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1.
2.
Inform Med Unlocked ; 37: 101188, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36742350

RESUMO

The aim of this observational retrospective study is to improve early risk stratification of hospitalized Covid-19 patients by predicting in-hospital mortality, transfer to intensive care unit (ICU) and mechanical ventilation from electronic health record data of the first 24 h after admission. Our machine learning model predicts in-hospital mortality (AUC = 0.918), transfer to ICU (AUC = 0.821) and the need for mechanical ventilation (AUC = 0.654) from a few laboratory data of the first 24 h after admission. Models based on dichotomous features indicating whether a laboratory value exceeds or falls below a threshold perform nearly as good as models based on numerical features. We devise completely data-driven and interpretable machine-learning models for the prediction of in-hospital mortality, transfer to ICU and mechanical ventilation for hospitalized Covid-19 patients within 24 h after admission. Numerical values of. CRP and blood sugar and dichotomous indicators for increased partial thromboplastin time (PTT) and glutamic oxaloacetic transaminase (GOT) are amongst the best predictors.

3.
Cancers (Basel) ; 15(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36672352

RESUMO

BACKGROUND: This bicentric study evaluated cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) for platinum-sensitive recurrent ovarian cancer patients. METHODS: The data of 88 patients with the first peritoneal recurrence of platinum-sensitive epithelial ovarian cancer who underwent CRS and HIPEC from a prospective HIPEC registry were retrospectively investigated. Endpoints were feasibility, chemotherapeutic compound, time of exposure, complications, and overall survival. RESULTS: The median follow-up was 4.7 years (95%-CI 4.6-5.5). The median age was 55.8 years (IQR: 50.3-66.2). Eighty-four patients (95.5%) had high-grade serous histology. The median peritoneal cancer index was 12.0 (IQR: 7.0-20.5). Sixty-five patients (73.9%) had complete cytoreduction (CCR 0). Thirty-eight patients (43.2%) received HIPEC for 60 min, and fifty patients (56.8%) for 90 min. Eighteen patients (20.5%) had grade III to IV complications. One patient (1.1%) died perioperatively. The overall median survival was 43.1 months (95%-CI 34.1-52.2), and the 5-year survival rate was 39.7%. Only 90 min HIPEC and cisplatin were associated with survival. CONCLUSION: In well-selected patients with platinum-sensitive recurrent ovarian cancer, survival may correlate with complete CRS and 90 min cisplatin-based HIPEC. We confirmed the results of primary OC studies; therefore, this combination should be used for further analysis in the recurrent situation.

4.
J Infect Dis ; 226(5): 901-906, 2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-35313340

RESUMO

Human immunodeficiency virus (HIV) infection is associated with impaired natural killer (NK) cell activity, which is only incompletely restored under antiretroviral therapy. Analyzing the bioenergetics profiles of oxygen consumption, we observed that several parameters were significantly reduced in HIV+ NK cells, indicating a mitochondrial defect. Accordingly, we found HIV+ CD56bright NK cells to display a decreased mitochondrial membrane potential and mitochondrial mass. Both parameters were positively correlated with interferon gamma (IFN-γ) production of NK cells. Finally, we demonstrated that stimulation of HIV+ NK cells with MitoTEMPO, a mitochondria-targeting antioxidant, significantly improved IFN-γ production. We identified mitochondrial dysfunction as a mechanism that contributes to impaired NK cell function.


Assuntos
Infecções por HIV , Antígeno CD56/metabolismo , Citocinas/metabolismo , HIV/metabolismo , Infecções por HIV/complicações , Humanos , Células Matadoras Naturais/metabolismo , Mitocôndrias/metabolismo
5.
Front Bioeng Biotechnol ; 9: 760500, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35083199

