Bright Polarized Single-Photon Source Based on a Linear Dipole.

Semiconductor quantum dots in cavities are promising single-photon sources. Here, we present a path to deterministic operation, by harnessing the intrinsic linear dipole in a neutral quantum dot via phonon-assisted excitation. This enables emission of fully polarized single photons, with a measured degree of linear polarization up to 0.994±0.007, and high population inversion-85% as high as resonant excitation. We demonstrate a single-photon source with a polarized first lens brightness of 0.50±0.01, a single-photon purity of 0.954±0.001, and single-photon indistinguishability of 0.909±0.004.

Field test comparison of two dermal tolerance assessment methods of hand hygiene products.

This study aimed to compare the sensitivity and workload requirement of two dermal tolerance assessment methods of hand hygiene products, in order to select a suitable pilot testing method for field tests. An observer-rating method and a self-assessment method were compared in 12 voluntary hospital departments (autumn/winter of 2005-2006). Three test-periods of three weeks were separated by two-week intervals during which the routine products were reintroduced. The observer rating method scored dryness and irritation on four-point scales. In the self-assessment method, the user rated appearance, intactness, moisture content, and sensation on a visual analogue scale which was converted into a 10-point numerical scale. Eleven products (soaps) were tested (223/250 complete reports for observer rating, 131/251 for self-assessment). Two products were significantly less well tolerated than the routine product according to the observers, four products according to the self-assessments. There was no significant difference between the two methods when products were classified according to tolerance (Fisher's test: P=0.491). For the symptom common to both assessment methods (dryness), there is a good correlation between the two methods (Spearman's Rho: P=0.032). The workload was higher for observer rating method (288 h of observer time plus 122 h of prevention team and pharmacist time compared with 15 h of prevention team and pharmacist time for self-assessment). In conclusion, the self-assessment method was considered more suitable for pilot testing, although further time should be allocated for educational measures as the return rate of complete self-assessment forms was poor.

Province-wide population survey of acute appendicitis in Canada. New twists to an old disease.

BACKGROUND: This study, sponsored and conducted by Le Collège des Médecins du Québec, audited the management of acute appendicitis in the Province of Québec (Population 7.6 million), Canada, over a period of 1 year (April 2002-March 2003). METHODS: A questionnaire was sent to the Health Records Department of all hospitals surgically treating appendicitis in the province. Data from 85 (100%) hospitals were received and reviewed. RESULTS: During the study period, 7,599 appendectomies were performed, and 5,707 (75%) were selected for study (55% men). The rate of normal and perforated appendix was 5.4% and 15.9% respectively. Median hospital stay for simple and perforated appendicitis was 2.6 and 5.8 days, respectively. At least one imaging procedure was done in 86% of cases (23% computed tomography [CT], 55% ultrasound). Antibiotics were not given in 7% of cases and in 8% of patients with a perforation. Seventeen percent of patients did not receive preoperative or intraoperative doses, and postoperatively, 69% of patients received unnecessary doses. Laparoscopy was used in 35% of cases and was associated with a reduction in postoperative stay for simple (2.6 versus 2.9 days, p < 0.001) and perforated appendicitis (4.6 versus 5.9 days, p = 0.004). A low rate of laparoscopy (<25%) was found in 53% of teaching (University and Affiliated) and 45% of nonteaching institutions. Conversion to open surgery was necessary in 9.7% of simple appendicitis and 29.3% of perforated ones (p < 0.001). CONCLUSIONS: Although results of this survey are comparable to those of similar published series, a few concerns emerge. Many have to do with patient noncompliance with recommended antibiotic usage for acute appendicitis. Further, although laparoscopy seems to be slowly making its way into the surgical armamentarium, the low rate of laparoscopic appendectomies in teaching hospitals raises the issue of appropriate resident training.

A new cytokine (IK) down-regulating HLA class II: monoclonal antibodies, cloning and chromosome localization.

The role of HLA class II Antigens in the control of the immune response is determined not only by the genetic polymorphism of these molecules, but also by their density on the cell surface. It is therefore essential to identify the signals that modulate HLA Class II gene activity in normal and neoplastic cells. We have purified a cytokine (IK factor, 19 kDa) secreted by the leukemic cell line K562 and several cancer cells, which inhibits HLA Class II antigen induction by IFN-gamma. We produced specific mAbs which antagonize the biological effect of IK in colon carcinoma Colo 205 cells induced to express HLA-DR molecules by IFN-gamma. Moreover, in Colo 205, HLA-DR can also be induced by the protein synthesis inhibitor Cycloheximide (0.1 micrograms ml-1); and addition of IK factor almost completely abolishes HLA class II expression. We have also performed the cloning and the sequencing of a specific cDNA. This probe recognizes a 2.1 Kb mRNA in different cell types. The nucleotide sequence exhibits no homologies with known cytokines. IK gene localization shows that it maps on chromosome 2p15-p14. The transient transfection of the cDNA in COS cells induces the secretion of a biologically active 19 kDa protein which is recognized in Western blot by 1C5B11 blocking mAb. This paper reports the characterization of a new cytokine down-regulating HLA class II Antigens, whose analysis will help to better understand HLA class II gene regulation and the mechanism of escape from immunorecognition in cancer cells.

