Evaluation of novel candidate filtration markers from a global metabolomic discovery for glomerular filtration rate estimation.

Creatinine and cystatin-C are recommended for estimating glomerular filtration rate (eGFR) but accuracy is suboptimal. Here, using untargeted metabolomics data, we sought to identify candidate filtration markers for a new targeted assay using a novel approach based on their maximal joint association with measured GFR (mGFR) and with flexibility to consider their biological properties. We analyzed metabolites measured in seven diverse studies encompasing 2,851 participants on the Metabolon H4 platform that had Pearson correlations with log mGFR and used a stepwise approach to develop models to < -0.5 estimate mGFR with and without inclusion of creatinine that enabled selection of candidate markers. In total, 456 identified metabolites were present in all studies, and 36 had correlations with mGFR < -0.5. A total of 2,225 models were developed that included these metabolites; all with lower root mean square errors and smaller coefficients for demographic variables compared to estimates using untargeted creatinine. Seventeen metabolites were chosen, including 12 new candidate filtration markers. The selected metabolites had strong associations with mGFR and little dependence on demographic factors. Candidate metabolites were identified with maximal joint association with mGFR and minimal dependence on demographic variables across many varied clinical settings. These metabolites are excreted in urine and represent diverse metabolic pathways and tubular handling. Thus, our data can be used to select metabolites for a multi-analyte eGFR determination assay using mass spectrometry that potentially offers better accuracy and is less prone to non-GFR determinants than the current eGFR biomarkers.

Glomerular Filtration Rate Estimation Using ß2-Microglobulin and ß-Trace Protein in Adults With Solid Tumors: A Prospective Cross-Sectional Study.

RATIONALE & OBJECTIVE: ß2-Microglobulin (B2M) and ß-trace protein (BTP) are novel endogenous filtration markers that may improve the accuracy of estimated glomerular filtration rate (eGFR) beyond creatinine and cystatin C (eGFRcr-cys), but they have not been assessed in patients with cancer. STUDY DESIGN: Cross-sectional analysis. SETTING & PARTICIPANTS: Prospective cohort of 1,200 patients with active solid tumors recruited between April 2015 and September 2017. EXPOSURE: CKD-EPI equations without race combining B2M and/or BTP with creatinine with or without cystatin C (2-, 3-, or 4-marker panel eGFR). OUTCOME: Performance of equations compared with eGFRcr-cys and non-GFR determinants of serum B2M and BTP (SB2M, and SBTP, respectively). Measured GFR (mGFR) was determined using the plasma clearance of chromium-51 labeled ethylenediamine tetraacetic acid (51Cr-EDTA). ANALYTICAL APPROACH: Bias was defined as the median of the differences between mGFR and eGFR, and 1-P30 was defined as the percentage of estimates that differed by more than 30% from the mGFR (1-P30). Linear regression was used to assess association of clinical and laboratory variables with SB2M, and SBTP after adjustment for mGFR. RESULTS: Mean age and mGFR were 58.8±13.2 SD years and 78.4±21.7 SD mL/min/1.73m2, respectively. Performance of the 3-marker and 4-marker panel equations was better than eGFRcr-cys (lesser bias and 1-P30). Performance of 2-marker panel equations was as good as eGFRcr-cys (lesser bias and similar 1-P30). SB2M and SBTP were not strongly influenced by cancer site. LIMITATIONS: Participants may have had better clinical performance status than the general population of patients with solid tumors. CONCLUSIONS: B2M and BTP can improve the accuracy of eGFR and may be useful as confirmatory tests in patients with solid tumors, either by inclusion in a multimarker panel equation with creatinine and cystatin C, or by substituting for cystatin C in combination with creatinine. PLAIN-LANGUAGE SUMMARY: The most accurate method to assess estimate kidney function is estimated glomerular filtration rate (eGFR) using creatinine and cystatin C (eGFRcr-cys). We studied whether using ß2-microglobulin (B2M) and/or ß-trace protein (BTP) with creatinine with or without cystatin C (2-, 3-, or 4-marker panel eGFR) might be useful in patients with active solid tumors. The performance of the 3-marker and 4-marker panel equations was better than eGFRcr-cys. Performance of 2-marker panel equations was as good as eGFRcr-cys. We conclude that B2M and BTP can improve the accuracy of eGFR and may be useful as a confirmatory test in patients with solid tumors either by inclusion in multimarker panel equation with creatinine and cystatin C or by substituting for cystatin C in combination with creatinine.

