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Biomedical subjects

R M Williams

Publications and source records attributed to R M Williams.

At least 55 records · Page 3Linked to original sources
PubMed2000

Attitudes to emotional expression and personality in predicting post-traumatic stress disorder.

OBJECTIVES: To test hypotheses derived from a suggestion of Williams (1989) that negative attitudes towards emotional expression act as a predisposing or maintaining factor for post-traumatic stress reactions following a traumatic event. DESIGN: The study employed a prospective design in which attitudes to emotional expression, the 'Big Five' personality factors (Costa & McCrae, 1992a) and initial symptoms and injury severity within 1 week of a road traffic accident were used to predict the development of post-traumatic stress disorder 6 weeks post-accident. METHOD: Sixty victims of road traffic accidents randomly selected from attenders at a large A&E department were assessed by questionnaire and interview. Measures comprised a 4-item scale relating to emotional expression, standardized scales for intrusion and avoidance features of traumatic experiences, and for anxiety and depression and the NEO-FFI Five Factor Personality Inventory. Forty-five of these participants responded to a postal questionnaire follow-up. In this survey the battery was repeated and also included a self-report diagnostic measure of post-traumatic stress disorder (PTSD). RESULTS: The percentage of the sample meeting DSM-IV diagnostic criteria for PTSD at 6 weeks post-trauma was 30.8%. A small but significant relationship was found for negative attitudes to emotional expression at 1 week to predict intrusive symptoms and diagnosis at 6 weeks, over and above the independent relationships of initial symptoms, initial injury severity, personality and coping. The emotional expression measure was largely stable between the two points of measurement. More negative attitudes to emotional expression were related to less openness, extraversion and agreeableness personality domains. CONCLUSIONS: Some support for the hypotheses was found in relation to the development of PTSD and for the status of attitudes to emotion as a stable trait related to personality factors. The potential importance of attitudes to emotional expression in therapy and other work is discussed.

Adolescent↗
PubMed1999

Mucosal mast cell secretion processes imaged using three-photon microscopy of 5-hydroxytryptamine autofluorescence.

The secretion process of the mucosal mast cell line RBL-2H3 was imaged using infrared three photon excitation (3PE) of serotonin (5-hydroxytryptamine, 5-HT) autofluorescence, a measurement previously difficult because of the technical intractability of deep UV optics. Images of prestimulation 5-HT distributions were analyzed in loaded cell populations (those incubated in a 5-HT-rich medium overnight) and in unloaded populations and were found to be strictly quantifiable by comparison with bulk population high-performance liquid chromatography measurements. Antigenically stimulated cells were observed to characteristically ruffle and spread as granular 5-HT disappeared with no detectable granule movement. Individual cells exhibited highly heterogeneous release kinetics, often with quasi-periodic bursts. Neighboring granule disappearances were correlated, indicative of either spatially localized signaling or granule-granule interactions. In one-half of the granule release events, weak residual fluorescence was visible suggestive of leftover 5-HT still bound to the granule matrix. The terminal stages of secretion (>300 s) consisted primarily of unresolved granules and remainder 5-HT leakage from already released granules.

Animals↗
PubMed1999

Hair removal using the long-pulsed ruby laser.

The long-pulsed ruby laser is a faster, more effective method for the removal of unwanted hair compared to older, temporary techniques like shaving, waxing, and chemical depilation. It is the only laser approved by the FDA for permanent hair removal. Patients experience minimal pain and side effects, observe immediate hair growth delay, an increase in vellus hairs, and have the potential for permanent hair removal. Although treatment sessions can be lengthy, the laser is easy to operate and the cooled handpiece allows patients to easily tolerate long sessions.

Hair Removal↗
PubMed1999

Treatment of facial rhytids with a nonablative laser: a clinical and histologic study.

