Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
36,003
result(s) for
"Quintero, A."
Sort by:
Soil nitrogen affects phosphorus recycling: foliar resorption and plant-soil feedbacks in a northern hardwood forest
Previous studies have attempted to link foliar resorption of nitrogen and phosphorus to their respective availabilities in soil, with mixed results. Based on resource optimization theory, we hypothesized that the foliar resorption of one element could be driven by the availability of another element. We tested various measures of soil N and P as predictors of N and P resorption in six tree species in 18 plots across six stands at the Bartlett Experimental Forest, New Hampshire, USA. Phosphorus resorption efficiency (
P
< 0.01) and proficiency (
P
= 0.01) increased with soil N content to 30 cm depth, suggesting that trees conserve P based on the availability of soil N. Phosphorus resorption also increased with soil P content, which is difficult to explain based on single-element limitation, but follows from the correlation between soil N and soil P. The expected single-element relationships were evident only in the O horizon: P resorption was high where resin-available P was low in the Oe (
P
< 0.01 for efficiency,
P
< 0.001 for proficiency) and N resorption was high where potential N mineralization in the Oa was low (
P
< 0.01 for efficiency and 0.11 for proficiency). Since leaf litter is a principal source of N and P to the O horizon, low nutrient availability there could be a result rather than a cause of high resorption. The striking effect of soil N content on foliar P resorption is the first evidence of multiple-element control on nutrient resorption to be reported from an unmanipulated ecosystem.
Journal Article
Defining the Origins of the NOD-Like Receptor System at the Base of Animal Evolution
Distinguishing self from nonself and the onset of defense effector mechanisms upon recognition of pathogens are essential for the survival of all life forms in the animal kingdom. The family of nucleotide -binding and oligomeriszation domain-like receptors (NLRs) was first identified in vertebrates and comprises a group of pivotal sensor protein of the innate immune system for microbial cell wall components or danger signals. Here, we provide first evidence that early diverging metazoans have large and complex NLR repertoires. The cnidarian NACHT/NB-ARC genes include novel combinations of domains, and the number of one specific type (NB-ARC and tetratricopeptide repeat containing) in Hydra is particularly large. We characterize the transcript structure and expression patterns of a selected HyNLR, HyNLR type 1 and describe putative interaction partners. In a heterologous expression system, we show induced proximity recruitment of an effector caspase (HyDD-Caspase) to the HyNLR type 1 protein upon oligomerization indicating a potential role of caspase activation downstream of NLR activation in Hydra. These results add substantially to our understanding of the ancestral innate immune repertoire as well as providing the first insights into putative cytoplasmic defense mechanisms at the base of animal evolution.
Journal Article
Contemporary demographics, diagnostics and outcomes in non-bacterial thrombotic endocarditis
ObjectiveNon-bacterial thrombotic endocarditis (NBTE) is a syndrome characterised by cardiac valve vegetations and/or thickening due to non-infective mechanisms. Nowadays, a premortem diagnosis of NBTE is possible based on echocardiographic findings. Therefore, to better characterise this disease, we performed a contemporary review of the epidemiology, demographics, diagnosis and clinical outcomes of these patients.MethodsAdults with a diagnosis of NBTE seen within the Mayo Clinic Enterprise from December 2014 to December 2021 were included. NBTE diagnosis was identified by clinicians representing at least two specialties including cardiology, infectious diseases, rheumatology and oncology. Patients with positive blood cultures, infective endocarditis, culture-negative endocarditis and denial of research authorisation were excluded. All patients had a 1-year follow-up.ResultsForty-eight cases were identified; mean age was 60.0±13.8 years, 75% were female. The most prevalent comorbidities were malignancy (52.1%) and connective tissue disease (37.5%). Valvular abnormalities included 41 (85.4%) patients with vegetations, 43 (89.6%) patients with thickening and 26 (54.2%) with moderate to severe regurgitation. Thirty-eight (79.2%) patients had an embolic event (stroke in 26 (54.2%) patients) within 1 month of NBTE diagnosis and 16 (33.3%) patients died within 1 year of NBTE diagnosis. Metastatic tumours and lung cancer were associated with 1-year all-cause mortality (p=0.0017 and p=0.0004, respectively).ConclusionsNBTE was more prevalent in females and embolic complications were the most frequent clinical finding. Overall, patients with NBTE had a poor prognosis, particularly in those with lung cancer or metastatic tumours. Further studies in patients with NBTE are needed given its morbidity and mortality.