RESUMO

l-Malic acid is a C4-dicarboxylic acid and a potential key building block for a bio-based economy. At present, malic acid is synthesized petrochemically and its major market is the food and beverages industry. In future, malic acid might also serve as a building block for biopolymers or even replace the commodity chemical maleic anhydride. For a sustainable production of l-malic acid from renewable resources, the microbial synthesis by the mold Aspergillus oryzae is one possible route. As CO2 fixation is involved in the biosynthesis, high yields are possible, and at the same time greenhouse gases can be reduced. In order to enhance the production potential of the wild-type strain Aspergillus oryzae DSM 1863, process characteristics were studied in shake flasks, comparing batch, fed-batch, and repeated-batch cultivations. In the batch process, a prolonged cultivation time led to malic acid consumption. Keeping carbon source concentration on a high level by pulsed feeding could prolong cell viability and cultivation time, however, did not result in significant higher product levels. In contrast, continuous malic acid production could be achieved over six exchange cycles and a total fermentation time of 19 days in repeated-batch cultivations. Up to 178 g/L l-malic acid was produced. The maximum productivity (0.90 ± 0.05 g/L/h) achieved in the repeated-batch cultivation had more than doubled than that achieved in the batch process and also the average productivity (0.42 ± 0.03 g/L/h for five exchange cycles and 16 days) was increased considerably. Further repeated-batch experiments confirmed a positive effect of regular calcium carbonate additions on pH stability and malic acid synthesis. Besides calcium carbonate, nitrogen supplementation proved to be essential for the prolonged malic acid production in repeated-batch. As prolonged malic acid production was only observed in cultivations with product removal, product inhibition seems to be the major limiting factor for malic acid production by the wild-type strain. This study provides a systematic comparison of different process strategies under consideration of major influencing factors and thereby delivers important insights into natural l-malic acid production.

7.
Cell ; 181(5): 1080-1096.e19, 2020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-32380006

RESUMO

Environmental signals shape host physiology and fitness. Microbiota-derived cues are required to program conventional dendritic cells (cDCs) during the steady state so that they can promptly respond and initiate adaptive immune responses when encountering pathogens. However, the molecular underpinnings of microbiota-guided instructive programs are not well understood. Here, we report that the indigenous microbiota controls constitutive production of type I interferons (IFN-I) by plasmacytoid DCs. Using genome-wide analysis of transcriptional and epigenetic regulomes of cDCs from germ-free and IFN-I receptor (IFNAR)-deficient mice, we found that tonic IFNAR signaling instructs a specific epigenomic and metabolic basal state that poises cDCs for future pathogen combat. However, such beneficial biological function comes with a trade-off. Instructed cDCs can prime T cell responses against harmless peripheral antigens when removing roadblocks of peripheral tolerance. Our data provide fresh insights into the evolutionary trade-offs that come with successful adaptation of vertebrates to their microbial environment.


Assuntos
Células Dendríticas/imunologia , Interferon Tipo I/imunologia , Microbiota/imunologia , Imunidade Adaptativa/imunologia , Imunidade Adaptativa/fisiologia , Animais , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/microbiologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microbiota/fisiologia , Receptor de Interferon alfa e beta/metabolismo , Transdução de Sinais/imunologia
8.
Immunity ; 52(4): 620-634.e6, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32268121

RESUMO

Innate lymphoid cells (ILCs) play an important role in the control and maintenance of barrier immunity. However, chronic activation of ILCs results in immune-mediated pathology. Here, we show that tissue-resident type 2 ILCs (ILC2s) display a distinct metabolic signature upon chronic activation. In the context of allergen-driven airway inflammation, ILC2s increase their uptake of both external lipids and glucose. Externally acquired fatty acids are transiently stored in lipid droplets and converted into phospholipids to promote the proliferation of ILC2s. This metabolic program is imprinted by interleukin-33 (IL-33) and regulated by the genes Pparg and Dgat1, which are both controlled by glucose availability and mTOR signaling. Restricting dietary glucose by feeding mice a ketogenic diet largely ablated ILC2-mediated airway inflammation by impairing fatty acid metabolism and the formation of lipid droplets. Together, these results reveal that pathogenic ILC2 responses require lipid metabolism and identify ketogenic diet as a potent intervention strategy to treat airway inflammation.


