Reliability of smartphone-based teleradiology for evaluating thoracolumbar spine fractures

BACKGROUND CONTEXT

Timely interpretation of computed tomography (CT) scans is of paramount importance in diagnosing and managing spinal column fractures, which can be devastating. Out-of-hospital, on-call spine surgeons are often asked to evaluate CT scans of patients who have sustained trauma to the thoracolumbar spine to make diagnosis and to determine the appropriate course of urgent treatment. Capturing radiographic scans and video clips from computer screens and sending them as instant messages have become common means of communication between physicians, aiding in triaging and transfer decision-making in orthopedic and neurosurgical emergencies.

PURPOSE

The present study aimed to compare the reliability of interpreting CT scans viewed by orthopedic surgeons in two ways for diagnosing, classifying, and treatment planning for thoracolumbar spine fractures: (1) captured as video clips from standard workstation-based picture archiving and communication system (PACS) and sent via a smartphone-based instant messaging application for viewing on a smartphone; and (2) viewed directly on a PACS.

STUDY DESIGN

Reliability and agreement study.

PATIENT SAMPLE

Thirty adults with thoracolumbar spine fractures who had been consecutively admitted to the Division of Orthopedic Surgery of a Level I trauma center during 2014.

OUTCOME MEASURE

Intraobserver agreement.

METHODS

CT scans were captured by use of an iPhone 6 smartphone from a computer screen displaying PACS. Then by use of the WhatsApp instant messaging application, video clips of the scans were sent to the personal smartphones of five spine surgeons. These evaluators were asked to diagnose, classify, and determine the course of treatment for each case. Evaluation of the cases was repeated 4 weeks later, this time using the standard method of workstation-based PACS. Intraobserver agreement was interpreted based on the value of Cohen's kappa statistic. The study did not receive any outside funding.

RESULTS

Intraobserver agreement for determining fracture level was near perfect (κ=0.94). Intraobserver agreement for AO classification, proposed treatment, neural canal penetration, and Denis classification were substantial (κ values, 0.75, 0.73, 0.71, and 0.69, respectively). Intraobserver agreement for loss of vertebral height and kyphosis were moderate (κ values, 0.55 and 0.45, respectively) CONCLUSIONS: Video clips of CT scans can be readily captured by a smartphone from a workstation-based PACS and then transmitted by use of the WhatsApp instant messaging application. Diagnosing, classifying, and proposing treatment of fractures of the thoracic and lumbar spine can be made with equal reliability by evaluating video clips of CT scans transmitted to a smartphone or by the standard method of viewing the CT scan on a workstation-based PACS. Evaluating video clips of CT scans transmitted to a smartphone is a readily accessible, simple, and inexpensive method. We believe that it can be reliably used for consultations between the emergency physicians or orthopedic or neurosurgical residents with offsite, on-call specialists. It might also enable rural orcommunity emergency department physicians to communicate more efficiently and effectively with surgeons in tertiary referral centers.

Global analyses of monocyte subsets revealed age-related alternations after stimulation of pathogen recognition receptors

In the aging population, intricate interactions between the innate and adaptive immune response is not as effective compared to younger adults. Monocytes play an important role in defense against microbes and express an array of pattern recognition receptors (PRRs). We applied a comprehensive approach to evaluate the effects of a broad range of innate immune agonists (LPS, CLO97, and 5′pppRNA) on monocyte subsets isolated from healthy non-frail adults and old subjects. We analyzed transcriptome data and measured cytokine and chemokine, ROS, and NO production. Under ex vivo conditions, we observed a larger proportion of genes were specifically upregulated in the classical (CD14+CD16−) and non-classical (CD14dimCD16+) monocytes while the intermediate (CD14+CD16+) monocytes showed a smaller proportion of upregulated genes. Distinct genes observed across both age groups for CD16+ monocytes included: CX3CR1, IL21R, IFITM1/2/3, SIGLEC10, and SOD1; whereas CD16− monocytes expressed CCR1/2, SELL, CD64, CD93, CD36, and CD14. Analysis of the transcriptional profiles elicited by innate agonists revealed age-related alternations in functional pathways. After stimulation of RIGI with 5′pppRNA, we observed that classical monocytes isolated from adults uniquely expressed the RIGI MDA5 mediated induction of IFNα and IFNβ pathway, as well as the IFNα transcript, which corresponded to higher levels of IFNα production. In addition, agonists elicited higher levels of IFNγ from non-classical monocytes isolated from adults. Our findings represent a comprehensive analysis of the influence of human aging on PRRs signaling and have implications for strategies to enhance the immune response in the context of infection or immunization.

