A simple, sensitive, label-free electrochemical immunosensor based on the chitosan-coated silver/cerium oxide (CS@Ag/CeO2) nanocomposites for the detection of alpha-fetoprotein (AFP)

Metal oxide-based sensors have the benefit of inexpensive, quick response, and high sensitivity in detecting specific biological species. In this article, a simple electrochemical immunosensor was fabricated using antibody-chitosan coated silver/cerium oxide (Ab-CS@Ag/CeO₂) nanocomposites on a gold electrode for sensitive alpha-fetoprotein (AFP) diagnosis in human serum samples. Successfully synthesis of AFP antibody-CS@Ag/CeO₂conjugates was confirmed through Fourier transform infrared spectra of the prototype. The amine coupling bond chemistry was then used to immobilize the resultant conjugate on a gold electrode surface. It was observed that the interaction of the synthesized Ab-CS@Ag/CeO₂nanocomposites with AFP prevented an electron transfer and reduced the voltammetric Fe(CN)₆^3-/4-peak current, which was proportional to the amount of AFP. The linear ranges of AFP concentration were found from 10^-12-10^-6g.ml^-1. The limit of detection was calculated using the calibration curve and came out to be 0.57 pg.ml^-1. The designed label-free immunosensor successfully detected AFP in human serum samples. As a result, the resulting immunosensor is a promising sensor plate form for AFP detection and could be used in clinical bioanalysis.

Integrated Capacitive- and Resistive-Type Bimodal Relative Humidity Sensor Based on 5,10,15,20-Tetraphenylporphyrinatonickel(II) (TPPNi) and Zinc Oxide (ZnO) Nanocomposite

The development of high-performance humidity sensors to cater for a plethora of applications, ranging from agriculture to intelligent medical monitoring systems, calls for the selection of a reliable and ultrasensitive sensing material. A simplistic device architecture, robust quantification of ambient relative humidity (% RH), and compatibility with the contemporary integrated circuit technology make a bimodal (capacitive and resistive) surface-type sensor to be a prominent choice for device fabrication. Herein, we have proposed and demonstrated a facile realization of a 5,10,15,20-tetraphenylporphyrinatonickel (II)-zinc oxide (TPPNi-ZnO) nanocomposite-based bimodal surface-type % RH sensor. The TPPNi macromolecule and ZnO nanoparticles have been synthesized by an eco-benign microwave-assisted technique and a thermal-budget chemical precipitation method, respectively. It is speculated from the morpohological study that specific surface area improvement, via the provision of ZnO nanoparticles on micro-pyramidal structures of TPPNi, may reinforce the sensing properties of the fabricated humidity sensor. The relative humidity sensing capacitive and resistive characteristics of the sensor have been monitored in 40-85% relative humidity (% RH) bandwidth. The fabricated sensor under the biasing conditions of 1 V of applied bias (V _rms) and 500 Hz AC test frequency exhibits a significantly higher sensitivity of 387.03 pF/% RH and 95.79 kΩ/% RH in bimodal operation. The average values of both the response and recovery times of the capacitive sensor have been estimated to be ∼30 s. It has also been debated why this high degree of sensitivity and considerable reduction in response/recovery time has been obtained. In addition, the intense and wide bandwidth spectral response of the TPPNi-ZnO nanocomposite indicates that it may also be utilized as a potential light-harvesting heterostructured nanohybrid in future studies.

