Cost-effectiveness of expanded latent TB infection testing and treatment: Lynn City, Massachusetts, USA.

BACKGROUND: Between October 2016 and March 2019, Lynn Community Health Center in Massachusetts implemented a targeted latent TB infection testing and treatment (TTT) program, increasing testing from a baseline of 1,200 patients tested to an average of 3,531 patients tested, or 9% of the population per year.METHODS: We compared pre-implementation TTT, represented by the first two quarters of implementation data, to TTT, represented by 12 quarters of data. Time, diagnostic, and laboratory resources were estimated using micro-costing. Other cost and testing data were obtained from the electronic health record, pharmaceutical claims, and published reimbursement rates. A Markov cohort model estimated future health outcomes and cost-effectiveness from a societal perspective in 2020 US dollars. Monte Carlo simulation generated 95% uncertainty intervals.RESULTS: The TTT program exhibited extended dominance over baseline pre-intervention testing and had an incremental cost-effectiveness ratio (ICER) of US$52,603 (US$22,008â-"US$95,360). When compared to baseline pre-TTT testing, the TTT program averted an estimated additional 7.12 TB cases, 3.49 hospitalizations, and 0.16 deaths per lifetime cohort each year.CONCLUSIONS: TTT was more cost-effective than baseline pre-implementation testing. Lynn Community Health Centerâ-™s experience can help inform other clinics considering expanding latent TB infection testing.

Generation and characterization of aptamers targeting factor XIa.

BACKGROUND: The plasma protease factor XIa (FXIa) has become a target of interest for therapeutics designed to prevent or treat thrombotic disorders. METHODS: We used a solution-based, directed evolution approach called systematic evolution of ligands by exponential enrichment (SELEX) to isolate RNA aptamers that target the FXIa catalytic domain. RESULTS: Two aptamers, designated 11.16 and 12.7, were identified that bound to previously identified anion binding and serpin bindings sites on the FXIa catalytic domain. The aptamers were non-competitive inhibitors of FXIa cleavage of a tripeptide chromogenic substrate and of FXIa activation of factor IX. In normal human plasma, aptamer 12.7 significantly prolonged the aPTT clotting time. CONCLUSIONS: The results show that novel inhibitors of FXIa can be prepared using SELEX techniques. RNA aptamers can bind to distinct sites on the FXIa catalytic domain and noncompetitively inhibit FXIa activity toward its primary macromolecular substrate factor IX with different levels of potency. Such compounds can be developed for use as therapeutic inhibitors.

Factors associated with recurrent tuberculosis more than 12 months after treatment completion.

SETTING: Even among persons who have completed a course of treatment for their first tuberculosis (TB) episode, patients with a history of TB are at higher risk for having TB. OBJECTIVE: To describe factors from the initial TB episode associated with recurrent TB among patients who completed treatment and remained free of TB for at least 12 months. DESIGN: During 1993-2006, US TB cases stratified by birth origin were examined. Cox proportional hazards regression was used to assess the association of factors during the initial episode with recurrence at least 12 months after treatment completion. RESULTS: Among 632 US-born patients, TB recurrence was associated with age 25-44 years (adjusted hazard ratio [aHR] 1.77, 99% confidence interval [CI] 1.02-3.09, attributable fraction [AF] 1-34%), substance use (aHR 1.57, 99%CI 1.23-2.02, AF 8-22%), and treatment supervised by health departments (aHR 1.42, 99%CI 1.03-1.97, AF 2-28%). Among 211 foreign-born patients, recurrence was associated with human immunodeficiency virus infection (aHR 2.24, 99%CI 1.27-3.98, AF 2-9%) and smear-positive TB (aHR 1.56, 99%CI 1.06-2.30, AF 3-33%). CONCLUSION: Factors associated with recurrence differed by origin of birth, and might be useful for anticipating greater risk for recurrent TB among certain patients with a history of TB.

Tuberculosis among the homeless, United States, 1994-2010.

