The Aging, Community and Health Research Unit Community Partnership Program (ACHRU-CPP) for older adults with diabetes and multiple chronic conditions: study protocol for a randomized controlled trial

BACKGROUND

Older adults (≥65 years) with diabetes and multiple chronic conditions (MCC) (> 2 chronic conditions) experience reduced function and quality of life, increased health service use, and high mortality. Many community-based self-management interventions have been developed for this group, however the evidence for their effectiveness is limited. This paper presents the protocol for a randomized controlled trial (RCT) comparing the effectiveness and implementation of the Aging, Community and Health Research Unit-Community Partnership Program (ACHRU-CPP) to usual care in older adults with diabetes and MCC and their caregivers.

METHODS

We will conduct a cross-jurisdictional, multi-site implementation-effectiveness type II hybrid RCT. Eligibility criteria are: ≥65 years, diabetes diagnosis (Type 1 or 2) and at least one other chronic condition, and enrolled in a primary care or diabetes education program. Participants will be randomly assigned to the intervention (ACHRU-CPP) or control arm (1:1 ratio). The intervention arm consists of home/telephone visits, monthly group wellness sessions, multidisciplinary case conferences, and system navigation support. It will be delivered by registered nurses and registered dietitians/nutritionists from participating primary care or diabetes education programs and program coordinators from community-based organizations. The control arm consists of usual care provided by the primary care setting or diabetes education program. The primary outcome is the change from baseline to 6 months in mental functioning. Secondary outcomes will include, for example, the change from baseline to 6 months in physical functioning, diabetes self-management, depressive symptoms, and cost of use of healthcare services. Analysis of covariance (ANCOVA) models will be used to analyze all outcomes, with intention-to-treat analysis using multiple imputation to address missing data. Descriptive and qualitative data from older adults, caregivers and intervention teams will be used to examine intervention implementation, site-specific adaptations, and scalability potential.

DISCUSSION

An interprofessional intervention supporting self-management may be effective in improving health outcomes and client/caregiver experience and reducing service use and costs in this complex population. This pragmatic trial includes a scalability assessment which considers a range of effectiveness and implementation criteria to inform the future scale-up of the ACHRU-CPP.

TRIAL REGISTRATION

Clinical Trials.gov Identifier NCT03664583 . Registration date: September 10, 2018.

Discovery and Optimization of DNA Gyrase and Topoisomerase IV Inhibitors with Potent Activity against Fluoroquinolone-Resistant Gram-Positive Bacteria

Herein, we describe the discovery and optimization of a novel series that inhibits bacterial DNA gyrase and topoisomerase IV via binding to, and stabilization of, DNA cleavage complexes. Optimization of this series led to the identification of compound 25, which has potent activity against Gram-positive bacteria, a favorable in vitro safety profile, and excellent in vivo pharmacokinetic properties. Compound 25 was found to be efficacious against fluoroquinolone-sensitive Staphylococcus aureus infection in a mouse thigh model at lower doses than moxifloxacin. An X-ray crystal structure of the ternary complex formed by topoisomerase IV from Klebsiella pneumoniae, compound 25, and cleaved DNA indicates that this compound does not engage in a water-metal ion bridge interaction and forms no direct contacts with residues in the quinolone resistance determining region (QRDR). This suggests a structural basis for the reduced impact of QRDR mutations on antibacterial activity of 25 compared to fluoroquinolones.

Effects of canagliflozin on cardiovascular death and hospitalization for heart failure by baseline estimated glomerular filtration rate: integrated analyses from the CANVAS Program and CREDENCE

Background

People with type 2 diabetes mellitus (T2DM) have a greater risk of cardiovascular (CV) disease, including hospitalization for heart failure (HHF), a complication that is more common as renal function declines. The sodium glucose co-transporter 2 (SGLT2) inhibitor canagliflozin (CANA) reduced the risk of HHF in patients with T2DM and high CV risk or nephropathy in the CANVAS Program and CREDENCE trials, respectively.

Methods

This post hoc analysis included integrated, pooled data from the CANVAS Program and the CREDENCE trial. The effects of CANA compared with placebo on CV death or HHF, HHF, and CV death were assessed in subgroups defined by baseline eGFR (<45, 45–60, and >60 mL/min/1.73 m2). Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression models, with subgroup by treatment interaction terms added to test for heterogeneity. Interaction P values were calculated by including treatment group and baseline eGFR in the model.

Results

A total of 14,543 participants from the CANVAS Program (N=10,142) and CREDENCE (N=4,401) were included, with mean age, 65 y; 65% male; 75% white; mean eGFR 70.3 mL/min/1.73 m2. 1919 (13.2%) participants had baseline eGFR <45 mL/min/1.73 m2 (mean, 36.7 mL/min/1.73 m2), 2972 (20.4%) participants had eGFR 45–60 mL/min/1.73 m2 (mean, 53.1 mL/min/1.73 m2), and 9649 (66.3%) participants had eGFR >60 mL/min/1.73 m2 (mean, 82.3 mL/min/1.73 m2). Rates of CV death or HHF, HHF, and CV death increased as eGFR declined (Figure). CANA significantly reduced the risk of CV death or HHF and HHF compared with PBO, with consistent effects observed across subgroups.

Conclusions

CV death or HHF, HHF, and CV death event rates increased with lower baseline eGFR. CANA significantly reduced the risk of CV death or HHF, jointly and individually, in participants with T2DM and high CV risk or CKD in the CANVAS Program and the CREDENCE trial, with consistent benefits observed regardless of baseline eGFR.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Janssen Scientific Affairs, LLC

Aerobic or strength training and flexibility activities and mild cognitive impairment: CETI cohort

Background

Previous studies have been notably criticized for not studying the different types of physical activity. The objective of this work was to examine the association between types of physical activity and cognitive decline in older people.