Fine-tuning of CD8(+) T-cell effector functions by targeting the 2B4-CD48 interaction

Polyfunctionality and cytotoxic activity dictate CD8(+) T-cell efficacy in the eradication of infected and malignant cells. The induction of these effector functions depends on the specific interaction between the T-cell receptor (TCR) and its cognate peptide-MHC class I complex, in addition to signals provided by co-stimulatory or co-inhibitory receptors, which can further regulate these functions. Among these receptors, the role of 2B4 is contested, as it has been described as either co-stimulatory or co-inhibitory in modulating T-cell functions. We therefore combined functional, transcriptional and epigenetic approaches to further characterize the impact of disrupting the interaction of 2B4 with its ligand CD48, on the activity of human effector CD8(+) T-cell clones. In this setting, we show that the 2B4-CD48 axis is involved in the fine-tuning of CD8(+) T-cell effector function upon antigenic stimulation. Blocking this interaction resulted in reduced CD8(+) T-cell clone-mediated cytolytic activity, together with a subtle drop in the expression of genes involved in effector function regulation. Our results also imply a variable contribution of the 2B4-CD48 interaction to the modulation of CD8(+) T-cell functional properties, potentially linked to intrinsic levels of T-bet expression and TCR avidity. The present study thus provides further insights into the role of the 2B4-CD48 interaction in the fine regulation of CD8(+) T-cell effector function upon antigenic stimulation.

A Canadian perspective on the use of immunoglobulin therapy to reduce infectious complications in chronic lymphocytic leukemia

Infections are a major cause of morbidity and mortality in patients with chronic lymphocytic leukemia (cll), who typically have increased susceptibility because of hypogammaglobulinemia (hgg) related to their disease and its treatment. Immunoglobulin replacement therapy (igrt) has been shown to reduce the frequency of bacterial infections and associated hospitalizations in patients with hgg or a history of infection, or both. However, use of igrt in cll is contentious. Studies examining such treatment were conducted largely before the use of newer chemoimmunotherapies, which can extend lifespan, but do not correct the hgg inherent to the disease. Thus, the utility of igrt has to be re-evaluated in the current setting. Here, we discuss the evidence for the use of igrt in cll and provide a practical approach to its use in the prevention and management of infections.

BCL6 orchestrates Tfh cell differentiation via multiple distinct mechanisms (LYM8P.628)

Generation of long term humoral immunity is a complex process predominantly dependent on germinal centers and CD4 T cell help to B cells. Follicular helper T cells (Tfh) are the specialized CD4 T cells for B cell help. We and others have now resolved many of the stages of Tfh differentiation, and molecules involved. BCL6 is the defining transcription factor of Tfh cells. However, the functions of BCL6 in Tfh have largely remained unclear. We have defined the BCL6 cistrome in primary human germinal center Tfh cells to assess mechanisms of BCL6 regulation of CD4 T cells, comparing and contrasting BCL6 function in T and B cells. BCL6 primarily acts as a repressor in Tfh cells, and BCL6 binding was associated with control of Tfh cell migration, Tfh differentiation, and repression of alternative cell fates. Interestingly, although some BCL6 bound genes possessed BCL6 DNA binding motifs, more BCL6-bound loci were instead characterized by the presence of DNA motifs for AP1 or STAT. AP1 complexes are key positive downstream mediators of TCR signaling and external stimuli. We show that BCL6 can directly bind AP1, and AP1 and BCL6 co-occupied BCL6 binding sites with AP1 motifs, suggesting that BCL6 subverts AP1 activity. These findings reveal that BCL6 has broad and multifaceted effects on Tfh biology, and provide insight into how this master regulator mediates distinct cell-context dependent phenotypes.