Assuntos
Alérgenos/administração & dosagem , Asma/dietoterapia , Diacilglicerol O-Aciltransferase/imunologia , Dieta Cetogênica/métodos , Interleucina-33/imunologia , Gotículas Lipídicas/metabolismo , Subpopulações de Linfócitos T/imunologia , Alternaria/química , Animais , Asma/induzido quimicamente , Asma/imunologia , Asma/patologia , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Citocinas/administração & dosagem , Diacilglicerol O-Aciltransferase/genética , Modelos Animais de Doenças , Ácidos Graxos/imunologia , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica , Glucose/imunologia , Glucose/metabolismo , Imunidade Inata , Interleucina-33/administração & dosagem , Interleucina-33/genética , Interleucinas/administração & dosagem , Gotículas Lipídicas/imunologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , PPAR gama/genética , PPAR gama/imunologia , Papaína/administração & dosagem , Fosfolipídeos/imunologia , Fosfolipídeos/metabolismo , Cultura Primária de Células , Subpopulações de Linfócitos T/classificação , Subpopulações de Linfócitos T/efeitos dos fármacos , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/imunologia , Linfopoietina do Estroma do Timo
9.
Front Immunol ; 10: 2555, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31736971

RESUMO

Compared to the innate immune system, the contribution of the adaptive immune response during obesity and insulin resistance is still not completely understood. Here we demonstrate that high fat diet (HFD) increases the frequencies of activated CD4+ and CD8+ T cells and frequencies of T cells positive for IFN-γ and IL-17 in the adipose tissue. The adipocyte-derived soluble factor adiponectin reduces IFN-γ and IL-17 positive CD4+ T cells from HFD mice and dampens the differentiation of naïve T cells into Th1 cells and Th17 cells. Adiponectin reduces Th17 cell differentiation and restrains glycolysis in an AMPK dependent fashion. Treatment with adult worm extracts of the rodent filarial nematode Litomosoides sigmodontis (LsAg) reduces adipose tissue Th1 and Th17 cell frequencies during HFD and increases adiponectin levels. Stimulation of T cells in the presence of adipocyte-conditioned media (ACM) from LsAg-treated mice reduces Th1 and Th17 frequencies and this effect was abolished when ACM was treated with an adiponectin neutralizing antibody. Collectively, these data reveal a novel role of adiponectin in controlling pro-inflammatory CD4+ T cells during obesity and suggest that the beneficial role of helminth infections and helminth-derived products on obesity and insulin resistance may be in part mediated by adiponectin.


Assuntos
Adiponectina/farmacologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Interferon gama/biossíntese , Interleucina-17/biossíntese , Obesidade/metabolismo , Adipócitos/metabolismo , Tecido Adiposo/imunologia , Tecido Adiposo/metabolismo , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Dieta Hiperlipídica , Glucose/metabolismo , Glicólise , Insulina/metabolismo , Ativação Linfocitária/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Obesidade/etiologia , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
10.
PLoS One ; 14(10): e0223675, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31648222

RESUMO

Inferring the evolutionary history of cognitive abilities requires large and diverse samples. However, such samples are often beyond the reach of individual researchers or institutions, and studies are often limited to small numbers of species. Consequently, methodological and site-specific-differences across studies can limit comparisons between species. Here we introduce the ManyPrimates project, which addresses these challenges by providing a large-scale collaborative framework for comparative studies in primate cognition. To demonstrate the viability of the project we conducted a case study of short-term memory. In this initial study, we were able to include 176 individuals from 12 primate species housed at 11 sites across Africa, Asia, North America and Europe. All subjects were tested in a delayed-response task using consistent methodology across sites. Individuals could access food rewards by remembering the position of the hidden reward after a 0, 15, or 30-second delay. Overall, individuals performed better with shorter delays, as predicted by previous studies. Phylogenetic analysis revealed a strong phylogenetic signal for short-term memory. Although, with only 12 species, the validity of this analysis is limited, our initial results demonstrate the feasibility of a large, collaborative open-science project. We present the ManyPrimates project as an exciting opportunity to address open questions in primate cognition and behaviour with large, diverse datasets.

