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PubMed2005

Negotiating a pathological identity in the clinical dialogue: discourse analysis of a family therapy.

Within the framework of social constructionism, psychotherapy has been re-conceptualized as a semiotic process, which consists of the creative generation of new meanings in the context of collaborative discourse. In recent years, research approaches that draw from social constructionism, such as discourse analysis, have been fruitfully employed in the study of psychotherapy processes, whilst being in line with the contemporary emphasis on language, narrative, and meaning making. This paper aims to further the exploration of the usefulness of discourse analysis in the study of psychotherapy processes, and in particular, in situations where the medical discourse is powerfully implicated in the construction of a person's identity. It is based on the analysis of a family therapy with a family whose child has a diagnosis of autism. The analysis focuses on two features of the family's talk, namely shifts in the flexibility of employment of a diverse range of discourses and subject positions, and shifts in the ways agency is constructed and discursively negotiated in the clinical conversations. It is suggested that these shifts can be used as indications of change in the family's network of meanings. The analysis suggests that an important aspect in clinical work with families with a member with a psychiatric diagnosis lies in decentring, or deconstructing, the dominant, pathology-maintaining accounts, and allowing for a wider range of less problematic narratives and subject positions to emerge.

Communication↗

PubMed1988

Dynamic relationship between the slow potential and spikes in cockroach ocellar neurons.

The relationship between the slow potential and spikes of second-order ocellar neurons of the cockroach, Periplaneta americana, was studied. The stimulus was a sinusoidally modulated light with various mean illuminances. A solitary spike was generated at the depolarizing phase of the modulation response. Analysis of the relationship between the amplitude/frequency of voltage modulation and the rate of spike generation showed that (a) the spike initiation process was bandpass at approximately 0.5-5 Hz, (b) the process contained a dynamic linearity and a static nonlinearity, and (c) the spike threshold at optimal frequencies (0.5-5 Hz) remained unchanged over a mean illuminance range of 3.6 log units, whereas (d) the spike threshold at frequencies of less than 0.5 Hz was lower at a dimmer mean illuminance. The voltage noise in the response was larger and the mean membrane potential level was more positive at a dimmer mean illuminance. Steady or noise current injection during sinusoidal light stimulation showed that (a) the decrease in the spike threshold at a dimmer mean illuminance was due to the increase in the noise variance: the noise had facilitatory effects on the spike initiation; and (b) the change in the mean potential level had little effect on the spike threshold. We conclude that fundamental signal modifications occur during the spike initiation in the cockroach ocellar neuron, a finding that differs from the spike initiation process in other visual systems, including Limulus eye and vertebrate retina, in which it is presumed that little signal modification occurs at the analog-to-digital conversion process.

Animals↗

PubMedDate not supplied

[Growth, development and genetic status of pea plants cultivated in space greenhouse "LADA"].

In the period between March 2003 and April 2005 five crops of genetically marked dwarf pea were cultivated in greenhouse LADA on the ISS Russian segment to study morphology and genetics in consecutive generations. Results of the first space experiment were analyzed and characteristics of ground plants grown from space seeds were studied. It was shown that parameters of growth, development and genetic status of pea plants that completed the ontogenetic cycle in LADA did not differ substantially from the laboratory control and that plants cultivated in space flight do not incur losses in the reproductive function and form viable seeds. Genetic analysis of plants from the first generation of space and ground seeds using the methods of RAPD-primers (10 markers) and chromosomal aberration analysis failed to reveal genetic polymorphism which means that the spaceflight factors had no effect on the genetic apparatus of the first generation of space-grown plants.

Ecosystem↗

PubMed2000

Evaluation of gastric motility by Fourier analysis of condensed images.

