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PubMed2001

Practice variation in the treatment of rheumatoid arthritis among German rheumatologists.

OBJECTIVE: To describe practice variation in the treatment of rheumatoid arthritis (RA) among German rheumatologists with regard to drug and non-drug therapy. METHODS: We used data of 7,326 patients with RA registered in a national German rheumatological database in 1998. In the database, every patient with an inflammatory rheumatic disease seen at one of the German Collaborative Arthritis Centres is registered once a year with a standard clinical data form and a patient questionnaire. We compared health care provided by 29 rheumatological outpatient units. For drug and non-drug treatment unit prescription rates, ranges and outliers were calculated. Logistic regression analysis was used for case mix adjustment and for the identification of practice patterns. RESULTS: We observed variation concerning the frequency of use of single disease modifying antirheumatic drugs (DMARD). The median of the prescription rates in the 29 units for methotrexate (MTX) was 55% in 1998 (1st quartile: 51%, 3rd quartile: 63%); sulfasalazine had a median of 15% (quartiles: 10%/19%), antimalarials a median of 8% (quartiles: 5%/21%). Combination DMARD therapy was used in 11% (quartiles: 6%/18%). Prescriptions of low dose steroids (< or = 7.5 mg) had a median of 45% (quartiles: 35%/55%), and nonsteroidal antiinflammatory drugs (NSAID) had a median prescription rate of 58% (quartiles: 50%/70%). High variation was also found concerning active physiotherapy (median: 41%; quartiles 34%/55%) and passive physical measures (median 14%, quartiles 9%/37%). Differences in case mix (age, sex, rheumatoid factor, disease duration, severity, disability) only explained a small proportion of the total variation. When the units were grouped according to the frequency of prescription of DMARD combination therapy, treatment patterns could be identified. Units with higher rates of DMARD combination therapy used more drugs for the prevention and treatment of osteoporosis, more active physiotherapy but fewer NSAID and fewer passive physical therapies. CONCLUSION: Variation in drug and non-drug treatment indicates significant differences in health care provision. Trends in the drug management of RA are adopted differentially by the members of the rheumatology community. The large variability in non-drug therapies may, apart from differences in availability, suggest a lack of agreement on therapeutic effectiveness.

Adrenal Cortex Hormones↗

PubMed1992

Regulation of a beta-galactoside-binding lectin and potential ligands during postnatal maturation of rat brain.

Variations in expression and activity of a beta-galactoside-specific lectin were quantified during postnatal maturation of the rat brain. Lectin expression, estimated from enzymatic immunoassay data, and lectin activity, evaluated by rabbit erythrocyte agglutination, are higher in the brains of young animals (5 days after birth) than in older ones (2 months of postnatal life). Concurrently, modifications in glycosylation during cellular differentiation were detected by affinoblotting using a biotinylated derivative of a beta-galactoside-specific brain lectin. This study shows that membrane and cytosolic glycoconjugates of the rat brain bear appropriate beta-galactoside moieties which may be recognized by an endogenous lectin expressed in the tissue itself in relation to brain maturation. The observed variations in the expression of lectin and complementary glycoconjugates can be correlated with significant events of rat brain development.

Aging↗

PubMedDate not supplied

Phenotypic drift and clonal variation in differentiation antigen expression on AKR T-cell lymphoma lines grown in vitro.

AKR T-cell lymphomas were adapted to tissue culture and analyzed for reactivity with monoclonal antibodies against Thy-1, Ly-1, Ly-2, Ly-5, and H-2K differentiation antigens to determine whether the original phenotype was maintained after adaptation to in vitro culture. Ly-1 and Ly-2 antigens were lost on the majority of lymphomas early in culture and the expression of other lymphocyte differentiation antigens fluctuated when the cell lines were reanalyzed at various time intervals. In addition, the T-lymphoma lines were cloned and the clonal progeny compared with each other and the parent cell lines for differentiation antigen expression. The results demonstrated marked intratumor heterogeneity with respect to antigenic profile. In vivo passage of the cell lines revealed that expression of various antigens was modified after transplantation suggesting that these lymphomas may be susceptible to microenvironmental influences effecting phenotypic alterations. Potential mechanisms contributing to the observed variations in antigenic phenotype on the cultured AKR T-lymphoma lines are discussed.

