The tumour suppressor gene PTEN, which maps to 10q23.3 and encodes a 403 amino acid dual specificity phosphatase (protein tyrosine phosphatase; PTPase), was shown recently to play a broad role in ...human malignancy. Somatic PTEN deletions and mutations were observed in sporadic breast, brain, prostate and kidney cancer cell lines and in several primary tumours such as endometrial carcinomas, malignant melanoma and thyroid tumours. In addition, PTEN was identified as the susceptibility gene for two hamartoma syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD families and seven BZS families was screened for germline PTEN mutations. PTEN mutations were identified in 30 of 37 (81%) CD families, including missense and nonsense point mutations, deletions, insertions, a deletion/insertion and splice site mutations. These mutations were scattered over the entire length of PTEN, with the exception of the first, fourth and last exons. A ‘hot spot’ for PTEN mutation in CD was identified in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD mutations identified in this exon. Seven of 30 (23%) were within the core motif, the majority (five of seven) of which were missense mutations, possibly pointing to the functional significance of this region. Germline PTEN mutations were identified in four of seven (57%) BZS families studied. Interestingly, none of these mutations was observed in the PTPase core motif. It is also worthy of note that a single nonsense point mutation, R233X, was observed in the germline DNA from two unrelated CD families and one BZS family. Genotype-phenotype studies were not performed on this small group of BZS families. However, genotype-phenotype analysis in the group of CD families revealed two possible associations worthy of follow-up in independent analyses. The first was an association noted in the group of CD families with breast disease. A correlation was observed between the presence/absence of a PTEN mutation and the type of breast involvement (unaffected versus benign versus malignant). Specifically and more directly, an association was also observed between the presence of a PTEN mutation and malignant breast disease. Secondly, there appeared to be an interdependent association between mutations upstream and within the PTPase core motif, the core motif containing the majority of missense mutations, and the involvement of all major organ systems (central nervous system, thyroid, breast, skin and gastrointestinal tract). However, these observations would need to be confirmed by studying a larger number of CD families.
Cowden disease is an autosomal dominant syndrome predisposing to cancer and characterised by the occurrence throughout life of hyperplastic, hamartomatous and tumoural lesions affecting various ...organs. In 60-80% of patients a germline intragenic point mutation of the PTEN tumour suppressor gene is identified, but at least 20% of patients with a well characterised phenotype remain without any identified mutation.
To evaluate the impact of large rearrangement involving the PTEN locus in Cowden disease, we analysed by a multiplex amplifiable probe hybridisation (MAPH) technique 80 unrelated patients referred for diagnosed or suspected Cowden disease, and in whom no PTEN point mutation was detected by a denaturing gradient gel electrophoresis (DGGE) screening.
Four heterozygous genomic deletions involving the PTEN gene were identified. These deletions ranged from 13.6-662 kb and are restricted to the PTEN locus in two cases. In the two other cases, the deletion encompassed PTEN and either two or three contiguous genes without any obvious phenotypic effect, except a possible consequence of PAPSS2 haploinsufficiency on bone growth. Sequence analysis of the four deleted alleles did not reveal identity or sequence homology at the two breakpoints of a same allele, suggesting that a mechanism such as non-homologous recombination of the breakage and reunion type could lead to the occurrence of these deletions.
Large rearrangements of the PTEN gene can be involved as causing mutation in Cowden disease and MAPH is an efficient screening methodology to detect such a genetic alteration.
To evaluate the efficacy and tolerability of an innovative absorbent wound dressing (UrgoClean; Laboratoires Urgo) in the local management of venous leg ulcers and pressure ulcers, during the sloughy ...stage of the healing process.
A pilot, prospective, non-controlled open-label clinical trial held in 21 investigating centres. Adult patients, presenting with either a venous leg ulcer (VLU) or a category III/IV pressure ulcer (PU) with more than 50% of the surface area covered with sloughy tissue, a duration of less than 24 months, and no clinical signs of infection were included in the study. Patients were followed over a 6-week period with weekly visits, which included a physical examination, wound-area tracings and photographs by the investigating physician. Evaluations by the nursing staff and by the patients were made at each dressing stage.
Fifty patients with either a VLU (n=35) or a PU (n=15) were recruited. At baseline, mean wound surface area was 11.9 ± 11.3 cm(2) and 12.5 ± 10.7 cm(2), with a mean duration of 8.3 ± 6.4 months and 2.9 ± 3.0 months in the VLU and PU groups, respectively. Wounds in both groups were covered with more than 70% sloughy tissue, and the peri-lesional skin was considered to be healthy in 19 patients. By 6 weeks, mean wound surface area reduction in the VLU and PU groups was 23.7% and 29.2%, respectively, with full healing in 6 patients. All treated wounds were considered to be debrided by week 3 (<40% slough for all wounds) and the median relative decrease of the sloughy tissue, at week 6, in the VLU and PU groups was 75% and 89%, respectively. Dressing acceptability was documented as being very good for both patients and nursing staff, particularly conformability and ease of use, with no residue left on the wound bed at dressing removal and the dressing also remained in one piece. Seven local adverse events were deemed to be potentially related to the trial dressing.
