High-spatial resolution functional chemistry of nitrogen compounds in the observed UK meteorite fall Winchcombe

Organic matter in extraterrestrial samples is a complex material that might have played an important role in the delivery of prebiotic molecules to the early Earth. We report here on the identification of nitrogen-containing compounds such as amino acids and N-heterocycles within the recent observed meteorite fall Winchcombe by high-spatial resolution spectroscopy techniques. Although nitrogen contents of Winchcombe organic matter are low (N/C ~ 1-3%), we were able to detect the presence of these compounds using a low-noise direct electron detector. These biologically relevant molecules have therefore been tentatively found within a fresh, minimally processed meteorite sample by high spatial resolution techniques conserving the overall petrographic context. Carbon functional chemistry investigations show that sizes of aromatic domains are small and that abundances of carboxylic functional groups are low. Our observations demonstrate that Winchcombe represents an important addition to the collection of carbonaceous chondrites and still preserves pristine extraterrestrial organic matter.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

The Winchcombe meteorite, a unique and pristine witness from the outer solar system

Direct links between carbonaceous chondrites and their parent bodies in the solar system are rare. The Winchcombe meteorite is the most accurately recorded carbonaceous chondrite fall. Its pre-atmospheric orbit and cosmic-ray exposure age confirm that it arrived on Earth shortly after ejection from a primitive asteroid. Recovered only hours after falling, the composition of the Winchcombe meteorite is largely unmodified by the terrestrial environment. It contains abundant hydrated silicates formed during fluid-rock reactions, and carbon- and nitrogen-bearing organic matter including soluble protein amino acids. The near-pristine hydrogen isotopic composition of the Winchcombe meteorite is comparable to the terrestrial hydrosphere, providing further evidence that volatile-rich carbonaceous asteroids played an important role in the origin of Earth's water.

Community engagement to improve access to healthcare: a comparative case study to advance implementation science for transgender health equity

BACKGROUND

Recent calls to action have been made for Implementation Science to attend to health inequities at the intersections of race, gender, and social injustice in the United States. Transgender people, particularly Black and Latina transgender women, experience a range of health inequities and social injustices. In this study, we compared two processes of transgender community engagement in Los Angeles and in Chicago as an implementation strategy to address inequitable access to care; we adapted and extended the Exploration Planning Implementation and Sustainment (EPIS) framework for transgender health equity.

METHODS

A comparative case method and the EPIS framework were used to examine parallel implementation strategies of transgender community engagement to expand access to care. To foster conceptual development and adaptation of EPIS for trans health equity, the comparative case method required detailed description, exploration, and analyses of the community-engagement processes that led to different interventions to expand access. In both cities, the unit of analysis was a steering committee made up of local transgender and cisgender stakeholders.

RESULTS

Both steering committees initiated their exploration processes with World Café-style, transgender community-engaged events in order to assess community needs and structural barriers to healthcare. The steering committees curated activities that amplified the voices of transgender community members among stakeholders, encouraging more effective and collaborative ways to advance transgender health equity. Based on analysis and findings from the Los Angeles town hall, the steering committee worked with a local medical school, extending the transgender medicine curriculum, and incorporating elements of transgender community-engagement. The Chicago steering committee determined from their findings that the most impactful intervention on structural racism and barriers to healthcare access would be to design and pilot an employment program for Black and Latina transgender women.

CONCLUSION

In Los Angeles and Chicago, transgender community engagement guided implementation processes and led to critical insights regarding specific, local barriers to healthcare. The steering committee itself represented an important vehicle for individual-, organizational-, and community-level relationship and capacity building. This comparative case study highlights key adaptations of EPIS toward the formation of an implementation science framework for transgender health equity.

Eating disorders are associated with increased risk of fall injury and fracture in Swedish men and women

In this retrospective cohort study, men and women with eating disorders (n = 8867) had higher risk of injurious falls and hip fractures than age, sex, and county-matched controls (n = 88670).

INTRODUCTION

Eating disorders have been associated with decreased bone mineral density and increased fracture risk, but the association with fall injuries without fracture has not previously been investigated. Furthermore, fracture risk in men with eating disorders has been insufficiently studied.

METHODS

In the present study, 8867 patients (9.4% men) with a diagnosed eating disorders and 88670 age-, sex-, and county-matched controls were investigated.

RESULTS

The mean (standard deviation) age of the patients and controls was 41.6 (13.7) years and the follow-up time 9.6 (5.2, 14.4) years (median, interquartile range) for patients and 10.1 (5.5, 14.2) years for controls. The proportions of injurious falls without fracture (17.3% vs. 9.0%) and of hip fracture (1.6% vs. 0.7%) were substantially greater in patients with an eating disorder than in their corresponding population controls. In an unadjusted Cox proportional hazards model, individuals with an eating disorder had a higher risk of injurious falls without fracture (Hazard ratio (HR) 95% confidence interval (CI): 2.07 (1.96-2.18), and hip fracture (HR 2.30 (1.92-2.75)) than the risk observed in the controls. The HR for any investigated outcome associated with an eating disorder did not differ by sex or age (interaction term p > 0.10). The risk of injurious falls without fracture and hip fracture was increased in both women (HR 2.07 (1.95-2.19) and HR 2.41 (1.98-2.93), respectively) and men (HR 2.09 (1.76-2.49) and HR 1.84(1.12-3.02), respectively), with an eating disorder.

CONCLUSION

The risk of injurious falls without fracture and of hip fracture is increased in both women and men with eating disorders, indicating measures to prevent both falls and fractures are important in these patients, regardless of age and sex.

