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PubMed2004

Model of unidirectional transluminal gene transfer.

Gene transfer assays in vitro are poor indicators of transduction efficacy observed in vivo. We designed and optimized an intermediate model for assessing and quantifying unidirectional transduction ex vivo. The model enables simultaneous transmucosal evaluation of up to 96 different variables under the same tissue conditions. We show that the model is versatile and suitable for use with different vectors (adenovirus and AAV), different reporter genes (beta-galactosidase and green fluorescent protein), and viscera with various tissue features such as peritoneum and urothelium. Ex vivo transduction assays may correlate better with in vivo gene transfer results. Because the experimental model described here can be performed in small samples, it may enable translational applications in tissues of human origin.

Animals↗

PubMed2003

Reliability and validity of Quality of Life assessed by the Short-Form 36 and the Modular System for Quality of Life in patients with schizophrenia and patients with depression.

Reliability and validity of the Quality of Life (QoL) construct were investigated in healthy controls (N=346), patients with depression (N=114) and patients with schizophrenia (N=91) using two different QoL instruments: the Short-Form 36 (SF-36), a well-established generic instrument measuring eight dimensions; and the Modular System for Quality of Life (MSQoL), a recently developed instrument measuring seven core dimensions and four specific modules (objective data, partnership, family, occupation). The MSQoL and the SF-36 were administered at three intervals (hospital admission, discharge and 4-month follow-up). Reliability, group profiles (clinical specificity), responsiveness, discriminant validity (with regard to sociodemographic, psychopathological, clinical and state variables) and convergent validity were tested. At admission, patients with depression had the lowest QoL level, patients with schizophrenia had an intermediate level, and controls had the highest QoL level. At discharge and follow-up, the two patient groups did not differ from each other, but still had lower levels than controls. Both patient groups improved significantly in QoL from admission to discharge. This improvement was confounded by improvement in depressive symptoms, but not in positive or negative symptoms. Current mood state influenced QoL assessments in all three samples substantially. In conclusion, QoL can be measured reliably and with sufficient responsiveness by the MSQoL and the SF-36 in psychiatric and non-clinical populations, although discriminant validity with regard to depression and current mood is questionable.

Adult↗

PubMed1987

Metabolism of the lactating cow. II. Digestive elements of a mechanistic model.

The structure and characteristics of a model suitable for estimating digestion within the rumen and rates and patterns of nutrient entry in lactating cows are presented. The model consists of 12 state variables comprising a large particle pool, small particle pools representing insoluble dietary nutrients, soluble pools representing soluble dietary nutrients, and fermentation intermediates and end products. The model was constructed assuming continuous feeding, using Michaelis-Menten or mass action kinetics. The computer program was written in ACSL to run on a VAX computer. A fourth-order Runge-Kutta procedure was used for numerical integration. Sensitivity and behavioural analysis demonstrated that overall stability and sensitivity of the model to individual parameters was generally satisfactory, but the need to improve the description and parameterization of aspects such as particle size in relation to availability, rate and affinity constants for amino acid degradation and rate constants for particle outflow from the rumen was established. Adjustments of the model to examine discontinuous feeding regimes were undertaken and initial results with respect to changes in fermentation rates, rumen acetate levels and microbial metabolism were considered realistic. Comparisons with experimental data were considered satisfactory on forage-based and medium concentrate-containing diets, but with diets comprising 90% cereal, some inconsistencies, especially with respect to predictions of volatile fatty acid production rates, were observed. Reasons for this are put forward and suggestions for improvements in the model are discussed.

Animals↗

PubMed1997

Genetics of homology-dependent gene silencing in Arabidopsis; a role for methylation.

