title: A pilot randomised controlled trial of oral doxycycline after endoscopic sinus surgery and its effects on the sinonasal microbiome

authors: Challis, Jacinda M.

subjects: endoscopic sinus surgery

abstract: Oral antibiotics are commonly prescribed after endoscopic sinus surgery (ESS) despite minimal clinical data supporting this practice. We aim to assess the effect of post-ESS doxycycline on clinical outcomes and on the diversity and composition of the sinonasal microbiome. Methods: Samples from the middle meatus were collected from twelve patients undergoing ESS to treat chronic rhinosinusitis. Patients were double-blind randomised to receive either oral doxycycline or placebo in the post-operative period. Further samples were collected at two weeks and three months post-operatively. The sinonasal microbiome was characterized using 16S ribosomal RNA (rRNA) gene amplicon sequencing. SNOT-22 scores, Lund Mackay scores, and Modified Lund Mackay Endoscopic Scores (MLMES) were collected. Results: After ESS, bacterial diversity increased while SNOT-22 score decreased for both treatments. Microbiome composition diverged between treatments, and random forest analysis identified nine taxa that may distinguish treatment groups. There was no significant difference in SNOT-22 score, 3-month MLMES or bacterial diversity between the placebo and doxycycline groups. The trends for all of these measures favour placebo. Conclusion: In this pilot study, we detected no significant difference between placebo and antibiotic treatments in clinical outcome. As patient symptoms improved after ESS, we detected a concurrent increase in the diversity of the sinonasal microbiome. Our data highlight the need for and facilitate the design of future larger studies to explore the relationship between prophylactic antibiotics and post-ESS recovery.

text: A pilot randomised controlled trial of oral doxycycline after endoscopic sinus surgery and its effects on the sinonasal microbiome Oral antibiotics are commonly prescribed after endoscopic sinus surgery (ESS) despite minimal clinical data supporting this practice. We aim to assess the effect of post-ESS doxycycline on clinical outcomes and on the diversity and composition of the sinonasal microbiome. Methods: Samples from the middle meatus were collected from twelve patients undergoing ESS to treat chronic rhinosinusitis. Patients were double-blind randomised to receive either oral doxycycline or placebo in the post-operative period. Further samples were collected at two weeks and three months post-operatively. The sinonasal microbiome was characterized using 16S ribosomal RNA (rRNA) gene amplicon sequencing. SNOT-22 scores, Lund Mackay scores, and Modified Lund Mackay Endoscopic Scores (MLMES) were collected. Results: After ESS, bacterial diversity increased while SNOT-22 score decreased for both treatments. Microbiome composition diverged between treatments, and random forest analysis identified nine taxa that may distinguish treatment groups. There was no significant difference in SNOT-22 score, 3-month MLMES or bacterial diversity between the placebo and doxycycline groups. The trends for all of these measures favour placebo. Conclusion: In this pilot study, we detected no significant difference between placebo and antibiotic treatments in clinical outcome. As patient symptoms improved after ESS, we detected a concurrent increase in the diversity of the sinonasal microbiome. Our data highlight the need for and facilitate the design of future larger studies to explore the relationship between prophylactic antibiotics and post-ESS recovery.

year: 2022-04-08

title: The evaluation of processed cancellous bovine bone as a bone graft substitute

authors: Worth, Andrew J.

subjects: biomaterials

abstract: Objective: To determine the ability of a novel bovine cancellous bone xenoimplant to act as an osteoconductive graft in an ovine femoral defect model. An autograft harvested from the xenoimplant site was placed in a contralateral limb defect for comparison.
Material and methods: The xenoimplant used had been rendered immunologically inert by a novel defatting and deproteinating process. Following surgical implantation of cores into condylar cancellous bone defects, fluorochrome labels were administered to 12 sheep at 2 1/2, 4 1/2 and 8 weeks. Incorporation of the xenoimplants and autografts into the host bone was compared radiographically and histomorphometrically at 10 weeks.
Results: Radiographically, the degree of osteointegration was comparable. Histomorphometric data, consisting of labelled surface (LS) estimates, confirmed osteoconductive properties of both the xenoimplants and autografts. Remodelling activity was greatest in the xenoimplants at 2 1/2, weeks. At 4 1/2 weeks, there was more activity in the autograft, but by 8 weeks they were performing similarly. Xenoimplant-LS estimates were comparable or greater than those of the autograft at all times.
Conclusions: Processed bovine cancellous bone xenoimplants were osteoconductive in this model and show promise for development as a biomaterial in human and veterinary orthopaedic surgery.

text: The evaluation of processed cancellous bovine bone as a bone graft substitute Objective: To determine the ability of a novel bovine cancellous bone xenoimplant to act as an osteoconductive graft in an ovine femoral defect model. An autograft harvested from the xenoimplant site was placed in a contralateral limb defect for comparison.
Material and methods: The xenoimplant used had been rendered immunologically inert by a novel defatting and deproteinating process. Following surgical implantation of cores into condylar cancellous bone defects, fluorochrome labels were administered to 12 sheep at 2 1/2, 4 1/2 and 8 weeks. Incorporation of the xenoimplants and autografts into the host bone was compared radiographically and histomorphometrically at 10 weeks.
Results: Radiographically, the degree of osteointegration was comparable. Histomorphometric data, consisting of labelled surface (LS) estimates, confirmed osteoconductive properties of both the xenoimplants and autografts. Remodelling activity was greatest in the xenoimplants at 2 1/2, weeks. At 4 1/2 weeks, there was more activity in the autograft, but by 8 weeks they were performing similarly. Xenoimplant-LS estimates were comparable or greater than those of the autograft at all times.
Conclusions: Processed bovine cancellous bone xenoimplants were osteoconductive in this model and show promise for development as a biomaterial in human and veterinary orthopaedic surgery.

year: 2005

title: The rhetorical organisation of Maori discourse: An illustration

authors: Crombie, Winifred

subjects: Māori medium education

abstract: Almost 20% all Māori students in New Zealand schools are involved in some form of Māori-medium education. These students need to develop competence in using the language for a wide range of purposes. They need, therefore, to understand a range of written discourse conventions. In seeking to assist them in this task, elders and scholars are turning to the works of major Māori figures of the past, works composed when the language was used widely in a range of discourse contexts. However, scholars need ways of analysing these texts and of communicating their findings to others. The primary aim of this paper is to demonstrate one such approach. A single letter of condolence written in Māori is analysed here in terms of rhetorical discourse structure. On the basis of the analysis, a number of hypotheses concerning epistolary discourse in Māori are put forward. The primary hypothesis is that letters of condolence written in Māori by highly competent users of the language are likely to be characterized by an overall Problem-Solution rhetorical prototype involving spiral multilayering.

text: The rhetorical organisation of Maori discourse: An illustration Almost 20% all Māori students in New Zealand schools are involved in some form of Māori-medium education. These students need to develop competence in using the language for a wide range of purposes. They need, therefore, to understand a range of written discourse conventions. In seeking to assist them in this task, elders and scholars are turning to the works of major Māori figures of the past, works composed when the language was used widely in a range of discourse contexts. However, scholars need ways of analysing these texts and of communicating their findings to others. The primary aim of this paper is to demonstrate one such approach. A single letter of condolence written in Māori is analysed here in terms of rhetorical discourse structure. On the basis of the analysis, a number of hypotheses concerning epistolary discourse in Māori are put forward. The primary hypothesis is that letters of condolence written in Māori by highly competent users of the language are likely to be characterized by an overall Problem-Solution rhetorical prototype involving spiral multilayering.

year: 2001-02