Vipul Gupta - Academia.edu (original) (raw)

Papers by Vipul Gupta

Asian Journal of Neurosurgery, 2014

Purpose: The technique of coiling has evolved in the last decade with evolution in both equipment... more Purpose: The technique of coiling has evolved in the last decade with evolution in both equipment and material. The preferable treatment of intracranial aneurysms at our center is endovascular coiling. We discuss the technical and management outcomes of consecutive patients treated with this approach and compare our results with a decade old International Subarachnoid Aneurysm Trial. Materials and Methods: Between January 2006 and November 2011, a total of 324 aneurysms in 304 consecutive patients were treated. Endovascular treatment was done in 308 aneurysms (95.0%) in 288 patients while 16 patients (5%) underwent surgical clipping. Of the 308 aneurysms treated endovascularly, 269 (87.3%) were ruptured, and 39 (12.7%) were unruptured aneurysms. Results: The endovascular coiling was feasible in all (99.6%) but 1 case. The immediate postoperative occlusion status was complete occlusion in 240 aneurysms (77.9%), neck remnant in 57 aneurysms (18.5%), and aneurysm remnant in 11 aneurysm...

Internet enabled wireless devices continue to proliferate and are expected to surpass traditional... more Internet enabled wireless devices continue to proliferate and are expected to surpass traditional Internet clients in the near future. This has opened up exciting new opportunities in the mobile e-commerce mar-ket. However, data security and privacy remain major concerns in the ...

100 Interesting Case Studies in Neurointervention: Tips and Tricks, 2019

An 82-year-old female presented with transient weakness of the right arm. MRI brain was normal. H... more An 82-year-old female presented with transient weakness of the right arm. MRI brain was normal. However, MRA revealed severe stenosis of bilateral ICA (Fig. 97.1a, b). The left CCA was rising at an acute angle from the brachiocephalic artery (Fig. 97.1c). Patient had received radiotherapy in neck region for laryngeal tumor 12 years back. As left ICA stenosis was symptomatic, revascularization was planned, and, in view of previous radiotherapy, endovascular approach was favored over endarterectomy.

100 Interesting Case Studies in Neurointervention: Tips and Tricks, 2019

A 24-year-old male presented with severe headache. He was drowsy but arousable and followed verba... more A 24-year-old male presented with severe headache. He was drowsy but arousable and followed verbal commands. He didn't have any focal deficits. CT scan revealed large right frontal haematoma with midline shift (Fig. 71.1a). DSA revealed a moderate-sized AVM with feeders from right ACA and MCA cortical branches (Fig. 71.1b) with venous drainage into superior sagittal sinus.

PLoS computational biology, 2018

Eradicating HIV-1 infection is difficult because of the reservoir of latently infected cells that... more Eradicating HIV-1 infection is difficult because of the reservoir of latently infected cells that gets established soon after infection, remains hidden from antiretroviral drugs and host immune responses, and retains the capacity to reignite infection following the cessation of treatment. Drugs called latency-reversing agents (LRAs) are being developed to reactivate latently infected cells and render them susceptible to viral cytopathicity or immune killing. Whereas individual LRAs have failed to induce adequate reactivation, pairs of LRAs have been identified recently that act synergistically and hugely increase reactivation levels compared to individual LRAs. The maximum synergy achievable with LRA pairs is of clinical importance, as it would allow latency-reversal with minimal drug exposure. Here, we employed stochastic simulations of HIV-1 transcription and translation in latently infected cells to estimate this maximum synergy. We incorporated the predominant mechanisms of acti...

Review of Business Information Systems (RBIS), 2011

During last few years, healthcare organizations have been increasingly focused on implementation ... more During last few years, healthcare organizations have been increasingly focused on implementation and use of electronic health records. This article identifies the benefits and challenges in implementing electronic health records utilizing service-oriented architecture. The paper also explores the potential of service-oriented architecture in the development of interoperable electronic health records.

