Change in macular thickness after uncomplicated phacoemulsification surgery using optical coherence tomography in a tertiary care hospital

Objectives

To determine the change in macular thickness after uncomplicated phacoemulsification surgery using optical coherence tomography in a tertiary care hospital.

Methods

This study was conducted at Department of Ophthalmology Jinnah Postgraduate Medical Centre Karachi, for 6 months from 10th Dec 2019 to 10th June 2020. Sample size calculation of 52 eyes was done by using open epi software. Patients who fulfilled the inclusion criteria that is age ranging from 50 to 75 years, either gender with senile cataract having no preexisting ocular or systemic disease and those giving consent were included in this study. Patients with any comorbidity ocular trauma, having pre-existing ocular diseases such as active ocular infection, glaucoma, maculopathy or retinopathy were excluded from study. Patients with secondary cataract also excluded from study. After complete history, all patients underwent detailed ophthalmologic examination and Pre-surgery macular thickness recorded by using swept source OCT (DRI-OCT-2 Triton; Topcon). Surgery was performed and intraocular lens was implanted in all cases. Post procedure Macular thickness was measured using swept source OCT at 1st postoperative day, 1st month and 6th month after surgery.

Results

The mean age of patients was 62.06 ± 5.1 years. Total of 52 eyes diagnosed with senile cataract were included in this study. There were 30 (57.7%) males and 22(42.3%) females. The mean preoperative central foveal thickness was 201.3±24.8μm. The postoperative central foveal thickness was 200.3±25.2μm (153-265μm) at day 1st of surgery, 224.1 ± 53.8 μm (151-458 μm) at 1st month and 212.4±28.3μm (167-255μm) 6th month after surgery. The mean preoperative BCVA was 0.70 ± 0.43 (0.1-1.7) logMAR. The postoperative mean BCVA was 0.26 ± 0.42 (0.00-3.10) logMAR at 1st day, 0.07± 0.10 (0.000.7) logMAR at 1st month and 0.05 ± 0.10 (0.00-0.3) logMAR at 6th month.

Conclusion

In our study we found an increase in macular thickness but there was no loss of BCVA from changes of macular thickness after surgery and the mean BCVA increased progressively in postoperative period.

A Review on Integrated ZnO-Based SERS Biosensors and Their Potential in Detecting Biomarkers of Neurodegenerative Diseases

Surface-enhanced Raman spectroscopy (SERS) applications in clinical diagnosis and spectral pathology are increasing due to the potential of the technique to bio-barcode incipient and differential diseases via real-time monitoring of biomarkers in fluids and in real-time via biomolecular fingerprinting. Additionally, the rapid advancements in micro/nanotechnology have a visible influence in all aspects of science and life. The miniaturization and enhanced properties of materials at the micro/nanoscale transcended the confines of the laboratory and are revolutionizing domains such as electronics, optics, medicine, and environmental science. The societal and technological impact of SERS biosensing by using semiconductor-based nanostructured smart substrates will be huge once minor technical pitfalls are solved. Herein, challenges in clinical routine testing are addressed in order to understand the context of how SERS can perform in real, in vivo sampling and bioassays for early neurodegenerative disease (ND) diagnosis. The main interest in translating SERS into clinical practice is reinforced by the practical advantages: portability of the designed setups, versatility in using nanomaterials of various matter and costs, readiness, and reliability. As we will present in this review, in the frame of technology readiness levels (TRL), the current maturity reached by semiconductor-based SERS biosensors, in particular that of zinc oxide (ZnO)-based hybrid SERS substrates, is situated at the development level TRL 6 (out of 9 levels). Three-dimensional, multilayered SERS substrates that provide additional plasmonic hot spots in the z-axis are of key importance in designing highly performant SERS biosensors for the detection of ND biomarkers.

SERS-based antibiotic susceptibility testing: Towards point-of-care clinical diagnosis

Emerging antibiotic resistant bacteria constitute one of the biggest threats to public health. Surface-enhanced Raman scattering (SERS) is highly promising for detecting such bacteria and for antibiotic susceptibility testing (AST). SERS is fast, non-destructive (can probe living cells) and it is technologically flexible (readily integrated with robotics and machine learning algorithms). However, in order to integrate into efficient point-of-care (PoC) devices and to effectively replace the current culture-based methods, it needs to overcome the challenges of reliability, cost and complexity. Recently, significant progress has been made with the emergence of both new questions and new promising directions of research and technological development. This article brings together insights from several representative SERS-based AST studies and approaches oriented towards clinical PoC biosensing. It aims to serve as a reference source that can guide progress towards PoC routines for identifying antibiotic resistant pathogens. In turn, such identification would help to trace the origin of sporadic infections, in order to prevent outbreaks and to design effective medical treatment and preventive procedures.

Comparison of choroidal thickness in eyes of diabetic patients with eyes of healthy individuals using optical coherence tomography in a tertiary care hospital

Objectives:

To compare the choroidal thickness in eyes of diabetic patients with eyes of age matched controls using optical coherence tomography in a tertiary care hospital.

