Transcription Elongation Factor NusA Is a General Antagonist of Rho-dependent Termination in Escherichia coli.

NusA is an essential protein that binds to RNA polymerase and also to the nascent RNA and influences transcription by inducing pausing and facilitating the process of transcription termination/antitermination. Its participation in Rho-dependent transcription termination has been perceived, but the molecular nature of this involvement is not known. We hypothesized that, because both Rho and NusA are RNA-binding proteins and have the potential to target the same RNA, the latter is likely to influence the global pattern of the Rho-dependent termination. Analyses of the nascent RNA binding properties and consequent effects on the Rho-dependent termination functions of specific NusA-RNA binding domain mutants revealed an existence of Rho-NusA direct competition for the overlappingnut(NusA-binding site) andrut(Rho-binding site) sites on the RNA. This leads to delayed entry of Rho at therutsite that inhibits the latter's RNA release process. High density tiling microarray profiles of these NusA mutants revealed that a significant number of genes, together with transcripts from intergenic regions, are up-regulated. Interestingly, the majority of these genes were also up-regulated when the Rho function was compromised. These results provide strong evidence for the existence of NusA-binding sites in different operons that are also the targets of Rho-dependent terminations. Our data strongly argue in favor of a direct competition between NusA and Rho for the access of specific sites on the nascent transcripts in different parts of the genome. We propose that this competition enables NusA to function as a global antagonist of the Rho function, which is unlike its role as a facilitator of hairpin-dependent termination.

Redundancy of primary RNA-binding functions of the bacterial transcription terminator Rho.

The bacterial transcription terminator, Rho, terminates transcription at half of the operons. According to the classical model derived from in vitro assays on a few terminators, Rho is recruited to the transcription elongation complex (EC) by recognizing specific sites (rut) on the nascent RNA. Here, we explored the mode of in vivo recruitment process of Rho. We show that sequence specific recognition of the rut site, in majority of the Rho-dependent terminators, can be compromised to a great extent without seriously affecting the genome-wide termination function as well as the viability of Escherichia coli. These terminators function optimally only through a NusG-assisted recruitment and activation of Rho. Our data also indicate that at these terminators, Rho-EC-bound NusG interaction facilitates the isomerization of Rho into a translocase-competent form by stabilizing the interactions of mRNA with the secondary RNA binding site, thereby overcoming the defects of the primary RNA binding functions.

A multipronged strategy of an anti-terminator protein to overcome Rho-dependent transcription termination.

One of the important role of Rho-dependent transcription termination in bacteria is to prevent gene expressions from the bacteriophage DNA. The transcription anti-termination systems of the lambdoid phages have been designed to overcome this Rho action. The anti-terminator protein N has three interacting regions, which interact with the mRNA, with the NusA and with the RNA polymerase. Here, we show that N uses all these interaction modules to overcome the Rho action. N and Rho co-occupy their overlapping binding sites on the nascent RNA (the nutR/tR1 site), and this configuration slows down the rate of ATP hydrolysis and the rate of RNA release by Rho from the elongation complex. N-RNA polymerase interaction is not too important for this Rho inactivation process near/at the nutR site. This interaction becomes essential when the elongation complex moves away from the nutR site. From the unusual NusA-dependence property of a Rho mutant E134K, a suppressor of N, we deduced that the N-NusA complex in the anti-termination machinery reduces the efficiency of Rho by removing NusA from the termination pathway. We propose that NusA-remodelling is also one of the mechanisms used by N to overcome the termination signals.

Nonalcoholic Fatty Liver Disease (NAFLD) and Cardiovascular Risk: Is Imaging Helpful?

