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T Pryor

Publications and source records attributed to T Pryor.

At least 19 recordsLinked to original sources
PubMed2001

Recombination between paralogues at the Rp1 rust resistance locus in maize.

Rp1 is a complex rust resistance locus of maize. The HRp1-D haplotype is composed of Rp1-D and eight paralogues, seven of which also code for predicted nucleotide binding site-leucine rich repeat (NBS-LRR) proteins similar to the Rp1-D gene. The paralogues are polymorphic (DNA identities 91-97%), especially in the C-terminal LRR domain. The remaining family member encodes a truncated protein that has no LRR domain. Seven of the nine family members, including the truncated gene, are transcribed. Sequence comparisons between paralogues provide evidence for past recombination events between paralogues and diversifying selection, particularly in the C-terminal half of the LRR domain. Variants selected for complete or partial loss of Rp1-D resistance can be explained by unequal crossing over that occurred mostly within coding regions. The Rp1-D gene is altered or lost in all variants, the recombination breakpoints occur throughout the genes, and most recombinant events (9/14 examined) involved the same untranscribed paralogue with the Rp1-D gene. One recombinant with a complete LRR from Rp1-D, but the amino-terminal portion from another homologue, conferred the Rp1-D specificity but with a reduced level of resistance.

Amino Acid Sequence↗
PubMed2000

The generation of plant disease resistance gene specificities.

We are gaining an understanding of the molecular basis of resistance specificity and of the natural processes that generate different specificities. This is a prerequisite for the genetic engineering of new plant disease-resistance genes to control diseases for which naturally occurring resistance is inadequate. DNA sequence analysis indicates that point mutation, recombination and selection can generate and maintain the high levels of polymorphism observed in resistance genes. Comparisons of closely related resistance proteins indicate that specificity can be determined by variation in at least two regions. One of these contains leucine-rich repeats, which are a common feature of most resistance proteins.

Amino Acid Sequence↗
PubMed2000

Structure, function and evolution of plant disease resistance genes.

Gene-for-gene plant disease resistance involves two basic processes: perception of pathogen attack, followed by responses to limit disease. Perception involves receptors with high degrees of specificity for pathogen strains, which are encoded by disease resistance genes. Large repertoires of distantly related resistance (R) genes with diverse recognitional specificities are found within a single plant species. The generation of R-gene polymorphism involves gene duplication, followed by DNA-sequence divergence by point mutation, and by deletion and duplication of intragenic DNA repeats encoding blocks of leucine-rich elements. Recombination between related genes reassorts this variation to further diversify gene sequences. Pathogen pressure selects functional resistance specificities and results in the maintenance of R-gene diversity. Recent genome-sequence data reveal that the NBS-LRR (i.e. nucleotide-binding site-leucine-rich repeat) class of R genes represents as much as 1% of the Arabidopsis genome. Experimental data have shown that the LRR has a role in determination of specificity. Mutation experiments, in which R-gene signaling has been dissociated from specificity in constitutive signal mutants, have provided the potential for non-specific resistance to be expressed from pathogen-infection-induced promoters in transgenic plants.

Evolution, Molecular↗
PubMed1999

Molecular characterization of the maize Rp1-D rust resistance haplotype and its mutants.

