Publications

BACKGROUND/INTRODUCTION: The Indian subcontinent faces a substantial healthcare challenge with allergic bronchopulmonary aspergillosis (ABPA). While numerous investigations have explored ABPA's occurrence in the general asthmatic population, there remains a significant knowledge gap regarding its specific prevalence among individuals with severe asthma. Current Indian research demonstrates considerable variation in reported ABPA prevalence rates among severe asthmatics, highlighting the need for more comprehensive investigation.

OBJECTIVE: This research initiative aimed to determine the precise prevalence of ABPA among severe asthma patients seeking treatment at a tertiary healthcare institution in northwestern India, with the goal of enhancing our understanding of this complex condition's burden in this specific patient population.

METHODOLOGY: We conducted a comprehensive cross-sectional investigation spanning August 2022 through July 2023. The study encompassed 247 patients diagnosed with severe asthma. Each participant underwent thorough clinical evaluation and provided blood samples for comprehensive analysis, including absolute eosinophil count measurement, total IgE quantification, and specific testing for Aspergillus fumigatus-related IgE antibodies. When clinically indicated, additional diagnostic procedures included Aspergillus-specific IgG testing and detailed chest imaging through X-ray or high-resolution computed tomography (HRCT).

RESULTS: Our investigation revealed that 63.2% (156 out of 247) of severe asthma patients met the diagnostic criteria for ABPA. The affected population showed a mean age of 41.6 years, with a relatively balanced gender distribution (80 females, 76 males). Among those diagnosed with ABPA, we observed a notably higher prevalence of ABPA-B (92.3%, 144 patients) compared to ABPA-S (7.7%, 12 patients).

CONCLUSION: This research represents one of the most extensive investigations to date documenting such a high ABPA prevalence (63.2%) among severe asthma patients in northern India. These findings underscore the critical need for expanded research initiatives to investigate the underlying factors contributing to such elevated ABPA rates in this geographical region, ultimately aiming to develop and implement effective preventive strategies at the community level.

BACKGROUND: The National Medical Commission (NMC) of India requires medical postgraduate students to conduct research in the form of a thesis or dissertation. However, students often face challenges throughout the process, including topic selection, protocol approval, data collection, and thesis writing. This study aimed to assess the effectiveness of a 1-day focused thesis writing workshop in improving the knowledge and confidence of medical postgraduate students.

METHODS: A cross-sectional mixed-methods study was conducted involving 68 postgraduate students from various medical disciplines who participated in a thesis writing workshop. Participants were administered pre- and post-test questionnaires to assess their knowledge of key thesis writing components, including literature review, results, discussion, and conclusion. The workshop included interactive sessions on each of these topics. Descriptive and inferential statistics were used to analyze the results, and qualitative feedback was gathered to assess participant satisfaction and perceived improvements in confidence.

RESULTS: The pre- and post-test scores showed a significant improvement in knowledge, particularly in the areas of literature review, results, and discussion (p < 0.05). However, the improvement in knowledge regarding thesis conclusions was not statistically significant. Feedback from participants indicated high satisfaction with the workshop, with 85% reporting increased confidence in their thesis writing skills. The majority of students (78%) found the workshop relevant and helpful in enhancing their understanding of thesis writing.

CONCLUSION: A focused, 1-day workshop significantly improved the knowledge and confidence of medical postgraduate students in thesis writing. This suggests that such workshops can be an effective intervention to support postgraduate students in completing their research. The study advocates for the integration of similar workshops into postgraduate curricula. Further research with larger, multicenter studies is needed to evaluate the long-term impact and feasibility of institutionalizing such programs.

BACKGROUND: Diabetes mellitus (DM) is a global health concern with rising prevalence, particularly in India, where undiagnosed cases are significant. A common yet often overlooked complication, diabetic gastroparesis impairs gastric motility and significantly reduces quality of life. Current treatments focus on symptom management, but the relationship between gastric motility patterns and therapeutic outcomes remains underexplored. This study evaluates the efficacy of levosulpiride in managing diabetic gastroparesis and its impact on gastric scintigraphy patterns.

