Aflibercept monotherapy versus aflibercept with targeted retinal laser to peripheral retinal ischemia for diabetic macular oedema (LADAMO)

OBJECTIVE

We tested the hypothesis that targeted retinal laser photocoagulation (TPRP) to peripheral retinal ischaemia reduces the overall burden of aflibercept injections when treating diabetic macular oedema (DMO) over a 24-month period.

METHODS

Prospective, double-masked, multicentre, randomised controlled trial in Australia comparing aflibercept monotherapy, following a treat-and-extend protocol, or combination therapy of aflibercept and TPRP for DMO. The aflibercept monotherapy group received placebo laser. The primary outcome measure was the mean number of intravitreal aflibercept injections for each group at 24 months. Secondary outcome included: mean change in central macular thickness (CMT) and vision at trial completion, the proportion of eyes whose DMO resolved and the mean injection treatment interval. Ocular and systemic adverse events were recorded.

RESULTS

We enrolled 48 eyes of 47 patients; 27 eyes were randomised to combination therapy (aflibercept and TPRP) and 21 to aflibercept monotherapy. Thirty-two eyes (67%) completed the 2-year study. The number of intravitreal treatments given were similar for combination therapy (10.5 (SD 5.8) and monotherapy (11.8 (SD5.6)) (P = 0.44). The mean visual improvement (+4.0 (-1.8, 9.8) and +7.8 (2.6, 12.9) letters, P = 0.32), mean decrease in CMT (-154 (-222,-87) µm and -152 (-218,-86) µm, P = 0.96), proportion of eyes with CMT < 300 µm (48% and 67%; P = 0.50) and safety outcomes were similar in both the combination and monotherapy treatment groups (respectively).

CONCLUSIONS

Laser to areas of ischaemic peripheral retina does not reduce the burden of intravitreal aflibercept injections when treating diabetic macular oedema.

Distribution of soil carbon fractions under different bamboo species in northwest Himalayan foothills, India

Soil carbon and its fractions are important in understanding the mechanism of soil carbon sequestration. The present study evaluated the impact of seven commercial bamboo species, viz., Bambusa balcooa, B. bambos, B. vulgaris, B. nutans, Dendrocalamus hamiltonii, D. stocksii, and D. strictus, on labile and non-labile carbon fractions. In the 0-15-cm layer, B. nutans had the highest very labile C (7.65 g kg^-1) followed by B. vulgaris > B. balcooa > D. stocksii > D. hamiltonii > B. bambos > D. strictus > open. The active carbon pool was significantly low under the control plot (i.e. the open) indicating the positive influence of bamboo in soil C build-up in the top 0-15 cm soil layer. Amongst the different species of bamboo evaluated in this study, D. strictus accumulated the highest active C pool in 0-30-cm soil layer followed by B. vulgaris. Of the total organic C in the 0-30 cm soil depth, majority (55-60%) was contributed by the passive C pool comprising the less labile and the non-labile fraction of SOC. A high value of carbon stratification ratio (> 2) was observed for D. strictus, B. bambos, and D. hamiltonii which proves their potential for restoration of the degraded lands. The majority of bamboo species except for B. balcooa and D. stocksii showed a higher carbon management index than open systems, thereby indicating higher rates of soil C rehabilitation. Of the seven bamboo species, B. vulgaris, D. strictus, and B. nutans can be adopted for cultivation in the northwest Himalayas given their ability to positively impact the SOC and its fractions in both surface and sub-surface soil.

In hospital outcomes of orbital/rotational coronary atherectomy in diabetic vs non-diabetic population: insights from the nationwide inpatient sample

Background

Atherectomy (AT) using an orbital/rotational system is useful in altering calcified plaque thereby facilitating stent placement and optimal stent expansion. Patients with diabetes mellitus (DM) are known to have a higher rate of complications after percutaneous coronary intervention. We aimed to assess the incidence of major adverse cardiovascular events after atherectomy in the diabetic population using a nationwide inpatient sample (NIS).

Methods

NIS-HCUP database from 2015–2017 was used to identify patients who underwent atherectomy. A cohort of patients with and without diabetes was identified. Demographics, in-hospital outcomes, complications in both groups were compared. Statistical significance was assigned at p&lt;0.05.

Results

Out of 6184 patients who underwent AT, 3134 (50.6%) patients had DM. Baseline characteristics have been outlined in the table below. Complications were comparable between the two groups except for higher incidence of post-procedure VTE in Diabetic patients. In-hospital mortality was lower among patients with DM (2.24% vs 3.29%, p-0.27), while the mean length of stay (5.92 vs 4.91 days, p-0.002) and the hospitalization charges ($165118.4 vs 151226, p-0.04) were higher, but this difference in length of stay and hospitalization charges were nullified on multivariate regression.

Conclusion

Our study suggests that an AT for severely calcified plaque in the coronary artery is a safe option in patients with DM with comparable in-hospital complications and outcomes to non-DM patients.