The Rp1-D gene for resistance to maize common rust (Puccinia sorghi) is a member of a complex locus (haplotype) composed of Rp1-D and approximately eight other gene homologs. The identity of Rp1-D was demonstrated by using two independent gene-tagging approaches with the transposons Mutator and Dissociation. PIC20, a disease resistance (R) gene analog probe previously mapped to the rp1 locus, detected insertion of Dissociation in an Rp1-D mutation and excision in three revertants. Independent libraries probed with the PIC20 or Mutator probes resulted in isolation of the same gene sequence. Rp1-D belongs to the nucleotide binding site, leucine-rich repeat class of R genes. However, unlike the rust resistance genes M and L6 from flax, the maize Rp1-D gene does not encode an N-terminal domain with similarity to the signal transduction domains of the Drosophila Toll protein and mammalian interleukin-1 receptor. Although the abundance of transcripts of genes from the rp1 complex changed with leaf age, there was no evidence of any change due to inoculation with avirulent or virulent rust biotypes. A set of 27 Rp1-D mutants displayed at least nine different deletions of Rp1-D gene family members that were consistent with unequal crossing-over events. One mutation (Rp1-D*-24) resulted in deletion of all but one gene family member. Other unique deletions were observed in the disease lesion mimic Rp1-D*-21 and the partially susceptible mutant Rp1-D*-5. Different rp1 specificities have distinct DNA fingerprints (haplotypes). Analysis of recombinants between rp1 specificities indicated that recombination had occurred within the rp1 gene complex. Similar analyses indicated that the rust R genes at the rp5 locus, 2 centimorgans distal to rp1, are not closely related to Rp1-D.

Amino Acid Sequence↗
PubMed1998

Comparison of rhabdomyosarcoma, buffalo green monkey kidney epithelial, A549 (human lung epithelial) cells and human embryonic lung fibroblasts for isolation of enteroviruses from clinical samples.

BACKGROUND: Traditionally, primary monkey kidney (PMK) epithelial cells have been one of the more widely used cell types for the isolation of enteroviruses from clinical samples. For the isolation of coxsackie A viruses, intraperitoneal inoculation of newborn mice has been used in some laboratories. OBJECTIVE: With the discontinued availability of PMK epithelial cells and the reported growth of coxsackie A viruses in rhabdomyosarcoma cells (RD), we compared the use of the latter cell line with our routinely used microwell cell cultures. STUDY DESIGN: Microwell cell cultures of buffalo green monkey epithelial cell line (BGM), human lung carcinoma epithelial cell line (A549) and human embryonic lung (HEL) fibroblasts were compared with RD cell line for the isolation of enteroviruses from clinical samples. RESULTS: A total of 39 enteroviruses was isolated from 3517 specimens. The HEL fibroblasts yielded 28 (72%) enteroviruses, followed by A549 (25 isolates, 64%), BGM (23 isolates, 59%) and RD cells (18 isolates, 46%). CONCLUSIONS: All isolates which grew in RD cells showed specific cytopathic effects in one or more of the other inoculated cell cultures. Quantitative determinations (TCID50) with five different enteroviruses showed that the HEL fibroblasts and RD cell line to be the most sensitive cell types, followed by BGM and A549 cell lines. However, integrity of the inoculated cell monolayers was best with HEL fibroblasts and A549 cells but morphology was not optimal with RD cells during the incubation period of 14 days.

Animals↗
PubMed1998

Personality features and expressed concerns of adolescents with eating disorders.

Differences between adolescent females diagnosed with either anorexia nervosa (n = 26) or bulimia nervosa (n = 30) were investigated using the Millon Adolescent Personality Inventory (MAPI; Millon, Green, & Meagher, 1982). About half of the total sample displayed an inhibited (avoidant) personality style. Anorexics scored higher than did bulimics on the Respectful (Compulsive) personality scale. Expressed concerns over self-concept, personal esteem, and sexual acceptance were common in the total sample. The behavioral correlates of MAPI score profiles indicated that few bulimics, and none of the anorexics, were likely to exhibit problems with impulse control, societal conformity, and scholastic achievement. Results are compared with clinical observations of adolescents with eating disorders and findings for adult eating-disordered samples.

Adolescent↗
PubMed1997

Body dissatisfaction and sexuality among women with bulimia nervosa.

OBJECTIVE: Past research and clinical observations have implicated sexuality as a factor involved in eating disorders. Yet little research has been conducted on possible links between body image and sexuality. We investigated such relationships within a large sample of women with bulimia nervosa. METHOD: A sample of adult women (N = 221) diagnosed with bulimia nervosa, purging type, completed a widely used measure of body dissatisfaction and answered questions about basic sexual experiences (coital and masturbation experience, age of onset of these activities, and self-rated satisfaction with current sexual activity). RESULTS: After controlling for age, age of onset of menses, and current body size, body dissatisfaction was unrelated to coital experience. However, even after controlling for these relevant covariates, current body dissatisfaction was predictive of lower incidence, and later onset, of masturbation. Current body dissatisfaction was marginally related (p < .10) to self-rated satisfaction with one's current sex life. DISCUSSION: Results are discussed with regard to past research, directions for future research, and clinical implications.

