Substrate stiffness promotes vascular smooth muscle cell calcification by reducing the levels of nuclear actin monomers

BACKGROUND

Vascular calcification (VC) is a prevalent independent risk factor for adverse cardiovascular events and is associated with diabetes, hypertension, chronic kidney disease, and atherosclerosis. However, the mechanisms regulating the osteogenic differentiation of vascular smooth muscle cells (VSMC) are not fully understood.

METHODS

Using hydrogels of tuneable stiffness and lysyl oxidase-mediated stiffening of human saphenous vein ex vivo, we investigated the role of substrate stiffness in the regulation of VSMC calcification.

RESULTS

We demonstrate that increased substrate stiffness enhances VSMC osteogenic differentiation and VSMC calcification. We show that the effects of substrate stiffness are mediated via a reduction in the level of actin monomer within the nucleus. We show that in cells interacting with soft substrate, elevated levels of nuclear actin monomer repress osteogenic differentiation and calcification by repressing YAP-mediated activation of both TEA Domain transcription factor (TEAD) and RUNX Family Transcription factor 2 (RUNX2).

CONCLUSION

This work highlights for the first time the role of nuclear actin in mediating substrate stiffness-dependent VSMC calcification and the dual role of YAP-TEAD and YAP-RUNX2 transcriptional complexes.

Reporting of paediatric osteoporotic vertebral fractures in Duchenne muscular dystrophy and potential impact on clinical management: the need for standardised and structured reporting

BACKGROUND

In boys with Duchenne muscular dystrophy (DMD), initiation of bisphosphonate is recommended upon identification of moderate or severe vertebral fractures, even if asymptomatic. Clear radiological reporting is important for consistency of clinical interpretation and management.

OBJECTIVES

To audit radiology reports of spine imaging for vertebral fracture assessment in DMD, and assess potential impact on diagnosis and management.

MATERIALS AND METHODS

Lateral thoracolumbar spine imaging (71 lateral spine radiographs and 13 lateral dual energy absorptiometry spine image) in 84 boys with DMD performed across two centres. Anonymised radiology reports by paediatric radiologists were circulated to two neuromuscular clinicians and two endocrinologists. Clinicians determined if there was vertebral fracture, no vertebral fracture, or unclear interpretation. Endocrinologists also determined if bisphosphonate was indicated. A single observer (a clinician with expertise in vertebral fracture assessment) performed vertebral fracture assessment in 37 images and re-reported using a structured format. Structured reports were re-circulated to the four clinicians to re-evaluate the degree of concordance in clinical diagnosis of vertebral fracture and treatment decisions with bisphosphonate.

RESULTS

The term "fracture" was used in 25/84 (30%) radiology reports and only in 8/43 (19%) with description of vertebral body abnormalities. Fracture grading was included in 7/43 (16%) radiology reports. Diagnostic concordance by the clinicians was noted in 36/84 (43%). Unclear interpretation was noted in 22% to 51% based on radiology reports. No unclear interpretation was noted with structured reports. Complete diagnostic (37/37, 100%) and treatment (37/37, 100%) concordance was noted with the structured reports, whereas complete diagnostic and treatment concordance was noted in only 16/37 (43%) and 17/37 (46%) of the radiology reports, respectively.

CONCLUSION

Only a third of radiology reports of spine imaging in DMD explicitly used the terminology "fracture". Grading was only noted in a small percentage. Variability in diagnostic interpretation by clinicians may lead to differing management plans. As identification of vertebral fracture is a trigger for treatment, developing reporting guidelines for paediatric vertebral fracture assessment will improve care. A structured template should be introduced for radiological reporting of paediatric vertebral fracture assessment.

Treatment Terminations during Radiation Therapy: A Ten-Year Experience

PURPOSE/OBJECTIVE(S)

Disruptionsin cancer care adversely affect clinical outcomes, particularly when a patient does not complete the prescribed course of treatment. The impact of treatment termination (TT) during radiation therapy has not been well studied. This study addresses TT in a large multi-center department of radiation oncology over a 10-year time period.

