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C J Douglas

Publications and source records attributed to C J Douglas.

At least 19 recordsLinked to original sources
PubMed1996

Two divergent members of a tobacco 4-coumarate:coenzyme A ligase (4CL) gene family. cDNA structure, gene inheritance and expression, and properties of recombinant proteins.

Several cDNA clones encoding 4-coumarate:coenzyme A ligase (4CL) were isolated from a tobacco (Nicotiana tabacum) cDNA library and grouped into two classes. Sequencing of one cDNA from each class showed that the clones were similar to other 4CL genes and about 80% identical with each other. Genomic Southern blots using DNA from Nicotiana sylvestris, Nicotiana tomentosiformis, and N. tabacum demonstrated the presence of both classes of 4CL sequences (4CL1 and 4CL2) in the progenitor species and in tobacco. Northern blots indicated that 4CL mRNA transcripts are highest in old stems and higher in the unpigmented corolla tubes than in the pigmented limbs of tobacco flowers. The 4CL genes are developmentally regulated and are wound and methyl jasmonate inducible. The relative abilities of recombinant 4CL1 and 4CL2 proteins to utilize 4-coumarate, ferulate, and caffeate as substrates were similar and comparable with that of 4CL in tobacco stem extracts. Surprisingly, both recombinant 4CL proteins utilized cinnamate as a substrate, an activity not observed in stem extracts. This activity was inhibited by a heat-labile, high-molecular-weight factor found in tobacco stem extracts, suggesting that the substrate specificity of 4CL is, in part, determined by the activity of proteinaceous cellular components.

Base Sequence↗
PubMed1995

The Arabidopsis thaliana 4-coumarate:CoA ligase (4CL) gene: stress and developmentally regulated expression and nucleotide sequence of its cDNA.

An Arabidopsis cDNA clone encoding 4-coumarate:CoA ligase (4CL), a key enzyme of phenylpropanoid metabolism, was identified and sequenced. The predicted amino acid sequence is similar to those of other cloned 4CL genes. Southern blot analysis indicated that 4CL is single-copy gene in Arabidopsis. Northern blots showed that 4CL expression was activated early during seedling development. The onset of 4CL expression was correlated with the onset of lignin deposition in cotyledons and roots 2-3 days after germination. The timing of the expression of a parsley 4CL1-GUS fusion in transgenic Arabidopsis seedlings was examined in parallel and was very similar to that of endogenous 4CL. In mature plants, highest 4CL expression was observed in bolting stems, where relatively large amounts of lignin accumulate. Both 4CL and 4CL1-GUS mRNA accumulation was strongly and transiently activated by wounding of mature Arabidopsis leaves. 4CL expression was specifically activated within 6 h after infiltration of Arabidopsis ecotype Columbia leaves with a Pseudomonas syringae pv. maculicola strain harboring the bacterial avirulence gene avrB, which causes in incompatible interaction. The timing of 4CL activation was identical to the previously observed activation of PAL gene expression in this interaction. No activation of 4CL expression was observed in a compatible interaction caused by a Pseudomonas syringae pv. maculicola strain without avrB.

Amino Acid Sequence↗
PubMed1995

Patients with multiple sclerosis presenting to psychiatric hospitals.

BACKGROUND: Although many neuropsychiatric syndromes are associated with multiple sclerosis, few recent studies have examined the clinical features of psychiatric illness in inpatients with multiple sclerosis. Florid psychopathology can obscure neurologic symptoms in multiple sclerosis. It is therefore important to consider the range of severe psychiatric states that can occur in multiple sclerosis and the frequency with which multiple sclerosis patients are seen in inpatient facilities. METHOD: We examined records for 2720 consecutive admissions to three psychiatric units and conducted a chart review comparing the DSM-III psychiatric diagnoses of patients with multiple sclerosis with those of the inpatient population as a whole. RESULTS: The 10 patients with multiple sclerosis were significantly more likely to present with histories of mania and manic psychosis than the inpatient population as a whole. Further, 7 of the 10 patients had psychiatric hospitalizations before the multiple sclerosis diagnosis. In 4 of these 7 patients, a review of the medical record documented neurologic symptoms that were not recognized as typical of multiple sclerosis. Three of these 4 patients were psychotic and the fourth was catatonic at the time of their admissions. CONCLUSION: While multiple sclerosis patients account for a small proportion of all psychiatric admissions, clinicians should consider the diagnosis of multiple sclerosis in patients exhibiting manic symptoms in tandem with unexplained neurologic findings.

