A zone melting device for the in situ observation of directional solidification using high-energy synchrotron x rays.

Directional solidification (DS) is an established manufacturing process to produce high-performance components from metallic materials with optimized properties. Materials for demanding high-temperature applications, for instance in the energy generation and aircraft engine technology, can only be successfully produced using methods such as directional solidification. It has been applied on an industrial scale for a considerable amount of time, but advancing this method beyond the current applications is still challenging and almost exclusively limited to post-process characterization of the developed microstructures. For a knowledge-based advancement and a contribution to material innovation, in situ studies of the DS process are crucial using realistic sample sizes to ensure scalability of the results to industrial sizes. Therefore, a specially designed Flexible Directional Solidification (FlexiDS) device was developed for use at the P07 High Energy Materials Science beamline at PETRA III (Deutsches Elektronen-Synchrotron, Hamburg, Germany). In general, the process conditions of the crucible-free, inductively heated FlexiDS device can be varied from 6 mm/h to 12 000 mm/h (vertical withdrawal rate) and from 0 rpm to 35 rpm (axial sample rotation). Moreover, different atmospheres such as Ar, N2, and vacuum can be used during operation. The device is designed for maximum operation temperatures of 2200 °C. This unique device allows in situ examination of the directional solidification process and subsequent solid-state reactions by x-ray diffraction in the transmission mode. Within this project, different structural intermetallic alloys with liquidus temperatures up to 2000 °C were studied in terms of liquid-solid regions, transformations, and decompositions, with varying process conditions.

Vaccination coverage among children and adolescents below 18 years of age in French Guiana: inventory and determinant factors.

OBJECTIVE: The purpose of this study was to estimate the vaccination coverage (VC) rate in persons aged from 9 months to 18 years and to describe it according to the predictive factors of good vaccination status. STUDY DESIGN: Descriptive and etiological study. METHODS: The study involved 1332 persons aged below 18 years and members of 521 representative households in French Guiana. VC was estimated by the proportion of people with complete immunization for 13 vaccines (four mandatory, seven recommended, and two specific). This vaccination status was described in terms of sociodemographic characteristics. The relationship between vaccination status and predictive factors was analyzed in a hierarchical mixed, polytomic, and ordered regression model. RESULTS: For compulsory vaccination, VC was 81.2% for yellow fever, 63.4% for diphtheria, 61.7% for tetanus, and 61.6% for poliomyelitis. The proportion of people with complete immunization for recommended vaccines remains well below 50% (11.7% for pneumococcus and 6.2% for meningitis). Regardless of the vaccine, respondents aged 3-7 years were 2.5 times more likely to have an up-to-date vaccination compared to respondents younger than 3 years of age (P < 0.001). CONCLUSION: The VC observed in this study is still below the departmental objectives. The link between age and vaccination status could be explained by the efforts of the national education authorities to systematically check health cards for preschool and school enrollment.

A bruise-like patch in a 4-year-old girl.

Dermatofibrosarcoma protuberans (DFSP), a rare medium grade sarcoma, occasionally occurs in childhood and is even more rarely present at birth. In children, the clinical appearance may be mistaken for a vascular malformation and so delayed diagnosis is not uncommon. Dermatofibrosarcoma protuberans is locally invasive and notorious for its high recurrence rate even after attempted wide local excision owing to extensive subclinical and asymmetrical extensions. In adult DFSP, Mohs Micrographic Surgery (MMS) is the treatment of choice because it offers a higher clearance rate compared to wide local excision. However, MMS may result in extended operating times owing to tissue processing and multiple stages. In children, this means a prolonged period under general anesthetic, which may be undesirable. We describe an interesting case of a 4- year-old girl diagnosed with DFSP. She underwent a modified MMS procedure in which she had two short general anesthetics. The advantage of MMS technique in which the full peripheral and deep margin of the specimen was examined.

Rate of acute adverse events for narrow-band UVB and Psoralen-UVA phototherapy.

