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Glial cell transplantation has the potential to be developed into a clinical treatment for human demyelinating diseases because of its demonstrated efficacy in remyelinating experimentally demyelinated axons. As a step towards clinical application it is necessary to demonstrate that the procedure is safe and efficacious in promoting behavioural recovery. In this study we transplanted glial cell progenitors into demyelinating lesions induced by intraspinal injection of ethidium bromide in the rat. Locomotor function after transplantation was assessed using a beam-walking test that has previously been shown able to detect deficits associated with demyelination in the dorsal funiculus of the rat spinal cord. Two groups of animals with transplants were examined. In one group, spontaneous remyelination was prevented by exposure of the lesion to 40 Gy of X-irradiation; in the other, male glial cells were transplanted into nonirradiated female recipients, permitting their identification by use of a probe specific to the rat Y chromosome. Following transplantation, there was severe axon loss in a large proportion of the irradiated animals and those affected did not recover normal behavioural function. In contrast, both the small proportion of the irradiated group that sustained only mild axon loss and the nonirradiated recipients of transplants recovered normal function on our behavioural test. We conclude that glial cell transplantation is able to reverse the functional deficits associated with demyelination, provided axonal loss is minimal.

Summary Deadwood is an integral and often substantial component of natural forests. It provides wildlife habitat, maintains ecosystem health and influences geomorphological processes. In managed forests, however, potential deadwood volumes are reduced by felling and extraction of timber to a small fraction of the volume found in natural forests. This impairs biodiversity and can affect some aspects of ecosystem health and geomorphological processes. Recent international conventions and national policy commitments aimed at sustaining biodiversity and ecosystem functions imply that British forests should contain more deadwood. This review identifies priorities and outlines a strategy whereby quantities of deadwood, and the benefits that it offers, may be usefully increased without disproportionate reductions in the output of timber and wood.

Summary Forty-six unmanaged urban and ex-industrial sites in the county of Avon, South Staffordshire and the West Midlands were visited in 1992/93 during a survey which aimed to relate site factors with natural colonization by trees and shrubs. The factors observed included: type and texture of substrate; the predominant type of vegetation; aspect; the presence of parents in the near vicinity of the site and the numbers and species of colonizing woody plants. The extent of woody colonization was very variable and despite an average stocking density of 1500 stems ha"1, only 19 per cent of the land surveyed was colonized to an acceptable woodland standard. Woodland produced by natural colonization was species poor with an average of three per site; the most abundant species were ash, birch, goat willow and hawthorn, which made up 85 per cent of the colonization recorded. Although there was variation between species, the presence of the parent was usually the most important factor associated with colonization; when potential parent trees were visible from the site there was, on average, a 58 per cent probability of finding colonization of the corresponding species. In general, colonizing plants were positively associated with subsoil, small stony substrates such as gravel and ballast, and a weak grass sward. Conversely colonization was negatively associated with loam soils, sand, unfractured rock/concrete substrates, and sites with grazed sward or no vegetation.

During the Persian Gulf War, soldiers may have inhaled, ingested, and/or experienced wound contamination by depleted uranium (DU), which is used in military projectiles and armor. DU is produced by depleting natural uranium of 234U and 235U during the uranium-enrichment process. Although the long-term effects of significant DU exposures require investigation, many veterans express fears about its impact on health. An assay by which DU exposure can be assessed would not only be a useful research tool, but the information could help mitigate the concerns of exposed individuals. In this study, urine samples from individuals enrolled in the Depleted Uranium Follow-Up Program at the Baltimore Veterans Administration Medical Center were examined for uranium content. Isotopic composition of urine uranium was determined by measuring the 235U/238U ratio, using an inductively coupled plasma mass spectrometer. Using this method, natural and depleted uranium could be readily differentiated. By demonstrating the absence of DU in soldiers who suspect exposure by inhalation or ingestion, the assay should reduce psychological stress in these individuals.

Glial cell transplantation has the potential to be developed into a clinical treatment for human demyelinating diseases because of its demonstrated efficacy in remyelinating experimentally demyelinated axons. As a step towards clinical application it is necessary to demonstrate that the procedure is safe and efficacious in promoting behavioural recovery. In this study we transplanted glial cell progenitors into demyelinating lesions induced by intraspinal injection of ethidium bromide in the rat. Locomotor function after transplantation was assessed using a beam-walking test that has previously been shown able to detect deficits associated with demyelination in the dorsal funiculus of the rat spinal cord. Two groups of animals with transplants were examined. In one group, spontaneous remyelination was prevented by exposure of the lesion to 40 Gy of X-irradiation; in the other, male glial cells were transplanted into nonirradiated female recipients, permitting their identification by use of a probe specific to the rat Y chromosome. Following transplantation, there was severe axon loss in a large proportion of the irradiated animals and those affected did not recover normal behavioural function. In contrast, both the small proportion of the irradiated group that sustained only mild axon loss and the nonirradiated recipients of transplants recovered normal function on our behavioural test. We conclude that glial cell transplantation is able to reverse the functional deficits associated with demyelination, provided axonal loss is minimal.

