Miracle-dz/UniFAR-FTUs huggingface dataset:
A case-control study of community-associated Clostridium difficile infection.

OBJECTIVES The aim of this study was to determine the incidence of and risk factors for community-associated Clostridium difficile infection (CDI). METHODS Prospective surveillance of community-derived faecal samples for C. difficile cytotoxin, followed by a questionnaire-based case-control study in two distinct patient cohorts (one semi-rural and the other urban). RESULTS The proportion of randomly selected faecal samples positive for C. difficile cytotoxin was 2.1% in both patient cohorts (median ages 73 and 45 years for the urban and semi-rural cohorts, respectively). Exposure to antibiotics in the previous 4 weeks, particularly multiple agents (P < 0.001), aminopenicillins (P < 0.05) and oral cephalosporins (P < 0.05), was significantly more frequent among cases than controls. Hospitalization in the preceding 6 months was significantly associated with CDI (45% versus 23%; P = 0.022). However, almost half the cases had not received antibiotic therapy in the month before C. difficile detection, and approximately one-third neither had exposure to antibiotics nor recent hospitalization. Contact with infants aged < or =2 years was significantly associated with CDI (14% versus 2%; P = 0.02). Prior exposure to gastrointestinal-acting drugs (proton pump inhibitor, H2 antagonist or non-steroidal anti-inflammatory) was not significantly more common in CDI cases. C. difficile PCR ribotype 001 caused 60% and 13% of urban and semi-rural community-associated CDI cases, respectively. CONCLUSIONS Reliance on antibiotic history and age (> or =65 years) will contribute to missed diagnoses of community-associated CDI. Potential risk factors for community-associated CDI should be explored further to explain the large proportion of cases not linked to recent antibiotic therapy or hospitalization.
Vulnerability of the global terrestrial ecosystems to climate change

Climate change has far‐reaching impacts on ecosystems. Recent attempts to quantify such impacts focus on measuring exposure to climate change but largely ignore ecosystem resistance and resilience, which may also affect the vulnerability outcomes. In this study, the relative vulnerability of global terrestrial ecosystems to short‐term climate variability was assessed by simultaneously integrating exposure, sensitivity, and resilience at a high spatial resolution (0.05°). The results show that vulnerable areas are currently distributed primarily in plains. Responses to climate change vary among ecosystems and deserts and xeric shrublands are the most vulnerable biomes. Global vulnerability patterns are determined largely by exposure, while ecosystem sensitivity and resilience may exacerbate or alleviate external climate pressures at local scales; there is a highly significant negative correlation between exposure and sensitivity. Globally, 61.31% of the terrestrial vegetated area is capable of mitigating climate change impacts and those areas are concentrated in polar regions, boreal forests, tropical rainforests, and intact forests. Under current sensitivity and resilience conditions, vulnerable areas are projected to develop in high Northern Hemisphere latitudes in the future. The results suggest that integrating all three aspects of vulnerability (exposure, sensitivity, and resilience) may offer more comprehensive and spatially explicit adaptation strategies to reduce the impacts of climate change on terrestrial ecosystems.
Warming and oligotrophication cause shifts in freshwater phytoplankton communities

While there is a lot of data on interactive effects of eutrophication and warming, to date, we lack data to generate reliable predictions concerning possible effects of nutrient decrease and temperature increase on community composition and functional responses. In recent years, a wide‐ranging trend of nutrient decrease (re‐oligotrophication) was reported for freshwater systems. Small lakes and ponds, in particular, show rapid responses to anthropogenic pressures and became model systems to investigate single as well as synergistic effects of warming and fertilization in situ and in experiments. Therefore, we set up an experiment to investigate the single as well as the interactive effects of nutrient reduction and gradual temperature increase on a natural freshwater phytoplankton community, using an experimental indoor mesocosm setup. Biomass production initially increased with warming but decreased with nutrient depletion. If nutrient supply was constant, biomass increased further, especially under warming conditions. Under low nutrient supply, we found a sharp transition from initially positive effects of warming to negative effects when resources became scarce. Warming reduced phytoplankton richness and evenness, whereas nutrient reduction at ambient temperature had positive effects on diversity. Our results indicate that temperature effects on freshwater systems will be altered by nutrient availability. These interactive effects of energy increase and resource decrease have major impacts on biodiversity and ecosystem function and thus need to be considered in environmental management plans.
Effect of transcriptional activators RamA and SoxS on expression of multidrug efflux pumps AcrAB and AcrEF in fluoroquinolone-resistant Salmonella Typhimurium.

