Miracle-dz/UniFAR-FTUs huggingface dataset:
Penicillin-binding protein 2 is required for induction of the Citrobacter freundii class I chromosomal beta-lactamase in Escherichia coli

Involvement of Escherichia coli penicillin-binding proteins (PBPs) in induction of the cloned ampC Citrobacter freundii beta-lactamase by 6-aminopenicillanic acid was investigated. The enzyme was not inducible at 42 degrees C in a mutant thermosensitive for expression of PBP 2. The results imply that PBP 2 is involved in the process leading to induction of ampC.
Colder is better during hypothermic circulatory arrest for acute type a aortic dissection

Abstract Objectives. To evaluate the influence, on early postoperative outcomes, of temperature during hypothermic circulatory arrest in emergent surgery for acute type A aortic dissection. Design. Hypothermic circulatory arrest (HCA) with antegrade cerebral perfusion was performed in 63 patients who underwent emergent surgery for acute type A aortic dissection between 2000 and 2009. Patients were retrospectively separated in two groups: (1) deep HCA, lowest nasopharyngeal temperature < 17°C (n = 29; 46%) and (2) moderate HCA, lowest nasopharyngeal temperature ≥ 17°C (n = 34; 54%). Results. Hospital mortality reached 27%. The nasopharyngeal temperature did not influence postoperative mortality or neurological outcome. Patients with deep HCA had significantly lower rate of infection (33% vs 69%; p = 0.009) and shorter median intensive care unit length of stay (4 days (17) vs 15.5 days (26) p = 0.017). Multiple regression analysis revealed that the lowest nasopharyngeal temperature was the only significant variable associated with intensive care unit length of stay (p = 0.005). Conclusions. Patients suffering from acute type A aortic dissection might benefit from colder hypothermia during circulatory arrest.
Biochemical and histopathological effects of glyphosate herbicide on Nile tilapia (Oreochromis niloticus)

In Oreochromis niloticus that had been exposed for 3 months to sublethal concentrations (5 and 15 ppm) of the commercial glyphosate herbicide (C3H8NO5P) Roundup, the organs exhibited varying degrees of histopathological change. In the gills filament cell proliferation, lamellar cell hyperplasia, lamellar fusion, epithelial lifting, and aneurysm were observed. In the liver there were vacuolation of hepatocytes and nuclear pyknosis. Kidney lesions consisted of dilation of Bowman's space and accumulation of hyaline droplets in the tubular epithelial cells. The structural damages could be correlated to the significant increase (p ≤ 0.05) in aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities in the second and third months of exposure. The results indicated that long‐term exposure to glyphosate at sublethal concentrations had adverse effects on the histopathological and biochemical alterations of the fish. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 260–267, 2003.
Medical Student Perceptions of Learner-Initiated Feedback Using a Mobile Web Application

Feedback, especially timely, specific, and actionable feedback, frequently does not occur. Efforts to better understand methods to improve the effectiveness of feedback are an important area of educational research. This study represents preliminary work as part of a plan to investigate the perceptions of a student-driven system to request feedback from faculty using a mobile device and Web-based application. We hypothesize that medical students will perceive learner-initiated, timely feedback to be an essential component of clinical education. Furthermore, we predict that students will recognize the use of a mobile device and Web application to be an advantageous and effective method when requesting feedback from supervising physicians. Focus group data from 18 students enrolled in a 4-week anesthesia clerkship revealed the following themes: (1) students often have to solicit feedback, (2) timely feedback is perceived as being advantageous, (3) feedback from faculty is perceived to be more effective, (4) requesting feedback from faculty physicians poses challenges, (5) the decision to request feedback may be influenced by the student’s clinical performance, and (6) using a mobile device and Web application may not guarantee timely feedback. Students perceived using a mobile Web-based application to initiate feedback from supervising physicians to be a valuable method of assessment. However, challenges and barriers were identified.
Effect of impedances line length to voltage sag propagation

