Caries-preventing effect of a hydroxyapatite-toothpaste in adults: a 18-month double-blinded randomized clinical trial

BackgroundDental caries is a worldwide challenge for public health. The aim of this 18-month double-blinded, randomized, clinical trial was to compare the caries-preventing effect of a fluoride-free, hydroxyapatite toothpaste (test) and a toothpaste with sodium fluoride (1450 ppm fluoride; positive control) in adults.MethodsThe primary endpoint was the percentage of subjects showing no increase in overall Decayed Missing Filled Surfaces (DMFS) index. The study was designed as non-inferiority trial. Non-inferiority was claimed if the upper limit of the exact one-sided 95% confidence interval for the difference of the primary endpoint DMFS between test and control toothpaste was less than the predefined margin of non-inferiority (Δ ≤ 20%).ResultsIn total, 189 adults were included in the intention-to-treat (ITT) analysis; 171 subjects finished the study per protocol (PP). According to the PP analysis, no increase in DMFS index was observed in 89.3% of subjects of the hydroxyapatite group and 87.4% of the subjects of the fluoride group. The hydroxyapatite toothpaste was not statistically inferior to a fluoride toothpaste with regard to the primary endpoint.ConclusionHydroxyapatite was proven to be a safe and efficient anticaries agent in oral care.Clinical trial registrationNCT04756557

Hypoxia increases susceptibility of non-small cell lung cancer cells to complement attack.

The complement system can be specifically targeted to tumor cells due to molecular changes on their surfaces that are recognized by complement directly or via naturally occurring antibodies. However, tumor cells often overexpress membrane-bound complement inhibitors protecting them from complement attack. We have previously shown that non-small cell lung cancer (NSCLC) cells, additionally to membrane-bound inhibitors, produce substantial amounts of soluble regulators such as factor I (FI) and factor H (FH). Since low oxygen concentration is associated with rapidly growing solid tumors, we studied how NSCLC cells protect themselves from complement attack under hypoxic conditions. Unexpectedly, mRNA levels and secretion of both FI and FH were significantly decreased already after 24 h exposure to hypoxia while cell viability measured by XTT assay and annexin V/7-AAD staining was affected only marginally. Furthermore, we observed decrease of mRNA level and loss of membrane-bound complement inhibitor CD46 and increased deposition of early (C3b) and terminal (C9) complement components on hypoxic NSCLC cells. All three complement pathways (classical, lectin and alternative) were employed to deposit C3b on cell surface. Taken together, our results imply that under hypoxic conditions NSCLC give up some of their available defense mechanisms and become more prone to complement attack

Neurofilament Light Chain (NfL) in Blood—A Biomarker Predicting Unfavourable Outcome in the Acute Phase and Improvement in the Late Phase after Stroke

Increased sensitivity of methods assessing the levels of neurofilament light chain (NfL), a neuron-specific intermediate filament protein, in human plasma or serum, has in recent years led to a number of studies addressing the utility of monitoring NfL in the blood of stroke patients. In this review, we discuss that elevated blood NfL levels after stroke may reflect several different neurobiological processes. In the acute and post-acute phase after stroke, high blood levels of NfL are associated with poor clinical outcome, and later on, the blood levels of NfL positively correlate with secondary neurodegeneration as assessed by MRI. Interestingly, increased blood levels of NfL in individuals who survived stroke for more than 10 months were shown to predict functional improvement in the late phase after stroke. Whereas in the acute phase after stroke the injured axons are assumed to be the main source of blood NfL, synaptic turnover and secondary neurodegeneration could be major contributors to blood NfL levels in the late phase after stroke. Elevated blood NfL levels after stroke should therefore be interpreted with caution. More studies addressing the clinical utility of blood NfL assessment in stroke patients are needed before the inclusion of NfL in the clinical workout as a useful biomarker in both the acute and the chronic phase after stroke

Cardioembolic and small vessel disease stroke show differences in associations between systemic C3 levels and outcome.