METHODS: This analytical observational study included 27 adult patients with type 2 DM (T2DM) and gastroparesis, conducted at a tertiary care hospital in North India from April 2021 to 2022. Patients received 25 mg levosulpiride thrice daily for 4 weeks. Gastroparesis symptoms were assessed using the Gastroparesis Cardinal Symptom Index (GCSI). Gastric motility was evaluated via gastric scintigraphy before and after treatment. Changes in GCSI scores and scintigraphy patterns were analyzed using paired t-tests and the Stuart-Maxwell test.

RESULTS: Participants (mean age 56.41 ± 9.48 years) showed significant improvement in GCSI scores (11.48 ± 3.02 to 6.04 ± 2.08, p < 0.001). Gastric scintigraphy revealed significant changes, with 66.7% of patients demonstrating normalized motility patterns posttreatment (χ2 = 14.000, p = 0.016). While delayed gastric emptying persisted in some cases, levosulpiride alleviated key symptoms like nausea, vomiting, and early satiety.

CONCLUSION: Levosulpiride significantly alleviated symptoms of diabetic gastroparesis, as evidenced by reduced GCSI scores and improvements in gastric scintigraphy patterns. Despite minimal changes in delayed gastric emptying, the drug's effect on motility dysfunction highlights its therapeutic potential. This study underscores the importance of focusing on motility patterns in symptom management, suggesting levosulpiride as a promising option for targeted treatment of diabetic gastroparesis.

PURPOSE: To compare the visibility of fundus lesions between RGB and RG images obtained with an ultra-widefield (UWF) fundus imaging device (Optos) for 10 types of fundus lesions.

METHODS: UWF images from 30 patients representing 10 types of fundus lesions were analyzed: vessel sheathing, optic disc cupping, cotton wool spots, epiretinal membrane, laser photocoagulation scars, retinal drusen, retinal hemorrhage, retinal/choroidal detachment, chorioretinal atrophy, and macular degeneration. Three images of each type of lesion were used, and 26 board-certified ophthalmologists compared them. The raters compared the visibility of lesions on a five-point scale: RG significantly better = -2; RG slightly better = -1; equal = 0; RGB slightly better = +1; and RGB significantly better = +2. The Wilcoxon signed-rank test was used to determine the significance of the differences.

RESULTS: RGB images were rated significantly more visually favorable than the RG images for all 10 lesions (P < 0.01). The greatest improvements in perceived visibility in RGB images were observed for vessel sheathing (50.7%), optic disc cupping (49.8%), cotton wool spots (46.9%), and an epiretinal membrane (46.7%). Conversely, macular degeneration (22.7%) and chorioretinal atrophy (25.1%) had minimal advantages in RGB images.

CONCLUSIONS: RGB imaging improves the visibility of white and superficial fundus lesions but adds little benefit for deeper located lesions.

TRANSLATIONAL RELEVANCE: The results indicate that RGB imaging, which includes blue laser light, improves the visibility of superficial and white retinal lesions. These findings support the optimized use of color imaging modalities in clinical practice based on lesion characteristics.

Visual crowding is the disruptive effect of nearby details on the perception of a target. This influence is dependent on both spatial separation and perceived similarity between target and flanker elements. However, it is not clear how these simultaneous influences combine to produce the final "crowded" percept as flankers traverse the limits of the crowding zone. We investigated the reported appearance of a peripherally presented Landolt-C target flanked by a pair of simultaneously presented Landolt-Cs across different levels of target-flanker similarity (relative orientation), spatial separation, and target eccentricity. The distributions of errors in reported target orientation were fitted with a pooling model that simulated errors using a weighted combination of target and flanker orientation signals. The change in error distribution with target-flanker spacing (the "spatial profile") was fitted with a logistic function, estimating both the rate at which target- and flanker-signal weighting varies as target-flanker spatial separation decreases (slope) and the spatial separation at which signals were balanced (midpoint). We found that the slope of the spatial profile increases as target-flanker similarity decreases, with similar modulation patterns across target eccentricities. In contrast, spatial profile midpoints increased linearly with eccentricity, in line with Bouma's law, but were invariant of target-flanker similarity. This suggests similarity-related modulation may operate within a fixed spatial extent at each eccentricity. Investigating the spatial profile of crowding disentangles effects related to the appearance of targets and flankers (i.e., similarity) from appearance-independent influences, which can be confounded when using other common measures to define crowding zone extent.

