Simple, narrow, and robust atomic frequency reference at 993 nm exploiting the rubidium (Rb) 5S1/2 to 6S1/2 transition using one-color two-photon excitation

We experimentally demonstrate a one-color two-photon transition from the 5S_1/2 ground state to the 6S_1/2 excited state in rubidium (Rb) vapor using a continuous wave laser at 993 nm. The Rb vapor contains both isotopes (⁸⁵Rb and ⁸⁷Rb) in their natural abundances. The electric dipole-allowed transitions are characterized by varying the power and polarization of the excitation laser. Since the optical setup is relatively simple, and the energies of the allowed levels are impervious to stray magnetic fields, this is an attractive choice for a frequency reference at 993 nm, with possible applications in precision measurements and quantum information processing.

Merging Orthovoltage X-Ray Minibeams spare the proximal tissues while producing a solid beam at the target

Conventional radiation therapy of brain tumors often produces cognitive deficits, particularly in children. We investigated the potential efficacy of merging Orthovoltage X-ray Minibeams (OXM). It segments the beam into an array of parallel, thin (~0.3 mm), planar beams, called minibeams, which are known from synchrotron x-ray experiments to spare tissues. Furthermore, the slight divergence of the OXM array make the individual minibeams gradually broaden, thus merging with their neighbors at a given tissue depth to produce a solid beam. In this way the proximal tissues, including the cerebral cortex, can be spared. Here we present experimental results with radiochromic films to characterize the method's dosimetry. Furthermore, we present our Monte Carlo simulation results for physical absorbed dose, and a first-order biologic model to predict tissue tolerance. In particular, a 220-kVp orthovoltage beam provides a 5-fold sharper lateral penumbra than a 6-MV x-ray beam. The method can be implemented in arc-scan, which may include volumetric-modulated arc therapy (VMAT). Finally, OXM's low beam energy makes it ideal for tumor-dose enhancement with contrast agents such as iodine or gold nanoparticles, and its low cost, portability, and small room-shielding requirements make it ideal for use in the low-and-middle-income countries.

An integrated transcriptomics and metabolomics analysis of the Cucurbita pepo nectary implicates key modules of primary metabolism involved in nectar synthesis and secretion

Nectar is the main reward that flowers offer to pollinators to entice repeated visitation. Cucurbita pepo (squash) is an excellent model for studying nectar biology, as it has large nectaries that produce large volumes of nectar relative to most other species. Squash is also monoecious, having both female and male flowers on the same plant, which allows comparative analyses of nectary function in one individual. Here, we report the nectary transcriptomes from both female and male nectaries at four stages of floral maturation. Analysis of these transcriptomes and subsequent confirmatory experiments revealed a metabolic progression in nectaries leading from starch synthesis to starch degradation and to sucrose biosynthesis. These results are consistent with previously published models of nectar secretion and also suggest how a sucrose-rich nectar can be synthesized and secreted in the absence of active transport across the plasma membrane. Nontargeted metabolomic analyses of nectars also confidently identified 40 metabolites in both female and male nectars, with some displaying preferential accumulation in nectar of either male or female flowers. Cumulatively, this study identified gene targets for reverse genetics approaches to study nectary function, as well as previously unreported nectar metabolites that may function in plant-biotic interactions.

Smartphone-based kanamycin sensing with ratiometric FRET

FRET aptamer based kanamycin detection enables reusable and smartphone sensing.

Isolation and molecular characterization of dengue virus clinical isolates from pediatric patients in New Delhi

OBJECTIVE

To characterize the in vitro replication fitness, viral diversity, and phylogeny of dengue viruses (DENV) isolated from Indian patients.

METHODS

DENV was isolated from whole blood collected from patients by passaging in cell culture. Passage 3 viruses were used for growth kinetics in C6/36 mosquito cells. Parallel efforts also focused on the isolation of DENV RNA from plasma samples of the same patients, which were processed for next-generation sequencing.

RESULTS

It was possible to isolate 64 clinical isolates of DENV, mostly DENV-2. Twenty-five of these were further used for growth curve analysis in vitro, which showed a wide range of replication kinetics. The highest viral titers were associated with isolates from patients with dengue with warning signs and severe dengue cases. Full genome sequences of 21 DENV isolates were obtained. Genome analysis mapped the circulating DENV-2 strains to the Cosmopolitan genotype.

CONCLUSIONS

The replication kinetics of isolates from patients with mild or severe infection did not differ significantly, but the viral titers varied by two orders of magnitude between the isolates, suggesting differences in replication fitness among the circulating DENV-2.

