On the mechanisms of brain blood flow regulation during hypoxia.

The brain requires an uninterrupted supply of oxygen and nutrients to support the high metabolic needs of billions of nerve cells processing information. In low oxygen conditions, increases in cerebral blood flow maintain brain oxygen delivery, but the cellular and molecular mechanisms responsible for dilation of cerebral blood vessels in response to hypoxia are not fully understood. This article presents a systematic review and analysis of data reported in studies of these mechanisms. Our primary outcome measure was the percent reduction of the cerebrovascular response to hypoxia in conditions of pharmacological or genetic blockade of specific signaling mechanisms studied in experimental animals or in humans. Selection criteria were met by 28 articles describing the results of animal studies and six articles describing the results of studies conducted in humans. Selected studies investigated the potential involvement of various neurotransmitters, neuromodulators, vasoactive molecules and ion channels. Of all the experimental conditions, blockade of adenosine-mediated signaling and inhibition of ATP-sensitive potassium (KATP) channels had the most significant effect in reducing the cerebrovascular response to hypoxia (by 49% and 37%, respectively). Various degree reductions of the hypoxic response were also reported in studies which investigated the roles of nitric oxide, arachidonic acid derivates, catecholamines and hydrogen sulphide, amongst others. However, definitive conclusions about the importance of these signaling pathways cannot be drawn from the results of this analysis. In conclusion, there is significant evidence that one of the key mechanisms of hypoxic cerebral vasodilation (accounting for ∼50% of the response) involves the actions of adenosine and modulation of vascular KATP channels. However, recruitment of other vasodilatory signaling mechanisms is required for the full expression of the cerebrovascular response to hypoxia.

Complications and treatment errors in periodontal therapy in medically compromised patients.

Patients who are medically compromised may be at an increased risk of complications and treatment errors following periodontal therapy. A review of the evidence on the topic is presented, in relation to the type of complication reported, of periodontal treatment, and of patients' medical status. Further, a framework for risk assessment and appropriate treatment modifications is introduced, with the aim of facilitating the management of patients with existing comorbidities and reducing the incidence of treatment complications.

Treatment of periodontitis and C-reactive protein: A systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: Systemic inflammation is implicated in the onset and progression of several chronic diseases. Periodontitis is a potential trigger of systemic inflammation. PURPOSE: To comprehensively appraise all the evidence on the effects of the treatment of periodontitis on systemic inflammation assessed by serum C-reactive protein (CRP) levels. DATA SOURCES: Six electronic databases were searched up to 10 February 2022 to identify and select articles in English language only. STUDY SELECTION: Twenty-six randomized controlled clinical trials reporting changes amongst 2579 participants about CRP levels at 6 months or more after treatment. DATA EXTRACTION: Two reviewers independently extracted data and rated the quality of studies. Meta-analyses were performed using random and fixed effect models. RISK OF BIAS: Risk of bias (RoB 2.0 tool) and quality of evidence (GRADEpro GDT tool) analyses were completed. DATA SYNTHESIS: Treatment of periodontitis reduced CRP levels by 0.69 mg/L (95% confidence interval: -0.97 to -0.40) after 6 months, but limited evidence was retrieved from studies with longer follow-ups. Similar findings were observed in participants with other co-morbidities in addition to periodontitis. Greatest reductions were observed in participants with concentrations of CRP >3 mg/L at baseline. LIMITATIONS: High level of heterogeneity. CONCLUSIONS: Treatment of periodontitis reduces serum CRP levels (up to 6 months follow-up) to a degree equivalent to that observed after traditional lifestyle or drug interventions. This evidence supports a causal association between periodontitis and systemic inflammation.

Invasive dental treatment and acute vascular events: A systematic review and meta-analysis.

