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Biomedical subjects

C F Vickers

Publications and source records attributed to C F Vickers.

At least 19 recordsLinked to original sources

A case of actinic prurigo and solar urticaria.

Actinic prurigo and solar urticaria are uncommon chronic idiopathic photodermatoses in the United Kingdom. To our knowledge, their occurrence in the same patient has not hitherto been described.

Child

A fully differentiating epidermal model with extended viability: development and partial characterization.

A highly differentiated porcine skin organ culture model has been developed for future investigations of membrane-coating granules (MCG) and their role in epidermal differentiation. In contrast to many previous systems, cultures do not undergo necrosis of the upper epidermis or display dermo-epidermal separation, but survive for at least 3 weeks, at which time mitotic cells are still evident. Although rete projections are gradually smoothed out and the viable epidermis thins at a rate of approximately 0.35 cells per day, the stratum corneum gains approximately 1.5 corneocytes per day. Furthermore, at 3 weeks all the major differentiation markers are expressed, including keratohyalin granules, MCG, and an orthokeratotic stratum corneum. The system is inexpensive, simple to establish, and does not require elevated oxygen levels. The main requirements are 1) the use of Dulbecco's minimal essential medium supplemented with 2) hydrocortisone (100 micrograms/ml), 3) growth at an air/liquid interface, and 4) attached connective tissue. The further addition of vitamin C (300 micrograms/ml) and/or bovine serum albumin (2 mg/ml) offered no obvious advantage. Degeneration of organ cultures in standard cell culture media was discovered to be caused by fetal bovine serum (FBS). FBS-induced degeneration was not prevented by adding any of the supplements tested, or the inclusion of 3T3 fibroblasts, even when culturing at an air/liquid interface. Complete submersion rapidly killed specimens, presumably through oxygen starvation. The ability to maintain a fully keratinizing system for several weeks, in a totally chemically defined medium, will prove valuable for research not only into the role(s) of MCG in epidermal biology but also studies of desquamation and epidermal differentiation.

Animals

Degenerative and regenerative changes in epidermal organ culture: a morphological study with reference to membrane-coating granules.

Membrane-coating granules (MCG) are poorly understood lamellate organelles unique to keratinized epithelia. This study provides data on a skin model for future in vitro investigations of MCG. Porcine ear epidermal organ cultures were used under standard cell culture conditions. This system was selected because it is easily established and, following a degenerative period in which MCG are lost, regenerates to form a highly differentiated epidermis. The epidermis appeared healthy during the first 2 d in vitro and contained MCG but lost keratohyalin granules (KHG). Overt degenerative changes were evident in the upper epidermis on Day 3, and MCG were now bloated. By Day 4 only one to three layers of viable undifferentiated cells remained. In the overlying necrotic epidermis MCG were rare, presumably due to the bursting of bloated MCG. Epidermal regeneration began around Day 5 and by Day 7 there were 8 to 13 layers, including a rudimentary parakeratotic stratum corneum (up to 4 layers). The stratum granulosum (two to three layers) now contained immature KHG and poorly lamellate MCG, but only amorphous material extracellularly. By Day 11 there were three to four layers of granular cells as in vivo, and an orthokeratotic stratum corneum (two to four layers). Improved cornification coincided with an increased number of mature KHG and cross-banded MCG, and lamellate MCG contents extracellularly. This model of epidermal regeneration will facilitate studies into the role played by MCG in keratinization because the epithelium initially lacked MCG but later expressed all the major morphologic features of epidermis. Furthermore the mechanisms by which MCG translocation and extrusion are effected may be probed by the inclusion of such agents as antimicrotubular drugs and calcium ionophores.

Animals

2% topical minoxidil solution in male-pattern baldness: preliminary European results.

