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The Antarctic marine environment is a dynamic ecosystem where microorganisms play an important role in key biogeochemical cycles. Despite the role that microbes play in this ecosystem, little is known about the genetic and metabolic diversity of Antarctic marine microbes. In this study we leveraged DNA samples collected by the Palmer Long Term Ecological Research (LTER) project to sequence shotgun metagenomes of 48 key samples collected across the marine ecosystem of the western Antarctic Peninsula (wAP). We developed an in silico metagenomics pipeline (iMAGine) for processing metagenomic data and constructing metagenome-assembled genomes (MAGs), identifying a diverse genomic repertoire related to the carbon, sulfur, and nitrogen cycles. A novel analytical approach based on gene coverage was used to understand the differences in microbial community functions across depth and region. Our results showed that microbial community functions were partitioned based on depth. Bacterial members harbored diverse genes for carbohydrate transformation, indicating the availability of processes to convert complex carbons into simpler bioavailable forms. We generated 137 dereplicated MAGs giving us a new perspective on the role of prokaryotes in the coastal wAP. In particular, the presence of mixotrophic prokaryotes capable of autotrophic and heterotrophic lifestyles indicated a metabolically flexible community, which we hypothesize enables survival under rapidly changing conditions. Overall, the study identified key microbial community functions and created a valuable sequence library collection for future Antarctic genomics research., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Dutta, Connors, Trinh, Erazo, Dasarathy, Ducklow, Steinberg, Schofield and Bowman.)

The krill surplus hypothesis of unlimited prey resources available for Antarctic predators due to commercial whaling in the 20th century has remained largely untested since the 1970s. Rapid warming of the Western Antarctic Peninsula (WAP) over the past 50 years has resulted in decreased seasonal ice cover and a reduction of krill. The latter is being exacerbated by a commercial krill fishery in the region. Despite this, humpback whale populations have increased but may be at a threshold for growth based on these human-induced changes. Understanding how climate-mediated variation in prey availability influences humpback whale population dynamics is critical for focused management and conservation actions. Using an 8-year dataset (2013-2020), we show that inter-annual humpback whale pregnancy rates, as determined from skin-blubber biopsy samples (n = 616), are positively correlated with krill availability and fluctuations in ice cover in the previous year. Pregnancy rates showed significant inter-annual variability, between 29% and 86%. Our results indicate that krill availability is in fact limiting and affecting reproductive rates, in contrast to the krill surplus hypothesis. This suggests that this population of humpback whales may be at a threshold for population growth due to prey limitations. As a result, continued warming and increased fishing along the WAP, which continue to reduce krill stocks, will likely impact this humpback whale population and other krill predators in the region. Humpback whales are sentinel species of ecosystem health, and changes in pregnancy rates can provide quantifiable signals of the impact of environmental change at the population level. Our findings must be considered paramount in developing new and more restrictive conservation and management plans for the Antarctic marine ecosystem and minimizing the negative impacts of human activities in the region., (© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

The West Antarctic Peninsula (WAP) is a climatically sensitive region where periods of strong warming have caused significant changes in the marine ecosystem and food-web processes. Tight coupling between phytoplankton and higher trophic levels implies that the coastal WAP is a bottom-up controlled system, where changes in phytoplankton dynamics may largely impact other food-web components. Here, we analysed the inter-decadal time series of year-round chlorophyll- a (Chl) collected from three stations along the coastal WAP: Carlini Station at Potter Cove (PC) on King George Island, Palmer Station on Anvers Island and Rothera Station on Adelaide Island. There were trends towards increased phytoplankton biomass at Carlini Station (PC) and Palmer Station, while phytoplankton biomass declined significantly at Rothera Station over the studied period. The impacts of two relevant climate modes to the WAP, the El Niño-Southern Oscillation and the Southern Annular Mode, on winter and spring phytoplankton biomass appear to be different among the three sampling stations, suggesting an important role of local-scale forcing than large-scale forcing on phytoplankton dynamics at each station. The inter-annual variability of seasonal bloom progression derived from considering all three stations together captured ecologically meaningful, seasonally co-occurring bloom patterns which were primarily constrained by water-column stability strength. Our findings highlight a coupled link between phytoplankton and physical and climate dynamics along the coastal WAP, which may improve our understanding of overall WAP food-web responses to climate change and variability.This article is part of the theme issue 'The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change'., (© 2018 The Author(s).)

