Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Stability analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,747 records · Page 97Linked to original sources
PubMed2002

Storage stability of simulator ethanol solutions for vapor-alcohol control tests in breath-alcohol analysis.

We conducted a one-year stability study on aqueous alcohol simulator solution, stored in sealed polyethylene bottles at 4 degrees C and at room temperature. Thirty-nine aliquots of simulator solution with a VAC target value of 0.079 +/- 0.010 g/210 L were stored and analyzed independently monthly at two locations: The University of Oklahoma HSC Toxicology Laboratories (OUHSC) and Oklahoma Department of Public Safety Alcohol and Drugs Countermeasures Unit (DPS/ADCU). Paired Intoxilyzer 5000 Evidential Breath-Alcohol Analyzers + Guth Breath Test Simulators were used to measure 20 consecutive VACs generated at 34 degrees C with individual simulator solution aliquots, followed by VAC control tests in triplicate. Control tests at OUHSC were carried out with a NIST-traceable compressed ethanol/nitrogen gas mixture with a validated label ethanol concentration of 0.085 g/210 L +/- 2% at 760 torr. Control tests at DPS/ADCU were carried out with simulator-generated vapor-alcohol samples with a validated VAC of 0.10 +/- 0.01 g/210 L. The measurement results were analyzed by standard statistical methods with a STATGRAPHICS Plus for Windows Version 6.0 microcomputer statistics program. No significant changes occurred during the one-year study period in the concentration of the aqueous simulator alcohol solution, as reflected by close agreement of the mean results of each set of 20 consecutive VAC analyses. The summary descriptive statistics for the VAC measurements were OUHSC (4 degrees C) mean +/- SD = 0.077 +/- 0.0004 g/210 L, median = 0.077, mode = 0.077, span = 0.075-0.079; DPS/ADCU (4 degrees C) mean +/- SD = 0.079 +/- 0.0013 g/210 L, median 0.079, mode = 0.078, span = 0.077-0.081; DPS/ADCU (Room Temp.) mean +/- SD = 0.078 +/- 0.0011 g/210 L, median = 0.078, mode = 0.078, span = 0.076-0.080. All OUHSC and DPS/ADCU VAC control tests were within acceptable target value ranges. The least squares linear regression model equations for y (= VAC, g/210) upon x (= time in months) were OUHSC (4 degrees C) y = 0.077 - 0.000021x; DPS/ADCU (4 degrees C) y = 0.079 + 0.000032x; and DPS/ADCU (Room Temp.) y = 0.078 + 0.000038x. The essentially zero slopes for all 3 models signify that no significant change occurred in the alcohol concentrations of all 39 simulator solutions aliquots measured over the 1-year study period, for either 4 degrees C or room temperature storage. The Pearson correlation coefficients for the above three regression models were R = -0.20, 0.10, and 0.13, respectively; each value is close to zero, confirming the absence of significant statistical relationship between VACs and passage of time. The coefficients of determination for the above three regression models were 4.3%, 1.0%, and 1.7%, respectively. These statistics indicate that the fitted models explain only 1 to 4% of the small total variability in the VAC as a function of time. ANOVA statistics for each of the three sets of VAC test results yield a P-value greater than 0.10, indicating that there is not a statistically significant relationship between VAC and the passage of time, at a 90% or higher confidence level. We conclude that the ethanol concentration of simulator alcohol solutions stored in sealed polyethylene bottles, at either 4 degrees C or normal room temperature, does not change significantly for at least one year after preparation, and that a correct initial VAC target value will remain valid during that time period.

Breath Tests↗
PubMed1981

Stability-indicating high-performance liquid chromatographic analysis of lidocaine hydrochloride and lidocaine hydrochloride with epinephrine injectable solutions.

