The effect of exotic grass Urochloa decumbens (Stapf) R.D.Webster (Poaceae) in the reduction of species richness and change of floristic composition of natural regeneration in the Floresta Nacional de Carajás, Brazil.

The introduction of exotic species is considered as one of the major causes of biodiversity loss. The National Forest of Carajás is one of the largest mineral provinces in the world. Mining activities caused changes of the natural habitats, leaving degraded areas after the mineral exploitation. One of the mining areas within FLONA Carajás was used for the extraction of gold. In the process of exploitation, a huge depression was formed by the removal of soil which was mounded up nearby. To prevent soil erosion of these mounds, an exotic grass, Urochloa decumbens (Stapf) R.D.Webster (Poaceae) was planted. The objective of this study was to compare the impact of this non-native grass on species richness and species composition of the natural regeneration in the degraded areas. Four areas were compared, two with and two without presence of U. decumbens. In each area, twenty four 1m²/plots were established. Species richness of the regeneration areas and population sizes were significantly lower in the plots where the exotic grass was present. Our study shows that U. decumbens had a negative effect on species richness and population density, and its presence changed the species composition and distribution of life forms of the natural regeneration.

Children with dermatological conditions admitted to paediatric intensive care: analysis of a national clinical audit database.

There is little published literature about dermatological conditions in paediatric intensive care units (PICUs). The aim of this study was to describe the range of skin disorders in children admitted to PICUs in the UK and Ireland using data from a national audit. An analysis was conducted using data for 2002 - 2010 from the Paediatric Intensive Care Audit Network (PICANet). In total, 999 admissions of 882 children were identified, representing 0.8% of all PICU admissions. The most frequent dermatological conditions were skin infections, including cellulitis and necrotizing fasciitis, and inflammatory conditions. In 28% of cases, the dermatological diagnosis was considered the reason for PICU admission, in 35% it was a manifestation of systemic disease and in 37% it was considered incidental. Overall mortality was similar to the general PICU population, with 52 deaths (5.2%), but was greater in children with vascular/haematological conditions.

Evidence-based development of a post-surgical lumbar discectomy leaflet intervention: a Delphi consensus study.

OBJECTIVE: To produce free, expert-informed postoperative information for lumbar discectomy patients, satisfying UK National Health Service Information Standards. DESIGN: A mixed methods approach utilising the Delphi technique and focus groups. SETTING: Five spinal centres across the UK. PARTICIPANTS: Panel members included 23 physiotherapists, 11 patients and 17 spinal surgeons. INTERVENTION: Three rounds of questionnaires including open and closed questions and attendance at a clinician/patient focus group. RESULTS: Response rates of 85%, 26% and 35% were achieved for the Delphi rounds. Ten clinicians and six patients participated in the focus groups. Consensus for leaflet sections was achieved in round 1 and content in round 3. The focus groups informed further revisions. CONCLUSIONS: A consensually agreed, Information Standard compliant, patient lumbar discectomy leaflet was produced containing: (1) normal spine anatomy; (2) anatomy disc herniation and surgery; (3) back protection strategies and (4) frequently asked questions. Illustrations of exercises enable tailoring to the individual patient.

Impacts of hydroelectric dams on alluvial riparian plant communities in Eastern Brazilian Amazonian.

The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

A case of focal dermal hypoplasia (Goltz) syndrome with exophytic granulation tissue treated by curettage and photodynamic therapy.

Focal dermal hypoplasia (Goltz) syndrome is a rare genetic disorder characterized by cutaneous, ectodermal and mesodermal defects. We present a case in which painful, exophytic granulation tissue has been the main symptom over the past 15 years. After unsatisfactory results with a number of treatment modalities including topical steroids, silver-nitrate applications, cryotherapy, curettage, excision and pulsed-dye laser, we achieved significant benefit with curettage in combination with photodynamic therapy. Although impaired wound healing has been described in focal dermal hypoplasia, this is, to our knowledge, the first time that pyogenic granuloma-like lesions have been reported.

Glaucoma induced by periorbital topical steroid use--a rare complication.

Eye complications arising during systemic and ophthalmic steroid use are well known. In contrast, there is little highlighting the similar risks associated with topical steroid use around the eyelids. We now describe a 29-year-old lady who used topical steroids in prolonged fashion throughout most of her life for severe eczema, with the recent application of large quantities of potent steroid continuously for one month, including to the periorbital region. Soon after, she presented to her ophthalmologist with severe bilateral glaucoma and irreversible visual loss attributed to the steroid use. Here we emphasise the possible risks of periorbital topical steroid use, as well as the importance of patient education and ophthalmological follow-up.

The molecular basis of plant cell wall extension.

In all terrestrial and aquatic plant species the primary cell wall is a dynamic structure, adjusted to fulfil a diversity of functions. However a universal property is its considerable mechanical and tensile strength, whilst being flexible enough to accommodate turgor and allow for cell elongation. The wall is a composite material consisting of a framework of cellulose microfibrils embedded in a matrix of non-cellulosic polysaccharides, interlaced with structural proteins and pectic polymers. The assembly and modification of these polymers within the growing cell wall has, until recently, been poorly understood. Advances in cytological and genetic techniques have thrown light on these processes and have led to the discovery of a number of wall-modifying enzymes which, either directly or indirectly, play a role in the molecular basis of cell wall expansion.

