Morphological and molecular characterization of Aedes aegypti variant collected from Tamil Nadu, India.

BACKGROUND & OBJECTIVES: Accurate mosquito species identification is the basis of entomological surveys and effective vector control. Mosquito identification is either done morphologically using diagnostic features mentioned in taxonomic keys or by molecular methods using cytochrome oxidase subunit 1 (coxI) and Internal transcribed spacer 2 (ITS2). METHODS: We performed a larval survey for Aedes mosquitoes from eight different geographical regions in Tamil Nadu, India. The mosquitoes collected during the survey were characterized using both morphological and molecular markers. RESULTS: During an entomological survey from eight different geographical regions in Southern India, a morphological variety named Aedes aegypti var. luciensis was observed. The variant mosquitoes were characterized using both morphological and molecular markers. The variant mosquitoes differed only in the dark scaling of 5th segment of hind-tarsi. Around one third to two third of the 5th segment in variant mosquitoes was dark which has been described as white in identification keys. No other significant difference was observed in adults or immature stages. The variation was heritable and coexisting in the field with the type form mosquitoes. Comparison of the genetic profile of coxI and ITS2 were similar in variant and the type form indicating both of them to be conspecific. INTERPRETATION & CONCLUSION: The morphological variant mosquitoes were found genetically similar to the Ae. aegypti type form. However, considering its high prevalence and coexistence with Ae. aegypti type form in different geographical regions, detailed studies on bionomics, ecology, genetics, behavior as well as its plausible role in disease transmission are warranted.

Molecular electronics sensors on a scalable semiconductor chip: A platform for single-molecule measurement of binding kinetics and enzyme activity.

For nearly 50 years, the vision of using single molecules in circuits has been seen as providing the ultimate miniaturization of electronic chips. An advanced example of such a molecular electronics chip is presented here, with the important distinction that the molecular circuit elements play the role of general-purpose single-molecule sensors. The device consists of a semiconductor chip with a scalable array architecture. Each array element contains a synthetic molecular wire assembled to span nanoelectrodes in a current monitoring circuit. A central conjugation site is used to attach a single probe molecule that defines the target of the sensor. The chip digitizes the resulting picoamp-scale current-versus-time readout from each sensor element of the array at a rate of 1,000 frames per second. This provides detailed electrical signatures of the single-molecule interactions between the probe and targets present in a solution-phase test sample. This platform is used to measure the interaction kinetics of single molecules, without the use of labels, in a massively parallel fashion. To demonstrate broad applicability, examples are shown for probe molecule binding, including DNA oligos, aptamers, antibodies, and antigens, and the activity of enzymes relevant to diagnostics and sequencing, including a CRISPR/Cas enzyme binding a target DNA, and a DNA polymerase enzyme incorporating nucleotides as it copies a DNA template. All of these applications are accomplished with high sensitivity and resolution, on a manufacturable, scalable, all-electronic semiconductor chip device, thereby bringing the power of modern chips to these diverse areas of biosensing.

Role of ultrasound in the evaluation of first-trimester pregnancies in the acute setting.

In patients presenting for an evaluation of pregnancy in the first trimester, transvaginal ultrasound is the modality of choice for establishing the presence of an intrauterine pregnancy; evaluating pregnancy viability, gestational age, and multiplicity; detecting pregnancy-related complications; and diagnosing ectopic pregnancy. In this pictorial review article, the sonographic appearance of a normal intrauterine gestation and the most common complications of pregnancy in the first trimester in the acute setting are discussed.

Prevalence of mandibular fractures.

AIM: The aim of this study was to determine the etiology, dissemination of mandibular fractures among different age, gender, and to determine the frequency of anatomic distribution in patients who reported to our institution from February 2015 to September 2015. MATERIALS AND METHODS: All patients who fulfilled the selection criteria and had mandible fracture were selected for the study. The values were subjected to Z and Chi-square tests. RESULTS: Out of 50 patients, 44 were male patients (88%) and 6 were female patients (12%). We found a peak occurrence of fractures in young adults, with mean age of 36 years. In case of etiology of fracture, road traffic accident was the most common (72%) and parasymphysis was most frequently involved site (n = 13.26%). CONCLUSION: In this study, the prevalence of mandibular fracture was more prevalent in male patients, especially during the third decade of life. The most common cause was road traffic accident and the more frequently affected region was parasymphysis of the mandible.

Evaluating the expression of GLUT-1 in oral leukoplakia.

