Selenium protects primary human keratinocytes from apoptosis induced by exposure to ultraviolet radiation.

The generation of reactive oxygen species has been implicated in ultraviolet radiation (UVR)-induced skin damage. In mice, increasing dietary selenium intake protects skin from UVR-induced DNA damage and photocarcinogenesis. We sought to determine whether selenium supplementation could protect keratinocytes from apoptosis resulting from exposure to broadband (TL20W/12) UVR. Unirradiated cultures contained 6.5 +/- 1% apoptotic cells; the maximum percentage of apoptotic cells (34 +/- 5%) was seen 16 h after UVR of 600 J/m(2). Under these conditions cell death from necrosis was 15 +/- 2.5% of the total cells. A 24-h preincubation with sodium selenite (10 nm(-1) microm) or selenomethionine (50 nm(-1) microm) protected cultured human keratinocytes from UVR-induced apoptosis. In primary keratinocytes the greatest reduction in apoptosis was found with 100 nm of either selenium compound (71% reduction in the numbers of total apoptotic cells; P < 0.01). Supplementation with 100-200 nm selenite or selenomethionine prevented UVR-induced apoptosis, but did not decrease the levels of UVR-induced p53, as measured by Western blotting. Collectively, this data suggests that selenium prevents UVR-induced cell death by inhibiting p53-independent cell death pathways.

Effects of selenium compounds on induction of DNA damage by broadband ultraviolet radiation in human keratinocytes.

Background Ultraviolet radiation (UVR), a ubiquitous environmental genotoxin for the skin, produces DNA damage. The trace element selenium induces synthesis of the glutathione peroxidase and thioredoxin reductase enzyme families. These selenoenzymes detoxify a range of toxic compounds generated by free radicals. Objectives To assess the effects of pretreatment of primary human keratinocytes with selenium on UVR-induced DNA damage. Methods Cells were irradiated with UVR from FS-20 lamps and were subjected to comet assay. Results Comet tail length due to UVR-induced T4 endonuclease V-sensitive sites (caused by cyclopyrimidine dimers, CPDs) increased to 35 +/- 4.5 microm (mean +/- SD) immediately after irradiation (time 0 h, 100%). After 4 h, 68% of the damage remained and after 24 h, 23% of the damage was still present. Treatment with up to 200 nmol L-1 selenomethionine or 50 nmol L-1 sodium selenite had no effect on CPD formation or rates of repair, or on the number of excision repair sites as measured by cytosine arabino furanoside and hydroxyurea treatment. However, selenite and selenomethionine protected against oxidative damage to DNA as measured by formation of formamidopyrimidine (FaPy) glycosylase-sensitive sites, which are indicative of 8-hydroxy-2-deoxyguanosine photoproduct formation. In this assay, irradiation of keratinocytes increased mean +/- SD glycosylase-specific comet tail length from 5 +/- 1.5 microm to 19 +/- 3.3 microm. Preincubation for 18 h with 50 nmol L-1 selenite abolished the UVR-induced increase in comet length. Preincubation with 200 nmol L-1 selenomethionine was similarly protective. Conclusions Selenite and selenomethionine protect keratinocytes from UVR-induced oxidative damage, but not from formation of UVR-induced excision repair sites.

Inhibition of ultraviolet B radiation-induced interleukin 10 expression in murine keratinocytes by selenium compounds.

BACKGROUND: Selenium is an essential trace nutrient necessary for the normal function of the immune system. Selenium compounds protect mice against ultraviolet (UV) B-induced tumours, probably by preventing oxidative damage to the host skin cells and to the host immune system. One possible mechanism of protection is that selenium can prevent oxidative stress-induced release of cytokines such as interleukin (IL)-10, which could suppress cell-mediated immunity. OBJECTIVES: To determine whether selenium compounds can inhibit UVB induction of IL-10 protein in murine keratinocytes. METHODS: The murine keratinocyte cell line PAM 212 was treated with or without selenomethionine (50-200 nmol L-1) or sodium selenite (1-50 nmol L(-1)) for 24 h before exposure to 200 J m(-2) UVB. The cells were stained with an antibody to IL-10, 24 h after irradiation. RESULTS: Preincubation with both selenium compounds inhibited UVB induction of IL-10 immunostaining, although selenomethionine was more effective. Pretreatment with 200 nmol L(-1) selenomethionine decreased IL-10 immunostaining to levels seen in the unirradiated controls. CONCLUSIONS: The protective effects of selenium against UVB-induced skin cancer in murine models may result, in part, from its ability to inhibit release of cytokines that are capable of suppressing cell-mediated immunity.

