Modifying TIMER to generate a slow-folding DsRed derivative for optimal use in quickly-dividing bacteria.

It is now well appreciated that members of pathogenic bacterial populations exhibit heterogeneity in growth rates and metabolic activity, and it is known this can impact the ability to eliminate all members of the bacterial population during antibiotic treatment. It remains unclear which pathways promote slowed bacterial growth within host tissues, primarily because it has been difficult to identify and isolate slow growing bacteria from host tissues for downstream analyses. To overcome this limitation, we have developed a novel variant of TIMER, a slow-folding fluorescent protein, named DsRed42, to identify subsets of slowly dividing bacteria within host tissues. The original TIMER folds too slowly for fluorescence accumulation in quickly replicating bacterial species (Escherichia coli, Yersinia pseudotuberculosis), however DsRed42 accumulates red fluorescence in late stationary phase cultures of E. coli and Y. pseudotuberculosis. We show DsRed42 signal also accumulates during exposure to sources of nitric oxide (NO), suggesting DsRed42 signal detects growth-arrested bacterial cells. In a mouse model of Y. pseudotuberculosis deep tissue infection, DsRed42 signal was detected, and primarily accumulates in bacteria expressing markers of stationary phase growth. There was no significant overlap between DsRed42 signal and NO-exposed subpopulations of bacteria within host tissues, suggesting NO stress was transient, allowing bacteria to recover from this stress and resume replication. This novel DsRed42 variant represents a tool that will enable additional studies of slow-growing subpopulations of bacteria, specifically within bacterial species that quickly divide.

Plague's partners in crime.

The hallmark of bubonic plague is the presence of grotesquely swollen lymph nodes, called buboes. This frenzied inflammatory response to Yersinia pestis is poorly understood. In this issue of Immunity, St. John et al. (2014) explore the mechanism by which Y. pestis spreads and thus leads to this striking lymphadenopathy.

NO-Stressed Y. pseudotuberculosis Has Decreased Cell Division Rates in the Mouse Spleen.

Fluorescence dilution approaches can detect bacterial cell division events and can detect if there are differential rates of cell division across individual cells within a population. This approach typically involves inducing expression of a fluorescent protein and then tracking partitioning of fluorescence into daughter cells. However, fluorescence can be diluted very quickly within a rapidly replicating population, such as pathogenic bacterial populations replicating within host tissues. To overcome this limitation, we have generated two revTetR reporter constructs, where either mCherry or yellow fluorescent protein (YFP) is constitutively expressed and repressed by addition of tetracyclines, resulting in fluorescence dilution within defined time frames. We show that fluorescent signals are diluted in replicating populations and that signal accumulates in growth-inhibited populations, including during nitric oxide (NO) exposure. Furthermore, we show that tetracyclines can be delivered to the mouse spleen during Yersinia pseudotuberculosis infection and defined a drug concentration that results in even exposure of cells to tetracyclines. We then used this system to visualize bacterial cell division within defined time frames postinfection. revTetR-mCherry allowed us to detect slow-growing cells in response to NO in culture; however, this strain had a growth defect within mouse tissues, which complicated results. To address this issue, we constructed revTetR-YFP using the less toxic YFP and showed that heightened NO exposure correlated with heightened YFP signal, indicating decreased cell division rates within this subpopulation in vivo. This revTetR reporter will provide a critical tool for future studies to identify and isolate slowly replicating bacterial subpopulations from host tissues.

For the Greater (Bacterial) Good: Heterogeneous Expression of Energetically Costly Virulence Factors.

Bacterial populations are phenotypically heterogeneous, which allows subsets of cells to survive and thrive following changes in environmental conditions. For bacterial pathogens, changes within the host environment occur over the course of the immune response to infection and can result in exposure to host-derived, secreted antimicrobials or force direct interactions with immune cells. Many recent studies have shown host cell interactions promote virulence factor expression, forcing subsets of bacterial cells to battle the host response, while other bacteria reap the benefits of this pacification. It still remains unclear whether virulence factor expression is truly energetically costly within host tissues and whether expression is sufficient to impact the growth kinetics of virulence factor-expressing cells. However, it is clear that slow-growing subsets of bacteria emerge during infection and that these subsets are particularly difficult to eliminate with antibiotics. This minireview will focus on our current understanding of heterogenous virulence factor expression and discuss the evidence that supports or refutes the hypothesis that virulence factor expression is linked to slowed growth and antibiotic tolerance.

