SARS-CoV-2 antibodies and their neutralizing capacity against live virus in human milk after COVID-19 infection and vaccination: prospective cohort studies

BACKGROUND

There is limited understanding of the impact of coronavirus disease 2019 (COVID-19) infection and vaccination type and interval on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) human milk antibodies and their neutralizing capacity.

OBJECTIVES

These cohort studies aimed to determine the presence of antibodies and live virus neutralizing capacity in milk from females infected with COVID-19, unexposed milk bank donors, and vaccinated females and examine impacts of vaccine interval and type.

METHODS

Milk was collected from participants infected with COVID-19 during pregnancy or lactation (Cohort-1) and milk bank donors (Cohort-2) from March 2020-July 2021 at 3 sequential 4-wk intervals and COVID-19 vaccinated participants with varying dose intervals (Cohort-3) (January-October 2021). Cohort-1 and Cohort-3 were recruited from Sinai Health (patients) and through social media. Cohort-2 included Ontario Milk Bank donors. Milk was examined for SARS-CoV-2 antibodies and live virus neutralization.

RESULTS

Of females with COVID-19, 53% (Cohort-1, n = 55) had anti-SARS-CoV-2 IgA antibodies in ≥1 milk sample. IgA+ samples (40%) were more likely neutralizing than IgA- samples (odds ratio [OR]: 2.18; 95% confidence interval [CI]: 1.03, 4.60; P = 0.04); however, 25% of IgA- samples were neutralizing. Both IgA positivity and neutralization decreased ∼6 mo after symptom onset (0-100 compared with 201+ d: IgA OR: 14.30; 95% CI: 1.08, 189.89; P = 0.04; neutralizing OR: 4.30; 95% CI: 1.55, 11.89; P = 0.005). Among milk bank donors (Cohort-2, n = 373), 4.3% had IgA antibodies; 23% of IgA+ samples were neutralizing. Vaccination (Cohort-3, n = 60) with mRNA-1273 and shorter vaccine intervals (3 to <6 wk) resulted in higher IgA and IgG than BNT162b2 (P < 0.04) and longer intervals (6 to <16 wk) (P≤0.02), respectively. Neutralizing capacity increased postvaccination (P = 0.04) but was not associated with antibody positivity.

CONCLUSIONS

SARS-CoV-2 infection and vaccination (type and interval) impacted milk antibodies; however, antibody presence did not consistently predict live virus neutralization. Although human milk is unequivocally the best way to nourish infants, guidance on protection to infants following maternal infection/vaccination may require more nuanced messaging. This study was registered at clinicaltrials.gov as NCT04453969 and NCT04453982.

Characterization of protein aggregates in cream and skimmed human milk after heat and high-pressure pasteurization treatments

Preservation processes applied to ensure microbial safety of human milk (HM) can modify the native structure of proteins and their bioactivities. Consequently, this study evaluated the effect of pasteurization methods (Holder pasteurization, high-temperature short-time (HTST), and high hydrostatic pressure (HHP)) of whole human milk (HM) on protein aggregates in skim milk and cream fractions. For heat-treated whole milk, insoluble protein aggregates at milk fat globule membrane (MFGM) were formed by disulfide and non-covalent bonds, but insoluble skim milk protein aggregates were only stabilized by non-covalent interactions. Contrary to heat treatment, the insolubilization of main proteins at the MFGM of HHP-treated HM was only through non-covalent interactions rather than disulfide bonds. Moreover, only heat treatment induced the insoluble aggregation of ⍺-lactalbumin. Overall, compared to heat treatment, HHP produced a milder effect on protein aggregation, validating the use of this process to better preserve the native state of HM bioactive proteins.

Digestion of human milk processed by high pressure processing and Holder pasteurization using a dynamic in vitro model of the preterm infant

Holder pasteurization (HoP) (62.5 °C, 30 min) of donor human milk is widely used to inactivate potential pathogens but may lead to denaturation and aggregation of bioactive proteins, reducing their functionality. In contrast, high pressure processing (HPP) is a non-thermal technique that minimally affects assessed bioactive components; however, it is unclear how HPP affects protein digestion, and retention of functional bioactive proteins. Raw or processed (HoP; HPP[500 MPa,10 min]) pools of milk (N = 3, from 9 donors) were subjected in triplicate to in vitro digestion simulating the preterm infant gastrointestinal tract. Compared to raw or HPP, HoP increased intestinal proteolysis of lactoferrin and bioactive milk fat globule membrane proteins. Lysozyme activity was impacted by digestion following HoP (72 % to 7 %)-significantly more than HPP (75 % to 34 %) or raw (100 % to 39 %), which did not differ. Proteins in HPP-treated donor milk are digested no different than raw milk, while preserved bioactivity remains functional upon digestion.

POS0098 LINC01871, IMPLICATED IN SJÖGREN’S DISEASE PATHOGENESIS, IS REGULATED BY INTERFERON-G AND CALCINEURIN SIGNALING

Background

Sjögren’s disease (SjD) is an autoimmune disease characterized by exocrine gland dysfunction. Long non-coding RNAs (lncRNAs) are a functionally diverse class of non-protein coding RNAs that are longer than 200 nucleotides. Our previous study using whole blood RNA-seq found that lncRNA, LINC01871, is overexpressed in SjD relative to controls [1]. CRISPR-Cas9 targeting in HSB2 T cells yielded a LINC01871-/- clone with altered expression of many genes implicated in immune regulation [1].

Objectives

The goal of this study was to analyze the gene expression perturbations resulting from the loss of LINC01871 and to characterize the regulation of LINC01871 in both the LINC01871-/- clone and primary human T cells in response to immune stimuli.

Methods

Flow cytometry and LegendPlex bead assays were used to compare surface and secreted protein expression changes, respectively, in LINC01871-/- cells and the parental HSB2 cells. Parental HSB2 T cells, LINC01871-/- cells, Kasumi-3 myeloid cells, and primary human T cells were stimulated in vitro and changes in gene expression were measured over time using qRT-PCR. Responses to interferons (IFN) were assessed using universal type I IFN (IFNα) or IFNγ. TCR signaling responses were assessed using PMA/Ionomycin (PMA/I) or anti-CD3/CD28 stimulations in the presence or absence of the calcineurin inhibitor, FK506.

