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1.
Cell Biochem Biophys ; 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38943009

RESUMEN

BACKGROUND: Chronic arsenic-exposure causes neuromuscular disorders and other health anomalies. Damage to DNA and cytoskeletal/extracellular matrix is brought on by reactive-oxygen-species (ROS)-induced intrinsic antioxidant depletion (thiols/urate). Therapeutic chelating-agents have multiple side-effects. OBJECTIVES: The protection of (Camellia sinensis) tea-extract and role of uric-acid (UA) or allopurinol (urate-depletor) on arsenic-toxicity were verified in rat model. METHODS: Camellia sinensis (CS dry-leaves), UA or allopurinol was supplemented to arsenic-intoxicated rats for 4-weeks. Purified theaflavins and their galloyl-ester were tested in-vitro on pure AChE (acetylcholinesterase) and their PDB/PubChem 3-D structures were utilized for in-silico binding studies. The primary chemical components were evaluated from CS-extracts. Biochemical analysis, PAGE-zymogram, DNA-stability comet analysis, HE-staining was performed in arsenic-exposed rat brain tissues. RESULTS: Animals exposed to arsenic showed symptoms of erratic locomotion, decreased intrinsic antioxidants (catalase/SOD1/uric acid), increased AChE, and malondialdehyde. Cerebellar and cerebrum tissue damages were shown with increased levels of matrix-metalloprotease (MMP2/9) and DNA damage (comets). Allopurinol- supplemented group demonstrated somewhat similar biochemical responses. In the CS-group brain tissues especially cerebellum is considerably protected which is evident from endogenous antioxidant and DNA and cytoskeleton protection with concomitant inactivation of MMPs and AChE. Present study indicates theaflavin-digallate (TFDG) demonstrated the highest inhibition of purified AChE (IC50 = 2.19 µg/ml with the lowest binding free-energy; -369.87 kcal/mol) followed by TFMG (IC50 = 3.86 µg/ml, -347.06 kcal/mol) suggesting their possible restoring effects of cholinergic response. CONCLUSIONS: Favorable responses in UA-group and adverse outcome in allo-group justify the neuro-protective effects of UA as an endogenous antioxidant. Role of flavon-gallate in neuro protection mechanism may be further studied.

2.
ACS Appl Mater Interfaces ; 15(21): 25184-25192, 2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-36583941

RESUMEN

A halogen bond-based water-soluble tetrapodal iodoimidazolium receptor, (L-I)(4Br), exhibited a high degree of efficiency (∼96%) in extracting ReO4- from 100% aqueous medium within a wide range of concentrations and of pH values along with excellent reusability. The solid-state X-ray diffraction study showed the trapping of ReO4- by (L-I)(4Br) via the Re-O····I halogen bonding interaction. XPS studies also suggested the interaction between I and ReO4- through polarization of the electron density of I atoms by ReO4-. (L-I)(4Br) is found to be capable of retaining its high extraction efficiency in the presence of competing anions such as F-, Cl-, I-, SO42-, H2PO4-, CO32-, NO3-, BF4-, ClO4-, Cr2O72-, and a mixture of these anions. Interestingly, (L-I)(4Br) was found to be superior in ReO4- extraction as compared to its hydrogen-bond donor analogue, (L-H)(4Br), as confirmed by a series of control experiments and theoretical calculations. Our synthesized dipodal and tripodal halogen bond donor receptors and their H-analogues validated the superiority of these classes of supramolecular halogen bond donor receptors over their hydrogen-bond analogues. (L-I)(4Br) also showed superior practical applicability in terms of the removal of ReO4- at anion concentrations as low as ∼100 ppm, which was a major shortcoming of (L-H)(4Br).