This paper describes Britain’s approach to the conservation of forest biodiversity and aims to show how the Forestry Commission is evolving systems of sustainable forest management and biodiversity evaluation suited to Britain’s substantial plantation forest resource. A Biodiversity Research Programme is an important part of this strategy, and is formulated to provide the guidance and decision support tools required by forest managers to follow an ecologically based forest design and management planning process.

Lentigo maligna (LM) is a pigmented neoplasm on sun-exposed skin of elderly patients. LM slowly increases in size and may become lentigo maligna melanoma (LMM), a potentially fatal malignancy. Complete excision is the treatment of choice. Mohs' micrographic surgery (MMS) with frozen and permanent sections may be used for complete eradication of the lesion, while sparing as much normal tissue as possible. The authors studied the efficacy of MMS for the treatment of LM and LMM.Between 1985 and 1992, 45 patients with LM (26) and LMM (19) were treated with MMS. The authors' technique was to use examination of frozen sections and rush permanent sections (prepared and read within 24 hours). Positive frozen sections warranted further excision. For negative or equivocal frozen sections, surgery was interrupted until the examination of permanent sections was performed.All 45 patients were free of local disease and evidence of metastases at an average of 29.2 months (range, 4-81 months) after therapy.MMS aided by rush permanent sections yielded a prolonged disease free survival for all 45 patients with LM or LMM. Because the MMS technique minimizes the removal of normal tissue, and the local cure rate in this study was superior to that reported for conventional surgery, the authors recommend this technique for the treatment of LM and LMM.

The appropriate method for surgical management of melanocytic lesions with disordered architecture and melanocytic atypia (formerly dysplastic nevi) has been controversial. Physicians often reexcise these lesions after primary removal because of their potential relation to malignant melanoma. The outcomes of these reexcisions and the original biopsy specimens have not been previously examined.The purpose of this study was to examine reexcision specimens and their respective original specimens to determine whether there were any characteristics predictive of the presence of residual nevus cells (RNCs) on reexcision.One hundred eighty-nine reexcision specimens of atypical melanocytic lesions were evaluated for this study. The original specimens were examined for specific histopathologic features without knowledge of the findings on reexcision. Clinical characteristics were also examined.Of the 189 reexcision specimens, 47 (24.9%) contained RNCs. The proportion of specimens with RNC on reexcision was significantly greater if the original lesion was removed by punch biopsy rather than by shave or elliptical excision (38.3% vs 22.0% vs 10.5%, respectively; p0.03). Lesions located on the chest had a higher likelihood of RNCs than those on the back or leg (52.2% vs 21.7%; p = 0.009; 52.2% vs 9.7%, p0.002, respectively). Mean age was greater in those with RNCs at reexcision than those without (43.6 vs 37.9 years, respectively; p0.0001). The proportion of specimens with RNCs at reexcision was greater in those that had both lateral margins involved than in those that had nevus cells in either one or neither of the lateral margins in the original biopsy specimens (39.7% vs 24.0% vs 7.8%, respectively; p = 0.0005). One of the 189 reexcision specimens (0.5%) contained melanoma, although the original histopathologic diagnosis was an atypical melanocytic nevus.We identified several clinical and histopathologic factors that are strongly associated with the presence of RNCs on reexcision.

We report herein a case of a linear nevus comedonicus associated with tumors of sweat gland origin. We propose the term "linear eccrine nevus with comedones" as a suitable title for this disorder. Several similar cases in the literature are reviewed.

Deficiency of the second component of complement (C2d) has been associated with systemic lupus erythematosus (LE)-like syndromes as well as recurrent infections. In particular, C2d has been associated with the LE subset of subacute cutaneous LE (SCLE), the presence of anti-Ro antibodies (anti-Ro or SS-A), and the human leukocyte antigen (HLA) types A25, B18, and DR2. A family with C2d in which three members have developed SCLE was observed and studied clinically, serologically, and immunogenetically. Deficiency of the second component of complement was present in all six family members, while anti-Ro was present in only two. There was a strong but incomplete association of C2d and SCLE with HLA-DR2, but the association was not complete with positivity of anti-Ro or antinuclear antibodies. Study of this family reconfirmed the close association of HLA-A25, -B18 and -DR2 with the C2 gene, but indicated a less close association of these loci with serologic markers.

A patient is presented herein with an acute generalized eczematoid eruption. The onset occurred in late spring and was caused by the American bird mite, Dermanyssus americanus. A review of mite infestations is presented. We suggest that puzzling cutaneous eruptions be evaluated closely as being possibly caused by mites.

Purpura fulminans is the cutaneous manifestation of acute activation of the clotting mechanism resulting in massive hemorrhage due to an intravascular consumption coagulopathy. Peripheral necrotizing purpura is a warning signal, and early recognition of the clinical situation and heparin therapy may be lifesaving. Clinical manifestations and histologic features of this condition, along with its pathogenesis, treatment, and differential diagnosis are discussed.

An 8-year-old boy with erythropoietic protoporphyria had a marked decrease in photosensitivity symptoms after several transfusions with washed, packed RBCs. The reduction in photosensitivity was associated with a decline in free erythrocyte protoporphyrin levels.