Identification, classification, and functional characterization of novel sponge-associated acidimicrobiial species

Sponges are known to harbour an exceptional diversity of uncultured microorganisms, including members of the phylum Actinobacteriota. While members of the actinobacteriotal class Actinomycetia have been studied intensively due to their potential for secondary metabolite production, the sister class of Acidimicrobiia is often more abundant in sponges. However, the taxonomy, functions, and ecological roles of sponge-associated Acidimicrobiia are largely unknown. Here, we reconstructed and characterized 22 metagenome-assembled genomes (MAGs) of Acidimicrobiia from three sponge species. These MAGs represented six novel species, belonging to five genera, four families, and two orders, which are all uncharacterized (except the order Acidimicrobiales) and for which we propose nomenclature. These six uncultured species have either only been found in sponges and/or corals and have varying degrees of specificity to their host species. Functional gene profiling indicated that these six species shared a similar potential to non-symbiotic Acidimicrobiia with respect to amino acid biosynthesis and utilization of sulfur compounds. However, sponge-associated Acidimicrobiia differed from their non-symbiotic counterparts by relying predominantly on organic rather than inorganic sources of energy, and their predicted capacity to synthesise bioactive compounds or their precursors implicated in host defence. Additionally, the species possess the genetic capacity to degrade aromatic compounds that are frequently found in sponges. The novel Acidimicrobiia may also potentially mediate host development by modulating Hedgehog signalling and by the production of serotonin, which can affect host body contractions and digestion. These results highlight unique genomic and metabolic features of six new acidimicrobiial species that potentially support a sponge-associated lifestyle.

Exploring African American Male Youth’s Perceptions of Community Involvement Through 4-H Programs

Civic engagement research suggests that youths’ involvement in their communities results in a number of positive personal and social attributes. However, among urban populations, there is still a dearth of research on their involvement and the impact of civic participation on their development. More importantly within these populations, there is limited understanding of how Black male youth engage within civic participatory spaces. Increasing but limited research on young Black male youth usually focuses on identity, participation in programs, and socioeconomic levels. Further understanding is needed as to the factors which influence and impact Black male youths’ interests and actual participation in community and extracurricular activities. This paper explores data from urban African American high school male youth that include their perceptions and knowledge and attitudes toward being involved in their community through 4-H youth programs. The authors find that opportunities to learn a new skill and building professional portfolios assist these young Black males in their perception of being effective in their communities and making a difference for themselves.

Comparative metabolomic analysis reveals shared and unique chemical interactions in sponge holobionts

BACKGROUND

Sponges are ancient sessile metazoans, which form with their associated microbial symbionts a complex functional unit called a holobiont. Sponges are a rich source of chemical diversity; however, there is limited knowledge of which holobiont members produce certain metabolites and how they may contribute to chemical interactions. To address this issue, we applied non-targeted liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography mass spectrometry (GC-MS) to either whole sponge tissue or fractionated microbial cells from six different, co-occurring sponge species.

RESULTS

Several metabolites were commonly found or enriched in whole sponge tissue, supporting the notion that sponge cells produce them. These include 2-methylbutyryl-carnitine, hexanoyl-carnitine and various carbohydrates, which may be potential food sources for microorganisms, as well as the antagonistic compounds hymenialdisine and eicosatrienoic acid methyl ester. Metabolites that were mostly observed or enriched in microbial cells include the antioxidant didodecyl 3,3'-thiodipropionate, the antagonistic compounds docosatetraenoic acid, and immune-suppressor phenylethylamide. This suggests that these compounds are mainly produced by the microbial members in the sponge holobiont, and are potentially either involved in inter-microbial competitions or in defenses against intruding organisms.

CONCLUSIONS

This study shows how different chemical functionality is compartmentalized between sponge hosts and their microbial symbionts and provides new insights into how chemical interactions underpin the function of sponge holobionts. Video abstract.

Intra-articular methylprednisolone and bupivacaine for treatment of sesamoid disease in dogs

INTRODUCTION

The sesamoid disease is a cause of lameness in dogs, and there is limited literature relating to diagnosis, treatment and outcome of treatment in dogs with the sesamoid disease. Our aim was to compare the efficacy of intra-articular metacarpophalangeal/metatarsophalangeal joint injection with methylprednisolone and bupivacaine (IMPB) or conservative management with nonsteroidal anti-inflammatories and rest (CMNR) for treatment of this disease.

MATERIALS AND METHODS

We conducted a retrospective survey of dogs treated for the sesamoid disease with IMPB or CMNR. The medical records of all dogs that received IMPB or were recommended CMNR for treatment of sesamoid pain were reviewed, and a client questionnaire was delivered to owners. Response to treatment, rapidity of response, length of resolution and recurrence of clinical signs associated with the sesamoid disease were assessed.

