Substantially Delayed Maturation of Growth Plate Chondrocytes in "Humanized" PTH1R Mice with the H223R Mutation of Jansen's Disease

Activating parathyroid hormone (PTH)/PTH-related Peptide (PTHrP) receptor (PTH1R) mutations causes Jansen's metaphyseal chondrodysplasia (JMC), a rare disease characterized by growth plate abnormalities, short stature, and PTH-independent hypercalcemia. Previously generated transgenic JMC mouse models, in which the human PTH1R allele with the H223R mutation (H223R-PTH1R) is expressed in osteoblasts via type Ia1 collagen or DMP1 promoters cause excess bone mass, while expression of the mutant allele via the type IIa1 collagen promoter results in only minor growth plate changes. Thus, neither transgenic JMC model adequately recapitulates the human disease. We therefore generated "humanized" JMC mice in which the H223R-PTH1R allele was expressed via the endogenous mouse Pth1r promoter and, thus, in all relevant target tissues. Founders with the H223R allele typically died within 2 months without reproducing; several mosaic male founders, however, lived longer and produced F1 H223R-PTH1R offspring, which were small and exhibited marked growth plate abnormalities. Serum calcium and phosphate levels of the mutant mice were not different from wild-type littermates, but serum PTH and P1NP were reduced significantly, while CTX-1 and CTX-2 were slightly increased. Histological and RNAscope analyses of the mutant tibial growth plates revealed markedly expanded zones of type II collagen-positive, proliferating/prehypertrophic chondrocytes, abundant apoptotic cells in the growth plate center and a progressive reduction of type X collagen-positive hypertrophic chondrocytes and primary spongiosa. The "humanized" H223R-PTH1R mice are likely to provide a more suitable model for defining the JMC phenotype and for assessing potential treatment options for this debilitating disease of skeletal development and mineral ion homeostasis. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The PYY/Y2R-deficient male mouse is not protected from bone loss due to Roux-en-Y gastric bypass

BACKGROUND

Peptide YY (PYY) is an anorexigenic gut hormone that also has anti-osteogenic effects, inhibiting osteoblastic activity and inducing catabolic effects. It has been postulated that increases in PYY after Roux-en-Y gastric bypass (RYGB) contribute to declines in bone mineral density (BMD) and increases in bone turnover. The aim of this study is to determine the role of the PYY Y2-receptor in mediating bone loss post-RYGB in mice.

METHODS

We compared adult male wildtype (WT) and PYY Y2 receptor-deficient (KO) C57BL/6 mice that received RYGB (WT: n = 8; KO: n = 9), with sham-operated mice (Sham; WT: n = 9; KO: n = 10) and mice that were food-restricted to match the weights of the RYGB-treated group (Weight-Matched, WM; WT: n = 7; KO: n = 5). RYGB or sham surgery was performed at 15-16 weeks of age, and mice sacrificed 21 weeks later. We characterized bone microarchitecture with micro-computed tomography (μCT) at the distal femur (trabecular) and femoral midshaft (cortical). Differences in body weight, bone microarchitecture and biochemical bone markers (parathyroid hormone, PTH; C-telopeptide, CTX; and type 1 procollagen, P1NP) were compared using 2-factor ANOVA with Tukey's adjustments for multiple comparisons.

RESULTS

Body weights were similar in the WT-RYGB, WT-WM, KO-RYGB, and KO-WM: 41-44 g; these groups weighed significantly less than the Sham surgery groups: 55-57 g. Trabecular BMD was 31-43 % lower in RYGB mice than either Sham or WM in WT and KO groups. This deficiency in trabecular bone was accompanied by a lower trabecular number (19 %-23 %), thickness (22 %-30 %) and increased trabecular spacing (25 %-34 %) in WT and KO groups (p < 0.001 for all comparisons vs. RYGB). RYGB led to lower cortical thickness, cortical tissue mineral density, and cortical bone area fraction as compared to Sham and WM in WT and KO groups (p ≤ 0.004 for all). There were no interactions between genotype and bone microarchitecture, with patterns of response to RYGB similar in both WT and KO groups. CTX and P1NP were significantly higher in RYGB mice than WM in WT and KO groups. PTH did not differ among groups.

CONCLUSIONS

RYGB induced greater trabecular and cortical deficits and high bone turnover than observed in weight-matched mice, with a similar pattern in the WT and Y2RKO mice. Thus, skeletal effects of RYGB are independent of weight loss, and furthermore, PYY signaling through Y2R is not a key mediator of bone loss post-RYGB.

The Effect of Zoledronic Acid on Bone Microarchitecture and Strength after Denosumab and Teriparatide Administration: DATA-HD Study Extension

The combination of denosumab and teriparatide is an effective treatment strategy in postmenopausal osteoporosis, though skeletal gains are promptly lost when these agents are discontinued. In the DATA-HD study, we reported that a single dose of zoledronic acid (ZOL) maintains the increases in areal spine and hip bone mineral density (BMD) achieved with this combination for at least 12 months. The capacity of ZOL to maintain corresponding improvements in peripheral volumetric BMD and microarchitecture, however, has not been reported. In the 15-month DATA-HD study, 76 postmenopausal osteoporotic women were randomized to receive 9 months of teriparatide (20-μg or 40-μg daily) overlapped with denosumab (60 mg at months 3 and 9). In the Extension study, 53 participants received a single dose of ZOL (5 mg intravenously) 24-35 weeks after the last denosumab dose. We measured volumetric BMD and microarchitecture at the distal radius and tibia using high-resolution peripheral quantitative computed tomography at months 27 and 42. Despite ZOL administration, total and cortical BMD gradually decreased over 27 months resulting in values similar to baseline at the radius but still significantly above baseline at the tibia. At both sites, cortical porosity decreased to values below pretreatment baseline at month 27 but then increased from month 27 to 42. There were no significant changes in trabecular parameters throughout the 27-month post-ZOL observation period. Stiffness and failure load, at both sites, decreased progressively from month 15 42 though remained above baseline at the tibia. These findings suggest that in contrast to the largely maintained gains in dual-energy X-ray absorptiometry (DXA)-derived spine and hip BMD, a single dose of ZOL was not as effective in maintaining the gains in volumetric peripheral bone density and microarchitecture produced by 15 months of overlapping treatment with denosumab and teriparatide. Alternative therapeutic approaches that can fully maintain improvements in peripheral bone parameters require further study. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Partial prevention of glucocorticoid-induced osteocyte deterioration in young male mice with osteocrin gene therapy

Glucocorticoid excess suppresses osteocyte remodeling of surrounding bone minerals, causes apoptosis of osteoblasts and osteocytes, and disrupts bone remodeling, eventually, leading to glucocorticoid-induced osteoporosis and bone fragility. Preventing apoptosis and preserving osteocyte morphology could be an effective means of preventing bone loss during glucocorticoid treatment. We hypothesized that osteocrin, which preserves osteocyte viability and morphology in Sp7-deficient mice, could prevent osteocyte death and dysfunction in a glucocorticoid excess model. We used adeno-associated virus (AAV8) to induce osteocrin overexpression in mice one week before implantation with prednisolone or placebo pellets. After 28 days, prednisolone caused the expected reduction in cortical bone thickness and osteocyte canalicular length in control AAV8-treated mice, and these effects were blunted in mice receiving AAV8-osteocrin. Glucocorticoid-induced changes in cortical porosity, trabecular bone mass, and gene expression were not prevented by osteocrin. These findings support a modest therapeutic potential for AAV8-osteocrin in preserving osteocyte morphology during disease.

