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Biomedical subjects

C Wilson

Publications and source records attributed to C Wilson.

At least 73 records · Page 4Linked to original sources
PubMed2000

A thermal spin transition in [Co(bpy)3][LiCr(ox)3] (ox = C2O4(2-); bpy = 2,2'-bipyridine).

In the three-dimensional oxalate network structures [M(II)(bpy)3][M(I)-M(III)(ox)3] (ox= C2O4(2-); bpy = 2,2'-bipyridine) the negatively charged oxalate backbone provides perfect cavities for tris-bipyridyl complex cations. The size of the cavity can be adjusted by variation of the metal ions of the oxalate backbone. In [Co(bpy)3][NaCr(ox)3], the [Co(bpy)3]2 + complex is in its usual 4T1(t2g5e(g)2) high-spin ground state. Substituting Na+ by Li+ reduces the size of the cavity. The resulting chemical pressure destabilises the high-spin state of [Co(bpy)3]2+ to such an extent that the 2E(t2g6e(g)1) low-spin state becomes the actual ground state. As a result. [Co(bpy)3][LiCr(ox)3] becomes a spin-crossover system, as shown by temperature-dependent magnetic susceptibility measurements and single-crystal optical spectroscopy, as well as by an X-ray structure determination at 290 and 10 K.

Journal Article↗
PubMed2000

MAP kinases in pollen.

The male gametophyte of flowering plants has a highly regulated developmental programme to ensure efficient fertilization of the ovule and the faithful transmission of genetic material to the offspring. Cell cycle control mechanisms dictate the formation of the vegetative and generative (sperm) cells, while an increase in transcriptional/translational activity and the accumulation of stored proteins and mRNA is followed by a quiescent state at maturation. A switch to a new developmental programme occurs after the pollen tube lands on the stigma with the formation of the pollen tube, growth through the style, and subsequent fertilization. Apart from the internal control mechanisms involved in this developmental programme, pollen grains must cope with physical changes during development within the anther (desiccation) and subsequently during germination on the stigma (rehydration). The metabolic and structural changes that occur throughout these processes should require signaling mechanisms to co-ordinate the appropriate response, and recent data demonstrate the presence in pollen of an array of molecules belonging to diverse signalling pathways, including mitogen-activated protein (MAP) kinases. The role of MAP kinases in pollen is discussed in the context of the various developmental and physical changes that occur throughout pollen maturation and germination.

MAP Kinase Signaling System↗
PubMed2000

Differential cytokeratin and glycoconjugate expression by the surface and crypt epithelia of human palatine tonsils.

Human palatine tonsils are clinically important due to their susceptibility to tonsillitis and association with other local and systemic diseases. Paradoxically, the tonsils function as antigen sampling sites of the mucosal immune system and, consequently, the tonsil epithelia perform both protective and antigen sampling roles. These epithelia are divided into stratified squamous epithelium overlying the tonsil surface and crypt epithelium lining the tonsil crypts, the latter of which includes reticular areas which are infiltrated by lymphocytes and are responsible for antigen sampling. In this study we characterised cytokeratin and glycoconjugate expression by healthy epithelia of human palatine tonsils. We identified pan-epithelial tonsil markers and also demonstrated that the surface and reticular crypt epithelia are differentiated by the expression of multiple cytokeratins. The latter finding supports the hypothesis that these epithelia undergo alternate differentiation pathways and possess different functional roles. In addition, we identified cell subpopulations in the tonsil epithelia which may represent distinct cell subtypes including specialised antigen sampling cells. These findings establish a basis for future studies to investigate histochemical changes in tonsil epithelia that are associated with or predispose to local and/or systemic disease.

Adolescent↗
PubMed2000

Effects of serotonergic agents on the transport response in rats.

