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Biomedical subjects

K P White

Publications and source records attributed to K P White.

At least 19 recordsLinked to original sources
PubMed2003

A protein interaction map of Drosophila melanogaster.

Drosophila melanogaster is a proven model system for many aspects of human biology. Here we present a two-hybrid-based protein-interaction map of the fly proteome. A total of 10,623 predicted transcripts were isolated and screened against standard and normalized complementary DNA libraries to produce a draft map of 7048 proteins and 20,405 interactions. A computational method of rating two-hybrid interaction confidence was developed to refine this draft map to a higher confidence map of 4679 proteins and 4780 interactions. Statistical modeling of the network showed two levels of organization: a short-range organization, presumably corresponding to multiprotein complexes, and a more global organization, presumably corresponding to intercomplex connections. The network recapitulated known pathways, extended pathways, and uncovered previously unknown pathway components. This map serves as a starting point for a systems biology modeling of multicellular organisms, including humans.

Animals↗
PubMed2001

A comparison of rheumatoid arthritis and fibromyalgia patients and healthy controls exposed to a pulsed (200 microT) magnetic field: effects on normal standing balance.

Specific weak time varying pulsed magnetic fields (MF) have been shown to alter animal and human behaviors, including pain perception and postural sway. Here we demonstrate an objective assessment of exposure to pulsed MF's on Rheumatoid Arthritis (RA) and Fibromyalgia (FM) patients and healthy controls using standing balance. 15 RA and 15 FM patients were recruited from a university hospital outpatient Rheumatology Clinic and 15 healthy controls from university students and personnel. Each subject stood on the center of a 3-D forceplate to record postural sway within three square orthogonal coil pairs (2 m, 1.75 m, 1.5 m) which generated a spatially uniform MF centered at head level. Four 2-min exposure conditions (eyes open/eyes closed, sham/MF) were applied in a random order. With eyes open and during sham exposure, FM patients and controls appeared to have similar standing balance, with RA patients worse. With eyes closed, postural sway worsened for all three groups, but more for RA and FM patients than controls. The Romberg Quotient (eyes closed/eyes open) was highest among FM patients. Mixed design analysis of variance on the center of pressure (COP) movements showed a significant interaction of eyes open/closed and sham/MF conditions [F=8.78(1,42), P<0.006]. Romberg Quotients of COP movements improved significantly with MF exposure [F=9.5(1,42), P<0.005] and COP path length showed an interaction approaching significance with clinical diagnosis [F=3.2(1,28), P<0.09]. Therefore RA and FM patients, and healthy controls, have significantly different postural sway in response to a specific pulsed MF.

Adaptation, Physiological↗
PubMed2001

Patterns of gene expression during Drosophila mesoderm development.

The transcription factor Twist initiates Drosophila mesoderm development, resulting in the formation of heart, somatic muscle, and other cell types. Using a Drosophila embryo sorter, we isolated enough homozygous twist mutant embryos to perform DNA microarray experiments. Transcription profiles of twist loss-of-function embryos, embryos with ubiquitous twist expression, and wild-type embryos were compared at different developmental stages. The results implicate hundreds of genes, many with vertebrate homologs, in stage-specific processes in mesoderm development. One such gene, gleeful, related to the vertebrate Gli genes, is essential for somatic muscle development and sufficient to cause neural cells to express a muscle marker.

Animals↗
PubMed2001

Classification, epidemiology, and natural history of fibromyalgia.

Fibromyalgia (FM), also known as fibromyalgia syndrome (FMS) and fibrositis, is a common form of nonarticular rheumatism that is associated with chronic generalized musculoskeletal pain, fatigue, and a long list of other complaints. Some have criticized the classification of FM as a distinct medical entity, but existing data suggest that individuals meeting the case definition for FM are clinically somewhat distinct from those with chronic widespread pain who do not meet the full FM definition. Clinic studies have found FM to be common in countries worldwide; these include studies in specialty and general clinics. The same is true of general population studies, which show the prevalence of FM to be between 0.5% and 5%. Knowledge about risk factors for FM is limited. Females are at greater risk, and risk appears to increase through middle age, then decline. Although some authors claim that an epidemic of FM has been fueled by an over-generous Western compensation system, there are no data that demonstrate an increasing incidence or prevalence of FM; moreover, existing data refute any association between FM prevalence and compensation. Claims that the FM label itself causes illness behavior and increased dependence on the medical system also are not supported by existing research. This article reviews the classification, epidemiology, and natural history of FM.

Adolescent↗
PubMed2001

Functional genomics and the study of development, variation and evolution.

