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Biomedical subjects

W L Weston

Publications and source records attributed to W L Weston.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of cutaneous algogenic responses to bradykinin and inhibition by bradykinin analogs.

Bradykinin has long been postulated to have a major role in physiologic human pain production. We have developed a method to systematically quantify the algogenic response to bradykinin in human skin by the direct application of bradykinin to suction blister bases. After determination of the pain threshold to bradykinin, we examined the ability of synthetic peptide analogs of bradykinin to block bradykinin-induced pain. One of the six analogs (B4642) inhibited bradykinin-induced pain with at least one concentration in all subjects tested. This result could not be predicted on the basis of inhibition of bradykinin binding to its guinea-pig ileum receptor or to previous studies of bradykinin-induced pain production in animal models. This peptide may have an eventual role as a physiologic pain inhibitor.

Amino Acid Sequence↗
PubMed1992

Detection of herpes simplex virus DNA in the peripheral blood during acute recurrent herpes labialis.

BACKGROUND: Although herpes simplex virus (HSV) has been detected in the peripheral blood of immunocompromised patients and in neonates with disseminated disease, the extent to which this virus may be present in the blood during a localized infection in otherwise healthy adults is unknown. OBJECTIVE: The purpose of this study was to determine whether HSV may be detected in the peripheral blood during acute recurrent herpes labialis. METHODS: Peripheral blood mononuclear cells (PBMCs) were obtained from otherwise healthy adults with recurrent herpes labialis, both during an acute episode and several weeks after the lesions had healed. The PBMCs were examined for the presence of HSV with the polymerase chain reaction (PCR) and viral culture. RESULTS: By PCR, HSV DNA was detected in 7 of 34 specimens from an acute episode but in none of 24 specimens in the convalescent stage (p less than 0.004). PBMCs from seven donors, who were seronegative for HSV, were also negative for HSV by PCR. Viral cultures of 22 PBMC specimens were negative (including four specimens that were positive by PCR). CONCLUSION: The presence of HSV DNA in the blood is a transient phenomenon limited to the period of active infection in a minority of patients with herpes labialis, although it may be important in the development of disseminated disease as well as in the pathogenesis of herpes-associated cutaneous processes such as erythema multiforme.

Acute Disease↗
PubMed1992

Interleukin-1 receptor antagonist production by human keratinocytes.

Human keratinocytes produce biologically active pro-IL-1 alpha and inactive pro-IL-1 beta with most protein remaining intracellular. IL-1 receptor antagonist (IL-1ra) is a newly described member of the IL-1 family that is secreted by stimulated monocytes and binds competitively to IL-1 receptors without stimulating target cells. We examined the characteristics of IL-1ra production by cultured human keratinocytes. By ELISA, keratinocyte lysates contained 390 ng IL-1ra/mg total protein with little IL-1ra detected in supernatants. In contrast, monocytes produced 297 ng IL-1ra/mg total protein during 24 h of culture on adherent IgG with about half of the IL-1ra detected in supernatants. By Western blot analysis, keratinocyte IL-1ra was approximately 20 kD in size and was slightly larger than recombinant monocyte IL-1ra. In contrast to monocytes, human keratinocyte IL-1ra was not secreted in 22-25-kD molecular weight glycosylated forms. Affinity-purified keratinocyte IL-1ra exhibited identical biologic activity to recombinant monocyte IL-1ra, each inhibiting IL-1-dependent augmentation of murine thymocyte proliferation to the same degree per amount of protein. An IL-1ra mRNA of 1.8 kb was detected by Northern blot analysis in RNA extracted from keratinocytes. In order to determine the effect of differentiation on IL-1 and IL-1ra production, human keratinocytes were cultured for 72 h in low (0.03 mM), medium (0.15 mM), or high (1.0 mM)-calcium concentrations. The absolute amounts of IL-1ra increased twofold and the ratio of IL-1ra to IL-1 alpha in keratinocyte lysates increased from approximately 12:1 to 25:1 during differentiation. These results indicate that keratinocytes constitutively produce large amounts of a biologically active intracellular variant of IL-1ra that increase with differentiation. IL-1ra released during keratinocyte damage may be important in modifying the inflammatory effects of IL-1 alpha in human skin.

Cell Differentiation↗
PubMed1992

Leukotriene C4 and TGF-alpha are stimulators of human melanocyte migration in vitro.