A 48-week, double-blind, randomized study was conducted in France, West Germany and the UK to compare the safety and efficacy of topical minoxidil 2% (Regaine; registered trade mark of the Upjohn Company) solution with placebo in the treatment of early male-pattern baldness. At week 24, the end of the placebo period, there were 225 evaluable patients, 116 in the treatment group and 109 in the placebo group. The 2% minoxidil group showed superiority to the placebo group with respect to the following parameters at week 24: (1) non-vellus hair counts (p = 0.0084); (2) changes in non-vellus hair counts compared with baseline values (p = 0.0227), and (3) investigators' evaluations of hair growth (p = 0.019). There was no significant difference between minoxidil and placebo treatment with regard to blood pressure, pulse or weight changes. No serious side effects were reported during the study. The greatest number of medical events were dermatological in nature and mainly local and mild in intensity. From week 24 to week 48 all patients received active medication and showed further hair growth. At week 48 the investigators evaluated the new hair growth as moderate or dense in 32.7% of the patients. Our conclusion confirms previous reported studies according to which topical minoxidil seems to offer a safe and efficacious treatment for early male-pattern baldness in some patients. Further studies need to be done to characterize the most likely responders.

Administration, Cutaneous

Pyoderma gangrenosum treated with cyclosporin A.

A 49-year-old woman with a 14-year history of pyoderma gangrenosum unresponsive to a variety of systemic and topical treatments was given oral cyclosporin A (CyA), a potent immunosuppressive agent widely used in organ transplantation for the prophylaxis of acute graft-versus-host disease. Improvement and subsequent healing of the lesions was evident within 3 weeks of starting treatment and has continued for the duration of treatment (12 months).

Adult

The mode of action of ethyl lactate as a treatment for acne.

We have shown that an alcoholic lotion containing ethyl lactate when applied topically to rat skin under occlusion became localized in the follicles and sebaceous glands. When applied to human facial skin the ethyl lactate was hydrolysed to ethanol and lactic acid, and thereby lowered the skin pH. Under such conditions the growth of recoverable skin bacteria, in particular the anaerobe Propionibacterium acnes, was inhibited, and the hydrolysis of sebum to free fatty acids by lipase derived from the bacteria was greatly impaired. These effects of ethyl lactate would account for its observed clinical efficacy in acne vulgaris.

Acne Vulgaris

Yellow nail syndrome associated with penicillamine therapy.

A patient is described in whom the nail changes of the yellow nail syndrome developed whilst she was taking penicillamine. Stopping the drug was associated with resolution of the nail changes. The yellow nail syndrome was first described in 1964 (Samman and White), but the cause is still unknown. Impaired lymphatic drainage is thought to be a factor in the pathogenesis, and lymphoedema is often an accompanying feature. We describe a case in which nail changes, typical of those described in the yellow nail syndrome, occurred in a patient treated with d-penicillamine, and in whom the nails reverted to normal on withdrawing the drug. (Received March 15, 1983.)

Adult

Electron-beam treatment of scleromyxoedema.

A 42-year-old man is described with progressive scleromyxoedema. Clinical features included the development of transient central nervous system symptoms and a 5-year delay before the appearance of an IgG lambda-chain paraproteinaemia. Electron beam therapy resulted in significant improvement which lasted for 18 months.

Adult

Photochemotherapy for mycosis fungoides: a clinical and histological study.

Nine patients with stages 2 or 3 mycosis fungoides (MF) and one with Sézary's syndrome were treated with oral methoxsalen and long-wave ultraviolet light. Previous therapy had either failed or achieved only partial control. Satisfactory clinical control was achieved in all but one case. Histological improvement was seen in all cases, but complete clearance of lymphoid infiltrate was noted mainly in epidermal and papillary dermal infiltrates. Lower dermal infiltrate remained largely unchanged. The case of Sézary's syndrome was inadequately controlled with systemic prednisone and cyclophosphamide, but addition of photochemotherapy improved the erythema and pruritus. This shows that photochemotherapy may have a place in MF treatment both alone and perhaps in conjunction with other treatments. An early relapse occurred on stopping photochemotherapy in four cases, but one patient has had three months' full remission.

Adult