In this study Fourier analysis was applied to condensed images of gastric emptying with the aim of evaluating the amplitude and frequency of gastric contractions as well as gastric emptying in patients with various well-defined disorders. In 15 controls, 65 patients with progressive systemic sclerosis (PSS), 41 patients with diabetes mellitus type I (DM), 12 patients with pyloric stenosis and 9 patients who had undergone gastric surgery, gastric emptying was determined after ingestion of a semi-solid test meal. In addition, condensed images were generated to evaluate the amplitude and frequency of gastric contractions by means of Fourier analysis. In PSS and DM patients, gastric emptying and contraction amplitudes were significantly reduced (P<0.01). Patients with pyloric stenosis displayed regular peristalsis but significantly delayed emptying (P<0.01). Patients who had undergone gastric surgery showed normal or rapid gastric emptying associated with decreased amplitudes (P<0.01). The frequency of gastric contractions in the patient groups was not different from that in controls. This study showed Fourier analysis of condensed images to be a rapid and feasible approach for the evaluation of gastric contractions. Depending on the underlying disorder, gastric emptying and peristalsis showed both corresponding and discrepant findings. Data on gastric contractions provided additional information compared with results obtained by conventional emptying studies. Therefore, both parameters should be routinely assessed to further improve characterisation of gastric dysfunction by scintigraphy.

Adult↗

PubMed1979

Genetic analysis of lines selected for wing vibration in Drosophila melanogaster.

Selection for the wing vibration component of courtship in the Oregon-R stock of D. melanogaster was practiced for 44 generations. Selection was successful, indicating that there is genetic variation for the trait in the Oregon-R stock. The mean realized heritability of the trait, based on the first 11 generations of selection, was 15%. Biometrical analysis showed that there is some additive genetic variance for the trait with the possibility of some ambidirectional dominance. No maternal effects for the trait were found.

Animals↗

PubMed1989

Preparative in vitro generation of lacto-series type 1 chain glycolipids catalyzed by beta 1----3-galactosyltransferase from human colonic adenocarcinoma Colo 205 cells.

Lacto-series glycolipids, comprising two isomeric types distinguished as type 1 or 2 based upon the linkage of the terminal galactose of the chains, form the basis for a diversity of cell surface antigens expressed on cells. Experimentally, type 2 chain precursors are generally more abundant in tissues for extractive purposes to yield rather large quantities of material compared to the type 1 chain structures. Conditions have been defined for in vitro conversion of terminal Gal beta 1----4GlcNAc linkages of type 2 chain precursors to yield type 1 lacto-series chain based terminal Gal beta 1----3GlcNAc structures in 5- to 10-mg amounts or higher. The terminal galactose of underivatized type 2 chain structures is removed by hydrolysis with jack bean beta-galactosidase followed by transfer of galactose in beta 1----3 linkage catalyzed by a beta 1----3-galactosyltransferase from human colonic adenocarcinoma Colo 205 cells which was first depleted of beta 1----4-galactosyltransferase by chromatography on alpha-lactalbumin-Sepharose. Scaled-up reaction mixtures provided a final yield of product after isolation of about 90% from the immediate Lc3Cer precursor in the 5-mg product range. The biosynthetic product was subjected to extensive chemical analysis by 1H NMR and mass spectrometric methods. These results indicated the presence of a high purity terminal Gal beta 1----3-linked product. The amount of material was sufficient for nondestructive characterization by 2-D NMR, with subsequent confirmation of structure by +FAB-MS and methylation analysis by GC-MS. The results indicate an effective means to rapidly generate lacto-series type 1 precursors in vitro as a superior alternative to direct tissue extractive procedures.

Adenocarcinoma↗

PubMed1993

Diagnostic accuracy of pancreatic enzymes evaluated by use of multivariate data analysis.