BACKGROUND: Acute infection/inflammation increases the risk of acute vascular events (AVEs). Invasive dental treatments (IDTs) trigger short-term acute inflammation. PURPOSE: The aim of this work is to critically appraise the evidence linking IDTs and AVEs. DATA SOURCES: Six bibliographical databases were searched up to 31 August 2021. A systematic review following PRISMA guidelines was performed. STUDY SELECTION: Intervention and observational studies reporting any AVEs following IDT were included. DATA EXTRACTION: Two reviewers independently extracted data and rated the quality of studies. Data were pooled using fixed-effect, inverse variance weights analysis. RISK OF BIAS: Risk of bias was assessed by the Newcastle-Ottawa Quality Assessment Scale for observational studies and the Cochrane Handbook-Rob 2.0 for randomized controlled trials. DATA SYNTHESIS: In 3 out of 16 clinical studies, a total of 533,175 participants, 124,344 myocardial infarctions, and 327,804 ischaemic strokes were reported. Meta-analysis confirmed that IDT did not increase incidence ratios (IR) for combined vascular events either at 1-4 weeks (IR of 1.02, 95% CIs: 0.92 to 1.13) and at 5-8 weeks (IR of 1.04, 95% CIs: 0.97 to1.10) after treatment. LIMITATIONS: A high level of heterogeneity (study designs and time point assessments) was found. CONCLUSION: Patients who received IDT exhibited no substantial increase in vascular risk over 8 weeks post treatment.

Recurrence and progression of periodontitis and methods of management in long-term care: A systematic review and meta-analysis.

AIM: To systematically review the literature to evaluate the recurrence of disease of people in long-term supportive periodontal care (SPC), previously treated for periodontitis, and determine the effect of different methods of managing recurrence. The review focused on stage IV periodontitis. MATERIALS AND METHODS: An electronic search was conducted (until May 2020) for prospective clinical trials. Tooth loss was the primary outcome. RESULTS: Twenty-four publications were retrieved to address recurrence of disease in long-term SPC. Eight studies were included in the meta-analyses for tooth loss, and three studies for disease progression/recurrence (clinical attachment level [CAL] loss ≥2 mm). For patients in SPC of 5-20 years, prevalence of losing more than one tooth was 9.6% (95% confidence interval [CI] 5%-14%), while experiencing more than one site of CAL loss ≥2 mm was 24.8% (95% CI 11%-38%). Six studies informed on the effect of different methods of managing recurrence, with no clear evidence of superiority between methods. No data was found specifically for stage IV periodontitis. CONCLUSIONS: A small proportion of patients with stage III/IV periodontitis will experience tooth loss in long-term SPC (tendency for greater prevalence with time). Regular SPC appears to be important for reduction of tooth loss. No superior method to manage disease recurrence was found.

Impact of the treatment of periodontitis on systemic health and quality of life: A systematic review.

AIM: To investigate the effect of treatment of periodontitis on systemic health outcomes, pregnancy complications, and associated quality of life. MATERIALS AND METHODS: Systematic electronic searches were conducted to identify randomized controlled trials with minimum 6-month follow-up and reporting on the outcomes of interest. Qualitative and quantitative analyses were performed as deemed suitable. RESULTS: Meta-analyses confirmed reductions of high-sensitivity C-reactive protein (hs-CRP) [0.56 mg/L, 95% confidence interval (CI) (-0.88, -0.25), p < .001]; interleukin (IL)-6 [0.48 pg/ml, 95% CI (-0.88, -0.08), p = .020], and plasma glucose [1.33 mmol/l, 95% CI (-2.41, -0.24), p = .016], and increase of flow-mediated dilation (FMD) [0.31%, 95% CI (0.07, 0.55), p = .012] and diastolic blood pressure [0.29 mmHg, 95% CI (0.10, 0.49), p = .003] 6 months after the treatment of periodontitis. A significant effect on preterm deliveries (<37 weeks) was observed [0.77 risk ratio, 95% CI (0.60, 0.98), p = .036]. Limited evidence was reported on quality-of-life (QoL) outcomes in the included studies. CONCLUSIONS: Treatment of periodontitis results in systemic health improvements including improvement in cardiometabolic risk, reduction in systemic inflammation and the occurrence of preterm deliveries. Further research is however warranted to confirm whether these changes are sustained over time. Further, appropriate QoL outcomes should be included in the study designs of future clinical trials.

Perioperative Care Pathways in Low- and Lower-Middle-Income Countries: Systematic Review and Narrative Synthesis.

