Thermodynamic and structural properties of lipid-photosensitizer conjugates mixed with phospholipids: Impact on the formation and stability of nano-assemblies

The photosensitizer Phenalenone (PN) was grafted with one or two lipid (C18) chains to form pure nano-assemblies or mixed lipid vesicles suitable for photodynamic therapy. Mixtures of PN-C18 conjugates with stearoyl-oleoyl phosphatidylcholine (SOPC) form vesicles that disintegrate into bilayer sheets as the concentration of PN-C18 conjugates increases. We hypothesized that PN-C18 conjugates control the thermodynamic and structural properties of the mixtures and induce the disintegration of vesicles due to PN π-π-interactions. Monolayers were analyzed by surface pressure and grazing incidence X-ray diffraction (GIXD) measurements, and vesicles by differential scanning calorimetry and cryo-TEM. The results showed that PN-triazole-C18 (1A) and PN-NH-C18 (1B) segregate from the phospholipid domains. PN-(C18)2 (conjugate 2) develops favorable interactions with SOPC and distearoyl-phosphatidylcholine (DSPC). GIXD demonstrates the contribution of SOPC to the structuring of conjugate 2 and the role of the major component in controlling the structural properties of DSPC-conjugate 2 mixtures. Above 10 mol% conjugate 2 in SOPC vesicles, the coexistence of domains with different molecule packing leads to conjugate segregation, vesicle deformation, and the formation of small bilayer discs stabilized by the inter-bilayer π-π stacking of PN molecules.

Gemcitabine lipid prodrug nanoparticles: Switching the lipid moiety and changing the fate in the bloodstream

A simple approach to achieve a lipoprotein (LP)-mediated drug delivery is to trigger the spontaneous drug insertion into endogenous lipoproteins in the bloodstream, by means of its chemical modification. Nanoparticles (NPs) made of the squalene-gemcitabine (SQGem) conjugate were found to have a high affinity for plasma lipoproteins while free gemcitabine did not, suggesting a key role of the lipid moiety in this event. Whether the drug conjugation to cholesterol, one of the major lipoprotein-transported lipids, could also promote an analogous interaction was a matter of question. NPs made of the cholesterol-gemcitabine conjugate (CholGem) have been herein thoroughly investigated for their blood distribution profile both in vitro and in vivo. Unexpectedly, contrarily to SQGem, no trace of the CholGem prodrug could be found in the lipoprotein fractions, nor was it interacting with albumin. The investigation of isolated NPs and NPs/LPs physical mixtures provided a further insight into the lack of interaction of CholGem NPs with LPs. Although essential for allowing the self-assembly of the prodrug into nanoparticles, the lipid moiety may not be sufficient to elicit interaction of the conjugated drug with plasma lipoproteins but the whole NP physicochemical features must be carefully considered.

Electrografting and Langmuir-Blodgett: Covalently Bound Nanometer-Thick Ordered Films on Graphite

We present two different molecular organizations obtained from octadecylamine (ODA) molecules on a highly oriented pyrolytic graphite (HOPG) surface: (i) self-organized physisorbed ODA molecules lying flat on the surface and (ii) a strongly electrografted compact crystalline monolayer of ODA molecules standing up on the surface. This new structure is obtained by combining the Langmuir-Blodgett transfer of an ODA Langmuir film onto HOPG with oxidative electrografting. The presence of an organic film on HOPG is characterized by attenuated total reflectance-infrared spectroscopy and Raman spectroscopy, while atomic force microscopy and scanning tunneling microscopy allow the observation of the two molecular organizations with adsorbed molecules lying flat on HOPG or strongly grafted in an upright position on the HOPG surface. Interestingly, the second molecular organization preserves a hexagonal symmetry and its lattice parameters are intermediate between those of ODA Langmuir films and that of the HOPG underlying surface. The functionalization of surfaces with organic films is a major issue in the design of sensors with biomedical applications or organic electronics and energy storage devices and these structures may find applications in these fields.

Bioinspired polydopamine nanoparticles: synthesis, nanomechanical properties, and efficient PEGylation strategy

Polydopamine (PDA) is a bioinspired fascinating polymer which is considered nowadays as a material of choice for designing drug delivery nanosystems. Indeed, PDA exhibits multiple interesting features including simple preparation protocols, biocompatibility, simple functionalization procedures, free radicals scavenging and photothermal/photoacoustic properties. However, because of its heterogeneous structure, clear procedures about PDA nanoparticles synthesis and PEGylation with well-defined and reproducible physicochemical properties such as size, shape and nanomechanics are still needed. In this work, we established tightly controlled experimental conditions to synthesize PDA nanoparticles with well-defined size and yield. This allowed us to identify the factors that affect the most these two parameters and to construct surface response plots with accurate predictive values of size and yield. The nanomechanical properties of PDA NPs exhibiting different sizes have been studied with AFM nanoindentation experiments. Our results demonstrated for the first time that the elasticity of PDA NPs was decreasing with their size. This could be explained by the higher geometric packing order of the stacked oligomeric fractions inside the core of the biggest PDA NPs. Next, in order to determine the best PEGylation experimental conditions of PDA NPs using thiol-terminated PEG that allow grafting the highest polymer density with proteins repelling properties, we have first optimized the PEGylation strategy on PDA films. By using a combination of QCM-D and AFM experiments, we could demonstrate that efficient PEGylation of PDA films could be done even at low PEG concentration but in the presence of NaCl which exerts a salting out effect on PEG chains improving thus the grafting density. Finally, we transposed these experimental conditions to PDA NPs and we could synthesize PEGylated PDA NPs exhibiting high stability in physiological conditions as revealed by FTIR and DLS experiments respectively.

From Langmuir-Blodgett to Grafted Films

A locally organized monolayer film strongly attached to a gold surface is obtained by transfer of a Langmuir-Blodgett (LB) film of octadecylamine (ODA) or alcohol (ODOH) onto a Au surface and simultaneous oxidative electrografting of this film still in contact with the aqueous subphase. As opposed to LB films, these films resist ultrasonication; and unlike electrografted films, they are organized monolayers by construction. They are characterized by AFM (atomic force microscopy), water contact angle, ellipsometry, XPS (X-ray photoelectron spectroscopy), IRRAS (infrared reflection absorption spectroscopy), and GIXD (grazing incidence X-ray diffraction).

Stacking as a Key Property for Creating Nanoparticles with Tunable Shape: The Case of Squalenoyl-Doxorubicin

The development of elongated nanoparticles for drug delivery is of growing interest in recent years, due to longer blood circulation and improved efficacy compared to spherical counterparts. Squalenoyl-doxorubicin (SQ-Dox) conjugate was previously shown to form elongated nanoparticles with improved therapeutic efficacy and decreased toxicity compared to free doxorubicin. By using experimental and computational techniques, we demonstrate here that the specific physical properties of SQ-Dox, which include stacking and electrostatic interactions of doxorubicin as well as hydrophobic interactions of squalene, are involved in the formation of nanoassemblies with diverse elongated structures. We show that SQ-Dox bioconjugate concentration, ionic strength, and anion nature can be used to modulate the shape and stiffness of SQ-Dox nanoparticles. As those parameters are involved in nanoparticle behavior in biological media, these findings could bring interesting opportunities for drug delivery and serve as an example for the design of original nanodrugs with stacking properties tuned for particular clinical purposes.

