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1.
Eur J Pediatr ; 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38095713

RESUMO

A subset of patients with post-COVID-19 condition (PCC) fulfill the clinical criteria of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). To establish the diagnosis of ME/CFS for clinical and research purposes, comprehensive scores have to be evaluated. We developed the Munich Berlin Symptom Questionnaires (MBSQs) and supplementary scoring sheets (SSSs) to allow for a rapid evaluation of common ME/CFS case definitions. The MBSQs were applied to young patients with chronic fatigue and post-exertional malaise (PEM) who presented to the MRI Chronic Fatigue Center for Young People (MCFC). Trials were retrospectively registered (NCT05778006, NCT05638724). Using the MBSQs and SSSs, we report on ten patients aged 11 to 25 years diagnosed with ME/CFS after asymptomatic SARS-CoV-2 infection or mild to moderate COVID-19. Results from their MBSQs and from well-established patient-reported outcome measures indicated severe impairments of daily activities and health-related quality of life.    Conclusions: ME/CFS can follow SARS-CoV-2 infection in patients younger than 18 years, rendering structured diagnostic approaches most relevant for pediatric PCC clinics. The MBSQs and SSSs represent novel diagnostic tools that can facilitate the diagnosis of ME/CFS in children, adolescents, and adults with PCC and other post-infection or post-vaccination syndromes. What is Known: • ME/CFS is a debilitating disease with increasing prevalence due to COVID-19. For diagnosis, a differential diagnostic workup is required, including the evaluation of clinical ME/CFS criteria. • ME/CFS after COVID-19 has been reported in adults but not in pediatric patients younger than 19 years. What is New: • We present the novel Munich Berlin Symptom Questionnaires (MBSQs) as diagnostic tools to assess common ME/CFS case definitions in pediatric and adult patients with post-COVID-19 condition and beyond. • Using the MBSQs, we diagnosed ten patients aged 11 to 25 years with ME/CFS after asymptomatic SARS-CoV-2 infection or mild to moderate COVID-19.

2.
Elife ; 112022 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-35781372

RESUMO

Background: Studies report a strong impact of the COVID-19 pandemic and related stressors on the mental well-being of the general population. In this paper, we investigated whether COVID-19 related concerns and social adversity affected schizotypal traits, anxiety, and depression using structural equational modelling. In mediation analyses, we furthermore explored whether these associations were mediated by healthy (sleep and physical exercise) or unhealthy behaviours (drug and alcohol consumption, excessive media use). Methods: We assessed schizotypy, depression, and anxiety as well as healthy and unhealthy behaviours and a wide range of sociodemographic scores using online surveys from residents of Germany and the United Kingdom over 1 year during the COVID-19 pandemic. Four independent samples were collected (April/May 2020: N=781, September/October 2020: N=498, January/February 2021: N=544, May 2021: N=486). The degree of schizotypy was measured using the Schizotypal Personality Questionnaire (SPQ), anxiety, and depression symptoms were surveyed with the Symptom Checklist (SCL-27), and healthy and unhealthy behaviours were assessed with the Coronavirus Health Impact Survey (CRISIS). Structural equation models were used to consider the influence of COVID-19 related concerns and social adversity on depressive and anxiety-related symptoms and schizotypal traits in relation to certain healthy (sleep and exercise) and unhealthy behaviours (alcohol and drug consumption, excessive media use). Results: The results revealed that COVID-19 related life concerns were significantly associated with schizotypy in the September/October 2020 and May 2021 surveys, with anxiety in the September/October 2020, January/February 2021, and May 2021 surveys, and with depressive symptoms in all surveys. Social adversity significantly affected the expression of schizotypal traits and depressive and anxiety symptoms in all four surveys. Importantly, we found that excessive media consumption (>4 hr per day) fully mediated the relationship between COVID-19 related life concerns and schizotypal traits in the January/February 2021 survey. Furthermore, several of the surveys showed that excessive media consumption was associated with increased depressive and anxiety-related symptoms in people burdened by COVID-19 related life. Conclusions: The ongoing uncertainties of the pandemic and the restrictions on social life have a strong impact on mental well-being and especially the expression of schizotypal traits. The negative impact is further boosted by excessive media consumption, which is especially critical for people with high schizotypal traits. Funding: FK received funding from the European Union's Horizon 2020 (Grant number 754,462). SN received funding from the Cundill Centre for Child and Youth Depression at the Centre for Addiction and Mental Health, Toronto, Canada and the Wellcome Trust Institutional Strategic Support Fund from the University of Cambridge.


