Susceptibility to Organophosphates in Culex quinquefasciatus from Colombia.

Susceptibility to organophosphates was evaluated in 2 populations of Culex quinquefasciatus from the department of Atlantico, Colombia. Bioassays for temephos, malathion, and pirimiphos-methyl were performed with 3rd-stage larvae and adult females of Cx. quinquefasciatus from the municipalities of Soledad and Puerto Colombia, following the methods of the World Health Organization and Centers for Disease Control and Prevention, respectively. The median lethal concentration (LC50) and 90% lethal concentration (LC90) resistance ratios (RRLC50 and RRLC90) were determined for each insecticide in the field populations evaluated, using the Cartagena strain as the susceptible control. Relative to LC50 and LC90 of the Cartagena strain, the population from Puerto Colombia was moderately resistant to temephos (RRLC50 5.7-fold) and malathion (RRLC50 8.6-fold, RRLC90 9-fold) and susceptible to pirimiphos-methyl (RRLC50 and RRLC90 < 5-fold). The population from Soledad was susceptible to temephos and pirimiphos-methyl (RRLC50 and RRLC90 < 5-fold) and showed moderate resistance to malathion (RRLC50 7.5-fold). It is important to emphasize that routine monitoring of insecticide resistance in Cx. quinquefasciatus helps us detect resistance early and improve the effectiveness of control strategies.

Ayahuasca, a psychedelic beverage, modulates neuroplasticity induced by ethanol in mice.

Alcohol use disorder needs more effective treatments because relapse rates remain high. Psychedelics, such as ayahuasca, have been used to treat substance use disorders. Our study aimed to evaluate the effects of ayahuasca on ethanol-induced behavioral sensitization (EIBS). Swiss mice received 2.2 g/kg ethanol or saline IP injections every other day across nine days (D1, D3, D5, D7, and D9), and locomotor activity was evaluated 10 min after each injection. Then, animals were treated daily with ayahuasca (corresponding to 1.76 mg/kg of N,N-dimethyltryptamine, DMT) or water by oral gavage for eight consecutive days. On the seventh day, mice were evaluated in the elevated plus maze. Then, mice were challenged with a single dose of ethanol to measure their locomotor activity. Dopamine receptors, serotonin receptors, dynorphin, and prodynorphin levels were quantified in the striatum and hippocampus by blot analysis. Repeated ethanol administration resulted in EIBS. However, those animals treated with ayahuasca had an attenuated EIBS. Moreover, ayahuasca reduced the anxiogenic response to ethanol withdrawal and prevented the ethanol-induced changes on 5-HT1a receptor and prodynorphin levels in the hippocampus and reduced ethanol effects in the dynorphin/prodynorphin ratio levels in the striatum. These results suggest a potential application of ayahuasca to modulate the neuroplastic changes induced by ethanol.

Mental health in patients with rheumatic diseases related to COVID-19 pandemic: Experience in a tertiary care center in Latin America.

OBJECTIVE: To determine the factors associated with anxiety, depression, and concern within the COVID-19 pandemic in a population with autoimmune diseases. METHODS: A telephonic survey was conducted during the early stages of the pandemic in a tertiary care center, which included patients with systemic autoimmune diseases. Mental health variables were assessed with Patient Health Questionnaire 2, General Anxiety Disorder 7 scores, and pandemic-related concern questions. Sociodemographic aspects were also evaluated. RESULTS: Of the total 334 participants, 291 (87.1%) were women, with a median age of 46 years; systemic lupus erythematosus (SLE) was the most frequent diagnosis (144, 43.2%); 44 patients (13.2%) showed depression and 32 (9.6%) anxiety. The variables associated with depression were all the pandemic concern items, body mass index, anxiety, and a higher COVID-19 symptom score. Anxiety was associated with depression, all pandemic concern items, and a higher COVID-19 symptom score. Women presented higher scores in all concern items. The SLE group presented higher scores in concern questions and difficulty finding medication. CONCLUSION: During the COVID-19 outbreak, rheumatic patients are vulnerable to psychiatric conditions, which makes it imperative for physicians who treat these patients to pay careful attention in order to detect them promptly and to settle coping strategies.