Clinical pharmacology and therapeutics, 1999

Artemether is a new and effective treatment for malaria, although relapse is a problem in monothe... more Artemether is a new and effective treatment for malaria, although relapse is a problem in monotherapy. These relapses could be related to a time-dependent decline in artemether plasma levels described in multiple-dose studies and probably caused by autoinduction. The aim of this study was to evaluate the effect of grapefruit juice on the decreasing bioavailability over time of artemether. In a randomized, two-phase crossover study, eight healthy male subjects took 100 mg oral artemether with 350 mL water or with 350 mL double-strength fresh frozen grapefruit juice once daily for 5 days. On day 1 and day 5, 17 blood samples were collected over a period of 8 hours. The mean peak artemether plasma concentration (Cmax) and the mean area under the concentration-time curve (AUC) after the last dose at day 5 were about one third compared with day 1, without a change in the elimination half-life after intake with water (P = .006 for Cmax; P = .005 for AUC) and with grapefruit juice (P < ...

52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 2011

This paper describes a broad effort that is aimed at understanding the fundamental mechanisms of ... more This paper describes a broad effort that is aimed at understanding the fundamental mechanisms of crack growth and using that understanding as a basis for designing materials and enabling predictions of fracture in materials and structures that have small characteristic dimensions. This area of research, herein referred to as Damage Science, emphasizes the length scale regimes of the nanoscale and the microscale for which analysis and characterization tools are being developed to predict the formation, propagation, and interaction of fundamental damage mechanisms. Examination of nanoscale processes requires atomistic and discrete dislocation plasticity simulations, while microscale processes can be examined using strain gradient plasticity, crystal plasticity and microstructure modeling methods. Concurrent and sequential multiscale modeling methods are being developed to analytically bridge between these length scales. Experimental methods for characterization and quantification of near-crack tip damage are also being developed. This paper focuses on several new methodologies in these areas and their application to understanding damage processes in polycrystalline metals. Ongoing and potential applications are also discussed.

Journal of Indian Association of Pediatric Surgeons, 2008

Appendicitis epiploicae is described as a rare entity in an 8-year-old boy presented with the fea... more Appendicitis epiploicae is described as a rare entity in an 8-year-old boy presented with the features of acute abdomen simulating acute appendicitis. Surgical exploration revealed a torsion of appendices epiploicae of the cecum. The excision of infarcted epiploicae with seromuscular inversion resulted in satisfactory recovery. Authors describe this uncommon cause of pediatric acute abdomen along with the review of pertinent literature.

American Journal of Physiology-Endocrinology and Metabolism, 2011

Estrogens can either relax or contract arteries via rapid, nongenomic mechanisms involving classi... more Estrogens can either relax or contract arteries via rapid, nongenomic mechanisms involving classic estrogen receptors (ER). In addition to ERα and ERβ, estrogen may also stimulate G protein-coupled estrogen receptor 1 (GPER) in nonvascular tissue; however, a potential role for GPER in coronary arteries is unclear. The purpose of this study was to determine how GPER activity influenced coronary artery reactivity. In vitro isometric force recordings were performed on endothelium-denuded porcine arteries. These studies were augmented by RT-PCR and single-cell patch-clamp experiments. RT-PCR and immunoblot studies confirmed expression of GPER mRNA and protein, respectively, in smooth muscle from either porcine or human coronary arteries. G-1, a selective GPER agonist, produced a concentration-dependent relaxation of endothelium-denuded porcine coronary arteries in vitro. This response was attenuated by G15, a GPER-selective antagonist, or by inhibiting large-conductance calcium-activate...