[Local guidelines and quality of antibiotic treatment in urinary tract infections: a clinical audit in two departments of a university hospital]. / Impact de recommandations locales sur la qualité de l'antibiothérapie dans l'infection urinaire. Audit clinique dans 2 services d'un hôpital universitaire.

AIM: To assess the effect of local guidelines implemented at the Nantes University Hospital regarding antibiotic therapy for urinary tract infections. DESIGN: Before/after study of one medical ward and one urologic surgery ward. Quality was measured by two principal criteria: compliance with guidelines and medical justification in the specific clinical situation. Both criteria considered simultaneously the choice of drug, dose and duration of treatment. Deviations from the guidelines were described. RESULTS: 1086 UTI cases were identified over two 12-month periods, before and after the dissemination of guidelines (for prostatitis, pyelonephritis, indwelling catheter-associated UTIs, and other undefined UTIs). The guidelines were applicable in 313 (30%) cases. Overall, after implementation of the guidelines, the percentage of justified prescriptions did not change significantly (41.8% compared with 38.7%, p=0.299), but the percentage of correct (conforming) prescriptions fell (from 30.4% to 15.7%, p=0.0022). The percentages of correct and justified prescriptions differed in the medical (respectively 45.0% and 46.6%,) and surgical units (13.1% and 36.5%). CONCLUSIONS: Issuing guidelines does not necessarily improve the quality of antibiotic therapy for UTIs in hospitals.

[Adequate prescription of antibiotic therapy for urinary tract infections in hospital: identifying and correcting non-observance of guidelines]. / Bonnes pratiques de prescription des antibiotiques pour la prise en charge des infections urinaires en milieu hospitalier: identification des écarts aux recommandations et actions correctrices.

OBJECTIVE: We analyzed the adequacy of antibiotic therapy prescribed for urinary tract infections (UTI): prostatitis, pyelonephritis, indwelling catheter-associated UTIs, or other undefined UTIs. DESIGN: The adequacy of prescriptions to local guidelines was assessed retrospectively in two wards (Internal Medicine and Surgical Urology) of the Nantes University Hospital. The principal criteria involved simultaneously: choice of the molecule, dose, and treatment duration. Non-observances of guidelines were major (non-adequacy of the molecule, prescription of a non-active molecule according to in vitro susceptibility tests, non-appropriate treatment abstention), or minor (non-justified treatment, non-justified bitherapy, no prescription of bitherapy when requested, no treatment adaptation when requested, too short or too long treatment length, dosage mistakes). RESULTS: One thousand eighty-six infections were collected over a 24-month period. The overall rate of adequate prescriptions was 40.1% (46.6% in Internal Medicine and 36.5% in Surgical Urology). In Internal Medicine (226 non observance among 389 prescriptions), the ratio of major non-observance of guidelines was 9.8%. Among them, 44.7% were non-appropriate treatment abstentions. In Surgical Urology (539 non observance out of 695 prescriptions), non-observance related to treatment length were the most frequent. The ratio of major non-observance was 19.9%. Among them, non-adequacy of the molecule reached 60.7%. Non-justified treatment and non-appropriate bitherapies were frequent. CONCLUSIONS: For both units, indwelling catheter-related UTIs and other UTIs accounted for more than 50% of the infections although not detailed in the local guidelines. Identifying and analyzing Non observance may lead to targeted correcting actions to improve prescription quality.

Characteristics of platelet aggregation induced by the monoclonal antibody ALB6 (acute lymphoblastic leukemia antigen p 24). Inhibition of aggregation by ALB6Fab.

The leukemia-associated cell surface antigen p 24 is found on normal platelets as well as on Bernard Soulier syndrome and thrombasthenia type I platelets. ALB6 IgG (a monoclonal antibody against p 24) induces the aggregation of platelets from normal donors but not from thrombasthenia. In contrast, ALB6 Fab inhibits platelet aggregation induced by collagen, ADP, thrombin, ionophore A 23187 and ALB6 IgG. The results suggest that ALB6 interferes with a mechanism common to all aggregation pathways; the possible mechanisms are discussed.

