1.High-sensitivity simultaneous liquid chromatography-tandem mass spectrometry assay of ethinyl estradiol and levonorgestrel in human plasma
Abhishek GANDHI ; Swati GUTTIKAR ; Priti TRIVEDI
Journal of Pharmaceutical Analysis 2015;5(5):316-326
A sensitive and simultaneous liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of ethinyl estradiol and levonorgestrel. The analytes were extracted with methyl-tert-butyl ether: n-hexane (50:50, v/v) solvent mixture, followed by dansyl derivatization. The chromatographic separation was performed on a Kinetex C18 (50 mm × 4.6 mm, 2.6μm) column with a mobile phase of 0.1% (v/v) formic acid in water and acetonitrile in gradient composition. The mass transitions were monitored in electrospray positive ionization mode. The assay exhibited a linear range of 0.100-20.0 ng/mL for levonorgestrel and 4.00-500 pg/mL for ethinyl estradiol in human plasma. A run time of 9.0 min for each sample made it possible to analyze a throughput of more than 100 samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic and bioequivalence studies.
2.Retrieval of a broken guide wire transfixing the hip through the proximal femoral nail hole.
Saurabh JAIN ; Abhishek PATHAK ; Rajeev Kant PANDEY
Chinese Journal of Traumatology 2014;17(1):50-53
Retrieval of a broken guide wire transfixing the acetabulum or with intrapelvic migration is challenging and frustrating for surgeons. We here present a case report on a method to remove a broken guide wire transfixing the acetabulum through the proximal hole of recon nail using a grasping forceps. This method is little invasive, easy, time-saving and without need for changing the inital fixation.
Adult
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Bone Wires
;
adverse effects
;
Fracture Fixation, Internal
;
instrumentation
;
Hip Fractures
;
surgery
;
Humans
;
Male
;
Prosthesis Failure
3.Determination of ergocalciferol in human plasma after Diels-Alder derivatization by LC–MS/MS and its application to a bioequivalence study
Contractor PRITESH ; Gandhi ABHISHEK ; Solanki GAJENDRA ; Shah A. PRIYANKA ; Shrivastav S. PRANAV
Journal of Pharmaceutical Analysis 2017;7(6):417-422
An accurate, sensitive and selective method is developed for determination of ergocalciferol (vitamin D2) in human plasma using LC–MS/MS.After liquid-liquid extraction with n-hexane,ergocalciferol was derivatized by reacting with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), a strong dienophile based on Diels-Alder reaction. Ergocalciferol and its deuterated internal standard, ergocalciferol-d6, were analyzed on X Select CSH C18 (100 mm×4.6 mm, 2.5μm) column using acetonitrile and 0.1% (v/v) formic acid in water containing 0.14% methylamine within 6.0 min under gradient elution mode. Tandem mass spectrometry in positive ionization mode was used to quantify ergocalciferol by multiple reaction monitoring(MRM).Entire data processing was done using Watson LIMS? software which provided excellent data integrity and high throughput with improved operational efficiency.The major advantage of this method includes higher sensitivity(0.10 ng/mL), superior extraction efficiency(≥83%)and small sample volume(100μL)for processing.The method was linear in the concentration range of 0.10–100 ng/mL for ergocalciferol.The intra-batch and inter-batch accuracy and precision (% CV) values varied from 97.3% to 109.0% and 1.01% to 5.16%, respectively. The method was successfully applied to support a bioequivalence study of 1.25 mg ergocalciferol capsules in 12 healthy subjects.
4. Sex differences in SARS-CoV-2 infections, anti-viral immunity and vaccine responses
Abhishek MOHANTY ; Aanchal SAWHNEY ; Vandana JAIN ; Abhishek MOHANTY ; Vishal RAO ; Shefali GUPTA ; Periyasamy GOVINDARAJ ; Sambit MOHANTY
Asian Pacific Journal of Tropical Medicine 2022;15(3):97-105
The COVID-19 pandemic has revealed sex-based differences in anti-viral responses, with a higher rate of SARS-CoV-2 infections as well as a higher rate of morbidity and mortality in men than in women. Males and females also show disparate immune responses to COVID-19 infection, which may be important contributors to lower rates of infection, disease severity and deaths in women than in men. Here, the authors review sex differences in SARSCoV- 2 infections, anti-viral immunity and vaccine responses, putting forth the importance of sex, the underappreciated variables in vaccine response and disease infectivity.
5.A rare case of obstructive azoospermia due to compression of the seminal vesicle and ejaculatory duct by a large lower ureteric stone.
Priyadarshi RANJAN ; Abhishek YADAV ; Rohit KAPOOR ; Ranjana SINGH
Singapore medical journal 2013;54(3):e56-8
Male infertility due to obstructive azoospermia is a well-known entity. It is characterised by obstruction to the outflow of sperms either in the epididymis, vas, seminal vesicles or the ejaculatory ducts. We describe a rare case of obstructive azoospermia due to compression of the ejaculatory duct and seminal vesicle by a large lower ureteric stone in a 30-year-old man who had infertility for the past ten years. The patient's azoospermia resolved after removal of the stone.
Adult
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Azoospermia
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diagnosis
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etiology
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therapy
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Constriction, Pathologic
;
diagnosis
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Ejaculatory Ducts
;
physiopathology
;
Humans
;
Infertility, Male
;
diagnosis
;
etiology
;
therapy
;
Male
;
Seminal Vesicles
;
physiopathology
;
Sperm Count
;
Tomography, X-Ray Computed
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Ureteral Calculi
;
complications
;
diagnosis
;
surgery