Community-wide Screening for Tuberculosis in a High-Prevalence Setting.

BACKGROUND: The World Health Organization has set ambitious targets for the global elimination of tuberculosis. However, these targets will not be achieved at the current rate of progress. METHODS: We performed a cluster-randomized, controlled trial in Ca Mau Province, Vietnam, to evaluate the effectiveness of active community-wide screening, as compared with standard passive case detection alone, for reducing the prevalence of tuberculosis. Persons 15 years of age or older who resided in 60 intervention clusters (subcommunes) were screened for pulmonary tuberculosis, regardless of symptoms, annually for 3 years, beginning in 2014, by means of rapid nucleic acid amplification testing of spontaneously expectorated sputum samples. Active screening was not performed in the 60 control clusters in the first 3 years. The primary outcome, measured in the fourth year, was the prevalence of microbiologically confirmed pulmonary tuberculosis among persons 15 years of age or older. The secondary outcome was the prevalence of tuberculosis infection, as assessed by an interferon gamma release assay in the fourth year, among children born in 2012. RESULTS: In the fourth-year prevalence survey, we tested 42,150 participants in the intervention group and 41,680 participants in the control group. A total of 53 participants in the intervention group (126 per 100,000 population) and 94 participants in the control group (226 per 100,000) had pulmonary tuberculosis, as confirmed by a positive nucleic acid amplification test for Mycobacterium tuberculosis (prevalence ratio, 0.56; 95% confidence interval [CI], 0.40 to 0.78; P<0.001). The prevalence of tuberculosis infection in children born in 2012 was 3.3% in the intervention group and 2.6% in the control group (prevalence ratio, 1.29; 95% CI, 0.70 to 2.36; P = 0.42). CONCLUSIONS: Three years of community-wide screening in persons 15 years of age or older who resided in Ca Mau Province, Vietnam, resulted in a lower prevalence of pulmonary tuberculosis in the fourth year than standard passive case detection alone. (Funded by the Australian National Health and Medical Research Council; ACT3 Australian New Zealand Clinical Trials Registry number, ACTRN12614000372684.).

Caregiver activation of relatives of patients with advanced cancer.

OBJECTIVE: Relatives of patients with advanced cancer often have many caring responsibilities. Not everyone may have sufficient knowledge, skills, and confidence-also known as caregiver activation-to provide such care. We assessed caregiver activation in relatives and its association with their personal characteristics and their own well-being. METHODS: A cross-sectional study among relatives of patients with advanced cancer. Measures included caregiver activation (C-PAM), resilience, personal self-care, caregiver burden, depressive symptoms, quality of life, and social well-being. The C-PAM distinguishes four levels of activation, ranging from poor (level 1) to adequate (level 4). Bivariate and multivariable regression analyses were performed. RESULTS: Two hundred fifty-four relatives were included; 32% had level 1 activation, 30% level 2, 27% level 3 and 11% level 4. Higher levels of caregiver activation were found among partners, those who provided more hours of informal care, were more resilient, and scored higher on personal self-care. Higher caregiver activation was associated with lower caregiver burden, less depressive symptoms, and better social well-being. CONCLUSION: In our study, the majority of relatives seem insufficiently prepared to provide care for their loved one. Supporting them in gaining knowledge, skills, and confidence to provide such care may improve their own well-being.

The malate-activated ALMT12 anion channel in the grass Brachypodium distachyon is co-activated by Ca2+/calmodulin.

In plants, strict regulation of stomatal pores is critical for modulation of CO2 fixation and transpiration. Under certain abiotic and biotic stressors, pore closure is initiated through anionic flux, with calcium (Ca2+) playing a central role. The aluminum-activated malate transporter 12 (ALMT12) is a malate-activated, voltage-dependent member of the aluminum-activated malate transporter family that has been implicated in anionic flux from guard cells controlling the stomatal aperture. Herein, we report the characterization of the regulatory mechanisms mediating channel activities of an ALMT from the grass Brachypodium distachyon (BdALMT12) that has the highest sequence identity to Arabidopsis thaliana ALMT12. Electrophysiological studies in a heterologous cell system confirmed that this channel is malate- and voltage-dependent. However, this was shown to be true only in the presence of Ca2+ Although a general kinase inhibitor increased the current density of BdALMT12, a calmodulin (CaM) inhibitor reduced the Ca2+-dependent channel activation. We investigated the physiological relevance of the CaM-based regulation in planta, where stomatal closure, induced by exogenous Ca2+ ionophore and malate, was shown to be inhibited by exogenous application of a CaM inhibitor. Subsequent analyses revealed that the double substitutions R335A/R338A and R335A/K342A, within a predicted BdALMT12 CaM-binding domain (CBD), also decreased the channels' ability to activate. Using isothermal titration calorimetry and CBD-mimetic peptides, as well as CaM-agarose affinity pulldown of full-length recombinant BdALMT12, we confirmed the physical interaction between the CBD and CaM. Together, these findings support a co-regulatory mechanism of BdALMT12 activation by malate, and Ca2+/CaM, emphasizing that a complex regulatory network modulates BdALMT12 activity.