Factors associated with adherence to follow-up calls in cancer patients receiving care at a community oncology practice.

BACKGROUND: Follow-up calls in the oncology setting are frequently used to augment care and encourage oral antineoplastic adherence. However, limited data are available on patient populations that would benefit from this intervention versus populations that may require alternative interventions. The purpose of this study was to identify characteristics among patients on oral antineoplastic agents that influence their likelihood to respond to follow-up calls. METHODS: Patients receiving care from one of the eight community oncology clinics within the same branch were analyzed. Patients were included if they were ≥18 years, received a new oral antineoplastic agent that was electronically prescribed between August 2018-October 2018, and picked up their first fill from their pharmacy of choice. Patients received up to six follow-up calls after picking up their first prescription. Calls were categorized as adherent (≥3 monthly interactions) or non-adherent (<3 monthly interactions). Logistic regression models were used to evaluate factors associated with follow-up call adherence. Factors included demographics, cancer stage, marital status, employment, pharmacy setting (internal pharmacy versus external pharmacy), and insurance used by the patient. Descriptive analysis was performed to analyze response rates, cancer diagnosis, and to determine the best time and day patients responded to follow-up calls. RESULTS: Data from 125 patients were analyzed, of which 65 patients (52%) were adherent to follow-up calls and the mean response rate over six months was 45% (range: 35% -- 54%). High success rates for follow-up calls were seen between 12-3 pm and on Tuesdays and Thursdays. After adjusting for covariates, patients with stage III-IV were 89% less likely to respond to follow-up calls compared to those with stage 0-II (95% CI: 0.02-0.64; p = 0.01), patients with commercial insurance were 79% less likely to adhere to follow-up calls compared to those on government insurance (95% CI: 0.06-0.71; p = 0.01), and patients using an external pharmacy had a 2.8 times increase odds of being adherent (95% CI 0.98-8.34; p = 0.05). All other factors were not significant. CONCLUSIONS: For patients taking oral antineoplastics, non-adherence to follow-up calls was observed in more than 45% of patients receiving care from a community oncology clinic. Findings demonstrated that those with advanced stages of cancer, on commercial insurance, and going to an internal pharmacy were at higher risk for not adhering to follow up calls. Therefore, alternative methods for managing adherence and side effects in these populations are warranted.

Studies of Classical Ballet Dancers' Equilibrium at Different Levels of Development and Versus Non-Dancers: A Systematic Review.

In classical ballet, the execution of extreme movements on small bases of support causes the dancers constantly to seek balance. The objective of this systematic literature review was to evaluate the effects of classical ballet training on static and dynamic balance in order to emphasize the differences between dancers and non-dancers and between dancers with different levels of experience. Searches for scientific papers were conducted by two independent researchers in the PubMed, Science Direct, and LILACS databases. A secondary search was carried out by "snowballing" references in the selected studies. A modified Downs and Black checklist and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) scale were used to evaluate the methodological quality and evidence strength of the included studies, respectively. From 364 initial studies, nine were found to be eligible (five did analyses in static situations, two in dyna- mic situations, and two in both). With a maximum potential of 10 points, the methodological quality ranged from 6 to 8 on the Downs and Black checklist. It was found that the level of experience in ballet makes for better balance. However, there are indications that classical ballet dancers become more dependent on vision to control balance compared to non-dancers.

Analysis of an N-terminal deletion in subunit a of the Escherichia coli ATP synthase.

Subunit a is a membrane-bound stator subunit of the ATP synthase and is essential for proton translocation. The N-terminus of subunit a in E. coli is localized to the periplasm, and contains a sequence motif that is conserved among some bacteria. Previous work has identified mutations in this region that impair enzyme activity. Here, an internal deletion was constructed in subunit a in which residues 6-20 were replaced by a single lysine residue, and this mutant was unable to grow on succinate minimal medium. Membrane vesicles prepared from this mutant lacked ATP synthesis and ATP-driven proton translocation, even though immunoblots showed a significant level of subunit a. Similar results were obtained after purification and reconstitution of the mutant ATP synthase into liposomes. The location of subunit a with respect to its neighboring subunits b and c was probed by introducing cysteine substitutions that were known to promote cross-linking: a_L207C + c_I55C, a_L121C + b_N4C, and a_T107C + b_V18C. The last pair was unable to form cross-links in the background of the deletion mutant. The results indicate that loss of the N-terminal region of subunit a does not generally disrupt its structure, but does alter interactions with subunit b.

