Changes in attitudes to awareness of hypoglycaemia during a hypoglycaemia awareness restoration programme are associated with avoidance of further severe hypoglycaemia episodes within 24 months: the A2A in HypoCOMPaSS study

AIMS/HYPOTHESIS

The aims of this study were to assess cognitions relating to hypoglycaemia in adults with type 1 diabetes and impaired awareness of hypoglycaemia before and after the multimodal HypoCOMPaSS intervention, and to determine cognitive predictors of incomplete response (one or more severe hypoglycaemic episodes over 24 months).

METHODS

This analysis included 91 adults with type 1 diabetes and impaired awareness of hypoglycaemia who completed the Attitudes to Awareness of Hypoglycaemia (A2A) questionnaire before, 24 weeks and 24 months after the intervention, which comprised a short psycho-educational programme with optimisation of insulin therapy and glucose monitoring.

RESULTS

The age and diabetes duration of the participants were 48±12 and 29±12 years, respectively (mean±SD). At baseline, 91% reported one or more severe hypoglycaemic episodes over the preceding 12 months; this decreased to <20% at 24 weeks and after 24 months (p=0.001). The attitudinal barrier 'hyperglycaemia avoidance prioritised' (η²_p=0.250, p=0.001) decreased from baseline to 24 weeks, and this decrease was maintained at 24 months (mean±SD=5.3±0.3 vs 4.3±0.3 vs 4.0±0.3). The decrease in 'asymptomatic hypoglycaemia normalised' from baseline (η²_p=0.113, p=0.045) was significant at 24 weeks (1.5±0.3 vs 0.8±0.2). Predictors of incomplete hypoglycaemia response (one or more further episodes of severe hypoglycaemia) were higher baseline rates of severe hypoglycaemia, higher baseline scores for 'asymptomatic hypoglycaemia normalised', reduced change in 'asymptomatic hypoglycaemia normalised' scores at 24 weeks, and lower baseline 'hypoglycaemia concern minimised' scores (all p<0.05).

CONCLUSIONS/INTERPRETATION

Participation in the HypoCOMPaSS RCT was associated with improvements in hypoglycaemia-associated cognitions, with 'hyperglycaemia avoidance prioritised' most prevalent. Incomplete prevention of subsequent severe hypoglycaemia episodes was associated with persistence of the cognition 'asymptomatic hypoglycaemia normalised'. Understanding and addressing cognitive barriers to hypoglycaemia avoidance is important in individuals prone to severe hypoglycaemia episodes.

CLINICAL TRIALS REGISTRATION

www.isrctn.org : ISRCTN52164803 and https://eudract.ema.europa.eu : EudraCT2009-015396-27.

Missed Opportunities? A retrospective study into adults hospitalized with invasive infection from airway pathogens

Background

Invasive disease caused by airway pathogens, including Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, and Moraxella catarrhalis, has high morbidity and mortality worldwide, with immunodeficiency being a known association with recurrent disease. The study aimed to describe the frequency of known immunodeficiency and predisposing factors in adult patients presenting with invasive infections and determine the frequency of screening for and detection of immunodeficiency.

Methods

A retrospective analysis was conducted at a large tertiary Australian health service, comprising multiple centers. Patients aged 18 years or older, in whom the above pathogens were isolated from sterile sites, were included as identified through a microbiology database, between 2015 and 2020. Using electronic medical records, patient demographics, medical history, outcomes of admission, and pathology results were captured and reviewed to address the aims.

Results

In 252 patients, S pneumoniae was the most common culprit, isolated in 73% (185/252), compared to 14.3% (36/252) and 11.5% (29/252) of infections caused by H influenzae and N meningitidis, respectively. Known diagnoses of secondary immunodeficiency were common (31% of patients). Of those presenting with invasive pneumococcal disease, 78% had at least 1 predisposing condition, though only 9 patients (6%) had previously received pneumococcal vaccination. Despite poor screening for immunodeficiency, 12 new diagnoses were made. While the commonest immunodeficiency was secondary, due to hematological and solid organ malignancies, 3 new primary immunodeficiency diagnoses were made.

Conclusions

Immunodeficiency is common in this patient population. Screening should be undertaken to ensure timely diagnosis and treatment of the underlying condition to avoid future morbidity and mortality.

Characteristics of adults with type 1 diabetes and treatment-resistant problematic hypoglycaemia: a baseline analysis from the HARPdoc RCT

AIMS/HYPOTHESIS

Problematic hypoglycaemia still complicates insulin therapy for some with type 1 diabetes. This study describes baseline emotional, cognitive and behavioural characteristics in participants in the HARPdoc trial, which evaluates a novel intervention for treatment-resistant problematic hypoglycaemia.

METHODS

We documented a cross-sectional baseline description of 99 adults with type 1 diabetes and problematic hypoglycaemia despite structured education in flexible insulin therapy. The following measures were included: Hypoglycaemia Fear Survey II (HFS-II); Attitudes to Awareness of Hypoglycaemia questionnaire (A2A); Hospital Anxiety and Depression Index; and Problem Areas In Diabetes. k-mean cluster analysis was applied to HFS-II and A2A factors. Data were compared with a peer group without problematic hypoglycaemia, propensity-matched for age, sex and diabetes duration (n = 81).

RESULTS

The HARPdoc cohort had long-duration diabetes (mean ± SD 35.8 ± 15.4 years), mean ± SD Gold score 5.3 ± 1.2 and a median (IQR) of 5.0 (2.0-12.0) severe hypoglycaemia episodes in the previous year. Most individuals had been offered technology and 49.5% screened positive for anxiety (35.0% for depression and 31.3% for high diabetes distress). The cohort segregated into two clusters: in one (n = 68), people endorsed A2A cognitive barriers to hypoglycaemia avoidance, with low fear on HFS-II factors; in the other (n = 29), A2A factor scores were low and HFS-II high. Anxiety and depression scores were significantly lower in the comparator group.

CONCLUSIONS/INTERPRETATION

The HARPdoc protocol successfully recruited people with treatment-resistant problematic hypoglycaemia. The participants had high anxiety and depression. Most of the cohort endorsed unhelpful health beliefs around hypoglycaemia, with low fear of hypoglycaemia, a combination that may contribute to persistence of problematic hypoglycaemia and may be a target for adjunctive psychological therapies.

Acute tubular necrosis and thrombocytopenia associated with rifampin use: Case Report and Review

A case of rifampin-induced acute tubular necrosis requiring hemodialysis in a patient receiving thrice-weekly rifampin with daily dapsone for retreatment of relapsed Hansen’s disease is reported. The patient had positive rifampin-dependent antiplatelet antibodies. Case reports of acute renal failure associated with the use of rifampin are summarized.

Personality traits of alexithymia and perfectionism in impaired awareness of hypoglycemia in adults with type 1 diabetes - An exploratory study

OBJECTIVE

Severe hypoglycemia complicates insulin therapy for type 1 diabetes, with impaired awareness of hypoglycemia (IAH) being a major risk factor. We explored associations between the personality traits, alexithymia and perfectionism, and cognitive barriers to hypoglycemia avoidance described in IAH, and evaluated their prevalence in people with and without IAH.

METHODS

Cross-sectional exploratory study. Ninety adults with type 1 diabetes, 54 hypoglycemia aware and 36 with IAH, completed validated questionnaires exploring alexithymia (Total Alexithymia Scale [TAS-20]) and perfectionism (Frost Multidimensional Perfectionism Scale [FMPS]); and cognitive barriers related to hypoglycemia avoidance (Attitudes to Awareness Questionnaire [A2A].

