Improved Magneto-Microfluidic Separation of Nanoparticles through Formation of the ß-Cyclodextrin-Curcumin Inclusion Complex.

Molecular adsorption to the nanoparticle surface may switch the colloidal interactions from repulsive to attractive and promote nanoparticle agglomeration. If the nanoparticles are magnetic, then their agglomerates exhibit a much stronger response to external magnetic fields than individual nanoparticles. Coupling between adsorption, agglomeration, and magnetism allows a synergy between the high specific area of nanoparticles (∼100 m2/g) and their easy guidance or separation by magnetic fields. This yet poorly explored concept is believed to overcome severe restrictions for several biomedical applications of magnetic nanoparticles related to their poor magnetic remote control. In this paper, we test this concept using curcumin (CUR) binding (adsorption) to ß-cyclodextrin (ßCD)-coated iron oxide nanoparticles (IONP). CUR adsorption is governed by host-guest hydrophobic interactions with ßCD through the formation of 1:1 and, possibly, 2:1 ßCD:CUR inclusion complexes on the IONP surface. A 2:1 stoichiometry is supposed to promote IONP primary agglomeration, facilitating the formation of the secondary needle-like agglomerates under external magnetic fields and their magneto-microfluidic separation. The efficiency of these field-induced processes increases with CUR concentration and ßCD surface density, while their relatively short timescale (<5 min) is compatible with magnetic drug delivery application.

Adsorption of Organic Dyes on Magnetic Iron Oxide Nanoparticles. Part II: Field-Induced Nanoparticle Agglomeration and Magnetic Separation.

This paper (part II) is devoted to the effect of molecular adsorption on the surface of magnetic iron oxide nanoparticles (IONP) on the enhancement of their (secondary) field-induced agglomeration and magnetic separation. Experimentally, we use Methylene Blue (MB) cationic dye adsorption on citrate-coated maghemite nanoparticles to provoke primary agglomeration of IONP in the absence of the field. The secondary agglomeration is manifested through the appearance of needlelike micron-sized agglomerates in the presence of an applied magnetic field. With the increasing amount of adsorbed MB molecules, the size of the field-induced agglomerates increases and the magnetic separation on a magnetized micropillar becomes more efficient. These effects are mainly governed by the ratio of magnetic-to-thermal energy α, suspension supersaturation Δ0, and Brownian diffusivity Deff of primary agglomerates. The three parameters (α, Δ0, and Deff) are implicitly related to the surface coverage θ of IONP by MB molecules through the hydrodynamic size of primary agglomerates exponentially increasing with θ. Experiments and developed theoretical models allow quantitative evaluation of the θ effect on the efficiency of the secondary agglomeration and magnetic separation.

Kinetics of field-induced phase separation of a magnetic colloid under rotating magnetic fields.

This paper is focused on the experimental and theoretical study of the phase separation of a magnetic nanoparticle suspension under rotating magnetic fields in a frequency range, 5 Hz ≤ ν ≤ 25 Hz, relevant for several biomedical applications. The phase separation is manifested through the appearance of needle-like dense particle aggregates synchronously rotating with the field. Their size progressively increases with time due to the absorption of individual nanoparticles (aggregate growth) and coalescence with neighboring aggregates. The aggregate growth is enhanced by the convection of nanoparticles toward rotating aggregates. The maximal aggregate length, Lmax ∝ ν-2, is limited by fragmentation arising as a result of their collisions. Experimentally, the aggregate growth and coalescence occur at a similar timescale, ∼1 min, weakly dependent on the field frequency. The proposed theoretical model provides a semi-quantitative agreement with the experiments on the average aggregate size, aggregation timescale, and size distribution function without any adjustable parameter.

Description and variability of temporal venous vascularization: clinical relevance in temporoparietal free flap technique.

The few studies on the venous vascularization of the temporal area indicate a high variability among individuals. The preoperative knowledge of the venous vascularization of the temporal area is critical for microsurgical reconstruction, such as temporoparietal fascia free flap, and especially in understanding the anatomy of the veins for flap survival. Therefore, we conducted an anatomic study to confirm the classification of Legre et al. and a radiologic study to examine the venous network of the temporal area. We found three frequent patterns of the temporal venous network: (1) Type I (the most common), with a predominant temporal vein; (2) Type II, with a predominant posterior auricular vein; (3) Type III, when both veins were equally important. Because of this great variability, the use of a temporal flap for reconstruction of the head and neck should be restricted, and the examination of venous vascularization appears to be necessary before surgery. Here, we report a three-dimensional description of the venous temporal vascularization by computer tomography, which is particularly useful before temporoparietal flaps.