Results

Previous RNA-seq analysis found 1166 differentially expressed (DE) transcripts (log2FC ≥1 or ≤-1; padj ≤0.05) in LINC01871-/- cells compared to parental HSB2 cells, including many prominent immune regulatory genes. Changes in the basal expression of 7 proteins in LINC01871-/- cells were confirmed using flow cytometry (significantly decreased: CD8a (p=0.0004), CD30 (p=0.0008), CXCR3 (p=0.037), T-Bet (p=0.0002), and Aiolos (p=0.02); significantly increased: CD226 (p=0.0059) and CD44 (p=0.024)). Analysis of LINC01871-/- cells revealed a growth inhibition in LINC01871-/- cells (p=0.0014 at 72h), in which multiple secreted growth and adhesion factors were significantly reduced: GM-CSF (p=2.0e-06), M-CSF (p=2.7e-09), IGBPF4 (p=1.2e-07), s-ICAM1 (p=0.015), MMP9 (p=3.0e-14), and MMP2 (p=6e-08). In contrast, the IL-6 cytokine family member, LIF, was significantly increased in LINC01871-/- cells (p=1.2e-07). Because HSB2 cells were not responsive to all IFNs, IFN-mediated regulation of LINC01871 expression was examined in the Kasumi-3 myeloid cell line. While LINC01871 expression was not modulated by type I IFN stimulation, it was robustly responsive to IFNγ treatment. Since LINC01871 was expressed in T cells and implicated in T cell pathways, responses to TCR signaling pathways were characterized in HSB2 cells or purified primary human T cells treated with PMA/I. In both cell types, LINC01871 exhibited a prolonged decrease in expression that was abrogated by concurrent treatment with FK506, indicating that LINC01871 is regulated by calcineurin signaling. Treatment of primary human T cells with anti-CD3/CD28 to mimic true TCR engagement resulted in a modest decrease of LINC01871 expression at early time points, followed by an increase in expression with longer stimulation (2d).

Conclusion

Our findings suggest that LINC01871 is a potential mediator of the dysregulated T cell inflammatory response pathways implicated in SjD pathogenesis. LINC01871 influences the expression of many important immune cell genes and growth factors, is inducible by IFNγ, and is regulated directly by calcineurin signaling and TCR ligand engagement. Although LINC01871 functions are still unknown, observed LINC01871 overexpression in whole blood of SjD cases and after prolonged TCR stimulation in primary human T cells suggests that it could be a biomarker of SjD.

References

[1]Joachims, et al. Annals of the Rheumatic Diseases 2020;79:90.

Disclosure of Interests

Michelle L Joachims: None declared, Bhuwan Khatri: None declared, Chuang Li: None declared, Kandice L Tessneer: None declared, John Ice: None declared, Anna M Stolarczyk: None declared, Nicolas Means: None declared, Kiely Grundahl: None declared, Stuart Glenn: None declared, Jennifer Kelly: None declared, David Lewis: None declared, Lida Radfar: None declared, Donald Stone: None declared, Joel Guthridge: None declared, Judith A. James: None declared, R Hal Scofield: None declared, Graham B Wiley: None declared, Jonathan Wren: None declared, Patrick M Gaffney: None declared, Courtney Montgomery: None declared, Kathy Sivils Employee of: Current employee of Janssen., Astrid Rasmussen: None declared, A Darise Farris: None declared, Indra Adrianto: None declared, Christopher Lessard: None declared

Preservation of Anti-cytomegalovirus Activity in Human Milk Following High-Pressure Processing Compared to Holder Pasteurization

Pasteurized donor human milk is recommended for hospitalized preterm infants when mother’s own milk is unavailable. Our aim was to compare the antiviral activity of human milk processed by Holder pasteurization (HoP) or high-pressure processing (HPP) against representative enveloped and non-enveloped viruses including cytomegalovirus and hepatitis A virus. Expressed milk from 20 donors collected from the Ontario Milk Bank was combined into 10 pools, each from two unique donors. Each pool was processed by HoP (62.5°C, 30 min) or HPP (500 MPa, 8 min, 4°C) and subsequently inoculated with cytomegalovirus or hepatitis A virus to achieve a final concentration of 5-log plaque-forming units/mL. Plaque reduction assays were used to quantify detectable virus after 30 min incubation (room temperature). Post hoc experiments using a 4 h incubation time were conducted if reductions were detected at 30 min. Irrespective of processing, cytomegalovirus concentrations declined in all pools after 30 min incubation (P &lt; 0.0001). Milk processed by HoP exhibited significantly less reduction compared to raw milk (P = 0.0069). In post hoc experiments, anti-cytomegalovirus activity was maintained at 4 h, with high inter-pool variability. Hepatitis A virus concentration remained unchanged after 30 min incubation in raw and processed milk. Anti-cytomegalovirus activity in human milk is preserved following HoP and HPP, persisting up to 4 h post-inoculation; anti-hepatitis A virus activity was not observed in raw or processed milk. Further research is needed to understand how HoP or promising alternative processing methods affect the antiviral activity of donated milk, given its potential importance to recipient infants.

Predicting Protein and Fat Content in Human Donor Milk Using Machine Learning

BACKGROUND

Donor milk is the standard of care for hospitalized very low birth weight (VLBW) infants when mother's milk is unavailable; however, growth of donor milk-fed infants is frequently suboptimal. Variability in nutrient composition of donated milk complicates the production of a uniform pooled product and, subsequently, the provision of adequate nutrition to promote optimal growth and development of VLBW infants. We reasoned a machine learning approach to construct batches using characteristics of the milk donation might be an effective strategy in reducing the variability in donor milk product composition.

OBJECTIVE

The objective of this study was to identify whether machine learning models can accurately predict donor milk macronutrient content. We focused on predicting fat and protein, given their well-established importance in VLBW infant growth outcomes.

METHODS

Samples of donor milk, consisting of 272 individual donations and 61 pool samples, were collected from the Rogers Hixon Ontario Human Milk Bank and analyzed for macronutrient content. Four different machine learning models were constructed using independent variable groups associated with donations, donors, and donor-pumping practices. A baseline model was established using lactation stage and infant gestational status. Predictions were made for individual donations and resultant pools.