RESULTS

Alexithymia and perfectionism scores correlated positively with cognitive barriers associated with IAH. Specifically, alexthymia scores correlated with the 'Hyperglycaemia Avoidance Prioritised' factor (r = 0.265; p = .02, n = 77) and the 'Asymptomatic Hypoglycemia Normalised' factor (r = 0.252-0.255; p = .03, n = 77). Perfectionism scores correlated with the 'Hyperglycaemia Avoidance Prioritised' factor (r = 0.525; p < .001, n = 66). Overall, IAH participants were significantly more likely to score at the high end for alexithymia (17.6% vs. 1.9%, p = .008, n = 87) and at the extreme ends (high and low) for perfectionism (69.0% vs. 40.0%, χ² (1) = 6.24, p = .01, n = 77).

CONCLUSION

These novel data showing associations between alexithymia and perfectionism scores and maladaptive health beliefs in IAH suggest the intriguing possibility that personality traits may contribute to the risk of IAH, perhaps through their influence on incentives to avoid hypoglycemia. If confirmed, measuring such traits may help tailor early adjunctive psychological intervention to reduce hypoglycemia burden for people with IAH.

Prospective Study of Policies and Use of Therapies for COVID-19 Amongst Australian Health Services during 2020

BACKGROUND

The COVID-19 pandemic has generated significant debate about how emerging infections can be treated in the absence of evidence-based therapies to combat disease. In particular, the use of off-label therapies outside of a clinical trial setting has been controversial.

AIM

We aimed to longitudinally study policies and prescribing practices pertaining to therapies for COVID-19 in Australian Health Services in 2020.

METHODS

Prospective data was collected from participating Australian health services who may care for patients with COVID-19 via an electronic portal. A single informant from each health service was emailed a survey link at regular intervals. Information was sought regarding changes to COVID-19 policy at their service and use of therapies for COVID-19.

RESULTS

Overall, 78 hospitals were represented from 39 respondents with longitudinal data collection from May to December 2020. All Australian states/territories were represented with the majority of respondents located in a major city (34/39; 87%). Just over half (20/39) of respondents had a written policy for COVID-19 therapy use at their health service at survey enrolment and policies changed frequently throughout the pandemic. Therapy use outside of a clinical trial was reported in 54% of health services, most frequently in Victoria, correlating with higher numbers of COVID-19 cases. At study commencement hydroxychloroquine was most frequently used, with corticosteroids and remdesivir use increasingly throughout the study period.

CONCLUSION

Our results reflect the reactive nature of prescribing of therapies for COVID-19 and highlight the importance of evidence-based guidelines to assist prescribers. This article is protected by copyright. All rights reserved.

A longitudinal observational study of aetiology and long-term outcomes of sepsis in Malawi revealing the key role of disseminated tuberculosis

Background

Sepsis protocols in sub-Saharan Africa are typically extrapolated from high-income settings, yet sepsis in sub-Saharan Africa is likely caused by distinct pathogens and may require novel treatment strategies. Data to guide such strategies are lacking. We aimed to define causes and modifiable factors associated with sepsis outcomes in Blantyre, Malawi, in order to inform the design of treatment strategies tailored to sub-Saharan Africa.

Methods

We recruited 225 adults who met a sepsis case definition defined by fever and organ dysfunction in an observational cohort study at a single tertiary center. Etiology was defined using culture, antigen detection, serology, and polymerase chain reaction. The effect of treatment on 28-day outcomes was assessed using Bayesian logistic regression.

Results

There were 143 of 213 (67%) participants living with human immunodeficiency virus (HIV). We identified a diagnosis in 145 of 225 (64%) participants, most commonly tuberculosis (TB; 34%) followed by invasive bacterial infections (17%), arboviral infections (13%), and malaria (9%). TB was associated with HIV infection, whereas malaria and arboviruses with the absence of HIV infection. Antituberculous chemotherapy was associated with survival (adjusted odds ratio for 28-day death, 0.17; 95% credible interval, 0.05–0.49 for receipt of antituberculous therapy). Of those with confirmed etiology, 83% received the broad-spectrum antibacterial ceftriaxone, but it would be expected to be active in only 24%.

Conclusions

Sepsis in Blantyre, Malawi, is caused by a range of pathogens; the majority are not susceptible to the broad-spectrum antibacterials that most patients receive. HIV status is a key determinant of etiology. Novel antimicrobial strategies for sepsis tailored to sub-Saharan Africa, including consideration of empiric antituberculous therapy in individuals living with HIV, should be developed and trialed.

Circular DNA viruses identified in short-finned pilot whale and orca tissue samples

Members of the Delphinidae family are widely distributed across the world's oceans. We used a viral metagenomic approach to identify viruses in orca (Orcinus orca) and short-finned pilot whale (Globicephala macrorhynchus) muscle, kidney, and liver samples from deceased animals. From orca tissue samples (muscle, kidney, and liver), we identified a novel polyomavirus (Polyomaviridae), three cressdnaviruses, and two genomoviruses (Genomoviridae). In the short-finned pilot whale we were able to identify one genomovirus in a kidney sample. The presence of unclassified cressdnavirus within two samples (muscle and kidney) of the same animal supports the possibility these viruses might be widespread within the animal. The orca polyomavirus identified here is the first of its species and is not closely related to the only other dolphin polyomavirus previously discovered. The identification and verification of these viruses expands the current knowledge of viruses that are associated with the Delphinidae family.

Experimental Human Pneumococcal Colonization in Older Adults Is Feasible and Safe, Not Immunogenic

Rationale: Pneumococcal colonization is key to the pathogenesis of invasive disease but is also immunogenic in young adults, protecting against recolonization. Colonization is rarely detected in older adults, despite high rates of pneumococcal disease.Objectives: To establish experimental human pneumococcal colonization in healthy adults aged 50-84 years, to measure the immune response to pneumococcal challenge, and to assess the protective effect of prior colonization against autologous strain rechallenge.Methods: Sixty-four participants were inoculated with Streptococcus pneumoniae (serotype 6B; 80,000 cfu in each nostril). Colonization was determined by bacterial culture of nasal wash, and humoral immune responses were assessed by anticapsular and antiprotein IgG concentrations.Measurements and Main Results: Experimental colonization was established in 39% of participants (25/64) with no adverse events. Colonization occurred in 47% (9/19) of participants aged 50-59 compared with 21% (3/14) in those aged ≥70 years. Previous pneumococcal polysaccharide vaccination did not protect against colonization. Colonization did not confer serotype-specific immune boosting, with a geometric mean titer (95% confidence interval) of 2.7 μg/ml (1.9-3.8) before the challenge versus 3.0 (1.9-4.7) 4 weeks after colonization (P = 0.53). Furthermore, pneumococcal challenge without colonization led to a drop in specific antibody concentrations from 2.8 μg/ml (2.0-3.9) to 2.2 μg/ml (1.6-3.0) after the challenge (P = 0.006). Antiprotein antibody concentrations increased after successful colonization. Rechallenge with the same strain after a median of 8.5 months (interquartile range, 6.7-10.1) led to recolonization in 5/16 (31%).Conclusions: In older adults, experimental pneumococcal colonization is feasible and safe but demonstrates different immunological outcomes compared with younger adults in previous studies.

Are there reliable and valid measures of anxiety for people with psychosis? A systematic review of psychometric properties

PURPOSE

Current models of psychosis posit a developmental and maintaining role for anxiety, supported by robust empirical evidence. Given the central role for anxiety in psychosis, valid and reliable assessment is necessary. This systematic review is the first to critically appraise measures of anxiety applied to psychosis samples.

METHODS

Web of Science, MEDLINE, PsycINFO, EMBASE, and CINAHL were systematically searched for studies evaluating psychometric properties of instruments measuring anxiety in samples with non-affective psychosis diagnoses. Psychometric properties were extracted and rated according to established criteria. The COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist was used to assess the methodological quality of studies.

