bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth phenotypes of Pseudomonas aeruginosa lasR mutants adapted to the airways of cystic fibrosis patients
Authors: D'Argenio David A. , Wu Manhong , Hoffman Lucas R. , Kulasekara Hemantha D. , Déziel Eric , Smith Eric E. , Nguyen Hai , Ernst Robert K. , Larson Freeman Theodore J. , Spencer David H. , Brittnacher Mitchell , Hayden Hillary S. , Selgrade Sara , Klausen Mikkel , Goodlett David R. , Burns Jane L. , Ramsey Bonnie W. , Miller Samuel I. 
Published: May 2007

SummaryThe opportunistic pathogen Pseudomonas aeruginosa undergoes genetic change during chronic airway infection of cystic fibrosis (CF) patients. One common change is a mutation inactivating lasR, which encodes a transcriptional regulator that responds to a homoserine lactone signal to activate expression of acute virulence factors. Colonies of lasR mutants visibly accumulated the iridescent intercellular signal 4‐hydroxy‐2‐heptylquinoline. Using this colony phenotype, we identified P. aeruginosa lasR mutants that emerged in the airway of a CF patient early during chronic infection, and during growth in the laboratory on a rich medium. The lasR loss‐of‐function mutations in these strains conferred a growth advantage with particular carbon and nitrogen sources, including amino acids, in part due to increased expression of the catabolic pathway regulator CbrB. This growth phenotype could contribute to selection of lasR mutants both on rich medium and within the CF airway, supporting a key role for bacterial metabolic adaptation during chronic infection. Inactivation of lasR also resulted in increased β‐lactamase activity that increased tolerance to ceftazidime, a widely used β‐lactam antibiotic. Loss of LasR function may represent a marker of an early stage in chronic infection of the CF airway with clinical implications for antibiotic resistance and disease progression.
The intramembrane active site of GlpG, an E. coli rhomboid protease, is accessible to water and hydrolyses an extramembrane peptide bond of substrates
Authors: Maegawa Saki , Koide Kayo , Ito Koreaki , Akiyama Yoshinori 
Published: May 2007

Summary Escherichia coli GlpG is an orthologue of the rhomboid proteases that catalyse intramembrane proteolysis of specific membrane proteins. We previously showed that it can cleave a type I model membrane protein, Bla‐LY2‐MBP, having the second transmembrane region of lactose permease (LY2) in vivo and in vitro at the predicted periplasm–membrane boundary region of LY2. Here we investigated the environment of the active site regions of GlpG in the membrane‐integrated state by examining the modifiability of Cys residues introduced into the regions around the catalytic residues with membrane‐permeable and ‐impermeable alkylating reagents. The results indicate that the enzyme active site is fully open to the external aqueous phase. GlpG also cleaved a similar fusion protein, Bla‐GknTM‐MBP, having the transmembrane region of Gurken (GknTM), a physiological substrate of Drosophila rhomboids. Engineered Cys residues in the cleavage site regions of the LY2 and GknTM sequences were efficiently modified with a membrane‐impermeable alkylating reagent, showing that these regions are exposed to the periplasm. These results suggest that GlpG cleaves an extramembrane region of substrates, unlike the currently prevailing view that this class of membrane proteases acts against a membrane‐embedded polypeptide segment after its lateral entrance into the enzyme's active site.
Increased Asymmetric Dimethylarginine Concentrations in Stimulated Peripheral Blood Mononuclear Cells
Authors: Schroecksnadel K. , Weiss G. , Stanger O. , Teerlink T. , Fuchs D. 
Published: May 2007