We analyzed pancreatic enzyme data from 508 patients with suspected pancreatitis by neural network analysis, by an Expert multirule generation protocol, and by receiver-operator characteristic (ROC) curve analysis of a single test result. Neural network analysis showed that use of lipase provided the best means for diagnosing pancreatitis. Diagnostic accuracies achieved by using amylase only, lipase only, and amylase and lipase in combination were 76%, 82%, and 84%, respectively. Use of the Expert rule generation protocol provided a diagnostic accuracy of 92% when rules for single and multiple samplings were combined. ROC curve analysis for initial enzyme activities showed the maximal diagnostic accuracy to be 82% and 85% for amylase and lipase, respectively; use of peak enzyme activities yielded accuracies of 81% and 88%, respectively. The evaluation of laboratory test data should include analysis of the diagnostic accuracy of laboratory tests by multivariate techniques such as neural network analysis or an Expert systems approach. Multivariate analysis should allow for a more realistic assessment of the diagnosis accuracy of laboratory tests because all the available data are included in the evaluation.

Amylases↗

PubMed1998

Hepatic structure-pharmacokinetic relationships: the hepatic disposition and metabolite kinetics of a homologous series of O-acyl derivatives of salicylic acid.

1. The hepatic disposition and metabolite kinetics of a homologous series of O-acyl (acetyl, propionyl, butanoyl, pentanoyl, hexanoyl and octanoyl) esters of salicylic acid (C2SA, C3SA, C4SA, C5SA, C6SA and C8SA, respectively) was determined using a single-pass, in-situ rat liver preparation. 2. The hepatic venous outflow profiles for the parent esters and the generated metabolite, salicylic acid (SA) were analysed by HPLC. Non-parametric moments analysis was used to determine the area under the curve (AUC'), mean transit time (MTT) and normalized variance (CV2) for the parent esters and generated SA. 3. Pregenerated SA ([14C]-salicylic acid) was injected into each liver with the parent ester to determine its distribution characteristics. 4. The overall recovery of ester plus metabolite was 89% of the ester dose injected and independent of the ester carbon number, suggesting that ester extraction was due to hepatic metabolism to salicylic acid. 5. The metabolite AUC' value increased directly with the lipophilicity of the parent ester (from 0.12 for C2SA to 0.95 for C8SA). By contrast, the parent AUC' decreased with the lipophilicity (from 0.85 for C2SA to zero for C8SA). The metabolite MTT value also showed a trend to increase with the lipophilicity of the parent ester (from 15.72 s for C3SA to 61.97 s for C8SA). However, the parent MTT value shows no significant change across the series. 6. The two-compartment dispersion model was used to derive the kinetic parameters for parent ester, pregenerated SA and generated SA. Consequently, these parameters were used to estimate the values of AUC', MTT and CV2 for the parent ester and metabolite. The moments values obtained using the two-compartment dispersion model show similar trends to the corresponding moments values obtained from the outflow profiles using a non-parametric approach. 7. The more lipophilic aspirin analogues are more confined to the portal circulation after oral administration than aspirin due to their more extensive hepatic elimination avoiding systemic prostacyclin inhibition. Given that aspirin's selectivity as an anti-thrombotic agent has been postulated to be due to selective anti-platelet effects in the portal circulation, the more lipophilic and highly extracted analogues are potentially more selective anti-thrombotic agents than aspirin.

Animals↗

PubMed1985

Quantitative determination of bacterial replication in vivo.

A new methodology which permits the quantitative measurement of absolute bacterial replication in vivo is proposed. Mice were inoculated with mixtures of temperature-sensitive mutants and parental wild types, and the changes in the ratios of the two strains were measured. The number of wild-type generations was calculated from the declining ratios over time with the formula n = log (r0/rt)/log 2; n is the number of generations, and r0 and rt are the ratio of temperature-sensitive mutants to the parental wild type at time zero and at the times sampled throughout the experiment. The replication rate was determined by regression analysis. A mathematical argument for the formula is presented. Using this technique, we determined the mean generation times of Escherichia coli (33 min) and Pseudomonas aeruginosa (20 min) in the peritoneal cavities of mice, in the face of host clearance mechanisms during the first stages of infection.

Animals↗

PubMed1999

Genome organization and mRNA structure of Periplaneta fuliginosa densovirus imply alternative splicing involvement in viral gene expression.