BACKGROUND: Ultraviolet (UV) radiation therapies are commonly used to treat a wide range of dermatological conditions. However, no published data exist regarding the rate of acute adverse events occurring within the different UV therapy modalities. AIM: The aim of this study was to determine the rate of acute adverse events experienced by patients receiving narrow-band UVB or photochemotherapy in 3 neighboring dermatology units. METHOD: Standardized adverse event forms from all 3 units were retrospectively analysed over a 12-month period between October 2003 and September 2004. The treatments included were narrow-band UVB and systemic, bath and hand/foot PUVA. RESULTS: A total of 8784 treatments were given over the study period. The total number of acute adverse events recorded for all phototherapy treatments was 70 (0.8%). The rates of acute adverse events for each treatment modality were 0.6% for narrow-band UVB, 1.3% for systemic PUVA, 1.3% for bath PUVA and 0.8% for hand/foot PUVA. Adverse events were due to patient non-compliance with standard operating procedures in 15 cases (21%) and operator error in 2 (3%). Only 4 of the acute adverse events were considered to be severe, accounting for 0.05% of all treatments. CONCLUSIONS: The rates of acute adverse events with phototherapy in this analysis were low, in particular the rate of severe adverse events. The highest rate was seen with both systemic and bath PUVA. The number of adverse events resulting from operator error was low. These published rates for adverse events associated with narrow-band UVB and PUVA may help other units when analyzing their own rate of adverse events.

Consequences of misdiagnosis of lymphomatoid papulosis.

We report two patients with lymphomatoid papulosis (LyP), who were initially diagnosed as systemic T-cell lymphoma. The patients presented with recurrent self-healing cutaneous lesions and skin biopsies showed a lymphocytic infiltrate with malignant features. Clinico-pathological correlation of findings was not performed and results of staging investigations were misinterpreted. Consequently, both patients were unnecessarily treated with multi-agent chemotherapy, radiotherapy and stem cell/bone marrow transplants and sustained long-term adverse effects. The clinical and histological features of LyP are described and appropriate management discussed in detail. Factors leading to the unnecessary treatment of both patients are examined and several learning points highlighted such as the importance of a multidisciplinary approach.

Controlled study of excimer and pulsed dye lasers in the treatment of psoriasis.

BACKGROUND AND OBJECTIVES: The excimer laser delivers high energy monochromatic ultraviolet (UV) B at 308 nm. Advantages over conventional UV sources include targeting of lesional skin, reducing cumulative dose and inducing faster clearance. Studies of the pulsed dye laser (PDL) in psoriasis report between 57% and 82% response rates; remission may extend to 15 months. To our knowledge, this is the first study assessing both excimer and PDL in psoriasis. METHODS: We conducted a within-patient controlled prospective trial of treatment of localized plaque psoriasis. Twenty-two adult patients, mean Psoriasis Area and Severity Index 7.1, were recruited. Fifteen patients completed the full treatment, of which 13 were followed up to 1 year. Two selected plaques were treated with excimer twice weekly and V Beam PDL, pretreated with salicylic acid (SA), every 4 weeks, respectively. Two additional plaques, treated with SA alone or untreated, served as controls. The primary outcome measures were: (i) changes in plaque-modified Psoriasis Activity and Severity Index (PSI) scores from baseline to end of treatment; (ii) clinical response to treatment (CR(T)), assessed by serial photographs; (iii) percentage of plaques clear at the end of treatment; and (iv) percentage of plaques clear at 1-year follow-up. The secondary outcome measures were: (i) number of laser treatments to clearance; (ii) time to relapse; (iii) frequency of side-effects; and (iv) qualitative observations with SIAscope. RESULTS: The mean improvement in PSI was 4.7 (SD 2.1) with excimer and 2.7 (SD 2.4) with PDL. PSI improvement was significantly greater in excimer than PDL (P = 0.003) or both control plaques (P < 0.001). CR(T) indicated 13 patients responded best with excimer, two patients best with PDL, and in seven patients there was no difference between the two lasers. CR(T) was significantly greater for excimer than PDL (P = 0.003) or both controls (P < 0.001). CR(T) was also significantly greater for PDL than SA alone (P = 0.004) or untreated control (P =0.002). Nine (41%) patients cleared with excimer, after mean 8.7, median 10 weeks treatment. Seven of these nine patients were followed up to 1 year; four remained clear, two relapsed at 1 month, and one at 6 months. Six (27%) patients cleared with PDL, after mean 3.3, median four treatments. All six patients were followed up to 1 year; four remained clear, one relapsed at 4 months and one at 9 months. Despite common side-effects including blistering and hyperpigmentation, patient satisfaction was high. Serial images obtained with the SIAscope during treatment indicated different mechanisms of action of the two lasers. CONCLUSIONS: Excimer and V Beam PDL are useful treatments for plaque psoriasis. Although the excimer appears to be on average more efficacious, a subset of patients may respond better to PDL. Long-term remission is achievable with both lasers.