Animals↗

PubMed2002

A survey of ethical issues surrounding supply of information to members of the public by hospital pharmacy medicines information centres.

OBJECTIVES: To examine ways in which medicines information pharmacists approach ethical dilemmas encountered in information supply, to appreciate the factors affecting any observed variation in responses, and to identify and training deficits among medicines information (MI) pharmacists in this area. METHOD: A questionnaire was circulated to all medicines information pharmacists working in the hospital pharmacy service in the United Kingdom. The survey presented ten realistic scenarios involving requests for information on a variety of topics from 'lay' callers. MAIN OUTCOME MEASURES: Respondents were asked to identify any perceived ethical dilemmas presented by the scenarios and to indicate their preferred replies. Details on training given or received in this area were also requested. RESULTS: The overall response rate was 151 of 286 questionnaires mailed (52.8%), representing 137 discrete DI centres throughout the UK. Postgraduate clinical qualifications were possessed by 71% of respondents. Just 32 (21.2%) indicated that they gave training on ethical issues surrounding information supply while 57 (37.1%) said they had received such training. Over half (54.3%) had neither received nor delivered training on ethical issues. Of the 32 who said they gave training, 21 had received training themselves. Only 4 (2.6%) said they had a protocol in place for dealing with enquiries from members of the public. CONCLUSIONS: There was considerable variation in how respondents thought the scenarios might be resolved, emphasising the varying levels of appreciation of the issues and lack of a uniform approach to management. An interesting dichotomy emerged between liberal and conservative approaches. Liberal pharmacists clearly believed that all MI data is in the public domain and should be produced and evaluated on request because patients have a "right" to it. The conservative pharmacists had a more protective attitude toward the patient and believed that patients should not be given information by MI pharmacists directly; rather that it should be channelled through the patient's doctor. These two approaches are not incompatible, and may be adopted by the same pharmacist at different times. From their observations, the authors propose a basis of an ethical guideline for MI pharmacists.

Confidence Intervals↗

PubMed1979

Growth phase related loss of measles virus surface-associated antigens and cytotoxic susceptibility in persistently infected cells.

Fluctuations in the expression of measles virus surface-associated antigens in persistently infected human Lu 106 cells were analysed by the use of human sera which preferentially reacted with the haemolysin or haemagglutinin component. The variations observed correlated with the proportion of cells expressing surface-antigen, as examined in population analysis by indirect immunofluorescence, a radio-labelled antiglobulin technique and a cytotoxicity assay. Microfluorometric analysis revealed no changes in antigen expression at the single-cell level. The number of cells that were positive by immunofluorescence among exponentially growing, low density cells remained relatively constant. These cells were more susceptible to cytotoxicity mediated by both antisera and complement than cells seeded at high density and kept in the stationary phase. The percentage of fluorescent cells among the latter cells gradually decreased. Thus cytotoxic susceptibility was related to the proportion of the total cell population that was antigen-bearing, rather than to variations in the expression of antigen at the single-cell level. In mitotic cells, polarization of antigen, as measured by indirect immunofluorescence of pre-fixed cells, was frequently seen. Often only one of the daughter cells expressed surface antigen. The results imply that cells in stationary phase may lose antigen from their surface, possibly by shedding, and furthermore that re-expression would demand a new cell cycle.

Antigens, Surface↗

PubMed2003

Does advertisement call variation coincide with genetic variation in the genetically diverse frog taxon currently known as Leptodactylus fuscus (Amphibia: Leptodactylidae)?