cis-Urocanic acid does not induce the expression of immunosuppressive cytokines in murine keratinocytes.

trans-Urocanic acid (UCA) acts as a chromophore for UV radiation in the epidermis and isomerizes to cis-UCA which then initiates some of the changes leading to UV-induced immunosuppression. The mechanism of the immunomodulation by cis-UCA is unknown at present, but one possibility is that the interaction between cis-UCA and keratinocytes causes the release of immunosuppressive cytokines locally. To test this hypothesis, PAM-212 cells, a murine keratinocyte cell line, were incubated with 0.10-100 micrograms/mL trans- and cis-UCA for 6 or 24 h, respectively. The expression of interleukin (IL)-10, transforming growth factor (TGF)-beta and tumor necrosis factor (TNF)-alpha messenger RNA (mRNA) was then measured by reverse transcription-polymerase chain reaction in comparison with the mRNA for the house-keeping gene, beta-actin. No change or significant induction of any of the cytokine messages occurred. However, the expression of IL-10 messenger RNA (mRNA) was induced 24 h after UVB irradiation (300 J/m2) and that of TNF-alpha mRNA occurred 6 h after treatment with phorbol myristate acetate. The expression of IL-10 protein was also examined by immunostaining in both PAM-212 cells and B16-F10 murine melanoma cells between 3 and 48 h after incubation with 10 and 100 micrograms/mL cis- and trans-UCA. No alteration was seen with either isomer at either concentration. In contrast, UVB irradiation of both cell lines resulted in a marked increase in intracellular IL-10 protein at 24 and 48 h. Therefore the upregulation of the immunosuppressive cytokines, IL-10, TNF-alpha and TGF-beta, in keratinocytes is unlikely to be the mechanism by which cis-UCA induces immunosuppression in mice.

Deliberate self-poisoning presenting at a rural hospital in Northern Ireland 1976-1996: relationship to prescribing.

PURPOSE: This study reports on a project to monitor deliberate self-poisoning in a rural area of Northern Ireland over a 20-year period. Comparison is made with reports from large urban centres. In addition, a local prescribing database allows assessment of any association between psychotropic drug prescription and use for deliberate self-poisoning. MATERIALS AND METHODS: Frequency of self-poisoning, demographic details and drugs used were recorded for all episodes of deliberate self-poisoning occurring at Craigavon Area Hospital for the years 1976, 1986, 1991 and 1996. It was possible to compare prescriptions of psychotropic drugs with their use for deliberate self-poisoning between the years 1991 and 1996 in the region served by the hospital, using the Defined Daily Dose (DDD) system. RESULTS: In this rural area the pattern of deliberate self-poisoning has changed, as in urban centres, with a rise in frequency and the male/female ratio approaching unity. The pattern of drug use has altered, with paracetamol overtaking benzodiazepines as the most commonly used agent. More recently, antidepressants have become the second most frequently used drug class for this purpose. Psychotropic medications used for self-poisoning altered in proportion to their prescription between the years 1991 and 1996. CONCLUSIONS: In the face of a continuing rise in deliberate self-poisoning, which is effecting both urban and rural areas, care should be taken to prescribe the least toxic agent available as this is associated with likely frequency of self-poisoning for most classes of psychotropic drug.

Field-by-field evaluation of intraoperative transoesophageal echocardiography interpretative skills.