Ninety-eight independent transformed (T1) Arabidopsis plants were generated, containing additional copies of the chalcone synthase (CHS) gene. Three T2 generation families (A, B and C) were found that showed reduced anthocyanin biosynthesis, consistent with homology-dependent gene silencing of CHS. Clonal sectors of tissue showing CHS silencing were seen in the early generations. Affected individuals in family A showed only slight silencing, in family C such plants were almost completely silenced, and in family B affected individuals were intermediate. Plants homozygous for a single silencing insert were isolated from each family. Plants homozygous or hemizygous for insert A showed variable penetrance and expressivity of silencing. Self-fertilization of plants hemizygous for the B and C-inserts suggested that these CHS-silencing inserts each behave as single Mendelian dominant traits. The CHS mRNA of the C-insert homozygotes was reduced to undetectable levels. Outcrosses of B- and C-insert homozygotes to wild-type plants resulted in F1 plants that were variegated. This variegation appears to be due to expression of the CHS allele from the wild-type parent, since use of a CHS mutant, tt4, as untransformed parent resulted in uniform green F1 plants. Southern blots revealed a correlation between DNA methylation and CHS silencing. In addition, derivative plants were generated from C-insert homozygotes that had lost the silencing inserts, and these showed a partial reversion towards wild-type phenotype and methylation of the cellular CHS gene at the TT4 locus. This result suggests that the TT4 copy of CHS became methylated during the C-insert-induced silencing and retained methylation and partial silencing after the silencing T-DNA was lost.

Acyltransferases↗

PubMed1998

Psychophysiological analysis of mental load during driving on rural roads--a quasi-experimental field study.

The objective of this study was the development and validation of an integrated measure-assessment approach (driving performance and psychophysiological indicators) for the assessment of driving demands of rural road segments as a starting point for design. With 31 student test drivers and a selection of six study roads, the reactivity of psychophysiological parameters was evaluated based on a general model of cognitive-energetic effort regulation according to Hockey (1993). The road curvature change rate was introduced as the independent variable, which served as a criterion of objective road difficulty. Based on a reliability analysis, the longitudinal and cross-sectional stability, especially for heart rate (HR) and blink rate (BR) measures, is sufficiently high. Both these psychophysiological variables and speed vary as a function of the curvature change rate of the rural road segments. The speed parameter differentiates very strongly the different curvature change rates. Among the psychophysiological indicators, changes in the blink rate almost exactly mirror the level of the curvature change rate owing to the fact that the BR decreases almost steadily with increasing curvature change rate. Cardiovascular parameters, such as heart rate (HR) and heart rate variability (HRV), and skin conductance response (SCR) also vary in relation to driving difficulty of road segments, but at levels of intermediate curvature other additional road characteristics may also influence these measures.

Adult↗

PubMed2003

Chemotherapy and antiangiogenesis--drug-specific, dose-related effects.

Dose-response effects of fluorouracil, paclitaxel, doxorubicin, cisplatin, methotrexate, cyclophosphamide and etoposide on VEGF165/164-mediated angiogenesis using the rat mesenteric-window angiogenesis assay are reported. VEGF is a pivotal pro-angiogenic factor in most tumors. Microvessel spatial extension, density, pattern formation and segment length were assessed quantitatively and objectively. A single i.v. injection of each drug was given at a low, intermediate or high dose, 7 days before sacrifice. All the drugs elicited significant responses in terms of one or more measured variables. Only paclitaxel, doxorubicin and cyclophosphamide significantly suppressed the overall angiogenic response (p < or = 0.0001, p < or = 0.0002 and p < or = 0.05, respectively), however. Taking toxicity into account, paclitaxel was more potent in inhibition of angiogenesis than the other agents. No clear correlation was found between drug half-life, the degree of toxic effects (in terms ofbody weight changes) and the antiangiogenic effect. The antiangiogenic effects were distinctly drug specific.

Animals↗

PubMed2006

The distinct contributions of age of acquisition and word frequency in auditory word perception.

We report two studies of the distinct effects that a word's age of acquisition (AoA) and frequency have on the mental lexicon. In the first study, a purely statistical analysis, we show that AoA and frequency are related in different ways to the phonological form and imageability of different words. In the second study, three groups of participants (34 seven-year-olds, 30 ten-year-olds, and 17 adults) took part in an auditory lexical decision task, with stimuli varying in AoA, frequency, length, neighbourhood density, and imageability. The principal result is that the influence of these different variables changes as a function of AoA: Neighbourhood density effects are apparent for early and late AoA words, but not for intermediate AoA, whereas imageability effects are apparent for intermediate AoA words but not for early or late AoA. These results are discussed from the perspective that AoA affects a word's representation, but frequency affects processing biases.

