Gene-centric metagenomics of the fiber-adherent bovine rumen microbiome reveals forage specific glycoside hydrolases

The complex microbiome of the rumen functions as an effective system for the conversion of plant cell wall biomass to microbial protein, short chain fatty acids, and gases. As such, it provides a unique genetic resource for plant cell wall degrading microbial enzymes that could be used in the production of biofuels. The rumen and gastrointestinal tract harbor a dense and complex microbiome. To gain a greater understanding of the ecology and metabolic potential of this microbiome, we used comparative metagenomics (phylotype analysis and SEED subsystems-based annotations) to examine randomly sampled pyrosequence data from 3 fiber-adherent microbiomes and 1 pooled liquid sample (a mixture of the liquid microbiome fractions from the same bovine rumens). Even though the 3 animals were fed the same diet, the community structure, predicted phylotype, and metabolic potentials in the rumen were markedly different with respect to nutrient utilization. A comparison of the glycoside hydrolase and cellulosome functional genes revealed that in the rumen microbiome, initial colonization of fiber appears to be by organisms possessing enzymes that attack the easily available side chains of complex plant polysaccharides and not the more recalcitrant main chains, especially cellulose. Furthermore, when compared with the termite hindgut microbiome, there are fundamental differences in the glycoside hydrolase content that appear to be diet driven for either the bovine rumen (forages and legumes) or the termite hindgut (wood).     

Estratégias Econômicas e Sociais para Anticoagulação de Pacientes com Fibrilação Atrial

Background:Atrial fibrillation is a public health problem associated with a fivefold increased risk of stroke or death. Analyzing costs is important when introducing new therapies and must be reconsidered in special situations, such as the novel coronavirus pandemic of 2020.Objective:This study aimed to evaluate the costs related to anticoagulant therapy in a one-year period, and the quality of life of atrial fibrillation patients treated in a public university hospital.Methods:Patient costs were those related to the anticoagulation and calculated by the average monthly costs of warfarin or direct oral anticoagulants (DOACs). Patient non-medical costs (eg., food and transportation) were calculated from data obtained by questionnaires. The Brazilian SF-6D was used to measure the quality of life. P-values < 0.05 were considered statistically significant.Results:The study population consisted of 90 patients, 45 in each arm (warfarin vs direct oral anticoagulants). Costs were 20% higher in the DOAC group ($55,532.62 vs $46,385.88), and mainly related to drug price ($23,497.16 vs $1,903.27). Hospital costs were higher in the warfarin group ($31,088.41 vs $24,604.74) and related to outpatient visits. Additionally, non-medical costs were almost twice higher in the warfarin group ($13,394.20 vs $7,430.72). Equivalence of price between the two drugs could be achieved by a 39% reduction in the price of DOACs. There were no significant group differences regarding quality of life.Conclusions:Total costs were higher in the group of patients taking DOACs than those taking warfarin. However, a nearly 40% reduction in the price of DOACs could make it feasible to incorporate these drugs into the Brazilian public health system.     

Degradation of Soluble Immunoglobulin Aggregates in Vitro by Monocytes from Normal Subjects and from Patients with Systemic Lupus Erythematosus

The capacity of human peripheral monocytes to degrade soluble immunoglobulin (IgG) aggregates (AIgG) was studied in vitro. Under serum-free conditions peripheral monocytes from normal donors were able to degrade soluble AIgG in a linear and time-dependent fashion. Addition of fresh human or fresh guinea-pig serum to the incubation mixtures caused a marked increase in degradation of the amount of soluble AIgG available. The stimulatory effect of fresh serum was complement-mediated, because it was abolished by heat treatment of the serum and was not seen when C4- or C3-deficient sera were tested. Functional inactivation of C3 receptors on the phagocytes by trypsin also abolished the complement-mediated stimulation, suggesting cooperation between Fc and C3 receptor in degradation of soluble AIgG. No significant differences were found between monocytes from normal donors and those from patients with systemic lupus erythematosus, as far as degradation is concerned in the presence of complement.     

Functional significance of a deep intronic mutation in the ATM gene and evidence for an alternative exon 28a

Screening for ATM mutations is usually performed using genomic DNA as a template for PCR amplification across exonic regions, with the consequence that deep intronic sequences are not analyzed. Here we report a novel pseudoexon-retaining deep intronic mutation (IVS28-159A>G; g.75117A>G based on GenBank U82828.1) in a patient with ataxia-telangiectasia (A-T), as well as the identification of a previously unrecognized alternative exon in the ATM gene (exon 28a) expressed in lymphoblastoid cell lines (LCL) derived from normal individuals. cDNA analysis using the A-T patient's LCL showed the retention of two aberrant intronic segments of 112 and 190 nt between exons 28 and 29. Minigenes were constructed to determine the functional significance of two genomic changes in the region of aberrant splicing: IVS28-193C>T (g.75083C>T) and IVS28-159A>G, revealing that: 1) the first is a polymorphism; 2) IVS28-159A>G weakens the 5' splice site of the alternative exon 28a and activates a cryptic 5' splice site (ss) 83 nt downstream; and 3) wild-type constructs also retain a 29-nt segment (exon 28a) as part of both the 112- and 190-nt segments. Maximum entropy estimates of ss strengths corroborate the cDNA and minigene findings. Such mutations may prove relevant in planning therapy that targets specific splicing aberrations.     

Causal pathways of the effects of age and the CCR5-Delta32, CCR2-64I, and SDF-1 3'A alleles on AIDS development

OBJECTIVE: To investigate the causal pathways by which age and the CCR5-Delta32, CCR2-64I, and SDF-1 3'A alleles influence progression to AIDS. DESIGN: Analysis of follow-up data from 2 cohort studies among homosexual men (n=400), having >10 years of follow-up. METHODS: The effects of the 4 cofactors on the CD4 and HIV-1 RNA trajectories after seroconversion were modeled in a random-effects model. A proportional hazards model was used to investigate their effect on the risk of AIDS after correction for CD4 cell count and RNA level. This approach allows investigation as to whether they influence AIDS progression by affecting CD4 count and RNA level or by other pathways. RESULTS: Persons of younger age or having the CCR2-64I or SDF-1 3'A mutation have significantly higher CD4 levels. Persons with the CCR5-Delta32 deletion or CCR2-64I mutation have significantly lower RNA levels. After correction for both CD4 count and RNA level, only the SDF-1 3'A mutation significantly increases the AIDS risk. CONCLUSIONS: Age and the CCR5-Delta32 deletion and CCR2-64I mutation influence AIDS progression by affecting CD4 and HIV-1 RNA. The SDF-1 3'A allele increases the AIDS risk, but this effect is countered by its effect on CD4 and HIV-1 RNA level.