961 resultados para Humans


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This study aimed to compare ESBL-producing Escherichia coli causing infections in humans with infecting or commensal isolates from animals and isolates from food of animal origin in terms of the strain types, the ESBL gene present and the plasmids that carry the respective ESBL genes. A collection of 353 ESBL-positive E. coli isolates from the UK, the Netherlands and Germany were studied by MLST and ESBL genes were identified. Characterization of ESBL gene-carrying plasmids was performed using PCR-based replicon typing. Moreover, IncI1-Iγ and IncN plasmids were characterized by plasmid MLST. The ESBL-producing E. coli represented 158 different STs with ST131, ST10 and ST88 being the most common. Overall, blaCTX-M-1 was the most frequently detected ESBL gene, followed by blaCTX-M-15, which was the most common ESBL gene in the human isolates. The most common plasmid replicon type overall was IncI1-Iγ followed by multiple IncF replicons. ESBL genes were present in a wide variety of E. coli STs. IncI1-Iγ plasmids that carried the blaCTX-M-1 gene were widely disseminated amongst STs in isolates from animals and humans, whereas other plasmids and STs appeared to be more restricted to isolates from specific hosts.

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Fire-centred studies have recently been highlighted as powerful avenues for investigation of energy flows and relations between humans, materials, environments and other species. The aim in this paper is to evaluate this potential first by reviewing the diverse theories and methods that can be applied to investigate the ecological and social significance of anthropogenic fire, and second by applying these to new and existing data sets in archaeology. This paper examines how fire-centred approaches can inform on one of the most significant step-changes in human lifeways and inter-relations with environment and other species – the transition from mobile hunting-gathering to more sedentary agriculture in a key heartland of change, the Zagros region of Iraq and Iran, c. 12,000–8,000 BP. In the review and case studies multiple links are investigated between human fire use and environment, ecology, energy use, technology, the built environment, health, social roles and relations, cultural practices and catastrophic events

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Humans’ unique cognitive abilities are usually attributed to a greatly expanded neocortex, which has been described as “the crowning achievement of evolution and the biological substrate of human mental prowess” [1]. The human cerebellum, however, contains four times more neurons than the neocortex [2] and is attracting increasing attention for its wide range of cognitive functions. Using a method for detecting evolutionary rate changes along the branches of phylogenetic trees, we show that the cerebellum underwent rapid size increase throughout the evolution of apes, including humans, expanding significantly faster than predicted by the change in neocortex size. As a result, humans and other apes deviated significantly from the general evolutionary trend for neocortex and cerebellum to change in tandem, having significantly larger cerebella relative to neocortex size than other anthropoid primates. These results suggest that cerebellar specialization was a far more important component of human brain evolution than hitherto recognized and that technical intelligence was likely to have been at least as important as social intelligence in human cognitive evolution. Given the role of the cerebellum in sensory-motor control and in learning complex action sequences, cerebellar specialization is likely to have underpinned the evolution of humans’ advanced technological capacities, which in turn may have been a preadaptation for language.

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Background: The aim of this study was to evaluate root coverage of gingival recessions and to compare graft vascularization in smokers and non-smokers. Methods: Thirty subjects, 15 smokers and 15 non-smokers, were selected. Each subject had one Miller Class I or II recession in a non-molar tooth. Clinical measurements of probing depth (PD), relative clinical attachment level (CAL), gingival recession (GR), and width of keratinized tissue (KT) were determined at baseline and 3 and 6 months after surgery. The recessions were treated surgically with a coronally positioned flap associated with a subepithelial connective tissue graft. A small portion of this graft was prepared for immunohistochemistry. Blood vessels were identified and counted by expression of factor VIII-related antigen-stained endothelial cells. Results: Intragroup analysis showed that after 6 months there a was gain in CAL, a decrease in GR, and an increase in KT for both groups (P<0.05), whereas changes in PD were not statistically significant. Smokers had less root coverage than non-smokers (58.02% +/- 19.75% versus 83.35% +/- 18.53%; P<0.05). Furthermore, the smokers had more GR (1.48 +/- 0.79 mm versus 0.52 +/- 0.60 mm) than the nonsmokers (P<0.05). Histomorphometry of the donor tissue revealed a blood vessel density of 49.01 +/- 11.91 vessels/200x field for non-smokers and 36.53 +/- 10.23 vessels/200x field for smokers (P<0.05). Conclusion: Root coverage with subepithelial connective tissue graft was negatively affected by smoking, which limited and jeopardized treatment results.

