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Kumar I, Paudyal A, Kádková A, Stewart M, Sørensen JB, Radecke J. An Improved Method for Growing Primary Neurons on Electron Microscopy Grids Co-Cultured with Astrocytes. Int J Mol Sci 2023; 24:15191. [PMID: 37894872 PMCID: PMC10606997 DOI: 10.3390/ijms242015191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
With the increasing popularity of cryo-electron tomography (cryo-ET) in recent years, the quest to establish a method for growing primary neurons directly on electron microscopy grids (EM grids) has been ongoing. Here we describe a straightforward way to establish a mature neuronal network on EM grids, which includes formation of synaptic contacts. These synapses were thin enough to allow for direct visualization of small filaments such as SNARE proteins tethering the synaptic vesicle (SV) to the active zone plasma membrane on a Titan Krios without prior focused ion-beam milling.
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Affiliation(s)
- Ishika Kumar
- Diamond Light Source, Harwell Science and Innovation Campus, Fermi Ave, Didcot OX11 0DE, UK;
| | - Anju Paudyal
- Mary Lyon Centre at MRC Harwell, Harwell Campus, Becquerel Ave, Didcot OX11 ORD, UK; (A.P.); (M.S.)
| | - Anna Kádková
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark (J.B.S.)
| | - Michelle Stewart
- Mary Lyon Centre at MRC Harwell, Harwell Campus, Becquerel Ave, Didcot OX11 ORD, UK; (A.P.); (M.S.)
| | - Jakob Balslev Sørensen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark (J.B.S.)
| | - Julika Radecke
- Diamond Light Source, Harwell Science and Innovation Campus, Fermi Ave, Didcot OX11 0DE, UK;
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark (J.B.S.)
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Dwivedi AND, Ganesh V, Shukla RC, Jain M, Kumar I. Colour Doppler evaluation of uterine and ovarian blood flow in patients of polycystic ovarian disease and post-treatment changes. Clin Radiol 2020; 75:772-779. [PMID: 32660710 DOI: 10.1016/j.crad.2020.05.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 05/18/2020] [Indexed: 02/05/2023]
Abstract
AIM To assess the morphology and colour Doppler parameters in patients with polycystic ovarian syndrome (PCOS) and also to assess the changes in Doppler parameters in follow-up patients, who underwent treatment. MATERIALS AND METHODS The study was conducted on 50 women of reproductive age who had clinical and biochemical findings suggestive of PCOS. Clinico-hormonal parameters were recorded. Ultrasound and colour Doppler flow measurements of bilateral ovaries were performed in the early proliferative phase of the menstrual cycle. After assessment of the bilateral ovaries, colour Doppler ultrasound was used to evaluate the main uterine artery at the cervico-uterine junction. Follow-up imaging after 3 months was undertaken in patients who underwent treatment (metformin) and changes in the imaging and hormonal parameters were correlated. RESULTS The mean value of luteinising hormone (LH) and the ratio of LH: follicle-stimulating hormone (FSH) was significantly higher in PCOS patients. Ultrasound parameters were significantly higher in PCOS patients. Ovarian stromal vessels in PCOS patients had a significantly higher peak systolic velocity (PSV), low resistance index (RI), and pulsatility index (PI). The PSV of uterine arteries were significantly decreased and the RI and PI were significantly increased. On follow-up patients revealed changes in hormonal parameters. CONCLUSION PCOS is a heterogeneous disorder and is a convergence of multisystem endocrine derangements. Ultrasound is good diagnostic tool for PCOS and the use of Doppler aids in the evaluation of haemodynamic changes in small vessels of utero-ovarian circulation and in response assessment.
