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1.
J Int AIDS Soc ; 22(12): e25437, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31854506

RESUMO

INTRODUCTION: Socio-behavioural factors may contribute to the wide variance in HIV prevalence between and within sub-Saharan African (SSA) countries. We studied the associations between socio-behavioural variables potentially related to the risk of acquiring HIV. METHODS: We used Bayesian network models to study associations between socio-behavioural variables that may be related to HIV. A Bayesian network consists of nodes representing variables, and edges representing the conditional dependencies between variables. We analysed data from Demographic and Health Surveys conducted in 29 SSA countries between 2010 and 2016. We predefined and dichotomized 12 variables, including factors related to age, literacy, HIV knowledge, HIV testing, domestic violence, sexual activity and women's empowerment. We analysed data on men and women for each country separately and then summarized the results across the countries. We conducted a second analysis including also the individual HIV status in a subset of 23 countries where this information was available. We presented summary graphs showing associations that were present in at least six countries (five in the analysis with HIV status). RESULTS: We analysed data from 190,273 men (range across countries 2295 to 17,359) and 420,198 women (6621 to 38,948). The two variables with the highest total number of edges in the summary graphs were literacy and rural/urban location. Literacy was negatively associated with false beliefs about AIDS and, for women, early sexual initiation, in most countries. Literacy was also positively associated with ever being tested for HIV and the belief that women have the right to ask their husband to use condoms if he has a sexually transmitted infection. Rural location was positively associated with false beliefs about HIV and the belief that beating one's wife is justified, and negatively associated with having been tested for HIV. In the analysis including HIV status, being HIV positive was associated with female-headed household, older age and rural location among women, and with no variables among men. CONCLUSIONS: Literacy and urbanity were strongly associated with several factors that are important for HIV acquisition. Since literacy is one of the few variables that can be improved by interventions, this makes it a promising intervention target.

2.
J Neurochem ; 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31630412

RESUMO

Perception of our environment entirely depends on the close interaction between the central and peripheral nervous system. In order to communicate each other, both systems must develop in parallel and in coordination. During development, axonal projections from the CNS as well as the PNS must extend over large distances to reach their appropriate target cells. To do so, they read and follow a series of axon guidance molecules. Interestingly, while these molecules play critical roles in guiding developing axons, they have also been shown to be critical in other major neurodevelopmental processes, such as the migration of cortical progenitors. Currently, a major hurdle for brain repair after injury or neurodegeneration is the absence of axonal regeneration in the mammalian CNS. By contrasts, PNS axons can regenerate. Many hypotheses have been put forward to explain this paradox but recent studies suggest that hacking neurodevelopmental mechanisms may be the key to promote CNS regeneration. Here we provide a seminar report written by trainees attending the second Flagship school held in Alpbach, Austria in September 2018 organized by the International Society for Neurochemistry (ISN) together with the Journal of Neurochemistry (JCN). This advanced school has brought together leaders in the fields of neurodevelopment and regeneration in order to discuss major keystones and future challenges in these respective fields.

3.
Development ; 146(18)2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31488566

RESUMO

During development, the p75 neurotrophin receptor (p75NTR) is widely expressed in the nervous system where it regulates neuronal differentiation, migration and axonal outgrowth. p75NTR also mediates the survival and death of newly born neurons, with functional outcomes being dependent on both timing and cellular context. Here, we show that knockout of p75NTR from embryonic day 10 (E10) in neural progenitors using a conditional Nestin-Cre p75NTR floxed mouse causes increased apoptosis of progenitor cells. By E14.5, the number of Tbr2-positive progenitor cells was significantly reduced and the rate of neurogenesis was halved. Furthermore, in adult knockout mice, there were fewer cortical pyramidal neurons, interneurons, cholinergic basal forebrain neurons and striatal neurons, corresponding to a relative reduction in volume of these structures. Thalamic midline fusion during early postnatal development was also impaired in Nestin-Cre p75NTR floxed mice, indicating a novel role for p75NTR in the formation of this structure. The phenotype of this strain demonstrates that p75NTR regulates multiple aspects of brain development, including cortical progenitor cell survival, and that expression during early neurogenesis is required for appropriate formation of telencephalic structures.