It has rarely been possible to connect the developmental and evolutionary branches of genetics, particularly with regard to the precise changes in the molecular control of development that are responsible for phenotypic variation and evolution. Making such connections will require a high-resolution molecular description of the genetic networks that underlie development and an understanding of their responses to genetic and environmental variation. Functional genomics approaches to development and evolution promise to accelerate the research necessary to accomplish these goals.

Animals↗
PubMed2001

The contributions of sex, genotype and age to transcriptional variance in Drosophila melanogaster.

Here we present a statistically rigorous approach to quantifying microarray expression data that allows the relative effects of multiple classes of treatment to be compared and incorporates analytical methods that are common to quantitative genetics. From the magnitude of gene effects and contributions of variance components, we find that gene expression in adult flies is affected most strongly by sex, less so by genotype and only weakly by age (for 1- and 6-wk flies); in addition, sex x genotype interactions may be present for as much as 10% of the Drosophila transcriptome. This interpretation is compromised to some extent by statistical issues relating to power and experimental design. Nevertheless, we show that changes in expression as small as 1.2-fold can be highly significant. Genotypic contributions to transcriptional variance may be of a similar magnitude to those relating to some quantitative phenotypes and should be considered when assessing the significance of experimental treatments.

Aging↗
PubMed2001

Lumbar pannus presenting as cauda equina syndrome in a patient with longstanding rheumatoid arthritis.

Relatively little attention has been paid to lumbar spine involvement in rheumatoid arthritis (RA), and indeed it is generally considered to be an uncommon and usually clinically minor manifestation of the disease. We describe a case of acute right lower extremity weakness secondary to compression of multiple lumbar nerve roots by a large interforaminal rheumatoid pannus, and review the literature on this complication and other lumbar spine involvement in RA.

Aged↗
PubMed2001

Vitamin D levels in women with systemic lupus erythematosus and fibromyalgia.

OBJECTIVE: Many patients with systemic lupus erythematosus (SLE) and fibromyalgia (FM) may spend less time exposed to the sun than healthy individuals and thus might have low vitamin D levels. It is known that hydroxychloroquine (HCQ) inhibits conversion of 25(OH)- to 1,25(OH)2-vitamin D both in vitro and in patients with sarcoidosis. We assessed winter serum 25(OH)- and 1,25(OH)2-vitamin D levels in patients with SLE and FM. METHODS: We recruited 25 consecutive female SLE and 25 female FM patients in London, Ontario, between January and March 2000. Subjects completed a brief questionnaire. Serum levels of 25(OH)-, 1,25(OH)2-vitamin D, and parathyroid hormone (PTH) were measured. RESULTS: In SLE patients mean 25(OH)-vitamin D was 46.5 nmol/l and mean 1,25(OH)2-vitamin D was 74.4 pmol/l. In FM patients these means were 51.5 nmol/l and 90.1 pmol/l, respectively. Serum 25(OH)-vitamin D levels did not significantly differ between SLE and FM patients, nor after adjusting for age and vitamin D, milk consumption, and sun block use. In 14 of the SLE patients and 12 of the FM patients 25(OH)-vitamin D levels < 50 nmol/l were found. SLE patients not using vitamin D supplements had lower 25(OH)-vitamin D levels than those who did. 1,25(OH)2-vitamin D tended to be lower in the SLE compared to the FM patients. This difference could be attributed to HCQ use: HCQ users (n = 17) had lower 1,25(OH)2-vitamin D levels than nonusers (n = 33); the mean adjusted difference was 24.4 pmol/l (95% CI 2.8-49.9). CONCLUSION: Half the SLE and FM patients had 25(OH)-vitamin D levels < 50 nmol/l, a level at which PTH stimulation occurs. Our data suggest that in SLE patients HCQ might inhibit conversion of 25(OH)-vitamin D to 1,25(OH)2-vitamin D.

Adolescent↗
PubMed2000

Haplotype dimorphism in a SNP collection from Drosophila melanogaster.

A moderate resolution single nucleotide polymorphism (SNP) map of the genome of Drosophila melanogaster that is designed for use in quantitative genetic mapping is described. Seventeen approximately 500 nucleotide gene sequences spaced at 10 to 20 centimorgan intervals were combined with 49 shorter sequence tag sites (STSs) at 5 to 10 centimorgan intervals to generate a map that should not leave any gaps greater than one half of a chromosome arm when any two wild type lines are compared. Of 20 markers with sufficient polymorphism to construct haplotype cladograms, 13 showed evidence for two divergent classes of haplotype. The possible mechanisms for and implications of the unexpected finding that two thirds of all short gene sequences in D. melanogaster may be dimorphic are discussed, including the suggestion that admixture between two separate lineages may have been a major event in the history of the species.