The radiation of nodulated Chamaecrista species from the rainforest into more diverse habitats has been accompanied by a reduction in growth form and a shift from fixation threads to symbiosomes.

All non-Mimosoid nodulated genera in the legume subfamily Caesalpinioideae confine their rhizobial symbionts within cell wall-bound 'fixation threads' (FTs). The exception is the large genus Chamaecrista in which shrubs and subshrubs house their rhizobial bacteroids more intimately within symbiosomes, whereas large trees have FTs. This study aimed to unravel the evolutionary relationships between Chamaecrista growth habit, habitat, nodule bacteroid type, and rhizobial genotype. The growth habit, bacteroid anatomy, and rhizobial symbionts of 30 nodulated Chamaecrista species native to different biomes in the Brazilian state of Bahia, a major centre of diversity for the genus, was plotted onto an ITS-trnL-F-derived phylogeny of Chamaecrista. The bacteroids from most of the Chamaecrista species examined were enclosed in symbiosomes (SYM-type nodules), but those in arborescent species in the section Apoucouita, at the base of the genus, were enclosed in cell wall material containing homogalacturonan (HG) and cellulose (FT-type nodules). Most symbionts were Bradyrhizobium genotypes grouped according to the growth habits of their hosts, but the tree, C. eitenorum, was nodulated by Paraburkholderia. Chamaecrista has a range of growth habits that allow it to occupy several different biomes and to co-evolve with a wide range of (mainly) bradyrhizobial symbionts. FTs represent a less intimate symbiosis linked with nodulation losses, so the evolution of SYM-type nodules by most Chamaecrista species may have (i) aided the genus-wide retention of nodulation, and (ii) assisted in its rapid speciation and radiation out of the rainforest into more diverse and challenging habitats.

The Immunoregulatory and Regenerative Potential of Activated Human Stem Cell Secretome Mitigates Acute-on-Chronic Liver Failure in a Rat Model.

Acute-on-chronic liver failure (ACLF) is a syndrome marked by sudden liver function decline and multiorgan failure, predominantly acute kidney injury (AKY), in patients with chronic liver disease. Unregulated inflammation is a hallmark of ACLF; however, the key drivers of ACLF are not fully understood. This study explores the therapeutic properties of human mesenchymal stem cell (MSC) secretome, particularly focusing on its enhanced anti-inflammatory and pro-regenerative properties after the in vitro preconditioning of the cells. We evaluated the efficacy of the systemic administration of MSC secretome in preventing liver failure and AKI in a rat ACLF model where chronic liver disease was induced using by the administration of porcine serum, followed by D-galN/LPS administration to induce acute failure. After ACLF induction, animals were treated with saline (ACLF group) or MSC-derived secretome (ACLF-secretome group). The study revealed that MSC-secretome administration strongly reduced liver histological damage in the ACLF group, which was correlated with higher hepatocyte proliferation, increased hepatic and systemic anti-inflammatory molecule levels, and reduced neutrophil and macrophage infiltration. Additionally, renal examination revealed that MSC-secretome treatment mitigated tubular injuries, reduced apoptosis, and downregulated injury markers. These improvements were linked to increased survival rates in the ACLF-secretome group, endorsing MSC secretomes as a promising therapy for multiorgan failure in ACLF.

Domestication of Lima Bean (Phaseolus lunatus) Changes the Microbial Communities in the Rhizosphere.