Methods

This is a sub-group analysis from the CETI cohort, a multicenter prospective study conducted by the Canadian Emergency Team Initiative Program (CETIE), between 2011 and 2016. Participants were community-dwelling seniors aged ≥ 65 years, consult emergency services for minor injuries with follow-up at 3 and 6 months. Physical activity was assessed by the RAPA (Rapid assessment of Physical activity), which describes the level of aerobic activities and the overall level of muscle strength and flexibility activities. The cognitive status was assessed with the Montreal Cognitive Assessment (MoCA) and the Telephone Interview for Cognitive Status (TICS), using their current cut-offs (MoCA <26/30 and TICS < = 35/50) for mild cognitive impairments (MCI). Logistic regression, COX models and splines were used to examine the association between the type of physical activities and the onset of cognitive impairment.

Results

At inclusion, 281 individuals were free of MCI, or 43.8% of the total sample, with an average age of 73 years. During follow-ups, MCI appeared in 31.7% of participants initially free of it. The risk of MCI was lower with higher muscular strength & flexibility physical activities (HR = 0.84 [0.70-0.99]), while the relationship with aerobic physical activities was not significant.

Conclusions

These results showed a potential link between strength & flexibility activities and cognitive impairments, but not with aerobic physical activities. Further analyses are needed to examine whether these relationships persist as a function of the adjustment variables, or statistical methods. This study contributes to the debate on the evaluation of physical activity in the elderly, and its link with neurodegenerative diseases.

Key messages

This study analyzed the link between types of physical activity and mild cognitive disorders. The aim is to put in place preventive policies of aging, specially in neurodegenerative diseases. The work allowed us to see the effect of the different types of physical activity and the impact of the statistical method on the results.

IID572: A New Potentially Best-In-Class β-Lactamase Inhibitor

Resistance in Gram-negative bacteria to β-lactam drugs is mediated primarily by the expression of β-lactamases, and co-dosing of β-lactams with a β-lactamase inhibitor (BLI) is a clinically proven strategy to address resistance. New β-lactamases that are not impacted by existing BLIs are spreading and creating the need for development of novel broader spectrum BLIs. IID572 is a novel broad spectrum BLI of the diazabicyclooctane (DBO) class that is able to restore the antibacterial activity of piperacillin against piperacillin/tazobactam-resistant clinical isolates. IID572 is differentiated from other DBOs by its broad inhibition of β-lactamases and the lack of intrinsic antibacterial activity.

Can patients be trained to expect shared decision making in clinical consultations? Feasibility study of a public library program to raise patient awareness

Introduction

Shared decision making (SDM) is a process whereby decisions are made together by patients and/or families and clinicians. Nevertheless, few patients are aware of its proven benefits. This study investigated the feasibility, acceptability and impact of an intervention to raise public awareness of SDM in public libraries.

Materials and methods

A 1.5 hour interactive workshop to be presented in public libraries was co-designed with Quebec City public library network officials, a science communication specialist and physicians. A clinical topic of maximum reach was chosen: antibiotic overuse in treatment of acute respiratory tract infections. The workshop content was designed and a format, whereby a physician presents the information and the science communication specialist invites questions and participation, was devised. The event was advertised to the general public. An evaluation form was used to collect data on participants’ sociodemographics, feasibility and acceptability components and assess a potential impact of the intervention. Facilitators held a post-workshop focus group to qualitatively assess feasibility, acceptability and impact.

Results

All 10 planned workshops were held. Out of 106 eligible public participants, 89 were included in the analysis. Most participants were women (77.6%), retired (46.1%) and over 45 (59.5%). Over 90% of participants considered the workshop content to be relevant, accessible, and clear. They reported substantial average knowledge gain about antibiotics (2.4, 95% Confidence Interval (CI): 2.0–2.8; P < .001) and about SDM (4.0, 95% CI: 3.4–4.5; P < .001). Self-reported knowledge gain about SDM was significantly higher than about antibiotics (4.0 versus 2.4; P < .001). Knowledge gain did not vary by sociodemographic characteristics. The focus group confirmed feasibility and suggested improvements.

Conclusions

A public library intervention is feasible and effective way to increase public awareness of SDM and could be a new approach to implementing SDM by preparing potential patients to ask for it in the consulting room.

Impact of Inducible blaDHA-1 on Susceptibility of Klebsiella pneumoniae Clinical Isolates to LYS228 and Identification of Chromosomal mpl and ampD Mutations Mediating Upregulation of Plasmid-Borne blaDHA-1 Expression

Twenty-three Klebsiella pneumoniae (blaDHA-1) clinical isolates exhibited a range of susceptibilities to LYS228, with MICs of ≥8 μg/ml for 9 of these. Mutants with decreased susceptibility to LYS228 and upregulated expression of blaDHA-1 were selected from representative isolates. These had mutations in the chromosomal peptidoglycan recycling gene mpl or ampD Preexisting mpl mutations were also found in some of the clinical isolates examined, and these had strongly upregulated expression of blaDHA-1.

Mode of Action of the Monobactam LYS228 and Mechanisms Decreasing In Vitro Susceptibility in Escherichia coli and Klebsiella pneumoniae

The monobactam scaffold is attractive for the development of new agents to treat infections caused by drug-resistant Gram-negative bacteria because it is stable to metallo-β-lactamases (MBLs). However, the clinically used monobactam aztreonam lacks stability to serine β-lactamases (SBLs) that are often coexpressed with MBLs. LYS228 is stable to MBLs and most SBLs. LYS228 bound purified Escherichia coli penicillin binding protein 3 (PBP3) similarly to aztreonam (derived acylation rate/equilibrium dissociation constant [k2/Kd ] of 367,504 s-1 M-1 and 409,229 s-1 M-1, respectively) according to stopped-flow fluorimetry. A gel-based assay showed that LYS228 bound mainly to E. coli PBP3, with weaker binding to PBP1a and PBP1b. Exposing E. coli cells to LYS228 caused filamentation consistent with impaired cell division. No single-step mutants were selected from 12 Enterobacteriaceae strains expressing different classes of β-lactamases at 8× the MIC of LYS228 (frequency, <2.5 × 10-9). At 4× the MIC, mutants were selected from 2 of 12 strains at frequencies of 1.8 × 10-7 and 4.2 × 10-9 LYS228 MICs were ≤2 μg/ml against all mutants. These frequencies compared favorably to those for meropenem and tigecycline. Mutations decreasing LYS228 susceptibility occurred in ramR and cpxA (Klebsiella pneumoniae) and baeS (E. coli and K. pneumoniae). Susceptibility of E. coli ATCC 25922 to LYS228 decreased 256-fold (MIC, 0.125 to 32 μg/ml) after 20 serial passages. Mutants accumulated mutations in ftsI (encoding the target, PBP3), baeR, acrD, envZ, sucB, and rfaI These results support the continued development of LYS228, which is currently undergoing phase II clinical trials for complicated intraabdominal infection and complicated urinary tract infection (registered at ClinicalTrials.gov under identifiers NCT03377426 and NCT03354754).