RESULTS

Machine learning models predicted protein of individual donations and pools with a mean absolute error (MAE) of 0.16 g/dL and 0.10 g/dL, respectively. Individual donation and pooled fat predictions had an MAE of 0.91 g/dL and 0.42 g/dL, respectively. At both the individual donation and pool levels, protein predictions were significantly more accurate than baseline, whereas fat predictions were competitive with baseline.

CONCLUSIONS

Machine learning models can provide accurate predictions of macronutrient content in donor milk. The macronutrient content of pooled milk had a lower prediction error, reinforcing the value of pooling practices. Future research should examine how macronutrient content predictions can be used to facilitate milk bank pooling strategies.

A Human Milk-Based Protein Concentrate Developed for Preterm Infants Retains Bioactive Proteins and Supports Growth of Weanling Rats

BACKGROUND

Bovine milk-based protein modulars are currently available to nutrient-enrich enteral feedings; however, they have limitations for use in very-low-birth-weight infants.

OBJECTIVES

Our objectives were to develop a human milk-based protein (HMP) concentrate and to conduct a preclinical assessment of the HMP concentrate in weanling rats.

METHODS

An HMP concentrate was produced from donor milk using pressure-driven membrane filtration processes and high hydrostatic pressure processing. Protein and lactoferrin concentrations and lysozyme activity were determined by Kjeldahl, HPLC, and turbidimetric assay, respectively. Male Sprague Dawley rats 24 d old (n = 30) were randomly assigned to 1 of 3 isocaloric AIN-93G diets for 4 wk containing 100% casein (control) or with 50% of the casein replaced with the HMP concentrate (treatment) or a bovine whey protein isolate (treatment). Body weight, food intake, fat mass, plasma amino acid profiles, and organ weights were measured. Data were analyzed using linear regression models.

RESULTS

Raw donor milk contained (mean ± SD) 101 ± 6 g protein/kg and 5 ± 1 g lactoferrin/kg of milk solids. Postprocessing, protein and lactoferrin concentrations were 589 ± 3 g/kg and 29 ± 10 g/kg, respectively. Lysozyme activity was initially 209 ± 4 U/kg and increased to 959 ± 39 U/kg in the HMP concentrate. There were no statistically significant differences in body weight, food intake, fat mass, or plasma amino acid profiles between rats fed diets containing the HMP concentrate and the control diet. Full cecum weights were higher in rats fed the HMP concentrate than in those fed control diets (mean difference: 5.59 g; 95% CI: 4.50, 6.68 g; P < 0.0001), likely reflecting the concentration of human milk oligosaccharides. No differences were found for other organ weights.

CONCLUSIONS

The HMP concentrate retained important bioactive proteins and supported normal rat growth in the preclinical assessment.

Term Infants Fed Exclusively With Donor Milk May Require Vitamin C Supplementation

BACKGROUND

When there is insufficient mother's milk for preterm infants, fortified human donor milk (DM) is the preferred supplement. Recently, there is growing interest in providing DM to term infants. Aside from vitamin D, mother's milk is a complete source of nutrition for term infants. It is unknown whether supplementation of micronutrients is required for term infants exclusively fed DM, particularly for nutrients affected by heat processing, such as vitamin C. The objective of this study was to determine the total vitamin C content in DM and whether it would be adequate for an infant exclusively fed DM.

METHODS

DM samples (n = 56) were collected at a Canadian milk bank from April to August 2018. Vitamin C concentration was determined by high-performance liquid chromatography.

RESULTS

DM samples had a vitamin C concentration of 17.7 ± 9.8 mg/L (mean ± SD) and were variable, ranging from 1.9 to 43.2 mg/L. Using these values and assuming an exclusive DM consumption of 780 mL/day, the estimated vitamin C intake would be 13.8 ± 8.6 mg (mean ± SD), falling below the adequate intake of 40 mg/day for infants (0-6 months old).

CONCLUSION

Vitamin C supplementation is required for all infants if DM is the sole source of nutrition. Future studies should investigate other heat- and light-sensitive nutrients.

Self-reported Dysphagia and Pharyngeal Volume Following Whiplash Injury

Difficulty swallowing has been reported following whiplash injury; however, the reasons remain poorly understood. A possible factor may be the observed changes in pharyngeal volume. The current exploratory study was designed to examine the prevalence of self-reported dysphagia after whiplash and the relationship with recovery status and change in pharyngeal volume. Data were available from a longitudinal study of adults with whiplash. Data included magnetic resonance imaging (MRI) of the cervical spine, the Dysphagia Handicap Index (DHI), and Neck Disability Index (NDI) collected over four timepoints (< 1 week, 2 weeks, 3 months, and 12 months post-injury). Initial cross-sectional analysis examined 60 patients with DHI data from at least one timepoint. A second, longitudinal analysis was conducted on 31 participants with MRI, NDI, and DHI data at both early (< 1-2 weeks) and late (3-12 months) timepoints. The pharynx was contoured on axial T2-weighted MRI slices using OsiriX image processing software and pharyngeal volume (mm³) was quantified. In the 60-patient cohort, prevalence of self-reported dysphagia (DHI ≥ 3) was observed in 50% of participants at least once in 12 months (M = 4.9, SD 8.16, range 0-40). In the longitudinal cohort (n = 31), mean total DHI significantly (p = 0.006) increased between early and late stages. There was no relationship (p = 1.0) between dysphagia and recovery status, per the NDI% score. Pharyngeal volume remained stable and there was no relationship between dysphagia and pharyngeal volume change (p = 1.0). This exploratory study supports the need for further work to understand the nature of dysphagia, extent of functional compromise, and the underlying pathophysiology post-whiplash.

