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Biomedical subjects

J L Hawk

Publications and source records attributed to J L Hawk.

At least 73 records · Page 4Linked to original sources
PubMed1994

A shot in the arm for children's health in Atlanta. Interview by Kathryn Taylor.

Three years ago, Atlanta's Scottish Rite Children's Medical Center began a statewide children's immunization program. The success of that program has encouraged other community organizations to model themselves after Scottish Rite's, including a similar initiative launched by The Atlanta Project (TAP). The medical center lent its expertise--and that of senior vice president Judson L. Hawk Jr., M.D.--to TAP. Staff Editor Kathryn Taylor recently spoke to Hawk about his three-year stint as senior adviser for children's issues at TAP, and his role in developing an immunization program for the Atlanta area.

Child↗
PubMed1994

Polymorphic light eruption: prevalence in Australia and England.

The prevalence and clinical characteristics of polymorphic light eruption were assessed by a questionnaire survey of 172, 196 and 182 subjects in Perth, Ballarat and London, respectively. The prevalence was 5.2% in Perth (latitude 32 degrees), 3.6% in Ballarat (37.5 degrees) and 14.8% in London (51.5 degrees). The age distribution (mostly first three decades) and male:female ratio (1:3) was similar for affected individuals in all three areas. Development of tolerance during the summer was more common in Perth (66.7%) and Ballarat (71.4%) than in London (40.7%).

Adolescent↗
PubMed1994

Cutaneous photosensitivity in dermatomyositis.

The incidence and nature of cutaneous photosensitivity were studied in 10 patients suffering from dermatomyositis. Five reported an abnormality, which consisted of photoaggravation of preexisting cutaneous lesions in three, and abnormal transient erythemal responses in two. Monochromatic irradiation testing of all 10 patients demonstrated reduced minimal erythemal doses in two, at 307.5 nm, and at 340 and 360 nm, respectively; only the latter individual had clinical light sensitivity. Exposure to low-dose, solar-simulated radiation of the unaffected skin of the former patient, and five others who agreed to the procedure, three of whom complained of light sensitivity, induced a lesion with the clinical and immunofluorescence characteristics of dermatomyositis in only the first one. Four other patients replied to a mailed questionnaire, and three of these reported aggravation of their rash and provocation of new lesions by sunlight. Photosensitivity may thus be an important cutaneous feature of dermatomyositis.

Adult↗
PubMed1994

The efficacy of localized PUVA therapy for chronic hand and foot dermatoses.

The response to treatment of all patients enrolled over an 18-month period for localized oral or topical psoralen photochemotherapy (PUVA) of chronic hand and foot dermatoses was retrospectively reviewed. There were broadly similar success rates for the two groups for complete clearance: 61.5% (eight of 13 patients who completed therapy)--oral PUVA, 47.8% (11 of 23 patients who completed therapy)--topical PUVA, and for significant improvement: 23.1% (three of 13 patients)--oral PUVA, 30.4% (seven of 23 patients)--topical PUVA; there were no significant differences in response when diagnostic subgroupings of the hand dermatoses were taken into account. The mean number of treatments (22 for oral PUVA and 24 for topical), treatment durations (122 and 129 days), maximum UVA doses (11.2 and 12.3 J/cm2) and to a lesser extent cumulative UVA doses (189.3 and 237.0 J/cm2) for the therapies were similar in the two groups; adverse effects were minimal for both treatment protocols. However, at least five of the eight patients in the oral PUVA group and five of the 11 in the topical group who cleared completely relapsed after a mean 86 (range 19-245) and 174 (range 23-596) days, respectively. These findings are in broad agreement with those of previous studies. Therefore to avoid generalized photosensitivity and a higher likelihood of adverse effects with systemic therapy, as well as a possible slower relapse rate, topical therapy seems preferable.

Administration, Cutaneous↗
PubMed1994

Heat shock protein 65 immunoreactivity in experimentally induced polymorphic light eruption.

