Rohan Ajaykumar Shah - Academia.edu (original) (raw)

Papers by Rohan Ajaykumar Shah

Journal of Coastal Life Medicine, 2015

To study the antibacterial and antibiofilm activities expressed by epibiotic bacteria associated ... more To study the antibacterial and antibiofilm activities expressed by epibiotic bacteria associated with the polychaetes Platynereis dumerilii and Syllis sp. Methods: A total of 32 cultivable bacterial strains were isolated from the two polychaete species. The crude extracts were tested for antibacterial activity and biofilm inhibitory activity against pathogenic and biofilm-forming bacterial strains. Extracts of the strains which showed strong activity were analyzed by thin-layer chromatography (TLC) and the bacterial strains were identified based on 16S rRNA gene sequencing. Results: Extracts of 13 bacterial strains showed inhibitory activity against pathogenic and biofilm-forming bacteria. The crude extracts also affected the synthesis of extracellular polymeric substances and cell surface hydrophobicity of the Alteromonas sp. isolated from marine biofilm. The adhesion of Alteromonas sp. on glass surface showed significant variation between surface-associated bacterial crude extract treatment and control groups. Among the 13 bacteria, two strains PA8 and PA19 were further analyzed for bioactive fractions. Thinlayer chromatography indicated the presence of a single active fraction in the crude extract of both the bacterial strains. The epibiotic bacterial strains P8 and P19 were identified as Exiguobacterium sp. and Actinobacterium sp. respectively based on 16S rRNA gene sequencing. Conclusions: The present study indicates that bacteria associated with marine invertebrates inhabiting the coastal waters could be used as a potential source for the isolation of bioactive metabolites.

Radiology Case Reports, 2015

Cavernous sinus hemangiomas are relatively rare but have characteristic imaging features. We pres... more Cavernous sinus hemangiomas are relatively rare but have characteristic imaging features. We present a case of a large extra-axial middle cranial fossa mass arising from the cavernous sinus in a 51-year-old female, and we describe the unique features and complications of this intracranial tumor. With the proper pre-operative diagnosis, an appropriate plan can be created for these highly vascular lesions, minimizing the risks involved with surgery.

Journal of Physical Therapy Science

Current Chemistry Letters, 2012

The aminolytic depolymerization of PET bottle waste with ethanolamine by conventional heating and... more The aminolytic depolymerization of PET bottle waste with ethanolamine by conventional heating and microwave irradiation heating method was attempted with heterogeneous, recyclable acid catalysts such as beta zeolite (SiO2/ AlO2= 15 Na-form) and montmorillonite KSF. The pure product bis-(2-hydroxyethyl) terephthalamide (BHETA) of aminolysis was obtained in good yield (85-88%). The BHETA, thus obtained, was subjected to cyclization reaction by heating with polyphosphoric acid as well as by chlorination (using phosphoryl chloride), bromination (using red phosphorous and liquid bromine) and nitration (conc. HNO3 + conc. H2SO4) followed by conventional and microwave irradiation heating in N,N-dimethyl formamide/ potassium carbonate solution. The product so obtained was 2, 2'-(1,4-phenylene)bis-(2-oxazoline) (PBO), which has applications in polymer synthesis as a chain extender/ chain coupling agent or a cross linker. The productswere analyzed by FTIR, DSC, Mass and NMR (1H and 13C NMR).

Biomedical Optics Express, 2015

Real-time intraocular optical coherence tomography (OCT) visualization of tissues with surgical f... more Real-time intraocular optical coherence tomography (OCT) visualization of tissues with surgical feedback can enhance retinal surgery. An intraocular 23-gauge B-mode forward-imaging co-planar OCT-forceps, coupling connectors and algorithms were developed to form a unique ophthalmic surgical robotic system. Approach to the surface of a phantom or goat retina by a manual or robotic-controlled forceps, with and without real-time OCT guidance, was performed. Efficiency of lifting phantom membranes was examined. Placing the co-planar OCT imaging probe internal to the surgical tool reduced instrument shadowing and permitted constant tracking. Robotic assistance together with real-time OCT feedback improved depth perception accuracy. The first-generation integrated OCTforceps was capable of peeling membrane phantoms despite smooth tips.

Computer Aided Surgery, 2004

Objective: Otologic surgery is undertaken to treat ailments of the ear, including persistent infe... more Objective: Otologic surgery is undertaken to treat ailments of the ear, including persistent infections, hearing loss, vertigo, and cancer. Typically performed on otherwise-healthy patients in outpatient facilities, the application of image-guided surgery (IGS) has been limited because accurate (,1 mm), non-invasive fiducial systems for otologic surgery have not been available. We now present such a fiducial system. Methods: A dental bite-block was fitted with a custom-designed rigid frame with 7 fiducial markers surrounding each external ear. The bones containing the ear (i.e., the temporal bones) of 3 cadaveric skulls were removed and replaced with discs containing 13 surgical targets arranged in a cross-hair pattern about the centroid of each ear. The surgical targets (26/ skull) and fiducial markers (14/skull) were identified both within CT scans using a published algorithm and in physical space using an infrared optical tracking system. Fiducial registration error (FRE), fiducial localization error (FLE), and target registration error (TRE) were calculated. Results: For all trials, root mean square FRE ¼ 0.66, FLE ¼ 0.72, and TRE ¼ 0.77 mm. The mean TRE for n ¼ 234 independent targets was 0.73 with a standard deviation of 0.25 mm. Conclusions: Using a novel, non-invasive fiducial system (the EarMark TM), submillimetric accuracy was repeatably achieved. This system will facilitate image-guided otologic surgery.