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Background: Preventing ridge collapse with the extraction of maxillary anterior teeth is vital to an esthetic restorative result. Several regenerative techniques are available and are used for socket preservation. The aim of this study is to analyze by clinical parameters the use of acellular dermal matrix (ADM) and anorganic bovine bone matrix (ABM) with synthetic cell-binding peptide P-15 to preserve alveolar bone after tooth extraction. Methods: Eighteen patients in need of extraction of maxillary anterior teeth were selected and randomly assigned to the test group (ADM plus ABM/P-15) or the control group (ADM only). Clinical measurements were recorded initially and at 6 months after ridge-preservation procedures. Results: In the clinical measurements (external vertical palatal measurement [EVPM], external vertical buccal measurement [EVBM], and alveolar horizontal measurement [AHM]) the statistical analysis showed no difference between test and control groups initially and at 6 months. The intragroup analysis, after 6 months, showed a statistically significant reduction in the measurements for both groups. In the comparison between the two groups, the differences in the test group were as follows: EVPM = 0.83 +/- 1.53 mm; EVBM = 1.20 +/- 2.02 mm; and AHM = 2.53 +/- 1.81 mm. The differences in the control group were as follows: EVPM = 0.87 +/- 1.13 mm; EVBM = 1.50 +/- 1.15 mm; and AHM = 3.40 +/- 1.39 mm. The differences in EVPM and EVBM were not statistically significant; however, in horizontal measurement (AHM), there was a statistically significant difference (P<0.05). Conclusion: The results of this study show that ADM used as membrane associated with ABM/P-15 can be used to reduce buccal-palatal dimensions compared to ADM alone for preservation of the alveolar ridge after extraction of anterior maxillary teeth. J Periodontol 2011;82:72-79.

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Forty-nine typical and atypical enteropathogenic Escherichia coli (EPEC) strains belonging to different serotypes and isolated from humans, pets (cats and dogs), farm animals (bovines, sheep, and rabbits), and wild animals (monkeys) were investigated for virulence markers and clonal similarity by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The virulence markers analyzed revealed that atypical EPEC strains isolated from animals have the potential to cause diarrhea in humans. A close clonal relationship between human and animal isolates was found by MLST and PFGE. These results indicate that these animals act as atypical EPEC reservoirs and may represent sources of infection for humans. Since humans also act as a reservoir of atypical EPEC strains, the cycle of mutual infection of atypical EPEC between animals and humans, mainly pets and their owners, cannot be ruled out since the transmission dynamics between the reservoirs are not yet clearly understood.

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Background and Objectives: There are some indications that low-level laser therapy (LLLT) may delay the development of skeletal muscle fatigue during high-intensity exercise. There have also been claims that LED cluster probes may be effective for this application however there are differences between LED and laser sources like spot size, spectral width, power output, etc. In this study we wanted to test if light emitting diode therapy (LEDT) can alter muscle performance, fatigue development and biochemical markers for skeletal muscle recovery in an experimental model of biceps humeri muscle contractions. Study Design/Materials and Methods: Ten male professional volleyball players (23.6 [SD +/- 5.6] years old) entered a randomized double-blinded placebo-controlled crossover trial. Active cluster LEDT (69 LEDs with wavelengths 660/850 nm, 10/30 mW, 30 seconds total irradiation time, 41.7J of total energy irradiated) or an identical placebo LEDT was delivered under double-blinded conditions to the middle of biceps humeri muscle immediately before exercise. All subjects performed voluntary biceps humeri contractions with a workload of 75% of their maximal voluntary contraction force (MVC) until exhaustion. Results: Active LEDT increased the number of biceps humeri contractions by 12.9% (38.60 [SD +/- 9.03] vs. 34.20 [SD +/- 8.68], P = 0.021) and extended the elapsed time to perform contractions by 11.6% (P = 0.036) versus placebo. In addition, post-exercise levels of biochemical markers decreased significantly with active LEDT: Blood Lactate (P = 0.042), Creatine Kinase (P = 0.035), and C-Reative Protein levels (P = 0.030), when compared to placebo LEDT. Conclusion: We conclude that this particular procedure and dose of LEDT immediately before exhaustive biceps humeri contractions, causes a slight delay in the development of skeletal muscle fatigue, decreases post-exercise blood lactate levels and inhibits the release of Creatine Kinase and C-Reative Protein. Lasers Surg. Med. 41:572-577, 2009. (C) 2009 Wiley-Liss, Inc.

