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At least 19 recordsLinked to original sources
PubMed1992

Phylogenetic continuum indicates "galaxies" in the protein universe: preliminary results on the natural group structures of proteins.

The markedly nonuniform, even systematic distribution of sequences in the protein "universe" has been analyzed by methods of protein taxonomy. Mapping of the natural hierarchical system of proteins has revealed some dense cores, i.e., well-defined clusterings of proteins that seem to be natural structural groupings, possibly seeds for a future protein taxonomy. The aim was not to force proteins into more or less man-made categories by discriminant analysis, but to find structurally similar groups, possibly of common evolutionary origin. Single-valued distance measures between pairs of superfamilies from the Protein Identification Resource were defined by two chi 2-like methods on tripeptide frequencies and the variable-length subsequence identity method derived from dot-matrix comparisons. Distance matrices were processed by several methods of cluster analysis to detect phylogenetic continuum between highly divergent proteins. Only well-defined clusters characterized by relatively unique structural, intracellular environmental, organismal, and functional attribute states were selected as major protein groups, including subsets of viral and Escherichia coli proteins, hormones, inhibitors, plant, ribosomal, serum and structural proteins, amino acid synthases, and clusters dominated by certain oxidoreductases and apolar and DNA-associated enzymes. The limited repertoire of functional patterns due to small genome size, the high rate of recombination, specific features of the bacterial membranes, or of the virus cycle canalize certain proteins of viruses and Gram-negative bacteria, respectively, to organismal groups.

Algorithms↗
PubMedDate not supplied

Structured group interaction: An intervention strategy for the continued development of elderly populations.

Structured group interaction, through an emphasis on pre-group structuring, didactic presentations, experiential learning, and evaluation, provides a flexible approach to achieving a variety of goals while compensating for many of the problem characteristics of an aged institutionalized population. Structured groups are characterized by adherence to a rigorous intervention planning methodology, with a high degree of pre-planned group structure, explicit behaviorally stated performance goals, and a concern for transferring group behavior to everyday settings. After a consideration of literature support and some of the limitations and hazards involved in the approach, it is concluded that structured groups represent a useful tool for the applied gerontologist.

Aged↗
PubMed1976

Stability of distance between structured groups in a social organism: empirical research.

The working hypothesis at the basis of the research is that in the development process of a social body the distance between structural groups of persons remain constant. The structural groups considered are men, women and a selected group of women (Soroptimists). The inquiry was carried out in 15 European countries in 1972. The total number of interviews was 4200. The six variables considered in the inquiry are the attitudes in respect of work, family, education, free time, sex and politics. The discriminatory analysis techniques are: entropy and factor analysis. Results seem to confirm the hypothesis of stability between groups and of countries between one another.

Group Structure↗
PubMed1976

Identification of drugs and other toxic compounds from their ultraviolet spectra. Part III: Ultraviolet absorption properties of 22 structural groups.

The ultraviolet absorption spectra of 22 different chemical (structural) groups of drugs and toxic compounds were studied. This paper completes a three-part series in which more than 500 individual compounds have been grouped according to structure as it pertains to characteristics of the ultraviolet absorption scan. Each group has a typical absorption profile with respect to the number of bands between 200 and 340 nm, the intensity of the band(s), and the changes in absorption pattern with solvent and pH changes. Phenothiazines, xanthines, coumarins, quinolines, naphthalene derivatives. O-alkyl benzene derivatives, opiates, ergot alkaloids, benzodiazepines, and various heterocyclic compounds are among the groups of compounds covered in this paper.

Forensic Medicine↗
PubMed2025

Meta-analysis models with group structure for pleiotropy detection at gene and variant level using summary statistics from multiple datasets.

