Lung cancer screening utilization rate varies based on patient, provider, and hospital factors.

OBJECTIVE: Low-dose computed tomography has been proven to reduce mortality, yet utilization remains low. The purpose of this study is to identify factors that impact the utilization of lung cancer screening. METHODS: We performed a retrospective review of our institution's primary care network from November 2012 to June 2022 to identify patients who were eligible for lung cancer screening. Eligible patients were 55 to 80 years of age and current or former smokers with at least a 30 pack-year history. Analyses were performed on the screened populations and patients who met eligibility criteria but were not screened. RESULTS: A total of 35,279 patients in our primary care network were current/former smokers aged 55 to 80 years. A total of 6731 patients (19%) had a 30 pack-year or more cigarette history, and 11,602 patients (33%) had an unknown pack-year history. A total of 1218 patients received low-dose computed tomography. The utilization rate of low-dose computed tomography was 18%. The utilization rate was significantly lower (9%) if patients with unknown pack-year history were included (P < .001). The utilization rates between primary care clinic locations were significantly different (range, 18% vs 41%, P < .05). Utilization of low-dose computed tomography on multivariate analysis was associated with Black race, former smoker, chronic obstructive pulmonary disease, bronchitis, family history of lung cancer, and number of primary care visits (all P < .05). CONCLUSIONS: Lung cancer screening utilization rates are low and vary significantly on the basis of patient comorbidities, family history of lung cancer, primary care clinic location, and accurate documentation of pack-year cigarette history. The development of programs to address patient, provider, and hospital-level factors is needed to ensure appropriate lung cancer screening.

Attenuated total internal reflection Fourier transform infrared spectroscopy: a quantitative approach for kidney stone analysis.

The impact of kidney stone disease is significant worldwide, yet methods for quantifying stone components remain limited. A new approach requiring minimal sample preparation for the quantitative analysis of kidney stone components has been investigated utilizing attenuated total internal reflection Fourier transform infrared spectroscopy (ATR-FT-IR). Calcium oxalate monohydrate (COM) and hydroxylapatite (HAP), two of the most common constituents of urinary stones, were used for quantitative analysis. Calibration curves were constructed using integrated band intensities of four infrared absorptions versus concentration (weight %). The correlation coefficients of the calibration curves range from 0.997 to 0.93. The limits of detection range from 0.07 +/- 0.02% COM/HAP where COM is the analyte and HAP is the matrix, to 0.26 +/- 0.07% HAP/COM where HAP is the analyte and COM is the matrix. This study shows that linear calibration curves can be generated for the quantitative analysis of stone mixtures provided the system is well understood especially with respect to particle size.

Influences of sigmaB and agr on expression of staphylococcal enterotoxin B (seb) in Staphylococcus aureus.

In Staphylococcus aureus, enterotoxin B (SEB) is a superantigen that activates host interleukins and induces adverse responses, ranging from food poisoning to toxic shock. The alternate sigma factor, sigmaB (SigmaB), and agr are two known regulators of S. aureus. Northern blots of strain COL, a sigB-positive strain, showed an inverse correlation between sigmaB expression and seb message. seb expression was also measured as a function of a seb promoter linked to green fluorescent protein (GFP) expression in RN6390, COL, and Newman. In sigB mutants of RN6390, SH1000, COL, and Newman, seb promoter activities, as measured by GFP expression, increased relative to the respective parental types but at differing levels, suggesting alternate strain-specific regulation. In agr mutants of RN6390 and Newman, seb promoter activities were intermediate between the high level seen for the sigB mutant and the low level in the sigB active strains. A sigB agr double mutant of RN6390 displayed lower GFP expression than the agr mutant. These results suggest that while sigmaB and agr regulate seb expression in a divergent manner, other activator(s) of seb that depend on sigB expression may be present in S. aureus.

SarT influences sarS expression in Staphylococcus aureus.

Staphylococcus aureus is a gram-positive pathogen that is capable of expressing a variety of virulence proteins in response to environmental signals. Virulence protein expression in S. aureus is controlled by a network of regulatory loci including sarA and agr. The sarA/agr network is associated with the expression of cell wall-associated adhesins during exponential growth and the expression of secreted enzymes and toxins in the transition to post-exponential growth. A number of sarA homologs, including sarT and sarS, have been identified in the S. aureus genome. Previous studies have shown that sarA influences expression of both sarT and sarS in the global regulatory network. SarS has been shown to bind to the spa promoter to induce expression of protein A. SarT, one of the SarA homologs that represses hla expression and is repressible by SarA and agr, was found to induce sarS expression in this report. Northern blot analysis of sarS and spa expression in S. aureus RN6390, and the isogenic sarT, sarT sarA, and sarT agr mutants showed that while sarA regulated spa expression directly, the agr locus used sarT as an intermediary to regulate sarS, thus leading to spa repression in agr-activated cells. Gel shift and footprinting analysis showed that SarT binds to the sarS promoter, indicating that the interaction of the sarT gene product with the upstream region of sarS is likely direct. Induction of sarS and spa by SarT in agr(+) strains was confirmed by a tetracycline-inducible system to titrate sarT expression.