AIM: The aim of the present study is to analyze the role of GLUT-1 in detection of early alterations occurring in oral leukoplakia. This study was to evaluate the expression of GLUT-1 in normal oral epithelium, the expression of GLUT-1 levels in the tissue samples of oral leukoplakia and to statistically compare the expression of GLUT-1 in normal epithelium and oral leukoplakia. MATERIALS AND METHODS: The study sample comprised formalin-fixed and paraffin-embedded tissue specimens from 23 cases of histopathologically diagnosed oral leukoplakia and formalin-fixed paraffin-embedded tissue specimens from 10 cases of normal oral mucosa. Sections were mounted on glass slide coated with Aminopropyltriethoxysilane (APES; Sigma chemical co., USA) and processed for subsequent immunohistochemical study to demonstrate GLUT-1. RESULTS: GLUT-1 expression in normal oral mucosa revealed weak positivity in all 10 cases (100%). The oral leukoplakia cases showed immunopositivity in all 23 cases (100%) of which 10 cases (39.14%) demonstrated focal positivity and 13 cases (60.86%) of diffuse positivity. The results were compared statistically using ANOVA test was significant at P = 0.002. CONCLUSION: The present study shows expression of GLUT-1 in leukoplakia may be used as a reliable marker to identify the high risk group for malignant transformation.

Role of ultrasound in the evaluation of first-trimester pregnancies in the acute setting

In patients presenting for an evaluation of pregnancy in the first trimester, transvaginal ultrasound is the modality of choice for establishing the presence of an intrauterine pregnancy; evaluating pregnancy viability, gestational age, and multiplicity; detecting pregnancy-related complications; and diagnosing ectopic pregnancy. In this pictorial review article, the sonographic appearance of a normal intrauterine gestation and the most common complications of pregnancy in the first trimester in the acute setting are discussed.

Medical Geological assessment of fluoride contaminated groundwater in parts of Indo-Gangetic Alluvial plains.

As drinking water is considered as a major pathway of exposure to fluoride in the human body, an endeavor has been made for the assessment of the non-carcinogenic health risk by using hazard quotient (HQ) of fluoride for males, females, and children separately in fluoride affected ground water areas of Indo-Gangetic Alluvial Plains. The study suggests that children groups are more prone to the non-carcinogenic risk of fluoride in the area as HQ for fluoride is more than unitary in 44% (Pre-monsoon) and 38% (Post-monsoon) samples respectively. Field survey conducted in fluoride-affected villagers of the study area portrays cases of mottling of teeth and bone deformities depending on the duration and dosage of fluoride consumption. Petrographic observations of host rocks coupled with molar ratios of chemical species studies exemplify that weathered material developed over the granite-gneiss, mica-schist, amphibolite, granitic intrusive and pegmatite veins due to weathering and extensive water-rock interaction resulting higher concentration of fluoride in groundwater. Likewise, the base exchange index (r1) and meteoric genesis index (r2) advocates that most of the samples belong to Na+-HCO3- type and meteoric origin respectively, and substantiate longer residence time of water along with solute acquisition processes are responsible for elevated fluoride in groundwater. It is, therefore, solar energy-driven electrolytic de-fluoridation technology ought to be provided on a priority basis to the affected inhabitants besides the implementation of rainwater harvesting schemes for mitigation/ dilution of elevated fluoride concentration.

3D spatial distribution of ore mineral phases using high resolution synchrotron micro-computed tomography (µCT) combined with optical microscopy.

Ore minerals in dolomites and Graphite Mica Schist (GMS) were studied by synchrotron radiation micro-computed tomography (SR-µCT) and optical microscopy. High resolution µCT images of ore minerals were obtained at Imaging Beamline (BL-4), Indus-2 synchrotron radiation source for the comprehensive volume characterization of minerals. Optical microscopy was used for mineral identification, mineral/rock characterization and quantification of ore mineral assemblages was also confirmed by XRD. 3D images from SR-µCT have shown spatial distribution of major minerals and crystals of different minerals in the volume of samples. The results obtained shows that the GMS and dolomitic hosted rocks mined from region near Udaipur, Rajasthan contains sulfide mineral phases. SR-µCT facilitates visualization of the association of the various metallic minerals with the host rock. The presence of economically important metallic minerals galena, sphalerite and pyrite found in the samples through SR-µCT has implications on exploration and processing of ores.

High-Density Redox Amplified Coulostatic Discharge-Based Biosensor Array.