Adult↗
PubMed1994

Phenylpropanolamine-induced psychosis. Potential predisposing factors.

Phenylpropanolamine (PPA) is a sympathomimetic drug contained in numerous over-the-counter and prescription decongestants and appetite suppressants. A range of adverse effects have been reported, including neuropsychiatric reactions in patients known to be taking recommended doses. Given that psychiatric symptoms are not included in the manufacturer's lists of adverse drug reactions, the incidence may be significantly higher. We report a cae of paranoid psychosis following use of a decongestant containing PPA and summarize the case report literature of psychiatric adverse effects to PPA in which doses were known and stated to be within recommended guidelines. A pattern of possible risk factors emerges from these reports. These may include 1) symptoms or history of mood spectrum disorder, 2) history of psychosis, 3) female sex, 4) family history of psychiatric disorder. The possibility that a higher incidence of adverse events occurs in a vulnerable population has not been systematically addressed, and seems called for. We recommend that physicians specifically inquire about patients' use of decongestants and diet aids. In half of the above cases, symptoms resolved without the use of antipsychotics.

Adult↗
PubMed1993

Combinatorial interactions between positive and negative cis-acting elements control spatial patterns of 4CL-1 expression in transgenic tobacco.

The phenylpropanoid enzyme 4-coumarate:coenzyme A ligase (4CL) plays a key role in linking general phenylpropanoid metabolism to end-product specific biosynthetic pathways. During vascular system and floral organ differentiation, the parsley 4CL-1 gene is expressed in a restricted set of tissues and cell types where 4CL activity is required to supply precursors for the synthesis of diverse phenylpropanoid-derived products such as lignin and flavonoids. In order to localize cis-acting elements which specify complex patterns of 4CL-1 expression, we analyzed the expression of internally deleted promoter fragment-GUS fusions in tobacco plants and parsley protoplasts. Elements located between -244 and -78 were required for most aspects of developmentally regulated expression. Within this region, three separate promotor domains containing partially redundant cis-elements directed vascular-specific expression when combined with a TATA-proximal domain. A negative cis-acting element which represses phloem expression was revealed in one of the domains and appears to be responsible for restricting vascular expression to the xylem. Distinct but overlapping promoter domain combinations were required for expression in floral organs, suggesting that different combinations of cis-acting elements may direct expression in different organs. Gel retardation assays were used to demonstrate the formation of DNA-protein complexes between factors present in nuclear extracts of parsley tissue culture cells and various tobacco organs and a 4CL-1 promoter fragment. Competition experiments showed that complex formation required the presence of a 42 bp promoter domain shown to be critical for 4CL-1 expression in vascular and floral tissues. The results are discussed in light of the coordinate expression of 4CL and other phenylpropanoid genes.

Base Sequence↗
PubMed1993

Structure, inheritance, and expression of hybrid poplar (Populus trichocarpa x Populus deltoides) phenylalanine ammonia-lyase genes.

