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PubMed1976

Stability of adult personality traits: fact or fable?

Theoretical positions for and against a stability model for adult personality traits are examined. Results of a sequential study of 19 personality factors over a 7-year period and with participants ranging in age from 22 to 84 years suggest that stability within generations appears to be the rule, albeit combined with many differences between successive population cohorts and subject to transient secular trends. A typology of 13 possible models is offered to account for the different developmental trends observed for the various personality factors.

Adult↗
PubMed1978

Detection of factor XIIIa (active fibrin-stabilizing factor) in normal plasma.

Factor XIIIa (active fibrin-stabilizing factor) generated in heat-defibrinated plasma by the addition of thrombin can be measured by 14C-putrescine incorporation into casein. Modification of this assay be substituting 3H-putrescine of high specific activity as the donor amine permits measurement of amine incorporation by plasma even in the absence of added thrombin. Incorporation is calcium dependent, inhibited by iodoacetamide, and absent from congenital factor XIII-deficient plasma and from normal platelets. The transamidating activity detected by radioenzymatic assay catalyzed the formation of gamma-gamma dimers and alpha polymers of fibrin and was thus biologically functional. This fibrin cross-linking activity was absent from factor XIII-deficient plasma. These experiments show (1) some factor XIII is present in plasma as factor XIIIa; (2) this factor XIIIa can cross-link fibrin and thus has biologic activity as well; and (3) this activity is not present in factor XIII-deficient plasma. Factor XIIIa in normal plasma is possibly activated in vivo, perhaps by circulating thrombin, factor Xa, or other proteolytic enzymes.

Blood Platelets↗
PubMed1991

Statistical analysis of collagen alignment in ligaments by scale-space analysis.

Injuries to ligaments in the knee are common in sports and other physical activities. Some clinical methods are available for qualitatively evaluating the degree of ligament injury and healing. It is, however, desirable to objectively assess the healing of ligaments and to predicate optimal treatment on quantitative measurements of their structure. Information such as areas of coverage and spatial orientations of collagen fibrils, for example, may provide important information about the internal structure of ligament tissues. Since normal ligament tissues are made up of collagen fibrils which are highly organized, they can be considered as oriented piecewise linear patterns. In this paper, we propose a computational technique for statistical analysis of collagen alignment in ligament images using the scale-space approach. In this method, a ligament image is preprocessed by a sequence of filters which are second derivatives of two-dimensional Gaussian functions with different scales. This gives a set of zero-crossing maps (the scale space) from which a stability map is generated. Significant linear patterns are captured by analyzing the stability map. The directional information in terms of orientation distributions of the collagen fibrils in the image and the area covered by the fibrils in specific directions are extracted for statistical analysis. Examples illustrating the performance of this method with scanning electron microscope images of the collagen fibrils in healing rabbit medial collateral ligaments are presented in this paper.

Animals↗
PubMed1991

Polar axis fixation in Fucus zygotes: components of the cytoskeleton and extracellular matrix.

Polar axis formation and polar axis stabilization (or fixation) can be separated and analyzed in synchronously developing zygotes of the brown alga Fucus. Extensive experimental evidence points to a role for both the cytoskeleton and the extracellular matrix (ECM) in the process of axis fixation in Fucus. A structural complex composed of the cytoskeleton and the ECM has been postulated to stabilize membrane asymmetries generated as a result of axis-forming vectors. This axis stabilizing complex (ASC) may take the form of transmembrane connections between the cytoskeleton on the cytoplasmic face and the ECM on the external side of the plasma membrane, similar to focal contacts in animal cells. At present we know of two components in the proposed ASC of Fucus: an adhesive sulfated glycoprotein which is localized in the ECM, and an actin network which is localized on the adjoining cytoplasmic face. This preliminary report describes evidence for the presence of molecules in two-celled Fucus embryos that are similar to those found in focal contacts in animal cells, i.e. vinculin, integrin and vitronectin. However, their localization and interaction with each other relative to the polar axis has yet to be determined. These initial observations will provide the basis to pursue further an analysis of these components in the process of polar axis fixation.

Cell Polarity↗
PubMed1991

Methods for the assessment of the stability of tablet disintegrants.