A reversed-phase, high-performance liquid chromatographic (HPLC) procedure, which is specific and quantitative for lidocaine hydrochloride, epinephrine, and methylparaben, was developed for the analysis of lidocaine hydrochloride and lidocaine hydrochloride with epinephrine solutions for injection. Epinephrine sulfonic acid and adrenochrome are separated in this system. Also separated are lidocaine and methylparaben and their respective degradation products, 2-6-xylidine and p-hydroxybenzoic acid. The analysis requires that three detectors (two UV and one electrochemical) be connected in series. By using this arrangement, lidocaine hydrochloride and methylparaben are quantitated by UV at 254 and 280 nm, respectively, while epinephrine is quantitated electrochemically. The method is simple, accurate, precise, and rapid. No sample preparation or internal standard is necessary, and only a 2-microliter sample volume is required for analysis. Chromatographic conditions include a mu Bondapak CN column and a mobile phase of 0.01 M 1-octanesulfonic acid sodium salt, 0.1 mM edetate disodium, 2% acetic acid, 2% acetonitrile, and 1% methanol in water.

Chromatography, High Pressure Liquid↗
PubMed2001

Increase in the stability and helical content of estrogen receptor alpha in the presence of the estrogen response element: analysis by circular dichroism spectroscopy.

Ligand-dependent stabilization of the estrogen receptor (ER) is often postulated, with limited support from experimental data. We studied the thermal unfolding of recombinant ERalpha by circular dichroism (CD) spectroscopy. The T(M) of unfolding of ERalpha was 38 +/- 2.4 degrees C, and the van't Hoff enthalpy of unfolding was 31.7 +/- 3.4 kcal/mol in the absence of ligands. Addition of estradiol (E(2)) increased the T(M) to 43.6 +/- 2.3 degrees C, while addition of E(2) and an oligonucleotide harboring the estrogen response element (ERE) increased the T(M) to 47.9 +/- 1.6 degrees C. Addition of the antiestrogen 4-hydroxytamoxifen (HT) alone did not increase the T(M); however, a combination of HT and the ERE increased the T(M) to 48.9 +/- 1.0 degrees C. The ERE alone increased the T(M) to 46.1 +/- 0.9 degrees C. Addition of E(2) alone had no effect on the apparent enthalpy of unfolding; however, the ERE alone increased the apparent enthalpy from 31.7 to 36.1 kcal/mol. ERalpha samples containing the ERE also exhibited an increase in the negative ellipticity at 208 and 222 nm, relative to that of ligand-free ERalpha, suggesting a stabilization of the alpha-helix. CD data analysis further showed that the presence of the ERE caused a large increase in alpha-helical content of ERalpha in both the presence and absence of the ligands. This increase in alpha-helical content of ERalpha was not observed in the presence of a nonspecific oligonucleotide. These results show that the ERE can increase the thermal stability of ERalpha, enhance its alpha-helical content, and facilitate the cooperativity of the folding transition.

Circular Dichroism↗
PubMed2006

Designer short peptide surfactants stabilize G protein-coupled receptor bovine rhodopsin.

Membrane proteins play vital roles in every aspect of cellular activities. To study diverse membrane proteins, it is crucial to select the right surfactants to stabilize them for analysis. Despite much effort, little progress has been made in elucidating their structure and function, largely because of a lack of suitable surfactants. Here we report the stabilization of a G protein-coupled receptor bovine rhodopsin in solution, using a new class of designer short and simple peptide surfactants. These surfactants consist of seven amino acids with a hydrophilic head, aspartic acid or lysine, and a hydrophobic tail with six consecutive alanines. These peptide surfactants not only enhance the stability of bovine rhodopsin in the presence of lipids and the common surfactants n-dodecyl-beta-D-maltoside and octyl-D-glucoside, but they also significantly stabilize rhodopsin under thermal denaturation conditions, even after lipids are removed. These peptide surfactants are simple, versatile, effective, and affordable. They represent a designer molecular nanomaterial for use in studies of diverse elusive membrane proteins.

Amino Acid Sequence↗
PubMed1990

Regulation of intracellular pH by cultured opossum kidney cells.

