Prevalence of cannabidiol (CBD) consumption and cancer patients' expectations in one oncology day-hospital: A cross-sectional study and questionnaire validation

INTRODUCTION

The growing interest of cannabidiol (CBD) in medical care prompted French health authorities to explore the potential of CBD in cancer-related severe symptoms. This study aimed to assess the prevalence of CBD use among cancer patients with potential associated factors and to measure the cancer patient's health literacy (HL) on CBD consumption.

METHODS

In a prospective study in oncology day-care hospital including patients from 29 October to 20 December 2021, we collected demographic, biological, and oncological characteristics. Patient CBD HL was measured by the hetero-questionnaire 8-item-CBD HL scale (HLS-8-CBD) whose conception has been validated by a psychometric analysis.

RESULTS

Among 363 participants, 20 patients (5.5%) reported CBD use. Factors associated with CBD use were: age <60 years (odd ratio = 7.80[1.36-13.32], p < 10^-4 versus ≥60 years), smoking history (OR = 5.53[1.81-16.88], p < 0.01), and no smoking cessation (OR = 5.07[1.66-15.46], p < 0.01). CBD use was also associated with a better CBD total HL score than non-users (p-value = 0.02).

CONCLUSION

Identification of factors associated with CBD use and a relatively high patient CBD HL in CBD users showed that CBD use in cancer patients care represented a new concern and should enhance health professionals to consider CBD with its associated drug-related problems.

Cannabidiol-drug interaction in cancer patients: A retrospective study in a real-life setting

Cannabidiol (CBD) consumption in cancer patients is growing and there is a need to investigate how to detect cannabidiol-drug interactions (CDIs). However, CDIs and the clinical relevance between CBD, anticancer treatment, supportive care and conventional drugs is poorly studied especially in real-life settings. In 1 oncology day-hospital, a cross-sectional study in 363 cancer patients treated with chemotherapy revealed 20 patients (5.5%) who consumed CBD. In this study we aimed to explore the prevalence and clinical relevance of CDIs among these 20 patients. CDI detection used the Food and Drug Administration Drugs.com database and clinical relevance was assessed accordingly. Ninety CDIs with 34 medicines were detected (4.6 CDI/patient). The main clinical risks were central nervous system depression and hepatoxicity. The main CDIs were assessed as moderate and anticancer treatment do not seem to add to the risk. CBD discontinuation appears to be the most consistent management. Future studies should explore the clinical relevance of drug interactions with CBD in cancer patients.

Using national data to describe characteristics and determine acceptance factors of pharmacists' interventions: a six-year longitudinal study

BACKGROUND

In France, hospital pharmacists perform medication order reviews during patients' hospital stays. This activity can be centralized in the pharmacy or carried out directly in the ward, in collaboration with the healthcare team. During this review, pharmacists can make recommendations to optimize therapeutics. Since 2006, they can document their interventions, via the national Act-IP© observatory.

AIM

To determine the characteristics of pharmacists' interventions and their acceptance by physicians in French hospitals.

METHOD

A 6-year observational study of pharmacists' interventions documented on the Act-IP© French observatory between 2009 and 2014 was performed. Multiple logistic regression was undertaken to determine the predictors of physicians' acceptance of interventions.

RESULTS

A total of 194,684 pharmacists' interventions were documented and concerned mainly "dosage adjustment" (25.6%). These interventions were mostly related to drugs from the central nervous system (23.7%). Seventy percent of pharmacists' interventions were accepted by physicians. Acceptance rate was higher when conducted by a pharmacist regularly practicing in the ward (ORa = 1.60, CI 95 [1.57-1.64]). Physicians' acceptance was significantly associated with (1) ward specialty: emergency (ORa = 1.24, CI 95 [1.14-1.35]); (2) type of intervention: "drug discontinuation", "drug switch" (ORa = 1.15, CI 95 [1.12-1.19]) and "addition of a new drug" (ORa = 1.15, CI 95 [1.12-1.19]); (3) drug group: antineoplastic and immunomodulators (ORa = 3.67, CI 95 [3.44-3.92]).

