Transcriptional programming mediated by the histone demethylase KDM5C regulates dendritic cell population heterogeneity and function.

Functional and phenotypic heterogeneity of dendritic cells (DCs) play crucial roles in facilitating the development of diverse immune responses essential for host protection. Here, we report that KDM5C, a histone lysine demethylase, regulates conventional or classical DC (cDC) and plasmacytoid DC (pDC) population heterogeneity and function. Mice deficient in KDM5C in DCs have increased proportions of cDC2Bs and cDC1s, which is partly dependent on type I interferon (IFN) and pDCs. Loss of KDM5C results in an increase in Ly6C- pDCs, which, compared to Ly6C+ pDCs, have limited ability to produce type I IFN and more efficiently stimulate antigen-specific CD8 T cells. KDM5C-deficient DCs have increased expression of inflammatory genes, altered expression of lineage-specific genes, and decreased function. In response to Listeria infection, KDM5C-deficient mice mount reduced CD8 T cell responses due to decreased antigen presentation by cDC1s. Thus, KDM5C is a key regulator of DC heterogeneity and critical driver of the functional properties of DCs.

Guideline-Concordant Therapy for Community-Acquired Pneumonia in the Hospitalized Population: A Systematic Review and Meta-analysis.

Background: A commonly used guideline for community-acquired pneumonia (CAP) is the joint American Thoracic Society and Infectious Diseases Society of America practice guideline. We aimed to investigate the effect of guideline-concordant therapy in the treatment of CAP. Methods: We systematically searched MEDLINE, Embase, CENTRAL, Web of Science, and Scopus from 2007 to December 2023. We screened citations, extracted data, and assessed risk of bias in duplicate. Primary outcomes were mortality rates, intensive care unit (ICU) admission, and length of stay. Secondary outcomes were guideline adherence, readmission, clinical cure rate, and adverse complications. We performed random-effect meta-analysis to estimate the overall effect size and assessed heterogeneity using the I2 statistics. Results: We included 17 observational studies and 82 240 patients, of which 10 studies were comparative and pooled in meta-analysis. Overall guideline adherence rate was 65.2%. Guideline-concordant therapy was associated with a statistically significant reduction in 30-day mortality rate (crude odds ratio [OR], 0.49 [95% confidence interval .34-.70; I2 = 60%]; adjusted OR, 0.49 [.37-.65; I2 = 52%]) and in-hospital mortality rate (crude OR, 0.63 [.43-.92]; I2 = 61%). Due to significant heterogeneity, we could not assess the effect of guideline-concordant therapy on length of stay, ICU admission, readmission, clinical cure rate, and adverse complications. Conclusions: In hospitalized patients with CAP, guideline-concordant therapy was associated with a significant reduction in mortality rate compared with nonconcordant therapy; however, there was limited evidence to support guideline-concordant therapy for other clinical outcomes. Future studies are needed to assess the clinical efficacy and safety of current guideline recommendations.

Addressing the physician burnout epidemic with resilience curricula in medical education: a systematic review.

BACKGROUND: A variety of stressors throughout medical education have contributed to a burnout epidemic at both the undergraduate medical education (UGME) and postgraduate medical education (PGME) levels. In response, UGME and PGME programs have recently begun to explore resilience-based interventions. As these interventions are in their infancy, little is known about their efficacy in promoting trainee resilience. This systematic review aims to synthesize the available research evidence on the efficacy of resilience curricula in UGME and PGME. METHODS: We performed a comprehensive search of the literature using MEDLINE, EMBASE, PsycINFO, Educational Resources Information Centre (ERIC), and Education Source from their inception to June 2020. Studies reporting the effect of resilience curricula in UGME and PGME settings were included. A qualitative analysis of the available studies was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Risk of bias was assessed using the ROBINS-I Tool. RESULTS: Twenty-one studies met the inclusion criteria. Thirteen were single-arm studies, 6 quasi-experiments, and 2 RCTs. Thirty-eight percent (8/21; n = 598) were implemented in UGME, while 62 % (13/21, n = 778) were in PGME. There was significant heterogeneity in the duration, delivery, and curricular topics and only two studies implemented the same training model. Similarly, there was considerable variation in curricula outcome measures, with the majority reporting modest improvement in resilience, while three studies reported worsening of resilience upon completion of training. Overall assessment of risk of bias was moderate and only few curricula were previously validated by other research groups. CONCLUSIONS: Findings suggest that resilience curricula may be of benefit to medical trainees. Resilience training is an emerging area of medical education that merits further investigation. Additional research is needed to construct optimal methods to foster resilience in medical education.