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Affiliation(s)
- A N D Dwivedi
- Department of Radiodiagnosis and Imaging, Institute of Medical Sciences, Banaras Hindu University, India.
| | - V Ganesh
- Department of Radiodiagnosis and Imaging, Institute of Medical Sciences, Banaras Hindu University, India
| | - R C Shukla
- Department of Radiodiagnosis and Imaging, Institute of Medical Sciences, Banaras Hindu University, India
| | - M Jain
- Department of Obstetrics and Gynaecology, Institute of Medical Sciences, Banaras Hindu University, India
| | - I Kumar
- Department of Radiodiagnosis and Imaging, Institute of Medical Sciences, Banaras Hindu University, India
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Verma A, Kumar I, Srivastava A, Shukla RC. Susceptibility weighted imaging: An important tool for early diagnosis of tacrolimus toxicity. Indian J Nephrol 2016; 26:151-2. [PMID: 27051144 PMCID: PMC4795435 DOI: 10.4103/0971-4065.156908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- A Verma
- Department of Radiodiagnosis, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - I Kumar
- Department of Radiodiagnosis, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - A Srivastava
- Department of Radiodiagnosis, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - R C Shukla
- Department of Radiodiagnosis, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
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Kumar I, Kumari G, Trivedi S, Dwivedi A. P0009 The sum of longest tumour diameter as a predictor for skeletal metastasis in renal cell carcinoma. Eur J Cancer 2014. [DOI: 10.1016/j.ejca.2014.03.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Singh V, Kumar I, Bhagol A. Comparative evaluation of 2.0-mm locking plate system vs 2.0-mm nonlocking plate system for mandibular fracture: a prospective randomized study. Int J Oral Maxillofac Surg 2011; 40:372-7. [DOI: 10.1016/j.ijom.2010.11.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Revised: 08/23/2010] [Accepted: 11/17/2010] [Indexed: 12/01/2022]
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Sarker SK, Maciocco M, Zaman A, Kumar I. Operative performance in laparoscopic cholecystectomy using the Procedural-Based Assessment tool. Am J Surg 2010; 200:334-40. [PMID: 20573336 DOI: 10.1016/j.amjsurg.2009.10.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 10/15/2009] [Accepted: 10/27/2009] [Indexed: 10/19/2022]
Abstract
AIMS The Intercollegiate Surgical Curriculum Project (ISCP) has devised assessment tools for index operations to assess trainee technical skills. In this study we used the Procedural-Based Assessment (PBA) tool to evaluate operations performed by trainees. METHODS Live and simulated laparoscopic cholecystectomies were performed by trainees. Two experienced surgeons assessed each operation blindly and independently. RESULTS Eighty-four live (supervised) and 112 simulated (unsupervised) operations were performed by 28 trainees. Mean inter-rater reliability was kappa = .86 and .84 for live and simulated operations, respectively. Construct validity using Mann-Whitney for generic technical skills was significant for live and simulated operations, P < or = .05. Assessing specific technical skills showed construct validity for simulated unsupervised operations only, Mann-Whitney P < .05, but not for supervised live operations, Mann-Whitney P > .05. CONCLUSIONS The PBA showed good inter-rater reliability. Assessing generic technical skills, PBA showed construct validity for both types of operations and for specific technical skills in the unsupervised simulated operations. We conclude that the PBA seems to be a reliable and valid assessment tool for generic technical skills in unsupervised simulated and live supervised laparoscopic cholecystectomies.