AbstractElevated concentrations of total homocysteine as well as of asymmetric dimethylarginine (ADMA) in the blood have been reported to reflect an increased cardiovascular risk. ADMA is formed by endothelial cells and is an endogenous inhibitor of NO synthase. Earlier we have found that human peripheral blood mononuclear cells (PBMC) produce homocysteine upon stimulation with mitogens concanavalin A, phytohaemagglutinin and pokeweed mitogen. In this study, the ability of PBMC to form ADMA and symmetric dimethylarginine (SDMA) was determined. Effects were compared with levels of cysteine, homocysteine and arginine in cultures. Increased concentrations of ADMA and SDMA were found in mitogen‐stimulated compared with unstimulated PBMC. Arginine and cysteine concentrations did not differ between stimulated and unstimulated PBMC. There existed significant associations between concentrations of homocysteine and ADMA (Spearman rank correlation (rs) = 0.575) as well as SDMA (rs = 0.436, both P < 0.001). Treatment of stimulated PBMC with the anti‐inflammatory compounds salicylic acid (5 mm) and atorvastatin (25 μm) decreased the rate of ADMA and SDMA formation. Results of these in vitro studies show that ADMA and SDMA formation coincides with homocysteine production in human PBMC. Activated PBMC not only release Th1‐type cytokine γ‐interferon, which is the most important inducer of nitric oxide synthase, but also ADMA, a natural inhibitor of the enzyme.
Social support, coping, and psychological distress in mothers and fathers of pediatric transplant candidates: A pilot study
Authors: Simons Laura , Ingerski Lisa M. , Janicke David M. 
Published: May 2007

Abstract: Both parents and children report significant psychological difficulties and family disruption prior to transplantation; however, there have been fewer studies examining predictors of distress in both mothers and fathers and across multiple transplant groups. Thirty‐four mothers and 22 fathers participated in this pilot study. Parents completed measures during a routine tertiary pretransplant psychological evaluation. Paired sample t‐test results indicated that mothers and fathers differed significantly on specific coping strategies employed, with fathers less likely to use engagement strategies than mothers. Correlation analyses demonstrated strong associations between engagement coping strategies and less psychological distress and the reverse with disengagement coping strategies for both mothers and fathers. Social support was associated with less psychological distress for mothers, but was unrelated to distress for fathers. Using regression analyses, for mothers, lack of social support, and disengagement coping predicted poor psychological outcomes. Taken together, these results suggest that assessing specific coping strategies employed by both mothers and fathers is an essential component of the pretransplant evaluation process. This study delineates areas for intervention that impact adjustment in parents of pediatric transplant candidates.
Expression of PIP1 and PIP2 aquaporins is enhanced in olive dwarf genotypes and is related to root and leaf hydraulic conductance
Authors: Lovisolo Claudio , Secchi Francesca , Nardini Andrea , Salleo Sebastiano , Buffa Rosalia , Schubert Andrea 
Published: May 2007

The expression of OePIP1.1 and OePIP2.1 aquaporins in root, stem and leaf was higher in Olea europaea L. (olive) plants carrying a dwarfing (D) clone as rootstock, than in plants carrying a vigorous (M) clone as rootstock. The highest difference of expression between plants with D and M rootstocks was detected in the root and for the PIP2 gene, the transcripts of which show a high water channel activity in oocytes. Compared with plants with M rootstock, plants with D rootstock showed reduced root and canopy biomass and reduced hydraulic conductance of the bulk root system (Kroot). Hydraulic conductance of D roots was higher than that of M roots when Kroot was scaled by root DW, in agreement with a higher expression of PIP genes. Leaf hydraulic conductance scaled by unit leaf surface area was almost twice as high in leaves from D plants compared with that in leaves from M plants. Modification of root growth imposed by grafting M onto D and D onto M slightly changed expression levels of root OePIP1.1 gene, the transcripts of which show almost null water channel activity in oocytes, suggesting a role less evident for OePIP1.1 in root hydraulic reequilibration. The role of PIP aquaporin gene expression in partially compensating reductions of plant hydraulic conductance is discussed.
Clinical, Bacteriological, Cytological and Pathological Features of Teat Disorders in Ewes
Authors: Mavrogianni V. S. , Fthenakis G. C. 
Published: May 2007

SummaryWe describe the features of 13 cases of teat disorders in ewes, as follows: lengthy teats (one case), papilloma infection (two), staphylococcal dermatitis (one), nodules and abscesses (two), teat bites (three), stenosis (one), orf (two), compressed teat (one). Mannheimia haemolytica, Staphylococcus epidermidis, Staphylococcus simulans or Staphylococcus aureus were isolated from samples. Sub‐epithelial leucocytic infiltration at the teat duct ‐ teat cistern border, but not lymphoid nodules, was the salient histological finding in the teat. Leucocytic infiltration and destruction of parenchyma were evident in the mammary gland. The results provide field evidence suggesting that teat lesions predispose ewes to mastitis.
Morphological Features of Spermatozoa of Swamp Buffalo AI Bulls in Thailand
Authors: Koonjaenak S. , Chanatinart V. , Ekwall H. , Rodriguez‐Martinez H. 
Published: May 2007