Legacy organochlorine pollutants in glacial watersheds: a review

Northern Hemisphere alpine glaciers have been identified as a point of concentration and reemergence of legacy organochlorine pollutants (OCPs). In this review, we compile a selection of published literature combining long-range, global atmospheric transport and distribution-based compartmental environmental flux models, as well as data from glacial meltwater, ice core, crevasse and proglacial lake sediment studies. Regional studies of ice and meltwater in alpine glaciers of the northern latitudes show similarities in sample deposition profiles and concentration due to chemical atmospheric residence time, precipitation type and glacier flow rates. In glaciated locations near areas of extensive OCPs use, such as the Swiss and Italian Alps, glacier sample concentrations are higher, while in areas more distant from use, including Arctic nations, OCPs concentrations in glaciers are significantly lower. Our review identifies alpine glaciers co-located with regions characterized by OCPs use as a significant organochlorine pollutant distribution source, secondary in timing and location to direct deposition, with subsequent bioaccumulation and potential human risk impacts.

Family physicians' intention to support women in making informed decisions about breast cancer screening with mammography: a cross-sectional survey

BACKGROUND

The net benefits of routine breast cancer screening with mammography have been questioned, and there is evidence to indicate that supporting women to make an informed decision about breast cancer screening with mammography is preferable. The aims of this study were to assess the intention of family physicians to provide women with this support and the determinants of this intention, and to identify factors that might influence family physicians adopting this behavior.

METHODS

Family physicians from the province of Quebec, Canada, attending a 45-min lecture on informed decision making and cancer screening were asked to complete a questionnaire after the lecture regarding their intention to adopt the behavior. The questions, based on the Theory of Planned Behavior, measured physicians' intention and its determinants (attitude, perceived behavioral control, and socio-professional norm) regarding supporting women to make informed decisions about breast cancer screening with mammography. Open-ended questions were also used to explore complementary factors influencing their intention.

RESULTS

Out of 800 questionnaires distributed, 301 (38 %) were returned and 288 were included in data analysis. The mean ± standard deviation and median score for intention were respectively 1.9 ± 1.2 and 2.0 on a 6-point Likert scale (-3 to +3). Perceived behavioral control was the variable most strongly associated with intention (high versus low score, odds ratio = 15.7, 95 % CI 6.7-36.6), followed by attitude (high versus low score, odds ratio = 7.5, 95 % CI 3.3-16.8), then social norm (high versus low score, odds ratio = 5.8, 95 % CI 2.6-12.9). The most-reported barrier to adopting the behavior was time constraints (41 %) while the most-reported facilitator was availability of relevant decision support tools (29 %).

CONCLUSIONS

Respondents showed strong intention to support women in informed decision-making about breast cancer screening, the strongest predictor being perceived behavioral control. These results could contribute to training physicians to integrate this behavior into their practices and to designing relevant decision support tools.

Multicenter, randomized clinical trial to compare the safety and efficacy of LFF571 and vancomycin for Clostridium difficile infections

Clostridium difficile infection causes serious diarrheal disease. Although several drugs are available for treatment, including vancomycin, recurrences remain a problem. LFF571 is a semisynthetic thiopeptide with potency against C. difficile in vitro. In this phase 2 exploratory study, we compared the safety and efficacy (based on a noninferiority analysis) of LFF571 to those of vancomycin used in adults with primary episodes or first recurrences of moderate C. difficile infection. Patients were randomized to receive 200 mg of LFF571 or 125 mg of vancomycin four times daily for 10 days. The primary endpoint was the proportion of clinical cures at the end of therapy in the per-protocol population. Secondary endpoints included clinical cures at the end of therapy in the modified intent-to-treat (mITT) population, the time to diarrhea resolution, and the recurrence rate. Seventy-two patients were randomized, with 46 assigned to receive LFF571. Based on the protocol-specified definition, the rate of clinical cure for LFF571 (90.6%) was noninferior to that of vancomycin (78.3%). The 30-day sustained cure rates for LFF571 and vancomycin were 56.7% and 65.0%, respectively, in the per-protocol population and 58.7% and 60.0%, respectively, in the modified intent-to-treat population. Using toxin-confirmed cases only, the recurrence rates were lower for LFF571 (19% versus 25% for vancomycin in the per-protocol population). LFF571 was generally safe and well tolerated. The incidence of adverse events (AEs) was higher for LFF571 (76.1% versus 69.2% for vancomycin), although more AEs in the vancomycin group were suspected to be related to the study drug (38.5% versus 32.6% for LFF571). One patient receiving LFF571 discontinued the study due to an AE. (This study has been registered at ClinicalTrials.gov under registration no. NCT01232595.).

Activity of telavancin against heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) in vitro and in an in vivo mouse model of bacteraemia

OBJECTIVES

Infections caused by heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) are associated with high rates of vancomycin treatment failure. Telavancin is a bactericidal lipoglycopeptide active in vitro against Gram-positive pathogens including hVISA and vancomycin-intermediate S. aureus (VISA). This study characterizes the microbiological activity of telavancin against vancomycin-susceptible S. aureus (VSSA), hVISA and VISA strains.

METHODS

Reference strains of VSSA, hVISA and VISA were assessed for potential telavancin heteroresistance by population analysis. In addition, the efficacies of telavancin (40 mg/kg subcutaneously every 12 h for 4 days) and vancomycin (110 mg/kg subcutaneously every 12 h for 8 days) were compared in a neutropenic murine model (immunocompromised female non-Swiss albino mice) of bacteraemia caused by hVISA strain Mu3. Blood and spleen bacterial titres were quantified from cohorts of mice euthanized pre-treatment and at 24 h intervals post-treatment for 8 days.