Methods:

This Cross sectional study was conducted at the Department of Ophthalmology, Jinnah Postgraduate Medical Centre Karachi, for six months from13^thJanuary 2020 to13^thJuly 2020. The study group comprised of 44 patients with 88 eyes. Patients who fulfill the inclusion criteria that is age ranging from 35 to 80years, either gender, known case of diabetes mellitus and having any type of diabetic retinopathy (HbA1c >7), non-diabetic healthy individuals (HbA1c < 7) and those giving informed consent were included in the study. However, patients having active ocular infections, history of myocardial infarction, stroke, uveitis, any ocular surgery, lasers, intravitreal injections, poor fundus view and not giving consent were excluded. A pre-designed proforma was filled. A baseline ocular examination was performed and choroidal thickness was assessed from retinal pigment epithelium to choroid sclera junction in diabetic and healthy participants of the study group using high resolution Swept source OCT (DRI-OCT-2 Triton; Topcon).

Results:

The average age of the patients was 39.41±15.95 years. According to our study mean central subfoveal choroidal thickness in diabetic eyes was 268.5 ± 66.22 (95% CI 240 – 297) and in non-diabetic healthy participants it was 339.3 ± 71.49 (95% CI 308 – 369) with a p-value of 0.001. However, average choroidal thickness was 261.8 ± 61.93 (95% CI 235 – 288) and 336.0 ± 74.35 (95% CI 304 – 367) in diabetic and non-diabetic healthy population with a p-value of 0.001. Choroidal thickness comparison between gender in diabetic and non-diabetic population also showed similar trend.

Conclusion:

In this study, mean central choroidal thickness as well as average choroidal thickness was significantly reduced in eyes having diabetic retinopathy as compared to participants with non-diabetic healthy eyes. These findings indicate that changes in choroid may be a probable route in the pathogenesis of diabetic retinopathy.

PATIENT AND OBSERVER SCAR ASSESSMENT FOLLOWING BASAL CELL CARCINOMA SURGERY: MULTICENTER QUASI EXPERIMENTAL STUDY

Objective: To assess patient and observer reported scar quality after Basal cell carcinoma surgery of face using the Patient and Observer Scar Assessment Scale (POSAS). Study Design: Quasi experimental study. Place and Duration of Study: Dermatology Department, Tertiary Care Hospitals at Multan and Karachi and Plastic Surgery Department, Tertiary Care Hospital Multan, from Apr to Sep 2020. Methodology: Patients with basal cell carcinoma that full filled inclusion and exclusion criteria were enrolled by consecutive sampling technique at Dermatology and Plastic Surgery Department after informed consent. Surgical excision was followed by reconstruction of defect either by direct closure or by rotation or advancement flap. Surgical scar was assessed independently at 8 weeks by POSAS. Data was analyzed with SPSS-23. Results: A total of 27 patients were enrolled in study. There were 11 (37.9%) males and 16 (59.25%) females between ages of 45-70 years. Basal cell carcinoma was located on cheek in 15 (55.5%), nose in 9 (33.3%), temple 2 (7.4%) and forehead 1 (3.7%) cases. Direct closure was performed in 6 (22.2%), rotation flaps in 10 (40.7%), and advancement flaps in 11 (40.7%) cases. Mean score of observer opinion about surgical scar between different surgical techniques was not statistically significant (p=0.191). How-ever, mean score of patient opinion of scar between different surgical techniques was statistically significant (p=0.032). Conclusion: POSAS is a valid tool for scar evaluation by patient and observer-reported scar qualities after Basal cell carcinoma surgery.

REVIEW- Covid-19: Diagnosis, summary of essays and evolving approaches

COVID-19 spread worldwide after its outbreak in December 2019. This review paper aims to educate the readers regarding SARS-CoV-2 diagnostic and detection tools and the issues experienced by researchers. We identify on-the-horizon point-of-care diagnostic tests and inspire scholars to develop their innovations past conception. It will also effectively avoid potential pandemics to establish plug-and-play diagnostic information to handle the SARS infection. The authors agree that arbitrary-access, interconnected systems with flexible functionality accessible at the point-of-care, would enable fast and precise diagnosis and tracking.

Correction: Surface-enhanced Raman spectroscopy for bioanalysis and diagnosis

Correction for 'Surface-enhanced Raman spectroscopy for bioanalysis and diagnosis' by Muhammad Ali Tahir et al., Nanoscale, 2021, 13, 11593-11634, DOI: .

Natural language understanding of map navigation queries in Roman Urdu by joint entity and intent determination

Navigation based task-oriented dialogue systems provide users with a natural way of communicating with maps and navigation software. Natural language understanding (NLU) is the first step for a task-oriented dialogue system. It extracts the important entities (slot tagging) from the user's utterance and determines the user's objective (intent determination). Word embeddings are the distributed representations of the input sentence, and encompass the sentence's semantic and syntactic representations. We created the word embeddings using different methods like FastText, ELMO, BERT and XLNET; and studied their effect on the natural language understanding output. Experiments are performed on the Roman Urdu navigation utterances dataset. The results show that for the intent determination task XLNET based word embeddings outperform other methods; while for the task of slot tagging FastText and XLNET based word embeddings have much better accuracy in comparison to other approaches.