Understanding the mechanisms by which climate variability affects multiple trophic levels in food webs is essential for determining ecosystem responses to climate change. Here we use over two decades of data collected by the Palmer Long Term Ecological Research program (PAL-LTER) to determine how large-scale climate and local physical forcing affect phytoplankton, zooplankton and an apex predator along the West Antarctic Peninsula (WAP). We show that positive anomalies in chlorophyll-a (chl-a) at Palmer Station, occurring every 4-6 years, are constrained by physical processes in the preceding winter/spring and a negative phase of the Southern Annular Mode (SAM). Favorable conditions for phytoplankton included increased winter ice extent and duration, reduced spring/summer winds, and increased water column stability via enhanced salinity-driven density gradients. Years of positive chl-a anomalies are associated with the initiation of a robust krill cohort the following summer, which is evident in Adélie penguin diets, thus demonstrating tight trophic coupling. Projected climate change in this region may have a significant, negative impact on phytoplankton biomass, krill recruitment and upper trophic level predators in this coastal Antarctic ecosystem.

Although dermatoses affecting the soles of the feet in children are regularly encountered in dermatology clinics, the relationship with allergic contact dermatitis affecting this part of the foot is not well established. The aim of this study was to evaluate the relevance of patch testing children with sole dermatoses. We reviewed the results of all patch tests performed in children (<18 years) presenting with dermatoses involving the soles between 1997 and 2009 from our departmental patch test database. Forty-one children were identified: 27 children with an inflammatory dermatitis affecting the sole and 14 children with juvenile plantar dermatosis (JPD). Seventeen (41%) children had at least one clinically relevant positive patch test reaction. Rubber additives and potassium dichromate were the most frequent allergens identified. Forty-eight percent of children with inflammatory dermatitis affecting the sole and 29% of children with JPD had at least one relevant reaction. Of the children with relevant reactions, 76% had a personal or family history of atopy. Our results demonstrate the importance of patch testing children with dermatoses affecting the soles and indicate that a history of atopy or a diagnosis of JPD should not deter investigation., (© 2011 Wiley Periodicals, Inc.)

The mechanisms of coral calcification at the molecular, cellular and tissue levels are poorly understood. In this study, we examine calcium carbonate precipitation using novel coral tissue cultures that aggregate to form "proto-polyps". Our goal is to establish an experimental system in which calcification is facilitated at the cellular level, while simultaneously allowing in vitro manipulations of the calcifying fluid. This novel coral culturing technique enables us to study the mechanisms of biomineralization and their implications for geochemical proxies. Viable cell cultures of the hermatypic, zooxanthellate coral, Stylophora pistillata, have been maintained for 6 to 8 weeks. Using an enriched seawater medium with aragonite saturation state similar to open ocean surface waters (Ω(arag)~4), the primary cell cultures assemble into "proto-polyps" which form an extracellular organic matrix (ECM) and precipitate aragonite crystals. These extracellular aragonite crystals, about 10 µm in length, are formed on the external face of the proto-polyps and are identified by their distinctive elongated crystallography and X-ray diffraction pattern. The precipitation of aragonite is independent of photosynthesis by the zooxanthellae, and does not occur in control experiments lacking coral cells or when the coral cells are poisoned with sodium azide. Our results demonstrate that proto-polyps, aggregated from primary coral tissue culture, function (from a biomineralization perspective) similarly to whole corals. This approach provides a novel tool for investigating the biophysical mechanism of calcification in these organisms.

The size structure of phytoplankton assemblages strongly influences energy transfer through the food web and carbon cycling in the ocean. We determined the macroevolutionary trajectory in the median size of dinoflagellate cysts to compare with the macroevolutionary size change in other plankton groups. We found the median size of the dinoflagellate cysts generally decreases through the Cenozoic. Diatoms exhibit an extremely similar pattern in their median size over time, even though species diversity of the two groups has opposing trends, indicating that the macroevolutionary size change is an active response to selection pressure rather than a passive response to changes in diversity. The changes in the median size of dinoflagellate cysts are highly correlated with both deep ocean temperatures and the thermal gradient between the surface and deep waters, indicating the magnitude and frequency of nutrient availability may have acted as a selective factor in the macroevolution of cell size in the plankton. Our results suggest that climate, because it affects stratification in the ocean, is a universal abiotic driver that has been responsible for macroevolutionary changes in the size structure of marine planktonic communities over the past 65 million years of Earth's history.