Towards a clinical application of freeze-dried squalene-based nanomedicines

Squalene-adenosine (SQAd) nanoparticles (NPs) were found to display promising pharmacological activity similar to many other nanomedicines, but their long-term stability was still limited, and their preparation required specific know-how and material. These drawbacks represented important restrictions for their potential use in the clinic. Freeze-drying nanoparticles is commonly presented as a solution to allow colloidal stability, but this process needs to be adapted to each nanoformulation. Hence, we aimed at developing a specific protocol for freeze-drying SQAd NPs while preserving their structural features. NPs were lyophilised, resuspended and analysed by dynamic light scattering, atomic force microscopy and small-angle scattering. Among four different cryoprotectants, trehalose was found to be the most efficient in preserving NPs physico-chemical characteristics. Interestingly, we identified residual ethanol in NP suspensions as a key parameter which could severely affect the freeze-drying outcome, leading to NPs aggregation. Long-term stability was also assessed. No significant change in size distribution or zeta potential could be detected after three-month storage at 4 °C. Finally, freeze-dried NPs innocuity was checked in vitro on cultured hepatocytes and in vivo on mice. In conclusion, optimisation of freeze-drying conditions resulted in safe lyophilised SQAd NPs that can be easily stored, shipped and simply reconstituted into an injectable form.

The puzzling construction of the conidial outer layer of Aspergillus fumigatus

If the mycelium of Aspergillus fumigatus is very short-lived in the laboratory, conidia can survive for years. This survival capacity and extreme resistance to environmental insults is a major biological characteristic of this fungal species. Moreover, conidia, which easily reach the host alveola, are the infective propagules. Earlier studies have shown the role of some molecules of the outer conidial layer in protecting the fungus against the host defense. The outer layer of the conidial cell wall, directly in contact with the host cells, consists of α-(1,3)-glucan, melanin, and proteinaceous rodlets. This study is focused on the global importance of this outer layer. Single and multiple mutants without one to three major components of the outer layer were constructed and studied. The results showed that the absence of the target molecules resulting from multiple gene deletions led to unexpected phenotypes without any logical additivity. Unexpected compensatory cell wall surface modifications were indeed observed, such as the synthesis of the mycelial virulence factor galactosaminogalactan, the increase in chitin and glycoprotein concentration or particular changes in permeability. However, sensitivity of the multiple mutants to killing by phagocytic host cells confirmed the major importance of melanin in protecting conidia.

Relevance of charges and polymer mechanical stiffness in the mechanism and kinetics of formation of liponanoparticles probed by the supported bilayer model approach

Parameters controlling the mechanism and kinetics of formation of liponanoparticles are determined using supported lipid bilayer models.

Mannose distribution in glycoconjugated tetraphenylporphyrins governs their uptake mechanism and phototoxicity

Tetraphenylporphyrins (TPPs) have been proposed for the treatment of retinoblastoma by photodynamic therapy. Glycoconjugated compounds were synthesized for improving TPP solubility and amphipathy, and to specifically target mannose receptors overexpressed at the surface of cells. The efficiency of four TPP derivatives with different chemical structures was compared by phototoxicity tests and flow cytometry experiments. Interestingly, the absence/presence and distribution of saccharide moieties in the various compounds affected differently their mechanism of interaction with cancer cells and their phototoxic efficiency. For glycodendrimeric TPP-1 and TPP-2 incubated with retinoblastoma cells, a fast two-step uptake-equilibrium process was observed, whereas for a dendrimeric TPP without saccharide moieties (TPP-1c) and a glycoconjugated compound with no dendrimeric structure (TPP(DegMan)[Formula: see text] uptake was very slow. The difference in uptake profiles and kinetics between TPP-1c on the one hand and TPP-1 and TPP-2 on the other hand would account for the interaction of the two glycodendrimeric compounds with a mannose receptor. These TPPs encapsulated in endosomes would induce less damage to cells upon illumination. TPP(DegMan)[Formula: see text] showed the highest phototoxicity, but its efficiency was unaffected by pretreatment of cells by mannan. The penetration of this glycoconjugated compound in cells and its phototoxic effect appeared independent of its interaction with a mannose receptor. Thus, if glycoconjugation influenced TPPs behavior in solution and interaction with serum proteins, phototoxicity was not necessarily related to upfront molecular recognition.

Novel Perfluorinated Triblock Amphiphilic Copolymers for Lipid-Shelled Microbubble Stabilization

Amphiphilic triblock (Atri) copolymers made of perfluorinated alkyl chain linked to hydrocarbon chain and methoxy-poly(ethylene glycol) of three different molecular weights were synthesized. In vitro evaluation demonstrated that these new compounds were noncytotoxic. Characterization and interaction of each triblock copolymer with a branched polyamine myristoyl lipid (2-{3[bis-(3-amino-propyl)-amino]-propylamino}- N-ditetradecyl carbamoyl methyl-acetamide, DMAPAP) were studied by the Langmuir film method and thermal analysis. The triblock copolymer/cationic lipids (1:10, w/w) were mixed with perfluorobutane gas to form microbubbles (MBs). The latter were characterized by optical microscopy to get the microbubble size and concentration by densimetry to determine the amount of encapsulated gas and by ultrasound to assess oscillation properties. Atri with the lowest and intermediate weights were shown to interact with the cationic lipid DMAPAP and stabilize the Langmuir film. In that case, monodisperse microbubbles ranging from 2.3 ± 0.1 to 2.8 ± 0.1 μm were obtained. The proportion of encapsulated gas within the MB shell increased up to 3 times after the incorporation of the copolymer with the lowest and intermediate weights. Moreover, the acoustic response of the microbubbles was maintained in the presence of the copolymers.

Disruption of Asymmetric Lipid Bilayer Models Mimicking the Outer Membrane of Gram-Negative Bacteria by an Active Plasticin

The outer membrane (OM) of Gram-negative bacteria is a complex and asymmetric bilayer that antimicrobial peptides must disrupt in order to provoke the cell lysis. The inner and external leaflets of the OM are mainly composed of phospholipids (PL), and lipopolysaccharide (LPS), respectively. Supported lipid bilayers are interesting model systems to mimic the lipid asymmetric scaffold of the OM and determine the quantitative and mechanistic effect of antimicrobial agents, using complementary physicochemical techniques. We report the formation of asymmetric PL/LPS bilayers using the Langmuir-Blodgett/Langmuir-Schaefer technique on two different surfaces (sapphire and mica) with synthetic phospholipids constituting the inner leaflet and bacteria-extracted mutant LPS making up the outer one. The combination of neutron reflectometry and atomic force microscopy techniques allowed the examination of the asymmetric scaffold structure along the normal to the interface and its surface morphology in buffer conditions. Our results allow discrimination of two structurally related peptides, one neutral and inactive, and the other cationic and active. The active cationic plasticin PTCDA1-KF disrupts the asymmetric OM at relevant concentrations through a carpeting scenario characterized by a dramatic removal of lipid molecules from the surface.