High-density biosensor arrays are essential for many cutting-edge biomedical applications including point-of-care vaccination screening to detect multiple highly-contagious diseases. Typical electrochemical biosensing techniques are based on the measurement of sub-pA currents for micron-sized sensors requiring highly-sensitive readout circuits. Such circuits are often too complex to scale down for high-density arrays. In this paper, a high-density 4,096-pixel electrochemical biosensor array in 180 nm CMOS is presented. It uses a coulostatic discharge sensing technique and interdigitated electrode geometry to reduce both the complexity and size of the readout circuitry. Each biopixel contains an interdigitated microelectrode with a 13 aA low-leakage readout circuit directly underneath. Compared to standard planar electrodes, the implemented interdigitated electrodes achieve a maximum amplification factor of 10.5× from redox cycling. The array's sensor density is comparable to state-of-the-art arrays, all without augmenting the sensors with complex post-processing. The detection of anti-Rubella and anti-Mumps antibodies in human serum is demonstrated.

Clinical detection of Hepatitis C viral infection by yeast-secreted HCV-core:Gold-binding-peptide.

Access to affordable and field deployable diagnostics are key barriers to the control and eradication of many endemic and emerging infectious diseases. While cost, accuracy, and usability have all improved in recent years, there remains a pressing need for even less expensive and more scalable technologies. To that end, we explored new methods to inexpensively produce and couple protein-based biosensing molecules (affinity reagents) with scalable electrochemical sensors. Previous whole-cell constructs resulted in confounding measurements in clinical testing due to significant cross-reactivity when probing for host-immune (antibody) response to infection. To address this, we developed two complimentary strategies based on either the release of surface displayed or secretion of fusion proteins. These dual affinity biosensing elements couple antibody recognition (using antigen) and sensor surface adhesion (using gold-binding peptide-GBP) to allow single-step reagent production, purification, and biosensor assembly. As a proof-of-concept, we developed Hepatitis C virus (HCV)-core antigen-GBP fusion proteins. These constructs were first tested and optimized for consistent surface adhesion then the assembled immunosensors were tested for cross-reactivity and evaluated for performance in vitro. We observed loss of function of the released reagents while secreted constructs performed well in in vitro testing with 2 orders of dynamic range, and a limit of detection of 32 nM. Finally, we validated the secreted platform with clinical isolates (n = 3) with statistically significant differentiation of positive vs. non-infected serum (p < 0.0001) demonstrating the ability to clearly distinguish HCV positive and negative clinical samples.

Geochemical signatures and isotopic systematics constraining dynamics of fluoride contamination in groundwater across Jamui district, Indo-Gangetic alluvial plains, India.

A data set of 76 water samples are obtained from surface and sub-surface water bodies to investigate chemical parameters and stable isotopic signatures in order to drive factors leading to fluoride (F-) contamination in groundwater of parts of Jamui district, India. Hydrochemical facies reveals that F- concentration is lower in Ca2+-HCO3- facies representative of recharge area, while discharge area has a tendency towards Na+-HCO3- facies with elevated F- concentration. The ionic ratios Na+/Ca2+>1, Na+/Cl->1, (Ca2++Mg2+)/HCO3-<1, Na++K+ = 0.5TZ+ and Ca2++Mg2+ = TZ+ witness silicate weathering by water-rock interaction coupled with ion exchange and prolonged residence time, are the principle factors for fluoride contamination (3.6 mg/L to 5.8 mg/L) in 67% of deeper bore wells. Geochemical modelling testifies excess of alkalinity due to the dominance of bicarbonate ion leading to calcite precipitation and dissolution of fluoride in solution contributing to fluoride contamination. The chemometric analysis reveals that the water chemistry of the study area is controlled by both anthropogenic and natural sources, and enrichment of fluoride in groundwater is possibly from geogenic source (fractured granite gneiss). The stable isotope plot shows that most of the samples fall along local meteoric water line indicating that the groundwater is originated from local precipitation with a possibility of evaporative enrichment. Groundwater enriched in δ18O is positively correlated with F- suggesting evaporation and longer residence time of water. Spatially elevated F- prevails in the eastern bank of Kiul River and along the groundwater flow direction, which is attributed to control of dynamics of hydrogeological conditions.

An Audio Jack-Based Electrochemical Impedance Spectroscopy Sensor for Point-of-Care Diagnostics.