CONCLUSION

This 6-year longitudinal study highlights the role of clinical pharmacists, and particularly the impact of those integrated into wards. This was found to improve intervention acceptance, potentially through collaboration with physicians in pursuit of patient care and drug safety.

Development and validation of a ready-to-use score to prioritise medication reconciliation at patient admission in an orthopaedic and trauma department

OBJECTIVE

Medication reconciliation (MR) is recognised as an important tool in preventing medication errors such as unintentional discrepancies (UDs). The aim of this study was to identify independent predictive factors of UDs during MR at patient admission to an orthopaedic and trauma department. The secondary objective was to build and validate a ready-to-use score to prioritise patients.

METHOD

A retrospective study was performed on 3.5 years of pharmacist-led MR in the orthopaedic and trauma department of a large university teaching hospital. Independent predictors of UD were identified by multivariable logistic regression. A priority score to identify patients at risk of at least one UD was constructed from the odds ratios of the risk factors, and validated in a separate cohort. Performance was assessed with sensitivity, specificity, C-statistic and Hosmer-Lemeshow goodness-of-fit.

RESULTS

In total, 888 patients were included and 387 UDs were identified, mainly drug omissions (65.1%). Five independent predictors of UD were identified: age >75 years (OR 2.05, 95% CI 1.41 to 3.00; p<0.001), admission during school holidays (OR 1.69, 95% CI 1.17 to 2.44; p=0.005), female gender (OR 2.20, 95% CI 1.53 to 3.16; p<0.001), emergency hospitalisation (OR 2.05, 95% CI 1.45 to 2.92; p<0.001), and ≥5 medications on the best possible medication history (BPMH) (OR 3.29, 95% CI 2.20 to 4.94; p<0.001). Based on these predictors, a priority score ranging from 0 to 10 was built and internally and externally validated (C statistic 0.72, 95% CI 0.67 to 0.76).

CONCLUSIONS

This study confirms the high prevalence of UD in patients admitted to orthopaedic and trauma surgery departments. Five independent predictive factors of UD during MR were identified (female gender, emergency hospitalisation, hospitalisation during school holidays, age ≥75 years, and ≥5 medicines on the BPMH). The developed risk score will help to prioritise MR among patients at risk of medication error and is ready-to-use in other orthopaedic and trauma departments.

Impact of Pharmacists-Led Interventions in Primary Care for Adults with Type 2 Diabetes on HbA1c Levels: A Systematic Review and Meta-Analysis

Type 2 diabetes mellitus (T2D) is responsible for an important premature mortality. Pharmacists involved in community-based pharmaceutical care services could help patients with diabetes through education and management as they participate in their regular and long-term care. This meta-analysis aimed to evaluate the association between interventions led by pharmacists in the primary care setting and mean change in HbA1c levels. Randomized controlled trials and quasi-experimental studies with a control group were included. Standardized mean differences (SMD) and their 95% confidence intervals (95% CI) were calculated to compare the mean change in HbA1c values between baseline and end of the intervention in each group. Subgroup analyses were performed to explore heterogeneity. Twelve articles were included. The results showed that pharmacist’s interventions significantly reduced HbA1c compared to usual care with an overall SMD of −0.67 (95% CI = [−0.87; −0.48], p < 0.0001). Even if no significant difference between subgroups were found, the reduction of HbA1c seemed more important when baseline HbA1c was ≥8.5%, the intervention occurred monthly, in a primary care center and in countries with a lower human development index. Our results suggest that pharmacists-led interventions in the primary care setting can improve glycemic control for adults with T2D.

Characteristics of Pharmacists' Interventions Related to Proton-Pump Inhibitors in French Hospitals: An Observational Study

METHODS

The study was based on a retrospective analysis of pharmacist interventions for DRPs detected during the medication order review and documented into the French Act-IP© database over a 12-year period. DRPs and PIs were analyzed, and independent factors of physician acceptance were assessed via multiple logistic regression.