Trait-based approaches to community structure are increasingly used in terrestrial ecology. We show that such an approach, augmented by a mechanistic analysis of trade-offs among functional traits, can be successfully used to explain community composition of marine phytoplankton along environmental gradients. Our analysis of literature on major functional traits in phytoplankton, such as parameters of nutrient-dependent growth and uptake, reveals physiological trade-offs in species abilities to acquire and utilize resources. These trade-offs, arising from fundamental relations such as cellular scaling laws and enzyme kinetics, define contrasting ecological strategies of nutrient acquisition. Major groups of marine eukaryotic phytoplankton have adopted distinct strategies with associated traits. These diverse strategies of nutrient utilization can explain the distribution patterns of major functional groups and size classes along nutrient availability gradients.

Eukaryotic genome size varies over five orders of magnitude; however, the distribution is strongly skewed toward small values. Genome size is highly correlated to a number of phenotypic traits, suggesting that the relative lack of large genomes in eukaryotes is due to selective removal. Using phylogenetic contrasts, we show that the rate of genome size evolution is proportional to genome size, with the fastest rates occurring in the largest genomes. This trend is evident across the 20 major eukaryotic clades analyzed, indicating that over long time scales, proportional change is the dominant and universal mode of genome-size evolution in eukaryotes. Our results reveal that the evolution of eukaryotic genome size can be described by a simple proportional model of evolution. This model explains the skewed distribution of eukaryotic genome sizes without invoking strong selection against large genomes.

We applied two numerical methods to in situ hyperspectral measurements of remote sensing reflectance Rrs to assess the feasibility of remote detection and monitoring of the toxic dinoflagellate, Karenia brevis, which has been shown to exhibit unique absorption properties. First, an existing quasi-analytical algorithm was used to invert remote sensing reflectance spectra, Rrs(lambda), to derive phytoplankton absorption spectra, a(phi)Rrs(lambda). Second, the fourth derivatives of the a(phi)Rrs(lambda) spectra were compared to the fourth derivative of a reference K. brevis absorption spectrum by means of a similarity index (SI) analysis. Comparison of reflectance-derived a(phi) with filter pad measured a(phi) found them to agree well (R2=0.891; average percentage difference, 22.8%). A strong correlation (R2=0.743) between surface cell concentration and the SI was observed, showing the potential utility of SI magnitude as an indicator of bloom strength. A sensitivity analysis conducted to investigate the effects of varying levels of cell concentrations and colored dissolved organic matter (CDOM) on the efficacy of the quasi-analytical algorithm and SI found that a(phi)Rrs(lambda) could not be derived for very low cell concentrations and that, although it is possible to derive a(phi)Rrs(lambda) in the presence of high CDOM concentrations, CDOM levels influence the a(phi)Rrs(lambda) amplitude and shape. Results suggest that detection and mapping of K. brevis blooms based on hyperspectral measurements of Rrs are feasible.

We present a simple nutrient-phytoplankton-zooplankton (NPZ) model that incorporates adaptive evolution and allometric relations to examine the patterns and consequences of adaptive changes in plankton body size. Assuming stable environmental conditions, the model makes the following predictions. First, phytoplankton should evolve toward small sizes typical of picoplankton. Second, in the absence of grazers, nutrient concentration is minimized as phytoplankton reach their fitness maximum. Third, increasing nutrient flux tends to increase phytoplankton cell size in the presence of phytoplankton-zooplankton coevolution but has no effect in the absence of zooplankton. Fourth, phytoplankton reach their fitness maximum in the absence of grazers, and the evolutionary nutrient-phytoplankton system has a stable equilibrium. In contrast, phytoplankton may approach their fitness minimum in the evolutionary NPZ system where phytoplankton and zooplankton are allowed to coevolve, which may result in oscillatory (unstable) dynamics of the evolutionary NPZ system, compared with the otherwise stable nonevolutionary NPZ system. These results suggest that evolutionary interactions between phytoplankton and zooplankton may have contributed to observed changes in phytoplankton sizes and associated biogeochemical cycles over geological time scales.