To allow assessment of the long-term stability of tablet disintegrants, two mechanisms for their functionality (i.e., water uptake and swelling force generation) were monitored. Three disintegrants, alginic acid, sodium starch glycolate, and crospovidone, were used to establish the methodology. The water uptake and swelling force methodologies developed were reproducible, thus allowing for the evaluation of the effect of time, temperature, and humidity on these properties of disintegrants. The data obtained suggest that the process of water uptake and swelling force generation was essentially a two-step process. Initially, water entered the pore space in the powder bed; there was a definitive lag time before a swelling force was generated. In the stability evaluation of alginic acid and sodium starch glycolate, samples were stored for 1-year. Above 30 degrees C and 75% relative humidity, the swelling force performance of alginic acid was markedly affected. Changes seen with sodium starch glycolate were much less marked.

Alginates↗
PubMed1991

Characterization of a region of the Enterococcus faecalis plasmid pAM beta 1 which enhances the segregational stability of pAM beta 1-derived cloning vectors in Bacillus subtilis.

The nucleotide sequence of a 2.13-kb EcoRI-HindIII, pAM beta 1-derived fragment, isolated from the gram-positive cloning vector pHV1431, has been determined and shown to encode two ORFs. ORF H encodes for a protein of 23,930 Da which exhibits substantial homology to bacterial site-specific recombinases, particularly the resolvases of the gram-positive transposons Tn917 (30.3% identity) and Tn552 (31.6% identity) and the clostridial plasmid pIP404 (27.1% identity). The second ORF (I) is incomplete and encodes a polypeptide which has significant homology with Escherichia coli topoisomerase I (26.0% identity). Insertion of either the entire 2.13-kb EcoRI-HindIII fragment or a 0.73-kb EcoRI-DraI subfragment encoding only the resolvase into the pAM beta 1-based cloning vector pMTL500E causes a significant enhancement of segregational stability (from 6.5 X 10(-2) to 3.0-4.0 X 10(-3) plasmid loss per cell per generation). Improved segregational stability is mirrored by a reduction in plasmid polymerization. The introduction of a stop codon into the resolvase coding region negates its ability to promote segregational stability. It is proposed that the identified determinant stabilizes pAM beta 1-based vectors in Bacillus subtilis by maintaining the plasmid population in the monomeric state, thereby reducing the chances of producing plasmid-free segregants.

Amino Acid Sequence↗
PubMed1992

Promoter methylation and progressive transgene inactivation in Arabidopsis.

Agrobacterium-transformed Arabidopsis plants were generated and the stability of their T-DNA-encoded resistance to kanamycin was examined. Of seven families, each homozygous for a single insertion event, two showed progressive inactivation of resistance over four generations of inbreeding. Loss of resistance was associated with methylation of an Sst II site in the nos promoter of the kanamycin resistance gene. Treatment of plant roots from inactive lines with the demethylating agent 5-azacytidine restored the ability of such lines to form callus on kanamycin-containing media. These observations are consistent with the view that methylation is a factor in the progressive inactivation of transgenes in Arabidopsis.

DNA, Bacterial↗
PubMedDate not supplied

Enhancing oxygen transfer in surface-aerated bioreactors by stable foams.

To enhance oxygen transfer in surface-aeration bioreactors, stabilized foams were generated to increase the gas-liquid interfacial area by slowly introducing coarse bubbles into media containing fetal bovine serum. The bubble sparging rates were so low (i.e., 20 and 50 mL/h) that the contribution to oxygen transfer from these bubbles was due to foaming instead of bubbling. Furthermore, no physical cell damage caused by bubble sparging was observed. Oxygen transfer coefficients, kLa, in the bioreactors were measured in cell-free media. Without the foam-stabilizing agent (i.e., serum), no appreciable change in kLa was observed due to the bubble sparging. On the other hand, with serum, kLa increased with increasing serum content and bubble sparging rate and corresponded well with the degree of foaming. With 10% fetal bovine serum and a bubble sparging rate of 50 mL/h, kLa increased approximately 90% compared with no foaming. The enhancing effect of foam on oxygen transfer in surface aeration bioreactors has been further demonstrated with hybridoma cultures simultaneously grown in three identical bioreactors with and without stabilized foams.