SIFTING FOR SAPPHIRES: SYSTEMATIC SELECTION OF TIDAL DISRUPTION EVENTS IN iPTF

We present results from a systematic selection of tidal disruption events (TDEs) in a wide-area (4800 deg²), g + R band, Intermediate Palomar Transient Factory (iPTF) experiment. Our selection targets typical optically-selected TDEs: bright (>60% flux increase) and blue transients residing in the center of red galaxies. Using photometric selection criteria to down-select from a total of 493 nuclear transients to a sample of 26 sources, we then use follow-up UV imaging with the Neil Gehrels Swift Telescope, ground-based optical spectroscopy, and light curve fitting to classify them as 14 Type Ia supernovae (SNe Ia), 9 highly variable active galactic nuclei (AGNs), 2 confirmed TDEs, and 1 potential core-collapse supernova. We find it possible to filter AGNs by employing a more stringent transient color cut (g - r < -0.2 mag); further, UV imaging is the best discriminator for filtering SNe, since SNe Ia can appear as blue, optically, as TDEs in their early phases. However, when UV-optical color is unavailable, higher precision astrometry can also effectively reduce SNe contamination in the optical. Our most stringent optical photometric selection criteria yields a 4.5:1 contamination rate, allowing for a manageable number of TDE candidates for complete spectroscopic follow-up and real-time classification in the ZTF era. We measure a TDE per galaxy rate of 1.7 - 1.3 + 2.9 × 10 - 4 gal - 1 yr - 1 (90% CL in Poisson statistics). This does not account for TDEs outside our selection criteria, thus may not reflect the total TDE population, which is yet to be fully mapped.

The Octadecanoid Pathway, but Not COI1, Is Required for Nectar Secretion in Arabidopsis thaliana

Over 75% of crop species produce nectar and are dependent on pollinators to achieve maximum seed set, yet little is known about the mechanisms regulating nectar secretion. The phytohormone jasmonic acid (JA) is recognized to be involved in several plant processes including development and defense. JA was also recently shown to positively influence nectar secretion in both floral and extrafloral nectaries. For example, endogenous JA levels peak in flowers just prior to nectar secretion, but the details of how JA regulates nectar secretion have yet to be elucidated. We have found that the octadecanoid pathway does indeed play a role in the production and regulation of floral nectar in Arabidopsis. Null alleles for several JA biosynthesis and response genes had significantly reduced amounts of nectar, as well as altered expression of genes known to be involved in nectar production. We additionally identified crosstalk between the JA and auxin response pathways in nectaries. For example, the nectar-less JA synthesis mutant aos-2 showed no auxin response in nectaries, but both nectar production and the auxin response were restored upon exogenous JA and auxin treatment. Conversely, coi1-1, a JA-Ile-insensitive receptor mutant, displayed no auxin response in nectaries under any circumstance, even in older flowers that produced nectar. Surprisingly, opr3-1, a mutant for 12-oxophytodienoate reductase 3 [an enzyme further down the JA biosynthetic pathway that reduces 12-oxo phytodienoic acid (OPDA)], produced no nectar in newly opened flowers, but did secrete nectar in older flowers. Furthermore, a similar phenotype was observed in coi1-1. Cumulatively, these observations strongly suggest an indispensable role for an octadecanoic acid- and auxin-dependent, but JA- and COI1-dispensible, pathway in regulating nectar production in Arabidopsis.

Single-molecule fluorescence imaging: Generating insights into molecular interactions in virology

Single-molecule fluorescence methods remain a challenging yet information-rich set of techniques that allow one to probe the dynamics, stoichiometry and conformation of biomolecules one molecule at a time. Viruses are small (nanometers) in size, can achieve cellular infections with a small number of virions and their lifecycle is inherently heterogeneous with a large number of structural and functional intermediates. Single-molecule measurements that reveal the complete distribution of properties rather than the average can hence reveal new insights into virus infections and biology that are inaccessible otherwise. This article highlights some of the methods and recent applications of single-molecule fluorescence in the field of virology. Here, we have focused on new findings in virus-cell interaction, virus cell entry and transport, viral membrane fusion, genome release, replication, translation, assembly, genome packaging, egress and interaction with host immune proteins that underline the advantage of single-molecule approach to the question at hand. Finally, we discuss the challenges, outlook and potential areas for improvement and future use of single-molecule fluorescence that could further aid our understanding of viruses.

