3.Finite Element Analysis Comparing the Biomechanical Parameters in Multilevel Posterior Cervical Instrumentation Model Involving Lateral Mass Screw versus Transpedicular Screw Fixation at the C7 Vertebra
Arvind Gopalrao KULKARNI ; Priyambada KUMAR ; Gautam Manjayya SHETTY ; Sandipan ROY ; Pechimuthu Susai MANICKAM ; Raja DHASON ; Aditya Raghavendra Sai Siva CHADALAVADA ; Yogesh Madhavrao ADBALWAD
Asian Spine Journal 2024;18(2):163-173
Methods:
Four FE models of multilevel posterior cervical fixation were created and tested by FEA in various permutations and combinations. Generic differences in fixation were determined, and the following parameters were assessed: (1) maximum moment at failure, (2) maximum angulation at failure, (3) maximum stress at failure, (4) point of failure, (5) intervertebral disc stress, and (6) influence of adding a C2 pars screw to the multilevel construct.
Results:
The maximum moment at failure was higher in the LMS fixation group than in the TPS group. The maximum angulation in flexion allowed by LMS was higher than that by TPS. The maximum strain at failure was higher in the LMS group than in the TPS group. The maximum stress endured before failure was higher in the TPS group than in the LMS group. Intervertebral stress levels at C6–C7 and C7–T1 intervertebral discs were higher in the LMS group than in the TPS group. For both models where C2 fixation was performed, lower von Mises stress was recorded at the C2–C3 intervertebral disc level.
Conclusions
Ending a multilevel posterior cervical fixation construct with TPS fixation rather than LMS fixation at the C7 vertebra provides a stiff and more constrained construct system, with higher stress endurance to compressive force. The constraint and durability of the construct can be further enhanced by adding a C2 pars screw in the fixation system.
4.Factors Associated With Neurocognitive Impairment Following Chemoradiotherapy in Patients With High-Grade Glioma: Results of a Prospective Trial
Prashasti SHARMA ; Partha Pratim MEDHI ; Apurba Kumar KALITA ; Mouchumee BHATTACHARYYA ; Jyotiman NATH ; Gautam SARMA ; Yanpothung YANTHAN
Brain Tumor Research and Treatment 2023;11(3):183-190
Background:
High-grade gliomas (HGG) are highly fatal tumors despite advanced multimodalitymanagement. They are also associated with neurocognitive impairment, both due to disease pathology and treatment. We aimed to assess various risk factors responsible for neurocognitive decline in HGG patients undergoing adjuvant chemoradiation.
Methods:
Newly diagnosed HGG patients who underwent maximal safe resection were includ-ed. Patients received volumetric modulated arc therapy to a dose of 60 Gy in 30 fractions, along with concurrent temozolomide (TMZ) at a dose of 75 mg/m2 /day orally; thereafter adjuvant TMZ (150–200 mg/m 2 for 5 days), given every 28 days for 6 to 8 cycles. The Mini-Mental State Examination questionnaire was used to measure cognitive impairment of each study patient at various time points. Cox regression model was used for univariate and multivariable analysis of data to establish possible risk factors.
Results:
Fifty-three patients were enrolled and analyzed. At a median follow-up of 15 months,30 patients (56.6%) developed cognitive impairment, and 23 patients (43.4%) did not. On univariate analysis, HGG with WHO grade 4, glioblastoma and diffuse midline glioma histology, IDH-wild type, recursive partitioning analysis class IV/V, and only biopsy of primary tumor were significantly associated with neurocognitive impairment, but none of them were independent risk factors on multivariable analysis. Planning target volume and dose received by ipsilateral hippocampus were also significantly correlated with cognitive decline in HGG patients.
Conclusion
Decline in neurocognitive functions in HGG patients is multifactorial and can be attrib-uted to an amalgam of various tumor, patient, and treatment-related factors.
