The production of a stable cDNA copy of an unstable RNA molecule by reverse transcription is a widely used and essential technology for many important applications, such as the construction of gene libraries, production of DNA probes, and analysis of gene expression by reverse transcriptase PCR (RT-PCR). However, the synthesis of full-length cDNAs is frequently inefficient, because the RT commonly used often produces truncated cDNAs. Synthesizing cDNA at higher temperatures, on the other hand, can provide a number of improvements. These include increasing the length of cDNA product, greater accuracy, and greater specificity during reverse transcription. Thus, an RT that remains stable and active at hot temperatures may produce better-quality cDNAs and improve the yield of full-length cDNAs. Described here is the discovery of a gene, designated trt, from the genome of the thermophilic bacterium Bacillus (Geobacillus) stearothermophilus strain 10. The gene codes for an open reading frame (ORF) similar to the ORFs encoded by group II introns found in bacteria. The gene was cloned and overexpressed in Escherichia coli, and its protein product was partially purified. Like the host organism, the Trt protein is a heat-stable protein with RT activity and can reverse transcribe RNA at temperatures as high as 75°C.

msDNAs are small, structurally unique satellite DNAs found in a number of Gram-negative bacteria. Composed of hundreds of copies of single-stranded DNA-hence the name multicopy single-stranded DNA-msDNA is actually a complex of DNA, RNA, and probably protein. These peculiar molecules are synthesized by a reverse transcription mechanism catalyzed by a reverse transcriptase (RT) that is evolutionarily related to the polymerase found in the HIV virus. The genes, including the RT gene, responsible for the synthesis of msDNA are encoded in a retron, a genetic element that is carried on the bacterial chromosome. The retron is, in fact, the first such retroelement to be discovered in prokaryotic cells. This report is a comprehensive review of the many interesting questions raised by this unique DNA and the fascinating answers it has revealed. We have learned a great deal about the structure of msDNA: how it is synthesized, the structure and functions of the RT protein required to make it, its effects on the host cell, the retron element that encodes it, its possible origins and evolution, and even its potential usefulness as a practical genetic tool. Despite the impressive gains in our understanding of the msDNAs, however, the simple, fundamental question of its natural function remains an enduring mystery. Thus, we have much more to learn about the msDNAs of bacteria.

Cilostazol is a phosphodiesterase inhibitor that has been shown to inhibit platelet activation. Endothelin is known to be the most potent endogenous growth promoting and vasoactive peptide. In patients and animal models with stroke, the level of circulating endothelin increases and complicates the recovery progress contributed by vascular constriction (an immediate pathology) and vascular proliferation (a long-term pathology). However, the effects of cilostazol on endothelin have not been explored. To demonstrate the dual-antagonizing effects of cilostazol on vasoconstriction and cell proliferation induced by endothelin, we used primary culture of mouse vascular smooth muscle cells in vitro, mouse femoral artery ex vivo, and intracranial basilar artery ex vivo. We show that the dual-inhibition effects of cilostazol are mediated by blocking endothelin-induced extracellular calcium influx. Although cilostazol does not inhibit endothelin-induced intraorganellar calcium release, blockade of extracellular calcium influx is sufficient to blunt endothelin-induced vasoconstriction. We also show that cilostazol inhibits endothelin-induced cellular proliferation by blocking extracellular calcium influx. Inhibition of cAMP-dependent protein kinase (PKA) can block anti-proliferation activity of cilostazol, confirming the downstream role of PKA in cellular proliferation. To further demonstrate the selectivity of the dual-antagonizing effects of cilostazol, we used a different phosphodiesterase inhibitor. Interestingly, sildenafil inhibits endothelin-induced vasoconstriction but not cellular proliferation in smooth muscle cells. For the first time, we show selective dual-antagonizing effects of cilostazol on endothelin. We propose that cilostazol is an excellent candidate to treat endothelin-associated diseases, such as stroke.