In two experiments, researchers investigated the effects of manipulating serotonin systems on the transport response and dorsal immobility response in developing rats. In Experiment 1, administration of ketanserin and cinanserin, but not metergoline, suppressed the transport response in 23-day-old rats. These agents were without effect on dorsal immobility durations. In Experiment 2, administration of quipazine to 30-, 40-, and 50-day-old rats resulted in significant increases in transport response intensities and dorsal immobility durations. Results are discussed with respect to the nature of the transport response.

Age Factors↗
PubMed2000

Sexual Assault Nurse Examiner programs in the United States.

STUDY OBJECTIVE: We sought to provide a descriptive study of the Sexual Assault Nurse Examiner (SANE) programs and their characteristics in the United States. METHODS: A confidential survey addressing patient and staff demographics, administration attributes, examination procedures, and medical and legal issues was mailed to SANE programs in the United States. RESULTS: Sixty-one (66%) of 92 programs responded. More than half of the programs (32/58 [55%]) had been in operation for less than 5 years. Thirty (52%) of the 58 programs performed the initial sexual assault examination in hospital emergency departments. Written consent (57/59 [97%]) was obtained for the initial examination, and most (51/59 [86%]) programs used preprepared commercial sexual assault kits. Program directors were predominately registered nurses. All but one program mandated specific training requirements for their staff, with a median requirement of 80 hours. Procedures used for initial examinations varied; most offered pregnancy testing (56/58 [97%]), pregnancy prophylaxis (57/59 [97%]), and sexually transmitted disease (STD) prophylaxis (53/59 [90%]). HIV testing was not offered in 32 (54%) of 59 programs. Almost all programs used Wood's lamp (51/59 [86%]), colposcopes (42/59 [71%]), and photographs (46/59 [78%]) for documentation. Median time required per patient for initial examination and evidence collection was 3 hours (range, 1 to 8 hours). Follow-up is consistently offered to the survivor. Most programs (45/61 [74%]) could report the number of survivors treated, but few could provide information on survivor medical follow-up or the number of prosecutions by survivors and their outcomes. CONCLUSION: This survey provided an overview of SANE programs. SANE programs are similar across the country with regard to staffing, training, STD and pregnancy prophylaxis, and documentation techniques. They are inconsistent in the use of STD cultures, HIV testing, and alcohol and drug screening. SANE programs were unable to provide data regarding survivor follow-up and legal outcomes. This information is essential to evaluate the programs' effectiveness and to improve performance. The need for better outcome data should be addressed to define success or failure of SANE programs.

Emergency Service, Hospital↗
PubMed2000

Interaction of alpha-melanotropin (alpha-MSH) and noradrenaline in the median eminence in the control of female sexual behavior.

In the present study, we examined the effects of the injection of alpha-melanotropin (alpha-MSH), noradrenaline (NA), and dopamine in the median eminence of ovariectomized-adrenalectomized rats on female sexual behavior. The animals were primed with l0 microg of estradiol benzoate, and 52-54 h later they were injected into the median eminence with either 1 microl of artificial cerebrospinal fluid, 1 microg/rat alpha-MSH, 200 ng/rat NA, 200 ng or 2 microg/rat dopamine, in 1 microl of artificial cerebrospinal fluid. Both alpha-MSH and NA significantly stimulated sexual behavior. This effect was antagonized by two beta-adrenergic antagonists: propranolol (500 ng/rat) and metoprolol (400 ng/rat) applied 15 min before the alpha-MSH or NA. The alpha-adrenergic antagonist prazosine (500 ng/rat) was ineffective in reducing the effect of alpha-MSH. The vehicle and dopamine at both doses had no effect on sexual activity. These results indicate that alpha-MSH and NA in the median eminence stimulate female sexual behavior and that NA mediates the action of alpha-MSH via beta-receptors.

Adrenalectomy↗
PubMed2000

Collagenous fibroma (desmoplastic fibroblastoma): a unique presentation as a goiter in an 88-year-old man.