Occurrences of faults in power system contribute extensive voltage sags (dips) in a network. These occurrences have introduced problems to consumers mainly at 415V where sensitive control equipment is located. This paper investigates the propagation and travelling of voltage sag event under the influence of transformer connections and impedance line length. PSS/ADEPT (Power System Simulator Advanced Distribution Engineering Productivity Tool) was used to construct and simulate the test system for the study. Installation of monitoring devices cannot be done in every part of voltage level because it increases cost and is difficult to manage. The test system used allows major variations in network parameter for understanding its influence on voltage sag propagation. It is important to understand on how voltage sag propagates and travels through different voltage levels in power system network as whether it reaches and harms consumer equipment.
Circulating complexes between tumour necrosis factor‐alpha and etanercept predict long‐term efficacy of etanercept in juvenile idiopathic arthritis

The relationship between tumour necrosis factor‐alpha (TNF‐α) and drug survival had not been studied in juvenile idiopathic arthritis (JIA), and there were no laboratory tests to predict the long‐term efficacy of biological drugs for JIA. We studied whether serum levels of TNF‐α, free or bound to etanercept, could predict long‐term efficacy of etanercept in children with JIA.
TURBINATES IN THERAPSIDS: EVIDENCE FOR LATE PERMIAN ORIGINS OF MAMMALIAN ENDOTHERMY

The structure and function of the nasal conchae of extant reptiles, birds, and mammals are reviewed, and the relationships to endothermy of the mammalian elements are examined. Reptilian conchae are relatively simple, recurved structures, which bear primarily sensory (olfactory) epithelium. Conversely, the conchae, or turbinates, of birds and mammals are considerably more extensive and complex, and bear, in addition, nonsensory (respiratory) epithelium. Of the mammalian turbinates, only the exclusively respiratory maxilloturbinal has a clear functional relationship with endothermy, as it reduces desiccation associated with rapid and continuous pulmonary ventilation. The other mammalian turbinates principally retain the primitive, olfactory function of the nasal conchae. The maxilloturbinates are the first reliable morphological indicator of endothermy that can be used in the fossil record. In fossil mammals and mammallike reptiles, the presence and function of turbinates are most readily revealed by the ridges by which they attach to the walls of the nasal cavity. Ridges for olfactory turbinals are located posterodorsally, away from the main flow of respiratory air, whereas those of the respiratory maxilloturbinals are situated in the anterolateral portion of the nasal passage, directly in the path of respired air. The maxilloturbinal is also characterized by its proximity to the opening of the nasolacrimal canal. Posterodorsal ridges, for olfactory turbinals, have long been recognized in many mammallike reptiles, including early forms such as pelycosaurs. However, ridges for respiratory turbinals have not been identified previously in this group. In this paper, the presence of anterolateral ridges, which most likely supported respiratory turbinals, is reported in the primitive therocephalian Glanosuchus and in several cynodonts. The presence of respiratory turbinals in these advanced mammallike reptiles suggests that the evolution of “mammalian” oxygen consumption rates may have begun as early as the Late Permian and developed in parallel in therocephalians and cynodonts. Full mammalian endothermy may have taken as much as 40 to 50 million yr to develop.
Pleural Pressure Swing and Lung Expansion After Malignant Pleural Effusion Drainage: The Benefits of High-Temporal Resolution Pleural Manometry

Background:Malignant pleural effusion is a common complication in end-stage cancer patients and can cause severe dyspnea. Therapeutic thoracentesis is often limited to 1 to 1.5 L. Pleural manometry can be used to recognize a not-expanded lung. Methods:Interval pleural pressure measurements with a high temporal resolution were performed after each removal of 200 mL of fluid to observe pleural pressure swings. Pleural elastance was defined as the difference in pleural pressure divided by the change in volume. Chest x-rays were performed to evaluate lung expansion, reexpansion pulmonary edema, and fluid residue. Results:Thirty-four procedures in 30 patients were eligible for analysis. Four patients had incomplete lung expansion after drainage. No reexpansion pulmonary edema was observed. Pleural pressure swing after 200 mL drainage was higher when the lung did not expand. Pleural elastance after removal of 500 mL was higher in the not-expanded subgroup. Conclusions:We demonstrated that a high pleural pressure swing after removal of only 200 mL was related to incomplete lung expansion. We confirmed the association between pleural elastance and lung expansion.
Energy Taxis Drives Campylobacter jejuni toward the Most Favorable Conditions for Growth