The Fe/S ratio of pyrrhotite group sulfides in chondrites: An indicator of oxidation and implications for return samples from asteroids Ryugu and Bennu

Determining compositional trends among individual minerals is key to understanding the thermodynamic conditions under which they formed and altered, and is also essential to maximizing the scientific value of small extraterrestrial samples, including returned samples and meteorites. Here we report the chemical compositions of Fe-sulfides, focusing on the pyrrhotite-group sulfides, which are ubiquitous in chondrites and are sensitive indicators of formation and alteration conditions in the protoplanetary disk and in small Solar System bodies. Our data show that while there are trends with the at.% Fe/S ratio of pyrrhotite with thermal and aqueous alteration in some meteorite groups, there is a universal trend between the Fe/S ratio and degree of oxidation. Relatively reducing conditions led to the formation of troilite during: (1) chondrule formation in the protoplanetary disk (i.e., pristine chondrites) and (2) parent body thermal alteration (i.e., LL4 to LL6, CR1, CM, and CY chondrites). Oxidizing and sulfidizing conditions led to the formation of Fe-depleted pyrrhotite with low Fe/S ratios during: (1) aqueous alteration (i.e., CM and CI chondrites), and (2) thermal alteration (i.e., CK and R chondrites). The presence of troilite in highly aqueously altered carbonaceous chondrites (e.g., CY, CR1, and some CM chondrites) indicates they were heated after aqueous alteration. The presence of troilite, Fe-depleted pyrrhotite, or pyrite in a chondrite can provide an estimate of the oxygen and sulfur fugacities at which it was formed or altered. The data reported here can be used to estimate the oxygen fugacity of formation and potentially the aqueous and/or thermal histories of sulfides in extraterrestrial samples, including those returned by the Hayabusa2 mission and due to be returned by the OSIRIS-REx mission in the near future.

A primordial 15N-depleted organic component detected within the carbonaceous chondrite Maribo

We report on the detection of primordial organic matter within the carbonaceous chondrite Maribo that is distinct from the majority of organics found in extraterrestrial samples. We have applied high-spatial resolution techniques to obtain C-N isotopic compositions, chemical, and structural information of this material. The organic matter is depleted in ¹⁵N relative to the terrestrial value at around δ¹⁵N ~ -200‰, close to compositions in the local interstellar medium. Morphological investigations by electron microscopy revealed that the material consists of µm- to sub-µm-sized diffuse particles dispersed within the meteorite matrix. Electron energy loss and synchrotron X-ray absorption near-edge structure spectroscopies show that the carbon functional chemistry is dominated by aromatic and C=O bonding environments similar to primordial organics from other carbonaceous chondrites. The nitrogen functional chemistry is characterized by C-N double and triple bonding environments distinct from what is usually found in ¹⁵N-enriched organics from aqueously altered carbonaceous chondrites. Our investigations demonstrate that Maribo represents one of the least altered CM chondrite breccias found to date and contains primordial organic matter, probably originating in the interstellar medium.

Lactobacillus species in drinking water had no main effects on sulphur compounds from manure, egg quality, and selected serum parameters of second cycle hens

1. The aim of this study was to investigate the effects of a combined probiotic product (Lactobacillus paracasei, L. plantarum, and L. rhamnosus) on egg quality, sulphur compounds in manure and serum biochemistry of second cycle hens. 2. A total of 48 White Leghorn hens, at 52- to 54 weeks of age, were treated in a completely randomised design with water containing 0 or 1.8375 × 10¹⁰ cfu/l of probiotics for 8 weeks. 3. Probiotic supplementation did not affect egg quality. Albumen height and Haugh units were in general lowest in week 2 and highest in week 6. 4. For manure and serum parameters, water with or without probiotics produced statistically similar effects. An interacting trend for increasing concentrations of methyl mercaptan in manure was noted for probiotics x week, and should be further investigated. The week of supplementation significantly affected hydrogen sulphide, dimethyl sulphide, and triglycerides.

Seeking a practical definition of stable glaucoma: a Delphi consensus survey of UK glaucoma consultants

BACKGROUND

To generate a practical and clinically useful consensus definition of 'stable glaucoma' to aid provision of glaucoma services in the UK and to provide guidance for the criteria that should be used for monitoring of glaucoma patients in primary care services.

METHODS

A Delphi exercise was undertaken to derive consensus through an online questionnaire. Participants were asked to score their strength of agreement for a series of clinical parameters. Results and comments from each round were used to inform subsequent rounds. A total of 3 rounds were undertaken.

RESULTS

Thirty-two glaucoma experts participated in the study with over 90% completion rate achieved over three rounds. The consensus was reached for the following parameters: IOP levels to be used for defining stability, visual field-testing techniques to define stability, the number of medication changes acceptable to define stability and the number of treatment medications allowed to define stability. No consensus was reached on the period of time over which stability was defined, however, there was considerable agreement that longer durations of follow up (36-48 months) were required. A combination of optic disc photos and ocular coherence topography (OCT) retinal nerve fibre layer (RNFL) assessment/ OCT disc structural evaluation are the preferred imaging methods for the assessment of structural stability. Oversight by a glaucoma consultant was considered important for glaucoma monitoring schemes.

CONCLUSION

The consensus definition of glaucoma stability generated through this Delphi exercise provides guidance for allocation of patients suitable for monitoring in primary care glaucoma monitoring schemes.

Dry season habitat use of fishes in an Australian tropical river

The modification of river flow regimes poses a significant threat to the world's freshwater ecosystems. Northern Australia's freshwater resources, particularly dry season river flows, are being increasingly modified to support human development, potentially threatening aquatic ecosystems and biodiversity, including fish. More information is urgently needed on the ecology of fishes in this region, including their habitat requirements, to support water policy and management to ensure future sustainable development. This study used electrofishing and habitat survey methods to quantify the dry season habitat use of 20 common freshwater fish taxa in the Daly River in Australia's wet-dry tropics. Of twenty measured habitat variables, water depth and velocity were the two most important factors discriminating fish habitat use for the majority of taxa. Four distinct fish habitat guilds were identified, largely classified according to depth, velocity and structural complexity. Ontogenetic shifts in habitat use were also observed in three species. This study highlights the need to maintain dry season river flows that support a diversity of riverine mesohabitats for freshwater fishes. In particular, shallow fast-flowing areas provided critical nursery and refuge habitats for some species, but are vulnerable to water level reductions due to water extraction. By highlighting the importance of a diversity of habitats for fishes, this study assists water managers in future decision making on the ecological risks of water extractions from tropical rivers, and especially the need to maintain dry season low flows to protect the habitats of native fish.

Consensus generation of a minimum set of outcome measures for auditing glaucoma surgery outcomes-a Delphi exercise

PURPOSE

To identify the key set of glaucoma surgery outcome measures considered most important and practical to collect by glaucoma specialists.

METHODS

One hundred two glaucoma specialists (57 members of the UK and Eire Glaucoma Society (UKEGS) and 45 members of the European Glaucoma society (EGS)) took part in an Online Delphi exercise. The RAND/UCLA appropriateness method was used analyse data from each round and generate a disagreement index.