Actions of Parathyroid Hormone Ligand Analogues in Humanized PTH1R Knockin Mice

Rodent models are commonly used to evaluate parathyroid hormone (PTH) and PTH-related protein (PTHrP) ligands and analogues for their pharmacologic activities and potential therapeutic utility toward diseases of bone and mineral ion metabolism. Divergence, however, in the amino acid sequences of rodent and human PTH receptors (rat and mouse PTH1Rs are 91% identical to the human PTH1R) can lead to differences in receptor-binding and signaling potencies for such ligands when assessed on rodent vs human PTH1Rs, as shown by cell-based assays in vitro. This introduces an element of uncertainty in the accuracy of rodent models for performing such preclinical evaluations. To overcome this potential uncertainty, we used a homologous recombination-based knockin (KI) approach to generate a mouse (in-host strain C57Bl/6N) in which complementary DNA encoding the human PTH1R replaces a segment (exon 4) of the murine PTH1R gene so that the human and not the mouse PTH1R protein is expressed. Expression is directed by the endogenous mouse promoter and hence occurs in all biologically relevant cells and tissues and at appropriate levels. The resulting homozygous hPTH1R-KI (humanized) mice were healthy over at least 10 generations and showed functional responses to injected PTH analog peptides that are consistent with a fully functional human PTH1R in target bone and kidney cells. The initial evaluation of these mice and their potential utility for predicting behavior of PTH analogues in humans is reported here.

Seropositivity to Campylobacter and association with abortion and lamb mortality in maiden ewes from Western Australia, South Australia and Victoria

This case‐control study investigated associations between Campylobacter fetus or Campylobacter jejuni titre and reproductive outcomes in 22 flocks of Merino and non‐Merino maiden ewes aged 1–2 years old. Campylobacter titres were also determined for multiparous ewes aged 3 years or older on the same farms. C. fetus ‘positivity’ (titre ≥1:80) was detected for 12% (57/462; 95% confidence interval [95% CI] 9.6 to 15.6) of maiden ewes and 31% (65/210; 95% CI 25.0 to 37.4) of mature ewes. The odds for failing to rear a lamb in C. fetus‐‘exposed’ maiden ewes (titre ≥1:10) was 2.01 times that of seronegative ewes (95% CI 1.09 to 3.77; P = 0.027), but there was no association between C. fetus‐‘positivity’ (titre ≥1:80) and failure to rise (OR 1.69; 95% CI 0.77 to 3.76; P = 0.191). C. fetus abortions were confirmed with microbial culture in one maiden ewe flock. In this flock, C. fetus titres fluctuated and often waned by lamb marking, highlighting the value of necropsies during abortion investigations. C. jejuni‐‘positivity’ (titre ≥1:80) was detected for 44% (204/462; 95% CI 39.7 to 48.7) maiden ewes, but odds of failing to rear were decreased for C. jejuni‐‘positive’ ewes (OR 0.52; 95% CI 0.32 to 0.83; P = 0.007). The association between Campylobacter serology and the reproductive outcome was inconsistent in these flocks. Serology should be considered in the context of other risk factors and used in conjunction with other strategies to investigate the impact of Campylobacter exposure on ewe reproductive performance such as monitoring for abortions and lamb necropsies to determine aetiological diagnosis, and vaccination trials.

Control of osteocyte dendrite formation by Sp7 and its target gene osteocrin

Some osteoblasts embed within bone matrix, change shape, and become dendrite-bearing osteocytes. The circuitry that drives dendrite formation during "osteocytogenesis" is poorly understood. Here we show that deletion of Sp7 in osteoblasts and osteocytes causes defects in osteocyte dendrites. Profiling of Sp7 target genes and binding sites reveals unexpected repurposing of this transcription factor to drive dendrite formation. Osteocrin is a Sp7 target gene that promotes osteocyte dendrite formation and rescues defects in Sp7-deficient mice. Single-cell RNA-sequencing demonstrates defects in osteocyte maturation in the absence of Sp7. Sp7-dependent osteocyte gene networks are associated with human skeletal diseases. Moreover, humans with a SP7R316C mutation show defective osteocyte morphology. Sp7-dependent genes that mark osteocytes are enriched in neurons, highlighting shared features between osteocytic and neuronal connectivity. These findings reveal a role for Sp7 and its target gene Osteocrin in osteocytogenesis, revealing that pathways that control osteocyte development influence human bone diseases.

Hepatitis B virus elimination status and strategies in circumpolar countries, 2020

Hepatitis B virus (HBV) infection remains a global health threat. The World Health Organization (WHO) established a goal to eliminate HBV infection as a public health threat by 2030, and defined targets for key interventions to achieve that goal. We evaluated HBV burden and relevant national recommendations for progress towards WHO targets in circumpolar countries. Viral hepatitis experts of circumpolar countries were surveyed regarding their country’s burden of HBV, achievement of WHO targets and national public health authority recommendations for HBV prevention and control. Eight of nine circumpolar countries responded. All countries continue to see new HBV infections. Data about HBV prevalence and progress in reaching WHO 2030 elimination targets are lacking. No country was able to report data for all seven WHO target measures. All countries have recommendations targeting the prevention of mother-to-child transmission. Only the USA and Greenland recommend universal birth dose vaccination. Four countries have recommendations to screen persons at high risk for HBV. Existing recommendations largely address prevention; however, recommendations for universal birth dose vaccination have not been widely introduced. Opportunities remain for the development of trackable targets and national elimination planning to screen and treat for HBV to reduce incidence and mortality.

Global Burden of Animal Diseases: a novel approach to understanding and managing disease in livestock and aquaculture

Investments in animal health and Veterinary Services can have a measurable impact on the health of people and the environment. These investments require a baseline metric that describes the burden of animal health and welfare in order to justify and prioritise resource allocation and from which to measure the impact of interventions. This paper is part of a process of scientific enquiry in which problems are identified and solutions sought in an inclusive way. It poses the broad question: what should a system to measure the animal disease burden on society look like and what value would it add? Moreover, it aims to do this in such a way as to be accessible by a wide audience, who are encouraged to engage in this debate. Given that farmed animals, including those raised by poor smallholders, are an economic entity, this system should be based on economic principles. These poor farmers are negatively impacted by disparities in animal health technology, which can be addressed through a mixture of supply-led and demand-driven interventions, reinforcing the relevance of targeted financial support from government and non-governmental organisations. The Global Burden of Animal Diseases (GBADs) Programme will glean existing data to measure animal health losses within carefully characterised production systems. Consistent and transparent attribution of animal health losses will enable meaningful comparisons of the animal disease burden to be made between diseases, production systems and countries, and will show how it is apportioned by people's socio-economic status and gender. The GBADs Programme will produce a cloud-based knowledge engine and data portal, through which users will access burden metrics and associated visualisations, support for decisionmaking in the form of future animal health scenarios, and the outputs of wider economic modelling. The vision of GBADs, strengthening the food system for the benefit of society and the environment, is an example of One Health thinking in action.

Use of Rapid Antigen Testing for SARS-CoV-2 in Remote Communities - Yukon-Kuskokwim Delta Region, Alaska, September 15, 2020-March 1, 2021

Controlling the spread of SARS-CoV-2, the virus that causes COVID-19, in Alaska is challenging. Alaska includes many remote and isolated villages with small populations (ranging from 15 to >1,000 persons) that are accessible only by air from larger communities. Until rapid point-of-care testing became widely available, a primary challenge in the diagnosis of COVID-19 in rural Alaska was slow turnaround times for SARS-CoV-2 test results, attributable to the need to transport specimens to testing facilities. To provide more timely test results and isolation of cases, the Yukon Kuskokwim Health Corporation (YKHC) introduced Abbott BinaxNOW COVID-19 Ag rapid antigen test (BinaxNOW) on November 9, 2020, in the rural Yukon-Kuskokwim Delta region in southwestern Alaska. To evaluate the impact of implementing antigen testing, YKHC reviewed the results of 54,981 antigen and molecular tests for SARS-CoV-2 performed in the Yukon-Kuskokwim Delta during September 15, 2020-March 1, 2021. Introduction of rapid, point-of-care testing was followed by a more than threefold reduction in daily SARS-CoV-2 case rates during approximately 1 month before the introduction of COVID-19 vaccination. The median turnaround time for SARS-CoV-2 test results decreased by >30%, from 6.4 days during September 15-November 8, 2020, to 4.4 days during November 9, 2020-March 1, 2021 (p<0.001). Daily incidence decreased 65% after the introduction of BinaxNOW, from 342 cases per 100,000 population during the week of November 9 to 119 during the week of December 13 (p<0.001). These findings indicate that point-of-care rapid antigen testing can be a valuable tool in reducing turnaround times in rural communities where local access to laboratory-based nucleic acid amplification testing (NAAT) is not readily available and could thereby reduce transmission by facilitating rapid isolation of infected persons, contact tracing, and implementation of local mitigation strategies.