MATERIALS/METHODS

TTs of patients undergoing radiation treatment between January 2013 and December 2022 were prospectively tracked as part of departmentalquality and safety monitoring. A TT was defined as the discontinuation of therapy at any point following consent and simulation. Causes of TTs were categorized as: hospice/death, physician choice related to toxicity, physician choice unrelated to toxicity, patient choice related to toxicity, patient choice unrelated to toxicity, progression of disease, non-cancer illness, or other. The rate of TT was calculated as a percentage of all new patients who start radiation treatments. As part of our ongoing department quality and safety program, incremental changes were made to pre-treatment evaluation and scheduling processes, collectively referred to as the "No-Fly" policy. TT rates during three iterations of this policy were compared.

RESULTS

Outof 28,707 planned treatment courses, a total of 1,467 TTs were identified (5.1%). 688 (46.9%) involved patients treated with curative intent, 770 (52.5%) with palliative intent, and 9 (0.6%) for benign disease. The rate of TT decreased from 9.3% in 2013 to 3.3% in 2022. Relative to evolutions of our No-Fly policy, the overall TT rate decreased from 8.8% under No-Fly 1 (2013-2014), to 5.2% during No-Fly 2 (2015-2018), and 4.0% with No-Fly 3 (2019-2022) (ANOVA, p<0.001). The most common sites for TT were H&N (19.3%), CNS (17.9%), and Bone Metastases (17.9%). The most common cause of TT was hospice and/or death (36.5%), 69.1% of which were in patients receiving palliative treatments. Other common causes included patient choice unrelated to toxicity (35%), physician choice unrelated to toxicity (8.8%), and progression of disease (7.6%). There were 473 TTs without radiation dose given (1.6% of planned treatments, 32.3% of TTs).

CONCLUSION

Radiation TTs reflect major deviations from the original care plan. This large cohort study highlights the value of open departmental discourse about TTs, which prompted quality improvement changes that reduced TTs over time. Future studies addressing clinical outcomes can direct treatment decision-making and improve care for our patients.

Expanding Radiotherapy Access in Sub-Saharan Africa: An Analysis of Travel Burdens and Patient-Related Benefits of Hypofractionation

PURPOSE/OBJECTIVE(S)

The purpose of this project was to examine the travel burdens for radiotherapy patients in Nigeria, Tanzania, and South Africa, and to assess the patient-related benefits of hypofractionated radiotherapy (HFRT) for breast and prostate cancer patients in these countries. The outcomes can inform the implementation of the recent Lancet Oncology Commission recommendations on increasing the adoption of HFRT in Sub-Saharan Africa (SSA) to enhance radiotherapy access in the region.

MATERIALS/METHODS

Data were extracted from electronic patient records at the NSIA-LUTH Cancer Center (NLCC) in Lagos, Nigeria and the Inkosi Albert Luthuli Central Hospital (IALCH) in Durban, South Africa, from written records at the University of Nigeria Teaching Hospital (UNTH) Oncology Center in Enugu, Nigeria, and from phone interviews at Ocean Road Cancer Institute (ORCI) in Dar Es Salaam, Tanzania. Google Maps was used to calculate the shortest driving distance between a patient's home address and their respective radiotherapy center. QGIS was used to map the straight-line distances to each center. Descriptive statistics were used to compare transportation costs, time expenditures, and lost wages when using HFRT versus conventionally fractionated radiotherapy (CFRT) for breast and prostate cancer. All transportation- and wage-related cost data were contextualized within each country's monthly adjusted net national income (MANNI) per capita, as reported by 2020 data from the World Bank.

RESULTS

Patients in Nigeria (n = 390) traveled a median distance of 24.0 km (interquartile range (IQR) = 238.5 km) to NLCC and 86.7 km (IQR = 87.3 km) to UNTH, patients in Tanzania (n = 23) traveled a median distance of 537.0 km (IQR = 587.5 km) to ORCI, and patients in South Africa (n = 412) traveled a median distance of 18.0 km (IQR = 15.0 km) to IALCH. Estimated transportation cost savings for breast cancer patients in Lagos and Enugu were 12,895 Naira and 7,369 Naira (20% and 11% of MANNI per capita), respectively, and for prostate cancer patients were 25,329 and 14,276 Naira (38% and 22% of MANNI per capita), respectively. Prostate cancer patients in Tanzania saved a median of 137,765 Shillings (78% of MANNI per capita) in transportation costs. Significant time expenditures - a relevant consideration for patient convenience - were also saved for ORCI patients, including a median of 80.0 hours (includes travel, treatment, and wait times). Mean transportation cost savings for patients in South Africa were 4,777 Rand (72% of MANNI per capita) for breast cancer and 9,486 Rand (143% of MANNI per capita) for prostate cancer.

