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150 citation(s) found for "Singh, Ravinder".

Abstract WP237: Uric Acid Expressed Within Carotid Atherosclerotic Plaque And Serum Uric Acid Are Associated With Cerebrovascular Events
Nardi, Valentina , Franchi, Federico , Prasad, Megha , Fatica, Erica M. , Alexander, Mariam P., Bois, Melanie C. , Lam, Josephine, Meyer, Fredric B. , Lanzino, Giuseppe, Lerman, Lilach O. , Nardi, Valentina , Lanzino, Giuseppe , Singh, Ravinder , Lerman, Amir

Mayo Clinic

Stroke | February 3, 2022 | Volume: 53 | Issue: Suppl_1 | Pages: No page available

10.1161/str.53.suppl_1.wp237 Get It

Introduction: Uric acid (UA) level within carotid plaque specimens and its association with cerebrovascular events has not been detected or quantified. Systemically, serum uric acid (SUA) is a marker of inflammation and risk factor for atherosclerosis. However, its association with carotid plaque instability and subsequent cerebrovascular events remains unclear. Hypothesis: We hypothesized that UA may play a role in carotid artery atherosclerosis and stroke pathogenesis. In patients undergoing carotid endarterectomy (CEA), we aimed to determine whether UA is present differentially in carotid plaques of symptomatic versus asymptomatic patients and whether SUA is associated with cerebrovascular symptoms before surgery and major adverse cardiovascular events (MACE) in the follow-up to CEA. Methods: We prospectively collected 32 carotid plaques during CEA. We qualitatively assessed the presence of UA by using Gomori methenamine silver (GMS) staining and immunohistochemistry with anti-UA antibodies. We extracted and measured the quantity of UA in carotid plaques by using an enzymatic colorimetric assay. A retrospective analysis of a clinical database of 534 consecutive patients who underwent CEA was performed. We defined as symptomatic those patients with history of stroke, TIA and amaurosis fugax. Results: UA positive staining was detected in higher number of carotid plaques from symptomatic compared to asymptomatic patients on both staining, GMS [20 (86.9%) vs 2 (22.2%); p=0.001] and immunohistochemistry anti-UA [16 (69.5%) vs 1 (11.1%); p=0.004]. Moreover, we found a significantly higher concentration of UA in carotid plaque from symptomatic compared to asymptomatic patients [25.1 (9.5) μg/g vs 17.9 (3.8) μg/g; p=0.021]. SUA level in patients prior to CEA was significantly higher in the symptomatic compared to the asymptomatic group [6.0 (4.8-7.1) mg/dL vs 5.2 (4.4-6.3) mg/dL; p<0.001] and it was significantly higher in patients who developed MACE after CEA versus those that did not [6.0 (4.8-7.1) mg/dL vs 5.4 (4.5-6.6) mg/dL; p=0.021]. Conclusions: UA may provide a mechanistic explanation as systemic biomarker and potential tissue contributor for carotid plaque instability and subsequent cerebrovascular and cardiovascular symptoms.
Overfeeding‐induced weight gain elicits decreases in sex hormone‐binding globulin in healthy males—Implications for body fat distribution
Singh, Prachi , Covassin, Naima , Marlatt, Kara L. , Romero‐Corral, Abel, Davison, Diane E., Jensen, Michael D. , Sert-Kuniyoshi, Fatima H, Romero-Corral, Abel, Singh, Prachi , Kuniyoshi, Fatima H. Sert , Singh, Ravinder J. , Somers, Virend K.

Mayo Clinic

Physiological Reports | December 8, 2021 | Volume: 9 | Issue: 23 | Pages: No page available

10.14814/phy2.15127 | PMID 34877821 Get It

Targeted Detection of SARS-CoV-2 Nucleocapsid Sequence Variants by Mass Spectrometric Analysis of Tryptic Peptides
Maus, Anthony , Renuse, Santosh , Kemp, Jennifer, Madugundu, Anil K. , Vanderboom, Patrick M. , Blommel, Joseph H. , Jerde, Calvin R. , Dasari, Surendra , Kipp, Benjamin R. , Grebe, Stefan K. , Pandey, Akhilesh , Blommel, Joseph, Jerde, Calvin, Pandey, Akhilesh , Pandey, Akhilesh , Maus, Anthony D , Singh, Ravinder J.