3.
Int J Health Sci (Qassim) ; 16(4): 46-57, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35949696

RESUMEN

Objectives: Because the damage of kidney tissue is associated with hypertension and impaired nitric oxide (NO) synthesis, and as aspirin is reported to stimulate the synthesis of renal r-cortexin, an anti-hypertensive protein, we investigated the role of aspirin as bolus dose on elevated blood pressure induced by deoxycorticosterone acetate (DOCA)-salt in animal model. Methods: The chronic antihypertensive effect of aspirin on DOCA treated with ASA group of rats (n = 6) was evaluated after ingestion of 0.35 µM aspirin as a bolus dose in every 24 h using tail cuff methods. The plasma aspirin, NO, and r-cortexin levels were determined by spectrophotometric, methemoglobin, and ELISA methods, respectively. Synthesis of r-cortexin mRNA was determined. Aspirin activated nitric oxide synthase (AANOS) was purified by chromatographic methods. Results: Our results showed after 3 h of administration of aspirin (0.35 µM) to the DOCA treated with ASA group of rats decreased the systolic blood pressure from 139.39 ± 7.36 mm of Hg to 116.57 ± 6.89 mm of Hg and diastolic blood pressure from 110.4 ± 7 mm of Hg to 86.4 ± 2.76 mm of Hg. The reduction of BPs was found to be related to the increased plasma aspirin from 0.00 µM to 0.042 µM, plasma NO from 0.4 ± 0.19 nM to 1.9 ± 0.5 nM, and cortexin levels from 64.36 ± 12.6 nM to 216.7 ± 21.3 nM. The molecular weight of purified AANOS is 18 kDa. Conclusion: It can be concluded that aspirin possesses antihypertensive effect on blood pressure in chronic administration. Aspirin can stimulate NO synthesis through the activation of AANOS, which stimulated the production of r-cortexin in kidney cortex cells and thereby reducing elevated BP in hypertensive rats.

4.
J Environ Manage ; 302(Pt A): 113800, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34678539

RESUMEN

Treatment of coking waste water has always been a challenge because of its complex and toxic nature. Numbers of technologies like biological treatment, advanced oxidation processes, activated carbon treatment etc. are available for removal of color and organic contaminants from wastewater. However, challenges and problems associated with application of biological, advanced oxidation methods for removal of color, chemical oxygen demand (COD), cyanides led to thrust for the development of new promising technologies. In this study, the application of coke breeze for the treatment of wastewater through adsorption has been demonstrated. A pseudo second order reaction kinetics has been observed through batch process adsorption study. Furthermore, adsorption data has found to be best fitted with the Freundlich adsorption isotherm model. Color removal efficiency of 80-90% along with COD removal efficiency of 40-50% was observed within 30 min by 120 g/L dosage of the adsorbent. The removal of phenolic and other organic compounds from coking wastewater has been measured through UV-Vis spectroscopy. The morphological changes of the adsorbent coke breeze have been captured through scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. However, because of the significant abundance in the steel plant, cost effectiveness and applicability of the post-treated coke breeze in sintered plant as fuel, turn it into a suitable adsorbent despite of having much lower specific surface area compared to commercial activated carbon (AC). Therefore, application of the coke breeze turns it into a very promising material and the technique is sustainable towards the coke quenching effluent treatment.


Asunto(s)
Coque , Contaminantes Químicos del Agua , Adsorción , Coque/análisis , Color , Eliminación de Residuos Líquidos , Aguas Residuales , Contaminantes Químicos del Agua/análisis
5.
Chem Commun (Camb) ; 57(45): 5578-5581, 2021 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-33969858

RESUMEN

A new imidazolium functionalized hexapodal polymeric receptor, [PHIm-Br], showed selective and efficient removal (>99%) of perrhenate (ReO4-), from 100% aqueous medium via solid-liquid extraction, which was 13% higher as compared to its monomeric analouge [HIm-Br]. Most importantly, [PHIm-Br] overcomes the drawback of [HIm-Br] in terms of removal of ReO4- at lower anion concentration of ∼100 ppm along with excellent radiation resistivity and reusability within a wide pH range, which implies its potential towards practical applications.