Plants modulate the soil microbiota and select a specific microbial community in the rhizosphere. However, plant domestication reduces genetic diversity, changes plant physiology, and could have an impact on the associated microbiome assembly. Here, we used 16S rRNA gene sequencing to assess the microbial community in the bulk soil and rhizosphere of wild, semi-domesticated, and domesticated genotypes of lima bean (Phaseolus lunatus), to investigate the effect of plant domestication on microbial community assembly. In general, rhizosphere communities were more diverse than bulk soil, but no differences were found among genotypes. Our results showed that the microbial community's structure was different from wild and semi-domesticated as compared to domesticated genotypes. The community similarity decreased 57.67% from wild to domesticated genotypes. In general, the most abundant phyla were Actinobacteria (21.9%), Proteobacteria (20.7%), Acidobacteria (14%), and Firmicutes (9.7%). Comparing the different genotypes, the analysis showed that Firmicutes (Bacillus) was abundant in the rhizosphere of the wild genotypes, while Acidobacteria dominated semi-domesticated plants, and Proteobacteria (including rhizobia) was enriched in domesticated P. lunatus rhizosphere. The domestication process also affected the microbial community network, in which the complexity of connections decreased from wild to domesticated genotypes in the rhizosphere. Together, our work showed that the domestication of P. lunatus shaped rhizosphere microbial communities from taxonomic to a functional level, changing the abundance of specific microbial groups and decreasing the complexity of interactions among them.

Genotype Prevalence of Lactose Deficiency, Vitamin D Deficiency, and the Vitamin D Receptor in a Chilean Inflammatory Bowel Disease Cohort: Insights from an Observational Study.

Lactose intolerance (LI) and vitamin D deficiency (VDD) have been linked to inflammatory bowel disease (IBD). We conducted an observational study in 192 Chilean IBD patients to investigate the prevalence of a specific gene variant (LCT-13910 CC genotype) associated with LI and the prevalence of VDD/Vitamin D Receptor (VDR) gene variants. Blood samples were analyzed using Illumina's Infinium Global Screening Array. The LCT-13910 CC genotype was found in 61% of IBD patients, similar to Chilean Hispanic controls and lower than Chilean Amerindian controls. The frequency of the LCT-13910-C allele in Chilean IBD patients (0.79) was comparable to the general population and higher than Europeans (0.49). Regarding VDR and VDD variants, in our study, the rs12785878-GG variant was associated with an increased risk of IBD (OR = 2.64, CI = 1.61-4.32; p-value = 0.001). Sixty-one percent of the Chilean IBD cohort have a genetic predisposition to lactose malabsorption, and a significant proportion exhibit genetic variants associated with VDD/VDR. Screening for LI and VDD is crucial in this Latin American IBD population.

Clinical research focused in European adult women with minority diseases: Do we try hard enough?

We analyzed the European countries participation in clinical trials addressing to new drug development focused on rare diseases in women comparing to more prevalent diseases as breast cancer. Participation was not associated with type of healthcare system neither socio-economic features, but it was associated with population size. Protocol ratios focused on breast cancer vs. orphan drugs and rare diseases was 15:1 and 9:1, respectively, mainly focused on ovarian cancer. Protocol number was insufficient to evaluate the success of Regulation (EC) 141/2000, it is necessary to increase the scientific quality and the number of really new molecules.

A prospective cross-sectional study estimated glomerular filtration rate from creatinine and cystatin C in adults with solid tumors.

