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Biomedical subjects

C M Lawrence

Publications and source records attributed to C M Lawrence.

At least 91 records · Page 5Linked to original sources

The effect of triethanolamine application on anthralin-induced inflammation and therapeutic effect in psoriasis.

Twenty patients with chronic plaque psoriasis were treated with short-contact anthralin followed by 10% triethanolamine application to one side of the body and aqueous cream to the other. Anthralin-induced inflammation was inhibited on the triethanolamine-treated side whereas anthralin therapy had to be temporarily stopped in 18 patients on the aqueous cream side because of anthralin-induced inflammation. Therapeutic response was not different in the two sides. This study shows that anthralin-induced inflammation and its therapeutic effect can be dissociated.

Adolescent↗

Symptomatic zinc deficiency in breast-fed premature infants.

We report two breast-fed premature infants who developed transient symptomatic zinc deficiency with scaly erythema of cheeks and napkin area, 9-13 weeks after birth. Serum zinc concentrations were 3.6 and 4.8 mumols/l, and the lesions healed rapidly in response to oral zinc supplements. Both mothers had low breast-milk zinc levels (2.3 and 3.2 mumols/l at 21 and 15 weeks respectively). The infants were both initially misdiagnosed as having eczema and infection. Premature infants are in negative zinc balance and though the additional factor of a low maternal breast milk zinc concentration may be necessary to provoke symptoms, rashes developing in such infants in the months following premature birth should raise the suspicion of zinc deficiency.

Breast Feeding↗

Effect of UVB therapy and a coal tar bath on short contact dithranol treatment for psoriasis.

The effect of UVB therapy after short contact dithranol therapy (SCDT) was examined in 53 patients with psoriasis. After dithranol application, patients were randomly allocated to receive either a tar bath and UVB therapy (27 patients) or an emulsifying ointment bath only (26 patients). Forty eight patients completed the study; 16 of the 21 dithranol only patients cleared in a mean of 19.5 days compared with 20 of the 27 dithranol + UVB patients who cleared in a mean of 20.3 days. These differences were not significant. Similarly there was no significant difference in response between the dithranol only and dithranol UVB group as measured by the change in plaque thickness measured using Harpenden calipers, and the severity of psoriasis assessed by the extent of the rash, the degree of scaling, redness and induration. Thirteen of the 16 dithranol only patients who cleared relapsed in a mean of 10.6 weeks compared with 14 of the 20 dithranol UVB patients who relapsed after a mean of 18.9 weeks (P less than 0.05). Comparison of pre- and post-treatment full blood count, biochemical screen and urinalysis showed no evidence of systemic toxicity due to SCDT. This study shows that UVB therapy does not improve the clearance of psoriasis in SCDT, but does significantly postpone relapse.

Adolescent↗

The use of antipyrine clearance to measure liver damage in psoriatic patients receiving methotrexate.

Salivary antipyrine clearance was measured in 15 patients with psoriasis receiving methotrexate and related to liver biopsy changes and routine liver function tests, to determine whether antipyrine clearance could be used as a non-invasive method for monitoring liver function. Comparison of the salivary antipyrine clearance in the methotrexate group (mean 0.51 ml/min/kg, range 0.26-0.81) with 15 matched psoriatic controls (mean 0.54 ml/min/kg, range 0.34-0.99) showed no significant difference. Liver biopsy changes were scored for fatty change, fibrosis, liver cell necrosis and portal tract infiltrate. Total liver biopsy scores correlated significantly with antipyrine clearance/kg body weight (r = -0.72, P less than 0.05). There was no significant correlation of total liver biopsy scores with the other liver function tests. Correlation of the individual liver biopsy changes and antipyrine clearance showed a significant correlation with fatty change (r = -0.75, P less than 0.01), but not with fibrosis (r = -0.53), liver cell necrosis (r = -0.54) or infiltrate (r = -0.41).

Adult↗

Effect of arachidonic acid on anthralin inflammation.

1 The effect of topical arachidonic acid on anthralin inflammation was studied using sequential measurements of erythema (reflectance photometry) and oedema (calipers). 2 Topical arachidonic acid in concentrations which produced a small short-lived inflammatory response greatly augmented the initial phase and depressed the later phase of the inflammatory response to anthralin. 3 The initial augmentation was inhibited by concomitant administration of alpha-tocopherol. 4 It is suggested that free radical formation by anthralin has a direct action on membrane substrates such as arachidonic acid forming inflammatory products by a non-enzymic process.

Administration, Topical↗

'Tin-tack' sign in localized pemphigus foliaceus.

Two patients with localized pemphigus foliaceus are described, in whom a positive 'tin-tack' sign was a significant feature; this is the appearance of small horny plugs attached to the undersurface of the scale removed from the affected site. This report is intended as a reminder that a positive 'tin-tack' sign is not exclusively a feature of discoid lupus erythematosus but is also seen in localized pemphigus foliaceus.

Adult↗

Reduction of anthralin inflammation by potassium hydroxide and Teepol.

Application of 1% potassium hydroxide (KOH) reduced subsequent development of anthralin inflammation without loss of its therapeutic effect on psoriasis. Teepol had a similar but smaller effect on subsequent development of inflammation. The action of KOH appears to have resulted from enhanced oxidation of anthralin to inactive products and the action of Teepol to have increased anthralin solubility and removal. The effect of KOH and Teepol decreased with time after anthralin application and both were ineffective by 24 h, indicating that anthralin persists on the skin in an active form for up to 24 h after a single application. The reduction of anthralin inflammation without loss of therapeutic effect is potentially useful in short contact anthralin therapy.