6.
Dalton Trans ; 50(4): 1486-1495, 2021 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-33439174

RESUMEN

Preparation of a stable U(v) complex in an aqueous medium is a challenging task owing to its disproportionation nature (conversion into more stable U(vi) and U(iv) species) and sensitivity to atmospheric oxygen. The stable uranyl (UO22+)/dipicolinic acid (DPA) complex ([U(VI)O2(DPA)(OH)(H2O)]-) was formed at pH 10.5-12.0, which was confirmed by potentiometric and spectrophotometric titrations, and NMR, ESI-MS and EXAFS spectroscopy. The complex [U(VI)O2(DPA)(OH)(H2O)]- can be electrochemically reduced on the Pt electrode at -0.9 eV (vs. Ag/AgCl) to [U(V)O2(DPA)(OH)(H2O)]2- in aqueous medium under an anaerobic environment. According to cyclic voltammetric analysis, a pair of oxidation and reduction waves at E'0 = -0.592 V corresponds to the [U(VI)O2(DPA)(OH)(H2O)]-/[U(V)O2(DPA)(OH)(H2O)]2- redox couple and the formation of [U(V)O2(DPA)(OH)(H2O)]2- was confirmed by the electron stoichiometry (n = 0.97 ± 0.05) of the reduction reaction of [U(VI)O2(DPA)(OH)(H2O)]-. The pentavalent uranyl complex [U(V)O2(DPA)(OH)(H2O)]2- was further characterized via UV-vis-NIR absorption spectrophotometry and X-ray absorption (XANES and EXAFS) spectroscopy. The [U(V)O2(DPA)(OH)(H2O)]2- complex is stable at pH 10.5-12.0 in anaerobic water for a few days. DFT calculation shows the strong complexing ability of DPA stabilizing the unstable oxidation state U(v) in aqueous medium.

7.
Cancer Cell Int ; 20: 70, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32158360

RESUMEN

BACKGROUND: Estrogen sulfotransferase catalyzes conjugation of sulfuryl-group to estradiol/estrone and regulates E2 availability/activity via estrogen-receptor or non-receptor mediated pathways. Sulfoconjugated estrogen fails to bind estrogen-receptor (ER). High estrogen is a known carcinogen in postmenopausal women. Reports reveal a potential redox-regulation of hSULT1E1/E2-signalling. Further, oxidatively-regulated nuclear-receptor-factor 2 (Nrf2) and NFκß in relation to hSULT1E1/E2 could be therapeutic-target via cellular redox-modification. METHODS: Here, oxidative stress-regulated SULT1E1-expression was analyzed in human breast carcinoma-tissues and in rat xenografted with human breast-tumor. Tumor and its surrounding tissues were obtained from the district-hospital. Intracellular redox-environment of tumors was screened with some in vitro studies. RT-PCR and western blotting was done for SULT1E1 expression. Immunohistochemistry was performed to analyze SULT1E1/Nrf2/NFκß localization. Tissue-histoarchitecture/DNA-stability (comet assay) studies were done. RESULTS: Oxidative-stress induces SULT1E1 via Nrf2/NFκß cooperatively in tumor-pathogenesis to maintain the required proliferative-state under enriched E2-environment. Higher malondialdehyde/non-protein-soluble-thiol with increased superoxide-dismutase/glutathione-peroxidase/catalase activities was noticed. SULT1E1 expression and E2-level were increased in tumor-tissue compared to their corresponding surrounding-tissues. CONCLUSIONS: It may be concluded that tumors maintain a sustainable oxidative-stress through impaired antioxidants as compared to the surrounding. Liver-tissues from xenografted rat manifested similar E2/antioxidant dysregulations favoring pre-tumorogenic environment.

8.
Dalton Trans ; 49(10): 3093-3097, 2020 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-32100800

RESUMEN

This work reports a new cationic imidazolium based hexapodal receptor, [L.6Br], for selective and efficient removal of perrhenate (ReO4-) as [L.6ReO4] from 100% aqueous medium via extraction through precipitation. Selective removal of ReO4- even in the presence of common anions such as halides and oxyanions in excess within a wide range of pH values from 1 to 14 by this receptor is also demonstrated. Importantly, [L.6Br] could easily be recovered upon heating [L.6ReO4] with tetrabutylammonium bromide (TBABr) in acetonitrile at 60 °C and recycled as a fresh extractant for ReO4-.