BACKGROUND: Current facial resurfacing modalities (laser, chemical peels, and dermabrasion) remove the epidermis and thus cause open wounds which carry significant risks and extended recovery periods. The nonablative laser is a novel Nd:YAG system designed to alleviate facial rhytids without injuring the epidermis. This new modality may offer patients rhytid removal without the risk seen in currently used resurfacing techniques. OBJECTIVE: To describe a novel nonablative laser system and assess its safety profile and efficacy. METHODS: Ten patients received laser treatments of their periocular rhytids and postauricular skin. Clinical variables (rhytid severity, hyperpigmentation, hypopigmentation, scarring, and level of discomfort) were assessed at 1 and 3 months posttreatment. Postauricular skin biopsies were taken both pre- and posttreatment for histologic analysis. RESULTS: Patient discomfort was minimal. Three months posttreatment, 4 of 10 patients showed a one-point improvement in periocular rhytid severity when judged on a six-point scale. The results were not statistically significant. Biopsy analysis showed a small posttreatment increase in the amount of dermal collagen in three patients. A small decrease in collagen was noted in one patient. Three patients also showed a small posttreatment increase in the degree homogenization of dermal collagen. No change from baseline was noted in other assessed histologic parameters. Complications observed included hyperpigmentation in three patients and pitted scarring in three patients. CONCLUSIONS: The nonablative laser gave clinically subtle and statistically insignificant improvement in rhytid severity. Unfortunately its use was associated with complications that included hyperpigmentation and scarring. This technology may eventually offer patients a new resurfacing option, but its efficacy and complication rate must be improved first.

Adult↗
PubMed1999

Hair removal using an 810 nm gallium aluminum arsenide semiconductor diode laser: A preliminary study.

BACKGROUND: Laser hair removal is a popular treatment method for removing unwanted hair. Several laser systems are available for laser hair removal. The gallium aluminum arsenide semiconductor diode (GAASD) laser is one of the newer laser modalities to be studied. OBJECTIVE: To evaluate the efficacy of the GAASD laser system in removing unwanted hair. METHODS: Twenty-six patients with brown or black hair growth were treated with the GAASD laser at fluences of 20-80 J/cm2. Hair regrowth was measured 4 weeks after the first treatment, 4 weeks after the second treatment, 4 weeks after the third treatment, and 4 weeks, 8 weeks, and 8 months after the fourth treatment. CONCLUSION: GAASD laser treatment resulted in hair growth delay in all treated regions. Repeated laser treatments did not produce an increased number of vellus hairs. The percentage of hair reduction fluctuated between 5% and 13% with the second or third treatment averaging the highest percent reduction. In all cases, the percentage of hair reduction of the treatment sites evaluated at 8 months after the fourth treatment was less than both the second and third treatments (highest average percent reduction) and the fourth (last) treatment.

Adult↗
PubMed1999

Effect of adrenocorticotrophic hormone on sodium appetite in mice.

A main vector of the effects of stress is secretion of corticotrophin releasing factor (CRF), adrenocorticotrophin (ACTH), and adrenal steroids. Systemic administration of ACTH (2.8 microgram/day sc) for 7 days in BALB/c mice caused a very large increase of voluntary intake of 0.3 M NaCl equivalent to turnover of total body sodium content each day. Intracerebroventricular infusion of ACTH (20 ng/day) had no effect. Intracerebroventricular infusion of ovine CRF (10 ng/h for 7 days) caused an increase of sodium intake. The large sodium appetite-stimulating effect of systemic ACTH was not influenced by concurrent systemic infusion of captopril (2 mg/day). Induction of stress by immobilization of mice on a running wheel caused an increase in Na appetite associated with a 50% decrease of thymus weight, indicative of corticosteroid effects. The present data suggest that stress and the hormone cascade initiated by stress evoke a large sodium appetite in mice, which may be an important survival mechanism in environmental conditions causing stress.

Adrenocorticotropic Hormone↗
PubMed1998

Biomimetic Diels-Alder cyclizations for the construction of the brevianamide, paraherquamide, sclerotamide, asperparaline and VM55599 ring systems.

A potentially bio-mimetic Diels-Alder cyclization to construct the bicyclo[2.2.2] ring system common to the paraherquamides, marcfortines, sclerotamides, brevianamides, VM55599, and asperparaline is reported. Epi-deoxybrevianamide E (22) is converted into the corresponding lactim ether (23) and then oxidized with DDQ to provide an azadiene (24) which is tautomerized in the presence of base to azadiene 25 which, spontaneously cyclizes to give a 2:1 mixture of cycloadducts 26 and 27. These cycloadducts are each in turn, converted into D,L-C-19-epi-brevianamide A (20) and D,L-brevianamide B (6). The stereochemical implications of the [4 + 2] cycloaddition is discussed in the context of a working hypothesis on the biosynthesis of this family, particularly VM55599.