5.Metformin Reduces the Progression of Atherogenesis by Regulating the Sestrin2-mTOR Pathway in Obese and Diabetic Rats
Saravanakumar SUNDARARAJAN ; Isaivani JAYACHANDRAN ; Gautam Kumar PANDEY ; Saravanakumar VENKATESAN ; Anusha RAJAGOPAL ; Kuppan GOKULAKRISHNAN ; Muthuswamy BALASUBRAMANYAM ; Viswanathan MOHAN ; Nagaraj MANICKAM
Journal of Lipid and Atherosclerosis 2023;12(3):290-306
Objective:
In previous research, we found that Sestrin2 has a strong association with plasma atherogenicity and combats the progression of atherogenesis by regulating the AMPK-mTOR pathway. Metformin, an activator of AMPK, is widely used as a first-line therapy for diabetes, but its role in preventing atherosclerosis and cardiac outcomes is unclear. Hence, we aimed to assess the effect of metformin on preventing atherosclerosis and its regulatory role in the Sestrin2-AMPK -mTOR pathway in obese/diabetic rats.
Methods:
Animals were fed a high-fat diet to induce obesity, administered streptozotocin to induce diabetes, and then treated with metformin (150 mg/kg body weight) for 14 weeks. Aorta and heart tissues were analyzed for Sestrin2 status by western blotting and immunohistochemistry, AMPK and mTOR activities were investigated using western blotting, and atherogenicity-related events were evaluated using reverse transcription quantitative polymerase chain reaction and histology.
Results:
Obese and diabetic rats showed significant decrease in Sestrin2 levels and AMPK activity, accompanied by increased mTOR activity in the heart and aorta tissues. Metformin treatment significantly restored Sestrin2 and AMPK levels, reduced mTOR activity, and restored the altered expression of inflammatory markers and adhesion molecules in obese and diabetic rats to normal levels. A histological analysis of samples from obese and diabetic rats showed atherosclerotic lesions both in aorta and heart tissues. The metformin-treated rats showed a decrease in atherosclerotic lesions, cardiac hypertrophy, and cardiomyocyte degeneration.
Conclusion
This study presents further insights into the beneficial effects of metformin and its protective role against atherosclerosis through regulation of the Sestrin2-AMPK-mTOR pathway.
6.Angioleiomyoma masquerading as shoulder pain
Surekh RAVI ; Lazar J CHANDY ; Gautam KUMAR ; Biju JACOB ; Ami M EMMANUEL
Clinics in Shoulder and Elbow 2021;24(1):32-35
Angioleiomyoma is a benign soft tissue tumor originating from vascular smooth muscle. We report a case of a 20-year-old student who presented with pain in the right shoulder of 4 years duration. Shoulder movements were pain-free throughout the range of motion except resisted external rotation. Magnetic resonance imaging visualized a well-circumscribed lesion over the infraspinatus tendon. The lesion was surgically removed and sent for histopathological analysis. Morphology and immunohistochemistry results were suggestive of angioleiomyoma. The most common location for such a lesion is the lower limb, with less than 1% being reported in the upper arm, of which an angioleiomyoma of the shoulder is extremely rare.
7.Endovascular management of large and giant intracranial aneurysms: Experience from a tertiary care neurosurgery institute in India
Gautam DUTTA ; Daljit SINGH ; Anita JAGETIA ; Arvind K SRIVASTAVA ; Hukum SINGH ; Anil KUMAR
Journal of Cerebrovascular and Endovascular Neurosurgery 2021;23(2):99-107
Objective:
With the development of endovascular technique and devices, large and giant intracranial aneurysms are increasingly being managed by this less invasive method. Here we discuss our experience on managing such aneurysms via endovascular technique.
Methods:
Retrospective data on 42 patients with large and giant intracranial aneurysms managed by endovascular techniques between September 2015 to December 2017 at our neurosurgery institute were included in this analysis.
Results:
There were a total 42 patients with 9 giant and 33 large aneurysms in this study. Eight aneurysms were treated by parent vessel occlusion, 22 aneurysms with coils and rest 12 aneurysms were treated with stent assisted coiling. Following the procedure, Raymond class I occlusion was accomplished in 31 (73.8%) patients while class Ⅱ in 9 (21.4%) and class Ⅲ in 2 (4.8%) patients. Overall morbidity and mortality were 9.5% and 14.3% respectively and favorable outcome was seen in 80.9% patients. Significant correlation was observed with clinical outcome and initial neurological status.