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Kumar I, Staton CA, Cross SS, Reed MWR, Brown NJ. Angiogenesis, vascular endothelial growth factor and its receptors in human surgical wounds. Br J Surg 2009; 96:1484-91. [PMID: 19918856 DOI: 10.1002/bjs.6778] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Angiogenesis plays an essential role in tissue repair. Vascular endothelial growth factor (VEGF) mediates angiogenesis through receptor kinases VEGF-R1 and VEGF-R2, and co-receptors, neuropilins Np1 and Np2. This study examined the spatial and temporal expression of these factors in relation to angiogenesis in surgical wounds. METHODS Scar biopsies were obtained from patients between 3 days and 2 years after surgery. Normal skin control biopsies were taken during surgery. Microvessel density (MVD) was quantified using a Chalkley grid. VEGF, VEGF-R1, VEGF-R2, Np1 and Np2 endothelial expression was determined by immunohistochemistry, and correlated with MVD and scar age. RESULTS Cumulative MVD was significantly greater in scars than controls (P = 0.011), and was related to scar age (P = 0.007). Expression of VEGF, VEGF-R2, Np1 and Np2 was increased significantly in all scars and correlated with MVD. In contrast, scar VEGF-R1 expression was decreased, and correlated with increased VEGF and VEGF-R2. CONCLUSION Levels of VEGF, VEGF-R2, Np1 and Np2 are increased, whereas VEGF-R1 expression is decreased in angiogenesis, suggesting a role for VEGF-receptor complexes in early wound healing. This altered protein expression and increased presence of vessels is prolonged, suggesting that structural remodelling continues for at least 2 years after surgery.
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Affiliation(s)
- I Kumar
- Academic Unit of Surgical Oncology, University of Sheffield Medical School, Sheffield, UK
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Wong D, Kumar I, Quah SA, Ali H, Valdeperas X, Romano MR. Erratum: Comparison of postoperative intraocular pressure in patients with Densiron-68 vs conventional silicone oil: a case–control study. Eye (Lond) 2009. [DOI: 10.1038/eye.2008.94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Wong D, Kumar I, Quah SA, Ali H, Valdeperas X, Romano MR. Comparison of postoperative intraocular pressure in patients with Densiron-68 vs conventional silicone oil: a case–control study. Eye (Lond) 2007; 23:190-4. [DOI: 10.1038/sj.eye.6703055] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Abstract
Neuropilin-1 (Np1) and neuropilin-2 (Np2) are transmembrane glycoproteins with large extracellular domains that interact with both class 3 semaphorins and vascular endothelial growth factor (VEGF), and are involved in the regulation of many physiological pathways, including angiogenesis. The neuropilins also interact directly with the classical receptors for VEGF, VEGF-R1 and -R2, mediating signal transduction. The heart, glomeruli and osteoblasts express both Np1 and Np2, but there is differential expression in the adult vasculature, with Np1 expressed mainly by arterial endothelium, whereas Np2 is only expressed by venous and lymphatic endothelium. Both neuropilins are commonly over-expressed in regions of physiological (wound-healing) and pathological (tumour) angiogenesis, but the signal transduction pathways, neuropilin-mediated gene expression and the definitive role of neuropilins in angiogenic processes are not fully characterized. This review details the current evidence for the role of neuropilins in angiogenesis, and suggests future research directions that may enhance our understanding of the mechanisms of action of this unique family of proteins.
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Affiliation(s)
- C A Staton
- Microcirculation Research Group, Academic Unit of Surgical Oncology, University of Sheffield, Sheffield S10 2JF, UK
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Abstract
Beta-lactam antibiotics restrict bacterial growth by inhibiting DD-peptidases. These enzymes catalyze the final transpeptidation step in bacterial cell wall biosynthesis. Although much structural information is now available for these enzymes, the mechanism of the actual transpeptidation reaction has not been studied in detail. The reaction is known to involve a double-displacement mechanism with an acyl-enzyme intermediate, which can be attacked by water, specific amino acids, peptides, and other acyl acceptors. We describe in this paper an investigation of acyl acceptor specificity and assess the need for general base catalysis in the deacylation transition state of the Streptomyces R61 DD-peptidase. We show, by the criterion of solvent deuterium kinetic isotope effect measurements and proton inventories, that the transition states of specific and nonspecific substrates are very similar, at least with respect to proton motion. The transition states for attack (tetrahedral intermediate formation) by d-amino acids and Gly-l-Xaa dipeptides do not include a general base catalyst, while such catalysis is essential for reaction with water and d-alpha-hydroxy acids. D-Alpha-hydroxy acids act as acyl acceptors for glycyl substrates but not for more specific d-alanyl substrates; hydroxy acids actually behave, more generally, as mixed inhibitors of the DD-peptidase. The structural and mechanistic bases of these observations are discussed; they should inform transition state analogue design.