The frog Leptodactylus fuscus is found throughout much of South America in open and disturbed habitats. Previous study of genetic differentiation in L. fuscus demonstrated that there was lack of genetic exchange among population units consistent with multiple species, rather than a single species. We examine advertisement vocalizations of L. fuscus to determine whether call variation coincides with genetic differentiation. Calls were analyzed for 32 individual frogs from 25 localities throughout the distributional range of L. fuscus. Although there is variation in calls among geographic samples, call variation is not concordant with genetic variation or geographic distance and the call variation observed is less than that typically found among other closely related species of Leptodactylus. This study is an example of the rare pattern of strong genetic differentiation unaccompanied by salient differences in advertisement calls. The relative infrequency of this pattern as currently understood may only reflect the lack of detailed analyses of genetic and acoustic differentiation within population systems currently understood as single species with substantial geographic distributions.

Animals↗

PubMed1991

Modeling symbiotic performance of introduced rhizobia in the field by use of indices of indigenous population size and nitrogen status of the soil.

The ability to predict the symbiotic performance of rhizobia introduced into different environments would allow for a more judicious use of rhizobial inoculants. Data from eight standardized field inoculation trials were used to develop models that could be used to predict the success of rhizobial inoculation in diverse environments based on indices of the size of indigenous rhizobial populations and the availability of mineral N. Inoculation trials were conducted at five diverse sites on the island of Maui, Hawaii, with two to four legumes from among nine species, yielding 29 legume-site observations. The sizes of indigenous rhizobial populations were determined at planting. Soil N mineralization potential, total soil N, N accumulation and seed yield of nonnodulating soybean, and N derived from N(2) fixation in inoculated soybean served as indices of available soil N. Uninoculated, inoculated, and fertilizer N treatments evaluated the impact of indigenous rhizobial populations and soil N availability on inoculation response and crop yield potential. The ability of several mathematical models to describe the inverse relationship between numbers of indigenous rhizobia and legume inoculation responses was evaluated. Power, exponential, and hyperbolic functions yielded similar results; however, the hyperbolic equation provided the best fit of observed to estimated inoculation responses (r = 0.59). The fact that 59% of the observed variation in inoculation responses could be accounted for by the relationship of inoculation responses to numbers of indigenous rhizobia illustrates the profound influence that the size of soil rhizobial populations has on the successful use of rhizobial inoculants. In the absence of indigenous rhizobia, the inoculation response was directly proportional to the availability of mineral N. Therefore, the hyperbolic response function was subsequently combined with several indices of soil N availability to generate models for predicting legume inoculation response. Among the models developed, those using either soil N mineralization potential or N derived from N(2) fixation in soybean to express the availability of mineral N were most useful in predicting the success of legume inoculation. Correlation coefficients between observed and estimated inoculation responses were r = 0.83 for the model incorporating soil N mineralization potential and r = 0.96 for the model incorporating N derived from N(2) fixation. Several equations collectively termed "soil N deficit factors" were also found to be useful in estimating inoculation responses. In general, models using postharvest indices of soil N were better estimators of observed inoculation responses than were those using laboratory measures of soil N availability. However, the latter, while providing less precise estimates, are more versatile because all input variables can be obtained through soil analysis prior to planting. These models should provide researchers, as well as regional planners, with a more precise predictive capability to determine the inoculation requirements of legumes grown in diverse environments.

Journal Article↗

PubMed2005

The relative importance of pre- and post-germination determinants for recruitment of an annual plant community on moving sandy land.

BACKGROUND AND AIMS: The relative importance of pre- and post-germination determinants for recruitment of natural plant communities is rarely explored. An annual plant community on moving sandy land was chosen for a case study. Answers to the following questions were sought: (a) Does recruitment of new individuals within the community of annual plants differ in time and space? (b) Is there spatial concordance between seed deposition, seedling emergence, survival and recruitment? (c) What are the direct and indirect effects of pre- and post-germination determinants on plant recruitment. METHODS: An integrative approach combining investigation of natural recruitment processes with regression, correlation and path analyses was adopted. Data on seed deposition and seedling recruitment were collected by monitoring the number of seeds deposited in the top 5 cm of the soil and the numbers of seedlings emerged and recruited from all annual plants at sites to a range of distances from the existing shrub Artemisia halodendron (Asteraceae) in eight compass directions for two consecutive growing seasons. KEY RESULTS: Community-level recruitment was strongly affected by inter-annual rainfall variation and was highly site- and density-dependent. Low recruitment rate in this system was due to low emergence rate and low post-emergence survival rate. Of the pre- and post-germination determinants studied, it was the number of seedlings which emerged and the post-emergence survival rate that had the greatest direct effects on recruitment, with a combination of both variables explaining the majority of the variance (97 %) in recruitment. CONCLUSIONS: This study suggests that post-germination determinants (emergence and survival) rather than pre-germination determinants (seed deposition) substantially determined the final pattern of recruitment. Although the density of seeds deposited did not have a significant direct effect on recruitment, it contributed to observed variation in recruitment indirectly through density-dependent emergence of seedlings.