RESULTS

Of 4,344 records identified, 11 studies were identified as eligible for inclusion, by two independent raters with high reliability. Reported psychometric properties for 17 different instruments ranged from unacceptable to excellent. The Scale of Anxiety Evaluation in Schizophrenia was assessed most extensively and demonstrated consistently good psychometric properties. The Beck Anxiety Index, Depression Anxiety Stress Scale, DSM-based Generalised Anxiety Disorder Symptoms Severity Scale, Liebowitz Social Anxiety Scale, Obsessive-Compulsive Inventory, Psychological Stress Index, Perseverative Thinking Questionnaire, and Yale-Brown Obsessive Compulsive Scale demonstrated adequate reliability and/or validity on the limited properties reported. Methodological quality was largely poor according to the requirements of the COSMIN checklist.

CONCLUSIONS

The instruments listed are recommended as at least adequate for the assessment of anxiety in psychosis on the basis of these preliminary data. Further validation of existing instruments designed to measure anxiety in people with psychosis is strongly recommended.

PRACTITIONER POINTS

Anxiety has a developmental and maintaining role in psychosis; therefore, we should routinely screen for symptoms of anxiety when working with people with psychosis spectrum disorders. Studies included in this review reported reliable and valid measures of anxiety for people with psychosis; however, the methodological quality of most studies was poor. We recommend the BAI, DASS, or SAES for general screening, and the DGSS, LSAS, OCI, PSI, PTQ, and Y-BOCS to assess symptoms associated with specific anxiety disorders and anxiety-related processes.

The deubiquitinase USP7 uses a distinct ubiquitin-like domain to deubiquitinate NF-ĸB subunits

The transcription factor NF-ĸB is a master regulator of the innate immune response and plays a central role in inflammatory diseases by mediating the expression of pro-inflammatory cytokines. Ubiquitination-triggered proteasomal degradation of DNA-bound NF-ĸB strongly limits the expression of its target genes. Conversely, USP7 (deubiquitinase ubiquitin-specific peptidase 7) opposes the activities of E3 ligases, stabilizes DNA-bound NF-ĸB, and thereby promotes NF-ĸB-mediated transcription. Using gene expression and synthetic peptide arrays on membrane support and overlay analyses, we found here that inhibiting USP7 increases NF-ĸB ubiquitination and degradation, prevents Toll-like receptor-induced pro-inflammatory cytokine expression, and represents an effective strategy for controlling inflammation. However, the broad regulatory roles of USP7 in cell death pathways, chromatin, and DNA damage responses limit the use of catalytic inhibitors of USP7 as anti-inflammatory agents. To this end, we identified an NF-ĸB-binding site in USP7, ubiquitin-like domain 2, that selectively mediates interactions of USP7 with NF-ĸB subunits but is dispensable for interactions with other proteins. Moreover, we found that the amino acids ⁷⁵⁷LDEL⁷⁶⁰ in USP7 critically contribute to the interaction with the p65 subunit of NF-ĸB. Our findings support the notion that USP7 activity could be potentially targeted in a substrate-selective manner through the development of noncatalytic inhibitors of this deubiquitinase to abrogate NF-ĸB activity.

Upper airways colonisation of Streptococcus pneumoniae in adults aged 60 years and older: A systematic review of prevalence and individual participant data meta-analysis of risk factors

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Systematic review and meta-analysis of 18 studies and more than 6000 participants.

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Adults over the age of 60 had a pooled prevalence of pneumococcal carriage of 9%.

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Risk factors: contact with children, smoking and residing in a nursing home.

Background

Colonisation with Streptococcus pneumoniae can lead to invasive pneumococcal disease and pneumonia. Pneumococcal acquisition and prevalence of colonisation are high in children. In older adults, a population susceptible to pneumococcal disease, colonisation prevalence is reported to be lower, but studies are heterogeneous.

Methods

This is a systematic review and meta-analysis of prevalence of, and risk factors for, pneumococcal colonisation in adults ≥ 60 years of age (PROSPERO #42016036891). We identified peer-reviewed studies reporting the prevalence of S. pneumoniae colonisation using MEDLINE and EMBASE (until April 2016), excluding studies of acute disease. Participant-level data on risk factors were sought from each study.

Findings

Of 2202 studies screened, 29 were analysable: 18 provided participant-level data (representing 6290 participants). Prevalence of detected pneumococcal colonisation was 0–39% by conventional culture methods and 3–23% by molecular methods. In a multivariate analysis, colonisation was higher in persons from nursing facilities compared with the community (odds ratio (OR) 2•30, 95% CI 1•26–4•21 and OR 7•72, 95% CI 1•15–51•85, respectively), in those who were currently smoking (OR 1•69, 95% CI 1•12–2•53) or those who had regular contact with children (OR 1•93, 95%CI 1•27–2•93). Persons living in urban areas had significantly lower carriage prevalence (OR 0•43, 95%CI 0•27–0•70).

Interpretation

Overall prevalence of pneumococcal colonisation in older adults was higher than expected but varied by risk factors. Future studies should further explore risk factors for colonisation, to highlight targets for focussed intervention such as pneumococcal vaccination of high-risk groups.

Funding

No funding was required.

The regulation of sequence specific NF-κB DNA binding and transcription by IKKβ phosphorylation of NF-κB p50 at serine 80

Phosphorylation of the NF-κB transcription factor is an important regulatory mechanism for the control of transcription. Here we identify serine 80 (S80) as a phosphorylation site on the p50 subunit of NF-κB, and IKKβ as a p50 kinase. Transcriptomic analysis of cells expressing a p50 S80A mutant reveals a critical role for S80 in selectively regulating the TNFα inducible expression of a subset of NF-κB target genes including pro-inflammatory cytokines and chemokines. S80 phosphorylation regulates the binding of p50 to NF-κB binding (κB) sites in a sequence specific manner. Specifically, phosphorylation of S80 reduces the binding of p50 at κB sites with an adenine at the -1 position. Our analyses demonstrate that p50 S80 phosphorylation predominantly regulates transcription through the p50:p65 heterodimer, where S80 phosphorylation acts in trans to limit the NF-κB mediated transcription of pro-inflammatory genes. The regulation of a functional class of pro-inflammatory genes by the interaction of S80 phosphorylated p50 with a specific κB sequence describes a novel mechanism for the control of cytokine-induced transcriptional responses.

Synthesis and structures of polyiodide radical cation salts of donors combining tetrathiafulvalene with multiple thiophene or oligo-thiophene substituents

The preparation and structures of the radical cation salts of a series of new TTF-based donors bearing thiophene or oligothiophene side chains with polyiodide counterions are described.

Proinsulin peptide promotes autoimmune diabetes in a novel HLA-DR3-DQ2-transgenic murine model of spontaneous disease

AIMS/HYPOTHESIS

The molecular basis for the pathological impact of specific HLA molecules on autoimmune diseases such as type 1 diabetes remains unclear. Recent natural history studies in children have indicated a link between specific HLA genotypes and the first antigenic target against which immune responses develop. We set out to examine this link in vivo by exploring the diabetogenicity of islet antigens on the background of a common diabetes-associated HLA haplotype.

METHODS

We generated a novel HLA-transgenic mouse model that expresses high-risk genes for type 1 diabetes (DRB1*03:01-DQA1*05:01-DQB1*02:01) as well as human CD80 under the rat insulin promoter and human CD4, on a C57BL/6 background. Adjuvanted antigen priming was used to reveal the diabetogenicity of candidate antigens and peptides.

RESULTS

HLA-DR3-DQ2⁺huCD4⁺IA/IE^-/-RIP.B7.1⁺ mice spontaneously developed autoimmune diabetes (incidence 46% by 35 weeks of age), accompanied by numerous hallmarks of human type 1 diabetes (autoantibodies against GAD65 and proinsulin; pancreatic islet infiltration by CD4⁺, CD8⁺ B220⁺, CD11b⁺ and CD11c⁺ immune cells). Disease was markedly accelerated and had deeper penetrance after adjuvanted antigen priming with proinsulin (mean onset 11 weeks and incidence 100% by 20 weeks post challenge). Moreover, the diabetogenic effect of proinsulin located to the 15-residue B29-C11 region.

