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PubMedDate not supplied

Verbal indicators of depression in conversations with stroke survivors.

TOPIC: This secondary analysis study examined patients' comments at 1 and 6 months poststroke when they had scores of > or = 16 on the Center for Epidemiologic Studies-Depression Scale. Stroke survivors' depressive comments were matched with items of two well-established depression instruments. METHODS: A qualitative study using content analysis to analyze the data (N = 7). FINDINGS: Verbal indicators of depression were evident in patients' comments, and depressive themes were identified. Depression instrument items were congruent with minor themes, except for spirituality. CONCLUSIONS: The analysis provides guidance for assessment of stroke survivor depression. It provides direction for designing interventions to decrease depression after stroke.

Aged↗
PubMed2006

Comparative analysis of neuroectodermal differentiation capacity of human bone marrow stromal cells using various conversion protocols.

Human adult bone marrow-derived mesodermal stromal cells (hMSCs) are able to differentiate into multiple mesodermal tissues, including bone and cartilage. There is evidence that these cells are able to break germ layer commitment and differentiate into cells expressing neuroectodermal properties. There is still debate about whether this results from cell fusion, aberrant marker gene expression or real neuroectodermal differentiation. Here we extend our work on neuroectodermal conversion of adult hMSCs in vitro by evaluating various epigenetic conversion protocols using quantitative RT-PCR and immunocytochemistry. Undifferentiated hMSCs expressed high levels of fibronectin as well as several neuroectodermal genes commonly used to characterize neural cell types, such as nestin, beta-tubulin III, and GFAP, suggesting that hMSCs retain the ability to differentiate into neuroectodermal cell types. Protocols using a direct differentiation of hMSCs into a neural phenotype failed to induce significant changes in morphology and/or expression of markers of early and mature glial/neuronal cells types. In contrast, a multistep protocol with conversion of hMSCs into a neural stem cell-like population and subsequent terminal differentiation in mature glia and neurons generated relevant morphological changes as well as significant increase of expression levels of marker genes for early and late neural cell types, such as nestin, neurogenin2, MBP, and MAP2ab, accompanied by a loss of their mesenchymal properties. Our data provide an impetus for differentiating hMSCs in vitro into mature neuroectodermal cells. Neuroectodermally converted hMSCs may therefore ultimately help in treating acute and chronic neurodegenerative diseases. Analysis of marker gene expression for characterization of neural cells derived from MSCs has to take into account that several early and late neuroectodermal genes are already expressed in undifferentiated MSCs.

Adolescent↗
PubMed2000

Conversion from thrice daily to twice daily administration of gabapentin (GBP) in partial epilepsy: analysis of clinical efficacy and plasma levels.

Gabapentin has been administered in placebo-controlled studies with a thrice daily (T.I.D.) schedule, because of its short half-life. However, clinical efficacy does not seem strictly related to plasma levels: a twice daily (B.I.D.) schedule might therefore be possible. The aim of our study was to verify if the conversion from a T.I.D. to a B.I.D. regimen affected the efficacy and safety of gabapentin therapy. Out of 171 patients treated with add-on gabapentin, we selected 29 stable responders, who were followed for three months with a T.I.D. schedule and then switched to B.I.D. regimen for further three months. Seizure number, side-effects and trough plasma levels of gabapentin were collected during both periods. Gabapentin mean dose was 2117.2 mg/day. Mean number of seizures/months was: 4.2 at baseline, 1.0 during the T.I.D., and 0.9 during the B.I.D. period. Mean trough plasma level of gabapentin was 5.9 microgram/ml during the T.I.D. and 5.2 microgram/ml during the B.I.D. period. Twelve side-effects were reported by 11 patients during the T.I.D. and 6 by 5 patients during the B.I.D. period., sedation and vertigo were the most frequent in both. Results of our study suggest that gabapentin can be administered safely and effectively either with a T.I.D. and a B.I.D. regimen.

Acetates↗
PubMed2001

[Determination of the human tissue interaction parameters for Monte Carlo dose calculations in radiotherapy].