SummaryThe appearance and incidence of sperm abnormalities was studied in 115 ejaculates, collected periodically over 1 year covering all seasons from five mature, healthy swamp buffalo (Bubalus bubalis) bulls reared under tropical conditions and serving as the current source of semen for artificial insemination (AI) in Thailand. Light microscopy of stained smears was used to investigate sperm head shape morphology, while unstained wet smears were used to examine other sperm abnormalities. The most commonly found morphological aberrations were pear‐shaped spermatozoa, knobbed acrosomes, proximal cytoplasmic droplets, simple bent tails and coiled tails under the head, whose ultrastructure (scanning electron microscopy) corresponded to what has been found in other species of bovidae, including varieties of buffalo. The mean prevalence (as least squares mean ± SEM) of sperm abnormalities was low (below 15%), corresponding to healthy spermiograms. The younger bulls (<10 years old, n = 3) had less abnormalities than the older ones (10.1 ± 0.6% versus 14.1 ± 0.8%, P < 0.001, n = 2), including abnormalities of sperm head shape (1.1 ± 0.3% versus 3.6 ± 0.3, P < 0.001), acrosome defects with knobbed acrosomes (1.1 ± 0.2% versus 1.2 ± 0.3%, P < 0.001), spermatozoa with proximal cytoplasmic droplets (2.7 ± 0.1% versus 1.4 ± 0.2%, P < 0.001), defective mid‐pieces (0.2 ± 0.1% versus 0.3 ± 0.1%) and abnormal sperm tails (3.1 ± 0.3% versus 5.7 ± 0.4%, P < 0.001). The within‐bull effect of the year solely affected the incidence of pear‐shaped spermatozoa while the incidences of abnormal contour, variable size of sperm head shapes, abnormal mid‐piece and simple bent tail among bulls were affected by ejaculate (week of collection). Interaction between age and ejaculate affected only the prevalence of spermatozoa with proximal cytoplasmic droplets. In conclusion, the types of defects encountered were similar to those found in other bovidae, with a very low prevalence over the year the AI sires were followed through.
Effect of Senna occidentalis Seeds on Immunity in Broiler Chickens
Authors: Hueza I. M. , Latorre A. O. , Raspantini P. C. F. , Raspantini L. E. R. , Mariano‐Souza D. P. , Guerra J. L. , Górniak S. L. 
Published: May 2007

SummaryThis study investigated possible immunotoxic effects of Senna occidentalis (So) seeds incorporated in broiler chicken rations at different concentrations (0.0%, 0.25%, 0.50% and 0.75%), for 28 or 42 days. We evaluated innate immune function (macrophage activities of spreading, phagocytosis, peroxide and nitric oxide production) and acquired immune function (humoral and cellular immune responses), as well as lymphoid organ weights and pathology. There was enhanced macrophage activity, as hydrogen peroxide production increased (P < 0.05) in cells of birds given 0.75%So, but there were no other pro‐inflammatory effects. Birds receiving 0.75% of So in ration for 42 days gained less weight (P < 0.01), and showed a decrease in relative weight of the bursa of Fabricius (P < 0.05) and spleen (P < 0.01). In addition, morphological changes were also noted in these lymphoid organs, with depletion of lymphoid cells on the spleen and bursa of Fabricius, resulting in lower relative weight of both lymphoid organs. No impairment of humoral immune response against Newcastle disease and in cellular immune response after a phytohaemagglutinin challenge was found. It is probable that mitochondrial damage and related apoptosis may be responsible for the enhanced peroxide production and the reduced relative weight of the bursa of Fabricius and spleen.
Articular Cartilage Repair with Autografting Under the Influence of Insulin‐Like Growth Factor‐1 in Rabbits
Authors: Singh N. K. , Singh G. R. , Amarpal  , Kinjavdekar P. , Sharma A. K. , Mohanty T. R. , Kumar S. , Chae H. S. , Yoo Y. M. , Ahn C. N. 
Published: May 2007

