RESUMO
Abdominal aortic aneurysm remains mostly asymptomatic. It is usually detected incidentally with imaging studies. Here we present a 55 years old hypertensive, non smoker, non diabetic, male patient who was diagnosed as a case of infrarenal abdominal aortic aneurysm. He was treated by endovascular means using endograft without laparatomy. Endografts were deployed through bilateral femoral artery cut down technique under general anesthesia. Completion angiogram following this endovascular aneurysm repair (EVAR) technique revealed good technical success with no endoleak. This hybrid procedure was performed in a cathlab having surgical instruments in hand. Three years after the procedure, patient is doing well.
Assuntos
Aneurisma da Aorta Abdominal , Correção Endovascular de Aneurisma , Humanos , Masculino , Pessoa de Meia-Idade , Aneurisma da Aorta Abdominal/cirurgia , Bangladesh , Correção Endovascular de Aneurisma/métodosRESUMO
Developing point-of-care (PoC) diagnostic platforms for carcinoembryonic antigen detection is essential. However, thefew implementations of transferring the signal amplification strategies in electrochemical sensing on paper-based platforms are not satisfactory in terms of detection limit (LOD). In the quest for pushing down LOD, majority of the research has been targeted towards development of improved nanostructured substrates for entrapping more analyte molecules and augmenting the electron transfer rate to the working electrode. But, such approaches have reached saturation. This paper focuses on enhancing the mass transport of the analyte towards the sensor surface through the application of an electric field, in graphene-ZnO nanorods heterostructure. These hybrid nanostructures have been deposited on flexible polyethylene terephthalate substrates with screen printed electrodes for PoC application. The ZnO nanorods have been functionalized with aptamers and the working sensor has been integrated with smartphone interfaced indigenously developed low cost potentiostat. The performance of the system, requiring only 50 µl analyte has been evaluated using electrochemical impedance spectroscopy and validated against commercially available ELISA kit. Limit of detection of 1 fg/ml in human serum with 6.5% coefficient of variation has been demonstrated, which is more than three orders of magnitude lower than the existing attempts on PoC device.
Assuntos
Antígeno Carcinoembrionário/sangue , Técnicas Eletroquímicas/instrumentação , Nanotubos/química , Sistemas Automatizados de Assistência Junto ao Leito , Testes Imediatos , Aptâmeros de Nucleotídeos/química , Grafite/química , Humanos , Limite de Detecção , Óxido de Zinco/químicaRESUMO
BACKGROUND: With 9.6 million deaths in 2018, cancer remains the second leading cause of death worldwide. Breast cancer is the most deadly type of cancer among females, with 55.2% of crude incidence rate and 16.6% of crude mortality rate. PURPOSE: The present study was aimed to investigate the anti-breast cancer potential of natural dietary flavonoid, apigenin isolated from Clerodendrum viscosum leaves. METHODS: Apigenin was evaluated for in-depth anticancer activity in MCF-7 cells using cell viability assay, cell cycle analysis, Annexin-V-FLUOS staining, ROS induction, morphological analysis, and western blot analysis. RESULTS: Apigenin showed selective cytotoxicity on MCF-7 cells with an IC50-56.72 ± 2.35 µM, while negligible cytotoxicity was observed on WI-38 cells. Further, the flow cytometer-based analysis showed that apigenin halted MCF-7 cells in the G2/M phase arrest followed by dose-dependent apoptosis. Moreover, the FACS and confocal microscopy results confirmed the elevation of intracellular ROS and nuclear fragmentation in apigenin-treated MCF-7 cells. Western blots showed up-regulation of cell cycle regulatory proteins, increased p53 expression, Bax/Bcl-2 ratio, activation of caspases, and cleavage of PARP. Finally, apigenin treatment in the presence of Pifithrin-µ showed decreased apoptotic population and it was further confirmed through western blotting study. The results revealed the vital role of p53 in apigenin-induced apoptosis in MCF-7 cells. CONCLUSIONS: In the present findings, treatment of apigenin-induced intracellular ROS in MCF-7 cells followed by induction of G2/M phase cell cycle arrest and further apoptosis through the regulation of p53 and caspase-cascade signaling pathway.