OBJECTIVES Multidrug resistance (MDR) including fluoroquinolone resistance in Salmonella Typhimurium can result from overexpression of efflux pumps. We examined the mechanisms of fluoroquinolone resistance among in vitro-induced ciprofloxacin-resistant Salmonella Typhimurium mutants, LTL and LTH, derived from laboratory strain LT2. METHODS Deletion mutation and RT-PCR techniques were employed to study the role of efflux pumps in fluoroquinolone resistance and their regulation cascades. RESULTS In addition to point mutations in DNA gyrase (gyrA, gyrB) and topoisomerase IV (parC, parE) genes, increased expression of efflux pump genes, such as acrAB and acrEF, was observed in fluoroquinolone-resistant Salmonella strains. Constitutive expression of ramA containing a 9 bp deletion in the promoter region was directly associated with the overexpression of acrAB and acrEF and conferred an MDR phenotype in LTL. Inactivation of ramA increased the antimicrobial susceptibility of LTL, whereas complementation with the mutant allele induced an MDR phenotype in drug-susceptible Salmonella Typhimurium LT2, as demonstrated by 2- to 64-fold increases in resistance to fluoroquinolones, tetracycline and chloramphenicol. On the other hand, inactivation of mutant soxRS resulted in a slight increase in the susceptibility of LTH to several fluoroquinolone drugs, and the introduction of the mutant allele had no effect on antimicrobial susceptibility of LT2, indicating that constitutive expression of soxRS played a minimum role in fluoroquinolone resistance. CONCLUSIONS Mutations in the promoter region of ramA appear to play a role in the up-regulation of RamA and AcrAB, and RamA is an activator of the MDR regulation cascade in Salmonella Typhimurium.
Physical Activity Levels In Obese And Non-Obese Women And Their Relationship With Body Mass Index, Perceived Self-Efficacy, Perceived Benefits And Barriers Of Exercise, And Commitment To A Plan Of Action

PHYSICAL ACTIVITY LEVELS IN OBESE AND NON-OBESE WOMEN AND THEIR RELATIONSHIP WITH BODY MASS INDEX, PERCEIVED SELF-EFFICACY, PERCEIVED BENEFITS AND BARRIERS OF EXERCISE, AND COMMITMENT TO A PLAN OF ACTION by ROSE M. LANGE August 2010 Advisor: Dr. Feleta Wilson Major: Nursing Degree: Doctor of Philosophy The purpose of this descriptive correlational study was to examine relationships among selected variables and concepts within the Health Promotion Model (perceived benefits, perceived barriers to exercise, self-efficacy, commitment to plan of action) in non-obese and obese women with a focus on the behavioral outcome of physical activity (leisure & lifestyle). A group of 137 women, aged 18-50 participated in this study. BMI was found to be positively correlated to an individual’s perceived barriers to action. Findings did not support the hypothesis that as BMI increases perceived benefits, self-efficacy, commitment to a plan of action and physical activity levels would decrease. Commitment to a plan of action was found to be a significant predictor of both types of physical activity. Commitment to a plan of action predicted 58% of the variance in leisure physical activity (exercise) and 6% of lifestyle physical activity. Non-obese women had lower levels of self-efficacy related to exercise in areas surrounding time commitments and interruptions in everyday life compared to the obese participants. The obese participants significantly reported lower levels of self-efficacy related to
Impact of biofilm on the in vitro activity of vancomycin alone and in combination with tigecycline and rifampicin against Staphylococcus aureus.