Collagenous fibroma (desmoplastic fibroblastoma) is a recently described entity in the medical literature. This entity has been reported in various locations, including the upper extremities, posterior neck, upper back, lower extremities, abdominal wall, and hip. We report an interesting case of an 88-year-old man who presented with an apparent goiter involving the right anterolateral neck. Histologic studies revealed a well-circumscribed, paucicellular lesion composed of stellate and spindle-shaped fibroblasts separated by bundles of collagen. No mitotic figures, necrosis, or calcification was observed. The stellate and spindle-shaped cells were positive for vimentin and focally positive for desmin, indicating myofibroblastic differentiation. Our case exemplifies the diagnostic difficulties that these tumors may pose from the clinical and radiologic standpoint when they clinically present as a goiter.

Aged↗
PubMed2000

Molecular mimicry between HLA-DR alleles associated with rheumatoid arthritis and Proteus mirabilis as the Aetiological basis for autoimmunity.

Molecular mimicry is one of the pathological mechanisms proposed to explain the association between microorganisms and autoimmune diseases. This review deals with the association between bacteria and rheumatic diseases with a special emphasis on rheumatoid arthritis where upper urinary tract infection by Proteus mirabilis is the possible cause of this severe, arthritic condition. Prospective trials involving anti-Proteus therapy should be carried out.

Alleles↗
PubMed2000

The effect of ablation sequence and duration on lesion shape using rapidly pulsed radiofrequency energy through multiple electrodes.

Sequences of energy application to multiple electrodes and a study of ablation duration with distal tip and multi-electrode ablations were explored with a radiofrequency controller that distributes energy from a generator to up to 4 electrodes with various duty cycles. In vitro ablations were performed on bovine left ventricle in circulating blood and lesions in goats were performed to verify the in vitro results. All of the ablation sequences with simultaneous electrode activation of contiguous electrodes resulted in deeper lesions than those created in sequence. There was also no scalloping of the lesion if contiguous electrodes were activated simultaneously. During all distal tip ablations, lesion volume and depth was greater after 3 minutes of energy delivery than after 1 minute, but did not increase from 3 minutes to 5 minutes. There was a significant increase in multi-electrode ablation lesion depth with each additional minute in the ablation cycle. The in vivo ablations verified these results at 120 and 300 second ablations. Pulsed energy distal tip ablations resulted in deeper lesions than continuous only if power amplitudes over 50 W were employed. In conclusion, contiguous electrodes in simultaneous use create lesions that resemble one large lesion rather than two lesions positioned next to each other. Multi-electrode ablation lesions continue to grow at ablation durations of up to 5 minutes compared to distal tip lesions which reach steady-state between 1 and 3 minutes. Pulsed energy delivery to distal tips may result in deeper lesions than conventional if high powers are employed.

Animals↗
PubMed2000

The structural basis for molecular recognition by the vitamin B 12 RNA aptamer.

Previous solution structures of ligand-binding RNA aptamers have shown that molecular recognition is achieved by the folding of an initially unstructured RNA around its cognate ligand, coupling the processes of RNA folding and binding. The 3 A crystal structure of the cyanocobalamin (vitamin B12) aptamer reported here suggests a different approach to molecular recognition in which elements of RNA secondary structure combine to create a solvent-accessible docking surface for a large, complex ligand. Central to this structure is a locally folding RNA triplex, stabilized by a novel three-stranded zipper. Perpendicular stacking of a duplex on this triplex creates a cleft that functions as the vitamin B12 binding site. Complementary packing of hydrophobic surfaces, direct hydrogen bonding and dipolar interactions between the ligand and the RNA appear to contribute to binding. The nature of the interactions that stabilize complex formation and the possible uncoupling of folding and binding for this RNA suggest a strong mechanistic similarity to typical protein-ligand complexes.

Base Pairing↗
PubMed2000

Genetic diversity in Proteus mirabilis isolates found in the urinary tract of rheumatoid arthritis patients.