Aerobiosis↗
PubMed1976

Rhythmic swimming activity in neurones of the isolated nerve cord of the leech.

1. Repeating bursts of motor neurone impulses have been recorded from the nerves of completely isolated nerve cords of the medicinal leech. The salient features of this burst rhythm are similar to those obtained in the semi-intact preparation during swimming. Hence the basic swimming rhythm is generated by a central oscillator. 2. Quantitative comparisons between the impulse patterns obtained from the isolated nerve cord and those obtained from a semi-intact preparation show that the variation in both dorsal to ventral motor neurone phasing and burst duration with swim cycle period differ in these two preparations. 3. The increase of intersegmental delay with period, which is a prominent feature of swimming behaviour of the intact animal, is not seen in either the semi-intact or isolated cord preparations. 4. In the semi-intact preparation, stretching the body wall or depolarizing an inhibitory motor neurone changes the burst duration of excitatory motor neurones in the same segment. In the isolated nerve cord, these manipulations also change the period of the swim cycle in the entire cord. 5. These comparisons suggest that sensory input stabilizes the centrally generated swimming rhythm, determines the phasing of the bursts of impulses from dorsal and ventral motor neurones, and matches the intersegmental delay to the cycle period so as to maintain a constant body shape at all rates of swimming.

Action Potentials↗
PubMed1978

Transfer of genetic information via isolated amphibian metaphase chromosomes.

The metaphase chromosome transfer system of McBride and Ozer (1973) has been adapted to a haploid, euploid, frog cell line. Genes coding for a deoxypyrimidine kinase and an enzyme responsible for a thymidine-specific saturable transport system have each been transferred at frequencies between 10(-6) and 10(-5) transferents per cell treated. Revertants for each of these two genes were observed at frequencies between 10(-8) and 10(-7) revertants per cell tested. Selfing controls showed no transferents. Two colonies were obtained in which cotransfer of both genes may have occurred. Activities of the transferred genes were assayed by incorporation of [3H]thymidine into alkali-stable, acid-precipitable material. Growth properties of 13 transferents in various media were also determined and presence of the appropriate enzymes inferred. These transferents were tested for stability early (25 generations) after transfer and were found to be stable. All 13 transferents possess the normal haploid number of chromosomes (n = 13) with no cytologically detectable chromosomal fragments.

Animals↗
PubMed1992

Round table on epidemiology and control of fox rabies.

The current epizootic of rabies in Europe has as its main host the fox. Oral vaccination of the fox population has proven to be particularly effective. It is clear that the major components for a successful vaccination programme are a potent and stable vaccine, and an effective baiting system; the latter should attract the target animal but no non-target species. Recently, vaccines of increased stability have been generated; amongst these is a vaccinia recombinant virus which expresses rabies virus glycoprotein. Consequently, both attenuated live virus vaccines and a recombinant vaccine are available for routine field vaccination of the fox population.

Animals↗
PubMed2025

Chemoselective Tagging of Protein Methacrylation.

Protein lysine methacrylation (Kmea) is a recently identified post-translational modification whose biofunction remains poorly understood. Until now, there has been no chemical labeling method for Kmea modification, which has severely hindered the discovery and functional studies of methacrylated proteins. Here, we developed a photocatalytic thia-Michael reaction system for the chemoselective labeling of protein methacrylation. By exploiting the dual effect of steric hindrance and the stability of the generated C-center radical, the reaction interference of the structural isomer crotonylation can be efficiently avoided. Based on this reaction, a multifunctional water-soluble benzenethiol-azide probe azDSH was designed and synthesized, and a workflow for the specific labeling, enrichment, and identification of Kmea proteins was developed. Proteomic identification of histone and nuclear protein extracts and whole-cell lysate revealed a number of novel Kmea proteins and modification sites besides histones, such as HMGB1, TdIF2, UHRF1, HNRPD, BRWD1, TAF1, TACC1, and SETD3, providing new targets for the study of epigenetic regulation. This study provides an effective method for the analysis of protein methacrylation modifications in biological systems.

Humans↗
PubMed1991

Familial transmission of alcohol use: IV. A seventeen-year follow-up on the relationships between parent and adult offspring alcohol use; Tecumseh, Michigan.

