Biomedical subjects

G Ghandour

Publications and source records attributed to G Ghandour.

10 recordsLinked to original sources

PubMed1992

Cholesterol-related counseling by registered dietitians in northern California.

BACKGROUND: An estimated 40 million Americans have serum cholesterol levels that warrant medically supervised dietary intervention. Although registered dietitians are expected to play an important role in treating these patients, current treatment practices in the community are largely unknown. METHODS: A questionnaire concerning treatment practices was mailed to all 377 registered dietitians listed in the directories of the American Dietetic Association for two large California districts. Number of patients seen and length and content of dietary counseling were ascertained for three types of patients: (a) hypercholesterolemic outpatients without heart disease, (b) hypercholesterolemic outpatients who have heart disease, and (c) inpatients with myocardial infarction. RESULTS: A return rate of 59% (n = 252) was obtained for the questionnaire. A total of 44% of the registered dietitians counseled hypercholesterolemic patients in any of the categories surveyed. About 30% of the respondents counseled hypercholesterolemic outpatients without heart disease. They saw an average of 4.9 such patients a week, spent an average of 53 min in an initial session, and usually did not see the patient again in follow-up. Fewer than 10% of patients had as many as four sessions. About 27% of the respondents saw hypercholesterolemic outpatients with heart disease, averaging 3.5 such contacts per week. The reported practices were similar to those provided to noncardiac outpatients. About 22% of registered dietitians worked with hospitalized myocardial infarction patients. They spent an average of a total of 41 min over 2.5 visits with each patient. CONCLUSION: Currently, outpatient registered dietitian counseling for hypercholesterolemia appears to be limited in both the number of patients reached and the duration of the counseling. Further research into the impact of, barriers to, and efficacy of alternative delivery methods of dietary counseling is needed.

Adult↗

PubMed1988

Efficient algorithms for molecular sequence analysis.

Efficient (linear time) algorithms are described for identifying global molecular sequence features allowing for errors including repeats, matches between sequences, dyad symmetry pairings, and other sequence patterns. A multiple sequence alignment algorithm is also described. Specific applications are given to hepatitis B viruses and the J5-C (J, joining; C, constant) region of the immunoglobulin kappa gene.

Algorithms↗

PubMed1988

Algorithms for identifying local molecular sequence features.

Efficient algorithms are described for identifying local molecular sequence features including repeats, dyad symmetry pairings and aligned matches between sequences, while allowing for errors. Specific applications are given to the genomic sequences of the Epstein-Barr virus, Varicella-Zoster virus and the bacteriophages lambda and T7.

Algorithms↗

PubMed1985

The use of multiple alphabets in kappa-gene immunoglobulin DNA sequence comparisons.

Comparisons within and between the human, mouse and rabbit immunoglobulin-kappa gene (J-C region) DNA sequences are carried out in terms of three two-letter nucleotide alphabets: (i) S-W alphabet (W = A or T; S = G or C); (ii) P-Q alphabet which distinguishes purines (P = A or G) from pyrimidines (Q = C or T); and (iii) a 'control' E-F alphabet (E = A or C; F = G or T). All statistically significant direct repeats within each of the three sequences and all significant block identities (a set of consecutive matching letters) shared by two or more sequences are determined for each alphabet. By contrast to the S-W and E-F alphabets, the P-Q alphabet comparisons reveal an abundance of statistically significant block identities not seen at the nucleotide level. Various interpretations of these P-Q structures with respect to control and functional roles are considered.

Animals↗

PubMed1985

DNA sequence patterns in human, mouse, and rabbit immunoglobulin kappa-genes.

DNA sequences of the human, mouse, and rabbit immunoglobulin kappa-gene (J-C regions) are compared with respect to various DNA patterns, including dyad symmetry pairings, runs of nucleotides, repeat clusters, and repeats that occur with unusually high frequency. The significant dyad symmetry pairings within each of the sequences emphasize the two "control-enhancer" elements of the J5-C intron. Dyad symmetry pairs between the J-C region and a number of kappa variable (V)-gene domains suggest differences in the affinities between the V and J segments. It is the "consensus heptamer" rather than the "consensus nonamer" that embodies the longest V-J dyad symmetry combinations. In the rabbit there are long runs and repeat clusters of the sequences that identify regions of high duplication; these regions are absent in the human and mouse sequences. High-frequency oligonucleotides feature the consensus nonamer 5' to the J segments, especially in the mouse sequence.