The 2020 COVID-19 pandemic, and the measures different governments took to contain it, harmed many people's mental well-being. The restrictions, combined with pandemic-related uncertainty, caused many individuals to experience increased stress, depression, and anxiety. Many people turned to unhealthy behaviours to cope, including consuming more alcohol or drugs, using media excessively, developing poor sleeping habits, or reducing the amount of exercise they did. Stress, drugs, poor sleep, and uncertainty can increase an individual's risk of developing psychotic symptoms, including delusions, hallucinations, or difficulty thinking clearly. These symptoms may be temporary or part of a more lasting condition, like schizophrenia. The risk of developing these symptoms increases in people with 'schizotypal traits', such as a lack of close relationships, paranoia, or unusual or implausible beliefs. These individuals may be especially vulnerable to the harmful mental health effects of the pandemic. Daimer et al. demonstrated that people who were more worried about their life stability or financial situation during the 2020 COVID-19 pandemic had worse mental well-being than those who felt secure. In the experiments, volunteers completed a series of online mental health questionnaires at four different time points during the pandemic. People who reported feeling lonely, having negative thoughts, or experiencing fewer positive social interactions had more symptoms of mental illness. People who experienced more life disruptions also reported more anxiety or depression symptoms and more schizotypal traits. Daily consumption of at least four hours of digital media exacerbated negative mental health symptoms, and people with more pandemic-related life concerns also spent more time on digital media Daimer et al. suggest that increased media consumption among people with pandemic-related hardships may have increased mental health symptoms and schizotypal traits in these individuals. The survey results suggest that maintaining a healthy lifestyle, including meaningful relationships, is essential to staying mentally healthy during extreme situations like a global pandemic. Protective interventions ­ such as strengthening social support networks, providing mental health education, or increasing mental healthcare provisions ­ are essential to prevent poor mental health outcomes during future crises.


Assuntos
COVID-19 , Transtorno da Personalidade Esquizotípica , Adolescente , Ansiedade/psicologia , COVID-19/epidemiologia , Criança , Estudos Transversais , Depressão/epidemiologia , Alemanha/epidemiologia , Humanos , Pandemias
3.
J Microbiol Methods ; 174: 105943, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32433995

RESUMO

Beer's Law explains how light attenuates into thick specimens, including thick biofilms. We use a Bayesian optimality criterion, the maximum of the posterior probability distribution, and computationally efficiently fit Beer's Law to the 3D intensity data collected from thick living biofilms by a confocal scanning laser microscope. Using this approach the top surface of the biofilm and an optimal image threshold can be estimated. Biofilm characteristics, such as bio-volumes, can be calculated from this surface. Results from the Bayesian approach are compared to other approaches including the method of maximum likelihood or simply counting bright pixels. Uncertainty quantification (i.e., error bars) can be provided for the parameters of interest. This approach is applied to confocal images of stained biofilms of a common lab strain of Pseudomonas aeruginosa, stained biofilms of Janthinobacterium isolated from the Antarctic, and biofilms of Staphylococcusaureus that have been genetically modified to fluoresce green.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Oxalobacteraceae/ultraestrutura , Pseudomonas aeruginosa/ultraestrutura , Staphylococcus aureus/ultraestrutura , Biofilmes , Microscopia Confocal , Oxalobacteraceae/fisiologia , Pseudomonas aeruginosa/fisiologia , Staphylococcus aureus/fisiologia
4.
Lett Appl Microbiol ; 66(3): 231-237, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29288553

