Peripheral neuron plasticity is enhanced by brief electrical stimulation and overrides attenuated regrowth in experimental diabetes

Peripheral nerve regrowth is less robust than commonly assumed, particularly when it accompanies common clinical scenarios such as diabetes mellitus. Brief extracellular electrical stimulation (ES) facilitates the regeneration of peripheral nerves in part through early activation of the conditioning injury response and BDNF. Here, we explored intrinsic neuronal responses to ES to identify whether ES might impact experimental diabetes, where regeneration is attenuated. ES altered several regeneration related molecules including rises in tubulin, Shh (Sonic hedgehog) and GAP43 mRNAs. ES was associated with rises in neuronal intracellular calcium but its strict linkage to regrowth was not confirmed. In contrast, we identified PI3K-PTEN involvement, an association previously linked to diabetic regenerative impairment. Following ES there were declines in PTEN protein and mRNA both in vitro and in vivo and a PI3K inhibitor blocked its action. In vitro, isolated diabetic neurons were capable of mounting robust responsiveness to ES. In vivo, ES improved electrophysiological and behavioral indices of nerve regrowth in a chronic diabetic model of mice with pre-existing neuropathy. Regrowth of myelinated axons and reinnervation of the epidermis were greater following ES than sham stimulation. Taken together, these findings identify a role for ES in supporting regeneration during the challenges of diabetes mellitus.

Autologous bone marrow cell transplantation in acute spinal cord injury--an Indian pilot study

STUDY DESIGN

Phase- I/II, prospective, randomized, single-blind, controlled pilot study.

PRIMARY OBJECTIVE

To determine the safety and feasibility of autologous bone marrow transplantation in patients with acute spinal cord injury (SCI) via two routes of transplantation as compared with controls.

SETTING

Indian Spinal Injuries Center, New Delhi.

METHODS

Twenty-one subjects with acute, American Spinal Injury Association Impairment Scale (AIS) A (complete), traumatic SCI with neurological level T1-T12, were recruited and randomized into three groups of seven subjects each. Two groups underwent cell transplantation through the intrathecal or intralesional route, whereas the third served as control. Participants were assessed at baseline and followed up at 6 months and 12-months post enrollment. Safety and tolerability were evaluated by monitoring for any adverse events. Efficacy was assessed through neurological, functional and psychological evaluation, as well as through electrophysiological studies and urodynamics.

RESULTS

Surgery was tolerated well by all participants. There were no significant adverse events attributable to the procedure. There was no significant improvement in the neurological, electrophysiological or urodynamic efficacy variables. A statistically significant improvement in functional scores as evaluated by the Spinal Cord Independence Measure and International Spinal Cord Injury Scale was observed in all groups.

CONCLUSIONS

The procedure is safe and feasible in AIS A participants with thoracic-level injuries at 12-months follow-up. No efficacy could be demonstrated that could be attributed to the procedure.

Correlation between measures of hypoglycemia and glycemic improvement in sulfonylurea treated patients with type 2 diabetes in India: results from the OBSTACLE hypoglycemia study

BACKGROUND

This study aimed to assess correlation between measures of hypoglycemia and glycemic control in patients with type 2 diabetes mellitus (T2DM) treated with sulfonylureas.

MATERIALS AND METHODS

T2DM patients being initiated on a sulfonylurea (SU) on background of a failing oral antihyperglycemic regimen were followed up for 12 weeks. (HbA1c) was measured at baseline and end of follow-up. Hypoglycemia was assessed using Stanford Hypoglycemia Questionnaire at week 12.

RESULTS

Of the total 1069 patients enrolled, 950 were considered evaluable. A weak negative correlation was observed between end of follow-up HbA1c values and hypoglycemia score, using both linear regression analysis (correlation coefficient -0.12; P = 0.0002) and negative binomial regression (β slope -0.09; P = 0.0010). A similar correlation was also observed between change in HbA1c from baseline and hypoglycemia score (β slope -0.07; P = 0.0048). Mean HbA1c reduction was lowest (0.65 ± 2.27%) in patients not reporting any hypoglycemia and highest (1.28 ± 2.40%) in patients with hypoglycemia score greater than median of 2 (P = 0.0031). There was no correlation between hypoglycemia frequency and end of follow-up HbA1c values (P = 0.4111).