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This study aimed to investigate the effect of 830 nm low-level laser therapy (LLLT) on skeletal muscle fatigue. Ten healthy male professional volleyball players entered a crossover randomized double-blinded placebo-controlled trial. Active LLLT (830 nm wavelength, 100 mW output, spot size 0.0028 cm(2), 200 s total irradiation time) or an identical placebo LLLT was delivered to four points on the biceps humeri muscle immediately before exercises. All subjects performed voluntary biceps humeri contractions with a load of 75% of the maximum voluntary contraction (MVC) force until exhaustion. After active LLLT the mean number of repetitions was significantly higher than after placebo irradiation [mean difference 4.5, standard deviation (SD) +/- 6.0, P = 0.042], the blood lactate levels increased after exercises, but there was no significant difference between the treatments. We concluded that 830 nm LLLT can delay the onset of skeletal muscle fatigue in high-intensity exercises, in spite of increased blood lactate levels.

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The natural diversity of the eft operons, encoding the heat-labile toxin LT-I (LT), carried by enterotoxigenic Escherichia coli (ETEC) strains isolated from humans was investigated. For many years, LT was supposed to be represented by a rather conserved toxin, and one derivative, produced by the reference H10407 strain, was intensively studied either as a virulence factor or as a vaccine adjuvant. Amplicons encompassing the two LT-encoding genes (eltA and eltB) of 51 human-derived ETEC strains, either LT+ (25 strains) only or LT+/ST+ (26 strains), isolated from asymptomatic (24 strains) or diarrheic (27 strains) subjects, were subjected to restriction fragment length polymorphism (RFLP) analysis and DNA sequencing. Seven polymorphic RFLP types of the H10407 strain were detected with six (BsaI, DdeI, HhaI, HincII, HphI, and MspI) restriction enzymes. Additionally, the single-nucleotide polymorphic analysis revealed 50 base changes in the eft operon, including 21 polymorphic sites at eltA and 9 at eltB. Based on the deduced amino acid sequences, 16 LT types were identified, including LT1, expressed by the H10407 strain and 23 other strains belonging to seven different serotypes, and LT2, expressed by 11 strains of six different serotypes. In vitro experiments carried out with purified toxins indicated that no significant differences in GM1-binding affinity could be detected among LT1, LT2, and LT4. However, LT4, but not other toxin types, showed reduced toxic activities measured either in vitro with cultured cells (Y-1 cells) or in vivo in rabbit ligated ileal loops. Collectively, these results indicate that the natural diversity of LTs produced by wild-type ETEC strains isolated from human hosts is considerably larger than previously assumed and may impact the pathogeneses of the strains and the epidemiology of the disease.

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In this study, we provide phylogenetic and biogeographic evidence that the Trypanosomo cruzi lineages T. cruzi I (TCI) and T. cruzi IIa (TCIIa) circulate amongst non-human primates in Brazilian Amazonia, and are transmitted by Rhodnius species in overlapping arboreal transmission cycles, sporadically infecting humans. TO presented higher prevalence rates, and no lineages other than TCI and TCIIa were found in this study in wild monkeys and Rhodnius from the Amazonian region. We characterised TO and TCIIa from wild primates (16 TO and five TCIIa), Rhodnius spp, (13 TCI and nine TCIIa), and humans with Chagas disease associated with oral transmission (14 TO and five TCIIa) in Brazilian Amazonia. To our knowledge, TCIIa had not been associated with wild monkeys until now. Polymorphisms of ssrDNA, cytochrome b gene sequences and randomly amplified polymorphic DNA (RAPD) patterns clearly separated TCIIa from TCIIb-e and TCI lineages, and disclosed small intra-lineage polymorphisms amongst isolates from Amazonia. These data are important in understanding the complexity of the transmission cycles, genetic structure, and evolutionary history of T cruzi populations circulating in Amazonia, and they contribute to both the unravelling of human infection routes and the pathological peculiarities of Chagas disease in this region. (C) 2008 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