The expression of 65 kiloDalton heat shock protein (HSP65) immunoreactivity of skin biopsies from experimentally induced polymorphic light eruption (PLE) lesions was studied, to investigate its possible role as a photo-induced antigen responsible for precipitating lesions. In each subject the 24-h minimal erythema dose of solar simulated radiation was determined and an area of skin previously affected by PLE subjected to 70% of the minimal erythema dose in order to induce PLE lesions. The irradiated areas were sequentially biopsied between 0 and 6 days. ML-30, a monoclonal antibody which recognises heat shock protein 65, was used to label the sections by means of an indirect immunoperoxidase technique. In PLE patients clinical inflammation was noted by 5 h post-irradiation, with subsequent evolution of PLE-like lesions; these were still present at 6 days. Increased ML-30 antibody labelling in epidermal keratinocyte and endothelial cell cytoplasm was recognisable from 1 h post-irradiation, and in dermal dendritic cells from 5 h sustained through to 6 days. In normal subjects neither clinical nor histological features of inflammation were noted after irradiation, nor any increase in HSP65 labelling.

Bacterial Proteins↗
PubMed1993

Low-dose ultraviolet-B irradiation depletes human epidermal Langerhans cells.

We have examined the effects of low-dose monochromatic UVB irradiation (295 +/- 5 nm), biologically equivalent to that generally incident on the skin during a 12-session sun-bed course, on the expression of the CD1a epidermal Langerhans cell surface marker in human skin in vivo. In five subjects, 1.5 minimal erythema doses (MEDs) at 295 nm depleted its expression by 50%. In five further subjects, a single 1.5 MED dose, 1.5 MEDs in 10 equal fractions on alternate days, and a single 1.5 MED dose at one-tenth the previously used irradiance, delivered to separate sites, also led to variable but significant depletion of CD1a expression of around 30-50%. Thus, low-dose UVB irradiation, whether received rapidly or slowly, appears significantly and approximately equally to deplete human epidermal Langerhans cell numbers as measured by CD1a expression.

Antigens, CD↗
PubMed1993

The efficacy of psoralen photochemotherapy in the treatment of aquagenic pruritus.

Psoralen photochemotherapy (PUVA) was effective in the treatment of five patients with aquagenic pruritus, associated in one with polycythaemia rubra vera and in another with the myelodysplastic syndrome. Relapse occurred within 2-24 weeks when treatment was discontinued. Maintenance therapy or a further course of PUVA was necessary to maintain remission. This requirement may limit the value of the therapy.

Adult↗
PubMed1993

Sesquiterpene lactone contact sensitivity: clinical patterns of Compositae dermatitis and relationship to chronic actinic dermatitis.

A mix of 3 sesquiterpene lactones (SL) (SL mix 0.1%) was evaluated over a 4-year period. Of 7420 patients with eczema investigated by patch testing, 135 (68 male, 67 female) (1.8%) demonstrated positive reactions, 114 (84%) considered clinically relevant. Females outnumbered males until the age of 60, after which men were more commonly affected. The clinical patterns varied from patients presenting with generalized eczema (20%) or eczema of the hands and face (24%), to patients with hand (36%) or facial eczema (11%) alone. 48 patients were investigated for suspected photosensitivity and 29 (21 male, mean age 69 years, and 8 female, mean age 66 years) had abnormal cutaneous monochromatic irradiation tests. These results highlight the varied clinical presentation of SL contact dermatitis and its association with chronic actinic dermatitis. The SL mix proved reliable and safe, supporting its inclusion in the European standard series of contact allergens.

Adolescent↗
PubMed1993

p53 immunoreactivity in cutaneous PUVA tumors is similar to that in other non-melanoma skin neoplasms.