4.
Gait Posture ; 62: 490-496, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29677664

RESUMO

BACKGROUND: Uphill walking is particularly challenging for elderly persons. However, there is a lack of age-differentiated studies investigating the underlying differences in muscle activation when walking on sloped surfaces. These studies are needed, e.g., for planning of evacuations of large modern cruise ships with long walking distances on often inclined surfaces. METHODS: An age-differentiated, gender-balanced study with 26 young (20-30 years) and 26 elderly people (60-77 years) was therefore conducted, investigating uphill walking at 7° and at 14° contrasted to level walking on a treadmill. EMG signals of musculus gluteus maximus (GMAX), m. biceps femoris (BF), m. rectus femoris (RF), m. vastus medialis (VM), m. gastrocnemius medialis (GAS) and m. soleus (SOL) were analysed with regard to mean and maximum muscle activities and timing during the gait cycle. RESULTS: The results showed that walking uphill at 14° was highly strainful for elderly people. In line with previous research, young people mostly "pushed" themselves uphill with the GAS and SOL. In contrast, elderly people not only used the known compensatory ability of hip muscles to propel the trailing leg, but also showed a high level of BF activation prolonged until the mid-stance phase at the steepest uphill gradient of 14°. SIGNIFICANCE: The strikingly long activation of the BF until the mid-stance phase in elderly people at steep gradients is an unexpected, new finding. It suggests that, instead of pushing, elderly people "pull" themselves uphill. In cases of evacuations, the lower physical fitness levels of elderly passengers and their increased need for assistance on inclined surfaces have to be planned for in advance. Considering the findings in (home) training programmes might help elderly people to strengthen lower limb muscles and to enhance the efficiency of muscle activation patterns enabling them to manage steep inclinations more easily.


Assuntos
Envelhecimento/fisiologia , Extremidade Inferior/fisiologia , Músculo Esquelético/fisiologia , Caminhada/fisiologia , Adulto , Idoso , Eletromiografia , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
Nat Commun ; 8(1): 1476, 2017 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-29133793

RESUMO

Small molecule splicing modifiers have been previously described that target the general splicing machinery and thus have low specificity for individual genes. Several potent molecules correcting the splicing deficit of the SMN2 (survival of motor neuron 2) gene have been identified and these molecules are moving towards a potential therapy for spinal muscular atrophy (SMA). Here by using a combination of RNA splicing, transcription, and protein chemistry techniques, we show that these molecules directly bind to two distinct sites of the SMN2 pre-mRNA, thereby stabilizing a yet unidentified ribonucleoprotein (RNP) complex that is critical to the specificity of these small molecules for SMN2 over other genes. In addition to the therapeutic potential of these molecules for treatment of SMA, our work has wide-ranging implications in understanding how small molecules can interact with specific quaternary RNA structures.


Assuntos
Atrofia Muscular Espinal/tratamento farmacológico , Piperazinas/farmacologia , Precursores de RNA/metabolismo , Processamento de RNA/efeitos dos fármacos , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Biflavonoides/farmacologia , Sistema Livre de Células , Biologia Computacional , Compostos de Epóxi/farmacologia , Éxons/genética , Fibroblastos , Células HEK293 , Células HeLa , Humanos , Ligantes , Macrolídeos/farmacologia , Atrofia Muscular Espinal/genética , Piperazinas/síntese química , Ligação Proteica , Estrutura Quaternária de Proteína , Proteômica/métodos , Precursores de RNA/genética , RNA Mensageiro/genética , Spliceossomos/efeitos dos fármacos , Spliceossomos/metabolismo , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Proteína 2 de Sobrevivência do Neurônio Motor/genética
6.
Appl Ergon ; 59(Pt A): 264-273, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27890136

RESUMO

This age-differentiated study investigated preferences for new digital, situation-adaptive escape route signage with informative and flashing elements under simulated emergency conditions of tilted passenger ships. The decision-making behaviour of 26 young (20-30 years) and 26 elderly (60-77 years) participants was observed in four conditions varying in applied stressors and in level versus uphill walking at 7° and 14°. In line with previous studies, decisions of young participants were significantly influenced by flashing elements on signs. In contrast, elderly participants based their decisions significantly stronger on integrated information about the sign's updatedness and reported irritation by flashing elements. These preferences were also persistent under increased mental, emotional and physical strain, evaluated by ratings and (psycho-)physiological measures. The findings demonstrate the importance to carefully design digital, situation-adaptive signage for passenger ships in a way that it not only attracts attention but also inspires trust especially for the elderly population.