Mayo Clinic

Journal of Proteome Research | November 15, 2021 | Volume: 21 | Issue: 1 | Pages: 142-150

10.1021/acs.jproteome.1c00613 | PMID 34779632 Get It

Interpretation of Abnormal Dexamethasone Suppression Test is Enhanced With Use of Synchronous Free Cortisol Assessment
Genere, Natalia , Kaur, Ravinder Jeet , Athimulam, Shobana , Thomas, Melinda, Nippoldt, Todd B., Norman, Molly Van, Grebe, Stefan K., Thomas, Melinda A, Nippoldt, Todd, Van Norman, Molly, Grebe, Stefan, Bancos, Irina , Singh, Ravinder J. , Bancos, Irina

Mayo Clinic

The Journal of Clinical Endocrinology & Metabolism | October 19, 2021 | Volume: 107 | Issue: 3 | Pages: e1221-e1230

10.1210/clinem/dgab724 | PMID 34648626 Get It

Abstract Context Interpretation of dexamethasone suppression test (DST) may be influenced by dexamethasone absorption and metabolism and by the altered cortisol binding. Objective We aimed to determine the normal ranges of free cortisol during DST in participants without adrenal disorders and to identify the population of patients where post-DST free cortisol measurements add value to the diagnostic workup. Design and Setting Cross-sectional study conducted in a tertiary medical center. Participants Adult volunteers without adrenal disorders (n = 168; 47 women on oral contraceptive therapy [OCP], 66 women not on OCP, 55 men) and patients undergoing evaluation for hypercortisolism (n = 196; 16 women on OCP). Measurements Post-DST dexamethasone and free cortisol (mass spectrometry) and total cortisol (immunoassay). Main Outcome Measures Reference range for post-DST free cortisol, diagnostic accuracy of post-DST total cortisol. Results Adequate dexamethasone concentrations (≥0.1 mcg/dL) were seen in 97.6% volunteers and 96.3% patients. Only 25.5% of women volunteers on OCP had abnormal post-DST total cortisol (&gt;1.8 mcg/dL). In volunteers, the upper post-DST free cortisol range was 48 ng/dL in men and women not on OCP, and 79 ng/dL in women on OCP. When compared with post-DST free cortisol, diagnostic accuracy of post-DST total cortisol was 87.3% (95% CI, 81.7-91.7); all false-positive results occurred in patients with post-DST cortisol between 1.8 and 5 mcg/dL. OCP use was the only factor associated with false-positive results (21.1% vs 4.9%, P = 0.02). Conclusions Post-DST free cortisol measurements are valuable in patients with optimal dexamethasone concentrations and post-DST total cortisol between 1.8 and 5 mcg/dL.
Challenges in Translating Clinical Metabolomics Data Sets from the Bench to the Bedside
Ulmer, Candice Z. , Hines, Jolaine, Maus, Anthony , Singh, Ravinder J.

Mayo Clinic

Clinical Chemistry | October 6, 2021 | Volume: 67 | Issue: 12 | Pages: 1581-1583

10.1093/clinchem/hvab210 | PMID 34718477 Get It

Initiation of Gender-Affirming Testosterone Therapy in a Lactating Transgender Man
Oberhelman, Sara S. , Chang, Alice Y. , González, César A. , Braith, Andrew, Lteif, Aida, Oberhelman, Sara , Chang, Alice, Gonzalez, Cesar, Gonzalez, Cesar , Singh, Ravinder J.

Mayo Clinic

Journal of Human Lactation | September 7, 2021 | Volume: 38 | Issue: 2 | Pages: 339-343

