PubMed Health⌕ Search

Biomedical subjects

C A Webb

Publications and source records attributed to C A Webb.

9 recordsLinked to original sources
PubMed2001

Resistance gene complexes: evolution and utilization.

More than 30 genes have been characterized from different plant species that provide resistance to a variety of different pathogen and pest species. The structures of most are consistent with a role in pathogen recognition and defense response signaling. Resistance genes are very abundant in plant genomes and most belong to tightly linked gene families. Evolution of R genes is driven by selection on allelic variation created by mutation and re-assorted by recombination between alleles and sometimes between different gene family members. Selection favors genes that can recognize pathogen avr gene products that are present in pathogen populations. Selection at linked gene families favors haplotypes with useful combinations of genes but a limited physiological cost to the plant. Future utilization of R genes will include transfer between related genera and identification or construction of genes that condition durable resistance to variable pathogens. Genes with durable resistance may interact with conserved pathogen elicitors or condition resistance responses that are independent of specific Avr gene interactions.

Evolution, Molecular↗
PubMed1998

The isolation and mapping of disease resistance gene analogs in maize.

Many of the plant disease resistance genes that have been isolated encode proteins with a putative nucleotide binding site and leucine-rich repeats (NBS-LRR resistance genes). Oligonucleotide primers based on conserved motifs in and around the NBS of known NBS-LRR resistance proteins were used to amplify sequences from maize genomic DNA by polymerase chain reaction (PCR). Eleven classes of non-cross-hybridizing sequences were obtained that had predicted products with high levels of amino acid identity to NBS-LRR resistance proteins. These maize resistance gene analogs (RGAs) and one RGA clone obtained previously from wheat were used as probes to map 20 restriction fragment length polymorphism (RFLP) loci in maize. Some RFLPs were shown to map to genomic regions containing virus and fungus resistance genes. Perfect cosegregation was observed between RGA loci and the rust resistance loci rp1 and rp3. The RGA probe associated with rp1 also detected deletion events in several rp1 mutants. These data strongly suggest that some of the RGA clones may hybridize to resistance genes.

Amino Acid Sequence↗
PubMed1992

Sexuality and self-concept: issues in skin disease.

Self-concept is closely tied to feelings of sexuality. Therefore, comprehensive nursing care of patients with skin disorders should include sexuality issues. This article addresses methods of assessment and a variety of interventions in dealing with sexuality and skin disease.

Attitude of Health Personnel↗
PubMed1987

Methicillin resistant Staphylococcus aureus in milk.

Three separate outbreaks of gentamicin and methicillin resistant Staphylococcus aureus in a special care baby unit are described. The outbreaks ceased only after a milk bank worker was identified as a carrier of the strain. It is postulated that the infant milk feeds served as a vehicle of spread.

Animals↗
PubMed1978

A complete dislocation of the thumb metacarpal.

Multiple dislocations of a single finger are rare. We report a patient with complete dislocation of the thumb metacarpal, a condition not reported previously. A 9 year follow-up shows the patient to have a normal-appearing, strong, and painless hand.

Adult↗
PubMedDate not supplied

Preparing to retake the NCLEX-RN. The experience of graduates who fail.

Many schools of nursing counsel and provide practice sessions to their students in initial preparation for the National Council Licensure Examination (NCLEX). What then of the graduates who fail and are now outside of the educational and often supportive environments of schools of nursing? Graduates cannot be employed to practice what they have learned, nor do schools of nursing have the programs to assist graduates who have failed. How can these graduates be enabled to succeed? The authors discuss the stories of 10 graduates who failed the examination and their preparation to retake it. Data from their study reveal important ways that nurse educators can help graduate nurses during this stressful period in their lives.

Education, Nursing↗