Assuntos
Fatores Etários , Tomada de Decisões , Diretórios de Sinalização e Localização , Navios , Estresse Psicológico/psicologia , Adulto , Idoso , Eletrônica , Emergências , Reação de Fuga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Fisiológico , Fatores de Tempo , Confiança , Caminhada/fisiologia , Adulto Jovem
7.
J Rehabil Med ; 48(2): 197-209, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26931074

RESUMO

BACKGROUND: Health conditions in people with spinal cord injury are major determinants for disability, reduced well-being, and mortality. However, population-based evidence on the prevalence and treatment of health conditions in people with spinal cord injury is scarce. OBJECTIVE: To investigate health conditions in Swiss residents with spinal cord injury, specifically to analyse their prevalence, severity, co-occurrence, and treatment. METHODS: Cross-sectional data (n = 1,549) from the community survey of the Swiss Spinal Cord Injury (SwiSCI) cohort study, including Swiss residents with spinal cord injury aged over 16 years, were analysed. Nineteen health conditions and their self-reported treatment were assessed with the spinal cord injury Secondary Conditions Scale and the Self-Administered Comorbidity Questionnaire. Prevalence and severity were compared across demographics and spinal cord injury characteristics. Co-occurrence of health conditions was examined using a binary non-metric dissimilarity measure and multi-dimensional scaling. Treatment rates were also examined. RESULTS: Number of concurrent health conditions was high (median 7; interquartile range 4-9; most frequent: spasticity, chronic pain, sexual dysfunction). Prevalence of health conditions increased with age and was higher in non-traumatic compared with traumatic spinal cord injury. Spinal cord injury specific conditions co-occurred. Relative frequencies of treatment were low (median 44%, interquartile range 25-64%), even for significant or chronic problems. DISCUSSION: A high prevalence of multimorbidity was found in community-dwelling persons with spinal cord injury. Treatment for some highly prevalent health conditions was infrequent.


Assuntos
Dor Crônica/epidemiologia , Espasticidade Muscular/epidemiologia , Disfunções Sexuais Psicogênicas/epidemiologia , Traumatismos da Medula Espinal/complicações , Adulto , Dor Crônica/etiologia , Estudos de Coortes , Comorbidade , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espasticidade Muscular/etiologia , Prevalência , Índice de Gravidade de Doença , Disfunções Sexuais Psicogênicas/etiologia , Traumatismos da Medula Espinal/epidemiologia , Inquéritos e Questionários , Suíça/epidemiologia
8.
Inj Epidemiol ; 2(1): 28, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26550554

RESUMO

BACKGROUND: Traumatic spinal cord injury (TSCI) has a high personal and socio-economic impact. Effective public health prevention policies that aim to reduce this burden are reliant on contemporary information of the risk and underlying causes of TSCI. This study contextualizes Swiss annual incidence rates within the European context, and provides detailed estimates by age, gender and etiology towards informing targeted intervention strategies. METHODS: TSCI cases that occurred in the years 2005 to 2012 were identified as part of the Swiss Spinal Cord Injury (SwiSCI) cohort study through a rehabilitation-based study of local medical files. RESULTS: The crude annual incidence rate (IR) estimate of TSCI for the study period was 18.0 (95 % confidence interval 16.9-19.2) per one million population; standardized to the WHO world population IR was 21.7 (20.3-23.1) population. The injury rate of TSCI in Switzerland was intermediate in comparison to estimates for other European countries, which ranged from around 8.3 in Denmark to 33.6 per million in Greece. Males exhibited consistently higher IRs than females, with a highest IR ratio (IRR) of 3.9 (2.8-5.5) in young adults (aged 16 to 30). Sports and leisure and transport-related injuries were the predominant causes of TSCI in the youngest age group (aged 16 to 30); falls were the predominant cause among the oldest age group (76 years or over). With increasing age, a greater proportion of fall-related TSCIs were due to low-level falls, with more than 80 % of fall-related TSCIs due to low-level falls in the oldest age group. CONCLUSIONS: Evidence suggests sports/leisure- and transport-related injuries in young men and falls among the elderly as prime targets for prevention policies and programs.