Adult↗

PubMed2000

Pituicytoma: a distinctive low-grade glioma of the neurohypophysis.

Pituicytoma is a rare, poorly characterized tumor of the sella and suprasellar region that is distinct morphologically from other local tumors and is thought to be derived from neurohypophyseal pituicytes. Clinical data, neuroimaging studies, and microsections were reviewed from nine such low-grade gliomas. Immunostains for glial, neuronal, and proliferation markers were performed on all nine tumors and six control neurohypophyses. Three tumors were studied ultrastructurally. Six men and three women, age 30 to 83 years (mean, 48 years), presented with visual symptoms, headache, or hypopituitarism. Magnetic resonance images showed solid, discrete, contrast-enhancing masses, four within the sella and five in the suprasellar space. The tumors consisted of sheets and/or fascicles of plump spindle cells with slightly fibrillar cytoplasm and slightly pleomorphic, oval-to-elongate nuclei with pinpoint nucleoli. Extracellular mucin was prominent in one tumor. Rosenthal fibers, granular bodies, and Herring bodies (granular axonal dilatations characteristic of the normal neurohypophysis) were lacking. Mitoses were rare or absent. MIB-1 labeling indices were low (0.5-2%). Tumor cells were strongly reactive for vimentin and S-100 protein, variably positive for glial fibrillary acidic protein, and nonreactive for synaptophysin and neurofilament protein. Cytoplasm varied in electron density and contained intermediate filaments. Neither meningothelial nor ependymal features were noted. Two tumors recurred at 20 and 26 months after subtotal resection, but none of the six completely resected tumors have done so. Pituicytomas are discrete, largely noninfiltrative low-grade gliomas of the sellar region that occur in adults. Their histologic appearance is distinct from pilocytic and ordinary, infiltrative astrocytomas. The distinction between pituicytoma and normal neurohypophysis is aided by the latter's content of axons, Herring bodies, and perivascular anucleate zones rich in axonal terminations. Although curable by total excision, subtotal resection can be associated with recurrence.

Adult↗

PubMed2001

A systematic review of the peripheral analgesic effects of intraarticular morphine.

The analgesic effects of intraarticular morphine are controversial. To systematically evaluate the effects, we performed a review of the literature and a metaanalysis of the peripheral effects of morphine injected intraarticularly. Research databases were searched to identify articles in which peripheral analgesic effects of morphine were studied in patients undergoing arthroscopic knee procedures under local, regional, or general anesthesia. The review was performed on three issues: does morphine injected intraarticularly produce analgesia, is it a dose-dependent effect, and, if so, is the effect systemic or mediated via peripheral opioid receptors? Visual analog score (VAS) and analgesic consumption were studied during the early phase (0-2 h), intermediate phase (2-6 h), and late phase (6-24 h) postoperatively after injection of morphine intraarticularly. Metaanalysis of these effect variables was performed by the weighted-analysis technique, and the essential homogeneity assumption was tested by the chi(2) test. Forty-five articles could be identified in which the effects of morphine were studied in a prospective, randomized manner, and 32 of these studies included a placebo control. Pooled analyses of data from 19 studies suitable for metaanalysis showed an improvement in analgesia after morphine compared with placebo in the order of 12-17 mm on the VAS during all three phases of treatment. Studies with high quality scores showed somewhat smaller improvements. Total analgesic consumption could not be analyzed statistically, but the number of studies showing decreased analgesic consumption or no differences between groups was identical (six and six). No clear dose-response effect was seen when VAS was used as a measure of pain, but it was seen when area under the curve was used as a measure of pain. A systemic effect of peripherally-injected morphine was not possible to exclude because of the very limited data available. We conclude from this metaanalysis that intraarticularly administered morphine has a definite but mild analgesic effect. It may be dose dependent, and a systemic effect cannot be completely excluded.