RESULTS

A total of 78 dogs were included in the study. One week after IMPB, 52/58 (89.7%) dogs demonstrated resolution of lameness compared with 1 week of CMNR, 0/18 (P < 0.001). There was limited statistical evidence in client satisfaction between treatment groups, IMPB 36/53 (67.9%) and CMNR 16/17 (94%) (P = 0.052). Dogs presenting with the sesamoid disease had comorbidities in 51/78 (65.4%) of cases. Elbow disease was the most common comorbidity 29/78 (37.2%).

CONCLUSION

Our results support the use of IMPB for short-term (1 week) resolution of lameness associated with sesamoid disease in dogs. Dogs treated with CMNR had slower improvement; however, there was no difference in lameness or client satisfaction between treatment groups at long-term follow-up (12 months).

Comparative Genomics Reveals Ecological and Evolutionary Insights into Sponge-Associated Thaumarchaeota

Thaumarchaeota are frequently reported to associate with marine sponges (phylum Porifera); however, little is known about the features that distinguish them from their free-living thaumarchaeal counterparts. In this study, thaumarchaeal metagenome-assembled genomes (MAGs) were reconstructed from metagenomic data sets derived from the marine sponges Hexadella detritifera, Hexadella cf. detritifera, and Stylissa flabelliformis Phylogenetic and taxonomic analyses revealed that the three thaumarchaeal MAGs represent two new species within the genus Nitrosopumilus and one novel genus, for which we propose the names "Candidatus UNitrosopumilus hexadellus," "Candidatus UNitrosopumilus detritiferus," and "Candidatus UCenporiarchaeum stylissum" (the U superscript indicates that the taxon is uncultured). Comparison of these genomes to data from the Sponge Earth Microbiome Project revealed that "Ca UCenporiarchaeum stylissum" has been exclusively detected in sponges and can hence be classified as a specialist, while "Ca UNitrosopumilus detritiferus" and "Ca UNitrosopumilus hexadellus" are also detected outside the sponge holobiont and likely lead a generalist lifestyle. Comparison of the sponge-associated MAGs to genomes of free-living Thaumarchaeota revealed signatures that indicate functional features of a sponge-associated lifestyle, and these features were related to nutrient transport and metabolism, restriction-modification, defense mechanisms, and host interactions. Each species exhibited distinct functional traits, suggesting that they have reached different stages of evolutionary adaptation and/or occupy distinct ecological niches within their sponge hosts. Our study therefore offers new evolutionary and ecological insights into the symbiosis between sponges and their thaumarchaeal symbionts.IMPORTANCE Sponges represent ecologically important models to understand the evolution of symbiotic interactions of metazoans with microbial symbionts. Thaumarchaeota are commonly found in sponges, but their potential adaptations to a host-associated lifestyle are largely unknown. Here, we present three novel sponge-associated thaumarchaeal species and compare their genomic and predicted functional features with those of closely related free-living counterparts. We found different degrees of specialization of these thaumarchaeal species to the sponge environment that is reflected in their host distribution and their predicted molecular and metabolic properties. Our results indicate that Thaumarchaeota may have reached different stages of evolutionary adaptation in their symbiosis with sponges.

The Intersection of Civic Engagement and Civic Attidues Among Latino Youth through a Factor Analysis

The extent to which civic and citizenship education captures the ways Latino youth perceive their roles as social change agents is largely absent from academic literature. This article examines how youth perceptions of and interactions with civic education define the civic lens they apply to their societies. The article examines a new way of interpreting the International Civic and Citizenship Study data and how it investigates new ways to view the civic lens of youth within three Latin American countries. Results of the exploratory factor analysis indicate a three-factor structure of civic lenses and show that youth who have been exposed to particular postconflict ideologies have developed a basic national understanding of civics. Findings provide insight into the utility of a tool for assessing youths' notions of social agents of change based upon pertinent civic perspectives. Such assessment may identify factors to be addressed by organizations seeking to deepen understanding and increase meaningfulness of civic action for youth.

Predicting the HMA-LMA Status in Marine Sponges by Machine Learning

The dichotomy between high microbial abundance (HMA) and low microbial abundance (LMA) sponges has been observed in sponge-microbe symbiosis, although the extent of this pattern remains poorly unknown. We characterized the differences between the microbiomes of HMA (n = 19) and LMA (n = 17) sponges (575 specimens) present in the Sponge Microbiome Project. HMA sponges were associated with richer and more diverse microbiomes than LMA sponges, as indicated by the comparison of alpha diversity metrics. Microbial community structures differed between HMA and LMA sponges considering Operational Taxonomic Units (OTU) abundances and across microbial taxonomic levels, from phylum to species. The largest proportion of microbiome variation was explained by the host identity. Several phyla, classes, and OTUs were found differentially abundant in either group, which were considered “HMA indicators” and “LMA indicators.” Machine learning algorithms (classifiers) were trained to predict the HMA-LMA status of sponges. Among nine different classifiers, higher performances were achieved by Random Forest trained with phylum and class abundances. Random Forest with optimized parameters predicted the HMA-LMA status of additional 135 sponge species (1,232 specimens) without a priori knowledge. These sponges were grouped in four clusters, from which the largest two were composed of species consistently predicted as HMA (n = 44) and LMA (n = 74). In summary, our analyses shown distinct features of the microbial communities associated with HMA and LMA sponges. The prediction of the HMA-LMA status based on the microbiome profiles of sponges demonstrates the application of machine learning to explore patterns of host-associated microbial communities.