RESULTS

Participants agreed on 13 baseline data points and 12 outcomes that were considered important and practical to collect. For intraocular pressure (IOP) percentage reduction in IOP from baseline (last three IOP readings pre-op) and reduction below a specified target were considered important. For visual fields, change in a global visual field index, e.g. MD, and development of progression as assessed by linear regression were considered important. From a safety perspective, any visual loss resulting in a doubling of the minimal angle of resolution, loss of 5 dB or more of visual field or development of advanced field loss (Hodapp Parrish Anderson Stage 4) was considered important. The importance of routinely using patient reported outcome measures (PROMs) was highlighted. Consensus suggested that outcomes of glaucoma treatments should be reported at 1, 5 and 10 years.

CONCLUSIONS

There was broad consensus on a minimum dataset for reporting the outcomes of glaucoma surgery and outcome measurement intervals.

The effect of acetazolamide on intra-ocular pressure after Trendelenburg positioning - a randomised double-blind crossover trial in volunteers

Recent evidence suggests Trendelenburg positioning can produce a significant rise in intra-ocular pressure. Peri-operative vision loss in patients undergoing laparoscopic colorectal surgery has been reported with the rise in intra-ocular pressure suggested as a possible factor. Acetazolamide decreases intra-ocular pressure by reducing the formation of aqueous humour, so we aimed to investigate if it could attenuate the intra-ocular pressure rise that can occur in the Trendelenburg position. Nine healthy volunteers were recruited and randomly assigned to a double-blind crossover comparison of placebo or acetazolamide with a minimal 4 days' washout period before the second study day. One and a half hours after taking the medication, volunteers lay head-down at 17° for 4 h. Intraocular pressure measurements were repeated in both eyes every 30 min over a 4-h period. There were two males and seven female volunteers, with a mean (SD) age of 54.3 (18.5) years. The mean (SD) increase in intra-ocular pressure following 4 h in the Trendelenburg position was 3.17 (4.63) mmHg after the placebo, and 0.02 (4.01) mmHg (p = 0.02) after acetazolamide. We have shown than acetazolamide can attenuate the rise that occurs in intra-ocular pressure when in the Trendelenburg position.

Variation and comparative effectiveness of patent ductus arteriosus pharmacotherapy in extremely low birth weight infants

BACKGROUND

Patent ductus arteriosus (PDA) occurs in 70% of extremely low birth weight (ELBW, birth weight <1000 g) infants. Approximately 34% of ELBW infants with a PDA have spontaneous closure. Failure of the ductus arteriosus to close has been associated with multiple morbidities.

OBJECTIVE

To examine variability over time and across hospitals in early therapeutic (2-7 day) use of indomethacin (INDO) vs ibuprofen (IBU) for PDA treatment in outborn ELBW infants and examine the outcomes and side effects of both pharmacological agents in this population.

METHODS

Data were extracted from the Pediatric Health Information System. ELBW infants born between January 1, 2007 and December 31, 2010 and admitted on day of life 0 were eligible for inclusion. 732 infants had a PDA diagnosis and met inclusion criteria. We explored the variability in PDA pharmacotherapy over time and across hospitals. We compared outcomes of both agents for in-hospital mortality, need for surgical ligation, intraventricular hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia, periventricular leukomalacia, renal failure, and persistent pulmonary hypertension. Statistical methods included chi square and multivariable regression analysis. Instrumental variable analysis was used to control for selection bias and omitted variables.

RESULTS

There was large variability in PDA pharmacotherapy over time and across hospitals. INDO use declined as IBU use grew from 12.8 to 38.9%. There was no difference in hospital or NICU characteristics between high and low IBU using NICUs. Renal failure was more common in infants receiving INDO compared to IBU.

CONCLUSION

We noted large variability in PDA pharmacotherapy. Renal failure was more common with INDO use. Until further studies to compare the long-term effects of both drugs, our data support IBU as the preferred medication for PDA pharmacotherapy in ELBW infants.

Visible implant elastomer (VIE) tagging and simulated predation risk elicit similar physiological stress responses in three-spined stickleback Gasterosteus aculeatus

The effect of visible implant elastomer (VIE) tagging on the immediate physiological stress response was tested in female three-spined stickleback Gasterosteus aculeatus, using non-invasive waterborne cortisol analysis. Post-tagging cortisol levels were significantly higher compared with pretreatment baseline concentrations; however, when comparing post-tagging cortisol levels with cortisol levels after exposure to a simulated aerial predator, no significant differences were found. This study indicates that VIE tagging elicits a physiological stress response similar to those occurring in the everyday lives of this important biological model organism.

Effect of hyperglycaemia on muscarinic M3 receptor expression and secretory sensitivity to cholinergic receptor activation in islets

AIMS

Islets are innervated by parasympathetic nerves which release acetylcholine (ACh) to amplify glucose-induced insulin secretion, primarily via muscarinic M3 receptors (M3R). Here we investigate the consequence of chronic hyperglycaemia on islet M3R expression and secretory sensitivity of mouse islets to cholinergic receptor activation.

METHODS

The impact of hyperglycaemia was studied in (i) islets isolated from ob/ob mice, (ii) alginate-encapsulated mouse islets transplanted intraperitoneally into streptozotocin-induced diabetic mice and (iii) mouse and human islets maintained in vitro at 5.5 or 16 mmol/l glucose. Blood glucose levels were assessed by a commercial glucose meter, insulin content by RIA and M3R expression by qPCR and immunohistochemistry.

RESULTS

M3R mRNA expression was reduced in both ob/ob islets and islets maintained at 16 mmol/l glucose for 3 days (68 and 50% control, respectively). In all three models of hyperglycaemia the secretory sensitivity to the cholinergic receptor agonist, carbachol, was reduced by 60-70% compared to control islets. Treatment for 72 h with the irreversible PKC activator, PMA, or the PKC inhibitor, Gö6983, did not alter islet M3R mRNA expression nor did incubation with the PI3K-inhibitor, LY294002, although enhancement of glucose-induced insulin secretion by LY294002 was reduced in islets maintained at 16 mmol/l glucose, as was mRNA expression of the PI3K regulatory subunit, p85α.