CONCLUSION

Cancer patients in SSA travel considerable distances to access radiotherapy services. HFRT decreases patient-related costs and time expenditures, which may increase radiotherapy access and alleviate the growing burden of cancer in the region.

The Murine Oral Metatranscriptome Reveals Microbial and Host Signatures of Periodontal Disease

Periodontal disease is accompanied by alterations to cellular profiles and biological activities of both the subgingival microbiome and host tissues. Although significant progress has been made in describing the molecular basis of the homeostatic balance of host-commensal microbe interactions in health compared to the destructive imbalance in disease, particularly with respect to immune and inflammatory systems, few studies have attempted a comprehensive analysis in diverse host models. Here, we describe the development and application of a metatranscriptomic approach to analysis of host-microbe gene transcription in a murine periodontal disease model, based on oral gavage infection using Porphyromonas gingivalis in C57BL6/J mice. We generated 24 metatranscriptomic libraries from individual mouse oral swabs, representing health and disease. On average, 76% ± 11.7% reads in each sample belonged to the murine host genome and the remainder to the microbes. We found 3,468 (2.4% of the total) murine host transcripts differentially expressed between health and disease, of which 76% were overexpressed in periodontitis. Predictably, there were prominent alterations to genes and pathways linked with the host immune compartment in disease-the CD40 signaling pathway being the top enriched biological process in this data set. However, in addition, we observed significant alterations to other biological processes in disease, particularly cellular/metabolic processes and biological regulation. The number of differentially expressed microbial genes particularly indicated shifts in carbon metabolism pathways in disease with potential consequences for metabolic end-product formation. Together, these metatranscriptome data reveal marked changes between the gene expression patterns in both the murine host and microbiota, which may represent signatures of health and disease, providing the basis for future functional studies of prokaryotic and eukaryotic cellular responses in periodontal disease. In addition, the noninvasive protocol developed in this study will enable further longitudinal and interventionist studies of host-microbe gene expression networks.

LB0003 WITHDRAWING METHOTREXATE AFTER BOTH VERSUS ONLY SECOND DOSE OF THE ChAdOx1 nCoV-19 VACCINE IN PATIENTS WITH AUTOIMMUNE INFLAMMATORY ARTHRITIS: TWO INDEPENDENT RANDOMIZED CONTROLLED TRIALS (MIVAC I AND II)

Background

Pausing methotrexate (MTX) for two to four weeks, improved immunogenicity of influenza vaccination in patients with rheumatoid arthritis (RA), albeit a risk of disease flare (1). This guided the framing of guidelines on MTX withdrawal for COVID-19 vaccination (2). However, evidence for MTX withdrawal for COVID-19 vaccination is limited to observational studies only.

Objectives

To compare the efficacy and safety of holding MTX after each (MIVAC 1) and only after the second dose (MIVAC II) of the ChAdOx1 vaccine versus continuation of MTX in two randomized controlled trials (RCTs).

Methods

Two single centre, investigator-blinded, RCTs were conducted in patients with RA or Psoriatic arthritis (PsA) on stable doses of MTX without prior COVID-19 (CTRI reg. no. MIVAC I: CTRI/2021/07/03463 & MIVAC II: CTRI/2021/07/035307). In MIVAC I, unvaccinated patients were randomised (1:1) to hold or continue MTX for two weeks after each dose of the vaccine. MIVAC II included patients who had continued MTX during the first dose of ChAdOx1 and were randomised (1:1) to hold or continue MTX for 2 weeks after the second vaccine dose. The primary outcome for both the trials was the anti-Receptor Binding Domain (RBD) antibody titres measured four weeks after the second vaccine dose (per protocol analysis). Secondary outcome was the flare rate, defined as an increase in disease activity scores (DAS28/cDAPSA) or physician intent to hike DMARDs.