Analysis of Variance↗

PubMed2003

Vaccine efficacy in spotted wolffish Anarhichas minor: relationship to molecular variation in A-layer protein of atypical Aeromonas salmonicida.

Atypical Aeromonas salmonicida strains comprise a heterogeneous group in terms of molecular and phenotypic characteristics. They cause various conditions of ulcer diseases or atypical furunculosis and are being isolated in increasing number from various fish species and geographical areas. Several marine fish species susceptible to atypical A. salmonicida, including spotted wolffish Anarhichas minor O., are now being farmed and new vaccines may be needed. A commercial furunculosis vaccine for salmon is reported to protect wolffish poorly against experimental challenge with atypical A. salmonicida. The protective antigen(s) in furunculosis vaccines is still unclear, but in oil-adjuvanted vaccine for Atlantic salmon Salmo salar L., the surface A-layer was shown to be important for protection. In spotted wolffish, the efficacy of atypical furunculosis vaccines seems to vary with the atypical A. salmonicida strains used as bacterin in the vaccine. In the present study we investigated whether differences in the A-layer protein among atypical strains might be responsible for the observed variation in vaccine efficacy. Atypical A. salmonicida strains from 16 fish species in 11 countries were compared by genome polymorphism analysis using amplified fragment length polymorphism (AFLP) fingerprinting and by comparative sequencing of the vapA genes encoding the A-protein. The A-protein sequences appeared to be highly conserved except for a variable region between Residues 90 to 170. Surprisingly, the grouping of strains based on AFLP- or A-protein sequence similarities was consistent. In addition, serological differences in the A-protein among the strains were demonstrated by an A-protein-specific monoclonal antibody. Vaccines based on atypical A. salmonicida strains possessing genetically and serologically different A-layer proteins were shown to result in significantly different protection in spotted wolffish.

Aeromonas↗

PubMed1996

The human drug metabolizing cytochromes P450.

The superfamily of heme-thiolate proteins known as the cytochromes P450 is responsible for the oxidative metabolism of the majority of drugs. Thus, the phenotypes of individuals with respect to their levels of catalytically active cytochromes P450 determines to a large part the substantial interindividual variation observed in the metabolic clearance of drugs. Over the past 10 years 15 different human cytochromes P450 involved in drug metabolism have been isolated and characterized to varying degrees. This brief review discusses the characterization of these cytochromes P450 and how this knowledge has been used by the pharmaceutical industry to aid in the development of new drugs.

Benzofurans↗

PubMed2005

Limited variations in 15N CSA magnitudes and orientations in ubiquitin are revealed by joint analysis of longitudinal and transverse NMR relaxation.