Iron-Sulfur Cluster Repair Contributes to Yersinia pseudotuberculosis Survival within Deep Tissues.

To successfully colonize host tissues, bacteria must respond to and detoxify many different host-derived antimicrobial compounds, such as nitric oxide (NO). NO has direct antimicrobial activity through attack on iron-sulfur (Fe-S) cluster-containing proteins. NO detoxification plays an important role in promoting bacterial survival, but it remains unclear if repair of Fe-S clusters is also important for bacterial survival within host tissues. Here we show that the Fe-S cluster repair protein YtfE contributes to the survival of Yersinia pseudotuberculosis within the spleen following nitrosative stress. Y. pseudotuberculosis forms clustered centers of replicating bacteria within deep tissues, where peripheral bacteria express the NO-detoxifying gene hmp. ytfE expression also occurred specifically within peripheral cells at the edges of microcolonies. In the absence of ytfE, the area of microcolonies was significantly smaller than that of the wild type (WT), consistent with ytfE contributing to the survival of peripheral cells. The loss of ytfE did not alter the ability of cells to detoxify NO, which occurred within peripheral cells in both WT and ΔytfE microcolonies. In the absence of NO-detoxifying activity by hmp, NO diffused across ΔytfE microcolonies, and there was a significant decrease in the area of microcolonies lacking ytfE, indicating that ytfE also contributes to bacterial survival in the absence of NO detoxification. These results indicate a role for Fe-S cluster repair in the survival of Y. pseudotuberculosis within the spleen and suggest that extracellular bacteria may rely on this pathway for survival within host tissues.

Decision-making processes among men with low-risk prostate cancer: A survey study.

OBJECTIVE: To characterize decision-making processes and outcomes among men expressing early-treatment preferences for low-risk prostate cancer. METHODS: We conducted telephone surveys of men newly diagnosed with low-risk prostate cancer in 2012 to 2014. We analyzed subjects who had discussed prostate cancer treatment with a clinician and expressed a treatment preference. We asked about decision-making processes, including physician discussions, prostate-cancer knowledge, decision-making styles, treatment preference, and decisional conflict. We compared the responses across treatment groups with χ2 or ANOVA. RESULTS: Participants (n = 761) had a median age of 62; 82% were white, 45% had a college education, and 35% had no comorbidities. Surveys were conducted at a median of 25 days (range 9-100) post diagnosis. Overall, 55% preferred active surveillance (AS), 26% preferred surgery, and 19% preferred radiotherapy. Participants reported routinely considering surgery, radiotherapy, and AS. Most were aware of their low-risk status (97%) and the option for AS (96%). However, men preferring active treatment (AT) were often unaware of treatment complications, including sexual dysfunction (23%) and urinary complications (41%). Most men (63%) wanted to make their own decision after considering the doctor's opinion, and about 90% reported being sufficiently involved in the treatment discussion. Men preferring AS had slightly more uncertainty about their decisions than those preferring AT. CONCLUSIONS: Subjects were actively engaged in decision making and considered a range of treatments. However, we found knowledge gaps about treatment complications among those preferring AT and slightly more decisional uncertainty among those preferring AS, suggesting the need for early decision support.

Defining heterogeneity within bacterial populations via single cell approaches.

Bacterial populations are heterogeneous, which in many cases can provide a selective advantage during changes in environmental conditions. In some instances, heterogeneity exists at the genetic level, in which significant allelic variation occurs within a population seeded by a single cell. In other cases, heterogeneity exists due to phenotypic differences within a clonal, genetically identical population. A variety of mechanisms can drive this latter strategy. Stochastic fluctuations can drive differential gene expression, but heterogeneity in gene expression can also be driven by environmental changes sensed by individual cells residing in distinct locales. Utilizing multiple single cell approaches, workers have started to uncover the extent of heterogeneity within bacterial populations. This review will first describe several examples of phenotypic and genetic heterogeneity, and then discuss many single cell approaches that have recently been applied to define heterogeneity within bacterial populations.

The challenge of measuring intra-individual change in fatigue during cancer treatment.

