Exploring the root canal microbiome in previously treated teeth: A comparative study of diversity and metabolic pathways across two geographical locations.

AIM: To analyse and compare the root canal microbiome present in root-filled teeth of two different geographical populations, and to study their functional potential using a next-generation sequencing approach. METHODOLOGY: Sequencing data obtained from surgical specimens from previously treated teeth with periapical bone loss from Spain and USA were included in the study. Taxa were classified using SILVA v.138 database. Differences in genera abundances among the 10 most abundant genera were evaluated using a Kruskal-Wallis test. Alpha diversity indices were calculated in mothur. The Shannon and Chao1 indices were used. Analyses of similarity (ANOSIM) to determine differences in community composition were done in mothur, with Bonferroni correction for multiple comparisons. p-Values < .05 were considered statistically significant. Identification of enriched bacteria function prediction in the study groups (KEGG pathways) was carried out by linear discriminant analysis effect size (LEfSe) via Python 3.7.6. RESULTS: A greater alpha-diversity (Shannon and Chao1 indices) was observed from samples obtained in Spain (p = .002). Geography showed no significant effects on community composition via an ANOSIM using Bray-Curtis dissimilarities (R = 0.03, p = .21). Bacterial functional analysis prediction obtained by PICRUSt showed that 5.7% KEGG pathways differed between the Spain and US samples. CONCLUSIONS: The taxonomic assessment alone does not fully capture the microbiome's differences from two different geographical locations. Carbohydrate and amino acid metabolism were enriched in samples from Spain, while samples from USA had a higher representation of pathways related to nitrogen, propanoate metabolism, and secretion systems.

Sclerostin serum levels in prostate cancer patients and their relationship with sex steroids.

UNLABELLED: The role of sclerostin on bone metabolism and its relation to sex steroids in patients with prostate cancer (PC) is not well known. We found that sclerostin levels are significantly increased in PC patients, particularly in those with androgen deprivation therapy (ADT), and there is an inverse relationship between sclerostin levels and testosterone. INTRODUCTION: Recent studies have evaluated sclerostin levels in bone diseases as osteoporosis. However, there are few data in PC patients, particularly in patients with hypogonadism related to ADT. The aim of the present study was to compare serum sclerostin levels in ADT/non-ADT-treated PC patients and healthy controls and to evaluate their relationship with sex steroids and bone metabolism. METHODS: We performed a cross-sectional study involving 81 subjects: 25 ADT-treated PC patients, 34 PC patients without ADT treatment, and 22 healthy controls. We measured serum sclerostin levels, bone turnover markers, bone mineral density (BMD) in all individuals, and sex steroids levels in PC patients. RESULTS: Serum sclerostin levels were significantly higher in PC patients compared to those in control subjects. ADT-treated patients had significantly higher sclerostin levels than PC patients without ADT treatment: ADT 64.52 ± 27.21 pmol/L, non-ADT 48.24 ± 15.93 pmol/L, healthy controls 38.48 ± 9.19 pmol/L, p < 0.05. In PC patients, we found a negative relationship between serum sclerostin levels and androgens after age adjustment (total testosterone: r = -0.309, p = 0.029; bioavailable testosterone: r = -0.280, p = 0.049; free testosterone: r = -0.299, p = 0.035). We did not observe any relationship between sclerostin levels and bone turnover markers or BMD in any group. CONCLUSIONS: Circulating sclerostin levels are significantly increased in patients with PC and particularly in those receiving ADT. The inverse relationship between serum sclerostin and testosterone in these patients suggests that androgens are key regulators of bone metabolism in this population.

Serum osteoprotegerin: bone or cardiovascular marker in Type 2 diabetes males?