RESUMO

Biofilms are microbial aggregates that show high tolerance to antibiotic treatments in vitro and in vivo. Killing and removal are both important in biofilm control, therefore methods that measure these two mechanisms were evaluated in a parallel experimental design. Kill was measured using the single tube method (ASTM method E2871) and removal was determined by video microscopy and image analysis using a new treatment flow cell. The advantage of the parallel test design is that both methods used biofilm covered coupons harvested from a CDC biofilm reactor, a well-established and standardized biofilm growth method. The control Staphylococcus aureus biofilms treated with growth medium increased by 0·6 logs during a 3-h contact time. Efficacy testing showed biofilms exposed to 400 µmol l-1 penicillin G decreased by only 0·3 logs. Interestingly, time-lapse confocal scanning laser microscopy revealed that penicillin G treatment dispersed the biofilm despite being an ineffective killing agent. In addition, no biofilm removal was detected when assays were performed in 96-well plates. These results illustrate that biofilm behaviour and impact of treatments can vary substantially when assayed by different methods. Measuring both killing and removal with well-characterized methods will be crucial for the discovery of new anti-biofilm strategies. SIGNIFICANCE AND IMPACT OF THE STUDY: Biofilms are tolerant to antimicrobial treatments and can lead to persistent infections. Finding new anti-biofilm strategies and understanding their mode-of-action is therefore of high importance. Historically, antimicrobial testing has focused on measuring the decrease in viability. While kill data are undeniably important, measuring biofilm disruption provides equally useful information. Starting with biofilm grown in the same reactor, we paired assessment of biofilm removal using a new treatment-flow-cell and real-time microscopy with kill data collected using the single tube method (ASTM E2871). Pairing these two methods revealed efficient biofilm removal properties of Penicillin G which were not detected during efficacy testing.


Assuntos
Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Penicilina G/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Meios de Cultura/farmacologia , Farmacorresistência Bacteriana Múltipla/fisiologia , Testes de Sensibilidade Microbiana , Microscopia Confocal , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/crescimento & desenvolvimento
5.
Acta Paediatr ; 107(3): 430-435, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29168250

RESUMO

AIM: To describe cerebral oxygenation during gavage feeding of preterm infants during incubator and skin-to-skin care. METHODS: Further analysis of data from two crossover studies comparing cerebral oxygenation, heart rate and oxygen saturation during skin-to-skin care with incubator care. Data were analysed in three epochs; 10 minutes prefeed, during-feed and 10 minutes postfeed. Measurements from infants fed during incubator care were compared with those obtained during skin-to-skin care. RESULTS: In 39 infants [median (IQR) 27.8 (26.1-30.0) weeks' gestation], there was no difference in cerebral oxygenation between pre-, during- and postfeed. Heart rate increased by three beats per minute postfeed compared with during-feed. Twenty infants received two gavage feeds, one feed in the incubator and another during skin-to-skin care. There was no difference in cerebral oxygenation and heart rate; peripheral oxygen saturation decreased by 3% during feeding whilst skin-to-skin care compared with feeding in the incubator. CONCLUSION: Cerebral oxygenation remained stable before, during and after gavage feeding in an incubator and during skin-to-skin care. The small decrease in oxygen saturation whilst receiving gavage feeding during skin-to-skin care is unlikely to be clinically important, providing reassurance that preterm infants maintain physiological stability during skin-to-skin care.


Assuntos
Circulação Cerebrovascular/fisiologia , Incubadoras para Lactentes , Recém-Nascido Prematuro , Intubação Gastrointestinal , Consumo de Oxigênio/fisiologia , Austrália , Intervalos de Confiança , Estudos Cross-Over , Nutrição Enteral/métodos , Feminino , Seguimentos , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Método Canguru , Masculino , Análise Multivariada , Estudos Prospectivos , Medição de Risco , Resultado do Tratamento
6.
Int J Occup Environ Med ; 7(4): 215-20, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27651082