A new set of monoclonal antibodies against acute lymphoblastic leukemia.

Six monoclonal antibodies produced by immunization of Balb/c mice with common acute lymphoblastic leukemia (cALL) cells were tested against various types of normal and malignant tissues. ALB1 and ALB2 are directed to the cALL antigen (CALLA gp100); ALB6 recognizes a determinant of p24; ALB7, ALB8 and ALB9 have a pattern of reactivity similar to Ba1. None of these antibodies specifically identify cALL but they should be useful tools for diagnosis or depletion of bone marrow in autologous therapy in transplantation. In addition, the example of ALB6 which acts as a platelet aggregating agent, suggests that the study of other cell systems expressing the antigens associated with cALL may shed light on the function of these antigens and subsequently on the physiopathology of the leukemic cells.

Molecular cloning of the mouse equivalent of CD9 antigen.

The CD9 antigen was originally described as a 24 kDa molecule present on B lineage-derived acute lymphoblastic leukemia cells and developing B-lymphocytes. However, platelets express a large amount of CD9 antigen and can be activated by CD9 antibodies. We report here the cloning and sequencing of a cDNA coding for the mouse CD9 antigen. There is 89% homology at amino acid level between the human and mouse CD9 molecules. Most of the differences (19 out of 24) are located in the large putative extracellular domain encoded by exons 5 and 6. CD9 antigen belongs to a new cell surface protein family which includes TAPA1 and the platelet activation antigen CD63. These proteins share common structural features with the CD9 antigen and a similar distribution of the evolutionarily variable region.

Are prescribed medications effective in the treatment of insomnia complaints?

Although frequently investigated in the general population, the epidemiology of insomnia complaints and their treatment have received little attention in general practice. This study recruited patients > or =15 years of age, consecutively, from 127 general practitioners in France. The physicians collected data from 11,810 of their patients, of whom 55.5% were women. Insomnia complaints were reported by 26.2% (25.4% to 27%) of the sample and use of sleep-promoting medication by 10.1% (9.7% to 10.7%). About 47% of the prescribed drugs used were anxiolytics and 45% hypnotics. Most consumers took sleep-enhancing drugs on a daily and long-term basis and most reported that the medication improved their quality of sleep. However, few distinctions emerged between elderly drug-taking insomniacs and elderly nontreated insomniacs with respect to the various dimensions of sleep. Results underscore the persistent general tendency among French general practitioners to overprescribe anxiolytics for the treatment of insomnia complaints and that they do so on a long-term basis, despite the findings of numerous studies showing that benzodiazepines are ineffective in the treatment of sleep complaints over the long term.

Evaluation of canines for accelerant detection at fire scenes.

In recent years, canines have been successfully used in fire investigations to detect accelerant residues. We set out to determine the lower limits at which canines could reliably detect potential accelerants. Measured amounts ranging from 10 to as little as 0.01 microL of gasoline, kerosene, and isopars were applied to preselected spots along a continuous sample path (25 to 40 feet long) made out of burned and unburned wood or nylon carpeting strips at the testing site. Two canines were led past this sample path at least three times and positive alerts and negative responses were recorded. Both dogs were generally able to alert on spots containing 0.01 microL or more of all three accelerants, at or beyond the purge and trap recovery and gas chromatographic detection method employed. The canines did alert occasionally on background, especially that containing traces of styrene residues, either purposely added in specific amounts or formed upon partial pyrolysis of carpeting material. The dogs alerted on sites containing 0.1 to 1.0 microL of freshly applied gasoline or kerosene placed at actual heavily damaged fire scenes, but were less successful on samples containing smaller amounts.

Evaluation of the CellaVision DM automated microscope in pediatrics.

The DM is an automated microscope, which performs WBC differential counts and monitors red cell morphology. The user either validates the cell recognition if the DM has correctly identified the WBCs or reclassifies the WBCs in the good category in case of a DM mis-assignment. Morphological anomalies of leukocytes, red blood cells or platelets are analyzed and registered. We studied 521 newborns and infants sorted by age and pathology. The results correlated well with those using conventional microscopy except for samples containing blasts, in which the percentage of malignant cells was underestimated. Newborns had the lowest rates of overall accuracy and postclassification agreement. For red cell analysis, 10% of the selected areas were considered unreadable. However, the DM diagnosed faithfully all studied red cell pathologies. The DM was also very useful in analyzing samples of storage diseases. Timesavings ranging from 1 up to 10 min (for vacuolated lymphocyte screening) were observed when performing analysis with the DM. The DM represents a useful diagnostic and training tool. However, conventional microscopy remains essential, in particular when the image quality is poor, such as in the case of lymphoblasts, and in the screening of platelet clusters.