Synthesis and characterization of pristine and strontium-doped zinc oxide nanoparticles for methyl green photo-degradation application

Herein we describe an effective route for the degradation of methyl green (MG) dye under visible light illumination by pristine and strontium (Sr)-doped zinc oxide (ZnO) photocatalysts (synthesized by the simple chemical precipitation method). The x-ray diffraction structural analysis has confirmed that both photocatalysts exhibit the hexagonal wurtzite structure; without any additional phase formation in Sr-doped ZnO, in particular. The optical properties of the synthesized photocatalysts have been investigated using UV-vis absorption spectroscopy in the wavelength range of 250-800 nm. Through Tauc's plot, the slight decrease from 3.3 to 3.2 eV in band gap energy has been elucidated (in the case of Sr-doped ZnO), which has been further confirmed by the quenching in the intensity of Photoluminescence (PL) emission spectrum. This may be due to sub-band level formation between valence and conduction band, caused by the impregnation of Sr²⁺ions into ZnO host. The morphological study has also been performed using Field Emission Scanning Electron Microscope, which indicates nanoparticles (NPs) based surface texture for both photocatalysts. During the photocatalytic activity study, after 30 min irradiation of visible light, ∼65.7% and ∼84.8% photocatalytic degradation of MG dye has been achieved for pristine and Sr-doped (2 wt%) ZnO photocatalysts, respectively. The rate of photocatalytic reaction (K) has been observed to be ∼0.06399 min^-1for Sr-doped (2 wt%), whereas nearly half magnitude ∼0.03403 min^-1has been observed for pristine ZnO, respectively. The significantly improved photodegradation activity may be ascribed to the relatively broader optical absorption capability, surface defects and the enhanced charge separation efficiency of the Sr-doped ZnO photocatalyst.

Management of Giant Cell Tumor of Talus With Extended Intralesional Curettage and Reconstruction Using Polymethylmethacrylate Cement

An 18-year-old man presented with complaints of pain and swelling around the left ankle region. Local examination revealed diffuse, hard, mildly tender swelling with ill-defined margins over the medial aspect of the left ankle joint just below the medial malleolus. Radiographic and computed tomographic assessment revealed osteolytic lesion with moderately defined margins. Provisional diagnosis of Campanacci grade 2 giant cell tumor was made, which was later confirmed on histopathology. Extended intralesional curettage and reconstruction with polymethylmethacrylate cement was done under spinal anesthesia. Full weight bearing was allowed at 4 weeks when the below knee back slab was removed. Radiographic assessment was done every 3 months during the first year of follow-up and then every 6 months. No evidence of recurrence of tumor, collapse of talus, or avascular necrosis was found during follow-up. Managing such rare form of bone tumors with extended intralesional curettage and bone cement is an appropriate treatment and gives good functional results.Level of Evidence: Level V.

Risk factors for outbreaks caused by variant strain of Newcastle disease on environmentally controlled broiler chicken farms in Lahore, Pakistan

Newcastle disease (ND) is a frequently reported disease in poultry among both vaccinated and non-vaccinated flocks in Pakistan. During 2011-2012 poultry industry in Punjab, mainly in Lahore region, faced fatal outbreaks of ND caused by a variant strain. An analytical study was conducted during outbreak period in Lahore region. A total of 114 environmentally controlled farms were selected with the help of convenient sampling method. A questionnaire was designed about the potential risk factors associated with the spread of ND outbreak. The bivariate relationships between ND status and independent variables were investigated by applying the Chi-square and Fisher's exact test. Multivariable logistic model was used to estimate the effect of each studied variable on the outcome by adjusting the other variables in the model. The variables which showed an association with ND outbreaks at commercial poultry farms were improper method for dead birds disposal (OR=4.96; 95% CI 1.63-15.12), use of same feed transporting vehicle at multiple poultry farms (OR=4.92; 95% CI 1.58-15.33), farm to farm distance of less than 1 km (OR=9.32; 95% CI(1.19-73.12), number of sheds at one farm (OR=2.31; 95% CI 0.93-5.69), labor type (OR=2.72; 95% CI 0.83-8.88) and biosecurity (OR= 4.47; 95% CI 0.56-35.66).

Timing of Surgery in Thoracolumbar Spine Injury: Impact on Neurological Outcome

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

We aimed to evaluate the improvement in neurological deficit following early versus late decompression and stabilization of thoracolumbar junctional fractures.