Building Bridges for Innovation in Ageing: Synergies between Action Groups of the EIP on AHA

The Strategic Implementation Plan of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) proposed six Action Groups. After almost three years of activity, many achievements have been obtained through commitments or collaborative work of the Action Groups. However, they have often worked in silos and, consequently, synergies between Action Groups have been proposed to strengthen the triple win of the EIP on AHA. The paper presents the methodology and current status of the Task Force on EIP on AHA synergies. Synergies are in line with the Action Groups' new Renovated Action Plan (2016-2018) to ensure that their future objectives are coherent and fully connected. The outcomes and impact of synergies are using the Monitoring and Assessment Framework for the EIP on AHA (MAFEIP). Eight proposals for synergies have been approved by the Task Force: Five cross-cutting synergies which can be used for all current and future synergies as they consider overarching domains (appropriate polypharmacy, citizen empowerment, teaching and coaching on AHA, deployment of synergies to EU regions, Responsible Research and Innovation), and three cross-cutting synergies focussing on current Action Group activities (falls, frailty, integrated care and chronic respiratory diseases).

The bacterial cell envelope as delimiter of anti-infective bioavailability - An in vitro permeation model of the Gram-negative bacterial inner membrane

Gram-negative bacteria possess a unique and complex cell envelope, composed of an inner and outer membrane separated by an intermediate cell wall-containing periplasm. This tripartite structure acts intrinsically as a significant biological barrier, often limiting the permeation of anti-infectives, and so preventing such drugs from reaching their target. Furthermore, identification of the specific permeation-limiting envelope component proves difficult in the case of many anti-infectives, due to the challenges associated with isolation of individual cell envelope structures in bacterial culture. The development of an in vitro permeation model of the Gram-negative inner membrane, prepared by repeated coating of physiologically-relevant phospholipids on Transwell^® filter inserts, is therefore reported, as a first step in the development of an overall cell envelope model. Characterization and permeability investigations of model compounds as well as anti-infectives confirmed the suitability of the model for quantitative and kinetically-resolved permeability assessment, and additionally confirmed the importance of employing bacteria-specific base materials for more accurate mimicking of the inner membrane lipid composition - both advantages compared to the majority of existing in vitro approaches. Additional incorporation of further elements of the Gram-negative bacterial cell envelope could ultimately facilitate model application as a screening tool in anti-infective drug discovery or formulation development.

The European Union Geriatric Medicine Society (EUGMS) Working Group on «Frailty in Older Persons»

The concept of frailty was introduced in literature to help atclinically depicting the transition of a robust older individualinto a different clinical phenotype of risk (1-5). Frailty isgenerally described as a multisystemic impairment responsiblefor a state of increased vulnerability to endogenous andexogenous stressors (6, 7). This syndrome may represent thefirst step towards the evident and clinically relevant functionaldisability (a cornerstone outcome for geriatric medicine)8, andhas shown to be predictive of major negative health-relatedevents, including

Operational Definition of Active and Healthy Ageing (AHA): A Conceptual Framework

Health is a multi-dimensional concept, capturing how people feel and function. The broad concept of Active and Healthy Ageing was proposed by the World Health Organisation (WHO) as the process of optimizing opportunities for health to enhance quality of life as people age. It applies to both individuals and population groups. A universal Active and Healthy Ageing definition is not available and it may differ depending on the purpose of the definition and/or the questions raised. While the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) has had a major impact, a definition of Active and Healthy Ageing is urgently needed. A meeting was organised in Montpellier, France, October 20-21, 2014 as the annual conference of the EIP on AHA Reference Site MACVIA-LR (Contre les Maladies Chroniques pour un Vieillissement Actif en Languedoc Roussillon) to propose an operational definition of Active and Healthy Ageing including tools that may be used for this. The current paper describes the rationale and the process by which the aims of the meeting will be reached.

Charge and aggregation pattern govern the interaction of plasticins with LPS monolayers mimicking the external leaflet of the outer membrane of Gram-negative bacteria

Bacterial resistance to antibiotics has become today a major public health issue. In the development of new anti-infectious therapies, antimicrobial peptides appear as promising candidates. However, their mechanisms of action against bacterial membranes are still poorly understood. We describe for the first time the interaction and penetration of plasticins into lipid monolayers and bilayers modeling the two leaflets of the asymmetrical outer membrane of Gram-negative bacteria. The lipid composition of these monolayers mimics that of each leaflet: mixtures of LPS Re 595 mutant and wild type S-form from Salmonella enterica for the external leaflet, and SOPE/SOPG/cardiolipin (80/15/5) for the inner one. The analysis of the interfacial behavior of native (PTCDA1) and modified (PTCDA1-KF) antimicrobial plasticins showed that PTCDA1-KF exhibited better surface properties than its unmodified counterpart. Both peptides could penetrate into the model monolayers at concentrations higher than 0.1 μM. The penetration was particularly enhanced for PTCDA1-KF into the mixed LPS monolayer, due to attractive electrostatic interactions. Grazing X-ray diffraction and atomic force microscopy studies revealed the changes in LPS monolayers organization upon peptide insertion. The interaction of plasticins with liposomes was also monitored by light scattering and circular dichroism techniques. Only the cationic plasticin achieved full disaggregation and structuration in α helices, whereas the native one remained aggregated and unstructured. The main steps of the penetration mechanism of the two plasticins into lipid models of the external leaflet of the outer membrane of Gram-negative bacteria have been established.

Integrated care pathways for airway diseases (AIRWAYS-ICPs)

The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy and will add value to existing public health knowledge by: 1) proposing a common framework of care pathways for chronic respiratory diseases, which will facilitate comparability and trans-national initiatives; 2) informing cost-effective policy development, strengthening in particular those on smoking and environmental exposure; 3) aiding risk stratification in chronic disease patients, using a common strategy; 4) having a significant impact on the health of citizens in the short term (reduction of morbidity, improvement of education in children and of work in adults) and in the long-term (healthy ageing); 5) proposing a common simulation tool to assist physicians; and 6) ultimately reducing the healthcare burden (emergency visits, avoidable hospitalisations, disability and costs) while improving quality of life. In the longer term, the incidence of disease may be reduced by innovative prevention strategies. AIRWAYSICPs was initiated by Area 5 of the Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing. All stakeholders are involved (health and social care, patients, and policy makers).

