Stable 2 W continuous-wave 261.5 nm laser for cooling and trapping aluminum monochloride.

We present a high-power tunable deep-ultraviolet (DUV) laser that uses two consecutive cavity enhanced doubling stages with LBO and CLBO crystals to produce the fourth harmonic of an amplified homebuilt external cavity diode laser. The system generates up to 2.75 W of 261.5 nm laser light with a ∼2 W stable steady-state output power and performs second harmonic generation in a largely unexplored high intensity regime in CLBO for continuous wave DUV light. We use this laser to perform fluorescence spectroscopy on the A1Π â† X1Σ+ transition in a cold, slow beam of AlCl molecules and probe the A1Π|v' = 0, J' = 1〉 state hyperfine structure for future laser cooling and trapping experiments. This work demonstrates that the production of tunable, watt-level DUV lasers is becoming routine for a variety of wavelength-specific applications in atomic, molecular and optical physics.

Contrasting associations between breeding coloration and parasitism of male Arctic charr relate to parasite species and life cycle stage.

Conspicuous carotenoid ornamentation is considered a signal of individual "quality" and one of the most intensely studied traits found to co-vary with parasitism. Since it has been suggested that only "high quality" individuals have enough resources to express excessive sexual ornaments and resist parasites, current theory struggles to explain cases where the brightest individuals carry the most parasites. Surprisingly little emphasis has been put on the contrasting routes to fitness utilized by different parasite species inhabiting the same host. Using Arctic charr (Salvelinus alpinus) as model species, we hypothesized that skin redness and allocation of carotenoids between skin and muscle (redness ratio) will be positively and negatively associated with parasites using the fish as an intermediate and final host, respectively. Both pigment parameters were indeed positively associated with abundances of parasites awaiting trophic transmission (Diplostomum sp. and Diphyllobothrium spp.) and negatively associated with the abundance of adult Eubothrium salvelini tapeworms. These empirical data demonstrate that contrasting associations between carotenoid coloration and parasite intensities relates to the specific premises of different parasite species and life cycle stages.

Preterm birth affects GABAA receptor subunit mRNA levels during the foetal-to-neonatal transition in guinea pigs.

Modulation of gamma-aminobutyric acid A (GABAA) receptor signalling by the neurosteroid allopregnanolone has a major role in late gestation neurodevelopment. The objective of this study was to characterize the mRNA levels of GABAA receptor subunits (α4, α5, α6 and δ) that are key to neurosteroid binding in the brain, following preterm birth. Myelination, measured by the myelin basic protein immunostaining, was used to assess maturity of the preterm brains. Foetal guinea pig brains were obtained at 62 days' gestational age (GA, preterm) or at term (69 days). Neonates were delivered by caesarean section, at 62 days GA and term, and maintained until tissue collection at 24 h of age. Subunit mRNA levels were quantified by RT-PCR in the hippocampus and cerebellum of foetal and neonatal brains. Levels of the α6 and δ subunits were markedly lower in the cerebellum of preterm guinea pigs compared with term animals. Importantly, there was an increase in mRNA levels of these subunits during the foetal-to-neonatal transition at term, which was not seen following preterm birth. Myelination was lower in preterm neonatal brains, consistent with marked immaturity. Salivary cortisol concentrations, measured by EIA, were also higher for the preterm neonates, suggesting greater stress. We conclude that there is an adaptive increase in the levels of mRNA of the key GABAA receptor subunits involved in neurosteroid action after term birth, which may compensate for declining allopregnanolone levels. The lower levels of these subunits in preterm neonates may heighten the adverse effect of the premature decline in neurosteroid exposure.

Brain-encysting trematodes and altered monoamine activity in naturally infected killifish Fundulus parvipinnis.

This paper presents novel evidence to address mechanisms by which trematode parasites effect behavioural changes in naturally infected fish hosts. California killifish Fundulus parvipinnis infected with the brain-encysting trematode Euhaplorchis californiensis display conspicuous swimming behaviours that render them 30 times more likely to be eaten by birds, the parasite's final host. Prevalence of E. californiensis reaches nearly 100% in most F. parvipinnis populations, with parasite biomass constituting almost 2% of F. parvipinnis biomass in some locations. Despite having thousands of cysts on their brains, infected fish grow and mature at rates comparable to those of uninfected populations. The lack of general pathology combined with the specificity of the altered behaviours suggests that the behavioural changes are due to parasite manipulation. The monoamine neurotransmitters serotonin and dopamine, which control locomotion and social behaviour in fishes and other vertebrates, were examined to explore the underlying mechanisms of this behaviour modification. Whereas previous studies were similarly conducted with experimentally infected fish, in this study, brain dopaminergic and serotonergic activity were analysed in naturally infected fish to assess how E. californiensis may alter F. parvipinnis monoamines in a naturally occurring system. A parasite density-associated decrease in serotonergic activity occurred in the hippocampus of naturally infected fish, as well as a decrease in dopaminergic activity in the raphe nuclei, suggesting that E. californiensis inhibits serotonin and dopamine signaling in naturally infected F. parvipinnis. The neurochemical profile of infected fish is consistent with the hypothesis that E. californiensis affects brain monoaminergic systems in order to induce impulse-driven, active, and aggressive behaviour in its hosts.