11.
Learn Behav ; 46(1): 89-100, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28840526

RESUMO

Quantity discrimination abilities are seen in a diverse range of species with similarities in performance patterns, suggesting common underlying cognitive mechanisms. However, methodological factors that impact performance make it difficult to draw broad phylogenetic comparisons of numerical cognition across studies. For example, some Old World monkeys selected a higher quantity stimulus more frequently when choosing between inedible (pebbles) than edible (food) stimuli. In Experiment 1 we presented brown capuchin (Cebus [Sapajus] paella) and squirrel monkeys (Saimiri sciureus) with the same two-choice quantity discrimination task in three different stimulus conditions: edible, inedible, and edible replaced (in which choice stimuli were food items that stood in for the same quantity of food items that were given as a reward). Unlike Old World monkeys, capuchins selected the higher quantity stimulus more in the edible condition and squirrel monkeys showed generally poor performance across all stimulus types. Performance patterns suggested that differences in subjective reward value might motivate differences in choice behavior between and within species. In Experiment 2 we manipulated the subjective reinforcement value of the reward by varying reward type and delay to reinforcement and found that delay to reinforcement had no impact on choice behavior, while increasing the value of the reward significantly improved performance by both species. The results of this study indicate that species presented with identical tasks may respond differently to methodological factors such as stimulus and reward types, resulting in significant differences in choice behavior that may lead to spurious suggestions of species differences in cognitive abilities.


Assuntos
Cognição/fisiologia , Alimentos , Motivação/fisiologia , Recompensa , Animais , Cebus , Feminino , Masculino , Saimiri , Fatores de Tempo
12.
NMR Biomed ; 30(11)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28915318

RESUMO

High-resolution magic angle spinning (HRMAS) MRS is a powerful method for gaining insight into the physiological and pathological processes of cellular metabolism. Given its ability to obtain high-resolution spectra of non-liquid biological samples, while preserving tissue architecture for subsequent histopathological analysis, the technique has become invaluable for biochemical and biomedical studies. Using HRMAS MRS, alterations in measured metabolites, metabolic ratios, and metabolomic profiles present the possibility to improve identification and prognostication of various diseases and decipher the metabolomic impact of drug therapies. In this review, we evaluate HRMAS MRS results on human tissue specimens from malignancies and non-localized diseases reported in the literature since the inception of the technique in 1996. We present the diverse applications of the technique in understanding pathological processes of different anatomical origins, correlations with in vivo imaging, effectiveness of therapies, and progress in the HRMAS methodology.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Encéfalo/metabolismo , Neoplasias Encefálicas/metabolismo , Cartilagem/metabolismo , Feminino , Neoplasias Gastrointestinais/metabolismo , Neoplasias dos Genitais Femininos/metabolismo , Neoplasias dos Genitais Femininos/patologia , Humanos , Neoplasias Pulmonares/metabolismo , Masculino , Metabolômica , Neoplasias da Próstata/metabolismo
13.
Eur J Radiol ; 85(8): 1390-4, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27423677

RESUMO

AIM: to determine whether [(18)F]2-fluoro-2-deoxyglucose (FDG) positron emission tomography and X-ray computed tomography (PET/CT) findings and metabolic parameters before combined chemo- and radiotherapy (CRT) have a prognostic value in patients with anal carcinoma. MATERIALS AND METHODS: 45 patients with anal cancer who underwent pre-treatment FDG-PET/CT were included. Metabolic parameters, recurrence and anal carcinoma specific survival were analyzed. RESULTS: SUV max and metabolic volume of the primary tumour were significantly higher in patients with lymph node or distant metastases than in those with locally confined disease (p=0.020 and p=0.015, respectively). The extent of disease (local tumour only, lymph node or distant metastases) was highly predictive of both for recurrence free and disease specific survival (p=0.010 and p<0.001, respectively). Recurrence free (p=0.010) and anal carcinoma specific survival (p=0.006) differed significantly between patients with a metabolic volume ≤45ml and >45ml. Multivariate analysis revealed that a metabolic volume >45ml was the only significant independent determinant (p=0.19) for recurrence free survival whereas for anal carcinoma specific survival the extent of disease was identified as the only significant independent determinant (p=0.002). CONCLUSIONS: the extent of disease on FDG PET/CT before combined radio-chemotherapy is strongly predictive of prognosis in anal cancer. Furthermore, patients with a large metabolic volume of the primary tumour (>45ml) are at significantly higher risk of recurrence.