9.
Nat Commun ; 6: 8015, 2015 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-26259702

RESUMO

Although chromosome partitioning during mitosis is well studied, the molecular mechanisms that allow proper segregation of cytoplasmic organelles in human cells are poorly understood. Here we show that mitochondria interact with growing microtubule tips and are transported towards the daughter cell periphery at the end of mitosis. This phenomenon is promoted by the direct and cell cycle-dependent interaction of the mitochondrial protein Miro and the cytoskeletal-associated protein Cenp-F. Cenp-F is recruited to mitochondria by Miro at the time of cytokinesis and associates with microtubule growing tips. Cells devoid of Cenp-F or Miro show decreased spreading of the mitochondrial network as well as cytokinesis-specific defects in mitochondrial transport towards the cell periphery. Thus, Miro and Cenp-F promote anterograde mitochondrial movement and proper mitochondrial distribution in daughter cells.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Proteínas dos Microfilamentos/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Mitose/fisiologia , Proteínas rho de Ligação ao GTP/metabolismo , Sequência de Aminoácidos , Linhagem Celular Tumoral , Proteínas Cromossômicas não Histona/genética , Regulação da Expressão Gênica/fisiologia , Humanos , Proteínas dos Microfilamentos/genética , Microtúbulos/fisiologia , Proteínas Mitocondriais/genética , Dados de Sequência Molecular , Plasmídeos , Proteínas rho de Ligação ao GTP/genética
10.
Neuroepidemiology ; 44(3): 182-98, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25997873

RESUMO

BACKGROUND/AIMS: Mortality and longevity studies of spinal cord injury (SCI) are essential for informing healthcare systems and policies. This review evaluates the current evidence among people with SCIs worldwide in relation to the WHO region and country income level; demographic and lesion characteristics; and in comparison with the general population. METHODS: A systematic review of relevant databases for original studies. Pooled estimates were derived using random effects meta-analysis, restricted to traumatic SCI. RESULTS: Seventy-four studies were included. In-hospital mortality varied, with pooled estimates of 24.1% (95% confidence interval (CI) 14.1-38.0), 7.6% (95% CI 6.3-9.0), 7.0% (95% CI 1.5-27.4), and 2.1% (95% CI 0.9-5.0) in the WHO regions of Africa, the Americas, Europe and Western Pacific. The combined estimate for low- and middle-income countries was nearly three times higher than for high-income countries. Pooled estimates of first-year survival were 86.5% (95% CI 75.3-93.1), 95.6% (95% CI 81.0-99.1), and 94.0% (95% CI 93.3-94.6) in the Americas, Europe and Western Pacific. Pooled estimates of standardized mortality ratios in tetraplegics were 2.53 (2.00-3.21) and 2.07 (1.47-2.92) in paraplegics. CONCLUSION: This study found substantial variation in mortality and longevity within the SCI population, compared to the general population, and between WHO regions and country income level. Improved standardization and quality of reporting is needed to improve inferences regarding the extent to which mortality outcomes following an SCI are related to healthcare systems, services and policies.


Assuntos
Longevidade , Traumatismos da Medula Espinal/mortalidade , Humanos
11.
Biochim Biophys Acta ; 1830(10): 4734-42, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23800578

RESUMO

BACKGROUND: The insulin-like growth factor (IGF) system is composed of ligands and receptors which regulate cell proliferation, survival, differentiation and migration. Some of these functions involve regulation by the extracellular milieu, including binding proteins and other extracellular matrix proteins. However, the functions and exact nature of these interactions remain incomplete. METHODS: IGF-I variants PEGylated at lysines K27, K65 and K68, were assessed for binding to IGFBPs using BIAcore, and for phosphorylation of the IGF-IR. Furthermore, functional consequences of PEGylation were investigated using cell viability and migration assays. In addition, downstream signaling pathways were analyzed using phospho-AKT and phospho-ERK1/2 assays. RESULTS: IGF-I PEGylated at lysines 27 (PEG-K27), 65 (PEG-K65) or 68 (PEG-K68) was employed. Receptor phosphorylation was similarly reduced 2-fold with PEG-K65 and PEG-K68 in 3T3 fibroblasts and MCF-7 breast cancer cells, whereas PEG-K27 showed a more than 10- and 3-fold lower activation for 3T3 and MCF-7 cells, respectively. In addition, all PEG-IGF-I variants had a 10-fold reduced association rate to IGF binding proteins (IGFBPs). Functionally, all PEG variants lost their ability to induce cell migration in the presence of IGFBP-3/vitronectin (VN) complexes, whereas cell viability was fully preserved. Analysis of downstream signaling revealed that AKT was preferentially affected upon treatment with PEG-IGF-I variants whereas MAPK signaling was unaffected by PEGylation. CONCLUSION: PEGylation of IGF-I has an impact on cell migration but not on cell viability. GENERAL SIGNIFICANCE: PEG-IGF-I may differentially modulate IGF-I mediated functions that are dependent on receptor interaction as well as key extracellular proteins such as VN and IGFBPs.