Nonalcoholic Fatty Liver Disease (NAFLD) is proving to be a globally prevalent condition. Moreover, NAFLD may be an independent risk factor associated with higher cardiovascular (CVD) morbidity and mortality. Further studies are needed to assess whether NAFLD needs to be included in the atherosclerotic risk score algorithms or whether patients with NAFLD need to be screened early on to assess their CVD risk especially since imaging such as positron emission tomography can be used to assess both NAFLD and CV disease at the same time. Therefore employing cardiovascular imaging modalities to investigate the incidence, extent, and nature of atherosclerotic lesions in NAFLD may be beneficial. Additionally, whether treating NAFLD halts the progression of CVD on imaging remains to be seen. Further research to delineate NAFLD and CVD associations, deciphering screening imaging modalities, and investigating targeted interventions could improve CVD morbidity and mortality in NAFLD.

Giant mandibular osteoma, CT findings for the primary care provider.

We report a very rare case of 35-year-old female with a giant mandibular osteoma in the angle of the mandible. We highlight the importance of CT in diagnosing as well as defining the extent of this rare case so that proper management can be undertaken. We also showcase the importance of angiography to show relationship of this mass with the surrounding vessels.

Role of Periodontal Infection, Inflammation and Immunity in Atherosclerosis.

BACKGROUND: Inflammation plays a major role in the development and progression of cardiovascular disease (CVD) morbidity and mortality. The well-established relationship between periodontal disease (PD) and CVD may be causal. Left untreated, PD can lead to high systemic inflammation, thus contributing to inflammatory CVD, such as atherosclerosis. Multiple mechanisms have been proposed to elucidate the causal relationship between PD and its contribution to CVD. OBJECTIVE: This review article highlights the current evidence supporting the role of PD in the development and progression of atherosclerosis. METHODS: After creating a list of relevant medical subject heading (MeSH) terms, a systematic search within PubMed in English for each MeSH term between 2000 and 2019 was used to generate evidence for this review article. CONCLUSION: There is overwhelming evidence in the current literature that supports an association between PD and CVD that is independent of known CVD risk factors. However, the supporting evidence that PD directly causes CVD in humans continues to remain elusive. Multiple biologically plausible mechanisms have been proposed and investigated, yet most studies are limited to mouse models and in vitro cell cultures. Additional studies testing the various proposed mechanisms in longitudinal human studies are required to provide deeper insight into the mechanistic link between these 2 related diseases.

Edentulism associated with obesity: a study of four national surveys of 16 416 Swedes aged 55–84 years.

OBJECTIVE: To investigate the association between edentulism and obesity in the Swedish population aged 55­84 years over a 22-year period as a result of changes in health and socio-economic factors. MATERIAL AND METHODS: Subjects aged 55­84 years (n = 16 416) were randomly sampled from the Swedish population by Statistics Sweden on four occasions (1980­81, 1988­89, 1996­97 and 2002). Trained interviewers collected information about dental status and anthropometric, demographic, socio-economic, lifestyle and health-related factors. Statistical analyses were based on logistic regression models. RESULTS: Edentulism decreased from 43% to 14% in the age group 55­84 years from 1980 to 2002, and the proportion of subjects with removable dentures decreased from 68% to 33%. In the age group 55­74 years, the proportion of subjects with low education decreased from 60% to 28%, and the proportion of obese subjects (body mass index ≥30 kg/m²) increased from 9% to 15%. In women aged 55­74 years, the association between obesity and edentulism, adjusted for health, lifestyle and socioeconomic factors, was significant in all surveys, and the odds ratio for obesity changed from 1.64 (95% confidence interval 1.18­2.27) in 1980 to 3.17 (95% confidence interval 1.69­6.18) in 2002. In men, the association was weaker and was significant only in the sample that combined all surveys and included individuals aged 55­84 years. CONCLUSION: The study indicated an association between edentulism and obesity, which was most obvious in women aged 55­74 years.

Differential Regulation of rRNA and tRNA Transcription from the rRNA-tRNA Composite Operon in Escherichia coli.