Arabidopsis thaliana and Saccharomyces cerevisiae NHX1 genes encode amiloride sensitive electroneutral Na+/H+ exchangers.

Sodium at high millimolar levels in the cytoplasm is toxic to plant and yeast cells. Sequestration of Na(+) ions into the vacuole is one mechanism to confer Na(+)-tolerance on these organisms. In the present study we provide direct evidence that the Arabidopsis thaliana At-NHX1 gene and the yeast NHX1 gene encode low-affinity electroneutral Na(+)/H(+) exchangers. We took advantage of the ability of heterologously expressed At-NHX1 to functionally complement the yeast nhx1-null mutant. Experiments on vacuolar vesicles isolated from yeast expressing At-NHX1 or NHX1 provided direct evidence for pH-gradient-energized Na(+) accumulation into the vacuole. A major difference between NHX1 and At-NHX1 is the presence of a cleavable N-terminal signal peptide (SP) in the former gene. Fusion of the SP to At-NHX1 resulted in an increase in the magnitude of Na(+)/H(+) exchange, indicating a role for the SP in protein targeting or regulation. Another distinguishing feature between the plant and yeast antiporters is their sensitivity to the diuretic compound amiloride. Whereas At-NHX1 was completely inhibited by amiloride, NHX1 activity was reduced by only 20-40%. These results show that yeast as a heterologous expression system provides a convenient model to analyse structural and regulatory features of plant Na(+)/H(+) antiporters.

Cutis verticis gyrata of the scalp in a patient with autosomal dominant insulin resistance syndrome.

Cutis verticis gyrata (CVG) is a rare disorder; it is characterized by thickening of the scalp which becomes raised to form ridges and furrows resembling the cerebral gyri. We report a case of CVG associated with the autosomal dominant insulin resistance syndrome. This syndrome is characterized by obesity, mild mental retardation, delayed puberty, acanthosis nigricans and hyperinsulinaemia. The association of CVG and autosomal dominant insulin resistance has not been previously described.

Childhood dermatitis herpetiformis: an unusual presentation.

Childhood dermatitis herpetiformis (DH) is rare. The true prevalence and incidence of this condition are unknown. We report a 7-year-old boy presenting with nonpruritic inflammatory papules on the buttocks and extensor surfaces, clinico-pathologically consistent with Sweet's neutrophilic dermatosis. Immunofluorescence studies showed IgA deposits in the dermal papillae consistent with DH. Remission was achieved with a gluten-free diet and dapsone. Childhood DH may present different clinical signs to the adult form and misdiagnosis can occur if immunofluorescence is not requested on skin biopsy.

Xanthoma disseminatum: a case with hepatic involvement, diabetes insipidus and type IIb hyperlipidaemia.

Xanthoma disseminatum (XD) is a rare benign non-X-histiocytic disorder of unknown aetiology. We report a 37-year-old man who presented with XD preceded by a decade of cranial diabetes insipidus, with associated type IIb hyperlipidaemia and computed tomographic evidence of hepatic involvement. A review of the literature is also included.

The prevalence of skin disease in HIV infection.

The frequency of skin problems in patients with HIV infection and AIDS is well known from clinical experience and from the reports of cohorts of patients followed over months and years. Decreased mucocutaneous immunity often accounts for the earliest clinical signs seen in HIV-infected patients. As HIV disease progresses, these skin manifestations may become more severe and varied. In advanced immunosuppression, opportunistic pathogens may present as atypical cutaneous lesions. The following two cases illustrate a number of important points in relation to the management of skin disease in HIV patients.

The prevalence of skin disease in HIV infection and its relationship to the degree of immunosuppression.

A cross-sectional study of human immunodeficiency virus (HIV) positive patients who attended the HIV clinic in Brighton over a 4-month period was carried out to describe the prevalence and severity of skin manifestations in HIV-positive patients and to elucidate their association with the peripheral CD4 cell count and with the HIV disease stage. The subjects were consecutively examined by an experienced dermatologist. Skin manifestations were classified into infections, dermatoses, pruritus and neoplasm. A severity index was derived by scoring each condition as either absent, mild, moderate or severe. One hundred and fifty-one patients were enrolled with a mean age of 38.3 years. One hundred and thirty-nine were homo/bisexual men; 58 were asymptomatic and 35 had acquired immune deficiency syndrome (AIDS); 37 had CD4 counts below 200. Skin conditions were present in 138 of the 151 subjects (91.4%). The total number of events was 331. The most frequent problem was infection followed by dermatoses, pruritus and malignancy. The most frequent condition was seborrhoeic eczema followed by tinea and xerosis. We have demonstrated a statistically significant association between CD4 count, disease stage and skin manifestations in HIV-positive individuals.