CONCLUSIONS

Cholinergic regulation of insulin release is impaired in three experimental islet models of hyperglycaemia consistent with reduced expression of M3 receptors. Our data suggest that the receptor downregulation is a PKC- and PI3K-independent consequence of the hyperglycaemic environment, and they imply that M3 receptors could be potential targets in the treatment of type 2 diabetes.

Identification of circulating microRNAs as diagnostic biomarkers for use in multiple myeloma

Background:

Multiple myeloma is a plasma cell disorder that is characterised by clonal proliferation of malignant plasma cells in the bone marrow, monoclonal paraprotein in the blood or urine and associated organ dysfunction. It accounts for approximately 1% of cancers and 13% of haematological cancers. Myeloma arises from an asymptomatic proliferation of monoclonal plasma cells termed monoclonal gammopathy of undetermined significance (MGUS).

Methods:

MicroRNA expression profiling of serum samples was performed on three patient groups as well as normal controls. Validation of the nine microRNAs detected as promising biomarkers was carried out using TaqMan quantitative reverse transcription PCR. MicroRNA levels in serum were normalised using standard curves to determine the numbers of microRNAs per μl of serum.

Results:

Three serum microRNAs, miR-720, miR-1308 and miR-1246, were found to have potential as diagnostic biomarkers in myeloma. Use of miR-720 and miR-1308 together provides a powerful diagnostic tool for distinguishing normal healthy controls, as well as patients with unrelated illnesses, from pre-cancerous myeloma and myeloma patients. In addition, the combination of miR-1246 and miR-1308 can distinguish MGUS from myeloma patients.

Conclusion:

We have developed a biomarker signature using microRNAs extracted from serum, which has potential as a diagnostic and prognostic tool for multiple myeloma.

Raised intraocular pressure (IOP) and perioperative visual loss in laparoscopic colorectal surgery: a catastrophe waiting to happen? A systematic review of evidence from other surgical specialities

BACKGROUND

Case reports of healthy patients experiencing total perioperative visual loss (POVL) after elective laparoscopic surgery, including colorectal resection, are appearing increasingly frequently in the literature. We reviewed the literature exploring the relationship between patient positioning and intraocular pressure (IOP) across all surgical specialties. This was then applied to the potential risk of developing POVL in patients undergoing laparoscopic colorectal surgery.

METHODS

A systematic review of the relevant literature was performed to identify all studies exploring the relationship between intraocular pressure and patient positioning.

RESULTS

Eight relevant studies on both elective patients and healthy non-anaesthetised volunteers in the spinal, neurosurgical and urological fields were identified which explore the changes in IOP according to patient positioning. These all reported significant rises in IOP in both head-down positioning and prone positioning, and the strongest effects were seen in those patients placed in combined head-down and prone position (such as prone jackknife). Rises in IOP were time-dependent in all studies.

CONCLUSIONS

Patients undergoing laparoscopic colorectal surgery in a prolonged head-down position are likely to experience raised IOP and thus are at risk of POVL. Those having a laparoscopic abdominoperineal excision with prone positioning for the perineal component are probably those in the greatest danger. Surgeons need to be aware of this under-recognised but potentially catastrophic complication.

A novel extract of Gymnema sylvestre improves glucose tolerance in vivo and stimulates insulin secretion and synthesis in vitro

Herbal medicines, especially plant-derived extracts, have been used to treat Type 2 diabetes mellitus (T2DM) for many centuries, and offer the potential of cheap and readily available alternatives to conventional pharmaceuticals in developing countries. Extracts of Gymnema sylvestre (GS) have anti-diabetic activities and have been used as a folk medicine in India for centuries. We have investigated the effects of a novel high molecular weight GS extract termed OSA® on glucose tolerance in insulin-resistant ob/ob mice, and on insulin secretion and synthesis by isolated mouse islets. Single administration of OSA® (500 mg/kg) to ob/ob mice 30 min before an intraperitoneal glucose load improved their abnormal glucose tolerance. In vitro studies indicated that OSA® (0.25 mg/ml) initiated rapid and reversible increases in insulin secretion from isolated mouse islets at substimulatory (2 mM) and stimulatory (20 mM) glucose concentrations. In addition, prolonged treatment (24-48 h) of mouse islets with OSA® elevated the expression of preproinsulin mRNA and maintained the total insulin content of mouse islets in the presence of stimulated insulin secretion. These effects of OSA® are consistent with its potential use as a therapy for the hyperglycemia associated with obesity-related T2DM.

Surveillance of late-onset bleb leak, blebitis and bleb-related endophthalmitis--a UK incidence study

AIMS

To determine the incidence of late-onset bleb leak (BL), blebitis (B) and bleb-related endophthalmitis (BRE) after trabeculectomy surgery, and report the management approaches employed by UK ophthalmologists.

METHODS

Prospective case ascertainment study reporting of incident cases fulfilling the study definitions of BL, B and BRE through the reporting mechanism provided by the British Ophthalmic Surveillance Unit (BOSU; United Kingdom) for the period July 2007 to August 2008 (13 months). Two questionnaires completed at initial reporting and 6 months later were used to collect clinical details related to presentation, early and late management and outcome.

RESULTS

Ninety-eight cases were reported to the British Ophthalmic Surveillance Unit during the study period. Seventy-one first questionnaires were returned (response rate 72.4%). Of these, 11 were erroneous/duplicated. Sixty second questionnaires were sent out, and of these 37 fully completed questionnaires were returned. Analysis was, therefore, based upon 60 initial and 37 follow-up questionnaires. Overall incidences were estimated for isolated bleb leak (0.22%), blebitis without bleb leak (0.1%), blebitis with bleb leak (0.11%), and BRE with or without bleb leak (0.17%). Visual outcome in the BL group was good; however, in the BRE group half the patients ended with visions of perception of light or worse. There was a great variance in the initial and late management of these conditions. Surgical intervention for bleb leak seemed to result in the best chance of leak closure.

CONCLUSIONS

These complications of trabeculectomy surgery are relatively low but potentially visually devastating. This study updates the knowledge of the incidence of these complications, and suggests that no consistent management approach to any of the reported conditions was practised. In view of the potentially catastrophic consequences of these complications, formal guidance as to best practice would be beneficial, and further research to establish this is required.

The willingness of patients presenting with advanced glaucoma to participate in a trial comparing primary medical vs primary surgical treatment

AIM

The aim of this study is to examine the attitudes of patients, who presented with advanced glaucoma in at least one eye, to participation in a randomised prospective trial comparing primary medical treatment with primary surgical treatment for advanced glaucoma.