We determined the complete nucleotide sequence of an infectious clone of the cockroach small spherical virus (CSSV) genome. Analysis of the genome organization and the predicted viral protein sequences showed clearly that this virus should be classified as a new member of the subfamily Densovirinae, genus Densovirus, and should be designated as PfDNV. However, our data revealed some differences between the gene expression strategies used by PfDNV and other DNVs. An internal promoter, in addition to the promoter (p3) at the genome terminus, was observed at map unit 18 (p18), implying transcriptional regulation of generation of the nonstructural proteins of PfDNV. Furthermore, the structural analysis of cDNAs complementary to mRNAs from the region coding for structural proteins suggested alternative splicing and polyadenylation as means for generation of the structural proteins of PfDNV.

Alternative Splicing↗

PubMedDate not supplied

Interlaboratory study of blood selenium determinations.

Fifty-one laboratories from 14 countries participated in a survey on the determination of selenium (Se) in 8 bovine blood samples with Se concentrations ranging from 0.2 mumol/L (0.016 microgram/mL) to 14 mumol/L (1.1 micrograms/mL). The methods used (and the percentage of participants using each method) were fluorometry (61), hydride-generation atomic absorption spectrophotometry (AAS) (23), graphite-furnace AAS (6), gas chromatography (4), neutron activation analysis (4), and X-ray fluorometry (2). There was little difference in the mean Se results obtained by fluorometry or hydride-generation AAS (P greater than 0.05). Mean intralaboratory coefficients of variation (CVs) from known replicates ranged from 4 to 14% for all samples. Interlaboratory CVs were related to blood Se concentration and increased to 55% at Se levels below 0.4 mumol/L (0.032 microgram/mL). Laboratories that used quality control (QC) schemes had lower interlaboratory CVs than those that did not, but the advantage began to diminish at blood Se concentration below 0.4 mumol/L (0.032 microgram/mL). The high interlaboratory CVs, coupled with the false assurance from the low intralaboratory CVs and the ineffectiveness of the QC schemes at blood Se concentrations below 0.4 mumol/L (0.032 microgram/mL), are of concern in diagnosis of marginal Se deficiency in livestock where the concentrations of interest are in the range 0.15-0.5 mumol/L (0.012-0.039 microgram/mL).

Animals↗

PubMed1996

Slow bolus injection of ribose in the identification of thallium-201 redistribution following combined adenosine/dynamic exercise stress.

AIM: A simple stress/redistribution thallium-201 myocardial perfusion imaging protocol may underestimate the degree of thallium redistribution in a defect identified on the stress images. We sought to investigate whether a slow-bolus injection of D-ribose improves the identification of thallium redistribution following combined adenosine/dynamic exercise stress. MATERIALS AND METHODS: Fifteen patients (10 males, five female, median age 63 years, range 50-75) were enrolled in the study. All underwent two successive adenosine plus exercise myocardial perfusion scintigraphy protocols 7-14 days apart. Adenosine was infused at 140 micrograms.kg-1.min-1 coupled with 25 W ergometer pedalling for 6 min with 74 Mbq of thallium-201 being injected at 4 min. Immediately following the stress image acquisition, patients received the one of either 60 mg.kg-1 of D-ribose or normal saline, injected over 5 min. Redistribution images were acquired after 4 h. The identical stress procedure was conducted in the crossover arm of the study, and patients received the alternative test article. SPECT images were visually analysed and scored in a nine segment model by two blinded observers. In addition, circumferential profile analysis was conducted. RESULTS: By visual interpretation 25 segments displayed redistribution of the ribose, but not in the saline study, 14 reversible segments were seen on the saline study alone and 18 were seen on both studies (P = ns). In six patients ribose identified a greater number of redistributing segments and in a further six patients saline identified more reversible segments. Comparison of mean values of defect extent severity and percentage reversibility scores generated from the circumferential profile analysis showed no significant difference between the two arms of the study. CONCLUSION: A 5 min bolus injection of D-ribose following combined adenosine/dynamic exercise stress confers little benefit on the identification of redistribution of thallium-201. These results differ from those of previous studies which showed that a 30 min infusion of D-ribose following treadmill exercise significantly enhanced thallium redistribution. The duration of the ribose infusion is likely to be an important factor influencing the effect brought to bear on the redistribution of the tracer, and should be run over 30 min, or longer.