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apigenina/farmacologia , Neoplasias da Mama/tratamento farmacológico , Caspases/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Apigenina/química , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Núcleo Celular/efeitos dos fármacos , Clerodendrum/química , Fragmentação do DNA , Feminino , Citometria de Fluxo , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Células MCF-7 , Folhas de Planta/química , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidoresRESUMO
The worldwide cancer incidences are remarkable despite the advancement in cancer drug discovery field, highlighting the need for new therapies focusing on cancer cell and its microenvironment, including inflammation. Several species of Drosera (family: Droseraceae) are used in various traditional as well as homeopathic systems of medicine. Drosera burmannii Vahl. is also enlisted in French Pharmacopoeia in 1965 for the treatment of inflammatory diseases, including chronic bronchitis, asthma and whooping cough. The present study is designed to substantiate the potential of D. burmannii in in vitro anticancer activity and its relation with anti-inflammatory property. In vitro anticancer study revealed that DBME is inhibiting the proliferation of MCF-7 cells without affecting the viability of other malignant and non-malignant cells. DBME induced G2/M phase arrest and apoptosis in MCF-7 cells by suppressing the expression of cyclin A1, cyclin B1 and Cdk-1 and increasing the expression of p53, Bax/Bcl-2 ratio leading to activation of caspases and PARP degradation. Presence of caspase-8 (Z-IETD-fmk) and caspase-9 (Z-LEHD-fmk) inhibitors alone did prevent the apoptosis partially while apoptosis prevention was significantly observed when used in combination, suggesting vital role of caspases in DBME-induced apoptosis in MCF-7 cells. DBME also downregulated LPS-induced increased expression of iNOS, COX-2 and TNF-α along with suppression on intracellular ROS production that confirms the potential of DBME as anti-inflammatory extract. GCMS analysis revealed the presence of four major compounds hexadecanoic acid, tetradecanoic acid, hexadecen-1-ol, trans-9 and 1-tetradecanol along with some other fatty acid derivatives and carotenoids (Beta-doradecin) in DBME. These findings confirmed the anti-inflammatory activity of DBME, which is already listed in French Pharmacopeia in 1965. Here we have additionally reported the anti-breast cancer activity of DBME and its relation to the anti-inflammatory potential. Hence, an ethnopharmacological approach can be considered as useful tool for the discovery of new drug leads.
RESUMO
AIMS: This study was aimed to evaluate different phytochemical constituents and the ameliorating effect of 70% methanol extract of Euglena tuba (ETME) on iron overload-induced liver injury, along with its in vitro iron-chelating and DNA protection effects. METHODS AND RESULTS: Phytochemicals of ETME were identified by GC-MS analysis. Iron chelation and protection of Fenton reaction-induced DNA damage was conducted in vitro. Post oral administration of ETME to iron-overloaded mice, the levels of serum parameters, antioxidant enzymes, liver iron, lipid peroxidation, protein carbonyl and hydroxyproline contents were measured. ETME showed inhibition of lipid peroxidation, protein oxidation and liver fibrosis. The serum markers and liver iron were lessened, whereas enhanced levels of liver antioxidant enzymes were detected in ETME-treated group. Furthermore, the histopathological observations also substantiated the protective effects of the extract. CONCLUSIONS: Several bioactive compounds identified by GC-MS may be the basis of hepatoprotective as well as antioxidant and iron-chelating effect of ETME. SIGNIFICANCE AND IMPACT OF THE STUDY: Currently available iron-chelating agents show several side effects and limitations which may be overcome by ETME, which suggest its benefit against pathology of iron overload-linked diseases. Hence, ETME can be used as a promising hepatoprotective agent.