Numerous taxonomic groups exhibit an evolutionary trajectory in cell or body size. The size structure of marine phytoplankton communities strongly affects food web structure and organic carbon export into the ocean interior, yet macroevolutionary patterns in the size structure of phytoplankton communities have not been previously investigated. We constructed a database of the size of the silica frustule of the dominant fossilized marine planktonic diatom species over the Cenozoic. We found that the minimum and maximum sizes of the diatom frustule have expanded in concert with increasing species diversity. In contrast, the mean area of the diatom frustule is highly correlated with oceanic temperature gradients inferred from the delta18O of foraminiferal calcite, consistent with the hypothesis that climatically induced changes in oceanic mixing have altered nutrient availability in the euphotic zone and driven macroevolutionary shifts in the size of marine pelagic diatoms through the Cenozoic.

Oral terbinafine is licensed for use in onychomycosis after positive confirmation of infection. We describe five cases of subacute cutaneous lupus erythematosus associated with terbinafine therapy. All cases had positive antibodies to extractable nuclear antigens, predominantly anti-Ro, and several had a history of pre-existing autoimmune disease. Terbinafine should only be prescribed after confirmation of infection by microscopy or culture.

The majority of organic carbon in the oceans is present as dissolved organic matter (DOM); therefore understanding the distribution and dynamics of DOM is central to understanding global carbon cycles. Describing the time-space variability in colored dissolved organic matter (CDOM) has been difficult, as standard spectrophotometric methods for CDOM determination are laborious and susceptible to methodological biases. Previously, measurements of CDOM absorption in discrete water samples by use of a liquid-waveguide capillary cell (LWCC) compared favorably with measurements made with a benchtop spectrophotometer. Given this, we focused on automating the LWCC technique to improve our spatial and temporal sampling capabilities for CDOM. We found strong correlations between CDOM absorption spectra collected from discrete water samples using standard methods and selected corresponding CDOM spectra collected by the automated LWCC system. The near-continuous measurements by the LWCC system made it possible to map the temporal, spatial, and spectral variability of CDOM absorption along the ship track.

Kawasaki disease is one of the commonest vasculitides seen in children. It presents with prolonged fever and a polymorphic exanthem. It is a major cause of acquired heart disease in western society. Its exact cause is not known, but exposure to a superantigen has been suggested as a possible aetiological factor. Diagnosis of Kawasaki disease still relies on clinical criteria (Table 1) and investigations are done mainly to exclude other diseases and to detect early or established cardiac complications. Coronary complications can be reduced significantly by the use of intravenous immunoglobulin therapy combined with oral aspirin. The serious consequences of Kawasaki disease require a heightened awareness of this condition when dealing with childhood exanthems.

Low light adapted cultures of the marine diatom Thalassiosira pseudonana (3H) were cultured and incubated for 30 min under different ultraviolet (UV) wavelengths of near monochromatic light with and without background photosynthetically active radiation (PAR, 380-700 nm). Maximum damage to the quantum yield for stable charge separations was found in the UVB (280-320 nm) wavelengths without background PAR light while the damage under PAR was 30% less. UV induced damage to carbon fixation in the cells was described by a function similar to non-linear functions of inhibiting irradiance previously published with the exception that damage was slightly higher in the UVA (320-380). Various measurements of fluorescent transients were measured and the results indicate localised damage most likely on the acceptor side of the Photosystem II reaction center. However, dark adapted measurements of fluorescence transients with and without DCMU do not result in similar functions. This is also true for the relationships between fluorescence transients and carbon fixation for this species of marine diatom. The correlation between the weightings varepsilon (H) from measurements of carbon fixation and the quantum yield for stable charge separation as calculated from induction curves with DCMU and without DCMU is R (2) 0.44 and R (2) 0.78, respectively. The slopes of the two measurements are 3.8 and 1.4, respectively. The strong correlation between the weightings of the induction curves without DCMU and carbon fixation are due to a loss of electron transport from the reaction center to plastoquinone. Under these experimental conditions of constant photon flux density (PFD) this is manifested as a strong linear relationship between the decrease in the operational quantum yield of Photosystem II and carbon fixation.