Animals↗
PubMed2000

Reliability of the six-minute walk test in people with fibromyalgia.

OBJECTIVE: To determine the test-retest reliability of the 6-minute walk test in people with fibromyalgia. METHODS: Twenty-six subjects (27-59 years of age) performed 3 walk tests over consecutive days before and after a 4-week treatment program. Reliability was determined using a one-way repeated measures analysis of variance and the intraclass correlation coefficient (ICC2,1). RESULTS: Reliability of the 6-minute walk test was excellent both at program intake (ICC2,1 = 0.91) and program completion (ICC2,1 = 0.98). On program intake, significant differences (P < 0.01) were found between test 1 (478 +/- 61 m) and test 2 (492 +/- 57 m), and between test 1 and test 3 (495 +/- 60 m). On program completion, there were no significant differences across the 3 replicate tests (507 m, 505 m, and 509 m). CONCLUSIONS: The 6-minute walk test is a reliable measure in people with fibromyalgia. In this study, two trials were required to achieve a stable walk performance before a treatment program. This learning effect was not present following the intervention.

Adult↗
PubMed2000

Trauma and fibromyalgia: is there an association and what does it mean?

OBJECTIVES: The primary objective is to review current research with respect to the role of trauma in fibromyalgia (FM). A secondary objective is to hypothesize which steps need to be taken, first to determine whether such an association truly exists, and second to clarify what such an association might mean. METHODS: An extensive literature review was undertaken, including Medline from 1979 to the present. RESULTS: The strongest evidence supporting an association between trauma and FM is a recently published Israeli study in which adults with neck injuries had greater than a 10-fold increased risk of developing FM within 1 year of their injury, compared with adults with lower extremity fractures (P= .001). Several other studies provide a hypothetical construct for such an association. These include studies on (1) postinjury sleep abnormalities; (2) local injury sites as a source of chronic distant regional pain; and (3) the concept of neuroplasticity. There are, however, several primary arguments against such an association: (1) FM may not be a distinct clinical entity; (2) FM may be a psychological, rather than physical, disease; (3) the evidence supporting any association is limited and not definitive; (4) the Israeli study, itself, has some methodological limitations; and (5) other factors may be more important than the injurious event in determining chronic symptoms after an acute injury. CONCLUSIONS: Although there is some evidence supporting an association between trauma and FM, the evidence is not definitive. Further prospective studies are needed to confirm this association and to identify whether trauma has a causal role.

Adult↗
PubMed2000

Co-existence of chronic fatigue syndrome with fibromyalgia syndrome in the general population. A controlled study.

OBJECTIVE: To determine the proportion of adults with fibromyalgia syndrome (FMS) in the general population who also meet the 1988 Centre for Disease Control (CDC) criteria for chronic fatigue syndrome (CFS). METHODS: Seventy-four FMS cases were compared with 32 non-FMS controls with widespread pain and 23 with localized pain, all recruited in a general population survey. RESULTS: Among females, 58.0% of fibromyalgia cases met the full criteria for CFS, compared to 26.1% and 12.5% of controls with widespread and localized pain, respectively (p=0.0006). Male percentages were 80.0, 22.2, and zero, respectively (p=0.003). Compared to those with FMS alone, those meeting the case definitions for both FMS and CFS reported a worse course, worse overall health, more dissatisfaction with health, more non-CFS symptoms, and greater disease impact. The number of total symptoms and non-CFS symptoms were the best predictors of co-morbid CFS. CONCLUSIONS: There is significant clinical overlap between CFS and FMS.

Adult↗
PubMed2000

Perspectives on posttraumatic fibromyalgia: a random survey of Canadian general practitioners, orthopedists, physiatrists, and rheumatologists.

OBJECTIVE: To determine which factors physicians consider important in patients with chronic generalized posttraumatic pain. METHODS: Using physician membership directories, random samples of 287 Canadian general practitioners, 160 orthopedists, 160 physiatrists, and 160 rheumatologists were surveyed. Each subject was mailed a case scenario describing a 45-year-old woman who sustained a whiplash injury and subsequently developed chronic, generalized pain, fatigue, sleep difficulties, and diffuse muscle tenderness. Respondents were asked whether they agreed with a diagnosis of fibromyalgia (FM), and what factors they considered to be important in the development of chronic, generalized posttraumatic pain. RESULTS: More-recent medical school graduates were more likely to agree with the FM diagnosis. Orthopedists (28.8%) were least likely to agree, while rheumatologists (83.0%) were most likely to agree. On multivariate analysis, 5 factors predicted agreement or disagreement with the diagnosis of FM: (1) number of FM cases diagnosed by the respondent per week (p < 0.0001); (2) patient's sex (p < 0.0001); (3) force of initial impact (p = 0.003); (4) patient's pre-collision psychiatric history (p = 0.03); and (5) severity of initial injuries (p = 0.03). The force of initial impact and the patient's pre-collision psychiatric history were both negatively correlated with agreement in diagnosis. Patient related factors (personality, emotional stress, pre-collision physical, mental health) were considered more important than trauma related factors in the development of chronic, widespread pain. CONCLUSION: Future studies of the association between trauma and FM should identify potential cases outside of specialty clinics, and baseline assessments should include some measurement of personality, stress, and pre-collision physical and mental health.

