Microbial signatures in the lower airways of mechanically ventilated COVID19 patients associated with poor clinical outcome

Mortality among patients with COVID-19 and respiratory failure is high and there are no known lower airway biomarkers that predict clinical outcome. We investigated whether bacterial respiratory infections and viral load were associated with poor clinical outcome and host immune tone. We obtained bacterial and fungal culture data from 589 critically ill subjects with COVID-19 requiring mechanical ventilation. On a subset of the subjects that underwent bronchoscopy, we also quantified SARS-CoV-2 viral load, analyzed the microbiome of the lower airways by metagenome and metatranscriptome analyses and profiled the host immune response. We found that isolation of a hospital-acquired respiratory pathogen was not associated with fatal outcome. However, poor clinical outcome was associated with enrichment of the lower airway microbiota with an oral commensal (Mycoplasma salivarium), while high SARS-CoV-2 viral burden, poor anti-SARS-CoV-2 antibody response, together with a unique host transcriptome profile of the lower airways were most predictive of mortality. Collectively, these data support the hypothesis that 1) the extent of viral infectivity drives mortality in severe COVID-19, and therefore 2) clinical management strategies targeting viral replication and host responses to SARS-CoV-2 should be prioritized.

The clinical significance of implant stability quotient (ISQ) measurements: A literature review.

Implant stability quotients (ISQ values) are obtained in dental clinical practice on a non-invasive basis by resonance frequency measurement rapidly after surgical placement of implants. The ISQ-values are used as indicator for mechanical implant stability, and are believed to have predictive power for clinical outcome. It is the aim of this review to provide a synopsis of all factors described in the literature that influence ISQ measurements by performing an exhaustive literature review; moreover, this review aims at elucidating the key factors relevant for a rapid clinical predictive assessment. We searched systematically and exhaustively all major databases for publications relating to ISQ measurement methodology and for ISQ-influencing factor analyses. The reports identified were ordered in experimental (preclinical) studies and in clinical publications. We were able to identify 13 basic factors influencing ISQ-measurements. Among these, local bone quality, playing a key role in such measurements, was subdivided in four specific subfactors; thus a total of 17 individual factors was identified and reported to influence ISQ-measurements. A comprehensive list of these factors is provided in Table-form. A critical analysis points out that only 6 of these factors are of a sound predictive power useful for a rapid clinical assessment; and only two of these factors appear to have a well-documented scientific basis.

The vicious circle between mitochondrial oxidative stress and dynamic abnormality mediates triethylene glycol dimethacrylate-induced preodontoblast apoptosis.

Oxidative stress (OS) plays crucial roles in triethylene glycol dimethacrylate (TEGDMA, a major component in dental resin)-induced apoptosis of dental pulp cells. Mitochondria are important target organelles for regulating the balance of OS, meanwhile, imbalance of the mitochondrial dynamic associated with mitochondrial dysfunction is one major molecular mechanism for oxidative damages. However, whether these mitochondrial dependent pathways were involved in the apoptosis of dental pulp cells induced by TDGDMA remains unclarified. We demonstrated that TEGDMA decreased viability and induced apoptosis of mouse preodontoblasts (mDPC6T cell line) in a time- and dose-dependent manner. Furthermore, TEGDMA elevated the mitochondrial OS status and induced mitochondrial dysfunction, as reflected by the significant decrease of mitochondrial membrane potential, ATP production, the activity of Complex III and citrate synthase. In this process, we detected a dramatically impaired mitochondrial dynamic that was reflected by significantly enhanced mitochondrial fragmentation. Consistently, we also found a significant enhancement of the key upstream regulators for mitochondrial fission, such as short form of optic atrophy 1, dynamic related protein 1 oligomer and Fission 1. The respective inhibition of mitochondrial OS or mitochondrial fission could mutually attenuate each other, thereby significantly preventing both mitochondrial dysfunction and cell apoptosis. In conclusion, TEGDMA-induced preodontoblasts apoptosis was mediated by the vicious circle between mitochondrial OS and dynamic abnormality, which represented a new target to prevent TEGDMA-induced dental pulp cells apoptosis.

Prevalence, awareness, treatment and control of hypertension in population older than 15 years of age in Beijing, 2013-2014 / 中华流行病学杂志

Objective: To investigate the rates on prevalence, awareness, treatment and control of hypertension in population older than 15 years of age in Beijing, 2013-2014. Methods: A cross-sectional survey was conducted in Beijing between 2013-2014. Stratified multistage random sampling method was used to select representative sample of 13 057 Chinese individuals aged over 15 years, from the general population. Blood pressure was measured for three readings at sitting position after resting for at least five minutes with an average reading recorded. A standardized structured questionnaire was developed to collect history of hypertension and antihypertensive treatment. Results: A total of 4 663 community residents aged over 15 years were hypertensive among the 13 057 individuals, with the standardized prevalence rate as 32.7%, in Beijing area. The age-standardized prevalence rates of hypertension appeared 34.6% in men and 30.8% in women. The age-and sexstandardized prevalence of hypertension rates were 33.3% in urban and 24.6% in rural areas. The prevalence of hypertension increased with age and appeared higher in men than in women, in urban than in rural residents. Among the hypertensive patients, rates of awareness, treatment and control were 66.8%, 64.6% and 31.6%, respectively. Conclusion: High prevalence of hypertension with low rates on awareness and treatment and control, appeared in the general population of Beijing. Related strategies should be developed regarding prevention, control and management of hypertension, to reduce the burden of this disease.