5'-Adenylylsulfate (APS) reductase was characterized in diverse marine algae. A cDNA encoding APS reductase from Enteromorpha intestinalis (EAPR) was cloned by functional complementation of an Escherichia coli cysH mutant. The deduced amino acid sequence shows high homology with APS reductase (APR) from flowering plants. Based on the probable transit peptide cleavage site the mature protein is 45.7 kD. EAPR expressed as a His-tagged recombinant protein catalyzes reduced glutathione-dependent reduction of APS to sulfite, exhibiting a specific activity of approximately 40 micromol min(-1) mg protein(-1) and Michealis-Menten kinetic constants of approximately 1.4 mM for reduced glutathione and approximately 6.5 microM for APS. APR activity and expression were studied in relation to the production of 3-dimethylsulfoniopropionate (DMSP), a sulfonium compound produced by many marine algae. A diverse group of DMSP-producing species showed extremely high enzyme activity (up to 400 times that found in flowering plants). Antibodies raised against a conserved peptide of APR strongly cross-reacted with a protein of 45 kD in several chlorophytes but insignificantly with chromophytes. In the chlorophyte Tetraselmis sp., APR activity varies significantly during the culture cycle and does not follow the changes in cellular DMSP content. However, a positive correlation was found between cell-based APR activity and specific growth rate.

Background and Design: In this study we developed an in vitro model of nodular basal cell carcinoma (BCC). We obtained pure cultures of BCC cells and compared the morphologic characteristics, ultrastructure, immunophenotype, and behavior of cultured tumor cells with those of their in vivo counterparts. Tumors were excised from patients undergoing Mohs micrographic surgery. We established 69 primary cell cultures from 32 patients with nodular BCC., Results: Three cell types grew in primary cultures: fibroblasts, normal-appearing keratinocytes, and cells with dual (spindle and epithelioid) morphologic characteristics. Contaminating fibroblasts were removed using 0.125% trypsin-0.02% edetic acid, and normal-appearing keratinocytes were cornified and eliminated by temporarily increasing the concentration of calcium in the growth medium. The cells with dual morphologic characteristics remained intact and exhibited relentless growth in pure cultures. That these seemingly immortal cell strains represent true nodular BCC was demonstrated by (1) their biphasic morphologic characteristics and very slow cell growth rate, (2) their capability for anchorage-independent growth in soft agar, (3) their ultrastructural similarities to freshly excised nodular BCC, (4) their ability to generate antibodies selectively labeling nodular BCC tumor nests in vivo, and (5) their immunophenotypic similarities to BCC in vivo on more than 20 different cell markers., Conclusions: This study provides a simple technique for establishing pure cell cultures of nodular BCC and describes extensively the in vitro parameters of tumor cell growth. The striking differences in behavior of cultured tumor cells in the presence or absence of normal-appearing keratinocytes suggest that normal human epidermal keratinocytes can suppress the growth of BCC cells.

We report a study of eight unrelated adult patients with a highly distinctive phenotype of dystrophic epidermolysis bullosa. It is characterized clinically by pruritus, lichenified or nodular prurigo-like lesions, violaceous linear scarring, occasional trauma-induced blistering, excoriations, milia, nail dystrophy and, in some cases, albopapuloid lesions on the trunk. The scarring is most evident on the limbs, particularly on the shins, with relative sparing elsewhere. Intact blisters are rarely seen. Physical signs were present at birth in three patients, but in the others skin manifestations were first noticed between 6 months and 10 years of age. Five cases are sporadic, but three of the eight patients have a history of familial involvement, with autosomal dominant inheritance in two cases and recessive transmission in the other case. Studies of the dermal-epidermal junction showed alterations in the number and ultrastructure of anchoring fibrils in lesional, perilesional and non-lesional skin, consistent with a diagnosis of dominant or localized recessive dystrophic epidermolysis bullosa. These patients represent an unusual, poorly recognized form or expression of dystrophic epidermolysis bullosa which has features in common with a variety of acquired inflammatory dermatoses.

