Bilateral Acute Anterior Uveitis and Optic Disc Edema Following a Snake Bite

Praveen K Kumar,Shashi Ahuja,Praveen S Kumar 대한안과학회 2014 Korean Journal of Ophthalmology Vol.28 No.2

The authors wish to report a case of bilateral acute anterior uveitis and optic disc edema following ahemotoxic snake bite, in order to highlight the concomitant occurrence of these conditions and the potentialadverse effects of anti-snake venom (ASV). A 35-year-old male was bitten by a viper at seventeen thirtyhours, and was started on ASV. Two days following treatment he experienced sudden onset redness andpainful diminution of vision in both eyes (OU). On examination, the patient’s visual acuity (VA) in OU was 20/ 200. Examination revealed fresh keratic precipitates, cells, and flare in the anterior chamber (AC), posteriorsynechiae, sluggish and ill-sustained pupillary reaction, and hyperemic, edematous disc with blurredmargins in OU. He was started on topical steroids, cycloplegics and intravenous methylprednisolone. Following treatment, the patient showed improvement and was continued on topical medications and oralprednisolone tapered over 3 weeks, after which VA OU improved, the AC showed no cells and flare anddisc edema resolved. Uveitis and optic disc edema in snake bite can either be due to the direct toxic effectsof the venom or the effect of ASV. Steroids have a beneficial role in the management of these symptoms.

Ocular Manifestations of Venomous Snake Bite over a One-year Period in a Tertiary Care Hospital

Praveen Kumar K V,Praveen Kumar S,Nirupama Kasturi,Shashi Ahuja 대한안과학회 2015 Korean Journal of Ophthalmology Vol.29 No.4

Purpose: Ocular manifestations in snake-bite injuries are quite rare. However, the unusual presentations, diagnosis and their management can pose challenges when they present to the ophthalmologist. Early detection of these treatable conditions can prevent visual loss in these patients who are systemically unstable and are unaware of their ocular condition. To address this, a study was conducted with the aim of identifying the various ocular manifestations of snake bite in a tertiary care center. Methods: This is a one-year institute-based prospective study report of 12 snake bite victims admitted to a tertiary hospital with ocular manifestations between June 2013 to June 2014, which provides data about the demographic characteristics, clinical profiles, ocular manifestations, and their outcomes. Results: Twelve cases of snake bite with ocular manifestations were included of which six were viper bites, three were cobra bites and three were unknown bites. Six patients presented with bilateral acute angle closure glaucoma (50%), two patients had anterior uveitis (16.6%) of which one patient had concomitant optic neuritis. One patient had exudative retinal detachment (8.3%), one patient had thrombocytopenia with subconjunctival hemorrhage (8.3%) and two patients had external ophthalmoplegia (16.6%). Conclusions: Bilateral angle closure glaucoma was the most common ocular manifestation followed by anterior uveitis and external ophthalmoplegia. Snake bite can result in significant ocular morbidity in a majority of patients but spontaneous recovery with anti-snake venom, steroids and conservative management results in good visual prognosis.

Pharmacokinetic evaluation of cefdinir-loaded floating alginate beads in rabbits using LC–MS/MS

Praveen R,Sandeep Kumar Singh,Priya Ranjan Prasad Verma 한국약제학회 2016 Journal of Pharmaceutical Investigation Vol.46 No.3

The present investigation aims to compare the pharmacokinetic parameters of Cefdinir in rabbits, from floating alginate (an anionic polysaccharide obtained from cell walls of brown algae) beads and conventional suspension, using a new LC–MS/MS method. Formulations equivalent to 20 mg/kg were administered orally to test and reference group and blood samples were collected at selected time intervals up to 24 h. Plasma concentrations of Cefdinir were determined using validated LC–MS/MS method and pharmacokinetic parameters were derived by non-compartment model. Statistically significant (p\0.05) increase in Cmax, Tmax, AUC0–? and MRT was observed in case of floating alginate beads, whereas KE and t1/2 remained relatively constant. MRT and tmax increased significantly as a result of controlled drug release. Relative bioavailability was 337.45 % for the floating beads. Thus, alginate based floating formulation improve the bioavailability (3.37 fold) of Cefdinir compared to suspension. The absorption of Cefdinir from floating beads was found mainly from duodenum (73.0 %) and Jejunum 1 and 2 (13.0 %).