RESULTS

Telavancin was active against all strains of S. aureus tested, with MIC values < or =0.5 mg/L. Population analyses revealed no evidence of subpopulations with reduced susceptibility to telavancin. In the murine bacteraemia model of hVISA infection, all animals were bacteraemic pre-treatment and mortality was 100% within 16-24 h post-infection in untreated animals. Treatment with telavancin was associated with lower spleen bacterial titres, lower rates of bacteraemia and lower overall mortality than treatment with vancomycin.

CONCLUSIONS

These in vitro and pre-clinical in vivo studies demonstrate that telavancin has the potential to be efficacious in infections caused by hVISA.

Do continuing medical education articles foster shared decision making?

INTRODUCTION

Defined as reviews of clinical aspects of a specific health problem published in peer-reviewed and non-peer-reviewed medical journals, offered without charge, continuing medical education (CME) articles form a key strategy for translating knowledge into practice. This study assessed CME articles for mention of evidence-based information on benefits and harms of available treatment and/or preventive options that are deemed essential for shared decision making (SDM) to occur in clinical practice.

METHODS

Articles were selected from 5 medical journals that publish CME articles and are provided free of charge to primary-care physicians of the Province of Quebec, Canada. Two individuals independently scored each article with the use of a 10-item checklist based on the International Patient Decision Aid Standards. In case of discrepancy, the item score was established by team consensus. Scores were added to produce a total article score ranging from 0 (no item present) to 10 (all items present).

RESULTS

Thirty articles (6 articles per journal) were selected. Total article scores ranged from 1 to 9, with a mean (+/- SD) of 3.1 +/- 2.0 (95% confidence interval 2.8-4.3). Health conditions and treatment options were the items most frequently discussed in the articles; next came treatment benefits. Possible harms, the use of the same denominators for benefits and harms, and methods to facilitate the communication of benefits and harms to patients were almost never described. No significant differences between journals were observed.

DISCUSSION

The CME articles evaluated did not include the evidence-based information necessary to foster SDM in clinical practice. Peer-reviewed and non-peer-reviewed medical journals should require CME articles to include this type of information.

Novel antibacterial azetidine lincosamides

The synthesis and evaluation of novel azetidine lincosamides 1 are described. Eleven new (3-trans-alkyl)azetidine-2-carboxylic acids were synthesized via alkylation of N-TBS-4-oxo-azetidine-2-carboxylic acid and subsequent elaboration then coupled to 7-chloro-1-methylthio-lincosamine. The resulting lincosamides differ from the drug clindamycin in both the size of the ring and the position/structure of the alkyl side-chain. SAR within the series was explored with attention to alkyl variants in positions 1 and 3 of the azetidine ring.

In vitro phototoxicity of glycoconjugated porphyrins and chlorins in colorectal adenocarcinoma (HT29) and retinoblastoma (Y79) cell lines

BACKGROUND

Retinoblastoma is the most common malignant intraocular tumor in children. The current treatment gives a good vital prognostic but there are several drawbacks to the arsenal of "classical antitumoral" therapies. Photodynamic therapy (PDT) could be an exciting non-toxic and non-mutagenic alternative protocol.

METHOD

In this paper, we report about the screening of the in vitro photocytotoxicity of hydrophenylporphyrins and chlorins and their glycoconjugated derivatives in a human retinoblastoma cell line (Y79) and for comparison in a colorectal adenocarcinoma cell line (HT29).

RESULTS

Despite lower photodynamic activity than that observed for hydroxylated photosensitizers, in particular Foscan(®) glycoconjugated derivatives display phototoxicity (IC50 2.4-0.05μM ±10%) against Y79 cells with examples of significant intrinsic cytotoxicity. Amongst them the triglucosyl porphyrin 10 is highly photocytotoxic (IC50 0.9μM ±10%) but is fully devoid of cytotoxicity (IC50>15μM). The photoactivity is highly modulated by the presence of a diethyleneglycol spacer between the chromophore and the glycoside (compounds 14-17, IC50 0.5, 0.6, 0.05 and 0.35μM ±10%) and by the anomeric configuration of the sugar (compound 15 and 17, IC50 0.6 and 0.05μM ±10% respectively). One of the main problems for the use of Foscan(®) is its poor solubility which might be improved by glycoconjugation. Moreover Foscan has been shown to induce necrosis after PDT leading to a possible ulceration of surrounding tissues unsuitable for a conservative treatment. A preferential mitochondrial subcellular localization which has been previously reported for some glycoconjugated photosensitizers could enhance the contribution of apoptosis process.

CONCLUSION

Tri-α-O-galactosyl porphyrin 16 is a better candidate than Foscan(®) for a clinical application of PDT for a conservative therapy of retinoblastoma.

Primary health care professionals' views on barriers and facilitators to the implementation of the Ottawa Decision Support Framework in practice

OBJECTIVE

To describe primary health care professionals' views on barriers and facilitators for implementing the Ottawa Decision Support Framework (ODSF) in their practice.

METHODS

Thirteen focus groups with 118 primary health care professionals were performed. A taxonomy of barriers and facilitators to implementing clinical practice guidelines was used to content-analyse the following sources: reports from each workshop, field notes from the principal investigator and written materials collected from the participants.

RESULTS

Applicability of the ODSF to the practice population, process outcome expectation, asking patients about their preferred role in decision making, perception that the ODSF was modifiable, time issues, familiarity with the ODSF and its practicability were the most frequently identified both as barriers as well as facilitators. Forgetting about the ODSF, interpretation of evidence, challenge to autonomy and total lack of agreement with using the ODSF in general were identified only as barriers. Asking about values, health professional's outcome expectation, compatibility with the patient-centered approach or the evidence-based approach, ease of understanding and implementation, and ease of communicating the ODSF were identified only as facilitators.

CONCLUSION

These results provide insight on the type of interventions that could be developed in order to implement the ODSF in academic primary care practice.

PRACTICE IMPLICATIONS

Interventions to implement the ODSF in primary care practice will need to address a broad range of factors at the levels of the health professionals, the patients and the health care system.