Genomic Diversity of Haemophilus influenzae Serotype a in an Outbreak Community, Alaska 2018

BACKGROUND

Haemophilus influenzae serotype a (Hia) can cause severe invasive disease, especially in young children. In 2018, four invasive Hia cases occurred in an Alaska community. We used whole-genome sequencing (WGS) to evaluate the relationship of the bacteria from this community and other Alaska patients with invasive Hia.

METHODS

All carriage (15) and invasive (4) Hia isolates from the outbreak community, together with 15 non-outbreak Alaska invasive Hia surveillance isolates from 2018, were tested for antimicrobial susceptibility and characterized using WGS.

RESULTS

Phylogenetic analysis of both invasive and carriage Hia isolates revealed two major clades that differed by an average of 300 core single nucleotide polymorphisms (SNPs). All isolates from the outbreak community were clustered in one subclade, within a larger clade containing 3 non-outbreak invasive Hia isolates. Comparative genomics did not reveal any genetic mutations that distinguished carriage from invasive isolates. Three (20%) community isolates were rifampin-resistant and had a previously unreported mutation in the rpoB gene.

CONCLUSIONS

In the outbreak community, Hia isolates from carriers were indistinguishable from the invasive Hia isolates. Overall, invasive Hia isolates from Alaska in 2018 were genetically similar. The rifampin resistance mutation is concerning as rifampin is the first-line medication for Hia prophylaxis.

Hepatitis A vaccine immunogenicity 25 years after vaccination in Alaska

The hepatitis A vaccine is recommended for all children greater than or equal to 1 year of age, however, the duration of vaccine protection is unknown and protection through adulthood is crucial to prevent symptomatic hepatitis later in life. We report on 25 years of follow-up of a cohort of Alaska Native individuals who were vaccinated in early childhood. We assessed the duration of vaccine protection by calculating the geometric mean concentration and proportion of participants with protective levels of IgG antibody to hepatitis A virus (anti-HAV) (≥20 mIU/mL) every 2 to 3 years. We estimated the amount of time until the anti-HAV dropped below protective levels using survival analyses. At 25 years, 43 of the original 144 participants were available, mean anti-HAV levels were 91.5 mIU/mL, and 35 (81.4%) had protective levels of anti-HAV. Using data from all persons and all time points, a survival analysis estimated 78.7% of participants had protective levels of anti-HAV at 25 years. The high level of protective antibodies in this cohort indicate that supplemental doses of hepatitis A vaccine are not needed 25 years after completion of the vaccine series.

The Effects of Ivacaftor on Bone Density and Microarchitecture in Children and Adults with Cystic Fibrosis

CONTEXT

Cystic fibrosis (CF) transmembrane conductance (CFTR) dysfunction may play a role in CF-related bone disease (CFBD). Ivacaftor is a CFTR potentiator effective in improving pulmonary and nutritional outcomes in patients with the G551D-CFTR mutation. The effects of ivacaftor on bone health are unknown.

OBJECTIVE

To determine the impact of ivacaftor on bone density and microarchitecture in children and adults with CF.

DESIGN

Prospective observational multiple cohort study.

SETTING

Outpatient clinical research center within a tertiary academic medical center.

PATIENTS OR OTHER PARTICIPANTS

Three cohorts of age-, race-, and gender-matched subjects were enrolled: 26 subjects (15 adults and 11 children) with CF and the G551D-CFTR mutation who were planning to start or had started treatment with ivacaftor within 3 months (Ivacaftor cohort), 26 subjects with CF were not treated with ivacaftor (CF Control cohort), and 26 healthy volunteers.

INTERVENTIONS

All treatments, including Ivacaftor, were managed by the subjects' pulmonologists.

MAIN OUTCOME MEASURES

Bone microarchitecture by high-resolution peripheral quantitative computed tomography (HR-pQCT), areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) and bone turnover markers at baseline, 1, and 2 years.

RESULTS

Cortical volume, area, and porosity at the radius and tibia increased significantly in adults in the Ivacaftor cohort. No significant differences were observed in changes in aBMD, trabecular microarchitecture, or estimated bone strength in adults or in any outcome measures in children.

CONCLUSIONS

Treatment with ivacaftor was associated with increases in cortical microarchitecture in adults with CF. Further studies are needed to understand the implications of these findings.

Effects of Combination Denosumab and High-Dose Teriparatide Administration on Bone Microarchitecture and Estimated Strength: The DATA-HD HR-pQCT Study

In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD; 40 μg) teriparatide increased spine and hip bone mineral density (BMD) more than combination with standard-dose teriparatide (SD; 20 μg). To assess the effects of these combinations on bone microarchitecture and estimated bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20 μg (n = 39) or 40 μg (n = 37) during months 0 to 9 overlapped with denosumab 60 mg s.c. given at months 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% versus 3.4%, p = 0.01) with a similar trend at the distal radius (2.6% versus 1.0%, p = 0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius in the HD-group and SD-group, respectively; p = NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% [p < 0.0001 versus baseline] and 1.5% [p < 0.0001 versus baseline] in the HD-group and SD-group, respectively; p = 0.75 for overall group difference). Improvements in trabecular microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared with SD-group but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high- or standard-dose teriparatide improves HR-pQCT measures of bone density, microstructure, and estimated strength, with greater gains in total bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. © 2020 American Society for Bone and Mineral Research (ASBMR).

641. Carriage and Genetics of Haemophilus influenzae Serotype A (Hia) in Alaska, 2018

Background

Haemophilus influenzae serotype a (Hia) is an important cause of infection among Alaska Native children. In 2018, 4 invasive Hia cases (iHia) occurred in an Alaska community. Our response aimed to prevent more iHia and evaluate Hia carriage in the community. Whole genome sequencing (WGS) was performed to compare Hia from iHia patients across Alaska in 2018, and from healthy outbreak community members.

Methods

We collected oropharyngeal (OP) samples from outbreak community members. Children aged < 10 years and people in close contact with cases (contacts) were offered rifampin prophylaxis. A second set of OP samples was collected 8 weeks later. Isolates from iHia from across the state were collected as part of the state surveillance. Hia was detected by PCR and culture, then characterized by antimicrobial susceptibility and WGS.

Results

At baseline, contacts had a higher prevalence of Hia carriage than non-contacts (4/27(14.8%) vs 7/364(1.9%), p=0.0043). Eight weeks after rifampin prophylaxis, carriage prevalence did not significantly change among contacts (5/42(11.9%) to 6/25(24%), p=0.18) or non-contacts (7/368(1.9%) to 2/114(1.8%), p=0.47). Phylogenetic analysis of 19 iHia isolates and 15 isolates from healthy outbreak community members, revealed two major clades that differed by an average of 300 core single nucleotide polymorphisms (SNPs). Invasive and carriage isolates from the outbreak community were clustered in one clade, along with 3 non-outbreak iHia isolates. Isolates from this community differed from each other by an average of 1.2 core SNPs. Comparative genomics did not reveal any genetic mutations that distinguished carriage from invasive isolates. Three (20%) community isolates were rifampin-resistant and had a previously unreported mutation in the rpoB gene.

Conclusion

We found Hia carriage prevalence was highest among persons in contact with iHia cases. Long-term community carriage was not affected by rifampin prophylaxis, possibly due to staggered prophylaxis. In the outbreak community, Hia isolates from carriers were nearly genetically identical to iHia isolates. Overall, iHia isolates from Alaska in 2018 were genetically similar. The mutation conferring rifampin resistance is concerning, as rifampin is used to prophylax contacts of iHia cases.