The sample for this study comprised 190 three member sets of father, mother, and adult son or daughter who were first interviewed in 1960 as part of Cardiovascular Examination I of the Tecumseh Community Health Study. At that time, alcohol data were collected from self-reports for both parents and offspring. In 1977 alcohol data were again collected for the adult offspring only, from self-reports. In 1960 offspring's drinking was significantly related to both fathers' and mothers' drinking and remained so in 1977 despite shifts over time in the proportions of offspring across five alcohol use categories. The majority of offspring did not fall into their parents' category, but the mode by and large reflected the parent category. The majority of offspring of non-drinkers did drink, but at low and not high volume; the majority of offspring of high volume drinkers drank at lower levels than their parents, and were not likely to be life-long abstainers, although they may have become past drinkers. Two non-drinking parents reinforced non-drinking in their adult offspring and two drinking parents reinforced the early onset and persistence of high volume drinking. Among offspring who changed their drinking level between 1960 and 1977, those who had drunk less than their parents were the most likely to have increased their drinking, and those who had drunk more than their parents were the most likely to have decreased their drinking. Patterns observed in this study may be viewed as intrafamilial sources of drinking stability transmitted across generations in a single community.

Adolescent↗
PubMed1992

Replication origin mutations affecting binding of pSC101 plasmid-encoded Rep initiator protein.

To investigate the role of binding sites for Rep initiation protein in the replication of pSC101, a series of plasmids was constructed which carried different combinations of mutations in three binding sites within the minimal origin of replication. Mutation of all three sites reduced the affinity of purified Rep protein for the origin by 100-fold, as measured by a competition binding assay. Mutations in individual binding sites prevented binding of Rep protein to the mutant site but not to adjacent wild-type sites. Transformation efficiency, copy number, and stability over 150 generations were measured for each of the mutant plasmids. Unlike other similar plasmids related to pSC101, the Rep binding sites were found not to be equivalent. A mutation in the site RS1, proximal to repeated sequences which serve as DnaB helicase entry sites in oriC, had a severe effect on replication activity. A similar mutation in the distal site RS3 caused a reduction in copy number, but the mutant plasmid was stably maintained despite a broadened distribution of copy number within the population. A mutation in the middle RS2 site had no significant effect on pSC101 replication.

Bacterial Proteins↗
PubMed2025

Characterization and purification of Pseudomonas aeruginosa phages for the treatment of canine infections.

BACKGROUND: Pseudomonas aeruginosa is an opportunistic pathogen that causes infections in both human and veterinary medicine, presenting significant challenges in treatment because of biofilm production and its intrinsic resistance. This problem is exacerbated by the increase in acquired antimicrobial resistance. Bacteriophage (phage) therapy has emerged as a promising alternative for treating infection classically treated with antibiotics, offering a targeted approach to combat this infection. This study aimed to evaluate the therapeutic potential of 7 phages, focusing on their suitability for treating canine infections, as well as their purification and safety analysis for therapeutic use. RESULTS: Two self-isolated phages and five provided phages were analysed. All tested phages reduced bacterial load in vitro; however, their efficacy varied across different concentrations. The host range analysis revealed a spectrum between 9.8 and 68.6% of canine clinical P. aeruginosa isolates. In our in vitro tests 3 out of 7 phages were able to significantly reduce the biofilm biomass, achieving reductions up to 93.38%. The sequence analysis did not discover known virulence factors and genes connected to antimicrobial resistance mechanisms. The self-isolated phages were classified as lysogenic, whereas the other phages had a lytic infection cycle. Through the purification of the phages, high-titre phage preparations (> 1011 PFU/ml) were generated with high stability for at least 1.5 years. The tested endotoxin units are below the regulatory limits. CONCLUSION: Investigating phages as alternative treatment option seems promising with lytic phages covering a broad host range and a genomic potential for biofilm degradation. These findings support the development of phage cocktails as a targeted alternative for treating canine P. aeruginosa infections, particularly in cases of antibiotic resistance, and highlight the importance of selecting well-characterized lytic phages for therapeutic efficacy and safety.

Pseudomonas aeruginosa↗