Genome-wide association studies (GWASs) have highlighted the importance of pleiotropy in human diseases, where one gene can impact 2 or more unrelated traits. Examining shared genetic risk factors across multiple diseases can enhance our understanding of these conditions by pinpointing new genes and biological pathways involved. Furthermore, with an increasing wealth of GWAS summary statistics available to the scientific community, leveraging these findings across multiple phenotypes could unveil novel pleiotropic associations. Existing selection methods examine pleiotropic associations one by one at a scale of either the genetic variant or the gene, and thus cannot consider all the genetic information at the same time. To address this limitation, we propose a new approach called MPSG (Meta-analysis model adapted for Pleiotropy Selection with Group structure). This method performs a penalized multivariate meta-analysis method adapted for pleiotropy and takes into account the group structure information nested in the data to select relevant variants and genes (or pathways) from all the genetic information. To do so, we implemented an alternating direction method of multipliers algorithm. We compared the performance of the method with other benchmark meta-analysis approaches such as GCPBayes, PLACO, and ASSET by considering as inputs different kinds of summary statistics. We provide an application of our method to the identification of potential pleiotropic genes between breast and thyroid cancers.

Humans↗
PubMed1991

Recognition by peptide mapping of three different structural groups of outer membrane protein YOP-1 of Yersinia enterocolitica and Yersinia pseudotuberculosis.

The structural relation of YOP-1 of "european" and "american" Yersinia enterocolitica serotypes O:3, O:9, O:5,27, and O:8 and O:20, respectively, and Y. pseudotuberculosis serotypes I, II, and III was compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis and peptide mapping using Staphylococcus aureus protease V8. Apparent molecular weights of YOP-1 ranged from 206,000 (O:3) to approx. 180,000 (O:8). According to their respective peptide maps YOP-1 of the "european" and "american" Y. enterocolitica serotypes and Y. pseudotuberculosis serotypes could be assigned to three different groups. Evaluation of several isolates of Y. enterocolitica serotypes O:3, O:9, and O:8 by peptide mapping indicated that YOP-1 is conserved within a serotype. However, one serotype O:8 isolate differed from the consensus peptide pattern of the other serotype O:8 and O:20 isolates. The similarity of the peptide patterns of Yersinia serotypes which predominate in certain geographical locations, i.e., "european" and "american" Y. enterocolitica serotypes, suggest common evolution of YOP-1 of these serotypes independent of the evolution of the other serotypes.

Adhesins, Bacterial↗
PubMedDate not supplied

[Cholinomimetic activity of acetylcholine and sebacinyldicholine derivatives with differing cationic group structures].

The intrinsic alpha activities and the D2 (frog, m, rectus abdominalis) concentrations were estimated for different acetylcholine and sebacinylcholine derivatives. So were also the A2 values for antagonists and the affinity constants Kc for some partial agonists. The results obtained disprove Paton's "rate-theory". The relationship between the cholinergic activity and the volume of cationic groups was studied and it could not possibly be explained by the steric hindrance alone. It is suggested that certain hydrophobic radicals of the cationic groups contact the receptor surface outside the anionic centre. Such contacts prevent the cholinoreceptor to change its conformation and thus inhibit the depolarization of the membrane. An approximate estimation of the anionic site dimensions is given.

Abdominal Muscles↗
PubMedDate not supplied

[A theoretical conformational analysis of several substrates of cholinesterase having a cyclic ammonium group structure].

Conformational possibilities of pirrolidine analogues of acetylcholine beta-(N-methyl pirrolidinium)-ethyl ester of acetic acid and beta-(N-ethyl pirrolidinium)-ethyl ester of acetic acid and beta-(N-ethyl pirrolidinium)-ethyl ester of acetic acid were investigated by the method of atomic potentials. The conformational energy was considered as a sum of non-bonded and electrostatical interactions, torsional energy and distortions of bond angles. It has been shown that the replacement of the nitrogen methyl group to ethyl group results in decrease of the average barrier height between two gauche conformations of the O--C--C--N fragment. Comparison of conformational properties of some cholinesterase substrates permit to draw a suggestion that the barrier height influences the rate of the enzymatic hydrolysis.

Acetylcholine↗
PubMed1975

Identification of drugs and other toxic compounds from their ultraviolet spectra. Part II: Ultraviolet absorption properties of thirteen structural groups.