METHODS

This is a retrospective evaluation of all patients with a traumatic spinal cord injury (SCI) from T11 to L2 treated at a teaching hospital between 2010 and 2017. Grouped analysis was performed comparing the cohort of patients who received early surgery within 24 hours (group 1) with those operated within 24 to 72 hours (group 2) and more than 72 hours after SCI (group 3). The primary outcome was the change in ASIA (American Spinal Injury Association) motor score at 12-month follow-up.

RESULTS

There were 317 patients (225 males and 92 females with mean age of 31.55 ± 12.43 years). A total of 144, 77, and 96 patients belonged to groups 1, 2, and 3 respectively. Improvement of at least 1 grade on ASIA classification was observed in 80, 45, and 33 patients in groups 1, 2, and 3 respectively (P = .001). Overall, 32, 12, and 10 patients improved ≥2 grades on ASIA classification in groups 1, 2, and 3, respectively (P = .069). On logistic regression analysis, early surgery and severity of initial injury (complete [ASIA A] vs incomplete SCI [ASIA B-D]) were found to significantly influence the potential for neurologic improvement (P = .004 and P < .0001, respectively).

CONCLUSION

We believe that the earlier the decompression, the better. The 72-hour cutoff represents the most promising time window during which surgical decompression has the potential to confer a neuroprotective effect in the setting of incomplete SCI (ASIA B-D) in the distal region of the spinal cord (conus medullaris).

Impact of metal density on deformity correction in posterior fusions for adolescent idiopathic scoliosis: A retrospective cohort study

Introduction

Optimal implant density for posterior spinal fusion in adolescent idiopathic scoliosis (AIS) remains controversial. We aimed to examine radiographic outcomes of AIS cases treated with limited density pedicle screw constructs.

Methods

This is a retrospective analysis of 96 patients (89 females and 7 males with mean age of 13.8 ± 4.4 years) with AIS who underwent posterior spinal instrumentation at Ghurki Trust Teaching Hospital between 2014 and 2016. Construct characteristics and radiographic measurements were compared preoperatively and at 2 year follow-up using paired t-test. Pearson's correlation coefficient between curve characteristics and metal density was calculated.

Results

Preoperative coronal Cobb angle was 68.5 ± 6.9°. Flexibility of the curve was 47.5 ± 10.3% based on push-prone films. The mean number of vertebrae in the fusion was 10.7 ± 1.6. The implant density was 62%. The mean postoperative Cobb angle was 18.6 ± 4.2°, giving a mean correction of 72.5 ± 6.8%. Metal density was not correlated with preoperative coronal or sagittal radiographic variables; MT Cobb angle (r = 0.02, p = 0.847), MT curve flexibility (r = 0.129, p = 0.210), preoperative thoracic kyphosis (r = -0.119, p = 0.247) or lumbosacral lordosis (r = −0.048, p = 0.645). There was a significant correlation between the flexibility of the curve as assessed by push-prone radiographs with the percentage correction achieved (r = 0.368, p < 0.0001) as well as absolute correction in degrees (r = 0.643, p < 0.0001). No significant correlations were present between metal density and MT curve coronal correction rate/percentage (r = 0.086, p = 0.407) or postoperative Cobb angle (r = 0.098, p = 0.344).

Conclusion

Metal density does not influence the coronal and sagittal correction of AIS. Neither larger nor stiffer curves necessitate high metal density.

Level of evidence

IV.

•

Metal density does not influence either amount of main thoracic curve correction or post-operative Cobb angle.

•

We conclude that posterior fusion constructs with implant densities of approximately 60% can safely be used in moderate, flexible (45–80°, average 47% flexibility) idiopathic curves to attain and maintain correction in adolescent idiopathic scoliosis.

•

There is a significant correlation between the flexibility of the curve as assessed by push-prone radiographs with the percentage correction achieved as well as absolute correction in degrees.

•

We found that preoperative coronal or sagittal radiographic variables like main thoracic Cobb angle, curve flexibility, preoperative thoracic kyphosis or lumbosacral lordosis did not influence surgeon's decision for implant density.

•

Longer fusions were required for larger and less flexible curves.