CONCLUSIONS/INTERPRETATION

Our study identifies a proinsulin-derived peptide region that is highly diabetogenic on the HLA-DR3-DQ2 background using an in vivo model. This approach and the peptide region identified may have wider implications for future studies of human type 1 diabetes.

Towards Genotype-Specific Care for Chronic Hepatitis B: The First 6 Years Follow Up From the CHARM Cohort Study

Objective

There is increasing evidence to suggest that, among those with chronic hepatitis B virus infection, the natural history and rate of progression to cirrhosis and hepatocellular carcinoma is influenced by hepatitis B virus genotype. The unique hepatitis B virus genotype C4 circulates among Indigenous Australians. The aim of this work is to describe the process of establishing this cohort and review the first 6 years of available data in an effort to understand the real-world clinical care and natural history of this subgenotype.

Method

We followed a longitudinal cohort of Indigenous Australians from the Northern Territory of Australia with established subgenotype C4 infections. We assigned phases of disease according to Gastroenterological Society of Australia and Asian Pacific Association for the Study of the Liver criteria using clinical and laboratory information that had been collected for clinical management.

Results

Of 193 patients followed over a median of 38 months, 58 (30%) individuals transitioned from 1 disease phase to another, 10 (5%) cleared hepatitis B e antigen, and 6 cleared hepatitis B surface antigen (3%). In this relatively young cohort (median age 40.3 years), 26 (13%) had cirrhosis by the end of the follow up period, with the majority of these being in the immune control phase of disease.

Conclusions

In this cohort of hepatitis B subgenotype C4 patients, we report an aggressive and dynamic clinical phenotype. High rates of cirrhosis at a young age appear to occur in the early phases of disease.

Case Report: Severe Disseminated Gonococcal Infection with Polyarticular Gout: Two Cases in Older Travelers

Two male travelers with histories of gout and hazardous alcohol consumption, presented with a triad of severe culture-positive disseminated gonococcal infection, crystal-positive polyarticular gout, and gonococcal soft tissue collections, following unprotected sexual contact in The Philippines. Both men initially attributed symptoms to gout, since their usual joints were affected, but clinical deterioration occurred with self-administration of anti-inflammatory agents alone. The clinical courses were severe and protracted, requiring aggressive management of infection with prolonged intravenous antimicrobials and repeated surgery, and prolonged anti-inflammatory agents for gout. Joint symptom onset in each case occurred within a week of sexual exposure in conjunction with hazardous alcohol ingestion. We speculate that acute dissemination of infection to previously damaged joints triggered polyarticular gout, with progressive infection, exacerbated by unopposed anti-inflammatory agents and delayed antibiotics. Disseminated gonococcal infection can occur with polyarticular gout and delays in recognition and treatment, including while traveling, can lead to severe disease from both.

Cognitions Associated With Hypoglycemia Awareness Status and Severe Hypoglycemia Experience in Adults With Type 1 Diabetes

OBJECTIVE

Impaired awareness of hypoglycemia (IAH) and recurrent severe hypoglycemia (RSH) remain problematic for people with type 1 diabetes (T1D), despite major therapeutic advances. We explored beliefs around hypo- and hyperglycemia in adults with T1D with, and without, IAH and RSH.

RESEARCH DESIGN AND METHODS

A cross-sectional U.S. multicenter survey included Attitudes to Awareness of Hypoglycemia (A2A; a 19-item questionnaire concerning beliefs about hypoglycemia), the Gold score (single item: awareness of hypoglycemia), and a question about severe hypoglycemia over the preceding year. The survey was emailed to 6,200 adult participants of the annual T1D Exchange clinic registry data collection. A2A data were subjected to principal component analysis with varimax rotation.

RESULTS

Among 1,978 respondents (response rate 32%), 61.7% were women, mean ± SD age was 39.6 ± 16.3 years, and T1D duration was 23.1 ± 13.8 years. Thirty-seven percent reported IAH, 16% RSH, and 9% both. A2A items segregated into three factors, differently distributed by hypoglycemia experience. Respondents with IAH or RSH expressed appropriate concern about hypoglycemia, but those with IAH were more likely to prioritize hyperglycemia concerns than those with intact awareness (P = 0.002). Those with RSH showed greater normalization of asymptomatic hypoglycemia than those without (P = 0.019) and trended toward prioritizing hyperglycemia concerns (P = 0.097), driven by those with both IAH and RSH.

CONCLUSIONS

Adults with T1D with IAH and RSH report specific cognitions about hypoglycemia and hyperglycemia, which may act as barriers to hypoglycemia avoidance and recovery of awareness. These may be modifiable and present a target for enhancing engagement of vulnerable people with strategies to avoid future hypoglycemia.

Peptide Immunotherapy for Type 1 Diabetes-Clinical Advances

Autoimmune and allergic diseases occur when an individual mounts an inappropriate immune response to a self-antigen or an innocuous environmental antigen. This triggers a pathogenic T-cell response resulting in damage to specific tissues and organs. In type 1 diabetes (T1D), this manifests as destruction of the insulin-secreting β cells, resulting in a life-long dependency on recombinant insulin. Modulation of the pathogenic T-cell response with antigen-specific peptide immunotherapy offers the potential to restore the immune homeostasis and prevent further tissue destruction. Recent clinical advances with peptide therapy approaches in both T1D and other diseases are beginning to show encouraging results. New technologies targeting the peptides to specific cell types are also moving from pre-clinical development to the clinic. While many challenges remain in clinical development, not least selection of the optimal dose and dosing frequency, this is clearly becoming a very active field of drug development.

Real-time in situ dynamic sub-surface imaging of multi-component electrodeposited films using event mode neutron reflectivity

We investigate the deposition, evolution and dissolution of single and two-component metal layers on Au substrates immersed in the deep eutectic solvent Ethaline.

The Regulation of NF-κB Subunits by Phosphorylation

The NF-κB transcription factor is the master regulator of the inflammatory response and is essential for the homeostasis of the immune system. NF-κB regulates the transcription of genes that control inflammation, immune cell development, cell cycle, proliferation, and cell death. The fundamental role that NF-κB plays in key physiological processes makes it an important factor in determining health and disease. The importance of NF-κB in tissue homeostasis and immunity has frustrated therapeutic approaches aimed at inhibiting NF-κB activation. However, significant research efforts have revealed the crucial contribution of NF-κB phosphorylation to controlling NF-κB directed transactivation. Importantly, NF-κB phosphorylation controls transcription in a gene-specific manner, offering new opportunities to selectively target NF-κB for therapeutic benefit. This review will focus on the phosphorylation of the NF-κB subunits and the impact on NF-κB function.

In Vivo Assessment of Bone Regeneration in Alginate/Bone ECM Hydrogels with Incorporated Skeletal Stem Cells and Single Growth Factors

The current study has investigated the use of decellularised, demineralised bone extracellular matrix (ECM) hydrogel constructs for in vivo tissue mineralisation and bone formation. Stro-1-enriched human bone marrow stromal cells were incorporated together with select growth factors including VEGF, TGF-β3, BMP-2, PTHrP and VitD3, to augment bone formation, and mixed with alginate for structural support. Growth factors were delivered through fast (non-osteogenic factors) and slow (osteogenic factors) release PLGA microparticles. Constructs of 5 mm length were implanted in vivo for 28 days within mice. Dense tissue assessed by micro-CT correlated with histologically assessed mineralised bone formation in all constructs. Exogenous growth factor addition did not enhance bone formation further compared to alginate/bone ECM (ALG/ECM) hydrogels alone. UV irradiation reduced bone formation through degradation of intrinsic growth factors within the bone ECM component and possibly also ECM cross-linking. BMP-2 and VitD3 rescued osteogenic induction. ALG/ECM hydrogels appeared highly osteoinductive and delivery of angiogenic or chondrogenic growth factors led to altered bone formation. All constructs demonstrated extensive host tissue invasion and vascularisation aiding integration and implant longevity. The proposed hydrogel system functioned without the need for growth factor incorporation or an exogenous inducible cell source. Optimal growth factor concentrations and spatiotemporal release profiles require further assessment, as the bone ECM component may suffer batch variability between donor materials. In summary, ALG/ECM hydrogels provide a versatile biomaterial scaffold for utilisation within regenerative medicine which may be tailored, ultimately, to form the tissue of choice through incorporation of select growth factors.