Funding Acknowledgement

Type of funding sources: None. Demographics and Outcomes of Atherectomy

Assessment of eco-hydrological parameters for important sympodial bamboo species in Himalayan foothills

Bamboos due to high soil water conservation potential are gaining increased attention in plantation programs across the globe. Large-scale plantation of fast-growing bamboo, however, can have important hydrological consequences. The study aims to quantify the eco-hydrological parameters, viz., throughfall (TF), stemflow (SF), and interception (I) in seven important sympodial bamboo species in north western Himalayan foothills of India. The species selected include Bambusa balcooa, Bambusa bambos, Bambusa vulgaris., Bambusa nutans, Dendrocalamus hamiltonii, Dendrocalamus stocksii, and Dendrocalamus strictus. Throughfall versus gross rainfall (GR) relationship in different species indicated high throughfall production during high rainfall events with r² > 0.90. Average throughfall was lowest (62.1%) in D. hamiltonii and highest in B. vulgaris (74.6%). SF ranged from 1.32% in B. nutans to 3.39% in D. hamiltonii. The correlation coefficient (r) between leaf area index (LAI), number of culms, and crown area with the interception were 0.746, 0.691, and 0.585, respectively. The funneling ratio (F) was highest (27.0) in D. hamiltonii and least in B. nutans. Canopy storage capacity was highest in D. strictus (3.57 mm) and least in D. hamiltonii (1.09 mm). Interception loss was highest (34.4%) in D. hamiltonii and lowest in B. vulgaris (23.5%) and D. strictus (23.6%). Higher interception in bamboos make them suitable for soil conservation, but careful selection of species is required in low rainfall areas.

Vessel Wall Enhancement and Focal Cerebral Arteriopathy in a Pediatric Patient with Acute Infarct and COVID-19 Infection

Herein, we report the findings of intracranial arterial wall enhancement, consistent with focal cerebral arteriopathy-inflammatory type, in a child presenting with acute infarct in the setting of coronavirus disease 2019 (COVID-19) infection. To our knowledge, this report provides the first description of vessel wall imaging findings in COVID-19-associated acute stroke.

Effect of the unfolded protein response and oxidative stress on mutagenesis in CSF3R: a model for evolution of severe congenital neutropenia to myelodysplastic syndrome/acute myeloid leukemia

Severe congenital neutropenia (SCN) is a rare blood disorder characterised by abnormally low levels of circulating neutrophils. The most common recurrent mutations that cause SCN involve neutrophil elastase (ELANE). The treatment of choice for SCN is the administration of granulocyte-colony stimulating factor (G-CSF), which increases the neutrophil number and improves the survival and quality of life. Long-term survival is however linked to the development of myelodysplastic syndrome/acute myeloid leukemia (MDS/AML). About 70% of MDS/AML patients acquire nonsense mutations affecting the cytoplasmic domain of CSF3R (the G-CSF receptor). About 70% of SCN patients with AML harbour additional mutations in RUNX1. We hypothesised that this coding region of CSF3R constitutes a hotspot vulnerable to mutations resulting from excessive oxidative stress or endoplasmic reticulum (ER) stress. We used the murine Ba/F3 cell line to measure the effect of induced oxidative or ER stress on the mutation rate in our hypothesised hotspot of the exogenous human CSF3R, the corresponding region in the endogenous Csf3r, and Runx1. Ba/F3 cells transduced with the cDNA for partial C-terminal of CSF3R fused in-frame with a green fluorescent protein (GFP) tag were subjected to stress-inducing treatment for 30 days (~51 doubling times). The amplicon-based targeted deep sequencing data for days 15 and 30 samples show that although there was increased mutagenesis observed in all the three genes of interest (partial CSF3R, Csf3r and Runx1), there were more mutations in the GFP region compared with the partial CSF3R region. Our findings also indicate that there is no correlation between the stress-inducing chemical treatments and mutagenesis in Ba/F3 cells. Our data suggest that oxidative or ER stress induction does not promote genomic instability, affecting partial C-terminal of the transduced CSF3R, the endogenous Csf3R and the endogenous Runx1 in Ba/F3 cells that could account for these targets to being mutational hotspots. We conclude that other mechanisms to acquire mutations of CSF3R that help drive the evolution of SCN to MDS/AML.

Outcomes of transcatheter mitral valve repair from the latest nationwide inpatient sample database 2016–2017

Background

Transcatheter mitral valve repair (TMVR) is an alternative treatment option for severe mitral regurgitation (severe MR) in patients with high surgical risk. Previous studies have demonstrated safety and efficacy of TMVR. The aim of our study was to assess comorbid and patient outcome data in a nationwide sample.

Methods

From the Nationwide Inpatient Sample (NIS) 2016–2017, all adult patients with mitral valve regurgitation were identified. Patients were divided into two group- TMVR and SMVR (surgical mitral valve repair). Patients requiring surgical valve replacement were excluded. Primary outcomes were inpatient mortality and length of stay. Multivariate analysis was performed to adjust for comorbidities.

Results

A total of 6211 TMVR were performed, while 3789 SMVR were performed. TMVR patients were older (78.34 vs 62.26 years) and had more females (48.86 vs 36.18%). Comorbidities were higher in the TMVR group [heart failure (81.02 vs 46.02%, p&lt;0.001), diabetes mellitus (27.13 vs 15.81%, p&lt;0.001), chronic kidney disease (39.3 vs 13.7%, p&lt;0.001), chronic lung disease (27.13 vs 16.65%, p&lt;0.001). Complications were higher in the SMVR [Cardiogenic shock (3.8 vs 6%, p=0.007), blood transfusion requirement (19.44 vs 4.85%, p=0.001), respiratory failure (10.99 vs 7.37, p=0.012)]. Mean length of stay was higher with SMVR [8.60±0.22 (4.139–5.17) days] compared to TMVR [4.65±0.26 (8.167–9.03) days]. In-patient mortality was lower in TMVR (2.01 vs 2.45%, p-0.02). After adjusting for comorbidities on multivariate analysis, there was no difference in mortality between the groups (adjusted OR=1.081±0.419 (0.506–2.311).

Conclusion

From nationwide data, we report TMVR as a relatively safe treatment modality for severe MR, with comparable inpatient mortality and fewer complications than SMVR, despite having a significantly higher burden of comorbidities.