The site-specific magnitudes and orientations of the chemical shift tensors have been estimated for 70 backbone (15)N-nuclei in human ubiquitin from the field dependence of dynamic independent ratios between relaxation rates, both longitudinal and transverse, measured at 9.4, 11.7, 14.1, and 18.8 T. The results were jointly analyzed with previously published relaxation data [Fushman; Tjandra; Cowburn. J.Am. Chem. Soc. 1998, 120, 10947-10952] [Kover; Batta. J. Mag. Reson. 2001, 150, 137-146]. The effective magnitudes of the anisotropies distribute around 169 ppm with a variability of 5 ppm. The orientation factors, reflecting the orientation of the CSA relative to the NH bond, distribute around -0.80 with a variability of 0.04, which corresponds to an angle between the symmetry axis of an assumed axially symmetric shielding tensor and the NH bond of 21.4 degrees, and a variability of 2.3 degrees. Correlations with the isotropic (15)N-chemical shifts are observed. Variations in the shielding anisotropies add uncertainty to the obtained order parameters proportional to the square of the magnetic field, when data are analyzed using an assumed invariant CSA tensor for all sites. Around 3% additional uncertainty in the order parameters for 800 MHz data is expected. The optimal TROSY field for amide nitrogen TROSY is estimated, with only marginal variations due to site-to-site variations. Variations in the shielding tensors add uncertainty to the exchange terms calculated from cross-correlation rates. An approach for estimating the exchange terms is suggested, where the uncertainty due to CSA-variations is minimized.

Glycine↗

PubMed1992

Proteolytic susceptibility of the central domain in chicken gizzard and skeletal muscle dystrophins.

We investigated proteolytic susceptibility of the central domain in dystrophin molecules from chicken smooth and skeletal muscles. Dystrophin-enriched preparations from both muscles were made as described in Pons et al. (Proc. Natl. Acad. Sci. USA (1990) 87, 7851-7855). These preparations contained other protein components in addition to dystrophin. Three enzymes (Staphylococcus aureus proteinase, chymotrypsin and trypsin) having different proteolytic specificities were used. Time-courses of proteinase degradation were examined by the Western immunoblot technique using a specific polyclonal serum directed against a fragment (residues 1173-1728) of the dystrophin central domain. We observed accumulation of some major proteinase-resistant fragments, in the 110-160 kDa range originating from that central region of the molecule. Cleavage patterns of the smooth and skeletal muscle preparations were quite similar, but molecular weights of the breakdown products differed slightly. Interpretation of the results was based on two predictive structural models of the dystrophin central domain (Koenig and Kunkel (1990) J. Biol. Chem. 265, 4560-4566 and Cross et al. (1990) FEBS Lett. 262, 87-90). Skip residues at the end of repeat 13 (around the 1740th residue of the dystrophin amino acid sequence), as hypothesized in the Cross model, constitute probably the most sensitive site within the dystrophin central domain for any exogenous (or even endogenous) proteinase. Variations observed between dystrophins from skeletal and smooth muscles also suggest that the structures of both dystrophins differ slightly even within the dystrophin central domain. This precise identification of proteinase-resistant dystrophin fragments of variable lengths is a first step towards further physicochemical studies on the very large and rare dystrophin molecule.

Animals↗

PubMed2005

Broad cross-clade T-cell responses to gag in individuals infected with human immunodeficiency virus type 1 non-B clades (A to G): importance of HLA anchor residue conservation.

We aimed to identify cross-clade human immunodeficiency virus type 1 (HIV-1) specific T-cell responses among 10 HLA-typed individuals who were infected with non-B HIV-1 strains (A, AG, C, D, G, or F) and to correlate these responses with genetic variation in documented T-cell epitopes. T-cell reactivity was tested against peptide pools spanning clade B Gag, Pol, Nef, Rev, and Tat consensus, with Gag and Nef providing the highest responses. Nine individuals who responded to clade B Gag demonstrated cross-reactive T-cell responses against clade A and C Gag pools, while six of seven responders to Nef-B reacted to clade A and C Nef pools. An inverse correlation between the height of the T-cell responses and the sequence divergence of the HLA class I-restricted epitopes was identified when we compared autologous Gag and Nef sequences with the reactive consensus pools. This could be explained for the Gag sequences through observed variations in the HLA anchor residues. Through mapping of 30 amino acid cross-clade-reactive regions using Gag-B pools, we were able to link 58% (14/24) of the T-cell responses to regions containing previously described HLA class I-restricted epitopes. Forty-two percent (10/24) of the responses were directed to regions containing new epitopes, for which predicted HLA class I motifs could be recognized in 70% (7/10) of individuals. We demonstrate here that cross-clade T-cell responses are frequently induced in individuals infected with distinct HIV-1 clades, suggesting that interclade variation outside of HLA anchor residues may have less impact on vaccine-induced T-cell reactivity than previously thought.