A Church, University, and Extension: A Partnership for Creating Healthy Youth and Healthy Living

Within many urban communities, there has been a steady decline in healthy living practices among minority families.  This decline is often due to the lack of health services and health knowledge of youth and adults (Shirley, Roark, & Lewis, 2012).  In order to better reach these particular audiences it has been suggested by scholars and practitioners to focus on community based programming. Partnerships formed through entities such as universities and community organizations have been shown to be quite successful in creating healthier families. This paper discusses one such program focused on increasing health knowledge of urban families. Activities offered included health screenings and healthy living programming for youth.  Program results showed that nearly 95% of youth found the activities informative and gave them ways to think about their health and the health of their families.

Larval behaviours and their contribution to the distribution of the intertidal coral reef sponge Carteriospongia foliascens

Sponges (Phylum Porifera) are an evolutionary and ecologically significant group; however information on processes influencing sponge population distributions is surprisingly limited. Carteriospongia foliascens is a common Indo-Pacific sponge, which has been reported from the intertidal to the mesophotic. Interestingly, the distribution of C. foliascens at inshore reefs of the Great Barrier Reef is restricted to the intertidal with no individuals evident in adjacent subtidal habitats. The abundance of C. foliascens and substrate availability was first quantified to investigate the influence of substrate limitation on adult distribution. Pre-settlement processes of larval spawning, swimming speeds, phototaxis, vertical migration, and settlement to intertidal and subtidal substrate cues were also quantified. Notably, suitable settlement substrate (coral rubble) was not limiting in subtidal habitats. C. foliascens released up to 765 brooded larvae sponge(-1) day(-1) during the day, with larvae (80%±5.77) being negatively phototactic and migrating to the bottom within 40 minutes from release. Subsequently, larvae (up to 58.67%±2.91) migrated to the surface after the loss of the daylight cue (nightfall), and after 34 h post-release >98.67% (±0.67) of larvae had adopted a benthic habit regardless of light conditions. Intertidal and subtidal biofilms initiated similar settlement responses, inducing faster (as early 6 h post-release) and more successful metamorphosis (>60%) than unconditioned surfaces. C. foliascens has a high larval supply and larval behaviours that support recruitment to the subtidal. The absence of C. foliascens in subtidal habitats at inshore reefs is therefore proposed to be a potential consequence of post-settlement mortalities.

A complex life cycle in a warming planet: gene expression in thermally stressed sponges

Sponges are abundant, diverse and functionally important components of aquatic biotopes with crucial associations for many reef fish and invertebrates. Sponges have strict temperature optima, and mass mortality events have occurred after unusually high temperatures. To assess how sponges may adapt to thermal stress associated with a changing climate, we applied gene expression profiling to both stages of their bipartite life cycles. Adult Rhopaloeides odorabile are highly sensitive to thermal stress (32 °C), yet their larvae can withstand temperatures up to 36 °C. Here, we reveal the molecular mechanisms that underpin these contrasting thermal tolerances, which may provide sponges with a means to successfully disperse into cooler waters. Heat shock protein 70 was induced by increasing temperature in adult sponges, and genes involved in important biological functions including cytoskeleton rearrangement, signal transduction, protein synthesis/degradation, oxidative stress and detoxification were all negatively correlated with temperature. Conversely, gene expression in larvae was not significantly affected until 36 °C when a stress response involving extremely rapid activation of heat shock proteins occurred. This study provides the first transcriptomic assessment of thermal stress on both life history stages of a marine invertebrate facilitating better predictions of the long-term consequences of climate change for sponge population dynamics.

Unsafe abortion: regulation of the social body even beyond time and space

This paper offers an analysis of women's performance of unsafe abortion in rural Ghana despite significant cultural sanctions that forbid the practice. Findings demonstrate how women in the study balance sanctions inherent in traditional belief structures against their own immediate physical and social best interests. In rural Ghana, a woman's body is not always her own to do with as she would wish. It is also a social body, which is embedded in multiple sets of relationships and subject to social regulation. Traditional authority over a woman's body belongs not only to the community elders in the immediate physical environment of the village but also extends beyond time and space to immaterial ancestral persons who watch over the actions and behaviours of those on earth. Authority resides also with Mawu, the Ewe God, who is offended by the practice of abortion. Data from this study reveal that the performance of unsafe abortion in this Ewe community is a desperate act in which the women must not only risk their physical lives, but must also step outside the boundaries of ideological cultural conformity to traditional values and carry the risk of their actions even into life after death.