CONCLUSION

With addition of SU on a background of a failing oral anti-hyperglycemic regimen, the extent of glycemic control correlates directly with measures of patient reported hypoglycemia.

Measurement of Long-Range Angular Correlation and Quadrupole Anisotropy of Pions and (Anti)Protons in Central d+Au Collisions at sqrt[s_{NN}]=200 GeV

We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d+Au and minimum bias p+p collisions at sqrt[s_{NN}]=200 GeV. The charged hadron is measured at midrapidity |η|<0.35, and the energy is measured at large rapidity (-3.7<η<-3.1, Au-going direction). An enhanced near-side angular correlation across |Δη|>2.75 is observed in d+Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v_{2} for inclusive charged hadrons at midrapidity up to p_{T}=4.5 GeV/c. We also present the measurement of v_{2} for identified π^{±} and (anti)protons in central d+Au collisions, and observe a mass-ordering pattern similar to that seen in heavy-ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p+Pb at sqrt[s_{NN}]=5.02 TeV. The magnitude of the mass ordering in d+Au is found to be smaller than that in p+Pb collisions, which may indicate smaller radial flow in lower energy d+Au collisions.

Beware of parotitis induced by iodine-containing contrast media

Carotid stenting is being increasingly used for revascularization of the moderate to severe carotid stenosis and thus its complications are increasingly being recognized. We report a rare complication of induced by iodine contrast in a patient undergoing carotid stenting. s. A 51 year old man after the second stenting developed multiple small infarcts in spite of the distal device. He also had painful parotid swelling which improved within a week. One should be aware of iodine parotitis s in the patients undergoing iodinated contrast study.

Hepatocyte nuclear factor-1β: A regulator of kidney development and cystogenesis

The understanding of the genomics of the renal tissue has gathered a considerable interest and is making rapid progress. The molecular mechanisms as well as the precise function of the associated molecular components toward renal pathophysiology have recently been realized. For the cystic kidney disease, the regulation of gene expression affecting epithelial cells proliferation, apoptosis as well as process of differentiation/de-differentiation represent key molecular targets. For the cystic disorders, molecular targets have been identified, which besides lending heterogeneity to cysts may also provide tools to unravel their functional importance to understand the renal tissue homeostasis. This review focuses on providing comprehensive information about the transcriptional regulatory role of hepatocyte nuclear factor-1β, a homeoprotein, as well as its interacting partners in renal tissue development and pathophysiology.

Incremental increase in percentage mouth opening after coronoidectomy in temporomandibular joint ankylosis

The aim of this study was to evaluate the incremental improvement in mouth opening following coronoidectomy. Twenty-three patients with unilateral temporomandibular joint (TMJ) ankylosis (Sawhney types I-III) were assessed preoperatively; physical and radiological examinations were done (panoramic radiography and computed tomography). Data including demographic and clinical parameters were recorded. Patients with bilateral ankylosis, recurrent cases, and those with Sawhney type IV TMJ ankylosis were not included. The improvement in mouth opening was measured after ostectomy, after ipsilateral coronoidectomy, and after contralateral coronoidectomy. The improvements in mouth opening at each stage were analysed using the Student's t-test and Pearson's correlation coefficient. There was a marked improvement in maximal incisal opening (MIO) from 5.7 ± 4.2mm to 23.7 ± 5.9 mm after removal of the ankylotic bony mass. MIO was significantly increased after ipsilateral coronoidectomy (31.6 ± 7.4mm), and after contralateral coronoidectomy, a mean MIO of 39.4 ± 11.2mm was achieved. At more than 1 year of follow-up, all patients showed improved mouth opening. In conclusion, coronoidectomy plays an important role in improving mouth opening in the treatment of TMJ ankylosis.