Surface-enhanced Raman spectroscopy for bioanalysis and diagnosis

In recent years, bioanalytical surface-enhanced Raman spectroscopy (SERS) has blossomed into a fast-growing research area. Owing to its high sensitivity and outstanding multiplexing ability, SERS is an effective analytical technique that has excellent potential in bioanalysis and diagnosis, as demonstrated by its increasing applications in vivo. SERS allows the rapid detection of molecular species based on direct and indirect strategies. Because it benefits from the tunable surface properties of nanostructures, it finds a broad range of applications with clinical relevance, such as biological sensing, drug delivery and live cell imaging assays. Of particular interest are early-stage-cancer detection and the fast detection of pathogens. Here, we present a comprehensive survey of SERS-based assays, from basic considerations to bioanalytical applications. Our main focus is on SERS-based pathogen detection methods as point-of-care solutions for early bacterial infection detection and chronic disease diagnosis. Additionally, various promising in vivo applications of SERS are surveyed. Furthermore, we provide a brief outlook of recent endeavours and we discuss future prospects and limitations for SERS, as a reliable approach for rapid and sensitive bioanalysis and diagnosis.

Au nanoring arrays as surface enhanced Raman spectroscopy substrate for chemical component study of individual atmospheric aerosol particle

Monolayer-ordered gold nanoring arrays were prepared by ion-sputtering method and used as surface enhanced Raman spectroscopy (SERS) substrates to test the individual atmospheric aerosols particle. Compared to other methods used for testing atmospheric aerosols particles, the collection and subsequent detection in our work is performed directly on the gold nanoring SERS substrate without any treatment of the analyte. The SERS performance can be tuned by changing the depth of the gold nanoring cavity as originating from coupling of dipolar modes at the inner and outer surfaces of the nanorings. The electric field exhibits uniform enhancement and polarization in the ordered Au nanoring substrate, which can improve the accuracy for detecting atmospheric aerosol particles. Combined with Raman mapping, the information about chemical composition of individual atmospheric aerosols particle and distribution of specific components can be presented visually. The results show the potential of SERS in enabling improved analysis of aerosol particle chemical composition, mixing state, and other related physicochemical properties.

Surface-Enhanced Raman Spectroscopy Facilitates the Detection of Microplastics <1 μm in the Environment

Micro- and nanoplastics are considered one of the top pollutants that threaten the environment, aquatic life, and mammalian (including human) health. Unfortunately, the development of uncomplicated but reliable analytical methods that are sensitive to individual microplastic particles, with sizes smaller than 1 μm, remains incomplete. Here, we demonstrate the detection and identification of (single) micro- and nanoplastics by using surface-enhanced Raman spectroscopy (SERS) with Klarite substrates. Klarite is an exceptional SERS substrate; it is shaped as a dense grid of inverted pyramidal cavities made of gold. Numerical simulations demonstrate that these cavities (or pits) strongly focus incident light into intense hotspots. We show that Klarite has the potential to facilitate the detection and identification of synthesized and atmospheric/aquatic microplastic (single) particles, with sizes down to 360 nm. We find enhancement factors of up to 2 orders of magnitude for polystyrene analytes. In addition, we detect and identify microplastics with sizes down to 450 nm on Klarite, with samples extracted from ambient, airborne particles. Moreover, we demonstrate Raman mapping as a fast detection technique for submicron microplastic particles. The results show that SERS with Klarite is a facile technique that has the potential to detect and systematically measure nanoplastics in the environment. This research is an important step toward detecting nanoscale plastic particles that may cause toxic effects to mammalian and aquatic life when present in high concentrations.

Secure Route-Obfuscation Mechanism with Information-Theoretic Security for Internet of Things

As accessibility of networked devices becomes more and more ubiquitous, groundbreaking applications of the Internet of Things (IoT) find their place in many aspects of our society. The exploitation of these devices is the main reason for the cyberattacks in IoT networks. Security design is still an open problem and a crucial step in making IoT applications successful. In dicey environments, such as e-health, smart grid, and smart cities, real-time commands must reach the end devices in the scale of milliseconds. Traditional public-key cryptosystem, albeit necessary in the context of general Internet security, falls short in establishing new session keys in the scale of milliseconds for critical messages. In this paper, a systematic perspective for securing IoT communication, specifically satisfying the real-time constraint against certain adversaries in realistic settings. First, at the network layer, we propose a secret random route computation scheme using the software-defined network (SDN) based on a capability scheme using the network actions. The computed routes are random in the eyes of the eavesdropper. Second, at the application layer, the source breaks command messages into secret shares and sends them through the network to the destination. Only the legitimate destination device can reconstruct the command. The secret sharing scheme is efficient compared to PKI and comes with information-theoretic security against adversaries. Our proof formalizes the notion of security of the proposed scheme, and our simulations validate our design.

Incorporating Noise Robustness in Speech Command Recognition by Noise Augmentation of Training Data

The advent of new devices, technology, machine learning techniques, and the availability of free large speech corpora results in rapid and accurate speech recognition. In the last two decades, extensive research has been initiated by researchers and different organizations to experiment with new techniques and their applications in speech processing systems. There are several speech command based applications in the area of robotics, IoT, ubiquitous computing, and different human-computer interfaces. Various researchers have worked on enhancing the efficiency of speech command based systems and used the speech command dataset. However, none of them catered to noise in the same. Noise is one of the major challenges in any speech recognition system, as real-time noise is a very versatile and unavoidable factor that affects the performance of speech recognition systems, particularly those that have not learned the noise efficiently. We thoroughly analyse the latest trends in speech recognition and evaluate the speech command dataset on different machine learning based and deep learning based techniques. A novel technique is proposed for noise robustness by augmenting noise in training data. Our proposed technique is tested on clean and noisy data along with locally generated data and achieves much better results than existing state-of-the-art techniques, thus setting a new benchmark.