Funding Acknowledgement

Type of funding source: None

MRI Brain Findings in 126 Patients with COVID-19: Initial Observations from a Descriptive Literature Review

BACKGROUND AND PURPOSE

Recently, numerous investigational studies, case series, and case reports have been published describing various MR imaging brain findings in patients with COVID-19. The purpose of this literature review was to compile and analyze brain MR imaging findings in patients with COVID-19-related illness.

MATERIALS AND METHODS

Literature searches of PubMed, publicly available Internet search engines, and medical journal Web sites were performed to identify articles published before May 30, 2020 that described MR imaging brain findings in patients with COVID-19.

RESULTS

Twenty-two articles were included in the analysis: 5 investigational studies, 6 case series, and 11 case reports, encompassing MR imaging of the brain in 126 patients. The articles originated from 7 different countries and were published in 14 medical journals. MR imaging brain findings included specific diagnoses (such as acute infarct, posterior reversible encephalopathy syndrome) or specific imaging features (such as cortical FLAIR signal abnormality, microhemorrhages).

CONCLUSIONS

The most frequent diagnoses made on brain MR imaging in patients with COVID-19 were acute and subacute infarcts. Other common findings included a constellation of leukoencephalopathy and microhemorrhages, leptomeningeal contrast enhancement, and cortical FLAIR signal abnormality.

Rooting behaviour and soil properties in different bamboo species of Western Himalayan Foothills, India

Due to extensive root system, connected rhizome bamboos are considered suitable for improving soil properties within a short period, though most of the claims are anecdotal and need to be supported with quantified data. The study evaluates seven bamboo species viz., Bambusa balcooa, Bambusa bambos, Bambusa vulgaris, Bambusa nutans, Dendrocalamus hamiltonii, Dendrocalamus stocksii and Dendrocalamus strictus for their rooting pattern and impact on soil health properties. Coarse and fine root intensity was maximum in B. vulgaris. Coarse root biomass ranged from 0.6 kg m⁻³ in B. nutans to 2.0 kg m⁻³ in B. vulgaris and B. bambos. Fine root biomass ranged from 1.1 kg m⁻³ in B. nutans to 4.5 kg m⁻³ in D. hamiltonii. Contribution of fine roots in terms of intensity and biomass was much higher than coarse roots. Fine root biomass showed declining trend with increase in soil depth in all the species. During sixth year, the litter fall ranged from 8.1 Mg ha⁻¹ in D. stocksii to 12.4 Mg ha⁻¹ in D. hamiltonii. Among soil physical properties significant improvement were recorded in hydraulic conductivity, water stable aggregates and mean weight diameter. Soil pH, organic carbon and available phosphorus under different species did not reveal any significant changes, while significant reduction was observed in total nitrogen and potassium. Significant positive correlation was observed between WSA and iron content. Soil microbial population and enzyme activities were higher in control plot. Considering root distribution, biomass, soil hydraulic conductivity and water stable aggregates, B. bambos, B. vulgaris and D. hamiltonii are recommended for rehabilitation of degraded lands prone to soil erosion.

A Retrospective Study of Administrative Data to Identify Factors Associated with Future Disability Status among Older Colorectal Cancer Survivors

Disability is associated with loss of independence and early mortality. Currently, only 1–2% of cancer survivors who reported physical limitations received rehabilitation services. It is critical to identify factors associated with the development of disability to guide clinical practice given treatment changes. We aimed to 1) identify demographic and cancer-related characteristics associated with future disability status among older colorectal cancer survivors, and 2) compared the future disability status among cancer and matched non-cancer cohorts. Methods: We conducted a retrospective cohort study using the Texas Cancer Registry-national Medicare linked database. The cancer cohort included Medicare beneficiaries with a primary colorectal cancer diagnosis between 2005 and 2013 (n = 13,229). The non-cancer cohort was identified from a 5% sample of Medicare beneficiaries (n = 11,416). Diagnosis dates from the cancer cohort were used as the index date for the non-cancer cohort. Cohorts were matched 1:1 based on index date, age, and gender. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals. Disability status was defined according to Davidoff and colleagues using inpatient, outpatient and durable medical equipment claims files, and assessed monthly, beginning 1 month after cancer diagnosis (or index date), continuing until disability, death, end of Medicare continuous enrollment, or end of study. Results: Factors that were significantly associated with disability status in the cancer cohort were age (HR = 3.50 for &gt;80 years old), female gender (HR = 1.50), race/ethnicity (HR = 1.34 for Hispanic and 1.21 for Black), stage (HR = 2.26 for distant stage), comorbidity (HR = 2.18 for &gt;1), and radiation (HR = 1.21). When compared to the non-cancer cohort, having a cancer diagnosis (HR = 1.07) and comorbidity (HR = 2.09 for &gt;1) were associated with developing disability. Conclusions: Colorectal diagnosis is an independent risk for disability status. Beyond well-known risk factors “age and mortality” subsets of survivors (Hispanic and Black survivors and those with comorbidity) are found to be at higher risk for developing disability. This warrants further investigation and may indicate targeted intervention to prevent future disability.

Cytokine receptor splice variants in hematologic diseases

Cytokine and cytokine receptors are important regulators of hematopoiesis. Hematopoietic stem cells (HSCs) and progenitors differentiate into the myeloid or lymphoid lineage in response to specific cytokines. Cell-type specific receptors are expressed on committed progenitors that bind to other late-acting cytokines that are involved in terminal differentiation of hematopoietic cells. In normal hematopoiesis, these receptors undergo alternative splicing and are developmentally regulated. Splicing changes can significantly affect the structure and function of the receptors resulting in alterations of either the extracellular ligand binding domain or the cytoplasmic signaling domain responsible for cellular growth and differentiation. Most alternatively spliced isoforms generally lose the ability to promote differentiation. Evidently, overexpression of naturally occurring cytokine receptor alternate isoforms are observed in multiple myeloid diseases such as myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and polycythemia vera (PV). The purpose of this review is to introduce the various isoforms of key cytokine receptors that play a crucial role in myeloid development and their potential role in myeloid diseases.