Adolescent↗
PubMed1997

A comparison of ever-married and never-married women with anorexia nervosa or bulimia nervosa.

OBJECTIVE: The results of the scant research on anorexia nervosa and marriage suggest that married anorexics may exhibit more severely disordered eating. However, past research has not controlled for the greater age of married versus unmarried anorexics, and very little research has been conducted on marriage and women with bulimia nervosa. We investigated differences in disordered eating and clinical traits between ever-married and never-married women with anorexia nervosa or bulimia nervosa and statistically controlled for age. METHOD: Adult women ages 20-45, who were assessed in an outpatient eating disorders clinic and diagnosed with anorexia nervosa (n = 91) or bulimia nervosa (n = 223), completed several measures of disordered eating and related traits at the point of initial evaluation. RESULTS: In simple comparisons, ever-married women differed from their never-married peers with regard to several indices of symptom history and severity. However, after controlling for age, ever-married women differed only with regard to an earlier onset of menarche and, for women with bulimia nervosa, an earlier onset of sexual intercourse. DISCUSSION: Results are discussed with regard to possible explanation and directions for future research.

Adult↗
PubMed1997

Advances in the molecular genetic analysis of the flax-flax rust interaction.

The L6 and M rust-resistance genes, representing two of the five rust-resistance gene loci in flax (Linum usitatissimum), have been cloned. The molecular data are fully consistent with earlier genetic data: the L locus is a single gene with multiple alleles expressing different rust resistance specificities, and the M locus is complex, containing an array of about 15 similar genes. Thus, while L6 and M resistance genes have 86% nucleotide identity, their locus structure is very different. These genes encode products belonging to the nucleotide binding site-leucine-rich repeat class of disease-resistance proteins. Analysis of alleles from the L locus and chimeric genes is providing evidence suggesting that important specificity determinants occur in the C-terminal half of the proteins, the region containing the leucine-rich repeats. The isolation and characterization of the rust (Melampsora lini) avirulence genes that correspond to the cloned rust-resistance genes is one of the major challenges remaining to the understanding of this system.

Journal Article↗
PubMed1997

Elevated antitoxin titers in a man with generalized tetanus.

Vaccination programs have significantly reduced the incidence of tetanus in the United States. The disease develops almost exclusively in those who have been inadequately immunized. This report describes severe, generalized tetanus in a 29-year-old man who had received a primary series as a child and two booster injections. Serum obtained before administration of tetanus immune globulin showed antibody titers to tetanus greater than 100 times the level considered protective. Aggressive supportive care can usually prevent serious consequences. Since most physicians have never seen a case of tetanus, however, the diagnosis can be difficult. Many disorders that exhibit signs and symptoms similar to tetanus must be carefully considered during the evaluation of these patients. Tetanus is a preventable disease. Prevention, however, requires both appropriate immunizations and prompt wound care. While controversy exists regarding the most effective policy to adequately immunize all individuals, this case shows that vaccination alone does not preclude the possibility of tetanus.

Adult↗
PubMed1996

The sexual experience of women diagnosed with anorexia nervosa or bulimia nervosa.