Opossum kidney (OK) cells (an epithelial cell line) were examined by flame photometry of cellular Na+ and K+ and by microfluorometric measurements of the intracellular pH (pHi) of single cells loaded with 2',7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF). The work concentrates on defining resting pHi values under different experimental conditions and examines factors that contribute to the maintenance of resting pHi. To use nigericin to calibrate the intracellular response of BCECF, cellular K+ levels were measured by a null point analysis, and the stability and magnitude of cellular Na+ and K+ levels were determined vs. time. Resting pHi in medium without added CO2 was high when measured by null point analysis of the population (pHi 7.6) and from measurements of single cells that have recovered from an acid load caused by NH4 prepulse (pHi 7.76 +/- 0.03, n = 20 cells). In single-cell measurements, addition of CO2-HCO3- to the medium results in cellular acidification of the steady-state pHi by 0.35 +/- 0.04 pH units. In medium equilibrated with room air, the resting pHi is shown to be a dynamic steady state composed of net flux due to apical Na(+)-dependent transport (Na(+)H+ exchange) plus acidifying processes. It is concluded that although 5-[N-ethyl-N-isopropyl]amiloride (EIPA) inhibits the forward reaction of Na(+)-H+ exchange, EIPA is either ineffective as an inhibitor of the reverse reaction of Na(+)-H+ exchange or Na(+)-H+ exchange does not reverse measurably in the OK cells.

Amiloride↗
PubMed2005

[The role of quarternary structure in fluorescent protein stability].

The stability of fluorescent proteins (FPs) is of great importance for their use as reporters in studies of gene expression, protein dynamics and localization in cell. A comparative analysis of conformational stability of fluorescent proteins, having different association state was done. The list of studied proteins includes EGFP (monomer of green fluorescent protein, GFP), zFP506 (tetramer GFP), mRFP1 and "dimer2" (monomer and dimmer of red fluorescent protein), DsRed1 (red tetramer). The character of fluorescence intensity changes induced by guanidine hydrochloride (GdnHCl) of these proteins differs significantly. Green tetramer zFP506 has been shown to be more stable than green monomer EGFP, red dimmer "dimer2" has been shown to be less stable than red tetramer DsRed1, while red monomer mRFP1 has been shown to be practically as stable as tetramer DsRedl. It is concluded that the quaternary structure, being an important stabilizing factor, does not represent the only circumstance dictating the dramatic variations between fluorescent proteins in their conformational stability.

Amino Acid Sequence↗
PubMed1992

Role of proline residues in human lysozyme stability: a scanning calorimetric study combined with X-ray structure analysis of proline mutants.

It has been shown that protein stability can be modulated from site-directed mutations that affect the entropy of protein unfolding [Matthews, B. W., Nicholson, H., & Becktel, W. J. (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 6663-6667]. However, the effect of a specific amino acid replacement on stability highly depends on the location of the mutation site and its environment in the protein structure [Yutani, K., Hayashi, S., Sugisaki, Y., & Ogasahara, K. (1991) Proteins Struct., Funct., Genet. 9, 90-98). To clarify the role of specific proline residues in the thermostability of human lysozyme (h-lysozyme), a series of proline mutants were investigated by means of scanning calorimetry and high-resolution X-ray crystallography. The thermodynamic properties of the mutant and wild-type h-lysozymes are compared and discussed on the basis of their three-dimensional structure. h-Lysozyme contains two proline residues at positions 71 and 103. The Pro71----Gly substitution was found to destabilize h-lysozyme by decreasing the entropic contribution of unfolding by about 2 kcal/mol at 68.8 degrees C. This is consistent with the theoretical expectations for such a substitution. However, the same substitution at position 103 (Pro103----Gly) does not affect h-lysozyme stability, and the thermodynamic properties of the P71G/P103G and P71G mutants are essentially the same. Pro71 which is conserved among lysozymes from other species, appears to be important for stability, whereas Pro103, which is not conserved, does not. These differences are explained in terms of residue accessibility to the solvent and crystallographic B-factor, which reflects the amino acid mobility.(ABSTRACT TRUNCATED AT 250 WORDS)

Calorimetry, Differential Scanning↗
PubMed2005

Distribution and pharmacokinetic analysis of angiostatin radioiodine labeled with high stability.