Testing an integrated model of eating disorders in paediatric type 1 diabetes mellitus

BACKGROUND

Eating disorders in young people with type 1 diabetes mellitus confer additional health risks beyond those conferred by the disease itself. Risk factors for developing eating disorders are poorly understood.

OBJECTIVE

The current study aimed to examine risk factors for eating disturbance in young people with type 1 diabetes mellitus. Both diabetes specific risk factors, such as body mass index (BMI), glycaemic control and diabetes-related conflict, and also more general risk factors such as dysfunctional perfectionism and low self-esteem were assessed.

METHODS

Fifty young people aged 14-16 and their primary caregiver were asked to complete interviews and questionnaires about their eating attitudes and behaviours, dysfunctional perfectionism, self-esteem, family conflict, and general mental health symptoms. Recent weight and height and glycaemic control were extracted from the medical file.

RESULTS

Different factors distinguished those young people who displayed eating disorder attitudes from those who did not (higher BMI-z, poorer glycaemic control, and lower self-esteem) and those young people who displayed eating disorder behaviour from those who did not (lower self-esteem and higher diabetes-related family conflict).

CONCLUSIONS

The results of the current study suggest that there might be different factors associated with eating disorders (ED) attitudes and ED behaviours, but that food/eating-related factors, family factors, and intra-personal factors are all important. Furthermore there are some gender differences in the presence of ED attitudes and behaviours and preliminary evidence that higher body mass indexes (BMIs) impact on girls more than they do on boys.

Clinical effectiveness of a residential pain management programme - comparing a large recent sample with previously published outcome data

OBJECTIVE

Observational studies using routinely collected data indicate that pain management programmes (PMPs) based on cognitive-behavioural principles are associated with clinically meaningful improvements for individuals with chronic pain. This study evaluated change across functional measures in a sample of chronic pain patients attending a 4-week residential PMP between 2006 and 2010. The findings were directly compared with published outcomes from an earlier period (1989-1998) at the same service.

METHODS

Participants included 760 consecutive completers of a multidisciplinary PMP. Data were collected at pre-PMP, post-PMP (1-month post-discharge) and at a 9-month follow-up session. Group-based treatment effects and the reliability and clinical significance of change across functional measures were calculated and compared across cohorts.

RESULTS

Effect sizes for the recent cohort ranged from small to medium (.43-.67) for pain and physical functioning outcomes to large (.90-1.12) for psychological outcomes at post-treatment (n = 654), and from small (.30-.51) to medium (.58-.71) at 9-month follow-up (n = 493). Clinically significant gains on pain and psychological measures were achieved by 19-55% of patients at post-treatment and 17-44% at follow-up. Comparisons with the earlier cohort showed significantly stronger post-treatment outcomes but differences at follow-up were less marked.

DISCUSSION

These results add to the evidence base supporting the effectiveness of cognitive-behavioural therapy (CBT)-based pain management interventions. There were significantly larger gains in patient functioning in the recent dataset, suggesting improved programme delivery. But effects were less marked in the longer term, indicating a need for improvements in therapeutic models and related methods to promote meaningful and lasting changes.

Managing outbreaks of invasive species--a new method to prioritize preemptive quarantine efforts across large geographic regions

In pest risk assessment it is frequently necessary to make time-critical decisions regarding management of expanding pest populations. When an invasive pest outbreak is expanding rapidly, preemptive quarantine of areas that are under imminent threat of infestation is one of only a few available management tools that can be implemented quickly to help control the expansion. The preemptive quarantine of locations that surround an infested area also acts as a safeguard to counteract the risk of failed detections of the pest in field surveys. In this paper, we present a method that assesses the suitability of preemptive quarantine measures at the level of small geographical subdivisions (U.S. counties). The cost of a preemptive quarantine in a given county is weighed against the protective benefit of delaying the spread of an outbreak to other neighboring counties. We demonstrate the approach with a decision support model that estimates the suitability of preemptive quarantine across multiple counties that surround areas infested with the emerald ash borer (Agrilus planipennis Fairmaire (EAB), Coleoptera: Buprestidae), an emerging major threat to ash tree species (Fraxinus spp.) in North America. The model identifies the U.S. counties where the installation of preemptive quarantine would most effectively slow the spread of EAB populations and reduce risk to high-value areas.

Exploring hydrocoele surgery accessibility and impact in a lymphatic filariasis endemic area of southern Malawi

BACKGROUND

Hydrocoele surgery is the recommended treatment for the common clinical manifestation of lymphatic filariasis in men. This study determined the geographical differences in surgery accessibility, and improvements in the quality of life of patients in Chikwawa district, Malawi.

METHODS

Surgery records from Chikwawa District Hospital (CDH), between 2008 and 2013, were used to map surgery rates by village, spatial dependence by census enumeration area and relationship of distance (kilometres) to CDH. A subset of patients were selected to quantify and compare their physical and socio-economic well-being and level of disability pre- and post-surgery using a standardised questionnaire.

RESULTS

A total of 476 hydrocoele surgical cases were identified with 260 cases geo-referenced and mapped. A significant negative relationship between village-level surgery rates and distance to CDH (r=-0.137; 95% CI: -0.47 to -0.26) was found, and clusters of enumeration areas with high surgery rates identified around the CDH. Significant improvements in patients' ability to walk and work were found and the overall level of disability was reduced post-surgery.

CONCLUSIONS

Hydrocoele surgery positively impacted on patients, improving their physical and socio-economic output. Surgical services need to scale-up and expand to reach cases that have less access to the best treatment currently available.

Failure to upregulate cell surface PD-1 is associated with dysregulated stimulation of T cells by TGN1412-like CD28 superagonist

The CD28 superagonist (CD28SA) TGN1412 was administered to humans as an agent that can selectively activate and expand regulatory T cells but resulted in uncontrolled T cell activation accompanied by cytokine storm. The molecular mechanisms that underlie this uncontrolled T cell activation are unclear. Physiological activation of T cells leads to upregulation of not only activation molecules but also inhibitory receptors such as PD-1. We hypothesized that the uncontrolled activation of CD28SA-stimulated T cells is due to both the enhanced expression of activation molecules and the lack of or reduced inhibitory signals. In this study, we show that anti-CD3 antibody-stimulated human T cells undergo time-limited controlled DNA synthesis, proliferation and interleukin-2 secretion, accompanied by PD-1 expression. In contrast, CD28SA-activated T cells demonstrate uncontrolled activation parameters including enhanced expression of LFA-1 and CCR5 but fail to express PD-1 on the cell surface. We demonstrate the functional relevance of the lack of PD-1 mediated regulatory mechanism in CD28SA-stimulated T cells. Our findings provide a molecular explanation for the dysregulated activation of CD28SA-stimulated T cells and also highlight the potential for the use of differential expression of PD-1 as a biomarker of safety for T cell immunostimulatory biologics.