OBJECTIVE: Women with bulimia nervosa generally have reported greater sexual activity and experience relative to women with anorexia nervosa. However, past research has been based on small samples and has not controlled for potential confounding variables or symptom severity. We further investigated sexual experience among women diagnosed with an eating disorder. METHODS: Women evaluated in an outpatient eating disorders program, and subsequently diagnosed with either anorexia nervosa (n = 131) or bulimia nervosa (n = 319), completed the Diagnostic Survey for Eating Disorders-Revised (DSED-R) at intake. Sexual experience variables (masturbation, coitus, sexual satisfaction), as well as control variables (age, weight, and menarche) and measures of symptom severity, were derived from the DSED-R. Logistic regression analyses were used to predict sexual experience. RESULTS: After controlling for relevant covariates, bulimics were more likely than anorexics to have engaged in sexual intercourse. Masturbation experience, as well as self-ratings of current sexual satisfaction, were inversely related to degree of restriction of caloric intake, particularly among women with anorexia nervosa. When compared to anorexics, bulimics reported greater sexual interest and earlier age of first coitus. DISCUSSION: Coitus (sexual activity involving a partner) was related to eating disorder diagnosis independent of symptoms, whereas masturbation (self-focused sexual activity) was related to caloric restriction for the sample as a whole and anorexia nervosa patients in particular. These relationships between sexual experience and eating disorder symptoms and diagnosis may illuminate the personality features of women with anorexia nervosa versus bulimia nervosa as well as the functional role of caloric restriction.

Adolescent↗
PubMed1996

Laxative abuse among women with eating disorders: an indication of psychopathology?

OBJECTIVE: The results of the scant research on laxative abuse among women with eating disorders suggest that laxative abuse is a diagnostic indicator of greater psychopathology. We further investigated the relationship of history of laxative abuse to eating and related attitudes, impulsivity, and personality pathology. METHOD: Women assessed in an outpatient clinical setting and diagnosed with anorexia nervosa, binge-eating/purging type (n = 51) or bulimia nervosa, purging type (n = 280) completed measures of laxative abuse, eating and related attitudes, and personality psychopathology at intake. RESULTS: More than one-half of both groups had abused laxatives at some point. History of laxative abuse was unrelated to eating disorder diagnostic category, current age or body weight, history of stealing, self-induced injury, having attempted suicide, interpersonal distrust, maturity fears, or compulsive or dependent personality features. Compared to nonabusers, laxative abusers demonstrated more perfectionism and avoidant personality features. Significant statistical interactions among variables revealed that bulimia nervosa patients who had abused laxatives exhibited the most pathological scores on scales measuring drive for thinness, body dissatisfaction, ineffectiveness, lack of interoceptive awareness, and passive-aggressive and borderline personality features. Anorexia nervosa patients who had abused laxatives had the highest scores on the histrionic scale. DISCUSSION: Results are discussed with regard to past research and clinical implications. We propose that laxative abuse among eating disordered women may serve different functions depending on diagnosis and underlying personality dynamics.

Adolescent↗
PubMed1996

Substance use among women with eating disorders.

OBJECTIVE: The results of past research suggest that bulimics are more likely than anorexics to engage in substance use, and that binge eating and/or purging may be an indicator of increased likelihood of substance use. We further investigated substance use among women with eating disorders. METHOD: We compared women with anorexia nervosa (n = 134) to women with bulimia nervosa (n = 320) with regard to history of substance use and investigated potential relationships between eating disorder symptom presentation and substance use. RESULTS: Even after controlling for age and eating disorder symptom severity, women with bulimia nervosa were more likely than those with anorexia nervosa to have used alcohol, amphetamines, barbituates, marijuana, tranquilizers, and cocaine. Independent of diagnostic category, severity of caloric restriction was predictive of amphetamine use, severity of binge eating was predictive of tranquilizer use, and severity of purging was predictive of alcohol, cocaine, and cigarette use. DISCUSSION: Results are discussed in relation to the results of past research and with an emphasis on the importance of considering eating disorder symptom presentation in addition to formal eating disorder diagnosis.

Adult↗
PubMed1996

Multi-impulsivity among women with bulimia nervosa.