New Family of Generalized Metrics for Comparative Imaging System Evaluation

A family of imaging task-specific metrics designated Relative Object Detectability (ROD) metrics was developed to enable objective, quantitative comparisons of different x-ray systems. Previously, ROD was defined as the integral over spatial frequencies of the Fourier Transform of the object function, weighted by the detector DQE for one detector, divided by the comparable integral for another detector. When effects of scatter and focal spot unsharpness are included, the generalized metric, GDQE, is substituted for the DQE, resulting in the G-ROD metric. The G-ROD was calculated for two different detectors with two focal spot sizes using various-sized simulated objects to quantify the improved performance of new high-resolution CMOS detector systems. When a measured image is used as the object, a Generalized Measured Relative Object Detectability (GM-ROD) value can be generated. A neuro-vascular stent (Wingspan) was imaged with the high-resolution Micro-Angiographic Fluoroscope (MAF) and a standard flat panel detector (FPD) for comparison using the GM-ROD calculation. As the lower integration bound increased from 0 toward the detector Nyquist frequency, increasingly superior performance of the MAF was evidenced. Another new metric, the R-ROD, enables comparing detectors to a reference detector of given imaging ability. R-RODs for the MAF, a new CMOS detector and an FPD will be presented. The ROD family of metrics can provide quantitative more understandable comparisons for different systems where the detector, focal spot, scatter, object, techniques or dose are varied and can be used to optimize system selection for given imaging tasks.

Anti-scatter grid artifact elimination for high resolution x-ray imaging CMOS detectors

Higher resolution in dynamic radiological imaging such as angiography is increasingly being demanded by clinicians; however, when standard anti-scatter grids are used with such new high resolution detectors, grid-line artifacts become more apparent resulting in increased structured noise that may overcome the contrast signal improvement benefits of the scatter-reducing grid. Although grid-lines may in theory be eliminated by dividing the image of a patient taken with the grid by a flat-field image taken with the grid obtained prior to the clinical image, unless the remaining additive scatter contribution is subtracted in real-time from the dynamic clinical image sequence before the division by the reference image, severe grid-line artifacts may remain. To investigate grid-line elimination, a stationary Smit Röntgen X-ray grid (line density: 70 lines/cm, grid ratio 13:1) was used with both a 75 micron-pixel CMOS detector and a standard 194 micron-pixel flat panel detector (FPD) to image an artery block insert placed in a modified uniform frontal head phantom for a 20 × 20cm FOV (approximately). Contrast and contrast-to-noise ratio (CNR) were measured with and without scatter subtraction prior to grid-line correction. The fixed pattern noise caused by the grid was substantially higher for the CMOS detector compared to the FPD and caused a severe reduction of CNR. However, when the scatter subtraction corrective method was used, the removal of the fixed pattern noise (grid artifacts) became evident resulting in images with improved CNR.

Secukinumab administration by pre-filled syringe: efficacy, safety and usability results from a randomized controlled trial in psoriasis (FEATURE)

BACKGROUND

Secukinumab, a fully human anti-interleukin-17A monoclonal antibody, demonstrated efficacy and safety in moderate-to-severe plaque psoriasis when administered via subcutaneous injection. Self-administration by pre-filled syringe (PFS) can offer patients clinical benefits of a drug, with increased convenience.

OBJECTIVES

To assess efficacy, safety and usability of secukinumab administration via PFS in subjects with moderate-to-severe plaque psoriasis.

MATERIALS AND METHODS

Subjects in this phase 3 trial were randomized 1 : 1 : 1 to secukinumab 300 or 150 mg or matching placebo. Results to week 12 are presented here. Each treatment was delivered using a PFS once weekly to week 4, and again at week 8. Co-primary endpoints were secukinumab superiority over placebo for week 12 PASI 75 (≥ 75% reduction in Psoriasis Area and Severity Index) and IGA mod 2011 (2011 modified Investigator's Global Assessment) 0/1 response rates. Secondary endpoints included PFS usability, determined by observer rating of successful, hazard-free self-injection and subject rating of acceptability by the Self-Injection Assessment Questionnaire (SIAQ).

RESULTS

Co-primary endpoints were met, with demonstration of superiority for each secukinumab dose vs. placebo at week 12 (PASI 75: 75·9%, 69·5% and 0% for secukinumab 300 mg, 150 mg and placebo; IGA mod 2011 0/1: 69·0%, 52·5% and 0%, respectively; P < 0·0001 for all comparisons vs. placebo). PFS usability was high: 100% of subjects successfully self-administered treatment at week 1, and subjects reported high SIAQ-assessed acceptability of the PFS throughout the trial. No new/unexpected safety signals were observed.