Disclosures

All Authors: No reported disclosures

Blind Source Separation for Clutter and Noise Suppression in Ultrasound Imaging: Review for Different Applications

Blind source separation (BSS) refers to a number of signal processing techniques that decompose a signal into several "source" signals. In recent years, BSS is increasingly employed for the suppression of clutter and noise in ultrasonic imaging. In particular, its ability to separate sources based on measures of independence rather than their temporal or spatial frequency content makes BSS a powerful filtering tool for data in which the desired and undesired signals overlap in the spectral domain. The purpose of this work was to review the existing BSS methods and their potential in ultrasound imaging. Furthermore, we tested and compared the effectiveness of these techniques in the field of contrast-ultrasound super-resolution, contrast quantification, and speckle tracking. For all applications, this was done in silico, in vitro, and in vivo. We found that the critical step in BSS filtering is the identification of components containing the desired signal and highlighted the value of a priori domain knowledge to define effective criteria for signal component selection.

Immunogenicity of the hepatitis A vaccine 20 years after infant immunization

To determine the duration of immunity provided by the Hepatitis A vaccination (HepA), we evaluated a cohort of participants in Alaska 20 years after being immunized as infants. At recruitment, participants received two doses of inactivated HepA vaccine on one of three schedules. We conducted hepatitis A antibody (anti-HAV) testing for participants at the 20-year time-point. Seventy-five of the original 183 participants (41%) were available for follow-up. The overall anti-HAV geometric mean concentration was 29.9 mIU/mL (95% CI 22.4 mIU/mL, 39.7 mIU/mL) and 50 participants (68%) remained seropositive (titer ≥ 20 mIU/mL). Using a fractional polynomial model, the predicted percent seropositive at 25 years was 55.3%, 49.8% at 30 years and 45.7% at 35 years, suggesting that the percent sero-positive could drop below 50% earlier than previously expected. Further research is necessary to understand if protection continues after seropositivity diminishes or if a HepA booster dose may become necessary.

Community water service and incidence of respiratory, skin, and gastrointestinal infections in rural Alaska, 2013-2015

BACKGROUND

Communities in rural Alaska have access to multiple types of water service (piped, vehicle-hauled, and self-hauled) and experience varying levels of water service coverage. We assessed the incidence rate of inpatient and outpatient infectious disease visits among communities with different water service types and coverage levels.

METHODS

We classified ICD-9 codes for inpatient and outpatient visits to the Yukon-Kuskokwim Health Corporation facilities between 2013 and 2015 into six infectious disease categories. Using Poisson models, we compared the incidence of visits in each category across communities with differing water service coverage levels as defined by water service billing data for the same years. Using census data, we adjusted for community median household income, median age, crowding, and health aide staffing.

RESULTS

We included 48 communities in this analysis. After adjusting for possible confounders, each 10% increase in piped water coverage was associated with a 4% lower incidence of pneumonia/influenza visits (adjusted incidence rate ratio [IRR] 0.96, 95% CI 0.93-0.98), a 2% lower incidence of other respiratory infection visits (adjusted IRR 0.98, 95% CI 0.97-0.99), an 8% lower incidence of methicillin-resistant Staphylococcus visits (adjusted IRR 0.92, 95% CI 0.87-0.97), and a 4% lower incidence of other skin infections visits (adjusted IRR 0.96, 95% CI 0.95-0.98). Each 10% increase in vehicle-hauled water coverage was associated with a 2% lower incidence of respiratory infection visits (adjusted IRR 0.98, 95% CI 0.97-0.996) and a 3% lower incidence of skin infection visits (adjusted IRR 0.97, 95% CI 0.95-0.99), also after adjustment.

CONCLUSIONS

Higher levels of water service coverage were associated with lower incidence rates of visits for several infectious disease categories. These associations were more pronounced for communities with piped water service compared to vehicle-hauled water service.

Prevalence of serum antibodies to Coxiella burnetii in Alaska Native Persons from the Pribilof Islands

BACKGROUND

Q fever is a febrile illness caused by infection with the bacterium Coxiella burnetii. It is most often transmitted by inhalation of the bacteria after it is shed by infected livestock. Recent studies have found very high C. burnetii infection rates among marine mammals, but it is not known if shedding by marine mammals creates a risk of Q fever among humans. To better understand infection of humans with exposure to marine mammals, the prevalence of antibodies against C. burnetii in serum samples taken from Alaskan Native persons residing on the Pribilof Islands was evaluated. The Pribilof Islands support large populations of northern fur seals infected with C. burnetii that may increase the risk of exposure for island residents.

METHODS

Serum testing for IgG antibodies against C. burnetii (phase I and phase II) was performed, and demographic data were analysed utilizing banked serum specimens drawn from island residents from 1980 to 2000.

RESULTS

The overall seroprevalence rate was 11.6% (95% CI = 9.3%-14.4%; 72/621). This is higher than the previously reported 3.1% (95% CI = 2.1%-4.3%) seroprevalence for the U.S.

POPULATION

CONCLUSIONS

These results suggest that Alaskan Native persons may be at higher risk for exposure to C. burnetii than the general US. population, possibly due to proximity to large populations of infected marine mammals.

Interiaboratory Evaluation of an Off-Line Supercritical Fluid Extraction/Infrared Spectrometric Method for Determination of Petroleum Hydrocarbons in Solid Matrixes

A collaborative study was conducted, with 14 laboratories participating, to determine the method accuracy and precision of the proposed U.S. Environmental Protection Agency Methods 3560 and 8440. These methods involve the extraction of petroleum hydrocarbons from solid matrixes with supercritical carbon dioxide at 340 atm and 80°C for 30 min (dynamic), collection of the extracted materials in tetrachloroethene (Method 3560), and analysis of the extracts by infrared (IR) spectrometry (Method 8440). The study design was based on the AOAC blind replicate design with balanced replicates. The study samples consisted of 4 solid matrixes that had petroleum hydrocarbon contents ranging from 614 to 32 600 mg/kg. Each of the 4 matrixes was extracted in triplicate, and the extracts were analyzed with 2 different IR spectrometers. In addition, each of the participating laboratories extracted a sample of unspiked clay soil, the same clay soil spiked with corn oil and reference oil at 1000 mg/kg each, and the same clay soil wetted to 30% water content and spiked with motor oil at 10 000 mg/kg (the latter 3 samples were extracted only once). Results indicated that the overall method accuracy for concentrations ranging from 614 to 32 600 mg/kg was 82.9%; the mean recoveries of petroleum hydrocarbons for each of the 4 solid matrixes ranged from 77.9 to 107% for analyses performed with the Perkin-Elmer Fourier transform IR spectrometer and from 75.9 to 101% for analyses performed with the Buck-Scientific IR spectrometer; the differences between the 2 instruments on a sample-bysample basis were less than 17% for the total petroleum hydrocarbon determinations. The interiaboratory method precisions (RSDR) appeared to be matrix-dependent and ranged from 17.3 to 45.4% for analyses performed with the Perkin- Elmer Fourier transform IR spectrometer and from 16.7 to 47.9% for the Buck-Scientific IR spectrometer. The intralaboratory method precisions (RSDr) appeared to be less matrix-dependent and ranged from 11.5 to 17.0% for analyses performed with the Perkin-Elmer FTIR spectrometer and from 11.1 to 18.2% for the Buck-Scientific IR spectrometer. Method accuracy and precision data are also presented for the 5 laboratories that used Isco supercritical fluid extraction systems and for the 7 laboratories that used vessels with volumes of 3.5 mL or less with different supercritical fluid extraction systems.