RESUMO

BACKGROUND: Adjustment disorder (AjD) is a transient mental health condition emerging after stressful life events. Its diagnostic criteria have recently been under revision which led to the development of the Adjustment Disorder--New Module 20 (ADNM-20) as a self-report assessment. OBJECTIVE: To identify a threshold value for people at high risk for AjD. METHODS: As part of a randomized controlled trial evaluating a self-help manual for burglary victims, the baseline data of all participants (n=80) were analyzed. Besides the ADNM-20, participants answered self-report questionnaires regarding the external variables post-traumatic stress disorder symptomatology, depression, anxiety, and stress levels. We used cluster analysis and ROC analysis to identify the most appropriate cut-off value. RESULTS: The cluster analysis identified three different subgroups. They differed in their level of AjD symptomatology from low to high symptom severity. The same pattern of impairment was found for the external variables. The ROC analysis testing the ADNM-20 sum scoreagainst the theory-based diagnostic algorithm, revealed an optimal cut-off score at 47.5 to distinguish between people at high risk for AjD and people at low risk. CONCLUSION: The ADNM-20 distinguishes between people with low, moderate, and high symptomatology. The recommendation for a cut-off score at 47.5 facilitates the use of the ADNM-20 in research and practice.


Assuntos
Transtornos de Adaptação/diagnóstico , Estresse Psicológico/psicologia , Inquéritos e Questionários , Transtornos de Adaptação/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Ansiedade/psicologia , Análise por Conglomerados , Depressão/psicologia , Feminino , Humanos , Acontecimentos que Mudam a Vida , Masculino , Pessoa de Meia-Idade , Curva ROC , Ensaios Clínicos Controlados Aleatórios como Assunto , Índice de Gravidade de Doença , Transtornos de Estresse Pós-Traumáticos/psicologia , Adulto Jovem
8.
Clin Oral Implants Res ; 24(12): 1339-46, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22924875

RESUMO

OBJECTIVES: The goal of the present study was to develop a theoretical analysis of errors in implant position, which can occur owing to minute registration errors of a reference marker in a cone beam computed tomography volume when inserting an implant with a surgical stent. MATERIAL AND METHODS: A virtual dental-arch model was created using anatomic data derived from the literature. Basic trigonometry was used to compute effects of defined minute registration errors of only voxel size. The errors occurring at the implant's neck and apex both in horizontal as in vertical direction were computed for mean ±95%-confidence intervals of jaw width and length and typical implant lengths (8, 10 and 12 mm). RESULTS: Largest errors occur in vertical direction for larger voxel sizes and for greater arch dimensions. For a 10 mm implant in the frontal region, these can amount to a mean of 0.716 mm (range: 0.201-1.533 mm). Horizontal errors at the neck are negligible, with a mean overall deviation of 0.009 mm (range: 0.001-0.034 mm). Errors increase with distance to the registration marker and voxel size and are affected by implant length. CONCLUSION: Our study shows that minute and realistic errors occurring in the automated registration of a reference object have an impact on the implant's position and angulation. These errors occur in the fundamental initial step in the long planning chain; thus, they are critical and should be made aware to users of these systems.


Assuntos
Implantação Dentária Endóssea/métodos , Implantes Dentários , Cirurgia Assistida por Computador/métodos , Tomografia Computadorizada de Feixe Cônico , Planejamento de Prótese Dentária , Humanos , Imageamento Tridimensional , Modelos Dentários , Planejamento de Assistência ao Paciente
9.
Artigo em Inglês | MEDLINE | ID: mdl-22858445

RESUMO

The chick chorioallantoic membrane (CAM) subserves gas exchange in the developing embryo and shell-less culture affords a unique opportunity for direct observations over time of individual blood vessels to pharmacologic interventions. We tested a number of lipids including prostaglandins PGE(1&2) for vascular effects and signaling in the CAM. Application of PGE(1&2) induced a decrease in the diameter of large blood vessels and a concentration-dependent, localized, reversible loss of blood flow through small vessels. The loss of flow was also mimicked by misoprostol, an agonist for 3 of 4 known PGE receptors, EP(2-4), and by U46619, a thromboxane mimetic. Selective receptor antagonists for EP(3) and thromboxane each partially blocked the response. This is a first report of the effects of prostaglandins on vasoreactivity in the CAM. Our model allows the unique ability to examine simultaneous responses of large and small vessels in real time and in vivo.