Klarite as a label-free SERS-based assay: a promising approach for atmospheric bioaerosol detection

We present a SERS-based Klarite interface for the rapid and culture-free detection and quantification of atmospheric bioaerosols in the real-world environment.

Boosting C2 products in electrochemical CO2 reduction over highly dense copper nanoplates

Exclusive C2 selectivity of Cu-Nplates over C1 during electrocatalytic CO₂ reduction offers opportunities for large scale, long-term renewable energy storage and lessens carbon emissions.

Cu/Ag Sphere Segment Void Array as Efficient Surface Enhanced Raman Spectroscopy Substrate for Detecting Individual Atmospheric Aerosol

Surface enhanced Raman spectroscopy (SERS) shows great promise in studying individual atmospheric aerosol. However, the lack of efficient, stable, uniform, large-array, and low-cost SERS substrates constitutes a major roadblock. Herein, a new SERS substrate is proposed for detecting individual atmospheric aerosol particles. It is based on the sphere segment void (SSV) structure of copper and silver (Cu/Ag) alloy. The SSV structure is prepared by an electrodeposition method and presents a uniform distribution, over large 2 cm² arrays and at low cost. The substrate offers a high SERS enhancement factor (due to Ag) combined with lasting stability (due to Cu). The SSV structure of the arrays generates a high density of SERS hotspots (1.3 × 10¹⁴/cm²), making it an excellent substrate for atmospheric aerosol detection. For stimulated sulfate aerosols, the Raman signal is greatly enhanced (>50 times), an order of magnitude more than previously reported substrates for the same purpose. For ambient particles, collected and studied on a heavy haze day, the enhanced Raman signal allows ready observation of morphology and identification of chemical components, such as nitrates and sulfates. This work provides an efficient strategy for developing SERS substrate for detecting individual atmospheric aerosol.

Is the photochemistry activity weak during haze events? – A novel exploration on the photoinduced heterogeneous reaction of NO&lt;sub&gt;2&lt;/sub&gt; on mineral dust.. [DOI: 10.5194/acp-2019-315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Abstract. Despite the increased awareness of heterogeneous reaction on mineral dust, the knowledge of how the intensity of solar irradiation influences the photochemistry activity remains a crucially important part in atmospheric research. Relevant studies have not seriously discussed the photochemistry under weak sunlight during haze, and thus ignored some underlying pollution and toxicity. Here, we investigated the heterogeneous formation of nitrate and nitrite under various illumination conditions by laboratory experiments and field observations. Observed by in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), water-solvated nitrate was the main surface product, followed by other species varying with illumination condition. The growth of nitrate formation rate tends to be slow after the initial fast with increasing light intensity. For example, the geometric uptake coefficient (γgeo) under 30.5 mW/cm2 (5.72 × 10−6) has exceeded the 50 % of that under 160 mW/cm2 (1.13 × 10−5). This case can be explained by the excess NO2 adsorption under weak illumination while the excess photoinduced active species under strong irradiation. Being negatively associated with nitrate (R2 = 0.748, P 

Nanosensors for diagnosis with optical, electric and mechanical transducers

Nanosensors with high sensitivity utilize electrical, optical, and acoustic properties to improve the detection limits of analytes.

Gadolinium-containing polymer microspheres: a dual-functional theranostic agent for magnetic resonance imaging and cancer therapy

Preparation of poly(gadolinium methacrylate-co-methacrylic acid) copolymer microspheres with high MRI contrast efficiency and controlled anti-cancer drug loading and release capability.

Pars plana vitrectomy in vitreous hemorrhage with or without Intravitreal Bevacizumab a comparative overview

Objective:

To compare the success in patients having vitreous hemorrhage undergoing pars plana vitrectomy with or without preoperative intravitreal injection of Bevacizumab.

Methods:

This Randomized controlled trial was conducted at Department of Ophthalmology, Jinnah Postgraduate Medical Centre. Karachi. Duration of study was six months from January 2010 to June 2010. In this study 56 patients of advanced diabetic eye disease were divided into two groups. Patients in Group-A underwent three ports pars plana vitrectomy with preoperative intravitreal injection of Bevacizumab (Avastin) 1.25mg/0.05ml, 3.5mm from the limbus seven days before surgery and in Group-B patients underwent vitrectomy without preoperative intravitreal Bevacizumab (Avastin). Intraoperative bleeding was monitored in both groups and was graded as no bleeding, mild bleeding and severe bleeding. The results were statistically analyzed through computer software SPSS 17.

Results:

Twenty eight patients in Group-A who were given an injection of intravitreal Bevacizumab (Avastin) before surgery, intraoperative bleeding monitored was, no bleeding in 17 cases (60.7%), mild was observed in 6 cases (21.4%) and severe bleeding requiring diathermy to stop was observed in only 5 cases (17.9%). 28 patients in Group-B that underwent surgery without Avastin no bleeding was observed in only 2 cases (7.1%), mild in 6 cases (21.4%) and severe in 20 cases (71.4%).