Interactions of antileishmanial drugs with monolayers of lipids used in the development of amphotericin B-miltefosine-loaded nanocochleates

The emergence of strains of Leishmania resistant to existing drugs complicates the treatment of life-threatening visceral leishmaniasis. The development of new lipid formulation (nanocochleates), containing two active drugs: amphotericin B (AmB) and miltefosine (hexadecylphosphocholine, HePC), could increase effectiveness, decrease toxicity and reduce the risk of appearance of resistance. Nanocochleates are cigar-shaped structures of rolled negatively charged lipid bilayers bridged by calcium, prepared from dioleoylphosphatidylserine (DOPS) and cholesterol (Cho) and able to accommodate drugs. To determine the interaction, the orientation and the stability of the amphiphilic drugs in the lipid mixture and the optimal drugs/lipids ratio, the Langmuir film balance and BAM (Brewster angle microscopy) were used. The drugs were mixed with the lipids (DOPS or 9DOPS/1Cho) and spread at the air-water interface. A stability study showed that DOPS maintained HePC at the interface at low molar fraction of HePC; this effect became more marked in the presence of Cho. The fact that HePC can be stably associated with the monolayer at low molar fraction (below 10%) suggests that in the nanocochleates HePC is inserted between the lipid molecules rather than between the bilayers. Phase diagrams and BAM images showed that, even at low pressure, DOPS maintains AmB at low molar fraction (below 10%) in the "erect" rather than the horizontal form at the interface and that the presence of Cho reinforces this effect. These results allowed us to predict the organization and the orientation of these drugs in the nanocochleates and to determine the optimal drugs/lipids ratio.

Tumor targeting in photodynamic therapy. From glycoconjugated photosensitizers to glycodendrimeric one. Concept, design and properties

In this paper, we discuss the evolution over the last 15 years in the Curie Institute of the concept, the development of the design and some properties of glycoconjugated photosensitizers with the aim to optimize the tumor targeting in photodynamic therapy. By this research, we have shown that specific interactions between a mannose-lectin and trimannosylglycodendrimeric porphyrins contributed to a larger extent than non-specific ones to the overall interaction of a glycosylated tetraarylporphyrin with a membrane. The studies of in vitro photocytotoxicity showed the relevance of the global geometry of the photosensitizer, the number and position of the linked glycopyranosyl groups on the chromophore and their lipophilicity. The two best compounds appeared to be porphyrins bearing three α-glycosyl groups on para-position of meso-phenyl via a flexible linker. Compound bearing α-manosyl moieties was evaluated successfully in two in vivo xenografted animal models of human retinoblastoma and colorectal cancers. Conversely, the presence on the chromophore of three sugars via a glycodendrimeric moiety induced a potential cluster effect, but decreased the in vitro photoefficiency despite a good affinity for a mannose-lectin.

Identification of older patients at risk of unplanned readmission after discharge from the emergency department

STUDY HYPOTHESIS: The Identification of Senior At Risk (ISAR) and the Triage Risk Stratification Tool (TRST) are the two most studied screening tools to detect high-risk patients for unplanned readmission after an emergency department (ED)-visit. Since their performance was unclear among ED-patients over 75 years, we evaluated their capacities to predict readmission at 1, 3, 6 and 12 months as well as their usefulness in avoiding unnecessary further comprehensive geriatric assessment (CGA) in negative screened patients. METHODS: Historical cohort study with systematic routine data collection of functional status, comorbid conditions and readmission rate of patients released home after an ED-visit between 2007 and 2009 at the Geneva University Hospitals. RESULTS: 345 patients were included (mean age 84y; 63% female). Readmission rates were 25%, 38%, 49%, and 60% at 1, 3, 6, and 12 months, respectively. Positive ISAR (≥2/6) and TRST (≥2/5) predicted modestly unplanned readmission at each time point (AUC range: 0.607–0.664). Prediction of readmission with ISAR or TRST was not modified after adjustment for variables significantly associated with readmission (being male, having poor functional or comorbid scores). In case of negative ISAR or TRST, their high negative predictive values (NPV) would safely allow avoiding 64 useless CGA (ISAR <2: 7/64 readmissions at 1 month). CONCLUSIONS: Both ISAR and TRST tools predicted modestly unplanned readmission after an ED-visit among patients over 75 years. Nevertheless, due to their low specificity and high NPV these screening tools are useful to select elderly ED-patients who can safely return home without any further CGA.

Diabetes, comorbidities and increased long-term mortality in older patients admitted for geriatric inpatient care

AIMS

To study the specific impact of diabetes on long-term mortality in very old subjects with multiple comorbidities and functional disabilities.

METHODS

The prevalence of vascular disorders, global comorbidity load (cumulative illness rating scale [CIRS]) and functional disabilities (activities of daily living [ADL] and Lawton's instrumental ADL [IADL] scores) were determined according to diabetes status in a cohort of 444 patients (mean age 85.3±6.7 years; 74.0% women) admitted to our geriatric service. Also, the specific impact of diabetes on 4-year mortality was analyzed using Cox proportional-hazards models.

RESULTS

Diabetic patients had higher BMI scores (27.1±4.9 vs. 23.4±4.7 kg/m(2) in controls; P<0.001), and higher prevalences of hypertension (81.9% vs. 65.1%, respectively; P=0.003) and ischaemic heart disease (33.7% vs. 22.2%, respectively; P=0.033), but not of stroke and renal insufficiency. They also had more comorbidities (CIRS score excluding diabetes: 15.1±4.5 vs. 13.8±4.8, respectively; P=0.016) and functional disabilities. Diabetes was associated with mortality (HR: 1.42, 95% CI: 1.02-1.99; P=0.041) after adjusting for age, gender and BMI, and this persisted after adjusting for individual vascular comorbidities, but disappeared after adjusting for CIRS, ADL or IADL scores.

CONCLUSION

Diabetes was associated with 4-year mortality after adjusting for the inverse relationship between mortality and BMI. This association was better accounted for by the global comorbidity load and functional disabilities than by the individual vascular comorbidities. These findings suggest that the active management of all--rather than selected--comorbidities is the key to improving the prognosis for older diabetic patients.

IAGG workshop: health promotion program on prevention of late onset dementia

IAGG, WHO, and SFGG organized a international workshop on Health promotion programs on prevention of late on-set dementia. Thirty world specialists coming from Europe, North America, Asia, South America, Africa and Australia, shared their experience on methods and results of large epidemiological interventions to reduce incidents of dementia or delay its on-set. Chaired by Laura FRATIGLIONI, an expert in Epidemiological studies on dementia issues, the workshop gave opportunity for discussions and controversies about the state-of-the-art. Based on different national and international trials (ADAPT, MAPT, FINGER, GUDIAGE, GEM etc) the questions remained opened for different aspects of methodology, the choice of domain or multi domain intervention, the choice and the definition of the target populations, the best age of candidates, the issues related to the discrepancy between late effects, and interventions' duration. We are please to publish in the Journal, the presentations presented to this workshop. These publications will complete previously task force published in the journal in the last two years on methodological issues for Alzheimer's trials including end point, biomarkers, and the experience of past therapeutic trials.