The American Journal of Cardiology, 1998

Background-Controversy persists regarding the optimal revascularization strategy for diabetic pat... more Background-Controversy persists regarding the optimal revascularization strategy for diabetic patients with multivessel coronary artery disease (MVD). Coronary artery bypass grafting (CABG) has been compared with percutaneous coronary intervention (PCI) using drug-eluting stents (DES) in recent randomized controlled trials (RCTs). Methods and Results-RCTs comparing PCI with DES versus CABG in diabetic patients with MVD who met inclusion criteria were analyzed (protocol registration No. CRD42013003693). Primary end point (major adverse cardiac events) was a composite of death, myocardial infarction, and stroke at a mean follow-up of 4 years. Analyses were performed for each outcome by using risk ratio (RR) by fixedand random-effects models. Four RCTS with 3052 patients met inclusion criteria (1539 PCI versus 1513 CABG). Incidence of major adverse cardiac events was 22.5% for PCI and 16.8% for CABG (RR 1.34, 95% CI 1.16 to 1.54, P<0.0001). Similar results were obtained for death (14% versus 9.7%, RR 1.51, 95% CI 1.09 to 2.10, P=0.01), and MI (10.3% versus 5.9%, RR 1.44, 95% CI 0.79 to 2.6, P=0.23). Stroke risk was significantly lower with DES (2.3% versus 3.8%, RR 0.59, 95% CI 0.39 to 0.90, P=0.01) and subsequent revascularization was several-fold higher (17.4% versus 8.0%, RR 1.85, 95% CI 1.0 to 3.40, P=0.05). Conclusions-These data demonstrate that CABG in diabetic patients with MVD at low to intermediate surgical risk (defined as EUROSCORE <5) is superior to MVD PCI with DES. CABG decreased overall death, nonfatal myocardial infarction, and repeat revascularization at the expense of an increase in stroke risk.

100 Interesting Case Studies in Neurointervention: Tips and Tricks, 2019

A 2-month-old female baby presented with severe congestive cardiac failure and was diagnosed with... more A 2-month-old female baby presented with severe congestive cardiac failure and was diagnosed with vein of Galen aneurysmal malformation. She needed ventilator support for managing the cardiorespiratory failure before being transferred to our center. On admission to our center, she had transient anuria secondary to prerenal acute renal failure with an elevated urea and normal creatinine, normal liver functions, and severe congestive heart failure causing respiratory failure needing ventilatory support. Echocardiography revealed flow reversal in the descending thoracic aorta, pulmonary artery hypertension, atrial septal defect, and shift of interventricular septum to the left. Ultrasound abdomen did not reveal hepatomegaly. She had an isolated convulsion, and the MRI of the brain did not show any evidence of encephalomalacia or ventriculomegaly. The Bicêtre neonatal evaluation score (BNES) was 9 (cardiac, 1; cerebral, 2; respiratory, 1; hepatic, 3; renal, 2). Cardiorespiratory failure was refractory to medical management needing ventilation, and with a BNES of 9, a decision to treat was undertaken.

Journal of Clinical Interventional Radiology ISVIR, 2019

Blister aneurysms pose significant diagnostic and therapeutic challenge to neurointerventionists ... more Blister aneurysms pose significant diagnostic and therapeutic challenge to neurointerventionists as well as neurosurgeons. Fragile nature of these aneurysms with involvement of the adjacent parent artery makes surgical options more difficult and complicated. Various endovascular treatment options such as overlapping stent, parent artery occlusion, and flow diverter placement are available in the present era. Though side wall aneurysms can be managed with flow diverter placement, bifurcation aneurysms are difficult to treat with these devices due to possibility of compromised flow in covered branch arteries. Blister aneurysms of the middle cerebral artery (MCA) are rare, and their treatment can be challenging when they are treated by endovascular methods with either overlapping stent or flow diverter placement. The authors report a case of ruptured MCA trifurcation blister aneurysm treated with shelfing technique using braided stent monotherapy along with coil embolization. The patie...