OBJECTIVE: Radiotracers of anticancer agents provide important information on its in vivo handling. Angiostatin (AST) is a promising anticancer drug with potent antiangiogenic effects, but reported AST radiotracers suffer from poor in vivo stability. In this study, we synthesized an AST probe radioiodinated via the Bolton-Hunter reagent (125I-BH-AST) and investigated its stability and biokinetics in mice. METHODS: 125I-BH-AST and conventional direct radioiodinated 125I-AST were evaluated for human endothelial cell binding characteristics. In vivo stability of the radiotracers was compared by biodistribution studies in normal ICR mice. Angiostatin pharmacokinetics was analyzed by serial blood sampling after intravenous injection of 125I-BH-AST with varying AST concentrations in mice. RESULTS: Both 125I-AST and 125I-BH-AST retained selective endothelial binding as demonstrated by dose-dependent inhibition by nonradiolabeled AST. 125I-BH-AST was substantially more stable in mice than 125I-AST, with 28- and 7-fold lower 24-h thyroid and blood activities, respectively (15.5+/-1.5 vs. 430.9+/-32.2 and 0.1+/-0.0 vs. 0.8+/-0.0 %ID/g; both P<.005). Using (125)I-BH-AST, we found that 24-h AST accumulation was highest in the kidneys, followed by the liver and lungs. Kinetic analysis of 125I-BH-AST revealed AST to have linear pharmacokinetics with a T(1/2) of 5.8+/-2.6 h, volume of distribution (V(d)) of 6.8+/-1.3 ml and clearance of 0.8+/-0.1 ml/h. CONCLUSION: Radioiodine-labeled AST prepared by the BH method provides a radioprobe with superior stability and improved in vivo biokinetics that is useful for distribution and pharmacokinetic studies.

Angiostatins↗
PubMed1999

A fast method to diagnose chromosome and plasmid loss in Saccharomyces cerevisiae strains.

We have developed a simple, fast and reliable method for the analysis of genetic stability in budding yeast strains. The assay relies on our previous finding that cells expressing the green fluorescent protein (GFP) can be detected and counted by flow cytometric analysis (FACS) (Niedenthal et al., 1996). Expression of a gfp-carrying CEN-plasmid in a wild-type strain resulted in the emission of strong fluorescence from 80% of the cell population. Strong fluorescence and presence of the plasmid, determined by the presence of the URA3 genetic marker, was strictly correlated. Expression of this plasmid in 266 yeast strains, each carrying a complete deletion of a novel, non-essential gene identified in the S. cerevisiae sequencing project, pinpointed 12 strains with an increased level of mitotic plasmid loss. Finally we have shown that measurement of mitotic loss of artificial chromosome fragments equipped with the gfp expression cassette can be performed quantitatively using FACS.

Chromosome Segregation↗
PubMed1999

Theoretical study of the conformation of the H-protein lipoamide arm as a function of its terminal group.

The glycine decarboxylase complex consists of four different proteins (the L-, P-, H-, and T-proteins). The H-protein plays a central role in communication among the other enzymes, as its lipoamide arm interacts successively with each of the components of the complex. The crystal structures of two states of the H-protein have been resolved: the oxidized form, Hox at 2 A and the methylamine-loaded form, Hmet at 2.2 A. However, the position of the arm for the reduced form, Hred, is still unknown. We have performed numerical free-energy calculations in order to better understand the differences in the structures and to elucidate the conformation of the arm in Hred. The results of the simulations are in agreement with the crystallographic results, as the minima of the free energy surface for Hox and Hmet correspond to the crystal structures. For Hred, we observe a single minimum in which the arm is on the surface of the H-protein, close to its position in the Hox structure. In all of our simulations, the lower, lysine portion of the arm remains bound to the protein, which substantially reduces the number of accessible arm configurations. An analysis of the stability of Hmet in the cavity shows that electrostatic interactions are crucial for locking the arm in the bottom of the cavity, especially near Glu14. In addition, the analysis shows that there is a water molecule, also observed in the crystallographic structure, that binds to the arm's terminal NH3+ group and helps to fix it in the cavity. In conclusion, because of the close agreement of the results of our calculations with the available experimental evidence, we are able to suggest a structural basis for the observed behavior. Proteins 1999;36: 228-237.