RESULTS

Out of the 620,620 PIs registered, 29,694 targeted a PPI (4.8%). PPI's DRPs were mostly related to the prescription of a "drug not available at the hospital" (26.1%) and a "drug use without indication" (18.3%); PIs were mostly "drug switch" (35.9%) and "drug discontinuation" (26.1%). In all, 18,919 PIs were accepted by physicians (63.7%). Acceptance was significantly associated with patient age: less accepted for the 18-75 years group (OR = 0.59, 95 CI [0.46-0.76]), and the >75 years group (OR = 0.57, 95 CI [0.44-0.73]) vs. <18 years group; for the type of DRP, "drug use without indication" was the less accepted (OR = 0.73, 95 CI [0.63-0.85]); for the type of PI, "dose adjustment" was the less accepted (OR = 0.32, 95 CI [0.23-0.45]).

CONCLUSION

Pharmacists contribute to preventing DRPs associated with PPI prescriptions during the medication order review process. Moreover, they often detect PPIs used without indication and they propose drug discontinuation, which contributes to the PPI deprescribing process. PIs should be further developed in the future to reduce PPI overprescription.

Clinical and Organizational Impacts of Medical Ordering Settings on Patient Pathway and Community Pharmacy Dispensing Process: The Prospective ORDHOSPIVILLE Study

During the dispensing process of medical orders (MOs), community pharmacists (CPs) can manage drug-related problems (DRPs) by performing pharmacist interventions (PIs). There is little evidence that the PI rate is higher with MOs from hospitals (MOHs) than ambulatory (MOAs) settings, and their impact on the patient and community pharmacy is unknown. The primary objective of this study was to compare the MOH and MOA PI rates. The secondary objective was to describe PIs and their clinical and organizational impacts on patient and community pharmacy workflow. A total of 120 CPs participated in a prospective study. Each CP included 10 MOH and 10 MOA between January and June 2020. DRP and PI description and clinical and organizational impacts between MOH and MOA were assessed and compared. We analyzed 2325 MOs. PIs were significantly more frequent in MOH than in MOA (9.7% versus 4.7%; p < 0.001). The most reported PI was the difficulty of contacting hospital prescribers (n = 45; 52.2%). MOHs were associated with a longer dispensing process time and a greater impact on patient pathway and community pharmacy workflow than MOAs. Lack of communication between hospital and primary care settings partly explains the results. Implementation of clinical pharmacy activities at patient discharge could alleviate these impacts.

Staphylococcus aureus Strain-Dependent Biofilm Formation in Bone-Like Environment

Staphylococcus aureus species is an important threat for hospital healthcare because of frequent colonization of indwelling medical devices such as bone and joint prostheses through biofilm formations, leading to therapeutic failure. Furthermore, bacteria within biofilm are less sensitive to the host immune system responses and to potential antibiotic treatments. We suggested that the periprosthetic bone environment is stressful for bacteria, influencing biofilm development. To provide insights into S. aureus biofilm properties of three strains [including one methicillin-resistant S. aureus (MRSA)] under this specific environment, we assessed several parameters related to bone conditions and expected to affect biofilm characteristics. We reported that the three strains harbored different behaviors in response to the lack of oxygen, casamino acids and glucose starvation, and high concentration of magnesium. Each strain presented different biofilm biomass and live adherent cells proportion, or matrix production and composition. However, the three strains shared common responses in a bone-like environment: a similar production of extracellular DNA and engagement of the SOS response. This study is a step toward a better understanding of periprosthetic joint infections and highlights targets, which could be common among S. aureus strains and for future antibiofilm strategies.

