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Biomedical subjects

W P Arnold

Publications and source records attributed to W P Arnold.

At least 19 recordsLinked to original sources
PubMed1998

Multicenter study of contaminated percutaneous injuries in anesthesia personnel.

BACKGROUND: Anesthesia personnel are at risk for occupational infection with bloodborne pathogens from contaminated percutaneous injuries (CPIs). Additional information is needed to formulate methods to reduce risk. METHODS: The authors analyzed CPIs collected during a 2-yr period at 11 hospitals, assessed CPI underreporting, and estimated risks of infection with human immunodeficiency virus and hepatitis C virus. RESULTS: Data regarding 138 CPIs were collected: 74% were associated with blood-contaminated hollow-bore needles, 74% were potentially preventable, 30% were considered high-risk injuries from devices used for intravascular catheter insertion or obtaining blood, and 45% were reported to hospital health services. Corrected for injury underreporting, the CPI rate was 0.27 CPIs per yr per person; per full-time equivalent worker, there were 0.42 CPIs/yr. The estimated average 30-yr risks of human immunodeficiency virus or hepatitis C virus infection per full-time equivalent are 0.049% and 0.45%, respectively. Projecting these findings to all anesthesia personnel in the United States, the authors estimate that there will be 17 human immunodeficiency virus infections and 155 hepatitis C virus infections in 30 yr. CONCLUSIONS: Performance of anesthesia tasks is associated with CPIs from blood-contaminated hollow-bore needles. Thirty percent of all CPIs would have been high-risk for bloodborne pathogen transmission if the source patients were infected. Most CPIs were potentially preventable, and fewer than half were reported to hospital health services. The results identify devices and mechanisms responsible for CPIs, provide estimates of risk levels, and permit formulation of strategies to reduce risks.

Anesthesiology↗
PubMed1996

Percutaneous injuries in anesthesia personnel.

Anesthesia personnel are at risk for occupationally acquired blood-borne infections from human immunodeficiency virus, hepatitis viruses, and others after percutaneous exposures to infected blood or body fluids. The risk is greater after an infected, blood-contaminated, percutaneous injury, especially from a hollow-bore blood-filled needle, than from other types of exposures. Few data are available on the specific occupational hazards to anesthesia personnel from needles and other sharp devices. Fifty-eight percutaneous injuries (PIs) from anesthesia personnel in nine hospitals were analyzed. Thirty-nine of 58 PIs were from contaminated devices (all needles), and 19 were from uncontaminated devices or of unknown contamination status. Forty-three percent of contaminated percutaneous injuries (CPI) were classified as moderate (some bleeding) or severe (deep injury with profuse bleeding), and most were to health-care workers' hands. Fifty-nine percent of CPI were potentially preventable. Eighty-seven percent of CPI were from hollow-bore needles, and 68% of these were potentially preventable. The largest categories of devices causing CPI were needle on syringe, intravenous (i.v.) or arterial catheter needle-stylet, suture needle, and standard hollow-bore needle for secondary i.v. infusion. Most CPI occurred between steps of a multistep procedure (8%), were recapping related (13%), or occurred at other times after use (41%). No CPI were reported from use of needlestick-prevention safety devices. The devices and mechanisms of injury identified in this study provide specific data that may lead to prevention strategies to reduce the risk of PI.

Anesthesiology↗
PubMed1995

Levels of skin-derived antileukoproteinase (SKALP)/elafin in serum correlate with disease activity during treatment of severe psoriasis with cyclosporin A.

The epidermal serine proteinase inhibitor SKALP (also known as elafin), directed against human leukocyte elastase and proteinase 3, is strongly induced in suprabasal keratinocytes during inflammation. The presence of SKALP/elafin in urine has been demonstrated for several inflammatory skin disorders, such as psoriasis, erythroderma, and erysipelas. In this study we investigated whether SKALP/elafin levels in serum and urine of psoriatic patients can be used as a marker for disease activity during treatment. Patients with severe chronic disabling psoriasis were treated for 16 weeks with cyclosporin A, which resulted in a marked clinical improvement as measured with the PASI score. SKALP/elafin levels both in serum and urine were determined with an enzyme-linked immunosorbent assay (ELISA). Measurements were performed at the start of the cyclosporin A treatment, and after regular intervals up to 16 weeks. The results indicate that 1) SKALP/elafin determination in serum rather than in urine is the preferred method, because the decrease in serum SKALP levels during therapy is more pronounced and correlated better with the clinical course of the patients; 2) SKALP/elafin levels in serum decreased during cyclosporin A treatment (p < 0.05); and 3) SKALP/elafin levels in serum correlate with the PASI score (p < 0.01). We conclude that SKALP/elafin measurement in serum of patients with severe psoriasis provides a tool for monitoring disease activity.