Assuntos
Euglena/química , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Fígado/patologia , Animais , Antioxidantes/metabolismo , Extratos Celulares/química , Extratos Celulares/uso terapêutico , Ferro/metabolismo , Sobrecarga de Ferro/enzimologia , Sobrecarga de Ferro/metabolismo , Sobrecarga de Ferro/patologia , Peroxidação de Lipídeos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Microalgas/química , Oxirredução , Compostos Fitoquímicos/química , Substâncias Protetoras/uso terapêuticoRESUMO
The chemically treated Labeo rohita scale is used for synthesizing hydroxyapatite (HAp) biomaterials. Thermogravimetric and differential thermal analyses of fish scale materials reveal the different phase changes with temperature and find out the suitable calcination temperatures. The composition and structures of wet ball-milled calcined HAp powders are characterized by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray analysis (EDX). The EDX as well as chemical analysis of fish scale-derived apatite materials confirms that the Ca/P ratio is 1.71. The compressive stress, hardness and porosity have been evaluated on sintered HAp biomaterials. The cell attachment on HAp surfaces, cytotoxicity evaluation and MTT assay, which are carried out in RAW macrophage-like cell line media demonstrate good biocompatibility. The histological analysis also supports the bioaffinity of processed HAp biomaterials in Wistar rat model for investigating the contact reaction and stability at the artificial or natural prosthesis interface.
Assuntos
Materiais Biocompatíveis/química , Cyprinidae , Durapatita/química , Alicerces Teciduais/química , Animais , Apatitas/química , Linhagem Celular , Força Compressiva , Macrófagos/metabolismo , Teste de Materiais , Camundongos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Porosidade , Pós , Ratos , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Difração de Raios XRESUMO
Herpes simplex virus type 1 (HSV-1) is the leading cause of corneal blindness in the developed world due to reactivation of infectious virus and the subsequent immune response. The innate response that facilitates viral control in the cornea is currently unknown. In the present study using a mouse chimera model, we found that a bone marrow component is crucial in inhibiting viral replication and identified inflammatory monocytes (F4/80(+) Gr1(+)) as the responsible cell. CCL2 was critical for recruiting inflammatory monocytes, and a loss of this chemokine in CCL2(-/-) mice resulted in a loss of viral containment and inflammatory monocyte recruitment. To confirm these results, clodronate depletion of inflammatory monocytes resulted in elevated viral titers. Furthermore, siRNA targeting the innate sensor p204/IFI-16 resulted in a loss of CCL2 production. In conclusion, CCL2 expression driven by IFI-16 recognition of HSV-1 facilitates the recruitment of inflammatory monocytes into the cornea proper to control viral replication.
Assuntos
Quimiocina CCL2/biossíntese , Inflamação/imunologia , Inflamação/metabolismo , Interferon-alfa/metabolismo , Animais , Córnea/imunologia , Córnea/metabolismo , Córnea/virologia , Feminino , Herpesvirus Humano 1/imunologia , Inflamação/genética , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/genética , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/imunologia , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/metabolismo , Masculino , Camundongos , Camundongos Knockout , Modelos Imunológicos , Monócitos/imunologia , Monócitos/metabolismo , Óxido Nítrico/biossíntese , Replicação ViralAssuntos
Abscesso Encefálico/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Óleos/metabolismo , Idoso , Abscesso Encefálico/complicações , Abscesso Encefálico/tratamento farmacológico , Abscesso Encefálico/patologia , Feminino , Infecções por Bactérias Gram-Positivas/complicações , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/patologia , Humanos , Imageamento por Ressonância Magnética , Neoplasias Meníngeas/cirurgia , Meningioma/cirurgia , Propionibacterium acnesRESUMO
The spatial distribution of chronic arsenicosis due to consumption of arsenic contaminated tube well water in different districts of West Bengal was gradually unfolding since 1983. Arsenical dermatosis was found to be the commonest and earliest manifestation of chronic arsenic toxicity. This study was conduct in Baruipur block of South 24 Parganas district of West Bengal. Total 313 people selected from three randomly selected villages with reported arsenic contamination in tube well water and 342 people living three randomly selected villages without such evidence of contamination were examined as control population. 5.97% of exposed population and 2.05% of unexposed population showed melanosis (p < 0.01). Moreover, 5.11% of exposed population and 0.88% of unexposed population showed keratosis (p < 0.01). The prevalence of dermatosis among exposed population was also seen to have increased with increasing age, from 7.19% in 0-19 year age group to 37.50% in above 40 year group (p < 0.001). Prevalence was also found to be more with increase in level of contamination. The prevalence rate of dermatosis among unexposedgroup was 2.92%. But age adjusted prevalence rate among exposed group was 19.08% at arsenic contamination level of 0.487 ppm. Mean arsenic concentration in nail and hair samples of exposed group was also found higher than the prescribed limit.