Conformational constraint in oxazolidinone antibacterials. Part 2: Synthesis and structure–activity studies of oxa-, aza-, and thiabicyclo[3.1.0]hexylphenyl oxazolidinones

A new class of oxazolidinone antibacterials incorporating oxygen-, nitrogen-, or sulfur-containing heterobicyclic C-rings is described. The in vitro potency and in vivo efficacy of these conformationally constrained oxazolidinone analogs are discussed.

A study of the stability of tri(glucosyloxyphenyl)chlorin, a sensitizer for photodynamic therapy, in human colon tumoural cells: a liquid chromatography and MALDI-TOF mass spectrometry analysis

Asymmetrical glycoconjugated tetrapyrrolic macrocycles are under study as efficient sensitizers for photodynamic therapy (PDT). In this context, tri(meta-O-beta-glucopyranosyloxyphenyl)chlorin [TPC(m-O-Glu)(3)] 2a/3a was found to be four times more photoactive in vitro than Foscan. In a further study of this interesting glycoconjugate, its metabolism by cellular glycosidases in HT29 cells has to be explored. Cellular extracts of HT29 cells incubated with TPC(m-O-Glu)(3) (24h, 6microM) were analyzed by MALDI-TOF mass spectrometry and high performance liquid chromatography (HPLC). In MALDI-TOF mass spectra, the presence of compounds distinct from TPC(m-O-Glu)(3) (m/z 1151) were observed at m/z 989, 827 and 665 corresponding to the loss of one, two or three glucose units (162u) and were be ascribed to TPC(m-OH)(m-O-Glu)(2) 2/3b,b',b", TPC(m-OH)(2)(m-O-Glu) 2/3c,c',c" and TPC(m-OH)(3) isomers 2d/3d, respectively. The porphyrins resulting from chlorin oxidation TPP(m-O-Glu)(3) 4a, TPP(m-OH)(m-O-Glu)(2) 4b,b", TPP(m-OH)(2)(m-O-Glu) 4c,c" and TPP(m-OH)(3) 4d were also observed. The HPLC profile (lambda(anal)=420 nm) showed eight peaks consistent with mass spectra. The kinetics of deglucosylation was studied from HPLC profiles between 1 and 48h incubation. The concentration of triglucoconjugated and diglucoconjugated molecules was maximum around 3 and 8h incubation, respectively, whereas, totally deglucosylated species appeared only after incubation for more than 10h. The fully deglycosylated porphyrin TPP(m-OH)(3) is the final metabolite, being observed at a concentration 15 times higher than that of the remaining TPC(m-O-Glu)(3) 2a/3a. Compared to the photobiological activity of the parent molecule [TPC(m-O-Glu)(3)], a three times higher TPP(m-OH)(3) concentration was necessary to observe a similar in vitro photoactivity.

Synthetic dihydropacidamycin antibiotics: a modified spectrum of activity for the pacidamycin class

Dihydropacidamycins having an antibacterial spectrum modified from that of the natural product pacidamycins and mureidomycins have been synthesized. Synthetic dihydropacidamycins with noteworthy antibacterial activity against wild-type and resistant Escherichia coli have been identified (MIC=4-8 microg/mL). Some dihydropacidamycins are shown to have activity against multi-resistant clinical strains of Mycobacterium tuberculosis. Compounds of this class are inhibitors of the cell wall biosynthetic enzyme, MraY.

Synthesis, cellular internalization and photodynamic activity of glucoconjugated derivatives of tri and tetra(meta-hydroxyphenyl)chlorins

Glucoconjugated tri and tetra(meta-hydroxyphenyl)chlorins have been synthesized in order to explore how glucoconjugation of the macrocycle affects the photoactivity of the molecule. Internalization processes, photosensitizing efficacy of TPC(m-O-GluOH)(3) and TPC(m-O-GluOH)(4), in HT29 human adenocarcinoma cells have been compared to those of tetra(meta-hydroxyphenyl) chlorin (m-THPC, Foscan). The tetra glucoconjugated chlorin, TPC(m-O-GluOH)(4), was found to be poorly internalized and weakly photoactive. In contrast, the asymmetric and more amphiphilic compound TPC(m-O-GluOH)(3), exhibited superior phototoxicity compared to m-THPC. Drug concentration, temperature and sodium azide effects indicated that TPC(m-O-GluOH)(3) internalization partly proceeds via an active receptor-mediated endocytosis mechanism. Cellular uptake appeared as a saturable process and remained 30% lower than for mTHPC. However, a maximum phototoxicity in HT29 cells (survival fraction of 2+/-0.6%) were observed for concentration as low as 2 microM. A 4-fold higher concentration of m-THPC was necessary to observe the same level of photoactivity. This higher phototoxicity has been correlated to a greater mitochondrial affinity. On the basis of these results, work is in progress to further evaluate the potential of glycosylated chlorins in photodynamic therapy (PDT).

Relationships between structure, antibacterial activity, serum stability, pharmacokinetics and efficacy in 3-(heteroarylthio)cephems. Discovery of RWJ-333441 (MC-04,546)

SAR studies in a series of related 3-(heteroarylthio)cephems determined that a relatively high chemical reactivity of the beta-lactam ring, modulated by electronic effects of substituents at C-3 and C-7, is necessary to achieve high in vitro activity against methicillin-resistant Staphylococcus aureus (MRSA). Such high reactivity results in lowered hydrolytic stability and concomitantly increases susceptibility to beta-lactam ring opening mediated by serum enzymes. Therefore, optimization of anti-MRSA activity versus stability toward serum-mediated degradation required a fine balance of substituent effects. Serum stability studies (measured as percentage of parent drug degraded after 60 min incubation) revealed up to 80-fold difference in degradation rate in a series of closely related (3-heteroarylthio)cephems. Of the compounds evaluated, RWJ-333441 (MC-04,546) possessed the best balance of serum stability (6% degradation after 60 min incubation) and in vitro activity versus MRSA (S. aureus COL MIC=1 microgram/mL). Accordingly, RWJ-333441 displayed excellent in vivo efficacy versus methicillin-susceptible Staphylococcus aureus (MSSA, ED(50)=0.39 mg/kg in mouse sepsis model with S. aureus Smith) and good pharmacokinetic properties in the rat (Cl(total)=0.39 L/h/kg).