[Clinical case of the month. An unusual sepsis]. / Un sepsis mystérieux.

Lemierre's syndrome is a rare, but significant pathology to recognize. It most often affects young patients in good health; a late diagnosis can be fatal. It consists in an anaerobic septicemia (usually, Fusobacterium necrophorum) originating from a suppurative thrombophlebitis of the internal jugular vein. Infection occurs during a common sore throat and spreads by contiguity. The clinical presentation is a sepsis with pulmonary embolisations, but other sites of dissemination can also occur. Treatment consists of prolonged intravenous antibiotherapy associated with supportive therapy, if needed. Anticoagulation remains controversial. The outcome is favorable in most cases provided diagnosis and treatment are early; mortality however remains significant, around 5%.

[Assessment of targeted clinical audit in suicide attempt]. / Prise en charge des suicidants. Quel apport d'une démarche d'audit clinique ciblé?

BACKGROUND: Suicide attempt is a serious condition that is frequent in France. Picardie ranks fifth in France for suicide (418 deaths in 2005 for 1,890,000 inhabitants). Suicide attempt is one of the priorities of the regional public health program. The National Agency for Accreditation and Evaluation in Health (Anaes) has designed targeted clinical audits (TCA) on various conditions to promote this method as the basic tool for quality improvement. AIM: We investigated the contribution of TCA for improving the quality of care of suicide attempt within a regional framework in Picardie. METHODS: TCA were conducted in 12 state hospitals (eight Surgical Medicine and Obstetrics, three specialized in psychiatry, one local) between 2004 and 2006. The standards from the Anaes had 16 criteria in three fields: care on admission (n=10); assessment of family and social environment (n=2); management for after hospital care (n=4). A project manager and a MD certified in health care quality supported the medical (MD certified in acute care and in psychiatry) and nursing staff of the emergency wards. All the wards analyzed 30 patients' files for the first cycle, set up and implemented improvement actions and then performed the second cycle of data collection. RESULTS: All wards fully satisfied the protocol with 30 patients' files per cycle and two cycles. In all wards the teams consisted of physicians (both certified for emergency or psychiatry) and others care providers (nurses, psychologists, social workers, secretary). For the first cycle, three criteria (patient assessment, somatic examination and coordination) met the 100% target for more than half of the wards while three criteria (sociofamily and environmental evaluation, management for after hospital care, monitoring of follow-up) did not conform by more than 50% in more than half of the wards. All wards implemented changes after the first cycle with a total of 29 interventions, each one specifically devoted to improving a particular criterion. Intervention included better coordination and communication, protocol design and reminders, and information tools. The second cycle showed modest and mixed changes. After the interventions only one criteria reached the 100% target in one ward; the degree of conformity decreased in nine cases (with a mean of -23%) and increased in 16 cases (+19%). Globally, three criteria improved by less than 10% while three slightly decreased. DISCUSSION: G. Shaw introduced clinical audits in 1989 to boost a poorly performing system within the "clinical governance" framework, a condition quite different from the French healthcare system in 2005. Therefore, the validation of clinical audit in a different context appeared necessary. Anaes has not yet published the evaluation of this method in a peer reviewed journal. Observed changes are modest and mixed. Moreover, the true impact on care delivery appears limited and one cannot rule out that the observed improvements are in fact related to an improvement in traceability or due to Hawthorne's effect. Quality improvement methods must be evaluated and validated by scientific methods such as for new treatments with clinical research. CONCLUSION: The feasibility of the method was excellent, due to the methodological and technical support, however the method did not significantly improve the quality of care.

[Autologous tissue engineering by means of distraction osteogenesis: Biomechanical considerations]. / Ingénierie tissulaire autologue par distraction ostéogénique : considérations biomécaniques.

Tissue engineering consists in producing functional replacement tissue. Distraction osteogenesis is a tissue engineering technique that uses the mechanical environment of cells to induce tissue regeneration, without need for exogenous biochemical factors. A better understanding of the optimal mechanical conditions of distraction callus stretching may reduce the duration, discomfort, and even social impact of distraction protocols, and complications and failures. We present the current state of knowledge in this field by addressing the fundamentals of elongating bone tissue biomechanics, the influence of rhythm and rate of distraction, and that of vectors and stability. Finally, we present the innovations currently studied, which may modify our clinical protocol in the short term.

