Usefulness of methadone plasma concentration measurement in patients receiving nevirapine or efavirenz.

Objective: To determine methadone plasma trough and peak concentrations in patients presenting opiate withdrawal symptoms after introduction of nevirapine or efavirenz. To describe the disappearance of these symptoms after methadone titration based on plasma concentrations rather than on the symptoms. Methods: Nine patients undergoing highly active antiretroviral therapy (HAART) and either nevirapine or efavirenz treatment were monitored daily for opiate withdrawal in a specialized drug addiction center. Methadone dose was titrated daily, and plasma concentrations were measured. The data are retrospective (case series). Results: Several patients complained of symptoms such as nausea, vomiting, accelerated intestinal transit, or insomnia. Even after methadone titration based on clinical symptoms, patients and health-care providers trained in infectious disease did not classify these as withdrawal symptoms and considered them as the side effects of HAART or anxiety. Methadone plasma trough concentration showed low levels of (R)- and (R,S)-methadone. Further methadone dose adjustment according to plasma level resulted in the disappearance of these withdrawal symptoms. The daily methadone dose was split when the peak/trough (R)-methadone ratio was more than 2. Conclusions: When introducing efavirenz or nevirapine to patients undergoing methadone treatment, withdrawal symptoms should be monitored, especially those such as insomnia, vomiting, or nausea. Methadone plasma trough and peak measurements can be of value in preventing unnecessary side effects of HAART.

Measurement with Some Theory: a New Approach to Evaluate Business Cycle Models

We propose a method to evaluate cyclical models which does not require knowledge of the DGP and the exact empirical specification of the aggregate decision rules. We derive robust restrictions in a class of models; use some to identify structural shocks and others to evaluate the model or contrast sub-models. The approach has good size and excellent power properties, even in small samples. We show how to examine the validity of a class of models, sort out the relevance of certain frictions, evaluate the importance of an added feature, and indirectly estimate structural parameters.

Interhuman transmission as a potential key parameter for geographical variation in the prevalence of Pneumocystis jirovecii dihydropteroate synthase mutations.

BACKGROUND: Pneumocystis jirovecii dihydropteroate synthase (DHPS) mutations are associated with failure of prophylaxis with sulfa drugs. This retrospective study sought to better understand the geographical variation in the prevalence of these mutations. METHODS: DHPS polymorphisms in 394 clinical specimens from immunosuppressed patients who received a diagnosis of P. jirovecii pneumonia and who were hospitalized in 3 European cities were examined using polymerase chain reaction (PCR) single-strand conformation polymorphism. Demographic and clinical characteristics were obtained from patients' medical charts. RESULTS: Of the 394 patients, 79 (20%) were infected with a P. jirovecii strain harboring one or both of the previously reported DHPS mutations. The prevalence of DHPS mutations was significantly higher in Lyon than in Switzerland (33.0% vs 7.5%; P < .001). The proportion of patients with no evidence of sulfa exposure who harbored a mutant P. jirovecii DHPS genotype was significantly higher in Lyon than in Switzerland (29.7% vs 3.0%; P < .001). During the study period in Lyon, in contrast to the Swiss hospitals, measures to prevent dissemination of P. jirovecii from patients with P. jirovecii pneumonia were generally not implemented, and most patients received suboptimal prophylaxis, the failure of which was strictly associated with mutated P. jirovecii. Thus, nosocomial interhuman transmission of mutated strains directly or indirectly from other individuals in whom selection of mutants occurred may explain the high proportion of mutations without sulfa exposure in Lyon. CONCLUSIONS: Interhuman transmission of P. jirovecii, rather than selection pressure by sulfa prophylaxis, may play a predominant role in the geographical variation in the prevalence in the P. jirovecii DHPS mutations.

Transmission Fourier transform infrared microspectroscopy allows simultaneous assessment of cutin and cell-wall polysaccharides of Arabidopsis petals.

A procedure for the simultaneous analysis of cell-wall polysaccharides, amides and aliphatic polyesters by transmission Fourier transform infrared microspectroscopy (FTIR) has been established for Arabidopsis petals. The combination of FTIR imaging with spectra derivatization revealed that petals, in contrast to other organs, have a characteristic chemical zoning with high amount of aliphatic compounds and esters in the lamina and of polysaccharides in the stalk of the petal. The hinge region of petals was particular rich in amides as well as in vibrations potentially associated with hemicellulose. In addition, a number of other distribution patterns have been identified. Analyses of mutants in cutin deposition confirmed that vibrations of aliphatic compounds and esters present in the lamina were largely associated with the cuticular polyester. Calculation of spectrotypes, including the standard deviation of intensities, allowed detailed comparison of the spectral features of various mutants. The spectrotypes not only revealed differences in the amount of polyesters in cutin mutants, but also changes in other compound classes. For example, in addition to the expected strong deficiencies in polyester content, the long-chain acyl CoA synthase 2 mutant showed increased intensities of vibrations in a wavelength range that is typical for polysaccharides. Identical spectral features were observed in quasimodo2, a cell-wall mutant of Arabidopsis with a defect in pectin formation that exhibits increased cellulose synthase activity. FTIR thus proved to be a convenient method for the identification and characterization of mutants affected in the deposition of cutin in petals.