CTRP2 is a secreted plasma protein of the C1q family that enhances glycogen deposition and fat oxidation in cultured myotubes. Its in vivo metabolic function, however, has not been established. We show here that acute and chronic metabolic perturbations induced by fasting or high-fat feeding up-regulated the mRNA expression of Ctrp2 in white adipose tissue without affecting its circulating plasma levels. We generated a transgenic mouse model with elevated circulating levels of CTRP2 to determine its metabolic function in vivo. When fed a low-fat diet, wild-type and CTRP2 transgenic mice exhibited no metabolic phenotypes. When challenged with a high-fat diet to induce obesity, wild-type and CTRP2 transgenic mice had similar weight gain, adiposity, food intake, metabolic rate, and energy expenditure. Fasting serum lipid and adipokine profiles were also similar between the two groups of mice. However, while glucose and insulin levels in the fasted state were comparable between wild-type and CTRP2 transgenic mice, insulin levels in the fed state were consistently lower in transgenic mice. Notably, CTRP2 transgenic mice had improved insulin tolerance and a greater capacity to handle acute lipid challenge relative to littermate controls. Our results highlight, for the first time, the in vivo role of CTRP2 in modulating whole-body metabolism.

Purpose: Dental hygiene students may struggle with hand function performance during their training. Currently, there is no universal aspect of dental hygiene programs that screens for hand function issues, nor is there a protocol in place to help students who lack needed hand function skills. The purpose of this study was to examine whether hand function could improve with specific hand function exercises and whether any improvement would be evident in higher instrumentation scores as a result of hand function exercises. Methods: A convenience sample of 20 dental hygiene students consented to participate in this 6-week pilot study. At the start of the study, an occupational therapist tested the hand function of the participants using 4 occupational therapy evaluations, which tested the students’ dexterity, motor skills, and pinch and grip strength. The results were recorded, and the students began a focused, 6-week hand function exercise regimen. After 6 weeks the same 4 evaluations were performed and the pre- and post-test data were compared using both a dependent t-test and a simple ANOVA test. Results: Results revealed significant improvement in assessed hand function following the test exercises. Scores measuring the use of a periodontal probe and 11/12 explorer when compared to student scores from the previous 5 years showed no significant differences. Of the 20 students enrolled in the study, 3 students dropped out leaving 17 to complete the study. Conclusions: This study demonstrated that 6 weeks of specific hand exercises improved students’ hand function scores. However, this raised level of hand function did not carry over to increased instrumentation proficiency.

Since the Patient Protection and Affordable Care Act (ACA) has dramatically reduced the number of uninsured, the U.S. healthcare system now faces a tougher challenge: to simultaneously improve quality of care and contain costs. Accountable Care Organizations (ACOs) that hold providers across settings collectively responsible for the quality and costs of care are currently the ACA’s best hope for pursuing the dual goal. Accompanied by the ACO momentum, physicians are increasingly employed by hospitals, leading to greater physician-hospital integration. Though there is evidence that provider consolidation elevated prices, little is known about whether physician-hospital integration in ACOs improves the efficiency of healthcare delivery. This dissertation comprises three studies that seek to understand the impact of physician-hospital integration on ACO efficiency through quantitative analyses of 16 commercial ACOs operating under the Alternative Quality Contract (AQC) launched by Blue Cross and Blue Shield of Massachusetts in 2009. Study 1, Profiling AQC Participants According to Physician-Hospital Integration, investigates whether there are systemic differences in organizational structure, patient population, and composition of healthcare spending between low- and high-integrated AQC participants. The findings suggest that high-integrated organizations tend to be larger in scale, serve more affluent patients, but generally spend more. Study 2, The Impact of Physician-Hospital Integration on ACO Efficiency in Inpatient Care Delivery, examines whether integration leads to improved ACO efficiency in inpatient care delivery. The results indicate that integration is correlated with a reduction in spending aggregated over an episode of inpatient care and a decline in length of stay, with no evidence of elevated readmission rates. Study 3, The Impact of ACO Physician-Hospital Integration on Health Care Spending and Delivery Patterns, explores the association between integration and annual health care expenditures and utilization per person (inpatient, outpatient, and overall). The results suggest that integration is correlated with reduced utilization and increased expenditures; the latter is almost entirely driven by higher spending in outpatient settings. The findings of this dissertation suggest that physician-hospital integration is associated with improved efficiency in inpatient settings. However, when considering a broader scope of health services, its impact on efficiency is mixed. / 2022-10-31T00:00:00Z