CONCLUSIONS

Secukinumab administration by PFS was effective, with an acceptable safety profile and high usability. The PFS provides a reliable, convenient form of secukinumab administration in subjects with moderate-to-severe plaque psoriasis.

A rapid and visual loop-mediated isothermal amplification assay to detect Leifsonia xyli subsp. xyli targeting a transposase gene

Leifsonia xyli subsp. xyli (Lxx), causal organism of ratoon stunt (RSD), does not produce any reliable internal or external symptoms on sugarcane. Its detection on a large scale is solely based on microscopic and serological methods. These methods require well-equipped laboratories, are time consuming and are not feasible for near-field detection of Lxx. In this study, we developed a loop-mediated isothermal amplification (LAMP) assay for rapid and sensitive detection of Lxx without the use of sophisticated equipment. To the best of our knowledge, this is the first report on the detection of Lxx in 30 min via an isothermal amplification method at 65°C. A transposase gene, ISLxx5, was used to design a set of six primers specifically targeting eight genomic sequences. The xylem sap was used as template, thus circumventing the need to isolate pure genomic DNA. The positive reactions were visually detected through a colour change of hydroxynaphthol blue (HNB) from violet to light blue, thus, eliminating the need for gel electrophoresis. The LAMP method was 10 times more sensitive than serological detection and as sensitive as immunofluorescence microscopy (IFM). The simplicity and sensitivity of the ISLxx5 LAMP assay makes it suitable for near-field diagnosis of RSD.

SIGNIFICANCE AND IMPACT OF THE STUDY

Detection of Leifsonia xyli subsp. xyli (Lxx) on a large scale is based on serological assays such as evaporative-binding enzyme-linked immunoassay (EB-EIA). These methods are time consuming and require well-equipped laboratories. This study presents the development of a loop-mediated isothermal amplification (LAMP) assay which allows detection of Lxx in 30 min at 65°C, using xylem sap as the template. The assay requires minimal laboratory equipment and could be used at near farm conditions, thus saving time and money required to transfer samples from remote areas to diagnostic laboratories. The LAMP method shows potential as an alternative detection method for RSD.

Optomechanical coupling between a multilayer graphene mechanical resonator and a superconducting microwave cavity

The combination of low mass density, high frequency and high quality factor, Q, of mechanical resonators made of two-dimensional crystals such as graphene make them attractive for applications in force/mass sensing and exploring the quantum regime of mechanical motion. Microwave optomechanics with superconducting cavities offers exquisite position sensitivity and enables the preparation and detection of mechanical systems in the quantum ground state. Here, we demonstrate coupling between a multilayer graphene resonator with quality factors up to 220,000 and a high-Q superconducting cavity. Using thermomechanical noise as calibration, we achieve a displacement sensitivity of 17 fm Hz(-1/2). Optomechanical coupling is demonstrated by optomechanically induced reflection and absorption of microwave photons. We observe 17 dB of mechanical microwave amplification and signatures of strong optomechanical backaction. We quantitatively extract the cooperativity C, a characterization of coupling strength, from the measurement with no free parameters and find C = 8, which is promising for the quantum regime of graphene motion.

Reasons for variation in sensitivity and specificity of visual inspection with acetic acid (VIA) for the detection of pre- cancer and cancer lesions of uterine cervix

Alternative strategies such as visual inspection of cervix with acetic acid, are real time, economical and easily implemented methods for cervical cancer screening. However, variable sensitivity and specificity have been observed in various community based studies. The possible reasons could include variation in man power training, light source used for visualization, and preparation of diluted (4-5%) acetic acid and its storage. A standardized protocol for training, teaching material (easy to understand in the local language) for trainees, supervision and reinforcement by intermittent and supplementary training to check the quality of their observation, a standard protocol for preparation dilute acetic acid and its storage and a standard good light source (equivalent to day light) are needed to minimize the variation in sensitivity and specificity of VIA in community settings.