Safety and Survival Outcomes in Lung Cancer Patients Receiving Carboplatin: Impact of Uncapped Dosage

The prescription of carboplatin is commonly based on the Calvert formula, and low serum creatinine values can lead to an overestimation of the glomerular filtration rate and of the carboplatin dose. Limited data recommend to cap carboplatin dose at 800 mg, but the risk of suboptimal carboplatin dose is concerning. This study compared hematologic toxicity occurrence and survival outcomes in lung cancer patients receiving carboplatin > or <800 mg based on the Calvert formula (target area under the curve = 5 mg/mL min). Our results show more severe cytopenia in patients receiving carboplatin >800 mg with significant difference for all grades of thrombocytopenia in the uncapped group (37% patients vs. 3%, p = 0.02). For metastatic non-small-cell lung cancer patients, we also observed hematologic toxicity in the uncapped group with more severe anemia (30% of patients vs. 0%, p = 0.03) and all grades of thrombocytopenia (39 vs. 0%, p = 0.02) than the capped group. Concerning the secondary endpoint, we obtained a trend of lower progression-free survival and overall survival in patients receiving carboplatin >800 mg, but no significant difference appears for the both survival criteria. This study aims to improve the determination of carboplatin dosage to know the real impact of carboplatin capping and to find the optimum balance between excessive toxicity and substandard therapeutics outcomes.

Interaction of implant infection-related commensal bacteria with mesenchymal stem cells: a comparison between Cutibacterium acnes and Staphylococcus aureus

Staphylococcus aureus and Cutibacterium acnes are involved in several tissue infections and can encounter mesenchymal stem cells (MSCs) during their role in tissue regenerative process. C. acnes and S. aureus internalization by three types of MSCs derived from bone marrow, dental pulp and Wharton's jelly; and bacterial biofilm production were compared. Internalization rates ranged between 1.7-6.3% and 0.8-2.7% for C. acnes and S. aureus, respectively. While C. acnes strains exhibited limited cytotoxic effect on MSCs, S. aureus were more virulent with marked effect starting after only 3 h of interaction. Both bacteria were able to produce biofilms with respectively aggregated and monolayered structures for C. acnes and S. aureus. The increase in C. acnes capacity to develop biofilm following MSCs' internalization was not linked to the significant increase in number of live bacteria, except for bone marrow-MSCs/C. acnes CIP 53.117 with 79% live bacteria compared to the 36% before internalization. On the other hand, internalization of S. aureus had no impact on its ability to form biofilms composed mainly of living bacteria. The present study underlined the complexity of MSCs-bacteria cross-interaction and brought insights into understanding the MSCs behavior in response to bacterial infection in tissue regeneration context.

[Barriers and enablers to pharmacist-led medication review in community pharmacy: A prospective study in Grand Est, France]

Since 2018, French community pharmacists are involved in pharmaceutical care program performing medication review (MR). Near graduated pharmacy students from two faculties of pharmacy were assigned to implement and perform 3 MR in order to identify enablers and barriers of the implementation of MR by community pharmacists. Among 179 MR performed by 117 pharmacists during 5 months, they reported 3 main barriers: the time spending to initiate and perform all steps in MR (lack of time), patients recruiting, and compensation by health care system. Communications initiatives to patients and health professionals in primary care could facilitate patient MR adhesion. Simplification of administrative approach and optimization of software will be welcome and useful in order to reinforced MR implementation and leading.

Antibiotic Tolerance of Staphylococcus aureus Biofilm in Periprosthetic Joint Infections and Antibiofilm Strategies

The need for bone and joint prostheses is currently growing due to population aging, leading to an increase in prosthetic joint infection cases. Biofilms represent an adaptive and quite common bacterial response to several stress factors which confer an important protection to bacteria. Biofilm formation starts with bacterial adhesion on a surface, such as an orthopedic prosthesis, further reinforced by matrix synthesis. The biofilm formation and structure depend on the immediate environment of the bacteria. In the case of infection, the periprosthetic joint environment represents a particular interface between bacteria, host cells, and the implant, favoring biofilm initiation and maturation. Treating such an infection represents a huge challenge because of the biofilm-specific high tolerance to antibiotics and its ability to evade the immune system. It is crucial to understand these mechanisms in order to find new and adapted strategies to prevent and eradicate implant-associated infections. Therefore, adapted models mimicking the infectious site are of utmost importance to recreate a relevant environment in order to test potential antibiofilm molecules. In periprosthetic joint infections, Staphylococcus aureus is mainly involved because of its high adaptation to the human physiology. The current review deals with the mechanisms involved in the antibiotic resistance and tolerance of Staphylococcus aureus in the particular periprosthetic joint infection context, and exposes different strategies to manage these infections.