METHODS

Patients who had presented with advanced glaucoma (>15 dB loss mean deviation on Humphrey visual field testing) in at least one eye were asked to participate. Five focus groups comprising of 4-8 patients and consisting of 29 patients in total were undertaken. The group interviews were conducted by two experienced qualitative researchers, an ophthalmic clinician was present to clarify technical issues. The focus group discussions were taped and transcribed in full, and analysed through a process of familiarisation, open (inductive) coding, theme generation, theme refinement, and thematic mapping.

RESULTS

Three overarching themes were identified: (1) the extent of patients' knowledge, (2) anxieties about surgery, and (3) concerns about compromised care due to trial involvement; these themes were further classified into eight sub-themes.

CONCLUSIONS

Patients' willingness to participate in randomised clinical studies is significantly connected to their level of comprehension and insight about the medical condition, its treatment, and the research process; misunderstandings about any of these aspects may act as a significant barrier to trial recruitment. Recruitment rates for future randomised trials may be enhanced by ensuring that patients have full and accurate information about the treatment alternatives, and that uncertainty exists for best patient outcomes between treatment options, and reassuring potential participants that the research process, in particular randomisation, will not compromise clinical care.

Translating HIV interventions into practice: community-based organizations' experiences with the diffusion of effective behavioral interventions (DEBIs)

Efficacious behavioral interventions developed to address the spread of HIV/STIs are currently being disseminated in the USA through a national diffusion program (DEBI) spearheaded by the Centers for Disease Control and Prevention (CDC). Understanding how interventions are translated to real world settings is necessary to further scientific knowledge of this process and to facilitate future translation efforts in public health. Prior studies have begun to elucidate how agencies translate behavioral interventions into practice, but further work is needed. Guided by the ADAPT framework, we examined agencies' assessment, preparation, and implementation of interventions. Our qualitative interview-based study focused on six community-based agencies in California (United States) funded to implement three group-level HIV interventions. Findings showed considerable variation in the extent to which agencies engaged in assessment and broad-based preparation and in the ease with which agencies implemented the interventions. The findings provide insight into the process that agencies undergo in the translation of effective behavioral interventions and illustrate how agencies can inform logic models that guide translation. We also identify relevant dimensions of existing models, including the ADAPT framework and Rogers's (1995, 2005) diffusion of innovations in organizations, that have value for agencies that are translating research to practice.

Phylogeography of microbial phototrophs in the dry valleys of the high Himalayas and Antarctica

High-elevation valleys in dry areas of the Himalayas are among the most extreme, yet least explored environments on Earth. These barren, rocky valleys are subjected to year-round temperature fluctuations across the freezing point and very low availability of water and nutrients, causing previous workers to hypothesize that no photoautotrophic life (primary producers) exists in these locations. However, there has been no work using modern biogeochemical or culture-independent molecular methods to test the hypothesis that photoautotrophs are absent from high Himalayan soil systems. Here, we show that although microbial biomass levels are as low as those of the Dry Valleys of Antarctica, there are abundant microbial photoautotrophs, displaying unexpected phylogenetic diversity, in barren soils from just below the permanent ice line of the central Himalayas. Furthermore, we discovered that one of the dominant algal clades from the high Himalayas also contains the dominant algae in culture-independent surveys of both soil and ice samples from the Dry Valleys of Antarctica, revealing an unexpected link between these environmentally similar but geographically very distant systems. Phylogenetic and biogeographic analyses demonstrated that although this algal clade is globally distributed to other high-altitude and high-latitude soils, it shows significant genetic isolation by geographical distance patterns, indicating local adaptation and perhaps speciation in each region. Our results are the first to demonstrate the remarkable similarities of microbial life of arid soils of Antarctica and the high Himalayas. Our findings are a starting point for future comparative studies of the dry valleys of the Himalayas and Antarctica that will yield new insights into the cold and dry limits to life on Earth.

Transscleral diode laser cycloablation in patients with good vision

PURPOSE

To investigate the effect of diode laser cyclophotocoagulation for glaucoma on central visual function in patients with good visual acuity (VA).

PATIENTS AND METHODS

Patients with preoperative VA 20/60 or better who had undergone cyclodiode treatment according to a standard protocol were evaluated retrospectively. The primary outcome variable was a recorded loss of two or more Snellen lines of best corrected VA during follow-up. Successful intraocular pressure (IOP) control was defined as being between 6 and 21 mmHg inclusive without oral acetazolamide or other glaucoma surgery.

RESULTS

49 eyes of 43 patients with a median pretreatment acuity of 20/30 were included (range 20/16-20/60). After a mean duration of follow-up of 5.0 years, median VA was 20/60 with a line loss of two or more recorded in 15 eyes (30.6%) (mean survival time 7.7 years). 67.3% (33/49) retained VA 20/60 or better, but VA deteriorated by one Snellen line or more in 31 (63.2%), and in 16.3% (8/49), final VA was <20/200. In cases experiencing a two-line loss in acuity, the main causes were glaucoma progression (nine cases) and macula oedema (four cases). Visual loss was unrelated to total treatment dose (mean 99.7 J), initial acuity or initial IOP level. IOP was controlled at final follow-up in 39/49 (79.6%) with no cases of hypotony.

CONCLUSIONS

Most of these eyes with difficult to manage glaucoma retained their good VA over long-term follow-up after undergoing diode laser cyclophotocoagulation. The proportion losing two Snellen lines is in line with that reported after trabeculectomy or tube surgery. These results suggest a possible role for the use of transscleral cyclodiode in selected eyes with significant visual potential. Further controlled prospective studies are required to better define this role.