9.
Inorg Chem ; 58(23): 15993-16003, 2019 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-31702136

RESUMEN

A new bis-heteroleptic RuII complex (1[PF6]2) with iodotriazole as the anion binding group along with the attached pyrene moiety is developed to investigate anion sensing properties and the origin of its selectivity toward a particular class of anions. Selective sensing of phosphates over other anions in both the solution and solid states by 1[PF6]2 is clearly evident from the perturbation of the absorption band and a large degree of amplification of 3MLCT emission band in the presence of phosphates. Importantly, macroscopic investigation such as Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS) indicated the formation of supramolecular architecture in the presence of dihydrogen phosphate via halogen bonding interaction and π-π stacking of pyrene moieties. Such macroscopic property is further corroborated by solution and solid state spectroscopic studies, e.g., 1H-DOSY NMR, single crystal X-ray crystallography, and solid state photoluminescence (PL) spectroscopy.

10.
Dalton Trans ; 48(20): 6853-6862, 2019 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-31020976

RESUMEN

A tris-amine and oxy-ether functionalised macrocyclic wheel (NaphMC) and various phenanthroline based multidentate axles (L1, L2 and L3) are utilised for the formation of [n]pseudorotaxanes (n = 2, 3, 4) in high yields via Cu(ii) temptation and π-π stacking interactions. The systematic development of threaded supramolecular architectures i.e. [2]pseudorotaxane {[2]CuPR(ClO4)2}, [3]pseudorotaxane {[3]CuPR(ClO4)4} and [4]pseudorotaxane {[4]CuPR(ClO4)6} from bidentate L1, linear tetradentate L2 and tripodal hexadentate L3 respectively is described. All the [n]pseudorotaxanes are well characterized by several spectroscopy and other experimental techniques such as electrospray ionization mass spectrometry (ESI-MS), isothermal titration calorimetric (ITC) study, UV/Vis, EPR, IR and elemental analysis. Moreover, the single crystal X-ray analysis of [2]pseudorotaxane confirmed the threading of L1 in the cavity of NaphMC, resulting in the formation of a penta-coordinated Cu(ii) ternary complex. ITC studies revealed the order of binding constant values for the formation of [n]pseudorotaxanes from the NaphMC-Cu(ii) complex and multidentate axles as L3 > L2 > L1. Finally, we have also shown the ability of Ni(ii) to act as a metal template in the formation of [n]pseudorotaxanes.

11.
Dalton Trans ; 48(14): 4538-4546, 2019 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-30860521

RESUMEN

A new RuII based bis-heteroleptic ditopic receptor, 1[PF6]2 (C44H33F12IN10OP2Ru), having integrated anion binding iodotriazole (halogen bond donor) and urea units (-NH bond donor) is employed for selective sensing of phosphates (e.g., H2PO4- and HP2O73-). 1[PF6]2 showed superiority in phosphate sensing in CH3CN as compared to its hydrogen bond donor analogue, 2[PF6]2 (C44H34F12N10OP2Ru), non-urea halogen bond analogue, 3[PF6]2 (C38H27F12IN8P2Ru) and non-urea hydrogen bond donor analogue, 4[PF6]2 (C38H28F12N8P2Ru) in terms of enhanced binding constant values, longer excited state lifetimes and lower detection limit values. 1H-NMR, Isothermal Titration Calorimetry (ITC) and photophysical studies revealed the implementation of the combined role of both the halogen bond donor iodotriazole unit and the -NH unit of the urea moiety for selective and enhanced binding of phosphates.

12.
Chem Commun (Camb) ; 55(21): 3085-3088, 2019 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-30785460

RESUMEN

A new multifunctional [2]catenane is synthesized by using a phenanthroline-based heteroditopic wheel and Axle, which acts as a receptor for the efficient binding of lanthanide ions such as Eu3+ and Gd3+.

