Fluid-structure interaction simulations of the Fontan procedure using variable wall properties.

Children born with single ventricle heart defects typically undergo a staged surgical procedure culminating in a total cavopulmonary connection (TCPC) or Fontan surgery. The goal of this work was to perform physiologic, patient-specific hemodynamic simulations of two post-operative TCPC patients by using fluid-structure interaction (FSI) simulations. Data from two patients are presented, and post-op anatomy is reconstructed from MRI data. Respiration rate, heart rate, and venous pressures are obtained from catheterization data, and inflow rates are obtained from phase contrast MRI data and are used together with a respiratory model. Lumped parameter (Windkessel) boundary conditions are used at the outlets. We perform FSI simulations by using an arbitrary Lagrangian-Eulerian finite element framework to account for motion of the blood vessel walls in the TCPC. This study is the first to introduce variable elastic properties for the different areas of the TCPC, including a Gore-Tex conduit. Quantities such as wall shear stresses and pressures at critical locations are extracted from the simulation and are compared with pressure tracings from clinical data as well as with rigid wall simulations. Hepatic flow distribution and energy efficiency are also calculated and compared for all cases. There is little effect of FSI on pressure tracings, hepatic flow distribution, and time-averaged energy efficiency. However, the effect of FSI on wall shear stress, instantaneous energy efficiency, and wall motion is significant and should be considered in future work, particularly for accurate prediction of thrombus formation.

Celtic ancestry, HLA phenotype and increased risk of skin cancer.

Individuals of Celtic ancestry are claimed to be at greater risk of skin cancer than non-Celts, and various positive and negative associations between certain human leucocyte antigen (HLA) phenotypes and the development of skin cancer have been described. The aims of this study were to determine whether any HLA phenotypes are associated either with Celtic or non-Celtic ancestry, or skin type. One thousand and ten members of the Welsh Bone Marrow Donor Registry (WBMDR), whose HLA phenotypes are known, were asked to complete a questionnaire which enquired as to their family origins and their 'Index of Celtic Ancestry' scored out of 12. Three groups were identified: non-Celts (score < 3), Celts (score > 9), and a subset of the Celts--'high scoring' Celts (score > 10). Details of hair and eye colour and skin type were also requested. Skin type and HLA-A, -B, -DR and -DQ frequencies were compared between the three groups (Celts, non-Celts and 'high scoring' Celts), and a random indigenous population of 9196 members of the WBMDR. Seven hundred and thirty-six replies were received (279 male, 457 female, mean age 31 years). One hundred and forty-four Celts, 51 'high scoring' Celts and 170 non-Celts were identified. Forty-six (32%) Celts had skin type I or II compared with 36 (21%) non-Celts (P = 0.039), and 37 (73%) 'high scoring' Celts had skin type I or II (P < 0.0001). However, there were no significant differences between the groups with regard to hair colour, eye colour or number of episodes of painful sunburn. The frequency of HLA-DR4 was 32% in the non-Celtic group, 44% in the Celtic group (not significant), and 53% in the 'high scoring' Celts (P = 0.008). However, the difference was not significant after correction. There were no significant associations between skin type and HLA phenotype. HLA-DR4 is known to be associated with an increased risk of both basal cell carcinoma and malignant melanoma and its increased frequency in Celts may be an independent risk factor for skin cancer in addition to skin type.

A practical guide to topical therapy in children.

The parents of children with skin disease are often unsure how much topical therapy, particularly of corticosteroids, they should apply. The aims of this study were to devise simple guidelines on topical therapy for children, parents, doctors and nurses, and to check the accuracy of these guidelines in practice. The guidelines are based upon four principles: the adult fingertip unit (FTU); the 'rule of 9s'; standard height and weight charts for children; and standard nomograms for calculating body surface area. Twenty-four children (11 boys and 13 girls) aged 6 months to 9 years 4 months with atopic eczema were recruited and the number of FTUs required to treat different anatomical areas calculated in accordance with the proposed guidelines. Ointment was applied and the number of FTUs needed for each area was recorded. The amount used was then compared with that predicted. No child required a greater number of FTUs than that predicted, and the number of FTUs predicted for each anatomical region was accurate to within 1 FTU. The guidelines provide a useful indication of how much topical therapy is required for children, and advice sheets have been prepared for children of different ages.