Evaluation of the specific interactions between glycodendrimeric porphyrins, free or incorporated into liposomes, and concanavalin A by fluorescence spectroscopy, surface pressure, and QCM-D measurements

In photodynamic therapy, the specificity of a photosensitizer and its penetration into tumor cells are crucial. We have analyzed the ability of newly synthesized meso-(tetraphenyl)porphyrins to be recognized by a model of mannose-specific proteins overexpressed at the surface of retinoblastoma cells. The specific interaction of porphyrin with Con A was studied by surface pressure measurements, fluorescence spectroscopy, dynamic light scattering, and QCM-D. The extent of porphyrins binding to Con A was highly dependent upon their chemical structure. Glycodendrimeric porphyrins showed the higher binding constant to Con A. The length of the spacer separating the sugar from the tetrapyrrolic ring appeared to be crucial in controlling the interaction of the compounds with the lectin in solution or immobilized onto a solid substrate. The methodology used proved to be efficient for the selection of potentially active compounds. The glycodendrimeric porphyrins, especially the derivative having the longer spacer, interacted more significantly with the lectin than the compound devoid of any sugar.

Effect of cholesterol and sugar on the penetration of glycodendrimeric phenylporphyrins into biomimetic models of retinoblastoma cells membranes

Photodynamic therapy (PDT) is considered one efficient treatment against retinoblastoma. The specificity of a photosensitizer and its penetration into cancerous cells are crucial for achieving tumor necrosis. The selection of photosensitizers such as porphyrin derivatives by tumor cells thus depends to a large extent on their ability to interact with the biological membrane. In this work, we have studied by surface pressure measurements and fluorescence spectroscopy the interaction between three newly synthesized dendrimeric phenylporphyrins and monolayers or liposomes with increasing cholesterol content mimicking the retinoblastoma cell membrane. The morphology of phospholipid-cholesterol-porphyrin mixed monolayers was also analyzed by Brewster angle microscopy. The results showed that the increase in cholesterol content in the model membranes had almost no effect on the effective penetration of the drugs into the lipid layers. Conversely, the chemical structure of the glycodendrimeric phenylporphyrins and the presence of sugar moieties especially appeared to play a crucial role. Although the non-glycoconjugated phenylporphyrin penetrated to a greater extent than glycodendrimeric ones into the liposome membrane, this could be achieved at a high lipid/porphyrin ratio only. Glycodendrimeric porphyrins exhibited improved surface properties compared to the non-glycoconjugated derivative and could penetrate into lipid layers even at low lipid/porphyrin ratios and high surface pressures. Our work highlights the role in the passive diffusion of porphyrins into biomimetic cancer cell membranes, of complex interactions among the lipid molecules, the sugar moieties, and the hydrophobic macrocycle of the porphyrins.

Consensus statement on dementia education and training in Europe

OBJECTIVES

The aim of the current statement is to agree on: (1) what is the current situation with education and training on dementia in Europe; (2) what are the minimum educational requirements for professionals (neurologists, psychiatrists, primary care providers, nurses, biologists, neuroradiologists, etc.) regarding Alzheimer's disease and dementia, and (3) how to start a course of action for the future.

DESIGN

In 2005, a simple questionnaire was sent to members of the European Alzheimer's Disease Consortium (EADC) concerning the education and training on dementia in their countries. Fourteen universities of the respective countries responded to this simple questionnaire. The answers varied, and the conclusion of this effort was that little was done concerning the training of students and health professionals on dementia. In 2008, another more structured and specified questionnaire was sent to professors in different universities of the same countries.

RESULTS

The answers obtained were different from those of the previous questionnaire and demonstrated that it is very difficult to know about training and education in the field of dementia in every European country.

CONCLUSION

From the data collected, it seems that although in the recent past little had been done concerning training on dementia, nowadays training has been developed in most European countries, and relevant educational projects exist both for medical students and doctors during their specialty training. Our main purpose is to develop training material or develop specific courses to improve the professional knowledge about dementia so that best medical and non-medical practice is implemented.

New strategy for targeting of photosensitizers. Synthesis of glycodendrimeric phenylporphyrins, incorporation into a liposome membrane and interaction with a specific lectin

Two glycodendrimeric phenylporphyrins were synthesized and their interaction with phospholipids was studied at the air-water interface and in liposome bilayers; such liposomes bearing glycodendrimeric porphyrin could constitute an efficient carrier for drug targeting in photodynamic therapy.

The disassembly, reassembly and stability of CCMV protein capsids

Efficient procedures are described for the disassembly of Cowpea Chlorotic Mottle Virus (CCMV) into its viral-RNA and capsid-protein components, the separation of the RNA and protein, and the reassembly of the purified protein into higher order nanoscale structures. These straightforward biochemical techniques result in high yield quantities of protein suitable for further biophysical studies (AFM, X-ray scattering, NMR, osmotic stress experiments, protein phase-diagram) and nanotechnology applications (protein enclosed nanoparticles, protein-lipid nanoemulsion droplets). Also discussed are solution conditions that affect the stability of the self-assembled protein structure and explicitly show that divalent cation is not required to obtain stable protein structures, while the presence of even small amounts of Ba(2+) have a significant impact on protein self-assembly. However, since high ionic strength solution conditions result in good yields of CCMV-like protein capsids, it is suggested that the highly charged cationic protein N-terminus could act as an electrostatic switch for protein self-assembly and therefore be modulated by ionic strength and salt type. It was also found that CaCl(2)/RNA precipitation methods do not yield sufficiently pure protein samples.

Planar anchoring and surface melting in the smectic-A phase

We study ultrathin films of 8CB in planar anchoring on a MoS2 inorganic substrate. We evidence an anchoring breakage for 60-nm-thick films, in favor of the homeotropic anchoring at the air interface. This allows one to determine the 8CB-MoS2 smectic anchoring energy. We then demonstrate for films thinner than 60 nm that, under the homeotropic bulk, an intermediate film remains in planar anchoring, associated with a melting of the smectic layers close to the substrate. Such a melting could be general for planar or tilted anchorings and we show that, for strong anchorings, the anchoring energy can be driven by the deformations of this intermediate nematic film.

Failure of viral shells

We report a combined theoretical and experimental study of the structural failure of viral shells under mechanical stress. We find that discontinuities in the force-indentation curve associated with failure should appear when the so-called Föppl-von Kármán (FvK) number exceeds a critical value. A nanoindentation study of a viral shell subject to a soft-mode instability, where the stiffness of the shell decreases with increasing pH, confirms the predicted onset of failure as a function of the FvK number.

Insulinemia and leptinemia or of undernutrition in geriatric patients: markers of the metabolic syndrome or of undernutrition?