Responsiveness of the EAT-10 to Clinical Change in Head and Neck Cancer Patients with Dysphagia

Purpose: This retrospective study evaluated the external responsiveness of the Eating Assessment Tool-10 (EAT-10) to clinical changes in a single cohort (n = 105) treated with chemoradiotherapy (CRT) or radiotherapy (RT) for head-and-neck cancer.Method: Patients completed the EAT-10 four times: (I) Within two weeks of commencing (C)RT, (II) in the final week of (C)RT, (III) two weeks post-(C)RT and (IV) following discharge from speech-language pathology services. Data was compared to their oral intake status, using the Functional Oral Intake Scale (FOIS).Result: Using Cohen's d, changes in the EAT-10 and FOIS were comparable, however, a difference was observed at data-point IV. At data-points I, II and III, the EAT-10 had a strong negative correlation with the FOIS (Spearman's ρ= -0.81, -0.80 and -0.81 resp.). At data-point IV the correlation strength decreased (Spearman's ρ= -0.69). Fisher's Z transformation found no statistically significant correlation coefficient differences between data-points I, II and III. A significant difference in correlation was found between these data-points and data-point IV (p = 0.027; p = 0.039 and p = 0.022 resp.). A very high internal consistency was found (Cronbach's α > 0.95) for all data-points.Conclusion: This study's results indicate that the EAT-10 has weaknesses in the external responsiveness and has redundancy of its question items.

P678Pericardiocentesis in thrombocytopenic cancer patients

Background

Pericardial effusion is a known complication in cancer patients, resulting in chest pain, cardiac tamponade, and cardiogenic shock. Although technological advances allow for early detection, treatment options are limited for those also suffering from thrombocytopenia.

Purpose

Our study aims to evaluate survivorship of thrombocytopenic cancer patients who underwent pericardiocentesis.

Methods

From 2008 to 2019, we assessed overall mortality and follow-up post-pericardiocentesis in cancer patients with concurrent thrombocytopenia (<150,000 cells/microliter) at our cancer center. Thrombocytopenia grading was determined on the procedure day via serology platelet cell count with the following thresholds: Grade 1 (<50x103 cells/mL), Grade 2 (51–100x103 cells/mL), and Grade 3 (101–149x103 cells/mL).

Results

In 137 patients, we identified 65 (47%) patients with Grade 1, 30 (22%) with Grade 2, and 42 (31%) with Grade 3 thrombocytopenia. The calculated platelet count average was 66x103 cells/mL, median was 59x103 cells/mL, and range was 6 to 147x103 cells/mL. Of note, 7 (5%) patients had platelets <10x103 cells/mL. One patient developed a hematoma at the percutaneous site of pericardial drain, no other complications were noted. Kaplan Meier survival analysis by log-rank (mantel-cox) showed statistical significance (p=0.025). Comparatively, the cumulative survival of patients at 30 days was 63% in Grade 1, 67% in Grade 2, and 83% in Grade 3 patients. At one year, it was 26% in Grade 1, 37% in Grade 2, and 48% in Grade 3 patients.

Conclusion

Pericardiocentesis offers rapid symptomatic relief and can be life-saving in cardiac tamponade. In cancer patients, the development of pericardial effusions and thrombocytopenia increases due to the underlying malignancy and cancer therapeutics. Although thrombocytopenia is thought to increase peri-procedural risks, in this cohort there was only one minor complication and this occurred in Grade 2 thrombocytopenia. For thrombocytopenic cancer patients suffering from large pericardial effusions, high pre-operative risk scores often exclude them from receiving surgical pericardial windows. Although mortality was higher in severe thrombocytopenia, this is likely due to the competing risk of more severe cancer; there were no complications with Grade 1 thrombocytopenia. Especially noteworthy, no complications in those with platelets <10,000 cells/uL. Our study shows that in this population of patients, pericardiocentesis is a feasible intervention with low complication rate to help improve quality of life and potentially life-saving treatment.

Whiplash-Associated Dysphagia: Considerations of Potential Incidence and Mechanisms

Non-specific self-reports of dysphagia have been described in people with whiplash-associated disorders (WAD) following motor vehicle collision (MVC); however, incidence and mechanistic drivers remain poorly understood. Alterations in oropharyngeal dimensions on magnetic resonance imaging (MRI), along with heightened levels of stress, pain, and changes in stress-dependent microRNA expression (e.g., miR-320a) have been also associated with WAD, suggesting multi-factorial issues may underpin any potential swallowing changes. In this exploratory paper, we examine key biopsychosocial parameters in three patients with persistent WAD reporting swallowing change and three nominating full recovery after whiplash with no reported swallowing change. Parameters included (1) oropharyngeal volume with 3D MRI, (2) peritraumatic miR-320a expression, and (3) psychological distress. These factors were explored to highlight the complexity of patient presentation and propose future considerations in relation to a potential deglutition disorder following WAD. The three participants reporting changes in swallowing all had smaller oropharyngeal volumes at < 1 week and at 3 months post injury and lower levels of peritraumatic miR-320a. At 3 months post MVC, oropharyngeal volumes between groups indicated a large effect size (Hedge's g = 0.96). Higher levels of distress were reported at both time points for those with persistent symptomatology, including self-reported dysphagia, however, this was not featured in those nominating recovery. This paper considers current evidence for dysphagia as a potentially under-recognized feature of WAD and highlights the need for future, larger-scaled, multidimensional investigation into the incidence and mechanisms of whiplash-associated dysphagia.

Is Frozen Human Milk That Is Refused by Mother's Own Infant Suitable for Human Milk Bank Donation?

Background: Infant refusal to feed previously frozen human milk is thought possibly attributable to lipase, an enzyme that cleaves fatty acids from milk triglycerides potentially changing the taste of the milk. Previous reports suggest that this milk is not harmful to infants; however, the lipase activity, macronutrient content, concentration of free fatty acids (FFAs), pH, and bacterial load of milk that meets this criterion are not fully understood. Objective: The objective was to determine whether refused frozen milk is different in composition from typical milk deposits received at a human milk bank. Methods: Frozen milk deposits previously refused by mother's own infant were collected from 16 mothers at five different time points when available (postpartum days 30, 60, 90, 120, and 150). Lipase activity, macronutrient composition, levels of FFA, pH, and bacteriology were determined. Analysis of mature donor milk and bacteriology data from the Ontario milk bank were used as controls. Results: The lipase activity for all samples was at or below literature values for mature human milk and lower compared with control milk (p < 0.001) for all time periods except at day 30. Macronutrient composition was not different from control values and did not change significantly over 150 days, with the exception of crude protein, which declined with milk maturity (p < 0.005). The pH for all postpartum time groups was lower (p < 0.02) in refused milk, and was inversely associated with lipase activity and FFA. FFA and bacterial counts were not different from control samples. Conclusions: Infant refusal of previously frozen milk may not be entirely due to endogenous lipase activity. This milk appears suitable for donation to human milk banks.