Tissue engineered bone using select growth factors: A comprehensive review of animal studies and clinical translation studies in man

There is a growing socio-economic need for effective strategies to repair damaged bone resulting from disease, trauma and surgical intervention. Bone tissue engineering has received substantial investment over the last few decades as a result. A multitude of studies have sought to examine the efficacy of multiple growth factors, delivery systems and biomaterials within in vivo animal models for the repair of critical-sized bone defects. Defect repair requires recapitulation of in vivo signalling cascades, including osteogenesis, chondrogenesis and angiogenesis, in an orchestrated spatiotemporal manner. Strategies to drive parallel, synergistic and consecutive signalling of factors including BMP-2, BMP-7/OP-1, FGF, PDGF, PTH, PTHrP, TGF-β3, VEGF and Wnts have demonstrated improved bone healing within animal models. Enhanced bone repair has also been demonstrated in the clinic following European Medicines Agency and Food and Drug Administration approval of BMP-2, BMP-7/OP-1, PDGF, PTH and PTHrP. The current review assesses the in vivo and clinical data surrounding the application of growth factors for bone regeneration. This review has examined data published between 1965 and 2013. All bone tissue engineering studies investigating in vivo response of the growth factors listed above, or combinations thereof, utilising animal models or human trials were included. All studies were compiled from PubMed-NCBI using search terms including 'growth factor name', 'in vivo', 'model/animal', 'human', and 'bone tissue engineering'. Focus is drawn to the in vivo success of osteoinductive growth factors incorporated within material implants both in animals and humans, and identifies the unmet challenges within the skeletal regenerative area.

Lymphatic filariasis morbidity mapping: a comprehensive examination of lymphoedema burden in Chikwawa district, Malawi

BACKGROUND

Managing lymphatic filariasis (LF) morbidity and reducing disability is one of the two primary goals of the Global Programme to Eliminate Lymphatic Filariasis. However, in order to achieve this, the geographical distribution of LF morbidity needs to be better estimated.

METHODS

All cases of lymphoedema within a single health centre catchment area (pop. 42 000) in the southern region of Malawi were examined. Maps of lymphoedema burden were produced and trends in patient demographics, severity of lymphoedema (Dreyer staging) and health-seeking behaviour were explored. The number of lymphoedema cases was compared with records maintained by the Ministry of Health, Malawi.

RESULTS

A total of 69 lymphoedema cases were identified (32 per 10 000 population), of which 48 (70%) were female and 21 (30%) male. The majority of cases (51/69) had Dreyer stage 2-3, and almost all (65/69) had experienced acute attacks as a result of their lymphoedema. This burden was much greater than that estimated by Ministry of Health (33 cases).

CONCLUSIONS

Current case detection methods underestimate the burden of lymphoedema in Malawi. There is a continued need to develop new LF morbidity identification and surveillance approaches to ensure that future morbidity management strategies are effectively targeted.

Evaluation of skeletal tissue repair, part 2: enhancement of skeletal tissue repair through dual-growth-factor-releasing hydrogels within an ex vivo chick femur defect model

There is an unmet need for improved, effective tissue engineering strategies to replace or repair bone damaged through disease or injury. Recent research has focused on developing biomaterial scaffolds capable of spatially and temporally releasing combinations of bioactive growth factors, rather than individual molecules, to recapitulate repair pathways present in vivo. We have developed an ex vivo embryonic chick femur critical size defect model and applied the model in the study of novel extracellular matrix (ECM) hydrogel scaffolds containing spatio-temporal combinatorial growth factor-releasing microparticles and skeletal stem cells for bone regeneration. Alginate/bovine bone ECM (bECM) hydrogels combined with poly(d,l-lactic-co-glycolic acid) (PDLLGA)/triblock copolymer (10-30% PDLLGA-PEG-PLDLGA) microparticles releasing dual combinations of vascular endothelial growth factor (VEGF), chondrogenic transforming growth factor beta 3 (TGF-β3) and the bone morphogenetic protein BMP2, with human adult Stro-1+bone marrow stromal cells (HBMSCs), were placed into 2mm central segmental defects in embryonic day 11 chick femurs and organotypically cultured. Hydrogels loaded with VEGF combinations induced host cell migration and type I collagen deposition. Combinations of TGF-β3/BMP2, particularly with Stro-1+HBMSCs, induced significant formation of structured bone matrix, evidenced by increased Sirius red-stained matrix together with collagen expression demonstrating birefringent alignment within hydrogels. This study demonstrates the successful use of the chick femur organotypic culture system as a high-throughput test model for scaffold/cell/growth factor therapies in regenerative medicine. Temporal release of dual growth factors, combined with enriched Stro-1+HBMSCs, improved the formation of a highly structured bone matrix compared to single release modalities. These studies highlight the potential of a unique alginate/bECM hydrogel dual growth factor release platform for bone repair.

Visual regulation of refractive development: insights from animal studies

Investigations employing animal models have demonstrated that ocular growth and refractive development are regulated by visual feedback. In particular, lens compensation experiments in which treatment lenses are used to manipulate the eye's effective refractive state have shown that emmetropization is actively regulated by signals produced by optical defocus. These observations in animals are significant because they indicate that it should be possible to use optical treatment strategies to influence refractive development in children, specifically to slow the rate of myopia progression. This review highlights some of the optical performance properties of the vision-dependent mechanisms that regulate refractive error development, especially those that are likely to influence the efficacy of optical treatment strategies for myopia. In this respect, the results from animal studies have been very consistent across species; however, to facilitate extrapolation to clinical settings, results are presented primarily for nonhuman primates. In agreement with preliminary clinical trials, the experimental data show that imposed myopic defocus can slow ocular growth and that treatment strategies that influence visual signals over a large area of the retina are likely to be most effective.

Information needs of cancer patients and survivors regarding diet, exercise and weight management: a qualitative study

While advanced cancer is often associated with weight loss, curative cancer treatment is often associated with weight gain. Weight gain during treatment may be associated with greater risk of cancer recurrence and development of lifestyle diseases. Currently, limited resources are available to cancer patients focussed on weight control. This study assessed the information needs of patients undergoing curative chemotherapy regarding diet, exercise and weight management for the purpose of developing weight management resources. Focus groups were held with oncology practitioners, patients and survivors to determine current information provision and needs. Focus groups highlighted a perception that information provision regarding diet, exercise and weight management is insufficient and no routine assessment of weight occurs during chemotherapy. Barriers to information provision described included lack of resources and time, and practitioners' uncertainty regarding appropriate messages to provide. Patients wanted more information regarding diet, exercise and weight during treatment time. The findings of this study suggest an increase in provision of diet, exercise and weight management information is needed. This information should be evidence-based and delivered at an appropriate time by the preferred health care professional. It would also be beneficial to implement protocols regarding assessment of weight during treatment.

A novel ex vivo culture model for inflammatory bone destruction

Pathological alterations in the balance of bone metabolism are central to the progression of inflammatory bone diseases such as periodontal disease. We have developed and characterized a novel ex vivo murine mandible model of inflammatory bone destruction. Slices of mandible were cultured for 14 days in the presence or absence of P. gingivalis lipopolysaccharide (LPS) or pro-inflammatory cytokines. Following culture, cell viability and tissue histomorphometry were assessed with quantification of matrix proteins, resident osteoclasts, ligament cells, monocytes, macrophages, and neutrophils. In the absence of inflammatory factors, culture viability, osteoclasts, and matrix components were maintained. LPS or TNFα stimulation demonstrated an increase in cellular proliferation, monocyte cells, osteoclast differentiation, and matrix degradation. Pathophysiological bone metabolism can be induced via exposure to LPS and direct influence of TNFα within the model despite the absence of systemic circulation, providing a model for inflammatory bone destruction and investigation of the effects of novel therapeutics.