OBJECTIVES This study evaluated vancomycin susceptibility and activity alone and in combination with rifampicin and tigecycline against low-biofilm- and high-biofilm-producing methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates. METHODS Forty MRSA isolates recovered from bloodstream infections were analysed. Susceptibilities were performed in planktonic and biofilm cultures by microbroth dilution. Biofilm production was determined using an adherent plate assay. Time-kill analysis was performed on six low- and six high-biofilm-producing isolates with 15 mg/L vancomycin alone and in combination with rifampicin or tigecycline at 4x MIC. RESULTS Vancomycin susceptibility displayed a 4-fold and an 8-fold increase in the MIC(50) and MIC(90), respectively, in the presence of biofilm. Rifampicin and tigecycline susceptibilities also increased in biofilms, but still remained within the susceptibility breakpoints except for a tigecycline MIC(90) of 1 mg/L. High biofilm production was detected in 60% of the isolates. In time-kill analysis, 15 mg/L vancomycin achieved bactericidal activity against only low-biofilm-producing strains with a 1.8 log(10) cfu/mL difference in bacterial kill compared with high-biofilm-producing strains (P < 0.001). Rifampicin alone had minimal activity, resulting in resistance. Tigecycline was minimally effective and was not bactericidal, but no difference was observed in the comparison of biofilm-producing strains. Vancomycin in combination with rifampicin or tigecycline was bactericidal against all strains (mean kill 4.5 +/- 0.5 log(10) cfu/mL), regardless of biofilm production. CONCLUSIONS Vancomycin exposures at 15 mg/L may not be adequate in eradicating biofilm-producing S. aureus. Alternative treatments or combination therapy should be explored to optimize outcomes in biofilm-associated infections.
Laboratory medicine in tropical medicine: Present situation

Abstract Laboratory medicine is an important branch of medicine dealing with the use of laboratory investigation. In tropical medicine, the principles of laboratory medicine are important knowledge for tropical physicians. Laboratory medicine is critical for the investigation of tropical diseases. In this article, the author will briefly summarize and discuss the current situation of laboratory medicine in the tropical world.
The impact of oral health on body image and social interactions among elders in long-term care.

OBJECTIVE The objective of this study was to explore how social interactions and body image are influenced by perceived oral health among older people who live in long-term care facilities. BACKGROUND Social interactions among frail elders in long-term care (LTC) facilities are limited, but to what extent body image and oral health influence their social relations is poorly understood. A positive body image and the perception of adequate oral health are linked to increased social contacts, as well as improved health and well-being irrespective of age. However, as frailty increases, it is unclear whether appearance and oral health priorities remain stable. MATERIALS AND METHODS Open-ended interviews were conducted with a purposefully selected group of cognitively intact, older men and women who exhibited varying degrees of frailty, social engagement and oral health conditions and lived in one of seven long-term care facilities. The interviews were analysed using a constant comparative technique, and a second interview with participants checked the trustworthiness of the analysis. RESULTS Three major categories were expressed by the participants: (1) My mouth is fine; (2) It depends; and (3) Not that important. Within each category, there were several contributing and influencing factors. CONCLUSIONS Social interactions among residents in LTC may be negatively impacted by poor oral health, but only if other personal and social issues are less bothersome than conditions with the mouth.
Impact of a sodium carbonate spray combined with professional oral hygiene procedures in patients with Sjögren's syndrome: an explorative study

OBJECTIVES The aim of this study was to make an initial estimation on the effects of a sodium bicarbonate and xylitol spray (Cariex® ), associated with non-surgical periodontal therapy, in participants with primary Sjögren's syndrome. BACKGROUND Sjögren's syndrome (SS) is a multisystem autoimmune disease that predominantly involves salivary and lachrymal glands, with the clinical effect of dry eyes and mouth. MATERIALS AND METHODS A prospective cohort of 22 women and two men has been evaluated. They were randomized into three groups (eight patients each): Group A) those treated once with non-surgical periodontal therapy, education and motivation to oral hygiene, associated with the use of Cariex® ; Group B) treated only with Cariex® ; Group C) treated only with non-surgical periodontal therapy, education and motivation to oral hygiene. Clinical variables described after treatment were unstimulated whole salivary flow, stimulated whole salivary flow, salivary pH, reported pain (using Visual Analogue Scale) and the Periodontal Screening and Recording index. RESULTS Salivary flow rate improved in all groups, but the difference was statistically significant only in those treated with Cariex® , alone or in combination with periodontal therapy. Gingival status improved in participants who underwent periodontal non-surgical therapy while remained unchanged in those only treated with Cariex® . Reported pain decreased in all groups, showing the best result in participants treated with periodontal therapy together with Cariex® . CONCLUSIONS We propose a practical approach for improving gingival conditions and alleviating oral symptoms in patients with SS. Future randomized and controlled trials are however required to confirm these results as well as larger population, and also assessing other parameters due to oral dryness, possible oral infections and more comprehensive periodontal indices.
Correlation of the expression of acrB and the regulatory genes marA, soxS and ramA with antimicrobial resistance in clinical isolates of Klebsiella pneumoniae endemic to New York City.