Current guidelines recommend estimating glomerular filtration rate (eGFR) using creatinine (eGFRcr) with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation as the first test for GFR evaluation, but the Cockcroft-Gault (CG) equation is still commonly used in oncology practice and clinical trials despite increasing evidence of its inaccuracy compared to measured GFR (mGFR). Guidelines recommend eGFR using cystatin C (eGFRcys) or both markers (eGFRcr-cys) as a confirmatory test, but neither was carefully evaluated in cancer patients. Therefore, we compared performance of the CKD-EPI equations and others to the CG equation in adults with a variety of solid tumors. The mGFR was determined by plasma clearance of 51Cr-EDTA. Bias was defined as the median of the differences between mGFR and eGFR while accuracy was defined as the percentage of estimates that differed by more than 30% from the measured GFR (1-P30). We prospectively recruited 1,200 patients between April 2015 and September 2017 with a mean age and mGFR of 58.8 years and 78.4 ml/min/1.73m2, respectively. Bias among eGFRcr equations varied from -8.1 to +6.1 ml/min/1.73 m2. CG was the least accurate, 1-P30 (95% confidence interval) was 24.9 (22.4- 27.3)%; CKD-EPI had 1-P30 of 19.1 (16.8-21.2)% while eGFRcr-cys had the best performance: bias -2.0 (-2.6 to -1.1) ml/min/1.73m2 and 1-P30 7.8 (6.3-9.4)%. Thus, the CG equation should not be preferred over CKD-EPI equation, and eGFRcr-cys can be used as a confirmatory test in adults with solid tumors. Hence, a major policy implication would be to adopt general practice guideline-recommended methods for GFR evaluation in oncology practice and clinical trials.

Sex in protists: A new perspective on the reproduction mechanisms of trypanosomatids.

The Protist kingdom individuals are the most ancestral representatives of eukaryotes. They have inhabited Earth since ancient times and are currently found in the most diverse environments presenting a great heterogeneity of life forms. The unicellular and multicellular algae, photosynthetic and heterotrophic organisms, as well as free-living and pathogenic protozoa represents the protist group. The evolution of sex is directly associated with the origin of eukaryotes being protists the earliest protagonists of sexual reproduction on earth. In eukaryotes, the recombination through genetic exchange is a ubiquitous mechanism that can be stimulated by DNA damage. Scientific evidences support the hypothesis that reactive oxygen species (ROS) induced DNA damage can promote sexual recombination in eukaryotes which might have been a decisive factor for the origin of sex. The fact that some recombination enzymes also participate in meiotic sex in modern eukaryotes reinforces the idea that sexual reproduction emerged as consequence of specific mechanisms to cope with mutations and alterations in genetic material. In this review we will discuss about origin of sex and different strategies of evolve sexual reproduction in some protists such that cause human diseases like malaria, toxoplasmosis, sleeping sickness, Chagas disease, and leishmaniasis.

Pseudorandom full-field electroretinograms reflect different light adaptation mechanisms.

PURPOSE: To investigate the magnitude and time course of pseudorandom ffERG during light adaptation. METHODS: Ten healthy subjects (26 ± 10.1 years) underwent 20 min of dark adaptation, and then the ffERG was evoked by pseudorandom flash sequences (4 ms per flash, 3 cd.s/m2) driven by m-sequences (210-1 stimulus steps) using Veris Science software and a Ganzfeld dome over a constant field of light adaptation (30 cd/m2). The base period of the m-sequence was 50 ms. Each stimulation sequence lasting 40 s was repeated at 0, 5, 10, 15 and 20 min of light adaptation. Relative amplitude and latency (corrected by values found at 0 min) of the three components (N1, P1, and N2) of first-order (K1) and first slice of the second-order (K2.1) kernel at 5 time points were evaluated. An exponential model was fitted to the mean amplitude and latency data as a function of the light adaptation duration to estimate the time course (τ) of the light adaptation for each component. Repeated one-way ANOVA followed by Tukey post-test was applied to the amplitude and latency data, considering significant values of p < 0.05. RESULTS: Regarding the K1 ffERG, N1 K1, P1 K1, and N2 K1 presented an amplitude increase as a function of the light adaptation (N1 K1 τ value = 2.66 min ± 4.2; P1 K1 τ value = 2.69 min ± 2.10; and N2 K1 τ value = 3.49 min ± 2.96). P1 K1 and N2 K1 implicit time changed as a function of the light adaptation duration (P1 K1 τ value = 3.61 min ± 5.2; N2 K1 τ value = 3.25 min ± 4.8). N1 K1 had small implicit time changes during the light adaptation. All the K2,1 components also had nonsignificant changes in amplitude and implicit time during the light adaptation. CONCLUSIONS: Pseudorandom ffERGs showed different mechanisms of adaptation to retinal light. Our results suggest that K1 ffERG is generated by retinal mechanisms with intermediate- to long-term light adaptation, while K2.1 ffERG is generated by retinal mechanism with fast light adaptation course.