ABSTRACT Campylobacter jejuni is a serious food-borne bacterial pathogen in the developed world. Poultry is a major reservoir, and C. jejuni appears highly adapted to the gastrointestinal tract of birds. Several factors are important for chicken colonization and virulence, including a taxis mechanism for environmental navigation. To explore the mechanism of chemotaxis in C. jejuni, we constructed mutants with deletions of five putative mcp (methyl-accepting chemotaxis protein) genes (tlp1, tlp2, tlp3, docB, and docC). Surprisingly, the deletions did not affect the chemotactic behavior of the mutants compared to that of the parental strain. However, the tlp1, tlp3, docB, and docC mutant strains displayed a 10-fold decrease in the ability to invade human epithelial and chicken embryo cells, hence demonstrating that the corresponding proteins affect the host interaction. l-Asparagine, formate, d-lactate, and chicken mucus were identified as new attractants of C. jejuni, and we observed that chemical substances promoting tactic attraction are all known to support the growth of this organism. The attractants could be categorized as carbon sources and electron donors and acceptors, and we furthermore observed a correlation between an attractant's potency and its efficiency as an energy source. The tactic attraction was inhibited by the respiratory inhibitors HQNO (2-n-heptyl-4-hydroxyquinoline N-oxide) and sodium azide, which significantly reduce energy production by oxidative phosphorylation. These findings strongly indicate that energy taxis is the primary force in environmental navigation by C. jejuni and that this mechanism drives the organism toward the optimal chemical conditions for energy generation and colonization.
Volume of distribution of radioactive chloride in dogs; comparisons with sodium, bromide and inulin spaces.

I N THIS study two of the radioactive isotopes of chlorine, Cl36 (half life 400,000 years) and C138 (half life 38 minutes) have been used in an effort to establish more definitively than has been done previously the relationships, in the dog, of the chloride space to the volumes of distribution of sodium, bromide and inulin. The first measurements of the radioactive chloride space in dogs were made by Winkler, Elkington and Eisenman (I) who reported that C138 distributed through approximately 25 per cent of the body weight compared to 28 per cent for Na? Burch, Ray and Threefoot (2), using C136, reported volumes of distribution varying from 32 to 38 per cent in five young dogs. Following the observation that the bromide distribution in the plasma and tissues was proportional to that of chloride (3, 4), several workers have used the dilution of stable bromide as a measure of the chloride space. Weir (s), Gaudino, Schwartz and Levitt (6), Brodie, Brand and Leshin (7) have reported bromide spaces of 30 to 32 per cent body weight. Berger, Dunning, Steele and Brodie (8) and Gaudino (6) measured volumes of distribution of bromide that were approximately 150 per cent of simultaneously determined inulin spaces. Emphasizing direct and simultaneous comparisons in three groups of experiments, the relationships of the radioactive chloride space to those of radioactive sodium (Na24), radioactive bromide (Br82) and inulin were observed. The radioactive chloride and the substance with which it was being compared were injected simultaneously and the volumes of distribution were calculated from plasma concentrations determined from the same blood sample. As will be described, both the shortlived and the long-lived isotopes of chlorine are easily combined with Na24 and Br82 in double tracer experiments. These double isotope experiments are simple to carry out and more consistently accurate comparisons of the dilutions of two agents are obtained than when chemical methods are used.
Human immunodeficiency virus (HIV)‐1 infects human hepatic stellate cells and promotes collagen I and monocyte chemoattractant protein‐1 expression: Implications for the pathogenesis of HIV/hepatitis C virus–induced liver fibrosis