Adenosine↗

PubMed1996

A human friendly reporting and database system for brain PET analysis.

We have developed a human friendly reporting and database system for clinical brain PET (Positron Emission Tomography) scans, which enables statistical data analysis on qualitative information obtained from image interpretation. Our system consists of a Brain PET Data (Input) Tool and Report Writing Tool. In the Brain PET Data Tool, findings and interpretations are input by selecting menu icons in a window panel instead of writing a free text. This method of input enables on-line data entry into and update of the database by means of pre-defined consistent words, which facilitates statistical data analysis. The Report Writing Tool generates a one page report of natural English sentences semi-automatically by using the above input information and the patient information obtained from our PET center's main database. It also has a keyword selection function from the report text so that we can save a set of keywords on the database for further analysis. By means of this system, we can store the data related to patient information and visual interpretation of the PET examination while writing clinical reports in daily work. The database files in our system can be accessed by means of commercially available databases. We have used the 4th Dimension database that runs on a Macintosh computer and analyzed 95 cases of 18F-FDG brain PET studies. The results showed high specificity of parietal hypometabolism for Alzheimer's patients.

Alzheimer Disease↗

PubMed1992

Reliability of kinematic measurements of rear-foot motion.

The purpose of this study was to examine the ability of a video-based, computer-interfaced motion analysis system to provide reliable data. Ten subjects with no significant orthopedic or neurological dysfunction and ranging in age from 22 to 45 years (mean = 29.6, SD = 7.8) were tested. Retroreflective markers were placed on the posterior shank and foot of each subject. Footswitches were attached to the plantar forefoot and rear foot. A video camera was placed behind the subject, and video data were collected while the subject walked on a treadmill. One representative gait cycle for each subject was selected and processed 10 times with a video processor and analysis software. Three intraclass correlation coefficients (ICCs) were calculated for variables generated by the analysis software, one for two individual measures and one each for the mean of three and five repeated measures. Except for temporal variables, processing data introduced additional variability into the measurement process, particularly for angular velocity data. Measurement of all variables was highly reliable (ICC values greater than or equal to .95) when based on the mean of at least three repeated measures. Although a single measure of temporal and angular position variables may be considered reliable, we recommend using a mean of three trials for angular velocity variables. Additional research is needed to determine tester and subject variability and validity of the measures.

Adult↗

PubMed1989

A factor analysis of the rat's corpus callosum.

Previous work from our laboratory (Berrebi et al., Brain Research, 438 (1988) 216-224) demonstrated region-specific sexual dimorphisms in the size of the rat's corpus callosum, which are modifiable by extra stimulation in early life. These differences are assumed to reflect regional corticocortical fibers of passage which are altered differentially by gender and our experimental manipulations. In this paper, we report our findings when the original data are reanalyzed using a newly developed computer program. This program not only reproduced, with very high accuracy, the original means, but also permitted us to examine computer generated callosal width scores via a factor analysis procedure. Such a procedure yields useful information concerning the clustering of callosal fibers and thus contributes significantly to our hypothesis that discrete cortical regions are selectively sensitive to experimental variables. Factor analyses of the callosal variables and brain weight of 155 rats found 7 width factors, and an eighth factor which contained the variables of brain weight, callosal length, and callosal perimeter. Callosal area did not load significantly on any of these factors. The percentile locations of the width factors, starting at the anterior (genu) end were: widths 1-5, 6-17, 24-38, 46-57, 62-72, 79-95 and 96-99. Use of these factor scores in analyses of variance revealed that the male callosum is wider than the female's, with the differences most pronounced in the genu and the most posterior portion of the splenium. Both age and early handling experience influenced the callosal width factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed2005

Assessing the learning curve for the acquisition of laparoscopic skills on a virtual reality simulator.

