evaluation using 294 nasopharyngeal swab specimens, DFA/culture detected 119 positives and the respiratory virus panel (RVP) test detected 112 positives, for a sensitivity of 97%. The RVP test detected an additional 61 positive specimens that either were not detected by DFA/culture or were positive for viruses not tested for by DFA/culture. After resolution of discordant results by using a second unique PCR assay and by using a combined reference standard of positivity, the RVP test detected 180 of 183 true positives, for a sensitivity of 98.5%, whereas DFA and culture detected only 126 of 183 true positives, for a sensitivity of 68.8%. The RVP test should improve the capabilities of hospital and public health laboratories for diagnosing viral respiratory tract infections and should assist public health agencies in identifying etiologic agents in respiratory tract infection outbreaks.
Requirement of Ca2+ influx- and phosphatidylinositol 3-kinase-mediated m-calpain activity for shear stress-induced endothelial cell polarity
Authors: Miyazaki Takuro , Honda Kazuo , Ohata Hisayuki
Published: June 2007

Proteolytic activity in sheared human umbilical vein endothelial cells (HUVECs) was measured using a fluorogenic substrate and laser scanning confocal microscopy to clarify the key role of an intracellular Ca2+-sensitive protease, calpain, in these cells in response to shear stress. Within physiological shear range, activity in the cells was enhanced in shear-dependent fashion. Short interfering RNA-induced silencing of m-calpain, but not of μ-calpain, suppressed the activity. Either removal of extracellular Ca2+ or application of an intracellular Ca2+ chelator (BAPTA/AM) or nonselective cation channel blocker (Gd3+) reduced proteolytic activity. Furthermore, activity was suppressed by phosphatidylinositol bisphosphate (PIP2) chelator (neomycin) or phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002); in contrast, activity, which was partially inhibited by ERK kinase inhibitor (U0126, PD98059), was unaffected by PLC inhibitor (U73122). Moreover, Akt phosphorylation downstream of PI3K, which was elicited by shear, was attenuated by neomycin but not by calpain inhibitor (calpeptin). Following assessment of shear stress-induced focal adhesion (FA) and cytoskeletal dynamics using interference reflection/green fluorescence protein-actin microscopy, we found that either calpain or PI3K inhibition impaired shear stress-induced polarization of FAs via stabilization of FA structures. Additionally, HUVEC alignment and cytoskeletal remodeling, which was accompanied by calpain-mediated cleavage of vinculin and talin, were also elicited by prolonged application of shear and impaired by m-calpain knockdown. Thus, these results revealed that physiological shear stress elicits Ca2+ influx-sensitive activation of m-calpain in HUVECs. This activity is facilitated primarily through the PI3K pathway; furthermore, it is essential for subsequent FA reorganization and cell alignment under shear conditions.
Wheel running affects seasonal acclimatization of physiological and morphological traits in the Djungarian hamster (Phodopus sungorus)
Authors: Scherbarth Frank , Rozman Jan , Klingenspor Martin , Brabant Georg , Steinlechner Stephan
Published: June 2007

Wheel running was previously shown to influence body mass and torpor in short-day-acclimatized Djungarian hamsters ( Phodopus sungorus). To determine whether the exercise-induced effect on body mass depends on the annual phase, hamsters were exposed to the natural change in photoperiod and given access to a running wheel (RW), either before, in the middle of, or at the end of the descending body mass trajectory during seasonal acclimatization. Due to wheel running, the seasonal weight cycle was prevented or aborted by abruptly rising body mass, resulting in a weight appropriate for summer, despite exposure to short days. Torpor was inhibited, and testicular recrudescence was advanced, compared with controls. In contrast, the change into winter fur remained unaltered. Analysis of body composition and plasma leptin revealed a low body fat mass in RW hamsters, not only in winter but also in summer, suggesting a lack of seasonal adiposity. Chronic leptin infusion in winter only decreased body mass in RW individuals, although their relative body fat mass probably was even lower than in sedentary hamsters. A constantly low body fat mass is conceivably reflecting an exercise-dependent change in metabolism, consistent with increased bone mineral content and density in RW hamsters. Additionally, bone area was increased, again supported by elongated vertebral columns. Together, the results show a striking effect of wheel running on body composition and the seasonal pattern of body mass, and they suggest that the photoperiodic regulation of body mass is regulated differently than the reproductive and pelage responses.
Protein appetite is increased after central leptin-induced fat depletion
Authors: Wiater Michael F. , Hudson Bryan D. , Virgin Yvette , Ritter Sue
Published: June 2007