Assuntos
Alprostadil/farmacologia , Membrana Corioalantoide/efeitos dos fármacos , Dinoprostona/farmacologia , Vasoconstritores/farmacologia , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Alprostadil/antagonistas & inibidores , Animais , Compostos de Bifenilo/farmacologia , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/fisiologia , Compostos Bicíclicos Heterocíclicos com Pontes , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Membrana Corioalantoide/metabolismo , Ácido Dibenzo(b,f)(1,4)oxazepina-10(11H)-carboxílico, 8-cloro-, 2-acetilidrazida/farmacologia , Dinoprostona/antagonistas & inibidores , Relação Dose-Resposta a Droga , Estradiol/farmacologia , Estrogênios/farmacologia , Ácidos Graxos Insaturados , Hidrazinas/farmacologia , Microssomos/efeitos dos fármacos , Microssomos/metabolismo , Misoprostol/farmacologia , Antagonistas de Prostaglandina/farmacologia , Ratos , Receptores de Prostaglandina/agonistas , Receptores de Prostaglandina/antagonistas & inibidores , Receptores de Prostaglandina/metabolismo , Receptores de Tromboxanos/agonistas , Receptores de Tromboxanos/antagonistas & inibidores , Receptores de Tromboxanos/metabolismo , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/antagonistas & inibidores , Xantonas/farmacologia , Ácido alfa-Linolênico/farmacologia
11.
J Neuroendocrinol ; 21(10): 841-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19686448

RESUMO

Oestrogens are powerful endogenous and exogenous neuroprotective hormones in animal models of brain injury, including focal cerebral ischaemia. This protective effect has been demonstrated under a variety of different treatments and injury paradigms, such as in vivo and in vitro stroke conditions. Neuroprotection in the central nervous system by progesterone is less defined. In the present study, cultured cortical and midbrain mouse neurones and human neuroblastoma cells (SH-SY5Y) were exposed to combined glucose-serum deprivation (CGSD), which is regarded as a reliable model mimicking the effects of ischaemia in vitro. Cell viability was assayed using lactate dehydrogenase release and metabolic activity. Conditions for CGSD treatment were chosen to yield half-maximal cell death rates. The validity of CGSD in vitro was compared with permanent middle cerebral artery occlusion (MCAO) in vivo. CGSD for 4 h induced half-maximal neuronal cell death. MCAO in vivo for the same period resulted in significant neuronal loss, also suggesting the validity of CGSD as a suitable stroke-like in vitro model. Combined steroid treatment (17beta-oestradiol and progesterone) but not the application of single steroids abolished CGSD-induced cell death of cortical neurones in vitro. By contrast, no cell protection was found in midbrain neurones or neuroblastoma cells. The co-application of oestrogen (ICI 182,780) or progesterone (RU-486) receptor antagonists did not obviously counteract the protective steroid effects. This suggests the operation of nonclassical steroid mechanisms and their implication in mediation of hormonal effects. The surplus of combined protective hormonal effects might be a result of the observed influence of progesterone application on neuronal oestradiol synthesis. The data obtained in the present study clearly highlight the potential of a combined steroid treatment under toxic degenerative brain pathologies.


Assuntos
Córtex Cerebral/efeitos dos fármacos , Estradiol/farmacologia , Mesencéfalo/efeitos dos fármacos , Neuroblastoma/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Progesterona/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Linhagem Celular Tumoral , Células Cultivadas , Córtex Cerebral/patologia , Córtex Cerebral/fisiologia , Quimioterapia Combinada , Estradiol/administração & dosagem , Glucose/deficiência , Humanos , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Mesencéfalo/patologia , Mesencéfalo/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Neuroblastoma/fisiopatologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Neurônios/fisiologia , Fármacos Neuroprotetores/administração & dosagem , Progesterona/administração & dosagem , Ratos , Ratos Wistar
12.
Appl Microbiol Biotechnol ; 66(6): 635-40, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15735965