PURPOSE: To evaluate how well three different patient-reported outcomes (PROs) measure individual change. METHODS: Two hundred and fourteen patients (from two sites) initiating first or new chemotherapy for any stage of breast or gastrointestinal cancer participated. The 13-item FACIT Fatigue scale, a 7-item PROMIS® Fatigue Short Form (PROMIS 7a), and the PROMIS® Fatigue computer adaptive test (CAT) were administered monthly online for 6 months. Reliability of measured change was defined, under a population mixed effects model, as the ratio of estimated systematic variance in rate of change to the estimated total variance of measured individual differences in rate of change. Precision of individual measured change, the standard error of measurement of change, was given by the square root of the rate-of-change sampling variance. Linear and quadratic models were examined up to 3 and up to 6 months. RESULTS: A linear model for measured change showed the following by 6 and 3 months, respectively: PROMIS CAT (0.363 and 0.342); PROMIS SF (0.408 and 0.533); FACIT (0.459 and 0.473). Quadratic models offered no noteworthy improvement over linear models. Both reliability and precision results demonstrate the need to improve the measurement of intra-individual change. CONCLUSIONS: These results illustrate the challenge of reliably measuring individual change in fatigue with a level of confidence required for intervention. Optimizing clinically useful measurement of intra-individual differences over time continues to pose a challenge for PROs.

Modulation of the host innate immune and inflammatory response by translocated bacterial proteins.

Bacterial secretion systems play a central role in interfering with host inflammatory responses to promote replication in tissue sites. Many intracellular bacteria utilize secretion systems to promote their uptake and survival within host cells. An intracellular niche can help bacteria avoid killing by phagocytic cells, and may limit host sensing of bacterial components. Secretion systems can also play an important role in limiting host sensing of bacteria by translocating proteins that disrupt host immune signalling pathways. Extracellular bacteria, on the other hand, utilize secretion systems to prevent uptake by host cells and maintain an extracellular niche. Secretion systems, in this case, limit sensing and inflammatory signalling which can occur as bacteria replicate and release bacterial products in the extracellular space. In this review, we will cover the common mechanisms used by intracellular and extracellular bacteria to modulate innate immune and inflammatory signalling pathways, with a focus on translocated proteins of the type III and type IV secretion systems.

A comparison of web-based versus print-based decision AIDS for prostate cancer screening: participants' evaluation and utilization.

BACKGROUND: Patient decision aids facilitate informed decision making for medical tests and procedures that have uncertain benefits. OBJECTIVE: To describe participants' evaluation and utilization of print-based and web-based prostate cancer screening decision aids that were found to improve decisional outcomes in a prior randomized controlled trial. DESIGN: Men completed brief telephone interviews at baseline, one month, and 13 months post-randomization. PARTICIPANTS: Participants were primary care patients, 45-70 years old, who received the print-based (N = 628) or web-based decision aid (N = 625) and completed the follow-up assessments. MAIN MEASURES: We assessed men's baseline preference for web-based or print-based materials, time spent using the decision aids, comprehension of the overall message, and ratings of the content. KEY RESULTS: Decision aid use was self-reported by 64.3 % (web) and 81.8 % (print) of participants. Significant predictors of decision aid use were race (white vs. non-white, OR = 2.43, 95 % CI: 1.77, 3.35), higher education (OR = 1.68, 95 % CI: 1.06, 2.70) and trial arm (print vs. web, OR = 2.78, 95 % CI: 2.03, 3.83). Multivariable analyses indicated that web-arm participants were more likely to use the website when they preferred web-based materials (OR: 1.91, CI: 1.17, 3.12), whereas use of the print materials was not significantly impacted by a preference for print-based materials (OR: 0.69, CI: 0.38, 1.25). Comprehension of the decision aid message (i.e., screening is an individual decision) did not significantly differ between arms in adjusted analyses (print: 61.9 % and web: 68.2 %, p = 0.42). CONCLUSIONS: Decision aid use was independently influenced by race, education, and the decision aid medium, findings consistent with the 'digital divide.' These results suggest that when it is not possible to provide this age cohort with their preferred decision aid medium, print materials will be more highly used than web-based materials. Although there are many advantages to web-based decision aids, providing an option for print-based decision aids should be considered.