Journal Article
Sputum Biomarkers in Wood and Tobacco Smoke Etiotypes of Chronic Obstructive Pulmonary Disease
There is a need to better understand the etiotypes of chronic obstructive pulmonary disease (COPD) beyond the tobacco-smoke (TS-COPD). Wood smoke COPD (WS-COPD) is characterized by greater airway compromise, milder emphysema, and slower rate of lung function decline than TS-COPD. However, it is unclear if these two etiotypes of COPD have differences in sputum biomarker concentrations. Objective was to compare sputum levels of selected sputum biomarkers between WS-COPD and TS-COPD, and healthy controls.
Eighty-eight women (69±12 years) were recruited and classified into: WS-COPD (n=31), TS-COPD (n=29) and controls (n=28). Using ELISA, we determined induced sputum levels of metalloproteinase 9 (MMP-9), chemokine ligand 5 (CCL5), interleukin-8 (IL-8), chemokine ligand 16 (CCL16/HCC-4) and vascular endothelial growth factor (VEGF-1). Differences were analyzed by Kruskal-Wallis and Mann-Whitney-
tests and correlation between airflow limitation and biomarkers by Spearman's test.
At similar degree of airflow obstruction, anthropometrics and medications use, the level of sputum CCL5 was higher in TS-COPD than WS-COPD (p=0.03) without differences in MMP-9, IL-8, CCL16/HCC-4, and VEGF-1. Women with WS-COPD and TS-COPD showed significantly higher sputum levels of MMP-9, IL-8 and CCL5 compared with controls (p<0.001). FEV
% predicted correlated negatively with levels of MMP-9 (rho:-0.26; P=0.016), CCL5 (rho:-0.37; P=0.001), IL-8 (rho:-0.42; P<0.001) and VEGF (rho:-0.22; P=0.04).
While sputum concentrations of MMP-9, IL-8, and CCL5 were higher in COPD women compared with controls, women with TS-COPD had higher levels of CCL5 compared with those with WS-COPD. Whether this finding relates to differences in pathobiological pathways remains to be determined.
Journal Article
Telemedicine consultation for emergency patients’ attention: a clinical experience from a high complex university hospital from Latin America
Introduction
As a result of the new coronavirus pandemic, a highly complex academic hospital in Latin America implemented a telemedicine service for the care of obstetric, pediatric, and adult patients. In 2020, regional emergency services collapsed due to the increase in demand for care, generating the need to open expansion services and seek strategies to provide timely care to consulting patients.
Objective
We retrospectively describe the clinical experience of patients who consulted the emergency department via telemedicine across a videoconference tool using digital platforms.
Methods
A descriptive study with retrospective data collection was conducted to describe the implementation of the teleconsultation care model for patients. We constructed the clinical process indicators to evaluate the model.
Results
A total of 4652 teleconsultations were registered. Telemedicine consultation was above 50% in the country and department and above 90% in Cali city. The average waiting time for care was estimated to be 1:59:52 h. A total of 275 patients were transferred to the emergency room after consultation. The principal reasons for consultation in the institutional telemedicine program were respiratory and gastrointestinal symptoms. Teleconsultations related to SARS-COV 2 infections reported 3775 patients (3127 with unidentified virus and 648 with the identified virus).
Conclusions
Telemedicine is a tool that provides support and guidance to patients who consult emergency departments, reducing barriers to access health care and decreasing emergency department collapse.