Assuntos
Neoplasias do Ânus/diagnóstico por imagem , Carcinoma/diagnóstico por imagem , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos , Carga Tumoral , Idoso , Antibióticos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Ânus/patologia , Neoplasias do Ânus/terapia , Carcinoma/secundário , Carcinoma/terapia , Quimiorradioterapia/métodos , Intervalo Livre de Doença , Feminino , Fluoruracila/administração & dosagem , Seguimentos , Previsões , Humanos , Metástase Linfática/patologia , Masculino , Pessoa de Meia-Idade , Mitomicina/administração & dosagem , Recidiva Local de Neoplasia/patologia , Prognóstico , Radioterapia de Intensidade Modulada/métodos , Taxa de Sobrevida
14.
J Exp Med ; 213(8): 1409-18, 2016 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-27432938

RESUMO

Innate lymphoid cells (ILC) play an important role in many immune processes, including control of infections, inflammation, and tissue repair. To date, little is known about the metabolism of ILC and whether these cells can metabolically adapt in response to environmental signals. Here we show that type 2 innate lymphoid cells (ILC2), important mediators of barrier immunity, predominantly depend on fatty acid (FA) metabolism during helminth infection. Further, in situations where an essential nutrient, such as vitamin A, is limited, ILC2 sustain their function and selectively maintain interleukin 13 (IL-13) production via increased acquisition and utilization of FA. Together, these results reveal that ILC2 preferentially use FAs to maintain their function in the context of helminth infection or malnutrition and propose that enhanced FA usage and FA-dependent IL-13 production by ILC2 could represent a host adaptation to maintain barrier immunity under dietary restriction.


Assuntos
Ácidos Graxos/imunologia , Helmintíase/imunologia , Imunidade Inata , Linfócitos/imunologia , Desnutrição/imunologia , Animais , Helmintíase/genética , Helmintíase/parasitologia , Interleucina-13/imunologia , Desnutrição/genética , Desnutrição/parasitologia , Camundongos , Camundongos Knockout
15.
Int J Radiat Oncol Biol Phys ; 94(4): 841-9, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26972657

RESUMO

PURPOSE: Most radiobiological models for prediction of tumor control probability (TCP) do not account for the fact that many events could remain unobserved because of censoring. We therefore evaluated a set of TCP models that take into account this censoring. METHODS AND MATERIALS: We applied 2 fundamental Bayesian cure rate models to a sample of 770 pulmonary metastasis treated with stereotactic body radiation therapy at German, Austrian, and Swiss institutions: (1) the model developed by Chen, Ibrahim and Sinha (the CIS99 model); and (2) a mixture model similar to the classic model of Berkson and Gage (the BG model). In the CIS99 model the number of clonogens surviving the radiation treatment follows a Poisson distribution, whereas in the BG model only 1 dominant recurrence-competent tissue mass may remain. The dose delivered to the isocenter, tumor size and location, sex, age, and pretreatment chemotherapy were used as covariates for regression. RESULTS: Mean follow-up time was 15.5 months (range: 0.1-125). Tumor recurrence occurred in 11.6% of the metastases. Delivered dose, female sex, peripheral tumor location and having received no chemotherapy before RT were associated with higher TCP in all models. Parameter estimates of the CIS99 were consistent with the classical Cox proportional hazards model. The dose required to achieve 90% tumor control after 15.5 months was 146 (range: 114-188) Gy10 in the CIS99 and 133 (range: 101-164) Gy10 in the BG model; however, the BG model predicted lower tumor control at long (≳20 months) follow-up times and gave a suboptimal fit to the data compared to the CIS99 model. CONCLUSIONS: Biologically motivated cure rate models allow adding the time component into TCP modeling without being restricted to the follow-up period which is the case for the Cox model. In practice, application of such models to the clinical setting could allow for adaption of treatment doses depending on whether local control should be achieved in the short or longer term.


Assuntos
Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Modelos Teóricos , Radiocirurgia/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Teorema de Bayes , Criança , Bases de Dados Factuais , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Recidiva Local de Neoplasia , Distribuição de Poisson , Probabilidade , Dosagem Radioterapêutica , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
16.
Anim Cogn ; 19(2): 417-28, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26615416