SummaryInsulin‐like growth factor (IGF)‐1 has been successfully demonstrated to stimulate proteoglycan synthesis, slow down its catabolism and promote cartilage formation through well defined in vitro studies. It was therefore, assumed that IGF‐1 would eventually serve to augment current cartilage repair techniques in vivo. Study was therefore, designed to determine the influence of IGF‐1 in cartilage repair with or without autografting. For this purpose articular cartilage repair model was created in the left knee of 48 New Zealand white rabbits of either sex, 6–7 months old, weighing 1–2 kg. The articular cartilage defect was created in the femoral groove of femoro‐patellar joint using hand held trephine under xylazine and ketamine anaesthesia in all the animals. The defect created was 3 mm in diameter and 2 mm in depth. For autografting, osteochondral tissues harvested from the proximal patellar groove of the femur were placed in the distal defect and vice versa. The experimental animals were divided mainly into four groups, i.e. Group A (control), Group B (autografting), Group C (control + IGF‐1) and Group D (autografting + IGF‐1). Animals of group A and B were provided only with collagen scaffolds at 10 μg/cm2 whereas animals of treatment group C and D were provided with collagen scaffolds holding 30 ng/30 μl of IGF‐1 into the defect. Evaluation of cartilage repair was done on days 15, 30 and 45 after ethically killing the animals. Initially IGF‐1 had shown the tendency for either in the maintenance of autografted cartilage or helped in proliferation of chondroblast for the repair process. However, later in the process, cartilage formation apparently declined and appeared to converge to osseous tissue. Collectively, non‐responsiveness of osteoarthritic chondrocytes to IGF‐1 could be partially attributed to either increased IGF‐binding proteins in the joint space, micromovement of the graft, lack of nutrition, dose of IGF‐1 or its half life in the current study.
Comparison of electrical velocimetry and transpulmonary thermodilution for measuring cardiac output in piglets
Authors: ALEXANDER OSTHAUS WILHELM , HUBER DIRK , BECK CARSTEN , WINTERHALTER MICHAEL , BOETHIG DIETMAR , WESSEL ARMIN , SÜMPELMANN ROBERT 
Published: May 2007

SummaryBackground:  Monitoring of cardiovascular function is essential during major pediatric and pediatric cardiac surgery. Invasive monitoring of cardiac output (CO) and oxygen delivery is expensive and sometimes associated with adverse events. Therefore, we investigated the accuracy of a new noninvasive CO monitoring device using electrical velocimetry (EV) in comparison with the more invasive transpulmonary thermodilution (TPTD) method.Methods:  In five fasted, anesthetized and mechanically ventilated piglets, CO was measured simultaneously using EV and TPTD under normal conditions, volume loading, inotropic support and exsanguination.Results:  In five piglets, 169 measurements could be performed. The correlations between EV–CO and TPTD–CO were significant for absolute values (P < 0.0001, r = 0.82) and relative changes from baseline (P < 0.0001, r = 0.93). The receiver operating characteristic (ROC) curve analysis of the relative changes of the EV–CO values in relation to the first EV–CO measurement showed a sensitivity of 91% and specificity of 94% (AUC 0.974, 95% CI 0.96–0.99). Changes in TPTD–CO greater than 15% lead to a change of EV–CO in the same direction in 93%. Bland–Altman analysis showed a mean difference between the two methods of −0.63 l·min−1 with an sd of 0.64 l·min−1. The lower and upper limits of agreement were −1.88 and 0.62 l·min−1, percentage limit of agreement was ±82.8%.Conclusions:  The results show that EV is a safe, simple, noninvasive and cost‐effective method for continuous trend monitoring of CO in piglets. The agreement of the EV–CO with TPTD–CO is not good enough to replace the standard method in our animal model. A correction factor for body habitus in piglets may be beneficial.
A qualitative systematic review of morphine treatment in children with postoperative pain
Authors: DUEDAHL TINA HOFF , HANSEN EBBA HOLME 
Published: May 2007