Human vitiligo is a disease of melanocyte destruction that leads to areas of depigmentation in the skin. The major form of treatment for vitiligo is photochemotherapy using psoralens and UVA radiation (PUVA), which induces the slow migration of pigment cells from hair follicles and normal skin into the depigmented areas. Our hypothesis is that immune cytokines and inflammatory mediators released as a result of the photochemotherapy are signals for melanocyte migration. We have developed an in vitro assay that quantitates the movement of individual cultured melanocytes over a 72-h period using time-lapse photography. Using this assay we found that both LTC4 and TGF-alpha were stimulators of melanocyte migration in vitro. The LTC4 effect was greater and lasted for the entire 72-h experimental period, whereas the TGF-alpha effect was significant only during the first 24 h of the experiment.

Cell Movement↗
PubMed1992

Herpes simplex virus in childhood erythema multiforme.

Although an association between herpes simplex virus (HSV) infection and erythema multiforme (EM) minor has been documented in adults, this has not been reported in the pediatric population. This study assessed the potential role of HSV infection in the pathogenesis of EM minor in children. Erythema multiforme skin lesions from 20 children, aged 1 to 16 years, were examined for the presence of HSV by using the polymerase chain reaction. The children included all fit strict clinical criteria for EM minor. Ten had a clinical history of an antecedent herpes infection ("herpes-associated EM"), and 10 did not ("idiopathic EM"). Herpes simplex virus DNA was detected in skin lesions of 8 of 10 children with herpes-associated EM and in 8 of 10 with idiopathic EM. Control skin biopsies from children with other bullous inflammatory diseases were negative. In addition, no HSV could be detected in a biopsy of normal uninvolved skin of a child in whom HSV was present in lesional skin. In situ hybridization on selected biopsies by means of an HSV-specific riboprobe confirmed the presence of HSV and localized it to the epidermis. It is concluded that HSV is a significant precipitating factor for EM minor in children, as it is in adults, and that clinicians should maintain a high index of suspicion of HSV even in the absence of a known history of herpes infection.

Adolescent↗
PubMed1991

Treatment of ulcerated hemangiomas with the pulsed tunable dye laser.

Hemangiomas are the most common tumor of infancy and are characterized by rapid growth during the first 6 months of life. During the rapid growth phase, approximately 5% to 10% of the hemangiomas ulcerate. Ulcerated lesions are painful, may bleed, and are at risk for bacterial infection. Previous therapy has included daily local wound care, topical antibiotics, and local and systemic steroids. We treated nine infants (eight female and one male) with ulcerated hemangiomas by means of a vascular-specific (585-nm) pulsed (450-microsecond) tunable dye laser. Eight of the nine patients had a single ulceration, whereas one patient had two ulcerations within a large hemangioma. Six of the ulcerations healed with a single laser treatment. One ulceration required two treatments to heal, and the remaining two required three treatments. Pain was subjectively decreased within 2 to 3 days in all patients after a single treatment. The pulsed tunable dye laser should be considered in the treatment of all ulcerated hemangiomas.

Evaluation Studies as Topic↗
PubMed1991

Location of port-wine stains and the likelihood of ophthalmic and/or central nervous system complications.

Of 310 patients with port-wine stains, 68% had more than one dermatome involved; 85% had unilateral and 15% had a bilateral distribution of their port-wine stain. At the time of examination, 8% of all patients with trigeminal port-wine stains had evidence of eye and/or central nervous system (CNS) involvement. Extensive involvement, with port-wine stain over the trunk and extremities as well as the head and neck, was observed in 12%. Patients who did not have port-wine stains on the areas served by branches V1 and V2 of the trigeminal nerve had no signs or symptoms of eye and/or CNS involvement. Port-wine stains of the eyelids, bilateral distribution of the birthmark, and unilateral port-wine stains involving all three branches of the trigeminal nerve were associated with a significantly higher likelihood of having eye and/or CNS complications. Twenty-four percent of those with bilateral trigeminal nerve port-wine stains had eye and/or CNS involvement compared with 6% of those with unilateral lesions. All those who had eye and/or CNS complications had port-wine stain involvement of the eyelids; in 91% both upper and lower eyelids were involved, whereas in 9% only the lower eyelid was involved. None of those with upper eyelid port-wine stains alone had eye and/or CNS complications. In addition, 3 (75%) of the 4 subjects with seizures alone had bilateral port-wine stain involvement. A third group, these with unilateral V1, V2, and V3 port-wine stains, had eye and/or CNS complications in 3 (19%) of 16 subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1991

Erythema multiforme minor in children.