BACKGROUND: Activation of the complement system has been proposed to play a role in the pathophysiology of stroke. As the specific involvement of the complement proteins may be influenced by stroke etiology, we compared plasma C3 and C3a levels in patients with cardioembolic (CE) and small vessel disease (SVD) subtypes of ischemic stroke and control subjects and evaluated their association to outcome at three months and two years. METHODOLOGY/PRINCIPAL FINDINGS: Plasma C3 and C3a levels in 79 CE and 79 SVD stroke patients, sampled within 10 days and at three months after stroke, and age- and sex-matched control subjects from The Sahlgrenska Academy Study on Ischemic Stroke were measured by ELISA. Functional outcome was assesed with modified Rankin Scale. In the CE group, plasma C3 levels were elevated only in the acute phase, whereas C3a was elevated at both time points. The follow-up phase plasma C3 levels in the upper third were associated with an increased risk of unfavorable outcome at three months (OR 7.12, CI 1.72-29.46, P = 0.007) as well as after two years (OR 8.25, CI 1.61-42.28, P = 0.011) after stroke. These associations withstand adjustment for age and sex. Conversely, three-month follow-up plasma C3a/C3 level ratios in the middle third were associated with favorable outcome after two years both in the univariate analysis (OR 0.19, CI 0.05-0.82, P = 0.026) and after adjustment for age and sex (OR 0.19, CI 0.04-0.88, P = 0.033). In the SVD group, plasma C3 and C3a levels were elevated at both time points but showed no significant associations with outcome. CONCLUSIONS: Plasma C3 and C3a levels are elevated after CE and SVD stroke but show associations with outcome only in CE stroke

Characterization of the complement inhibitory function of Rhesus rhadinovirus complement control protein (RCP).

Rhesus Rhadinovirus (RRV) is currently the closest known, fully sequenced homolog of human Kaposi's sarcoma-associated herpesvirus (KSHV). Both these viruses encode complement inhibitors: KSHV-complement control protein (KCP) and RRV-complement control protein (RCP). Previously we characterized in detail the functional properties of KCP as complement inhibitor. Herein, we performed comparative analyses for two variants of RCP protein, encoded by RRV strains H26-95 and 17577. Both RCP variants and KCP inhibited human and rhesus complement when tested in hemolytic assays measuring all steps of activation via the classical and the alternative pathway. RCP variants from both RRV strains supported C3b- and C4b-degradation by factor I and decay-acceleration of the classical C3 convertase, similar to KCP. Additionally, the 17577 RCP variant accelerated decay of the alternative C3 convertase, which was not seen for KCP. In contrast to KCP, RCP showed no affinity to heparin and is the first described complement inhibitor in which the binding site for C3b/C4b does not interact with heparin. Molecular modeling shows a structural disruption in the region of RCP that corresponds to the KCP-heparin binding site. This makes RRV a superior model for future in vivo investigations of complement evasion, as RCP does not play a supportive role in viral attachment as KCP does

Attenuation of reactive gliosis in stroke-injured mouse brain does not affect neurogenesis from grafted human iPSC-derived neural progenitors

Induced pluripotent stem cells (iPSCs) or their progeny, derived from human somatic cells, can give rise to functional improvements after intracerebral transplantation in animal models of stroke. Previous studies have indicated that reactive gliosis, which is associated with stroke, inhibits neurogenesis from both endogenous and grafted neural stem/progenitor cells (NSPCs) of rodent origin. Here we have assessed whether reactive astrocytes affect the fate of human iPSC-derived NSPCs transplanted into stroke-injured brain. Mice with genetically attenuated reactive gliosis (deficient for GFAP and vimentin) were subjected to cortical stroke and cells were implanted adjacent to the ischemic lesion one week later. At 8 weeks after transplantation, immunohistochemical analysis showed that attenuated reactive gliosis did not affect neurogenesis or commitment towards glial lineage of the grafted NSPCs. Our findings, obtained in a human-to-mouse xenograft experiment, provide evidence that the reactive gliosis in stroke-injured brain does not affect the formation of new neurons from intracortically grafted human iPSC-derived NSPCs. However, for a potential clinical translation of these cells in stroke, it will be important to clarify whether the lack of effect of reactive gliosis on neurogenesis is observed also in a human-to-human experimental setting