99 research outputs found
Amphibian diversity in Serranía de Majé, an isolated mountain range in eastern Panamá
Eastern Panama is within the Mesoamerican biodiversity hotspot and supports an understudied amphibian fauna. Here we characterize the amphibian diversity across an elevational gradient in one of the least studied mountain ranges in eastern Panama, Serrania de Maje. A total of 38 species were found, which represent 17% of all species reported for Panama. Based on expected richness function and individual-based rarefaction curves, it is estimated that this is an underestimate and that at least 44 amphibian species occur in this area. Members of all three amphibian orders were encountered, represented by ten families and 22 genera, including five species endemic to Central America. Estimated species richness decreased with elevation, and the mid-elevation site supported both lowland and highland species. Our study provides a baseline for understanding the distribution pattern of amphibians in Panama, for conservation efforts, and for determining disease-induced changes in amphibian communities.85911713
Soft matter science and the COVID-19 pandemic
Much of the science underpinning the global response to the COVID-19 pandemic
lies in the soft matter domain. Coronaviruses are composite particles with a
core of nucleic acids complexed to proteins surrounded by a protein-studded
lipid bilayer shell. A dominant route for transmission is via air-borne
aerosols and droplets. Viral interaction with polymeric body fluids,
particularly mucus, and cell membranes control their infectivity, while their
interaction with skin and artificial surfaces underpins cleaning and
disinfection and the efficacy of masks and other personal protective equipment.
The global response to COVID-19 has highlighted gaps in the soft matter
knowledge base. We survey these gaps, especially as pertaining to the
transmission of the disease, and suggest questions that can (and need to) be
tackled, both in response to COVID-19 and to better prepare for future viral
pandemics.Comment: 15 page
Absorption of ipratropium and L-carnitine into the pulmonary circulation of the ex-vivo rat lung is driven by passive processes rather than active uptake by OCT/OCTN transporters
The organic cation transporters OCT and OCTN have been reported to play a significant role in the cellular uptake of substrates within in vitro lung cells. However, no studies to date have investigated the effect of these transporters upon transepithelial absorption of substrates into the pulmonary circulation. We investigated the contribution of OCT and OCTN transporters to total pulmonary absorption of L-carnitine and the anti-muscarinic drug, ipratropium, across an intact isolated perfused rat lung (IPRL). The results obtained from the IPRL were contrasted with active transport in vitro using three human pulmonary cell lines and primary rat alveolar epithelial cells. Ex-vivo studies showed that OCT/OCTN transporters do not play a role in the overall pulmonary absorption of L-carnitine or ipratropium, as evidenced by the effect of chemical inhibition of these transporters upon pulmonary absorption. In contrast, in-vitro studies showed that OCT/OCTN transporters play a significant role in cellular accumulation of substrates with preferential uptake of ipratropium by OCTs, and of L-carnitine uptake by OCTNs. The results show that in-vitro uptake studies cannot be predictive of airway to blood absorption in-vivo. Nevertheless, localised submucosal pulmonary concentrations of inhaled drugs and their pulmonary pharmacodynamic profiles may be influenced by OCT/OCTN transport activity
Pigmentation and Vitamin D Metabolism in Caucasians: Low Vitamin D Serum Levels in Fair Skin Types in the UK
Background: Vitamin D may play a protective role in many diseases. Public health messages are advocating sun avoidance to reduce skin cancer risk but the potential deleterious effects of these recommendations for vitamin D metabolism have been poorly investigated. Methodology/Principal Findings: We investigated the association between 25-hydroxy-vitamin D (25(OH)D), skin type and ultraviolet exposure in 1414 Caucasian females in the UK. Mean age of the cohort was 47 years (18–79) and mean 25(OH)D levels were 77 nmol/L (6–289). 25(OH)D levels were strongly associated with season of sampling with higher levels in the spring and summer months (p,0.0001). Light skin types (skin type 1 and 2) have lower levels of 25(OH)D (mean 71 nmol/L) compared to darker skin types (skin type 3 and 4) (mean 82 nmol/L) after adjusting for multiple confounders (p,0.0001). The trend for increasing risk of low vitamin D with fairer skin types was highly significant despite adjustment for all confounders (p = 0.001). Conclusions/Significance: Contrary to previous studies across different ethnic backgrounds, this study within Caucasian UK females shows that fair skin types have lower levels of 25(OH)D compared to darker skin types with potential detrimental health effects. Public health campaigns advocating sun avoidance in fair skinned individuals may need to be revised in vie
