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1.
Endothelin-1 (ET-1) is a potent, vasoconstrictive peptide isolated from culture media of vascular endothelial cells. The binding of ET-1 to membrane preparations from rat and bovine lung was studied using radioiodinated ET-1 (125I-ET-1). With both membrane preparations, 125I-ET-1 showed saturable binding to a single class of high affinity sites. Scatchard analysis of the binding data gave dissociation constants (Kd) for ET-1 of 0.22 nM and 0.15 nM, and receptor densities (Bmax) of 6.1 pmol/mg and 2.7 pmol/mg for rat and bovine lung membranes, respectively. Photo-reactive radioiodinated ET-1, N epsilon 9-azidobenzoyl-125I-ET-1, was synthesized and purified as a mono-reactive affinity labeling reagent. This reagent was used for affinity labeling of ET-1 receptor in bovine and rat lung membranes. Photoaffinity labeling followed by sodium dodecyl sulfate gel electrophoresis and autoradiography gave a radiolabeled protein band with an apparent Mr of 34,000 in both membrane preparations. The labeling of this protein band was inhibited by cold ET-1 in a concentration-dependent manner. Labeling was not abolished by unrelated peptides such as angiotensin II and [Arg8]-vasopressin, or by structurally related bee venom apamin. These results indicate that the ET-1 receptor or its ligand binding subunit consists of a 34,000 Da polypeptide. 相似文献
2.
The propagation speed (C) of surface acoustic waves (SAW), e.g. Rayleigh (R-waves) and longitudinal lateral waves (L-waves), the latter being the surface manifestation of the longitudinal waves, strongly reflect mechanical properties of materials. In view of an increasing interest in ultrasonic methodology in the field of bone biomechanics, we tested the hypothesis that both R- and L-waves can be excited in trabecular bone using an acoustic microscope at 1 GHz and that their speeds (C(R) and C(L)) can be extracted from V(z)-curves, i.e. plots of lens output voltage as a function of the lens focal point position with respect to the specimen surface. In accordance with V(z)-curves theoretically synthesized on the basis of incident field theory, experimental curves for canine femoral trabecular bone showed evidence of both R- and L-waves in almost all regions of recording. The measured CR ranged between 1.93 and 2.07 km/s (mean +/- SD.: 2.00=0.06 km/s) and the C(L) ranged between 2.33 and 4.33 km/s (3.37+/-0.61 km/s). Knowledge of both speeds allowed computation of a number of material constants by means of simple theory of elasticity and assumptions of the material density. We found values of Poisson ratio (v) ranging from 0.14 to 0.32 (0.23+/-0.07). Young's modulus (E) from 15 to 22.8 GPa (19.9+/-2.5 GPa) and the shear modulus (G) from 7.6 to 8.9 GPa (8.4+/-0.5 GPa). Anisotropy in the trabecular bone material was clearly detected at the micrometer level. In conclusion, the V(z)-curve method was successfully used to determine the distribution of material elastic constants of trabecular bone with micrometer resolution. 相似文献
3.
Singh P Mathur SK Kundu ZS Singh S Marwah N Arora B 《Indian journal of pathology & microbiology》2005,48(2):206-208
Extraskeletal chondroma is a rare entity. A fairly benign condition, it is usually seen in adults. It presents as an enlarging mass, most commonly in the hand. Local excision is the treatment of choice. We present a case of extraskeletal chondroma of hand in a 12 year male child. Its variable histological appearance not infrequently leads to a mistaken diagnosis of chondrosarcoma. 相似文献
4.
Detection of beet yellows virus by RT-PCR and immunocapture RT-PCR in Tetragonia expansa and Beta vulgaris 总被引:1,自引:0,他引:1
Two sensitive methods, RT-PCR with phenol-extracted RNA or Triton X-100-released RNA and immunocapture RT-PCR (IR-RT-PCR) were used for the detection of Beet yellows virus (BYV) in young and old leaves of Tetragonia expansa and sugar beet (Beta vulgaris) and in sugar beet roots. Four oligonucleotide primer pairs proved suitable for the detection of BYV. The release of BYV RNA with Triton X-100 was shown to be a very effective and easy as compared to isolation of total RNA by phenol extraction with the same or higher sensitivity of subsequent PCR. Using the Triton X-100 release of RNA and IC-RT-PCR the sensitivity of detection was so high that pg amounts of BYV RNA occurring in dilutions up to 10(-6) of saps from young Tetragonia and sugar beet leaves could be detected. 相似文献
5.