Adult↗
PubMed2000

A general population study of fibromyalgia tender points in noninstitutionalized adults with chronic widespread pain.

OBJECTIVE: To assess the distribution and predictive ability of fibromyalgia (FM) tender points (TP) in adults with chronic widespread pain. METHODS: Using published classification criteria, we confirmed 100 FM cases and 76 controls with widespread pain not meeting the 1990 American College of Rheumatology (ACR) classification criteria for FM (pain controls) in a survey of 3,395 adults screened for widespread musculoskeletal pain in a general population survey. RESULTS: At each of the 18 FM tender points, FM cases were more likely than pain controls to have tenderness, and the likelihood ratio (LR) was statistically greater than 1.0 for 13 of 18 points. However, the LR for individual points ranged from 4.0 to as low as 1.2. Females were more likely to have TP, especially at lower body points; however, lower body points were more discriminatory in males. CONCLUSION: TP differ in their ability to predict FM among adults in the general population with chronic widespread pain.

Adult↗
PubMed1999

Microarray analysis of Drosophila development during metamorphosis.

Metamorphosis is an integrated set of developmental processes controlled by a transcriptional hierarchy that coordinates the action of hundreds of genes. In order to identify and analyze the expression of these genes, high-density DNA microarrays containing several thousand Drosophila melanogaster gene sequences were constructed. Many differentially expressed genes can be assigned to developmental pathways known to be active during metamorphosis, whereas others can be assigned to pathways not previously associated with metamorphosis. Additionally, many genes of unknown function were identified that may be involved in the control and execution of metamorphosis. The utility of this genome-based approach is demonstrated for studying a set of complex biological processes in a multicellular organism.

Animals↗
PubMed1999

Comparing self-reported function and work disability in 100 community cases of fibromyalgia syndrome versus controls in London, Ontario: the London Fibromyalgia Epidemiology Study.

OBJECTIVE: To compare function and disability in fibromyalgia syndrome (FMS) cases in the community versus controls, and to identify variables predicting poor function and disability. METHODS: We identified 100 FMS cases, 76 pain controls, and 135 general controls in a random survey of 3,395 noninstitutionalized adults. RESULTS: FMS cases reported worse function (P < 0.00001), more days in bed (P < 0.001), and more healthy years of life lost (P < 0.0001). More FMS cases were disabled (P < 0.00001) and receiving pensions (P < 0.00001). Risk factors for disability included middle age and previous heavy manual labor. Pain, fatigue, and weakness were most often claimed to affect the ability to work Variables predicting work disability were the Fibromyalgia Impact Questionnaire (FIQ) score, a prior diagnosis of FMS, nonrestorative sleep, and past heavy physical labor. Variables influencing the FIQ score were the number of major symptoms, self-reported health satisfaction, tender point count, and education level. CONCLUSION: FMS commonly results in loss of function and work disability.

Adult↗
PubMed1999

The occurrence and impact of generalized pain.

A major problem with estimating the impact of chronic generalized pain is that the term remains undefined. It appears to encompass several distinct clinical entities, including rheumatoid arthritis and fibromyalgia, which can exist alone or together in a given individual. Nonetheless, chronic generalized pain appears to have a sizable impact on both the individual and society. Although little is known about causal relationships, demographic risk factors for chronic generalized pain are female sex, age in the forties and fifties, lower income, lower education, and being divorced or separated. Chronic generalized pain affects the individual in several ways, including physical and psychological distress, losses of function, quality of life, employment and income, and prolonged litigation for many. Its impact on society includes increased utilization of health care resources, loss of work productivity, disability and insurance costs, costs of litigation and social policy. Future research into the impact of chronic generalized pain must begin by defining this term in a way that is both valid in construct and convenient to use. Research is also warranted to develop and validate diagnostic tools that may better distinguish various subsets of chronic generalized pain, both to better understand the pathological processes involved and to allow for estimates of the relative contribution of each subset to societal costs.

Chronic Disease↗