The Role of Community Pharmacists in the Detection of Clinically Relevant Drug-Related Problems in Chronic Kidney Disease Patients

Community pharmacists (CPs) have traditionally had limited access to patients’ estimated glomerular filtration rate (eGFR) during the medication-dispensing process. The increasing access to shared electronic health records is making eGFR available, but the skills needed to detect and manage clinically relevant drug-related problems (DRPs) are poorly documented. The primary objective of this study was to investigate the role of CPs in the medication-dispensation process for elderly patients with renal impairment. A total of 70 CPs participated in this 6 month study. Community pharmacists asked all patients ≥65 years to bring their laboratory test values for the next medication-dispensing process. Drug-related problem detection rates were compared between CPs (prospective period) and expert pharmacists (retrospectively). The clinical relevance of each DRP was assessed by nephrologists and general practitioners using an appropriate tool. Community pharmacists recruited n = 442 patients with eGFR < 60 mL/min/1.73 m² and detected n = 99 DRPs, whereas expert pharmacists detected n = 184 DRPs. The most frequently detected DRPs were dosage problems and contraindications. According to assessment by clinicians, CPs and expert pharmacists identified 54.0% and 84.7% of clinically relevant DRPs, respectively. This study suggests a positive impact of the systematic availability of eGFR to CPs on the detection of several DRPs with clinical relevance.

Interaction of Cutibacterium acnes with human bone marrow derived mesenchymal stem cells: a step toward understanding bone implant- associated infection development

Crosstalk between mesenchymal stem cells (MSCs) and bacteria plays an important role in regulating the regenerative capacities of MSCs, fighting infections, modulating immune responses and maintaining tissue homeostasis. Commensal Cutibacterium acnes (C. acnes) bacterium becomes an opportunistic pathogen causing implant-associated infections. Herein, we examined MSCs/C. acnes interaction and analysed the subsequent bacteria and MSCs behaviours following infection. Human bone marrow derived MSCs were infected by two clinical and one laboratory C. acnes strains. Following 3h of interaction, all bacterial strains were able to invade MSCs. Viable intracellular bacteria acquired virulence factors by increasing biofilm formation and/or by affecting macrophage phagocytosis. Although the direct and indirect (through neutrophil stimulation) antibacterial effects of the MSCs secretome were not enhanced following C. acnes infection, ELISA analysis revealed that C. acnes clinical strains are able to license MSCs to become immunosuppressive cell-like by increasing the secretion of IL-6, IL-8, PGE-2, VEGF, TGF-β and HGF. Overall, these results showed a direct impact of C. acnes on bone marrow derived MSCs, providing new insights into the development of C. acnes during implant-associated infections. STATEMENT OF SIGNIFICANCE: The originality of this work relies on the study of relationship between human bone marrow derived mesenchymal stem cells (MSCs) phenotype and C. acnes clinical strains virulence following cell infection. Our major results showed that C. acnes are able to invade MSCs, inducing a transition of commensal to an opportunistic pathogen behaviour. Although the direct and indirect antibacterial effects were not enhanced following C. acnes infection, secretome analysis revealed that C. acnes clinical strains were able to license MSCs to become immunosuppressive and anti-fibrotic cell-like. These results showed a direct impact of C. acnes on bone marrow derived MSCs, providing new insights into the development of C. acnes during associated implant infections.