Layer-by-layer microcapsules for pH-controlled delivery of small molecules

Praveen Kumar Mandapalli,Venkata Vamsi Krishna Venuganti 한국약제학회 2015 Journal of Pharmaceutical Investigation Vol.45 No.2

The aim of this study is to investigate the influence of pH on the encapsulation and release behavior of charged and neutral small molecules in layer-by-layer microcapsules (LbL-MC). Alternative layers of polystyrene sulfonate and polyallylamine hydrochloride polyelectrolytes were adsorbed onto calcium carbonate sacrificial templates. Six model small molecules including ascorbic acid, indomethacin, imatinib mesylate, rhodamine, 5-fluorouracil and estradiol were studied for their encapsulation in LbL-MC. Encapsulation efficiency was optimized for solute concentration, pH, incubation time and NaCl concentration. In vitro release studies were performed using dialysis membrane method at pH 4, 7.4 and 9. Optical microscopy and zetasizer results showed particles of 3.1 ± 0.2 lm diameter and 1.67 ± 0.87 mV potential. FTIR and differential scanning calorimeter studies confirmed the encapsulation of small molecules in LbL-MC. Encapsulation efficiency (%) of model molecules in LbLMC increased with increase in solute concentration and increase in pH from 2 to 6. Interestingly, encapsulation efficiency was significantly greater for charged small molecules compared to neutral molecules. Extended release of charged molecules was achieved at pH 9. Kinetic modelling of release studies showed Fickian and non-Fickian diffusion of small molecules. In conclusion, LbL-MC can be developed as a potential carrier for small molecules depending on their physical and chemical properties.

Isolation of a Potent Mosquito Repellent from Vitex negundo L.: An Alternative Source of Rotundial

Praveen K. Amancharla,Patrick S. Muthuraj,Gottumukkala V. Rao,Om V. Singh 한국생약학회 1999 Natural Product Sciences Vol.5 No.2

The chloroform fraction of the aqueous extract of the fresh leaves of Vitex negundo by bioactivity guided isolation yielded a pure compound, rotundial (1) which has shown potent mosquito repellent activity. Using spectral data (LN, IR, ¹H & ¹³C NMR and MS) its structure has been elucidated.

Influence of supplementary cementitious materials on strength and durability characteristics of concrete

Praveen Kumar, V.V.,Ravi Prasad, D. Techno-Press 2019 Advances in concrete construction Vol.7 No.2

The present study is focused on the mechanical and durability properties of ternary blended cement concrete mix of different grades 30 MPa, 50 MPa and 70 MPa. Three mineral admixtures (fly ash, silica fume and lime sludge) were used as a partial replacement of cement in the preparation of blended concrete mix. The durability of ternary blended cement concrete mix was studied by exposing it to acids HCl and $H_2SO_4$ at 5% concentration. Acid mass loss factors (AMLF), acid strength loss factor (ASLF) and acid durability factor (ADF) were determined, and the results were compared with the control mix. Chloride ions penetration was investigated by conducting rapid chlorination penetration test and accelerated corrosion penetration test on control mix and ternary blended cement concrete. From the results, it was evident that the usage of these mineral admixtures is having a beneficiary role on the strength as well as durability properties. The results inferred that the utilization of these materials as a partial replacement of cement have significantly enhanced the compressive strength of blended concrete mix in 30 MPa, 50 MPa and 70 MPa by 42.95%, 32.48% and 22.79%. The blended concrete mix shown greater resistance to acid attack compared to control mix concrete. Chloride ion ingress of the blended cement concrete mix was low compared to control mix implying the beneficiary role of mineral admixtures.

In vitro and in vivo evaluation of gastro-retentive carvedilol loaded chitosan beads using Gastroplus(TM)

Praveen, R.,Prasad Verma, P.R.,Venkatesan, J.,Yoon, D.H.,Kim, S.K.,Singh, S.K. ELSEVIER 2017 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES Vol.102 No.-

The objective of present investigation was to develop gastro-retentive controlled release system of carvedilol using biological macromolecule, chitosan. 3<SUP>2</SUP> full factorial design was adopted for optimization of tripolyphosphate (X<SUB>1</SUB>) and curing time (X<SUB>2</SUB>). Bead stability in 0.1N HCl, buoyancy duration, density, drug loading, dissolution efficiency and cumulative percentage release at 8th hour were evaluated as dependent variables. The levels of X<SUB>1</SUB> and X<SUB>2</SUB> of optimized formulation having maximum desirability was found to 2.0% w/v and 62.66min, respectively. The in silico predicted responses and observed response were found to be in good agreement (percent bias error: -13.295 to +13.269). SEM images showed numerous pores in the cross sectional image that renders buoyancy. AUC<SUB>0-~</SUB> of optimized formulation was 1.47 times higher as compared to suspension corroborating enhanced extent of absorption. T<SUB>max</SUB> and mean residence time were significantly higher from optimized formulation vis a vis suspension. In silico study indicated maximum regional absorption from the duodenum (94.1%) followed by jejunum (5.6%). Wagner-Nelson and Loo-Reigelman method were the preferred deconvolution approach over numerical deconvolution to establish IVIVC. In conclusion, the study showed that gastro-retentive controlled release system prepared using chitosan could be a potential drug carrier of carvedilol with improved bioavailability.