High Hydrostatic Pressure Processing Better Preserves the Nutrient and Bioactive Compound Composition of Human Donor Milk

BACKGROUND

When mother's milk is insufficient, pasteurized human donor milk (DM) is the recommended supplement for hospitalized very-low-birth-weight infants. The current method of pasteurization (Holder, 62.5°C, 30 min) negatively affects heat-sensitive nutrients and bioactive proteins.

OBJECTIVES

Objectives of this study were to compare changes in DM composition after thermal pasteurization (Holder and flash-heating) and nonthermal methods [UV-C irradiation and high hydrostatic pressure (HHP)]. We hypothesized that nonthermal techniques would result in fewer changes to composition.

METHODS

Holder, flash-heating (brought to boil), UV-C irradiation (250 nm, 25 min), and HHP (500 MPa, 8 min) were studied. Pools of milk from 17 women known to contain bacteria at >5 × 107 colony forming units (CFU)/L were collected from the Rogers Hixon Ontario Human Milk Bank and underwent each pasteurization technique. Macronutrients, heat-sensitive micronutrients (vitamin C, folate), and bioactive components [bile-salt-stimulated lipase (BSSL), lysozyme, lactoferrin] were measured in raw and pools of pasteurized milk. Milk was cultured to determine how well each technique produced a culture negative result (detection limit <1 × 103 CFU/L).

RESULTS

Folate was reduced by 24-27% after Holder, flash-heating, and UV-C (P < 0.05); no reduction was observed after HHP. All pasteurization methods reduced vitamin C (60-75%, P < 0.001). BSSL was abolished after Holder and flash-heating (P < 0.001), reduced after UV-C (48%, P < 0.001), but unaffected by HHP. Lysozyme activity was reduced after flash-heating (44%) and UV-C (74%, P < 0.004) but unaffected by Holder or HHP. Lactoferrin was reduced by all methods (P < 0.02) but most severely by flash-heating (74%) and least severely by HHP (25%). Holder and UV-C reduced lactoferrin by ∼48%. All pasteurization methods reduced the number of culture positive DM samples (P < 0.001).

CONCLUSIONS

HHP better preserves human milk composition than Holder pasteurization. Future research on the feasibility of HHP for pasteurizing human milk is warranted because its implementation may improve the nutritional status and health of DM-fed infants.

Serological evidence of widespread exposure of Grenada fruit bats to chikungunya virus

Antibody detection against selected potentially zoonotic vector-borne alphaviruses and flaviviruses was conducted on sera from bats from all six parishes in Grenada, West Indies. Sera were tested for (i) antibodies to flaviviruses West Nile virus, St. Louis encephalitis virus, Ilhéus virus, Bussuquara virus (BSQV), Rio Bravo virus and all four serotypes of dengue virus (DENV) by plaque reduction neutralization test (PRNT); (ii) antibodies to alphaviruses western equine encephalitis virus, Venezuelan equine encephalitis virus and eastern equine encephalitis virus by epitope-blocking enzyme-linked immunosorbent assay (ELISA); and (iii) antibodies to the alphavirus chikungunya (CHIKV) by PRNT. Two species of fruit bats were sampled, Artibeus jamaicensis and Artibeus lituratus, all roosting in or within 1,000 m of human settlements. Fifteen (36%) of the 42 bats tested for neutralizing antibodies to CHIKV were positive. The CHIKV-seropositive bats lived in localities spanning five of the six parishes. All 43 bats tested for epitope-blocking ELISA antibody to the other alphaviruses were negative, except one positive for Venezuelan equine encephalitis virus. All 50 bats tested for neutralizing antibody to flaviviruses were negative, except one that had a BSQV PRNT80 titre of 20. The CHIKV serology results indicate that bats living close to and within human settlements were exposed to CHIKV in multiple locations. Importantly, bats for this study were trapped a year after the introduction and peak of the human CHIKV epidemic in Grenada. Thus, our data indicate that bats were exposed to CHIKV possibly during a time of marked decline in human cases.

Impact of Neonatal Intensive Care Unit Admission on Bacterial Colonization of Donated Human Milk

BACKGROUND

Unpasteurized human donor milk typically contains a variety of bacteria. The impact of neonatal intensive care unit (NICU) admission of the donor's infant and duration of lactation on bacterial contamination of human milk is unknown. Research aim: This study aimed (a) to describe the frequency/concentration of skin commensal bacteria and pathogens in unpasteurized human donor milk and (b) to assess the impact of NICU admission and (c) the duration of milk expression on bacterial colonization of donated milk.

METHODS

The authors conducted a retrospective cohort study of human milk donated to the Rogers Hixon Ontario Human Milk Bank from January 2013 to June 2014. Milk samples from each donor were cultured every 2 weeks.

RESULTS

The study included 198 donor mothers, of whom 63 had infants admitted to the NICU. Of 1,289 cultures obtained, 1,031 (80%) had detectable bacterial growth and 363 (28%) yielded bacterial growth in excess of 10⁷ cfu/L, a local threshold for allowable bacteria prior to pasteurization. The mean (standard deviation) donation period per donor was 13.0 (7.5) weeks. Milk from mothers with NICU exposure had significantly higher concentrations of commensals, but not pathogens, at every time period compared with other mothers. For every 1-month increase in donation from all donors, the odds ratio of presence of any commensal in milk increased by 1.13 (95% confidence interval [1.03, 1.23]) and any pathogen by 1.31 (95% confidence interval [1.20, 1.43]).

CONCLUSION

Commensal bacteria were more abundant in donor milk expressed from mothers exposed to neonatal intensive care. Bacterial contamination increased over the milk donation period.