Prevalence of methicillin-resistant <em>Staphylococcus aureus</em> and other pathogens in pus samples of orthopedic department at a tertiary care hospital in Pakistan

BACKGROUND Orthopedic infections are difficult to manage. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most dangerous and harmful bacteria and is difficult to eradicate because of its changing strains as well as sensitivity to different antibiotics. The main aim of this study was to determine the prevalence of pathogens, especially MRSA, associated with orthopedic wounds and their sensitivity to different antibiotics. METHODS A prospective study was conducted from September 2015 to August 2016. Pus samples of 1,350 patients who presented at the out-patient department or admitted with a wound infection after an orthopedic intervention were taken with the help of culture swab and were sent for culture and sensitivity according to hospital protocol. Data analyses were made using the SPSS software, version 17 (IBM). RESULTS Adults aged between 15 and 30 years were most affected, with 444 (32.9%) cases. Of the patients, 268 (19.9%) had negative cultures. Among the patients with positive cultures, the gram-positive cocci and gram-negative rods were 497 (36.8%) and 377 (27.9%), respectively. The most common pathogen was MRSA (240; 17.8%), followed by Escherichia coli and methicillin-sensitive S. aureus. CONCLUSIONS Multiple pathogens are involved in patients having an orthopedic surgical intervention. The high occurrence of MRSA and E. coli has an increasing economic burden on patients because of these pathogens high resistance to antibiotics. Thus, proper preventive measures should be done to decrease the occurrence of such infections as well as their associated morbidity.

Diagnostic accuracy of magnetic resonance imaging in detecting anterior cruciate ligament injuries

Background: The anterior cruciate ligament (ACL) stabilizes the joint during hyperextension and prevents anterior translation over femur. The objective of this study was to determine the diagnostic accuracy of magnetic resonance imaging (MRI) in detecting ACL injury by taking arthroscopy as gold standard in patients with traumatic knee injury.Methods: Patients fulfilling the study criteria were treated with clinical examination, MRI and then arthroscopy at the Department of Orthopedics and Spine in the Ghurki Trust Teaching Hospital, Lahore. The accuracy, sensitivity and specificity of MRI in diagnosing  the anterior cruciate ligament injury were calculated based on arthroscopic findings. All the data were analyzed using SPSS 17.0 version.Results: A total 185 patients were included. 91.1% were males and 8.9% were females with Mean age of 28.25±0.433. The accuracy of MRI in diagnosing the anterior cruciate ligament was 91.89%, with sensitivity of 93.33%, specificity of 85.71%, positive predictive value of 96.55% and the negative predictive value  of 75%.Conclusion: MRI is accurate and non-invasive modality for the assessment of ligamentous injuries. It can be used as a first line investigation to patients with suspicion of ACL injury.

The assessment of fetal brain growth in diabetic pregnancy using in utero magnetic resonance imaging

AIM

To assess fetal brain growth over the third trimester in pregnant women with diabetes using in utero magnetic resonance imaging (iuMRI) to determine if greater brain growth occurs in type 1 (T1DM) when compared to gestational (GDM) diabetes mellitus.

MATERIALS AND METHODS

Each consented participant was scanned at three fixed times during the third trimester using iuMRI. One hundred and fifty-seven patients were approached, 48 participants were recruited, and 36 complete data sets were analysed. Three-dimensional (3D) iuMRI volume data sets were manually segmented using software to construct models of the fetal brain from which brain volumes could be calculated. Inter-rater analysis was performed, and volume differences and growth rates were compared between T1DM and GDM.

RESULTS

Recruitment proved difficult with low uptake and high attrition rates (77.1%). Inter-rater analysis revealed excellent correlation (intraclass correlation coefficient=0.93, p<0.001) and agreement with no significant difference between operators (p=0.194). There was no evidence of increased brain volume in the T1DM group. Growth rates between visit 1 and 3 for T1DM and GDM were not significantly different (p=0.095).