BACKGROUND: Monte Carlo dose calculation techniques for clinical photon and electron beams potentially predict the dose with an accuracy of better than +/- 2%. However, to achieve this precision, knowledge of the interaction properties in each volume element is essential. MATERIAL AND METHODS: In the present paper a method for mass density to total cross section conversion is described. This method is based on a detailed analysis of the interaction data for body tissues (ICRU Report 46) and allows the conversion without knowing the atomic composition. RESULTS: The analysis resulted in various fit functions allowing the calculation of interaction parameters for arbitrary materials using the corresponding cross sections in water. CONCLUSION: Together with standard procedures to calculate mass densities from a given CT number distribution, the method represents an effective and accurate algorithm to determine photon interaction coefficients, electron stopping powers as well as electron scatter parameters.

Decision Support Techniques↗
PubMed1996

A sequence analysis of von Willebrand factor mRNA, gene, and pseudogene in two patients with von Willebrand disease type 2B, and an investigation of gene conversion in its gene.

We identified the point mutations in two unrelated patients with von Willebrand disease (vWD) type 2B using sequence analyses of the gene, pseudogene and messenger RNA of vWF. Both patients were determined to be heterozygotes with amino acid transitions of 1308 Arg-->Cys in Case 1 and 1316 Val-->Met in Case 2. Moreover, we also found single base transitions 7541 A-->G in intron 27 of the active gene, and 7642 A-->G, which thus destroyed the Kpn 1 site, in its pseudogene in both cases. Since these mutations represented changes in the base between the gene and its pseudogene, we studied the presence of gene conversion in exon 28 of vWF gene to clarify its pathological role. Using RT-PCR and an allele-specific restriction enzyme analysis, we identified no gene conversions in this region in four other patients with vWD, 25 normal subjects and one cell line, MEG01. Based on these findings, gene conversion in the vWF gene is not considered to be a frequent phenomenon in either vWD patients or normal subjects.

Adult↗
PubMed2006

Method for the analysis of delta18O in water.

A new method has been developed for the oxygen isotopic analysis of water utilizing the exchange of oxygen atoms with nitrite followed by conversion of nitrite to nitrous oxide by hydrazoic acid. This method is analogous to that employing carbon dioxide equilibration in that the analyte is added as a reagent to the water sample and exchanges oxygen isotopes with the water. In this procedure, however, the equilibration is more rapid and less sensitive to changes in ambient temperature, as the exchange is terminated by conversion of nitrite to nitrous oxide prior to analysis. The nitrous oxide is then analyzed using an on-line purge and trap system coupled to an isotope ratio mass spectrometer. This method makes use of previously established methods for nitrite isotopic analysis and commercially available equipment. It has high throughput, relatively low standard deviation (0.1 per thousand or better), and small sample size (down to 100 microL), is simple, and is applicable to both fresh- and seawater samples.

Azides↗
PubMed1994

Native TIMP-free 70 kDa progelatinase (MMP-2) secreted at elevated levels by RSV transformed fibroblasts.

Rous sarcoma virus-transformed cultures of chicken embryo fibroblasts (RSVCEF) secrete elevated levels of a 70 kDa progelatinase, an avian form of the 72 kDa matrix metalloproteinase-2 (MMP-2). Affinity-purified preparations of secreted 70 kDa progelatinase are composed of two distinct populations of zymogen: a 70 kDa progelatinase tightly complexed with an avian form of TIMP-2 and a native 70 kDa progelatinase free of any detectable TIMP-2. These two forms of the progelatinase can be separated by Mono Q FPLC in the absence of denaturing agents. The homogeneity of the two separated forms is demonstrated by both SDS-PAGE and nondenaturing, native gel electrophoresis. The purified TIMP-free 70 kDa progelatinase is stable in aqueous conditions and does not spontaneously autoactivate. Treatment of the TIMP-free progelatinase with the organomercurial, p-aminophenylmercuric acetate (APMA), results in rapid (5-60 minutes) autolytic conversion of the 70 kDa progelatinase to 67 kDa, 62 kDa and lower molecular weight forms of the enzyme. APMA treatment of the TIMP-free progelatinase yields a preparation that is enzymatically active with a high specific activity towards a peptide substrate. Identical treatment of TIMP-complexed progelatinase with APMA results in a significantly slower conversion process in which the 70 kDa progelatinase is only 50% converted after 6-24 hours and the specific enzyme activity of the preparation is 8 to 18-fold lower. Purified avian TIMP-2 added to the TIMP-free progelatinase forms a complex with the progelatinase and prevents the rapid autolytic conversion induced by APMA. Comparative analysis of parallel cultures of transformed RSVCEF and normal CEF demonstrates that the transformed cultures contain threefold higher levels of the TIMP-free progelatinase than the normal CEF cultures which produce predominantly TIMP-complexed progelatinase. The presence in transformed cultures of elevated levels of a more readily activated TIMP-free progelatinase, the suppression of its rapid activation by TIMP-2, and the potential effect of the altered balance between TIMP-free and TIMP-complexed 70 kDa progelatinase on the invasive, malignant phenotype, are discussed.