A comparative study between light transmission aggregometry and flow cytometric platelet aggregation test for the identification of platelet function defects in patients with bleeding

Praveen Sharma,Man Updesh Singh Sachdeva,Narender Kumar,Sunil Bose,Parveen Bose,Varun Uppal,Pankaj Malhotra,Deepak Bansal,Neelam Varma,Jasmina Ahluwalia 대한혈액학회 2021 Blood Research Vol.56 No.2

Background Platelet aggregation studies using conventional light transmission aggregometry (LTA) have several disadvantages and require strict pre-analytical measures for reliable results. We aimed to examine the utility of flow cytometric platelet aggregation (FCA) assay in detecting platelet function defects (PFDs) in patients with a history of bleeding symptoms. Methods Sixty-four participants (24 patients and 40 healthy controls) were included in this study. LTA and FCA assay were performed simultaneously in patients and healthy controls. In the FCA assay, two portions of platelets from the same individual were labeled separately with CD31-FITC and CD31-PE. After mixing and stimulation with agonists, the double- colored platelet aggregates were visualized using a flow cytometer. The results generated using the two techniques were compared and correlated. Results The patients’ median age was 17 years (range, 3‒72 yr) with a male-to-female ratio of 1:1.7. There was substantial agreement between LTA and FCA assay in detecting a PFD (=0.792). Four patients showing a Glanzmann thrombasthenia-like pattern on LTA exhibited an abnormal FCA. A functional defect in collagen binding was detected on the FCA assay conducted in two immune thrombocytopenic patients with severe bleeding. Conclusion FCA assay can be used to identify functional defects in platelets, with potential applications in thrombocytopenic individuals. It also facilitates the diagnosis of inherited bleeding disorders with platelet defects.

Peptide Transporter Substrate Identification during Permeability Screening in Drug Discovery: Comparison of Transfected MDCK-hPepT1 Cells to Caco-2 Cells

Praveen. V. Balimane,Saeho Chong,Karishma Patel,Yong Quan,Julita Timoszyk,한용해,Bonnie Wang,Balvinder Vig,Teresa N. Faria 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.4

The purpose of this study was to investigate the utility of stably transfected MDCK-hPepT1 cells for identifying peptide transporter substrates in early drug discovery and compare the characteristics of this cell line with Caco-2 cells. MDCK-hPepT1, MDCK-mock, and Caco-2 cells grown to confluence on 24-well Transwell‚ were used for this study. Expression levels of different transporter proteins (PepT1, PepT2, P-gp) in these cell lines were assessed by qRTPCR. Permeability studies were conducted in parallel in all the cells with a diverse set of peptide substrates using the optimized experimental condition: 100 µM, apical pH 6.0, basolateral pH 7.4, 2 hr incubation at 37°C. Permeability studies were also conducted with classical P-gp substrates (tested in bi-directional mode) and paracellularly absorbed probes to investigate the differences between the cell lines. As expected, MDCK-hPepT1 cells express significantly higher level of PepT1 mRNA compared to both Caco-2 and MDCK-mock cells. Efflux transporter, P-gp, was expressed adequately in all the cell lines. Permeability studies demonstrated that classical peptide substrates had significantly higher permeability in stably transfected MDCK-hPepT1 cells compared to MDCK-mock and Caco-2 cells. The transfected MDCKhPepT1 cells were qualitatively similar to Caco-2 cells with respect to functional P-gp efflux activity and paracellular pore activity. Stably transfected MDCK-hPepT1 cells have been demonstrated as a viable alternative to Caco-2 cells for estimating the human absorption potential of peptide transporter substrates. These cells behave similar to Caco-2 cells with regards to Pgp efflux and paracellular pore activity but demonstrate greater predictability of absorption values for classical peptide substrates (for which Caco-2 cells under-estimate oral absorption).

Multifocal large aggregates of pseudo-Gaucher cells in chronic myeloid leukemia

Praveen Sharma,Narender Kumar,Neelam Varma 대한혈액학회 2018 Blood Research Vol.53 No.3