A new take on an old story: chick limb organ culture for skeletal niche development and regenerative medicine evaluation

Scientific research and progress, particularly in the drug discovery and regenerative medicine fields, is typically dependent on suitable animal models to develop new and improved clinical therapies for injuries and diseases. In vivo model systems are frequently utilised, but these models are expensive, highly complex and pose a number of ethical considerations leading to the development and use of a number of alternative ex vivo model systems. The ex vivo embryonic chick long bone and limb bud models have been utilised in the scientific research field as a model to understand skeletal development for over eighty years. The rapid development of avian skeletal tissues, coupled with the ease of experimental manipulation, availability of genome sequence and the presence of multiple cell and tissue types has seen such model systems gain significant research interest in the last few years in the tissue engineering field. The models have been explored both as systems for understanding the developmental bone niche and as potential testing tools for tissue engineering strategies for bone repair and regeneration. This review details the evolution of the chick limb organ culture system and presents recent innovative developments and emerging techniques and technologies applied to these models that are aiding our understanding of skeletal developmental and regenerative medicine research and application.

A clinical tool for evaluating emotional well-being: self-drawings of hospitalized children

This study investigated how the emotional wellbeing of children with congenital heart defect (CHD) hospitalized for heart surgery was expressed in self-drawings before and after their surgical treatment. A sample of 293 children produced self-drawings (hospitalized n=168, non-hospitalized n=125). The results indicate significant differences between drawings by hospitalized compared to non-hospitalized children, including size, color and omission of body parts. These differences were interpreted in line with previous analyses of projective drawing. We conclude that self-drawing evaluation is a useful tool to reveal insights into emotional wellbeing, promoting safe and easy communication.

Developmental cues for bone formation from parathyroid hormone and parathyroid hormone-related protein in an ex vivo organotypic culture system of embryonic chick femora

Enhancement and application of our understanding of skeletal developmental biology is critical to developing tissue engineering approaches to bone repair. We propose that use of the developing embryonic femur as a model to further understand skeletogenesis, and the effects of key differentiation agents, will aid our understanding of the developing bone niche and inform bone reparation. We have used a three-dimensional organotypic culture system of embryonic chick femora to investigate the effects of two key skeletal differentiation agents, parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP), on bone and cartilage development, using a combination of microcomputed tomography and histological analysis to assess tissue formation and structure, and cellular behavior. Stimulation of embryonic day 11 (E11) organotypic femur cultures with PTH and PTHrP initiated osteogenesis. Bone formation was enhanced, with increased collagen I and STRO-1 expression, and cartilage was reduced, with decreased chondrocyte proliferation, collagen II expression, and glycosaminoglycan levels. This study demonstrates the successful use of organotypic chick femur cultures as a model for bone development, evidenced by the ability of exogenous bioactive molecules to differentially modulate bone and cartilage formation. The organotypic model outlined provides a tool for analyzing key temporal stages of bone and cartilage development, providing a paradigm for translation of bone development to improve scaffolds and skeletal stem cell treatments for skeletal regenerative medicine.

Ion Transfer Mechanisms Accompanying p-Doping of Poly(3,4-Ethylenedioxythiophene) Films in Deep Eutectic Solvents

Redox-driven ion transfer processes accompanying p-doping and undoping were investigated for poly(3,4-ethylenedioxythiophene) (PEDOT) films. The PEDOT films were potentiostatically grown from acetonitrile solutions of monomer onto the Au electrodes of 10 MHz AT-cut quartz crystal resonators. The films were then sequentially exposed to 0.1 M LiClO4/CH3CN solution and to two deep eutectic solvent (DES) media, Ethaline 200 (choline chloride and ethylene glycol in 1:2 molar ratio) and Propaline 200 (choline chloride and propylene glycol in 1:2 molar ratio). In each case, the electron and ion transfer processes accompanying PEDOT redox switching were investigated using the EQCM. The maintenance of film electroneutrality was achieved in quite different ways in the three media. In contrast to anion transfer domination in 0.1 M LiClO4/CH3CN solution, cation transfer (in the opposite direction) was dominant in Ethaline 200. In Propaline 200, a two stage mixed mechanism was observed, with cation transfer domination in the early stages of p-doping (later stages of undoping) and anion transfer domination in the later stages of p-doping (earlier stages of undoping). The roles of thermodynamic and kinetic factors in these competitive situations were explored by observing the effect of experimental timescale (potential scan rate) in voltammetric experiments.

A novel approach for studying the temporal modulation of embryonic skeletal development using organotypic bone cultures and microcomputed tomography

Understanding the structural development of embryonic bone in a three dimensional framework is fundamental to developing new strategies for the recapitulation of bone tissue in latter life. We present an innovative combined approach of an organotypic embryonic femur culture model, microcomputed tomography (μCT) and immunohistochemistry to examine the development and modulation of the three dimensional structures of the developing embryonic femur. Isolated embryonic chick femurs were organotypic (air/liquid interface) cultured for 10 days in either basal, chondrogenic, or osteogenic supplemented culture conditions. The growth development and modulating effects of basal, chondrogenic, or osteogenic culture media of the embryonic chick femurs was investigated using μCT, immunohistochemistry, and histology. The growth and development of noncultured embryonic chick femur stages E10, E11, E12, E13, E15, and E17 were very closely correlated with increased morphometric indices of bone formation as determined by μCT. After 10 days in the organotpyic culture set up, the early aged femurs (E10 and E11) demonstrated a dramatic response to the chondrogenic or osteogenic culture conditions compared to the basal cultured femurs as determined by a change in μCT morphometric indices and modified expression of chondrogenic and osteogenic markers. Although the later aged femurs (E12 and E13) increased in size and structure after 10 days organotpypic culture, the effects of the osteogenic and chondrogenic organotypic cultures on these femurs were not significantly altered compared to basal conditions. We have demonstrated that the embryonic chick femur organotpyic culture model combined with the μCT and immunohistochemical analysis can provide an integral methodology for investigating the modulation of bone development in an ex vivo culture setting. Hence, these interdisciplinary techniques of μCT and whole organ bone cultures will enable us to delineate some of the temporal, structural developmental paradigms and modulation of bone tissue formation to underpin innovative skeletal regenerative technology for clinical therapeutic strategies in musculoskeletal trauma and diseases.

Local sensitivity to stimulus orientation and spatial frequency within the receptive fields of neurons in visual area 2 of macaque monkeys

We used dynamic dense noise stimuli and local spectral reverse correlation methods to reveal the local sensitivities of neurons in visual area 2 (V2) of macaque monkeys to orientation and spatial frequency within their receptive fields. This minimized the potentially confounding assumptions that are inherent in stimulus selections. The majority of neurons exhibited a relatively high degree of homogeneity for the preferred orientations and spatial frequencies in the spatial matrix of facilitatory subfields. However, about 20% of all neurons showed maximum orientation differences between neighboring subfields that were greater than 25 deg. The neurons preferring horizontal or vertical orientations showed less inhomogeneity in space than the neurons preferring oblique orientations. Over 50% of all units also exhibited suppressive profiles, and those were more heterogeneous than facilitatory profiles. The preferred orientation and spatial frequency of suppressive profiles differed substantially from those of facilitatory profiles, and the neurons with suppressive subfields had greater orientation selectivity than those without suppressive subfields. The peak suppression occurred with longer delays than the peak facilitation. These results suggest that the receptive field profiles of the majority of V2 neurons reflect the orderly convergence of V1 inputs over space, but that a subset of V2 neurons exhibit more complex response profiles having both suppressive and facilitatory subfields. These V2 neurons with heterogeneous subfield profiles could play an important role in the initial processing of complex stimulus features.