Conclusions:

Intravitreal injection of Bevacizumab (Avastin) was effective before vitrectomy in the surgical management of Advanced Diabetic Eye disease.

Evaluation of carbon nanotube based copper nanoparticle composite for the efficient detection of agroviruses

We report a biosensor that combines the construction of a three-dimensional nanocomposite with electrochemical methods for the detection of viruses in plants. This is the first report, where carbon nanotubes are used as a conductive frame to anchor highly electrolytic agglomerates of copper nanoparticles to detect agroviruses. Morphological analysis of nanocomposite revealed the presence of carbon nanotubes having a diameter of 50-100nm with copper nanoparticles of 20-100nm, attached in the form of bunches. This material was applied to assess the infection caused by geminiviruses which are a major threat to the cotton plants in Asian and African countries. The hybridization events were studied by monitoring differential pulse voltammetry signals using methylene blue as a redox indicator. In the presence of target DNA, sensor signals decreased from 7×10^-4 to 1×10^-4Ampere. The probe exhibited 97.14% selectivity and the detection limit was found to be 0.01ngμL^-1. The developed biosensor is stable for at least four weeks, losing only 4.3% of the initial signal value. This sensor was able to detect the presence of viruses in sap extracted from cotton leaves, thus providing a promising platform to detect a range of other crops-infecting viruses.

Investigating nanohybrid material based on 3D CNTs@Cu nanoparticle composite and imprinted polymer for highly selective detection of chloramphenicol

Nanotechnology holds great promise for the fabrication of versatile materials that can be used as sensor platforms for the highly selective detection of analytes. In this research article we report a new nanohybrid material, where 3D imprinted nanostructures are constructed. First, copper nanoparticles are deposited on carbon nanotubes and then a hybrid structure is formed by coating molecularly imprinted polymer on 3D CNTs@Cu NPs; and a layer by layer assembly is achieved. SEM and AFM revealed the presence of Cu NPs (100-500nm) anchored along the whole length of CNTs, topped with imprinted layer. This material was applied to fabricate an electrochemical sensor to monitor a model veterinary drug, chloramphenicol. The high electron transfer ability and conductivity of the prepared material produced sensitive response, whereas, molecular imprinting produces selectivity towards drug detection. The sensor responses were found concentration dependent and the detection limit was calculated to be 10μM (S/N=3). Finally, we showed how changing the polymer composition, the extent of cross linking, and sensor layer thickness greatly affects the number of binding sites for the recognition of drug. This work paves the way to build variants of 3D imprinted materials for the detection of other kinds of biomolecules and antibiotics.

Visual and anatomical outcome of macular hole surgery at a tertiary healthcare facility

Objective:

To assess visual and anatomical outcome of full thickness macular hole (FTMH) surgery with ILM peeling using brilliant blue G dye.

Methods:

Thirty patients who had clinically evident macular hole were selected. Pre-operative Optical Coherence Tomography (OCT) was done. In all cases vitrectomy was performed via 23guage 3 ports pars plana (3PPV) vitrectomy system and Brilliant blue G dye, 0.5ml dye was injected over macula which resulted in light blue stain of ILM and peeling was performed around hole in circular motion and after gas fluid exchange gas tamponade with SF6 was done. Final visual and anatomical outcome was measured as postoperative BCVA and postoperative OCT at three months respectively. Descriptive statistics were computed. Paired t-test was applied. P value≤0.05 were considered as significant.

Results:

There were 12 male and 18 female patients. The mean age was 57.40±4.76 years. The mean size of macular hole was 452.20±242.33μm. The mean duration of symptoms was 16.73±13.49 weeks. Mean pre operative BCVA was 1.30±0.73 log MAR and post operative was 0.51±0.23 log MAR. Mean increased BCVA was found to be 0.22±0.13 log MAR. Primary closure of hole was achieved in 29(96.7%). Significant mean difference was found in pre operative and post operative BCVA.

Conclusion:

Brilliant blue G exhibits sufficient staining qualities and safety profile to peel ILM in the management of full thickness macular hole with significant visual and anatomical improvement.

Investigating the potential of multiwalled carbon nanotubes based zinc nanocomposite as a recognition interface towards plant pathogen detection

The emergence of nanotechnology has opened new horizons for constructing efficient recognition interfaces. This is the first report where the potential of a multiwalled carbon nanotube based zinc nanocomposite (MWCNTs-Zn NPs) investigated for the detection of an agricultural pathogen i.e. Chili leaf curl betasatellite (ChLCB). Atomic force microscope analyses revealed the presence of multiwalled carbon nanotubes (MWCNTs) having a diameter of 50-100nm with zinc nanoparticles (Zn-NPs) of 25-500nm. In this system, these bunches of Zn-NPs anchored along the whole lengths of MWCNTs were used for the immobilization of probe DNA strands. The electrochemical performance of DNA biosensor was assessed in the absence and presence of the complementary DNA during cyclic and differential pulse voltammetry scans. Target binding events occurring on the interface surface patterned with single-stranded DNA was quantitatively translated into electrochemical signals due to hybridization process. In the presence of complementary target DNA, as the result of duplex formation, there was a decrease in the peak current from 1.89×10^-04 to 5.84×10^-05A. The specificity of this electrochemical DNA biosensor was found to be three times as compared to non-complementary DNA. This material structuring technique can be extended to design interfaces for the recognition of the other plant viruses and biomolecules.