Coral reef invertebrate microbiomes correlate with the presence of photosymbionts

Coral reefs provide habitat for an array of marine invertebrates that host symbiotic microbiomes. Photosynthetic symbionts including Symbiodinium dinoflagellates and diatoms potentially influence the diversity of their host-associated microbiomes by releasing carbon-containing photosynthates and other organic compounds that fuel microbial metabolism. Here we used 16S ribosomal RNA (rRNA) gene amplicon pyrosequencing to characterise the microbiomes of 11 common Great Barrier Reef marine invertebrate species that host photosynthetic symbionts and five taxa in which they are absent. The presence of photosynthetic symbionts influenced the composition but not the species richness, evenness and phylogenetic diversity of invertebrate-associated microbiomes. Invertebrates without photosynthetic symbionts were dominated by Alphaproteobacteria, whereas those hosting photosynthetic symbionts were dominated by Gammaproteobacteria. Interestingly, many microbial species from photosymbiont-bearing invertebrates, including Oceanospirillales spp., Alteromonas spp., Pseudomonas spp., Halomonas spp., are implicated in the metabolism of dimethylsulfoniopropionate (DMSP). DMSP is produced in high concentrations by photosynthetic dinoflagellates and is involved in climate regulation by facilitating cloud formation. Microbiomes correlated with host taxa and replicate individuals from most sampled species grouped in distance-based redundancy analysis of retrieved 16S rRNA gene sequences. This study highlights the complex nature of invertebrate holobionts and confirms the importance of photosynthetic symbionts in structuring marine invertebrate bacterial communities.

Sponge-microbe associations survive high nutrients and temperatures

Coral reefs are under considerable pressure from global stressors such as elevated sea surface temperature and ocean acidification, as well as local factors including eutrophication and poor water quality. Marine sponges are diverse, abundant and ecologically important components of coral reefs in both coastal and offshore environments. Due to their exceptionally high filtration rates, sponges also form a crucial coupling point between benthic and pelagic habitats. Sponges harbor extensive microbial communities, with many microbial phylotypes found exclusively in sponges and thought to contribute to the health and survival of their hosts. Manipulative experiments were undertaken to ascertain the impact of elevated nutrients and seawater temperature on health and microbial community dynamics in the Great Barrier Reef sponge Rhopaloeides odorabile. R. odorabile exposed to elevated nutrient levels including 10 µmol/L total nitrogen at 31°C appeared visually similar to those maintained under ambient seawater conditions after 7 days. The symbiotic microbial community, analyzed by 16S rRNA gene pyrotag sequencing, was highly conserved for the duration of the experiment at both phylum and operational taxonomic unit (OTU) (97% sequence similarity) levels with 19 bacterial phyla and 1743 OTUs identified across all samples. Additionally, elevated nutrients and temperatures did not alter the archaeal associations in R. odorabile, with sequencing of 16S rRNA gene libraries revealing similar Thaumarchaeota diversity and denaturing gradient gel electrophoresis (DGGE) revealing consistent amoA gene patterns, across all experimental treatments. A conserved eukaryotic community was also identified across all nutrient and temperature treatments by DGGE. The highly stable microbial associations indicate that R. odorabile symbionts are capable of withstanding short-term exposure to elevated nutrient concentrations and sub-lethal temperatures.

Thermal stress responses in the bacterial biosphere of the Great Barrier Reef sponge, Rhopaloeides odorabile

Marine sponges are diverse, abundant and provide a crucial coupling point between benthic and pelagic habitats due to their high filtration rates. They also harbour extensive microbial communities, with many microbial phylotypes found exclusively in sponge hosts and not in the seawater or surrounding environment, i.e. so-called sponge-specific clusters (SCs) or sponge- and coral-specific clusters (SCCs). We employed DNA (16S rRNA gene) and RNA (16S rRNA)-based amplicon pyrosequencing to investigate the effects of sublethal thermal stress on the bacterial biosphere of the Great Barrier Reef sponge Rhopaloeides odorabile. A total of 8381 operational taxonomic units (OTUs) (97% sequence similarity) were identified, affiliated with 32 bacterial phyla from seawater samples, 23 bacterial phyla from sponge DNA extracts and 18 bacterial phyla from sponge RNA extracts. Sublethal thermal stress (31°C) had no effect on the present and/or active portions of the R. odorabile bacterial community but a shift in the bacterial assemblage was observed in necrotic sponges. Over two-thirds of DNA and RNA sequences could be assigned to previously defined SCs/SCCs in healthy sponges whereas only 12% of reads from necrotic sponges could be assigned to SCs/SCCs. A rapid decline in host health over a 1°C temperature increment suggests that sponges such as R. odorabile may be highly vulnerable to the effects of global climate change.