A heterologous probe encoding phenylalanine ammonia-lyase (PAL) was used to identify PAL clones in cDNA libraries made with RNA from young leaf tissue of two Populus deltoides x P. trichocarpa F1 hybrid clones. Sequence analysis of a 2.4-kb cDNA confirmed its identity as a full-length PAl clone. The predicted amino acid sequence is conserved in comparison with that of PAL genes from several other plants. Southern blot analysis of popular genomic DNA from parental and hybrid individuals, restriction site polymorphism in PAL cDNA clones, and sequence heterogeneity in the 3' ends of several cDNA clones suggested that PAL is encoded by at least two genes that can be distinguished by HindIII restriction site polymorphisms. Clones containing each type of PAL gene were isolated from a poplar genomic library. Analysis of the segregation of PAL-specific HindIII restriction fragment-length polymorphisms demonstrated the existence of two independently segregating PAL loci, one of which was mapped to a linkage group of the poplar genetic map. Developmentally regulated PAL expression in poplar was analyzed using RNA blots. Highest expression was observed in young stems, apical buds, and young leaves. Expression was lower in older stems and undetectable in mature leaves. Cellular localization of PAL expression by in situ hybridization showed very high levels of expression in subepidermal cells of leaves early during leaf development. In stems and petioles, expression was associated with subepidermal cells and vascular tissues.

Amino Acid Sequence↗
PubMed1992

Molecular signals in the interactions between plants and microbes.

The field of plant-microbe interactions has witnessed several recent breakthroughs, such as the molecular details of vir gene induction, identification of Nod factors, and the cloning and characterization of avr genes. Other breakthroughs, such as the cloning and characterization of R genes, appear imminent. Parallels to mammalian systems are emerging in the world of plant-microbe interactions, for example, ion channels formed by Rhizobium proteins, similarities of hrp genes to pathogenicity genes of mammalian pathogens, and plant signal transduction via calcium and protein phosphorylation. We remain, however, largely ignorant of many facets of signaling in plant-microbe interactions. We know little about how microbial signals are perceived by plants or how subsequent signal transduction occurs within plant cells and are probably unaware of many of the microbe-generated signals to which plants respond or of plant-generated signals to which bacteria and fungi respond. Contributions from those working on the genetics, molecular biology, and physiology of bacteria, fungi, and plants will be required to address these questions. The many nonpathogenic plant-microbe interactions in addition to the Rhizobium-plant interaction remain relatively unexplored. Genetic and molecular approaches are being initiated to investigate the signaling that is likely to underlie interactions such as those between mycorrhizal fungi and plant roots and between epiphytic bacteria and plant leaf surfaces. The importance of these interactions to plant growth and development makes it likely that they will figure more prominently at future symposia.(ABSTRACT TRUNCATED AT 250 WORDS)

Plant Physiological Phenomena↗
PubMed1992

Clozapine treatment of psychosis in Parkinson's disease: a report of five consecutive cases.

BACKGROUND: Clozapine has gained acceptance as an antipsychotic in treatment-resistant schizophrenia. Its low propensity to induce extrapyramidal side effects makes clozapine an attractive treatment for patients with Parkinson's disease and dopaminomimetic psychosis. Recent evidence demonstrates that Parkinson's patients are exquisitely sensitive to both the antipsychotic and the potential extrapyramidal effects of clozapine. The uncontrolled studies suggest that low-dose clozapine may be efficacious in this population. The dose range, side effect profiles, and length of treatment varied in these reports. METHOD: We report our experience with five patients with Parkinson's disease and psychosis who were treated with clozapine in an open trial. RESULTS: Three patients were successfully treated with clozapine (25-100 mg/day, mean = 66.7 mg) without worsening their parkinsonism. Adverse effects unrelated to the motor disability required discontinuation of clozapine in the other two patients. At 1- to 2-year follow-up, each patient had required increased dosages of clozapine (75-150 mg/day, mean = 125 mg) for continued management of their psychosis and parkinsonism. The higher dose range was well tolerated. CONCLUSION: These results suggest that clozapine may effectively treat psychosis in Parkinson's disease.

Aged↗
PubMed1991

Exonic sequences are required for elicitor and light activation of a plant defense gene, but promoter sequences are sufficient for tissue specific expression.