Escherichia coli contains seven rRNA operons, each consisting of the genes for three rRNAs (16S, 23S and 5S rRNA in this order) and one or two tRNA genes in the spacer between 16S and 23S rRNA genes and one or two tRNA genes in the 3' proximal region. All of these rRNA and tRNA genes are transcribed from two promoters, P1 and P2, into single large precursors that are afterward processed to individual rRNAs and tRNAs by a set of RNases. In the course of Genomic SELEX screening of promoters recognized by RNA polymerase (RNAP) holoenzyme containing RpoD sigma, a strong binding site was identified within 16S rRNA gene in each of all seven rRNA operons. The binding in vitro of RNAP RpoD holoenzyme to an internal promoter, referred to the promoter of riRNA (an internal RNA of the rRNA operon), within each 16S rRNA gene was confirmed by gel shift assay and AFM observation. Using this riRNA promoter within the rrnD operon as a representative, transcription in vitro was detected with use of the purified RpoD holoenzyme, confirming the presence of a constitutive promoter in this region. LacZ reporter assay indicated that this riRNA promoter is functional in vivo. The location of riRNA promoter in vivo as identified using a set of reporter plasmids agrees well with that identified in vitro. Based on transcription profile in vitro and Northern blot analysis in vivo, the majority of transcript initiated from this riRNA promoter was estimated to terminate near the beginning of 23S rRNA gene, indicating that riRNA leads to produce the spacer-coded tRNA. Under starved conditions, transcription of the rRNA operon is markedly repressed to reduce the intracellular level of ribosomes, but the levels of both riRNA and its processed tRNAGlu stayed unaffected, implying that riRNA plays a role in the continued steady-state synthesis of tRNAs from the spacers of rRNA operons. We then propose that the tRNA genes organized within the spacers of rRNA-tRNA composite operons are expressed independent of rRNA synthesis under specific conditions where further synthesis of ribosomes is not needed.

Waist circumference, body mass index, and risk for stroke in older people: a 15 year longitudinal population study of 70- year-olds.

OBJECTIVES: To investigate waist circumference (WC) and body mass index (BMI) at age 70 as risk factors for stroke. DESIGN: Cohort study of 70-year-olds with 15-year follow-up. SETTING: Geriatric Medicine Department, Göteborg University, Sweden. PARTICIPANTS: Two thousand two hundred eighty-seven (1,045 men; 1,242 women) 70-year-olds examined between 1971 and 1981 in Göteborg, Sweden. MEASUREMENTS: Cox regression model was used to calculate relative risk (RR) and 95% confidence interval (CI) for first-ever stroke (fatal and nonfatal) in reference to the lowest quartiles of WC and BMI. Tests for trend were performed fitting WC and BMI in their original continuous form. RESULTS: In men and women, RRs for stroke, in the highest WC quartile were 1.65 (95% CI = 1.08-2.51) and 1.31 (95% CI = 0.88-1.92), respectively, after adjustment for cohorts, smoking habit, coronary heart disease (CHD), diabetes mellitus, total cholesterol (TC), systolic blood pressure (SBP), and height at age 70. In men, RR for stroke in the highest BMI quartile (> or=28 kg/m2) was 1.68 (95% CI = 1.12-2.53) after adjustment for cohorts, smoking habits, CHD, diabetes mellitus, TC, and SBP at age 70. In women, adjusted RRs for stroke across the BMI quartiles were not significantly different. In men, population attributable fractions of stroke were 24.8% and 25.2% for the highest quartiles of WC and BMI, respectively. CONCLUSIONS: High WC (> or =99 cm) and BMI (> or =28 kg/m2) are risks for stroke in older men but not in older women.

Comparison of bioelectrical impedance prediction equations for fat-free mass in a population-based sample of 75 y olds: the NORA study.