Mortality profile of patients with traumatic spinal injuries at a level I trauma care centre in India

BACKGROUND & OBJECTIVES

There is no national spinal trauma registry available in India at present and the research on epidemiology of these injuries is also very limited. The purpose of this study was to describe the mortality profile of patients with spinal injuries brought to a level I trauma centre in India, and to understand the predictive factors which identify patients at an increased risk of spinal trauma mortality.

METHODS

Retrospective data were collected from computerized patients records and autopsy reports maintained in the department of Forensic Medicine. All the cases with spinal injuries whether in isolation or as a part of polytrauma were reviewed. A total of 341 such cases were identified between January 2008 to December 2011. The demographic data, type of trauma, duration of survival, body areas involved, level of spinal injury and associated injuries if any, were recorded.

RESULTS

There were 288 (84.45%) males and 53 (15.55%) females. Most victims (73%) were between 25 and 64 yr of age, followed by young adults between 16 and 24 yr (19.35%). Male: female ratio was 5.4:1. Fifty five per cent cases had spinal injuries in isolation. Injury to the cervical spine occurred in 259 (75.95%) patients, thoracic spine in 56 (16.42%) and thoraco-lumbar spine in 26 (7.62%) patients. The commonest cause of injury was high energy falls (44.28%), followed by road traffic accidents (41.93%). The majority of deaths (51.6%) occurred in the phase IV (secondary to tertiary complications of trauma, i.e. >1 wk). Forty patients died in phase I (brought dead or surviving <3 h), 55 in phase II (>3 to 24 h) and 70 in phase III (> 24 h to 7 days).

INTERPRETATION & CONCLUSIONS

Our data suggest that there is an urgent need to take steps to prevent major injuries, strengthen the pre-hospital care, transportation network, treatment in specialized trauma care units and to improve injury surveillance and the quality of data collected which can guide prevention efforts to avoid loss of young active lives.

Cold-nuclear-matter effects on heavy-quark production at forward and backward rapidity in d + Au collisions at √sNN = 200 GeV

The PHENIX experiment has measured open heavy-flavor production via semileptonic decay over the transverse momentum range 1 < p(T) < 6  GeV/c at forward and backward rapidity (1.4 < |y| < 2.0) in d+Au and p + p collisions at √sNN = 200  GeV. In central d+Au collisions, relative to the yield in p + p collisions scaled by the number of binary nucleon-nucleon collisions, a suppression is observed at forward rapidity (in the d-going direction) and an enhancement at backward rapidity (in the Au-going direction). Predictions using nuclear-modified-parton-distribution functions, even with additional nuclear-p(T) broadening, cannot simultaneously reproduce the data at both rapidity ranges, which implies that these models are incomplete and suggests the possible importance of final-state interactions in the asymmetric d + Au collision system. These results can be used to probe cold-nuclear-matter effects, which may significantly affect heavy-quark production, in addition to helping constrain the magnitude of charmonia-breakup effects in nuclear matter.

Performance of a low cost magnifying device, Magnivisualizer, versus colposcope for detection of pre-cancer and cancerous lesions of uterine cervix

Objective

To assess the performance of a low cost magnifying device (Magnivisualizer) compared to a standard optical colposcope for detection of precancerous and cancerous lesions of the uterine cervix.

Methods

A total of 659 consecutive symptomatic women attending a gynecologic outpatient clinic underwent unaided visual inspection followed by cytology, visual inspection of the cervix using 5% acetic acid (VIA), and VIA under magnification (VIAM) with the Magnivisualizer. All women, independently of test results, were referred for colposcopic examination. Colposcopic-directed biopsies were obtained from all positive lesions and compared to positive VIAM cases.

Results

The detection rate for VIA positive lesions was 12% (134/659), while it was 29% for VIAM positive lesions (191/659). The sensitivities of detection of cervical intraepithelial neoplasia (CIN) 2 and higher lesions were 61.7% for VIA, 88.3% for VIAM, and 86.7% for colposcopy, with a specificity of 58.5% for VIA, 55.8% for VIAM, and 90.4% for colposcopy. The performance of colposcopy and VIAM was moderate (κ, 0.48; 95% confidence interval [CI], 0.41 to 0.54) for detection of CIN 1 and higher lesions and excellent (κ, 0.87; 95% CI, 0.82 to 0.94) for detection of CIN 2 and higher lesions.