Bone Environment Influences Irreversible Adhesion of a Methicillin-Susceptible Staphylococcus aureus Strain

Prosthesis and joint infections are an important threat in public health, especially due to the development of bacterial biofilms and their high resistance to antimicrobials. Biofilm-associated infections increase mortality and morbidity rates as well as hospitalization costs. Prevention is the best strategy for this serious issue, so there is an urgent need to understand the signals that could induce irreversible bacterial adhesion on a prosthesis. In this context, we investigated the influence of the bone environment on surface adhesion by a methicillin-susceptible Staphylococcus aureus strain. Using static and dynamic biofilm models, we tested various bone environment factors and showed that the presence of Mg²⁺, lack of oxygen, and starvation each increased bacterial adhesion. It was observed that human osteoblast-like cell culture supernatants, which contain secreted components that would be found in the bone environment, increased bacterial adhesion capacity by 2-fold (p = 0.015) compared to the medium control. Moreover, supernatants from osteoblast-like cells stimulated with TNF-α to mimic inflammatory conditions increased bacterial adhesion by almost 5-fold (p = 0.003) without impacting on the overall biomass. Interestingly, the effect of osteoblast-like cell supernatants on bacterial adhesion could be counteracted by the activity of synthetic antibiofilm peptides. Overall, the results of this study demonstrate that factors within the bone environment and products of osteoblast-like cells directly influence S. aureus adhesion and could contribute to biofilm initiation on bone and/or prosthetics implants.

Pharmacists' interventions on prescription problems in one French community pharmacy: A prospective pilot study

OBJECTIVES

While many international studies widely describe pharmacists' interventions (PIs) on drug-related problems (DRP) in community pharmacies, in France, these activities are underreported. The aim of this study is to describe the PI rate, given as the number of interventions in among all prescriptions reviewed during the study period.

MATERIAL AND METHODS

This study was conducted in one French rural community pharmacy during a 7-month period. Age, sex, type of prescriber, type of problems, intervention and the outcome were prospectively recorded. PIs were prospectively formalized and classified using the validated tool from the French Society of Clinical Pharmacy. In addition, all interventions were reviewed by an independent pharmacist.

RESULTS

Among the 20,238 prescriptions, n=211 pharmacists' interventions on 159 prescriptions (0.79%) were performed. Prescriptions were ordered by general practitioners in 78.6%. The most common DRP were the improper prescription (30.8%), a drug or medical device not received by the patient (21.8%, all linked to drug shortages) or a dosage problem (18.9%). Antibiotics were the most common drugs involved in DRP (13.3%). The main PI were the drug switch/establishment of a therapeutic alternative (38.4%), dose adjustment (25.6%) and optimization of the dispensing/administration modalities (25.1%). The overall acceptance rate of PIs was 93.4%.

CONCLUSION

We found a PI rate, as well as acceptance rate by prescribers, in the same range than as reported in studies performed in other countries. A consequent large part percentage of PIs can be classified as "administrative". This first prospective French study needs to be further supported by multi-site studies.

Predictive factors for clinically significant pharmacist interventions at hospital admission

Pharmaceutical care activities at hospital admission have a significant impact on patient safety. The objective of this study was to identify predictive factors for clinically significant pharmacist interventions (PIs) performed during medication reconciliation and medication review at patient hospital admission.A 4-week prospective study was conducted in 4 medicine wards. At hospital admission, medication reconciliation and medication review were conducted and PIs were performed by the pharmaceutical team. The clinical impact of PIs was determined using the clinical economic and organizational (CLEO) tool. Clinical characteristics, laboratory results, and medication data for each patient were collected and analyzed as potential predictive factors of clinically significant PIs. Univariate and multivariate binary logistic regression were subsequently used to identify independent predictive factors for clinically relevant PIs.Among 265 patients admitted, 150 patients were included. Among 170 PIs performed at hospital admission, 71 were related to unintentional discrepancies (41.8%) during medication reconciliation, and 99 were related to drug-related problems (DRPs) (58.8%) during medication review. Overall, 115 PIs (67.7%) were considered to have a clinical impact. By multivariate analysis, number of medications ≥5 (P = .01) based on the best possible medication history, and Charlson comorbidity index score ≥2 (P < .01) were found to be independent predictive factors of clinically significant PIs at hospital admission.Identifying predictive factors of clinically significant PIs is valuable to optimize clinical pharmacist practices at hospital admission during both medication reconciliation and medication review. These 2 steps of the pharmaceutical care process improve medication safety at hospital admission.