RESUMO

Social comparisons are a fundamental characteristic of human behaviour, yet relatively little is known about their evolutionary foundations. Adapting the co-acting paradigm from human research (Seta in J Pers Soc Psychol 42:281-291, 1982. doi: 10.1037//0022-3514.42.2.281), we examined how the performance of a partner influenced subjects' performance in long-tailed macaques (Macaca fascicularis). Using parallel testing in touch screen setups in which subjects had to discriminate familiar and novel photographs of men and women, we investigated whether accuracy and reaction time were influenced by partner performance and relationship quality (affiliate vs. non-affiliate). Auditory feedback about the alleged performance of the co-actor was provided via playback; partner performance was either moderately or extremely better or worse than subject performance. We predicted that subjects would assimilate to moderately different comparison standards as well as to affiliates and contrast away from extreme standards and non-affiliates. Subjects instantly generalized to novel pictures. While accuracy was not affected by any of the factors, long reaction times occurred more frequently when subjects were tested with a non-affiliate who was performing worse, compared to one who was doing better than them (80% quantile worse: 5.1, better: 4.3 s). For affiliate co-actors, there was no marked effect (worse: 4.4, better: 4.6 s). In a control condition with no auditory feedback, subjects performed somewhat better in the presence of affiliates (M = 77.8% correct) compared to non-affiliates (M = 71.1%), while reaction time was not affected. Apparently, subjects were sensitive to partner identity and performance, yet variation in motivation rather than assimilation and contrast effects may account for the observed effects.


Assuntos
Comportamento Cooperativo , Macaca fascicularis/psicologia , Comportamento Social , Animais , Cognição , Discriminação Psicológica , Feminino , Masculino , Tempo de Reação
17.
J Hand Surg Am ; 40(9): 1812-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26211716

RESUMO

PURPOSE: To compare the biomechanical properties of the modified Kessler, Lahey, Adelaide, and Becker repairs, which are marked by either a locking-loop or a cross-lock configuration. METHODS: Ninety-six lacerated porcine flexor tendons were repaired using the respective core suture and an epitendinous repair. Biomechanical testing was conducted under static and cyclic loads. Parameters of interest were 2-mm gap formation force, displacement during different loads, stiffness, maximum force, and mode of failure. RESULTS: The meaningful gap formation occurred in all 4 repairs at similar tension loads without any significant differences. Maximum force was highest in the Becker repair with a considerable difference compared with the modified Kessler and Lahey sutures. The Adelaide repair showed the highest stiffness. Overall, the displacement during cyclic loading demonstrated similar results with an exception between the Lahey and the Adelaide repairs at 10 N load. Failure by suture pull-out occurred in 42% in the modified Kessler, in 38% in the Lahey, and in 4% in the Adelaide repairs. The Becker repair failed only by suture rupture. CONCLUSIONS: The results of our study suggest that the difference between the 4-strand repairs with a cross-lock or a locking-loop configuration is minor in regard to gap formation. A strong epitendinous suture and the application of core suture pretension might prevent differences in gapping. However, the modified Kessler and Lahey repairs had an inferior maximum tensile strength and were prone to early failure caused by the narrow locking loops with their limited locking power. CLINICAL RELEVANCE: We suggest that surgeons should use pre-tension in repaired tendons to improve gap resistance and should avoid narrow locking loop anchoring to the tendon.


Assuntos
Suturas , Tendões/cirurgia , Animais , Fenômenos Biomecânicos , Teste de Materiais , Técnicas de Sutura , Suínos , Resistência à Tração
18.
PLoS One ; 9(3): e91348, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24646501

RESUMO

Methodological variations in experimental conditions can strongly influence animals' performances in cognitive tests. Specifically, the procedure of the so-called object-choice task has been controversially discussed; here, a human experimenter indicates the location of hidden food by pointing or gazing at one of two or more containers. Whereas dogs usually succeed, results for nonhuman primates are ambiguous. In the standard version of the task the majority of subjects do not respond appropriately to human pointing. However, modifying the task setup, such as placing the containers further apart, seems to improve subjects' performances, suggesting that cue salience may be an important variable. Here we investigated whether the visibility of the experimenter inhibits long-tailed macaques' (Macaca fascicularis) usage of the pointing cue. In our baseline condition, with the experimenter fully visible, the monkeys chose the correct container in 61% of the trials. The performance increased significantly, however, when the experimenter was hidden behind a curtain and only the arm of the experimenter, a doll's arm, or a stick was visible. Furthermore, the monkeys performed significantly better when the tip of the pointing finger or device was close to the target compared to the more distant condition. Intriguingly, after these experiments the monkeys' performance was also significantly improved in the baseline condition (70%). Apparently, the monkeys were first distracted by the presence of the experimenter, but then learned to use the cue. These findings highlight the importance of the test conditions, and question some of the assumptions about species-specific differences in the object-choice task.