BACKGROUND: The role of osteoprotegerin (OPG) as a marker of cardiovascular disease (CVD) in Type 2 diabetes (T2DM) is not well established. Moreover, the relationship between OPG, osteoporosis, and vertebral fractures in T2DM remains to be elucidated. AIM: To determine the role of serum OPG in the prediction of CVD and bone disease in T2DM males. SUBJECTS AND METHODS: Cross-sectional study with 68 males, 43 with T2DM and 25 subjects without diabetes. We measured: serum OPG by inmunoassay, the presence of CVD (coronary heart disease, cerebrovascular and peripheral artery disease), surrogate markers of CVD [intima- media thickness (IMT) and aortic calcification] and bone disease (bone mineral density and prevalent vertebral fractures). RESULTS: OPG serum levels (in pmol/l) were significantly higher in T2DM males with abnormal IMT (5.12 ± 1.59 vs 3.76 ± 1.98), carotid plaque (5.46 ± 1.67 vs 4.20 ± 1.81), aortic calcification (5.91 ± 1.39 vs 4.07 ± 1.76), hypertension (5.11 ± 1.86 vs 3.81 ± 1.47), and peripheral artery disease (6.24 ± 1.64 vs 4.21 ± 1.63, p < 0.05 for all comparisons). In the logistic regression analysis (after adjustment for age and main cardiovascular risk factors), serum OPG (per 1 pmol/l increase in OPG) was associated with increased risk of abnormal IMT [odds ratio (OR) 1.84, confidence interval (CI) 1.21-2.79, p = 0.004), carotid plaque (OR 1.71, CI 1.13-2.58, p = 0.012), aortic calcification (OR 2.21, CI 1.27-3.84, p = 0.05) and peripheral artery disease (OR 4.02, CI 1.65-9.8 p = 0.002). However, OPG were not related to bone mass or vertebral fractures. CONCLUSIONS: Our results suggest that in T2DM males OPG serum concentrations constitute a marker of CVD, but not a marker of bone disease.

Relationship between serum levels of osteocalcin and atherosclerotic disease in type 2 diabetes.

AIMS: To analyze the relationship between serum levels of osteocalcin and parameters of atherosclerosis in patients with type 2 diabetes mellitus (T2DM). METHODS: This cross-sectional study of 78 patients with T2DM evaluated intima-media thickness, and the prevalence of coronary heart disease, atherosclerotic plaques and aortic calcifications. Serum osteocalcin levels were also determined by radioimmunoassay. RESULTS: The patients' mean age was 57.8±6.4 years (duration of diabetes: 13.4 years; mean HbA(1c) level: 8.01%), and 37.2% had coronary heart disease, 56% had an abnormal intima-media thickness, 26.9% had carotid plaques and 32.1% had aortic calcifications. Coronary heart disease was associated with higher levels of osteocalcin in male vs female patients (1.95±1.36 vs 0.93±0.86 ng/mL, respectively; P=0.006). Also, higher concentrations of osteocalcin were found in female patients with vs without abnormal intima-media thicknesses (2.17±1.84 vs 1.25±0.67 ng/mL, respectively; P=0.042), carotid plaques (2.86±2.10 vs 1.43±1.09 ng/mL, respectively; P=0.03) and aortic calcifications (2.85±1.97 vs 1.26±0.83 ng/mL, respectively; P=0.002). Serum osteocalcin levels were associated with coronary heart disease on multivariate logistic regression (odds ratio: 2.27, 95% confidence interval: 1.21-4.25; P=0.01). CONCLUSION: In T2DM patients, serum osteocalcin levels were associated with parameters of atherosclerosis, suggesting that osteocalcin is involved not only in bone metabolism, but also in atherosclerotic disease.

Complications during clinical evolution in lung transplantation: pulmonary embolism.