Modeling how reversal of immune exhaustion elicits cure of chronic hepatitis C after the end of treatment with direct-acting antiviral agents

A fraction of chronic hepatitis C patients treated with direct‐acting antivirals (DAAs) achieved sustained virological responses (SVR), or cure, despite having detectable viremia at the end of treatment (EOT). This observation, termed EOT⁺/SVR, remains puzzling and precludes rational optimization of treatment durations. One hypothesis to explain EOT⁺/SVR, the immunologic hypothesis, argues that the viral decline induced by DAAs during treatment reverses the exhaustion of cytotoxic T lymphocytes (CTLs), which then clear the infection after treatment. Whether the hypothesis is consistent with data of viral load changes in patients who experienced EOT⁺/SVR is unknown. Here, we constructed a mathematical model of viral kinetics incorporating the immunologic hypothesis and compared its predictions with patient data. We found the predictions to be in quantitative agreement with patient data. Using the model, we unraveled an underlying bistability that gives rise to EOT⁺/SVR and presents a new avenue to optimize treatment durations. Infected cells trigger both activation and exhaustion of CTLs. CTLs in turn kill infected cells. Due to these competing interactions, two stable steady states, chronic infection and viral clearance, emerge, separated by an unstable steady state with intermediate viremia. When treatment during chronic infection drives viremia sufficiently below the unstable state, spontaneous viral clearance results post‐treatment, marking EOT⁺/SVR. The duration to achieve this desired reduction in viremia defines the minimum treatment duration required for ensuring SVR, which our model can quantify. Estimating parameters defining the CTL response of individuals to HCV infection would enable the application of our model to personalize treatment durations.

Correlating Transcription Initiation and Conformational Changes by a Single-Subunit RNA Polymerase with Near Base-Pair Resolution

We provide a comprehensive analysis of transcription in real time by T7 RNA Polymerase (RNAP) using single-molecule fluorescence resonance energy transfer by monitoring the entire life history of transcription initiation, including stepwise RNA synthesis with near base-pair resolution, abortive cycling, and transition into elongation. Kinetically branching pathways were observed for abortive initiation with an RNAP either recycling on the same promoter or exchanging with another RNAP from solution. We detected fast and slow populations of RNAP in their transition into elongation, consistent with the efficient and delayed promoter release, respectively, observed in ensemble studies. Real-time monitoring of abortive cycling using three-probe analysis showed that the initiation events are stochastically branched into productive and failed transcription. The abortive products are generated primarily from initiation events that fail to progress to elongation, and a majority of the productive events transit to elongation without making abortive products.

Review: Nectar biology: From molecules to ecosystems

Plants attract mutualistic animals by offering a reward of nectar. Specifically, floral nectar (FN) is produced to attract pollinators, whereas extrafloral nectar (EFN) mediates indirect defenses through the attraction of mutualist predatory insects to limit herbivory. Nearly 90% of all plant species, including 75% of domesticated crops, benefit from animal-mediated pollination, which is largely facilitated by FN. Moreover, EFN represents one of the few defense mechanisms for which stable effects on plant health and fitness have been demonstrated in multiple systems, and thus plays a crucial role in the resistance phenotype of plants producing it. In spite of its central role in plant-animal interactions, the molecular events involved in the development of both floral and extrafloral nectaries (the glands that produce nectar), as well as the synthesis and secretion of the nectar itself, have been poorly understood until recently. This review will cover major recent developments in the understanding of (1) nectar chemistry and its role in plant-mutualist interactions, (2) the structure and development of nectaries, (3) nectar production, and (4) its regulation by phytohormones.

TNO1, a TGN-localized SNARE-interacting protein, modulates root skewing in Arabidopsis thaliana

BACKGROUND

The movement of plant roots within the soil is key to their ability to interact with the environment and maximize anchorage and nutrient acquisition. Directional growth of roots occurs by a combination of sensing external cues, hormonal signaling and cytoskeletal changes in the root cells. Roots growing on slanted, impenetrable growth medium display a characteristic waving and skewing, and mutants with deviations in these phenotypes assist in identifying genes required for root movement. Our study identifies a role for a trans-Golgi network-localized protein in root skewing.

RESULTS

We found that Arabidopsis thaliana TNO1 (TGN-localized SYP41-interacting protein), a putative tethering factor localized at the trans-Golgi network, affects root skewing. tno1 knockout mutants display enhanced root skewing and epidermal cell file rotation. Skewing of tno1 roots increases upon microtubule stabilization, but is insensitive to microtubule destabilization. Microtubule destabilization leads to severe defects in cell morphology in tno1 seedlings. Microtubule array orientation is unaffected in the mutant roots, suggesting that the increase in cell file rotation is independent of the orientation of microtubule arrays.

