Divergent functional isoforms drive niche specialisation for nutrient acquisition and use in rumen microbiome

Many microbes in complex competitive environments share genes for acquiring and utilising nutrients, questioning whether niche specialisation exists and if so, how it is maintained. We investigated the genomic signatures of niche specialisation in the rumen microbiome, a highly competitive, anaerobic environment, with limited nutrient availability determined by the biomass consumed by the host. We generated individual metagenomic libraries from 14 cows fed an ad libitum diet of grass silage and calculated functional isoform diversity for each microbial gene identified. The animal replicates were used to calculate confidence intervals to test for differences in diversity of functional isoforms between microbes that may drive niche specialisation. We identified 153 genes with significant differences in functional isoform diversity between the two most abundant bacterial genera in the rumen (Prevotella and Clostridium). We found Prevotella possesses a more diverse range of isoforms capable of degrading hemicellulose, whereas Clostridium for cellulose. Furthermore, significant differences were observed in key metabolic processes indicating that isoform diversity plays an important role in maintaining their niche specialisation. The methods presented represent a novel approach for untangling complex interactions between microorganisms in natural environments and have resulted in an expanded catalogue of gene targets central to rumen cellulosic biomass degradation.

mRNA expression of genes regulating oxidative phosphorylation in the muscle of beef cattle divergently ranked on residual feed intake

Our objective was to evaluate the effects of phenotypic ranking on residual feed intake (RFI) on the transcription of genes 1) involved in the respiratory chain complex and 2) coding for transcriptional factors regulating mitochondrial biogenesis, across two contrasting diet types. Beef heifers (n = 86) fed a diet comprising 70:30 concentrate-corn silage [low forage (LF)] over a 82-day period were ranked on RFI. The 10 highest (feed inefficient, high-RFI) and 10 lowest (feed efficient, low-RFI) ranking animals were selected for the current study. Biopsies of the M. longissimus dorsi were harvested following initial selection (LF diet) and again following a 6 wk period while the animals were offered a high-forage (HF) grass silage-only diet. Real-time PCR was used to quantify mRNA transcripts of 17 genes associated with cellular energetic efficiency. The mRNA expression of UCP3 tended to be upregulated (2.2-fold, P = 0.06) for the high-RFI compared with the low-RFI animals. mRNA transcripts coding for the transcription factor PGC-1α was 1.7-fold higher (P = 0.01) in low compared with high-RFI animals. A phenotype × diet interaction was evident for the abundance of ANT1 mRNA transcript, with greater (P = 0.04) expression levels detected in the low-RFI phenotype during the HF period, but no difference (P = 0.50) between phenotypes during the LF period. A phenotype × diet interaction was also evident for COX II with greater expression levels detected (P = 0.04) in the low compared with the high RFI phenotype while on LF but not the HF diet (P = 0.22). These data suggest an association between cellular energetic efficiency and RFI in cattle.

Privileged position: preparing nurses to work in the community

Nurses nurse, end of story, but is it? Is nursing any one thing? Nursing is many things and the positions that nurses occupy in any particular setting are multiple. In an educational project aimed at facilitating student learning, I set out to expose the multipositionality of community nursing and to acknowledge that discursive pressures shape and limit practice. A set of resources using story method was produced for use in educational settings. Story method was chosen as an emancipatory vehicle for learning. A worrisome question that arose from reflection on the project was that although the educational aim of the project was emancipatory, did the singularity of the professional voice offered through the stories sabotage that goal?

Contesting competency: cultural safety in advanced nursing practice

A central tenet of the competency approach to nursing education and regulation is that it ensures the safe care of clients and communities with whom nurses work. However, the competency approach is problematic in its conception and application to nursing. Incorporation of this framework into advanced practice requires that its limitations are acknowledged so that current interpretations and applications can be challenged and resisted. Through exploring the concept of cultural competence some of the problems associated with the application of the competency approach to professional nursing practice will be exposed. The issues revealed in this exploration prompt the question whether the competency framework is the best way to ensure competent professional practice.

Clinical, pathologic, and immunologic features of human T-lymphotrophic virus type I-associated infective dermatitis in children

OBJECTIVES

To define the clinical and laboratory features associated with infective dermatitis (ID) and confirm its association with human T-lymphotrophic virus type I (HTLV-I).

DESIGN

A case series of patients with ID were compared with patients with atopic dermatitis (AD), which is an important disease in the differential diagnosis of ID.

SETTING

Patients were recruited from dermatology and pediatric clinics at the University Hospital of the West Indies and the Bustamante Children's Hospital, Kingston, Jamaica.

MAIN OUTCOME MEASURES

Clinical and laboratory features of patients with AD were compared with those of patients with ID.

PATIENTS

Consecutive patients older than 1 1/2 years diagnosed as having ID (n=50) and AD (n=35) were enrolled based on clinical findings.

RESULTS

The mean ages of patients with ID and AD were 6.9 and 7.8 years, respectively. Histologically, both diseases were predominantly chronic dermatitis with propensity for skin colonization with Staphylococcus aureus and beta-hemolytic streptococci; however, the distribution of sites of skin involvement differed. Infection with HTLV-I was the most distinguishing feature among patients with ID, with seropositive results in 100%; only 5 (14%) of the 35 patients with AD had results seropositive for HTLV-I. Infective dermatitis was further characterized by dermatopathic lymphadenitis in 16 (67%) of 24 patients with palpable nodes. Anemia, lymphocytosis, and low albumin and elevated serum globulin levels were more prevalent among patients with ID. Significant elevations of IgA, IgD, and IgG levels were observed among patients with ID compared with those with AD. However, both patients with AD and those with ID had levels of IgD and IgE elevated above the normal range. T-cell subsets among patients with ID revealed T-cell activation with a high percentage of HLA-DR antigen positivity, elevated CD4 (2.4 x 10(9)/L) and CD8 (1.4 x 10(9)/L) cell counts, with an increased CD4/CD8 ratio of 1:73.

CONCLUSION

Infective dermatitis is a distinct clinical entity associated with HTLV-I, which plays a role in the pathogenesis and immune perturbations observed.

Outcomes steering practice: when the ends determine the means

A discussion of outcomes and outcomes measurement will be presented through an examination of achievements of a collaborative project awarded a federal best practice grant in 1995. The project, which established a new service for women of nonEnglish-speaking background, was part of a national venture which sought to benchmark best practice in the primary health care field. The process of benchmarking demanded that the approach to outcomes and outcomes measurement adopted by the project participants be articulated. The approach adopted acknowledges that outcomes are affected by the processes involved in care, which in turn are dependent upon the organisational environment in which care is offered and experienced. Both these contributing factors to outcomes can be hard to measure and, therefore, could be at risk of being omitted from the outcome equation in these economically stringent times. This paper aims to contribute to debate on the topic by recommending an approach to outcomes measurement which is comprehensive, values quality and embraces the short, medium and longer term.

Tropical spastic paraparesis occurring in HTLV-1 associated infective dermatitis. Report of two cases

An association between HTLV-1 infection and infective dermatitis (ID) a relapsing eczematous condition of Jamaican children, was reported in 1990. These patients are at risk of developing other known HTLV-1 related diseases. We have observed the development of HTLV-1 associated myelopathy/tropical spastic paraparesis in two patients, ages 14 and 35 years, who were diagnosed with ID at ages 2 and 10 years, respectively. Infective dermatitis of children serves as an early marker of HTLV-I infection and may predict later development of either the malignant outcome, adult T-cell leukaemia/lymphoma or the neurologic manifestation HAM/TSP among adult carriers of HTLV-1 infection.