A quality assurance system is essential for the credibility and structured growth of anaesthesiology-based transoesophageal echocardiography (TEE) programmes. We have developed software (Q/A Kappa), involving a 400-line source code, capable of directly reporting kappa correlation coefficient values, using external reviewer interpretations as the 'gold standard', and thereby allowing systematic assessment of the validity of intraoperative echocardiographic interpretation. This paper presents assessment of the validity of 240 intraoperative anaesthesiologists' echocardiographic interpretations, and, in addition, the results of field testing of this prototypical software. Data, derived from consecutive cardiac surgery patients, consisted of standardized two-dimensional transoesophageal echocardiographic, colour flow and Doppler imaging sequences. Intraoperative and off-line 'gold standard' TEE interpretations were compared for 19 fields or variables using the Q/A Kappa program. The kappa correlation coefficients were highly variable and dependent on the examination field, ranging from 0.08 for apical regional wall motion scores to 1.00 for tricuspid regurgitation grade, left atrial measurement, aortic valve anatomy and left ventricular long axis and short axis global function. The correlation coefficients were also operator dependent. These data (480 interpretations) were also manually integrated into the equation required for calculation of values of the variable kappa correlation coefficient. The relationship between Q/A Kappa-derived values and manually calculated values was highly significant (p < 0.001; r = 1.0). The implications and possible explanations of the results for particular examination fields are discussed. This study also demonstrates successful seamless functioning of this software program from data entry, segmentation into tables and valid statistical analysis. These findings suggest that it is practical to provide sophisticated continuous quality improvement TEE data on a routine basis.

Differential expression of selenoproteins by human skin cells and protection by selenium from UVB-radiation-induced cell death.

The generation of reactive oxygen species has been implicated as part of the mechanism responsible for UVB-radiation-induced skin damage. In mice, evidence suggests that increased dietary selenium intake may protect skin from many of the harmful effects of UVB radiation. We sought to determine the selenoprotein profile of cultured human skin cells and whether selenium supplementation could protect keratinocytes and melanocytes from the lethal effects of UVB radiation. Labelling experiments using [75Se]selenite showed qualitative and quantitative differences in selenoprotein expression by human fibroblasts, keratinocytes and melanocytes. This was most noticeable for thioredoxin reductase (60 kDa) and phospholipid glutathione peroxidase (21 kDa); these proteins were identified by Western blotting. Despite these differences, we found that a 24 h preincubation with sodium selenite or selenomethionine protected both cultured human keratinocytes and melanocytes from UVB-induced cell death. With primary keratinocytes, the greatest reduction in cell death was found with 10 nM sodium selenite (79% cell death reduced to 21.7%; P<0.01) and with 50 nM selenomethionine (79% cell death reduced to 13.2%; P<0.01). Protection could be obtained with concentrations as low as 1 nM with sodium selenite and 10 nM with selenomethionine. When selenium was added after UVB radiation, little protection could be achieved, with cell death only being reduced from 88.5% to about 50% with both compounds. In all of the experiments sodium selenite was more potent than selenomethionine at providing protection from UVB radiation.

Multiplane transesophageal echocardiography: a basic oblique plane patient imaging sequence.

We have previously reported a standardized 10-step sequence of monoplane (transverse plane) transesophageal two-dimensional echocardiographic views and a standardized 7-step vertical plane examination, both suitable for expeditious intraoperative use by the beginning practitioner. A multiplane transesophageal examination involves transverse plane views, vertical plane views and the remaining "in-between" oblique plane views. This report describes a sequence of specific oblique views to be used as a framework for the completion of a multiplane transesophageal examination. Each of these steps is illustrated with a two-dimensional echocardiographic image, a matching diagram and a schematic representation of the corresponding axis of interrogation. This description of oblique plane imaging, therefore, completes the components of a multiplane transesophageal examination.

Transesophageal echocardiographic imaging workshop: a basic transverse plane examination sequence.

This workshop describes a 10-step sequence of transverse plane two-dimensional transesophageal echocardiographic views of the heart and great vessels that constitutes a basic standardized examination capable of being performed by a beginning practitioner.

How has fundholding in Northern Ireland affected prescribing patterns? A longitudinal study.

OBJECTIVE: To compare prescribing patterns in general practices before and after the introduction of fundholding in April 1993 to determine whether fundholding changed prescribing patterns among practices that joined the scheme. DESIGN: Analysis of prescribing data from the Drug Utilisation Research Unit's database for all practices in Northern Ireland during April 1989 to March 1996. SETTING: Northern Ireland. SUBJECTS: 23-first wave fundholders, 34 second wave fundholders, 9 third wave fundholders, and 268 non-fundholders. MAIN OUTCOME MEASURES: Prescribing costs per 1000 patients, prescription items per 1000 patients, average cost per item, and rate of generic prescribing. RESULTS: Prescribing costs and frequency increased in all groups throughout the study. Among the fundholders the rate of increase in costs after fundholding was significantly lower than among non-fundholders. The rate of increase in cost per item fell, coinciding with a significant increase in the rate of generic prescribing. However, with regard to first wave fundholders, their yearly increase in costs in their third year as fundholders (1995-6) was similar to that of the non-fundholders. The earlier practices that joined the scheme seemed to differ in some important respects from those that joined later. CONCLUSIONS: After fundholders joined the fundholding scheme their patterns of prescribing changed compared with those of non-fundholders: the rate of increase in costs fell and there was a significant rise in the rate of generic prescribing.