Adolescent↗

Time course and intensity of anthralin inflammation on involved and uninvolved psoriatic skin.

Anthralin inflammatory oedema was measured using Harpenden calipers on psoriatic plaque and clinically uninvolved skin 6-48 h after anthralin application. There was a highly significant reduction in oedema response on the psoriatic plaque compared with the uninvolved skin (P less than 0.001). Both sites produced a maximal oedema response at 24 h. These results do not support the theory that the decreased anthralin reactivity of psoriatic plaque is due to the high levels of arachidonic acid found in involved psoriatic skin.

Adult↗

Site variation in anthralin inflammation on forearm skin.

The effect of application site on anthralin inflammation was measured at 10 clinically normal volar skin sites on each forearm of 31 subjects as the increase in skin thickness at 48 h using Harpenden calipers. Pre-treatment and increase in skin thickness were significantly related to application site. Pre-treatment thickness increased distally and laterally by an amount depending on sex, and to a lesser extent other factors, whilst the increase in skin thickness values was greater proximally, laterally and on the right arm but was not affected by age, sex or skin type. When increases in skin thickness values were adjusted for pre-treatment thickness, the difference between proximal and distal sites was lost but there was still a significant difference between the medial and lateral aspect and the right and left arms. The absolute differences were small but demonstrate the need to use symmetrical forearm skin sites and randomized treatment sides when comparing the effects of topical agents on anthralin inflammation.

Adolescent↗

Excision of skin tumours without wound closure.

Sixty-two patients with 67 large or poorly defined skin tumours predominantly on the head and neck (58 basal cell carcinomas) were treated by excision of the lesion and allowing the defect created to heal by second intention. Histological control of the adequacy of excision was monitored using routine vertical sections of formalin-fixed tissue. Further re-excisions were performed in 17 patients in whom tumour extended up to or within 1 high power field (approximately 0.44 mm) of the excision margin. The formalin-fixed specimens ranged from 6-60 (mean 21) mm in diameter and 2-12 (mean 5) mm in depth. After one excision the time to complete re-epithelialization was directly proportional to the surface area (r = 0.73) and ranged from 13 to 60 days (mean 33 days). Measurements of the movements of fixed reference points tattooed at the wound edges in six patients showed that movement of surrounding tissue into the defect accounted for 39-62% (mean 45%) of the reduction in surface area of the defect during healing. Post-operative complications were rare and the cosmetic results were considered good or excellent in 48 patients, fair in nine and poor, i.e. requiring corrective surgery, in three patients. Poor results were due to distortions of free margins, e.g. lower eyelid and nasal margin. The major benefit of this technique is the ease with which further excisions can be performed when histologically indicated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The nature of mycosis fungoides.

Thirty-four patients with a clinical diagnosis of plaque stage mycosis fungoides, poikiloderma atrophicans vasculare (poikiloderma) and parapsoriasis en plaques (parapsoriasis) were investigated for evidence of extracutaneous disease using a biochemical screen, blood films, bone marrow examination, chest radiograph, abdominal ultrasound, isotope liver scan, liver biopsy and lymphangiography. Skin biopsies were also taken from these patients and, in order to rule out non-specific histological change, from 29 controls with inflammatory skin disease; the slides were examined blind by two independent observers for evidence of mycosis fungoides or poikiloderma and graded accordingly. Both observers were able to differentiate significantly histological grades of mycosis fungoides corresponding to the clinical diagnosis although exact histological grades only corresponded on 35 per cent of slides. Features graded as classical or probable mycosis fungoides were found in between 22 and 67 per cent of patients with parapsoriasis and between 67 and 100 per cent of those with poikiloderma. We found no evidence of extracutaneous disease in any of our patients. Lymphangiograms were abnormal in 30 of 31 examinations but the changes were non-specific and did not correspond to disease type, duration or extent. Four patients had apparently unrelated co-existing disease including chronic lymphatic leukaemia in two, a monoclonal gammopathy and autoimmune haemolytic anaemia. This study shows that in its early stages mycosis fungoides is predominantly if not primarily a cutaneous disease. The findings also suggest that parapsoriasis and poikiloderma are part of the same disorder as mycosis fungoides or evolve into it. Aggressive treatment to prevent progression to mycosis fungoides plaque and tumour stage should therefore be tried. The findings support the idea that mycosis fungoides is a reactive rather than a neoplastic disorder.

Adolescent↗

Enzymatic synthesis and hydrolysis of [32P]phosphatidylinositol phosphate.

Phosphatidylinositol kinase activity in plasma membrane preparations of mouse liver was found to be comparable to that in A431 cells and higher than that in three human tumor xenografts. This activity was exploited in preparing 32P-labeled phosphatidylinositol phosphate of high specific radioactivity in which approximately 4% of the radioactivity of the substrate, [gamma-32P]ATP, was incorporated into the lipid. The subcellular distribution of phosphatidylinositol phosphate phosphatase in a human astrocytoma xenograft was determined using [32P]phosphatidylinositol phosphate as a substrate. The highest phosphatase activity was found in the plasma membranes.

1-Phosphatidylinositol 4-Kinase↗