OBJECTIVE: Elevated levels of anti-Proteus antibodies but not antibodies to E. coli have been reported in patients with rheumatoid arthritis (RA). The suggestion has been made that P. mirabilis may have a role in the aetiopathogenesis of rheumatoid arthritis. The aim of this study was to determine whether there are differences at the genetic level inisolates of P. mirabilis obtained from controls and RA patients. METHODS: A blind study was performed whereby P. mirabilis isolates obtained from urinary cultures of RA patients and controls were analysed using RAPD PCR. Isolates were then grouped on the basis of their DNA band profile after agarose gel electrophoresis, thereby allowing the composition of the Proteus population in the urinary tract to be analysed at the genetic level. RESULTS: Fourteen different DNA band profiles were obtained from the 93 isolates tested: 70% of these isolates fell into only five of the 14 groups and approximately 25% of all isolates fell into one group. No differences were observed in the frequency of isolates from either control or RA subjects. CONCLUSIONS: There is genetic diversity in P. mirabilis populations found in the urinary tract, but there are no differences in the frequency of these bacteria between RA patients and controls.

Adult↗
PubMed2000

The effects of atropine and adrenergic antagonists on behavioral arousal in rats.

Two experiments investigated the mechanism for changes in measures of behavioral arousal inhibition in rats following administration of atropine. In Experiment 1, 40-day-old rats were given administrations of atropine sulfate, the alpha-, beta-adrenergic blocker labetalol, or both. The drugs, either alone or in combination, increased transport response intensity, whereas both together increased dorsal immobility durations. In Experiment 2, rats were given atropine, the beta-adrenergic antagonist propranolol, the alpha-adrenergic antagonist phentolamine, or a combination of two of the drugs. Propranolol blocked atropine-induced increases in transport response, and phentolamine was without effect. Phentolamine, when combined with atropine, increased dorsal immobility durations. Results are discussed with respect to aspects common to both transport response and dorsal immobility.

Adrenergic alpha-Antagonists↗
PubMed2000

HLA molecules, bacteria and autoimmunity.

It has been well established that many diseases are linked to HLA antigens. Two of the most interesting HLA associations may provide some insight into the pathogenesis of rheumatic inflammatory conditions. In ankylosing spondylitis (AS), 96% of patients possess HLA-B27, whilst the frequency of this marker in the general population is c. 8%. In rheumatoid arthritis (RA), >90% of patients possess either HLA-DR1 or some subtypes of HLA-DR4, whilst the frequency of this marker in the general population is c. 35%. The association between HLA-B27 and reactive arthritis (ReA) has also been well established. Furthermore, it has been shown that ReA is triggered by infection via the gastrointestinal tract due to Yersinia, Salmonella or Campylobacter spp. and in the genitourinary tract due to chlamydia. In a similar way, microbiological and immunological studies have revealed an association between Klebsiella pneumoniae in AS and Proteus mirabilis in RA. This article reviews the possible pathological implications of the associations between HLA-B27, K. pneumoniae and AS, as well as HLA-DR1/DR4, P. mirabilis and RA.

Arthritis, Rheumatoid↗
PubMed2000

Tris(2-methylphenyl)phosphonium tetrachloroborate.

The title compound, C(21)H(22)P(+).BCl(4)(-), is the first structurally characterized example of the [HP(o-tolyl)(3)](+) cation, presented here with BCl(4)(-) as the counter-ion. The cation has a near-tetrahedral P atom and the BCl(4)(-) anion is near-tetrahedral at boron. There are no unusually short cation-anion contacts.

Journal Article↗
PubMed2000

Being strong: how black West-Indian Canadian women manage depression and its stigma.