Results

250 patients were randomized for MIVAC 1 and 178 for MIVAC II and after due exclusions, 158 and 157 were eligible for analysis respectively (Figure 1). In MIVAC I, median anti-RBD titres were significantly high in the MTX hold group [2484 (1050-4388) versus 1147(433-2360), p=0.001] but the flare rate was higher in the hold group [20 (25%) versus 6(8%) p=0.005] compared to continue group. In MIVAC II median anti-RBD titres were significantly high for the MTX hold group [2553 (1792-4823) versus 990 (356-2252), p=0.001] when compared to continue group but there was no difference in the flare rate between the groups [9(11.8%) and 4(7.9%), p=0.15] (Table 1). Since both were parallel studies in similar population, MTX hold arms across both the trials were compared for anti-RBD titres and flare. There was no difference in the anti-RBD titres [p=0.2] between the groups. In MIVAC I, 29(36.25%) patients had reported flare (19 in either first or second dose, 10 for both doses) when compared to MIVAC II where only 9(11.84%) patients had reported flare after the second dose (P <0.001).

Table 1.

Baseline demographics and key results

VariableMIVAC IMIVAC IIMTX HoldMTX ContinuePMTX HoldMTX ContinueP valueN=80N=78valueN=76N=81Age†48 (38-53.3)49 (39-59)0.1953 (42.3-59)53(50-62)0.14Female (%) ‡73 (91.3)75 (96.2)0.3365 (85.5)70 (86.4)>0.99RA (%) ‡69(86.3)69 (93.2)70 (85.6)80 (87.7)PsA (%) ‡11(13.8)6 (8.1)0.316 (7.9)1 (1.2)0.057DAS28†2.7 (2.4-3.2)2.6 (2-3.3)0.62.7(2.3-3.4)2.8 (2.1-3.5)0.78cDAPSA †2(3-4.5)2.5(1.3-3.8)0.463(2.8-3)30.15Prednisolone (%) ‡29 (36.3)23(31.1)0.424(31.6)26 (32.1)>0.99MTX mg/week†17.5 (10-25)15 (10-20)0.05715 (9.4-25)17.5(7.5-25)0.92Anti- RBD antibody titres post second dose (IU/mL) †2484 (1050-4388.8)1147.5 (433.5-2360.3)<0.0012553.5 (1792.5-4823.8)990.5 (356.1-2252.5)<0.001Flare (N%) ‡Post first dose20 (25)6 (8)0.005NANAPost second dose19 (23.8)10(13.3)0.19 (11.8)4 (7.9)0.15

All analysis as per protocol population.

†Median (interquartile range): Mann Whitney U test.

‡ N (%): Fisher Exact test

. Bolded if p<0.05.

Conclusion

Holding MTX after both the doses or only after the second dose of ChAdOx1 yields higher anti-RBD antibody titres as compared to continuing MTX. Comparing across the trials, holding MTX only after the second dose appears to be non-inferior to holding MTX after both doses of the vaccine with a lesser risk of flare.

References

[1]Park JK et al. Clin Rheumatol. 2020 Feb; 39(2):375-379.

[2]Curtis JR, et al. Arthritis & Rheumatology. 2021 Oct;73(10): e60-75.

Acknowledgements

Acknowledgments to all participating investigators, patients and their families

Disclosure of Interests

Anu Sreekanth: None declared, Teny Skaria: None declared, Sneha Joseph: None declared, Rashwith Umesh: None declared, Manju Mohanan: None declared, Aby Paul: None declared, Sakir Ahmed Speakers bureau: Sakir Ahmed had received honorarium as speaker from Pfizer, Dr Reddy’s, Cipla, and Novartis unrelated to this Comment, Pankti Mehta: None declared, Seena Oomen: None declared, Janet Benny: None declared, Justin George: None declared, Anagha Paulose: None declared, K Narayanan: None declared, Sanjana Joseph: None declared, Anuroopa Vijayan: None declared, Kaveri Nalianda: None declared, Padmanabha Shenoy: None declared

Impact of the COVID-19 Pandemic on Radiation Treatment Termination Patterns at a Large Multi-Center Institution

Purpose/Objective(s)

Premature discontinuation of radiation therapy (RT) is a significant challenge portending inferior outcomes, particularly with curative intent RT. This study measures the impact of the COVID-19 pandemic compared to prior treatment terminations (TTs) from a multi-institutional health system in the New York Metropolitan area.

