A pilot non-randomized trial of smartphone-based anaglyph system for treatment of adult amblyopia through VR (Virtual Reality)

Purpose

To evaluate the effectiveness of amblyopia treatment through a smartphone-based anaglyph system by virtual reality (VR) in adult patients.

Methods

A total of 10 subjects diagnosed with anisometropic amblyopia were enrolled during the study period. Best Corrected Visual Acuity (BCVA), stereoacuity, and contrast acuity were evaluated during three visits (at presentation, 3 months and 6 months) of smartphone-based anaglyph video run in the VR mode. All the amblyogenic factors including stereopsis, color vision, and contrast acuity were compared using Friedman two-way analysis of variance. Statistical significance was considered if P < 0.05.

Results

Mean BCVA in amblyopic eye improved significantly from a logMAR value of 0.73 ± 0.64 before Virtual reality vision therapy (VRVT) to a post-training VRVT value of 0.48 ± 0.44 (P < 0.01). Mean stereoacuity changed from a value of 560.00 ± 301.58 before VRVT to a value of 263.00 ± 143.58 seconds of arc after training (VRVT) (P < 0.01). Mean accommodation changes from a value of 15.00 ± 7.40 before training or VRVT to value of 12.60 ± 6.10 cm after training (P < 0.01). Mean contrast acuity changes from a value of 1.21 ± 0.72 at presentation to a value of 1.52 ± 0.49 log unit after VRVT.

Conclusion

A smartphone-based anaglyph system using VR vision therapy appears to be an effective treatment option for amblyopia in adults.

Effectiveness of Kanna photoscreener in detecting amblyopia risk factors

Purpose:

Amblyopia is a significant public health problem. Photoscreeners have been shown to have significant potential for screening; however, most are limited by cost and display low accuracy. The purpose of this study was validate a novel artificial intelligence (AI) and machine learning–based facial photoscreener “Kanna,” and to determine its effectiveness in detecting amblyopia risk factors.

Methods:

A prospective study that included 654 patients aged below 18 years was conducted in our outpatient clinic. Using an android smartphone, three images of each the participants’ face were captured by trained optometrists in dark and ambient light conditions and uploaded onto Kanna. Deep learning was used to create an amblyopia risk score based on our previous study. The algorithm generates a risk dashboard consisting of six values: five normalized risk scores for ptosis, strabismus, hyperopia, myopia and media opacities; and one binary value denoting if a child is “at-risk” or “not at-risk.” The presence of amblyopia risk factors (ARF) as determined on the ophthalmic examination was compared with the Kanna photoscreener.

Results:

Correlated patient data for 654 participants were analyzed. The mean age of the study population was 7.87 years. The algorithm had an F-score, 85.9%; accuracy, 90.8%; sensitivity, 83.6%; specificity, 94.5%; positive predictive value, 88.4%; and negative predictive value, 91.9% in identifying amblyopia risk factors. The P value for the amblyopia risk calculation was 8.5 × 10⁻¹⁴² implying strong statistical significance.

Conclusion:

The Kanna photo-based screener that uses deep learning to analyze photographs is an effective alternative for screening children for amblyopia risk factors.

Application of deep learning and image processing analysis of photographs for amblyopia screening

Purpose

Photo screeners and autorefractors have been used to screen children for amblyopia risk factors (ARF) but are limited by cost and efficacy. We looked for a deep learning and image processing analysis-based system to screen for ARF.

Methods

An android smartphone was used to capture images using a specially coded application that modified the camera setting. An algorithm was developed to process images taken in different light conditions in an automated manner to predict the presence of ARF. Deep learning and image processing models were used to segment images of the face. Light settings and distances were tested to obtain the necessary features. Deep learning was thereafter used to formulate normalized risks using sigmoidal models for each ARF creating a risk dashboard. The model was tested on 54 young adults and results statistically analyzed.

Results

A combination of low-light and ambient-light images was needed for screening for exclusive ARF. The algorithm had an F-Score of 73.2% with an accuracy of 79.6%, a sensitivity of 88.2%, and a specificity of 75.6% in detecting the ARF.

Conclusion

Deep-learning and image-processing analysis of photographs acquired from a smartphone are useful in screening for ARF in children and young adults for a referral to doctors for further diagnosis and treatment.