Assuntos
Arsenicais/efeitos adversos , População Rural , Dermatopatias/induzido quimicamente , Poluentes Químicos da Água/efeitos adversos , Adolescente , Adulto , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Índia/epidemiologia , Lactente , Recém-Nascido , Masculino , Dermatopatias/epidemiologiaRESUMO
Anthropometry and morbidity profile of fifty randomly selected workers of coal handling plant at a thermal power station of West Bengal having at least five years experience were studied. The mean value of their age, duration of present job and Body Mass Index (BMI) were 34.8 years, 7.86 years and 19.24 respectively. As they were exposed to coal dust (Av. concentration 300-350 mg/M3 of air), warmth (Ambient temperature 40 +/- 5 degrees C), humidity (Relative humidity 80 +/- 5%) and noise [Av. 80 dB(A)], respiratory system was most commonly (72%) effected followed by greying of hair (5.6%), Cloth dusters used by some could not render any discernable protective effect. Addiction was also prevent (62%). Use of proper protective equipments (PPE) supplemented by adequate preplacement and periodic medical examination followed by successful rehabilitation were suggested.
Assuntos
Carvão Mineral/estatística & dados numéricos , Doenças Profissionais/epidemiologia , Centrais Elétricas/estatística & dados numéricos , Adulto , Índice de Massa Corporal , Comorbidade , Humanos , Índia/epidemiologia , Pessoa de Meia-Idade , Prevalência , Doenças Respiratórias/epidemiologia , Fatores de Risco , Fumar/epidemiologiaRESUMO
A group of asymptomatic amicrofilaraemic individuals (endemic normals) aged > 12 years was identified in 2 filaria-endemic villages of Orissa, India in 1990 (Bajapur village, n = 40) and in 1994 (Olosingh village, n = 47). They were re-examined for microfilaraemia and disease status in the year 2000 after a 10-year and a 6-year period. Studies conducted at both villages yielded a similar pattern in the development of disease. Above 85% of the females remained normal, compared to 54% of males. Remaining individuals had acquired hydrocoele (males) and adenolymphangitis (both males and females). Only 1 individual converted to having asymptomatic microfilariae. No case of elephantiasis was observed. Results indicate that most females remained normal and males faced considerable risk of developing hydrocoele in these Wuchereria bancrofti-endemic areas.
Assuntos
Filariose/epidemiologia , Adolescente , Adulto , Idoso , Animais , Doenças Endêmicas , Feminino , Seguimentos , Humanos , Índia/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Wuchereria bancroftiRESUMO
Zidovudine, the anti-AIDS drug, caused inhibition of mitogen-induced proliferation and perturbation of cell-cycle progression of cultured bone marrow cells of mice. There was significant hypoploidy observed in flow cytometric analysis of AZT-treated bone marrow cells. In apo-direct analysis, cells showed apoptosis in G0/G1 phase. In DNA gel analysis, characteristic laddering of apoptosis was observed in AZT-treated bone marrow cells. We demonstrated that, when the animals were pretreated with protein A (PA) of Staphylococcus aureus, the apoptotic changes could be prevented in bone marrow cells of AZT-treated animals. There is a significant (p < 0.05) increase in proliferation of bone marrow cells subjected to mitogen treatment in PA+AZT-treated animals, compared to only AZT-treated animals. However, cell-cycle phase distribution was not hampered and no laddering in DNA gel analysis was also observed in this group. In apo-direct analysis, PA treatment showed significant (p < 0.001) inhibition of AZT-induced apoptosis. These observations indicate that by using a suitable agent such as protein A the toxic side effects of AZT could be minimized.