Materials/Methods

TT data was collected from the internal quality assurance records of a multicenter radiation oncology department for the September 2019-February 2020 pre-pandemic interval (BP) and the March 2020-August 2020 post-pandemic interval (AP). We measured aggregate and monthly CT simulations (CT sims), TTs, and terminations with zero fractions of radiation given (0Fx), the latter stratified by palliative vs. curative intent (0Fx-P vs. 0Fx-C). AP TTs attributed to COVID-19 anxiety were also obtained. The data were analyzed as aggregate ratios with monthly weighting of TTs/CT sims, 0Fx/CT sims, and 0Fx/TTs. Ratio statistics were employed and 95% confidence intervals generated. 0Fx-P and 0Fx-C were tested for association with BP and AP by chi-square analysis.

Results

For BP and AP respectively: TTs/CT sims were 8.1% (95% CI 5.2%-11.0%) and 11.2% (95% CI 9.2%-13.3%); 0Fx/CT sims were 1.4% (95% CI 0.16%-2.70%) and 2.5% (95% CI 1.49%-3.6%); 0Fx/TTs were 15.8% (95% CI 6.35%-25.21%) and 22% (95% CI 16.0%-27.9%). The association of 0Fx-P and 0Fx-C with BP and AP yielded chi-square = 0.43, P = 0.51. TTs attributed to COVID-19 anxiety comprised 3.9% of TTs in AP.

Conclusion

The endpoints for TTs in the BP and AP periods in our study cohort were suggestive of a COVID impact on patients discontinuing radiation therapy, but without statistical significance. Given the subtleties of TT dynamics and uncertainties such as the count of COVID-19 anxiety-related terminations, along with a relatively small sample size, it is reasonable to infer that this review was underpowered. Moreover, direct statistical attribution of TTs to COVID understates knock-on effects, e.g., the case of a 0Fx TT that would have occurred regardless of COVID but under the stress of the pandemic exacerbates the harm of the waste of resources. At the patient care level, understanding how COVID affects TT patterns may enable interventions that facilitate completion of care as intended by the treating physician. At the health system level, such understanding may elucidate a plausible mechanism of COVID's cascading downstream influence on oncologic outcomes. Nevertheless, it will require a multi-institutional cohort to quantitatively discern the impact of the pandemic on TT dynamics.

Role of MR cisternography in the diagnosis of cerebrospinal fluid rhinorrhoea with diagnostic nasal endoscopy and surgical correlation

Objectives : To study the usefulness and accuracy of MR cisternography as noninvasive study in the diagnosis of cerebrospinal fluid (CSF) fistula with diagnostic sinonasal endoscopy and surgical correlation. Material and Methods: Twenty four patients with clinically suspected CSF rhinorrhoea were examined for CSF fistula with MR cisternography. The MR imaging technique included 3mm thin T2 weighted coronal and sagittal sections using Fast spin echo. In addition 1.5mm thin T2 weighted coronal sections were also obtained using CISS (Constructive Interference in Steady State) sequence. MR findings were correlated with diagnostic sinonasal endoscopy and surgical findings. Results : MR cisternography demonstrated the presence of fistula in 17 patients, absence of fistula in seven patients. Out of 17 patients with fistula, the diagnosis could be confirmed in 14 patients by diagnostic sinonasal endoscopy/surgery. Out of the seven patients without fistula, there was positive correlation in six patients when they were followed up clinically and by diagnostic nasal endoscopy. However in one patient, fistula was demonstrated on CT cisternography and was confirmed on sinonasal endoscopic surgery. The accuracy, sensitivity of MR cisternography was 96, 94% respectively. Conclusion : MR cisternography is a useful and accurate noninvasive study in localizing the site and extent of CSF fistula.

KNOWLEDGE, RISK PERCEPTION AND PREVENTIVE PRACTICES OF COVID-19 AMONG STAFF OF PRIMARY AND SECONDARY SCHOOLS IN KADUNA STATE, NIGERIA

INTRODUCTION

Kaduna State is among the three States with the highest number of confirmed COVID-19 cases. The objective of this study was to assess the knowledge, risk perception and practices of staff towards prevention and control of COVID-19 infection in schools to provide policy makers, education and health managers required information to manage the epidemic as the schools prepare to re-open.

METHODS

This was a school-based survey conducted using purposive sampling of 55 schools located in nine LGAs with the highest number of reported COVID-19 cases as at October 2020. Five schools with the highest students'/pupils' enrollment in each of the LGA were selected and all staff were interviewed. Information on knowledge, risk perception and practices of prevention was collected. Descriptive statistics were generated using Stata v14 software.