Animals↗

PubMed1985

Comparative statistics for DNA and protein sequences: single sequence analysis.

Four categories of data representations are used to help interpret structures and similarities of nucleic acid and protein sequences. Statistical significance of the observed relationships revealed by these representations are assessed by a hierarchy of permutation procedures and by comparisons with theoretical random models. Applications are presented for various DNA sequences including papovaviruses, Epstein-Barr virus, mitochondrial genomes, and several globin and immunoglobulin genes.

Amino Acid Sequence↗

PubMed1985

Comparative statistics for DNA and protein sequences: multiple sequence analysis.

Concepts and methods [Karlin, S. & Ghandour, G. (1985) Proc. Natl. Acad. Sci. USA 82, 5800-5804] for the analysis of patterns and relationships are extended to multiple DNA and protein sequences. Functionals include multiple sequence common word occurrence distributions, characterizations of high frequency shared words, and ascertainment of long block identities. Various comparisons of sequences using natural alphabets obtained from grouping nucleotides or amino acids by their chemical and functional characteristics are described. Specific applications are given to globin genes, mitochondrial genomes, and a variety of mammalian viruses.

Amino Acid Sequence↗

PubMed1985

Multiple-alphabet amino acid sequence comparisons of the immunoglobulin kappa-chain constant domain.

We compare the amino acid sequences of the constant domains of the immunoglobulin kappa chain of human, mouse, and rabbit by using four classification schemes ("alphabets") of the 20 amino acids based on their chemical, functional, charge, and structural properties. The comparison reveals three regions of pronounced similarity across the three species, independent of allotype. Two of these regions (residues 65-73 and 99-103) entail a high degree of identity at the DNA level and are distinguished from the rest of the constant domain in codon usage and in the dinucleotide sequence at abutting sites of adjacent codons. Residues 22-29 are highly conserved among the three species in the chemical and functional alphabets but do not show any three-sequence significant amino acid block identities. These results are discussed in terms of transcript processing, effector functions, and structural interactions within the constant domain and with the heavy chain.

Amino Acid Sequence↗

PubMed1985

DNA sequence comparisons of the human, mouse, and rabbit immunoglobulin kappa gene.

A comparative analysis between human, mouse, and rabbit immunoglobulin (Ig) kappa-gene DNA sequences is presented. New formulas for determining the expected length and variance of the longest block identity (a succession of matching nucleotides) between multiple random sequences are given and are used to establish statistical criteria for ascertaining the significance of block identities shared in r out of s sequences. The statistically significant block identities within and between the Ig-kappa-gene sequences are ascertained, and alignment maps based on these similarities are constructed. The human and rabbit sequences (especially in the noncoding regions) and the human and mouse sequences (on the coding regions) show a similarity much stronger than that between the mouse and rabbit sequences. The existence of several highly significant shared oligonucleotides occurring in alignment with each other or with respect to the J- and C-gene segments suggests a configuration of multiple control sites. Discussion and interpretations of the form and distribution of the block identities are given.

Animals↗

PubMed1985

Alignment maps and homology analysis of the J-C intron in human, mouse, and rabbit immunoglobulin kappa gene.

The statistically significant shared oligonucleotides (block identities) of the intervening region (J5-C) in the human, mouse, and rabbit immunoglobulin (Ig)-kappa gene were determined. These identities maintain their order (do not cross) and never connect with any Ig-kappa segment external to the intron region. The two regions of pronounced similarity are (1) the vicinity of the established enhancer element (Queen and Baltimore 1983) and (2) a 200-bp region approximately 1 kb upstream that we have labeled the second enhancer element. Similarity is strong between the human and mouse sequences in the neighborhood of the first enhancer element and more pronounced between the human and rabbit sequences in the vicinity of the second enhancer region. The overall extent of similarity between the mouse and rabbit sequences is less than that between the human and mouse sequences and that between the human and rabbit sequences. All close and large dyad-symmetry pairings were ascertained and their possible relations to the enhancer elements discussed.

Animals↗