Kinetic studies of C1 and C2 Criegee intermediates with SO2 using laser flash photolysis coupled with photoionization mass spectrometry and time resolved UV absorption spectroscopy

Kinetics of CH₂OO + SO₂ confirmed over a wide range of [SO₂]. Acetaldehyde observed as a major product of the reaction of CH₃CHOO + SO₂.

Emergence of carp edema virus (CEV) and its significance to European common carp and koi Cyprinus carpio

Carp edema virus disease (CEVD), also known as koi sleepy disease, is caused by a poxvirus associated with outbreaks of clinical disease in koi and common carp Cyprinus carpio. Originally characterised in Japan in the 1970s, international trade in koi has led to the spread of CEV, although the first recognised outbreak of the disease outside of Japan was not reported until 1996 in the USA. In Europe, the disease was first recognised in 2009 and, as detection and diagnosis have improved, more EU member states have reported CEV associated with disease outbreaks. Although the structure of the CEV genome is not yet elucidated, molecular epidemiology studies have suggested distinct geographical populations of CEV infecting both koi and common carp. Detection and identification of cases of CEVD in common carp were unreliable using the original PCR primers. New primers for conventional and quantitative PCR (qPCR) have been designed that improve detection, and their sequences are provided in this paper. The qPCR primers have successfully detected CEV DNA in archive material from investigations of unexplained carp mortalities conducted >15 yr ago. Improvement in disease management and control is possible, and the principles of biosecurity, good health management and disease surveillance, applied to koi herpesvirus disease, can be equally applied to CEVD. However, further research studies are needed to fill the knowledge gaps in the disease pathogenesis and epidemiology that, currently, prevent an accurate assessment of the likely impact of CEVD on European koi and common carp aquaculture and on wild carp stocks.

Carp edema virus in Polish aquaculture - evidence of significant sequence divergence and a new lineage in common carp Cyprinus carpio (L.)

Fish samples initially collected by local veterinarians on the common and koi carp farms in Poland between 2013 and 2015 as part of a KHV surveillance programme, when the water temperature was between 16 and 26 °C, and were also tested for CEV by qPCR. A partial 478 nucleotide fragment of the 4a gene was subsequently generated from 17 qPCR-positive common carp Cyprinus carpio samples from 36 farm sites tested during the period. Sequence alignments and analysis revealed the presence of CEV in Poland both in common carp as well as in koi carp farms, and phylogenetic analysis assigned the Polish CEV sequences into three distinct genogroups. A lineage which includes the original sequences obtained from koi carp in Japan (genogroup II) included sequences from both koi carp and common carp, and the second lineage (genogroup I) contained sequences from common carp only. A third lineage (genogroup III) which was more closely related to the genogroup II also consisted of sequences from common carp only. The latter represents a lineage of CEV not previously described in the literature.

An experimental means of transmitting pancreas disease in Atlantic salmon Salmo salar L. fry in freshwater

A challenge model for pancreas disease in Atlantic salmon, Salmo salar L. fry, was developed comparing two salmonid alphavirus (SAV) subtypes: SAV1 and SAV5. Viral doses of 3 × 10(5) TCID50  mL(-1) for SAV1 and 3 × 10(4) for SAV5 were tested in triplicate tanks, each containing 450 salmon fry. Cumulative mortalities of 1.2% were recorded. Titres of virus recovered from the mortalities ranged from 10(2) to 10(7) TCID50  mL(-1) . Fry were sampled at 3, 5 and 7.5 weeks post-challenge. Sampling after 3 weeks revealed a high prevalence of infection in the absence of clinical signs, and infectious virus was recovered from 80% and 43% of sampled fry infected with SAV1 and SAV5, respectively. After 5 weeks pancreas, heart and red skeletal muscle lesions were generally observed, whilst degeneration in white skeletal muscle was observed only in fish infected with SAV1. In situ hybridisation confirmed the presence of viral genome in infected pancreas, heart and muscle. After 7.5 weeks, infectious virus (both isolates) was recovered from 13.3% of the fish sampled, with a viral titre of 10(2) TCID50  mL(-1) . Clearly, salmon fry are susceptible to SAV infection and pancreas disease.

Characterization of a normal control group: are they healthy?

We examined the health of a control group (18-81years) in our aging study, which is similar to control groups used in other neuroimaging studies. The current study was motivated by our previous results showing that one third of the elder control group had moderate to severe white matter hyperintensities and/or cortical volume loss which correlated with poor performance on memory tasks. Therefore, we predicted that cardiovascular risk factors (e.g., hypertension, high cholesterol) within the control group would account for significant variance on working memory task performance. Fifty-five participants completed 4 verbal and spatial working memory tasks, neuropsychological exams, diffusion tensor imaging (DTI), and blood tests to assess vascular risk. In addition to using a repeated measures ANOVA design, a cluster analysis was applied to the vascular risk measures as a data reduction step to characterize relationships between conjoint risk factors. The cluster groupings were used to predict working memory performance. The results show that higher levels of systolic blood pressure were associated with: 1) poor spatial working memory accuracy; and 2) lower fractional anisotropy (FA) values in multiple brain regions. In contrast, higher levels of total cholesterol corresponded with increased accuracy in verbal working memory. An association between lower FA values and higher cholesterol levels were identified in different brain regions from those associated with systolic blood pressure. The conjoint risk analysis revealed that Risk Cluster Group 3 (the group with the greatest number of risk factors) displayed: 1) the poorest performance on the spatial working memory tasks; 2) the longest reaction times across both spatial and verbal memory tasks; and 3) the lowest FA values across widespread brain regions. Our results confirm that a considerable range of vascular risk factors are present in a typical control group, even in younger individuals, which have robust effects on brain anatomy and function. These results present a new challenge to neuroimaging studies both for defining a cohort from which to characterize 'normative' brain circuitry and for establishing a control group to compare with other clinical populations.