Amino Acid Sequence↗
PubMed2000

Evaluation of direct and cooperative contributions towards the strength of buried hydrogen bonds and salt bridges.

An experimental approach to evaluate the net binding free energy of buried hydrogen bonds and salt bridges is presented. The approach, which involves a modified multiple-mutant cycle protocol, was applied to selected interactions between TEM-1-beta-lactamase and its protein inhibitor, BLIP. The selected interactions (two salt bridges and two hydrogen bonds) all involving BLIP-D49, define a distinct binding unit. The penta mutant, where all side-chains constructing the binding unit were mutated to Ala, was used as a reference state to which combinations of side-chains were introduced. At first, pairs of interacting residues were added allowing the determination of interaction energies in the absence of neighbors, using double mutant cycles. Addition of neighboring residues allowed the evaluation of their cooperative effects on the interaction. The two isolated salt bridges were either neutral or repulsive whereas the two hydrogen bonds contribute 0.3 kcal mol(-1 )each. Conversely, a double mutant cycle analysis of these interactions in their native environment showed that they all stabilize the complex by 1-1.5 kcal mol(-1). Examination of the effects of neighboring residues on each of the interactions revealed that the formation of a salt bridge triad, which involves two connected salt bridges, had a strong cooperative effect on stabilizing the complex independent of the presence or absence of additional neighbors. These results demonstrate the importance of forming net-works of buried salt bridges. We present theoretical electrostatic calculations which predict the observed mode of cooperativity, and suggest that the cooperative networking effect results from the favorable contribution of the protein to the interaction. Furthermore, a good correlation between calculated and experimentally determined interaction energies for the two salt bridges, and to a lesser extent for the two hydrogen bonds, is shown. The data analysis was performed on values of DeltaDeltaG(double dagger)K(d) which reflect the strength of short range interactions, while DeltaDeltaG(o)K(D) values which include the effects of long range electrostatic forces that alter specifically DeltaDeltaG(double dagger)k(a) were treated separately.

Allosteric Site↗
PubMed1990

Short DNA fragments induce site specific recombination in mammalian cells.

A defective hprt gene was corrected by homologous recombination in a lymphocyte cell line deficient in Hypoxanthine-phosphoribosyl-transferase activity (hprt). In a novel approach, only a fragment of a cDNA clone of the functional hprt gene was used to induce homologous recombination. The mutation that was corrected corresponds to a single base change in exon III of the hprt gene. Two transfection methods, electroporation and the previously unreported use of polyoma capsids containing only short DNA fragments, were able to induce the recombinational event. After transfection cells with a functional hprt gene were selected and homologous recombination events were identified using polymerase chain reaction. Double stranded fragments and both coding and non-coding single stranded fragments resulted in conversion to a functional gene. Analysis of the resulting hprt positive cells revealed that most cells had undergone a simple replacement reaction. Interestingly, however, some cells had lost an intron adjacent to the site of mutation. Potential mechanisms for this phenomenon, including the possible involvement of RNA in DNA repair, are discussed.

Amino Acid Sequence↗
PubMed1993

Effects of dilution rate and pH on the ruminal cellulolytic bacterium Fibrobacter succinogenes S85 in cellulose-fed continuous culture.