BACKGROUND: The aim of this study was to develop summary metrics and assess the construct validity for a virtual reality laparoscopic simulator (LapSim) by comparing the learning curves of three groups with different levels of laparoscopic expertise. METHODS: Three groups of subjects ('expert', 'junior', and 'naïve') underwent repeated trials on three LapSim tasks. Formulas were developed to calculate scores for efficiency ('time-error') and economy of 'motion' ('motion') using metrics generated by the software after each drill. Data (mean +/- SD) were evaluated by analysis of variance (ANOVA). Significance was set at p < 0.05. RESULTS: All three groups improved significantly from baseline to final for both 'time-error' and 'motion' scores. There were significant differences between groups in time error performances at baseline and final, due to higher scores in the 'expert' group. A significant difference in 'motion' scores was seen only at baseline. CONCLUSION: We have developed summary metrics for the LapSim that differentiate among levels of laparoscopic experience. This study also provides evidence of construct validity for the LapSim.

Adult↗

PubMed1998

Fractal organization of the pointwise correlation dimension of the heart rate.

OBJECTIVE: To depict and quantify the degree of organization of the heart rate variability (HRV) in normal subjects. METHODS: A modified algorithm was created to estimate series of 'point-dimensions' (PD2) from interbeat (R-R) interval series of 10 healthy subjects (21-56 years). Our innovation is twofold: (i) we quantified instances of low-dimensional chaos, random fluctuations, and those for which our method failed to provide either (due to poor statistics); (ii) consecutive subepochs of PD2s underwent a relative dispersion (RD) analysis, yielding an index (D) which quantifies the dynamical organization of the heart rate generator. RESULTS: The mean values of PD2 series varied between 4.58 and 5.88 (mean+/-SD= 5.21+/-0.41, n = 10). For group 1 (21-30 years, n = 6) we found an averaged PD2 of 5.49+/-0.27, while for group 2 (47-56 years, n = 4) PD2 averaged 4.79+/-0.17. The RD analysis performed for subepochs of PD2s yielded both instances obeying fractal scaling (D < 1.5) and stochasticity (D > 1.5). The average D for group 1 was 1.39+/-0.04 (14 subepochs) and for group 2, 1.20+/-0.008 (8 subepochs). Paired t-test and Hartley F-max test for comparison between D values and homogeneity of variance between the two groups were performed, yielding P-values 0.004 and 0.02, respectively. CONCLUSIONS: The complexity of the HRV seems to be modulated by a non-random fractal mechanism of a 'hyperchaotic' system, i.e. it can be hypothesized to contain more than one attractor. Also, our results support the 'chaos hypothesis' put forth recently, namely, the complexity of the cardiovascular dynamics is reduced with aging. The index of relative dispersion of the dimensional complexity has to be tested in various clinico-pathological settings, in order to corroborate its value as a potential new physiological measure.

Adult↗

PubMed1992

Consonant clusters in disordered speech: constraints and correspondence patterns.

Comparison of patterns of cluster realization from 47 children ranging in age from 3;4 to 6;8 with functional (non-organic) speech disorders with those reported in the literature for normal acquisition reveals that these patterns are essentially the same for both groups. Using a two-level generative phonology for children's independent systems, further analysis of cluster realizations by means of feature geometry and underspecification theory reveals that there are systematic and principled relationships between adult representations of clusters and children's underlying representations and between children's underlying representations and their phonetic representations. With special emphasis on coalescence phenomena, it is suggested that the apparent diversity in children's cluster realizations can be reduced to four constraints on the form of underlying and phonetic representations.

Child↗