Background: Patients with recessive dystrophic epidermolysis bullosa (RDEB) frequently have painful erosions that are slow to heal. There is no definitive treatment; therefore any therapy that improves wound healing would be beneficial to these patients., Objective: Our purpose was to assess the effects of cultured allogeneic keratinocytes on wound healing in RDEB., Methods: Ten patients with RDEB and dermatome-induced superficial dermal wounds were studied. Cultured keratinocyte grafts were applied to part of the wound, with another part left ungrafted. Both sites were assessed clinically and microscopically, particularly with regard to basement membrane zone reconstitution., Results: Apart from minor differences in keratinocyte differentiation and a moderate analgesic effect induced by the graft, there were no other distinguishing findings in wound healing in the grafted and nongrafted sites., Conclusion: There was little clinical benefit from cultured keratinocyte allografts in wound healing in RDEB. However, this study showed that RDEB keratinocytes have an inherent capacity to express some type VII collagen epitopes transiently during wound healing, although this was not associated with the detection of anchoring fibrils.

The mouth, oesophagus, and anus are often involved in dystrophic and junctional epidermolysis bullosa, but the frequency is unknown. Among 246 patients with epidermolysis bullosa, dysphagia developed in 76% of those with recessive dystrophic, in 20% of those with dominant dystrophic, in 15% of those with junctional, and in 2% of those with simplex forms. Lingual adhesions or microstomia occurred in dystrophic epidermolysis bullosa only, but were eight times more common in recessive than in dominant subtypes. These lesions are provoked by the trauma of eating and further reduce food intake, which exacerbates constipation caused by anal blisters and results in malnutrition. Management requires specialised multidisciplinary care.

The clinicopathological features of 22 cases of the Dowling-Meara form of epidermolysis bullosa simplex (DM-EBS) (11 males, 11 females; aged 5 days-46 years) were reviewed using data collected over a 10-year period. All cases presented clinically within the first 5 days of life. Early blisters were often large (up to 5 cm in diameter), and were mostly acral and particularly periungual. Some cases presented with more widespread erosive skin changes, and two neonates with extensive skin involvement died as a result of overwhelming sepsis. After the neonatal period a different pattern of blistering occurred with more proximal haemorrhagic, herpetiform clusters of blisters. Central healing with recurrent blistering at the margins of these areas was frequently noted. Other physical signs included varying degrees of intra-oral blistering, nail shedding, nail dystrophy, minor scarring, palmo-plantar keratoderma, a lack of seasonal variation and improvement during later childhood. The underlying pathological mechanism in DM-EBS is basal cell cytolysis, or rarely acantholysis, in association with tonofilament (TF) clumping. TF clumping was found in lesional, perilesional and some non-lesional skin, suggesting that the tonofilament abnormality may be of primary aetiological significance in DM-EBS. TF clumping may be due to specific keratin abnormalities because the altered TF were found in a distribution similar to the known distribution of the basal cell keratins, K5 and K14. The level of blistering was invariably very low within the epidermal basal layer and often less than 0.5 microns above the basement membrane. We conclude that DM-EBS is a distinct, and probably under-recognized genodermatosis which tends to have a good prognosis. However, the disease can occasionally be severe, especially during the neonatal period, when it may be confused with junctional or severe recessive dystrophic EB. Electron microscopy is the best means for demonstrating the characteristics cytoskeletal disorder and confirming the diagnosis.

Epidermolysis bullosa (EB) refers to a group of hereditary mechano-bullous conditions, many of which are associated with chronic scarring. Several forms of the disease have been reported in association with cutaneous malignancy. We present a series of 10 EB patients (eight generalised recessive dystrophic EB, one dominant dystrophic EB, one non-lethal junctional EB) aged 24-55 years with a total of 29 squamous cell carcinomas (SCC). Three patients died from metastatic disease associated with invasive, poorly differentiated SCC. Six cases had multiple primary SCC, including three patients with simultaneous multifocal disease. Twenty-eight of the 29 SCC arose on the limbs. Histology revealed that most of the SCC were well or moderately differentiated (22/29). Unusual histological findings included two verrucous SCC, as well as a spindle cell (angiosarcoma-like) SCC. Most of the SCC developed in areas of chronic non-healing ulceration (10/29) or longstanding hyperkeratotic crusting (14/29). The dermis around or beneath the carcinomas was densely scarred, more so than in non-malignant areas. In some cases it was difficult to distinguish the clinical appearances of certain areas of chronic ulceration, scarring, and crusting typical of dystrophic EB from many of the SCC. This study underlines the need for constant vigilance for the development of carcinomas in this group of patients, the occasional diagnostic difficulty, and the potential for metastasis.