Examination of nitrate concentration, loading and isotope dynamics in subsurface drainage under standard agricultural cropping in Atlantic Canada

Intensive agricultural farming practices have the potential to cause high levels of nitrate-nitrogen (NO(3)(-)-N) to be released from tile drainage systems. A better understanding of the temporal dynamics of NO(3)(-)-N loading, δ(15)N and δ(18)O from standard drainage systems is needed, in order to improve our understanding of NO(3)(-)-N transport and transformation processes; particularly, with regards to the imperfectly drained agricultural soils found within Atlantic Canada. Three conventional subsurface drainage plots (48 × 48 m) placed at a 0.80 m soil depth were monitored over a seven month period on sandy loam soil in Onslow, Nova Scotia. Each plot received similar applications of both organic and inorganic fertilizer. Water samples were obtained and analyzed for NO(3)(-)-N concentrations and isotopic signatures of δ(15)N and δ(18)O for NO(3)(-)-N. Maximum NO(3)(-)-N loads were observed in the winter and fall, when both discharge and concentration of the NO(3)(-)-N were highest. Mean isotope values in NO(3)(-) ranged from 3.1 to 8.5‰ for δ(15)N and -3.2 to 17.7‰ for δ(18)O. Results suggest that NO(3)(-)-N from the drainage water was derived from organic sources (i.e. manure and soil organic matter) and that loss via denitrification does not impart an identifiable signature upon the NO(3)(-)-N pool. The dual isotope approach examined here provides insight into N source and transformation processes which may be contributing to the NO(3)(-)-N found within the drainage water.

Nitrate loading and isotopic signatures in subsurface agricultural drainage systems

Artificially draining soils using subsurface tiles is a common practice on many agricultural fields. High levels of nitrate-nitrogen (NO-N) are often released from these systems; therefore, knowledge on the sources and processes controlling NO-N in drainage systems is needed. A dual isotope study (δN and δO) was used to investigate three subsurface drainage systems (shallow, conventional, and controlled) in Onslow, Nova Scotia, Canada. The objectives of this study were (i) to identify which drainage system more effectively reduced the NO-N loading, (ii) to examine differences in isotopic signatures under identical nutrient and cropping regimes for a fixed soil type, and (iii) to identify the utility of different drainage systems in controlling nutrient flows. Nitrate concentrations measured ranged from 0.92 to 11.8, from 2.3 to 17.3, and from 2.1 to 19.8 mg L for the shallow, conventional, and controlled drains, respectively. Total NO-N loading from shallow and controlled drains were 20 and 5.6 kg ha, respectively, lower than conventional (39.1 kg ha). The isotopic composition of NO-N for all drainage types appeared to be a mixture of two organic sources (manure and soil organic matter) via the process of nitrification. There was no evidence that denitrification played a significant role in removing NO-N during transport. Overall, shallow drainage reduced NO-N loading but offered no water conservation benefits. Combining the benefits of decreased NO-N loading from shallow systems with water control capability may offer the best solution to reducing nutrient loadings into water systems, achieving optimal crop yield, and decreasing drainage installation costs.

TGF-beta1 exposure from bone surfaces by chemical treatment modalities

Growth factors are known to be sequestered to the mineralised matrix of bone. The aim of this study was to investigate the ability of citric acid, EDTA, calcium hydroxide and sodium hydroxide to release active growth factors from bone surfaces, able to promote osteoblast differentiation. All chemical treatments increased surface levels of TGF-beta1 (used as a biomarker of growth factor release), compared to control bone surfaces treated with PBS. Differences were observed in the kinetics of TGF-beta1 exposure at the surface and its subsequent release into the aqueous environment for the different chemical treatments. Surface levels of growth factor following chemical treatment were low, but of sufficient concentration to stimulate cell expansion and osteoblast differentiation of bone marrow stromal cells grown on EDTA and calcium hydroxide treated surfaces compared to PBS treated surfaces. The increased osteogenic potential on these surfaces may relate to an increase in growth factor availability and changes to the surface chemistry and topography.

Neuronal responses in visual area V2 (V2) of macaque monkeys with strabismic amblyopia

Amblyopia, a developmental disorder of spatial vision, is thought to result from a cascade of cortical deficits over several processing stages beginning at the primary visual cortex (V1). However, beyond V1, little is known about how cortical development limits the visual performance of amblyopic primates. We quantitatively analyzed the monocular and binocular responses of V1 and V2 neurons in a group of strabismic monkeys exhibiting varying depths of amblyopia. Unlike in V1, the relative effectiveness of the affected eye to drive V2 neurons was drastically reduced in the amblyopic monkeys. The spatial resolution and the orientation bias of V2, but not V1, neurons were subnormal for the affected eyes. Binocular suppression was robust in both cortical areas, and the magnitude of suppression in individual monkeys was correlated with the depth of their amblyopia. These results suggest that the reduced functional connections beyond V1 and the subnormal spatial filter properties of V2 neurons might have substantially limited the sensitivity of the amblyopic eyes and that interocular suppression was likely to have played a key role in the observed alterations of V2 responses and the emergence of amblyopia.

Technical advances in the sectioning of dental tissue and of on-section cross-linked collagen detection in mineralized teeth

Immunohistochemical detection of cross-linked fibrillar collagens in mineralized tissues is much desired for exploring the mechanisms of biomineralization in health and disease. Mineralized teeth are impossible to section when embedded in conventional media, thus limiting on-section characterization of matrix proteins by immunohistochemistry. We hypothesized that by using an especially formulated acrylic resin suitable for mineralized dental tissues, not only sectioning of teeth would be possible, but also our recently developed immunofluorescence labeling technique would be amenable to fully calcified tissues for characterization of dentinal fibrillar collagens, which remains elusive. The hypothesis was tested on fixed rodent teeth embedded in Technovit 9100 New. It was possible to cut thin (1 mum) sections of mineralized teeth, and immunofluorescence characterization of cross-linked type I fibrillar collagen was selected due to its abundance in dentine. Decalcified samples of teeth embedded in paraffin wax were also used to compare immunolabeling from either method using the same immunoreagents in equivalent concentrations. In the decalcified tissue sections, type I collagen labeling in the dentine along the tubules was "patchy" and the signal in the predentine was very weak. However, enhanced signal in mineralized samples with type I collagen was detected not only in the predentine but also at the limit between intertubular dentine, within the elements of the enamel organ and subgingival stroma. This report offers advances in sectioning mineralized dental tissues and allows the application of immunofluorescence not only for on-section protein detection but importantly for detecting cross-linked fibrous collagens in both soft and mineralized tissue sections.

Cognitive follow up of a small cohort of Huntington's disease patients over a 5 year period

A small group of patients with manifest Huntington's disease (HD) were followed longitudinally to assess cognitive decline in relation to time from disease diagnosis. This article looks at performance on a range of computerised and pencil and paper cognitive tasks in patients 5 years post diagnosis, who were assessed annually for a 5 year follow up period. The almost universal cognitive decline reported in other longitudinal studies of HD was not replicated in this study. It was proposed that longitudinal follow up in HD is complicated by the varying degree to which different tasks are able to withstand repeated administration; a finding which would have significant implications on study design in future trials of cognitive enhansing interventions.

INTERMITTENT STIMULATION BY LIGHT : VI. AREA AND THE RELATION BETWEEN CRITICAL FREQUENCY AND INTENSITY

1. In the retina, central areas whose diameter is less than 2° possess only cones, while larger areas have rods and cones. In conformity with this, the relation of critical fusion frequency to intensity is a single function for centrally fixated areas below 2°, and a double function for similarly fixated, larger areas. The two sections of such data are easily identified with rod activity at low intensities and with cone activity at high intensities. 2. The curves describing the rod data are the same for all areas, differing only in the values of the associated dimensional constants which control the location of the curves on the coordinate axes. Similarly, the curves for the cone data are the same for all areas; the tendency for an increase in maximal frequency with area is the expression merely of the value of a constant which determines the position of the data on the frequency axis. Area, therefore, does not influence the fundamental nature of the flicker relation through each receptor system, but merely alters the extraneous constants of the relation. 3. The curves which describe the measurements are represented by two equations, one for rods and one for cones; both equations are derived from the stationary state descriptive of the initial event in the photoreceptor process.