Sickle cell anemia in the state of Maranhão: a haplotype study.

Sickle cell anemia (SCA) is the most severe form of sickle cell disease caused by homozygosity of the ßS-gene (S/S or ßSßS) and has worldwide distribution. Six polymorphic sites in the ß-globin gene cluster were analyzed from a sample of 56 chromosomes of patients with SCA from the state of Maranhão, northeastern Brazil. PCR-RFLP showed that the CAR haplotype was predominant with a frequency of 64.28%, followed by the BEN haplotype (28.57%). Atypical haplotypes were identified at a frequency of 7.15%. Genotypes CAR/CAR, BEN/BEN, and CAR/BEN were present in 46.43%, 10.71%, and 35.71% of patients, respectively. ß-Globin haplotype determination is important not only for the monitoring and prognosis of patients with SCA, but it also serves to inform anthropological studies that contribute to elucidating any peculiarities associated with African influences that contributed to the ethnological, economic, cultural, and social formation of Brazil. The high frequency of the CAR/CAR and CAR/BEN haplotypes in this study, which are associated with low levels of fetal hemoglobin, may ultimately reflect a severe clinical course and poor prognosis in patients with SCA in Maranhão.

1,4-Disubstituted-1,2,3-Triazole Compounds Induce Ultrastructural Alterations in Leishmania amazonensis Promastigote: An in Vitro Antileishmanial and in Silico Pharmacokinetic Study.

The current standard treatment for leishmaniasis has remained the same for over 100 years, despite inducing several adverse effects and increasing cases of resistance. In this study we evaluated the in vitro antileishmanial activity of 1,4-disubstituted-1,2,3 triazole compounds and carried out in silico predictive study of their pharmacokinetic and toxicity properties. Ten compounds were analyzed, with compound 6 notably presenting IC50: 14.64 ± 4.392 µM against promastigotes, IC50: 17.78 ± 3.257 µM against intracellular amastigotes, CC50: 547.88 ± 3.256 µM against BALB/c peritoneal macrophages, and 30.81-fold selectivity for the parasite over the cells. It also resulted in a remarkable decrease in all the parameters of in vitro infection. Ultrastructural analysis revealed lipid corpuscles, a nucleus with discontinuity of the nuclear membrane, a change in nuclear chromatin, and kinetoplast swelling with breakdown of the mitochondrial cristae and electron-density loss induced by 1,4-disubstituted-1,2,3-triazole treatment. In addition, compound 6 enhanced 2.3-fold the nitrite levels in the Leishmania-stimulated macrophages. In silico pharmacokinetic prediction of compound 6 revealed that it is not recommended for topical formulation cutaneous leishmaniasis treatment, however the other properties exhibited results that were similar or even better than miltefosine, making it a good candidate for further in vivo studies against Leishmania parasites.

Design, synthesis, structural characterization and in vitro evaluation of new 1,4-disubstituted-1,2,3-triazole derivatives against glioblastoma cells.