CONCLUSION

T1DM brain volumes were not significantly larger than GDM volumes and there was no significant divergence of brain growth over the third trimester. Constructing volume models from 3D iuMRI acquisitions is a novel technique that can be used to assess fetal brain growth. No specialist software or knowledge is required. Larger studies attempting to recruit pregnant women in the later stages of pregnancy should employ multicentre recruitment to overcome recruitment difficulties and high attrition rates.

One Stage Bilateral Knee And Hip Arthroplasties In 42 Years Old Female

Knee and hip joint replacement surgeries are the mainstay of treatment in patients having grade 3 or grade 4 arthritis either due to degenerative process, rheumatoid disease or due to some other disease process. The main aims of these surgeries are to decrease the morbidity, early rehabilitation and decrease management costs of such patients. We report the first case in which bilateral total knee and total hip replacement surgery were done in single anaesthesia in 42 years old female patient suffering from Rheumatoid Arthritis.

Pulmonary surfactant protein a is expressed in mouse retina by Müller cells and impacts neovascularization in oxygen-induced retinopathy

PURPOSE

Surfactant protein A (SP-A) up-regulates cytokine expression in lung disease of prematurity. Here we present data that for the first time characterizes SP-A expression and localization in the mouse retina and its impact on neovascularization (NV) in the mouse.

METHODS

Retinal SP-A was localized in wild-type (WT) mice with the cell markers glutamine synthetase (Müller cells), neurofilament-M (ganglion cells), glial acid fibrillary acid protein (astrocytes), and cluster of differentiation 31 (endothelial cells). Toll-like receptor 2 and 4 (TLR-2 and TLR-4) ligands were used to up-regulate SP-A expression in WT and myeloid differentiation primary response 88 (MyD88) protein (necessary for NFκB signaling) null mouse retinas and Müller cells, which were quantified using ELISA. Retinal SP-A was then measured in the oxygen-induced retinopathy (OIR) mouse model. The effect of SP-A on retinal NV was then studied in SP-A null (SP-A(-/-)) mice.

RESULTS

SP-A is present at birth in the WT mouse retina and colocalizes with glutamine synthetase. TLR-2 and TLR-4 ligands increase SP-A both in the retina and in Müller cells. SP-A is increased at postnatal day 17 (P17) in WT mouse pups with OIR compared to that in controls (P = 0.02), and SP-A(-/-) mice have reduced NV compared to WT mice (P = 0.001) in the OIR model.

CONCLUSIONS

Retinal and Müller cell SP-A is up-regulated via the NFκB pathway and up-regulated during the hypoxia phase of OIR. Absence of SP-A attenuates NV in the OIR model. Thus SP-A may be a marker of retinal inflammation during NV.

Hepatoprotective effect of Matricaria chamomilla.L in paraquat induced rat liver injury

Paraquat (PQ), an effective and widely used herbicide, has been proven to be safe when appropriately applied to eliminate weeds. However, PQ poisoning is an extremely frustrating clinical condition with a high mortality and with a lack of effective treatments in humans. PQ is known to induce injury via a redox cyclic reaction. The purpose of this study was to investigate the effect of aqueous extract Matricaria chamomilla.L (M. chamomilla) against PQ-induced liver injury in association with its antioxidant activity.The male rats were treated by gastric gavage daily with PQ (5 mg/kg/day) and M. chamomilla (50 mg/kg/day) were administered alone or in combination for 7 days. After treatments, total antioxidant capacity (TAC), total thiol molecules (TTG) levels and catalase (CAT) activity in liver tissue were measured. At the end of the experiment, plasma and lung tissue of the animals was separated. The activity of enzymatic scavengers such as CAT, TAC and TTG were measured in liver homogenate.In this sample, the TAC and TTG were lower in the PQ group as compared with control group. Co-administration of PQ with M. chamomilla extract increased TAC and TTG in liver tissue as compared with PQ group.In conclusion, M. chamomilla as natural antioxidant may be considered beneficial for the protection oxidative liver injury in PQ poisoning.