OBJECTIVE: We evaluated the performance of different prediction equations to estimate fat-free mass (FFM) from bioelectrical impedance analysis (BIA) in the elderly. METHODS: This study was based on 106 (51 male and 55 female) free-living 75-y-old subjects who participated in the Göteborg part of the Nordic Research on Ageing (NORA) study during 1991 and 1992. FFM predicted from BIA (FFM(GOT)) was validated against FFM estimated from measurements of total body water and total body potassium (FFM(REF)). FFM was calculated from BIA prediction equations for the elderly developed by Deurenberg et al. (FFM(WAG)) and Roubenoff et al. (FFM(FHS)). FFM also was calculated from an equation developed in subjects with a wide age range by Kyle et al. (FFM(GEN)). Bland-Altman analysis was performed to compare FFM(REF) with FFM(GOT), FFM(WAG), FFM(FHS), and FFM(GEN), respectively. FFM(GOT) also was compared with FFM derived from these published equations. RESULTS: Compared with FFM(REF), the FFM(FHS) and FFM(WAG) underestimated FFM by 2.6 and 7.9 kg in males and 4.2 and 9 kg in females, respectively. The FFM(GEN) underestimated FFM in females by 1.3 kg but not in males (mean difference, -0.04 kg). FFM calculated from the BIA equation developed in this population (FFM(GOT)) neither underestimated nor overestimated FFM as compared with FFM(REF), as expected. The differences between FFM(GOT) and FFMs predicted from these equations were of the same magnitude as that observed with FFM(REF). CONCLUSION: Different prediction equations produced different values for FFM. The age-specific equations developed in other populations underestimated FFM, whereas FFM(GEN) produced an unbiased estimate of FFM in males but not in females. Thus, the BIA prediction equation needs to be developed and validated in the population under study.

Do systolic murmurs predict mortality in the elderly? A 15-year longitudinal population study of 70-year-olds.

Systolic murmurs are common in the elderly but there is a striking paucity regarding published reports on their clinical significance and relation with mortality. This study describes prevalence of systolic murmurs in the elderly and cardiovascular diseases in 70-year-olds with or without systolic murmurs, and investigates the relation between systolic murmurs at age 70 and 15-year mortality. This cohort study is based on 973 (449 males and 524 females) 70-year-olds from Göteborg, Sweden who were examined in 1971/1972 at the Department of Geriatric Medicine, Göteborg University, and was followed-up to the year 2001. The prevalence of systolic murmur was 31% (females 36.4%, males 23.9%). Among subjects with systolic murmurs the prevalence of coronary heart disease (CHD) and hypertension was significantly higher in both sexes and congestive heart failure (CHF) in females only. Systolic murmur was a predictor for mortality in females (RR 1.49, 95% CI 1.17-1.91) but not in males (RR 1.14, 95% CI 0.89-1.49). Diagnosis of a cardiovascular disease was a significant predictor in both sexes for mortality irrespective of having systolic murmurs. In conclusion, there is a significant positive association of cardiovascular diseases with systolic murmurs in the elderly. The increased risk for mortality due to the presence of systolic murmur at age 70 is mediated through cardiovascular diseases.

The compression of morbidity debate in aging: an empirical test using the gerontological and geriatric population studies in Göteborg, Sweden (H70).

The H70 longitudinal study of aging, Göteborg, Sweden is used to empirically test the compression of morbidity theory advanced by. We reconceptualize compression as postponement of morbidity in the sense of decreasing amounts of illness for increasingly long life spans. Operationally, morbidity is defined as the average number of hospital days in the last year of life. The date of death and the date of 1-year prior to death define the risk period. The linear regression model with age at death, age at death squared, year of birth, and sex are statistically significant with the oldest having the fewest hospital days. The findings offer partial support for the compression of morbidity theory.

Olanzapine in pregnancy and breastfeeding: a review of data from global safety surveillance.