Digenean metacercariae of fishes from the lagoon flats of Palmyra Atoll, Eastern Indo-Pacific.

Although many studies on the taxonomy of digenean trematodes of marine fishes have been completed in the Eastern Indo-Pacific (EIP) marine ecoregion, only a few have considered metacercarial stages. Here, the results are presented of a taxonomic survey of the digenean metacercariae of fishes from Palmyra Atoll, a remote and relatively pristine US National Wildlife Refuge located 1680 km SSW of Hawaii. Up to 425 individual fish were collected, comprising 42 fish species, from the sand flats bordering the lagoon of the atoll. Quantitative parasitological examinations of each fish were performed. Morphological descriptions of the encountered digenean metacercariae are provided, together with their prevalence, mean intensities, host and tissue-use. Up to 33,964 individuals were recovered representing 19 digenean metacercaria species from eight families. The species composition of digeneans in lagoon fishes at Palmyra Atoll is a subset of what has previously been reported for the EIP. Further, the large diversity and abundance of metacercariae reported in this study highlight the utility of including this group in future ecological research in the EIP marine ecoregion.

Ecology of the brain trematode Euhaplorchis californiensis and its host, the California killifish ( Fundulus parvipinnis ).

We describe the distribution and abundance of the brain-encysting trematode Euhaplorchis californiensis and its second intermediate host, the California killifish (Fundulus parvipinnis), in 3 estuaries in southern California and Baja California. We quantified the density of fish and metacercariae at 13-14 sites per estuary and dissected 375 killifish. Density (numbers and biomass) was examined at 3 spatial scales, i.e., small replicate sites, habitats, and entire estuaries. At those same scales, factors that might influence metacercaria prevalence, abundance, and aggregation in host individuals and populations were also examined. Metacercaria prevalence was 94-100% among the estuaries. Most fish were infected with 100s to 1,000s of E. californiensis metacercariae, with mean abundance generally increasing with host size. Although body condition of fish did not vary among sites or estuaries, the abundance of metacercariae varied significantly among sites, habitats, estuaries, and substantially with host size and gender. Metacercariae were modestly aggregated in killifish (k > 1), with aggregation decreasing in larger hosts. Across the 3 estuaries, the total populations of killifish ranged from 9,000-12,000 individuals/ha and from 7-43 kg/ha. The component populations of E. californiensis metacercariae ranged from 78-200 million individuals/ha and from 0.1-0.3 kg/ha. Biomass of E. californiensis metacercariae constituted 0.5-1.7% of the killifish biomass in the estuaries. Our findings, in conjunction with previously documented effects of E. californiensis, suggest a strong influence of this parasite on the size, distribution, biomass, and abundance of its killifish host.

Melanin-based skin spots reflect stress responsiveness in salmonid fish.

Within animal populations, genetic, epigenetic and environmental factors interact to shape individual neuroendocrine and behavioural profiles, conferring variable vulnerability to stress and disease. It remains debated how alternative behavioural syndromes and stress coping styles evolve and are maintained by natural selection. Here we show that individual variation in stress responsiveness is reflected in the visual appearance of two species of teleost fish; rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). Salmon and trout skin vary from nearly immaculate to densely spotted, with black spots formed by eumelanin-producing chromatophores. In rainbow trout, selection for divergent hypothalamus-pituitary-interrenal responsiveness has led to a change in dermal pigmentation patterns, with low cortisol-responsive fish being consistently more spotted. In an aquaculture population of Atlantic salmon individuals with more spots showed a reduced physiological and behavioural response to stress. Taken together, these data demonstrate a heritable behavioural-physiological and morphological trait correlation that may be specific to alternative coping styles. This observation may illuminate the evolution of contrasting coping styles and behavioural syndromes, as occurrence of phenotypes in different environments and their response to selective pressures can be precisely and easily recorded.

Parasite manipulation of brain monoamines in California killifish (Fundulus parvipinnis) by the trematode Euhaplorchis californiensis.

California killifish (Fundulus parvipinnis) infected with the brain-encysting trematode Euhaplorchis californiensis display conspicuous swimming behaviours rendering them more susceptible to predation by avian final hosts. Heavily infected killifish grow and reproduce normally, despite having thousands of cysts inside their braincases. This suggests that E. californiensis affects only specific locomotory behaviours. We hypothesised that changes in the serotonin and dopamine metabolism, essential for controlling locomotion and arousal may underlie this behaviour modification. We employed micropunch dissection and HPLC to analyse monoamine and monoamine metabolite concentrations in the brain regions of uninfected and experimentally infected fish. The parasites exerted density-dependent changes in monoaminergic activity distinct from those exhibited by fish subjected to stress. Specifically, E. californiensis inhibited a normally occurring, stress-induced elevation of serotonergic metabolism in the raphae nuclei. This effect was particularly evident in the experimentally infected fish, whose low-density infections were concentrated on the brainstem. Furthermore, high E. californiensis density was associated with increased dopaminergic activity in the hypothalamus and decreased serotonergic activity in the hippocampus. In conclusion, the altered monoaminergic metabolism may explain behavioural differences leading to increased predation of the infected killifish by their final host predators.