Conclusion

In low resource settings, where colposcopic facilities are not available at the community level, a simple low-cost, handheld Magnivisualizer can be considered a valid option for detection of cervical precancerous and cancerous lesions. However, it cannot replace traditional colposcopy because it has a low specificity that results in many unnecessary biopsies.

Azimuthal-angle dependence of charged-pion-interferometry measurements with respect to second- and third-order event planes in Au+Au collisions at √[S(NN)]=200 GeV

Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au+Au collisions at sqrt[s_{NN}]=200  GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.

Role of the QuantiFERON®-TB Gold In-Tube test in the diagnosis of intrathoracic childhood tuberculosis

SETTING

Tertiary care hospitals in India.

OBJECTIVE

To compare the performance of the QuantiFERON®-TB Gold In-Tube test (QFT-GIT) with that of the tuberculin skin test (TST) in the diagnosis of intrathoracic childhood tuberculosis (TB).

METHODS

Children with intrathoracic TB were enrolled in a randomised controlled trial studying micronutrient supplementation in intrathoracic TB. They underwent TST and QFT-GIT before starting daily anti-tuberculosis treatment.

RESULTS

Of 362 children (median age 115.5 months, IQR 73-144, 55% girls) enrolled in the study, microbiological confirmation of TB was obtained in 128 (35%). The TST was positive in 337 (93%, 95%CI 90-95.5) and QFT-GIT in 297 (82%, 95%CI 77.8-85.6). Sensitivity of TST and QFT-GIT in culture-confirmed TB cases was respectively 90.5% (95%CI 84.1-94.5) and 82.6% (95%CI 74.9-88.4). QFT-GIT positivity rate correlated with TST induration (P < 0.001). TST was influenced by the disease spectrum (P = 0.004) and the age of the children (P = 0.002); QFT-GIT remained unaffected by these factors. Bacille Calmette-Guérin immunisation status, weight-for-age Z-scores and microbiological confirmation of Mycobacterium tuberculosis did not influence the performance of either test.

CONCLUSION

In high-burden countries, QFT-GIT is comparable to TST and offers no added advantage in the diagnosis of childhood intrathoracic TB.

Effect of plasmon-enhancement on photophysics in upconverting nanoparticles

Surface plasmon polaritons (SPP) waves have been shown to significantly affect the near-field photophysical phenomenon. In particular, strong Coulombic interactions can enhance nearby non-linear optics and energy transfer process, while SPP waves also affect other photophysical processes like quenching observed in fluorescent and excitonic systems. Here, using different plasmonic substrates, we show the effect of plasmon-enhancement on quenching, phonon-assisted non-radiative decay, weak Purcell effect or electromagnetic field enhancement, and energy transfer rates of upconverting doped-lanthanide nanoparticles. While the resonant plasmons enhance the local electromagnetic field and the rate of energy transfer leading to enhanced upconversion photoluminescence of infrared radiation to visible light, it can also increase the quenching and non-radiative decay rates of photoexcited electron-hole pairs leading to losses and lower efficiency. These results can guide the design of optimized substrate geometry for using surface plasmons to modulate the photophysics in other applications too.

Low cost technology for screening early cancerous lesions of oral cavity in rural settings

BACKGROUND

Low cost technologies are needed in resource poor rural settings for detection of pre-cancer and cancer lesions of the oral cavity.

AIM

The study was undertaken to investigate the feasibility of a low cost technology (Magnivisualizer) for the early detection any lesions of the oral cavity among tobacco users in a resource poor rural field setting.

SUBJECTS AND METHODS

A total of 1329 tobacco users were motivated to come forward for oral examination in the camp organized for this purpose. Their oral cavities were screened with a torch and Magnivisualizer by a Dentist.

RESULTS

With torch light, 104/1329 (7.8%) lesions were identified, though only 62/104 (59.6%) positive lesions could be differentiated into various categories. However, through Magnivisualizer 156/1329 (11.7%) lesions were detected and 153/156 (98.1%) positive lesions were differentiated into different categories.