Bacterial clearance reverses a skewed T-cell repertoire induced by Salmonella infection.

Salmonella typhimurium invades the spleen, liver, and peripheral lymph nodes and has recently been detected in the bone marrow and thymus, resulting in a reduced thymic size and a decline in the total number of thymic cells. A specific deletion of the double-positive cell subset has been characterized, yet the export of mature T cells to the periphery remains normal. We analyzed Salmonella pathogenesis regarding thymic structure and the T-cell maturation process. We demonstrate that, despite alterations in the thymic structure, T-cell development is maintained during Salmonella infection, allowing the selection of single-positive T-cell clones expressing particular T-cell receptor beta chains (TCR-Vß). Moreover, the treatment of infected mice with an antibiotic restored the normal thymic architecture and thymocyte subset distribution. Additionally, the frequency of TCR-Vß usage after treatment was comparable to that in non-infected mice. However, bacteria were still recovered from the thymus after 1 month of treatment. Our data reveal that a skewed T-cell developmental process is present in the Salmonella-infected thymus that alters the TCR-Vß usage frequency. Likewise, the post-treatment persistence of Salmonella reveals a novel function of the thymus as a potential reservoir for this infectious agent.

Salmonella impairs CD8 T cell response through PD-1: PD-L axis.

We have shown that Salmonella remains for a long period of time within B cells, plasma cells, and bone marrow B cell precursors, which might allow persistence and dissemination of infection. Nonetheless, how infected cells evade CD8 T cell response has not been characterized. Evidence indicates that some pathogens exploit the PD-1: PD-L (PD-L1 and PD-L2) interaction to inhibit CD8 T cells response to contribute the chronicity of the infection. To determine whether the PD-1: PD-L axis plays a role during Salmonella infection; we evaluated PD-1 expression in antigen-specific CD8 T cells and PD-1 ligands in Salmonella-infected cells. Our results show that infected B cells and macrophages express continuously co-stimulatory (CD40, CD80, and CD86) and inhibitory molecules (PD-L1 and PD-L2) in early and late stages of chronic Salmonella infection, while antigen-specific CD8 T cells express in a sustained manner PD-1 in the late stages of infection. Blocking this axis restores the ability of the CD8 T cells to proliferate and eliminate primary infected APCs. Therefore, a continuous PD-1: PDL interaction might be a mechanism employed by Salmonella to negatively regulate Salmonella-specific CD8 T cell cytotoxic response in order to remain within the host for a long period of time.

Interactions between subunits a and b in the rotary ATP synthase as determined by cross-linking.

The interaction of the membrane traversing stator subunits a and b of the rotary ATP synthase was probed by substitution of a single Cys into each subunit with subsequent Cu(2+) catalyzed cross-linking. Extensive interaction between the transmembrane (TM) region of one b subunit and TM2 of subunit a was indicated by cross-linking with 6 Cys pairs introduced into these regions. Additional disulfide cross-linking was observed between the N-terminus of subunit b and the periplasmic loop connecting TM4 and TM5 of subunit a. Finally, benzophenone-4-maleimide derivatized Cys in the 2-3 periplasmic loop of subunit a were shown to cross-link with the periplasmic N-terminal region of subunit b. These experiments help to define the juxtaposition of subunits b and a in the ATP synthase.

Mutagenesis of the L, M, and N subunits of Complex I from Escherichia coli indicates a common role in function.