The results suggest that the dressing promoted the healing process of chronic wounds, showing itself to be a credible therapeutic alternative for the sloughy stage of the wound-healing process. It also demonstrated good tolerance and acceptability.
To evaluate the efficacy, tolerance and acceptability of Urgotul and DuoDERM E dressings in the local management of venous or mixed-aetiology leg ulcers.
This was a prospective multicentre randomised ...phase IV clinical trial conducted open-label in parallel groups. It involved 20 investigating centres, including hospital dermatology and vascular medicine departments, and private practices. Dermatologists and angiologists/phlebologists took part. Subjects were adult, non-immunosuppressed patients presenting with a non-infected, non-malignant leg ulcer of predominantly venous origin (ABPI > 0.8). Ulcers were between 4cm2 and 40cm2 in size, with granulation tissue covering more than 50% of their surface area. Ulcer duration ranged from three to 18 months. Patients were followed-up by the investigating physician for eight weeks on a weekly basis; this included clinical examination, wound area tracings and photographs. Nurses (hospital or visiting) assessed exudate volume and clinical appearance at dressing changes.
Ninety-one patients were included: 47 in the Urgotul group and 44 in the DuoDERM E group. Baseline patient demographic data and wound characteristics were comparable in the two groups. After eight weeks of treatment wound surface area had reduced by a mean of 61.3% in the Urgotul group and 52.1% in the DuoDERM E group (NS); dressings were changed more frequently in the DuoDERM E group (2.54 +/- 0.57 times per week versus 2.31 +/- 0.45 in the Urgotul group, p = 0.047). Thirty-three local adverse events were recorded in 27 patients: 10 in the Urgotul group and 23 in the DuoDERM E group (p = 0.039). Nurses reported better acceptability for the Urgotul dressing, based on pain on removal, maceration and odour (p < 0.0001).
Both dressings showed similar efficacy for the local treatment of venous leg ulcers. Nevertheless, medical and nursing staff reported better tolerance and acceptability for the Urgotul dressing.
Acute cutaneous sarcoidosis is generally spontaneously regressive but persistent chronic cutaneous lesions are esthetically prejudicial. There have been several case reports on thalidomide efficacy ...but long-term outcome is unknown. We report results in 10 cases of cutaneous sarcoidosis treated with thalidomide.
Data from ten patients with sarcoidosis treated with thalidomide between January 1998 and March 1999 were collected from delivery authorizations and analyzed. All ten patients had chronic cutaneous sarcoidosis resistant to conventional therapy. Six patients had an associated visceral localization and disease duration of 2 to 18 years (median 6 years). We considered that regression was complete when erythema and infiltration had totally disappeared, that regression was incomplete when cutaneous signs remained, and that treatment had failed when no effect was observed or when the disease worsened.
Disease regression was noted in 7 patients for a daily dose of 1.84 mg/kg for 2.8 months. Skin lesions totally regressed in 3 patients, an incompletely in 4. Treatment failed in 3 patients. Patients were treated for 10 months (2 to 21 months). The daily dose of thalidomide was gradually reduced in 5 of 7 patients for whom treatment was effective. Three of these 5 patients relapsed and thalidomide was again given and was effective again at the same dose and after the same delay. We observed improved kidney function in one patient, improvement in nasal infiltration in one other and complete regression in 3 patients who achieved long lasting reduction in angiotensin convertase level. When treatment failed, the daily dose was 1.15 mg/kg and the treatment had to be stopped for 2 patients. Side effects were minor, excepting 2 cases of neuropathy.
This open study of 10 patients treated with thalidomide showed the efficacy of a 1.84 mg/kg daily dose in 7 out of 10, but complete regression of the lesions was obtained in only 3 patients. Thalidomiide appears to suspend the disease, with relapse when the drug is discontinued and efficacy at re-introduction. This would argue against a placebo effect. The mode of action could involve immunomodulating and antiinflammatory mechanisms.
Cyclosporin is an effective treatment for psoriasis but its efficacy is only palliative. The aim of this study was to evaluate the percentage of patients in whom a short term therapy may be used ...without relapse after discontinuation of cyclosporin. In this multicenter, open, non-controlled study fifty-eight patients were included who had severe and extensive chronic plaque-type psoriasis. Treatment duration was 28 weeks. The absence of relapse was defined as the requirement to resume systemic treatment at 16 weeks after discontinuation of Sandimmun . The overall efficacy of Sandimmun at W20 was 72%. No relapse or premature withdrawal occurred in 18 cases out of 39 (47%). In these cases local treatment was sufficient following discontinuation. Thus we show the potential value of a single 5 month course of cyclosporin treatment. In this study tapering of cyclosporin was not useful. In 50% of cases short-term cyclosporin treatment was not followed by resumption of systemic treatment and constitutes an improvement in qualify of life.
PDF