Journal of NeuroInterventional Surgery, 2016

Solitaire FR stent-based mechanical thrombectomy provides clinical benefit in selected patients w... more Solitaire FR stent-based mechanical thrombectomy provides clinical benefit in selected patients with acute ischaemic stroke due to large vessel occlusion. A dreaded device complication that is associated with poor technical and clinical outcome is stent detachment. Retrieval of the detached stent can be technically challenging and has been attempted with variable success. The key benefit of this strategy is the lack of need to administer fibrinolytic/antiplatelet agents that can potentially be catastrophic in the setting of acute stroke. Therefore, retrieval may be preferred to other strategies (balloon angioplasty, lytic/glycoprotein 2b/3a inhibitors administration) to address detached stent. We report two patients in whom the detached stent was retrieved using alternative techniques—‘deploy and engage’ and ‘loop and snare’—as snare retrieval failed.

JACC. Cardiovascular interventions, Jan 21, 2015

The purpose of this study was to assess usage patterns of transradial access in rescue percutaneo... more The purpose of this study was to assess usage patterns of transradial access in rescue percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) and associations between vascular access site choice and outcomes. Transradial access reduces bleeding and mortality in STEMI patients undergoing primary PCI. Little is known about access site choice and outcomes in patients undergoing rescue PCI after receiving full-dose fibrinolytic therapy for STEMI. Patients in the National Cardiovascular Data Registry's CathPCI Registry undergoing rescue PCI for STEMI between 2009 and 2013 were studied. Patients were divided on the basis of access site. Patterns of access use and baseline demographics were noted. Unadjusted and propensity-matched analyses were performed comparing in-hospital bleeding, vascular complications, and mortality outcomes among transradial and transfemoral access patients. The falsification endpoint of gastrointestinal bleeding was spe...

Clinical Radiology Extra, 2004

Proceedings. 15th IEEE International Conference on Application-Specific Systems, Architectures and Processors, 2004.

We describe a general-purpose processor architecture for accelerating public-key computations on ... more We describe a general-purpose processor architecture for accelerating public-key computations on server systems that demand high performance and flexibility to accommodate large numbers of secure connections with heterogeneous clients that are likely to be limited in the set of cryptographic algorithms supported. Flexibility is achieved in that the processor supports multiple public-key cryptosystems, namely RSA, DSA, DH, and ECC, arbitrary key sizes and, in the case of ECC, arbitrary curves over fields GF (p) and GF (2 m). At the core of the processor is a novel dual-field multiplier based on a modified carrysave adder (CSA) tree that supports both GF (p) and GF (2 m). In the case of a 64-bit integer multiplier, the necessary modifications increase its size by a mere 5%. To efficiently schedule the multiplier, we implemented a multiply-accumulate instruction that combines several steps of a multiple-precision multiplication in a single operation: multiplication, carry propagation, and partial product accumulation. We have developed a hardware prototype of the cryptographic processor in FPGA technology. If implemented in current 1.5 GHz processor technology, the processor executes 5,265 RSA-1024 op/s and 25,756 ECC-163 op/s-the given key sizes offer comparable security strength. Looking at future security levels, performance is 786 op/s for RSA-2048 and 9,576 op/s for ECC-233.

Lecture Notes in Computer Science, 2003

Since its proposal by Victor Miller [17] and Neal Koblitz [15] in the mid 1980s, Elliptic Curve C... more Since its proposal by Victor Miller [17] and Neal Koblitz [15] in the mid 1980s, Elliptic Curve Cryptography (ECC) has evolved into a mature public-key cryptosystem. Offering the smallest key size and the highest strength per bit, its computational efficiency can benefit both client devices and server machines. We have designed a programmable hardware accelerator to speed up point multiplication for elliptic curves over binary polynomial fields GF (2 m). The accelerator is based on a scalable architecture capable of handling curves of arbitrary field degrees up to m = 255. In addition, it delivers optimized performance for a set of commonly used curves through hard-wired reduction logic. A prototype implementation running in a Xilinx XCV2000E FPGA at 66.4 MHz shows a performance of 6987 point multiplications per second for GF (2 163). We have integrated ECC into OpenSSL, today's dominant implementation of the secure Internet protocol SSL, and tested it with the Apache web server and open-source web browsers.