OBJECTIVES: 1) To describe homeless persons diagnosed with tuberculosis (TB) during the period 1994-2010, and 2) to estimate a TB incidence rate among homeless persons in the United States. METHODS: TB cases reported to the National Tuberculosis Surveillance System were analyzed by origin of birth. Incidence rates were calculated using the US Department of Housing and Urban Development homeless population estimates. Analysis of genotyping results identified clustering as a marker for transmission among homeless TB patients. RESULTS: Of 270,948 reported TB cases, 16,527 (6%) were homeless. The TB incidence rate among homeless persons ranged from 36 to 47 cases per 100,000 population in 2006-2010. Homeless TB patients had over twice the odds of not completing treatment and of belonging to a genotype cluster. US- and foreign-born homeless TB patients had respectively 8 and 12 times the odds of substance abuse. CONCLUSIONS: Compared to the general population, homeless persons had an approximately 10-fold increase in TB incidence, were less likely to complete treatment and more likely to abuse substances. Public health outreach should target homeless populations to reduce the excess burden of TB in this population.

Inhibiting the intrinsic pathway of coagulation with a factor XII-targeting RNA aptamer.

BACKGROUND: Exposure of the plasma protein factor XII (FXII) to an anionic surface generates activated FXII that not only triggers the intrinsic pathway of blood coagulation through the activation of FXI but also mediates various vascular responses through activation of the plasma contact system. While deficiencies of FXII are not associated with excessive bleeding, thrombosis models in factor-deficient animals have suggested that this protein contributes to stable thrombus formation. Therefore, FXII has emerged as an attractive therapeutic target to treat or prevent pathological thrombosis formation without increasing the risk for hemorrhage. OBJECTIVES: Using an in vitro directed evolution and chemical biology approach, we sought to isolate a nuclease-resistant RNA aptamer that binds specifically to FXII and directly inhibits FXII coagulant function. METHODS AND RESULTS: We describe the isolation and characterization of a high-affinity RNA aptamer targeting FXII/activated FXII (FXIIa) that dose dependently prolongs fibrin clot formation and thrombin generation in clinical coagulation assays. This aptamer functions as a potent anticoagulant by inhibiting the autoactivation of FXII, as well as inhibiting intrinsic pathway activation (FXI activation). However, the aptamer does not affect the FXIIa-mediated activation of the proinflammatory kallikrein-kinin system (plasma kallikrein activation). CONCLUSIONS: We have generated a specific and potent FXII/FXIIa aptamer anticoagulant that offers targeted inhibition of discrete macromolecular interactions involved in the activation of the intrinsic pathway of blood coagulation.

An extreme test of mutational meltdown shows mutational firm up instead.

Traditionally, the accumulation of new deleterious mutations in populations or species in low numbers is expected to lead to a reduction in fitness and mutational meltdown, but in this study the opposite was observed. Beginning with a highly inbred populations of Drosophila melanogaster, new mutations that accumulated in experiments of two females and two males or of one female and one male each generation for 52 generations did not cause a decline in progeny numbers over time. Only two lines went extinct among 52 tested lines. In three of four experiments there was a significant increase in progeny numbers over time (mutational firm up), which had to be due to new beneficial, compensatory, overdominant, or back mutations.

Epidemiology of recurrent tuberculosis in the United States, 1993-2010.

Recurrent tuberculosis (TB) can result from reactivation of a previous TB episode or reinfection with a new Mycobacterium tuberculosis strain. A retrospective analysis of all recurrent TB cases reported in the United States during 1993-2010 was conducted. The proportion of recurrent cases remained stable during the study period (annual range 4.2-5.7%). Compared with persons without a previous diagnosis of TB, persons with recurrent TB experienced lower treatment completion within 12 months and higher mortality during the recurrent episode. Persons with recurrent TB have poorer outcomes, suggesting the need for targeted interventions to ensure treatment completion.

Antidote control of aptamer therapeutics: the road to a safer class of drug agents.

Aptamers, or nucleic acid ligands, have gained clinical interest over the past 20 years due to their unique characteristics, which are a combination of the best facets of small molecules and antibodies. The high binding affinity and specificity of aptamers allows for isolation of an artificial ligand for theoretically any therapeutic target of interest. Chemical manipulations of aptamers also allow for fine-tuning of their bioavailability, and antidote control greatly expands their clinical use. Here we review the various methods of antidote control of aptamer therapeutics--matched oligonucleotide antidotes and universal antidotes. We also describe the development, recent progress, and potential future therapeutic applications of these types of aptamer-antidote pairs.