CONCLUSIONS

We conclude that TNO1 modulates root skewing in a mechanism that is dependent on microtubules but is not linked to disruption of the orientation of microtubule arrays. In addition, TNO1 is required for maintenance of cell morphology in mature regions of roots and the base of hypocotyls. The TGN-localized SNARE machinery might therefore be important for appropriate epidermal cell file rotation and cell expansion during root growth.

Floquet Topological Order in Interacting Systems of Bosons and Fermions

Periodically driven noninteracting systems may exhibit anomalous chiral edge modes, despite hosting bands with trivial topology. We find that these drives have surprising many-body analogs, corresponding to class A, which exhibit anomalous charge and information transport at the boundary. Drives of this form are applicable to generic systems of bosons, fermions, and spins, and may be characterized by the anomalous unitary operator that acts at the edge of an open system. We find that these operators are robust to all local perturbations and may be classified by a pair of coprime integers. This defines a notion of dynamical topological order that may be applied to general time-dependent systems, including many-body localized phases or time crystals.

Long-term results and recurrence patterns from SCOPE-1: a phase II/III randomised trial of definitive chemoradiotherapy +/- cetuximab in oesophageal cancer

BACKGROUND

The SCOPE-1 study tested the role of adding cetuximab to conventional definitive chemoradiotherapy (dCRT), and demonstrated greater toxicity and worse survival outcomes. We present the long-term outcomes and patterns of recurrence.

METHODS

SCOPE-1 was a phase II/III trial in which patients were randomised to cisplatin 60 mg m-2 (day 1) and capecitabine 625 mg m-2 bd (days 1-21) for four cycles +/- cetuximab 400 mg m-2 day 1 then by 250 mg m-2 weekly. Radiotherapy consisted of 50 Gy/25# given concurrently with cycles 3 and 4. Recruitment was between February 2008 and February 2012, when the IDMC recommended closure on the basis of futility.

RESULTS

About 258 patients (dCRT=129; dCRT+cetuximab (dCRT+C)=129) were recruited from 36 centres. About 72.9% (n=188) had squamous cell histology. The median follow-up (IQR) was 46.2 (35.9-48.3) months for surviving patients. The median overall survival (OS; months; 95% CI) was 34.5 (24.7-42.3) in dCRT and 24.7 (18.6-31.3) in dCRT+C (hazard ratio (HR)=1.25, 95% CIs: 0.93-1.69, P=0.137). Median progression-free survival (PFS; months; 95% CI) was 24.1 (15.3-29.9) and 15.9 (10.7-20.8) months, respectively (HR=1.28, 95% CIs: 0.94-1.75; P=0.114). On multivariable analysis only earlier stage, full-dose RT, and higher cisplatin dose intensity were associated with improved OS.

CONCLUSIONS

The mature analysis demonstrates that the dCRT regimen used in the study provided useful survival outcomes despite its use in patients who were largely unfit for surgery or who had inoperable disease. Given the competing risk of systemic and local failure, future studies should continue to focus on enhancing local control as well as optimising systemic therapy.

A randomised phase II trial and feasibility study of palliative chemotherapy in frail or elderly patients with advanced gastroesophageal cancer (321GO)

BACKGROUND

Elderly patients are commonly under-represented in cancer clinical trials. The 321GO was undertaken in preparation for a definitive phase three trial assessing different chemotherapy regimens in a frail and/or elderly population with advanced gastroesophageal (GO) cancer.

METHODS

Patients with advanced GO cancer considered unfit for conventional dose chemotherapy were randomly assigned in a 1 : 1 : 1 ratio to: epirubicin, oxaliplatin and capecitabine (EOX); oxaliplatin and capecitabine (OX); and capecitabine alone (X) (all 80% of full dose and unblinded). The primary end point was patient recruitment over an 18-month period. A registration study recorded treatment choice for all patients with advanced GO cancer at trial centres.