Microbial activity and diversity during extreme freeze-thaw cycles in periglacial soils, 5400 m elevation, Cordillera Vilcanota, Perú

High-elevation periglacial soils are among the most extreme soil systems on Earth and may be good analogs for the polar regions of Mars where oligotrophic mineral soils abut with polar ice caps. Here we report on preliminary studies carried out during an expedition to an area where recent glacial retreat has exposed porous mineral soils to extreme, daily freeze-thaw cycles and high UV fluxes. We used in situ methods to show that inorganic nitrogen (NO(3) (-) and NH(4) (+)) was being actively cycled even during a period when diurnal soil temperatures (5 cm depth) ranged from -12 to 27 degrees C and when sub-zero, soil cooling rates reached 1.8 degrees C h(-1) (the most rapid soil cooling rates recorded to date). Furthermore, phylogenetic analyses of microbial phylotypes present at our highest sites (5410 m above sea level) showed the presence of nitrifying bacteria of the genus Nitrospira and newly discovered nitrite-oxidizing Betaproteobacteria. These soils were overwhelmingly dominated (>70% of phylotypes) by photosynthetic bacteria that were related to novel cyanobacteria previously found almost exclusively in other plant-free, high-elevation soils. We also demonstrated that soils from our highest sites had higher potential for mineralizing glutamate and higher microbial biomass than lower elevation soils that had been more recently covered by ice. Overall, our findings indicate that a diverse and robustly functioning microbial ecosystem is present in these previously unstudied high-elevation soils.

Kisspeptin stimulation of insulin secretion: mechanisms of action in mouse islets and rats

AIMS/HYPOTHESIS

Kisspeptin is a novel peptide identified as an endogenous ligand of the G-protein-coupled receptor 54 (GPR-54), which plays a crucial role in puberty and reproductive function. High levels of GPR-54 and kisspeptin have been reported in the pancreas and we have previously shown that kisspeptin potentiates glucose-induced insulin release from isolated islets, although the mechanisms underlying this effect were unclear.

METHODS

Insulin secretion from isolated mouse islets was measured to characterise the effects of kisspeptin. The effects of kisspeptin on both p42/44 mitogen-activated protein kinase (MAPK) phosphorylation and intracellular Ca(2+)([Ca(2+)](i)) in mouse islets were also investigated. Furthermore, kisspeptin was administered to rats in vivo and effects on plasma insulin levels measured.

RESULTS

In the current study, kisspeptin induced a concentration-dependent potentiation of glucose-induced (20 mmol/l) insulin secretion from mouse islets, with maximal effects at 1 micromol/l, but had no effect on insulin secretion at a substimulatory concentration of glucose (2 mmol/l). Activation of GPR-54 by kisspeptin also caused reversible increases in [Ca(2+)](i) in Fura-2 loaded dispersed islet cells. The kisspeptin-induced potentiation of glucose-induced insulin secretion was completely abolished by inhibitors of phospholipase C and p42/44 MAPK, but not by inhibitors of protein kinase C or p38 MAPK. Intravenous administration of kisspeptin into conscious, unrestrained rats caused an increase in circulating insulin levels, whilst central administration of kisspeptin had no effect, indicating a peripheral site of action.

CONCLUSIONS/INTERPRETATION

These observations suggest that neither typical protein kinase C isoforms nor p38 MAPK are involved in the potentiation of glucose-induced insulin release by kisspeptin, but intracellular signalling pathways involving phospholipase C, p42/44 MAPK and increased [Ca(2+)](i) are required for the stimulatory effects on insulin secretion. The observation that kisspeptin is also capable of stimulating insulin release in vivo supports the conclusion that kisspeptin is a regulator of beta cell function.

Phylogeny and ecophysiology of opportunistic "snow molds" from a subalpine forest ecosystem

Mats of coenocytic "snow molds" are commonly observed covering the soil and litter of alpine and subalpine areas immediately following snow melt. Here, we describe the phylogenetic placement, growth rates, and metabolic potential of cold-adapted fungi from under-snow mats in the subalpine forests of Colorado. SSU rDNA sequencing revealed that these fungi belong to the zygomycete orders Mucorales and Mortierellales. All of the isolates could grow at temperatures observed under the snow at our sites (0 degrees C and -2 degrees C) but were unable to grow at temperatures above 25 degrees C and were unable to grow anaerobically. Growth rates for these fungi were very high at -2 degrees C, approximately an order of magnitude faster than previously studied cold-tolerant fungi from Antarctic soils. Given the rapid aerobic growth of these fungi at low temperatures, we propose that they are uniquely adapted to take advantage of the flush of nutrient that occurs at the soil-snow interface beneath late winter snow packs. In addition, extracellular enzyme production was relatively high for the Mucorales, but quite low for the Mortierellales, perhaps indicating some niche separation between these fungi beneath the late winter snow pack.

Views of glaucoma patients on provision of follow-up care; an assessment of patient preferences by conjoint analysis

AIMS

To determine patients' preferences for provision of glaucoma follow-up services examining preferences for location, access and personnel for delivery of this care.

METHODS

100 patient patients attending the glaucoma outpatient clinic for follow-up review underwent an interview-based assessment during which they completed the visual function questionnaire 25 and ranking of scenario options for provision of follow-up care for their glaucoma. Percentage preferences for aspects of care offered in the conjoint analysis scenario packages and generation of utility values for each of the factor levels included in the scenario design were calculated.

RESULTS

Travel time and training of health professional were the most important factors for patients (accounting for over 60%) of their preference. Utility scores were generated for each factor, with shorter travel time and examination by a doctor being the most important features to the patients. Patients who lived furthest from the hospital and had severe visual disability considered the number of visits to complete an episode to be an important feature.

CONCLUSION

Patients ideally would like to travel a short distance and be seen by a doctor when being followed up for their glaucoma.

Sound localization behavior in ferrets: comparison of acoustic orientation and approach-to-target responses

Auditory localization experiments typically either require subjects to judge the location of a sound source from a discrete set of response alternatives or involve measurements of the accuracy of orienting responses made toward the source location. To compare the results obtained by both methods, we trained ferrets by positive conditioning to stand on a platform at the center of a circular arena prior to stimulus presentation and then approach the source of a broadband noise burst delivered from 1 of 12 loudspeakers arranged at 30 degrees intervals in the horizontal plane. Animals were rewarded for making a correct choice. We also obtained a non-categorized measure of localization accuracy by recording head-orienting movements made during the first second following stimulus onset. The accuracy of the approach-to-target responses declined as the stimulus duration was reduced, particularly for lateral and posterior locations, although responses to sounds presented in the frontal region of space and directly behind the animal remained quite accurate. Head movements had a latency of approximately 200 ms and varied systematically in amplitude with stimulus direction. However, the final head bearing progressively undershot the target with increasing eccentricity and rarely exceeded 60 degrees to each side of the midline. In contrast to the approach-to-target responses, the accuracy of the head orienting responses did not change much with stimulus duration, suggesting that the improvement in percent correct scores with longer stimuli was due, at least in part, to re-sampling of the acoustical stimulus after the initial head turn had been made. Nevertheless, for incorrect trials, head orienting responses were more closely correlated with the direction approached by the animals than with the actual target direction, implying that at least part of the neural circuitry for translating sensory spatial signals into motor commands is shared by these two behaviors.