Short- and long-term outcome of linear morphoea in children

BACKGROUND

Linear morphoea (LM) is a rare fibrosing disorder of the limbs or the face that may cause functional disability and severe aesthetic sequelae. Despite a wide range of therapeutics reported for LM, there is currently a lack of consensus on the optimal therapy. Little is known about the long-term outcome of this disease.

OBJECTIVES

To describe the short- and long-term outcome of a large series of patients with LM acquired in childhood.

METHODS

A retrospective chart review of 52 paediatric patients with LM seen in our centre during a 20-year span (1990-2010) and a telephone survey in 2011 to assess the long-term outcome of these patients.

RESULTS

Limbs were affected twice as often as the face, with a higher proportion of female patients. Stabilization was obtained after a mean disease duration of 5·4 years. Patients sometimes experienced long stretches of disease quiescence followed by reactivation; 31% of patients reported active disease after 10 years. All but one patient had aesthetic sequelae, and 38% had functional limitations. The effectiveness of methotrexate and systemic corticosteroids was apparent in the short term.

CONCLUSIONS

LM needs prolonged monitoring as the disease can have very long periods of quiescence followed by reactivation. The combination of methotrexate and systemic corticosteroids was effective in the early stages of the disease but did not seem to prevent long-standing active disease or relapse in the long term.

Relationship of vitamin D levels to blood pressure in a biethnic population

BACKGROUND AND AIMS

Accumulating epidemiological and clinical studies have suggested that vitamin D insufficiency may be associated with hypertension. Blacks tend to have lower vitamin D levels than Whites, but it is unclear whether this difference explains the higher blood pressure (BP) observed in Blacks in a population with healthy lifestyle practices.

METHODS AND RESULTS

We examined cross-sectional data in the Adventist Health Study-2 (AHS-2), a cohort of non-smoking, mostly non-drinking men and women following a range of diets from vegan to non-vegetarian. Each participant provided dietary, demographic, lifestyle and medical history data. Measurements of weight, height, waist circumference, percent body fat and blood pressure and fasting blood samples were obtained from a randomly selected non-diabetic sample of 284 Blacks and 284 Whites aged 30-95 years. Multiple regression analyses were used to assess independent relationships between blood pressure and 25(OH)D levels. Levels of 25(OH)D were inversely associated with systolic BP in Whites after control for age, gender, BMI, and use of BP-lowering medications (β-coefficient -0.23 [95% CI, -0.43, -0.03; p = 0.02]). This relationship was not seen in Blacks (β-coefficient 0.08 [95% CI, -0.14, 0.30; p = 0.4]). Results were similar when controlling for waist circumference or percentage body fat instead of BMI. No relationship between serum 25(OH)D and diastolic BP was seen.

CONCLUSION

Systolic BP is inversely associated with 25(OH)D levels in Whites but not in Blacks. Vitamin D may not be a major contributor to the White-Black differential in BP.

Human blood Tfh cells (P4534)

Follicular helper (Tfh) CD4 T cells are the specialized T cells for B cell help, required for development of germinal centers and most B cell memory. T cell help is frequently a limiting factor for these processes. Therefore understanding Tfh cells is important for developing rational vaccine strategies. Tfh cells are also potentially extremely useful biomarkers in human vaccine clinical trials as predictors of long-term humoral immunity. We have therefore pursued an understanding of the phenotype, transcription factors, and functions of Tfh cells in humans. CXCR5+ CD4 T cells are present in human blood, and constitute ~20% of CD45RO+ cells. There are differences of opinion as to whether these “blood Tfh” are memory cells or not. We have performed a series of experiments subsetting the blood CXCR5+ cells into 4 groups based on differential expression of Tfh associated surface markers. Gene expression profiling indicates that one of the four groups is the most related to active Tfh in human lymphoid tissue. All four populations have significant gene expression differences from CXCR5lo memory CD4 T cells in blood. Furthermore, a series of functional studies indicates that these four subsets of CXCR5+ cells differ in their capacity to help B cells. We are assessing whether long term memory cells are present in one or more of these blood Tfh subpopulations. These studies examining the functions and ontogeny of blood Tfh cells are important for the field of vaccine design.