Assuntos
Comportamento Animal/fisiologia , Comportamento de Escolha/fisiologia , Sinais (Psicologia) , Aprendizagem/fisiologia , Macaca fascicularis/psicologia , Animais , Atenção , Feminino , Humanos , Macaca fascicularis/fisiologia , Masculino , Resolução de Problemas
19.
Exp Gerontol ; 48(12): 1379-86, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24055797

RESUMO

Aging is associated with multiple changes in the proliferative and functional abilities of the immune system which are not related to any pathology but consequences in immunosenescence and inflammaging. T helper (TH) 17 cells have been implicated in the development of autoimmune and chronic inflammatory diseases in humans. Additionally, a reciprocal relationship between these pro-inflammatory TH17 and the anti-inflammatory regulatory T cells (Tregs) has been described. Recent studies reported an increase of TH17 cells in aged humans and aged mice, but the role of TH17 cells and their relation to Tregs is poorly understood in human aging. This study investigated the proportion of TH17 (CD4+ IL23 receptor(R)+) cells and Tregs (CD4+ Foxp3+) as well as Interleukin (IL)-17 and IL-10 production in four different age groups from human healthy donors. The data revealed a continual increase of basal CD4+ IL23R+ cell amounts in the different age groups. By analyzing the balance of both T-cell subsets it was observed that, on a basal resting level, TH17 cells were significantly increased in older individuals whereas Tregs were reduced. However, the TH17/Treg ratio decreased age-dependently after stimulation and was accompanied by elevated Foxp3 mRNA and IL-10 protein expressions. In conclusion, changes of the TH17/Treg ratios in combination with altered cytokine expression during aging may contribute to an imbalance between the pro-inflammatory and the anti-inflammatory immune response. This indicates a higher susceptibility to develop inflammatory diseases with increasing age.


Assuntos
Envelhecimento/imunologia , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Células Cultivadas , Feminino , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Voluntários Saudáveis , Humanos , Mediadores da Inflamação/metabolismo , Interleucina-10/metabolismo , Interleucina-17/genética , Interleucina-17/metabolismo , Masculino , Pessoa de Meia-Idade , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Fenótipo , Fito-Hemaglutininas/farmacologia , RNA Mensageiro/metabolismo , Receptores de Interleucina/metabolismo , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/metabolismo , Células Th1/efeitos dos fármacos , Células Th1/metabolismo , Adulto Jovem
20.
Anim Cogn ; 16(5): 829-38, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23443407

RESUMO

Whether the cognitive competences of monkeys and apes are rather similar or whether the larger-brained apes outperform monkeys in cognitive experiments is a highly debated topic. Direct comparative analyses are therefore essential to examine similarities and differences among species. We here compared six primate species, including humans, chimpanzees, bonobos, gorillas (great apes), olive baboons, and long-tailed macaques (Old World monkeys) in a task on fine-grained size discrimination. Except for gorillas, subjects of all taxa (i.e. humans, apes, and monkeys) were able to discriminate three-dimensional cubes with a volume difference of only 10 % (i.e. cubes of 50 and 48 mm side length) and performed only slightly worse when the cubes were presented successively. The minimal size discriminated declined further with increasing time delay between presentations of the cubes, highlighting the difficulty to memorize exact size differences. The results suggest that differences in brain size, as a proxy for general cognitive abilities, did not account for variation in performance, but that differential socio-ecological pressures may better explain species differences. Our study highlights the fact that differences in cognitive abilities do not always map neatly onto phylogenetic relationships and that in a number of cognitive experiments monkeys do not fare significantly worse than apes, casting doubt on the assumption that larger brains per se confer an advantage in such kinds of tests.


Assuntos
Discriminação Psicológica , Percepção de Tamanho , Adulto , Animais , Feminino , Gorilla gorilla/psicologia , Humanos , Macaca/psicologia , Masculino , Pessoa de Meia-Idade , Pan paniscus/psicologia , Pan troglodytes/psicologia , Papio anubis/psicologia
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