Frequency of bleb manipulations after trabeculectomy surgery

AIM

To quantify the type and frequency of postoperative bleb manipulations undertaken after modern glaucoma surgery.

METHODS

Bleb manipulations were recorded after trabeculectomy surgery on 119 consecutive patients with at least 1 year of follow-up. The type of intervention and time after surgery were recorded. Statistical analysis identified success rates at various intraocular pressure (IOP) cut-off definitions and identified factors that increased the risk for bleb manipulation.

RESULTS

In all, 78.2% of trabeculectomies were followed by some form of bleb manipulation. Almost 49% of blebs underwent massage and a similar number required at least one suture removal, 31.1% required at least one 5-fluorouracil (5-FU) injection and 25.2% required at least one needling and 5-FU injection. The median time to the first intervention for massage, suture removal, 5-FU injection, and needling and 5-FU injection were 1, 14, 14 and 43 days, respectively. IOP measurements were higher at all follow-up time points in the intervention group. Failure to achieve specific IOP target pressures was also generally poorer in the 5-FU, and needling and 5-FU intervention groups.

CONCLUSIONS

Postoperative intervention is a frequent occurrence after modern glaucoma surgery. This requires intensive postoperative follow-up and is a labour-intensive undertaking. Despite interventions in our group of patients, IOP in the intervention group was always higher than in the group that required no intervention.

A novel use of amniotic membrane in the management of tube exposure following glaucoma tube shunt surgery

AIM

To report a novel technique using amniotic membrane to cover exposed glaucoma tube shunts.

METHODS

A consecutive series of three cases that underwent drainage tube shunt surgery with the Ahmed valve for intractable glaucoma. All three patients developed exposure of the tube secondary to necrosis of the overlying bovine pericardial patch and conjunctiva. Repair of the defect was carried out with a double layer of amniotic membrane, the inner one acting as a graft and the outer as a patch. Autologous serum was used to promote epithelial growth.

RESULTS

Successful lasting closure of the conjunctival defect was achieved in all cases.

CONCLUSION

Erosion of the drainage tube following shunt surgery is a potentially serious problem. It can be successfully managed using a double layer of amniotic membrane.

Longitudinal glaucoma screening for siblings of patients with primary open angle glaucoma: the Nottingham Family Glaucoma Screening Study

AIMS

To assess the prevalence and cumulative incidence of open angle glaucoma (OAG) in a cohort group of siblings of OAG probands.

METHODS

Between 1994 and 2003, a group of siblings of OAG probands underwent both initial and follow up standardised ophthalmic examinations. Siblings were classified as "definite glaucoma" (primary OAG (POAG) and normal tension glaucoma (NTG)), "glaucoma suspects" (NTG suspects or ocular hypertension (OHT)), and normal. The prevalence and cumulative incidence of OAG over the follow up interval were calculated.

RESULTS

At the initial study, 271 siblings (mean age 63.6 years; female to male ratio 1.2) from 156 probands were examined. 32 (11.8%) were classified as definite glaucoma and 15 (5.5%) as suspects. In the follow up study, 157 of the 224 "normal" siblings from the initial study were examined (mean interval from initial study 7.0 (SD 1.0) years). 11 (7%) were classified as definite glaucoma and 30 (19.1%) as suspects. There were significant trends of increasing prevalence and incidence of OAG with age and a lifetime risk estimated at approximately 20% by age 70.

CONCLUSION

Siblings of glaucoma patients have an increased risk of developing glaucoma and the risk increases with age. An effective and repeated screening programme should be considered for this high risk group.

Spatial distribution of functional superficial-deep connections in the adult ferret superior colliculus

Numerous studies have identified connections between the superficial visual and deeper multisensory layers of the superior colliculus (SC), but the functional distribution of the superficial-deep projection has not been mapped. This question was assessed in the present study using extracellular electrophysiological stimulation and recording techniques. In vitro slices from adult ferrets were used to functionally map the rostro-caudal, medio-lateral, and dorso-ventral distribution of these superficial-deep connections. For each coronal (n=6) or parasagittal (n=10) slice, single and multi-unit responses to electrical stimulation of a point in the superficial layers were systematically recorded at different locations along a grid (approximately 300 microm intervals) across the slice. Recording sites with similar activation thresholds were grouped on the histological reconstruction of each slice to plot the functional access of superficial stimulation site to the deeper layers. Low intensity stimulation (defined as a current threshold < or =75 microA) activated areas of the subjacent intermediate layers in most cases (75%; 12/16). Higher intensity stimuli (> 75-600 microA) accessed larger areas which, in 50% of the slices, extended into the deepest layers of the SC. However, regardless of the rostro-caudal or medio-lateral position of the superficial layer stimulation site, the proportion of the deeper layers activated remained remarkably constant, although the volume of activated deep layer tissue was shifted in each case toward the central regions of the SC. This last observation argues against the precise alignment of the superficial and deep layer visual maps, suggesting instead that the arrangement of the superficial layer projection may more closely relate to the organization of deep layer auditory and/or somatosensory representations.

A protocol for low contamination risk of autologous serum drops in the management of ocular surface disorders

AIM

To assess microbial contamination of 20% autologous serum (AS) eye drops used in a hospital inpatient setting.

METHOD

14 patients received autologous serum drops from 4 to 14 days with a cumulative total of 67 days. For each day the first and last drop (total 134 samples) was cultured on broth and blood agar.

RESULTS

Four patients (9 samples) grew Staphylococcus epidermidis only. One patient (1 sample) showed Staphylococcus epidermidis and a scanty growth of viridans streptococci in the same sample, and on different days the same patient grew Staphylococcus aureus in one sample and Staphylococcus epidermidis in another sample. One patient (1 sample) grew micrococcus. There was no clinical or microbial evidence of infection in any of these six patients.

CONCLUSION

This study shows that autologous serum drops can be safely used in an inpatient setting, under a strict protocol of preparation and storage, without significant risk of bacterial contamination and consequent infection.