Leptin reduces body fat selectively, sparing body protein. Accordingly, during chronic leptin administration, food intake is suppressed, and body weight is reduced until body fat is depleted. Body weight then stabilizes at this fat-depleted nadir, while food intake returns to normal caloric levels, presumably in defense of energy and nutritional homeostasis. This model of leptin treatment offers the opportunity to examine controls of food intake that are independent of leptin's actions, and provides a window for examining the nature of feeding controls in a “fatless” animal. Here we evaluate macronutrient selection during this fat-depleted phase of leptin treatment. Adult, male Sprague-Dawley rats were maintained on standard pelleted rodent chow and given daily lateral ventricular injections of leptin or vehicle solution until body weight reached the nadir point and food intake returned to normal levels. Injections were then continued for 8 days, during which rats self-selected their daily diet from separate sources of carbohydrate, protein, and fat. Macronutrient choice differed profoundly in leptin and control rats. Leptin rats exhibited a dramatic increase in protein intake, whereas controls exhibited a strong carbohydrate preference. Fat intake did not differ between groups at any time during the 8-day test. Despite these dramatic differences in macronutrient selection, total daily caloric intake did not differ between groups except on day 2. Thus controls of food intake related to ongoing metabolic and nutritional requirements may supersede the negative feedback signals related to body fat stores.
Hypothalamic neuropeptide gene expression during recovery from food restriction superimposed on short-day photoperiod-induced weight loss in the Siberian hamster
Authors: Archer Zoë A. , Moar Kim M. , Logie Tracy J. , Reilly Laura , Stevens Valerie , Morgan Peter J. , Mercer Julian G.
Published: June 2007

Previously, 40% food restriction of male Siberian hamsters over 21 days in short-day (SD) photoperiod induced characteristic changes in expression of hypothalamic arcuate nucleus energy balance genes; mRNAs for neuropeptide Y, agouti-related peptide, and leptin receptor were upregulated, and those of proopiomelanocortin and cocaine- and amphetamine-regulated transcript were depressed. The present study examined the effect of refeeding hamsters for 6 days (∼50% recovery of weight differential) or 19 days (resumption of appropriate weight trajectory). Hyperphagia continued throughout refeeding, but differences in fat pad weights and leptin levels had disappeared after 19 days. Cocaine- and amphetamine-regulated transcript gene expression was depressed by prior restriction in both refed groups. The depressive effect of prior restriction on proopiomelanocortin gene expression had disappeared after 19 days of refeeding. There was no effect of prior food restriction on neuropeptide Y or agouti-related peptide gene expression. Expression of the anorexigenic brain-derived neurotrophic factor was downregulated in the ventromedial nucleus after SD exposure for 12 wk. In the SD food restriction study, there were effects of photoperiod on brain-derived neurotrophic factor gene expression but not of prior food restriction. Hypothalamic energy balance genes in the hamster respond asynchronously to return to a seasonally appropriate body weight. The achievement of this weight rather than the weight at which caloric restriction was imposed is the critical factor. The differential responses of hypothalamic energy balance genes to food restriction and refeeding are poorly characterized in any species, a critical issue given their potential relevance to human weight loss strategies that involve caloric restriction.
Cyclosporine A induces senescence in renal tubular epithelial cells
Authors: Jennings Paul , Koppelstaetter Christian , Aydin Sonia , Abberger Thomas , Wolf Anna Maria , Mayer Gert , Pfaller Walter
Published: June 2007

The nephrotoxic potential of the widely used immunosuppressive agent cyclosporine A (CsA) is well recognized. However, the mechanism of renal tubular toxicity is not yet fully elucidated. Chronic CsA nephropathy and renal organ aging share some clinical features, such as renal fibrosis and tubular atrophy, raising the possibility that CsA may exert some of its deleterious effects via induction of a stress-induced senescent phenotype. We investigated this hypothesis in HK-2 cells and primary proximal tubular cells in vitro. CsA induced the production of H2O2, caused cell cycle arrest in the G0/G1 phase, and inhibited DNA synthesis. Furthermore, CsA exposure lead to a reduction of telomere length, increased p53 serine 15 phosphorylation, and caused an upregulation of the cell cycle inhibitor p21Kip1(CDKN1A) mRNA levels. CsA caused an increase in p16INK4a(CDKN2A) expression after a 13-day exposure in primary proximal tubular cells but not in HK-2 cells. Coincubation of cells with CsA and catalase was able to prevent telomere shortening and partially restored DNA synthesis. In summary, CsA induces cellular senescence in human renal tubular epithelial cells, which can be attenuated by scavenging reactive oxygen species.
Differential effect of tetradecythioacetic acid on the renin-angiotensin system and blood pressure in SHR and 2-kidney, 1-clip hypertension
Authors: Bivol Liliana Monica , Berge Rolf Kristian , Iversen Bjarne Magnus
Published: June 2007