BACKGROUND: Pulmonary nodules are a frequent incidental finding on CT imaging and present a diagnostic challenge to clinicians, who must balance the risks of under-evaluation and over-evaluation. Determining why patients have delayed or no follow-up for incidentally found nodules is critical to optimizing pulmonary nodule outcomes and improving early detection of potential lung malignancy. METHODS: I performed a retrospective analysis of all patients found to have new pulmonary nodules on CT imaging at Boston University Medical Center between January 1, 2011 and June December 31, 2014. The primary outcome was rate of pulmonary nodule follow-up consistent with the 2005 Fleischner Society Guidelines. I assessed how various patient demographic and clinical factors were associated with whether timely follow-up occurred in order to identify potential characteristics that may contribute to non-guideline adherent evaluation. RESULTS: Among 3916 patients found to have a pulmonary nodule during the study period, 1152 patients met study criteria. In the study population, 613 patients (53.2%) had follow-up consistent with the 2005 Fleischner Society Guidelines. In bivariate analysis, increasing nodule size, white non-Hispanic race/ethnicity, and a co-diagnosis of COPD were associated with guideline concordant follow-up. In multivariate analysis, patients with nodules measuring 7–8mm (OR 1.58, CI 1.06–2.37) and greater than 8mm (OR 1.63, CI 1.12–2.37) were more likely to have guideline concordant follow-up as were patients with a co-diagnosis of COPD (OR 2.00, CI 1.45–2.75). Hispanic patients were significantly less likely to have guideline concordant follow-up (OR 0.59, CI 0.36–0.97) compared to white non-Hispanics and uninsured patients were less likely to have guideline concordant follow-up (OR 0.56, CI 0.33–0.96) than patients with Medicare. Similar patterns were noted in analysis of nodules at highest risk of malignancy measuring 7mm or greater. CONCLUSION: Overall, the rate of guideline concordant pulmonary nodule follow-up evaluation was found to be low. Guideline concordant follow-up was significantly associated with nodule size and presence of COPD, while delayed or absent follow-up was associated with Hispanic ethnicity and lack of insurance. While these factors may highlight potential targets for quality improvement, further research is needed to better understand the complexities in delivering guideline concordant care to patients in order to improve pulmonary nodule outcomes.

No description available.

Worldwide, the prevalence of overweight and obese individuals is increasing at a drastic rate. This has created a major public health challenge and has a profound impact on the healthcare system in the United States, both in terms of health and economics. Obesity is a complex health issue and the reasons for its increase in prevalence is multifaceted. Primary care providers (PCPs) are in a unique position to intervene and facilitate healthy weight loss goals for overweight and obese patients. However, an evaluation of the primary care system found that obese patients are underdiagnosed and even many of those diagnosed are not given an obesity management plan. Existing weight loss programs are challenged by high attrition rates, weight regain, resource-intensive requirements, and poor scalability. Furthermore, there are provider barriers that include limited visit time, inadequate reimbursement, lack of training, and incompetency. Technology-assisted interventions have the potential to address these issues through time and cost savings, improved feedback, enhanced self-monitoring, and convenience of use. Wearable activity monitors are growing at a fast rate and are integrating into individuals’ everyday lives. Existing research has provided mixed evidence on the efficacy of wearable activity monitors and what role they have in weight loss management. There is data to support that these monitors could be useful in increasing weight loss and physical activity and could be as effective as standard of care. These studies are limited by the use of older models of activity monitors, short study duration times, and study populations which are lacking diversity in age, gender, and race. The proposed study will compare weight loss and physical activity changes in overweight and obese individuals in the primary care setting utilizing a wearable activity monitor compared to standard of care. This study will use current technology, will be conducted over a duration of two years, and will focus on recruiting a diverse group of participants in age, gender, and race. The final goal is to create a better understanding of how these monitors could be potentially used by both providers and patients to aid in weight loss management. As wearable technology becomes more embedded in people’s everyday lives, it is important to have a better understanding of how it affects individual’s health. This will allow PCPs to be better equipped to individualize care and council their overweight and obese patients.

No description available.