A high-fibre bean-rich diet versus a low-carbohydrate diet for obesity

BACKGROUND

High-fibre and low-carbohydrate diets may enhance satiety and promote weight loss. We compared a diet rich in beans aiming to increase dietary fibre and promote weight loss with a low-carbohydrate diet in a randomised controlled trial to assess effect and tolerability of the high-fibre bean-rich diet.

METHODS AND RESULTS

One hundred and seventy-three women and men, with a mean body mass index of approximately 36 kg m(-2) (one-fifth with diabetes type 2) were randomised to a high-fibre bean-rich diet that achieved mean (SD) fibre intakes of 35.5 (18.6) g day(-1) for women and 42.5 (30.3) g day(-1) for men, or a low-carbohydrate diet. Both diets were induced gradually over 4 weeks and included a 3-day feeding phase. Among 123 (71.1%) completers at 16 weeks, mean (SD) weight loss was 4.1 (4.0) kg in the high-fibre versus 5.2 (4.5) kg in the low-carbohydrate group [difference, 1.1 kg, 95% confidence interval (CI) = -2.6 to -0.5; P = 0.2], with results similar to the intent-to-treat population. Low-density lipoprotein (LDL)-cholesterol levels decreased with the high-fibre diet (difference in LDL-cholesterol versus low-carbohydrate diet, 0.2 mmol L(-1) , 95% CI = 0.01-0.44 mmol L(-1) ; P = 0.045), as did total cholesterol (P = 0.038), whereas changes in other lipids and glucose did not differ. After 52 weeks, the low-carbohydrate (n = 24) group tended to retain weight loss better than the high-fibre group (P = 0.06), although total cholesterol remained lower with the bean-rich diet (P = 0.049).

CONCLUSIONS

A high-fibre bean-rich diet was as effective as a low-carbohydrate diet for weight loss, although only the bean-rich diet lowered atherogenic lipids.

Phosphodiesterase 5 inhibition protects against increased intra-abdominal pressure-induced renal dysfunction in experimental congestive heart failure

AIMS

Congestive heart failure (CHF) is associated with impaired renal function. Previously, we have demonstrated that rats with decompensated CHF exhibited exaggerated sensitivity to the adverse renal effects of increased increased intra-abdominal pressure (IAP) as compared with normal controls. This study tested whether phosphodiesterase 5 (PDE5) inhibition protects against the adverse renal effects of increased IAP in rats with CHF.

METHODS AND RESULTS

Following baseline periods, rats with compensated and decompensated CHF induced by the placement of an aorto-caval fistula (ACF), rats with myocardial infarction (MI) induced by left anterior descending (LAD) artery ligation, and sham controls were subjected to consecutive IAPs: 7, 10, or 14 mmHg. Urine flow (V), Na(+) excretion (U(Na)V), glomerular filtration rate (GFR), and renal plasma flow (RPF) were determined. The effects of pre-treatment with tadalafil on the adverse renal effects of IAP were examined in rats with decompensated CHF and MI. Elevation of IAP to 10 and 14 mmHg produced linear reductions in these parameters. Basal renal function and haemodynamics were lower in CHF rats. Decompensated CHF rats and MI rats that were subjected to 10 and 14 mmHg exhibited exaggerated declines in V, U(Na)V, GFR, and RPF. In contrast, no adverse renal effects were observed in rats with compensated CHF subjected to IAP. Pre-treatment of decompensated CHF rats and MI rats with tadalafil ameliorated the adverse renal effects of high IAP.