Portable and easy-to-use point-of-care (POC) diagnostic devices hold high promise for dramatically improving public health and wellness. In this paper, we present a mobile health (mHealth) immunoassay platform based on audio jack embedded devices, such as smartphones and laptops, that uses electrochemical impedance spectroscopy (EIS) to detect binding of target biomolecules. Compared to other biomolecular detection tools, this platform is intended to be used as a plug-and-play peripheral that reuses existing hardware in the mobile device and does not require an external battery, thereby improving upon its convenience and portability. Experimental data using a passive circuit network to mimic an electrochemical cell demonstrate that the device performs comparably to laboratory grade instrumentation with 0.3% and 0.5° magnitude and phase error, respectively, over a 17 Hz to 17 kHz frequency range. The measured power consumption is 2.5 mW with a dynamic range of 60 dB. This platform was verified by monitoring the real-time formation of a NeutrAvidin self-assembled monolayer (SAM) on a gold electrode demonstrating the potential for POC diagnostics.

Smartphone-Based pH Sensor for Home Monitoring of Pulmonary Exacerbations in Cystic Fibrosis.

Currently, Cystic Fibrosis (CF) patients lack the ability to track their lung health at home, relying instead on doctor checkups leading to delayed treatment and lung damage. By leveraging the ubiquity of the smartphone to lower costs and increase portability, a smartphone-based peripheral pH measurement device was designed to attach directly to the headphone port to harvest power and communicate with a smartphone application. This platform was tested using prepared pH buffers and sputum samples from CF patients. The system matches within ~0.03 pH of a benchtop pH meter while fully powering itself and communicating with a Samsung Galaxy S3 smartphone paired with either a glass or Iridium Oxide (IrOx) electrode. The IrOx electrodes were found to have 25% higher sensitivity than the glass probes at the expense of larger drift and matrix sensitivity that can be addressed with proper calibration. The smartphone-based platform has been demonstrated as a portable replacement for laboratory pH meters, and supports both highly robust glass probes and the sensitive and miniature IrOx electrodes with calibration. This tool can enable more frequent pH sputum tracking for CF patients to help detect the onset of pulmonary exacerbation to provide timely and appropriate treatment before serious damage occurs.

A Smartphone-Based Colorimetric Reader for Human C-Reactive Protein Immunoassay.

A smartphone-based colorimetric reader (SBCR), comprising a Samsung Galaxy SIII mini, a gadget (iPAD mini, iPAD4, or iPhone 5s) and a custom-made dark hood and base holder assembly, is used for human C-reactive protein (CRP) immunoassay. A 96-well microtiter plate (MTP) is positioned on the gadget's screensaver to provide white light-based bottom illumination only in the specific regions corresponding to the well's bottom. The images captured by the smartphone's back camera are analyzed by a novel image processing algorithm. Based on one-step kinetics-based human C-reactive protein immunoassay (IA), SBCR is evaluated and compared with a commercial MTP reader (MTPR). For analysis of CRP spiked in diluted human whole blood and plasma as well as CRP in clinical plasma samples, SBCR exhibits the same precision, dynamic range, detection limit, and sensitivity as MTPR for the developed IA (DIA). Considering its compactness, low cost, advanced features and a remarkable computing power, SBCR is an ideal point-of-care (POC) colorimetric detection device for the next-generation of cost-effective POC testing (POCT).

Emerging Human Fetuin A Assays for Biomedical Diagnostics.

Human fetuin A (HFA) plays a prominent pathophysiological role in numerous diseases and pathophysiological conditions with considerable biomedical significance; one example is the formation of calciprotein particles in osteoporosis and impaired calcium metabolisms. With impressive advances in in vitro diagnostic assays during the last decade, ELISAs have become a workhorse in routine clinical diagnostics. Recent diagnostic formats involve high-sensitivity immunoassay procedures, surface plasmon resonance, rapid immunoassay chemistries, signal enhancement, and smartphone detection. The current trend is toward fully integrated lab-on-chip platforms with smartphone readouts, enabling health-care practitioners and even patients to monitor pathological changes in biomarker levels. This review provides a critical analysis of advances made in HFA assays along with the challenges and future prospects.

An Efficient Power Harvesting Mobile Phone-Based Electrochemical Biosensor for Point-of-Care Health Monitoring.

