In JoVE (1)

Other Publications (7)

Articles by Surendra K. Jain in JoVE

Other articles by Surendra K. Jain on PubMed

Noninvasive Assessment of the Stenotic Mitral Valve Orifice by Two-dimensional Echocardiography

Cardiovascular Diseases. Mar, 1981  |  Pubmed ID: 15216223

Two-dimensional echocardiographic imaging of the mitral valve orifice was attempted in 26 patients with isolated mitral stenosis. The intention was to examine further the clinical usefulness and limitations of this technique for estimating the severity of mitral stenosis. Technically adequate recordings of the mitral orifice were obtained in 20 patients (77%). Mitral valve area calculated from echocardiography compared favorably to the valve area derived from cardiac catheterization with the use of the Gorlin formula (r = 0.95). The average difference between the two methods was 0.109 cm(2). Two-dimensional echocardiography does provide clinically useful data for predicting the degree of mitral stenosis in the majority of patients provided that critical technical limitations are recognized.

Molecular Modeling of Porous Carbons Using the Hybrid Reverse Monte Carlo Method

Langmuir : the ACS Journal of Surfaces and Colloids. Nov, 2006  |  Pubmed ID: 17106983

We apply a simulation protocol based on the reverse Monte Carlo (RMC) method, which incorporates an energy constraint, to model porous carbons. This method is called hybrid reverse Monte Carlo (HRMC), since it combines the features of the Monte Carlo and reverse Monte Carlo methods. The use of the energy constraint term helps alleviate the problem of the presence of unrealistic features (such as three- and four-membered carbon rings), reported in previous RMC studies of carbons, and also correctly describes the local environment of carbon atoms. The HRMC protocol is used to develop molecular models of saccharose-based porous carbons in which hydrogen atoms are taken into account explicitly in addition to the carbon atoms. We find that the model reproduces the experimental pair correlation function with good accuracy. The local structure differs from that obtained with a previous model (Pikunic, J.; Clinard, C.; Cohaut, N.; Gubbins, K. E.; Guet, J. M.; Pellenq, R. J.-M.; Rannou, I.; Rouzaud, J. N. Langmuir 2003, 19 (20), 8565). We study the local structure by calculating the nearest neighbor distribution, bond angle distribution, and ring statistics.

Ring Connectivity: Measuring Network Connectivity in Network Covalent Solids

Langmuir : the ACS Journal of Surfaces and Colloids. Jan, 2007  |  Pubmed ID: 17241022

In atomistic models of amorphous materials, ring statistics provide a measure of medium-range order. However, while ring statistics tell us the number of rings present in the model, they do not give us any information about the arrangement of rings, e.g., whether the rings are clustered and how big the cluster is. In this work we present a method to calculate the ring connectivity, or clustering, of rings. We first calculate the rings present in the model using the shortest path criteria of Franzblau and then find the rings that are connected together and group them into clusters. We apply our method to a set of models of disordered carbons, obtained using a reverse Monte Carlo procedure developed in a recent work. We found that in these carbon models the five-, six-, and seven-membered rings are connected together, forming clusters. After isolating the clusters, we found that they resemble defective graphene segments twisted in a complex way. The clusters give further insight about the arrangement of carbon atoms in microporous carbons at a larger length scale. Moreover, the method can be applied to any network covalent solid that contains rings and thus gives information about the ring connectivity present in such materials.

Antiparasitic and Antimicrobial Indolizidines from the Leaves of Prosopis Glandulosa Var. Glandulosa