Host stress drives tolerance and persistence: The bane of anti-microbial therapeutics.

Antibiotic resistance, typically associated with genetic changes within a bacterial population, is a frequent contributor to antibiotic treatment failures. Antibiotic persistence and tolerance, which we collectively term recalcitrance, represent transient phenotypic changes in the bacterial population that prolong survival in the presence of typically lethal concentrations of antibiotics. Antibiotic recalcitrance is challenging to detect and investigate-traditionally studied under in vitro conditions, our understanding during infection and its contribution to antibiotic failure is limited. Recently, significant progress has been made in the study of antibiotic-recalcitrant populations in pathogenic species, including Mycobacterium tuberculosis, Staphylococcus aureus, Salmonella enterica, and Yersiniae, in the context of the host environment. Despite the diversity of these pathogens and infection models, shared signals and responses promote recalcitrance, and common features and vulnerabilities of persisters and tolerant bacteria have emerged. These will be discussed here, along with progress toward developing therapeutic interventions to better treat recalcitrant pathogens.

Estradiol mediates greater germinal center responses to influenza vaccination in female than male mice.

Adult females of reproductive age develop greater antibody responses to inactivated influenza vaccines (IIV) than males. How sex, age, and sex steroid concentrations impact B cells and durability of IIV-induced immunity and protection over 4 months post-vaccination (mpv) was analyzed. Vaccinated adult females had greater germinal center B cell and plasmablast frequencies in lymphoid tissues, higher neutralizing antibody responses 1-4 mpv, and better protection against live H1N1 challenge than adult males. Aged mice, regardless of sex, had reduced B cell frequencies, less durable antibody responses, and inferior protection after challenge than adult mice, which correlated with diminished estradiol among aged females. To confirm that greater IIV-induced immunity was caused by sex hormones, four core genotype (FCG) mice were used, in which the testes-determining gene, Sry, was deleted from chromosome Y (ChrY) and transferred to Chr3 to separate gonadal sex (i.e., ovaries or testes) from sex chromosome complement (i.e., XX or XY complement). Vaccinated, gonadal female FCG mice (XXF and XYF) had greater numbers of B cells, higher antiviral antibody titers, and reduced pulmonary virus titers following live H1N1 challenge than gonadal FCG males (XYM and XXM). To establish that lower estradiol concentrations cause diminished immunity, adult and aged females received either a placebo or estradiol replacement therapy prior to IIV. Estradiol replacement significantly increased IIV-induced antibody responses and reduced morbidity after the H1N1 challenge among aged females. These data highlight that estradiol is a targetable mechanism mediating greater humoral immunity following vaccination among adult females.IMPORTANCEFemales of reproductive ages develop greater antibody responses to influenza vaccines than males. We hypothesized that female-biased immunity and protection against influenza were mediated by estradiol signaling in B cells. Using diverse mouse models ranging from advanced-age mice to transgenic mice that separate sex steroids from sex chromosome complement, those mice with greater concentrations of estradiol consistently had greater numbers of antibody-producing B cells in lymphoid tissue, higher antiviral antibody titers, and greater protection against live influenza virus challenge. Treatment of aged female mice with estradiol enhanced vaccine-induced immunity and protection against disease, suggesting that estradiol signaling in B cells is critical for improved vaccine outcomes in females.

Monitoring of health-related quality of life and symptoms in prostate cancer survivors: a randomized trial.

BACKGROUND: Routine symptom and health-related quality of life (HRQOL) assessments can engage patients, give provider feedback, and improve doctor/patient communication. OBJECTIVE: We compared the impact of a technology-assisted symptom monitoring system versus usual care on HRQOL and doctor/patient communication in early-stage prostate cancer (PCa) survivors. METHODS: Men (N = 94) were on average 62-years old, mostly African American (AA; 61.7%), and 10-19 months post-treatment. They were randomized to symptom monitoring plus feedback (SM + F; n = 49) or usual care (UC; n = 45). SM+F participants completed a 12-item telephoneassisted monitoring intervention. All participants completed a baseline and 2 follow-up interviews. RESULTS: Among the SM+F participants, perceptions of the monitoring system were positive: 97.1% endorsed it as easy/very easy to use and 85% felt all patients could benefit from it. At baseline, men reported favorable general and cancer-specific HRQOL and doctor/patient communication, but poorer urinary and sexual function. Although there was no overall impact of the intervention, post hoc exploratory analyses indicated that among AA men, those who received SM+F improved relative to UC on doctor/patient communication (P < .05), general HRQOL (P < .06), and sexual function (P < .05). LIMITATIONS: Variability in survivor follow-up care, limited access to eligible participants, and minimal physician training in the use of reports likely decreased physician investment. CONCLUSION: Overall, PCa survivors were receptive to this monitoring system. Exploratory analyses suggest that this technology-assisted monitoring system may be of particular benefit to African American men. Additional studies with larger samples, more intervention time-points, and increased physician training are needed to strengthen the intervention's impact.