Salt-inducible kinases dictate parathyroid hormone 1 receptor action in bone development and remodeling

The parathyroid hormone 1 receptor (PTH1R) mediates the biologic actions of parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP). Here, we showed that salt-inducible kinases (SIKs) are key kinases that control the skeletal actions downstream of PTH1R and that this GPCR, when activated, inhibited cellular SIK activity. Sik gene deletion led to phenotypic changes that were remarkably similar to models of increased PTH1R signaling. In growth plate chondrocytes, PTHrP inhibited SIK3, and ablation of this kinase in proliferating chondrocytes rescued perinatal lethality of PTHrP-null mice. Combined deletion of Sik2 and Sik3 in osteoblasts and osteocytes led to a dramatic increase in bone mass that closely resembled the skeletal and molecular phenotypes observed when these bone cells express a constitutively active PTH1R that causes Jansen's metaphyseal chondrodysplasia. Finally, genetic evidence demonstrated that class IIa histone deacetylases were key PTH1R-regulated SIK substrates in both chondrocytes and osteocytes. Taken together, our findings establish that SIK inhibition is central to PTH1R action in bone development and remodeling. Furthermore, this work highlights the key role of cAMP-regulated SIKs downstream of GPCR action.

1625. Risk of Invasive Group A Streptococcus, Group B Streptococcus, and Streptococcus pneumoniae Infection Among Adults Experiencing Homelessness—Anchorage, Alaska, 2002–2015

Background

People experiencing homelessness (PEH) have an increased risk of infectious disease. However, for many infections, this increased risk has not been clearly quantified. For example, the risk of invasive streptococcal infection has not been established among PEH in the United States.

Methods

We compared the incidence of detected cases of invasive group A Streptococcus (GAS) infection, group B Streptococcus (GBS) infection, and Streptococcus pneumoniae (pneumococcal) infection among adult PEH to that in the general adult population in Anchorage, Alaska from 2005 through 2015 using data from the CDC Arctic Investigations Program surveillance system, the US census, and the Anchorage Point in Time count (PIT [a yearly census of PEH]).

Results

During 2005–2015, the PIT counted a mean number of 970 adults (minimum 795, maximum 1486) in Anchorage who were homeless, which accounted for 0.4% of the total population. Compared with the general population, PEH were 53 times as likely to have invasive GAS infection (95% CI 47–61), 7 times as likely to have invasive GBS infection (95% CI 6, 8), and 36 times as likely to have invasive pneumococcal infection (95% CI 33, 40). Of all invasive GAS cases in Anchorage over the time period, 19% occurred within the homeless population, while 3% of invasive GBS cases and 14% of invasive pneumococcal cases were within the homeless population. Additionally, the predominant subtypes of GAS and pneumococcus differed among PEH compared with the general population.

Conclusion

A disproportionate burden of invasive streptococcal disease in Anchorage was detected among PEH, indicating a need for further focus on this high-risk group.

Disclosures

All authors: No reported disclosures.

1604. Response to a Cluster of Haemophilus influenzae Serotype A Cases in a Small Alaska Community, 2018

Background

Between May and July 2018, four invasive cases of Haemophilus influenzae type a (Hia) occurred in a remote Alaska community. A public health response was performed to prevent further illness and to understand local Hia transmission.

Methods

The team identified close contacts of the Hia patients, collected oropharyngeal (OP) swabs and provided prophylactic rifampin. Close contacts were persons who spent ≥4 hours with a Hia patient for ≥ 5 of the 7 days preceding hospitalization. Five days later, OP swabs were collected community-wide and prophylactic rifampin was offered to community members aged <10 years. Eight weeks later, OP swabs were collected from all willing community members. Samples were tested using PCR and culture to identify Hi carriage.

Results

No Hia cases occurred in this community after the response. The pretreatment carriage prevalence is shown in Figure 1. There was a significant difference in prevalence of Hia carriage between contacts (4/27, 14.8%) and non-contacts (7/364, 1.9%) (P = 0.0043). Contacts aged <10 years were significantly more likely to carry Hia compared with contacts aged ≥10 years (11/18 [61.1%] vs. 3/34 [8.8%], P = 0.0001). The case households had the highest proportion of individuals who carried Hia at any time, with 54%–60% of individuals in three case households carrying Hia at least once. Hia carriage was eliminated in two carriers who completed treatment and were tested immediately after rifampin prophylaxis. Testing 8 weeks later found that the prevalence of carriage did not significantly change in the contacts (5/42 [11.9%] to 6/25 [24%], P = 0.18) or the non-contacts (7/368 [1.9%] to 2/114 [1.8%], P = 0.47).

Conclusion

Children aged <10 years who had close contact with the Hia patients were the most likely to carry Hia. These findings suggest that people who do not have close contact do not benefit from prophylaxis as they have very low Hia carriage. While rifampin prophylaxis eliminated carriage of Hia in the short term, carriage prevalence did not change in the long term. Further research is needed to understand why contacts have such a high prevalence of carriage even after receiving appropriate prophylactic medication.

Disclosures

All authors: No reported disclosures.

The relationship between bronchoalveolar lavage fluid cytology and airway hyper-reactivity in a population of Australian horses presented for poor performance

OBJECTIVE

To investigate the relationship between bronchoalveolar lavage fluid cytology, particularly mast cells, and airway hyper-reactivity in athletic horses presented for poor performance that included a respiratory tract evaluation in two disparate locations in Australia.

DESIGN

Multi-centre, retrospective and prospective cross-sectional study METHODS: Eighty four adult horses underwent both pulmonary function testing and histamine bronchoprovocation with a commercial flowmetric plethysmography system. A bronchoalveolar lavage was performed four to twelve hours later. Bronchoalveolar lavage fluid cytology was categorised using two differing classification systems to define mild equine asthma. Statistical analysis was used to assess associations between bronchoalveolar lavage fluid relative inflammatory cell percentages, and airway hyper-reactivity and their associated categorisations.

RESULTS

Sixty four percent (54/84) of horses displayed airway hyper-reactivity, as defined by PC₃₅  < 6 mg/ml of histamine. A relative mastocytosis was the most common bronchoalveolar lavage fluid cytological abnormality. Horses with a sole mast cell response of ≥ 5% within their bronchoalveolar lavage fluid displayed airway hyper-reactivity at a lower dose of nebulized histamine than horses with normal bronchoalveolar lavage fluid cytology. Horses with mixed cell responses (relative mast cell percentage > 2% and/or relative neutrophil percentage > 5% and/or eosinophil relative cell percentage ≥ 1%) displayed airway hyper-reactivity at a lower dose of nebulized histamine than horses with normal bronchoalveolar lavage fluid cytology.

CONCLUSION

In the Australian context, recently revised increased bronchoalveolar lavage fluid cytology relative cell percentage cut offs appear appropriate for sole mast cell responses. The historical lower cut offs appear to be appropriate for mixed inflammatory cell responses.

Reptarenaviruses in apparently healthy snakes in an Australian zoological collection

BACKGROUND

Inclusion body disease (IBD) is a disease of snakes with a global distribution and has recently been shown to be caused by reptarenaviruses. Testing for this group of viruses in asymptomatic snakes allows the association between infection and disease to be further elucidated.

METHODS

A reptarenavirus was detected by RT-PCR in a reticulated python (Malayopython reticulatus) from an Australian zoological collection that was open-mouth breathing and had erythematous oral mucosa. Another 27 pythons, 4 elapids, 2 colubrids and 2 boas from this collection were then screened. From these animals, swabs, whole blood and/or tissue were tested for reptarenaviruses by RT-PCR. Additionally, blood films from 10 snakes were examined by light microscopy for the presence of inclusion bodies. The majority of samples were collected over a 484-day period.

RESULTS

A total of 8 animals were RT-PCR-positive (8/36 = 22.2%): 6 were pythons, 1 was a corn snake (Pantherophis guttatus) and 1 was a Madagascar tree boa (Sanzinia madagascariensis). From them, 57 samples were collected, but only one from each animal was RT-PCR-positive (8/57 = 14.0%). From all 36 animals in this study, 8/182 samples were RT-PCR-positive (4.4%). Inclusion bodies were not recognised in any of the blood films. Only the reticulated python showed signs of illness, which improved without any further intervention. All other RT-PCR-positive snakes were apparently healthy throughout the duration of the study.