RESULTS

A total of 1065 staff in 55 schools completed the interview. Major sources of information are television (73%), radio (61%), and social media (57%); and 76% indicated that a virus is the causative agent of COVID-19. Overall, 70%, 19%, 7%, 9.3% and 0% respectively had adequate knowledge of cause, preventive measures, respiratory hygiene, modes of transmission and symptoms of COVID-19; however only 14% ever attended a workshop on COVID-19. Eighty-two percent and 89% respectively believed in the efficacy of face masks and handwashing as means of prevention; 39% thought that they are likely to contract COVID-19. Ninety-nine percent and 90% have ever used face mask and hand sanitizer to prevent COVID-19; 96% and 85% respectively have use these methods in previous 24hours. Between 42% and 73% of schools needed additional commodities/requirements/supplies to comply fully with COVID-19 prevention protocols.

CONCLUSION

While knowledge of COVID-19 is suboptimal, perception is positive and practice is high. Thus, teachers need to be well informed and encouraged to sustain current levels of preventive measures. Government needs to provide schools with adequate preventive commodities to ensure compliance.

Left Ventricular Assist Device Implantation in a COVID-19 Positive Patient

Introduction

Case Report

Summary

Safety and efficacy of hysteroscopic resection of uterine leiomyoma embedded at the base of a uterine septum

BACKGROUND

To determine the safety and efficacy of hysteroscopic resection of uterine leiomyoma embedded at the base of a uterine septum.

METHODS

This case series included 11 patients with infertility or recurrent pregnancy loss who were found to have a uterine septum (one septate and 10 sub-septate) and a uterine leiomyoma embedded at the base of the uterine septum. All patients underwent a hysteroscopic division of the uterine septum and hysteroscopic resection of the uterine leiomyoma. Safety was determined by any intra-operative complications, and any immediate or late postoperative complications. Efficacy was determined based on the findings on a postoperative trans-vaginal 3D ultrasound (TV 3D US) with a saline infusion sonohysterogram (SIH) and reproductive outcomes.

RESULTS

There were no reported intra-operative complications, or immediate or late postoperative complications. Eleven patients underwent TV 3D US with SIH; findings were normal in 8 (72.7%); 3 patients underwent a second operative hysteroscopy and subsequent TV 3D US with SIH were also normal. The analysis of reproductive outcomes was limited to patients who were < 40 years (9 patients). Seven patients conceived (77.8%), six delivered (66.7%) and one miscarried (14.3%).

CONCLUSIONS

Hysteroscopic myomectomy of a leiomyoma, which is embedded at the base of a uterine septum, can be safely performed at the same session of hysteroscopic division of the uterine anomaly. Improvement in reproductive outcomes is to be expected after such procedures.

γδ T cells compose a developmentally regulated intrauterine population and protect against vaginal candidiasis

This most comprehensive analysis to date of γδ T cells in the murine uterus reveals them to compose a unique local T-cell compartment. Consistent with earlier reports, most cells expressed a canonical Vγ6Vδ1 TCR, and produced interleukin (IL)-17A upon stimulation. Nonetheless, contrasting with earlier reports, uterine γδ T cells were not obviously intraepithelial, being more akin to sub-epithelial Vγ6Vδ1+ T cells at several other anatomical sites. By contrast to other tissues however, the uterine compartment also included non-Vγ6+, IFN-γ-producing cells; was strikingly enriched in young mice; expressed genes hitherto associated with the uterus, including the progesterone receptor; and did not require microbes for development and/or maintenance. This notwithstanding, γδ T-cell deficiency severely impaired resistance to reproductive tract infection by Candida albicans, associated with decreased responses of IL-17-dependent neutrophils. These findings emphasise tissue-specific complexities of different mucosal γδ cell compartments, and their evident importance in lymphoid stress-surveillance against barrier infection.

Feasibility of Dual Energy X-Ray Absorptiometry Based Images for Measurement of Height, Sitting Height, and Leg Length in Children

BACKGROUND

Interpretation of pediatric bone mineral density by dual energy absorptiometry (DXA) requires adjustment for height (Ht). This is often not easily obtainable in nonambulant subjects.