Analgesics, Opioid↗

PubMedDate not supplied

Precise determination of paraspinous musculature by quantitative CT.

The ability to quantify muscular size has important implications in monitoring the effects of muscle disorders, in assessing the efficacy of interventions aimed at abbreviating muscle atrophy, and in examining the association between muscle and bone as a correlate of osteoporosis. We have developed an autocontouring technique for the precise determination of paraspinous musculature that can be implemented as an adjunct to our current CT method of spinal trabecular densitometry without additional scanning time or radiation exposure. Using two distinct patient groups, we evaluated the validity of this technique by assessing intra- and interobserver variability. Using the average coefficient of variation (CV) as an estimate of precision, we found intraobserver variability to be essentially equivalent whether evaluated in young, healthy men (0.69%) or in older, mildly osteoporotic women (0.74%). When the muscle evaluations of two observers were compared, the variability was somewhat higher, 1.81 and 1.83% in older and younger subjects, respectively. We scanned an additional 10 subjects twice, with intermediate repositioning, and found the reproducibility (CV) of determining paraspinous muscle area to be 0.97%. Given this estimated high level of precision, we derived the approximate magnitude of change in muscle size that could be observed using two-point measurements in time. Small average changes, on the order of 1-2%, could be detected using small groups of subjects (10-20/group). Moreover, we found that, even in the individual patient, relatively small changes (3-6%) could be detected given our low imprecision estimate. We believe this quantitative approach holds promise for monitoring muscle changes in vivo as well as for rigorously exploring the relationship between muscle and bone.

Adult↗

PubMed2002

Malignant pineal parenchymal tumors in adult patients: patterns of care and prognostic factors.

OBJECTIVE: The aim of our study was to analyze patterns of care and to identify prognostic factors in patients at least 18 years of age who received radiotherapy for malignant pineal parenchymal tumors. METHODS: In a multicenter, retrospective study, we analyzed data for 37 previously published cases and 64 patients treated at the participating institutions. RESULTS: A total of 56 patients received postoperative radiotherapy, and 45 patients received primary radiotherapy. Chemotherapy was administered to 34 patients. The median follow-up period was 38 months, and median overall survival was 100 months. The variables that significantly influenced overall survival were the extent of disease (localized versus disseminated; P = 0.0002), differentiation (pineal parenchymal tumor of intermediate differentiation versus pineoblastoma; P = 0.001), and residual disease (> or = 50% versus < 50% reduction in size; P < 0.0001). In a multivariate analysis, the parameters turned out to be independent risk factors. The median survival in patients with local or spinal failure was 15 months. Local control was better in older patients (> or = 32 yr versus < 32 yr; P = 0.02). Spinal control was more successful in patients with pineal parenchymal tumors of intermediate differentiation than it was in patients with pineoblastomas (P = 0.03). Nine of 45 treatment failures occurred later than 5 years after treatment. CONCLUSION: Stage, histological characteristics, and response are independent risk factors in adults with malignant pineal parenchymal tumors. Late relapses are common.

Adolescent↗

PubMed2001

Sex among the flowers: the distribution of plant mating systems.

Previous reviews of plant outcrossing rate survey data have agreed that predominant selfing and predominant outcrossing are alternative stable states of mating system evolution. We reanalyzed the most recent data and plot outcrossing rates as a continuous variable rather than as a class variable. Wind-pollinated species are indeed bimodal. However, the shape of the distributions for animal-pollinated species reveals that intermediate rates of outcrossing are common (49% of species fall between 20% and 80% outcrossing). Consequently, we suggest that mating system is best considered a continuous rather than a discrete character of plant populations.

Adaptation, Physiological↗

PubMed1991

Neurophysiological aspects of smoking behaviour: a neuroelectric perspective.