The ruminal cellulolytic bacterium Fibrobacter succinogenes S85 was grown in cellulose-fed continuous culture at 22 different combinations of dilution rate (D, 0.014-0.076 h-1) and extracellular pH (6.11-6.84). Effects of pH and D on the fermentation were determined by subjecting data on cellulose consumption, cell yield, product yield (succinate, acetate, formate), and soluble sugar concentration to response surface analysis. The extent of cellulose conversion decreased with increasing D. First-order rate constants at rapid growth rates were estimated as 0.07-0.11 h-1, and decreased with decreasing pH. Apparent decreases in the rate constant with increasing D was not due to inadequate mixing or preferential utilization of the more amorphous regions of the cellulose. Significant quantities of soluble sugars (0.04-0.18 g/l, primarily glucose) were detected in all cultures, suggesting that glucose uptake was rather inefficient. Cell yields (0.11-0.24 g cells/g cellulose consumed) increased with increasing D. Pirt plots of the predicted yield data were used to determine that maintenance coefficient (0.04-0.06 g cellulose/g cells.h) and true growth yield (0.23-0.25 g cells/g cellulose consumed) varied slightly with pH. Yields of succinate, the major fermentation endproduct, were as high as 1.15 mol/mol anhydroglucose fermented, and were slightly affected by dilution rate but were not affected by pH. Comparison of the fermentation data with that of other ruminal cellulolytic bacteria indicates that F. succinogenes S85 is capable of rapid hydrolysis of crystalline cellulose and efficient growth, despite a lower mu max on microcrystalline cellulose.

Animals↗
PubMed1992

Comparative analysis of spontaneous mitotic recombination in [cir0] and [cir+] strains of the yeast Saccharomyces cerevisiae.

The influence of the 2 microns plasmid on homologous recombination in the right arm of chromosome XV of the yeast Saccharomyces cerevisiae has been examined. No differences between spontaneous mitotic recombination rates in [cir0] and [cir+] derivatives of two yeast diploid tester strains were detected. In the course of analysis an unusually high coincident conversion frequency at ADE2, HIS3, and two RFLP loci adjacent to ADE2, was observed. The character of coincident homozygotization of linked markers argues for a "break-and-replicate" mechanism underlying the coincident conversion events.

DNA, Fungal↗
PubMed1988

cis-9,10-epoxystearic acid in human leukocytes: isolation and quantitative determination.

Racemic cis-9,10-epoxystearic acid was isolated from total lipids of human leukocytes. Identification of the epoxy acid was based mainly on gas liquid chromatographic-mass spectrometric analysis and on its chemical conversion into threo-9,10-dihydroxystearic acid. A mass spectrometric method for quantitative determination of cis-9,10-epoxystearic acid using the tetradeuterated compound as internal standard was developed. Using this method, nonstimulated human leukocytes were found to contain 5.1 +/- 2.2 micrograms (SD) of cis-9,10-epoxystearic acid per 10(9) cells (n = 8). More than 90% of the epoxy acid occurred in its esterified form in leukocyte lipids.

Gas Chromatography-Mass Spectrometry↗
PubMed1997

A case report: immune responses and clinical course of the first human use of granulocyte/macrophage-colony-stimulating-factor-transduced autologous melanoma cells for immunotherapy.