Assessing the complex sponge microbiota: core, variable and species-specific bacterial communities in marine sponges

Marine sponges are well known for their associations with highly diverse, yet very specific and often highly similar microbiota. The aim of this study was to identify potential bacterial sub-populations in relation to sponge phylogeny and sampling sites and to define the core bacterial community. 16S ribosomal RNA gene amplicon pyrosequencing was applied to 32 sponge species from eight locations around the world's oceans, thereby generating 2567 operational taxonomic units (OTUs at the 97% sequence similarity level) in total and up to 364 different OTUs per sponge species. The taxonomic richness detected in this study comprised 25 bacterial phyla with Proteobacteria, Chloroflexi and Poribacteria being most diverse in sponges. Among these phyla were nine candidate phyla, six of them found for the first time in sponges. Similarity comparison of bacterial communities revealed no correlation with host phylogeny but a tropical sub-population in that tropical sponges have more similar bacterial communities to each other than to subtropical sponges. A minimal core bacterial community consisting of very few OTUs (97%, 95% and 90%) was found. These microbes have a global distribution and are probably acquired via environmental transmission. In contrast, a large species-specific bacterial community was detected, which is represented by OTUs present in only a single sponge species. The species-specific bacterial community is probably mainly vertically transmitted. It is proposed that different sponges contain different bacterial species, however, these bacteria are still closely related to each other explaining the observed similarity of bacterial communities in sponges in this and previous studies. This global analysis represents the most comprehensive study of bacterial symbionts in sponges to date and provides novel insights into the complex structure of these unique associations.

An Agricultural Apprenticeship Program for Youth in Trinidad, West Indies: Can it Meet the Caribbean’s Urgent Need for Younger Farmers?

To address the aging farmer population in Trinidad, W.I., a situation common to the Caribbean region, a Youth Apprenticeship Program in Agriculture (YAPA) was initiated. An assessment of its effectiveness was conducted in 2007. Results indicated that present trainees went into agriculture to make “additional” income and for self employment, with “contributing to national food security” being ranked lower. They were generally satisfied with the extent of field work, the experience gained and trainers’ knowledge and skills. However, they would leave agriculture if they received other employment opportunities or if they were not provided with key resources such as land and soft loans. Past YAPA trainees had significantly changed (p

Purification and characterization of a collagenolytic enzyme from a pathogen of the great barrier reef sponge, Rhopaloeides odorabile

Background

In recent years there has been a global increase in reports of disease affecting marine sponges. While disease outbreaks have the potential to seriously impact on the survival of sponge populations, the ecology of the marine environment and the health of associated invertebrates, our understanding of sponge disease is extremely limited.

Methodology/Principal Findings

A collagenolytic enzyme suspected to enhance pathogenicity of bacterial strain NW4327 against the sponge Rhopaloeides odorabile was purified using combinations of size exclusion and anion exchange chromatography. After achieving a 77-fold increase in specific activity, continued purification decreased the yield to 21-fold with 7.2% recovery (specific activity 2575 collagen degrading units mg⁻¹protein) possibly due to removal of co-factors. SDS-PAGE of the partially pure enzyme showed two proteins weighing approximately 116 and 45 kDa with the heavier band being similar to reported molecular weights of collagenases from Clostridium and marine Vibrios. The enzyme degraded tissue fibres of several sponge genera suggesting that NW4327 could be deleterious to other sponge species. Activity towards casein and bird feather keratin indicates that the partially purified collagenase is either a non-selective protease able to digest collagen or is contaminated with non-specific proteases. Enzyme activity was highest at pH 5 (the internal pH of R. odorabile) and 30°C (the average ambient seawater temperature). Activity under partially anaerobic conditions also supports the role of this enzyme in the degradation of the spongin tissue. Cultivation of NW4327 in the presence of collagen increased production of collagenase by 30%. Enhanced enzyme activity when NW4327 was cultivated in media formulated in sterile natural seawater indicates the presence of other factors that influence enzyme synthesis.

Conclusions/Significance

Several aspects of the sponge disease etiology were revealed, particularly the strong correlation with the internal tissue chemistry and environmental temperature. This research provides a platform for further investigations into the virulence mechanisms of sponge pathogens.