Revista española de cardiología, 2011

Asian Journal of Neurosurgery, 2014

Purpose: The technique of coiling has evolved in the last decade with evolution in both equipment... more Purpose: The technique of coiling has evolved in the last decade with evolution in both equipment and material. The preferable treatment of intracranial aneurysms at our center is endovascular coiling. We discuss the technical and management outcomes of consecutive patients treated with this approach and compare our results with a decade old International Subarachnoid Aneurysm Trial. Materials and Methods: Between January 2006 and November 2011, a total of 324 aneurysms in 304 consecutive patients were treated. Endovascular treatment was done in 308 aneurysms (95.0%) in 288 patients while 16 patients (5%) underwent surgical clipping. Of the 308 aneurysms treated endovascularly, 269 (87.3%) were ruptured, and 39 (12.7%) were unruptured aneurysms. Results: The endovascular coiling was feasible in all (99.6%) but 1 case. The immediate postoperative occlusion status was complete occlusion in 240 aneurysms (77.9%), neck remnant in 57 aneurysms (18.5%), and aneurysm remnant in 11 aneurysm...

Internet enabled wireless devices continue to proliferate and are expected to surpass traditional... more Internet enabled wireless devices continue to proliferate and are expected to surpass traditional Internet clients in the near future. This has opened up exciting new opportunities in the mobile e-commerce mar-ket. However, data security and privacy remain major concerns in the ...

100 Interesting Case Studies in Neurointervention: Tips and Tricks, 2019

An 82-year-old female presented with transient weakness of the right arm. MRI brain was normal. H... more An 82-year-old female presented with transient weakness of the right arm. MRI brain was normal. However, MRA revealed severe stenosis of bilateral ICA (Fig. 97.1a, b). The left CCA was rising at an acute angle from the brachiocephalic artery (Fig. 97.1c). Patient had received radiotherapy in neck region for laryngeal tumor 12 years back. As left ICA stenosis was symptomatic, revascularization was planned, and, in view of previous radiotherapy, endovascular approach was favored over endarterectomy.

100 Interesting Case Studies in Neurointervention: Tips and Tricks, 2019

A 24-year-old male presented with severe headache. He was drowsy but arousable and followed verba... more A 24-year-old male presented with severe headache. He was drowsy but arousable and followed verbal commands. He didn't have any focal deficits. CT scan revealed large right frontal haematoma with midline shift (Fig. 71.1a). DSA revealed a moderate-sized AVM with feeders from right ACA and MCA cortical branches (Fig. 71.1b) with venous drainage into superior sagittal sinus.

PLoS computational biology, 2018

Eradicating HIV-1 infection is difficult because of the reservoir of latently infected cells that... more Eradicating HIV-1 infection is difficult because of the reservoir of latently infected cells that gets established soon after infection, remains hidden from antiretroviral drugs and host immune responses, and retains the capacity to reignite infection following the cessation of treatment. Drugs called latency-reversing agents (LRAs) are being developed to reactivate latently infected cells and render them susceptible to viral cytopathicity or immune killing. Whereas individual LRAs have failed to induce adequate reactivation, pairs of LRAs have been identified recently that act synergistically and hugely increase reactivation levels compared to individual LRAs. The maximum synergy achievable with LRA pairs is of clinical importance, as it would allow latency-reversal with minimal drug exposure. Here, we employed stochastic simulations of HIV-1 transcription and translation in latently infected cells to estimate this maximum synergy. We incorporated the predominant mechanisms of acti...

Review of Business Information Systems (RBIS), 2011

During last few years, healthcare organizations have been increasingly focused on implementation ... more During last few years, healthcare organizations have been increasingly focused on implementation and use of electronic health records. This article identifies the benefits and challenges in implementing electronic health records utilizing service-oriented architecture. The paper also explores the potential of service-oriented architecture in the development of interoperable electronic health records.