CONCLUSION

Magnivisualizer offers an alternative instrument for detecting most of the early cancerous and high-grade precancerous lesions and it can be used in the rural field settings.

Limitations of anti-scatter grids when used with high resolution image detectors

Anti-scatter grids are used in fluoroscopic systems to improve image quality by absorbing scattered radiation. A stationary Smit Rontgen X-ray grid (line density: 70 lines/cm, grid ratio: 13:1) was used with a flat panel detector (FPD) of pixel size 194 micron and a high-resolution CMOS detector, the Dexela 1207 with pixel size of 75 microns. To investigate the effectiveness of the grid, a simulated artery block was placed in a modified uniform frontal head phantom and imaged with both the FPD and the Dexela for an approximately 15 × 15 cm field of view (FOV). The contrast improved for both detectors with the grid. The contrast-to-noise ratio (CNR) does not increase as much in the case of the Dexela as it improves in the case of the FPD. Since the total noise in a single frame increases substantially for the Dexela compared to the FPD when the grid is used, the CNR is degraded. The increase in the quantum noise per frame would be similar for both detectors when the grid is used due to the attenuation of radiation, but the fixed pattern noise caused by the grid was substantially higher for the Dexela compared to the FPD and hence caused a severe reduction of CNR. Without further corrective methods this grid should not be used with high-resolution fluoroscopic detectors because the CNR does not improve significantly and the visibility of low contrast details may be reduced. Either an anti-scatter grid of different design or an additional image processing step when using a similar grid would be required to deal with the problem of scatter for high resolution detectors and the structured noise of the grid pattern.

Relative object detectability (ROD): a new metric for comparing x-ray image detector performance for a specified object of interest

Relative object detectability (ROD) quantifies the relative performance of two image detectors for a specified object of interest by taking the following ratio: the integral of detective quantum efficiency of a detector weighted by the frequency spectrum of the object divided by that for a second detector. Four different detectors, namely the micro-angiographic fluoroscope (MAF), the Dexela Model 1207 (Dex) and Hamamatsu Model C10901D-40 (Ham) CMOS x-ray detectors, and a flat-panel detector (FPD) were compared. The ROD was calculated for six pairs of detectors: (1) Dex/FPD, (2) MAF/FPD, (3) Ham/FPD, (4) Dex/Ham, (5) MAF/Ham and (6) MAF/Dex for wires of 5 mm fixed length, solid spheres ranging in diameter from 50 to 600 microns, and four simulated iodine-filled blood vessels of outer diameters 0.4 and 0.5 mm, each with wall thicknesses of 0.1 and 0.15 mm. Marked variation of ROD for the wires and spheres is demonstrated as a function of object size for the various detector pairs. The ROD of all other detectors relative to the FPD was much greater than one for small features and approached 1.0 as the diameter increased. The relative detectability of simulated small iodine-filled blood vessels for all detector pairs was seen to be independent of the vessel wall thickness for the same inner diameter. In this study, the ROD is shown to have the potential to be a useful figure of merit to evaluate the relative performance of two detectors for a given imaging task.

Pediatric lupus: varied haematological picture and presentation

Systemic lupus erythematosus (SLE) is a chronic, multisystem, autoimmune disease characterized by periods of increased disease activity caused by inflammation of blood vessels and connective tissue. Pediatric patients with SLE have a more severe clinical course when compared with adults. Patients commonly present with rash, fever, and arthritis, although the presentation may be unpredictable. Hematological findings are more predominant in children than adults. Thirty-nine percent of children with SLE will develop hematological abnormalities, one of the American Rheumatic Association criteria for classifying the disease. In our case series we found varied hematological picture and presentation. We present here four case reports of SLE cases with interesting hematological features. Our first case is a 13 month old female child who was initially diagnosed as Evans syndrome and 2 years later diagnosed as SLE. Second case is a 3 year old male child who had SLE with warm antibody AIHA. Third case is a 6 year old female child who presented with AIHA and was diagnosed with SLE 6 years later. Fourth case is a 6 year old female child diagnosed as SLE with aplastic anemia. Hematological findings should be carefully assessed and treated in order to decrease disease related morbidity.