Adult↗

PubMed1993

Evaluation of exercise intensity indicated by serum lactate dehydrogenase activity in healthy adults.

Noting relationship between exercise and serum LDH and alpha-HBD activities, we prescribed 3 exercise regimens of various intensities for 22 healthy adult subjects over predetermined periods. Variations in the serum enzyme activities were determined in relation to these exercise programs. We studied whether these enzyme levels may serve as new indices to evaluate the amount of exercise. The test subjects were divided into 3 groups to perform 3 types of exercise (30%, 50%, 70% of VO2max) for 6 weeks. The serum enzyme activities at the start and completion of the experiment were determined and compared. The results obtained were as follows: A rise in the serum LDH activity was noted in association with exercise. The mean increases for these groups were 10.2%, 7.5% and 23.5%. A statistically significant decrease in the serum alpha-HBD activity was noted in association with exercise. It has been suggested that by observing variations in these enzyme levels in normal individuals for an extended period, change in the intensity of physical exertion within the range of daily activities can be estimated.

Adult↗

PubMed2000

Spectroscopic detection of adrenaline-quinone formation in micelles.

Spectral changes, from 200 nm to 600 nm, of the oxidation of adrenaline to adrenochrome induced by periodate in electrically charged and neutral micelles at pH 3.77 were studied. The observed variations of the peak position, intensity and shape of the fluorescence spectra indicated that depending on the charge of the micelle adrenaline ion is partially embedded into the micellar core. Fluorescence lifetime measurements using Omnilyzer allowed to calculate partition coefficients of 0.36, 0.05 and 0.01 in sodium dodecyl sulphate, tetradodecyltrimethylammonium bromide and Triton X-100, respectively. Kinetics of adrenaline decay during oxidation were followed by its fluorescence what overcame spectral interference in the absorption spectra of adrenaline from the formed intermediates. Scanning absorption spectroscopy, with 100 ms resolution, allowed the recording of spectral changes during the transformation. With this method, the formation of adrenaline-quinone with absorption maxima at 388 nm and 274 nm was detected. The calculated rate constants of the observed kinetics during oxidation were significantly lowered in both charged micelles compared to buffer solution and in Triton X-100 neutral micelles. The observed phenomena are discussed in terms of the electrostatic forces mechanism and in the frame of the Raper-Mason scheme of adrenaline transformation.

Adrenochrome↗

PubMed2004

Genetic structure and affinities among tribal populations of southern India: a study of 24 autosomal DNA markers.

We describe the genetic structure and affinities of five Dravidian-speaking tribal populations inhabiting the Nilgiri hills of Tamil Nadu, in south India, using 24 autosomal DNA markers. Our goals were: (i). to examine what evolutionary forces have most significantly impacted south Indian tribal genetic variation, and (ii). to test whether the phenotypic similarities of some south Indian tribal groups to Africans represent a signature of close relationship to Africans or are due to convergence. All loci were polymorphic and average heterozygosities were substantial (range: 0.347-0.423). Genetic differentiation was high (Gst= 6.7%) and genetic distances were not significantly correlated with geographic distances. Genetic drift therefore probably played a significant role in shaping the patterns of genetic variation observed in southern Indian tribal populations. Otherwise, analyses of population relationships showed that Indian populations are closely related to one another, regardless of phenotypic characteristics, and do not show particular affinities to Africans. We conclude that the phenotypic similarities of some Indian groups to Africans do not reflect a close relationship between these groups, but are better explained by convergence.

Adult↗

PubMed1999

Bioavailability investigation of a new tilidine/naloxone liquid formulation compared to a reference formulation.