Conclusions
The study indicates that endovascular intervention is a safe and effective method in managing large and giant intracranial aneurysms with lesser morbidity and mortality.
8.Natural compounds as potential inhibitors of SARS-CoV-2 main protease: An in-silico study
Mishra AMARESH ; Pathak YAMINI ; Kumar ANUJ ; Mishra Kirti SURABHI ; Tripathi VISHWAS
Asian Pacific Journal of Tropical Biomedicine 2021;11(4):155-163
Objective:To explore natural compounds as potential inhibitors against main protease (Mpro) of SARS-CoV-2. Methods:In the current study, systematic molecular docking analysis was conducted using AutoDock 4.2 to determine the binding affinities and interactions between natural compounds and Mpro. Selected natural compounds were further validated using a combination of molecular dynamic (MD) simulations and molecular mechanic Poisson-Boltzmann surface area (MM/PBSA) free energy calculations. Results:Out of twenty natural compounds, four natural metabolites namely, amentoflavone, guggulsterone, puerarin, and piperine were found to have strong interaction with Mpro of SARS-CoV-2 based on docking analysis. During MD simulations, all four natural compounds bound to Mpro at 50 ns and MM/G/P/BSA free energy calculations showed that all four shortlisted ligands had stable and favorable energies with strong binding to Mpro protein. Conclusions:Guggulsterone is a potential inhibitor of COVID-19 main protease Mpro. Further in vitro and pre-clinical studies are needed.
9.Angioleiomyoma masquerading as shoulder pain
Surekh RAVI ; Lazar J CHANDY ; Gautam KUMAR ; Biju JACOB ; Ami M EMMANUEL
Clinics in Shoulder and Elbow 2021;24(1):32-35
Angioleiomyoma is a benign soft tissue tumor originating from vascular smooth muscle. We report a case of a 20-year-old student who presented with pain in the right shoulder of 4 years duration. Shoulder movements were pain-free throughout the range of motion except resisted external rotation. Magnetic resonance imaging visualized a well-circumscribed lesion over the infraspinatus tendon. The lesion was surgically removed and sent for histopathological analysis. Morphology and immunohistochemistry results were suggestive of angioleiomyoma. The most common location for such a lesion is the lower limb, with less than 1% being reported in the upper arm, of which an angioleiomyoma of the shoulder is extremely rare.
10.Endovascular management of large and giant intracranial aneurysms: Experience from a tertiary care neurosurgery institute in India
Gautam DUTTA ; Daljit SINGH ; Anita JAGETIA ; Arvind K SRIVASTAVA ; Hukum SINGH ; Anil KUMAR
Journal of Cerebrovascular and Endovascular Neurosurgery 2021;23(2):99-107
Objective:
With the development of endovascular technique and devices, large and giant intracranial aneurysms are increasingly being managed by this less invasive method. Here we discuss our experience on managing such aneurysms via endovascular technique.
Methods:
Retrospective data on 42 patients with large and giant intracranial aneurysms managed by endovascular techniques between September 2015 to December 2017 at our neurosurgery institute were included in this analysis.
Results:
There were a total 42 patients with 9 giant and 33 large aneurysms in this study. Eight aneurysms were treated by parent vessel occlusion, 22 aneurysms with coils and rest 12 aneurysms were treated with stent assisted coiling. Following the procedure, Raymond class I occlusion was accomplished in 31 (73.8%) patients while class Ⅱ in 9 (21.4%) and class Ⅲ in 2 (4.8%) patients. Overall morbidity and mortality were 9.5% and 14.3% respectively and favorable outcome was seen in 80.9% patients. Significant correlation was observed with clinical outcome and initial neurological status.
Conclusions
The study indicates that endovascular intervention is a safe and effective method in managing large and giant intracranial aneurysms with lesser morbidity and mortality.

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