Mutation, drift and selection in single-driver hematologic malignancy: Example of secondary myelodysplastic syndrome following treatment of inherited neutropenia

Cancer development is driven by series of events involving mutations, which may become fixed in a tumor via genetic drift and selection. This process usually includes a limited number of driver (advantageous) mutations and a greater number of passenger (neutral or mildly deleterious) mutations. We focus on a real-world leukemia model evolving on the background of a germline mutation. Severe congenital neutropenia (SCN) evolves to secondary myelodysplastic syndrome (sMDS) and/or secondary acute myeloid leukemia (sAML) in 30–40%. The majority of SCN cases are due to a germline ELANE mutation. Acquired mutations in CSF3R occur in >70% sMDS/sAML associated with SCN. Hypotheses underlying our model are: an ELANE mutation causes SCN; CSF3R mutations occur spontaneously at a low rate; in fetal life, hematopoietic stem and progenitor cells expands quickly, resulting in a high probability of several tens to several hundreds of cells with CSF3R truncation mutations; therapeutic granulocyte colony-stimulating factor (G-CSF) administration early in life exerts a strong selective pressure, providing mutants with a growth advantage. Applying population genetics theory, we propose a novel two-phase model of disease development from SCN to sMDS. In Phase 1, hematopoietic tissues expand and produce tens to hundreds of stem cells with the CSF3R truncation mutation. Phase 2 occurs postnatally through adult stages with bone marrow production of granulocyte precursors and positive selection of mutants due to chronic G-CSF therapy to reverse the severe neutropenia. We predict the existence of the pool of cells with the mutated truncated receptor before G-CSF treatment begins. The model does not require increase in mutation rate under G-CSF treatment and agrees with age distribution of sMDS onset and clinical sequencing data.

Cancer develops by multistep acquisition of mutations in a progenitor cell and its daughter cells. Severe congenital neutropenia (SCN) manifests itself through an inability to produce enough granulocytes to prevent infections. SCN commonly results from a germline ELANE mutation. Large doses of the blood growth factor granulocyte colony-stimulating factor (G-CSF) rescue granulocyte production. However, SCN frequently transforms to a myeloid malignancy, commonly associated with a somatic mutation in CSF3R, the gene encoding the G-CSF Receptor. We built a mathematical model of evolution for CSF3R mutation starting with bone marrow expansion at the fetal development stage and continuing with postnatal competition between normal and malignant bone marrow cells. We employ tools of probability theory such as multitype branching processes and Moran models modified to account for expansion of hematopoiesis during human development. With realistic coefficients, we obtain agreement with the age range at which malignancy arises in patients. In addition, our model predicts the existence of a pool of cells with mutated CSF3R before G-CSF treatment begins. Our findings may be clinically applied to intervene more effectively and selectively in SCN patients.

Captopril mitigates splenomegaly and myelofibrosis in the Gata1low murine model of myelofibrosis

Allogeneic stem cell transplantation is currently the only curative therapy for primary myelofibrosis (MF), while the JAK2 inhibitor, ruxolitinib. Has been approved only for palliation. Other therapies are desperately needed to reverse life-threatening MF. However, the cell(s) and cytokine(s) that promote MF remain unclear. Several reports have demonstrated that captopril, an inhibitor of angiotensin-converting enzyme that blocks the production of angiotensin II (Ang II), mitigates fibrosis in heart, lung, skin and kidney. Here, we show that captopril can mitigate the development of MF in the Gata1low mouse model of primary MF. Gata1low mice were treated with 79 mg/kg/d captopril in the drinking water from 10 to 12 months of age. At 13 months of age, bone marrows were examined for fibrosis, megakaryocytosis and collagen expression; spleens were examined for megakaryocytosis, splenomegaly and collagen expression. Treatment of Gata1low mice with captopril in the drinking water was associated with normalization of the bone marrow cellularity; reduced reticulin fibres, splenomegaly and megakaryocytosis; and decreased collagen expression. Our findings suggest that treating with the ACE inhibitors captopril has a significant benefit in overcoming pathological changes associated with MF.

Abstract B2-50: Stochastic population genetics modeling of the evolution of the myelodysplastic syndrome

We are developing new models to understand the evolution of Myelodysplastic Syndromes (MDS), a group of pre-leukemic blood diseases, which are increasing in incidence as the population is aging and which remain difficult to treat. In the early stage of MDS, exaggerated apoptosis of myeloid blood cells occurs, but as the disease evolves, survival of undifferentiated cells dominates. As a model we study progression to MDS/AML from severe congenital neutropenia (SCN), an inherited bone marrow failure with known germ-line mutations, e.g. ELANE which encodes the neutrophil elastase. Administration of granulocyte colony-stimulating factor (GCSF) improves the neutropenia but is associated with transformation to MDS and acute myeloid leukemia (AML), defined by greater than 20% blasts in the marrow. Of note, ~ 70% of SCN patients who progress to MDS acquire a truncating D715 mutation in the GCSF Receptor. We previously developed a model of the SCN -&gt; MDS -&gt; AML sequence [1], which however did not include the MDS stage.