Histopathological features of coeliac disease in a sample of Sudanese patients

INTRODUCTION

Coeliac disease can occur at any age but is more common in children. Its diagnosis requires correlation between clinical presentations, serological results, endoscopic findings and histopathological classification using the modified Marsh grading system. This study of coeliac disease with biopsies received in the department of histopathology at Soba University Hospital, and Fedail Hospital aimed to gain insight into the demographic profile, clinical presentations and histopathological classification of patients with coeliac disease.

METHODS

This was a descriptive study carried out at Soba University Hospital and Fedail Hospital during the period from January 2010-December 2013. Haematoxylin & Eosin and CD3-stained slides of small intestinal biopsies of coeliac disease patients were reviewed for various histological features (1) intraepithelial lymphocytes (IEL) count per 100 enterocytes, (2) crypt hyperplasia and (3) degree of villous atrophy. Based on the histopathological findings, the cases were categorized according to the modified Marsh classification. Demographic and clinical data were obtained from the patient request forms. The data were analyzed using Statistical Package for Social Sciences Software (SPSS).

RESULTS

The study included 60 patients. Their age ranged from 2 to 70 years with a mean of 19.5 years (±15.7 SD). The most common age group was below 10 years old (41.6%). Male and female are equally affected. The most common clinical presentation was chronic diarrhoea (55.0%), followed by iron deficiency anemia (41.7%). The degree of villous atrophy ranged from complete atrophy (45.0%), marked atrophy (38.3%) to mild atrophy (16.6%). Marsh grade IIIC was the most common grade. The younger age-groups had a higher prevalence of iron deficiency anaemia and higher Marsh grade.

Surgical audit of outcome of rhegmatogenous retinal detachment repair at Vitreoretinal unit JPMC in year 2014

Objective:

To investigate the outcome of rhegmatogenous retinal detachment repair at Vitreoretinal unit of Jinnah Post Graduate Medical Centre Karachi in year 2014.

Methods:

One hundred and three eyes of one hundred and three patients, who underwent three ports parsplana vitrectomy + band + silicone oil, three ports pars plana vitrectomy + silicone oil, three ports pars plana vitrectomy + C3F8 for rhegmatogenous retinal detachment (RRD) repair, at Jinnah Post Graduate Medical Centre, were included in this observational prospective study. Parsplana vitrectomy was done using 23G vitrectomy system. Duration of study was one year. Removal of silicone oil (ROSO) was done on the basis of completely flat retina at least for eight weeks or because of complications due to silicone oil. Patients were followed up post operatively on day one and after one week and then at four weekly interval till the end of the study.

Results:

Anatomical success was achieved in 91 eyes (88.3%). However in 12 eyes (11.7%) retina redetached after removal of silicone oil. Functional success achievement of visual acuity of 3/60 or better was achieved in 85 (82.5%) of eyes post operatively after removal of silicone oil or absorption of gas C3F8 as the case may be.

Conclusion:

Re-detachment is common after removal of silicone oil and incidence of re-detachment is related to the degree of preoperative PVR and location of breaks. Re-detachment occurs more commonly if the breaks are inferiorly located as compared to the superior ones.

Frequency of Hepatitis-B and C in patients undergoing cataract surgery in a tertiary care Centre

Objective:

To analyze the frequency of hepatitis B and C in patients undergoing cataract surgery.

Methods:

This descriptive study was conducted at department of Ophthalmology Jinnah Post Graduate Medical Centre. The duration of study was seven months from May 2013 to November 2013. After taking informed consent from the patient and hospital ethical committee all patients presenting with cataract and undergoing cataract surgery were evaluated for the existence of hepatitis C and B. Diagnosis of hepatitis C or B was made on the criteria that a patient must be positive for either Anti-HCV or HBsAg or both. Proformas were filled and data was collected and analysis was done. Pearson’s correlation coefficients were calculated to calculate the occurrence of hepatitis C and B in general population undergoing cataract surgery.

Results:

Six hundred and forty-eight patients were operated on for cataract surgery at Jinnah Post Graduate Medical Centre during the study period. Mean age of patients was 63 years, 300 (46.29%) were male and 348 (53.70%) female. Out of them 57 (8.79%) patients were carriers of either Hepatitis C or B. Hepatitis B accounted for 17 cases (2.62%) however Hepatitis C positive were 40 cases (6.17%). Nobody was simultaneously affected by both hepatitis C and B.

Conclusion:

Significant number of asymptomatic carriers of hepatitis C and B were found in preoperative cataract patients. It is recommended that preoperative screening of all cataract patients should be done so that asymptomatic carriers might not become a threat for spread of disease.

Intravitreal injection of Bevacizumab in diabetic macular edema

OBJECTIVE

To assess the effectiveness of intravitreal injection of Bevacizumab in the treatment of diabetic macular edema.