Purification and characterization of a novel monocyte chemotactic and activating factor produced by a human myelomonocytic cell line.

A novel basic heparin-binding monocyte chemotactic factor (MCF) was purified to homogeneity from the conditioned media of human myelomonocytic cell line THP-1 based on its in vitro monocyte chemotactic activity. The purified MCF was homogenous and estimated to be 15 kD on SDS-PAGE. Purified MCF stimulated normal human monocytes to be growth inhibitory in vitro at 2-3 d for several human tumor cell lines. This represents the first report of the identification and purification of a chemoattractant cytokine that also activates monocytes but is distinct from interferons and other known cytokines.

Nonnutritive sweeteners: taste-structure relationships for some new simple dihydrochalcones.

Six sweet and five nonsweet simple nonglycosidic dihydrochalcones were prepared, two of which have properties comparable to those of the intensely sweet neohesperidin dihydrochalcone.

Identification of HTLV-III/LAV sor gene product and detection of antibodies in human sera.

The nucleotide sequence of the genome of HTLV-III, the infectious agent etiologically associated with the acquired immune deficiency syndrome, predicts a small open reading frame, termed sor, located between the pol and env genes. A DNA segment containing 82 percent of the sor region was inserted into a prokaryotic expression vector, pJL6, to determine whether sor encodes a viral protein and to gain some insight into its possible function. The bacterially synthesized sor protein reacted with sera from individuals infected with HTLV-III, indicating that sor is expressed as a protein product or products that are immunogenic in vivo. Antibodies to the purified, bacterially synthesized sor protein were found to react specifically with the same protein and also with a protein of molecular weight 23,000 (23K) in HTLV-III-infected H9 cell extracts. The 23K protein comigrated with a protein immunoprecipitated by the serum of a hemophiliac patient with antibodies to HTLV-III, suggesting that this protein is probably the sor gene product.

[A regional plan against tobacco smoking during pregnancy]. / Grossesse sans tabac: une mobilisation régionale des professionnels des maternités de Picardie.

OBJECTIVES: We aimed to evaluate the management of smoking cessation in private and public maternity wards of Picardy. MATERIALS AND METHODS: All regions' wards participated and the strategy for quality improvement associated teaching sessions and availability of carbon monoxide analysers indicating foetal CO. RESULTS: One hundred and thirteen professionals were enrolled in the teaching sessions. The number of analysers available rose from 25 to 61. All wards signed up the national charter "Pregnancy without smoking", whereas previously only 35% where engaged in this program. CONCLUSION: Picardy is the first region of France to offer a quality program for smoking cessation to pregnant women. Professionals' involvement in smoking cessation programs must be improved, this needs the support of health care authorities.

Development of rebiana, a natural, non-caloric sweetener.

Rebiana is the common name for high-purity rebaudioside A, a natural non-calorie sweetener 200-300 times more potent than sucrose. It provides zero calories and has a clean, sweet taste with no significant undesirable taste characteristics. It is functional in a wide array of beverages and foods and can be blended with other non-calorie or carbohydrate sweeteners. It is stable under dry conditions, and has much better stability than aspartame or neotame in aqueous food systems. Studies undertaken for the development of a purification process and for the full characterization of the properties of rebiana are reported here.

A complete finite element model of a mandibular implant-retained overdenture with two implants: comparison between rigid and resilient attachment configurations.

PURPOSE: The aim of this study was to evaluate the influence of the retention mechanism on the behavior of a mandibular implant-retained overdenture (IRO) during the simulation of mastication. Therefore, a complete three-dimensional finite element model of a mandible with its IRO was developed. MATERIALS AND METHODS: The geometry of the edentulous mandible and overdenture was generated from computed tomography. Two MKIII implants (Nobel Biocare) with ball abutments and Dalbo Plus (Cendres et Métaux) attachments were placed in the canine areas. Three foodstuff positions were analyzed for two retention mechanisms, "resilient" or "rigid". Special attention was given to the modeling of the mandibular environment and of the existing contact between the different components. A probable muscular action was determined following the minimal work principle. RESULTS: The food-crushing force was provided by masseters with a two-third/one-third ratio between working and non-working sides. The "resilient" configuration provided a wider contact area between the mucosa of the denture bearing area and the prosthesis. An increase of the mastication force transiting through the mucosa was also noted and lower stresses were observed in the bone surrounding implants. CONCLUSION: Resilient attachments allowed for an increase of the mastication load transiting through denture bearing surface. Furthermore, this study proposed an accurate model of the mandibular IRO, including its environment and faithful behavior reproduction.