RESUMO

Fermentation residues (consisting of incompletely fermented fiber, adherent bacterial cells, and a glycocalyx material that enhanced bacterial adherence) were obtained by growing the anaerobic cellulolytic bacteria Ruminococcus albus 7 or Clostridium thermocellum ATCC 27405 on a fibrous fraction derived from lucerne (Medicago sativa L.). The dried residue was able to serve as an effective co-adhesive for phenol-formaldehyde (PF) bonding of aspen veneer sheets to one another. Testing of the resulting plywood panels revealed that the adhesive, formulated to contain 30% of its total dry weight as fermentation residue, displayed shear strength and wood failure values under both wet and dry conditions that were comparable with those of industry standards for PF that contained much smaller amounts of fillers or extenders. By contrast, PF adhesives prepared with 30% of dry weight as either unfermented lucerne fiber or conventional fillers or extenders rather than as fermentation residues, displayed poor performance, particularly under wet conditions.


Assuntos
Adesivos , Biotecnologia/métodos , Clostridium thermocellum/metabolismo , Medicago sativa/metabolismo , Ruminococcus/metabolismo , Adesivos/química , Clostridium thermocellum/crescimento & desenvolvimento , Fermentação , Formaldeído/química , Fenol/química , Ruminococcus/crescimento & desenvolvimento , Madeira
13.
Climacteric ; 7(1): 70-7, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15259285

RESUMO

OBJECTIVE: To examine the effects of dietary isoflavone supplementation with an extract from red clover on cognitive function in postmenopausal women. DESIGN: Thirty postmenopausal women aged greater than 60 years received either two tablets of an extract of aglycone isoflavones from red clover (each containing formononetin 25 mg, biochanin 2.5 mg and less than 1 mg of daidzein and genistein) for 6 months in a randomized, controlled clinical trial. Cognitive function tests were performed at baseline and at the end of isoflavone or placebo therapy. RESULTS: Isoflavone supplementation was associated with an apparent improvement in block design (a test of visual-spatial intelligence) compared to placebo (isoflavone +12%, placebo -3%; p = 0.03), no improvement in verbal memory compared to an improvement on placebo (isoflavone +1%, placebo +29%; p = 0.023) and a deterioration in digit recall compared to placebo (isoflavone -6%, placebo +12%; p = 0.029). However, these findings were not statistically significant when corrections were made for potential chance findings due to multiple comparisons. CONCLUSION: Isoflavone supplementation does not appear to have major short-term effects on cognitive function in postmenopausal women. However, further clinical trials are required to determine whether small effects or long-term effects on cognitive function occur during isoflavone supplementation.


Assuntos
Cognição/efeitos dos fármacos , Suplementos Nutricionais , Isoflavonas/uso terapêutico , Fitoterapia , Pós-Menopausa/fisiologia , Trifolium , Cognição/fisiologia , Inibidores Enzimáticos/uso terapêutico , Estrogênios não Esteroides/uso terapêutico , Feminino , Genisteína/uso terapêutico , Humanos , Rememoração Mental/efeitos dos fármacos , Rememoração Mental/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Preparações de Plantas/uso terapêutico , Aprendizagem Verbal/efeitos dos fármacos , Aprendizagem Verbal/fisiologia
14.
Appl Microbiol Biotechnol ; 63(1): 29-34, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12819957

RESUMO

Residues from the fermentation of cellulose by the anaerobic bacteria Ruminococcus albus (strain 7) or Ruminococcus flavefaciens (strains FD-1 or B34b) containing residual cellulose, bacterial cells and their associated adhesins, were examined for their ability to serve as components of adhesives for plywood fabrication. The residues contained differing amounts of protein (0.4-4.2% of dry weight), but the ratios of monosaccharides recovered following two-stage treatment of the residue with detergent (pH 7) and TFA were similar for all three strains (0.71 glucose:0.18 xylose:0.08 mannose:0.02 galactose), suggesting similarities in exopolysaccharide composition. Three-ply aspen panels prepared with fermentation residues (FR) displayed better shear strength and wood failure under dry conditions than following a vacuum/pressure/soak/dry treatment, but adhesive properties were inferior to those prepared with conventional phenol-formaldehyde (PF) adhesives. However, panels prepared by incorporating the R. albus 7 FR into PF formulation, at 73% by weight of the total adhesive, exhibited shear strength and wood failure similar to that obtained with PF adhesive alone. Use of residues from fermentations by these bacteria as components of adhesives may add value to biomass fermentations aimed primarily at producing ethanol and other chemical products.