Expression of the p53 tumor suppressor gene product was determined in keratoses and skin cancers associated with psoralen photochemotherapy (PUVA). An immunocytochemical study was employed using CM-1 (polyclonal) and Do-1 (monoclonal) antibodies to human wild-type p53. Thirty-two cutaneous lesions and 20 perilesional PUVA-irradiated skin biopsies were examined from 7 patients, all of whom had received more than 200 PUVA treatments and/or a cumulative UVA dose of greater than 1000J/cm2 as treatment for widespread plaque psoriasis. p53 immunoreactivity was seen in 7 of 15 squamous cell carcinomas (46.7%), 5 of 8 dysplastic keratoses (62.5%) and in no basal cell carcinomas or benign keratoses. The overall prevalence of p53 immunoreactivity in 46.2% of malignant or dysplastic PUVA-associated skin tumors is similar to that previously found by our group in comparable skin tumors from the general population. Most patients with lesions showing positive p53 immunoreactivity had, however, been exposed to additional risk factors before receiving PUVA therapy. p53 gene sequencing of PUVA-associated non-melanoma skin cancer (NMSC) may clarify whether p53 mutation contributes to the development of these tumors and whether this relates to PUVA therapy or prior carcinogen exposure.

Adult↗
PubMed1992

Adhesion molecule expression in polymorphic light eruption.

Endothelial leukocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) are cytokine-regulated cell-surface leukocyte adhesion molecules. We have investigated the in vivo kinetics and pattern of expression of these adhesion molecules in relation to tissue accumulation of leukocytes in the photodermatosis, polymorphic light eruption (PMLE), which is characterized by dense perivascular leukocytic infiltration. Immunohistology was performed on biopsies taken at varying time points from PMLE lesions induced in 11 subjects by suberythemal solar simulated irradiation. Vascular endothelial ELAM-1 expression was first observed at 5 h, maximal at 24 to 72 h, and remained elevated at 6 d. VCAM-1, minimally expressed in control skin, was induced above background levels on endothelium and some perivascular cells after 24 h and maintained at 6 d. Endothelial cell ICAM-1 expression was increased above control levels at 72 h and 6 d. Keratinocyte ICAM-1 expression, most marked overlying areas of dermal leukocytic infiltration, began at 5 h and was strong at 72 h and 6 d. In addition to lymphocytes, significant numbers of neutrophils but not eosinophils were detected in the dermal leukocytic infiltrate that appeared at 5 h and persisted at 6 d. The pattern of adhesion molecule expression that we have observed is similar to that seen in normal skin during a delayed hypersensitivity reaction. These observations support an immunologic basis for PMLE.

Biopsy↗
PubMed1991

Photoprotection and 5-MOP photochemoprotection from UVR-induced DNA damage in humans: the role of skin type.

Sites on previously unexposed buttock skin in 18 subjects (skin types I-V) were treated daily for 2 weeks with suberythemogenic doses of solar-simulated radiation (SSR) alone, SSR plus a UVB sunscreen, and SSR plus the same sunscreen with 5-methoxypsoralen at 30 ppm. The three sites of treatment (designated SSR, SSR/S, and SSR/S/5-MOP), and a control site that received no SSR or topical treatment, were challenged with 2MED SSR 1 week after the treatment had ceased. Biopsy samples, taken within 15 min after the challenge dose, were assessed for unscheduled DNA synthesis (UDS, interpreted as a measure of DNA damage), melanin deposition, and stratum corneum thickening. Within a given skin type, when compared with controls, the significant increase in either pigmentation or stratum corneum thickening was similar for SSR and SSR/S/5-MOP. SSR/S inhibited these endpoints. Compared with controls, UDS was significantly reduced in skin types III-V by SSR and in all skin types by SSR/S/5-MOP. SSR/S elicited no effect apart from minimal reductions in skin types IV and V. Thus, the increases in pigmentation and stratum corneum thickening seen in all skin types with SSR and SSR/S/5-MOP were accompanied by reduced UDS in all skin types with SSR/S/5-MOP but only in skin types III-V with SSR. These findings suggest that, although induced pigmentation and stratum corneum thickening may account in part for the reduction of UDS, qualitative differences in induced pigmentation may exist in skin types I-II between SSR and SSR/S/5-MOP treatments. The findings can also be interpreted to indicate that SSR/S/5-MOP treatment can afford protection against DNA damage from subsequent exposure to solar ultraviolet radiation. Risk-benefit considerations on the use of sunscreens with and without 5-MOP are discussed and the conclusion is drawn that the judicious use of 5-MOP sunscreens, particularly in skin types I-II, affords an alternative option to those seeking a suntan.

DNA↗