The parsley 4CL-1 gene encodes 4-coumarate:CoA ligase, a key enzyme of general phenylpropanoid metabolism. As well as being transcriptionally activated by such stresses as pathogen infection, UV-irradiation, and wounding, expression of 4CL-1 is developmentally regulated. In this paper we present evidence that 4CL-1 cis-acting elements which control stress-induced and developmental expression are physically separated. The ability of a series of 4CL gene constructions to respond to elicitor and light in stably or transiently transformed parsley cells was tested. While inducible expression was observed from all templates in which the 4CL-1 structural gene was fused to the 4CL-1 promoter, fusions of the promoter to the GUS reporter gene were completely unresponsive. The element(s) required for responsiveness appear to be exonic, since 4CL-1 introns and 3' flanking DNA had no effect on inducibility. Furthermore, this unconventional regulatory mode operates in transgenic tobacco plants, where we show that a 4CL-1 promoter fragment specifies correct cell-specific expression when fused to GUS yet is unresponsive to elicitor and light.

Base Sequence↗
PubMed1991

A parsley 4CL-1 promoter fragment specifies complex expression patterns in transgenic tobacco.

The 4CL-1 gene is one of two highly homologous parsley genes encoding 4-coumarate:coenzyme A ligase, a key enzyme of general phenylpropanoid metabolism. Expression of these genes is essential for the biosynthesis of both defense-related and developmentally required phenylpropanoid derivatives. We examined the developmental regulation of the 4CL-1 promoter by analyzing the expression of 4CL-1-beta-glucuronidase fusions in transgenic tobacco plants. A 597-base pair 4CL-1 promoter fragment specified histochemically detectable expression in a complex array of vegetative and floral tissues and cell types. The activity of a series of 5' deleted promoter fragments was analyzed in parsley protoplasts and transgenic tobacco plants. Deletions past -210 base pairs led to a drastic decline in beta-glucuronidase activity in protoplasts and loss of tissue-specific expression in transgenic tobacco. These results were put into the context of potential protein-DNA interactions by in vivo footprint analysis of the 4CL-1 promoter in parsley cells. Loss of promoter activity in parsley protoplasts and transgenic tobacco was correlated with the deletion or disruption of the distal portion of a large (100-base pair) footprinted region within the first 200 base pairs of the 4CL-1 promoter.

Base Composition↗
PubMed1988

Adaptive responses to illness and disability. Healthy denial.

The authors attempt to understand the nature and sources of "resilience" by a comparison of three individuals who showed unusual courage in the face of death, illness, and congenital disability. Various adaptive traits that enabled them to function effectively and remain optimistic are discussed. The authors specifically consider the role of "healthy" denial and argue that it does not fully explain or account for their singular optimism confronting adversity. The term "resilience" is proposed to describe both the particular cognitive style of "hardiness" and the "ego strength" that characterize such patients. Possible sources and origins of resilience are suggested. Finally, implications for the treatment of such patients are considered.

Adaptation, Psychological↗
PubMed1987

Denial of illness: a reappraisal.

The authors attempt to understand the nature of denial of illness by an examination of two patients with serious and disfiguring physical disorders who postponed medical treatment for over a decade. Both patients subsequently had dramatic negative reactions to the therapeutic efforts of physicians caring for them. Various social, experiential, and characterologic determinants are discussed. In addition, the authors argue that the illness served important organizing functions: it sheltered these patients from the exigencies of everyday life; it allowed them to defeat the physician's efforts to effect a cure; and, finally, the disfigured physical state appeared to correspond to their internalized defective self-image and self-esteem.

Adult↗
PubMed1986

In-vitro effect of itraconazole, ketoconazole and amphotericin B on the phagocytic and candidacidal function of human neutrophils.