Temporal trends in drug use in one UK region, revealed by chemical group matching.

(1) The pharmaceutical pricing data for Northern Ireland were amended to include defined daily dosages (DDD) for all single chemical entities. Eight therapeutic groups were studied: antiasthmatics, antidepressants, antimicrobials, benzodiazepines, hormone replacement therapy (HRT), hypoglycaemics, lipid-lowering agents and ulcer-healing drugs. Each group was then subdivided into its main chemical groups. The regional use of each chemical group was defined as the combined DDDs of its individual chemical entities per quarter year, from January 1989 until December 1994. (2) During this period, drug use increased in all eight therapeutic groups and in most of their constituent chemical groups. Increased use of newer drugs did not cause the expected decrease in use of established drugs. Use of all broad-spectrum antimicrobials increased by 314%. Use of sedative benzodiazepines decreased slowly and steadily (16%) throughout the study period but use of all hypnotics increased inexplicably by 21% in 1992 reaching a plateau in 1993 and 1994. SSRI antidepressant use increased sharply (5333%) following their introduction in 1989, accompanied by a 24% increase in use of tricyclic antidepressants. There was a 23,626% increase in the use of proton pump inhibitors and a smaller but steady increase of 38% in use of histamine H(2) antagonists; it is unlikely that much of the prescribing of anti-ulcer and antimicrobials was accurately targeted and rationally defensible. (3) More positively, use of beta(2)-agonist inhalers increased by 45% despite a 254% increase in the use of inhaled steroids. Use of HRT increased by 389% though evidence of under-use is given. There was a steady increase in the use of both insulins (28%) and oral hypoglycaemics (34%). The use of 'statins' (690%) and fibrates (123%) increased. (4) The possible interpretations and implications of these patterns of drug use is discussed, together with their potential as proxies for morbidity incidence in the community.

Validation of a test of competence in transesophageal echocardiography.

OBJECTIVE: A test was developed that is based on intraoperative findings to evaluate knowledge of intraoperative echocardiography. This study examines the performance of attending anesthesiologists and residents at various levels of training in order to validate the test's ability to measure physician competence in intraoperative echocardiographic diagnosis. DESIGN: This study was a prospective evaluation of a test of competence in transesophageal echocardiography. SETTING: Two university medical centers. PARTICIPANTS: Volunteer anesthesia faculty and residents. INTERVENTIONS: The participants took an echocardiographic examination that consisted of 34 "K"-type multiple-choice questions and a 45-second video-loop sequence for each question. The video sequences were chosen for their high quality and unambiguous representation of both normal and pathologic images obtained by transverse transesophageal echocardiographic imaging. The questions were written by experienced echocardiographers. The test was administered to 25 individuals at two academic institutions: 11 residents with minimal transesophageal echocardiography exposure and 14 faculty who were relatively experienced with transesophageal echocardiography. All of the residents repeated the examination at the end of their third clinical anesthesia year, which included transesophageal echocardiography training. The differences between the groups' scores were analyzed using the Kruskal-Wallis test and Wilcoxon's rank-sum test. To correct for the multiple comparisons, p < 0.025 was deemed significant. MEASUREMENTS AND MAIN RESULTS. Before their transesophageal echocardiography training, the residents scored significantly lower than the faculty (p < 0.002). After 1 year of training, their scores significantly increased (p = 0.021), and their scores were not significantly different from the faculty level (p = 0.052). CONCLUSIONS: Test performance differed according to level of experience. This suggests that the test is a valid measure of intraoperative transesophageal echocardiography competence.

Intraoperative transesophageal two-dimensional echocardiography: a basic vertical plane patient examination sequence.

We have previously reported a standardized stepwise transesophageal echocardiography transverse plane (monoplane) patient examination sequence suitable for intraoperative use. Biplane transesophageal echocardiography furnishes images of the heart and great vessels in both transverse and vertical planes. This report describes a seven-step vertical plane examination, the completion component of a comprehensive intraoperative biplane evaluation. Each step is illustrated by presentation of a two-dimensional echocardiographic image, a matching diagram and a schematic representation of the corresponding axis of interrogation. Examples of clinical presentations complete the report.