Patients coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) develop more rapid fibrosis than those infected with HCV only. In HIV/HCV‐coinfected patients, fibrosis progression correlates with HIV RNA levels, suggesting a direct role of HIV in liver fibrogenesis. Chemokine (C‐C motif) receptor 5 (CCR5) and cysteine‐X‐cysteine receptor 4 (CXCR4), the two major coreceptors required for HIV entry into cells, are expressed on activated hepatic stellate cells (HSCs), the principle fibrogenic cell type in the liver. We therefore examined whether HIV can infect HSCs, explored the potential mechanisms of viral entry, and assessed the impact of infection as reflected by the ability of HSCs to transfer virus to T lymphocytes and elicit a proinflammatory and profibrogenic response. We report that the laboratory‐adapted viruses HIV‐IIIB (CXCR4‐tropic or X4) and HIV‐BaL (CCR5‐tropic or R5) and primary HIV isolates can infect both a human stellate cell line, LX‐2, and primary human HSCs. HIV entry and gene expression in HSCs was confirmed using HIV–green fluorescent protein (GFP) expression viral constructs in the presence or absence of the reverse‐transcriptase inhibitor azidothymidine. CD4 expression on a subset of primary HSCs was demonstrated using fluorescence‐activated cell sorting and immunofluorescence staining. Blocking experiments in the presence of anti‐CD4, anti‐CXCR4, and anti‐CCR5 revealed that HIV entry into HSCs is predominantly CD4/chemokine coreceptor–independent. HIV infection promoted HSC collagen I expression and secretion of the proinflammatory cytokine monocyte chemoattractant protein‐1. Furthermore, infected LX‐2 cells were capable of transferring GFP‐expressing virus to T lymphocytes in a coculture system. Conclusion: Taken together, our results suggest a potential role of HIV in liver fibrosis/inflammation mediated through effects on HSCs. The role of early highly active antiretroviral therapy initiation in patients with HIV/HCV coinfection warrants further investigation. (HEPATOLOGY 2010)
Ca2+ binding to synaptotagmin: how many Ca2+ ions bind to the tip of a C2‐domain?

C2‐domains are widespread protein modules with diverse Ca2+‐regulatory functions. Although multiple Ca2+ ions are known to bind at the tip of several C2‐domains, the exact number of Ca2+‐binding sites and their functional relevance are unknown. The first C2‐domain of synaptotagmin I is believed to play a key role in neurotransmitter release via its Ca2+‐dependent interactions with syntaxin and phospholipids. We have studied the Ca2+‐binding mode of this C2‐domain as a prototypical C2‐domain using NMR spectroscopy and site‐directed mutagenesis. The C2‐domain is an elliptical module composed of a β‐sandwich with a long axis of 50 Å. Our results reveal that the C2‐domain binds three Ca2+ ions in a tight cluster spanning only 6 Å at the tip of the module. The Ca2+‐binding region is formed by two loops whose conformation is stabilized by Ca2+ binding. Binding involves one serine and five aspartate residues that are conserved in numerous C2‐domains. All three Ca2+ ions are required for the interactions of the C2‐domain with syntaxin and phospholipids. These results support an electrostatic switch model for C2‐domain function whereby the β‐sheets of the domain provide a fixed scaffold for the Ca2+‐binding loops, and whereby interactions with target molecules are triggered by a Ca2+‐induced switch in electrostatic potential.
Limited Role for Interleukin-18 in the Host Protection Response to Pulmonary Infection with Pseudomonas aeruginosa in Mice

ABSTRACT We report that clearance of Pseudomonas aeruginosa, accumulation of neutrophils, and synthesis of tumor necrosis factor alpha and macrophage inflammatory protein 2 in the infected lung were not largely different in interleukin-18 (IL-18) knockout or transgenic mice compared with control mice. Our results suggest a limited role for IL-18 in the host defense against P. aeruginosa.
Influence of a vital capacity maneuver on pulmonary gas exchange after cardiopulmonary bypass.