MicroRNA-9 Fine-Tunes Dendritic Cell Function by Suppressing Negative Regulators in a Cell-Type-Specific Manner.

Dendritic cells, cells of the innate immune system, are found in a steady state poised to respond to activating stimuli. Once stimulated, they rapidly undergo dynamic changes in gene expression to adopt an activated phenotype capable of stimulating immune responses. We find that the microRNA miR-9 is upregulated in both bone marrow-derived DCs and conventional DC1s but not in conventional DC2s following stimulation. miR-9 expression in BMDCs and conventional DC1s promotes enhanced DC activation and function, including the ability to stimulate T cell activation and control tumor growth. We find that miR-9 regulated the expression of several negative regulators of transcription, including the transcriptional repressor Polycomb group factor 6 (Pcgf6). These findings demonstrate that miR-9 facilitates the transition of DCs from steady state to mature state by regulating the expression of several negative regulators of DC function in a cell-type-specific manner.

Chromatin Architecture as an Essential Determinant of Dendritic Cell Function.

Epigenetics has widespread implications in a variety of cellular processes ranging from cell identity and specification, to cellular adaptation to environmental stimuli. While typically associated with heritable changes in gene expression, epigenetic mechanisms are now appreciated to regulate dynamic changes in gene expression-even in post-mitotic cells. Cells of the innate immune system, including dendritic cells (DC), rapidly integrate signals from their microenvironment and respond accordingly, undergoing massive changes in transcriptional programming. This dynamic transcriptional reprogramming relies on epigenetic changes mediated by numerous enzymes and their substrates. This review highlights our current understanding of epigenetic regulation of DC function. Epigenetic mechanisms contribute to the maintenance of the steady state and are important for precise responses to proinflammatory stimuli. Interdependence between epigenetic modifications and the delicate balance of metabolites present another layer of complexity. In addition, dynamic regulation of the expression of proteins that modify chromatin architecture in DCs significantly impacts DC function. Environmental factors, including inflammation, aging, chemicals, nutrients, and lipid mediators, are increasingly appreciated to affect the epigenome in DCs, and, in doing so, regulate host immunity. Our understanding of how epigenetic mechanisms regulate DC function is in its infancy, and it must be expanded in order to discern the mechanisms underlying the balance between health and disease states.

Complementary oligonucleotides regulate induced fit ligand binding in duplexed aptamers.

Duplexed aptamers (DAs) are engineered by hybridizing an aptamer-complementary element (ACE, e.g. a DNA oligonucleotide) to an aptamer; to date, ACEs have been presumed to sequester the aptamer into a non-binding duplex state, in line with a conformational selection-based model of ligand binding. Here, we uncover that DAs can actively bind a ligand from the duplex state through an ACE-regulated induced fit mechanism. Using a widely-studied ATP DNA aptamer and a solution-based equilibrium assay, DAs were found to exhibit affinities up to 1 000 000-fold higher than predicted by conformational selection alone, with different ACEs regulating the level of induced fit binding, as well as the cooperative allostery of the DA (Hill slope of 1.8 to 0.7). To validate these unexpected findings, we developed a non-equilibrium surface-based assay that only signals induced fit binding, and corroborated the results from the solution-based assay. Our findings indicate that ACEs regulate ATP DA ligand binding dynamics, opening new avenues for the study and design of ligand-responsive nucleic acids.

Clinical pharmacology study of Bramitob, a tobramycin solution for nebulization, in comparison with Tobi.