Contamination in sediments, bivalves and sponges of McMurdo Sound, Antarctica

This study examined the concentrations of total hydrocarbons (THC), polychlorinated biphenyls (PCB), polyaromatic hydrocarbons (PAH), and trace metals (Cu, Zn, Cd, Pb, Hg and As) in marine sediments off Scott Base (NZ) and compared them with sediments near the highly polluted McMurdo Station (US) as well as less impacted sites including Turtle Rock and Cape Evans. The Antarctic mollusc, Laternula elliptica and three common sponge species were also analysed for trace metals. The mean THC concentration in sediments from Scott Base was 3 fold higher than the pristine site, Turtle Rock, but 10 fold lower than samples from McMurdo Station. McMurdo Station sediments also contained the highest concentrations of PAHs, PCBs and the trace metals, Cu, Zn, Pb, Cd and Hg. Copper was significantly higher in bivalves from McMurdo Station than other sites. Trace metal concentrations in sponges were generally consistent within sites but no spatial patterns were apparent.

Laparoscopic insemination technique with low numbers of spermatozoa in superovulated prepuberal gilts for biotechnological application

New biotechnologies, such as sperm-mediated gene transfer (SMGT), spermatozoa freezing and spermatozoa sorting have improved the possibilities to produce animals with desirable features. The main problem associated with these technologies is the scarce availability of spermatozoa for insemination. The objective of this study was to develop a laparoscopic insemination (LI) technique in gilt that allows the use of low semen doses resulting in high fertilization rates (FR) and minimal distress to the animal; the efficiency of this technique was compared to conventional artificial insemination (AI). Ten gilts were inseminated 36 h post hCG treatment near both utero-tubal junctions (UTJ) with 1.5 x 10(9)spermatozoa/5 mL per horn and 10 gilts (C) underwent conventional AI. Embryos were collected either at two to four cell stage (LI, n = 5; C, n = 5) for determination of fertilization rate or at day 6 for evaluation of developmental competence (LI, n = 5; C, n = 5). LI gilts showed a slightly higher FR than control animals. In a second trial, 24 gilts underwent LI with varying doses (1.5 x 10(8), 1.5 x 10(7), 1 x 10(7), 5 x 10(6) or 1 x 10(6)) of semen. Two to four stage embryos were collected and FR was evaluated in each tube. FR obtained with the lowest dose was significantly different from that with other dosages (P < 0.05). Embryos were cultured in vitro to blastocyst stages (percentage of blastocysts: 79.2 +/- 3.6%). In a third trial, five gilts were inseminated with semen processed by SMGT technique; both FR (86.1 +/- 9.9%) and transgene protein expression were satisfactory. In conclusion, this study shows that LI can be a useful tool for reducing doses of insemination, without affecting the efficiency of fertilization; this technique could have a wide range of biotechnological applications.

Racial and ethnic disparities in infant mortality: risk in social context

This article presents the multifaceted efforts of Syracuse Healthy Start, a federally funded initiative of the Onondaga County Health Department and over 20 partnering agencies to reduce racial and ethnic disparities in infant mortality. The analyses presented in this article demonstrate that many women--Caucasian, African American, and Hispanic--have serious risks for low birth weight and infant death. In many cases, multiple, simultaneous risks complicate a pregnant woman's situation and in other cases the longitudinal cumulative risks impact health across generations. Infant mortality decreased overall, and for both Caucasian and African American infants during the first 3 years of the project.

Towards a public health approach to bioethics

In this paper we examine the central commitments of bioethical enquiry and reasoning from a public health perspective. We argue that a core element of American national culture is individualism, which resonates in scholarly and popular debates. Our contention is that the habitus of bioethical debate is in large measure animated by an overriding concern with the individual, and the resulting social practice of the community has been to downplay the importance and legitimacy of group-level health care dilemmas. This paper calls for re-focusing of bioethics by employing a public health perspective, which would include a population focus, evidence-based research topics, and engagement of the ethical dilemmas that arise from decisions concerning prevention. Racial and ethnic health disparities throughout the life span of a population in central New York State are used to illustrate the need for a public health focus in bioethics.

Fine-bore cannulas for peripheral intravenous nutrition: polyurethane or silicone?

The peripheral intravenous route is being used more frequently for the administration of short- to medium-term parenteral nutritional support. Dedicated fine bore cannulas have significantly reduced the incidence of thrombophlebitis. Currently available cannulas are made of polyurethane or silicone. We present our experience with a 23G silicone cannula and a 22G polyurethane alternative. Fifty-four silicone cannulas were used with a median survival of only 3 days, compared with 7 days for 90 polyurethane cannulas (P < 0.0001). Only 22% of silicone cannulas were removed electively compared with 56% of polyurethane cannulas (P < 0.00005). The most common cause for silicone cannula removal was occlusion (48%), which occurred in only 8% of polyurethane cannulas (P < 0.00001). Polyurethane cannulas develop fewer complications and are more effective in the delivery of peripheral intravenous nutritional support.