Pigmentation and Vitamin D Metabolism in Caucasians: Low Vitamin D Serum Levels in Fair Skin Types in the UK
Background: Vitamin D may play a protective role in many diseases. Public health messages are advocating sun avoidance to reduce skin cancer risk but the potential deleterious effects of these recommendations for vitamin D metabolism have been poorly investigated. Methodology/Principal Findings: We investigated the association between 25-hydroxy-vitamin D (25(OH)D), skin type and ultraviolet exposure in 1414 Caucasian females in the UK. Mean age of the cohort was 47 years (18–79) and mean 25(OH)D levels were 77 nmol/L (6–289). 25(OH)D levels were strongly associated with season of sampling with higher levels in the spring and summer months (p,0.0001). Light skin types (skin type 1 and 2) have lower levels of 25(OH)D (mean 71 nmol/L) compared to darker skin types (skin type 3 and 4) (mean 82 nmol/L) after adjusting for multiple confounders (p,0.0001). The trend for increasing risk of low vitamin D with fairer skin types was highly significant despite adjustment for all confounders (p = 0.001). Conclusions/Significance: Contrary to previous studies across different ethnic backgrounds, this study within Caucasian UK females shows that fair skin types have lower levels of 25(OH)D compared to darker skin types with potential detrimental health effects. Public health campaigns advocating sun avoidance in fair skinned individuals may need to be revised in vie
Dietary intake and stress fractures among elite male combat recruits
<p>Abstract</p> <p>Background</p> <p>Appropriate and sufficient dietary intake is one of the main requirements for maintaining fitness and health. Inadequate energy intake may have a negative impact on physical performance which may result in injuries among physically active populations. The purpose of this research was to evaluate a possible relationship between dietary intake and stress fracture occurrence among combat recruits during basic training (BT).</p> <p>Methods</p> <p>Data was collected from 74 combat recruits (18.2 ± 0.6 yrs) in the Israeli Defense Forces. Data analyses included changes in anthropometric measures, dietary intake, blood iron and calcium levels. Measurements were taken on entry to 4-month BT and at the end of BT. The occurrence of stress reaction injury was followed prospectively during the entire 6-month training period.</p> <p>Results</p> <p>Twelve recruits were diagnosed with stress fracture in the tibia or femur (SF group). Sixty two recruits completed BT without stress fractures (NSF). Calcium and vitamin D intakes reported on induction day were lower in the SF group compared to the NSF group-38.9% for calcium (589 ± 92 and 964 ± 373 mg·d<sup>-1</sup>, respectively, <it>p </it>< 0.001), and-25.1% for vitamin D (117.9 ± 34.3 and 157.4 ± 93.3 IU·d<sup>-1</sup>, respectively, <it>p </it>< 0.001). During BT calcium and vitamin D intake continued to be at the same low values for the SF group but decreased for the NSF group and no significant differences were found between these two groups.</p> <p>Conclusions</p> <p>The development of stress fractures in young recruits during combat BT was associated with dietary deficiency before induction and during BT of mainly vitamin D and calcium. For the purpose of intervention, the fact that the main deficiency is before induction will need special consideration.</p
Is Chytridiomycosis an Emerging Infectious Disease in Asia?
The disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has caused dramatic amphibian population declines and extinctions in Australia, Central and North America, and Europe. Bd is associated with >200 species extinctions of amphibians, but not all species that become infected are susceptible to the disease. Specifically, Bd has rapidly emerged in some areas of the world, such as in Australia, USA, and throughout Central and South America, causing population and species collapse. The mechanism behind the rapid global emergence of the disease is poorly understood, in part due to an incomplete picture of the global distribution of Bd. At present, there is a considerable amount of geographic bias in survey effort for Bd, with Asia being the most neglected continent. To date, Bd surveys have been published for few Asian countries, and infected amphibians have been reported only from Indonesia, South Korea, China and Japan. Thus far, there have been no substantiated reports of enigmatic or suspected disease-caused population declines of the kind that has been attributed to Bd in other areas. In order to gain a more detailed picture of the distribution of Bd in Asia, we undertook a widespread, opportunistic survey of over 3,000 amphibians for Bd throughout Asia and adjoining Papua New Guinea. Survey sites spanned 15 countries, approximately 36° latitude, 111° longitude, and over 2000 m in elevation. Bd prevalence was very low throughout our survey area (2.35% overall) and infected animals were not clumped as would be expected in epizootic events. This suggests that Bd is either newly emerging in Asia, endemic at low prevalence, or that some other ecological factor is preventing Bd from fully invading Asian amphibians. The current observed pattern in Asia differs from that in many other parts of the world