Assuntos
Adesivos/metabolismo , Celulose/metabolismo , Ruminococcus/metabolismo , Fermentação , Madeira
15.
J Med Entomol ; 37(1): 89-101, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15218911

RESUMO

We used a histologic technique to study multiple blood feeding in a single gonotrophic cycle by engorged Aedes aegypti (L.) that were collected weekly for 2 yr from houses in a rural village in Thailand (n = 1,891) and a residential section of San Juan, Puerto Rico (n = 1,675). Overall, mosquitoes from Thailand contained significantly more multiple meals (n = 1,300, 42% double meals, 5% triple meals) than mosquitoes collected in Puerto Rico (n = 1,156, 32% double meals, 2% triple meals). The portion of specimens for which frequency of feeding could not be determined was 31% at both sites. We estimated that on average Ae. aegypti take 0.76 and 0.63 human blood meals per day in Thailand and Puerto Rico, respectively. However, frequency of multiple feeding varied among houses and, in Puerto Rico, the neighborhoods from which mosquitoes were collected. In Thailand 65% of the mosquitoes fed twice on the same day, whereas in Puerto Rico 57% took multiple meals separated by > or = 1 d. At both sites, the majority of engorged specimens were collected inside houses (Thailand 86%, Puerto Rico 95%). The number of blood meals detected was independent of where mosquitoes were collected (inside versus outside of the house) at both sites and the time of day collections were made in Puerto Rico. Feeding rates were slightly higher for mosquitoes collected in the afternoon in Thailand. Temperatures were significantly higher and mosquitoes significantly smaller in Thailand than in Puerto Rico. At both sites female size was negatively associated with temperature. Rates of multiple feeding were associated positively with temperature and negatively with mosquito size in Thailand, but not in Puerto Rico. Multiple feeding during a single gonotrophic cycle is a regular part of Ae. aegypti biology, can vary geographically and under different climate conditions, and may be associated with variation in patterns of dengue virus transmission.


Assuntos
Aedes , Mordeduras e Picadas de Insetos/epidemiologia , Aedes/crescimento & desenvolvimento , Aedes/parasitologia , Ração Animal , Animais , Sangue , Humanos , Estudos Longitudinais , Porto Rico/epidemiologia , Saúde da População Rural , Estações do Ano , Tailândia/epidemiologia , Saúde da População Urbana
16.
J Med Entomol ; 37(1): 77-88, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15218910

RESUMO

Aspiration collections of adult Aedes aegypti (L.) were made weekly from inside and outside of houses for 3 yr in a rural Thai village (n = 9,637 females and n = 11,988 males) and for 2 yr in a residential section of San Juan, Puerto Rico (n = 5,941 females and n = 6,739 males). In Thailand, temperature and rainfall fell into distinct seasonal categories, but only temperature was correlated with fluctuations in female abundance. Average weekly temperature 6 wk before mosquitoes were collected and minimum weekly temperature during the week of collection provided the highest correlations with female abundance. Accounting for annual variation significantly improved Thai models of temperature and mosquito abundance. In Puerto Rico, temperature, but not rainfall, could be categorized into seasonal patterns. Neither was correlated with changes in female abundance. At both sites the vast majority of females were collected inside houses and most contained a blood meal. Most teneral females were collected outside. Wing length--an indicator of female size--and parity, egg development or engorgement status were not correlated, indicating that feeding success and survival were not influenced by female size. At both sites, females fed almost exclusively on human hosts (> or = 96%), a pattern that did not change seasonally. In Puerto Rico more nonhuman blood meals were detected in mosquitoes collected outside than inside houses; no such difference was detected in Thailand. Gut contents of dissected females indicated that females in the Thai population had a younger age distribution and fed more frequently on blood than did Ae. aegypti in Puerto Rico. Our results indicated that aspects of this species' biology can vary significantly from one location to another and 1 yr to the next.