Estradiol Mediates Greater Germinal Center Responses to Influenza Vaccination in Female than Male Mice.

Adult females of reproductive ages develop greater antibody responses to inactivated influenza vaccine (IIV) than males. How sex, age, and sex steroid changes impact B cells and durability of IIV-induced immunity and protection over 4-months post-vaccination (mpv) was analyzed. Vaccinated adult females had greater germinal center (GC) B cell and plasmablast frequencies in lymphoid tissues, higher neutralizing antibody responses 1-4 mpv, and better protection against live H1N1 challenge than adult males. Aged mice, regardless of sex, had reduced B cell frequencies, less durable antibody responses, and inferior protection after challenge than adult mice, which correlated with diminished estradiol among aged females. To confirm that greater IIV-induced immunity was caused by sex hormones, four core genotype (FCG) mice were used, in which the testes determining gene, Sry, was deleted from ChrY and transferred to Chr3, to separate gonadal sex (i.e., ovaries or testes) from sex chromosome complement (i.e., XX or XY complement). Vaccinated, gonadal female FCG mice (XXF and XYF) had greater numbers of B cells, higher antiviral antibody titers, and reduced pulmonary virus titers following live H1N1 challenge than gonadal FCG males (XYM and XXM). To establish that lower estradiol concentrations cause diminished immunity, adult and aged females received either a placebo or estradiol replacement therapy prior to IIV. Estradiol replacement significantly increased IIV-induced antibody responses and reduced morbidity after the H1N1 challenge among aged females. These data highlight that estradiol is a targetable mechanism mediating greater humoral immunity following vaccination among adult females.

A novel rodent model of chronic spinal implant-associated infection.

BACKGROUND CONTEXT: Bacterial infection of spinal instrumentation is a significant challenge in spinal fusion surgery. Although the intraoperative local application of powdered vancomycin is common practice for mitigating infection, the antimicrobial effects of this route of administration are short-lived. Therefore, novel antibiotic-loaded bone grafts as well as a reliable animal model to permit the testing of such therapies are needed to improve the efficacy of infection reduction practices in spinal fusion surgery. PURPOSE: This study aims to establish a clinically relevant rat model of spinal implant-associated infection to permit the evaluation of antimicrobial bone graft materials used in spinal fusion. STUDY DESIGN: Rodent study of chronic spinal implant-associated infection. METHODS: Instrumentation anchored in and spanning the vertebral bodies of L4 and L5 was inoculated with bioluminescent methicillin-resistant Staphylococcus aureus bacteria (MRSA). Infection was monitored using an in vivo imaging system (IVIS) for 8 weeks. Spines were harvested and evaluated histologically, and colony-forming units (CFUs) were quantified in harvested implants and spinal tissue. RESULTS: Postsurgical analysis of bacterial infection in vivo demonstrated stratification between MRSA and phosphate-buffered saline (PBS) control groups during the first 4 weeks of the 8-week infection period, indicating the successful establishment of acute infection. Over the 8-week chronic infection period, groups inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU demonstrated significantly higher bioluminescence than groups inoculated with PBS control (p = 0.009 and p = 0.041 respectively). Histological examination at 8 weeks postimplantation revealed the presence of abscesses localized to implant placement in all MRSA inoculation groups, with the most pervasive abscess formation in samples inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU. Quantification of CFU plated from harvested spinal tissue at 8 weeks post-implantation revealed the 1 × 105 MRSA CFU inoculation group as the only group with a significantly greater average CFU count compared to PBS control (p = 0.017). Further, CFU quantification from harvested spinal tissue was greater than CFU quantification from harvested implants across all inoculation groups. CONCLUSION: Our model demonstrated that the inoculation dosage of 1 × 105 MRSA CFU exhibited the most robust chronic infection within instrumented vertebral bodies. This dosage had the greatest difference in bioluminescence signal from control (p < 0.01), the lowest mortality (0% compared to 50% for samples inoculated with 1 × 106 MRSA CFU), and a significantly higher amount of CFUs from harvested spine samples than CFUs from control harvested spine samples. Further, histological analysis confirmed the reliability of this novel rodent model of implanted-associated infection to establish infection and biofilm formation of MRSA for all inoculation groups. CLINICAL SIGNIFICANCE: This model is intended to simulate the infection of instrumentation used in spinal fusion surgeries concerning implant locality and material. This model may evaluate potential antimicrobial and osteogenic biomaterials and investigate the relationship between implant-associated infection and failed fusion.