Azithromycin resistance mechanisms in typhoidal salmonellae in India: A 25 years analysis

Background & objectives

: Azithromycin has been in use as an alternate treatment option for enteric fever even when the guidelines on the susceptibility testing were not available. There is lack of data on susceptibility and mechanisms of resistance of azithromycin in Salmonella Typhi and S. Paratyphi A. The aim of the present study was to determine the azithromycin susceptibility and resistance mechanisms in typhoidal salmonellae isolates archived in a tertiary care centre in north India for a period of 25 years.

Methods

: Azithromycin susceptibility was determined in 602 isolates of S. Typhi (469) and S. Paratyphi A (133) available as archived collection isolated during 1993 to 2016, by disc diffusion and E-test method.PCR was done for ereA, ermA, ermB, ermC, mefA, mphA and msrA genes from plasmid and genomic DNA and sequencing was done to detect mutations in acrR, rplD and rplV genes.

Results

: Azithromycin susceptibility was seen in 437/469 [93.2%; 95% confidence interval (CI), 90.5 to 95.1%] isolates of S. Typhi. Amongst 133 isolates of S. Paratyphi A studied, minimum inhibitory concentration (MIC) of ≤16 mg/l was found in 102 (76.7%; 95% CI, 68.8 to 83.0). MIC value ranged between 1.5 and 32 mg/l with an increasing trend in MIC₅₀and MIC₉₀with time. Mutations were found in acrR in one and rplV in two isolates of S. Typhi. No acquired mechanism for macrolide resistance was found.

Interpretation & conclusions

: Azithromycin could be considered as a promising agent against typhoid fever on the basis of MIC distribution in India. However, due to emergence of resistance in some parts, there is a need for continuous surveillance of antimicrobial susceptibility and resistance mechanisms. There is also a need to determine the breakpoints for S. Paratyphi A.

Adipokine Visfatin's Role in Pathogenesis of Diabesity and Related Metabolic Derangements

Visfatin is one of the prominent adipokines secreted by adipose tissue. The level of visfatin increases significantly in persons with obesity owing to increased body mass index (BMI). During obesity, the adipocytes, which populate adipose tissue, undergo hypertrophy and hyperplasia and secrete a number of adipocytokines including visfatin. Visfatin, which also acts as an enzyme nicotinamide phosphoribosyl transferase, is one of the prominent adipokines that influence metabolic homeostasis in the body. Visfatin exists in two forms, extracellular and intracellular, and enacts a multitude of actions. The direct and indirect evidence gathered from in-vitro, in-vivo and clinical studies indicate that visfatin modulates obesity and metabolic syndrome-related pathophysiological activities including enhanced inflammation, angiogenesis, synthesis of NAD mononucleotide, and upregulation of antiapoptotic proteins in a number of cell types. It has been implicated in a number of obesity-related alterations and metabolic derangement such as diabetes, cardiovascular complications and some forms of cancers. In this review, the novel hypothesis about the role of visfatin in diabesity has been proposed which implies recent advances in studies about the pathophysiological roles of visfatin during obesity and chronic high glucose in the circulation. Visfatin at high concentration attracts immune cells and produces chronic inflammation in adipocytes. Additionally, it induces insulin resistance in many tissues and causes pancreatic beta cells dysfunction at later stages. Further, its potential as an important target to develop molecular medicine in diabesity and related metabolic syndrome has been highlighted.

Changing trends of culture-positive typhoid fever and antimicrobial susceptibility in a tertiary care North Indian Hospital over the last decade

Purpose

The present study was undertaken to analyse the trend in prevalence of culture-positive typhoid fever during the last decade and to determine antimicrobial susceptibility profile of Salmonella Typhi and Salmonella Paratyphi A isolated from patients of enteric fever presenting to our hospital.

Methods

All the culture-positive enteric fever cases during 2005-2016 presenting to our Hospital were included in the study. Antimicrobial susceptibility was done against chloramphenicol, amoxicillin, co-trimoxazole, ciprofloxacin, ofloxacin, levofloxacin, pefloxacin, ceftriaxone and azithromycin as per corresponding CLSI guidelines for each year. We also analysed the proportion of culture positivity during 1993-2016 in light of the antibiotic consumption data from published literature.