We hypothesize that the propagation of the D715 mutant in MDS secondary to SCN follows a newly developed Moran model with directional selection and co-localization. Selection is caused by alterations in the STAT/SOCS feedback loop with the truncated GCSF receptor, leading to changes in proliferation and differentiation [2]. Usually, mathematical models assume that bone marrow is a well-mixed environment and the normal and malignant precursors freely interact. However, these subpopulations occupy distinct niches [3] and their competition is limited by physical separation, which is a factor in our variant of the Moran model. We estimate the selective advantage of mutant cells based on competitive repopulation assay and flow cytometry cell-cycle distribution and find the time at onset of MDS consistent with the published median of 13 years [1].

We built an ODE model of the STAT/SOCS circuit, and investigated its sensitivity to reduced binding of JAK/STAT complexes to the D715 mutant receptor, even that the circuit exhibits extremely strong stabilizing properties. A link to cell cycle characteristics via distributions of cell-cycle-phase dependent activated STATs suggests connection with differentiation and proliferation. Further, to investigate a fuller model in which a number of driver mutations may occur at a different order, we developed a new version of the infinite-allele branching process of Griffiths and Pakes [4, 5]. Mathematical modeling of SCN-&gt;MDS -&gt; AML will lead to a greater understanding of homeostatic and aberrant myelopoiesis as well as designing better predictive biomarkers for malignant clonal evolution.

References:

[1] Kimmel, M., and Corey, S. (2013). Stochastic hypothesis of transition from inborn neutropenia to AML. Frontiers in oncology, 3.

[2] Whichard, Z. L., Sarkar, C. A., Kimmel, M., and Corey, S. J. (2010). Hematopoiesis and its disorders: a systems biology approach. Blood, 115(12), 2339-2347.

[3] Colmone, A., Amorim, M., Pontier, A. L., Wang, S., Jablonski, E., and Sipkins, D. A. (2008). Leukemic cells create bone marrow niches that disrupt the behavior of normal hematopoietic progenitor cells. Science, 322(5909), 1861-1865.

[4] Griffiths, R. C., and Pakes, A. G. (1988). An infinite-alleles version of the simple branching process. Advances in applied probability, 20(3), 489-524.

[5] McDonald, T. A., and Kimmel, M. (2014) A multitype infinite-allele branching process with applications to cancer evolution. Journal of applied probability, accepted for publication.

Note: This abstract was not presented at the conference.

Citation Format: Tomasz Wojdyla, Hrishikesh Mehta, Taly Glaubach, Thomas McDonald, Seth J. Corey, Marek Kimmel. Stochastic population genetics modeling of the evolution of the myelodysplastic syndrome. [abstract]. In: Proceedings of the AACR Special Conference on Computational and Systems Biology of Cancer; Feb 8-11 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 2):Abstract nr B2-50.

Minimizing Radiation Exposure in Evaluation of Pediatric Head Trauma: Use of Rapid MR Imaging

BACKGROUND AND PURPOSE

With >473,000 annual emergency department visits for children with traumatic brain injuries in the United States, the risk of ionizing radiation exposure during CT examinations is a real concern. The purpose of this study was to assess the validity of rapid MR imaging to replace CT in the follow-up imaging of patients with head trauma.

MATERIALS AND METHODS

A retrospective review of 103 pediatric patients who underwent initial head CT and subsequent follow-up rapid MR imaging between January 2010 and July 2013 was performed. Patients had minor head injuries (Glasgow Coma Scale, >13) that required imaging. Initial head CT was performed, with follow-up rapid MR imaging completed within 48 hours. A board-certified neuroradiologist, blinded to patient information and scan parameters, then independently interpreted the randomized cases.

RESULTS

There was almost perfect agreement in the ability to detect extra-axial hemorrhage on rapid MR imaging and CT (κ = 0.84, P < .001). Evaluation of hemorrhagic contusion/intraparenchymal hemorrhage demonstrated a moderate level of agreement between MR imaging and CT (κ = 0.61, P < .001). The ability of MR imaging to detect a skull fracture also showed a substantial level of agreement with CT (κ = 0.71, P < .001). Detection of diffuse axonal injury demonstrated a slight level of agreement between MR imaging and CT (κ = 0.154, P = .04). However, the overall predictive agreement for the detection of an axonal injury was 91%.

CONCLUSIONS

Rapid MR imaging is a valid technique for detecting traumatic cranial injuries and an adequate examination for follow-up imaging in lieu of repeat CT.

Structural changes of the choroid in sarcoid- and tuberculosis-related granulomatous uveitis

AIM

The aim of this study is to characterise the choroidal features of patients diagnosed with sarcoid- and tuberculosis (TB)-associated granulomatous uveitis using spectral domain optical coherence tomography (OCT).

METHODS

Twenty-seven patients (27 eyes) diagnosed with sarcoid- (13 eyes) and TB (14 eyes)-related uveitis were included in this retrospective, cross-sectional study. Over a six-month period, patients diagnosed with sarcoid and TB granulomatous uveitis were scanned using enhanced depth imaging OCT. Clinical and demographical characteristics were recorded, including the method of diagnosis, disease activity, site of inflammation (anterior or posterior), treatments, and visual acuity (VA). Manual segmentation of the choroidal layers was performed using custom image analysis software.

RESULTS

The main outcome measure was OCT-derived thickness measurements of the choroid and choroidal sublayers (Haller's large vessel and Sattler's medium vessel layers) at the macula region. The ratio of Haller's large vessel to Sattler's medium vessel layer was significantly different at the total macula circle in eyes diagnosed with TB uveitis (1.47 (=140.71/95.72 μm)) compared with sarcoid uveitis (1.07 (=137.70/128.69 μm)) (P=0.001). A thinner choroid was observed in eyes with a VA ≥0.3 LogMAR (Snellen 6/12; 198.1 μm (interquartile range (IQR)=147.0-253.4 μm) compared with those with VA <0.3 LogMAR (292.4 μm (IQR=240.1-347.6 μm)) at the total macula circle (P=0.004). At the foveal central subfield, the median choroidal thickness was 336.8 μm (IQR=272.3-375.4 μm) in active compared with 239.3 μm (IQR=195.3-330.9 μm) in quiescent disease (P=0.04).