Comparison of intestinal glucose flux and electrogenic current demonstrates two absorptive pathways in pig and one in Nile tilapia and rainbow trout.

The mucosal-to-serosal flux of 14C 3-O-methyl-d-glucose was compared against the electrogenic transport of d-glucose across ex vivo intestinal segments of Nile tilapia, rainbow trout, and pig in Ussing chambers. The difference in affinities (Km "fingerprints") between pig flux and electrogenic transport of glucose, and the absence of this difference in tilapia and trout, suggest two absorptive pathways in the pig and one in the fish species examined. More specifically, the total mucosal-to-serosal flux revealed a super high-affinity, high-capacity (sHa/Hc) total glucose transport system in tilapia; a super high-affinity, low-capacity (sHa/Lc) total glucose transport system in trout and a low-affinity, low-capacity (La/Lc) total glucose transport system in pig. Comparatively, electrogenic glucose absorption revealed similar Km in both fish species, with a super high-affinity, high capacity (sHa/Hc) system in tilapia; a super high-affinity/super low-capacity (sHa/sLc) system in trout; but a different Km fingerprint in the pig, with a high-affinity, low-capacity (Ha/Lc) system. This was supported by different responses to inhibitors of sodium-dependent glucose transporters (SGLTs) and glucose transporter type 2 (GLUT2) administered on the apical side between species. More specifically, tilapia flux was inhibited by SGLT inhibitors, but not the GLUT2 inhibitor, whereas trout lacked response to inhibitors. In contrast, the pig responded to inhibition by both SGLT and GLUT2 inhibitors with a higher expression of GLUT2. Altogether, it would appear that two pathways are working together in the pig, allowing it to have continued absorption at high glucose concentrations, whereas this is not present in both tilapia and trout.

Antigen-binding fragments with improved crystal lattice packing and enhanced conformational flexibility at the elbow region as crystallization chaperones.

It has been shown previously that a set of three modifications-termed S1, Crystal Kappa, and elbow-act synergistically to improve the crystallizability of an antigen-binding fragment (Fab) framework. Here, we prepared a phage-displayed library and performed crystallization screenings to identify additional substitutions-located near the heavy-chain elbow region-which cooperate with the S1, Crystal Kappa, and elbow modifications to increase expression and improve crystallizability of the Fab framework even further. One substitution (K141Q) supports the signature Crystal Kappa-mediated Fab:Fab crystal lattice packing interaction. Another substitution (E172G) improves the compatibility of the elbow modification with the Fab framework by alleviating some of the strain incurred by the shortened and bulkier elbow linker region. A third substitution (F170W) generates a split-Fab conformation, resulting in a powerful crystal lattice packing interaction comprising the biological interaction interface between the variable heavy and light chain domains. In sum, we have used K141Q, E172G, and F170W substitutions-which complement the S1, Crystal Kappa, and elbow modifications-to generate a set of highly crystallizable Fab frameworks that can be used as chaperones to enable facile elucidation of Fab:antigen complex structures by x-ray crystallography.

A qualitative study on redefining normality in relatives of patients with advanced cancer.

OBJECTIVE: To obtain insight into adaptation processes of redefining normality and its influencing factors in relatives of patients with advanced cancer. METHODS: An exploratory qualitative study among relatives of patients with advanced cancer was conducted. Participants were purposively recruited. Ten in-depth individual (relative only) and 16 dyad (relative and patient together) interviews were conducted, transcribed verbatim, and analyzed by means of thematic analysis, drawing on elements of grounded theory, combining both inductive and deductive elements. RESULTS: Two adaptation processes of (redefining) normality were identified: assimilation and accommodation. The latter was found to be the main way of adapting to new events. Assimilative coping strategies entailed "continuing to do the same activities as done before the disease," "difficulty accepting the situation," "avoiding to think about the disease," and "living in the short term." Accommodative strategies involved "arranging practical matters," "thinking about the future," "doing what is feasible," "engaging in new activities," "accepting the situation," "seeking distraction," "living in the short term," and "focusing on what truly matters in life." The interplay between the diagnosis and treatment of cancer, a deteriorating disease status, and the accompanying uncertainty about the future was of influence on the relatives' coping strategies. CONCLUSION: When the new situation is too divergent to assimilate, accommodation may be necessary for relatives to cope with the growing complexity of the consequences of their loved one's illness. Accommodative coping then involves accepting the changing reality and actively making the necessary adjustments to build resilience and cope with the new circumstances.