Assuntos
Movimento Celular/fisiologia , Fator de Crescimento Insulin-Like I/fisiologia , Lisina/metabolismo , Polietilenoglicóis/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Humanos , Células MCF-7 , Camundongos , Células NIH 3T3 , Fosforilação , Polietilenoglicóis/química , Receptor IGF Tipo 1/metabolismo , Proteínas Recombinantes/metabolismo
12.
Psychoneuroendocrinology ; 35(9): 1287-93, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20299158

RESUMO

OBJECTIVE: Body weight development is closely regulated by central nervous mechanisms. As has been demonstrated recently, the capability of the brain to actively demand energy from the body (brain-pull) is indispensable for the maintenance of systemic homeostasis. A deficit in this brain-pull may result in compensatory ingestive behavior followed by weight gain in the medium or long term. The aim of this study was to establish a biomarker of such an incompetent brain-pull. Since lactate is an alternative cerebral energy substrate to glucose, we investigated whether low fasting plasma lactate concentrations are associated with weight gain and increased feelings of hunger in patients with type 2 diabetes over a 3-year period. METHODS: In a population based cohort study 134 type 2 diabetes patients were examined at baseline and 3-year follow-up. Plasma lactate concentrations and additional hormones associated with food intake such as e.g. insulin, or leptin, as well as psychological variables like hunger feelings before and after a standardized breakfast were measured. The relation between fasting plasma lactate concentrations and postprandial hunger as well as follow-up weight was analyzed. RESULTS: Low fasting plasma lactate concentrations predicted a higher 3-year follow-up weight (B=-1.268, SE=0.625, p=0.04). Moreover, low fasting plasma lactate concentrations were associated with more pronounced feelings of postprandial hunger (B=-0.406, SE=0.137, p<0.01). CONCLUSIONS: We conclude that low plasma lactate concentrations may represent a biomarker of an incompetent brain-pull, which is associated with weight gain and increased postprandial hunger in patients with type 2 diabetes mellitus. These results are in line with the view that plasma lactate can be used by the brain as an alternative energy substrate and thereby to some extent prevent overeating and obesity.


Assuntos
Encefalopatias Metabólicas/diagnóstico , Diabetes Mellitus Tipo 2/complicações , Ácido Láctico/sangue , Obesidade/etiologia , Ganho de Peso , Adulto , Biomarcadores/análise , Biomarcadores/sangue , Encefalopatias Metabólicas/sangue , Encefalopatias Metabólicas/complicações , Encefalopatias Metabólicas/metabolismo , Estudos de Coortes , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/metabolismo , Metabolismo Energético/fisiologia , Feminino , Seguimentos , Humanos , Hiperfagia/etiologia , Hiperfagia/metabolismo , Ácido Láctico/análise , Masculino , Pessoa de Meia-Idade , Obesidade/diagnóstico , Obesidade/metabolismo , Concentração Osmolar , Fatores de Risco , Ganho de Peso/fisiologia
13.
Antimicrob Agents Chemother ; 54(2): 734-41, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19995923

RESUMO

In passaging experiments, we isolated HIV strains resistant to MAb3952, a chemokine (C-C motif) receptor 5 (CCR5) monoclonal antibody (MAb) that binds to the second extracellular domain (extracellular loop 2 [ECL-2]) of CCR5. MAb3952-resistant viruses remain CCR5-tropic and are cross-resistant to a second ECL-2-specific antibody. Surprisingly, MAb3952-resistant viruses were more susceptible to RoAb13, a CCR5 antibody binding to the N terminus of CCR5. Using CCR5 receptor mutants, we show that MAb3952-resistant virus strains preferentially use the N terminus of CCR5, while the wild-type viruses preferentially use ECL-2. We propose this switch in the CCR5 binding site as a novel mechanism of HIV resistance.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Epitopos/imunologia , Infecções por HIV/tratamento farmacológico , HIV/efeitos dos fármacos , Receptores CCR5/imunologia , Fármacos Anti-HIV/farmacologia , Sítios de Ligação/genética , Linhagem Celular Tumoral , Células Cultivadas , Farmacorresistência Viral/genética , Epitopos/química , Epitopos/genética , HIV/genética , Infecções por HIV/virologia , Humanos , Receptores CCR5/química , Receptores CCR5/genética
14.
Clin Anat ; 20(4): 448-54, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17072868

