Influence of middle ear tumours on the biomechanical behaviour of the chorda tympani

Chronic otitis media may lead to the development of a cholesteatoma, a benign middle ear tumour. If this occurs, the chorda tympani nerve, a facial nerve branch that crosses the middle ear, may be compromised. The influence of cholesteatoma development near chorda tympani nerve was studied, in order to assess the consequences of this mass in terms of possible facial paralysis. To do so, an ear model based on the finite element method was used. The chorda tympani nerve was originally discretized and assembled in the model. Two different sized tumours were created so cholesteatoma growth could be simulated. The pressure in this nerve were assessed in two moments - when the tumour first interacts with it, pushing it down, and when the tumour compresses it against the incus. Moreover, the effect of applying pressure directly on the nerve was also evaluated, so tumour geometry did not interfere in the analysis. The obtained stress allowed to infer on the consequences regarding taste disturbance and facial paralysis, although some studies report that when pressure fades away, it is possible to fully recover. The von Mises stress was higher when the chorda tympani nerve was pushed against the incus by the large tumour, in the contact area between the nerve and the ossicle.info:eu-repo/semantics/publishedVersio

On the hearing effects of a cholesteatoma growing: A biomechanical study

Chronic otitis media enables the appearance of a benign middle ear tumor, known as a cholesteatoma, that may compromise hearing. To evaluate the influence of a cholesteatoma growth on the hearing function, a computational middle ear model based on the finite element method was used and three different size of cholesteatoma were modeled. The cholesteatoma solidification and the consequent degradation of the ossicles were also simulated as two condition that commonly occurs during cholesteatoma evolution. A sound pressure level of 80 dB SPL was applied in the tympanic membrane and a steady state analysis was performed for frequencies from 100 Hz to 10 kHz. The displacements of both the tympanic membrane and the stapes footplate were measured. The results were compared with a healthy case and it was shown that the cholesteatoma development leads to a decrease in the umbo and stapes displacements. The ossicles degradation simulation showed the higher difference comparing with the cholesteatoma in an initial stage, with lower displacements in the stapes footplate mainly for high frequencies. The observed displacement differences are directly connected to hearing loss, being possible to conclude that cholesteatoma evolution in the middle ear will lead to hearing problems, mainly in an advanced stage.info:eu-repo/semantics/publishedVersio

Modelação computacional de um tumor do ouvido médio e análise biomecânica do seu impacto na audição

A otite média crónica é uma condição que pode levar ao aparecimento e crescimento de um tumor benigno do ouvido médio, um colesteatoma, o que poderá comprometer a audição [1]. De forma a avaliar a influência do crescimento de um colesteatoma na função auditiva, foi utilizado um modelo do ouvido médio desenvolvido através do método de elementos finitos. O colesteatoma foi modelado na conexão entre o martelo e a bigorna, e foram desenvolvidos três tumores de diferente tamanho [2]. Os deslocamentos da membrana timpanica e da platina do estribo foram analisados após a imposição de um nível de pressão sonora de 80dB SPL na membrana timpânica. Foi realizada uma análise entre as frequências de 100Hz a 10kHz para estado estacionário. Os resultados foram comparados com a situação saudável e a análise indica que o desenvolvimento do colesteatoma leva à diminuição dos deslocamentos das estruturas no inicio e no fim da cadeia ossicular. Outras simulações que foram realizadas incluem a atribuição de diferentes propriedades ao tumor de maiores dimensões, considerando que estas estruturas se tornam mais duras e densas ao longo do tempo. A degradação dos ossículos simulando uma situação real e atribuindo propriedades do tumor a alguns elementos ósseos também foi analisada. Nos resultados correspondentes a estas simulações foram observadas as maiores diferenças de deslocamento. É cientificamente aceite que estas diferenças no deslocamento estão relacionadas com a perda auditiva, desta forma é possível concluir que o crescimento de um tumor no ouvido médio irá conduzir a problemas auditivos.info:eu-repo/semantics/publishedVersio

Genetic diversity and population structure of Cynara cardunculus L. in southern Portugal

Cynara cardunculus L. is a cardoon species native to the Mediterranean region, which is composed of three botanical taxa, each having distinct biological characteristics. The aim of this study was to examine wild populations of C. cardunculus established in Portugal, in order to determine their genetic diversity, geographic distribution, and population structure. Based on SSR markers, 121 individuals of C. cardunculus from 17 wild populations of the Portuguese Alentejo region were identified and analysed. Ten SSRs were found to be efficient markers in the genetic diversity analysis. The total number of alleles ranged from 9 to 17 per locus. The expected and observed means in heterozygosity, by population analysed, were 0.591 and 0.577, respectively. The wild population exhibited a high level of genetic diversity at the species level. The highest proportion of genetic variation was identified within a geographic group, while variation was lower among groups. Geographic areas having highest genetic diversity were identified in Alvito, Herdade da Abo´boda, Herdade da Revilheira and Herdade de São Romão populations. Moreover, significant genetic differentiation existed between wild populations from North-Alentejo geographic locations (Arraiolos, E´ vora, Monte da Chamine´ ) and Centro Hortofrutı´cola, compared with other populations. This study reports genetic diversity among a representative number of wild populations and genotypes of C. cardunculus from Portugal. These results will provide valuable information towards future management of C. cardunculus germplasm.info:eu-repo/semantics/publishedVersio