[How can we optimize medical orderings in intensive care unit (ICU)?]. / Optimisation des prescriptions en réanimation.

OBJECTIVES: To evaluate whether intensivists would accept to optimize their orderings of biological samplings, x-rays and target drugs and to assess the consequence on patient's outcome. STUDY DESIGN: Monocentric evaluation of medical economic procedure. METHODS: Meetings of consultants, registrars and residents started on Dec 21, 2006 with two to three sessions a year in order to evaluate the process of medical ordering. The physicians and pharmacists gave the results of orderings at each meeting. Orderings of systematic samplings, bedside x-rays and unjustified expansive drugs were discouraged, but target samplings and lung ultrasonography were encouraged. New residents were systematically taught about this programme. Meanwhile, monthly morbidity-mortality meetings were pursued in order to assess the consequences of this politics. RESULTS: While ICU total production increased by 3.4% and potentially evitable deaths decreased by 34%, annual expenses decreased by approximatively € 777,000 from 2006 to 2008. This was due to decreased orderings in biology by 30%, bedside x-rays by 10%, computed tomographic scans by 16% and target drugs by 35%. However, an increased ordering in four target drugs was observed in 2008 as compared with 2007. CONCLUSION: Multidisciplinary optimization of medical ordering can be efficient in ICU. However, a profit-sharing with ordering physicians would be necessary to prolong these effects.

Effects of differentiation inducers on diphenylhexatriene fluorescence polarization in intracytoplasmic and plasma membranes from Friend erythroleukemia cells.

Treatment of Friend leukemia cells with dimethylsulfoxide or hexamethylenbisacetamide, which induced erythroid differentiation, resulted in enhancement of fluorescence polarization of diphenylhexatriene in not only plasma membranes, but also in intracellular membranes. In a cell variant resistant to induction, the polarization values of intracellular membranes were not affected by the inducing agents, whereas plasma membranes had the same enhancement of polarization values as in sensitive cells. Therefore, Friend cell differentiation can be associated with the effect of the inducers on intracellular membranes, but not with the effect on plasma membranes.

[Macroscopic anatomy of the human fetal thymus in the 2d half of uterine life]. / Anatomie macroscopique du thymus foetal humain dans la seconde moitié de la vie intra-utérine.

The dissection under an operative microscope of 46 foetuses from a homogeneous series measuring 80 to 390 mm C-R (crown-rump) is the subject of a gross anatomic study of the thymus. The authors point out the size, the lobulation and connections with the vascular pedicles of the neck: the thyropericardeal sheet.

Hospital dispersion of Staphylococcus epidermidis isolates resistant to a fluoroquinolone, pefloxacin.

Since 1985, nosocomial infections have been frequently treated with a new fluoroquinolone, pefloxacin, at the Cardiological and Neurological Hospital in Lyon. From 1986 to 1988, the incidence of resistance of clinical Staphylococcus epidermidis strains to pefloxacin increased from 31 to 57%. Dispersion of these resistant strains in the hospital environment was recognized when they were detected on 22% of staff members' fingers (139 samples were investigated) and in 28% of the environmental samples (180 were investigated). There was an association between carriage rate and work place. Most of the pefloxacin-resistant S. epidermidis were resistant to oxacillin, gentamicin, erythromycin, cotrimoxazole and fosfomycin. Intensive use of pefloxacin selected multiresistant S. epidermidis which became ubiquitous in the hospital environment.

CD46 (membrane cofactor protein) associates with multiple beta1 integrins and tetraspans.

The tetraspans associate with a large number of surface molecules, including a subset of beta1 integrins and, indirectly through CD19, with the complement receptor CD21. To further characterize the tetraspan complexes we have raised and selected monoclonal antibodies (mAb) for their ability to immunoprecipitate a molecule associated with CD9. A unique mAb was identified which recognizes the complement regulator CD46 (membrane cofactor protein). CD46 associated in part with several tetranspans and with all beta1 integrins that were tested (CD29/CD49a, CD29/CD49b, CD29/CD49c, CD29/CD49e, CD29/CD49f) but not with beta4 integrins. These data, together with cross-linking experiments showing the existence in living cells of CD46/integrin complexes, suggest that CD46 associates directly with beta1 integrins and indirectly with tetraspans. CD46 also acts as a receptor for measles virus; however, mAb to various integrins and tetraspans did not modify the virus fusion entry step.