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Background: The rat has been a mainstay of physiological and metabolic research, and more recently mice. This study aimed at characterizing the postprandial triglyceride profile of two members of the Muridae family: the Wistar rats (Rattus norvegicus albinus) and C57BL/6 mice (Mus musculus) plus comparing them to the profile obtained in humans. Methods: Thirty-one male and twelve female Wistar rats, ten C57BL/6 male and nine female mice received a liquid meal containing fat (17%), protein (4%) and carbohydrates (4%), providing 2 g fat/Kg. Thirty-one men and twenty-nine women received a standardized liquid meal containing fat (25%), dextromaltose (55%), protein (14%), and vitamins and minerals (6%), and providing 40 g of fat per square meter of body surface. Serial blood samples were collected at 2, 4, 6, 8 and 10 h after the ingestion in rats, at 1, 2, 3, 4, 5 and 6 h in mice and in humans at 2, 4, 6 and 8 h. Wilcoxon and Mann-Whitney tests were used. Results/Discussion: The triglyceride responses were evaluated after the oral fat loads. Fasting and postprandial triglyceridemia were determined sequentially in blood sample. AUC, AUIC, AR, RR and late peaks were determined. Conclusions: Rats are prone to respond in a pro-atherogenic manner. The responses in mice were closer to the ones in healthy men. This study presents striking differences in postprandial triglycerides patterns between rats and mice not correlated to baseline triglycerides, the animal baseline body weight or fat load in all animal groups.

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BACKGROUND: Increased circulating cathepsin S levels have been linked to increased risk of cardiometabolic diseases and cancer. However, whether cathepsin S is a modifiable risk factor is unclear. We aimed to investigate the effects of a prudent diet on plasma cathepsin S levels in healthy individuals. FINDINGS: Explorative analyses of a randomized study were performed in 88 normal to slightly overweight and hyperlipidemic men and women (aged 25 to 65) that were randomly assigned to ad libitum prudent diet, i.e. healthy Nordic diet (ND) or a control group (habitual Western diet) for 6 weeks. Whereas all foods in the ND were provided, the control group was advised to consume their habitual diet throughout the study. The ND was in line with dietary recommendations, e.g. low in saturated fats, sugars and salt, but high in plant-based foods rich in fibre and unsaturated fats.The ND significantly decreased cathepsin S levels (from 20.1 (+/-4.0 SD) to 19.7 μg/L (+/-4.3 SD)) compared with control group (from 18.2 (+/-2.9 SD) to 19.1 μg/L (+/-3.8 SD)). This difference remained after adjusting for sex and change in insulin sensitivity (P = 0.03), and near significant after adjusting for baseline cathepsin S levels (P = 0.06), but not for change in weight or LDL-C. Changes in cathepsin S levels were directly correlated with change in LDL-C. CONCLUSIONS: Compared with a habitual control diet, a provided ad libitum healthy Nordic diet decreased cathepsin S levels in healthy individuals, possibly mediated by weight loss or lowered LDL-C. These differences between groups in cathepsin S were however not robust and therefore need further investigation.

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# 1.
To evaluate the role of adrenaline in regulating carbohydrate metabolism during moderate exercise, 10 moderately trained men completed two 20 min exercise bouts at 58 ± 2 % peak pulmonary oxygen uptake (̇Vo2,peak). On one occasion saline was infused (CON), and on the other adrenaline was infused intravenously for 5 min prior to and throughout exercise (ADR). Glucose kinetics were measured by a primed, continuous infusion of 6,6-[2H]glucose and muscle samples were obtained prior to and at 1 and 20 min of exercise.

# 2.
The infusion of adrenaline elevated (P < 0.01) plasma adrenaline concentrations at rest (pre-infusion, 0.28 ± 0.09; post-infusion, 1.70 ± 0.45 nmol l−1; means ±s.e.m.) and this effect was maintained throughout exercise. Total carbohydrate oxidation increased by 18 % and this effect was due to greater skeletal muscle glycogenolysis (P < 0.05) and pyruvate dehydrogenase (PDH) activation (P < 0.05, treatment effect). Glucose rate of appearance was not different between trials, but the infusion of adrenaline decreased (P < 0.05, treatment effect) skeletal muscle glucose uptake in ADR.

# 3.
During exercise muscle glucose 6-phosphate (G-6-P) (P = 0.055, treatment effect) and lactate (P < 0.05) were elevated in ADR compared with CON and no changes were observed for pyruvate, creatine, phosphocreatine, ATP and the calculated free concentrations of ADP and AMP.

# 4.
The data demonstrate that elevated plasma adrenaline levels during moderate exercise in untrained men increase skeletal muscle glycogen breakdown and PDH activation, which results in greater carbohydrate oxidation. The greater muscle glycogenolysis appears to be due to increased glycogen phosphorylase transformation whilst the increased PDH activity cannot be readily explained. Finally, the decreased glucose uptake observed during exercise in ADR is likely to be due to the increased intracellular G-6-P and a subsequent decrease in glucose phosphorylation.