The metabolic syndrome (MS) describes a cluster of metabolic disturbances including type 2 diabetes and/or insulin resistance, hypertension, dyslipidemia and obesity, which predict a high risk of cardiovascular disorders. The associated hyperinsulinemia and hyperleptinemia may contribute to the cardiovascular risk. However, the operational value of the MS in elderly patients is questionable. We therefore investigated the prevalence and significance of the MS in geriatric care. In a survey of 98 consecutive admissions of diabetic patients, <40% had a MS; this is a low value compared to younger diabetic adults, due to a low prevalence of obesity and dyslipidemia. We found a high prevalence of low BMI (<20 kg/m2), hypoalbuminemia and low total cholesterol levels, suggesting that the MS may be modified by undernutrition. The interplay between the MS and undernutrition was further studied in 30 non-diabetic patients. Both leptinemia and insulin resistance indexes (HOMA-IR and QUICKI) were strongly associated with BMI and body fat (measured by Bioelectrical impedance Analysis). BMI, leptinemia and insulin resistance indexes were associated with the Mini Nutritional Assessment (MNA) score. Thus, undernutrition is associated with low leptin and insulin levels and may obscure the association of these parameters with cardiovascular risk. In conclusion, the MS has a low prevalence in our population of elderly diabetic patients, and is of questionable prognostic value. It can be oveshadowed by undernutrition, which is associated with low body weight, leptinemia and insulin resistance indexes. Prevention of undernutrition and/or adjustment to its consequences should receive higher priority in the care of elderly diabetic patients.

Structure of smectic defect cores: x-ray study of 8CB liquid crystal ultrathin films

We study the structure of very thin liquid crystal films frustrated by antagonistic anchorings in the smectic phase. In a cylindrical geometry, the structure is dominated by the defects for film thicknesses smaller than 150 nm and the detailed topology of the defects' cores can be revealed by x-ray diffraction. They appear to be split in half tube-shaped rotating grain boundaries (RGB). We determine the RGB spatial extension and evaluate its energy per unit length. Both are significantly larger than the ones usually proposed in the literature.

Efficient purification of bromoviruses by ultrafiltration

Ultrafiltration using polyethersulfone-membranes was evaluated as an efficient and preferred method for purifying Cowpea Chlorotic Mottle Virus (CCMV). Cesium chloride (CsCl) ultracentrifugation and ultrafiltration protocols are described, and comparative UV-spectroscopic and electron micrograph results are presented. CCMV purified by ultrafiltration are shown to be equivalent to CCMV purified by ultracentrifugation, while reducing purification time by two days and avoiding the need for expensive capital overheads such as ultracentrifuges, rotors and toxic CsCl chemical waste.

Optical gratings formed in thin smectic films frustrated on a single crystalline substrate

Through the combination of three different, complementary techniques (optical microscopy, x-ray diffraction and atomic force microscopy), we reveal the deformations inside thin smectic films frustrated between two interfaces imposing antagonistic anchorings. We study the model system, 4-n-octyl-4'-cyanobiphenyl (8CB) between MoS2 and air, which is characterized by the competition between homeotropic anchoring at air and planar unidirectional anchoring on the substrate, with thicknesses varying around 0.3 microm. Optical microscopy and x-ray diffraction demonstrate the continuous topology of smectic layers between the interfaces, which are stacked into periodic flattened hemicylinders. These latter are one-dimensional (1D) focal conic domains which form an optical grating in the smectic film, of a period ranging from 1 to 2.5 microm. The interpretation of our results through an energetic model, associated with the atomic force microscopy (AFM) measurements, shows the presence below a critical thickness of a new type of curvature wall between neighboring hemicylinders.

Evaluation of the European Academy for Medicine of Ageing "Teaching the Teachers" program (EAMA course II 1997- 1998)

The European Academy for Medicine of Ageing, founded by professors in geriatric medicine, provides a geriatric education program for European postgraduate physicians in geriatric medicine who are future academics in geriatric medicine in their countries. The course is organized for 30 participants involved in four one week residential sessions over two years. The program of each session involves 20 teachers, and includes state of the art lectures, student's lectures and working-group discussions. A first course took place in 1995-96, a second in 1997-98, a third has been accomplished in 1999-00, a fourth for 2001-02 and a fifth is ongoing for 2003--2004. The sessions are subjected to an evaluation program regarding the skills of the students, the value of the presentations and the satisfaction about the educational activities. The evaluations of the four sessions of EAMA course II (1997-1998) are presented here, with emphasis on the changes across the sessions for the whole group and for the individual students. The results are good to excellent for the main goals of the course, both by self-evaluation and by peer-evaluation. The dynamic process of this European academic-oriented geriatric education program attracts an increasing number of participants seeking the necessary skills and expertise to obtain academic position in geriatrics, and to meet international colleagues for further collaborative opportunities. Changes and adaptations of the following programs are fostered by the evaluation program to enhance weaker points. Accordingly, improvements in the programs and in the evaluation methods have been introduced during the third course, and are tested during the fourth and the fifth course.

[Depression among the elderly in Switzerland]

Data for this analysis came from a cross-sectional study on dementia, depression, and disability conducted in Zurich and Geneva in 1995/96. The random sample stratified by age and gender consisted of 921 subjects aged 65 and more. Based on the Canberra Interview for the Elderly, depression was assessed by means of psychogeriatric assessment scales (PAS) according to DSM-III-R criteria. The number of depressive symptoms (NDS) and the prevalence rate of depression (PRD) were computed for the whole sample as well as according to age and gender. To evaluate the independent effects of age as well as gender with regard to the risk of being depressed, multivariate analyses were conducted. On average, 13% of females vs 8% of males reported having at least one depressive symptom. The PAS yielded 298 (41.8%) subjects without depressive symptoms, 341 (50.2%) with 1-3 symptoms, and 60 (8.0%) with four or more. The average NDS was 1.27 (95% CI 1.16-1.39). For females, NDS values statistically significantly higher than those for males were calculated (1.53, 95% CI 1.35-1.70 vs 1.05, 95% CI 0.90-1.20). The NDS increased significantly with age. Subjects with low education levels and being divorced or widowed had statistically significantly higher NDS values than highly educated, married, or single persons. There were strong positive associations between NDS, dementia, and activities of daily living. Multivariate regression analysis revealed gender - however, not age - as a strong risk factor for NDS. Overall PRD amounted to 8.0% (95% CI 5.7-10.2%). Females had statistically significantly higher PRD values than males (10.4%, 95% CI 7.0-13.9% vs 3.9, 95% CI 2.0-5.9%). The PRD increased substantially with age. After adjustment for other risk factors, multivariate logistic regression analysis confirmed the positive statistically significant association between age, gender, and depression.