13.
Dalton Trans ; 47(22): 7561-7570, 2018 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-29790530

RESUMEN

Two new RuII-based bis-heteroleptic ditopic receptors 1[PF6]2 (C44H34F12N10OP2Ru) and 2[PF6]2 (C40H27F17N10OP2Ru), decorated with a 1-naphthyl and pentafluorophenyl urea pendant arm, respectively, along with the previously reported 3[PF6]2 (C40H31F13N10OP2Ru), containing a pendant 4-fluorophenyl urea unit and 4[PF6]2, devoid of a pendant urea arm, have been studied to establish the role of urea proton acidity on the sensing and extraction of oxyanions in the presence of triazole C-H as an additional hydrogen bonding motif. 1H-NMR, isothermal titration calorimetry (ITC) and photophysical experiments show selective binding of 1[PF6]2 and 2[PF6]2 toward oxyanions such as phosphates (e.g., H2PO4- and HP2O73-) and carboxylates (e.g., CH3CO2- and PhCO2-) like 3[PF6]2. This generalizes the role of triazole C-H and urea in the RuII-based bis-heteroleptic ditopic receptors towards recognition of such anions. Interestingly, complex 1[PF6]2 having intermediate acidic urea -NH protons showed the highest binding affinity with phosphates as compared to the other urea analogues 2[PF6]2 and 3[PF6]2 as well as the non-urea analogue, 4[PF6]2 (C32H24F12N8P2Ru). Moreover, 2[PF6]2 having the most acidic -NH protons showed higher binding affinity towards carboxylates as compared to that of 1[PF6]2/3[PF6]2. Detailed photo-physical studies revealed that 1[PF6]2 is a farsuperior and more selective H2PO4- sensor compared to 2[PF6]2/3[PF6]2/4[PF6]2, as evidenced by the higher degree of amplification of RuII center-based MLCT emission, greater change in excited state lifetime, lower detection limit and higher degree of selectivity. Furthermore, 1[PF6]2 also acts as a moderate liquid-liquid extraction agent of H2PO4-, CH3CO2- and PhCO2- anions, which was comparable to 3[PF6]2 and much higher as compared to 2[PF6]2/4[PF6]2.

14.
High Blood Press Cardiovasc Prev ; 25(1): 79-88, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29307050

RESUMEN

INTRODUCTION: Hypertension is a metabolic disease which is caused by vasoconstriction and that results into elevated blood pressure. A chronic hypertensive condition affects and even damages to various systems in the body. Presence of renal cortexin (r-cortexin), an antihypertensive protein, which is released from the kidney cortex controls the blood pressure. The effect of r-cortexin was mediated through nitric oxide (NO), a universal vasodilating agent. AIM: In our study, acetyl salicylic acid (aspirin), a well-known activator of the endothelial nitric oxide synthase (eNOS) induced r-cortexin synthesis. METHODS: The hypertensive rat model was prepared by injecting deoxy corticosterone acetate (DOCA). Synthesis of r-cortexin was measured by the anti-r-cortexin antibody which was raised in adult white Wister albino rat model. NO level was determined by using methemoglobin method and later confirmed by chemiluminescence method. Change in blood pressure was determined indirectly by using NIBP monitoring system. RESULTS: Aspirin increased the r-cortexin expression from 64.36 ± 12.6 nM to 216.7 ± 21.31 nM in DOCA induced hypertensive rats. The mechanism was proved with the findings of increased level of NO from 0.4 to 1.9 µM. The DOCA induced blood pressure was also decreased from 139.39 ± 7.36 mm of Hg to 116.57 ± 6.89 mm of Hg in case of systolic blood pressure and in case of diastolic pressure from 110.41 ± 7 mm of Hg to 86.4 ± 2.76 mm of Hg that are quite approximate. CONCLUSION: So, from this study it has been found that aspirin induces the r-cortexin synthesis in kidney cortex through the activation of eNOS in DOCA induced hypertensive rats.


Asunto(s)
Antihipertensivos/farmacología , Aspirina/farmacología , Presión Sanguínea/efectos de los fármacos , Acetato de Desoxicorticosterona , Hipertensión/prevención & control , Riñón/efectos de los fármacos , Péptidos/metabolismo , Cloruro de Sodio Dietético , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Animales , Relación Dosis-Respuesta a Droga , Hipertensión/inducido químicamente , Hipertensión/metabolismo , Hipertensión/fisiopatología , Péptidos y Proteínas de Señalización Intercelular , Riñón/metabolismo , Riñón/fisiopatología , Masculino , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Ratas Wistar , Transducción de Señal , Factores de Tiempo
15.
ACS Omega ; 3(9): 10647-10656, 2018 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-31459185