[Outcomes after a 2-year pharmaceutical care program for patients taking vitamin K antagonist therapy? Community pharmacist's perception]

OBJECTIVES

Since 2013 French community pharmacist are involved in pharmaceutical care program (PCP) for patients treated with vitamin K antagonist (VKA). While PCPs are now extending to other patient populations, we aimed to evaluate pharmacists' perception after 2-years implementation and leading of PCP.

METHODS

A prospective investigational survey from 1st August to 31st December, 2015 from 400 community pharmacies in Champagne-Ardenne Region. Survey focuses on 3 points: first about implementation and leading of PCP; secondly about patient's population description; finally on the global perception by CP about new tasks.

RESULTS

Among n=47, 72% of pharmacists performed VKA PCP. Almost all received appropriate training (96%). Remuneration appears to be insufficient given the time spent for 73%. Ninety-five percent met patient's refusal mainly because of interest lacking or time lacking (54% and 22%, respectively). Pharmacists reported 3 main lacks of knowledges of patients: drugs, which increase drug-drug interaction risk (28%), VKA overdose effects (27%) and VKA-food interactions (23%). Overall view of pharmacist for PCP appears to be positive (81%) in part because of improvement of pharmacist-patient relationship perception for 66%.

CONCLUSIONS

Community pharmacists' perception for PCP for patients treated by VKA is broadly positive. However, organizational or economic constraints can lead to a decreasing adherence by pharmacists to PCPs. A global issue about amount of compensation and communications campaigns to patients and others health professionals will be useful in order to reinforced PCP implementation and leading taxonomy.

Impact of the Maturation of Human Primary Bone-Forming Cells on Their Behavior in Acute or Persistent Staphylococcus aureus Infection Models

Staphylococcus aureus is one of the most frequently involved pathogens in bacterial infections such as skin abscess, pneumonia, endocarditis, osteomyelitis, and implant-associated infection. As for bone homeostasis, it is partly altered during infections by S. aureus by the induction of various responses from osteoblasts, which are the bone-forming cells responsible for extracellular matrix synthesis and its mineralization. Nevertheless, bone-forming cells are a heterogeneous population with different stages of maturation and the impact of the latter on their responses toward bacteria remains unclear. We describe the impact of S. aureus on two populations of human primary bone-forming cells (HPBCs) which have distinct maturation characteristics in both acute and persistent models of interaction. Cell maturation did not influence the internalization and survival of S. aureus inside bone-forming cells or the cell death related to the infection. By studying the expression of chemokines, cytokines, and osteoclastogenic regulators by HPBCs, we observed different profiles of chemokine expression according to the degree of cell maturation. However, there was no statistical difference in the amounts of proteins released by both populations in the presence of S. aureus compared to the non-infected counterparts. Our findings show that cell maturation does not impact the behavior of HPBCs infected with S. aureus and suggest that the role of bone-forming cells may not be pivotal for the inflammatory response in osteomyelitis.