RESUMO

A multitude of various materials are available for the visualization of cadaveric vessels, ranging from natural materials like gelatin and latex to synthetic materials like silicone rubber or acrylates. To achieve a detailed overview of the vascular architecture in microvascular studies in experimental flap surgery, the injected material should have low viscosity to assure perfusion of even the smallest vessels. In addition, the material ideally should have either no or only minimal shrinkage, and should harden within a reasonable time, but retain sufficient elasticity and resistance to withstand tearing off the delicate vessels during subsequent dissection or casting. Because none of the available injection materials adequately combines these attributes, we evaluated the polyurethane elastomer "PU4ii" in latissimus dorsi muscles as a new material for the visualization of cadaveric vessels in comparison with the frequently used silicone rubber. The dissection of vessels injected with PU4ii proved easy largely because of its exceptional hardness. Even if not visible before dissection, the completely perfused vessels were easily palpated in the surrounding fat or muscle tissue of the microsurgical latissimus dorsi model. Despite the significantly higher hardness of PU4ii over silicone rubber (98 Sh-A vs. 12 Sh-A), PU4ii proved enough elasticity (20-25 N/mm(2) E modulus) and a high tear resistance (64-68 N/mm vs. 15 N/mm) preventing breakage during dissection even within the smallest vessels. In contrast to silicone rubber (and latex or gelatin), the high corrosion resistance and form stability of PU4ii also allowed building of casts for qualitative examination by scanning electron microscopy and quantitative analysis of the vessel density using micro-computed tomography with accurate 3D representation. In this study we show that PU4ii has physical characteristics that make it a multi-purpose material that allows at the same breath an excellent gross visualization of the architecture of cadaveric blood vessels as well as a detailed evaluation of casts by modern microscopic and or radiologic tools. Thus, the new polyurethane elastomer PU4ii is in many respects superior to the widely used silicone rubber and can be strongly recommended as a visualization material for a comprehensive evaluation of cadaveric blood vessels in microsurgery.


Assuntos
Vasos Sanguíneos/anatomia & histologia , Elastômeros , Embalsamamento/métodos , Poliuretanos , Idoso , Idoso de 80 Anos ou mais , Vasos Sanguíneos/citologia , Vasos Sanguíneos/ultraestrutura , Cadáver , Molde por Corrosão , Feminino , Humanos , Masculino , Teste de Materiais , Músculo Esquelético/irrigação sanguínea , Elastômeros de Silicone , Retalhos Cirúrgicos
15.
ALTEX ; 21(3): 135-8, 2004.
Artigo em Alemão | MEDLINE | ID: mdl-15329777

RESUMO

AIM: Systematic training of the manual skills is inevitable in learning microsurgery. Generally, first exercises are done on two-dimensional models, then the training continues on animals. With the growing ethical awareness, the obligation to protect animals and the stricter animal protection laws, realistic three-dimensional models have become necessary for training of microsurgery. However, the available alternatives all have certain disadvantages. We tested vessels made of polyurethane for microvascular surgical training and compared them to the available three-dimensional synthetic alternatives. DESCRIPTION OF THE TRAINING MODEL: Rose-coloured (arteries) or blue (veins), opaque vessels with a minimal wall thickness of 0.12 mm and a minimal internal diameter of 1 mm are used. To mimic the surgical access and the depth of the operative field, the vessels can be embedded in a synthetic box with or without a cap. The completed anastomosis is checked by injection of a coloured fluid. EXPERIENCES: The consistency and the variable relation of the thickness of the wall to the internal diameter very closely reflect the biological situation. Even training on very fragile venous walls is possible in all manners. After completion of anastomosis the vessels can be opened longitudinally to check the patency of the anastomotic site. DISCUSSION: The described polyurethane vessels are very suitable for microsurgical training as a useful step between the two-dimensional model and the animal. The number of animals required for microsurgical training can clearly be reduced by the use of such synthetic polyurethane vessels.