The first use of granulocyte/macrophage-colony-stimulating-factor-transduced, lethally irradiated, autologous melanoma cells as a therapeutic vaccine in a patient, with rapidly progressive, widely disseminated malignant melanoma resulted in the generation of a novel antitumour immune response associated with partial, albeit temporary, clinical benefit. An initially negative reaction to non-transduced, autologous melanoma cells was converted to a delayed-type hypersensitivity (DTH) reaction of increasing magnitude following successive vaccinations. While intradermal vaccine sites showed prominent dendritic cell accrual, DTH sites revealed a striking influx of eosinophils in addition to activated/memory T lymphocytes and macrophages, recalling the histology of challenge tumour cell rejection in immune mice. Cytotoxic T lymphocytes (CTL) reactive with autologous melanoma cells were detectable at high frequency after vaccination, not only in limiting-dilution analysis, but also in bulk culture without added cytokines. Clonal analysis of CTL showed a conversion from a purely CD8+ response to a high proportion of CD4+ clones following vaccination. A prominent acute-phase response manifested by a five- to tenfold increase in C-reactive protein was observed, as was a systemic eosinophila. Vaccination resulted in the regression of axillary lymphatic metastases, stabilisation of pulmonary metastases, and a dramatic, reversible increase in cerebral oedema associated with multiple central nervous system metastases: however, lesions in the adrenal glands, pancreas and spleen proved refractory. The antitumour effects and immune response were not detectable 2 months following the last vaccination. Irradiation of the extensive cerebral metastases resulted in rapid deterioration and death of the patient.

Autopsy↗
PubMed1999

Urinary lead as a possible surrogate of blood lead among workers occupationally exposed to lead.

OBJECTIVES: The aim of the present study is to investigate whether lead (Pb) in urine (Pb-U) can be a valid surrogate of lead in blood (Pb-B), the traditional biomarker of exposure to lead in occupational health. METHODS: Blood and spot urine samples were collected from 258 workers of both sexes occupationally exposed to lead. The samples were analyzed for lead by graphite furnace atomic absorption spectrometry, and the correlation between Pb-B and Pb-U was examined by linear regression analysis before and after logarithmic conversion. RESULTS: The correlation coefficient (0.824; P < 0.01) was largest when the relationship between Pb-B and Pb-U was examined with 214 cases of one sex (i.e., men) after Pb-U was corrected for a specific gravity (1.016) of urine (Pb-Usg) and both Pb-B and Pb-Usg were converted to logarithms. The geometric means (GMs) of Pb-B and Pb-Usg for the 214 men were 489 microG/l and 81 microg/l, respectively. When Pb-Usg was assumed to be 100 microg/l in this set of correlations, the 95% confidence range of Pb-B for the group mean was narrow, i.e., 543-575 microg/l (with GM of 559 microg/l), whereas that for individual Pb-B values was as wide as 355-881 microg/l. CONCLUSIONS: The correlation of Pb-U with Pb-B among workers occupationally exposed to Pb was close enough to suggest that Pb-U may be a good alternative to Pb-B on a group basis, but not close enough to allow Pb-U to predict Pb-B on an individual basis.

Bias↗
PubMed2001

Activated alumina as an energy source for peptide bond formation: consequences for mineral-mediated prebiotic processes.

The catalytic properties of various forms of alumina were tested for alanine dimerization reaction. The catalytic efficiency of alumina depends on the structure, as well as on acid/base properties of the catalyst. The highest yields of Ala2 were achieved on activated alumina with surface of neutral pH (about 3% conversion after 2 weeks). Thermal analysis of Ala + alumina reaction systems shows that the thermal behavior of amino acid changes substantially in contact with the activated surface of the alumina catalyst. The reaction of Ala is detected as being strongly endothermic by differential thermal analysis of pure amino acid (above 250 degrees C). The alanine endothermic reaction is shifted substantially to lower values (below 200 degrees C) and hardly detectable if activated alumina is present. The reaction mechanism of amino acid activation on alumina surface and its significance for mineral-catalyzed prebiotic peptide bond formation are discussed.

Aluminum Oxide↗
PubMed1987

A FORTRAN technique for correlating a circular environmental variable with a linear physiological variable in the sugar maple.

This paper deals with a computer program adapted to a statistical method for analyzing an unlimited quantity of binary recorded data of an independent circular variable (e.g. wind direction), and a linear variable (e.g. maple sap flow volume). Circular variables cannot be statistically analyzed with linear methods, unless they have been transformed. The program calculates a critical quantity, the acrophase angle (PHI, phi o). The technique is adapted from original mathematics [1] and is written in Fortran 77 for easier conversion between computer networks. Correlation analysis can be performed following the program or regression which, because of the circular nature of the independent variable, becomes periodic regression. The technique was tested on a file of approximately 4050 data pairs.

Air Movements↗