Planta Medica. Sep, 2011  |  Pubmed ID: 21384317

A new indolizidine alkaloid, named Δ¹,⁶-juliprosopine (1), together with previously known indolizidine analogs (2- 6), was isolated from the leaves of Prosopis glandulosa var. glandulosa, collected from Nevada, USA; while two other known indolizidines, juliprosopine (6) and juliprosine (7), were isolated from P. glandulosa leaves collected in Texas, USA. The structures of compound 1 and 7 were determined using a combination of NMR and MS techniques. Compound 7 exhibited potent antiplasmodial activity against Plasmodium falciparum D6 and W2 strains with IC (50) values of 170 and 150 ng/mL, respectively, while 1 was found to be less active (IC₅₀ values 560 and 600 ng/mL, respectively). Both compounds were devoid of VERO cells toxicity up to a concentration of 23 800 ng/mL. The antileishmanial activity of indolizidines was evaluated against Leishmania donovani promastigotes, axenic amastigotes, and amastigotes in THP1 macrophage cultures. When tested against macrophage cultures, the tertiary bases (1, 3, 6) were found to be more potent than quaternary salts (2, 5, 7), displaying IC₅₀ values between 0.8-1.7 µg/mL and 3.1-6.0 µg/mL, respectively. In addition, compound 7 showed potent antifungal activity against Cryptococcus neoformans and antibacterial activity against Mycobacterium intracellulare, while 1 was potent only against C. neoformans and weakly active against other organisms.

Antiparasitic and Antimicrobial Isoflavanquinones from Abrus Schimperi

Natural Product Communications. Nov, 2011  |  Pubmed ID: 22224279

The EtOH extract of Abrus schimperi (Fabaceae), collected in Kenya, demonstrated significant activity against Leishmania donovani promastigotes with IC50 value of 3.6 microg/mL. Bioassay-guided fractionation of CHCl3 fraction using Centrifugal Preparative TLC afforded two antiparasitic isoflavanquinones, namely amorphaquinone (1) and pendulone (2). They displayed IC50 values of 0.63 microg/mL and 0.43 microg/mL, respectively, against L. donovani promastigotes. Both the compounds were also evaluated against L. donovani axenic amastigotes and amastigotes in THPI macrophage cultures. In addition, compounds 1 and 2 showed antiplasmodial activity against Plasmodium falciparum D6 and W2 strains, while 2 displayed antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus (each IC50 1.44 microg/mL). The 1H and 13C data of 1, not fully assigned previously, were unambiguously assigned using 1D and 2D NMR HMBC and HMQC experiments. In addition, the absolute stereochemistry of the isolated compounds 1 and 2 was revised as C-(3S) based on Circular Dichroism experiments. This appears to be the first report of amorphaquinone (1) and pendulone (2) from the genus Abrus.

Acute Promyelocytic Leukemia As a Cause of Intracoronary Drug-eluting-stent Thrombosis

Texas Heart Institute Journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital. 2012  |  Pubmed ID: 22719158

Stent thrombosis is a potentially lethal complication of percutaneous coronary intervention. We describe the case of a 51-year-old man who presented with acute anterior ST-segment-elevation myocardial infarction and underwent successful percutaneous transluminal coronary angioplasty and placement of 3 drug-eluting stents in the left anterior descending coronary artery. Despite receiving dual antiplatelet therapy, the patient presented a week later with a non-ST-segment-elevation myocardial infarction and was found to have nonocclusive thrombosis of the left anterior descending coronary artery stents and his ostial left main and left circumflex coronary arteries. Subsequently, bone marrow biopsy analysis indicated that the patient had acute myelogenous leukemia, which we believe was the underlying cause of his prothrombotic state and stent thrombosis.

Percutaneous Closure of a Left Ventricular Pseudoaneurysm in a High-risk Surgical Candidate

Texas Heart Institute Journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital. 2012  |  Pubmed ID: 23109767

Few cases of percutaneous device closure of a left ventricular pseudoaneurysm have been reported. We describe the case of a 67-year-old man with a history of coronary artery disease who presented with shortness of breath and chest pain. Computed tomographic angiography showed a left ventricular pseudoaneurysm that was filling from a small leak in the anterolateral aspect of the ventricle. The patient had undergone 3 previous sternotomies and was a high-risk candidate for surgical treatment of the pseudoaneurysm. Despite technical challenges, we closed the pseudoaneurysm percutaneously with use of a 6-mm AMPLATZER muscular ventricular septal defect occluder. The patient was released from the hospital the next day and was asymptomatic a year later.To our knowledge, this is the first report of the percutaneous closure of a left ventricular pseudoaneurysm via the femoral vein. We show that this manner of closure can be feasible in patients who have undergone multiple sternotomies and who are at high surgical risk.

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