CONCLUSION

This study showed a weak association between the presence of reptarenaviruses and disease. Testing serially collected swab and whole-blood samples increased the number of animals in which reptarenaviruses were detected.

Subfascial endoscopic perforator surgery (SEPS) for treating venous leg ulcers

BACKGROUND

Venous leg ulcers are complex, costly, and their prevalence is expected to increase as populations age. Venous congestion is a possible cause of venous leg ulcers, which subfascial endoscopic perforator surgery (SEPS) attempts to address by removing the connection between deep and superficial veins (perforator veins). The effectiveness of SEPS in the treatment of venous leg ulcers, however, is unclear.

OBJECTIVES

To assess the benefits and harms of subfascial endoscopic perforator surgery (SEPS) for the treatment of venous leg ulcers.

SEARCH METHODS

In March 2018 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of interventions that examined the use of SEPS independently or in combination with another intervention for the treatment of venous leg ulcers.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data, assessed risk of bias, and assessed the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included four RCTs with a total of 322 participants. There were three different comparators: SEPS plus compression therapy versus compression therapy (two trials); SEPS versus the Linton procedure (a type of open surgery) (one trial); and SEPS plus saphenous surgery versus saphenous surgery (one trial). The age range of participants was 30 to 82, with an equal spread of male and female participants. All trials were conducted in hospital settings with varying durations of follow-up, from 18 months to 6 years. One trial included participants who had both healed and active ulcers, with the rest including only participants with active ulcers.There was the potential for reporting bias in all trials and performance bias and detection bias in three trials. Participants in the fourth trial received one of two surgical procedures, and this study was at low risk of performance bias and detection bias.SEPS + compression therapy versus compression therapy (2 studies; 208 participants)There may be an increase in the proportion of healed ulcers at 24 months in people treated with SEPS and compression therapy compared with compression therapy alone (risk ratio (RR) 1.17, 95% confidence interval (CI) 1.03 to 1.33; 1 study; 196 participants); low-certainty evidence (downgraded twice, once for risk of bias and once for imprecision).It is uncertain whether SEPS reduces the risk of ulcer recurrence at 24 months (RR 0.85, 95% CI 0.26 to 2.76; 2 studies; 208 participants); very low-certainty evidence (downgraded three times, twice for very serious imprecision and once for risk of bias).The included trials did not measure or report the following outcomes; time to complete healing, health-related quality of life (HRQOL), adverse events, pain, duration of hospitalisation, and district nursing care requirements.SEPS versus Linton approach (1 study; 39 participants)It is uncertain whether there is a difference in ulcer healing at 24 months between participants treated with SEPS and those treated with the Linton procedure (RR 0.95, 95% CI 0.83 to 1.09; 1 study; 39 participants); very low-certainty evidence (downgraded three times, twice for very serious imprecision and once for risk of bias).It is also uncertain whether there is a difference in risk of recurrence at 60 months: (RR 0.47, 95% CI 0.10 to 2.30; 1 study; 39 participants); very low-certainty evidence (downgraded three times, twice for very serious imprecision and once for risk of bias).The Linton procedure is possibly associated with more adverse events than SEPS (RR 0.04, 95% CI 0.00 to 0.60; 1 study; 39 participants); very low-certainty evidence (downgraded three times, twice for very serious imprecision and once for risk of bias).The outcomes time to complete healing, HRQOL, pain, duration of hospitalisation and district nursing care requirements were either not measured, reported or data were not available for analysis.SEPS + saphenous surgery versus saphenous surgery (1 study; 75 participants)It is uncertain whether there is a difference in ulcer healing at 12 months between participants treated with SEPS and saphenous surgery versus those treated with saphenous surgery alone (RR 0.96, 95% CI 0.64 to 1.43; 1 study; 22 participants); very low certainty evidence (downgraded three times, twice for very serious imprecision and once for high risk of reporting bias).It is also uncertain whether there is a difference in the risk of recurrence at 12 months: (RR 1.03, 95% CI 0.15 to 6.91; 1 study; 75 participants); very low certainty evidence (downgraded three times, twice for very serious imprecision and once for high risk of reporting bias).Finally, we are uncertain whether there is an increase in adverse events in the SEPS group (RR 2.05, 95% CI 0.86 to 4.90; 1 study; 75 participants); very low certainty evidence (downgraded three times, twice for very serious imprecision and once for high risk of reporting bias).The outcomes time to complete healing, HRQOL, serious adverse events, pain, duration of hospitalisation, and district nursing care requirements were either not measured, reported or data were not available for analysis.

AUTHORS' CONCLUSIONS

The role of SEPS for the treatment of venous leg ulcers remains uncertain. Only low or very low-certainty evidence was available for inclusion. Due to small sample sizes and risk of bias in the included studies, we were unable to determine the potential benefits and harms of SEPS for this purpose. Only four studies met our inclusion criteria, three were very small, and one was poorly reported. Further high-quality studies addressing the use of SEPS in venous leg ulcer management are likely to change the conclusions of this review.

Antimicrobial resistance among Helicobacter pylori isolates in Alaska, 2000-2016

OBJECTIVES

Alaska Natives experience a high burden of Helicobacter pylori infection and concomitant high rates of gastric cancer. Additionally, the prevalence of antimicrobial-resistant H. pylori has been shown to be high in Alaska. In this study, antimicrobial resistance over time among sentinel surveillance isolates was evaluated and risk factors for carrying antimicrobial-resistant H. pylori were assessed.

METHODS

Through Alaska's H. pylori sentinel surveillance system, antral and fundal biopsies from Alaska Native patients undergoing esophagogastroduodenoscopy for clinical indications during 2000-2016 were collected and cultured. For positive cultures, minimum inhibitory concentrations (MICs) of metronidazole, amoxicillin, clarithromycin, tetracycline and levofloxacin were determined.

RESULTS

A total of 800 H. pylori isolates obtained from 763 patients were tested. Resistance to metronidazole was most common (342/800; 42.8%), followed clarithromycin (238/800; 29.8%), both clarithromycin and metronidazole (128/800; 16.0%) and levofloxacin (113/800; 14.1%). Low proportions of isolates were resistant to amoxicillin and tetracycline. Levofloxacin resistance increased between 2000 and 2016 (P<0.001), but resistance to other antimicrobials did not change over time. Metronidazole and clarithromycin resistance were more common among women (P<0.001 for both), whilst levofloxacin resistance was more common among those with an urban residence (P=0.003). Metronidazole and levofloxacin resistance were more common among older patients (P<0.05).

CONCLUSION

Between 2000 and 2016, a large percentage of H. pylori isolates received by the Alaska Sentinel Surveillance System demonstrated resistance to common antimicrobials. The surveillance system provides valuable information for clinicians to make informed treatment choices for patient with H. pylori.

Serum NGAL can act as an early renal safety biomarker during long-term nucleos(t)ide analogue antiviral therapy in chronic hepatitis B

Tubular renal toxicity is a side-effect of long-term therapy with nucleos(t)ide analogue(s) (NA) in chronic hepatitis B (CHB). There are no established surrogate markers in plasma of early NA-related toxicity. Neutrophil gelatinase-associated lipocalin (NGAL) is a protein produced by tubular cells following renal damage. We aimed therefore to retrospectively compare conventional renal markers (estimated glomerular filtration rates (eGFR) and urinary protein/creatinine ratio uPCR) with a sensitive biomarker (NGAL) in CHB patients on long-term NA therapy and assess the ability of new markers to predict NA-related renal toxicity (new onset of nonalbumin proteinuria). A total of 192 naïve CHB patients (median age 41 years, 78% males, 25% HBeAg+, 35% cirrhosis) were NA treated for at least 5 years (median 8.34 years, range 5.54-11.1 years). The eGFR and uPCR were compared at baseline and last clinical visit with serum NGAL concentrations measured by ELISA at same time-points and assessed according to the presence/absence of nonalbumin proteinuria at last visit. While baseline and last visit eGFR were similar (median:78 vs 84 mL/min), serum NGAL concentrations increased during therapy (median:9.4 vs 16.4 ng/mL, P < .05). The proportion of patients with proteinuria (uPCR > 15) increased between baseline and last visit (4.6% vs 21.4%, P < .05), with 30 (16%) patients having de novo nonalbumin proteinuria at last visit. High baseline NGAL concentrations were exclusive to patients with de novo nonalbumin proteinuria (median:31.7 vs 7.8 ng/mL, P < .01) and baseline NGAL levels >25 mg/mL were predictive of nonalbumin proteinuria at last visit (AUROC = 0.813). In conclusion, serum NGAL can act as a surrogate marker of early renal injury (de novo nonalbumin proteinuria) in CHB on long-term NA therapy.