An oral solution available as ethanol-free droplets of the fixed drug combination tilidine-HCl 50 mg/naloxone-HCl 4 mg (CAS 27107-79-5 and CAS 465-65-6, respectively; Tilidin-ratiopharm plus Tropfen) was investigated in 12 healthy volunteers together with an ethanol-containing reference preparation for comparable bioavailability. The study was conducted in an open, randomized, two-way cross-over design applying single doses of 20 droplets (equivalent to 50 mg tilidine-HCl/4 mg naloxone-HCl) of either formulation in the fasting state. The drug plasma profiles were monitored for a period of 48 h by means of LC-MS/MS for tilidine and its active metabolite nortilidine, whereas GC-MS was employed in order to determine naloxone and its phase I metabolite, 6-beta-naloxole. Maximum concentrations (Cmax) achieved were 22.28 ng/ml (tilidine) and 92.78 ng/ml (nortilidine) for the test preparation. Corresponding values for the reference preparation were 24.95 ng/ml (tilidine) and 100.73 ng/ml (nortilidine). The extent of drug absorption (AUC0-infinity) amounted to 38.83 ng h/ml and 467.63 ng h/ml for the prodrug tilidine and the metabolite nortilidine of the test preparation and corresponded well to 43.81 ng h/ml and 493.85 ng h/ml of the reference. Regarding the rate of drug absorption, essentially identical tmax and Rabs values for both tilidine and nortilidine of either preparation in addition pointed to well comparable liquid formulations and equipotent analgesia may be inferred from opioid pharmakokinetic profiles. Pharmacokinetics of the opioid antagonist naloxone and 6-beta-naloxole were also determined and resulted in well coinciding profiles for both preparations. Thus despite the fact that only minimum oral naloxone bioavailabilities were observed, plasma level monitoring of naloxone and 6-beta-naloxole allowed for demonstration of systemic exposure of opioid antagonistic compounds throughout a period of 2-3 h after oral drug administration. Due to the limited number of subjects involved, the primary aim of the study did not consist in demonstration of drug bioequivalence. Rather a comparable bioavailability between preparations was assumed if AUC and Cmax point estimators of 90% confidence intervals would be contained within a 0.80-1.20 range. The study outcome revealed that all four investigated analytes met this requirement, whilst nortilidine pharmacokinetic parameters even fulfilled commonly accepted bioequivalence criteria, i.e. inclusion of 90% confidence intervals of AUC- and Cmax-ratios within acceptance limits of 80% and 125%. Increased data variation observed with bioavailability parameters of tilidine, naloxone and 6-beta-naloxole prevented their bioequivalence demonstration based on only 12 study participants. In conclusion, single doses of two different tilidine/naloxone 50 mg/4 mg liquid formulations revealed well comparable bioavailability for all 4 analytes investigated. Both treatments were fairly well tolerated. Most frequently reported adverse events were dizziness, headache and nausea, which all recovered without sequelae and necessity of concomitant treatment.

Adult↗

PubMedDate not supplied

Arm movement and EMG mean power frequency in the trapezius muscle: a comparison between surface and intramuscular recording techniques.

In a previous study it has been shown that there is a systematic variation of the EMG mean power frequency recorded under dynamic conditions with surface electrodes from non-fatigued trapezius muscle. The variation was most pronounced in relation to shoulder joint angle. The aim of the present study was to find out whether this variation was caused by geometric factors such as electrode displacement, or by neuromuscular factors within the muscle. A comparison has been made between surface and intramuscular recordings. EMG was recorded with standard surface electrodes and with a monopolar "hooked wire" intramuscular electrode. The recordings were analyzed for calculation of mean power frequency (MPF) and root mean squared (RMS) signal level. For MPF we found a low, but statistically significant correlation (r = 0.30) between surface and intramuscular recordings. For RMS the corresponding correlation was high (r = 0.92). Analysis of variance showed a high proportion of explained variance related to the shoulder joint angle for surface recordings, but not for intramuscular recordings. The results were confirmed in the regression analysis. The results indicate that the observed variation is largely caused by geometric displacement of the surface electrodes and not by intrinsic neuro-muscular factors.

Adult↗