PURPOSE: To discover how women from a nondominant cultural background (West Indian) experience and manage depression. DESIGN: Explanatory using grounded theory. METHODS: Semistructured interviews were conducted with 12 Black West-Indian Canadian women who experienced depression. Between 1994 and 1996, the first author engaged in participant observation. FINDINGS: The women used the basic social process they called "being strong" to manage or ameliorate depression. Being strong included "dwelling on it," "diverting myself," and "regaining my composure." For most of the women, the range of available life choices was limited to the three processes; however, a few engaged in "trying new approaches." These women were less limited in their range of cultural and behavioral boundaries than were the others, and began tentatively to explore other options for themselves. CONCLUSIONS: Black West-Indian Canadian women in this study managed their depression in culturally defined ways by being strong and not showing vulnerability. Because being strong was also evident in a previous study of dominant-culture women as a prelude to depression, the process may be widespread in women prone to depression. The findings provide helpful information for intervening in an unfamiliar culture.

Black or African American↗
PubMed2000

How mental illness is portrayed in children's television. A prospective study.

BACKGROUND: There are no published studies concerning the depiction of mental illness in children's television programmes. AIMS: To determine whether mental illness was depicted in children's television. METHOD: Sample of one complete week of children's television (57 hours, 50 minutes; 128 series episodes: 69 cartoon animations, 12 non-cartoon animations, 47 real life) provided for children under the age of 10 years. Disclosure analysis of portrayals of mental illness through repeated viewings identified patterns in the use of linguistic, semiotic and rhetorical resources. RESULTS: Of the 128 episodes, 59 (46%) contained one or more references to mental illness, predominantly in cartoons (n = 47, 80%) compared with other episode types (chi 2 = 17.1, d.f. = 2, P < 0.05). Commonly occurring terms such as 'crazy' (n = 28), 'mad' (n = 19) and 'losing your mind' (n = 13) were employed to denote loss of control. The six consistently mentally ill characters were almost entirely devoid of admirable attributes. CONCLUSION: Young viewers are being socialized into stigmatizing conceptions of mental illness.

Attitude to Health↗
PubMed2000

Leucovorin and fluorouracil with or without oxaliplatin as first-line treatment in advanced colorectal cancer.

PURPOSE: In a previous study of treatment for advanced colorectal cancer, the LV5FU2 regimen, comprising leucovorin (LV) plus bolus and infusional fluorouracil (5FU) every 2 weeks, was superior to the standard North Central Cancer Treatment Group/Mayo Clinic 5-day bolus 5FU/LV regimen. This phase III study investigated the effect of combining oxaliplatin with LV5FU2, with progression-free survival as the primary end point. PATIENTS AND METHODS: Four hundred twenty previously untreated patients with measurable disease were randomized to receive a 2-hour infusion of LV (200 mg/m(2)/d) followed by a 5FU bolus (400 mg/m(2)/d) and 22-hour infusion (600 mg/m(2)/d) for 2 consecutive days every 2 weeks, either alone or together with oxaliplatin 85 mg/m(2) as a 2-hour infusion on day 1. RESULTS: Patients allocated to oxaliplatin plus LV5FU2 had significantly longer progression-free survival (median, 9.0 v 6.2 months; P =.0003) and better response rate (50.7% v 22.3%; P =.0001) when compared with the control arm. The improvement in overall survival did not reach significance (median, 16.2 v 14.7 months; P =. 12). LV5FU2 plus oxaliplatin gave higher frequencies of National Cancer Institute common toxicity criteria grade 3/4 neutropenia (41. 7% v 5.3% of patients), grade 3/4 diarrhea (11.9% v 5.3%), and grade 3 neurosensory toxicity (18.2% v 0%), but this did not result in impairment of quality of life (QoL). Survival without disease progression or deterioration in global health status was longer in patients allocated to oxaliplatin treatment (P =.004). CONCLUSION: The LV5FU2-oxaliplatin combination seems beneficial as first-line therapy in advanced colorectal cancer, demonstrating a prolonged progression-free survival with acceptable tolerability and maintenance of QoL.

Adenocarcinoma↗