Prevalence and genetic basis of first-line drug resistance of Mycobacterium tuberculosis in Ca Mau, Vietnam.

Background and objective: Data on the prevalence of anti-tuberculous drug resistance and its association with genetic mutations in Mycobacterium tuberculosis are limited. Our study explores the genomics of tuberculosis in Ca Mau, Vietnam. Methods: Patients ≥15 years in Ca Mau Province, Vietnam, were screened annually for tuberculosis between 2014 and 2017. Isolates underwent drug susceptibility testing (DST) using the breakpoint method. DNA was extracted and whole genome sequencing (WGS) was performed. Results: We identified 365 positive sputum cultures for M. tuberculosis and processed 237 for DST and 265 for WGS. Resistance to isoniazid was present in 19.8% (95% CI 14.7 to 24.9%), rifampicin in 3.5% (1.1 to 5.7%) and ethambutol in 2.5% (0.9 to 5.4%) of isolates. Relevant mutations in rpoB gene were detected in 3.8% (1.8 to 6.8%). katG, inhA or fabG1 mutations were found in 19.6% (15.0 to 24.9%) with KatG being most common at 12.8% (9.1-17.5%). We found 38.4% of isolates were of Beijing lineage, 49.4% East-African-Indian lineage and 8.4% European-American lineage. There were no associations between resistance profiles and clinical features. Conclusion: The high burden of isoniazid resistance and the katG mutation highlights the challenges facing Vietnam in its efforts to achieve its EndTB goals.

Reassessment of the positive predictive value and specificity of Xpert MTB/RIF: a diagnostic accuracy study in the context of community-wide screening for tuberculosis.

BACKGROUND: Community-wide screening for tuberculosis with Xpert MTB/RIF as a primary screening tool overcomes some of the limitations of conventional screening. However, concerns exist about the low positive predictive value of this test in screening settings. We did a cross-sectional assessment of this diagnostic test to directly estimate the actual positive predictive value of Xpert MTB/RIF when used in the setting of community-wide screening for tuberculosis, and to draw an inference about the specificity of the test for tuberculosis detection. METHODS: Field staff visited households in 60 randomly selected villages in Ca Mau province, Vietnam. We included people aged 15 years or older who provided written informed consent and were able to produce 0·5 mL or more of sputum, irrespective of reported symptoms. Participants were tested with Xpert MTB/RIF, then those with positive results had two further sputum samples tested for smear microscopy and culture, and underwent chest radiography at the provincial TB Health Center. The positive predictive value of Xpert MTB/RIF was compared against two reference standards for tuberculosis diagnosis-a positive sputum culture for Mycobacterium tuberculosis, and a positive sputum culture or a chest radiograph consistent with active pulmonary tuberculosis. We then calculated the specificity of Xpert MTB/RIF for tuberculosis detection on the basis of these positive predictive values and disease prevalence in this setting. FINDINGS: 43 435 adults consented to screening with Xpert MTB/RIF. Sputum samples of 0·5 mL or greater were collected from 23 202 participants, producing 22 673 valid results. 169 participants had positive Xpert MTB/RIF results (0·39% of those screened and 0·75% of those with valid sputum results). The positive predictive value of Xpert MTB/RIF was 61·0% (95% CI 52·8-68·7) when compared against a positive sputum culture and 83·9% (76·8-89·2) when compared against a positive sputum culture or chest radiograph consistent with active tuberculosis. On the basis of these positive predictive values, the specificity of Xpert MTB/RIF was determined to be between 99·78% (95% CI 99·71-99·84) and 99·93% (99·88-99·96). INTERPRETATION: The positive predictive value and specificity of Xpert MTB/RIF in the context of community-wide screening for tuberculosis is substantially higher than that predicted in previous studies. Our findings support the potential role of Xpert MTB/RIF as a primary screening tool to detect prevalent cases of tuberculosis in the community. FUNDING: Australian National Health and Medical Research Council.