CONCLUSION

A disproportionately enlarged Sattler's layer may indicate a diagnosis of sarcoid-related uveitis, and choroidal thickening may be a feature of active granulomatous uveitis.

Observation and quantification of nanoscale processes in lithium batteries by operando electrochemical (S)TEM

An operando electrochemical stage for the transmission electron microscope has been configured to form a "Li battery" that is used to quantify the electrochemical processes that occur at the anode during charge/discharge cycling. Of particular importance for these observations is the identification of an image contrast reversal that originates from solid Li being less dense than the surrounding liquid electrolyte and electrode surface. This contrast allows Li to be identified from Li-containing compounds that make up the solid-electrolyte interphase (SEI) layer. By correlating images showing the sequence of Li electrodeposition and the evolution of the SEI layer with simultaneously acquired and calibrated cyclic voltammograms, electrodeposition, and electrolyte breakdown processes can be quantified directly on the nanoscale. This approach opens up intriguing new possibilities to rapidly visualize and test the electrochemical performance of a wide range of electrode/electrolyte combinations for next generation battery systems.

Vibration platform for mice to deliver precise, low intensity mechanical signals to the musculoskeleton

OBJECTIVE

Low intensity vibration as a therapeutic and training modality has received increased attention despite the lack of clear mechanistic pathways. Thus, to determine mechanisms underpinning vibration-induced musculoskeletal adaptations, a vibration platform for mice was designed, constructed, and validated.

METHODS

Critical aspects of the platform include use of off-the-shelf components to (1) tailor individual parameter selection (acceleration and frequency), (2) produce low error across the plate's surface and throughout the range of vibration parameters, and (3) utilize accelerometer feedback to ensure fidelity within and between bouts of vibration. The vibration device is controlled by a centrally-mounted linear actuator on the underside of the platform that is modulated by accelerometer feedback.

RESULTS

Triaxial accelerometers confirmed that vibrations were purely vertical and acceleration responses were within 5% of target stimuli for all accelerations (0.2-1.0 g) and frequencies (25-90 Hz). The platform produced acceleration responses with ≤4% error between 25-90 Hz. Vibration modes were not detected indicating that the circular plate produced uniform stimuli across the platform (error ≤1.1%, P≥0.23) and mouse body mass did not affect the platform's performance (P≥0.43).

CONCLUSIONS

Our vibration device for mice improves upon existing devices and enables precise, low intensity mechanical signals to be applied with confidence.

Biomechanical analysis of pedicle screw thread differential design in an osteoporotic cadaver model

BACKGROUND

Pedicle screw fixation, the standard surgical care for posterior stabilization in the thoraco-lumbar spine has a high rate of failure in osteoporotic individuals. Screw design factors and insertion techniques have been shown to influence the biomechanical performance of pedicle screws. Our objective was to investigate the biomechanical characteristics of pedicle screw fixation in osteoporotic bone by comparing standard screws with newly designed differential crest thickness dual lead screws.

METHODS

An in-vitro spinal-level paired factorial study design was used to examine thoraco-lumbar spine biomechanical outcomes for differential pedicle screw thread designs. Six cadaveric human spines (T8-L5) were tested for six groups (n=20) consisting of 2 different crest thickness and 3 different insertion techniques. Bone mineral density was assessed and peak insertion torque measured while placing one screw of new design and control on the contralateral side. Screw pullout properties were measured from classical American Society for Testing and Materials protocols.

FINDINGS

The screws designed specifically for osteoporotic bone showed significantly larger insertion torque compared with the standard screw design irrespective of insertion technique. Much of the variability in pullout failure and stiffness was explained by bone mineral density. The osteoporotic screws of different crest thickness were statistically similar to each other in all outcome measures.

INTERPRETATION

Compared with standard pedicle screws, the dual lead osteoporotic-specific pedicle screws demonstrated significantly larger insertion torques and similar pullout properties. Non-significant increased biomechanical strength was observed for thin crest compared to thick crest dual lead pedicle screws indicating their enhanced purchase in osteoporotic bone.

Skeletal muscle MRI magnetisation transfer ratio reflects clinical severity in peripheral neuropathies

MRI may provide treatment outcome measures in neuromuscular conditions. The authors assessed MRI magnetisation transfer ratios (MTRs) in lower-limb musculature as markers of pathology in peripheral neuropathies and compared the findings with associated clinical data. Ten patients with Charcot-Marie-Tooth disease type 1A (CMT1A) and nine patients with chronic inflammatory demyelinating polyneuropathy (CIDP) were compared with 10 healthy subjects. The MTR in the calf muscles was significantly lower than controls in the two patient groups (both p<0.001). The median MTRs (IQR) were 50.5(1.6) percentage units (p.u.) (control), 41.5(10.6) p.u. (CMT1A) and 39.3(8.7) p.u. (CIDP). Moreover, anterior lower leg MTR correlated strongly with strength of ankle dorsiflexion, measured with the Medical Research Council scale, in CIDP (ρ=0.88, p<0.001) and also in CMT1A (ρ=0.50, p<0.05), where MTR also showed an association with disease duration (ρ=-0.86, p<0.001). Short tau inversion recovery MRI of the same muscles showed abnormalities associated with regions of reduced MTR (p<0.001), and MTR was also reduced in other muscles otherwise deemed normal appearing (p<0.001), indicating that MTR may be more sensitive to muscle damaged by denervation than conventional MRI. The significant reductions in muscle MTR in peripheral neuropathies and the associated correlations with clinical measures indicate that MTR has potential as an imaging outcome measure in future therapeutic trials.