A new series of 1,4-disubstituted-1,2,3-triazole derivatives were synthesized through the copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (Click chemistry) and their inhibitory activities were evaluated against different human glioblastoma (GBM) cell lines, including highly drug-resistant human cell lines GBM02, GBM95. The most effective compounds were 9d, containing the methylenoxy moiety linked to triazole and the tosyl-hydrazone group, and the symmetrical bis-triazole 10a, also containing methylenoxy moiety linked to triazole. Single crystal X-ray diffraction analysis was employed for structural elucidation of compound 9d. In silico analyses of physicochemical, pharmacokinetic, and toxicological properties suggest that compounds 8a, 8b, 8c, 9d, and 10a are potential candidates for central nervous system-acting drugs.

Using sellar region tumor's size as a predictor of psychophysical and electrophysiological perimetric visual losses: a logistic regression approach.

BACKGROUND: Sellar region tumor growth represents an important cause of visual loss due to mechanical compression of the optic nerve apparatus. Many investigations have used non-invasive tools to evaluate the visual field consequences of this damage, and good associations have been reported between psychophysical and electrophysiological perimetries. Few reports have considered the tumor size as a predictor of visual field loss. AIMS: In the present study, we evaluated the association between the visual perimetry measured by Humphrey visual field analyzer and multifocal visual evoked cortical potential (mfVECP) and the tumor size. METHODS: Our sample was composed of 14 patients diagnosed with sellar tumors by magnetic resonance imaging. We accounted the number of sectors with negative visual responses for both methods. A simple logistic regression analysis was used to evaluate the association between the tumor dimensions and the visual field features RESULTS: Three patients had preserved visual fields, three patients showed hemianopic defects, and eight patients had generalized visual field losses at both evaluations. We observed that the three maximum diameters of the tumor and total tumor volume had different predictive abilities regarding the extent of visual field loss when using psychophysical and mfVECP data. The maximum craniocaudal diameter of the tumor was the better predictor of the psychophysical measurements, whereas for the mfVECP results, all tumor dimensions and volumes had similar values that predict visual field losses. CONCLUSION: Tumor size as a predictor of visual loss has potential to assist in the clinical intervention and to prevent the irreversible visual impairment caused by tumors of the sellar region.

Toxic and Beneficial Potential of Silver Nanoparticles: The Two Sides of the Same Coin.

Nanotechnology has allowed great changes in chemical, biological and physical properties of metals when compared to their bulk counterparts. Within this context, silver nanoparticles (AgNPs) play a major role due to their unique properties, being widely used in daily products such as fabrics, washing machines, water filters, food and medicine. However, AgNPs can enter cells inducing a "Trojan-horse" type mechanism which potentially leads to cellular autophagy, apoptosis or necrosis. On the other hand, this cytotoxicity mechanism can be optimized to develop drug nanocarriers and anticancer therapies. The increasing use of these NPs entails their release into the environment, damaging ecosystems balance and representing a threat to human health. In this context, the possible deleterious effects that these NPs may represent for the biotic and abiotic ecosystems components represent an obstacle that must be overcome in order to guarantee the safety use of their unique properties.

[Development of an instrument to assess clinical reasoning]. / Instrumento para el desarrollo del razonamiento clínico.

BACKGROUND: Teaching clinical reasoning is a challenge in medical education. AIM: To design a clinical reasoning assessment instrument. MATERIAL AND METHODS: Structured interviews were carried out to six physicians with at least five years experience. The Grounded Theory method was used to determine the relevant categories of the clinical reasoning process and the modified Delphi expert judgment method to validate the categories, the definition of observable behaviors and the format of the instrument. RESULTS: The relevant reasoning categories were the reason for consultation, medical history, physical examination, additional tests, diagnosis, therapeutic options and reasoning reassessment capacity. Expert judgment assessed at a level of "strongly agree" and "agree" the sufficiency, clarity and pertinence of all categories, related observable behaviors and instrument format. The internal Kappa consistency yielded an index of 0.92. CONCLUSIONS: The resulting instrument was constructed with the following axes derived from the main categories and subcategories: reason for consultation, history, physical examination, additional tests, diagnosis, therapeutic options and reassessment capacity.