OBJECTIVES Nosocomial isolates of Klebsiella pneumoniae resistant to all commonly used antimicrobial agents have emerged in many regions of the world. It is unknown if efflux systems contribute to the multidrug resistance phenotype. METHODS The expression of genes encoding the efflux pump AcrAB and the global regulators MarA, SoxS and RamA were examined and correlated with antimicrobial resistance. RESULTS Twenty isolates belonged to the two important clones representing KPC-possessing strains endemic to our region. Virtually all of these isolates had negligible or absent expression of the genes, and resistance to fluoroquinolones and aminoglycosides could be explained by alternative mechanisms. All of these isolates were susceptible to tigecycline. A group of 14 heterogeneous isolates was also examined. There was a correlation between expression of marA with expression of soxS. Only expression of soxS was significantly correlated with expression of acrB. With a background substitution in GyrA, increased expression of acrB and marA appeared to contribute to fluoroquinolone resistance in some isolates. A correlation was noted between expression of soxS and ramA (but not marA and acrB) and tigecycline MICs. Following in vitro exposure to tigecycline, resistance occurred in association with a marked increase in marA and acrB expression in isolates lacking expression of soxS and ramA. CONCLUSIONS While laboratory-derived tigecycline resistance was associated with increased acrB expression, the variation in tigecycline MICs in clinical isolates was associated only with selected regulator genes. It appears that other mechanisms beyond activation of the acrAB system mediate tigecycline resistance.
In vitro effect of physiological concentrations of human albumin on the antibacterial activity of tigecycline.

OBJECTIVES To determine C(max) tigecycline activity in the presence/absence of physiological concentrations of human albumin with free fraction concentrations as controls. METHODS Killing curves (final inoculum: 1.0-5.0 x 10(7) cfu/mL) were performed with 0.88 mg/L final concentrations (serum C(max) after a 100 mg 1 h infusion) in Mueller-Hinton broth supplemented with Ca(2+) and Mg(2+) (MH) and in MH with 4 g/dL human albumin. Controls were curves in MH with concentrations similar to the free fraction (fC(max) = 0.17 mg/L) calculated using protein binding. Activity was measured as log(10) initial inoculum reduction (log(10) initial inoculum-log(10) at 12 h/24 h). Target strains (tigecycline MIC/MBC; mg/L) were: methicillin-resistant Staphylococcus aureus heteroresistant to vancomycin (0.12/0.25); Enterococcus faecium (0.12/0.25); Escherichia coli producing extended-spectrum beta-lactamase (0.12/0.25); and Acinetobacter baumannii (0.25/1). RESULTS At 24 h the fC(max) produced mean decreases of < or =0.1 cfu/mL for all strains, in contrast to the bactericidal activity (mean >3 log(10) reduction) provided by C(max) concentrations in the presence or absence of albumin for E. coli and E. faecium, and an activity nearly bactericidal for S. aureus (mean approximately 2.8 log(10) reduction). In the case of the A. baumannii isolate the C(max) in the presence or absence of albumin produced a mean reduction of 2.56 log(10) cfu/mL at 12 h (time of one dosing interval), with a bacteriostatic profile when considering 24 h colony counts (similar counts at 0 and 24 h). CONCLUSIONS Correcting the total concentration for the reported literature binding values is unreliable since tigecycline antibacterial activity was greater than that suggested by the free fraction of the drug.
Genetic changes associated with glycopeptide resistance in Staphylococcus aureus: predominance of amino acid substitutions in YvqF/VraSR.