K(+)-induced dilation of a small renal artery: no role for inward rectifier K+ channels

OBJECTIVE

To investigate the mechanism of K(+)-induced vasodilation in a small artery from the kidney, with a particular emphasis on the role of inward rectifier K+ channels.

METHODS

Lumen diameter and isometric tension recordings have been made from rabbit renal arcuate artery using pressurised- and wire-myography respectively. In addition, conventional whole-cell and amphotericin-perforated patch whole-cell recordings have been made from single smooth muscle cells isolated from the vessel.

RESULTS

Arcuate arteries dilated when the extracellular K+ concentration was raised to 8-10 mM from either zero or a normal physiological level of about 6 mM. The effect was not endothelium-dependent. Application of 0.01-1 mM Ba2+ to block inward rectifier K+ channels had no significant effect on K(+)-induced vasodilation in the arcuate artery, but under the same experimental conditions K(+)-induced dilation of the rat posterior cerebral artery was abolished by Ba2+. In the presence of 60 mM extracellular K+, inward rectifier K(+)-current was detectable in some single smooth muscle cells isolated from arcuate arteries but on average the current density was low (-1.44 pA pF-1 at -60 mV). K(+)-induced vasodilation of the arcuate artery was abolished by 10 microM ouabain and the half-effective concentration of K+ which induced vasodilation was 0.9-1.5 mM.

CONCLUSIONS

The observations suggest that an increase in the extracellular K+ concentration (up to about 10 mM) dilates the rabbit renal arcuate artery and that the primary mechanism underlying the effect may be stimulation of Na(+)-K+ ATPase in the smooth muscle cell membrane. Inward rectifier K+ channels have a low average density in smooth muscle cells isolated from arcuate arteries and play no significant role in K(+)-induced vasodilation.

The efficacy of exit site povidone-iodine ointment in the prevention of early peritoneal dialysis-related infections

Infections are the main complications of peritoneal dialysis, and currently there is no established method for prevention. A prospective, randomized, single-blind study was performed to evaluate the efficacy of regular application of povidone-iodine ointment at the catheter site (during the entire time on the study) in peritoneal dialysis. One hundred twenty patients were randomized; three were excluded for not completing the study. Sixty-one patients received application of povidone-iodine and 56 patients received standard care. Povidone-iodine ointment was effective in delaying infectious complications, with a lower proportion of treated patients having infections (exit site and peritonitis) within 140 days of starting dialysis compared with the controls (P = 0.04, Wilcoxon test). This protective benefit was lost after 140 days on dialysis. Staphylococcus aureus infections developed in only two (3.3%) of the treated patients compared with 10 (21.4%) of the controls (P = 0.009), despite the higher rate of S aureus nasal carriage in the treated group (22 of 61 patients [36%] v 14 of 56 patients [25%]).

Neutrophil adhesion molecule expression and response to stimulation with bacterial wall products in humans is unaffected by parenteral nutrition

1. Total parenteral nutrition is associated with a high incidence of septic complications. This may be partly due to neutrophil dysfunction induced by the parenteral nutrition. 2. Neutrophil adhesion molecule expression and the expression of CD11b in response to stimulation with formylmethionyl-leucyl-phenylalanine and lipopolysaccharide were determined before and after 24 h of lipid-containing parenteral nutrition. Eighteen adult patients referred for parenteral nutrition were studied. 3. There was no change in the expression of neutrophil L-selectin (CD62L), CD11a, CD11b, CD11c or CD15. Neutrophil response to stimulation with formylmethionyl-leucyl-phenylalanine and lipopolysaccharide as determined by CD11b expression was unaffected by parenteral nutrition. 4. This study has shown no evidence of parenteral nutrition-induced neutrophil dysfunction.

Obstructive jaundice causes reduced expression of polymorphonuclear leucocyte adhesion molecules and a depressed response to bacterial wall products in vitro

BACKGROUND

Obstructive jaundice is associated with an increased incidence of infection and endotoxaemia, which may result from impaired host immunity. Neutrophil adhesion to vascular endothelium is a key part of the inflammatory response.

AIMS

To investigate neutrophil adhesion molecule expression and activation in obstructive jaundice.

PATIENTS

Nine adult patients with obstructive jaundice and 11 control subjects.

METHODS

The expression of the neutrophil adhesion receptors L-selectin, CD11a, CD11b, CD11c, and CD15 was determined using flow cytometry. CD11b expression in response to stimulation with fMLP and endotoxin was measured.

RESULTS

The basal expression of L-selectin, CD11a, and CD15 was significantly decreased in jaundiced patients (p < 0.05) and the expression of CD11b in response to stimulation with fMLP and endotoxin was significantly impaired in the jaundiced group. Endotoxin stimulation without plasma did not reverse the impaired response showing that it is not caused by endotoxin inactivation by plasma proteins.