The ultraviolet absorption spectra of 13 different chemical classes of drugs and toxic organic compounds were studied. A classification system has been developed in which compounds with the same conjugated molecular system and auxochrome substituents are grouped together. Each of these groups has characteristic absorption spectra, showing similarities in the number of major bands, position of maximum absorbance, pH effects, and solvent effects. The absorption maxima and molecular absorptivities are tabulated for approximately 100 compounds, and characteristic spectra of each designated group are illustrated. Classes of drugs included in this study are pyridine derivatives, hydrazines, pyridylamine derivatives, variously substituted phenols, barbiturates, ureides, imides, hydantoins, and conjugted ketones (enones).

Amines↗
PubMedDate not supplied

The pregnant adolescent--a group approach.

This paper has described the groups for pregnant teenagers developed in the Rochester Adolescent Maternity Project. One and one-half year's experience with these groups has allowed the authors time to begin their study of groups and to write a descriptive paper of their evolution. The groups' development goes on while the leaders continue their own theoretical study of groups at this writing. Groups for pregnant adolescents have ranged from group therapy sessions to structured groups where only didactic material is presented. The literature is somewhat limited in its discussion of types of groups and especially in describing group process. This paper differs from others in that both group structure and process, based on the group objectives, are discussed. Information on approaches beneficial to the adolescent have been included. The goals of the group are to help the teenagers work through the developmental tasks of adolescence and pregnancy and to prepare them for the labor, delivery, and initial parenthood experience. Group structure is based on the intent to engage teenagers in resolution of these tasks in order to be prepared at a variety of levels, i.e. cognitive, emotional, etc., for labor, delivery, and parenthood. Co-leadership of the groups and an unstructured format facilitate the movement of the group toward accomplishment of its objectives. Group content issues were explored and techniques developed to handle these issues were suggested. Included were the following: 1. Commitment to the group by the members is assisted by the structure set for the group and the leaders' active outreach to members. 2. Descriptions of emotions and thoughts are made in concrete rather than abstract terms because of the developmental status of the teenagers. 3. Expression of personal feelings, often difficult for teenagers, is aided by the use of a projective technique. 4. Transition from leader-oriented to group-directed discussion is made possible by the group leaders gradually changing their leadership from one of direct interaction to one of facilitating discussion. 5. Polarization of the group in a negative or positive direction is prevented through the use of a neutral group member or active intervention by the group leaders taking on a neltral role. 6. Control, an issue of pregnancy and adolescence, is dealt with on interactional, educational, and emotional levels. 7. Termination is determined by the stage of the group "work" and is identified and facilitated by the group leaders. Research questions needed to document the effectiveness of the group approach to the pregnant adolescent were addressed.

Adolescent↗
PubMed1992

Cloning and structure of group C1 O antigen (rfb gene cluster) from Salmonella enterica serovar montevideo.

The Salmonella enterica group C1 O antigen structure has a Man-Man-Man-Man-GlcNAc backbone with a glucose branch, which differs from the S. enterica group B O antigen structure which has a Man-Rha-Gal backbone with abequose as side-chain. We have cloned the group C1 rfb (O antigen) gene cluster from serovar montevideo strain M40, using a low-copy-number cosmid vector. The restriction map of the group C1 (M40) rfb gene cluster was compared with that of group B strain LT2 by Southern hybridization and restriction enzyme analysis. The results indicate that the flanking genes are very similar in the two strains, but there is no detectable similarity in the rfb regions. We localized the mannose pathway genes rfbM and rfbK and one of the genes, rfbK, shows considerably similarity to cpsG of strain LT2, suggesting that part of the mannose pathway in the group C1 rfb cluster is derived from a gene of the M antigen (cps) cluster. The M antigen, which forms a capsule, is comprised of four sugars, including fucose. The biosynthetic pathway of GDP-fucose has steps in common with the GDP-mannose pathway, and the cps cluster has isogenes of rfbK and rfbM, presumably as part of a fucose pathway. We discuss the structure and possible evolution of the group C1 rfb gene cluster.

Blotting, Southern↗