Cumulative cultural dynamics and the coevolution of cultural innovation and transmission: an ESS model for panmictic and structured populations.

When individuals in a population can acquire traits through learning, each individual may express a certain number of distinct cultural traits. These traits may have been either invented by the individual himself or acquired from others in the population. Here, we develop a game theoretic model for the accumulation of cultural traits through individual and social learning. We explore how the rates of innovation, decay, and transmission of cultural traits affect the evolutionary stable (ES) levels of individual and social learning and the number of cultural traits expressed by an individual when cultural dynamics are at a steady-state. We explore the evolution of these phenotypes in both panmictic and structured population settings. Our results suggest that in panmictic populations, the ES level of learning and number of traits tend to be independent of the social transmission rate of cultural traits and is mainly affected by the innovation and decay rates. By contrast, in structured populations, where interactions occur between relatives, the ES level of learning and the number of traits per individual can be increased (relative to the panmictic case) and may then markedly depend on the transmission rate of cultural traits. This suggests that kin selection may be one additional solution to Rogers's paradox of nonadaptive culture.

Measurement of nurses' workload in an oncology outpatient clinic

The growing demand and the degree of patient care in oncological outpatient services, as well as the complexity of treatment have had an impact on the workload of nurses. This study aimed at measuring the workload and productivity of nurses in an oncological outpatient service. An observational study using a work sampling technique was conducted and included seven nurses working in an oncological outpatient service in the south-eastern region of Brazil. A total of 1,487 intervention or activity samples were obtained. Nurses used 43.2% of their time on indirect care, 33.2% on direct care, 11.6% on associated activities, and 12% on personal activities. Their mean productivity was 88.0%. The findings showed that nurses in this service spend most of their time in indirect care activities. Moreover, the productivity index in this study was above that recommended in the literature.

Activity assays and immunoassays for plasma Renin and prorenin: information provided and precautions necessary for accurate measurement.

BACKGROUND: Measurement of plasma renin is important for the clinical assessment of hypertensive patients. The most common methods for measuring plasma renin are the plasma renin activity (PRA) assay and the renin immunoassay. The clinical application of renin inhibitor therapy has thrown into focus the differences in information provided by activity assays and immunoassays for renin and prorenin measurement and has drawn attention to the need for precautions to ensure their accurate measurement. CONTENT: Renin activity assays and immunoassays provide related but different information. Whereas activity assays measure only active renin, immunoassays measure both active and inhibited renin. Particular care must be taken in the collection and processing of blood samples and in the performance of these assays to avoid errors in renin measurement. Both activity assays and immunoassays are susceptible to renin overestimation due to prorenin activation. In addition, activity assays performed with peptidase inhibitors may overestimate the degree of inhibition of PRA by renin inhibitor therapy. Moreover, immunoassays may overestimate the reactive increase in plasma renin concentration in response to renin inhibitor therapy, owing to the inhibitor promoting conversion of prorenin to an open conformation that is recognized by renin immunoassays. CONCLUSIONS: The successful application of renin assays to patient care requires that the clinician and the clinical chemist understand the information provided by these assays and of the precautions necessary to ensure their accuracy.

Health education of diabetes as a chronic disease : transmission of information or active appropriation ?

Résumé du poster : Diabetes is both an important chronic disease and a real public health problem. It requires a great control over the body and a great mastery of the tools used in the daily struggle to reach a physiological balance. It is therefore a disease in which health education plays an important role, since patients are expected to reach a certain autonomy in the management of their disease. But how can the patients' autonomy be promoted? This is the question to which this study tried to answer from the perspective of socio-cultural psychology. The study was launched by the Cantonal Diabetes Program Vaud and aimed at evaluating a health education setting located in the east region of the Canton Vaud. It was based on both quantitative and qualitative methodological approaches. The results showed that there is a correlation between the number of hospitalizations and the quality of support provided by this particular health education setting. Moreover, the acquisition of expertise appears to be a distributed and collective process based upon the actors' active participation in various types of activities and involving and extended network. Further research is now required in order to examine how health education might be grasped through the lens of social-cultural psychology.

Radioimmuno positron emission tomography with monoclonal antibodies: a new approach to quantifying in vivo tumour concentration and biodistribution for radioimmunotherapy.