Many of the current neurobiological hypotheses of tobacco smoking concern relationships between nicotine-induced neurotransmitter alterations--events at the level of the individual neuron--and mental behavioural states. Since non-invasive physiological variables may reflect neural activity more directly than overt indices, neuroelectric studies are suggested to be particularly helpful in understanding the intermediate steps between the neuronal effects of smoke/nicotine and behavioural change. The intent of this paper is to offer direction and suggestion regarding electroencephalographic (EEG) and event-related brain potential (ERP) research into smoke/nicotine effects on mood and performance. Suggested directions revolve around multi-component measurement strategies and the employment of study designs and test paradigms which may offer a more dynamic and detailed neurobiological view of smoke/nicotine effects on these processes.

Animals↗

PubMed1999

Motivational climate and goal orientations as predictors of perceptions of improvement, satisfaction and coach ratings among tennis players.

One purpose of this work was to study the relationship of goal orientations and the perceived motivational climate created by the coach in relation to 219 competitive Spanish tennis players': a) perceived improvement in different facets of the game, b) satisfaction with their competitive results, overall level of play, and coach, and c) ratings of their coach. The second purpose was to examine whether the dependent variables were best predicted by the perceived situationally emphasized goal structure created by the coach and/or the athletes' dispositional goal perspective. Intermediate (N=70), advanced (N=124), and professional (N=25) level players completed Spanish versions of the TEOSQ and the PMCSQ-2 and items assessing perceived improvement specific to tennis, satisfaction and coach ratings. The results were consistent with the tenets of goal perspective theory and provide further support for the promotion of a task involving atmosphere in sport.

Achievement↗

PubMed1998

Identification of transmembrane regions critical for ligand binding to the human D3 dopamine receptor using various D3/D1 transmembrane chimeras.

To investigate the roles of individual transmembrane segments (TM) of the human D3 dopamine receptor in its ligand-receptor interactions, we generated chimeric receptors in which its TMs were replaced, one at a time, partially or entirely, by the corresponding TM of the homologous human D1 receptor. Ligand binding properties of the chimeras, as expressed heterologously in Sf9 cells using recombinant baculoviruses, indicate that the critical binding regions for D3-selective (over D1) ligands reside at narrow regions (6 to 8 residues) near the extracellular surface for TMI, II, IV and VI, while TMV seems to be minimally involved in the ligand selectivity. For TMIII and TMVII, the critical regions seem to be deeper, involving at least the 10 residues near the extracellular surface for TMIII, and the entire TM segment for TMVII. This is based on our current observations that the chimeras with the D3 sequence in the critical regions, although the rest of the TM is of D1 origin (except TMVII), showed the binding properties indistinguishable from those of the wild-type receptor. The chimeras with the D1 sequence in the regions, on the other hand, showed ligand binding characteristics wildly variable depending on substituted TMs: Most marked decreases in ligand affinities were observed with the chimeras of TMIII and VII, and intermediate changes with those of TMIV and VI. Replacements of TMV produced no appreciable effects on the affinities of 14 test ligands (except for one). The chimeras of TMI and II with the D1 sequence in the critical regions showed no appreciable specific binding for several radioactive D3-selective ligands, possibly reflecting their critical roles in assembly and folding of the receptor. These critical regions of the D3 receptor were highly homologous to those of the D2 receptor, except for several nonconservatively substituted residues, which could be exploited to develop ligands selective for the D3 over D2 dopamine receptor or vice versa.

Amino Acid Sequence↗

PubMed1993

Copper-resistant enteric bacteria from United Kingdom and Australian piggeries.