Adolescent↗
PubMed1995

Epidermal regeneration and occlusion.

Disruption of the stratum corneum, by tape stripping or chemical injury, results in epidermal recovery of the skin barrier. In human skin, 40-48 h after surface trauma, epidermal proliferation is maximal. In a previous study in mice, occlusion with plastic or the hydrocolloid Duoderm proved to inhibit the regenerative response. The aim of the present investigation was to find out whether occlusion modulates epidermal proliferation following removal of the stratum corneum in normal healthy volunteers by sellotape stripping. Epidermal proliferation was assessed, using a multiparameter approach, by measuring ornithine decarboxylase activity, keratin 16 expression and DNA synthesis. Following tape stripping without subsequent occlusion, ornithine decarboxylase activity, keratin 16 expression and DNA synthesis were induced to the same extent as observed in previous studies. However, in contrast to the experiments in mice, no indication of a modulation of these responses was observed by the application of the hydrocolloids Duoderm and Comfeel. In human skin, a direct effect of the artificial restoration of the skin barrier on epidermal regeneration remains unsubstantiated.

Adolescent↗
PubMed1994

Response of the clinically uninvolved skin of psoriatic patients to repeated tape stripping during cyclosporin A treatment.

It is well established that cyclosporin A (CyA), a widely used immunosuppressant in human organ transplantation, is an effective drug in the treatment of psoriasis. Although it has been postulated that the effect of CyA in psoriasis is mediated through antilymphocyte activity, there is also evidence suggesting that CyA exerts a direct cytostatic effect on epidermal keratinocytes, but results of studies relating to the latter have been contradictory. Using immunohistochemical methods we investigated the influence of systemic CyA on proliferation and differentiation in the tape-stripped uninvolved skin of psoriatic patients, a model which provides the opportunity of studying epidermal regeneration in the absence of a significant accumulation of T lymphocytes. We addressed the question of whether CyA (3-5 mg/kg/day) modulates epidermal proliferation and differentiation following standardized injury in uninvolved skin of psoriatic patients. Ten patients with severe psoriasis participated in this study. The dosages of CyA were sufficient to induce a marked and statistically significant improvement (PASI, week 0, 20.5 +/- 4.4; PASI, week 16, 4.3 +/- 0.6). Before CyA treatment, and during week 16 of treatment, Sellotape stripping was carried out on a 2-cm2 area of the uninvolved skin of psoriatic patients. After 48 h punch biopsies were taken. Immunohistochemical assessment of recruitment of cycling cells (Ki-67), filaggrin, involucrin, T lymphocytes and tenascin, was carried out. We did not find any significant alteration during the treatment period in the tape-stripped uninvolved skin of psoriatic patients. We conclude that epidermal hyperproliferation and abnormal keratinization are not modulated directly by CyA at therapeutic doses in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Adhesion Molecules, Neuronal↗
PubMed1993

Effects of sphingosine, isoquinoline and tannic acid on the human tape-stripping model and the psoriatic lesion.