CONCLUSIONS

Neutrophils from patients with obstructive jaundice show decreased adhesion receptor expression and an impaired response to stimulation with bacterial products. This cellular dysfunction may be responsible for the high incidence of septic complications in these patients.

A review of 2000 consecutive ICU admissions

The working practices and outcomes from UK intensive care units are poorly documented to date. We have reviewed 2000 consecutive admissions to one intensive care unit in a tertiary referral centre with initially six, then eight beds. The study was a retrospective review of contemporaneous data collection within the period 1986-1990. Demographic details, referral source, admission time, admission diagnosis, APACHE II score, therapeutic interventions, and outcome were recorded. A high overall mortality in the intensive care unit (23%), proportional to APACHE II scoring on admission, was demonstrated. This reflects the referral of many patients who have, or who develop, multiple organ failure. Mortality was significantly higher in patients over the age of 40 years. A total of 69.5% of patients were admitted outside the hours 0800-1800 h on Monday to Friday and admissions peaked between 1200 and 2100 h, demonstrating the need for senior out-of-hours cover. These figures may be used to compare future mortality and work practices in this and other units. The report illustrates some of the advantages and disadvantages of one method of data collection. As it represents one unit only, care must be taken in extrapolating results to others. The timing of admissions suggests that a review of medical staffing practices would be useful.

A clinical evaluation of the 'Rapitrach'. A bedside percutaneous tracheostomy technique

A number of percutaneous tracheostomy devices are now available commercially. We report a preliminary clinical study of the use of the 'Rapitrach' kit (Fresenius, Runcorn, Cheshire, UK). Twenty critically ill adult patients underwent tracheostomy using the kit. Nineteen of the procedures were carried out at the bedside in the intensive therapy unit. Correct tube placement was achieved in all cases.

Percutaneous dilational tracheostomy. A bedside procedure on the intensive care unit

Tracheostomy is performed commonly to aid weaning from assisted ventilation in patients who require intensive care. The procedure carries a significant mortality and morbidity, in part due to problems in moving unstable patients. We report the use of a bedside percutaneous tracheostomy technique for use in adult patients who require intensive care. The procedure was successful in 19 of 20 cases. The one failure, in the first case, resulted from transection of a superficial midline vein. The lack of significant haemorrhage was notable in all other cases. The procedure has proved to be efficient and cost-effective in this unit and has now replaced conventional surgical tracheostomy in this group of patients.

The human estrogen receptor has two independent nonacidic transcriptional activation functions

We have previously reported the presence of a hormone-inducible transcriptional activation function (TAF-2) within the region of the estrogen receptor (ER) that contains the hormone binding domain. We show here that the N-terminal A/B region of the ER contains an independent constitutive activation function (TAF-1) that exhibits cell type specificity since it activates transcription efficiently in chicken embryo fibroblasts, but only poorly in HeLa cells. By analyzing the ability of TAF-1, TAF-2, and the GAL4 and VP16 acidic activating domains (AADs) to homosynergize and heterosynergize with one another and with the factor binding to the upstream element (UE) of the adenovirus 2 major late promoter, we show that the activation properties of TAF-1 and TAF-2 are different and distinct from those of AADs, in agreement with the absence of acidic amino acid stretches in TAF-1 and TAF-2.

The yeast UASG is a transcriptional enhancer in human HeLa cells in the presence of the GAL4 trans-activator

The yeast trans-activator protein GAL4, when expressed in HeLa cells, stimulates transcription from several class B (II) eukaryotic promoters containing GAL4 binding sites either as the full UASG or as synthetic 17-mers. The characteristics of this activation are indistinguishable from those of the SV40 enhancer. Transcription was similarly stimulated from either complex promoter regions containing multiple upstream elements or from a simple promoter region composed of only a TATA box. Addition of a 17-mer GAL4 binding site to the SV40 enhancer resulted in a synergistic enhancement of transcription in the presence of GAL4. Furthermore, chimeras of the human estrogen receptor DNA binding domain and either GAL4 or GCN4 activating "acidic" regions can activate a promoter region controlled by an estrogen-responsive enhancer. Together, these data indicate that the molecular mechanisms responsible for transcriptional enhancement have been conserved from yeast to man.

A clinical comparison of two methods of glare testing

We evaluated two methods of glare testing, the Miller-Nadler Glare Tester (M-NGT, Titmus Optical, Inc.) and the Brightness Acuity Tester (BAT, Mentor O & O, Inc.). Resulting Snellen visual acuities both for a control group of normal volunteers and for a study group with cataract or posterior capsule opacification were compared using the two glare testers. The decreases in Snellen visual acuities were comparable in the eyes with cataract. No glare disability was measured in the control group. There was greater glare disability using the BAT compared with the Miller-Nadler test when eyes with posterior capsule opacities were compared.