HBsAg and HBcrAg as predictors of HBeAg seroconversion in HBeAg-positive patients treated with nucleos(t)ide analogues

HBeAg seroconversion marks an important spontaneous change and treatment end-point for HBeAg-positive patients and is a pre-requisite for HBsAg loss or functional cure. In this retrospective analysis, we aimed to identify predictors of seroconversion using serum quantitative HBsAg and HBcrAg, in HBeAg-positive patients treated with nucleos(t)ide analogues (NA). Data and samples from 118 HBeAg-positive adults (genotypes A-G) started on NA between Jan 2005 and Sept 2016 were retrospectively analysed at several time-points. The predictive power of on-treatment levels of HBsAg and HBcrAg was determined using receiver operating curve (ROC) analysis and cut-off values determined by maximized Youden's index. About 36.4% of patients achieved HBeAg seroconversion after a median of 39 months' treatment. On treatment kinetics of HBV DNA, HBsAg and HBcrAg differed between HBeAg seroconverters and nonseroconverters. A combination of HBsAg and HBcrAg had the greatest predictive value for HBeAg seroconversion: at 6 months, HBsAg of 3.9 log₁₀  IU/mL and HBcrAg of 5.7 log₁₀ U/mL had a sensitivity of 71.4%, specificity of 79.5%, positive predictive value (PPV) of 65.2% and negative predictive value (NPV) of 83.8%, with AUROC of 0.769 (0.668, 0.869; 95%CI), and at 12 months, HBsAg 3.8 log₁₀  IU/mL and HBcrAg 5.5 log₁₀ U/mL had a sensitivity of 73.7%, specificity of 79.5%, PPV of 63.6% and NPV of 86.1%, with AUROC 0.807 (0.713, 0.901; 95% CI). In conclusion, our results may be used to identify patients who are unlikely to achieve treatment end-points, which will be important as the future management of chronic hepatitis B looks to therapies that offer functional cure.

Detection of endoscopic looping during colonoscopy procedure by using embedded bending sensors

Background

Looping of the colonoscope shaft during procedure is one of the most common obstacles encountered by colonoscopists. It occurs in 91% of cases with the N-sigmoid loop being the most common, occurring in 79% of cases.

Purpose

Herein, a novel system is developed that will give a complete three-dimensional (3D) vector image of the shaft as it passes through the colon, to aid the colonoscopist in detecting loops before they form.

Patients and methods

A series of connected links spans the middle 50% of the shaft, where loops are likely to form. Two potentiometers are attached at each joint to measure angular deflection in two directions to allow for 3D positioning. This 3D positioning is converted into a 3D vector image using computer software. MATLAB software has been used to display the image on a computer monitor. For the different configuration of the colon model, the system determined the looping status.

Results

Different configurations (N loop, reverse gamma loop, and reverse splenic flexure) of the loops were well defined using 3D vector image.

Conclusion

The novel sensory system can accurately define the various configuration of the colon during the colonoscopy procedure.

Hepatitis A vaccine immune response 22 years after vaccination

In the United States, the incidence of hepatitis A virus (HAV) infection has been reduced through universal childhood vaccination. However, the duration of immunogenicity for the hepatitis A vaccine is not known. We report on the 22 year follow-up time point of a cohort of Alaska children who were randomized to three different vaccine schedules: A) 0, 1, and 2 months; B) 0, 1, and 6 months; and C) 0, 1, and 12 months. Among 46 participant available for follow-up, 40 (87%) maintained protective levels of anti-hepatitis A antibody. These results indicate that a supplemental booster dose is not yet necessary at or before the 22-year time point.

Slip-Shod or Safely Shod: The Bighorn Sheep as a Natural Model for Research

Over a million injuries caused by slipping of footwear are believed to require treatment by doctors every year in the United Kingdom and many domestic animals are injured by slipping. Recent research has revealed that surface roughness of solings and floors is an important determinant of grip on lubricated surfaces and it is also known that soling friction is affected by hardness. The bighorn sheep (Ovis canadensis) an animal species which has adapted to a slippery environment, was studied to elucidate optimum roughness and hardness and other features which influence grip. Four adult ewes were examined in the London Zoo. The cloven hooves of this species are very mobile and the cranial tips of the hooves are the first parts to make contact with the ground. A very small contact area ensures penetration of a film of water. Mean roughness of the contact area was found to be 53 microns Rtm and the mean hardness 63 Shore A. These characteristics appear to facilitate an excellent grip on wet slippery rock but not on smooth ice. Further studies of the feet of wild species could contribute to an understanding of the factors which determine the safety of solings and floors.

The economic efficiency and equity of government policies on brucellosis: comparative insights from Albania and the United States of America

Brucellosis is a zoonotic bacterial disease that causes recurring febrile illness in humans, as well as reproductive failure and reduced milk production in livestock. The cost of brucellosis is equal to the sum of lost productivity of humans and animals, as well as private and public expenditures on brucellosis surveillance, prevention, control and treatment. In Albania, Brucella abortus and B. melitensis affect humans, cattle and small ruminants. In the United States, B. abortus affects cattle and wild ungulates in the Greater Yellowstone Area. These two case studies illustrate the importance of place-specific context in developing sustainable and effective brucellosis mitigation policies. Government regulations and mitigation strategies should be designed with consideration of all costs and benefits, both to public agencies and private stakeholders. Policy-makers should, for example, weigh the benefits of a regulation that increases epidemiological certainty against the costs of compliance for producers and households. The distribution of costs and benefits amongst public agencies and private individuals can have important implications for a policy's economic efficiency and equity quite apart from their total magnitude.

Risk of end-stage liver disease, hepatocellular carcinoma, and liver-related death by fibrosis stage in the hepatitis C Alaska Cohort

Long-term prospective studies of the outcomes associated with hepatitis C virus (HCV) infection are rare and critical for assessing the potential impact of HCV treatment. Using liver biopsy as a starting point, we analyzed the development of end-stage liver disease (ESLD), hepatocellular carcinoma (HCC), and liver-related death (LRD) according to fibrosis stage among a cohort of American Indian/Alaska Native persons in Alaska. Persons were classified as having no/mild (Ishak = 0,1), moderate (Ishak = 2), or severe (Ishak = 3,4) fibrosis or cirrhosis (Ishak = 5,6). We examined time until development of ESLD, HCC, and LRD and report survival probabilities at 3, 5, 7, and 10 years. Of 407 persons, 39% (n = 150) had no/mild fibrosis, 32% (n = 131) had moderate fibrosis, 22% (n = 88) had severe fibrosis, and 9% (n = 38) had cirrhosis. The average time of follow-up was 7.3 years. Within 5 years of biopsy, 1.7% (95% confidence interval [CI]: 0.4-6.8) of persons with no/mild fibrosis developed ESLD compared with 7.9% (95% CI, 4.0-15.2), 16.4% (95% CI, 9.6-27.2), and 49.0% (95% CI, 33.0-67.7) with moderate, severe fibrosis, and cirrhosis, respectively (P < 0.01). The 5-year outcome of HCC was 1.0% (95% CI, 0.1-7.0), 1.0% (95% CI, 0.1-6.6), 1.1% (95% CI, 0.2-7.7), and 13.4% (95% CI, 4.4-36.7) among persons with no/mild fibrosis, moderate fibrosis, severe fibrosis, and cirrhosis, respectively (P < 0.01). Five years after biopsy, 0.0% (95% CI, 0.0-14.8) of persons with no/mild fibrosis had suffered an LRD compared with 1.0% (95% CI, 0.2-7.5) of persons with moderate fibrosis, 4.7% (95% CI, 1.5-14.1) with severe fibrosis, and 16.3% (95% CI, 7.0-35.1) with cirrhosis (P < 0.01).