AIMS

To investigate the feasibility of using DXA images to evaluate measurements of Ht, sitting height (SH), and leg length (LL).

METHODOLOGY

A total of 2 observers performed measurements of Ht, SH, and LL on 3 separate occasion using DXA digital images in 125 children. Intraclass correlation and relative technical error of measurement (rTEM) were performed to assess reliability of repeated measurements. In 25 children, Ht and SH were measured in clinic on the same day and Bland-Altman analysis was performed to compare DXA measured Ht, SH, LL with clinic measurements for these 25 children.

RESULTS

Intraclass correlation for DXA based Ht, SH, and LL measurements ranged from 0.996 to 0.998 (p < 0.0001). rTEM of Ht, SH, and LL for observer 1 was 0.0016%, 0.002%, and 0.0034%, respectively. rTEM of Ht, SH, and LL between observer 1 and 2 was 0.0047%, 0.0049%, and 0.0087%, respectively. Mean difference between clinic and DXA measurements from Bland-Altman plots were +0.57 cm (95% confidence interval [CI] -0.54 to +1.68) for Ht, +1.33cm (-1.60 to +4.24) for SH, and -0.76cm (-3.88 to +2.37) for LL.

CONCLUSIONS

Our study demonstrated for the first time that Ht, SH, and LL in children can be measured very precisely using DXA images. Ht can be measured accurately. We believe this may be a convenient method to obtain Ht measurements to allow size adjustment of DXA bone mineral density in immobile children with chronic conditions.

Development of a microsphere-based immunoassay for the serological detection of glanders in equids

Burkholderia mallei is the etiologic agent of glanders, an infectious disease of solipeds, with renewed scientific interest due to its increasing incidence in different parts of the world. More rapid, sensitive and specific assays are required by laboratories for confirmatory testing of this disease. A microsphere-based immunoassay consisting of beads coated with B. mallei recombinant proteins (BimA, GroEL, Hcp1, and TssB) has been developed for the serological diagnosis of glanders. The proteins' performance was compared with the OIE reference complement fixation test (CFT) and an indirect enzyme-linked immunosorbent assay (iELISA) on a large panel of sera comprised of uninfected horses (n=198) and clinically confirmed cases of glanders from India and Pakistan (n=99). Using Receiver Operating Characteristics (ROC) analysis and adjusting the cutoff levels, Hcp1 (Se=100%, Sp=99.5%) and GroEL (Se= 97%, Sp=99.5%) antigens exhibited the best specificity and sensitivity. Neither Hcp1 and GroEL proteins, nor iELISA reacted with doubtful and positive CFT samples from glanders free countries which further confirmed the false positive reactions seen in CFT.

Horizontal and Vertical Transfer of Oral Microbial Dysbiosis and Periodontal Disease

One of the hallmark features of destructive periodontal disease, well documented over the last 50 y, is a change to the quantitative and qualitative composition of the associated microbiology. These alterations are now generally viewed as transformational shifts of the microbial populations associated with health leading to the emergence of bacterial species, which are only present in low abundance in health and a proportionate decrease in the abundance of others. The role of this dysbiosis of the health associated microbiota in the development of disease remains controversial: is this altered microbiology the driving agent of disease or merely a consequence of the altered environmental conditions that invariably accompany destructive disease? In this work, we aimed to address this controversy through controlled transmission experiments in the mouse in which a dysbiotic oral microbiome was transferred either horizontally or vertically into healthy recipient mice. The results of these murine studies demonstrate conclusively that natural transfer of the dysbiotic oral microbiome from a periodontally diseased individual into a healthy individual will lead to establishment of the dysbiotic community in the recipient and concomitant transmission of the disease phenotype. The inherent resilience of the dysbiotic microbial community structure in diseased animals was further demonstrated by analysis of the effects of antibiotic therapy on periodontally diseased mice. Although antibiotic treatment led to a reversal of dysbiosis of the oral microbiome, in terms of both microbial load and community structure, dysbiosis of the microbiome was reestablished following cessation of therapy. Collectively, these data suggest that an oral dysbiotic microbial community structure is stable to transfer and can act in a similar manner to a conventional transmissible infectious disease agent with concomitant effects on pathology. These findings have implications to our understanding of the role of microbial dysbiosis in the development and progression of human periodontal disease.