Journal Article
Effect of supplementation with vitamins D3 and K2 on undercarboxylated osteocalcin and insulin serum levels in patients with type 2 diabetes mellitus: a randomized, double-blind, clinical trial
Background
Patients with type 2 diabetes mellitus (T2DM) are characterized by chronic hyperglycemia as a consequence of decreased insulin sensitivity, which contributes to bone demineralization and could also be related to changes in serum levels of osteocalcin and insulin, particularly when coupled with a deficiency in the daily consumption of vitamins D3 and K2. The objective of this study was to evaluate the effect of vitamin D3 and vitamin K2 supplements alone or in combination on osteocalcin levels and metabolic parameters in patients with T2DM.
Methods
A double-blind, randomized clinical trial was carried out in 40 patients aged between 30 and 70 years old for 3 months. Clinical and laboratory assessment was carried out at the beginning and at the end of the treatment. The patients were divided into three groups: (a) 1000 IU vitamin D3 + a calcinated magnesium placebo (n = 16), (b) 100 µg of Vitamin K2 + a calcinated magnesium placebo (n = 12), and (c) 1000 IU vitamin D3 + 100 µg vitamin K2 (n = 12).
Results
After treatment in the total studied population, a significant decrease in glycemia (p = 0.001), HOMA-IR (Homeostatic model assessment-insulin resistance) (p = 0.040), percentage of pancreatic beta cells (p < 0.001), uOC/cOC index and diastolic blood pressure (p = 0.030) were observed; in vitamin D3 group, differences in serum undercarboxylated osteocalcin (p = 0.026), undercarboxylated to carboxylated osteocalcin index (uOC/cOC) (p = 0.039) glucose (p < 0.001) and % of functional pancreatic beta cells (p < 0.001) were demonstrated. In vitamin K2 group a significant decrease in glycemia (p = 0.002), HOMA-IR (p = 0.041), percentage of pancreatic beta cells (p = 0.002), and in cOC (p = 0.041) were observed, conversely cOC concentration was found high. Finally, in the vitamins D3 + K2 a significant decrease in glycemia (p = 0.002), percentage of pancreatic beta cells (p = 0.004), and in the uOC/cOC index (p = 0.023) were observed.
Conclusion
Individual or combined supplementation with vitamins D3 and K2 significantly decreases the glucose levels and % of functional pancreatic beta cells, while D3 and D3 + K2 treatments also induced a reduction in the uOC/cOC index. Only in the group with vitamin D3 supplementation, it was observed a reduction in undercarboxylated osteocalcin while vitamin K2 increased the carboxylated osteocalcin levels.
Trial registration
NCT04041492
Journal Article
Principal causes of acute poisoning in an emergency service: experience between 2014 and 2021 at a University Hospital in Southwestern Colombia
Acute poisonings are a global public health problem, which implies costs and disease burden for society. In Colombia, there is a significant underreporting of data on acute poisoning and data gaps on the toxicological profile of the population. This study aims to identify the epidemiology of acute poisoning in a high-complexity hospital in southwestern Colombia. A descriptive study with retrospective data collection was performed. The variables were expressed through the measure of central tendency and dispersion. Categorical variables were described in proportions. A total of 406 patients were included. The median age was 31 years (IQR 23–48), 56.2% were male, and only 19.2% had a history of mental illness. Suicidal intent represented 58.8% of the cases, and the most frequent route of exposure was the oral route (81.6%). The most prevalent groups of substances were pesticides (34.2%) and medicines (32%). The most common etiological agent was organophosphates (16.5%). Cholinergic toxidrome was the most common. The average stay in the ICU was 4.5 days (± 4.8), and the mortality was 4.2%. The principal causes of acute poisoning were drugs and pesticides, with a predominant etiology of organophosphates and depressants of the central nervous system. There was a significant predominance of young male patients with suicidal intent, low mental disorders, elevated unemployment rate, and similar mortality reported in other studies. This study improves the knowledge about acute poisoning in southwestern Colombian to carry out multicenter analytic studies.
Journal Article