Amino Acid Oxidoreductases↗
PubMed1984

Analysis of two forms of molybdate-stabilized estrogen receptor.

We recently reported that the calf uterine estrogen receptor prepared in 10-mM molybdate elutes as two components (peaks I and II) from DEAE-Sephadex columns with a linear KCl gradient. We have extended these studies and report that unoccupied cytosol receptors also elute as two peaks (0.21 and 0.25 m KCl), as determined by postlabeling experiments with [3H]estradiol. Since molybdate-stabilized cytosol estrogen receptors incubated in the presence of 0.3 M KCl as well as estrogen receptors in peaks I and II did not demonstrate receptor binding to DNA-cellulose, we conclude that both receptor forms are nonactivated. Also, [3H]estradiol-receptor complexes from cytosol prepared in 10 mM molybdate sediment as 6.7S in 5-20% sucrose density gradients containing 0.3 M KCl, whereas receptor complexes from cytosol prepared without molybdate sediment as 4.5S. Both peaks I and II were eluted from DEAE-Sephadex columns prepared with either 10 mM molybdate or 10 mM tungstate, with both phosphatase inhibitors having effectively blocked salt activation of the receptor. However, receptor preparations in the presence of 10 mM arsenate were not eluted from DEAE-Sephadex, and arsenate was unable to inhibit receptor activation by KCl. Sucrose density gradient analysis of peaks I and II indicates that peak I sediments at approximately 4.8S, whereas peak II sediments at approximately 6.3S. If pooled fractions of the leading portion of peak I are rechromatographed on another DEAE-Sephadex column, both peaks I and II are recovered. Likewise, if pooled fractions of the descending portion of peak II are rechromatographed, both peaks I and II were measured. Therefore, we conclude that there may be an equilibrium between two forms of the molybdate-stabilized calf uterine estrogen receptor.

Animals↗
PubMed2006

Comparative study of protein stabilization in white wine using zirconia and bentonite: physicochemical and wine sensory analysis.

A semi-industrial application of the continuous stabilization of white wine protein using a column packed with zirconia was studied and compared to the traditional bentonite treatment using a Macabeu white wine. Physicochemical and wine sensory properties were evaluated using a rating system and triangle tests. Continuous protein stabilization was analyzed in three residence times, and the equivalent of 300 BV of wine was used for both treatments. Wine protein content was reduced by 21%, 40%, and 42% using the continuous process with residence times of 7.5, 15, and 30 min, respectively, and by 61.4% using the bentonite treatment. The wines obtained from the packed column were protein stable up to 25, 75, and 175 BV for residence times of 7.5, 15, and 30 min, respectively. The amount of polyphenol removed was less than 10%, and similar amounts were removed from the wine regardless of residence time, while 20.6% of polyphenol was removed using bentonite. The physicochemical and sensory properties of wine treated with bentonite were similar to those of wine treated with zirconia.

Adsorption↗
PubMed2004

Development and validation of a kinetic assay for analysis of anti-human interleukin-5 monoclonal antibody (SCH 55700) and human interleukin-5 interactions using surface plasmon resonance.

A method to assess the kinetic interactions of a humanized anti-human interleukin-5 (IL-5) monoclonal antibody (SCH 55700) with native human IL-5 using surface plasmon resonance (SPR) has been developed and validated. Since there are no clearly defined validation requirements for a SPR-based binding kinetic assay, the validation strategy was based on the guidelines stipulated by the International Conference on Harmonization for Analytical Method Validation. Due to the uniqueness of the method, however, proper interpretation of the guidance was critical for establishing a validation plan. Validation was designed to assess repeatability, intermediate precision, specificity, linearity, and robustness which included analysis of baseline stability and reproducibility of ligand immobilization. Additionally, system suitability criteria were established to assure that the assay consistently performs as it was intended. The experimental artifacts that can complicate kinetic analysis using biosensor technology, such as heterogeneity of the ligand, mass transport, and nonspecific binding, were considered during the development of this assay. For each run, replicate concentrations of SCH 55700 were injected randomly over the immobilized surfaces to acquire association- and dissociation-phase data. The data were transformed and double referenced to remove systematic deviations seen in the binding responses. Association and dissociation rates were determined using a bivalent analyte model for curve fitting.