A 22-year-old woman, whose first infant had died of lethal junctional epidermolysis bullosa (JEB), requested prenatal diagnosis for her third pregnancy. At 20 weeks gestation, fetal biopsy was performed under direct vision by fetoscopy. A semithin section of epon-embedded skin showed dermo-epidermal separation at the light microscopic level. Electron microscopy revealed the site of separation to be within the lamina lucida of the epidermal basement membrane (EBM). Indirect immunofluorescence on a 5 microns cryostat specimen of skin showed a complete absence of GB3 monoclonal antibody immunostaining at the EBM compared with a control 18 week old normal fetal skin sample. The diagnosis was therefore made that the fetus was affected with lethal JEB and a prostaglandin termination performed. The diagnosis was confirmed by further studies on the aborted fetus. 54 cases of prenatal diagnosis of various types of epidermolysis bullosa performed at Institute of Dermatology over the last 10 years are briefly reviewed. Several social and practical problems to launch prenatal diagnosis in Japan are also discussed.

We report a patient with generalized recessive dystrophic epidermolysis bullosa (RDEB) who developed 3 squamous cell carcinomas. The tumours appeared simultaneously at acral sites on both upper limbs and were poorly differentiated. Despite surgery and radiotherapy the patient died from metastatic disease within 6 months of presentation. This case highlights many of the typical features of this complication of RDEB, including the overall poor prognosis. Of particular interest was the histology of one of the tumours which caused diagnostic difficulties: haematoxylin and eosin staining suggested an angiosarcomatous pathology, but the use of immunocytochemistry proved that the tumour was a squamous cell carcinoma in origin.

GB3 monoclonal antibody detects a normal basement membrane component (GB3 antigen) that is variably expressed in junctional epidermolysis bullosa. To assess the accuracy of GB3 in the diagnosis of junctional epidermolysis bullosa, we have reviewed its use in 250 cases of the major types of epidermolysis bullosa. In the majority of cases of the simplex and dystrophic forms of epidermolysis bullosa, GB3 antigen is normally expressed. In the Herlitz variant of junctional epidermolysis bullosa, GB3 antigen expression is consistently abnormal, but in the non-Herlitz and indeterminate forms of junctional epidermolysis bullosa, 40% of cases express GB3 antigen normally. We propose that GB3 monoclonal antibody is useful in the accurate identification of patients with Herlitz junctional epidermolysis bullosa and may prove equal to electron microscopy for the diagnosis of this disease. For the non-Herlitz variants, it should not be used as an alternative to electron microscopy but may be of special value in the determination of prognosis.

From 4 weeks estimated gestational age (EGA) until the end of the second trimester (24 weeks EGA) the fetal epidermis is covered by a specialised epithelium, the periderm. The origin and function of periderm remain speculative. We have demonstrated, using indirect immunofluorescence and immunoperoxidase staining, that periderm is recognised by a mouse IgM monoclonal antibody (Mab) GB1, which has been raised against a simple extract of human amnion. Immunoelectron microscopy localises GB1 to the amniotic surface of periderm, particularly in association with the microvilli, and also bordering cellular identations of the periderm cells. GB1 antigen (ag) is also expressed by the epithelium of fetal oesophagus, fetal and adult conjunctiva and cornea but is absent in a variety of other fetal and adult tissues including bladder, oral mucosa and thymus. The similar distribution of GB1 ag in both periderm and membranes possibly suggests a common origin and the shared expression with fetal oesophagus and fetal and adult eye may indicate a function related to the fluid environment. We therefore feel that GB1 Mab may be of use in further investigations into the origin, structure and function of human periderm.

The ocular findings in a series of patients with dystrophic epidermolysis bullosa are presented. An immunopathological technique using monoclonal antibodies for examining components of the epithelial basement membrane of the conjunctiva is described and the results obtained on a conjunctival biopsy from a patient with dystrophic epidermolysis bullosa are presented.

The ocular findings in a group of five patients with the nonlethal form of junctional epidermolysis bullosa are presented. A history of recurrent corneal erosion and the presence of corneal scarring were the most common findings. We discuss the possible mechanisms of the ocular changes and describe how the recent application of monoclonal antibody probes to components of the basement membrane are helping to elucidate the basic defect in this condition.