Intron retention in the Drosophila melanogaster Rieske Iron Sulphur Protein gene generated a new protein.

Genomes can encode a variety of proteins with unrelated architectures and activities. It is known that protein-coding genes of de novo origin have significantly contributed to this diversity. However, the molecular mechanisms and evolutionary processes behind these originations are still poorly understood. Here we show that the last 102 codons of a novel gene, Noble, assembled directly from non-coding DNA following an intronic deletion that induced alternative intron retention at the Drosophila melanogaster Rieske Iron Sulphur Protein (RFeSP) locus. A systematic analysis of the evolutionary processes behind the origin of Noble showed that its emergence was strongly biased by natural selection on and around the RFeSP locus. Noble mRNA is shown to encode a bona fide protein that lacks an iron sulphur domain and localizes to mitochondria. Together, these results demonstrate the generation of a novel protein at a naturally selected site.

Adaptation of Drosophila melanogaster to increased NaCl concentration due to dominant beneficial mutations.

New beneficial mutations, combined with selection, were responsible for quick adaptation of Drosophila melanogaster to a novel environment. Using a highly inbred homozygous stock of D. melanogaster, we observed that in thirty generations the original stock had evolved to resist a previously toxic level of dietary salt (NaCl) and to produce a significantly higher number of progeny when reared in elevated salt concentrations. Survival in higher salt-stressed environments was due to new dominant genetic changes on the second and third chromosomes.

Rapid increase in viability due to new beneficial mutations in Drosophila melanogaster.

It is usually assumed that new beneficial mutations are extremely rare. Yet, few experiments have been performed in multicellular organisms that measure the effect of new beneficial mutations on viability and other measures of fitness. In most experiments, it is difficult to clearly distinguish whether adaptations have occurred due to selection on new beneficial mutations or on preexisting genetic variation. Using a modification of a Dobzhansky and Spassky (Evolution 1:191-216, 1947) assay to study change in viability over generations, we have observed an increase in viability in lines homozygous for the second and third chromosomes of Drosophila melanogaster in 6-26 generations due to the occurrence of new beneficial mutations in population sizes of 20, 100 and 1,000. The lines with the lowest initial viability responded the fastest to new beneficial mutations. These results show that new beneficial mutations, along with selection, can quickly increase viability and fitness even in small populations. Hence, new advantageous mutations may play an important role in adaptive evolution in higher organisms.

Passage through vertebrate gap junctions of 17/18kDa molecules is primarily dependent upon molecular configuration.

In fish, amphibians and mammals, gap junctions of some cells allow passage of elongate molecules as large as 18kDa, while excluding smaller, less elongate molecules. Fluorescently labeled Calmodulin (17kDa) and fluorescently labeled Troponin-C (18kDa), when microinjected into oocytes of Danio rerio, Xenopus laevis or Mus domestica, were able to transit the gap junctions between these oocytes and the granulosa cells which surrounded them. Co-microinjected with these Ca(2+)-binding proteins, Texas-red-labeled dextran (10kDa) remained in the microinjected cell. Osteocalcin (6kDa), also a Ca(2+)-binding protein, but with a wide "V" shape proved unable to transit these gap junctions. Calmodulin, but not Troponin-C, was able to transit gap junctions of gonadotropin treated WB cells in culture. We show evidence that molecules as large as 18kDa can pass through some vertebrate gap junctions, both homologous and heterologous, and that it is primarily molecular configuration which governs gap junctional permeability.

Passage of 17 kDa calmodulin through gap junctions of three vertebrate species.

Gap junctions of some vertebrates are capable of passing the elongate molecule, calmodulin, with a molecular weight 8-17 times greater than the previously recognized size limits. Fluorescently labeled calmodulin (FCaM) (17.34 kDa) microinjected into oocytes of ovarian follicles from an amphibian, Xenopus laevis, and from two species of teleost fish, Danio rerio (Zebrafish) and Oryzias latipes (Medaka), is shown to transit their gap junctions and enter the surrounding epithelial cells. Passage of FCaM was terminated when follicles were first treated with 1 mM octanol, a molecule known to down-regulate gap junctions. There was no FCaM detected in the surrounding medium, nor did epithelial cells become fluorescent when follicles were incubated in medium containing dye. Calmodulin is well known to modulate many cytoplasmic reactions; thus, its passage through gap junctions opens possibilities of additional means by which cells may be supplied with this signaling molecule, and by which their supply may be regulated.