OBJECTIVES To further understand the mechanism of intermediate-level glycopeptide resistance, resulting from multiple endogenous mutations, in both laboratory-derived and clinically isolated Staphylococcus aureus. METHODS Laboratory-derived S. aureus strains were generated under selection using a variety of cell-wall-active antibiotics. Complete sequences of 27 genes, including 17 two-component histidine kinase sensors, were then compared with those of their susceptible parent strain. Further genetic analysis was performed on 125 clinical S. aureus isolates and 42 geographically diverse isolates of vancomycin-intermediate S. aureus (VISA). RESULTS Selective pressure using imipenem resulted in single point mutations leading to amino acid substitutions in two genes: vraS, encoding a two-component histidine kinase sensor; and SA1702 (also called yvqF, located immediately upstream of vraS), encoding a conserved hypothetical protein. The accumulation of the mutation in two distinct proteins-MsrR, a peptide methionine sulphoxide reductase regulator, and TcaA, a teicoplanin-resistance-associated protein-correlated with further increases in the glycopeptide MIC. The prevalence of YvqF/VraSR mutants among 125 clinical isolates along with the corresponding teicoplanin MICs was as follows: 0% (0/39), < or =1 mg/L; 48.6% (17/35), 2 mg/L; 72.7% (24/33), 4 mg/L; 93.8% (15/16), 8 mg/L; and 100% (2/2), 16 mg/L. Genetic analysis of 42 VISA isolates also identified the predominant amino acid substitutions in YvqF/VraS: 9 isolates (21.4%) revealed mutations in YvqF, followed by 7 isolates with mutations in VraS (16.7%). CONCLUSIONS Our findings provide novel insights into the high prevalence and genetic diversity of YvqF/VraSR mutants among clinical S. aureus isolates with reduced susceptibility to teicoplanin.
Antibacterial activity of guanidinylated neomycin B- and kanamycin A-derived amphiphilic lipid conjugates.

OBJECTIVES Neomycin B exhibits poor antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, while kanamycin A shows weak activity against MRSA, methicillin-resistant Staphylococcus epidermidis (MRSE) and P. aeruginosa. The main purpose of this work was to study whether lipid conjugation of guanidinylated neomycin B- and kanamycin A-derived cationic headgroups could restore antibacterial activity against neomycin B- and kanamycin A-resistant strains, while retaining antibacterial activity against non-resistant strains. METHODS Seven polyguanidinylated neomycin B-lipids differing in the nature of the lipid tail and two cationic kanamycin A-lipids were prepared, and their in vitro activity was assessed against a variety of neomycin B- and kanamycin A-resistant and neomycin B- and kanamycin A-non-resistant Gram-positive and Gram-negative strains. RESULTS Conjugation of neomycin B- and kanamycin A-derived polyamine or polyguanidinylated headgroups to hydrophobic C16 or C20 lipid tails restored the anti-MRSA activity of both aminoglycosides and the anti-MRSE activity of kanamycin A. Polyguanidinylation of the neomycin B-derived headgroup lowers the hydrophobic requirement of the lipid tail segment to provide broad-spectrum antibacterial activity from C16 to C12. Moreover, guanidinylation of the polycationic headgroup in neomycin B-derived cationic lipids enhances antibacterial activity against a neomycin B-, kanamycin A- and gentamicin-resistant P. aeruginosa strain, and reduces haemolytic activity. CONCLUSIONS These findings suggest that lipid conjugation of neomycin B- and kanamycin A-derived cationic lipids provides a general tool to enhance the antibacterial activity of these two aminoglycosides against resistant strains.
A Comparative Study of Skin Diseases of Dog and Man

The authors are to be commended for their pioneering effort in comparative dermatology. This analytical study should be especially valuable to dermatologists interested in research and experimental work. In order to be useful as a laboratory animal for research in problems of human dermatology, the anatomical, histochemical, and physiological features of the skin of dogs and of man should be similar. A discussion of these features occupies the opening chapters of the book and makes interesting reading. Whereas man, with the development of eccrine sweat glands, has acquired protection against severe heat superior to that of other mammals, the dog makes use of its hair coat. The hair of man, however, has lost its sensory value, which the hair of dog has retained. Otherwise no great dissimilarity was found, although the skin of man is thicker than that of dogs, possibly because of the dog's hair coat. Canine skin is