[Cognitive impact of mitoxantrone and methylprednisolone in multiple sclerosis: an open label study]. / Impact cognitif d'un traitement associant mitoxantrone et méthylprednisolone dans la sclérose en plaques.

Interferons beta have shown some positive effects on cognitive function in multiple sclerosis (MS). The potential immunosuppressive impact of mitoxantrone on cognitive dysfunction in MS has never been evaluated. We assessed changes in cognitive dysfunction in patients with very active MS treated with mitoxantrone combined with methylprednisolone. We assessed a non randomized controlled trial including successively 15 consecutive MS patients. Very active MS was defined by a progression of at least two EDSS points or more than two relapses during the previous year and at least one enhanced lesion after gadolinium infusion on MRI. All patients received a monthly intravenous pulse of mitoxantrone (20mg) for six months with methylprednisolone (1g). Global cognitive efficiency, memory and executive function were assessed before treatment (M0) and after six months (M6) and 12 months (M12) of treatment. To evaluate the learning effect, 15 healthy subjects also participated. A significant improvement in global cognitive efficiency was observed at M6 and was sustained at M12, as a few parameters on memory and executive functions. We suggest that mitoxantrone combined with methylprednisolone has a potential positive effect on cognitive functions.

[Etiology, epidemiology, biology. Tobacco use and smoking in France]. / Le tabac et le tabagisme en France.

Since 1976, France improved its anti tobacco legislation and regulation with the help of the Non-governmental organizations under the umbrella of the Alliance Against Tobacco. Since then were implemented a total ban of tobacco advertising (1991), a total ban of smoking in enclosed public and work places (2006), a high taxation of tobacco products, strong media campaigns to de normalize smoking and tobacco products, improved availability, accessibility and affordability of treatments of tobacco dependence. Since 1991, the number of cigarettes smoked per adult was halved.

[Morbidity/mortality review: usefulness and shortcomings]. / Revue de mortalité et de morbidité (RMM): apports et freins.

GOAL: The Morbidity-Mortality Conference is a formalized exercise validated by the Haute Autorité de Santé (HAS) whose aim is to improve the quality and safety of care through periodic (weekly or monthly) analysis of deaths and complications. In France, no data is available concerning the implementation of the MMC methodology despite the interest of the National Institute of Healthcare Quality (HAS) in using the MMC as part of the physician recredentialling process and of hospital accreditation (mandatory in France since the laws of 2005 and 1997 respectively). We aimed to study the experience and perceptions of physicians with this specific methodology in the context of a large regional project aimed to improve clinical risk management. METHODS: A one page questionnaire with eight confidential questions and a space for free commentary was sent to 150 hospitals in the north of France. RESULTS: We received 83 responses from 29 hospitals (range: 1-14 responses per hospital). Analysis of unexpected adverse events is performed mainly in informal meetings (76%) and mandatory reports (77%); the MMC methodology is rarely used (11%). The analysis of adverse events is considered to be an important tool for the improvement of patient care and safety (90%) and continuing education (61%), and it results in modification of care protocols (70%) or organizational change (71%). Lack of knowledge of the MMC methodology (66%) and lack of available time (50%) are the main obstacles to the adoption of the MMC. Fear that the findings of the MMC could be available for use in litigation (1%) was not an obstacle. Physicians interested in implementing the MMC are motivated by a desire for improved patient safety (86%) and care management on the surgical service (54%). Self-responsibility is more important than the mandatory process for re-credentialing. CONCLUSION: The implementation of the MMC requires specific measures such as teaching and support.

A geostatistical autopsy of the Austrian indoor radon survey (1992-2002).

Indoor radon (Rn) concentrations have been measured intensively in many countries to assess the burden of diseases associated with exposure to this radioactive gas. So-called radon-risk maps have consequently been produced to delineate areas with high levels. Geostatistical techniques are commonly used nowadays to map a range of environmental variables, in particular to generate probability maps of exceeding a given threshold. However, very few case studies in which indoor radon measurements have been investigated using geostatistical techniques have been published so far. By analyzing around 12,000 Rn measurements made in Austrian ground floors during a 10-year survey, we aim here to review and discuss the potential of geostatistics for mapping an environmental variable that shows very strong local variability. In particular, we show how kriging of the scale components can shed new light on various factors that affect the very high spatial variability of the variable.