Assuntos
Antivirais/toxicidade , Apoptose , Proteína Estafilocócica A/farmacologia , Zidovudina/toxicidade , Animais , Células da Medula Óssea/efeitos dos fármacos , Ciclo Celular , Divisão Celular , Citometria de Fluxo , Masculino , Camundongos , Fito-Hemaglutininas , Zidovudina/antagonistas & inibidoresRESUMO
A double-blind, randomised, placebo-controlled trial was conducted to compare the efficacy of metoclopramide with the 5-HT3 antagonist, ondansetron, for the prevention of postoperative emesis in children undergoing elective strabismus surgery. None of the children received any premedication and a similar anaesthetic technique was used for all. Ondansetron 0.15 mg.kg-1, metoclopramide 0.25 mg.kg-1 or saline placebo were administered following intravenous catheter placement. Episodes of emesis were recorded for the first 24 h for the intervals of 0-2, 2-6 and 6-24 h. The incidence of emesis in the first 24 h was observed to be 71.7% in the placebo group, 34.4% in the ondansetron group (p < 0.001) and 61.4% in the metoclopramide group (p = NS). The severity of vomiting was less in the ondansetron group as compared with metoclopramide (p < 0.01) and placebo (p < 0.001). Recovery room scores were comparable in all the groups. No serious side-effects were observed in the ondansetron group. We conclude that prophylactic ondansetron is effective and superior to metoclopramide in the prevention of postoperative emesis in children following elective strabismus surgery.
Assuntos
Antieméticos/uso terapêutico , Náusea/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Estrabismo/cirurgia , Vômito/prevenção & controle , Distribuição por Idade , Criança , Pré-Escolar , Método Duplo-Cego , Feminino , Humanos , Lactente , Masculino , Metoclopramida/uso terapêutico , Ondansetron/uso terapêutico , Período Pós-OperatórioRESUMO
BACKGROUND: To treat tracheal stenosis and permit wound healing to occur an inert stent is required which resists the contraction process and prevents re-stenosis. The newer stents of polyvinyl chloride are not readily available in India and endotracheal tubes are used in many centres. In our centre polyvinyl chloride tubes are used nasotracheally for prolonged periods. We prospectively studied the pattern of laryngeal changes that occur because of prolonged nasotracheal stenting with polyvinyl chloride tubes. METHODS: The incidence and pattern of laryngeal changes due to stents was prospectively studied at the time of removal of stents, using an operating microscope. Twenty-nine patients underwent tracheal reconstructive surgery for tracheal stenosis (post-intubation or post-tracheostomy) and tracheal injuries. RESULTS: Twelve different lesions were noted and their pattern was related to the period of stenting. Fibrosis, fibrous band formation and webs were noted after four weeks. A high incidence of laryngeal changes was seen in all age groups with an overall incidence of 79% (males 79%; females 88%; adults 82%, children 75%). The mean (SD) duration of stenting was 50 (33) days. Patients with laryngeal changes had a significantly (p < 0.05) longer duration of stenting [56 (34) days] compared to those without any lesion [29 (15) days]. CONCLUSIONS: After four weeks of stenting the severity and incidence of laryngeal changes increase. We recommend restriction of the use of polyvinyl chloride stents to less than four weeks to prevent permanent laryngeal damage.
Assuntos
Laringoestenose/terapia , Laringe/patologia , Stents/efeitos adversos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cloreto de Polivinila , Estudos Prospectivos , Fatores de TempoRESUMO
For many tRNAs, the discriminator base preceding the CCA sequence at the 3' end is important for aminoacylation. We show that the discriminator base influences the stability of the 1.72 base pair onto which it is stacked. Mutations of the discriminator base from adenosine to cytidine or uridine make the cytidine residue in the C1-G72 base pair of mutant Escherichia coli initiator tRNAs more reactive toward sodium bisulfite, the single-strand-specific reagent. The activity of the enzyme Met-tRNA transformylase toward these and other mutant initiator tRNAs is also consistent with destabilization of the 1.72 base pair in vitro and in vivo. By influencing the strength of the 1.72 base pair, the discriminator base could affect the energetic cost of opening the base pair and modulate the structure of the tRNA near the site of aminoacylation. For some aminoacyl-tRNA synthetases and other proteins that interact with tRNA, these factors could be important for specific recognition and/or formation of the transition state during catalysis.