METHODS

This case series was conducted at Department of Ophthalmology, Jinnah Post Graduate Medical Centre (JPMC), Karachi. The duration of study was six months from May 26, 2011 to November 25, 2011. The study group comprised of 54 patients of the Diabetic Macular Edema (DME). Intravitreal injection of 1.25 mg of bevacizumab (Avastin) was injected 3.5 mm from the limbus under topical anaesthetic drops. Post procedure follow up was scheduled on 1(st) post procedure day and after one month. Post procedure Optical Coherence tomography (OCT) was performed in all patients 1 week before and 1(st) month after 1(st) injection. The results were statistically analyzed through SPSS 17.

RESULTS

Out of the 54 Eyes of 54 Patients who were given the Intravitreal injection of Avastin (Bevacizumab), 43 Eyes (79.6%) showed more than ten percent decrease in macular thickness from pre-injection thickness, 10 Eyes (18.5%) showed less than ten percent decrease and 1 Eye (1.9%) showed increase in macular thickness post operatively after one month.

CONCLUSIONS

Intravitreal injection of Bevacizumab (Avastin) is effective in the treatment of diabetic macular edema.

Outcome of unilateral lateral rectus recession and medial rectus resection in primary exotropia

BACKGROUND

The purpose of this study was to measure the success rate of unilateral lateral rectus recession and medial rectus resection in primary exotropia.

METHODS

This is an interventional case series of 55 patients with primary exotropia (degree of deviation 15-85 PD), above the age of 5 years. Patients were treated in the Department of Ophthalmology, Jinnah Postgraduate Medical Center, Karachi, Pakistan, during the period of July 2009 to March 2010. All the patients underwent surgical procedure i.e., lateral rectus muscle recession (maximum up to 10 mm) and medial rectus muscle resection (up to 6 mm) of one eye, according to the Park's method. Surgery was done based on prism cover test measurements obtained at 6 m with appropriate optical correction in place. Patients were re evaluated at one day, one month, two months and six months post operatively. Final outcome was considered at the end of six months at which achievement of ≤10 PD of exotropia was the success. Data was analyzed on SPSS version 17.0.

RESULTS

We obtained success (≤10 PD) in 42 out of 55 patients (76.4%) and 13 out of 55 patients (23.6%) did not meet our criteria for surgical success (>10 PD). Analysis of success with the type of primary exotropia showed that success was achieved in 22 out of 24 cases of intermittent type (91.6%) and 20 out of 31 cases of constant type (64.5%)(P Value 0.019). The highest percentage of success was achieved in patients with the pre-operative deviation of ≤70 PD i.e., 93.3% (42 out of 45 cases), while none of the patients with the pre-operative deviation of >70 PD (10 out of 10 cases) achieved the criteria for success.

CONCLUSION

We conclude that pre-operative deviation is one of the strongest predictor for favorable surgical outcome. Therefore, eliminating the factors causing error in the correct determination of pre-operative deviation should improve the success and predictability of the surgical outcome. Despite the obstacles in the surgical management of strabismus, our results are encouraging.

Distribution of HLA-DQA1, polymarker, CSF1PO, vWA, TH01, TPOX, D16S539, D7S820, D13S317, and D5S818 alleles in East Bengali and West Punjabi populations from Indo-Pak Subcontinent

Blood samples were collected from 115 individuals residing in the Pakistani state of West Punjab and 81 Bengali individuals residing in the state of East Bengal, India. These samples were analyzed for the loci HLA-DQA1, PM (LDLR, GYPA, HBGG, D7S8, and GC) and eight short tandem repeats: CSF1PO, TPOX, THO1, vWA, D16S539, D7S820, D13S317, and D5S818. Departures from Hardy-Weinberg (HWE) were observed in Punjabi population at LDLR, THO1, D13S317, D5S818, and D16S539 and at CSF1PO and THO1 in Bengali population.

DNA typing of samples for polymarker, DQA1, and nine STR loci from a human body exhumed after 27 years

A body was exhumed from the ground after 27 years. Samples of femur bone, tooth, and a fingernail were collected and successfully subjected to DNA extraction, quantitation, amplification, and subsequently typed for DQA1, polymarker, and nine STR loci. All three types of samples were typed for D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S17, D7S820, and amelogenin using ABI Prism 377 DNA sequencer.

Allelic distribution of nine short tandem repeat (STR), HLA-DQA1, and polymarker loci in an Omani sample population

Allele frequency distributions of nine short tandem repeat (STR) loci, D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D7S820, and D13S317, HLA-DQA1 and polymarker (PM) loci were studied in a sample population from Sultanate of Oman, Middle East. Blood samples were collected from 162 unrelated individuals. For all STR, HLA-DQA1 and PM loci, no deviations from Hardy-Weinberg equilibrium, based on the exact test, were observed. The most discriminating loci were D18S51 (PD=0.966) and FGA (PD=0.964), while the least informative locus is GYPA (PD=0.585). The allele frequency data may be useful in forensic case work.

Distribution of D1S80 alleles in the Bahrainian population

This study demonstrates that the locus D1S80 is highly polymorphic in the Bahrainian population. There were 24 different D1S80 alleles and 51 distinct genotypes observed in 198 Bahrainians. There was one allele observed that was smaller than the 14 repeat allele. This data set meets the Hardy-Weinberg expectations (HWE) and could be a useful marker for parentage testing and forensic applications.