BACKGROUND: The membrane arm of Complex I (NADH:ubiquinone oxidoreductase) contains three large, and closely related subunits, which are called L, M, and N in E. coli. These subunits are homologous to components of multi-subunit Na(+)/H(+) antiporters, and so are implicated in proton translocation. METHODOLOGY/PRINCIPAL FINDINGS: Nineteen site-specific mutations were constructed at two corresponding positions in each of the three subunits. Two positions were selected in each subunit: L_K169, M_K173, N_K158 and L_Q236, M_H241, N_H224. Membrane vesicles were prepared from all of the resulting mutant strains, and were assayed for deamino-NADH oxidase activity, proton translocation, ferricyanide reductase activity, and sensitivity to capsaicin. Corresponding mutations in the three subunits were found to have very similar effects on all activities measured. In addition, the effect of adding exogenous decylubiquinone on these activities was tested. 50 µM decylubiquinone stimulated both deamino-NADH oxidase activity and proton translocation by wild type membrane vesicles, but was inhibitory towards the same activities by membrane vesicles bearing the lysine substitution at the L236/M241/N224 positions. CONCLUSIONS/SIGNIFICANCE: The results show a close correlation with reduced activity among the corresponding mutations, and provide evidence that the L, M, and N subunits have a common role in Complex I.

Construction of a deletion strain and expression vector for the Escherichia coli NADH:ubiquinone oxidoreductase (Complex I).

Complex I of Escherichia coli is encoded by 13 consecutive genes, called the nuo operon. A chromosomal deletion of all nuo genes has been achieved by homologous recombination. A vector that encodes all of the nuo genes has been constructed, and it expresses a functional enzyme.

The role of transmembrane span 2 in the structure and function of subunit a of the ATP synthase from Escherichia coli.

The importance of the second transmembrane span of subunit a of the ATP synthase from Escherichia coli has been established by two approaches. First, biochemical analysis of five cysteine-substitution mutants, four of which were previously constructed for labeling experiments, revealed that only D119C, found within the second transmembrane span, was deleterious to ATP synthase function. This mutant had a greatly reduced growth yield, indicating inefficient ATP synthesis, but it retained a significant level of ATP-driven proton translocation and sensitivity to N,N(')-dicyclohexyl-carbodiimide, indicating more robust function in the direction of ATP hydrolysis. Second, the entire second transmembrane span was probed by alanine-insertion mutagenesis at six different positions, from residues 98 to 122. Insertions at the central four positions from residues 107 to 117 resulted in the inability to grow on succinate minimal medium, although normal levels of membrane-bound ATPase activity and significant levels of subunit a were detected. Double mutants were constructed with a mutation that permits cross-linking to the b subunit. Cross-linked products in the mutant K74C/114iA were seen, indicating no major disruption of the a-b interface due to the insertion at 114. Analysis of the K74C/110iA double mutant indicated that K74C is a partial suppressor of 110iA. In summary, the results support a model in which the amino-terminal, cytoplasmic end of the second transmembrane span has close contact with subunit b, while the carboxy-terminal, periplasmic end is important for proton translocation.

Characterization of the first cytoplasmic loop of subunit a of the Escherichia coli ATP synthase by surface labeling, cross-linking, and mutagenesis.

The first cytoplasmic loop of subunit a of the Escherichia coli ATP synthase has been analyzed by cysteine substitution mutagenesis. 13 of the 26 residues tested were found to be accessible to the reaction with 3-(N-maleimidylpropionyl)-biocytin. The other 13 residues predominantly found in the central region of the polypeptide chain between the two transmembrane spans were more resistant to labeling by 3-(N-maleimidylpropionyl)-biocytin while in membrane vesicle preparations. This region of subunit a contains a conserved residue Glu-80, which when mutated to lysine resulted in a significant loss of ATP-driven proton translocation. Other substitutions including glutamine, alanine, and leucine were much less detrimental to function. Cross-linking studies with a photoactive cross-linking reagent were carried out. One mutant, K74C, was found to generate distinct cross-links to subunit b, and the cross-linking had little effect on proton translocation. The results indicate that the first transmembrane span (residues 40-64) of subunit a is probably near one or both of the b subunits and that a less accessible region of the first cytoplasmic loop (residues 75-90) is probably near the cytoplasmic surface, perhaps in contact with b subunits.