Biomedical subjects
Publications and source records attributed to C J Stephens.
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In order to gain a greater insight into the complex mechanisms of action of different irritant chemicals on the skin, we have studied the behavior of epidermal CD1+ cells in experimentally induced irritant contact dermatitis. Healthy, human volunteers were patch tested for 48 h with the following six chemically unrelated irritants and their appropriate vehicle controls; benzalkonium chloride, sodium lauryl sulphate, dithranol, nonanoic acid, croton oil, and propylene glycol. After visually assessing and grading the resulting inflammatory reactions, punch biopsies were taken and the morphology and density of CD1+ cells in the epidermis studied using immunocytochemical techniques in combination with image analysis and electron microscopy. Statistically significant decreases in the epidermal density of CD1+ cells occurred in the responses to dithranol (p less than 0.05) and nonanoic acid (p less than 0.01). Importantly, these changes in density were not simply due to variations in the intensity of inflammatory response (r = 0.1157). Alterations in the length of the dendritic processes of CD1+ cells were also induced, and semi-quantitative analysis revealed significant decreases in dendrite length in the reactions to sodium lauryl sulphate (p less than 0.05), nonanoic acid (p less than 0.001), croton oil (p less than 0.05), and dithranol (p less than 0.005). Unlike epidermal density, however, this effect on cell morphology was directly related to the severity of inflammation (r = -0.74, p less than 0.01). Morphologic evidence of cellular injury to Langerhans cells was seen by electron microscopy in the majority of biopsies, although relatively few cells were affected in sodium lauryl sulphate and propylene glycol reactions. Benzalkonium chloride, unlike the other irritants, also induced a state of metabolic activation in a high proportion of epidermal Langerhans cells. Lymphocyte/Langerhans cell apposition was observed in most samples, but was particularly prevalent in the reactions to dithranol. The results of this study demonstrate that significant changes in the morphology and density of Langerhans cells occur in irritant contact dermatitis, some of which are directly influenced by the chemical nature of the irritant.
Irritant contact dermatitis may be induced by many chemicals and has a far greater incidence than allergic contact dermatitis. Despite this, it receives relatively little attention and its pathogenesis remains poorly understood. To gain a greater understanding of the interaction of irritants with the skin, we investigated the histopathological changes resulting from the topical application of a series of structurally unrelated irritants. Human volunteers were patch-tested with appropriate concentrations of nonanoic acid, sodium lauryl sulphate, dithranol, benzalkonium chloride, croton oil, and propylene glycol, which produced generally mild to moderate responses. Biopsy specimens were taken after 48 h and examined by light and electron microscopy. Spongiosis and the infiltration of predominantly mononuclear cells were observed in the epidermis of the majority of biopsy specimens, and were particularly pronounced and extensive in croton oil reactions. In addition, several irritants induced distinct and characteristic patterns of keratinocyte damage. Nonanoic acid and sodium lauryl sulphate caused morphologic changes indicative of disturbances in keratinocyte metabolism and differentiation, giving rise to dyskeratosis and parakeratosis respectively, while dithranol induced marked swelling of keratinocytes in the upper epidermis. The results suggest that there is a diversity and specificity in the histopathology of irritant contact dermatitis, reflecting the different ways in which chemicals may interact with components of the skin.
A case of autoimmune progesterone dermatitis is described. Exacerbation occurred premenstrually and after intramuscular and oral challenge with synthetic progesterone. The condition failed to respond to oestrogen, but there has been a marked improvement with the anti-oestrogen drug Tamoxifen.
We report the case of a 5-year-old girl who developed a remarkably extensive kerion of the scalp due to Microsporum canis infection. Total scalp involvement of this severity and prolonged duration is now unusual, but there has been surprisingly little residual cicatricial alopecia. Microsporum canis does not respond well to ketoconazole, and griseofulvin remains the drug of choice for dermatophyte infections involving hair; a prolonged course may be necessary. This case also demonstrates the benefit of corticosteroids for certain cases of inflammatory ringworm where the host's response to the fungus is exceptionally marked.
A 65-year-old female suffered trauma to her left hand on which acrodermatitis continua (psoriasis of Hallopeau) developed. It is suggested that the persistent pain of this skin condition, its poor response to treatment and her allied mental state led to the development of a severe algodystrophy with marked underlying osteoporosis.