The tetradecythioacetic acid (TTA) is a modified fatty acid known to exhibit pleiotropic effects. First, we compared the effect of TTA on the blood pressure in spontaneously hypertensive rats (SHR) with two-kidney, one-clip (2K1C)-hypertensive rats. Second, we examined mechanisms involved in the blood pressure reduction. TTA had minor effect on systolic blood pressure (SBP) in young SHR up to 8 wk of age. In 2K1C we confirmed the blood pressure-lowering effect of TTA (SBP: 173 ± 4 before vs. 138 ± 3 mmHg after TTA, P < 0.001). No effect on SBP was seen in Wistar-Kyoto rat (WKY) controls. Plasma renin activity (PRA) was low in SHR and WKY controls and TTA did not change it. PRA decreased from 22.9 ± 1.3 to 16.2 ± 2.2 ng·ml−1·h−1 ( P = 0.02) in 2K1C. Plasma ANG II concentration declined from 101 ± 3 to 81 ± 5 fmol/l after TTA treatment ( P = 0.005). In the clipped kidney, tissue ANG I concentration decreased from 933 ± 68 to 518 ± 60 fmol/g tissue ( P = 0.001), and ANG II decreased from 527 ± 38 to 149 ± 21 fmol/g tissue ( P < 0.001) after TTA treatment. In the nonclipped kidney, TTA did not change ANG I and moderately reduced ANG II levels. The renal blood flow response to injection of ANG II into the nonclipped kidney was blunted compared with controls and normalized with TTA treatment (10 ± 2 before vs. 20 ± 2%, P < 0.001). The results indicate that TTA downregulates the renin-angiotensin system in high renin animals but has no effect in low renin models.
Isoflurane protects against renal ischemia and reperfusion injury and modulates leukocyte infiltration in mice
Authors: Lee H. Thomas , Kim Mihwa , Kim Minjae , Kim NaLa , Billings Frederic T. , D'Agati Vivette D. , Emala Charles W.
Published: June 2007

Inflammation after renal ischemia-reperfusion (IR) injury is a major contributor to renal cell death. We previously demonstrated that several volatile anesthetics protect against renal IR injury and necrosis in rats in vivo. We subsequently showed that volatile anesthetics produced direct anti-inflammatory and anti-necrotic effects in cultured proximal tubule cells in vitro. In this study, we wanted to determine whether the volatile anesthetic isoflurane protects against renal IR injury by producing anti-inflammatory effects in mice. C57BL/6 mice subjected to renal IR under isoflurane anesthesia demonstrated improved renal function and reduced necrosis compared with mice subjected to renal IR under pentobarbital anesthesia. Mice subjected to renal IR under isoflurane anesthesia also showed a reduction in inflammation evidenced by a reduced renal influx of neutrophils and macrophages, reduced ICAM-1 expression, less upregulation of proinflammatory mRNAs (TNF-α, ICAM-1, KC, and IL-1β) as well as reduced nuclear translocation of NF-κB 24 h after renal IR injury. Analysis of specific lymphocyte subset trafficking to the kidney using flow cytometry demonstrated that isoflurane anesthesia reduced intrarenal influx of CD3+, CD4+, CD8+, and NK1.1+ lymphocytes at 3 h after renal ischemia compared with pentobarbital anesthesia. However, only the differential reduction of NK1.1+ lymphocytes persisted 24 h after renal ischemia. Therefore, we conclude that isoflurane anesthesia significantly attenuated renal IR injury in mice by reducing inflammation and modulating leukocyte influx. In particular, neutrophil, macrophage, and NK1.1+ lymphocyte cell modulation may play a significant role in renal protection by isoflurane anesthesia.
Knockdown of endosomal/lysosomal divalent metal transporter 1 by RNA interference prevents cadmium-metallothionein-1 cytotoxicity in renal proximal tubule cells
Authors: Abouhamed Marouan , Wolff Natascha A. , Lee Wing-Kee , Smith Craig P. , Thévenod Frank
Published: June 2007

Chronic exposure to Cd2+ causes renal proximal tubular (PT) damage. Cd2+ reaches the PT mainly as cadmium-metallothionein 1 (CdMT-1) complexes that are filtered at the glomerulus and then internalized in part via endocytosis mediated by megalin and cubulin. Subsequently, Cd2+ is thought to be released in the cytosol to activate cell death pathways. The proton-coupled divalent metal transporter DMT1 also transports Cd2+ and is expressed exclusively in endosomes/lysosomes in rat PT cells. Using vector-based RNA interference with short-hairpin small-interfering RNAs (shRNAs) to downregulate DMT1 in the rat renal PT cell line WKPT-0293 Cl.2, we tested the hypothesis that endosomal/lysosomal DMT1 is involved in CdMT-1 nephrotoxicity. One out of 5 shRNAs tested (sh3) significantly reduced expression of DMT1 protein detected by immunoblotting and DMT1 mRNA as determined by RT-PCR by 45.1 ± 9.6 and 36.9 ± 14.4% ( n = 5–6), respectively. Similarly, sh3 reduced perinuclear DMT1 immunostaining in transfected cells. Consistent with the assumed role of DMT1 in CdMT-1 cytotoxicity, sh3, but not the empty vector or sh5, significantly attenuated cell death induced by a 24-h exposure to 14.3 μM CdMT-1 by 35.6 ± 4.2% ( n = 13). In contrast, neither fluorescently labeled metallothionein-1 (MT-1) uptake nor free Cd2+ toxicity was altered by the effective DMT1 shRNA (sh3), indicating that cellular uptake of metal-MT-1 complexes and Cd2+-induced cell death signaling are not affected by DMT1 knockdown. Thus we conclude that endosomal/lysosomal DMT1 plays a role in renal PT CdMT-1 toxicity.