RWJ-54428 (MC-02,479), a new cephalosporin with high affinity for penicillin-binding proteins, including PBP 2a, and stability to staphylococcal beta-lactamases

RWJ-54428 (MC-02,479) is a new cephalosporin active against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). The potency of this new cephalosporin against MRSA is related to a high affinity for penicillin-binding protein 2a (PBP 2a), as assessed in a competition assay using biotinylated ampicillin as the reporter molecule. RWJ-54428 had high activity against MRSA strains COL and 67-0 (MIC of 1 micro g/ml) and also showed affinity for PBP 2a, with a 50% inhibitory concentration (IC(50)) of 0.7 micro g/ml. RWJ-54428 also displayed excellent affinity for PBP 5 from Enterococcus hirae R40, with an IC(50) of 0.8 micro g/ml and a MIC of 0.5 micro g/ml. The affinity of RWJ-54428 for PBPs of beta-lactam-susceptible S. aureus (MSSA), enterococci (E. hirae), and Streptococcus pneumoniae showed that the good affinity of RWJ-54428 for MRSA PBP 2a and E. hirae PBP 5 does not compromise its binding to susceptible PBPs. RWJ-54428 showed stability to hydrolysis by purified type A beta-lactamase isolated from S. aureus PC1. In addition, RWJ-54428 displayed low MICs against strains of S. aureus bearing the four classes of staphylococcal beta-lactamases, including beta-lactamase hyperproducers. The frequency of isolation of resistant mutants to RWJ-54428 from MRSA strains was very low. In summary, RWJ-54428 has high affinity to multiple PBPs and is stable to beta-lactamase, properties that may explain our inability to find resistance by standard methods. These data are consistent with its excellent activity against beta-lactam-resistant gram-positive bacteria.

[The patient-centered interview and the way it is taught. What do family physicians who have recently received their degree think?]

OBJECTIVE

To describe how family physicians perceive the patient-centred interview (PCI) and the way in which it is taught during residency training.

DESIGN

Mailed survey.

SETTING

Family physicians from a variety of practice settings in Quebec.

PARTICIPANTS

Ninety-one family physicians who graduated from Laval University between 1996 and 1998.

METHOD

Survey was conducted in 1999 using the modified Dillman method. The original questionnaire had mainly open-ended questions on perception of the PCI and learning activities associated with it during residency training. All qualitative data were subject to content analysis using triangulation strategies.

MAIN FINDINGS

A PCI mainly involves exploring patients' experience of their illnesses; this helps physicians to better understand patients. Patients are more content with this type of interview and are, therefore, more likely to follow physicians' recommendations. Respondents reported the main drawback to be longer interview times; this was particularly true for emergency and walk-in care. The most useful learning activities during residency were reported to be supervision by direct observation and observation of supervisor-patient consultations.

CONCLUSION

Patient-centred interviews enabled physicians to understand and help their patients better. Results of this study can help teachers who are developing and consolidating activities to teach residents how to conduct PCIs and how to integrate them into practice.

Biodistribution of meta-tetra(hydroxyphenyl)chlorin incorporated into surface-modified nanocapsules in tumor-bearing mice

meta-Tetra(hydroxyphenyl)chlorin (mTHPC), a second generation photosensitizer used in photodynamic therapy (PDT), was incorporated into long circulating carriers with the aim of improving the tumor selectivity by limiting the reticuloendothelial system (RES) uptake. Biodistribution of mTHPC (0.06 mg kg(-1) was studied directly in nude mice bearing HT29 human tumor by optical fiber fluorimetry and tissue drug contents were determined by HPLC after extraction. The drug was incorporated in the oily core of nanocapsules surrounded by poly(D,L lactic acid) (PLA NCs), PLA grafted with polyethylene glycol (PLA-PEG) or PLA coated with poloxamer 188 (polox PLA). Compared to PLA NCs, incorporation of mTHPC in surface-modified nanocapsules resulted in strong modifications of the drug biodistribution and tumoral retention with a three-fold increase of drug level as early as 24 h post-administration. A reduced liver uptake was observed at early times post-administration indicating that surface-modified NCs are effective in limiting the RES uptake and could be potential carriers to enhance the therapeutic ratio of lipophilic photosensitizers. Furthermore, in situ fluorescence measurements and concentration data were found in broad agreement showing that optical fiber fluorimetry is a very sensitive method that can be used to follow the biodistribution of fluorescent drugs in real-time.

Participants' perception of impact of a workshop on their preventive practices

A 90-minute interactive workshop, offered to small groups on request, was developed to help physicians include evidence-based preventive interventions in their practices. Between 25 September 1996 and 10 December 1997, 593 family physicians throughout the Province of Quebec (Canada) participated in one of the 40 workshops presented in all the regions of Quebec. Almost all participants (98%) completed the self-administered questionnaire. Their opinion of the achievement of three workshop objectives were evaluated using a seven-point Likert scale (-3 to +3)as their perception of the direct impact of the workshop on their practice. The workshop objectives were reached to a high degree: 2.1 (sd 0.90) for prescribing a proper check-up for adults; 1.83(sd 1.02) for explaining to the patient the reasons motivating his/her choice to include or exclude certain tests; 2.09 (sd 0.93)for using concrete and useful tool facilitating the integration of preventive measures in his/her professional practice. Female physicians and those under 40 perceived that the objectives were reached to a greater degree. Participants indicate their intention to modify their practice according to the clinical practice guidelines presented in the workshop.