Results

A total of 1066 strains-S. Typhi (772) and S. Paratyphi A (294) were isolated from the blood cultures during the study. A maximum number of cases were found in July-September. Antimicrobial susceptibility for chloramphenicol, amoxicillin and co-trimoxazole was found to be 87.9%, 75.5%, 87.3% for S. Typhi and 94.2%, 90.1% and 94.2% for S. Paratyphi A, respectively. Ciprofloxacin, ofloxacin and levofloxacin susceptibility were 71.3%, 70.8% and 70.9% for S. Typhi and 58.1%, 57.4% and 57.1% for S. Paratyphi A, respectively. Azithromycin susceptibility was 98.9% in S. Typhi. Although susceptibility to ceftriaxone and cefixime was 100% in our isolates, there is a continuous increase in ceftriaxone minimum inhibitory concentration (MIC)₅₀and MIC₉₀values over the time. The proportion of blood culture-positive cases during 1993-2016 ranged from a minimum of 0.0006 in 2014 to a maximum of 0.0087 in 1999.

Conclusion

We found that the most common etiological agent of enteric fever is S. Typhi causing the majority of cases from July to October in our region. MIC to ceftriaxone in typhoidal salmonellae is creeping towards resistance and more data are needed to understand the azithromycin susceptibility.

Pefloxacin as a surrogate marker for quinolone susceptibility in Salmonella enterica serovars Typhi & Paratyphi A in India

Background & objectives:

The emergence of resistance to fluoroquinolones in enteric fever despite the pathogen being susceptible by in vitro laboratory results, led to repeated changes in Clinical and Laboratory Standard Institute (CLSI) guidelines for this class of antibiotics to have specific and sensitive interpretative criteria. In 2015, CLSI added pefloxacin disk diffusion criteria as a surrogate marker for fluoroquinolone susceptibility. This study was carried out to evaluate the use of pefloxacin as a surrogate marker for ciprofloxacin, ofloxacin and levofloxacin susceptibility in clinical isolates of Salmonella Typhi and S. Paratyphi A.

Methods:

A total of 412 strains of S. Typhi and S. Paratyphi A were studied for pefloxacin disk diffusion test as a surrogate marker for susceptibility to ciprofloxacin, ofloxacin and levofloxacin as per CLSI and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Molecular mechanisms of resistance to fluoroquinolones were also determined and correlated with pefloxacin susceptibility breakpoints.

Results:

Of the total 412 strains, 34 were susceptible to ciprofloxacin and 33 each to levofloxacin and ofloxacin using CLSI minimum inhibitory concentration (MIC) breakpoints. There was a positive correlation between MICs with correlation coefficients 0.917, 0.896 and 0.958 for the association between ciprofloxacin and ofloxacin, ciprofloxacin and levofloxacin and ofloxacin and levofloxacin, respectively (P <0.001). The sensitivity, specificity and positive predictive value of pefloxacin as a surrogate marker using ciprofloxacin MIC as a gold standard were 100, 99.5 and 94.4 per cent, while 100, 99.2 and 91.7 per cent taking ofloxacin and levofloxacin MIC as gold standard. Mutations in target genes correlated with the pefloxacin susceptibility results.

Interpretation & conclusions:

Our results showed that pefloxacin served as a good surrogate marker for the detection of susceptibility to ciprofloxacin, ofloxacin and levofloxacin in S. Typhi and S. Paratyphi A. Further studies are required to confirm these findings.

Biodegradation of pyrene and phenanthrene by bacterial consortium and evaluation of role of surfactant

High molecular weight poly aromatic hydrocarbons (HMW PAHs) are well known for their hydrophobicity and they get strongly adsorbed onto the soil particles. Generally, surfactants facilitate the biodegradation of PAH by enhancing their solubility and desorption of hydrophobic compounds from soil particles. To investigate the role of synthetic surfactant in biodegradation of PAHs, two bacterial strains BP10 and P2 were incubated in soil spiked with pyrene and phenantherene (100 μg g-1of soil each) in isolation and in combination with/without Tween 80. After 14 days of incubation, pyrene and phenantherene were degraded by a combination of BP10 and P2 to the extent of 98% and 99%, respectively. Addition of tween 80 reduced the degradation of pyrene and phenantherene by 35 and 10%, respectively. Biosurfactant produced by selected strains i.e. BP10 and P2 could enhance desorption of pyrene (100 μg g-1of soil) by about 27% and 12%, respectively. However, desorption activity was relatively higher (32 and 29%, respectively) in case of phenanthrene (100 μg g-1of soil) from the spiked soil. Present study showed that in spite of additional chemical surfactant, bioaugmentation of highly petroleum hydrocarbon degrading bacterial combination was very effective in boosting the bioremediation of PAHs- contaminated sites.