Radioimmunodetection of tumours with monoclonal antibodies is becoming an established procedure. Positron emission tomography (PET) shows better resolution than normal gamma camera single photon emission tomography and can provide more precise quantitative data. Thus, in the present study, these powerful methods have been combined to perform radioimmuno PET (RI-PET). Monoclonal antibodies directed against carcinoembryonic antigen (CEA) an IgG, its F(ab')2 and a mouse-human chimeric IgG derived from it were labelled with 124I, a positron-emitting radionuclide with a convenient physical half-life of four days. Mice, xenografted with a CEA-producing human colon carcinoma, were injected with the 124I-MAb and the tumours were visualized using PET. The concentrations of 124I in tumour and normal tissue were determined by both PET and direct radioactivity counting of the dissected animals, with very good agreement. To allow PET quantification, a procedure was established to account for the presence of radioactivity during the absorption correction measurement (transmission scan). Comparison of PET and tissue counting indicates that this novel combination of radioimmunolocalization and PET (RI-PET) will provide, in addition to more precise diagnosis, more accurate radiation dosimetry for radioimmunotherapy.

Assessement of Malaria Transmission in an Area with Very Low Mosquito Density

The increase in world travel in recent years, especially to and from areas where vector-borne diseases are endemic, has resulted in a substantial rise in imported cases of those diseases. In particular, malaria is a cause of concern. In those countries at the edge of its distribution, it can be difficult to distinguish between autochthonous and imported cases. However, distinguishing between the two is important because of the different allocation of resources to combat the disease that each requires. In general, observation of the various stages of parasite development in wild-caught female mosquitoes is considered evidence of autochthonous transmission. Observation of oocysts in the mosquito mid-gut testifies that mosquitoes are susceptible to infection but conclusions cannot be reached about their ability to complete the transmission cycle. Perhaps the best indication of autochthonous transmission is microscopic observation of sporozoites in mosquito salivary glands, since this detects parasites ready to be inoculated (BELER et al., 1990). Detection of circumsporozoite protein (CSP)(BURKOT, WILLIAMS & SCHNEIDER, 1984) in dry mosquito thoraxes, by Enzyme Linked Immunosorbent Assay (ELISA) is also widely used to determine transmission, especially when large numbers of mosquitoes need to be processed. Such assays provide information about the parasite species infecting the mosquito (BURKOT & WIRTZ, 1986; WIRTZ et al., 1987; BELER et al., 1990).

Influence of reconstruction parameters during filtered backprojection and ordered-subset expectation maximization in the measurement of the left-ventricular volumes and function during gated SPECT.

A crucial method for investigating patients with coronary artery disease (CAD) is the calculation of the left ventricular ejection fraction (LVEF). It is, consequently, imperative to precisely estimate the value of LVEF--a process that can be done with myocardial perfusion scintigraphy. Therefore, the present study aimed to establish and compare the estimation performance of the quantitative parameters of the reconstruction methods filtered backprojection (FBP) and ordered-subset expectation maximization (OSEM). METHODS: A beating-heart phantom with known values of end-diastolic volume, end-systolic volume, and LVEF was used. Quantitative gated SPECT/quantitative perfusion SPECT software was used to obtain these quantitative parameters in a semiautomatic mode. The Butterworth filter was used in FBP, with the cutoff frequencies between 0.2 and 0.8 cycles per pixel combined with the orders of 5, 10, 15, and 20. Sixty-three reconstructions were performed using 2, 4, 6, 8, 10, 12, and 16 OSEM subsets, combined with several iterations: 2, 4, 6, 8, 10, 12, 16, 32, and 64. RESULTS: With FBP, the values of end-diastolic, end-systolic, and the stroke volumes rise as the cutoff frequency increases, whereas the value of LVEF diminishes. This same pattern is verified with the OSEM reconstruction. However, with OSEM there is a more precise estimation of the quantitative parameters, especially with the combinations 2 iterations × 10 subsets and 2 iterations × 12 subsets. CONCLUSION: The OSEM reconstruction presents better estimations of the quantitative parameters than does FBP. This study recommends the use of 2 iterations with 10 or 12 subsets for OSEM and a cutoff frequency of 0.5 cycles per pixel with the orders 5, 10, or 15 for FBP as the best estimations for the left ventricular volumes and ejection fraction quantification in myocardial perfusion scintigraphy.

Mesurer l'amplitude articulaire du genou: goniométre universel ou smartphone [Measurement of the knee range of motion: standard goniometer or smartphone?].

Universal standard goniometer is an essential tool to measure articulations' range of motion (ROM). In this time of technological advances and increasing use of smartphones, new measurement's tools appear as specific smartphone applications. This article compares the iOS application "Knee Goniometer" with universal standard goniometer to assess knee ROM. To our knowledge, this is the first study that uses a goniometer application in a clinical context. The purpose of this study is to determine if this application could be used in clinical practice.

Resolving inconsistencies in utility measurement under risk: Tests of generalizations of expected utility

This paper explores biases in the elicitation of utilities under risk and the contribution that generalizations of expected utility can make to the resolution of these biases. We used five methods to measure utilities under risk and found clear violations of expected utility. Of the theories studies, prospect theory was most consistent with our data. The main improvement of prospect theory over expected utility was in comparisons between a riskless and a risky prospect(riskless-risk methods). We observed no improvement over expected utility in comparisons between two risky prospects (risk-risk methods). An explanation why we found no improvement of prospect theory over expected utility in risk-risk methods may be that there was less overweighting of small probabilities in our study than has commonly been observed.