Alkaloids↗
PubMed1998

A new approach to measuring recovery in injured workers with acute low back pain: Resumption of Activities of Daily Living Scale.

BACKGROUND AND PURPOSE: Spontaneous recovery, job satisfaction, and multiple other factors make return to work a highly problematic indicator. Available client questionnaires fail to consider what was "normal" or "usual" prior to low back injury. Based on themes described by injured persons, we suggest a new approach to determining "recovery"--the Resumption of Activities of Daily Living (RADL) Scale. SUBJECTS: Injured persons and their therapists from 8 different clinics participated in the study. METHODS: Twenty subjects completed the RADL twice, about 2 days apart, for assessment of test-retest reliability. The RADL was administered, along with other questionnaires, to a separate group of 94 subjects at clinic entry and at discharge or 3 weeks after clinic entry. Both subjects and clinicians made baseline predictions concerning return to work and global ratings of improvement and ability to return to work at follow-up. RESULTS: The RADL showed good psychometric properties (i.e., test-retest reliability, internal consistency, responsiveness to change, and discriminative abilities). CONCLUSION AND DISCUSSION: The RADL provides a new, standardized measure for assessing the extent of recovery from the time of injury to initiation of treatment, and concurrent with the course of treatment, using the individual's customary level of functioning as the benchmark.

Activities of Daily Living↗
PubMed1998

Functional Abilities Confidence Scale: a clinical measure for injured workers with acute low back pain.

BACKGROUND AND PURPOSE: The Functional Abilities Confidence Scale (FACS) measures self-confidence concerning various movements and postures affected by low back pain (LBP). This article describes the scale's development, based on qualitative themes suggested by clinicians and patients, and its psychometric properties. SUBJECTS: People with work-related LBP injuries and clinicians from 8 different rehabilitation clinics participated in the study. METHODS: A group of 20 subjects completed the FACS twice, about 2 days apart, for assessment of test-retest reliability. The FACS was also administered, together with other measures, to a separate group of 94 subjects at clinic entry and at discharge or 3 weeks after clinic entry for validity testing. Clinicians rated each subject's physical abilities at each point. RESULTS: The FACS showed good psychometric properties (i.e., test-retest reliability, internal consistency, responsiveness to change, discriminant abilities, and convergent validity). CONCLUSION AND DISCUSSION: The FACS is a measure that has potential use in guiding therapists in determining a person's initial level of confidence and in monitoring progress during the rehabilitation process.

Activities of Daily Living↗
PubMed1998

The StpA protein functions as a molecular adapter to mediate repression of the bgl operon by truncated H-NS in Escherichia coli.

The mechanism of repression of the beta-glucoside utilization (bgl) operon of Escherichia coli by a carboxy-terminally truncated derivative of the nucleoid-associated protein H-NS which is defective in DNA binding was investigated. The DNA-binding function of the H-NS-like protein StpA was found to be necessary for repression, which is consistent with a role for StpA as a DNA-binding adapter for mutant derivatives of H-NS.

Amino Acid Transport Systems↗
PubMed1998

Stimulated release of fluorescently labeled IgE fragments that efficiently accumulate in secretory granules after endocytosis in RBL-2H3 mast cells.