Tumour necrosis factor and PI3-kinase control oestrogen receptor alpha protein level and its transrepression function

Oestrogen receptor alpha (ERα) is an oestrogen-activated transcription factor, which regulates proliferation and differentiation of mammary epithelial cells by activating or repressing gene expression. ERα is a critical prognostic indicator and a therapeutic target for breast cancer. Patients with tumours that express higher level of ERα have better prognosis than patients with tumours that are ERα negative or express lower level of ERα. Better prognosis in ERα-positive patients is believed to be due to repression of proinvasive gene expression by ERα. Oestrogen receptor alpha represses gene expression by transrepressing the activity of the transcription factors such as nuclear factor-kappaB or by inducing the expression of transcriptional suppressors such as MTA3. In this report, we show that ERα transrepresses the expression of the proinvasive gene interleukin 6 (IL-6) in ERα-negative MDA-MB-231 breast cancer cells stably overexpressing ERα. Using these cells as well as ERα-positive MCF-7 and ZR-75-1 cells, we show that tumour necrosis factor alpha (TNFα) and the phosphatidylinositol-3-kinase (PI3-kinase) modulate transrepression function of ERα by reducing its stability. From these results, we propose that TNFα expression or PI3-kinase activation lead to reduced levels of ERα protein in cancer cells and corresponding loss of transrepression function and acquisition of an invasive phenotype.

Dynamic behaviour of polycyclic aromatic hydrocarbons in Brighton marina, UK

The distribution of polycyclic aromatic hydrocarbons (PAHs) between various phases is fundamental in the control of their movement and impact in the marine environment. In this study samples of water and sediments were regularly collected from Brighton marina, UK, to quantify the intensity, spatial and temporal variations of PAH contamination. The results show clearly that PAH behaviour in marine systems is highly complex, and controlled by the interplay of PAH sources, compound physicochemical properties, water and sediment movement, and field conditions. Levels of total PAHs (16 compounds) in the dissolved phase were found to vary between <2 and 11,400 ng/l, with higher values observed in the winter months. Total PAH concentration in sediment samples varied between 24 and 4710 ng/g dry weight. PAHs in water were dominated by low molecular mass compounds (2-ring), while PAHs in sediments were mainly derived from 2-4 ring compounds. In addition, dissolved concentrations were increased during sediment dredging and after a period of severe rainfall. PAHs in Brighton marina are likely to be from both pyrolytic and petrogenic sources; as a result, field-derived distribution coefficients for individual PAHs between sediment and water tend to follow the equilibrium partition models, although slight exceedance is apparent. The extended partition model incorporating soot carbon has achieved limited success in better predicting PAH behaviour.

Impact of iron dextran on polymorphonuclear cell function among hemodialysis patients

BACKGROUND

Polymorphonuclear cell (PMN) dysfunction and the increased use of parenteral iron may be important contributory factors to bacterial infections among patients with end-stage renal disease (ESRD) on maintenance hemodialysis (HD). We compared the in vitro impact of a commonly used parenteral iron preparation, iron dextran, on PMN function and viability between a group of HD patients with normal iron indices and healthy subjects.

METHODS

Eleven patients with ESRD on HD and 10 healthy subjects were studied. PMN harvested from heparinized blood were incubated with iron dextran (0 - 20 mM) in culture medium (RPMI) for 24 hours at 37 degrees C with 5% CO2 following which function and viability were assessed by flow cytometry using appropriate fluorescent labels.

RESULTS

Unstimulated, S. aureus and N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated hydrogen peroxide (H2O2) production was significantly higher in PMN unexposed to iron dextran from HD patients compared to those from healthy subjects. Iron dextran had no impact on unstimulated PMN H2O2 production in either group. In the healthy group, the only significant change occurred with 4-beta-phorbol 12-beta-myristate 13-alpha-acetate (PMA) stimulation, where cells exposed to 0.2 and 2.0 mM iron dextran produced less H2O2 relative to PMN unexposed to iron dextran (p < 0.05). In the HD group, all concentrations of iron dextran significantly attenuated H2O2 production stimulated by S. aureus, fMLP and PMA compared to PMN unexposed to iron dextran. Although PMN phagocytosis decreased with exposure to increasing concentration of iron dextran in both healthy subjects and HD patients, these changes did not achieve statistical significance. No significant changes in PMN viability or apoptosis were seen in either group after exposure to iron dextran.

CONCLUSIONS

These results indicate that iron dextran, a standard parenteral iron preparation, attenuates PMN function in HD patients with normal iron indices at clinically relevant concentrations. Further studies are required to evaluate and compare the impact of newer preparations of parenteral iron, such as iron sucrose and ferric gluconate, on PMN function.

Linear processing of spatial cues in primary auditory cortex

To determine the direction of a sound source in space, animals must process a variety of auditory spatial cues, including interaural level and time differences, as well as changes in the sound spectrum caused by the direction-dependent filtering of sound by the outer ear. Behavioural deficits observed when primary auditory cortex (A1) is damaged have led to the widespread view that A1 may have an essential role in this complex computational task. Here we show, however, that the spatial selectivity exhibited by the large majority of A1 neurons is well predicted by a simple linear model, which assumes that neurons additively integrate sound levels in each frequency band and ear. The success of this linear model is surprising, given that computing sound source direction is a necessarily nonlinear operation. However, because linear operations preserve information, our results are consistent with the hypothesis that A1 may also form a gateway to higher, more specialized cortical areas.

Role of the polymorphic region 1 of the Bordetella pertussis protein pertactin in immunity

In several countries pertussis is re-emerging, despite a high vaccination coverage. It is suggested that antigenic divergence between Bordetella pertussis vaccine strains and circulating strains, in particular with respect to pertactin, has contributed to pertussis re-emergence. Polymorphism in pertactin is essentially limited to region 1, which is composed of repeats and is located adjacent to an Arg-Gly-Asp motif implicated in adherence. Evidence is provided for the immunological relevance of polymorphism in region 1. Region 1 was found to contain a B-cell epitope recognized in both humans and mice. Furthermore, variation in region 1 affected antibody binding and, in a mouse respiratory infection model, the efficacy of a whole-cell vaccine. Moreover, passive and active immunization indicated that region 1 confers protective immunity. An mAb directed against a linear conserved epitope conferred cross-immunity against isolates with distinct pertactin variants. The results indicate an important role of region 1 of pertactin in immunity.