Serologic detection of antibodies to Brucella spp. using a commercial ELISA in cattle in Grenada, West Indies

Bovine brucellosis, caused mainly by Brucella abortus, a zoonotic bacterium, has been reported from many areas of the world, including Central and South America, and the Caribbean island state of Trinidad and Tobago. Although brucellosis has been eradicated from domestic cattle in Canada it still exists in one or two herds in the United States. Serological tests are important in estimating prevalence of Brucella exposure in order to target eradication programmes. In this study, serum samples from 150 cattle were tested using a commercial competitive enzyme linked immunosorbent assay (SVANOVIR®Brucella-Ab C-ELISA) which detects antibodies to both B. abortus and Brucella melitensis. All cattle tested were greater than 6 months old and were unvaccinated. Sampled cattle were from 35 herds representing animals from all 6 parishes of Grenada. Nine of the 150 animals (6%) were positive for antibodies to B. abortus and/or melitensis by the C-ELISA. Of the 35 herds, 7 (20%) had C-ELISA- positive animals. Three of the 6 parishes contained positive herds. Based on the high sensitivity (98%) and specificity (99.7%) of the C-ELISA, these results strongly indicate the presence of cattle exposed to B. abortus and/or melitensis in Grenada.

Clinical predictors for the aetiology of peripheral lymphadenopathy in HIV-infected adults

OBJECTIVES

The aim of the study was to determine the aetiology and clinical predictors of peripheral lymphadenopathy in HIV-infected individuals during the antiretroviral (ARV) era in a nontuberculosis endemic setting.

METHODS

A multicentred, retrospective cohort study of peripheral lymph node biopsies in HIV-positive adults was carried out. A total of 107 charts were identified and reviewed for clinical features, lymphadenopathy size, and ARV use and duration. Biopsy results were categorized, and multivariate logistic regression determined independent predictors of lymphadenopathy aetiology.

RESULTS

Evaluation of 107 peripheral lymph node biopsies revealed that 42.9% of peripheral lymphadenopathy was attributable to malignancy, 49.5% to reactive changes, and 7.5% to infections, with only 2.8% of all cases secondary to tuberculosis. Fevers, weight loss, ARV use, and lower viral loads are significantly associated with nonreactive lymphadenopathy.

CONCLUSIONS

Lymphadenopathy is likely to be reactive or malignant in nontuberculosis endemic regions. Readily available clinical features can aid clinicians in predicting the underlying aetiology, those at risk for malignancy, and who to biopsy.

Managing osteoporosis in a rural community

Managing long-term conditions, such as osteoporosis in a rural community, presents particular challenges. This article describes how a specialist service identified patients at high risk of fragility fracture and raised awareness of bone health.

European freshwater VHSV genotype Ia isolates divide into two distinct subpopulations

Viral haemorrhagic septicaemia (VHS), caused by the novirhabdovirus VHSV, often leads to significant economic losses to European rainbow trout production. The virus isolates are divided into 4 distinct genotypes with additional subgroups including sublineage Ia, isolates of which are the main source of outbreaks in European rainbow trout farming. A significant portion of Danish rainbow trout farms have been considered endemically infected with VHSV since the first disease outbreak was observed in the 1950s. However, following a series of sanitary programs starting in 1965, VHSV has not been detected in Denmark since January 2009. Full-length G-genes of all Danish VHSV isolates that were submitted for diagnostic analyses in the period 2004-2009 were sequenced and analysed. All 58 Danish isolates from rainbow trout grouped with sublineage Ia isolates. Furthermore, VHSV isolates from infected Danish freshwater catchments appear to have evolved into a distinct clade within sublineage Ia, herein designated clade Ia-1, whereas trout isolates originating from other continental European countries cluster in another distinct clade, designated clade Ia-2. In addition, phylogenetic analyses indicate that VHSV Ia-1 strains have caused a few outbreaks in Germany and the UK. It is likely that viruses have been transmitted from infected site(s) out of the Danish environment, although a direct transmission pathway has not been identified. Furthermore, VHSV Ia-2 isolates seem to have been transmitted to Denmark at least once. Interestingly, one viral isolate possibly persisted in a Danish watershed for nearly 4 yr without detection whereas other subclades of VHSV isolates appear to have been eliminated, probably because of implemented eradication procedures.

The atmospheric chemistry of trace gases and particulate matter emitted by different land uses in Borneo

We report measurements of atmospheric composition over a tropical rainforest and over a nearby oil palm plantation in Sabah, Borneo. The primary vegetation in each of the two landscapes emits very different amounts and kinds of volatile organic compounds (VOCs), resulting in distinctive VOC fingerprints in the atmospheric boundary layer for both landscapes. VOCs over the Borneo rainforest are dominated by isoprene and its oxidation products, with a significant additional contribution from monoterpenes. Rather than consuming the main atmospheric oxidant, OH, these high concentrations of VOCs appear to maintain OH, as has been observed previously over Amazonia. The boundary-layer characteristics and mixing ratios of VOCs observed over the Borneo rainforest are different to those measured previously over Amazonia. Compared with the Bornean rainforest, air over the oil palm plantation contains much more isoprene, monoterpenes are relatively less important, and the flower scent, estragole, is prominent. Concentrations of nitrogen oxides are greater above the agro-industrial oil palm landscape than over the rainforest, and this leads to changes in some secondary pollutant mixing ratios (but not, currently, differences in ozone). Secondary organic aerosol over both landscapes shows a significant contribution from isoprene. Primary biological aerosol dominates the super-micrometre aerosol over the rainforest and is likely to be sensitive to land-use change, since the fungal source of the bioaerosol is closely linked to above-ground biodiversity.

Neoplastic and nonneoplastic cutaneous tumors of dogs in grenada, west indies

This retrospective survey was undertaken between 2002 and 2007 on samples from dogs residing in Grenada. The objectives of the study were to identify the most common histologic types of canine cutaneous tumors, determine the relative frequency of each tumor type, and compare results to reports from other regions. In a series of 225 skin masses examined, the proportion of neoplasms was 72% whereas nonneoplastic tumors accounted for 15.6%, and inflammatory conditions constituted 12.4%. There were 10 types of nonneoplastic tumors with hamartomas being the most common (28.5%), followed by sebaceous hyperplasia (25.7%) and fibroepithelial polyps (22.8%). The 10 most common cutaneous neoplasms were hemangiosarcomas (19.1%), histiocytomas (8.6%), melanocytomas (8%), mast cell tumors (6.8%), lipomas (6.8%), hemangiopericytomas (6.2%), papillomas (5.6%), fibrosarcomas (5.6%), hemangiomas (4.9%), and squamous cell carcinomas (4.3%). Tumors of vascular origin and transmissible venereal tumors were more common in dogs in our study than reported from other regions.