Pseudoxanthoma elasticum.

Pseudoxanthoma elasticum (PXE) is a rare multisystem disorder characterised by progressive calcification and fragmentation of elastic fibres. Recent genetic advances have identified the underlying defect to the ABCC6 gene on chromosome 16p13.1. Patients typically develop cutaneous, ocular, and cardiovascular manifestations but there is considerable phenotypic variability. The skin changes are usually apparent in adulthood, and rarely observed in childhood. Since the prognosis of PXE largely depends on the extent of extracutaneous organ involvement early recognition, intervention and lifestyle adjustments are important to reduce morbidity. First-degree family members should be carefully examined for any cutaneous or ophthalmologic features of PXE.

Lymphomatoid papulosis in a patient with atopic eczema on long-term ciclosporin therapy.

We report a 36-year-old man with atopic eczema who developed lymphomatoid papulosis while taking ciclosporin. Latent membrane protein 1 and in situ hybridization for Epstein-Barr virus were negative. There are only two reports in the literature of patients taking ciclosporin to control atopic eczema who developed primary cutaneous CD30+ T-cell lymphoproliferative disorders. The development of T-cell lymphoproliferative disorders including lymphomas is well described in patients with solid organ transplants who are taking ciclosporin. Also, it has been noted in patients taking ciclosporin for rheumatological conditions or psoriasis.

Laser treatment of rosacea.

Rosacea is a common condition often resulting in persistent erythema and telangiectasia as well as rhinophyma in a number of patients. Over the last two decades lasers have been increasingly used in the treatment of these permanent changes. The literature is reviewed in terms of the different laser systems, side-effects and comparison with other surgical techniques. Laser studies on rosacea-associated telangiectasia and erythema are limited. Copper-bromide, krypton and KTP lasers have been used with good to excellent results. However, the most commonly applied system is the flash lamp-pumped pulsed dye laser. Rhinophyma can be treated with a variety of different surgical methods, including laser resurfacing. CO(2) lasers are the most widely used lasers, others are the Er:YAG and Nd:YAG lasers. Cosmetic end results are comparable to partial excision with a scalpel or electrosurgery. There does not appear to be an increased risk of infection or scarring, but the conventional surgical methods are quicker to perform and more cost effective.

Adverse effects with PUVA and UVB phototherapy.

PUVA and UVB phototherapy are very effective and popular treatments for a variety of dermatological problems. This article gives an overview of the possible acute and chronic adverse effects of these therapies.

Decreased exercise blood lactate concentrations after respiratory endurance training in humans.

For many years, it was believed that ventilation does not limit performance in healthy humans. Recently, however, it has been shown that inspiratory muscles can become fatigued during intense endurance exercise and decrease their exercise performance. Therefore, it is not surprising that respiratory endurance training can prolong intense constant-intensity cycling exercise. To investigate the effects of respiratory endurance training on blood lactate concentration and oxygen consumption (VO2) during exercise and their relationship to performance, 20 healthy, active subjects underwent 30 min of voluntary, isocapnic hyperpnoea 5 days a week, for 4 weeks. Respiratory endurance tests, as well as incremental and constant-intensity exercise tests on a cycle ergometer, were performed before and after the 4-week period. Respiratory endurance increased from 4.6 (SD 2.5) to 29.1 (SD 4.0) min (P < 0.001) and cycling endurance time was prolonged from 20.9 (SD 5.5) to 26.6 (SD 11.8) min (P < 0.01) after respiratory training. The VO2 did not change at any exercise intensity whereas blood lactate concentration was lower at the end of the incremental [10.4 (SD 2.1) vs 8.8 (SD 1.9) mmol x l(-1), P < 0.001] as well as at the end of the endurance exercise [10.4 (SD 3.6) vs 9.6 (SD 2.7) mmol x l(-1), P < 0.01] test after respiratory training. We speculate that the reduction in blood lactate concentration was most likely caused by an improved lactate uptake by the trained respiratory muscles. However, reduced exercise blood lactate concentrations per se are unlikely to explain the improved cycling performance after respiratory endurance training.