Total body mass, fat mass, fat-free mass, and skeletal muscle in older people: cross-sectional differences in 60-year-old persons

OBJECTIVES

To evaluate body composition parameters, including fat-free mass (FFM), appendicular skeletal muscle mass (ASMM), relative skeletal muscle mass (RSM) index, body cell mass (BCM), BCM index, total body potassium (TBK), fat mass, percentage fat mass (FM), and their differences between age groups and to evaluate the frequency of sarcopenia in healthy older subjects

DESIGN

Cross-sectional, nonrandomized study.

SETTING

Outpatient clinic.

PARTICIPANTS

Ninety-one healthy men and 100 healthy women age 60 and older.

MEASUREMENTS

FFM, ASMM, FM, and percentage fat mass by whole-body dual-energy x-ray absorptiometry; TBK, BCM, and TBK/FFM ratio by whole body potassium-40 counter.

RESULTS

All lean body mass parameters were significantly (P <.05) lower in subjects age 80 and older than in those age 70 to 79, except ASMM in women. Mean FFM was 4.2 kg (7.3%) lower in men age 80 and older than in those younger than 70 and 2.9 kg (6.8%) lower in women age 80 and older than in those younger than 70. The skeletal muscle mass, reflected by ASMM, decreased more than FFM. This suggests that nonskeletal muscle mass is proportionally preserved during aging. Forty-five percent of men and 30% of women were sarcopenic by definition of BCM index and 11.0% of men and women by definition of RSM index.

CONCLUSIONS

Significant age-related differences exist in body composition of older men and women between age 60 and 95. The greater decrease in TBK and BCM than the decrease in FFM and skeletal muscle mass suggests changing composition of FFM with age. Lack of agreement between two independent sarcopenia indexes suggests that further refinement in the definition of a sarcopenia index is necessary.

Comparison of four bioelectrical impedance analysis formulas in healthy elderly subjects

BACKGROUND

Changes of body composition occur with aging and influence health status. Thus accurate methods for measuring fat-free mass (FFM) in the elderly are essential.

OBJECTIVE

The purpose of this study was to compare FFM obtained by three bioelectrical impedance analysis (BIA) published formulas specific for the elderly and one equation intended for all age groups, with FFM derived from dual-energy X-ray absorptiometry (FFM(DXA)), in healthy elderly subjects.

METHODS

Healthy Caucasian subjects over 65 years (106 women, age 75 +/- 6.2, body mass index 25.2 +/- 4.1 and 100 men, age 74.6 +/- 6.6, body mass index 25.8 +/- 3.0) were measured by DXA (Hologic QDR-4500) and BIA (Xitron, 50 kHz). FFM(BIA) was calculated by the published formulas of Deurenberg, Baumgartner, Roubenoff and Kyle and compared to FFM(DXA) by a Bland-Altman analysis.

RESULTS

The Deurenberg and Roubenoff BIA formulas underestimated FFM compared to DXA by -7.1 and -2.9 kg in women and -6.7 and -2.3 kg in men, respectively. The Baumgartner formula overestimated FFM by 4.3 kg in women and 1.4 kg in men. The Kyle formula showed differences of 0.0 kg in women and 0.2 kg in men, and the limits of agreement of FFM(BIA (Kyle)) relative to FFM(DXA) were -3.3 and +3.3 kg for women and -3.8 and +4.3 kg for men.

CONCLUSION

The Kyle BIA formula accurately predicts FFM in elderly Swiss subjects between 65 and 94 years, with a body mass index of 17 to 34.9 kg/m(2). The other BIA formulas developed especially for the elderly are not valid in this population.

[Acute community acquired pneumopathy caused by Nocardia asteroides in a 93-year-old female patient]

BACKGROUND

Lower respiratory tract infection (LRTI) by Nocardia species is most often considered as an opportunistic infection occurring mainly in middle-aged adults.

CASE REPORT

A 93-year old woman without any significant comorbidity other than a mild asthma, presenting with a non-resolving pneumonia, was successfully treated for a community-acquired LRTI by Nocardia asteroides.

DISCUSSION

LRTI by Nocardia asteroides is a rare occurrence. Although more frequent in immuno-compromised patients (50 to 85% of cases reported), Nocardia asteroides infection also occurs in immuno-competent individuals. Very few reports describe LRTI infection by Nocardia sp. in the very old, and almost exclusively in patients with major co-morbidities or variable degrees of immuno-suppression.

Brain energy metabolism in Alzheimer's disease: 99mTc-HMPAO SPECT imaging during verbal fluency and role of astrocytes in the cellular mechanism of 99mTc-HMPAO retention

The central hypothesis of the study which has been carried out as part of the NRP38 program, is that perturbations of brain energy metabolism are critically involved in the neurodegeneration occurring in Alzheimer's disease (AD) and that they may correlate with early cognitive dysfunctioning. In the present multidisciplinary study we set out to monitor brain energy metabolism using FDG-PET and HMPAO-SPECT imaging in a cohort of individuals over 65 years of age, drawn from the general population. HMPAO-SPECT imaging, which is a simpler and more widely accessible imaging procedure than FDG-PET, was performed under basal conditions and during the performance of a cognitive task (verbal fluency test). Three groups were studied. Two groups (groups I and II) included individuals age 65 or more, with no cognitive impairment and carrying an APOE4 positive or APOE4 negative phenotype, respectively; a third group (group III) included patients with clinical signs of AD. Each subject entering the study underwent an FDG-PET, an HMPAO-SPECT and an extensive battery of neuropsychological tests which assess various aspects of cognitive functioning, with a strong emphasis on working memory, divided attention and executive functions. A total of 101 participants were submitted to brain imaging and neuropsychological testing. Among these, 60 participants received the same set of imaging and neuropsychological tasks 24-36 months after the first set (phase II). In this article, we present a preliminary analysis performed on ten subjects from groups I and II and nine subjects from group III: activation (verbal fluency task) induced a specific pattern of increase in HMPAO retention (including BA 9/10, BA 18 bilaterally and right BA 17). In contrast to controls, in nine AD subjects no significant differences in HMPAO retention were observed when comparing activation and basal conditions. The cellular and molecular mechanisms that underlie the retention of HMPAO, the tracer used for single photon emission computed tomography (SPECT) imaging, has been studied in vitro in purified preparations of neurons and astrocytes with the aim of investigating the contribution of different cell types to hexamethyl-propyleneamineoxime labeled with technetium-99m (99mTc-HMPAO) retention in vitro. Results show that 99mTc-HMPAO retention predominates in astrocytes over neurons by a factor of approximately 2.5. Diethyl maleate, ethacrynic acid and buthionine sulfoximine, three agents which significantly reduce glutathione levels, also decreased 99mTc-HMPAO retention in both astrocytes and in neurons. Decrease did not always correlate with glutathione levels however, thus suggesting that other factors could be involved. The data presented indicate that astrocytes might constitute a prominent site of 99mTc-HMPAO retention and most likely contribute significantly to the SPECT signal. In addition, they also suggest that specific alterations in glial cell metabolism could explain flow-independent changes in 99mTc-HMPAO retention in the brain as observed by SPECT in certain pathologies (including Alzheimer's disease). In particular, these observations suggest a key role of astrocytes in the signal detected with the imaging procedure, which is altered in the Alzheimer's cohort subjected to the verbal fluency activation task.