Retina, 2014

Purpose: To determine the 1-year and 2-year likelihood of vitrectomy in diabetic patients undergo... more Purpose: To determine the 1-year and 2-year likelihood of vitrectomy in diabetic patients undergoing initial pan retinal photocoagulation (PRP). Methods: Diabetic eyes receiving initial PRP for proliferative diabetic retinopathy (PDR) were analyzed to determine their risk for vitrectomy based on clinical findings. Results: In total, 374 eyes of 272 patients were analyzed. The percentage of eyes undergoing vitrectomy 1 year and 2 years following initial PRP was 19.1% and 26.2%, respectively. Of the eyes in Group 1 (PDR alone), Group 2 (PDR and vitreous hemorrhage), and Group 3 (PDR and iris neovascularization, vitreous hemorrhage with traction or fibrosis, or fibrosis alone), the percentage receiving pars plana vitrectomy at 1 year and 2 years was 9.73% (18/185) and 15.7% (29/185), 26.9% (43/160) and 34.4% (55/160), and 37.9% (11/29) and 48.3% (14/29), respectively. Eyes in Group 2 had 2.78 times greater likelihood (P , 0.0001) and eyes in Group 3 had 3.54 times higher likelihood (P , 0.0001) of requiring pars plana vitrectomy within 2 years than those with PDR alone. Conclusion: Eyes receiving PRP for PDR with associated hemorrhage or traction were more likely to undergo pars plana vitrectomy within 1 year and 2 years following initial PRP compared with eyes with only PDR, providing important prognostic information for PRP-naive patients.

JAMA Ophthalmology, 2014

cytokines may have therapeutic effects in diabetic retinopathy (DR). OBJECTIVE To compare aqueous... more cytokines may have therapeutic effects in diabetic retinopathy (DR). OBJECTIVE To compare aqueous and vitreous levels of 17 inflammatory cytokines in patients treated preoperatively with topical ketorolac tromethamine, 0.45%, or placebo before pars plana vitrectomy for complications related to proliferative DR (PDR). DESIGN, SETTING, AND PARTICIPANTS A prospective, randomized, placebo-controlled, patient-masked interventional study performed in a university academic hospital included 20 eyes from 20 patients undergoing pars plana vitrectomy for complications of PDR. INTERVENTIONS Eyes were randomized to ketorolac tromethamine, 0.45% (Acuvail), or placebo 4 times daily for 3 days before pars plana vitrectomy. Undiluted aqueous and vitreous samples were taken at the time of surgery and immediately frozen at −80°C. MAIN OUTCOMES AND MEASURES Aqueous and vitreous levels of prostaglandin E 2 and 16 other inflammatory cytokines implicated in the pathogenesis of DR. RESULTS Prostaglandin E 2 , platelet-derived growth factor (PDGF) AA, eotaxin, vascular endothelial growth factor, interferon γ-inducible protein of 10 kDa, monocyte chemoattractant protein 1, growth-related oncogene, interleukin 6, interleukin 8 (IL-8), and tumor necrosis factor were detectable in the aqueous and vitreous of at least half of the eyes, and these cytokines were analyzed further. Aqueous levels were lower in the ketorolac group for all cytokines detected, but only the difference in IL-8 was statistically significant (52% reduction; P = .04). Levels of IL-8 (41% reduction; P = .002) and PDGF-AA (21% reduction; P = .009) were significantly lower in the vitreous of patients treated with ketorolac. CONCLUSIONS AND RELEVANCE Topical ketorolac tromethamine, 0.45%, significantly lowered aqueous IL-8 levels and vitreous IL-8 and PDGF-AA levels in this series of eyes, suggesting that it may cause meaningful inhibition of inflammatory cytokines implicated in the pathogenesis of DR.

Ophthalmic Technologies XVII, 2007

Purpose: Orbital tumors and pseudotumor cerebri are sometimes treated with surgical approaches. O... more Purpose: Orbital tumors and pseudotumor cerebri are sometimes treated with surgical approaches. Our previous studies suggest that potentially endoscopy may be useful for minimally invasive orbital surgery. This study proposed to improve the approach technique for accessing the posterior orbital space via endoscopy, as well as assess visibility improvements with CO2 insufflation to posterior orbital tissues. Methods: An inferior transconjunctival

Lipid Nanoparticles: Production, Characterization and Stability, 2014

SpringerBriefs in Pharmaceutical Science & Drug Development, 2015

The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.