MRI shows increased sciatic nerve cross sectional area in inherited and inflammatory neuropathies

Measurements of the cross sectional area of the sciatic nerve are described in a group of 10 patients with genetically confirmed Charcot-Marie-Tooth disease type 1A (CMT1A), nine patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and 10 healthy controls using MRI. One mid-thigh of each individual was imaged using a short tau inversion recovery sequence and the nerve appearance evaluated radiologically with respect to the signal intensity and visibility of the internal neural structure. The cross sectional area of the sciatic nerve of each individual was measured by defining irregular enclosing regions of interest on the MRI images. The sciatic nerve area was enlarged in both CMT1A (p<0.001) and CIDP (p=0.008) compared with controls and in CMT1A compared with CIDP (p<0.001). Median (interquartile range) areas were 67.6 (16.2) mm(2) for the CIDP group, 135.9 (46.5) mm(2) for the CMT1A group and 43.3 (19.9) mm(2) for the control group. The critical upper value for discriminating pathologically enlarged nerves from normal controls with p<0.05 was 64.4 mm(2). Quantification of sciatic nerve hypertrophy on MRI may be of assistance in cases where the diagnosis is still in doubt, providing an objective pathological marker complimenting other clinical investigations.

Cytoplasmic polyadenylation element binding protein is a conserved target of tumor suppressor HRPT2/CDC73

Parafibromin, a tumor suppressor protein encoded by HRPT2/CDC73 and implicated in parathyroid cancer and the hyperparathyroidism-jaw tumor (HPT-JT) familial cancer syndrome, is part of the PAF1 transcriptional regulatory complex. Parafibromin has been implicated in apoptosis and growth arrest, but the mechanism by which its loss of function promotes neoplasia is poorly understood. In this study we report that a hypomorphic allele of hyrax (hyx), the Drosophila homolog of HRPT2/CDC73, rescues the loss-of-ventral-eye phenotype of lobe (Akt1s1). Such rescue is consistent with previous reports that hyx/parafibromin is required for the nuclear transduction of Wingless (Wg)/Wnt signals and that Wg signaling antagonizes lobe function. A screen using double hyx/lobe heterozygotes identified an additional interaction with orb and orb2, the homologs of mammalian cytoplasmic polyadenylation element binding protein (CPEB), a translational regulatory protein. Hyx and orb2 heterozygotes lived longer and were more resistant to starvation than controls. In mammalian cells, knockdown of parafibromin expression reduced levels of CPEB1. Chromatin immunoprecipitation (ChIP) showed occupancy of CPEB1 by endogenous parafibromin. Bioinformatic analysis revealed a significant overlap between human transcripts potentially regulated by parafibromin and CPEB. These results show that parafibromin may exert both transcriptional and, through CPEB, translational control over a subset of target genes and that loss of parafibromin (and CPEB) function may promote tumorigenesis in part by conferring resistance to nutritional stress.

Identification of critical residues within the conserved and specificity patches of nerve growth factor leading to survival or differentiation

Afflicted neurons in Alzheimer disease have been shown to display an imbalance in the expression of TrkA and p75(NTR) at the cell surface, and administration of nerve growth factor (NGF) has been considered and attempted for treatment. However, wild-type NGF causes extensive elaboration of neurites while providing survival support. This study was aimed at developing recombinant NGF muteins that did not support neuritogenesis while maintaining the survival response. Critical residues were identified at the ligand-receptor interface by point mutagenesis that played a greater importance in neuritogenesis versus survival. By combining point mutations, two survival-selective recombinant NGF muteins, i.e./7-84-103 and KKE/7-84-103, were generated. Both muteins reduced neuritogenesis in PC12 (TrkA(+)/p75(NTR+)) cells by >90%, while concurrently retaining near wild-type survival activity in MG139 (TrkA(+) only) and PCNA fibroblast (p75(NTR+)-only) cells. Additionally, survival in both naive and terminally differentiated PC12 cells was shown to be intermediate between NGF and negative controls. Dose-response curves with 7-84-103 showed that the differentiation curve was shifted by about 100-fold, whereas the EC(50) for survival was only increased by 3.3-fold. Surface plasmon resonance analysis revealed a 200-fold decrease in binding of 7-84-103 to TrkA. The retention of cell survival was attributed to maintenance of signaling through the Akt survival pathway with reduced MAPK signaling for differentiation. The effect of key mutations along the NGF receptor interface are transmitted inside the cell to enable the generation of survival-selective recombinant NGF muteins that may represent novel pharmacologic lead agents for the amelioration of Alzheimer disease.

Cigarette smoking and innate immunity

Cigarette smoking is a worldwide epidemic and the most prevalent cause of many diseases leading to increased morbidity and mortality globally. The impact of smoking on pathogenesis of cancer is being extensively studied however cigarette smoke as an immunosuppressant is less well recognized. Here we review the immunosuppressive effects of cigarette smoke and the mechanisms by which smoking affects host innate immunity including structural and functional changes in the respiratory ciliary epithelium, lung surfactant protein, and immune cells such as alveolar macrophages, neutrophils, lymphocytes and natural killer (NK) cells. Thus smoking cessation should be emphasized not only for prevention of cancer and coronary artery disease but also for patients with recurrent infections and immunosuppressive states.

Malignant myelomatous pleural effusion with good response to combination chemotherapy

Malignant pleural effusion in myeloma is a rare terminal event with 91 cases reported so far. Majority of the patients survive less than 4 months. We are presenting a short series of four such cases, who had a good clinical response to combination chemotherapy.