Cellular phone penetration has grown continually over the past two decades with the number of connected devices rapidly approaching the total world population. Leveraging the worldwide ubiquity and connectivity of these devices, we developed a mobile phone-based electrochemical biosensor platform for point-of-care (POC) diagnostics and wellness tracking. The platform consists of an inexpensive electronic module (< $20) containing a low-power potentiostat that interfaces with and efficiently harvests power from a wide variety of phones through the audio jack. Active impedance matching improves the harvesting efficiency to 79%. Excluding loses from supply rectification and regulation, the module consumes 6.9 mW peak power and can measure < 1 nA bidirectional current. The prototype was shown to operate within the available power budget set by mobile devices and produce data that matches well with that of an expensive laboratory grade instrument. We demonstrate that the platform can be used to track the concentration of secretory leukocyte protease inhibitor (SLPI), a biomarker for monitoring lung infections in cystic fibrosis patients, in its physiological range via an electrochemical sandwich assay on disposable screen-printed electrodes with a 1 nM limit of detection.

TSC but not PTEN loss in starving cones of retinitis pigmentosa mice leads to an autophagy defect and mTORC1 dissociation from the lysosome.

Understanding the mechanisms that contribute to secondary cone photoreceptor loss in retinitis pigmentosa (RP) is critical to devise strategies to prolong vision in this neurodegenerative disease. We previously showed that constitutive activation of the mammalian target of rapamycin complex 1 (mTORC1), by loss of its negative regulator the tuberous sclerosis complex protein 1 (Tsc1; also known as Hamartin), was sufficient to promote robust survival of nutrient-stressed cones in two mouse models of RP by improving glucose uptake and utilization. However, while cone protection remained initially stable for several weeks, eventually cone loss resumed. Here we show that loss of Tsc1 in the cones of RP mice causes a defect in autophagy, leading to the accumulation of ubiquitinated aggregates. We demonstrate that this defect was not due to an inhibition of autophagy initiation, but due to an accumulation of autolysosomes, suggesting a defect in the end-stage of the process causing an amino-acid shortage in cones, thereby hampering long-term cone survival. Because cells with TSC loss fail to completely inhibit mTORC1 and properly activate autophagy in the absence of amino acids, we sporadically administered the mTORC1 inhibitor rapamycin, which was sufficient to correct the defects seen in cones, further enhancing the efficiency of cone survival mediated by Tsc1 loss. Concordantly, activation of mTORC1 by loss of the phosphatase and tensin homolog (Pten) did not affect autophagy and amino-acid metabolism, leading to a more sustained long-term protection of cones. As loss of Pten, which in cones results in less robust mTORC1 activation when compared with loss of Tsc1, still affords long-term cone survival, therapeutic interventions with mTORC1 activators or gene therapy with selected mTORC1 targets that improve glucose metabolism are potential strategies to delay vision loss in patients with RP.

Detection of Hepatitis C core antibody by dual-affinity yeast chimera and smartphone-based electrochemical sensing.

Yeast cell lines were genetically engineered to display Hepatitis C virus (HCV) core antigen linked to gold binding peptide (GBP) as a dual-affinity biobrick chimera. These multifunctional yeast cells adhere to the gold sensor surface while simultaneously acting as a "renewable" capture reagent for anti-HCV core antibody. This streamlined functionalization and detection strategy removes the need for traditional purification and immobilization techniques. With this biobrick construct, both optical and electrochemical immunoassays were developed. The optical immunoassays demonstrated detection of anti-HCV core antibody down to 12.3pM concentrations while the electrochemical assay demonstrated higher binding constants and dynamic range. The electrochemical format and a custom, low-cost smartphone-based potentiostat ($20 USD) yielded comparable results to assays performed on a state-of-the-art electrochemical workstation. We propose this combination of synthetic biology and scalable, point-of-care sensing has potential to provide low-cost, cutting edge diagnostic capability for many pathogens in a variety of settings.

Bioanalytical advances in assays for C-reactive protein.

This review presents advances in assays for human C-reactive protein (CRP), the most important biomarker of infection and inflammation for a plethora of diseases and pathophysiological conditions. Routine assays in clinical settings are based on analyzers, enzyme-linked immunosorbent assays and lateral flow assays. However, assays encompassing novel sensing schemes, improved chemistry, signal enhancement, lab-on-a-chip, microfluidics and smartphone detection, have emerged in recent years. The incorporation of immune-transducing chips or sensing interfaces with nanomaterials enables multiplexing analysis of CRP with co-existing biomarkers. However, there are still considerable challenges in the development of rapid diagnostics for both pentameric and monomeric CRP forms.