OBJECTIVE To investigate the effect of a single, vital capacity breath (vital capacity maneuver [VCM]), administered at the end of cardiopulmonary bypass (CPB), on pulmonary gas exchange in patients undergoing coronary artery bypass graft surgery. DESIGN Prospective, randomized, double-blind study. SETTING University-affiliated hospital. PARTICIPANTS Forty patients scheduled for elective coronary artery bypass graft surgery and early tracheal extubation. INTERVENTIONS Patients were randomized to 1 of 2 groups. VCM patients received a VCM at the conclusion of CPB. Control patients received no VCM. MEASUREMENTS AND MAIN RESULTS Intrapulmonary shunt (Q(S)/Q(T)), arterial oxygenation (PaO2), and alveolar-arterial oxygen gradients (P(A-a)O2) were measured after induction of anesthesia, CPB, intensive care unit (ICU) arrival, and extubation. The duration of postoperative intubation was recorded for each group. Q(S)/Q(T) increased significantly 30 minutes after CPB in the control group (15.7 +/- 1.8% to 27.4 +/- 2.6%; p = 0.01). In the VCM group, a small decrease in Q(S)/Q(T) occurred (16.1 +/- 2.0% to 14.9 +/- 2.0%). After ICU arrival and extubation, no significant difference in Q(S)/Q(T) existed between the 2 groups. With the exception of a higher P(A-a)O2 in the control group at induction of anesthesia, no differences in PaO2 or P(A-a)O2 were present between the 2 groups at any measurement interval. Patients who received a VCM were extubated earlier than the control group (6.5 +/- 2.1 hours v 9.4 +/- 4.2 hours; p = 0.01). CONCLUSION The use of a VCM prevented an increase in Q(S)/Q(T) from occurring in the operating room. Although a VCM did not influence pulmonary gas exchange in the ICU, its application in the operating room appears to exert a beneficial effect on tracheal extubation times after cardiac surgery.
Feasibility of Patient Navigation in Resident Primary Care Practice: A Screening Mammography Quality Improvement Initiative

Patient navigation (PN) has been used to improve breast cancer outcomes but has not been evaluated in resident practices. The objective of this study was to evaluate the feasibility of PN in resident clinics to improve biennial screening mammography. All participants whose last screening mammogram was at 18 months or after received PN. Feasibility outcomes included practicality (ability to carry out intervention), effectiveness (ability of intervention to increase biennial screening mammography rates), and acceptability (resident satisfaction with PN). Despite difficulty contacting patients, we found PN improved screening mammography adherence in resident practices serving vulnerable populations. Adherence rates increased significantly postintervention. Residents reported interest in using PN in practice.
Functional Mapping of Brucella abortus Cyclic β-1,2-Glucan Synthase: Identification of the Protein Domain Required for Cyclization

ABSTRACT Cyclic β-1,2-glucans (CβG) are periplasmic homopolysaccharides that have been shown to play an important role in several symbiotic and pathogenic relationships. Cyclic β-1,2-glucan synthase (Cgs), the enzyme responsible for the synthesis of CβG, is an integral membrane polyfunctional protein that catalyzes the four enzymatic activities (initiation, elongation, phosphorolysis, and cyclization) required for the synthesis of CβG. Recently, we have identified the glycosyltransferase and the β-1,2-glucooligosaccharide phosphorylase domains of Brucella abortus Cgs. In this study, we performed large-scale linker-scanning mutagenesis to gain further insight into the functional domains of Cgs. This analysis allowed us to construct a functional map of the enzyme and led to the identification of the minimal region required for the catalysis of initiation and elongation reactions. In addition, we identified the Cgs region (residues 991 to 1544) as being the protein domain required for cyclization and demonstrated that upon cyclization and releasing of the CβG, one or more glucose residues remain attached to the protein intermediate that serves as a primer for the next round of CβG synthesis. Finally, our results indicate that the overall control of the degree of polymerization of CβG is the result of a balance between elongation, phosphorolysis, and cyclization reactions.
The influence of ischemia upon the energy reserves of inner ear tissues

Ischemic changes in the levels of glucose, glycogen, ATP and P‐creatine are determined under “closed system” conditions in the organ of Corti, stria vascularis, ganglion spirale, cochlear nerve and vestibular sensory epithelia. From the resting levels of these compounds the total energy reserve in terms of equivalents of high energy phosphate, both preformed and potentially available from anaerobic glycolysis, is computed. The energy reserves are highest in the organ of Corti, intermediate in stria vascularis, spiral ganglion and vestibular structures, and lowest in the cochlear nerve. The rate of depletion of these energy reserves in ischemia is used as an indicator of the energy requirements of the respective tissues. The metabolic rate is by far the highest in the stria vascularis, intermediate in ganglion spirale and cochlear nerve and lowest in the organ of Corti and vestibular structures. There is no correlation between the total energy reserve and the initial energy use rates. The obtained data are compared with the dynamic patterns of the corresponding biopotentials and with pertinent results of enzymatic and respirometric studies; in addition, ischemic changes in glucose and lactate levels of perilymph are described.