Assuntos
Aedes , Animais , Mordeduras e Picadas/parasitologia , Humanos , Dinâmica Populacional , Porto Rico , População Rural , Estações do Ano , Tailândia , Fatores de Tempo
17.
Cell Mol Life Sci ; 55(11): 1355-7, 1999 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-10518985

RESUMO

The mechanisms that generate the immense complexity of synaptic connections within the developing nervous system have fascinated biologists for decades. Analysis of nervous system development in simple systems, such as insects, has made a major contribution to our understanding of the cellular and molecular mechanisms that control the formation of axon pathways and precise connections. This enterprise has a long, interesting, and somewhat controversial history. This collection of reviews on axon guidance in insects provides a brief update to integrate current molecular and developmental insights in a number of areas from initial axon pathfinding to the recognition of synaptic partners.


Assuntos
Axônios/ultraestrutura , Invertebrados/embriologia , Sistema Nervoso/embriologia , Animais , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/genética , Drosophila/embriologia , Drosophila/genética , Insetos/embriologia , Insetos/genética , Invertebrados/genética , Vias Neurais/embriologia
18.
J Prof Nurs ; 15(3): 192-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10377629

RESUMO

The purpose of this qualitative research was to explore the effect that current nursing attire has on the image of the nursing profession. A number of nurses and a nonnurse were interviewed to determine how attire affected their perception of today's nurses. The two research questions were as follows: (1) is the changing dress of nurses projecting a negative image to the public? and (2) What components of a nurse's apparel indicate professionalism? Content analysis was performed on transcriptions from the tape-recorded responses of a purposeful sample of health care workers: 12 registered nurses, 1 bachelor of nursing student, and 1 layperson. The responses for the first research question were not directly addressed by the participants. However, one overall theme emerged, which was labeled "I can't tell you what it is, but I know it when I see it." The main theme that emerged for the second research question was labeled "total package," with role identification and competency being related themes. As a result of this research, nursing administrators and other health care professionals could gain an understanding of the importance of nursing attire as an indicator of nursing professionalism. Future research needs to examine the same research questions with health care consumers in a variety of acute and community-based health care settings.


Assuntos
Atitude do Pessoal de Saúde , Atitude Frente a Saúde , Vestuário/psicologia , Enfermeiras e Enfermeiros , Competência Profissional , Percepção Social , Adulto , Emblemas e Insígnias , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Comunicação não Verbal , Enfermeiras e Enfermeiros/psicologia , Pesquisa Metodológica em Enfermagem , Inquéritos e Questionários , Simbolismo
20.
Am J Trop Med Hyg ; 59(2): 341-6, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9715958

RESUMO

The traditional view of interactions between arboviruses and their arthropod vectors is that vector hosts become increasingly resistant to parasites; parasite attenuation occurs; or through the process of coevolution, resistance and attenuation occur in concert. Detrimental effects from arboviruses are only seen when vector and virus are not yet well adapted. Results from this study indicate that eastern equine encephalomyelitis (EEE) virus reduces survival and reproduction (fitness) of the mosquito Culiseta melanura, which is required for transmission of EEE virus in North America. Mosquito virulence was not measurably attenuated in virus isolates recovered 55 year apart. This virus did not affect the ability of mosquitoes to obtain a blood meal or the rate of mosquito oocyte development. Results from this study support those from earlier investigations with other mosquito-virus interactions and suggest that reproductively successful arboviruses can have detrimental effects on their mosquito vectors.


Assuntos
Culicidae/virologia , Vírus da Encefalite Equina do Leste/fisiologia , Insetos Vetores/virologia , Animais , Sangue , Linhagem Celular , Galinhas , Culicidae/fisiologia , Ingestão de Alimentos , Fertilidade , Insetos Vetores/fisiologia , Tábuas de Vida , Oogênese , Reprodução
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