Erythema multiforme minor is an acute, self-limited cutaneous or mucocutaneous disorder. Although it most commonly afflicts young adults, it is also frequently seen in children. An antecedent infection with herpes simplex virus is often the precipitating factor. Recent studies detailing the usual clinical course and histologic features of erythema multiforme minor, together with investigative studies examining potential pathomechanisms, have begun to provide a clearer picture of this disease process such that a more rational approach to therapy is now possible.

Acyclovir↗
PubMed1990

Photochemotherapy of dominant, diffuse, cutaneous mastocytosis.

Diffuse, cutaneous mastocytosis is a rare variant of cutaneous mast cell infiltration that can arise in neonates or infants as a generalized bullous eruption. The mode of transmission is suggested as autosomal dominant. We report four infants from two unrelated families with diffuse cutaneous mastocytosis whose cutaneous disease was not controlled by initial therapies. Treatment of the four infants with photochemotherapy dramatically reduced or eliminated symptoms. One course of therapy resulted in improvement, and retreatment has not been required two to six years later.

Child↗
PubMed1989

Recurrent erythema multiforme.

In a prospective clinical study of erythema multiforme (EM), we identified 22 subjects who experienced more than 1 episode. These subjects were young, with an average age of 29 years. They had an average number of 12 previous episodes, with each episode lasting 3 weeks. The average interval between episodes was 4.9 months. We counted the number and location of each skin lesion and found that patients had an average of 188 EM skin lesions at the time of their evaluation. We found the isomorphic phenomenon, that is, lesions appearing at sites of skin trauma, in 19 of the 22 study subjects; photodistribution of skin lesions in 15 of the 22, grouping of the lesions over the elbow and knees in 7 of the 22, and nailfold involvement in 7 of the 22. In this study there was compelling evidence for herpes simplex virus association with recurrent EM. All 22 patients had histories of herpes simplex virus infections preceding at least 1 of their previous episodes of EM. Sera from all study subjects had antibodies to HSV detectable by enzyme immunoassay. None, however, had HSV isolated from the throat at the time of the EM or from an EM skin lesion. All 11 patients who were subsequently tested had positive viral cultures for HSV taken from the suspected recurrent herpes lesion. When 8 EM skin biopsies were examined by indirect immunofluorescence with a monoclonal antibody to the type common HSV glycoprotein gB, all had positive staining of keratinocytes. Only one-third of patients with a single episode of EM had a history of possible herpes lesions preceding EM.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Detection of herpes simplex virus DNA in cutaneous lesions of erythema multiforme.

The association between erythema multiforme (EM) and herpes simplex virus (HSV) infection has long been appreciated, although the exact role which HSV may play in the pathogenesis of this herpes-associated EM (HAEM), is unknown. Previous studies have suggested, but not definitively demonstrated, the presence of HSV in lesions of HAEM. The presence of HSV would support the hypothesis that an immune-mediated response directed against HSV-specific antigens in the skin is central to lesion development in HAEM. The purpose of this study was to examine lesions of EM for the presence of HSV DNA by using the polymerase chain reaction (PCR). In addition, in situ hybridization using an HSV-specific RNA probe was performed to further localize the HSV nucleic acids within the skin. DNA was extracted from formalin-fixed, paraffin-embedded specimens of cutaneous lesions of HAEM and also from EM for which no precipitating factor could be documented, otherwise known as idiopathic EM (IPEM). DNA from lesions of bullous pemphigoid served as a negative control. Using PCR to specifically amplify HSV sequences which might be present, and then performing Southern analysis, we demonstrated HSV DNA in 9/13 HAEM and 6/9 IPEM biopsies. No HSV was detected in six lesions of bullous pemphigoid. In situ hybridization of three cutaneous HAEM lesions using an 35S-labeled HSV-specific RNA probe localized the HSV nucleic acids predominantly to the epidermis. Three biopsies of chronic dermatitis, used as negative controls, did not demonstrate this specific hybridization. These findings confirm the presence of HSV in lesions of HAEM and are consistent with the concept of an HSV-specific immune-mediated pathogenesis for this disease. In addition, most cases of IPEM appear to be herpes associated despite the absence of clinically apparent HSV infection.