RESULTS

A total of 313 patients were considered for palliative chemotherapy for GO cancer over the 18-month period: 115 received full dose treatment, 89 less than standard treatment or entered 321GO and 111 no treatment. Within 321GO, 55 patients were randomly assigned (19 to OX and X; 17 to EOX). Progression-free survival (PFS) for all patients was 4.4 months and by arm 5.4, 5.6 and 3.0 months for EOX, OX and X, respectively. The number of patients with a good overall treatment utility (OTU), a novel patient-centred endpoint, at 12 weeks was 3 (18%), 6 (32%) and 1 (6%) for EOX, OX and X, respectively. At 6 weeks, 22 patients (41%) had experienced a non-haematologic toxicity ⩾grade 3, most commonly lethargy or diarrhoea. The OTU was prognostic for overall survival in patients alive at week 12 (logrank test P=0.0001).

CONCLUSIONS

It is feasible to recruit elderly and/or frail patients with advanced GO cancer to a randomised clinical trial. The OX is the preferred regimen for further study. Overall treatment utility shows promise as a comparator between treatment regimens for feasibility and randomised trials in the elderly and/or frail GO cancer population.

Primary Testicular Leiomyosracoma with Local Recurrence: a Case Report

Primary testicular leiomyosarcomas (LMS) are very rare tumours, with only 20 cases reported so far in the literature (Abdullazade et al. Turk Patoloji Derg 29:227-230, 2013; Komeya et al. Indian J Urol 28:343-346, 2012). We present a case of a 70-year-old male patient who presented with recurrence in the right hemiscrotum 10 weeks after right inguinal orchidectomy for a testicular mass which diagnosed as primary intratesticular leiomyosarcoma. He was treated with wide local excision and adjuvant radiotherapy.

Geometry of the Poisson Boolean model on a region of logarithmic width in the plane

Consider the region L = {(x, y): 0 ≤ y ≤ Clog(1 + x), x > 0} for a constant C > 0. We study the percolation and coverage properties of this region. For the coverage properties, we place a Poisson point process of intensity λ on the entire half space R+ x R and associated with each Poisson point we place a box of a random side length ρ. Depending on the tail behaviour of the random variable ρ we exhibit a phase transition in the intensity for the eventual coverage of the region L. For the percolation properties, we place a Poisson point process of intensity λ on the region R2. At each point of the process we centre a box of a random side length ρ. In the case ρ ≤ R for some fixed R > 0 we study the critical intensity λc of the percolation on L.

On the coverage of space by random sets

Let ξ1, ξ2,… be a Poisson point process of density λ on (0,∞)d, d ≥ 1, and let ρ, ρ1, ρ2,… be i.i.d. positive random variables independent of the point process. Let C := ⋃i≥1 {ξi + [0,ρi]d}. If, for some t > 0, (0,∞)d ⊆ C, then we say that (0,∞)d is eventually covered by C. We show that the eventual coverage of (0,∞)d depends on the behaviour of xP(ρ > x) as x → ∞ as well as on whether d = 1 or d ≥ 2. These results may be compared to those known for complete coverage of ℝd by such Poisson Boolean models. In addition, we consider the set ⋃{i≥1:Xi=1} [i,i+ρi], where X1, X2,… is a {0,1}-valued Markov chain and ρ1, ρ2,… are i.i.d. positive-integer-valued random variables independent of the Markov chain. We study the eventual coverage properties of this random set.

On a random directed spanning tree

We study the asymptotic properties of a minimal spanning tree formed by n points uniformly distributed in the unit square, where the minimality is amongst all rooted spanning trees with a direction of growth. We show that the number of branches from the root of this tree, the total length of these branches, and the length of the longest branch each converges weakly. This model is related to the study of record values in the theory of extreme-value statistics and this relation is used to obtain our results. The results also hold when the tree is formed from a Poisson point process of intensity n in the unit square.

Factors influencing the uptake of neonatal bereavement support services - Findings from two tertiary neonatal centres in the UK

BACKGROUND

Research on perinatal bereavement services is limited. The aim of the study was to compare the uptake of bereavement support services between two tertiary neonatal units (NNU), and to investigate influencing factors.

METHOD

The medical and bereavement records of all neonatal deaths were studied from January 2006 to December 2011. Data collected included parent and baby characteristics, mode of death, consent for autopsy and bereavement follow-up. The categorical data were compared by chi-square or Fisher's exact test and continuous data by Wilcoxon signed-rank test; a multivariable regression analysis was performed using STATA 12.0.