BACKGROUND: Safe and effective care for surgical patients requires high-quality perioperative care. In high-income countries (HICs), care pathways have been shown to be effective in standardizing clinical practice to optimize patient outcomes. Little is known about their use in low- and middle-income countries (LMICs) where perioperative mortality is substantially higher. METHODS: Systematic review and narrative synthesis to identify and describe studies in peer-reviewed journals on the implementation or evaluation of perioperative care pathways in LMICs. Searches were conducted in MEDLINE, EMBASE, CINAHL Plus, WHO Global Index, Web of Science, Scopus, Global Health and SciELO alongside citation searching. Descriptive statistics, taxonomy classifications and framework analyses were used to summarize the setting, outcome measures, implementation strategies, and facilitators and barriers to implementation. RESULTS: Twenty-seven studies were included. The majority of pathways were set in tertiary hospitals in lower-middle-income countries and were focused on elective surgery. Only six studies were assessed as high quality. Most pathways were adapted from international guidance and had been implemented in a single hospital. The most commonly reported barriers to implementation were cost of interventions and lack of available resources. CONCLUSIONS: Studies from a geographically diverse set of low and lower-middle-income countries demonstrate increasing use of perioperative pathways adapted to resource-poor settings, though there is sparsity of literature from low-income countries, first-level hospitals and emergency surgery. As in HICs, addressing patient and clinician beliefs is a major challenge in improving care. Context-relevant and patient-centered research, including qualitative and implementation studies, would make a valuable contribution to existing knowledge.

Evidence on the accreditation of health professionals' education in the WHO Africa region: a scoping review protocol.

OBJECTIVE: This scoping review aims to map and examine the extent and type of available evidence on health professionals' education accreditation within Africa. INTRODUCTION: The demand for health professionals is unprecedentedly high globally. One response to this challenge has been expanding training through more liberal education policies, facilitating private sector participation in education service provision. Some evidence suggests that this is a double-edged sword, increasing quantity but compromising the quality of health professionals produced. Regulation can provide a framework to assure and continuously improve quality, with such regulation in place in 79% of World Health Organization African countries. However, it is unclear how much and what evidence has been generated on how accreditation happens, where it is concentrated, and the prevailing evidence gaps within this region; therefore, we propose to conduct a scoping review. INCLUSION CRITERIA: This review will include articles and dissertations focusing on the accreditation of health professionals' education in Africa. All methodological approaches and designs will be included. Conference abstracts and protocols will be excluded. METHODS: This review will be carried out according to the JBI scoping review methodology. We conducted an initial search of CINAHL and MEDLINE to identify relevant articles. This informed our selection of keywords, along with index terms, to create a comprehensive search strategy for CINAHL (EBSCOhost), MEDLINE (Ovid), Global Health (Ovid), ERIC (EBSCOhost), Web of Science Core Collection, Embase, and Scopus. Sources included will be limited to those published starting from 2000 onwards. Data will be presented using tables and charts, accompanied by a narrative summary. DETAIL OF THIS REVIEW PROJECT CAN BE FOUND IN OPEN SCIENCE FRAMEWORK: https://doi.org/10.17605/OSF.IO/W5G7T.

Circulating inflammatory cell profiling and periodontitis: A systematic review and meta-analysis.

Inflammation is a key driver of common noncommunicable diseases. Among common triggers of inflammation, chronic gingival inflammation (periodontitis) triggers a consistent humoral host inflammatory response, but little is known on its impact on circulating inflammatory cell profiles. We aimed to systematically appraise all the evidence linking periodontitis and its treatment to circulating inflammatory cell profiles. From 6 databases, 157 studies were eligible for qualitative synthesis and 29 studies for meta-analysis. Our meta-analysis showed that participants with periodontitis exhibited a significant mean increase in circulating CD4+ , CD4+ CD45RO+ , IFNγ-expressing CD4+ and CD8+ T cells, CD19+ CD27+ and CD5+ B cells, CD14+ CD16+ monocytes, and CD16+ neutrophils but decrease in CD8+ T and CD14++ CD16- monocytes. Our qualitative synthesis revealed that peripheral blood neutrophils of patients with periodontitis consistently showed elevated production of reactive oxygen species (ROS) when compared with those of healthy controls. Some evidence suggested that the treatment of periodontitis reversed the exaggerated ROS production, but limited and inconclusive data were found on several circulating inflammatory cell profiling. We conclude that periodontitis and its treatment are associated with minor but consistent alterations in circulating inflammatory cell profiles. These changes could represent key mechanisms explaining the association of periodontitis with other comorbidities such as cardiovascular disease, diabetes, and rheumatoid arthritis.