10.1177/08903344211037646 | PMID 34490813 Get It

Introduction: Transgender and gender diverse individuals may choose to provide their infants with human milk. Lactating transgender men may experience gender dysphoria and desire to initiate or reinitiate gender-affirming testosterone therapy. However, there is limited safety data regarding use of testosterone during lactation. Main Issue: A 30-year-old G2P2 transgender man with gender dysphoria sought to initiate gender-affirming testosterone therapy while lactating. Management: Subcutaneous testosterone was self-administered beginning at 13 months post-partum. We prospectively collected data on circulating testosterone concentrations in parent serum, milk, and infant serum over 5 months until the infant self-weaned. The infant was monitored for growth and development at routine pediatric outpatient appointments. Parent serum testosterone concentrations rose with the initiation of testosterone therapy, reaching therapeutic concentrations by Day 14. Milk testosterone concentrations also increased with a maximum concentration of 35.9 ng/dl when the lactating parent was on a dose of 80 mg subcutaneous testosterone cypionate weekly. The calculated milk/plasma ratio remained under 1.0 and the calculated relative infant dose remained under 1%. The infant had no observable side effects, and his serum testosterone concentrations remained undetectable throughout the study period. Conclusion: This is the first study with data regarding human milk and infant serum testosterone concentrations during the initiation of gender-affirming testosterone therapy in a lactating individual. This evidence can help families and clinicians with decisions regarding lactation and testosterone use.
Fisetin for COVID ‐19 in skilled nursing facilities: Senolytic trials in the COVID era
Verdoorn, Brandon P. , Evans, Tamara K., Hanson, Gregory J. , Zhu, Yi , Prata, Larissa , Pignolo, Robert J. , Atkinson, Elizabeth J. , Wissler-Gerdes, Erin O., Kuchel, George A. , Mannick, Joan B. , Rizza, Stacey A. , Musi, Nicolas , Lipsitz, Lewis A. , Yung, Raymond , McCarthy, Teresa , Puskarich, Michael A. , Niedernhofer, Laura J. , Kirkland, James L. , Gerdes, Erin O. Wissler , Langhi Prata, Larissa G P, Sorenson, Matthew, Tchkonia, Tamara, Wissler Gerdes, Erin O , Prata, Larissa G P Langhi , Niedernhofer, Laura J , Kuchel, George A , Zhu, Yi , Hanson, Gregory J., Kritchevsky, Stephen B. , Khosla, Sundeep , Walston, Jeremy D , Kiel, Douglas P. , LeBrasseur, Nathan K. , Singh, Ravinder J. , Robbins, Paul D. , Sorenson, Matthew , Tchkonia, Tamar

Mayo Clinic

Journal of the American Geriatrics Society | August 10, 2021 | Volume: 69 | Issue: 11 | Pages: 3023-3033

10.1111/jgs.17416 | PMID 34375437 Get It

Abstract The burden of senescent cells (SnCs), which do not divide but are metabolically active and resistant to death by apoptosis, is increased in older adults and those with chronic diseases. These individuals are also at the greatest risk for morbidity and mortality from SARS‐CoV‐2 infection. SARS‐CoV‐2 complications include cytokine storm and multiorgan failure mediated by the same factors as often produced by SnCs through their senescence‐associated secretory phenotype (SASP). The SASP can be amplified by infection‐related pathogen‐associated molecular profile factors. Senolytic agents, such as Fisetin, selectively eliminate SnCs and delay, prevent, or alleviate multiple disorders in aged experimental animals and animal models of human chronic diseases, including obesity, diabetes, and respiratory diseases. Senolytics are now in clinical trials for multiple conditions linked to SnCs, including frailty; obesity/diabetes; osteoporosis; and cardiovascular, kidney, and lung diseases, which are also risk factors for SARS‐CoV‐2 morbidity and mortality. A clinical trial is underway to test if senolytics decrease SARS‐CoV‐2 progression and morbidity in hospitalized older adults. We describe here a National Institutes of Health‐funded, multicenter, placebo‐controlled clinical trial of Fisetin for older adult skilled nursing facility (SNF) residents who have been, or become, SARS‐CoV‐2 rtPCR‐positive, including the rationale for targeting fundamental aging mechanisms in such patients. We consider logistic challenges of conducting trials in long‐term care settings in the SARS‐CoV‐2 era, including restricted access, consent procedures, methods for obtaining biospecimens and clinical data, staffing, investigational product administration issues, and potential solutions for these challenges. We propose developing a national network of SNFs engaged in interventional clinical trials.
Response to the Letter to the Editor From Jialal and Sood: “New Cutoffs for the Biochemical Diagnosis of Adrenal Insufficiency After ACTH Stimulation Using Specific Cortisol Assays”
Javorsky, Bradley R. , Raff, Hershel , Carroll, Ty B , Colón-Franco, Jessica M , Findling, James W. , Jit Singh, Ravinder, Carroll, Ty B , Algeciras‐Schimnich, Alicia , Singh, Ravinder

Mayo Clinic

Journal of the Endocrine Society | July 4, 2021 | Volume: 5 | Issue: 9 | Pages: No page available