OBJECTIVE: The results of past research suggest the possible existence of a distinct subgroup of bulimic individuals who display multiple behaviors indicative of impulsivity (e.g., stealing, self-injury, attempted suicide, drug abuse). We further investigated potential relationships between multi-impulsivity and other clinical variables. METHOD: We compared women with bulimia nervosa (purging type) who displayed "multi-impulsivity" (n = 40) to those who did not (n = 177) with regard to symptom history and presentation, eating-disordered attitudes, and sexual experience. RESULTS: The two groups did not differ in mean age, body mass index, scores on scales of eating-disordered attitudes and traits, incidence of self-induced vomiting, sexual intercourse, or masturbation, and current frequency of binge eating and self-induced vomiting. However, relative to the comparison group, women in the multi-impulsive group reported earlier onset of binge eating and sexual intercourse, a greater incidence of laxative abuse, and use of a greater number of different substances. There were statistical trends (p < .10) toward the multi-impulsive group displaying earlier onset of self-induced vomiting, laxative abuse, and masturbation. DISCUSSION: Results are discussed in relation to the results of past research and the implications for treatment of bulimic women.

Adult↗
PubMed1996

Use of the MMPI-2 in the outpatient assessment of women with Anorexia Nervosa or Bulimia Nervosa.

Past research has shown that women with eating disorders commonly display clinical elevations on several scales of the Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1983), so the MMPI may be useful for the differentiation of women with Anorexia Nervosa from those with Bulimia Nervosa. In the study presented here, 116 women diagnosed with either Bulimia Nervosa or Anorexia Nervosa completed the Minnesota Multiphasic Personality Inventory-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989). Multivariate analyses failed to reveal any differences among the diagnostic subtypes. Consideration of profile code types was suggestive of possible group differences that mirror those discussed in previous literature on the personality features of women with eating disorders. Results are discussed with regard to past research and the clinical utility of the MMPI in the outpatient assessment of women with Anorexia Nervosa or Bulimia Nervosa.

Adult↗
PubMed1996

Measurement of nonclinical personality characteristics of women with anorexia nervosa or bulimia nervosa.

Past research on personality and eating disorders has most often emphasized personality psychopathology and personality disorders. We further investigated nonclinical personality characteristics among women with anorexia nervosa (n = 35) or bulimia nervosa (n = 45) using the Multidimensional Personality Questionnaire (MPQ; Tellegen, 1982, 1985). The MPQ measures several personality traits that have been shown to consist of a substantial genetic component (Tellegen et al., 1988). In logistic regression analyses, women with anorexia nervosa evidenced greater degrees of control (vs. impulsivity) and general constraint, and a lower degree of absorption in sensory experiences relative to those with bulimia nervosa. Relative to the normative population (Tellegen, 1982), our sample evidenced very low scores on Well-being, Social Closeness, and Positive Affectivity and high scores on Stress Reaction, Alienation, and Negative Affectivity. Our results emphasize the importance of considering nonclinical personality features and temperament, and varying methods of assessment, in the understanding of predisposing factors for eating disorders.

Adult↗
PubMed1996

Clinical correlates of anorexia nervosa subtypes.

OBJECTIVE: Past research has suggested that subtypes of anorexia nervosa (restricting vs. binge eating/purging) correspond to differing degrees of impulsivity and personality psychopathology. We further investigated potential differences between these diagnostic subtypes. METHOD: We compared restricting anorexics (n = 100) to binge/purging anorexics (n = 71) with regard to symptom presentation and history, impulsivity, eating and related attitudes (Eating Disorders Inventory), and personality psychopathology. RESULTS: We found that the two diagnostic subtypes did not differ in age at intake, body mass index at intake, or age at first diet. Binge/purging anorexics were more likely than restricters to have attempted suicide or engaged in stealing, but the two groups did not differ in likelihood of having engaged in self-injury or in reported drug problems. The two anorexia nervosa subtypes did not differ in age at onset of menses, likelihood of having engaged in masturbation or sexual intercourse, age of onset of sexual activity, or satisfaction with current levels of sexual activity. Likewise, the two groups of anorexia nervosa patients did not differ with regard to scores on the Eating Disorders Inventory or Millon personality measures. DISCUSSION: Results are discussed in relation to the results of past research as well as historical fluctuation in the diagnosis of anorexia nervosa subtypes. We propose that subtyping may be less useful than consideration of eating disorder symptoms along continua.

Adolescent↗