Integrating Tobacco Use Assessment and Treatment in the Oncology Setting: Quality Improvement Results from the Georgetown Lombardi Smoking Treatment and Recovery Program.

As part of the NCI's Cancer Center Cessation (C3i) initiative, we initiated, expanded, and maintained an evidence-based tobacco treatment program at the Georgetown Lombardi Comprehensive Cancer Center. We present a quality improvement (QI) assessment of the implementation process and patient-level outcomes. At two hematology/oncology outpatient clinical sites, five oncology-based teams (clinical administrators, clinical staff, pharmacy, information technology, and tobacco treatment staff) developed implementation strategies for opt-out patient assessment and enrollment, centralized tobacco treatment, audit, feedback, and staff training. Among eligible patients (tobacco use in ≤30 days), we assessed demographic, clinical, and tobacco-related characteristics to examine predictors of enrollment (baseline completed), treatment engagement (≥one sessions completed), and self-reported 7-day abstinence (6 months post-enrollment). Across both sites, medical assistants screened 19,344 (82.4%) patients for tobacco use, which identified 1345 (7.0%) current tobacco users, in addition to 213 clinician referrals. Of the 687/1256 (54.7%) eligible patients reached, 301 (43.8%) enrolled, and 199 (29.0%) engaged in treatment, of whom 74.5% were African American and 68% were female. At the larger site, significant multivariate predictors of enrollment included African American race (vs. white/other) and clinician referral (vs. MA assessment). Treatment engagement was predicted by greater nicotine dependence, and abstinence (27.4%) was predicted by greater treatment engagement. In summary, the systematic utilization of multiple oncology-based teams and implementation strategies resulted in the development and maintenance of a high-quality, population-based approach to tobacco treatment. Importantly, these strategies addressed inequities in tobacco treatment, as the program reached and engaged a majority-African-American patient population. Finally, the opt-out patient assessment strategy has been implemented in multiple oncology settings at MedStar Health through the Commission on Cancer's Just Ask program.

Protocol for detecting Yersinia pseudotuberculosis nitric oxide exposure during in vitro growth.

Yersinia pseudotuberculosis (Yptb) is a bacterial pathogen that causes foodborne illness. Defense against the host antimicrobial gas, nitric oxide (NO), by the bacterial NO-detoxifying gene, hmp, promotes Yptb replication in mouse models of infection. Here, we detail the use of fluorescent signals as readouts for NO exposure within individual cells and subsequent detection of heterogeneity within a population, using single-cell imaging and analysis. This protocol quantifies NO exposure in culture, without capturing the full complexity of the host environment. For complete details on the use and execution of this protocol, please refer to Patel et al. (2021).

Psychological predictors of delayed active treatment following active surveillance for low-risk prostate cancer: The Patient REported outcomes for Prostate cARE prospective cohort study.