DNA, Viral↗
PubMed1988

Comparison of hypothalamus-pituitary-adrenal axis suppression from superpotent topical steroids by standard endocrine function testing and gas chromatographic mass spectrometry.

We evaluated 38 males who had psoriasis vulgaris for evidence of hypothalamus-pituitary-adrenal axis suppression (HPAS) during treatment with superpotent topical glucocorticosteroids. All men were treated with 49 g per week of either Betamethasone Diproprionate in an optimized vehicle or Clobetasol Proprionate ointment. Three methods used to assess HPAS were compared. Classic 8 a.m. plasma cortisol measurements, urinary-free cortisol, and 17-hydroxycorticosteroid determinations and gas chromatograph-mass spectrometry (GCMS) quantitation of urinary cortisol metabolites were compared. Values for all methods were obtained just prior to therapy and at days 4, 7, 14, and 21 during therapy and at day 28 after treatment was stopped for 7 d. Plasma cortisol measurements correlated well with other measures of HPAS. GCMS determination of urinary cortisol metabolites was slightly more sensitive at detecting HPAS than the other two methods. Persistent HPAS after day 7 was only appreciated by GCMS. Urinary-free cortisol and 17-hydroxycortisol was the least sensitive of the three methods. Analysis of urinary cortisol metabolites by GCMS may be most useful in the monitoring of HPAS resulting from use of topical glucocorticosteroid preparations.

17-Hydroxycorticosteroids↗
PubMed1988

Development of an in vitro keratinocyte model for use in the study of HSV specific cytotoxicity.

Herpes simplex virus (HSV) specific immune mediated cytotoxicity may be involved in control of HSV infections and in the tissue damage induced by HSV infection or HSV related skin disease such as herpes associated erythema multiforme. Developing an in vitro model to study this process has proved difficult due to the lack of an appropriate target cell that will express HSV antigens but is not simultaneously subject to viral induced cell death. The purpose of this study was to develop a model in which keratinocytes express cell surface HSV specific antigens but at the same time are protected from death due to viral infection. We found that keratinocytes infected with HSV in the presence of acyclovir (ACV) expressed such antigens yet remained viable for a period of time after the onset of antigen expression such that cytotoxicity studies could be successfully performed. Rabbit skin cells, a transformed keratinocyte line, or second passage human neonatal foreskin keratinocytes were grown in culture medium with or without 200 microM ACV and were infected with HSV. Examination by direct immunofluorescence with anti-HSV antibody revealed uniform HSV antigen expression by cells both with and without ACV by 8 h after infection. Cells infected without ACV exhibited marked structural abnormalities including formation of multinucleated giant cells, while cells with ACV showed fewer such changes throughout a 24-h period. An Ethidium Bromide-Acridine Orange cytotoxicity assay demonstrated significant increases in the cytotoxicity of infected cells not protected by ACV compared to that of cells with ACV (p less than .001). This in vitro model should prove useful in the investigation of HSV specific immune mediated cytotoxicity.

Acridine Orange↗
PubMed1988

Characterization and practical benefits of keratinocytes cultured in strontium-containing serum-free medium.

Strontium (Sr2+) can substitute for Ca2+ and stimulate a variety of functions of numerous types of cells. The purpose of this study was to investigate the details of the biologic effects of Sr2+ on human keratinocyte growth, cell cycle, viability, and differentiation and to compare these effects with Sr2+ effects on cultured skin melanocytes. Cultured keratinocytes stimulated with 1.0-3.0 mM Sr2+ showed higher viability and almost a twofold increase in cell number compared with those grown in a standard calcium concentration. Time course studies revealed that 2.0 mM Sr2+ had no effects on growth of cultured melanocytes or fibroblasts. Sr2+ increased the percentage of cultured keratinocytes in G2/M phase, with a decrease in cells in G0/G1 phase. This effect of Sr2+ on the cell cycle was not seen in cultured melanocytes or fibroblasts. A 2 mM concentration of Sr2+ produced an increase in low-density keratinocytes separated by a Percoll gradient. In addition, increased expression of human fibronectin was observed in the cytoplasm and on cell membranes of keratinocytes cultured in Sr2+. Sr2+ can be of practical benefit in the culture of human keratinocytes in serum-free medium, increasing the viability and proliferative rate and producing a more uniform population of basaloid cells with increased expression of cell surface fibronectin.

Cell Count↗