Assuntos
Hidroximetil e Formil Transferases , RNA de Transferência de Metionina/química , Aciltransferases/metabolismo , Sequência de Bases , Ligação de Hidrogênio , Cinética , Metionina tRNA Ligase/metabolismo , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Conformação de Ácido Nucleico , Ligação Proteica , RNA de Transferência de Metionina/metabolismo , Ribonucleoproteínas/química , Relação Estrutura-Atividade , Aminoacilação de RNA de TransferênciaRESUMO
Bacteriophage lambda, having a mutation replacing glycine by glutamic acid at the 48th codon of cro, kills the host under N- conditions; we call this the hk mutation. In lambda N-N-cl-hk phage-infected bacteria, the late gene R is expressed to a significant level, phage DNA synthesis occurs with better efficiency, and the Cro activity is around 20% less, all compared to those in lambda N-N-cl-hk(+)-infected bacteria. Segments of lambda DNA from the left of pR to the right of tR2, carrying cro, cII, O, P, and the genes of the nin5 region from the above hk and hk+ phages, were cloned in pBR322. Studies with these plasmids and their derivatives having one or more of the lambda genes deleted indicate that the hk mutation is lethal only when a functional P gene is also present. When expression of P from pR is elevated, due to the deletion of tR1, host killing also occurs without the hk mutation. We conclude that the higher levels of P protein, produced either (1) when cro has the hk mutation or (2) when tR1 is deleted, are lethal to the host. We also show that due to the hk mutation, the Cro protein becomes partially defective in its negative regulation at pR, resulting in the expression of P to a lethal level even in the absence of N protein-mediated antitermination. This P protein-induced host killing depends neither on lambda DNA replication nor on any other gene functions of the phage.
Assuntos
Bacteriófago lambda/patogenicidade , Regulação Viral da Expressão Gênica , Genes Virais , Proteínas Virais/genética , Proteínas Estruturais Virais/genética , Sequência de Aminoácidos , Bacteriófago lambda/genética , Sequência de Bases , Replicação do DNA , Escherichia coli/genética , Genes Letais , Dados de Sequência Molecular , Mutação , Regiões Promotoras Genéticas , RNA Viral/genética , Transcrição Gênica , Replicação ViralRESUMO
Both spontaneous and NTG-induced mutants of Escherichia coli 594 insensitive to the lethal action of lambda P gene were isolated and called rpl (resistant to P lethality). These mutants were of two types, showing different phenotypes. On type I rpl mutants, lambda cl- and lambda v1v3 did not plate, while lambda vir, lambda cl- c17, lambda imm434, and lambda imm21 did; plasmid pMR45 carrying the lambda P gene could not complement lambda imm21P- phage in type I mutants. On the other hand, the type II rpl mutants support the growth of all the above phages including lambda cl-. Neither type of rpl mutation affects growth of the bacteria.
Assuntos
Bacteriófago lambda/genética , Escherichia coli/genética , Genes Virais , Proteínas Estruturais Virais/genética , Bacteriófago lambda/patogenicidade , Genes Letais , Replicação ViralRESUMO
The theoretical prediction of induction of metachromasia [V Czikkely, H D Foersterling & H Kuhn (1970), Chem Phys Lett, 6,207] in a dye by a polyanion having only four to six anionic sites is proved experimentally, for the first time, in ATP--1.9-dimethyl methylene blue system. The findings show that ATP induces metachromasia in the dye at neutral pH, when ATP molecule remains fully charged providing four anionic sites to the dye cations. Conductometric titration shows that the dye molecules bind stoichiometrically to ATP (four dyes/ATP). However ATP at acidic pH and ADP and AMP at any pH fail to induce metachromasia. This is also the first report of induction of circular dichroism in bound dyes by ATP. Though the chiral moiety of ribose sugar in ATP may induce dichroism in the bound achiral dyes, the observed high molar ellipticity values indicate aggregation of bound dyes with twist in one sense initiated by the twisted conformation of the triphosphate chain in ATP. This inference on the state of conformation of ATP in its native environment is in agreement with that derived from PMR and spin lattice relaxation technique. It is thus interesting that the conformation of crystalline disodium ATP, as concluded from X-ray crystallography, is maintained by tetrasodium ATP in dilute aqueous solution--the native environment of ATP.