Objectives: In a prospective, comparative effectiveness study, we assessed clinical and psychological factors associated with switching from active surveillance (AS) to active treatment (AT) among low-risk prostate cancer (PCa) patients. Methods: Using ultra-rapid case identification, we conducted pretreatment telephone interviews (N = 1139) with low-risk patients (PSA ≤ 10, Gleason≤6) and follow-up interviews 6-10 months post-diagnosis (N = 1057). Among men remaining on AS for at least 12 months (N = 601), we compared those who continued on AS (N = 515) versus men who underwent delayed AT (N = 86) between 13 and 24 months, using Cox proportional hazards models. Results: Delayed AT was predicted by time dependent PSA levels (≥10 vs. <10; HR = 5.6, 95% CI 2.4-13.1) and Gleason scores (≥7 vs. ≤6; adjusted HR = 20.2, 95% CI 12.2-33.4). Further, delayed AT was more likely among men whose urologist initially recommended AT (HR = 2.13, 95% CI 1.07-4.22), for whom tumour removal was very important (HR = 2.18, 95% CI 1.35-3.52), and who reported greater worry about not detecting disease progression early (HR = 1.67, 1.05-2.65). In exploratory analyses, 31% (27/86) switched to AT without evidence of progression, while 4.7% (24/515) remained on AS with evidence of progression. Conclusions: After adjusting for clinical evidence of disease progression over the first year post-diagnosis, we found that urologists' initial treatment recommendation and patients' early treatment preferences and concerns about AS each independently predicted undergoing delayed AT during the second year post-diagnosis. These findings, along with almost one-half undergoing delayed AT without evidence of progression, suggest the need for greater decision support to remain on AS when it is clinically indicated.

A Randomized Trial of Telephone-Based Smoking Cessation Treatment in the Lung Cancer Screening Setting.

BACKGROUND: Lung cancer mortality is reduced via low-dose computed tomography screening and treatment of early-stage disease. Evidence-based smoking cessation treatment in the lung screening setting can further reduce mortality. We report the results of a cessation trial from the National Cancer Institute's Smoking Cessation at Lung Examination collaboration. METHODS: Eligible patients (n = 818) aged 50-80 years were randomly assigned (May 2017-January 2021) to the intensive vs minimal arms (8 vs 3 phone sessions plus 8 vs 2 weeks of nicotine patches, respectively). Bio-verified (primary) and self-reported 7-day abstinence rates were assessed at 3, 6, and 12 months post random assignment. Logistic regression analyses evaluated the effects of study arm. All statistical tests were 2-sided. RESULTS: Participants reported 48.0 (SD = 17.2) pack-years, and 51.6% were not ready to quit in less than 30 days. Self-reported 3-month quit rates were statistically significantly higher in the intensive vs minimal arm (14.3% vs 7.9%; odds ratio [OR] = 2.00, 95% confidence interval [CI] = 1.26 to 3.18). Bio-verified abstinence was lower but with similar relative differences between arms (9.1% vs 3.9%; OR = 2.70, 95% CI = 1.44 to 5.08). Compared with the minimal arm, the intensive arm was more effective among those with greater nicotine dependence (OR = 3.47, 95% CI = 1.55 to 7.76), normal screening results (OR = 2.58, 95% CI = 1.32 to 5.03), high engagement in counseling (OR = 3.03, 95% CI = 1.50 to 6.14), and patch use (OR = 2.81, 95% CI = 1.39 to 5.68). Abstinence rates did not differ statistically significantly between arms at 6 months (OR = 1.2, 95% CI = 0.68 to 2.11) or 12 months (OR = 1.4, 95% CI = 0.82 to 2.42). CONCLUSIONS: Delivering intensive telephone counseling and nicotine replacement with lung screening is an effective strategy to increase short-term smoking cessation. Methods to maintain short-term effects are needed. Even with modest quit rates, integrating cessation treatment into lung screening programs may have a large impact on tobacco-related mortality.

Modifications to the peptidoglycan backbone help bacteria to establish infection.

Bacterial pathogens that colonize mucosal surfaces have acquired resistance to antimicrobials that are abundant at these sites. One of the main antimicrobials present on mucosal surfaces is lysozyme, a muramidase that hydrolyzes the peptidoglycan backbone of bacteria. Cleavage of the peptidoglycan backbone leads to bacterial cell death and lysis, which releases bacterial fragments, including peptidoglycan, at the site of infection. Peptidoglycan fragments can be recognized by host receptors and initiate an immune response that will aid in clearing infection. Many mucosal pathogens modify the peptidoglycan residues surrounding the cleavage site for lysozyme to avoid peptidoglycan degradation and the release of these proinflammatory fragments. This review will focus specifically on peptidoglycan modifications, their role in lysozyme resistance, and downstream effects on the host immune response to infection.