Clinical pharmacology and therapeutics, 1999

Artemether is a new and effective treatment for malaria, although relapse is a problem in monothe... more Artemether is a new and effective treatment for malaria, although relapse is a problem in monotherapy. These relapses could be related to a time-dependent decline in artemether plasma levels described in multiple-dose studies and probably caused by autoinduction. The aim of this study was to evaluate the effect of grapefruit juice on the decreasing bioavailability over time of artemether. In a randomized, two-phase crossover study, eight healthy male subjects took 100 mg oral artemether with 350 mL water or with 350 mL double-strength fresh frozen grapefruit juice once daily for 5 days. On day 1 and day 5, 17 blood samples were collected over a period of 8 hours. The mean peak artemether plasma concentration (Cmax) and the mean area under the concentration-time curve (AUC) after the last dose at day 5 were about one third compared with day 1, without a change in the elimination half-life after intake with water (P = .006 for Cmax; P = .005 for AUC) and with grapefruit juice (P < ...

52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 2011

This paper describes a broad effort that is aimed at understanding the fundamental mechanisms of ... more This paper describes a broad effort that is aimed at understanding the fundamental mechanisms of crack growth and using that understanding as a basis for designing materials and enabling predictions of fracture in materials and structures that have small characteristic dimensions. This area of research, herein referred to as Damage Science, emphasizes the length scale regimes of the nanoscale and the microscale for which analysis and characterization tools are being developed to predict the formation, propagation, and interaction of fundamental damage mechanisms. Examination of nanoscale processes requires atomistic and discrete dislocation plasticity simulations, while microscale processes can be examined using strain gradient plasticity, crystal plasticity and microstructure modeling methods. Concurrent and sequential multiscale modeling methods are being developed to analytically bridge between these length scales. Experimental methods for characterization and quantification of near-crack tip damage are also being developed. This paper focuses on several new methodologies in these areas and their application to understanding damage processes in polycrystalline metals. Ongoing and potential applications are also discussed.

Journal of Indian Association of Pediatric Surgeons, 2008

Appendicitis epiploicae is described as a rare entity in an 8-year-old boy presented with the fea... more Appendicitis epiploicae is described as a rare entity in an 8-year-old boy presented with the features of acute abdomen simulating acute appendicitis. Surgical exploration revealed a torsion of appendices epiploicae of the cecum. The excision of infarcted epiploicae with seromuscular inversion resulted in satisfactory recovery. Authors describe this uncommon cause of pediatric acute abdomen along with the review of pertinent literature.

American Journal of Physiology-Endocrinology and Metabolism, 2011

Estrogens can either relax or contract arteries via rapid, nongenomic mechanisms involving classi... more Estrogens can either relax or contract arteries via rapid, nongenomic mechanisms involving classic estrogen receptors (ER). In addition to ERα and ERβ, estrogen may also stimulate G protein-coupled estrogen receptor 1 (GPER) in nonvascular tissue; however, a potential role for GPER in coronary arteries is unclear. The purpose of this study was to determine how GPER activity influenced coronary artery reactivity. In vitro isometric force recordings were performed on endothelium-denuded porcine arteries. These studies were augmented by RT-PCR and single-cell patch-clamp experiments. RT-PCR and immunoblot studies confirmed expression of GPER mRNA and protein, respectively, in smooth muscle from either porcine or human coronary arteries. G-1, a selective GPER agonist, produced a concentration-dependent relaxation of endothelium-denuded porcine coronary arteries in vitro. This response was attenuated by G15, a GPER-selective antagonist, or by inhibiting large-conductance calcium-activate...