[Dementia, depression and activity of daily living as risk factors for falls in elderly patients]

OBJECTIVES

Falls among elderly are a well-recognised public health problem. The purpose of the present study was to explore the relation between dementia, number of depressive symptoms, activities of daily living, setting, and risk of falling.

METHODS

Data for the analysis came from a cross-sectional study about dementia, depression, and disabilities, carried out 1995/96 in Zurich and Geneva. The random sample stratified, by age and gender consisted of 921 subjects aged 65 and more. The interview was conducted by means of the Canberra interview for the Elderly, extended by short questionnaire. The subject was classified as a faller if the subject and/or the informant had reported a fall within the last 12 months prior to the interview. Logistic-regression analysis was used to determine the independent impact of dementia, depressive symptoms, and ADL-score on risk of falling.

RESULTS

The stepwise logistic regression analysis has revealed a statistically significant association between dementia (OR 2.14, 95% CI 1.15-3.96), two resp. three depressive symptoms (OR 1.64, 95% CI 1.04-2.60) as well as four or more depressive symptoms (OR 2.64, 95% CI 1.39-5.02) and the risk of falling. There was no statistically significant relationship between studied risk factors and the risk of being one-time faller. However, we found a strong positive association between dementia (OR 3.92, 95% CI 1.75-8.79), four or more depressive symptoms (OR 3.90, 95% CI 1.55-9.83) and the risk of being recurrent faller. Moreover, residents of nursing homes (OR 8.50, 95% CI 2.18-33.22) and elderly aged 85 or more (OR 2.29, 95% CI 1.08-4.87) were under statistically significant higher risk of sustaining recurrent falls.

CONCLUSIONS

The results of the present study confirm that dementia and depression substantially increase the risk of falling.

Economic considerations of Alzheimer's disease and related disorders

Economic analyses of geriatric syndromes are seldom performed. However, demographic and epidemiological imperatives have led to significant interest in the evaluation of AD-related costs. Over 300 papers devoted to economic considerations of Alzheimer's disease have been published in peer-reviewed journals, within the last five years. In these papers, the chosen perspective (costs to society or to specific payers) is important. Analytical methods are still evolving and remain complex. Unresolved methodological issues will need to be addressed to further our understanding of long-term economic consequences. At present, it is clear that diagnostic and drug costs are low compared to the major cost of institutionalization. Thus, directing efforts at early diagnosis and delaying nursing home placement are two key cost-containment interventions. In this respect, the need to support informal care should not be underestimated.

Immediate causes of death of demented and non-demented elderly

OBJECTIVE

To investigate the immediate causes of death, in autopsied demented and non-demented elderly.

DESIGN

Retrospective clinicopathologic correlations.

SETTING

Acute and intermediate care geriatric hospital.

PARTICIPANTS

342 hospitalized demented and non-demented elderly (mean age 84.94 +/- 6.9 years) who underwent consecutive postmortem examinations: 120 demented patients with either vascular dementia (VaD, n = 34), mixed dementia (MD, n = 65) or Alzheimer's disease (AD, n=21) neuropathologically confirmed and 222 nondemented elderly.

RESULTS

Primary causes of death were similar in both demented and non-demented patients; the commonest were cardiovascular disease and bronchopneumonia. Cardiac causes of death and especially cardiac failure were more frequent in VaD than in AD or MD (respectively P = 0.027 and 0.005). Dementia was an underlying but never a primary cause of death.

CONCLUSIONS

Immediate causes of death are similar in elderly demented and non-demented patients.

Diagostic value of respiratory impedance measurements in elderly subjects

Obstructive lung disease (OLD) is highly prevalent in elderly subjects but markedly under-diagnosed. Indeed, only 40-50% of hospitalized elderly patients are able to adequately perform spirometric tests. This study aimed to evaluate, in an acute-care geriatric hospital, the diagnostic value of measuring airway impedance (Zrs) by the forced oscillation technique (FOT) for: (1) identifying OLD and (2) identifying responders vs. non-responders to bronchodilators. Sixty-seven patients (aged 82+/-8 years) underwent consecutive measurement of Zrs and forced expiratory volumes before and after bronchodilators. Zrs was measured by FOT at frequencies of 4-30 Hz. Correlations, ROC curves and logistic regression models were established to determine the sensitivity (Se) and specificity (Sp) of Zrs in identifying OLD. Significant correlations were found between spirometric and Zrs measurements. The Zrs parameters yielding the best Se and Sp for detecting OLD were: Fn (resonant frequency; Se: 76%; Sp: 78%) and R0 (resistance extrapolated for a frequency of 0: Se: 76%; Sp: 74%). Using the logistic regression models, 76% of the patients were correctly classified as having OLD or not. Zrs was however not contributive in identifying responders to bronchodilators. Zrs measurements by FOT are contributive to the diagnosis of OLD in elderly hospitalized patients.

Cause of death in older patients with anatomo-pathological evidence of chronic bronchitis or emphysema: a case-control study based on autopsy findings

OBJECTIVES

To determine the most frequent causes of death of hospitalized older patients based on anatomo-pathological evidence and to compare the relative frequency of fatal events between patients with and without evidence of either chronic bronchitis (CB) or emphysema (E).

DESIGN

Retrospective, case-control study based on a computerized database including anatomo-pathological data of patients deceased and autopsied over a 25-year period.

SETTING

Two geriatric hospitals in Geneva.

PARTICIPANTS

Not applicable.

MEASUREMENTS

Autopsy records for cause(s) of death in patients with CB or E.

RESULTS

3,685 patients deceased in our institution (1,540 men; 2,145 women) were autopsied between 1972 and 1996; mean age at death was 81.5 +/- 8.0 years. Anatomo-pathological evidence of CB or E was found in 983 patients (26.6% of total); 262 (7.2%) had predominantly CB, and 456 (12.3%) predominantly E. Pneumonia was the most frequent cause of death in all patients (21.8%). Myocardial infarction (MI) (17.6% vs 14%), and respiratory failure (5.1% vs 1.5%) occurred more frequently in subjects with CB and/or E than in controls. Fatal pulmonary embolism (PE) was more frequent in patients with E (18.4%) than in patients with CB (10.7%; odds ratio ( OR) = 1.89, P =.008), or in controls (12.7%; OR = 1.56, P =.0008).

CONCLUSION

Anatomo-pathological evidence of CB or E is highly prevalent in older patients, suggesting that CB and E are clinically underdiagnosed in this age group. Fatal MI occurred significantly more frequently in older patients with E or CB than in controls. Furthermore, patients with E were at significantly higher risk of fatal PE than patients with CB or controls.