Effects of pasteurization on adiponectin and insulin concentrations in donor human milk

Although pasteurization is recommended before distributing donor human milk in North America, limited data are available on its impact on metabolic hormones in milk. We aimed to investigate the effects of pasteurization on adiponectin and insulin concentrations in donor human milk. The study investigates concentrations of components in donor human milk before and after Holder pasteurization. After the guidelines of the Human Milk Bank Association of North America, human milk samples were pooled to produce 17 distinct batches (4 individuals per batch) and pasteurized at 62.5°C for 30 min. Adiponectin, insulin, energy, fat, total protein, and glucose concentrations were measured pre- and postpasteurization. Pasteurization reduced milk adiponectin and insulin by 32.8 and 46.1%, respectively (both p < 0.0001). Adiponectin and insulin were significantly correlated with energy and fat milk composition (r = 0.36-0.47; all p < 0.05). Pasteurization effects on milk hormone concentrations remained significant after adjusting for fat and energy (beta ± SEE: -4.11 ± 1.27, p = 0.003 for adiponectin; -70.0 ± 15.0, p < 0.0001 for insulin). Holder pasteurization reduced adiponectin and insulin concentrations in donor human milk. In view of emerging knowledge on the importance of milk components, continued work to find the optimal pasteurization process that mitigates risks but promotes retention of bioactive components is needed.

Microstructure and chemical analysis of blood-contaminated mineral trioxide aggregate

AIM

To test the hypothesis that blood contamination has a detrimental effect on the chemical properties of Mineral trioxide aggregate (MTA).

METHODOLOGY

The effects of whole, fresh human blood on the microstructure and elemental chemistry of MTA were evaluated using scanning electron microscopy and energy-dispersive X-ray analysis, respectively. The phase compositions of contaminated and uncontaminated MTA were also analysed using X-ray diffraction analysis.

RESULTS

The hydration state of specimens partially mixed with blood were more complete than those mixed entirely with blood and less than those entirely mixed with water. Acicular crystals, characteristic of ettringite, were abundant in specimens mixed entirely with water and absent from specimens mixed partially or entirely with blood. Calcium hydroxide crystals were absent in specimens contaminated entirely with blood and the unhydrated MTA powder, but present in the other groups.

CONCLUSION

Mixing MTA with blood resulted in the lack of formation of the crystalline calcium hydroxide in the early stage of the hydration process.

Sphaerothecum destruens pathology in cyprinids

Sphaerothecum destruens is a significant intracellular parasite of fish which has caused disease and mortalities in cultured north American Chinook salmon Oncorhynchus tshawytscha and Atlantic salmon Salmo salar. Several hosts for S. destruens have been identified within the Salmonidae family, and the histopathology of the infection can differ between hosts. Recently, S. destruens has been associated with the most invasive cyprinid species in Europe, topmouth gudgeon Pseudorasbora parva. Accurate disease identification based on thorough descriptions of clinical signs and histopathology in this new range of hosts is thus paramount to support further epizootiological studies. In this study, the associated histopathology of S. destruens infection is described along with its pathogenesis in the endangered cyprinid sunbleak Leucaspius delineatus. Histological examination of 100 L. delineatus in a wild population in the south of England revealed the presence of S. destruens infections, with a prevalence of 5% with S. destruens, suggesting an over-dispersed distribution within the L. delineatus sample. Clinical signs of the infection were absent, but histological examination revealed the presence of both disseminated and nodular lesions in several organs.

Indentation Load Relaxation Studies of Thin Film-Substrate Systems

Results from indentation load relaxation (ILR) tests on thin film-substrate systems are reported. In the case of a 1 pum aluminum film on silicon, the data can be interpreted as reflecting both the properties of the film and the interface between film and substrate. Data from a 37μm TiN film on 304 SS are believed to reflect the combined behavior of the film and substrate.

Viral load of various tissues of rainbow trout challenged with viral haemorrhagic septicaemia virus at various stages of disease

Market-sized rainbow trout Oncorhynchus mykiss were challenged by waterborne exposure to viral haemorrhagic septicaemia virus (VHSV isolate of genogroup Ia). Fish were sampled at 4 stages of infection (before onset of clinical signs, clinically affected fish, mortalities and survivors) and the viral load determined in (1) internal organs, (2) muscle tissue and (3) brain and gill tissue. Virus levels were determined by virus titration and real-time RT-PCR. VHSV was detected by either method in the majority of fish before onset of clinical signs and in the survivor group as well as in all fish in the clinically affected fish and mortality groups. Mean virus amounts per mg of tissue determined by virus titration (TCID50) or real-time RT-PCR (copy number) were > 10(4) in preclinical fish, > 10(3.8) in clinically affected fish, > 10(3.9) in mortalities and > 10(1.2) in survivors. Virus levels tended to be highest in the internal organs of subclinical and clinically affected fish and in brain and gill tissue of survivors. The results demonstrate that significant levels of VHSV can be found in tissues of rainbow trout that may be marketed for human consumption, which may have relevance for the biosecurity of VHS-free areas.

Risks associated with commodity trade: transmission of viral haemorrhagic septicaemia virus (VHSV) to rainbow trout fry from VHSV-carrying tissue-homogenates

Movements of commodity fish present a potential risk of transferring pathogens. Within a study to estimate the risk from imported rainbow trout Oncorhynchus mykiss carcases, fry were exposed to tissue homogenates from market size rainbow trout infected experimentally with viral haemorrhagic septicaemia (VHS) by waterborne exposure to VHS virus (VHSV, isolate of genotype Ia). Tissues were collected from fish that showed clinical signs and from recent mortalities. Homogenates of (i) internal organs, (ii) brain/gills and (iii) muscle tissue were prepared and added to tanks holding the fry. Virus transmission occurred from all tissues tested, causing high mortality of the fry. The results underline the potential risk of introduction of VHSV through the trade of fish products.