The American Journal of Cardiology, 1998

Background-Controversy persists regarding the optimal revascularization strategy for diabetic pat... more Background-Controversy persists regarding the optimal revascularization strategy for diabetic patients with multivessel coronary artery disease (MVD). Coronary artery bypass grafting (CABG) has been compared with percutaneous coronary intervention (PCI) using drug-eluting stents (DES) in recent randomized controlled trials (RCTs). Methods and Results-RCTs comparing PCI with DES versus CABG in diabetic patients with MVD who met inclusion criteria were analyzed (protocol registration No. CRD42013003693). Primary end point (major adverse cardiac events) was a composite of death, myocardial infarction, and stroke at a mean follow-up of 4 years. Analyses were performed for each outcome by using risk ratio (RR) by fixedand random-effects models. Four RCTS with 3052 patients met inclusion criteria (1539 PCI versus 1513 CABG). Incidence of major adverse cardiac events was 22.5% for PCI and 16.8% for CABG (RR 1.34, 95% CI 1.16 to 1.54, P<0.0001). Similar results were obtained for death (14% versus 9.7%, RR 1.51, 95% CI 1.09 to 2.10, P=0.01), and MI (10.3% versus 5.9%, RR 1.44, 95% CI 0.79 to 2.6, P=0.23). Stroke risk was significantly lower with DES (2.3% versus 3.8%, RR 0.59, 95% CI 0.39 to 0.90, P=0.01) and subsequent revascularization was several-fold higher (17.4% versus 8.0%, RR 1.85, 95% CI 1.0 to 3.40, P=0.05). Conclusions-These data demonstrate that CABG in diabetic patients with MVD at low to intermediate surgical risk (defined as EUROSCORE <5) is superior to MVD PCI with DES. CABG decreased overall death, nonfatal myocardial infarction, and repeat revascularization at the expense of an increase in stroke risk.

100 Interesting Case Studies in Neurointervention: Tips and Tricks, 2019

A 2-month-old female baby presented with severe congestive cardiac failure and was diagnosed with... more A 2-month-old female baby presented with severe congestive cardiac failure and was diagnosed with vein of Galen aneurysmal malformation. She needed ventilator support for managing the cardiorespiratory failure before being transferred to our center. On admission to our center, she had transient anuria secondary to prerenal acute renal failure with an elevated urea and normal creatinine, normal liver functions, and severe congestive heart failure causing respiratory failure needing ventilatory support. Echocardiography revealed flow reversal in the descending thoracic aorta, pulmonary artery hypertension, atrial septal defect, and shift of interventricular septum to the left. Ultrasound abdomen did not reveal hepatomegaly. She had an isolated convulsion, and the MRI of the brain did not show any evidence of encephalomalacia or ventriculomegaly. The Bicêtre neonatal evaluation score (BNES) was 9 (cardiac, 1; cerebral, 2; respiratory, 1; hepatic, 3; renal, 2). Cardiorespiratory failure was refractory to medical management needing ventilation, and with a BNES of 9, a decision to treat was undertaken.

Journal of Clinical Interventional Radiology ISVIR, 2019

Blister aneurysms pose significant diagnostic and therapeutic challenge to neurointerventionists ... more Blister aneurysms pose significant diagnostic and therapeutic challenge to neurointerventionists as well as neurosurgeons. Fragile nature of these aneurysms with involvement of the adjacent parent artery makes surgical options more difficult and complicated. Various endovascular treatment options such as overlapping stent, parent artery occlusion, and flow diverter placement are available in the present era. Though side wall aneurysms can be managed with flow diverter placement, bifurcation aneurysms are difficult to treat with these devices due to possibility of compromised flow in covered branch arteries. Blister aneurysms of the middle cerebral artery (MCA) are rare, and their treatment can be challenging when they are treated by endovascular methods with either overlapping stent or flow diverter placement. The authors report a case of ruptured MCA trifurcation blister aneurysm treated with shelfing technique using braided stent monotherapy along with coil embolization. The patie...