Study on clinico-epidemiological profile of HIV patients in eastern India

In this study, 438 HIV positive patients attending the HIV clinic of Sir Sundar Lal Hospital, IMS, BHU were enrolled. Of these 354 were males (mean CD4 count 179 +/- 9.3 cells/microl) and 84 were females (mean CD4 count 323 +/- 28.26 cells/microl). The mean age of the study subjects at the time of diagnosis was 32.6 years. Heterosexual contact was the commonest mode of transmission in 352 (80.4%) patients followed by blood transfusion in 2.5%. History suggestive of a risk factor for HIV transmission could not be elicited in 62 (14.1%) patients. Among male patients, 71.5% were migrant workers. Fever (70.6%), weight loss (53.3%), chronic diarrhea (43.9%) and cough (40.3%) were the common presenting symptoms. Out of the 438 patients, 66.4% had opportunistic infections at the time of reporting to the hospital. The most common opportunistic infection was tuberculosis (38.8%) followed by oropharyngeal candidiasis (20.3%) and diarrhea (12.7%). CD4 counts of the patients were significantly inversely correlated with the number of symptoms and the number of opportunistic infections (correlation coefficient were -.289 and -.236 respectively).

Complete agenesis of the right and left pulmonary arteries, with main pulmonary artery originating from the right ventricle, presenting as primary pulmonary hypertension of the newborn: case report

A female infant who had been misdiagnosed as having primary pulmonary hypertension of the newborn was found to have agenesis of the branch pulmonary arteries with collateral-dependent pulmonary circulation. The intracardiac anatomy was completely normal. Unifocalization of branch pulmonary artery was done, followed by stenting of the ductus arteriosus.

Percutaneous closure of patent foramen ovale: impact of device design on safety and efficacy

OBJECTIVE

To compare the safety and efficacy of percutaneous closure of patent foramen ovale (PFO) with the Amplatzer PFO occluder (Amplatzer) or the PFO STAR device (STAR) in patients with presumed paradoxical embolism.

METHODS

Implantation characteristics, procedural complications, residual shunt, and recurrence of thromboembolic events were recorded prospectively in 100 consecutive patients undergoing percutaneous PFO closure with the STAR (n = 50) or Amplatzer (n = 50) devices between 1998 and 2001. The study was not randomised. Device implantation was successful in all cases.

RESULTS

There were more procedural complications in the STAR than in the Amplatzer group (8/50 v 1/50, p = 0.01). More than one device placement attempt was an independent predictor of procedural complications (odds ratio (OR) 8.5, 95% confidence interval (CI) 1.3 to 55.8; p = 0.03). A residual shunt six months after PFO closure, assessed by transoesophageal contrast echocardiography, occurred more often in the STAR than the Amplatzer group (17/50 v 3/50, p = 0.004), and was predicted in the STAR group by the use of a device with a 5 mm as opposed to a 3 mm disc connector (OR 6.1, 95% CI 1.1 to 34.0; p = 0.04). The actuarial risk of recurrent thromboembolic events after 3.5 years was 16.8% (95% CI 7.6% to 34.6%) in the STAR and 2.7% (95% CI 0.4% to 17.7%) in the Amplatzer group after three years (p = 0.08).

CONCLUSIONS

Percutaneous PFO closure with the Amplatzer PFO occluder had fewer procedural complications and was more likely to be complete than with the STAR device. These findings underline the importance of device design for successful percutaneous PFO closure.

Review of readmissions due to complications from uterine fibroid embolization

AIM

To determine the frequency, nature and outcome of complications resulting in readmission to hospital following uterine artery embolization (UAE).

MATERIAL AND METHODS

A retrospective review of the medical notes and available imaging of 42 consecutive patients who had undergone elective uterine artery embolization for the treatment of fibroid disease was performed.

RESULTS

The mean age of the patients was 42 years (range 31--54 years) and seven patients (17%) were readmitted to hospital. The median time to readmission was 3 weeks (range 1-29 weeks). All seven patients were admitted with signs and symptoms of infection. In four patients an organism was isolated from high vaginal swabs, and in one patient the midstream urine sample was confirmed as the source of infection. In the other two patients no definite source of infection was identified. All patients were treated with intravenous antibiotics. Six of the seven patients responded to treatment. The remaining patient required hysterectomy for uncontrolled uterine sepsis.

CONCLUSION

Readmission following UAE is common and arises secondary to infection. Infection can occur several months after the procedure.

Noninvasive management of Indian visceral leishmaniasis: clinical application of diagnosis by K39 antigen strip testing at a kala-azar referral unit

Firm diagnosis of visceral leishmaniasis (kala-azar) requires organ aspiration and microscopic examination of tissue specimens. To determine the usefulness of noninvasive diagnosis by strip test detection of anti-K39 immunoglobulin (Ig) G antibody in blood specimens obtained by fingerstick, 143 Indian patients with suspected kala-azar (fever, splenomegaly, anemia) were studied. Of 120 strip test-positive subjects (subjects with presumed kala-azar [group A]), amphotericin B treatment induced clinical cure in 119. Of 23 strip test-negative subjects (subjects presumed to have other diseases [group B]), 16 had other disorders diagnosed at entry, 4 responded to empiric antimalarial therapy, 2 were proven to have kala-azar, and 1 died elsewhere after undergoing splenic aspiration. Six months after treatment ended, all 120 patients in group A and the 18 assessable patients in group B were healthy. In a region in India where visceral infection is prevalent, strip test detection of anti-K39 IgG is a clinically promising diagnostic guide in persons with suspected kala-azar.