BACKGROUND: Olanzapine use has been reported during pregnancy and breastfeeding, but there are no controlled clinical trials assessing the safety of olanzapine exposure to infants and fetuses. The purpose of this report was to review and analyze prospective post-marketing cases of pregnancy and breastfeeding with olanzapine, in order to guide clinicians and women on the use of olanzapine therapy during pregnancy and/or breastfeeding. METHODS: A worldwide safety database maintained by Eli Lilly and Company was searched for all spontaneous-reported data regarding olanzapine use during pregnancy and/or breastfeeding. Cases reported prior to pregnancy outcome were considered to be prospective, and follow-up was pursued after the delivery date to assess outcome. RESULTS: Outcome data were available for 610 prospectively identified pregnancies during which olanzapine was used. The majority of women had normal births (66%), although premature births were reported in 9.8% and perinatal conditions in 8% of the pregnancies. A total of 102 pregnancies reported olanzapine treatment during breastfeeding. In these infants, the most commonly reported adverse events were somnolence (3.9%), irritability (2%), tremor (2%), and insomnia (2%), although the majority of pregnancies reported no adverse events (82.3%). CONCLUSIONS: The frequency of fetal outcomes in these prospectively identified pregnancies exposed to olanzapine did not differ from rates of outcomes reported in the general population. These data may be useful to help guide clinicians and women decide to continue, or discontinue, olanzapine therapy during pregnancy and/or breastfeeding, but should be considered within the limitations associated with spontaneously reported data. Women should notify their clinicians if they become pregnant or intend to become pregnant while being treated with olanzapine. Because of limited experience in humans, olanzapine should be used in pregnancy only when potential benefit justifies potential risk to the fetus. Olanzapine should only be considered during breastfeeding when the potential benefit justifies the potential risk to the infant.

Efficacy and safety of tadalafil 5 mg once daily for lower urinary tract symptoms suggestive of benign prostatic hyperplasia: subgroup analyses of pooled data from 4 multinational, randomized, placebo-controlled clinical studies.

OBJECTIVE: To assess the efficacy and safety of tadalafil, a phosphodiesterase 5 (PDE5) inhibitor efficacious for erectile dysfunction and lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH), in population subgroups, using pooled data from 4 international, randomized, placebo-controlled studies in men with LUTS/BPH. METHODS: The safety database included 1500 men randomized to tadalafil 5 mg once daily or placebo for 12 weeks. Changes in total International Prostate Symptom Score (IPSS), IPSS-quality of life index, and BPH impact index were examined overall, and changes in IPSS or adverse events (AEs) were examined across subgroups of interest. Treatment-group differences were assessed using analysis of covariance. RESULTS: Results of pooled data confirmed that tadalafil (N = 752) resulted in significant improvements from baseline vs placebo (N = 746) in IPSS (mean difference -2.3; P <.001), and also in BPH impact index and IPSS-quality of life index (both P <.001). Subgroup analyses demonstrated that IPSS improvements were significant regardless of baseline LUTS severity (IPSS <20/≥20), age (≤65/>65 years), recent previous use of α-blockers or PDE5 inhibitors, total testosterone level (<300/≥300 ng/dL), or prostate-specific antigen predicted prostate volume (<40/≥40 mL). [corrected] Rates of treatment emergent AEs were comparable between subgroups of baseline age (≤65/>65 years), previous PDE5 inhibitor use, and the presence or absence of pre-existing diabetes, hypertension, or cardiovascular disease (including hypertension), but somewhat higher for recent previous α-blocker use. CONCLUSION: In these pooled data analyses, tadalafil 5 mg improved LUTS/BPH across subgroups of age, LUTS severity, testosterone levels, and prostate volume. Rates of AEs were similar across the subgroups assessed.

Changes in body composition and its relation to muscle strength in 75-year-old men and women: a 5-year prospective follow-up study of the NORA cohort in Göteborg, Sweden.

OBJECTIVE: The purpose of this study was to explore the association between body composition in the elderly and subsequent changes in muscle strength during aging. METHODS: This was a longitudinal study with a 5-y follow-up. Eighty-seven men (n = 38) and women (n = 49) from a random sample of 75-y-old subjects in the Göteborg part of the Nordic Research on Aging study who were investigated at ages 75 and 80 y and were free from any major diseases at baseline were included. Body composition was estimated from bioelectrical impedance. The maximal isometric strengths of handgrip, arm flexion, and knee extension were measured on the side of the dominant hand while a subject was in a sitting position in an adjustable dynamometer chair. RESULTS: Fat-free mass decreased significantly (P < 0.001) in both sexes, but more in men. Percentage of body fat increased only in men (P < 0.05). Body height decreased in both sexes, but more in women (P < 0.001). Declines in muscle strengths were evident for all muscle groups in both sexes but more prominent in men. It was observed that body composition status at baseline, measured as fat-free mass and fat-free mass index, was a statistically significant predictor for decline in muscle strength, particularly in the extremities. CONCLUSION: Fat-free mass at age 75 y was associated with lower 5-y decline in muscle strength. This finding underscores the potential importance of fat-free mass for maintaining functional ability during aging.