RESUMEN

A tris(2-aminoethyl)-amine-based dimeric capsular assembly of pentafluorophenyl urea (C1) has been employed as a catalyst in a wide range of Michael addition reactions. This capsular catalyst assembly dramatically accelerates the Michael addition reaction of ß-nitrostyrenes (2a-2d) with various Michael donors such as ketoesters (3a, 3e), 1,3-diketones (3b), diesters (3C), and cyanoesters (3d) at room temperature to yield the corresponding nitroalkanes in significantly high yields within a very short reaction time. Significant improvement in solubility and use of conventional organic solvents in reaction along with a drastic decrease in reaction time (high value of the rate constant of the reaction) has been achieved through C1 as compared to the previously reported homologous tripodal monomeric urea catalyst (L1). The addition of enolate to ß-nitrostyrenes to generate an anionic intermediate seemed to be highly stabilized by the six urea units of capsular assembly. Control experiments and in situ kinetic studies are performed for this addition reaction and based on the results, a plausible mechanism has been proposed for the formation of Michael adduct inside the capsular cavity.

16.
Inorg Chem ; 56(9): 5371-5382, 2017 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-28414235

RESUMEN

A new bis-heteroleptic RuII complex based ditopic receptor, 1[PF6]2, having an anion binding triazole -CH unit and appended 4-fluorophenyl urea arm has been developed. 1H NMR and isothermal titration calorimetry (ITC) experiments showed binding of 1[PF6]2 toward oxyanions such as phosphates (e.g., H2PO4- and HP2O73-) and carboxylates (e.g., CH3CO2- and C6H5CO2-) anions selectively. 1H NMR studies showed that highly basic phosphate anions such as HP2O73-/H2PO4- are bound by both -CH and -NH units of complex 1[PF6]2. However, comparatively less basic CH3CO2-, C6H5CO2- anions interacted with the urea -NH protons only. Thermodynamic parameters obtained from ITC experiments suggested that binding of all the interacting anions with complex 1[PF6]2 are highly enthalpy and entropy driven processes. Importantly, complex 1[PF6]2 showed extraction of H2PO4-, CH3CO2-, and C6H5CO2- anions from aqueous solution via liquid-liquid extraction with efficiencies of 28%, 74%, and 80%, respectively. The influential role of the urea moiety in the course of extraction is demonstrated by comparison with a model complex, 2[PF6]2. Additionally, complex 1[PF6]2 is capable of selective sensing of phosphate anions among all investigated anions.

17.
Inorg Chem ; 55(7): 3640-52, 2016 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-26998549

RESUMEN

A ditopic receptor L1, having metal binding bis(2-picolyl) donor and anion binding urea group, is synthesized and explored toward metal sulfate recognition via formation of dinuclear assembly, (L1)2M2(SO4)2. Mass spectrometric analysis, (1)H-DOSY NMR, and crystal structure analysis reveal the existence of a dinuclear assembly of MSO4 with two units of L1. (1)H NMR study reveals significant downfield chemical shift of -NH protons of urea moiety of L1 selectively with metal sulfates (e.g., ZnSO4, CdSO4) due to second-sphere interactions of sulfate with the urea moiety. Variable-temperature (1)H NMR studies suggest the presence of intramolecular hydrogen bonding interaction toward metal sulfate recognition in solution state, whereas intermolecular H-bonding interactions are observed in solid state. In contrast, anions in their tetrabutylammonium salts fail to interact with the urea -NH probably due to poor acidity of the tertiary butyl urea group of L1. Metal sulfate binding selectivity in solution is further supported by isothermal titration calorimetric studies of L1 with different Zn salts in dimethyl sulfoxide (DMSO), where a binding affinity is observed for ZnSO4 (Ka = 1.23 × 10(6)), which is 30- to 50-fold higher than other Zn salts having other counteranions in DMSO. Sulfate salts of Cd(II)/Co(II) also exhibit binding constants in the order of ∼1 × 10(6) as in the case of ZnSO4. Positive role of the urea unit in the selectivity is confirmed by studying a model ligand L2, which is devoid of anion recognition urea unit. Structural characterization of four MSO4 [M = Zn(II), Cd(II), Co(II), Mn(II)] complexes of L1, that is, complex 1, [(L1)2(Zn)2(µ-SO4)2]; complex 2, [(L1)2(H2O)2(Cd)2(µ-SO4)2]; complex 3, [(L1)2(H2O)2(Co)2(µ-SO4)2]; and complex 4, [(L1)2(H2O)2(Mn)2(µ-SO4)2], reveal the formation of sulfate-bridged eight-membered crownlike binuclear complexes, similar to one of the concentration-dependent dimeric forms of MSO4 as observed in solid state. Finally, L1 is found to be highly efficient in removing ZnSO4 from both aqueous and semiaqueous medium as complex 1 in the presence of other competing Zn(II) salts via precipitation through crystallization. Powder X-ray diffraction analysis has also confirmed bulk purity of complex 1 obtained from the above competitive crystallization experiment.