Concurrent Validation and Reference Values of Gluteus Medius Clinical Test

# Context The hip abductor muscles, mainly the gluteus medius, are responsible for controlling hip adduction in a closed kinetic chain. Frontal plane knee alignment, assessed during functional activities such squatting, jumping and running, may overload joint structures, like the anterior cruciate ligament and patellofemoral joint. The hand-held dynamometer is reliable and effective for testing the muscular strength of the hip abductors. # Objectives (1) To assess the concurrent validity between the gluteus medius clinical test and a maximum isometric force test of the hip abductors using the hand-held dynamometer; (2) to determine the intra and inter-examiner reliability for the application of the gluteus medius clinical test; and (3) to describe reference values of gluteus medius clinical test on a population of youth athletes. # Design Cross-sectional. # Methods Thirty healthy individuals were recruited for validity and reliability testing. On the first day, participants performed the maximal isometric test of the hip abductors, measured via hand-held dynamometry. On the following week, the gluteus medius clinical test was performed. Intraclass correlation coefficients (ICC~2,2~) were computed for the reliability analysis, with a 95% confidence interval. To generate reference values, the gluteus medius clinical test was performed on 273 athletes. # Results The results of this study indicated a weak positive correlation (r = 0.436, p = 0.001) between tests, which indicates that they examine different domains of gluteus medius muscle function, likely endurance and muscle strength. The magnitude of computed ICCs (\>0.95) indicates excellent intra- and inter-examiner reliability. # Conclusion The findings of the current study indicate that the gluteus medius clinical test is reliable and examines a domain of muscular function not fully captured by HHD. The clinical test developed in this study is low-cost and can be included for gluteus medius assessment. # Level of evidence Level 3

Potentiation of combined p19Arf and interferon-beta cancer gene therapy through its association with doxorubicin chemotherapy

Balancing safety and efficacy is a major consideration for cancer treatments, especially when combining cancer immunotherapy with other treatment modalities such as chemotherapy. Approaches that induce immunogenic cell death (ICD) are expected to eliminate cancer cells by direct cell killing as well as activation of an antitumor immune response. We have developed a gene therapy approach based on p19Arf and interferon-β gene transfer that, similar to conventional inducers of ICD, results in the release of DAMPS and immune activation. Here, aiming to potentiate this response, we explore whether association between our approach and treatment with doxorubicin (Dox), a known inducer of ICD, could further potentiate treatment efficacy without inducing cardiotoxicity, a critical side effect of Dox. Using central composite rotational design analysis, we show that cooperation between gene transfer and chemotherapy killed MCA205 and B16F10 cells and permitted the application of reduced viral and drug doses. The treatments also cooperated to induce elevated levels of ICD markers in MCA205, which correlated with improved efficacy of immunotherapy in vivo. Treatment of subcutaneous MCA205 tumors associating gene transfer and low dose (10 mg/kg) chemotherapy resulted in inhibition of tumor progression. Moreover, the reduced dose did not cause cardiotoxicity as compared to the therapeutic dose of Dox (20 mg/kg). The association of p19Arf/interferon-β gene transfer and Dox chemotherapy potentiated antitumor response and minimized cardiotoxicity

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Is There a Seamount Effect on Microbial Community Structure and Biomass? The Case Study of Seine and Sedlo Seamounts (Northeast Atlantic)

Seamounts are considered to be “hotspots” of marine life but, their role in oceans primary productivity is still under discussion. We have studied the microbial community structure and biomass of the epipelagic zone (0–150 m) at two northeast Atlantic seamounts (Seine and Sedlo) and compared those with the surrounding ocean. Results from two cruises to Sedlo and three to Seine are presented. Main results show large temporal and spatial microbial community variability on both seamounts. Both Seine and Sedlo heterotrophic community (abundance and biomass) dominate during winter and summer months, representing 75% (Sedlo, July) to 86% (Seine, November) of the total plankton biomass. In Seine, during springtime the contribution to total plankton biomass is similar (47% autotrophic and 53% heterotrophic). Both seamounts present an autotrophic community structure dominated by small cells (nano and picophytoplankton). It is also during spring that a relatively important contribution (26%) of large cells to total autotrophic biomass is found. In some cases, a “seamount effect” is observed on Seine and Sedlo microbial community structure and biomass. In Seine this is only observed during spring through enhancement of large autotrophic cells at the summit and seamount stations. In Sedlo, and despite the observed low biomasses, some clear peaks of picoplankton at the summit or at stations within the seamount area are also observed during summer. Our results suggest that the dominance of heterotrophs is presumably related to the trapping effect of organic matter by seamounts. Nevertheless, the complex circulation around both seamounts with the presence of different sources of mesoscale variability (e.g. presence of meddies, intrusion of African upwelling water) may have contributed to the different patterns of distribution, abundances and also changes observed in the microbial community

Foot Reflexotherapy Induces Analgesia in Elderly Individuals with Low Back Pain: A Randomized, Double-Blind, Controlled Pilot Study

Introduction. This study evaluated the effects of foot reflexotherapy on pain and postural balance in elderly individuals with low back pain. Design. Randomized, controlled pilot study. Participants (n=20) were randomly assigned to 2 groups: individuals submitted to conventional foot massage (control group) or foot reflexotherapy (RT, intervention group) for a period of 5 weeks. Questionnaires on pain and disability (visual analogue scale [VAS] and Roland-Morris Disability Questionnaire [RMDQ]), heart rate variability, and orthostatic balance and baropodometric analysis were assessed at two intervals: before and after intervention. Results. RT group showed statistically significant differences when compared to control group in the following parameters: decrease in VAS scores for pain throughout the study, decrease in parasympathetic activity, and improvement in RMDQ scores. The two groups did not statistically differ in either orthostatic balance or baropodometric analyses. Conclusion. This study demonstrated that foot reflexotherapy induced analgesia but did not affect postural balance in elderly individuals with low back pain