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Affiliation(s)
| | | | - R.F. Pratt
- Corresponding Author: Dr. R.F. Pratt, address above, telephone 860-685-2629; e-mail: ; Fax: 860-685-2211
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Abstract
[figure: see text] A thioesterase, isolated from a strain of Alcaligenes sp. ISH108, chemoselectively hydrolyzes thiol esters. The application of the enzyme has been demonstrated in the preparation of the antihypertensive agent captopril.
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Affiliation(s)
- I Kumar
- Department of Chemistry, Institute of Microbial Technology, Sector 39, Chandigarh 160 036, India
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Sidhu PK, Kaur K, Kumar I, Lata S. Glucose-6-phosphate dehydrogenase deficiency in blood donors: screening by micromethaemoglobin reduction test. INDIAN J PATHOL MICR 2001; 44:23-5. [PMID: 12561990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
500 blood donors were screened for G6PD deeiciency using micromethaemoglobin reduction (microMRT) test. Most of the blood donors were young adult males (95.8%). The overall incidence of G6PD deficiency was found to be 0.8%. There, was apparently decreased frequency of G6PD deficient blood donors with increasing age, and no relation could be ascertained between G6PD) deficiency and blood groups.
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Affiliation(s)
- P K Sidhu
- Department of Clinical Pathology, Government Medical College & Rajendra Hospital, Patiala
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Abstract
The isomeric compounds 1 and 3, which differ only in the position of a methyl substituent, give opposite chemoselectivities in an esterase-catalyzed hydrolysis reaction. The esterase was chemoselective for the oxoester in 1, but for the thiol ester group in 3. A high enantioselectivity was observed for both 1 and 3.
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Affiliation(s)
- I Kumar
- Department of Chemistry, Institute of Microbial Technology, Chandigarh, India
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Kumar I, Khush GS, Juliano BO. Genetic analysis of waxy locus in rice (Oryza sativa L.). Theor Appl Genet 1987; 73:481-488. [PMID: 24241102 DOI: 10.1007/bf00289183] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/1986] [Accepted: 08/18/1986] [Indexed: 06/02/2023]
Abstract
Inheritance of waxy locus was studied in crosses of a waxy variety with four non-waxy parents having high-, intermediate-, low- or very low-amylose content. The analysis for amylose content was done on a single grain basis in parents, F1, F2, B1F1, and B2F1 seeds. The waxy parent lacking synthesis of amylose content was found to differ from the ones having high-, intermediate-, low- or very low-amylose content by one gene with major effect. Dosage effects for amylose content were observed to have great influence on segregation pattern and efficiency of selection. Selection efficiency for amylose content can be enhanced by selecting for endosperm appearance in early segregating generations.
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Affiliation(s)
- I Kumar
- International Rice Research Institute, Los Baños, Laguna, Philippines
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Abstract
Crude alkaloidal fraction isolated from the leaves of Solanum melongena was screened for its effects on the central nervous system. It exhibited significant analgesic effect and some CNS depression but no anticonvulsant action. The analgesic effects were of non-narcotic type. LD50 was estimated to be higher than 1 g/kg i.p. in mice.
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Vohora SB, Kumar I, Shah SA, Khan MS. Effect of biflavonoids of Taxus baccata on the central nervous system. Indian J Med Res 1980; 71:815-20. [PMID: 6967860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Srivastava KN, Gupta PR, Kumar I, Jain BS, Rai L, Manchanda RC. Solitary eosinophilic granuloma of orbit. Eye Ear Nose Throat Mon 1968; 47:639-42. [PMID: 5726540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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