CONCLUSION

Decompensated CHF and MI rats are vulnerable to the adverse renal effects of IAP. Tadalafil abolishes IAP-induced renal dysfunction, supporting a therapeutic role for PDE5 inhibition in CHF associated with ascites.

Type I IFN induced by adenovirus serotypes 28 and 35 has multiple effects on T cell immunogenicity

Recombinant adenovirus (rAd) vectors are being investigated as vaccine delivery vehicles in preclinical and clinical studies. rAds constructed from different serotypes differ in receptor usage, tropism, and ability to activate cells, aspects of which likely contribute to their different immunogenicity profiles. In this study, we compared the infectivity and cell stimulatory capacity of recombinant adenovirus serotype 5 (rAd5), recombinant adenovirus serotype 28 (rAd28), and recombinant adenovirus serotype 35 (rAd35) in association with their respective immunogenicity profiles. We found that rAd28 and rAd35 infected and led to the in vitro maturation and activation of both human and mouse dendritic cells more efficiently compared with rAd5. In stark contrast to rAd5, rAd28 and rAd35 induced production of IFN-α and stimulated IFN-related intracellular pathways. However, the in vivo immunogenicity of rAd28 and rAd35 was significantly lower than that of rAd5. Deletion of IFN-α signaling during vaccination with rAd28 and rAd35 vectors increased the magnitude of the insert-specific T cell response to levels induced by vaccination with rAd5 vector. The negative impact of IFN-α signaling on the magnitude of the T cell response could be overcome by increasing the vaccine dose, which was also associated with greater polyfunctionality and a more favorable long-term memory phenotype of the CD8 T cell response in the presence of IFN-α signaling. Taken together, our results demonstrate that rAd-induced IFN-α production has multiple effects on T cell immunogenicity, the understanding of which should be considered in the design of rAd vaccine vectors.

Intrinsic role of FoxO3a in the contraction of CD8+ T cell response (110.14)

CD8+ T cells undergo rapid expansion during infection with intracellular pathogens, which is followed by swift and massive culling of primed CD8+ T cells. The mechanisms that govern the massive contraction of primed CD8+ T cells are not clear. We show that the transcription factor Foxo3a plays a key role in the contraction, not expansion, of CD8+ T cell response against Listeria monocytogenes (LM). FoxO3a-mutant OVA-specific CD8+ T cells isolated during peak of response displayed reduced expression of pro-apoptotic molecules BIM and PUMA, and underwent reduced apoptosis during contraction phase in comparison to WT cells. A higher number of memory precursor effector cells (MPECs) were detectable in FoxO3a-mutant mice compared to WT mice during contraction phase. Furthermore, FoxO3a-mutant OVA-specific CD8+ T cells upon transfer into normal mice underwent highly reduced contraction. These results show for the first time that FoxO3a acts in a cell intrinsic manner to promote the culling of primed CD8+T cells during the contraction phase.

Use of immunoglobulins in the prevention of GvHD in a xenogeneic NOD/SCID/γc- mouse model

The efficacy of IVIG in preventing GvHD has not been definitely demonstrated clinically. Using a xenogeneic model of GvHD in NOD/SCID/γc- (NSG) mice, we showed that weekly administration of IVIG significantly reduced the incidence and associated mortality of GvHD to a degree similar to CsA. Unlike CsA and OKT3, IVIG were not associated with inhibition of human T-cell proliferation in mice. Instead, IVIG significantly inhibited the secretion of human IL-17, IL-2, IFN-γ and IL-15 suggesting that IVIG prevented GvHD by immunomodulation. Furthermore, the pattern of modification of the human cytokine storm differed from that observed with CsA and OKT3. Finally, in a humanized mouse model of immune reconstitution, in which NSG mice were engrafted with human CD34(+) stem cells, IVIG transiently inhibited B-cell reconstitution, whereas peripheral T-cell reconstitution and thymopoiesis were unaffected. Together these in vivo data raise debate related to the appropriateness of IVIG in GvHD prophylaxis. In addition, this model provides an opportunity to further elucidate the precise mechanism(s) by which IVIG inhibit GvHD.