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Assessment of erythema in experimentally-induced irritant contact dermatitis has been performed visually and using the laser Doppler flowmeter (LDF). A close correlation was shown between the 2 methods (r = 0.9079, p less than 0.001), with the LDF producing mean blood flow values which were able to discriminate between the different visual scores. Of the 100 patch tests evaluated, 3 gave poor correlations between their visual and LDF readings, including 2 dithranol reactions and 1 sodium hydroxide response. Patch tests with no visible erythema had blood flow values similar to those of normal untreated skin. Although the LDF was an easy instrument to operate, it was not considered suitable for use in the routine patch test clinic, due mainly to the unacceptable length of time required to measure each patch test.
The data reported are from a 20% probability sample (n = 2516) of all adult patients seeking care in the emergency room at San Francisco General Hospital during a 60-day period. Thirty-five percent (35%) of the injured and 18% of the non-injured reported drinking prior to the event. This paper compares the following variables related to drinking-in-the-event for injured and non-injured: drinking places, drinking companions, amount consumed, time lapsed between drinking and the event, effects of drinking and causality attributed by the patient to drinking and the event. When these variables were entered into a logistic regression to evaluate their predictive value on injury status, only time lapsed since the last drink and drug use prior to the event were predictive of injury with both being negatively associated with admission to the emergency room for an injury. Injuries were more likely than non-injuries to occur in close proximity to drinking (44% of injuries occurred in less than 1 h of the last drink), and close to a third of the injured attributed a causal association of drinking with the event, with 60% of these feeling they were drunk at the time of injury.
While the effects of alcohol consumption during pregnancy have been well documented, variables associated with drinking during pregnancy have received little attention. This study sought to determine the importance of situational and ethnic/cultural-specific support on alcohol consumption during pregnancy among Black and White women in a U.S. southern urban prenatal population. A consecutive sample of 311 prenatal patients were interviewed during both the fourth month and the eighth month of pregnancy. Using standard regressions, the two components of expressive support--general support and pregnancy support--were found to be working in opposite directions, with pregnancy support showing a negative association with alcohol consumption during pregnancy. Pregnancy support was found to contribute significantly to the variance in alcohol consumption among Whites but was not found to be a significant contributor among Blacks. These findings suggest that social support, specifically pregnancy support, is a significant variable in accounting for alcohol consumption during pregnancy, but this association may not be consistent across ethnic groups.
As national survey data on American drinking practices have suggested a higher rate of heavy drinking among Southern city women compared to women in other regions, this study sought to determine drinking patterns during pregnancy in this group. A consecutive sample of 428 prenatal patients, who were residents of a Southern metropolitan area, were interviewed during the fourth month prenatal clinic visit. Although close to 50% of this sample were abstainers, 11% of the drinkers were found to be heavy drinkers, averaging more than two drinks daily, while 18% were high-maximum drinkers, consuming at least five drinks on an occasion prior to pregnancy. Forty-eight percent of the drinkers had become abstainers during the first 4 months of pregnancy, which was significantly higher than the 35% found in a representative non-Southern population (P less than 0.01). More frequent high-maximum drinking and increased drinking during pregnancy, both of which are potentially risky drinking practices for fetal outcome, were found primarily among blacks and those 14-19 years of age. The large proportion of both blacks (85%) and those 14-19 (33%) in this sample may put this population at high risk for adverse fetal outcomes related to alcohol consumption during pregnancy.
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Although an association between alcohol consumption during pregnancy and adverse fetal outcomes has been well documented, variables related to alcohol consumption during pregnancy have remained neglected. Since pregnancy has been considered a time of crisis and stress for pregnant women, this study sought to determine the association of perceptions of pregnancy and social support to alcohol consumption during pregnancy. The 311 Southern metropolitan prenatal patients sampled were interviewed twice during pregnancy. Perception of pregnancy was not found to be correlated with either social support or alcohol consumption during pregnancy. Social support was significantly associated with decreased alcohol consumption during pregnancy. Using standard multiple regressions, two components of social support, general support and pregnancy support, were found to be working in opposite directions prior to pregnancy, with general support showing a positive association with alcohol consumption. Only pregnancy support continued to account for a significant amount of the variance in alcohol consumption during the first 4 months of pregnancy. Pregnancy support, additionally, showed a significant negative association with high maximum drinking (consuming five or more drinks on occasion) prior to pregnancy. These findings suggest that social support may be an important predictor of alcohol consumption both prior to and during pregnancy and merits further investigation.
Sneddon's syndrome refers to the rare association of extensive livedo reticularis with multiple ischaemic cerebrovascular episodes. Endarteritis obliterans is the most common cutaneous pathology. It is likely that several pathogenic mechanisms may give rise to Sneddon's syndrome, as the condition is associated with a high incidence of generalised atherosclerosis, hypertension, valvular heart disease and the presence of antiphospholipid antibodies.
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