Sweet's syndrome and malignancy in the U.K.

Acute febrile neutrophilic dermatosis (Sweet's syndrome) is reported to be a marker for underlying malignancy. Much of the evidence for this is based on case reports, small series of cases and reviews of the literature. In order to clarify the association with malignancy and determine the common clinical features of Sweet's syndrome, we reviewed the case notes of patients presenting to six dermatology units in the U.K. Eighty-seven cases of histologically proven Sweet's syndrome were reviewed. Fourteen patients (16%) developed associated malignancy, predominantly haematological, two patients (2%) had a history of previous malignancy and four patients (5%) had premalignant conditions (monoclonal gammopathy, two: myelodysplasia, two). Malignancy developed up to a year after presentation with Sweet's syndrome. Patients with associated malignancy were more likely to be anaemic (P < 0.01) at presentation, had a lower mean platelet count (207 x 10(9)/L vs. 332 x 10(9)/L; P < 0.003) and were, on average, older (59 years vs. 49 years; P = 0.002). Contrary to previous reports, a greater percentage of females developed malignancy than males.

Treatment of angioma serpiginosum using a pulsed tunable dye laser.

Angioma serpiginosum (AS) is a rare vascular naevoid disorder due to ectatic dilation of capillaries in the papillary dermis. The condition is found almost exclusively in females who have grouped erythematous punctate lesions usually on the lower limbs or buttocks, which may be unsightly. We report five patients with AS treated using a Candela SPLT1 pulsed tunable dye laser. All patients had a good to excellent response. The lesion resolved in one patient, virtually resolved in two and is considerably improved in a further patient in whom treatment is continuing. In one patient, the angiomatous lesion improved but the patient developed hyperpigmentation at the treatment site and the treatment has been temporarily suspended. The results suggest that treatment using the pulsed dye laser is very effective for AS and, in most patients, produces an excellent cosmetic result.

Multiple linear lichen planus in the lines of Blaschko.

The lines of Blaschko describe a distribution pattern which may represent embryological development pathways. The distribution may occasionally be followed by some skin disorders. We report a patient who had multiple lesions of linear lichen planus which followed Blaschko's lines. There were multiple streaks affecting several different areas of the body.

Increased risk of skin cancer: another Celtic myth? A review of Celtic ancestry and other risk factors for malignant melanoma and nonmelanoma skin cancer.

It is often stated that persons of Celtic origin have an increased risk of skin cancer, but the evidence for this is almost exclusively anecdotal. We believe that the possibility of the Celts being at greater risk of skin cancer has important implications with regard to management in particular and in assisting our understanding of carcinogenesis in general. For these reasons we have reviewed all those studies implicating Celtic ancestry in the development of both malignant melanoma and nonmelanoma skin cancer.

Effect of terbinafine on the pharmacokinetics of cyclosporin in humans.

Cyclosporin is largely metabolized by hepatic cytochrome P450 enzymes, and azole drugs that inhibit cytochrome P450 may precipitate cyclosporin toxicity. The allylamine terbinafine binds to a small subfraction of hepatic cytochrome P450 in type I fashion, and has no effect upon hepatic metabolism of cyclosporin in vitro. The purpose of this study was to determine whether oral terbinafine alters the pharmacokinetics of oral cyclosporin in vivo. Twenty male volunteers (age 19-44 years), were randomly allocated to two groups. The first group received three single oral doses of cyclosporin 300 mg at intervals of 21 d. The second and third doses of cyclosporin were preceded by a 6-d course of oral terbinafine 250 mg each morning. A further 250 mg of terbinafine was taken with the second and third doses of cyclosporin. Blood levels of cyclosporin and terbinafine were monitored for 36 h after each dose. The second group received a 7-d course of terbinafine 250 mg each morning. On the seventh day a single dose of cyclosporin 300 mg was taken together with the terbinafine. Blood levels of both cyclosporin and terbinafine were monitored for 36 h. Two further single doses of cyclosporin 300 mg were given at intervals of 2 weeks and the cyclosporin levels again monitored. In both groups each cyclosporin dose was preceded by an 8-h fast. The mean peak blood concentration of cyclosporin when taken alone was 958 micrograms/l, and 822 when taken with terbinafine. The mean area under the curve for cyclosporin was 4207 micrograms/l/h when taken alone and 3665 when taken with terbinafine. The mean absorption half-life for cyclosporin when taken alone was 0.29 h, and 0.33 when taken with terbinafine. The mean time of maximum concentration and elimination half-life of cyclosporin were unaltered by terbinafine. The results suggest that terbinafine is likely to prove a safe systemic anti-fungal treatment for patients who are taking cyclosporin.