BACKGROUND AND OBJECTIVES: To compare in vitro characteristics and pharmacokinetics of Bramitob, a preservative-free tobramycin solution for nebulization, and Tobi in patients with cystic fibrosis (CF) and Pseudomonas aeruginosa infection. METHODS: In vitro characteristics of Bramitob and Tobi were evaluated using Pari TurboBoy/LC Plus and the Systam 290 LS nebulizers. In the randomized, double-blind, two-way crossover pharmacokinetic study, 11 patients with CF received a single nebulized dose (300mg) of Bramitob or Tobi, separated by a 7-day washout period. Plasma and sputum tobramycin concentrations were measured immediately before and over 24 hours after administration. RESULTS: Bramitob and Tobi performed alike during nebulization. The fine particle fraction was 33-37% and the mass median aerodynamic diameter was <5microm. Nine patients completed the pharmacokinetic study. Tobramycin plasma profiles after administration of Bramitob or Tobi were similar, with a peak at 90 and 72 minutes after inhalation of Bramitob and Tobi, respectively. The elimination half-life was ~5 hours for both products. The relative bioavailability of Bramitob to Tobi was 1.01, indicating comparable systemic exposure. Peak sputum concentration of tobramycin was 816 +/- 681 microg/g for Tobi and 1289 +/- 851 microg/g for Bramitob and was >400 microg/g (threshold sufficient for an antibacterial effect against P. aeruginosa) in 5 out of 9 patients receiving Tobi and 8 out of 9 patients receiving Bramitob. All adverse events were considered mild and judged not related to the study drugs. CONCLUSIONS: In vitro performance of Bramitob((R)) was similar when nebulized with Pari TurboBoy k/LC Plus and Systam 290 LS nebulizers and comparable to that of TobiThe systemic bioavailability of tobramycin was similar after administration of either Bramitob or Tobi; however, in sputum samples the tobramycin peak concentration was slightly greater after administration of Bramitob than after Tobi.

A positron emission tomography microdosing study with a potential antiamyloid drug in healthy volunteers and patients with Alzheimer's disease.

This work describes a microdosing study with an investigational, carbon 11-labeled antiamyloid drug, 1,1'-methylene-di-(2-naphthol) (ST1859), and positron emission tomography (PET) in healthy volunteers (n = 3) and patients with Alzheimer's disease (n = 6). The study aimed to assess the distribution and local tissue pharmacokinetics of the study drug in its target organ, the human brain. Before PET studies were performed in humans, the toxicologic characteristics of ST1859 were investigated by an extended single-dose toxicity study according to guidelines of the Food and Drug Administration and European Medicines Agency, which are relevant for clinical trials with a single microdose. After intravenous bolus injection of 341 +/- 21 MBq [(11)C]ST1859 (containing <11.4 nmol of unlabeled ST1859), peripheral metabolism was rapid, with less than 20% of total plasma radioactivity being in the form of unchanged parent drug at 10 minutes after administration. In both the control and patient groups, uptake of radioactivity into the brain was relatively fast (time to reach maximum concentration, 9-17 minutes) and pronounced (maximum concentration [standardized uptake value], 1.3-2.2). In both healthy volunteers and patients, there was a rather uniform distribution of radioactivity in the brain, including both amyloid-beta-rich and -poor regions, with slow washout of radioactivity (half-life, 82-185 minutes). In conclusion, these data provide important information on the blood-brain barrier penetration and metabolism of an investigational antiamyloid drug and suggest that the PET microdosing approach is a useful method to describe the target-organ pharmacokinetics of radiolabeled drugs in humans.

Clinical study of the therapeutic efficacy and safety of emedastine difumarate versus terfenadine in the treatment of seasonal allergic rhinitis.

OBJECTIVE: Emedastine is a new H1-receptor antagonist endowed with potent and selective antihistamine activity. The aim of this study was to evaluate the therapeutic efficacy and tolerability of emedastine difumarate (CAS 87233-62-3) in Caucasian patients in the treatment of seasonal allergic rhinitis as compared to terfenadine (CAS 50679-08-8). METHODS: A total of 130 patients suffering from grass pollen allergic rhinitis were randomly assigned to 14 days treatment with either emedastine difumarate (2 mg b.i.d.) or terfenadine (60 mg b.i.d.) in a double-blind, randomised, crossover design. Primary efficacy parameter was a Total Severity Symptom Score, including among symptoms nasal congestion, sneezing, rhinorrhea, nasal/throat/palate itching, eye itching and lacrimation. Safety was assessed on routine laboratory tests and recording vital signs and adverse events (AEs). RESULTS: Emedastine 2 mg b.i.d. was significantly more effective than terfenadine 60 mg b.i.d. in reducing Total Symptom Severity Score (p = 0.0258). This statistical significant difference was also obtained in controlling sneezing and rhinorrhea (p = 0.003). Moreover, both the physician and patients indicated emedastine as the preferred therapy (p < 0.01). Forty-seven drug related AEs were reported for emedastine (= 51.07 %) and 53 for terfenadine (64.15 %), most of them involving the CNS. CONCLUSION: The results of study show that emedastine difumarate is more effective than terfenadine in the symptomatic management of seasonal allergic rhinitis and is particularly active in controlling the main nasal symptoms, such as sneezing and rhinorrhea; it is safe and well tolerated in this therapeutic indication, while related AEs are less if compared to those displayed by terfenadine.