Typing of eight short tandem repeat (STR) loci in a Saudi Arabian population

Allele frequency data for eight short tandem repeat (STR) loci, HUMF13A01, HUMFESFPS, HUMF13B, HUMLPL, HUMCSF1PO, HUMTPOX, HUMTHO1 and HUMvWA, were obtained for unrelated individuals in a Saudi Arabian population. All loci, except F13B (P = 0.037) and LPL (P = 0.035), meet Hardy-Weinberg expectations, based on the exact test. The most informative locus is HUMvWA (PD = 0.936) and the least discriminating is the HUMTPOX locus (PD = 0.820). There was only one observation of a departure from expectation from pairwise locus comparisons. These data can be used for estimating the frequency of STR profiles in a Saudi Arabian population.

Alu insertion polymorphisms and human evolution: evidence for a larger population size in Africa

Alu insertion polymorphisms (polymorphisms consisting of the presence/absence of an Alu element at a particular chromosomal location) offer several advantages over other nuclear DNA polymorphisms for human evolution studies. First, they are typed by rapid, simple, PCR-based assays; second, they are stable polymorphisms-newly inserted Alu elements rarely undergo deletion; third, the presence of an Alu element represents identity by descent-the probability that different Alu elements would independently insert into the exact same chromosomal location is negligible; and fourth, the ancestral state is known with certainty to be the absence of an Alu element. We report here a study of 8 loci in 1500 individuals from 34 worldwide populations. African populations exhibit the most between-population differentiation, and the population tree is rooted in Africa; moreover, the estimated effective time of separation of African versus non-African populations is 137,000 +/- 15,000 years ago, in accordance with other genetic data. However, a principal coordinates analysis indicates that populations from Sahul (Australia and New Guinea) are nearly as close to the hypothetical ancestor as are African populations, suggesting that there was an early expansion of tropical populations of our species. An analysis of heterozygosity versus genetic distance suggests that African populations have had a larger effective population size than non-African populations. Overall, these results support the African origin of modern humans in that an earlier expansion of the ancestors of African populations is indicated.

Distribution of HLA-DQ alpha and polymarker (LDLR, GC, GYPA, HBGG, and D7S8) alleles in Arab and Pakistani populations living in Abu Dhabi, United Arab Emirates

Randomly collected blood samples from 100 Arabs and 100 Pakistanis residing in Abu Dhabi were analyzed using the HLA-DQ alpha and polymarker (LDLR, GC, GYPA, HBGG, D7S8) PCR based reverse dot blot systems. Allelic frequencies for each allele and observed heterozygosity for each locus were calculated. Departures from Hardy-Weinberg expectations (HWE) were determined using the unbiased estimate of the expected homozygote/ heterozygote frequencies, the likelihood ratio test and the exact test. No significant departures from HWE expectations were detected.

Distribution of HLA-DQA1 alleles in Arab and Pakistani individuals from Dubai, United Arab Emirates

PCR-based typing of the HLA-DQA1 locus, using allele specific oligonucleotide (ASO) probes and reverse dot blot methodology was used to determine allelic distributions and construct a database for Arab and Pakistani individuals living in Dubai. Genotype and allelic frequencies were calculated, and the data were tested for departures from Hardy-Weinberg (HWE) equilibrium. The most frequent HLA-DQA1 alleles among Dubaian Arabs are DQA1 4 and 1.2. Among Pakistanis, the most frequent allele is also DQA1 4. No significant deviations from HWE were detected.

Deoxyribonucleic acid profiling by restriction fragment length polymorphism analysis--a compilation of validation studies

In preparation for the application of restriction fragment length polymorphism (RFLP) analysis methods to casework, validation studies were performed at the Indianapolis-Marion County Forensic Services Agency (IMCFSA). They encompassed the following areas: standard specimens, sample consistency, reproducibility, mixed specimens, environmental insults, minimum sample requirements, non-probative casework, repetitive sizing accuracy, precision and match criteria analysis, and population studies including K562 data analysis. All studies yielded results as expected, were consistent with those previously reported by other laboratories, and formed a strong foundation on which to base future casework analysis.

Typing of DNA HLA-DQ alpha alleles extracted from human nail material using polymerase chain reaction

The deoxyribonucleic acid (DNA) typing of human Leukocyte Antigen (HLA) DQ alpha from human fingernails is described. HLA-DQ alpha genotypes can be accurately determined from clipped fingernails. We have typed 26 nails accurately, while one did not give any type since that one sample did not amplify due to the low quantity of DNA. The cut off limit for the digested material to be amplified is approximately 9 mgs of nail material.

Restriction fragment length polymorphism (RFLP) typing of DNA extracted from nasal secretions

The restriction fragment length polymorphism (RFLP) analysis of blood, semen, and other body fluids, has become increasingly important in violent criminal cases. The identification of additional tissues suitable for comparison with suspected donors has obvious potential benefit. One type of tissue, that found in nasal secretions, has previously received little attention with regards to genetic analysis. We collected blood and nasal secretion samples from eight individuals, subjected them to traditional RFLP typing methods, and analyzed the results using probes for loci D2S44, D1S7, D10S28, D4S139, and D17S79. All nasal samples provided high DNA yields and hybridization results that matched the corresponding blood standards. Thus, nasal secretions are shown to have potentially significant evidentiary value.