A 'compass' for general practitioner prescribers.

This paper records the result of research and development in interrogating a general practitioner prescription pricing database to provide customised analysis for every practice. The system 'COMPASS' (Computerised On-line Monthly Prescribing Analysed for Science and Stewardship) is described, and identifies instances where each practice might improve cost-effectiveness and scientific rationality in prescribing. One hundred and two such instances are interrogated. This initial COMPASS report is then supplemented by screening the database to show a practice's: 1. range of drugs used--an excessive range should be discouraged. 2. use of drugs often used imprecisely--eg, antibiotics. 3. predicted prescribing cost--based on practice demography. 4. use of drugs with very limited GP value--eg, peripheral vasodilators. Northern Irish fundholding general practitioners are finding COMPASS valuable in planning improvement in cost-effectiveness and quality.

A clinical computer database entry form for an intraoperative anesthesiology-based transesophageal echocardiography monitoring service.

Transesophageal echocardiography (TEE) has been increasingly applied to supplement and, in instances, to supplant conventional intraoperative cardiac monitoring. Our body of experience (> 1600 intraoperative TEE procedures), combined with insights gleaned from an intramural quality assurance study, and clinical implications of certain recent advances in the field, led us to develop the following TEE computer database entry form. The form, completed intraoperatively, consists of a patient and surgical procedure demographics section, followed by fields based on the TEE examination. The scans encompass transverse plane basal short axis, long axis, and transgastric views of the heart and great vessels. The two-dimensional echocardiographic, saline-contrast, color flow and pulsed Doppler data represent both right and left ventricular performance, valvular function and specific lesions. This database entry form is intended to serve as a guide for performance of a nominally complete intraoperative study and facilitate maintenance of a TEE archive consistent with current advances.

An integrated software system for quality assurance-related kappa coefficient analysis of intraoperative transesophageal echocardiography interpretive skills.

This report describes the development of a quality assurance-oriented integrated software system designed for an anesthesiology-based intraoperative transesophageal echocardiography service. Entry data include patient and operation demographics, two-dimensional echocardiographic, saline-contrast, and color flow/pulsed Doppler assessments of the heart and great vessels, presented in a defined sequence. A statistical analysis component (kappa coefficient analysis) allows for comparison of intraoperative real-time interpretations with laboratory interpretations made by experienced full-time echocardiographers on a field-by-field basis. This provides a means of quantifying expertise in each individual aspect of the patient examination sequence. We believe that such self-appraisal data are essential for delineating the status and tracking the progress of service being provided.

Intraoperative two-dimensional echocardiography and color flow Doppler imaging: a basic transesophageal single plane patient examination sequence.

Recent advances in technology have allowed application of transesophageal echocardiography to intraoperative care of critically ill patients. Early clinical application primarily involved evaluation of left ventricular regional wall motion. However, valid intraoperative use of transesophageal echocardiography should also encompass systematic assessment of the entire heart as well as the great vessels. This report describes a 10-step sequence of single plane, two-dimensional echocardiographic views which constitute a basic patient examination capable of being performed by a practitioner whose primary responsibility is the delivery of anesthesia care. A 5-step color flow Doppler examination sequence is also presented. These views complement the two-dimensional echocardiographic steps. Representations of methods for grading Doppler-defined valvular regurgitation complete the report.

Transoesophageal echocardiographic assessment of haemodynamic function during laparoscopic cholecystectomy.

We have measured cardiovascular changes associated with insufflation of carbon dioxide and the reverse Trendelenburg position during laparoscopic cholecystectomy, using transoesophageal echocardiography in 13 healthy patients. End-tidal carbon dioxide values increased after insufflation of carbon dioxide, with values significantly (P < 0.05) increased after lateral tilt positioning. Creation of a pneumoperitoneum was associated with increases (P < 0.05) in left ventricular end-systolic wall stress, concomitant with increases (P < 0.01) in peak airway pressure and systemic arterial pressure. In addition, left ventricular end-diastolic area decreased (P < 0.05) after reverse Trendelenburg positioning. Left ventricular ejection fraction was maintained throughout the study.