A direct sensitized fluorimetric determination of 5,10,15,20-tetra(m-hydroxyphenyl)chlorin [m-THPC (Foscan)] in human plasma using a cyclodextrin inclusion complex

The 5,10,15,20-tetra(m-hydroxyphenyl)chlorin (m-THPC) (Foscan) is a photosensitizer used in the photodynamic therapy (PDT) of cancers which is currently under clinical trial. The formation of a m-THPC inclusion complex with dimethyl-beta-cyclodextrin (Me-beta-CD) in solution was demonstrated on the basis of circular dichroism experiments. A 1:2 complex stoichiometry was found and an inclusion constant beta 2 = 2.8(+/- 0.4) x 10(10) M-2 was determined. The formation of such a complex was shown to enhance the m-THPC fluorescence intensity. It could be exploited to improve the sensitivity of the direct m-THPC detection in human plasma. Optimization of the operating conditions shows that the best results were obtained by the addition of 100 microL of a concentrated Me-beta-CD solution (3.2 x 10(-2) M) to 1 mL plasma samples. Compared to the standard conditions, a 90% increase in sensitivity was obtained. The proposed analytical method which showed a linear response function [0-300 ng mL-1 (440 pM)] and a low limit of detection [1.5 ng mL-1 (2 pM) (S/N = 3)] appears, especially due to the absence of metabolism, a simple and specific method suitable for pharmacokinetics studies in patients.

In vitro activities of RWJ-54428 (MC-02,479) against multiresistant gram-positive bacteria

RWJ-54428 (MC-02,479) is a new cephalosporin with a high level of activity against gram-positive bacteria. In a broth microdilution susceptibility test against methicillin-resistant Staphylococcus aureus (MRSA), RWJ-54428 was as active as vancomycin, with an MIC at which 90% of isolates are inhibited (MIC(90)) of 2 microg/ml. For coagulase-negative staphylococci, RWJ-54428 was 32 times more active than imipenem, with an MIC(90) of 2 microg/ml. RWJ-54428 was active against S. aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus isolates with reduced susceptibility to glycopeptides (RWJ-54428 MIC range, < or = 0.0625 to 1 microg/ml). RWJ-54428 was eight times more potent than methicillin and cefotaxime against methicillin-susceptible S. aureus (MIC(90), 0.5 microg/ml). For ampicillin-susceptible Enterococcus faecalis (including vancomycin-resistant and high-level aminoglycoside-resistant strains), RWJ-54428 had an MIC(90) of 0.125 microg/ml. RWJ-54428 was also active against Enterococcus faecium, including vancomycin-, gentamicin-, and ciprofloxacin-resistant strains. The potency against enterococci correlated with ampicillin susceptibility; RWJ-54428 MICs ranged between < or = 0.0625 and 1 microg/ml for ampicillin-susceptible strains and 0.125 and 8 microg/ml for ampicillin-resistant strains. RWJ-54428 was more active than penicillin G and cefotaxime against penicillin-resistant, -intermediate, and -susceptible strains of Streptococcus pneumoniae (MIC(90)s, 0.25, 0.125, and < or = 0.0625 microg/ml, respectively). RWJ-54428 was only marginally active against most gram-negative bacteria; however, significant activity was observed against Haemophilus influenzae and Moraxella catarrhalis (MIC(90)s, 0.25 and 0.5 microg/ml, respectively). This survey of the susceptibilities of more than 1,000 multidrug-resistant gram-positive isolates to RWJ-54428 indicates that this new cephalosporin has the potential to be useful in the treatment of infections due to gram-positive bacteria, including strains resistant to currently available antimicrobials.

Importance of the ionization states of m-THPC for its HPLC fluorescence detection

An original, rapid and sensitive high-performance liquid chromatographic (HPLC) method has been developed for the detection of 5, 10, 15, 20 tetra-meso-hydroxyphenylchlorine (m-THPC), a photosensitizer used in the photodynamic therapy (PDT) of cancers. Chromatographic separation was carried out on a C(8) Zorbax column (80 x 4 mm, 5 microm). The mobile phase was an ethanol/aqueous sulphuric acid, pH 2.0 (65/35 v/v), in an isocratic mode yielding to rapid analysis (3.1 min) with narrow peaks. As the fluorescence intensity was found to be highly pH-dependent and to increase with pH values, a post-column device prior to the fluorescence detection (lambda(exc) = 423 nm, lambda(em) = 650 nm) was used to allow the addition of a 0.05 mol/L Na(2)HPO(4) solution to the mobile phase. Compared to standard conditions, a 300% increase of the fluorescence intensity was obtained for optimized operating conditions using experimental design. The validation of this analytical method showed that the response function was linear for concentrations up to 1000 microg/L (1.47 x 10(-6) mol/L) with a detection limit of 188 pg (S/N = 3).

Identification and characterization of inhibitors of multidrug resistance efflux pumps in Pseudomonas aeruginosa: novel agents for combination therapy

Whole-cell assays were implemented to search for efflux pump inhibitors (EPIs) of the three multidrug resistance efflux pumps (MexAB-OprM, MexCD-OprJ, MexEF-OprN) that contribute to fluoroquinolone resistance in clinical isolates of Pseudomonas aeruginosa. Secondary assays were developed to identify lead compounds with exquisite activities as inhibitors. A broad-spectrum EPI which is active against all three known Mex efflux pumps from P. aeruginosa and their close Escherichia coli efflux pump homolog (AcrAB-TolC) was discovered. When this compound, MC-207,110, was used, the intrinsic resistance of P. aeruginosa to fluoroquinolones was decreased significantly (eightfold for levofloxacin). Acquired resistance due to the overexpression of efflux pumps was also decreased (32- to 64-fold reduction in the MIC of levofloxacin). Similarly, 32- to 64-fold reductions in MICs in the presence of MC-207,110 were observed for strains with overexpressed efflux pumps and various target mutations that confer resistance to levofloxacin (e.g., gyrA and parC). We also compared the frequencies of emergence of levofloxacin-resistant variants in the wild-type strain at four times the MIC of levofloxacin (1 microg/ml) when it was used either alone or in combination with EPI. In the case of levofloxacin alone, the frequency was approximately 10(-7) CFU/ml. In contrast, with an EPI, the frequency was below the level of detection (<10(-11)). In summary, we have demonstrated that inhibition of efflux pumps (i) decreased the level of intrinsic resistance significantly, (ii) reversed acquired resistance, and (iii) resulted in a decreased frequency of emergence of P. aeruginosa strains that are highly resistant to fluoroquinolones.