Tumor invasion induced by oxidative stress is dependent on membrane ADAM 9 protein and its secreted form

Oxidative stress plays a role in the regulation of cancer cell metastasis which involves cell invasion and adhesion that could be supported by ADAM proteins through the activities of their metalloprotease and disintegrin domains. We hypothesized that oxidative stress could act through the induction of ADAM9 protein in some cancer cells. Indeed, Western blot analysis for ADAM9 performed on A549 cells exposed to H(2) O(2) reveals a dose-dependent induction of two proteins (80 and 68 kDa) correlated with a sharp increase of the ADAM protease activity measured in supernatant while the activity measured on the cell layer was slightly affected. The 80kDa protein corresponds to the mature form of ADAM9. Immunoprecipitation analysis performed on concentrated supernatants revealed that the 68 kDa protein is a secreted form of ADAM9. When exposed to H(2) O(2) , A549 cells cocultured with confluent endothelial vascular cells resulted in a 5.5 fold (p < 0.001) increase in the number of adherent cells. Similarly, matrigel assay revealed a 3.25 fold (p < 0.01) increase in the number of invasive cells. The suppression of ADAM9 expression by specific small interfering RNA reduced oxidative stress-induced invasiveness and adhesiveness. These functions could be mediated by an interaction between ADAM9 and β1 integrin because each of them were inhibited when the experiment is performed in presence of mAbs targeting ADAM9 ectodomain or β1-integrin. These results emphasize the importance of oxidative stress in the regulation of cancer cell metastasis and suggest that ADAM9 and its secreted isoform can be important determinants in the ability of cancer cells to disseminate.

Targeting ADAM-17/notch signaling abrogates the development of systemic sclerosis in a murine model

OBJECTIVE

Systemic sclerosis (SSc) is characterized by the fibrosis of various organs, vascular hyperreactivity, and immunologic dysregulation. Since Notch signaling is known to affect fibroblast homeostasis, angiogenesis, and lymphocyte development, we undertook this study to investigate the role of the Notch pathway in human and murine SSc.

METHODS

SSc was induced in BALB/c mice by subcutaneous injections of HOCl every day for 6 weeks. Notch activation was analyzed in tissues from mice with SSc and from patients with scleroderma. Mice with SSc were either treated or not treated with the γ-secretase inhibitor DAPT, a specific inhibitor of the Notch pathway, and the severity of the disease was evaluated.

RESULTS

As previously described, mice exposed to HOCl developed a diffuse cutaneous SSc with pulmonary fibrosis and anti-DNA topoisomerase I antibodies. The Notch pathway was hyperactivated in the skin, lung, fibroblasts, and splenocytes of diseased mice and in skin biopsy samples from patients with scleroderma. ADAM-17, a proteinase involved in Notch activation, was overexpressed in the skin of mice and patients in response to the local production of reactive oxygen species. In HOCl-injected mice, DAPT significantly reduced the development of skin and lung fibrosis, decreased skin fibroblast proliferation and ex vivo serum-induced endothelial H(2)O(2) production, and abrogated the production of anti-DNA topoisomerase I antibodies.

CONCLUSION

Our results show the pivotal role of the ADAM-17/Notch pathway in SSc following activation by reactive oxygen species. The inhibition of this pathway may represent a new treatment of this life-threatening disease.

Prediction of the evolution of ceftazidime resistance in extended-spectrum beta-lactamase CTX-M-9

A random mutagenesis technique was used to predict the evolutionary potential of beta-lactamase CTX-M-9 toward the acquisition of improved catalytic activity against ceftazidime. Thirty CTX-M mutants were obtained during three rounds of mutagenesis. These mutants conferred 1- to 128-fold-higher MICs of ceftazidime than the parental enzyme CTX-M-9. The CTX-M mutants contained one to six amino acid substitutions. Mutants harbored the substitutions Asp240Gly and Pro167Ser, which were previously observed in clinical CTX-M enzymes. Additional substitutions, notably Arg164His, Asp179Gly, and Arg276Ser, were observed near the active site. The kinetic constants of the three most active mutants revealed two distinct ways of improving catalytic efficiency against ceftazidime. One enzyme had a 17-fold-higher k(cat) value than CTX-M-9 against ceftazidime. The other two had 75- to 300-fold-lower Km values than CTX-M-9 against ceftazidime. The current emergence of CTX-M beta-lactamases with improved activity against ceftazidime may therefore be the beginning of an evolutionary process which might subsequently generate a great diversity of CTX-M-type ceftazidimases.