Clinical study of the therapeutic efficacy and safety of emedastine difumarate versus cetirizine in the treatment of seasonal allergic rhinitis.

OBJECTIVE: The therapeutic efficacy and tolerability of emedastine difumarate (CAS 87233-62-3) in male and female Caucasian patients with seasonal allergic rhinitis as compared to cetirizine (CAS 83881-51-0) was evaluated. METHODS: The study was designed as a double-blind, randomised, parallel groups comparison of two antihistamines administered by oral route (emedastine 4 mg o.d. versus cetirizine 10 mg o.d.) in a population of 120 patients suffering from grass pollen allergic rhinitis. The duration of the treatment period was 14 days. Primary efficacy variable was a total symptoms score (including among symptoms nasal congestion, sneezing, rhinorrhea, nasal/throat/palate itching, eye itching and lacrimation) evaluated after 14 days of treatment vs. baseline value. Safety was assessed on routine laboratory assays and recording vital signs and adverse events (AEs). RESULTS: The between-group difference in primary efficacy variable averaged over the 2-week treatment period was not statistically significant. Results clearly showed that no significant difference exists between the two treatments as far as total symptoms score evaluated after 14 days of treatment vs. baseline values are concerned. Therefore, the efficacy profiles of the study medications are overlapping. The pattern and incidence of AEs was similar in both treatment groups. The most frequent AEs with both compounds were related to the CNS, headache being the most reported one. In particular, this study seems to disclose a slighter tendency to drowsiness with emedastine than with cetirizine. CONCLUSIONS: Both drugs under investigation in this trial appear to be effective for relieving the symptoms of seasonal allergic rhinitis in Caucasian adult patients. The results demonstrate that emedastine 4 mg o.d. is comparable in efficacy to cetirizine 10 mg once daily in the symptomatic management of seasonal allergic rhinitis. Moreover, based on the results of this study, emedastine can be considered a safe and well-tolerated drug and its safety profile seems to resemble that of cetirizine.

A tolerability and pharmacokinetic study of a new injectable formulation of disodium clodronate in healthy female volunteers.

Disodium clodronate (dichloromethylene bisphosphonic acid, disodium salt; CAS 22560-50-5) is a bisphosphonate that has demonstrated efficacy in patients with a variety of diseases of enhanced bone resorption. Intramuscular clodronate can determine pain at the injection site, it is therefore particularly useful to co-administer a local anaesthetic with clodronate to reduce pain at the injection site. The tolerability and pharmacokinetic of a new formulation of 100 mg disodium clodronate containing 1% lidocaine (test formulation, Chiesi Farmaceutici S.p.A) were investigated in comparison to the same formulation without the local anaesthetic (Clody) and a marketed formulation containing 1% benzyl alcohol (Clasteon). Thirty healthy female volunteers were treated according to a single dose, double-blind, randomised, three-way cross-over design. The local tolerability was investigated by assessing reddening and hardening at the injection site, and plasma CPK levels. Pain intensity was investigated on the VAS (visual analogue scale) and on the VRS (verbal rating score). Urinary clodronic acid concentrations were determined using a validated specific GC/MS/NCI assay. The statistical analysis on pain assessment showed a significant reduction of pain intensity immediately and up to 2 hours after administration of the new formulation compared to the marketed ones. CPK levels and occurrence of hardening at the injection site did not show statistically significant differences between formulations. No local redness was reported. Clodronate urinary excretion during the 48 h collection interval was not statistically different among the formulations and the 95% confidence intervals were inside the bioequivalence acceptance region, demonstrating comparable bioavailability. It was concluded that the investigated new formulation of 100 mg disodium clodronate was better tolerated than the reference marketed formulations.