Neither itraconazole nor ketoconazole had significant effects on the phagocytosis or killing of Candida albicans blastospores by human neutrophil polymorphonuclear (PMN) leucocytes, whether following simultaneous addition of drug with the blastospores, prior treatment of the PMN cells with drug, or prior treatment of the blastospores with drug. Following simultaneous addition, amphotericin B caused significant impairment of phagocytosis in tests with PMN cells from one of two donors, but had no effect on subsequent killing of ingested blastospores. Prior treatment of PMN cells or blastospores with amphotericin B had no effect on phagocytosis or killing. In tests in which blastospores of an azole-sensitive and an azole-resistant strain of C. albicans were added to PMN cells, fewer than 25% of ingested blastospores of either strain had initiated germ tube formation after 6 h. Addition of ketoconazole had no effect on the proportion of ingested blastospores of either strain which germinated. Ketoconazole had no effect on germ tube elongation of ingested blastospores of the azole-resistant strain, but caused marked inhibition of germ tube elongation of ingested blastospores of the azole-sensitive strain. After 24 h, the azole-resistant strain had produced abundant mycelium and few phagocytic cells remained intact. With the azole-sensitive strain, PMN cells were still evident at 24 h, with ingested germ-tube-forming blastospores, most of which were dead.

Amphotericin B↗
PubMed1985

Identification and genetic analysis of an Agrobacterium tumefaciens chromosomal virulence region.

A genetic analysis of Agrobacterium tumefaciens chromosomal functions required for virulence was undertaken. Large Tn5-containing cosmid clones were isolated from DNA of avirulent A. tumefaciens mutants having chromosomal Tn5 insertions and exhibiting defective attachment to plant cells. The clones from several different mutants each contained overlapping segments of a 30-kilobase A. tumefaciens chromosomal region, which were physically mapped. All chromosomal Tn5 insertions leading to the avirulent, attachment-defective phenotype were localized within an 11-kilobase portion of this chromosomal virulence region. Transposon Tn3::HoHo1 (Tn3 containing lacZ) was used to simultaneously mutagenize and create lac fusions within the virulence region. This analysis demonstrated the presence of two distinct chromosomal virulence loci, which were 1.5 and 5 kilobases long; transposon insertions into these loci led to avirulence and defective attachment. The beta-galactosidase activity associated with various Tn3::HoHo1-created lac fusions indicated that the loci are transcribed in opposite directions, and complementation studies suggested that each locus consists of a single transcriptional unit. A cosmid clone of the chromosomal virulence region containing a lac fusion in the extreme 3' portion of the 5-kilobase locus was used to demonstrate that expression of this region is dependent on the presence of sequences in the 5' portion of the locus, confirming its operon-like nature.

Chromosomes, Bacterial↗
PubMed1985

Role for 2-linked-beta-D-glucan in the virulence of Agrobacterium tumefaciens.

Phenol-water cell extracts of virulent Agrobacterium tumefaciens A348 and several avirulent mutants with a reduced ability to attach to plant surfaces were examined. A low-molecular-weight 2-linked-beta-D-glucan was identified in the cell wall extracts of the virulent wild-type strain. Analyses of phenol-water extracts and culture filtrates of four mutant strains showed that the mutants did not produce any 2-linked-beta-D-glucan. When these mutants were complemented, the ability to produce the glucan described above was restored. These results suggest that there is a role for 2-linked-beta-D-glucans in the attachment of A. tumefaciens to plant cells. One avirulent, attachment-defective mutant retained its ability to produce the low-molecular-weight glucan. This mutation, however, mapped to a different transcriptional unit than the mutants deficient in the glucan described above. Thus, it appears that 2-linked-beta-D-glucan is only one component that may be necessary for attachment of A. tumefaciens to plant cell surfaces.

Adhesiveness↗
PubMed1985

Homophobia among physicians and nurses: an empirical study.

In a large urban teaching hospital treating many patients with AIDS, 37 medical house officers and 91 registered nurses completed a questionnaire designed to measure attitudes about homosexuality. Mean scores for both physicians and nurses fell in the low-grade homophobic range. No significant differences were found between scores for doctors and nurses, but women respondents were significantly more homophobic than men. Respondents who had a friend or relative who was homosexual were less homophobic than those who did not. Nearly 10 percent of respondents agreed with the statement that homosexuals who contract AIDS are getting what they deserve. The authors consider this to be an alarming statistic and conclude from the findings that homophobia is higher than desirable in this group of health professionals.

Acquired Immunodeficiency Syndrome↗