RESULTS

The neonatal deaths of 297 babies (182 in NNU1 and 115 in NNU2) with full datasets were analysed. Baby characteristics were similar between units except for lower median gestational age in NNU1 (p = 0.03). Significantly more NNU1 parents were non-Caucasian (p < 0.01), from lower socio-economic status (p = 0.01) and had previous stillbirth/miscarriage (p = 0.03). More babies had care withdrawn in NNU2 (p < 0.01). A significantly higher proportion of parents from NNU1 (61 %) attended bereavement follow-up compared to NNU2 (34 %; p < 0.01). On multivariable analysis, significantly more parents who were married or co-habiting (p = 0.02) and consented for an autopsy (p = 0.01) attended bereavement services.

CONCLUSION

Uptake of bereavement services varied between the two NNUs, which could be due to differences in the ethnic and socio-economic mix of the population. Significantly more parents who were married or co-habiting, or consented for autopsy, attended bereavement follow up services.

Expedient synthesis of functional single-component glycoliposomes using thiol-yne chemistry

The preparation of a set of eight unprecedented amphiphilic neoglycolipids forming liposome nanoparticles is reported. The small library was readily obtained from various peracetylated propargyl glycopyranosides via efficient radical-initiated thiol-yne (TYC) coupling reactions using alkanethiols of different chain lengths. In addition, using sequential thiol-yne, both the nature and positioning of the lipophilic alkanethiols could be varied at will, thus providing unparalleled variability within the glycolipid structures. Two different classes of self-assemblies were prepared from the new neoglycolipids. First, liposomes of 150-300 nm were obtained by solvent injection of their ethanol or tetrahydrofuran (THF) solution in water. The resulting structures were analyzed by dynamic light scattering (DLS) and atomic force microscopy (AFM). The mannosylated lipid nanoparticle (compound 14) showed good stability in water. Alternatively, giant soft unilamellar vesicles were also obtained by film hydration and visualized by differential interference contrast microscopy (DIC). Incorporation of a hydrophobic dye to the solution prior to evaporation allowed visualization by confocal microscopy. Finally, the biological functions of the newly formed glycolipid vesicles were evaluated by multivalent carbohydrate-protein binding interactions using concanavalin A (ConA). Agglutination assays and the binding of glycolipid by dendritic cells (DCs) resulted in an increase in DCs immunostimulatory potential. Importantly, we did not see changes in cells viability at tested doses. This study provides a new, simple and highly efficient methodology to produce novel glyconanoparticle candidate as model in development of vaccine adjuvant and drug delivery system.

Critical intensities of Boolean models with different underlying convex shapes

We consider the Poisson Boolean model of percolation where the percolating shapes are convex regions. By an enhancement argument we strengthen a result of Jonasson (2000) to show that the critical intensity of percolation in two dimensions is minimized among the class of convex shapes of unit area when the percolating shapes are triangles, and, for any other shape, the critical intensity is strictly larger than this minimum value. We also obtain a partial generalization to higher dimensions. In particular, for three dimensions, the critical intensity of percolation is minimized among the class of regular polytopes of unit volume when the percolating shapes are tetrahedrons. Moreover, for any other regular polytope, the critical intensity is strictly larger than this minimum value.

Post-traumatic endophthalmitis in 143 eyes of children and adolescents from India

PURPOSE

The purpose of this study was to describe clinical features, risk factors, causative organisms, treatment options, and outcomes of post-traumatic endophthalmitis in children and adolescents.

METHODS

Retrospective interventional case series. Case records of 143 consecutive eyes presenting with post-traumatic endophthalmitis between 1997 and 2007 were reviewed. Univariate and multivariate analysis were done to analyze factors associated with adverse outcomes.

RESULTS

Mean age at presentation was 9.2 years (median 8 years, range: 2 months to 18 years). Broomstick and hypodermic needle were most common causes for injuries. Common presenting features were cataract (n=51), hypopyon (n=45) and retinal detachment (n=29). Corneal abscess (n=21; OR: 5, CI: 1.4-18.7) and retinal detachment (n=29, OR: 5, CI: 1.6-11.3) were independent risk factors for poor outcome (P=0.04 and 0.012, respectively). Gram-positive bacteria were isolated in 54% (n=31) of culture-positive cases. Forty-nine (34%) patients had ambulatory vision at final visit. Patients who received treatment within 24 h were 3.6 and 9 times more likely to have better anatomical outcome than those treated at 2-7 days, or >7 days, respectively (P=0.0001). Patients undergoing early vitrectomy were 27 times more likely to have better outcome (P=0.0001).

CONCLUSION

Post-traumatic endophthalmitis in children is more common in boys <10 years of age and most often caused by injury with organic matter. Corneal abscess and retinal detachment are associated with poor outcome. E. fecalis is the most common causative organism. Early vitrectomy results in better outcomes.