Thirty-three enteric isolates from Australian (Escherichia coli only) and United Kingdom (U.K.) (Salmonella sp., Citrobacter spp., and E. coli) piggeries were characterized with respect to their copper resistance. The copper resistance phenotypes of four new Australian E. coli isolates were comparable with that of the previously studied E. coli K-12 strain ED8739(pRJ1004), in that the resistance level in rich media was high (up to 18 mM CuSO4) and resistance was inducible. Copper resistance was transferable by conjugation from the new Australian isolates to E. coli K-12 recipients. DNA similarity between the new Australian isolates and the pco copper resistance determinant located on plasmid pRJ1004 was strong as measured by DNA-DNA hybridization; however, the copper resistance plasmids were nonidentical as indicated by the presence of restriction fragment length polymorphisms between the plasmids. DNA-DNA hybridization and polymerase chain reaction analysis demonstrated DNA homology between the pco determinant and DNA from the U.K.E. coli, Salmonella sp., and Citrobacter freundii isolates. However, the copper resistance level and inducibility were variable among the U.K. strains. Of the U.K. E. coli isolates, 1 demonstrated a high level of copper resistance, 4 exhibited intermediate resistance, and 16 showed a low level of copper resistance; all of these resistances were expressed constitutively. A single U.K. C. freundii isolate, had a high level of copper resistance, inducible by subtoxic levels of copper. Transconjugants from one E. coli and one C. freundii donor, with E. coli K-12 strain UB1637 as a recipient, showed copper resistance levels and inducibility of resistance which differed from that expressed from plasmid pRJ1004.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Husbandry↗

PubMed2006

Characteristics of Staphylococcus aureus strains isolated in Poland in 1996 to 2004 that were deficient in species-specific proteins.

One hundred seventy Staphylococcus aureus isolates, collected in 1996 to 2004, were reidentified by phenotypic and genotypic methods. One hundred ten of these (65%) were confirmed, as previously denoted, to be clumping factor (CF)- or free coagulase-deficient S. aureus, based on their phenotype. Based on the CF or coagulase production, three groups of phenotypically deficient S. aureus isolates were distinguished. Group 1 encompassed CF-positive and coagulase-deficient isolates, group 2 consisted of CF-deficient and coagulase-positive isolates, and group 3 included isolates that were CF positive, had delayed coagulase activity, and were deficient in other species-specific features. All investigated strains harbored the clfA, clfB, coa, spa, and nuc genes, but the presence of their products was not detected by the phenotypic methods. Glycopeptide susceptibility testing showed that 26 isolates (23.6%) were hetero-glycopeptide-intermediate S. aureus(hGISA) or hetero-teicoplanin-intermediate S. aureus (hTISA), based on the population analysis profile. The relatedness of the isolates was evaluated by multiple-locus variable number of tandem repeats analysis, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing. The phenotypically deficient S. aureus isolates were classified into PFGE types B (ST239-III) and D (ST246-IA) and were related to the common clones, Hungarian and Iberian, respectively, which have been widely disseminated in Poland and globally. The simultaneous occurrence of hGISA/hTISA and the CF-deficient phenotypes was found for 62.1% of isolates belonging to group 2. The majority of these isolates were assigned to the Iberian clone (PFGE type D; ST247-IA). An association between the defect in coagulase and that in thermonuclease production was observed, which concerned 59.2% of isolates of group 1. The majority of these isolates belonged to the Hungarian clone (PFGE type B; ST239-III).

Bacterial Typing Techniques↗

PubMed1982

Azlocillin, a ureido penicillin active against Pseudomonas aeruginosa: interpretive zone standards and quality control parameters for tests with 75-mu g disks.

A nine-laboratory coordinated study was performed to establish tentative control limits for 75-mu g azlocillin disks tested against the standard control strain of Pseudomonas aeruginosa (ATCC 27853). Control limits for individual tests were 24 to 30 mm (25 to 29 mm for means of five separate tests). To establish interpretive zone standards for 75-mu g azlocillin disks, three separate laboratories each tested 93 strains of P. aeruginosa or related species. Geometric mean minimal inhibitory concentrations (MICs) were plotted against arithmetic mean zone diameters. Regression analyses were performed with zone diameter as the independent variable and also with MIC as the independent variable. The following interpretive categories were recommended: resistant, less than or equal to 14 mm (MIC, greater than 128 mu g/ml); intermediate, 15 to 17 mm (MIC, 128 mu g/ml); and susceptible, greater than or equal to 18 mm (MIC, less than or equal to 64 mu g/ml).

Azlocillin↗

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