Kundu Abhishake Feijoo Felipe Martinez Diego A. Hermosilla Manuel Matis Timothy 《Health care management science》2022,25(1):89-99
Health Care Management Science - Proactive and objective regulatory risk management of ongoing clinical trials is limited, especially when it involves the safety of the trial. We seek to... 相似文献
6.
Rheumatic heart disease is a significant clinical entity in young children, especially in the developing world. One of the major long-term effects of ill managed rheumatic fever is irreversible damage to the cardiac valve leaflets, primarily on the left side. With the limited success of currently available mechanical and bioprosthetic valves, there is an urgent need for new directions in bioprosthetic valves, both in material, including source, degree of fixation, surface, bulk modifications, etc., and design. In the present paper, new proposals in the material selection and fabrication of bioprosthetic valves are proposed based on electron microscopic studies of natural valve leaflets and the pericardial surface. Current approaches for bioprosthetic valve fabrications include the wide use of the pericardium as a leaflet material. The present study indicates a need for nondestructive surface examination of pericardial sheets for the elimination of areas of surface voids resulting from gross fiber disorientation. Also, there seems to be a need for incorporation of an in situ fiber renewal mechanism in bioprosthetic leaflets to emulate the natural valve more closely. Apparently natural leaflets have built-in fiber renewal mechanism(s). 相似文献
7.
Taniya Sharma Nikita Kundu Sarvpreet Kaur Amlan Chakraborty Aman Kumar Mahto Rikeshwer Prasad Dewangan Jadala Shankaraswamy Sarika Saxena 《RSC advances》2022,12(34):21760
Research in recent decades has revealed that the guanine (G)-quadruplex secondary structure in DNA modulates a variety of cellular events that are mostly related to serious diseases. Systems capable of regulating DNA G-quadruplex structures would therefore be useful for the modulation of various cellular events to produce biological effects. A high specificity for recognition of telomeric G-quadruplex has been observed for BLM helicase. We identified peptides from the HRDC domain of BLM using a molecular docking approach with various available solutions and crystal structures of human telomeres and recently created a peptide library. Herein, we tested one peptide (BLM HRDC peptide) from the library and examined its interaction with human telomeric variant-1 (HTPu-var-1) to understand the basis of G4-protein interactions. Our circular dichroism (CD) data showed that HTPu-var-1 folded into an anti-parallel G-quadruplex, and the CD intensity significantly decreased upon increasing the peptide concentration. There was a significant decrease in hypochromicity due to the formation of G-quadruplex-peptide complex at 295 nm, which indicated the unfolding of structure due to the decrease in stacking interactions. The fluorescence data showed quenching upon titrating the peptide with HTPu-var-1-G4. Electrophoretic mobility shift assay confirmed the unfolding of the G4 structure. Cell viability was significantly reduced in the presence of the BLM peptide, with IC50 values of 10.71 μM and 11.83 μM after 72 and 96 hours, respectively. These results confirmed that the selected peptide has the ability to bind to human telomeric G-quadruplex and unfold it. This is the first report in which a peptide was identified from the HRDC domain of the BLM G4-binding protein for the exploration of the G4-binding motif, which suggests a novel strategy to target G4 using natural key peptide segments.Schematic representation of (HTPu–var-1-G4) located at the 3′ end, formation of G-quadruplex, model of the G-quadruplex structure, base stacking between G-quadruplex planes, G-quadruplex structure-peptide complex and twisting of G-quadruplex planes upon peptide binding. 相似文献
8.