BACKGROUND: Medical complications after lung transplantation (LT) are frequent despite the advances in management. The objectives of this study were to evaluate the incidence and clinical features of pulmonary embolism (PE) among LT recipients in our center. PATIENTS AND METHODS: We performed a retrospective descriptive study of 280 patients who underwent LT between June 1999 and December 2009. RESULTS: Five patients with PE (1.78%) had undergone single LT due to idiopathic pulmonary fibrosis (IPF). PE developed in the transplanted lung and was bilateral in 2 cases. The only associated risk factor was obesity in 3 patients. The clinical presentation was nonspecific; the most frequent symptom being dyspnea. Computed tomography (CT) angiography and ventilation-perfusion scan were used for diagnosis. Patients underwent treatment with low-molecular weight heparin followed by oral anticoagulation. CONCLUSIONS: Our study showed a low incidence of PE (1.78%), although we focused exclusively on this condition, excluding other entities such as deep vein thrombosis. All PE events occurred in the subpopulation of IPF transplant recipients. Possibly some factors predisposed these patients to PE, although they remain unclear. Because PE can cause significant morbidity in LT recipients, it is important to include PE in the differential diagnosis among LT patients presenting with dyspnea, hypoxia, or clinical deterioration.

Neuropeptides kill African trypanosomes by targeting intracellular compartments and inducing autophagic-like cell death.

Trypanosoma brucei is the causative agent of African sleeping sickness. Available treatments are ineffective, toxic and susceptible to resistance by the parasite. Here we show that various endogenous neuropeptides act as potent antitrypanosome agents. Neuropeptides exerted their trypanolytic activity through an unusual mechanism that involves peptide uptake by the parasite, disruption of lysosome integrity and cytosolic accumulation of glycolytic enzymes. This promotes an energetic metabolism failure that initiates an autophagic-like cell death. Neuropeptide-based treatment improved clinical signs in a chronic model of trypanosomiasis by reducing the parasite burden in various target organs. Of physiological importance is the fact that hosts respond to trypanosome infection producing neuropeptides as part of their natural innate defense. From a therapeutic point of view, targeting of intracellular compartments by neuropeptides suppose a new promising strategy for the treatment of trypanosomiasis.

Regulated transcription of the histone H2B genes of Trypanosoma brucei.

In Trypanosoma brucei, the genes encoding histone H2B are organized in a cluster of about 10-15 tandemly linked copies per haploid genome. The H2B transcripts are processed by trans-splicing and polyadenylation, and encode a polypeptide of 111 residues with a molecular mass of 12.5 kDa. H2B mRNAs are differentially expressed during the parasite life-cycle and are present at higher levels in dividing procyclic and bloodstream slender forms than in the nondividing bloodstream stumpy forms. Analysis of H2B mRNA levels during the synchronous differentiation from stumpy to procyclics forms revealed that the abundance of these transcripts is regulated through the cell-cycle, reaching maximum levels during S-phase. Addition of hydroxyurea to procyclic forms in culture specifically decreased H2B mRNA levels by about twofold, an effect not linked to its 3' untranslated region. Inhibition of protein synthesis prevented this decrease.

Molecular characterization and transcription of the histone H2B gene from the protozoan parasite Trypanosoma cruzi.

The structure, genomic organization and transcription of the gene encoding histone H2B in the protozoan parasite Trypanosoma cruzi have been studied. This gene consists of a 746-nucleotide unit, tandemly repeated at least 18 times in each of two clusters. DNA probes corresponding to histones H2B and H3 hybridized to different chromosomes revealing that the genes coding for these two histones are not physically linked in the genome of T. cruzi. The primary transcription product of the H2B gene is processed by trans-splicing and polyadenylation. Inhibition of DNA synthesis with aphidicolin resulted in the reduction of histone H2B mRNA to undetectable levels in about two hours, suggesting that its abundance is regulated throughout the cell cycle as it occurs in other eukaryotes. In addition, a concomitant inhibition of translation by cycloheximide reverted this effect indicating that de novo protein synthesis is required for RNA instability. Histone mRNA abundance was dependent on the life-cycle stage of T. cruzi: abundant in amastigotes and epimastigotes, the dividing forms in the host cell and the insect vector, respectively, while undetected in trypomastigotes, the parasite's non-dividing life stage.