Published data (mainly from rodent skin) suggest a correlation between compounds which inhibit protein kinase C (PKC), have anti-inflammatory or antitumor characteristics and possess antipsoriatic potential. We have investigated the effects of topical application of sphingosine (a naturally occurring PKC inhibitor), isoquinoline (a component of coal tar which showed antipsoriatic capacities in the mouse tail model) and tannic acid (a plant phenol with antitumor activity) on human skin. In each case we have assessed (a) the level of induction of ornithine decarboxylase (ODC) following Sellotape stripping as an indicator for potential PKC inhibition in vivo, and (b) its effects on the lesions of chronic plaque psoriasis. The control group consisted of 18 healthy volunteers, used for the ODC induction experiments (0.0/0.1/0.2 M sphingosine in ethanol, 100% coal tar and 0/50 mM tannic acid in acetone) and 17 psoriatic patients used for double-blind scoring of two randomly selected lesions (0.0/0.1 M sphingosine in ethanol, 0.0/0.2% isoquinoline in white vaseline/lanette wax cream 50%/50% and 0/10% tannic acid in lanette wax cream) and also for some of the ODC induction experiments (0.0/0.2% isoquinoline and 0/10% tannic acid). Biopsies were taken 8 h after stripping and ODC activity was assessed by measurement of 14CO2 release. Lesions were scored with a modified psoriasis area and severity index on days 0, 7 (isoquinoline and tannic acid), 13 (sphingosine) and 21 (isoquinoline and tannic acid). Application of 0.1 or 0.2 M sphingosine resulted in a decrease of ODC activity of 52% and 66%, respectively (p < 0.01), but histologic sections showed intraepidermal necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1993

The induction of epidermal ornithine decarboxylase following UV-B irradiation is inhibited by estriol.

The induction of epidermal ornithine decarboxylase (ODC) can be partially blocked by corticosteroids, retinoic acid or active vitamin D3. The influence of the other members of this so-called "steroid hormone receptor superfamily", namely the sex-steroids and thyroid hormone, is unknown in epidermis, but they enhance ODC induction in certain other tissues. Here we investigated whether topical estriol leads to a spontaneous and/or enhanced epidermal ODC induction 8 h after UV-B irradiation of 6 postmenopausal women. Contrary to expectation, estriol did not stimulate induction but reduced induction by 44%. This observation raises the possibility that all members of the steroid hormone receptor superfamily may share a common AP-1 binding site.

Administration, Cutaneous↗
PubMed1992

The induction of ornithine decarboxylase in human epidermis is independent of lipoxygenase and cyclo-oxygenase pathways.

In vivo studies in rodents suggest that prostaglandins and/or leukotrienes are involved in the epidermal induction of ornithine decarboxylase (ODC). Recently, we have shown that, in human epidermis, prostaglandins are not involved in this process. Here we report the role of leukotrienes in epidermal ODC induction in human skin. Topical flufenamic acid (Dignodolin), vehicle, or nothing was applied under plastic occlusion to three sites on the backs of healthy volunteers. This was followed 1 h later by Sellotape stripping. After renewed application and occlusion for 8 h, biopsies were carried out for the estimation of ODC levels. There were no significant differences in the levels of ODC between the flufenamic acid treated and control sites. To confirm this finding, test sites were irradiated with 3 MED of UVB. This was immediately followed by the application of flufenamic acid, vehicle, or nothing to the three irradiated sites. After 8 h, biopsies were taken, and the levels of ODC were again similar in the flufenamic acid- and the vehicle-treated sites. The data indicate that, following Sellotape stripping or UVB irradiation, neither lipoxygenase not cyclooxygenase products contribute to the in vivo induction of ODC in human epidermis.

Adult↗
PubMed1991

The induction of epidermal ornithine decarboxylase following tape stripping is inhibited by a topical vitamin D3 analogue (MC903).

The efficacy of MC903, a vitamin D3 analogue, in reducing hyperproliferation as determined by levels of ornithine decarboxylase (ODC) was investigated in a double-blind study of 15 patients with chronic plaque psoriasis. The lesions of psoriasis were treated for 8 weeks with MC903 in one of two different cream bases or with a placebo cream. Biopsies were taken before and after treatment. In addition an uninvolved area of skin was treated during the last 3 weeks and this as well as control areas were then sellotape stripped and biopsied after 8 h. Clinical improvement was seen in eight out of 11 patients treated with MC903 but there was no reduction in the level of ODC in psoriatic lesions after 8 weeks of treatment. The levels of ODC in the tape-stripped uninvolved skin after 3 weeks of treatment with MC903 averaged 22.5 +/- 4.2 pmol/min/mg protein as compared to 58.6 +/- 12.6 pmol/min/mg protein (P = 0.004). The trauma-induced induction of ODC activity was markedly inhibited by the application of MC903.

Adult↗