Elevated levels of the mismatch repair protein PMS2 are associated with prostate cancer.

BACKGROUND: Defects in mismatch repair (MMR) proteins have been identified in various types of cancer. However, an association with prostate cancer has been controversial. Defective MMR results in genome instability with detrimental consequences that significantly contribute to tumorigenesis. This study determined alterations in key MMR protein levels in prostate cancer with the goal to identify prognostic markers. METHODS: Prostatectomy samples were immunohistochemically stained and the relative presence or absence of key proteins MSH2, MLH1, and PMS2 determined. Cancer tissue of distinct grades was compared with the normal surrounding tissue. Microsatellite instability (MSI) in altered tissues was determined according to NCI guidelines. RESULTS: In contrast to reports that associate a lack of individual MMR proteins with tumorigenesis, a significant increase in PMS2 levels was identified in PIN lesions and prostate cancer tissue. This elevation in PMS2 was independent of changes in levels in its heterodimeric partner, MLH1. Prostate tumors with elevated levels of PMS2 were genetically unstable, which was corrected by MLH1 co-elevation. CONCLUSIONS: This is the first documentation of detrimental consequences associated with the increase in a MMR protein in human cancer. This study recognizes PMS2 elevation as a prognostic marker in pre-neoplastic and prostate cancer lesions. This result has significant implications for future diagnostic and treatment measures.

Long-term patterns of genomic P element content and P-M characteristics of Drosophila melanogaster in eastern Australia.

A latitudinal cline in characteristics associated with the P DNA transposable element is well known in eastern Australian populations of Drosophila melanogaster. In order to survey the long-term patterns of P-M system characteristics and genomic P element content, we established 292 isofemale lines from 54 localities in 1996-1997 and evaluated them for gonadal dysgenesis (GD) sterility and the ratio of KP to full-size P elements (KP/FP ratio). The results were compared to those from collections made in 1983-1986 and 1991-1994. Over 10-14 years, 1) the cross A GD scores of the northern-middle populations declined dramatically; 2) the clinal pattern of the cross A* GD scores did not change; 3) the latitudinal pattern of the KP/FP ratio did not change. The results suggest that only a few P elements determine P-M characteristics and that there has been selection for genomes with fewer active P elements, but not for a great change in proportions of size classes.

Effect of deleterious mutations on life span in Drosophila melanogaster.

Evolutionary theories of aging assume that the accumulation of deleterious mutations will reduce life span. We tested this assumption in Drosophila melanogaster by a newly designed mating scheme, in which mutations accumulate on the Binscy balancer X chromosome in heterozygous females in the absence of selection and recombination. We found that the life span of Binscy/RY(L) males from this cross decreased faster than the life span of their sibling controls over time in two of three runs, and that there was an age-specific increase in mortality in the Binscy/RY(L) males with time in one of three runs. Therefore, the accumulation of deleterious mutations can decrease life span by increasing fragility and can cause age-specific changes in mortality. These results support the evolutionary theory of aging.

The influence of premeiotic clusters of mutation on indirect estimations of mutation rate.

Based on the hypothesis that rare alleles are in mutation and random loss equilibrium, mutation rate can be indirectly estimated by measuring the number of rare variants and the average existing time of a mutant allele. This method can be applied to estimate the mutation rate in humans. However, this estimation of mutation rate is affected by the presence of premeiotic clusters of mutation. Mutation clusters change both the number of initial mutants and the average existing time of a mutant allele. As a result, the formula indirectly estimating mutation rate should be modified. The influence of premeiotic clusters is more obvious when the population size is small or the average cluster size is big. For example, if the population size is 3,000 and average cluster size is two, instead of one, the mutation rate is increased by about 9.4%.

The fundamental theorem of neutral evolution: rates of substitution and mutation should factor in premeiotic clusters.

Mutations do not always arise as single events. Many new mutations actually occur in the cell lineage before germ cell formation or meiosis and are therefore replicated pre-meiotically. The increased likelihood of substitutions caused by these clusters of new mutant alleles can change the fundamental theorem of neutral evolution.