What is the impact of dynamic changes in facial visibility on identifying the eye and forehead region? This study examines how wearing or removing a mask affects the ability to visually identify the eyes. We investigate whether these changes impact the recognition of upper facial features and alter sensitivity to the misalignment of the face's upper and lower halves, which disrupts holistic face processing. Results show that removing a mask generally impairs visual identification, suggesting that the perception of the whole face hinders recognition of the upper half. This hindering is evident from the fact that the interference decreases when the face is misaligned. In contrast, the impairment in identification caused by adding a mask to a target face rises from losing original support of the holistic processing, given that it was not diminished when the upper and bottom halves were misaligned. Additional findings show that misalignment negatively affects the identification of faces where a mask was either maintained or added, suggesting that masks may actually help direct attention to relevant facial features, rather than being integrated into a holistic representation. We discuss these results in light of their theoretical and practical implications for visual identification, particularly in the context of dynamic changes to facial appearance.

A key limitation shared by both electronic and optogenetic sight recovery technologies is that they cause simultaneous rather than complementary firing within on- and off-center cells. Here, using "virtual patients"-sighted individuals viewing distorted input-we examine whether gamified training improves the ability to compensate for distortions in neuronal population coding. We measured perceptual learning using dichoptic input, filtered so that regions of the image that produced on-center responses in one eye produced off-center responses in the other eye. The Non-Gaming control group carried out an object discrimination task over five sessions using this filtered input. The Gaming group carried out an additional 25 hours of gamified training using a similarly filtered variant of the video game Fruit Ninja. Both groups showed improvements over time in the object discrimination task. However, there was no significant transfer of learning from the "Fruit Ninja" task to the object discrimination task. The lack of transfer of learning from video game training to object recognition suggests that gamification-based rehabilitation for sight recovery technologies may have limited utility and may be most effective when targeted on learning specific visual tasks.

Computational models that explain lightness/brightness illusions have been proposed. These models have been assessed using a simplistic criterion: the number of illusions each model can correctly predict from the test set. This simple method of evaluation assumes that each illusion is independent; however, because the independence and similarity among lightness illusions have not been well established, potential interdependencies among the illusions in the test set could distort the evaluation of models. Moreover, evaluating models with a single value obscures where the model's strengths and weaknesses lie. We collected the magnitudes of various lightness illusions through two online experiments and applied exploratory factor analyses. Both experiments identified some underlying factors in these illusions, suggesting that they can be classified into a few distinct groups. Experiment 1 identified three common factors; assimilation, contrast, and White's effect. Experiment 2, with a different illusion set, identified two factors-assimilation and contrast. We then examined three well-known models that are based on early visual processes, using the outcomes of the experiments. The examination of these models revealed biases in the models toward specific factors or sets of illusions, which suggested their limitations. This study clarified that correlations of illusion magnitudes provide valuable insights into both illusions and models and highlighted the need to assess models based on their ability to account for underlying factors rather than individual illusions.

Facial color is closely linked to the perception of emotion, with reddish tones often being associated with anger. Although previous studies have shown that static reddish facial tones enhance the perception of anger, whether dynamic changes in facial color further amplify this effect remains unclear. This study investigated how differences in facial color influence the perception of expression using a judgment task that involved morphed facial stimuli (fearful to angry). The participants evaluated facial expressions under two conditions: faces with dynamic color changes and faces with static colors. Experiment 1 compared redder (CIELAB a*+) faces to original-colored faces, and Experiment 2 compared greener (CIELAB a*-) faces to original-colored faces. Experiment 3 compared redder faces to original-colored faces under rapid facial color change conditions. None the experiments revealed significant differences between dynamic and static facial colors; however, faces with a final reddish color (higher a* value) were more likely to be perceived as angry. These findings suggest that the final facial color influences the perception of anger independent of whether the color change is dynamic or static. Our findings support the idea that the recognition of anger is modulated by the relationship between an angry expression and the color red. This study provides a new perspective on the interaction between facial expression and facial color, suggesting that the final facial color plays a significant role in facial expression judgment.