Eruptive tufted angiomas in a patient with Crohn's disease.

Angioblastoma is a rare, benign vascular tumour composed of undifferentiated mesenchymal cells with a tendency to form lumina. This entity was first described by Nakagawa in 1949 as angioblastoma, and Wilson Jones was the first to use the term "tufted angioma" in 1976. Tufted angiomas usually occur in infancy and spread slowly. This report describes lesions from the right side of the forehead, forearms, and thighs of a 24 year old man with a four year history of Crohn's disease, who was receiving infliximab in addition to long standing azathioprine and ciprofloxacillin. He developed numerous small itchy erythematous vascular appearing papules, which on histological examination resembled tufted angiomas, showing the classic "cannon ball" appearance. The lesions regressed within three months. This case may represent an eruptive acquired tufted angioma in which immunosuppression or drug induced modification of angiogenesis played a role in its development and regression. One previous case of eruptive tufted angioma has been reported in an immunosuppressed patient.

CL22 - a novel cationic peptide for efficient transfection of mammalian cells.

Condensing peptide-DNA complexes have great potential as nonviral agents for gene delivery. To date, however, such complexes have given transfection activities greatly inferior to adenovirus and somewhat inferior to cationic lipid-DNA complexes, even for cell lines and primary cells in vitro. We report here the identification of a novel condensing peptide, CL22, which forms DNA complexes that efficiently transfect many cell lines, as well as primary dendritic and endothelial cells. We report studies with sequence and structure variants that define some properties of the peptide that contribute to efficient transfection. We demonstrate that the superior transfection activity of CL22 compared with other DNA condensing peptides is conferred at a step after uptake of the complexes into cells. We show that CL22-DNA complexes have transfection activity that is at least equivalent to the best available nonviral agents.

Plasma cortisol, cortisone and urinary glucocorticoid metabolites in preterm infants.

OBJECTIVE AND METHODS: In the fetal circulation, there is a low cortisol:cortisone (F:E) ratio ( approximately 0.3) suggesting high activity of 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2). The circulating F:E ratio rises after birth in term infants, but little is known about infants born prematurely. Our hypothesis was that the low fetal plasma F:E ratio would persist in infants born prematurely, due to persistently high tissue 11betaHSD2 activity. To test this hypothesis, a longitudinal observational study of plasma F, E levels and urinary F and E metabolites was performed in 22 preterm infants of 24-31 weeks gestation. RESULTS: Median plasma F was 234-380 nmol l(-1), median 124-177 nmol l(-1) from 1 to 14 days age. Plasma F fell with increasing postnatal and postconceptional age. The F:E ratio was 3 in the first week of life, and thereafter was 1-2, falling with postnatal age. Urinary glucocorticoid metabolites were low in quantity ( approximately 48-120 microg kg(-1) day(-1)), consisted of E metabolites until term, and did not reflect the plasma F:E ratio. CONCLUSIONS: The fetal plasma F:E ratio did not persist in these preterm infants, due to tenfold higher levels of F. The F:E ratios were similar to those reported in term infants. These data suggest that the low F:E ratio in utero is due to low fetal production of cortisol, and effective placental inactivation of maternal F by 11betaHSD2.

Hormonal therapy in dermatology.

Hormonal therapy in dermatology is used primarily to reverse or diminish the effect of androgens, which are responsible for causing acne, hirsutism, and androgenetic alopecia. Although hormonal therapy is one of many treatments for acne, it is the only medical therapy available for hirsutism, and likely the only hope for the successful medical treatment of androgenetic alopecia. This article addresses the pathophysiologic rationale for the use of hormonal therapies in dermatology, the patients, the diseases for which they are used, the drugs most used, and what pretreatment evaluation should be considered.

Low-dose adjunctive spironolactone in the treatment of acne in women: a retrospective analysis of 85 consecutively treated patients.

BACKGROUND: Despite advances in acne therapy in recent years, treatment failures are common, especially in adult women. Spironolactone, an established androgen receptor blocker, is successful in treating adult women with acne, but side effects are common at the doses reported in published studies to date. OBJECTIVE: The purpose of this study was to assess the therapeutic effect and tolerance of low doses of spironolactone used alone or as an adjunct in the treatment of acne in adult women. METHODS: Records were reviewed from 85 women with acne treated consecutively with spironolactone 50 to 100 mg/day, administered either as single-drug therapy or as an adjunct to standard therapies. The maximum length of treatment was 24 months. RESULTS: Clearing of acne occurred in 33% of patients treated with low doses of spironolactone; 33% had marked improvement, 27.4% showed partial improvement, and 7% showed no improvement. The treatment regimen was well tolerated, with 57.5% reporting no adverse effects. CONCLUSION: Spironolactone can be used in low doses as a single drug or as an adjunct to standard acne therapies in women with adult acne. When used in this fashion, treatment outcomes are favorable, and the drug is well tolerated.