What do members of the National Eczema Society really want?

In order to assess the impact of eczema on the lives of affected individuals a postal questionnaire was sent to all members of the National Eczema Society (NES). The survey also sought to ascertain their expectations of their initial consultation with general practitioners and hospital doctors; to assess their satisfaction with these consultations; to obtain their views on the treatment prescribed, and their reasons for joining the NES. Information on 1972 adults (614 male, 1358 female) and from 1944 parents of affected children was received, representing an overall response rate of 29%. The work of 1061 (54%) adults, and the choice of career of 391 (20%) had been affected. Eczema affected the ability to perform domestic duties in 1128 (83%) women compared with 439 (71%) men. Social and leisure activities were affected in 1269 (64%) of adults. The development of personal relationships had been impaired in 273 (14%), and the sex lives of 373 (19%) had been affected. In children sleep (60%) was the most commonly affected activity. The expectations of the initial consultation with their general practitioner of 659 (17%) had not at all been met, of 2528 (65%) partly met, and of only 483 (12%) completely met; 2638 patients had seen a hospital specialist. The expectations of 478 (18%) had not at all been met, of 1164 (62%) partly met, and of only 512 (19%) completely met. Forty-four per cent (1713) were either 'extremely satisfied' or 'satisfied' with the treatments they had been given, 1529 (40%) were 'neutral', 480 (12%) were dissatisfied, and 103 (2.6%) were extremely dissatisfied.(ABSTRACT TRUNCATED AT 250 WORDS)

Suprabasal acantholysis--an unusual feature of necrolytic migratory erythema.

A 67-year-old man with diabetes, weight loss and anaemia initially presented with a widespread scaling erythematous rash; a skin biopsy demonstrated marked suprabasal acantholysis. A subsequent biopsy showed localized upper epidermal necrolysis and the diagnosis of glucagonoma syndrome was later confirmed. Glucagonoma syndrome should be considered in patients with diabetes, weight loss and anaemia who present with a scaling rash, the histology of which shows suprabasal acantholysis. The extent of any upper epidermal necrolysis may be be very limited.

Stratum corneum changes in patients with senile pruritus.

BACKGROUND: Generalized pruritus in the elderly is a common and distressing problem; often there is no evidence of skin disease other than xerosis. OBJECTIVE: The aim of the study was to determine whether any abnormality could be detected in the structure and function of the skin of patients with generalized pruritus. METHODS: The skin of 13 elderly patients with generalized pruritus, without skin disease or any underlying cause, was contrasted with that of age- and sex-matched normal control subjects. RESULTS: The patients had clinically drier skin (mean visual analogue scale score 2.9 [standard deviation +/- 2.2], controls 0.52 [+/- 0.59], p = 0.002). The severity of the pruritus was related to the degree of xerosis (r = 0.66). The patients had decreased skin surface conductance (10.7 mumho [+/- 3.4], controls 16 mumho [+/- 5.3], p = 0.017), and increased intracorneal cohesion (240.5 g [+/- 88], controls 162.7 g [+/- 39.8], p = 0.001). The patients also had statistically significantly diminished parameters of skin surface contour. CONCLUSION: The findings of increased intracorneal cohesion and altered skin surface contour parameters suggest that elderly patients with generalized pruritus may have an acquired abnormality of keratinization.

Lichenoid eruption induced by low dose captopril.

A patient with congestive cardiac failure developed a rash following captopril treatment. The clinical and histological features were consistent with a lichenoid eruption. The rash spontaneously resolved without any treatment three months after captopril was discontinued.