Endoscopic ultraviolet-induced autofluorescence spectroscopy of the esophagus: tissue characterization and potential for early cancer diagnosis

BACKGROUND AND STUDY AIMS

Endoscopic identification of dysplasia and early carcinoma of the esophagus is difficult and is currently done through random pinch biopsies. This study assesses the potential of ultraviolet-induced autofluorescence spectroscopy for early diagnosis with special focus on Barrett's esophagus.

PATIENTS AND METHODS

Measurements were performed on 24 patients using 330 nm light excitation. The determination of the spectral distribution typical of each histological tissue type was done using three fluorescence intensity ratios: RI = I390nm/I450nm; R2 = I550nm/I450nm; R3 - I390nm/I550nm.

RESULTS

The spectral distribution of normal esophageal mucosa and specialized columnar Barrett's mucosa were similar. A strong modification of the spectral distribution was observed for high grade dysplasia and intramucosal carcinoma. Statistical analysis indicated that the spectral shape modification associated with neoplastic transformation was greater than intra- and interpatient spectral variations. These results allow the determination of discriminating criteria based on ratios R1 and R3. Using ratio R3, the spectroscopy-based diagnosis differentiated neoplastic tissue from normal esophageal mucosa and specialized columnar Barrett's mucosa with a sensitivity and specificity of 86% and 95 %, respectively.

CONCLUSIONS

The use of ultraviolet autofluorescence spectroscopy should improve the diagnostic yield of standard endoscopy in patients with Barrett's esophagus.

A comparative study of the cellular uptake, localization and phototoxicity of meta-tetra(hydroxyphenyl) chlorin encapsulated in surface-modified submicronic oil/water carriers in HT29 tumor cells

The poor selectivity of photosensitizers for tumor tissue remains a drawback in photodynamic therapy (PDT) and could be improved by adapted formulations. The cellular uptake, localization and phototoxicity of meta-tetra(hydroxyphenyl)chlorin (mTHPC) encapsulated in submicronic colloidal carriers have been studied in macrophage-like J774 cells and HT 29 human adenocarcinoma cells. Nanocapsules with an external layer made of poly(D,L lactic acid) (PLA NCs), PLA grafted with polyethylene glycol (PLA-PEG NCs), PLA coated with poloxamer 188 (polox PLA NCs) and oil/water nanoemulsion (NE) have been examined. The cellular uptake by J774, as determined by microspectroflorimetry, is reduced with mTHPC encapsulated into surface-modified NCs--PLA-PEG and polox PLA--compared with naked PLA, indicating a possible limitation of the clearance of such carriers by the reticuloendothelial system. Encapsulation also modifies the interaction between mTHPC and HT29 cells. Compared with the manufacturer's solution (PEG, ethanol, water), the cellular uptake is strongly reduced. However, the HT29 phototoxicity is much less affected and a protecting effect against plasma proteins is observed. Fluorescence microscopy reveals a specific punctate fluorescence pattern with PLA-PEG and polox PLA NCs in contrast to a more diffuse distribution with NE and solution, indicating that photodamage targeting could be different. These findings suggest that photosensitizers encapsulated into surface-modified nanocapsules could be a promising approach for improving PDT efficacy and this has to be confirmed in vivo.

Fluorescence and mass spectrometry studies of meta-tetra(hydroxyphenyl)chlorin photoproducts

The meta-tetra(hydroxyphenyl)chlorin (m-THPC), a second-generation sensitizer used in photodynamic therapy (PDT), is currently under clinical trial. In vivo fluorometry provides direct evidence that photobleaching processes are induced at the tumor site during PDT. Photoproduct formation has thus to be taken into account to fully understand PDT treatment. A preliminary step is to determine the fluorescence characteristics of photoproducts formed in solution. Solutions of m-THPC irradiated at 514 nm have been separated by HPLC using absorption and fluorescence detection. Six main photoproducts have been isolated. According to matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) results, five fluorescent photoproducts emitting at 652 nm have been attributed to three mono-, one di- and one tri-hydroxy derivatives (m/z 697, 713 and 729, respectively). Fluorescence characteristics of mono-hydroxy forms were found to be similar to those of m-THPC, whereas fluorescence yields in di- and tri-hydroxy derivatives were very low. Another product, corresponding to a MALDI-TOF MS main signal at m/z 542, showed an absorption spectrum maximum at 522 nm while a weak fluorescence was detected at 480 nm. The loss of the Soret band suggests that this photoproduct results from the opening of the reduced pyrrole ring. The part played by each of these products in the photobleaching phenomenon of m-THPC is discussed.

Palliative education: a didactic and experiential approach to teaching end-of-life care

BACKGROUND

The training in palliative care that health professionals receive is inadequate. An aging population, changing systems of health care delivery, and the debate about euthanasia and physician-assisted suicide increase the importance of ongoing education about palliative care.

METHODS

Three modules are offered by the University of California, Davis, West Coast Center for Palliative Education (WCCPE). Module 1, offered on-site, blends didactic and field learning using lectures, case studies, patient contact, and role modeling. Module 2 programs, held off-site, are customized in collaboration with the sponsor to address local needs and concerns. This module emphasizes group discussion and problem solving. Module 3 trains health care and custody staff and volunteer inmates at correctional facilities. Inmate training focuses on developing communication skills and a capacity to empathize through experiential exercises, dialog, and role-playing.

RESULTS

Off-site training significantly improved self-assessed knowledge about pain management and attitudes towards end-of-life care. Qualitative measures showed enhanced care-delivery skills for participants in all three modules.

CONCLUSIONS

Palliative care education can be enhanced when delivered close to the point of care using multimodal techniques that influence attitudes as well as knowledge.

Fungicidal properties of meso-arylglycosylporphyrins: influence of sugar substituents on photoinduced damage in the yeast Saccharomyces cerevisiae

A series of neutral meso-arylglycosylporphyrins has been tested in order to evaluate their potency as antifungal agents against the yeast Saccharomyces cerevisiae. Photodynamic activity of these molecules results in intracellular damage as evidenced by the loss of clonogenicity and DNA fragmentation. The ability of these photosensitizers to permeate yeast cells is determined by microspectrofluorimetry and is correlated with their antifungal potency. Amphiphilic porphyrin derivatives are shown to exhibit the more pronounced photoactivity.