Sensitization of RBL-2H3 mast cells with monomeric fluorescein-5-isothiocyanate (FITC)-labeled immunoglobulin E (IgE) results in slow but highly efficient accumulation of labeled IgE fragments in a pool of acidic peripheral vesicles that are visible by fluorescence microscopy after raising endosomal pH with ammonium chloride. Stimulation of cells containing these FITC-IgE fragments by aggregation of high affinity receptors for IgE (FcepsilonRI) or by Ca2+ ionophore and phorbol 12-myristate 13-acetate results in release of FITC fluorescence from the cells, which can be monitored continuously with a spectrofluorometer. The fluorescence release process corresponds to cellular degranulation: it is prevented under conditions that prevent stimulated beta-hexosaminidase release, and these two processes exhibit the same antigen dose-dependence and kinetics. Pulse-chase labeling reveals that aggregation of FITC-IgE bound to FcepsilonRI at the cell surface causes internalization and delivery to the regulated secretory vesicles with a high efficiency similar to monomeric IgE-FcepsilonRI, but more rapidly. Binding of Cy3-modified IgE to FcepsilonRI results in labeling of the same secretory vesicles as in FITC-IgE-sensitized cells, and these Cy3-labeled vesicles can be observed by fluorescence microscopy without neutralization of intracellular compartments. Simultaneous three-photon microscopy of serotonin fluorescence and two-photon microscopy of Cy3 fluorescence reveals that these Cy3-labeled vesicles coincide with serotonin-labeled secretory granules. After stimulation of the cells via aggregation of IgE-FcepsilonRI or addition of Ca2+ ionophore and phorbol 12-myristate 13-acetate, depletion of the Cy3 label from the intracellular vesicles is observed with confocal microscopy. These results provide strong evidence for the lysosomal nature of secretory granules in these cells. In addition, they provide the basis for a direct, real-time method for monitoring single cell degranulation.

Animals↗
PubMed1998

Synthesis and antimicrobial evaluation of TAN-1057A/B analogs.

TAN-1057A-D, dipeptides isolated from bacteria Flexibacter sp. PK-74 and PK-176, are new antibiotics with potent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). We describe, in detail, the synthesis of several TAN-1057A/B analogs by a convergent route featuring a new method to construct the cyclic amidinourea functional group. The biological activity of these substances against methicillin-resistant Staphylococcus aureus (MRSA) is reported.

Anti-Bacterial Agents↗
PubMed1998

Structural volume changes upon photoisomerization of the bilirubin-albumin complex: a laser-induced optoacoustic study.

The Z-->E photoisomerization of the 1:1 complexes of human serum albumin (HSA) and several bilirubins (BR-IX alpha, -III alpha, meso-IX alpha and a mixture of -IX alpha, -III alpha and XIII alpha) affords in every case an almost negligible structural volume change (delta VR approximately 0) within detection limits (i.e. less than 2-4 cm3/mol for this isomerization with very low quantum yield) as determined by laser-induced optoacoustic spectroscopy. Based on previous model studies of photoisomerizations in aqueous environment, this negligible small change is interpreted as indicating that the part of the molecule undergoing photoisomerization is not exposed to water but is located in a hydrophobic protein cavity that shields the molecule from the aqueous medium. The BR-protein interaction within this cavity seems to be very loose in view of the small structural volume change observed. The energy difference between the Z and E isomers of the BR-HSA complexes was estimated to be less than 4 kJ/mol, probably close to zero (delta H approximately 0).

Bilirubin↗
PubMed1997

Molecular aspects of the E. coli nucleoid protein, H-NS: a central controller of gene regulatory networks.

The nucleoid-associated protein H-NS has a central role in the structuring and control of the enteric bacterial chromosome. This protein has been demonstrated to contribute to the regulation of expression for approximately thirty genes. In this article, the molecular aspects of H-NS structure and function are briefly reviewed. H-NS contains at least two independent structural domains: a C-terminal domain, involved in the DNA-protein interactions, and a N-terminal domain, likely involved in protein-protein interactions. Recent reports have revealed that H-NS is a key factor in a multi-component gene regulatory system. Factors have now been discovered which can backup or antagonise H-NS action at certain promoters. These recent findings are summarised and discussed in relationship to the role of H-NS in DNA packaging and nucleoid structure.

Bacterial Proteins↗
PubMed1997

Measuring serotonin distribution in live cells with three-photon excitation.

Tryptophan and serotonin were imaged with infrared illumination by three-photon excitation (3PE) of their native ultraviolet (UV) fluorescence. This technique, established by 3PE cross section measurements of tryptophan and the monoamines serotonin and dopamine, circumvents the limitations imposed by photodamage, scattering, and indiscriminate background encountered in other UV microscopies. Three-dimensionally resolved images are presented along with measurements of the serotonin concentration ( approximately 50 mM) and content (up to approximately 5 x 10(8) molecules) of individual secretory granules.

Animals↗