The influence of micrometastases on prognosis and survival in stage I-II colon cancer patients: the Enroute⊕ Study
<p>Abstract</p> <p>Background</p> <p>The presence of lymph node metastases remains the most reliable prognostic predictor and the gold indicator for adjuvant treatment in colon cancer (CC). In spite of a potentially curative resection, 20 to 30% of CC patients testing negative for lymph node metastases (i.e. pN0) will subsequently develop locoregional and/or systemic metastases within 5 years. The presence of occult nodal isolated tumor cells (ITCs) and/or micrometastases (MMs) at the time of resection predisposes CC patients to high risk for disease recurrence. These pN0<sub>micro+ </sub>patients harbouring occult micrometastases may benefit from adjuvant treatment. The purpose of the present study is to delineate the subset of pN0 patients with micrometastases (pN0<sub>micro+</sub>) and evaluate the benefits from adjuvant chemotherapy in pN0<sub>micro+ </sub>CC patients.</p> <p>Methods/design</p> <p>EnRoute+ is an open label, multicenter, randomized controlled clinical trial. All CC patients (age above 18 years) without synchronous locoregional lymph node and/or systemic metastases (clinical stage I-II disease) and operated upon with curative intent are eligible for inclusion. All resected specimens of patients are subject to an <it>ex vivo </it>sentinel lymph node mapping procedure (SLNM) following curative resection. The investigation for micrometastases in pN0 patients is done by extended serial sectioning and immunohistochemistry for pan-cytokeratin in sentinel lymph nodes which are tumour negative upon standard pathological examination. Patients with ITC/MM-positive sentinel lymph nodes (pN0<sub>micro+</sub>) are randomized for adjuvant chemotherapy following the CAPOX treatment scheme or observation. The primary endpoint is 3-year disease free survival (DFS).</p> <p>Discussion</p> <p>The EnRoute+ study is designed to improve prognosis in high-risk stage I/II pN0 <sub>micro+ </sub>CC patients by reducing disease recurrence by adjuvant chemotherapy.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01097265">NCT01097265</a></p
Atopic dermatitis and vitamin D: facts and controversies
Patients with atopic dermatitis have genetically determined risk factors that affect the barrier function of the skin and immune responses that interact with environmental factors. Clinically, this results in an intensely pruriginous and inflamed skin that allows the penetration of irritants and allergens and predisposes patients to colonization and infection by microorganisms. Among the various etiological factors responsible for the increased prevalence of atopic diseases over the past few decades, the role of vitamin D has been emphasized. As the pathogenesis of AD involves a complex interplay of epidermal barrier dysfunction and dysregulated immune response, and vitamin D is involved in both processes, it is reasonable to expect that vitamin D's status could be associated with atopic dermatitis' risk or severity. Such association is suggested by epidemiological and experimental data. in this review, we will discuss the evidence for and against this controversial relationship, emphasizing the possible etiopathogenic mechanisms involved.Univ Brasilia UNB, Brasilia, DF, BrazilFed Dist Hlth State Dept SES DF, Brasilia, DF, BrazilUniv Brasilia HUB UNB, Brasilia Univ Hosp, Brasilia, DF, BrazilSão Paulo Fed Univ UNIFESP, Brasilia, DF, BrazilSão Paulo Fed Univ UNIFESP, Brasilia, DF, BrazilWeb of Scienc
Levels of DNA methylation vary at CpG sites across the BRCA1 promoter, and differ according to triple negative and "BRCA-like" status, in both blood and tumour DNA
Triple negative breast cancer is typically an aggressive and difficult to treat subtype. It is
often associated with loss of function of the BRCA1 gene, either through mutation, loss of
heterozygosity or methylation. This study aimed to measure methylation of the BRCA1
gene promoter at individual CpG sites in blood, tumour and normal breast tissue, to assess
whether levels were correlated between different tissues, and with triple negative receptor
status, histopathological scoring for BRCA-like features and BRCA1 protein expression.
Blood DNA methylation levels were significantly correlated with tumour methylation at 9 of
11 CpG sites examined (p<0.0007). The levels of tumour DNA methylation were significantly
higher in triple negative tumours, and in tumours with high BRCA-like histopathological
scores (10 of 11 CpG sites; p<0.01 and p<0.007 respectively). Similar results were
observed in blood DNA (6 of 11 CpG sites; p<0.03 and 7 of 11 CpG sites; p<0.02 respectively).
This study provides insight into the pattern of CpG methylation across the BRCA1
promoter, and supports previous studies suggesting that tumours with BRCA1 promoter
methylation have similar features to those with BRCA1 mutations, and therefore may be
suitable for the same targeted therapies
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