10.1210/jendso/bvab113 | PMID 34278181 Get It

Analytical Sensitivity and Specificity of Four Point of Care Rapid Antigen Diagnostic Tests for SARS-CoV-2 Using Real-Time Quantitative PCR, Quantitative Droplet Digital PCR, and a Mass Spectrometric Antigen Assay as Comparator Methods
Karon, Brad S. , Bridgeman, Amber R. , Blommel, Joseph H. , Kipp, Benjamin R. , Renuse, Santosh , Kemp, Jennifer, Madugundu, Anil K. , Vanderboom, Patrick M. , Dasari, Surendra , Grebe, Stefan K. , Pandey, Akhilesh , Donato, Leslie J. , Kipp, Benjamin, Maus, Anthony , Pandey, Akhilesh , Chavan, Sandip , Pandey, Akhilesh , Singh, Ravinder

Mayo Clinic

Clinical Chemistry | July 2, 2021 | Volume: 67 | Issue: 11 | Pages: 1545-1553

10.1093/clinchem/hvab138 | PMID 34240163 Get It

Abstract Background We evaluated the analytical sensitivity and specificity of 4 rapid antigen diagnostic tests (Ag RDTs) for severe acute respiratory syndrome coronavirus 2, using reverse transcription quantitative PCR (RT-qPCR) as the reference method and further characterizing samples using droplet digital quantitative PCR (ddPCR) and a mass spectrometric antigen test. Methods Three hundred fifty (150 negative and 200 RT-qPCR positive) residual PBS samples were tested for antigen using the BD Veritor lateral flow (LF), ACON LF, ACON fluorescence immunoassay (FIA), and LumiraDx FIA. ddPCR was performed on RT-qPCR–positive samples to quantitate the viral load in copies/mL applied to each Ag RDT. Mass spectrometric antigen testing was performed on PBS samples to obtain a set of RT-qPCR–positive, antigen-positive samples for further analysis. Results All Ag RDTs had nearly 100% specificity compared to RT-qPCR. Overall analytical sensitivity varied from 66.5% to 88.3%. All methods detected antigen in samples with viral load &gt;1 500 000 copies/mL RNA, and detected ≥75% of samples with viral load of 500 000 to 1 500 000 copies/mL. The BD Veritor LF detected only 25% of samples with viral load between 50 000 to 500 000 copies/mL, compared to 75% for the ACON LF device and &gt;80% for LumiraDx and ACON FIA. The ACON FIA detected significantly more samples with viral load &lt;50 000 copies/mL compared to the BD Veritor. Among samples with detectable antigen and viral load &lt;50 000 copies/mL, sensitivity of the Ag RDT varied between 13.0% (BD Veritor) and 78.3% (ACON FIA). Conclusions Ag RDTs differ significantly in analytical sensitivity, particularly at viral load &lt;500 000 copies/mL.
Suppression of 11b‐Hydroxysteroid Dehydrogenase Type 1 with RNA Interference Substantially Attenuates 3T3‐L1 Adipogenesis
Pietrusz, Jennifer L., Jia, Guangfu, Netzel, Brian C., Liu, Yong , Park, Frank , Singh, Ravinder , Liang, Mingyu

Mayo Clinic

The FASEB Journal | June 21, 2021 | Volume: 22 | Issue: S1 | Pages: No page available

10.1096/fasebj.22.1_supplement.1162.7 Get It

Overexpression of 11b‐hydroxysteroid dehydrogenase type 1 (11b‐HSD1) in adipose tissue leads to obesity in mice. We hypothesized that endogenous 11b‐HSD1 played a significant functional role in adipogenesis. Stable transfection of 3T3‐L1 cells with small hairpin RNA (shRNA), compared to a nucleotide‐substituted control, silenced 11b‐HSD1 expression and substantially attenuated the accumulation of lipid droplets and the expression of adipogenesis marker genes induced by a mixture containing either corticosterone or dexamethasone. 11b‐HSD1 silencing significantly elevated the concentration of 11‐dehydrocorticosterone in the culture supernatant, but did not affect the levels of corticosterone or dexamethasone, measured by LC‐MS/MS. 11b‐HSD1 silencing significantly attenuated the translocation of glucocorticoid receptors to the nucleus and reduced the number of cells entering the S phase in response to glucocorticoids (13 ± 1% vs. 30 ± 1% in control, n=5, P<0.05), a critical event in the initiation of adipogenesis. 11b‐HSD1 shRNA delivered by lentiviral vectors after the induction of differentiation reduced 11b‐HSD1 expression, but did not affect the further progression of adipogenesis. Our results established a functional and stage‐dependent role of 11b‐HSD1 in the initiation of 3T3‐L1 adipogenesis, and provided new insights into the development of obesity and related diseases.