Animals↗
PubMed1987

Paramagnetic carbon-13 NMR relaxation studies on the kinetics and mechanism of the HCO3-/CO2 exchange catalyzed by manganese(II) human carbonic anhydrase I.

A detailed analysis of the stability and activity of Mn(II) human carbonic anhydrase I and the kinetics and mechanism of its catalysis of the HCO3-/CO2 exchange have been performed at pH 8.5. The analysis was based on the paramagnetic relaxation rates R1p and R2p of the 13C atom of HCO3- in the Mn2+/apoenzyme/HCO3-/CO2 system and the HCO3(-)----CO2 interconversion rate obtained by the magnetization-transfer technique. The R1p and R2p rates were measured as functions of the temperature, magnetic field strength, and substrate and apoenzyme concentrations and were interpreted on the basis of the Solomon-Bloembergen-Morgan theories and general equations for the ligand exchange [Led, J. J., & Grant, D. M. (1977) J. Am. Chem. Soc. 99, 5845-5858]. From the analysis of the data, a formation constant for the Mn(II) enzyme of log KMAM = 5.8 +/- 0.4 was obtained while the activity of the Mn(II) enzyme, measured as the HCO3-/CO2 interconversion rate at [HCO3-] = 0.100 M and pH 8.5, was found to be about 4% of that of the native Zn(II) enzyme. However, an effective dissociation constant KeffHCO3- less than or approximately 12 mM and a maximal exchange rate constant kcatexch approximately equal to 400 s-1, also derived by the analysis, result in an apparent second-order rate constant kcatexch/KeffHCO3- only a factor of 4 smaller than the corresponding rate constant for the native Zn(II) isoenzyme I. Most conspicuously, the resulting distance of only 2.71 +/- 0.03 A between the Mn2+ ion of the enzyme and the 13C atom of HCO3- in the enzyme-bicarbonate complex indicates that the bicarbonate is bound to the metal ion by two of its oxygen atoms in the central catalytic step, thereby supporting the modified Zn(II)-OH mechanism [Lindskog, S., Engberg, P., Forsman, C., Ibrahim, S. A., Jonsson, B.-H., Simonsson, I., & Tibell, L. (1984) Ann. N.Y. Acad. Sci. 429, 61-75 (and references cited therein)]. In contrast, this binding mode differs from the structure of the complexes suggested in the rapid-equilibrium kinetic model [Pocker, Y., & Deits, T. L. (1983) J. Am. Chem. Soc. 105, 980-986; Pocker, Y., & Deits, T. L. (1984) Ann. N.Y. Acad. Sci. 429, 76-83].

Bicarbonates↗
PubMed2001

Conformational stabilization and crystallization of the SecA translocation ATPase from Bacillus subtilis.

SecA is the peripheral membrane-associated subunit of the enzyme complex 'preprotein translocase' which assists the selective transport of presecretory proteins into and across bacterial membranes. The SecA protein acts as the molecular motor that drives the translocation of presecretory proteins through the membrane in a stepwise fashion concomitant with large conformational changes accompanying its own membrane insertion/retraction reaction cycle coupled to ATPase activity. The high flexibility of SecA causes a dynamic conformational heterogeneity which presents a barrier to growth of crystals of high diffraction quality. As shown by fluorescence spectroscopy, the T(m) of the endothermic transition of cytosolic SecA from Bacillus subtilis is shifted to higher temperatures in the presence of 30% glycerol, indicating stabilization of the protein in its compact membrane-retracted conformational state. High glycerol concentrations are also necessary to obtain three-dimensional crystals suitable for X-ray diffraction analysis, suggesting that stabilization of the conformational dynamics of SecA may be required for effective crystallization. The SecA crystals grow as hexagonal bipyramids in the trigonal space group P3(1)12; they possess unit-cell parameters a = 130.8, b = 130.8, c = 150.4 A at 100 K and diffract X-rays to approximately 2.70 A using a high-flux synchrotron-radiation source.