Obesity in 70-year-old subjects as a risk factor for 15-year coronary heart disease incidence.

OBJECTIVE: To investigate the role of obesity in general and waist circumference (WC) and BMI in particular as risk factors for 15-year incidence of coronary heart disease (CHD) in the elderly. RESEARCH METHODS AND PROCEDURES: This prospective study was based on 1597 (737 males and 860 females) 70-year-olds free from CHD and participants of three birth cohorts examined in 1971 to 1972 (Cohort I), 1976 to 1977 (Cohort II), and 1981 to 1982 (Cohort III) at Göteborg, Sweden. Fifteen-year incidence of CHD (fatal and nonfatal) was ascertained from follow-up examinations and registers. Relative risk (RR) for first ever CHD in reference to the lowest quartiles of WC and BMI was calculated from Cox regression. RESULTS: In males, RRs for CHD in the highest WC and BMI quartiles were 1.36 [95% confidence interval (CI) 1.00 to 1.85] and 1.42 (95% CI 1.04 to 1.92), respectively, after adjustment for cohorts, smoking habits, diabetes, systolic blood pressure, and total cholesterol. In men, the risk associated with WC was independent of BMI. Neither WC nor BMI was related to CHD risk in females. After exclusion of first 5-year all-cause deaths, the adjusted RRs in the highest WC and BMI quartiles in males were 1.47 (95% CI 1.06 to 2.04) and 1.42 (1.04 to 1.92), respectively. In females, a significantly higher RR of 1.41 (95% CI 1.02 to 1.94) was observed in the second BMI quartile only after such exclusions. DISCUSSION: WC, an indicator of both central and general obesity, appears to be a stronger predictor of CHD than BMI in elderly males, but in females, obesity was not a risk factor for CHD.

ECG abnormalities in the elderly: prevalence, time and generation trends and association with mortality.

BACKGROUND AND AIMS: Electrocardiographic (ECG) abnormalities are often found in older patients but relatively few epidemiological studies have been performed. This study describes: a) cross-sectional differences in ECG abnormalities among three 70-year-old cohorts born over a period of 30 years; b) longitudinal changes in ECG abnormalities from the age of 70 to 85; and c) the relationship between ECG abnormalities at age 70 and subsequent 10- and 15-year mortality in men and women. METHODS: Trends in the prevalence of ECG abnormalities were investigated among 2100 70-year olds (994 men, 1106 women) from three cohorts born in 1901/02 (I), 1911/12 (III) and 1930 (VI). Longitudinal changes and mortality risks were investigated among 973 70-year olds (449 men and 524 women) from cohort I, which was followed from 1971 until 2001. RESULTS: In both sexes, the prevalence of ECG abnormalities was significantly lower in the later-born cohorts. From age 70 to 85, there was an increase in both men and women of large or intermediate Q-waves, left axis deviation, negative T-waves (0-5 mm), complete right bundle branch block (RBBB), and atrial fibrillation or flutter. Compared with those with no ECG abnormalities, the mortality risk was higher among individuals with large and intermediate Q-waves and negative T-waves (> or = 1 mm) in both sexes, and STJ depression > or = 0.5 mm and complete LBBB together with complete RBBB and intraventricular block; QRS > or = 0.12 sec in men only. CONCLUSIONS: ECG abnormalities are frequent in the elderly, they increase with age, and are associated with increased mortality.