Simultaneous spectrophotometric estimation of norfloxacin and ornidazole in tablet dosage form

Three simple, accurate and economical methods have been developed for the estimation of norfloxacin and ornidazole in tablet dosage form. First method is based on the simultaneous equations, wavelengths selected for analysis were 273.0 nm (λ_max of norfloxacin) and 318.5 nm (λ_max of ornidazole), respectively, in 0.1N NaOH. Second method is Q-analysis method, based on absorbance ratio at two selected wavelengths 297.0 nm (iso-absorptive point) and 318.5 nm (λ_max of ornidazole). Third method is first order derivative spectroscopy using 297.5 nm (zero cross for norfloxacin) and 264.0 nm (zero cross for ornidazole). The linearity was obtained in the concentration range of 4-20 μg/ml and 5-25 μg/ml for norfloxacin and ornidazole, respectively. The results of the analysis have been validated statistically and by recovery studies.

Biodiversity, bioaccumulation and physiological changes in lichens growing in the vicinity of coal-based thermal power plant of Raebareli district, north India

The lichen diversity assessment carried out around a coal-based thermal power plant indicated the increase in lichen abundance with the increase in distance from power plant in general. The photosynthetic pigments, protein and heavy metals were estimated in Pyxine cocoes (Sw.) Nyl., a common lichen growing around thermal power plant for further inference. Distributions of heavy metals from power plant showed positive correlation with distance for all directions, however western direction has received better dispersion as indicated by the concentration coefficient-R(2). Least significant difference analysis showed that speed of wind and its direction plays a major role in dispersion of heavy metals. Accumulation of Al, Cr, Fe, Pb and Zn in the thallus suppressed the concentrations of pigments like chlorophyll a, chlorophyll b and total chlorophyll, however, enhanced the level of protein. Further, the concentrations of chlorophyll contents in P. cocoes increased with the decreasing the distance from the power plant, while protein, carotenoid and phaeophytisation exhibited significant decrease.

Isolation and structure elucidation of a new antifungal and antibacterial antibiotic produced by Streptomyces sp. 201

An antibacterial and antifungal antibiotic was isolated from the culture filtrate of Streptomyces sp. 201, and its structure was determined as 2-methyl-heptyl isonicotinate by extensive use of NMR spectroscopy. The compound exhibited marked antimicrobial activity against Bacillus subtilis, Shigella sp., Klebsiella sp., E. coli, Proteus mirabilis, and the pathogenic fungi, Fusarium moniliforme, F. semitectum, F. oxysporum, F. solani and Rhizoctonia solani.

Experimental biofilm and its application in malathion degradation

Mixed bacterial culture consisting of three different strains of Micrococcus sp. (AG 36, AG 94 and AG 98) and two strains of Pseudomonas sp. (AG 7 and AG 52) and its individual components was passed through a sand column and 25.5-92% of cell dry mass was found to be retained (adsorbed) on it. Incubation of sand soaked in mineral medium containing glucose as a sole carbon source resulted in formation of a biofilm with 1.2-2.5-fold increase in biomass. A 61% degradation of malathion by the mixed culture biofilm could be achieved in 4 d.

Degradation of fenitrothion by Bacillus stearothermophilus adhering to silica

B. stearothermophilus strain AG-49, when cultivated in mineral medium in the presence of silica (SA), adhered to SA. Adhesion depended on age of culture, contact time and glucose concentration of the culture medium. Mid-exponential phase culture (5 h) required minimum contact time (30 min) for maximum adhesion. 0.6% glucose concentration was optimum. Quantitative variation in protein and saccharide extractable in sodium chloride and sodium dodecyl sulfate (SDS) was observed. Five % degradation of fenitrothion by adherent B. stearothermophilus could be achieved in 4 d.

Possible involvement of plasmids in degradation of malathion and chlorpyriphos by Micrococcus sp

Two plasmid-harboring strains of Micrococcus sp. (M-36 and AG-43) degrade malathion and chlorpyriphos. Derivatives of the strains (SDS-36 and AO-43) treated with acridine orange and sodium dodecyl sulfate could not utilize malathion and chlorpyriphos for growth as the sole carbon source. Agarose gel electrophoresis of cell extracts of M-36 and AG-43 revealed the presence of a plasmid which was absent in SDS-36 and AO-43--suggesting probable involvement of plasmids in the degradation of malathion and chlorpyriphos by M-36 and AG-43. Nalidixic acid resistance in M-36 was also lost upon elimination of plasmids.