CONCLUSION

For prevention of HCC, LRD, and ESLD in the short term, HCV therapy should target individuals who have more than mild fibrosis. (Hepatology 2017;66:37-45).

Caring for a patient with rabies: implications of the Milwaukee protocol for infection control and public health measures

This article discusses the infection control and public health measures taken whilst managing a case of laboratory-confirmed rabies, and the challenges faced in implementing these measures. Case management requires intensive multi-disciplinary co-ordination. The Milwaukee protocol, which to date has five reported human rabies survivors associated with its use, has been suggested as a potential management pathway for human rabies. Consensus among hospital and public health clinicians would aid future deployment of this approach in selected cases.

Effect of BMI on Resting-state Functional Architecture of the Brain in Healthy Individuals and Patients with Psychosis

Elevated body mass index (BMI) is associated with increased multi-morbidity and mortality. The investigation of the relationship between BMI and brain organization has the potential to provide new insights relevant to clinical and policy strategies for weight control. Here, we quantified the effect of BMI on the functional connectivity of the Default-Mode (DMN), Central Executive (CEN), Sensorimotor (SMN) and Visual (VN) networks in 496 healthy individuals that were studied as part of the Human Connectome Project. We found that elevated BMI was associated with disrupted functional integration of sensory-guided (SMN, VN) with internally controlled (DMN, CEN) networks, implicating increased attention to sensory stimuli as a possible mechanism underpinning overeating and weight gain. Our results suggest that weight control strategies should expand to include wider societal policies that incorporate modifications to eating environments and to the visual presentation and branding of food products.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Infection With Hepatitis C Virus Genotype 3 Is an Independent Risk Factor for End-Stage Liver Disease, Hepatocellular Carcinoma, and Liver-Related Death

BACKGROUND & AIMS

Few studies have examined factors associated with disease progression in hepatitis C virus (HCV) infection. We examined the association of 11 risk factors with adverse outcomes in a population-based prospective cohort observational study of Alaska Native/American Indian persons with chronic HCV infection.

METHODS

We collected data from a population-based cohort study of liver-related adverse outcomes of infection in American Indian/Alaska Native persons with chronic HCV living in Alaska, recruited from 1995 through 2012. We calculated adjusted hazard ratios (aHR) and 95% confidence intervals (CIs) for end-stage liver disease (ESLD; presence of ascites, esophageal varices, hepatic encephalopathy, or coagulopathy), hepatocellular carcinoma (HCC), and liver-related death using a Cox proportional hazards model.

RESULTS

We enrolled 1080 participants followed up for 11,171 person-years (mean, 10.3 person-years); 66%, 19%, and 14% were infected with HCV genotypes 1, 2, and 3, respectively. On multivariate analysis, persons infected with HCV genotype 3 had a significantly increased risk of developing all 3 adverse outcomes. Their aHR for ESLD was 2.1 (95% CI, 1.5-3.0), their aHR for HCC was 3.1 (95% CI, 1.4-6.6), and their aHR for liver-related death was 2.4 (95% CI, 1.5-4.0) compared with genotype 1. Heavy alcohol use was an age-adjusted risk factor for ESLD (aHR, 2.2; 95% CI, 1.6-3.2), and liver-related death (aHR, 2.9; 95% CI, 1.8-4.6). Obesity was a risk factor for ESLD (aHR, 1.4; 95% CI, 1.0-1.9), and diabetes was a risk factor for ESLD (aHR, 1.5; 95% CI, 1.1-2.2). Male sex was a risk factor for HCC (aHR, 3.6; 95% CI, 1.6-8.2).

CONCLUSIONS

In a population-based cohort study of American Indian/Alaska Native persons with chronic HCV infection, we found those infected with HCV genotype 3 to be at high risk for ESLD, HCC, and liver-related death.

Randomised clinical trial: exploratory phase 2 study of ONO-2952 in diarrhoea-predominant irritable bowel syndrome

BACKGROUND

ONO-2952 is a novel and selective inhibitor of translocator protein 18 kDa that reduces stress-induced defecation and visceral hyperalgesia in rat models.

AIM

To evaluate the efficacy and safety of ONO-2952 in females with irritable bowel syndrome with diarrhoea in an exploratory proof-of-concept study.

METHODS

A randomised, double-blind, placebo-controlled study was conducted at 49 US centres. Two hundred subjects with irritable bowel syndrome with diarrhoea (Rome III criteria) were randomised to ONO-2952 20 mg, or 60 mg, or placebo. Subjects recorded irritable bowel syndrome symptoms daily during a 2-week baseline period, the 4-week treatment period and for 4 weeks post-treatment. The co-primary endpoints were change from baseline to week 4 in abdominal pain, stool consistency and stool frequency.

RESULTS

Improvements in irritable bowel syndrome symptoms were seen with ONO-2952 over placebo in per-protocol analyses for all three co-primary endpoints, but these did not reach statistical significance at the 5% level. The largest improvement was seen with ONO-2952 60 mg. ONO-2952 was well tolerated with a safety profile similar to that of placebo. Most adverse events were mild or moderate in severity and not treatment related.

CONCLUSION

ONO-2952 showed evidence of clinical efficacy in reducing irritable bowel syndrome-related symptoms in female subjects with irritable bowel syndrome with diarrhoea, and further evaluation is, therefore, warranted to assess its potential as a treatment for irritable bowel syndrome with diarrhoea (NCT01844180).

Incidence of hepatocellular carcinoma according to hepatitis B virus genotype in Alaska Native people

BACKGROUND & AIMS

Most regions of the world have ≤3 co-circulating hepatitis B virus (HBV) genotypes, which limits direct comparisons of hepatocellular carcinoma (HCC) risk among HBV-infected persons by genotype. We evaluated HCC incidence by HBV genotype in a cohort of Alaska Native (AN) persons where five HBV genotypes (A, B, C, D, F) have been identified.

METHODS

Our cohort comprised AN persons with chronic HBV infection identified during 1983-2012 who consented to participate in this study. Cohort persons were offered annual hepatitis B e antigen (HBeAg) testing and semi-annual HCC screening. We developed a logistic regression model to compare HCC risk by genotype, adjusting for age, sex, region and HBeAg status.

RESULTS

Among the 1235 consenting study participants, 711 (57.6%) were male, 510 (41.3%) were HBeAg positive at cohort entry and 43 (3.5%) developed HCC. The HBV genotype was known for 1142 (92.5%) persons (13.5% A, 3.9% B, 6.7% C, 56.9% D, 19.0% F). The HCC incidence/1000 person-years of follow-up for genotypes A, B, C, D and F was 1.3, 0, 5.5, 0.4 and 4.2 respectively. Compared with persons with HBV genotype B/D infection, the HCC risk was higher for persons with genotypes A [adjusted odds ratio (aOR): 3.9, 95% confidence interval (CI): 1.14-13.74], C (aOR: 16.3, 95% CI: 5.20-51.11) and F (aOR: 13.9, 95% CI: 5.30-36.69).

CONCLUSION

HBV genotype is independently associated with HCC risk. AN persons with genotypes A, C and F are at higher risk compared with genotypes B or D.

International circumpolar surveillance interlaboratory quality control program for emm typing of Streptococcus pyogenes, 2011-2015

In 2011, an interlaboratory quality control (QC) program for emm typing group A streptococci (GAS) was incorporated into existing international circumpolar surveillance QC programs. From 2011 - 2015, 35 GAS isolates were distributed to three laboratories; emm type-level concordance was 100%, while the overall sub-type level concordance was 83%.