Helena Plchov Tom Moravec Noemi eovsk Zuzana Poboilov Jakub Duek Kateina Kratochvílov Oldich Navrtil Jiban Kumar Kundu 《Viruses》2022,14(5)
We have developed a Potato virus X (PVX)-based vector system compatible with the GoldenBraid 2.0 (GB) cloning strategy to transiently express heterologous proteins or peptides in plants for biotechnological purposes. This vector system consists of three domestication vectors carrying three GB parts—the cauliflower mosaic virus (CaMV) 35S promoter with PVX upstream of the second subgenomic promoter of the PVX coat protein (PVX CP SGP), nopaline synthase (NOS) terminator with PVX downstream of the first PVX CP SGP and the gene of interest (GOI). The full-length PVX clone carrying the sequence encoding a green fluorescent protein (GFP) as GOI was incorporated into the binary GB vector in a one-step reaction of three GB parts using the four-nucleotide GB standard syntax. We investigated whether the obtained vector named GFP/pGBX enables systemic PVX infection and expression of GFP in Nicotiana benthamiana plants. We show that this GB-compatible vector system can be used for simple and efficient assembly of PVX-based expression constructs and that it meets the current need for interchange of standard biological parts used in different expression systems. 相似文献
9.
Raymond F. Hamilton Zheqiong Wu Megha Thakkar Somenath Mitra 《Inhalation toxicology》2013,25(11-12):429-438
AbstractObjective: The toxicity of silver nanomaterials in various forms has been extensively evaluated, but the toxicity of silver nanocarbon composites is less well understood. Therefore, silver-carbon nanotube composites (Ag-MWCNT-COOH) and silver-graphene oxide composites (Ag-GO) were synthesized by microwave irradiation and evaluated in two in vitro cell models.Materials/Methods: Toxicity of silver nanosphere (Ag), Ag-MWCNT-COOH and Ag-GO were analyzed by MTS assay and LDH assay in primary C57BL/6 murine alveolar macrophages and human THP-1 cells. Activation of NLRP3 inflammasome by particle variants in these models was done by proxy using LPS co-culture and IL-1β release.Results: The results depended on the model, as the amount of Ag on the modified carbon resulted in slightly increased toxicity for the murine cells, but did not appear to affect toxicity in the human cell model. IL-1β release from carbon particle-exposures was decreased by the presence of Ag in both cell models. Suspensions of Ag-MWCNT-COOH, Ag-GO and Ag in artificial lysosomal fluid were prepared and ICP-MS was used to detect Ag ions concentration in three silver suspension/solutions. The amount of Ag ions released from Ag-MWCNT-COOH and Ag-GO were similar, which were both lower than that of Ag nanospheres.Conclusions: The results suggest the bioactivity of silver composites may be related to the amount of Ag ions released, which can be dependent on the cell model under investigation. 相似文献
10.
Shinjini Kundu Shari Rogal Abdulkader Alam David J Levinthal 《World journal of gastroenterology : WJG》2014,20(21):6671-6674
We report the case of a 34-year-old woman with severe post-infectious gastroparesis who was transferred from an outside medical facility for a second opinion regarding management.This patient had no prior history of gastrointestinal symptoms.However,in the aftermath of a viral illness,she developed two months of intractable nausea,vomiting,and oral intake intolerance that resulted in numerous hospitalizations for dehydration and electrolyte disturbances.A solid-phase gastric emptying scan had confirmed delayed emptying,confirming gastroparesis.Unfortunately,conventional pro-kinetic agents and numerous anti-emetic drugs provided little or no relief of the patient’s symptoms.At our institution,the patient experienced a cessation of vomiting,reported a significant reduction in nausea,and toler-ated oral intake shortly after taking mirtazapine.Based on mirtazapine’s primary action as a serotonin(5-HT)1a receptor agonist,we infer that this receptor system mediated the clinical improvement through a combination of peripheral and central neural mechanisms.This report highlights the potential utility of 5-HT1a agonists in the management of nausea and vomiting.We conclude that mirtazapine may be effective in treating symptoms associated with non-diabetic gastroparesis that are refractory to conventional therapies. 相似文献