Adenosine Triphosphatases↗
PubMed2005

Personality stability in late adulthood: a behavioral genetic analysis.

A sample of 833 twins from the Minnesota Twin Study of Adult Development and Aging completed the Multidimensional Personality Questionnaire (MPQ; Tellegen, 1982) twice, averaging 59.4 (sd=9.7) years of age at first and 64.4 (sd=10.2) years of age at second testing (average retest interval 5.0 years, sd=2.36, range 1.0-10.4 years). Both means and standard deviations of scale scores were extremely stable from first to second testing. In addition, sample participants tended to retain their rank order on the scales (average r=.76 across scales). Bivariate biometric analyses showed that the genetic influences on most of the scale scores were almost perfectly correlated across the two waves (range .95 to 1.00). The nonshared environmental influences were also highly correlated across the two waves (range .53 to .73). Models specifying identical variance components at the two time points and fixing the genetic correlation to 1.00 provided improved fit. The results suggest that the high stability of personality in later adulthood has a strong genetic foundation, supplemented by stability of environmental effects.

Aged↗
PubMedDate not supplied

[The characteristics of the enzymatic amplification of locus D17S5 alleles: the need to assess the stability of the amplification profile].

Amplification behavior of one chromosome locus (D17S5), widely used in identification studies, is investigated. The effect of preferable amplification of alleles, characteristic of this locus, often leads to an erroneous conclusion about homozygosity. Our studies showed, that along with the hazard of typing false homozygotes in analysis of locus D17S5, more intricate cases with genotype distortion can occur in expert practice, which may be characterized not only by partial loss of the true alleles, but even by amplification of nonspecific (nonallele) fragments simulating the false-heterozygotic allele profile. Analysis of the stability of amplification profile helps solve this problem.

Alleles↗
PubMedDate not supplied

[Personal care habits of individuals over age 65 having no cognitive impairment and residing in the Guadalajara Health Care District].

BACKGROUND: The aim of this study is that of ascertaining the characteristics of the personal care habits of those individuals over age 65 who have no cognitive impairment within the province of Guadalajara who are residents of the community based on the hypotheses that the same are deficient and therefore subject to improvement. METHODS: This is an observational, analytical cross-sectional study within a Primary Care, distinguishing between the urban and rural environments. A questionnaire (involving prior trial and reliability study by means of an analysis of the stability of the answers based on a kappa factor) was given out to a random, layered ample divided into different stages and proportional by age, gender and centers of population. An analysis was conducted of the following variables: A) Personal care habits. A. Personal care--daily washing/dressing: procedure and frequency, Hair Care, Always washing hands before eating and after going to the bathroom; Shaving for men, Oral hygiene. b. Sleep routine. B) Sociodemographic variables. The data was analyzed using proprietary descriptive, analytical and multivariable logistic regression procedures. RESULTS: The losses fell within the 16%-26% range (refusal was found to be the leading cause in the rural environmental and non-location in the urban environment). The sample finally studied included 388 individuals in the rural environment and 392 individuals in the urban environment. Half showered and washed their hair at least once a week. As high as 15% doe not wash always wash their hands before eating and as high as 44% do not do so after going to the bathroom. Over 50% of the males shave using the correct procedure. A high percentage of those missing part of their teeth as well as those completely toothless do not use dentures, and those who do are lacking in hygiene. Sleep routines shows better results. CONCLUSIONS: Personal care habits among senior citizens in our province are patently subject to improvement in all of the aspects analyzed, especially in the rural environment and among males. This should be a priority task under the charge of anyone assigned to the Primary Care Teams.

Aged↗