18.
PLoS Negl Trop Dis ; 9(10): e0004138, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26485704

RESUMEN

Post Kala-azar Dermal Leishmaniasis (PKDL) is a chronic but not life-threatening disease; patients generally do not demand treatment, deserve much more attention because PKDL is highly relevant in the context of Visceral Leishmaniasis (VL) elimination. There is no standard guideline for diagnosis and treatment for PKDL. A species-specific PCR on slit skin smear demonstrated a sensitivity of 93.8%, but it has not been applied for routine diagnostic purpose. The study was conducted to determine the actual disease burden in an endemic area of Malda district, West Bengal, comparison of the three diagnostic tools for PKDL case detection and pattern of lesion regression after treatment. The prevalence of PKDL was determined by active surveillance and confirmed by PCR based diagnosis. Patients were treated with either sodium stibogluconate (SSG) or oral miltefosine and followed up for two years to observe lesion regression period. Twenty six PKDL cases were detected with a prevalence rate of 27.5% among the antileishmanial antibody positive cases. Among three diagnostic methods used, PCR is highly sensitive (88.46%) for case confirmation. In majority of the cases skin lesions persisted after treatment completion which gradually disappeared during 6-12 months post treatment period. Reappearance of lesions noted in two cases after 1.5 years of miltefosine treatment. A significant number of PKDL patients would remain undiagnosed without active mass surveys. Such surveys are required in other endemic areas to attain the ultimate goal of eliminating Kala-azar. PCR-based method is helpful in confirming diagnosis of PKDL, referral laboratory at district or state level can achieve it. So a well-designed study with higher number of samples is essential to establish when/whether PKDL patients are free from parasite after treatment and to determine which PKDL patients need treatment for longer period.


Asunto(s)
Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Visceral/complicaciones , Administración Oral , Adolescente , Adulto , Animales , Gluconato de Sodio Antimonio/administración & dosificación , Antiprotozoarios/administración & dosificación , Niño , Preescolar , Transmisión de Enfermedad Infecciosa , Monitoreo Epidemiológico , Femenino , Humanos , India/epidemiología , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/transmisión , Masculino , Fosforilcolina/administración & dosificación , Fosforilcolina/análogos & derivados , Reacción en Cadena de la Polimerasa , Prevalencia , Recurrencia , Población Rural , Adulto Joven
19.
Indian J Pathol Microbiol ; 45(1): 83-7, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12593571

RESUMEN

31 patients of peptic ulcer (PU) treated in the past by vagotomy with Gastrojejunostomy (GJ)/pyloroplasty, later presented with dyspesia. These postvagotomy dyspeptic patients were investigated. Antral and corpus endoscopic biopsies were taken to evaluate for Helicobacter pylori (Hp) infection by inhouse rapid urease test (RUT), histopathological examination and scanning electron microscopy (SEM). Dyspepsia score was done in both pre and post treatment phase. Hp positive patients were randomised to receive anti H. pylori therapy. Hp eradication was recorded by repeat RUT and endoscopic biopsy followed by SEM. Coccoid form of Hp were detected in 76.92% cases of vagotomy with gastrojejunostomy (GJ) and coccobacillary forms of Hp were seen in 75% cases of pyloroplasty. After treatment with anti Hp therapy coccoid forms persisted in 69.23% of GJ cases, whereas 22% of pyloroplasty cases showed coccoid transformation. Anti Hp therapy did not reveal any statistically significant improvement in 'Dyspepsia Score' in GJ group, whereas it improved significantly in pyloroplasty group (p=0.002).


Asunto(s)
Dispepsia/microbiología , Helicobacter pylori/ultraestructura , Úlcera Péptica/cirugía , Vagotomía , Infecciones por Helicobacter/microbiología , Humanos , Microscopía Electrónica de Rastreo
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