Assuntos
Anastomose Cirúrgica , Microcirurgia/métodos , Procedimentos Cirúrgicos Vasculares/métodos , Alternativas aos Testes com Animais , Humanos , Microcirurgia/educação , Procedimentos Cirúrgicos Vasculares/educação
16.
J Neurosurg ; 97(2): 354-62, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12186464

RESUMO

OBJECT: The authors undertook a prospective study of frameless, magnetic resonance (MR)-guided stereotactic brain biopsy procedures performed with the aid of an open MR system. Morbidity and mortality rates, frequency of postoperative hemorrhage, and histological yield were evaluated, as well as the size and location of the lesions under investigation. METHODS: During a period of 51 months (July 1996-November 2000), 114 consecutive frameless stereotactic biopsy procedures were performed with the aid of an open intraoperative MR system to investigate supratentorial lesions in 113 patients. The median volume of the lesions was 33.5 cm3, and 31.9% were deep seated. All biopsy samples comprised pathological tissue and in 111 (97.4%) of 114 a specific neuropathological diagnosis was made. A follow-up computerized tomography (CT) scan was obtained on the 1st postoperative day in all patients to evaluate postoperative complications. In two cases (1.8%), a hemorrhage was found on postoperative CT scans, with no neurological worsening of the patients. Morbidity with neurological worsening was seen in three patients; it was transient in two of them (1.8%), and in one (0.9%) subsequent emergency craniotomy was necessary because of increased edema. There were no infections, but there was one death (0.9%) CONCLUSIONS: Open intraoperative MR imaging transforms a blind conventional stereotactic procedure into a visually controlled procedure that is adaptable to dynamic anatomical changes. Routine postprocedural MR imaging makes follow-up CT scanning obsolete. This largest reported series of intraoperative MR-guided biopsy procedures shows results that are at least comparable with those in reports of larger series of conventional stereotactic biopsy sampling. The mean procedure time was 60 minutes including planning, and this method produced low morbidity and complication rates and a high histological yield.


Assuntos
Biópsia/efeitos adversos , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Cuidados Intraoperatórios/efeitos adversos , Imagem por Ressonância Magnética/efeitos adversos , Complicações Pós-Operatórias , Técnicas Estereotáxicas/efeitos adversos , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/diagnóstico por imagem , Criança , Pré-Escolar , Seguimentos , Humanos , Lactente , Pessoa de Meia-Idade , Estudos Prospectivos , Tomografia Computadorizada por Raios X
17.
Anesth Analg ; 94(3): 494-9; table of contents, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11867364

RESUMO

UNLABELLED: Chin lift and jaw thrust are two common maneuvers used to improve the patency of the upper airway during general anesthesia. We investigated the effect of these maneuvers combined with continuous positive airway pressure (CPAP) on the size of glottic opening and on stridor score. Forty children, aged 2--9 yr, premedicated with midazolam and spontaneously breathing end-tidal 1% halothane and equal parts of nitrous oxide and oxygen, were studied. A flexible fiberoptic bronchoscope was placed via mask and one nostril to the level of the junction of the soft palate and oropharynx. Video recordings and simultaneous stridor scores were obtained during six conditions: 1) chin unsupported, 2) manual chin lift, 3) chin lift and CPAP 10 cm H(2)O, 4) repeat chin unsupported, 5) manual jaw thrust, and 6) jaw thrust and CPAP 10 cm H(2)O. Videos were analyzed to determine the percentage of glottic opening (POGO) score. POGO score increased (P < 0.05) in Conditions 2, 3, 5, and 6. With increasing POGO score there was a decrease in stridor score (P < 0.05). IMPLICATIONS: Chin lift and jaw thrust maneuvers combined with continuous positive airway pressure improve the view of the glottic opening as viewed by flexible nasal laryngoscopy and decrease stridor in anesthetized, spontaneously breathing children.


Assuntos
Anestesia Geral , Queixo/fisiologia , Glote/fisiologia , Arcada Osseodentária/fisiologia , Respiração com Pressão Positiva , Sons Respiratórios , Criança , Pré-Escolar , Humanos
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