Journal of NeuroInterventional Surgery, 2016

Solitaire FR stent-based mechanical thrombectomy provides clinical benefit in selected patients w... more Solitaire FR stent-based mechanical thrombectomy provides clinical benefit in selected patients with acute ischaemic stroke due to large vessel occlusion. A dreaded device complication that is associated with poor technical and clinical outcome is stent detachment. Retrieval of the detached stent can be technically challenging and has been attempted with variable success. The key benefit of this strategy is the lack of need to administer fibrinolytic/antiplatelet agents that can potentially be catastrophic in the setting of acute stroke. Therefore, retrieval may be preferred to other strategies (balloon angioplasty, lytic/glycoprotein 2b/3a inhibitors administration) to address detached stent. We report two patients in whom the detached stent was retrieved using alternative techniques—‘deploy and engage’ and ‘loop and snare’—as snare retrieval failed.

JACC. Cardiovascular interventions, Jan 21, 2015

The purpose of this study was to assess usage patterns of transradial access in rescue percutaneo... more The purpose of this study was to assess usage patterns of transradial access in rescue percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) and associations between vascular access site choice and outcomes. Transradial access reduces bleeding and mortality in STEMI patients undergoing primary PCI. Little is known about access site choice and outcomes in patients undergoing rescue PCI after receiving full-dose fibrinolytic therapy for STEMI. Patients in the National Cardiovascular Data Registry's CathPCI Registry undergoing rescue PCI for STEMI between 2009 and 2013 were studied. Patients were divided on the basis of access site. Patterns of access use and baseline demographics were noted. Unadjusted and propensity-matched analyses were performed comparing in-hospital bleeding, vascular complications, and mortality outcomes among transradial and transfemoral access patients. The falsification endpoint of gastrointestinal bleeding was spe...

Clinical Radiology Extra, 2004

Proceedings. 15th IEEE International Conference on Application-Specific Systems, Architectures and Processors, 2004.

We describe a general-purpose processor architecture for accelerating public-key computations on ... more We describe a general-purpose processor architecture for accelerating public-key computations on server systems that demand high performance and flexibility to accommodate large numbers of secure connections with heterogeneous clients that are likely to be limited in the set of cryptographic algorithms supported. Flexibility is achieved in that the processor supports multiple public-key cryptosystems, namely RSA, DSA, DH, and ECC, arbitrary key sizes and, in the case of ECC, arbitrary curves over fields GF (p) and GF (2 m). At the core of the processor is a novel dual-field multiplier based on a modified carrysave adder (CSA) tree that supports both GF (p) and GF (2 m). In the case of a 64-bit integer multiplier, the necessary modifications increase its size by a mere 5%. To efficiently schedule the multiplier, we implemented a multiply-accumulate instruction that combines several steps of a multiple-precision multiplication in a single operation: multiplication, carry propagation, and partial product accumulation. We have developed a hardware prototype of the cryptographic processor in FPGA technology. If implemented in current 1.5 GHz processor technology, the processor executes 5,265 RSA-1024 op/s and 25,756 ECC-163 op/s-the given key sizes offer comparable security strength. Looking at future security levels, performance is 786 op/s for RSA-2048 and 9,576 op/s for ECC-233.

Lecture Notes in Computer Science, 2003

Since its proposal by Victor Miller [17] and Neal Koblitz [15] in the mid 1980s, Elliptic Curve C... more Since its proposal by Victor Miller [17] and Neal Koblitz [15] in the mid 1980s, Elliptic Curve Cryptography (ECC) has evolved into a mature public-key cryptosystem. Offering the smallest key size and the highest strength per bit, its computational efficiency can benefit both client devices and server machines. We have designed a programmable hardware accelerator to speed up point multiplication for elliptic curves over binary polynomial fields GF (2 m). The accelerator is based on a scalable architecture capable of handling curves of arbitrary field degrees up to m = 255. In addition, it delivers optimized performance for a set of commonly used curves through hard-wired reduction logic. A prototype implementation running in a Xilinx XCV2000E FPGA at 66.4 MHz shows a performance of 6987 point multiplications per second for GF (2 163). We have integrated ECC into OpenSSL, today's dominant implementation of the secure Internet protocol SSL, and tested it with the Apache web server and open-source web browsers.

Revista española de cardiología, 2011