SummaryBackground:  Postoperative pain management in children is often empirical rather than evidence based. Morphine is the pharmacological treatment most widely used and although considered safe for children, adequate scientific data on morphine’s pharmacokinetics, efficacy and safety are lacking. This systematic review aimed to evaluate the available literature examining different pediatric morphine regimens with respect to dosage, analgesic efficacy and incidence of side effects.Methods:  Thirty‐six randomized, double‐blind controlled clinical trials with 49 comparisons, including multiple dosage regimens and routes of administration were included. The primary outcome measures for analgesic efficacy (pain intensity, time to first analgesic request and need for rescue analgesics) together with the incidence of morphine‐related side effects were evaluated qualitatively by significant difference (P < 0.05) as reported in the original investigations.Results:  Overall, significant improvements in the defined outcome measures on analgesic efficacy were only observed when morphine was compared with inactive control interventions. No relation between morphine dosage and analgesic efficacy was detected. The most common morphine‐related side effects were vomiting and sedation, with significantly higher incidences observed after morphine administration in half of all comparisons.Conclusions:  Although several factors may justify its use as first line therapy in many parts of the world, morphine alone is not the most suitable analgesic for postoperative pain in pediatric patients, as it does not have superior analgesic effect and a higher incidence of side effects compared with active control interventions. More standardized clinical trials with multimodal regimens as well as guidelines for evaluating pediatric medicines are desirable in the future.
Early scale development inHeterodontus(Heterodontiformes; Chondrichthyes): a novel chondrichthyan scale pattern
Authors: Johanson Zerina , Smith Moya M. , Joss Jean M. P. 
Published: May 2007

AbstractIn two species ofHeterodontus,H. portusjacksoniandH. galeatus, the first scales to develop form two opposing rows along the caudal fin axis on both the left and right sides of the fin. The opposing rows originate from an initial scale located on either side of the posterior tip of the caudal fin, with subsequent scales erupting in a posterior to anterior direction along the tail axis. These scale rows may strengthen tail movements, providing aeration in the egg case, but are lost later in ontogeny. Development of subsequent body scales shows a more irregular origin and arrangement, from anterior to posterior, to cover the dorsal and ventral lobes of the caudal fin. Although the early developmental pattern of the scale associated with theHeterodontuscaudal fin has not been previously described, several chondrichthyan taxa, including chimeroids, likewise possess ordered rows of flank scales early in ontogeny that are subsequently lost. These ordered scales contrast with previous suggestions that chondrichthyan scale development is entirely random. Instead, regulated and sequential development of scales may be a plesiomorphic character for both chondrichthyans and osteichthyans, with the less organized arrangement in later ontogenetic stages being a derived condition within Chondrichthyes.
Differential effect of β‐blocker therapy on insulin resistance as a function of insulin sensitizer use: results from GEMINI
Authors: Fonseca V. , Bakris G. L. , Bell D. S. H. , McGill J. B. , Raskin P. , Messerli F. H. , Phillips R. A. , Katholi R. E. , Wright J. T. , Waterhouse B. , Lukas M. A. , Anderson K. M. ,   for the GEMINI Investigators
Published: May 2007

AbstractAims  To determine whether the beneficial effects of carvedilol on insulin resistance (IR) are affected by the concomitant use of insulin sensitizers [thiazolidinediones (TZDs) and metformin].Methods  Changes in HbA1c and homeostasis model assessment‐insulin resistance (HOMA‐IR) were assessed over 5 months, comparing carvedilol with metoprolol tartrate according to insulin sensitizer (TZDs and metformin) use.Results  In TZD/metformin users, carvedilol patients showed a 5.4% decrease [95% confidence interval (CI) −11.9, 1.6; P = 0.13] and metoprolol tartrate patients showed a 2.8% decrease (95% CI −8.5, 3.2; P = 0.35) in HOMA‐IR. The −2.6% difference between treatments was not significant (95% CI −10.7, 6.2; P = 0.55). In contrast, those not taking TZD/metformin experienced a 13.2% increase in HOMA‐IR on metoprolol tartrate (95% CI 3.2, 24.1; P < 0.01) and a 4.8% decrease in HOMA‐IR on carvedilol (95% CI −14.6, 6.0; P = 0.37), with a significant treatment difference of −15.9% favouring carvedilol (95% CI −26.6, −3.6; P = 0.01). There was no significant treatment interaction for the use of TZD/metformin and HbA1c. A statistically significant treatment difference was observed for HbA1c after 5 months favouring carvedilol after adjusting for insulin sensitizer use (−0.11%, 95% CI −0.214, −0.009; P = 0.03).Conclusions  In patients with diabetes and hypertension not taking insulin sensitizers, the use of metoprolol tartrate resulted in a worsening of insulin resistance, an effect not seen with carvedilol. However, in TZD/metformin users the difference between the β‐blockers was not statistically significant.