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1.
Lancet Reg Health Southeast Asia ; 16: 100235, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37694177

RESUMO

Background: Childhood cancers are emerging as an essential concern in India where there is lack of a specific programme component or policy to address childhood cancer control. There is limited information on the status and quality of childhood cancer care services in India. This paper describes the childhood cancer care services available at secondary and tertiary-level hospitals in India through a cross sectional study design. Methods: The survey was conducted in 137 tertiary-level and 92 secondary-level hospitals in 26 states and 4 Union Territories (UTs), ensuring a uniform representation of public and private care hospitals. The study tool collected data on the organisational infrastructure, type of oncology services, health workforce, equipment, treatment and referral protocols, and treatment guidelines. Descriptive statistics was used to primarily present the health service status and data on childhood cancer care services in proportions and mean. Findings: A dedicated pediatric oncology department was available in 41.6% of the public, 48.6% of private, and 64% Non Government Organization (NGO) managed tertiary-level hospitals. In 36 (39%) of the 92 hospitals providing secondary care, childhood cancer care was provided. The availability of bone (41.5%) and positron emission tomography (PET) scans (25.9%) was lower in public tertiary hospitals, whereas histopathology, computerised tomography (CT scan), and magnetic resonance imaging (MRI) were lower in public secondary hospitals than private and NGO managed hospitals for the corresponding level of care. Most tertiary hospitals had the required supportive care facilities except for play therapy and hospice care. Less than 50% of the public tertiary hospitals had stocks of the four categories of cancer-treating drugs and essential infrastructure for radiotherapy and chemotherapy. Most secondary-level hospitals not treating childhood cancer had referral linkages with tertiary hospitals. Interpretation: The situational analysis of childhood cancer care services in India showed the concentration of availability of childhood cancer care services at the tertiary level of health care. There were gaps in the availability of specialised pediatric oncology care in all the tertiary hospitals. The availability of childhood cancer care services was higher in private and NGO-managed hospitals than in public hospitals. Integration of childhood cancer as a part of the national cancer control response should be taken up as a matter of priority. The need of the hour is to formulate a childhood cancer policy that will enable timely access to care universally. Funding: World Health Organization, India provided funding and technical support.

2.
Kathmandu Univ Med J (KUMJ) ; 20(79): 273-279, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37042365

RESUMO

Background The burden and complication of hypertension is increasing as most of the people living with hypertension are unaware of their condition and those who are already diagnosed with it do not have their blood pressure under control. Objective To assess the prevalence of undiagnosed and uncontrolled hypertension among residents of Itahari sub metropolitan city of eastern Nepal, along with its associated socio demographic and behavioral risk factors and access to health care services. Method Cross sectional study was conducted in five wards of Itahari, among 1161 participants, using population proportionate to sample size sampling technique. Face to face interview was conducted with participants for data collection applying semi- structured questionnaire and physical measurement like blood pressure, weight and height. Result Prevalence of hypertension was 26.5% includingundiagnosed 11.0% and previously diagnosed 15.5%. Among diagnosed, 76.6% had uncontrolled blood pressure and 56.70% were taking anti-hypertensive medicine, and 7.8% were under Ayurvedic medicine. More than 70% participants preferred private health facility for treatment and 22.7% had faced financial barrier to seek healthcare. About 64% of participants did not visit health services or had visited only once in past six months. Increasing age, Body Mass Index (BMI), smoking status and positive family history were found to be significantly associated with hypertension at < 0.05 level. Conclusion Prevalence of hypertension is high and awareness regarding available health services in local primary health center and its utilization is lacking among participants. Regular screening program for hypertension and awareness program to disseminate the knowledge of availability of primary health center should be conducted.


Assuntos
Hipertensão , Humanos , Estudos Transversais , Nepal/epidemiologia , Hipertensão/diagnóstico , Acessibilidade aos Serviços de Saúde , Instalações de Saúde
3.
Int Immunopharmacol ; 44: 123-136, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28092864

RESUMO

Hippophae rhamnoides L. commonly known as Seabuckthorn (SBT), a wild shrub of family Elaegnacea, has extensively used for treating various ailments like skin diseases, jaundice, asthma, lung troubles. SBT leaves have been reported to possess several pharmacological properties including immunomodulatory, antioxidant, anti-inflammatory, antimicrobial and tissue regeneration etc. The present study was undertaken to evaluate the adjuvant property of supercritical carbon dioxide extracts (SCEs 300ET and 350ET) of SBT leaves in balb/c mice immunized with Tetanus and Diphtheria toxoids. The dynamic changes in the immune response were measured in terms of humoral and cell-mediated immune responses. We have seen the effect of SCEs on immunoglobulin subtypes and secondary immune response generation. In addition, the effect of SCEs on antigen specific cellular immunity was evaluated. Our results show that SCEs 300ET and 350ET significantly enhanced antibody titers in response to both TT and DT antigens. The secondary immune response generated was significantly increased in case of TT immunized animals. SCEs also enhanced cytokine levels (IFN-γ, IL-4, TNF-α and IL-1ß) and increased lymphoproliferation. Besides, both SCEs did not show any toxic effects. Therefore, the study suggests that SCEs are safe and have potent immunostimulatory activity and hence, seems to be a promising balanced Th1 and Th2 directing immunological adjuvant for various veterinary as well as human vaccines.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Toxoide Diftérico/imunologia , Difteria/imunologia , Hippophae/imunologia , Extratos Vegetais/administração & dosagem , Toxoide Tetânico/imunologia , Tétano/imunologia , Animais , Citocinas/imunologia , Difteria/prevenção & controle , Feminino , Humanos , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral , Imunização Secundária , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Folhas de Planta , Tétano/prevenção & controle
4.
Neuroscience ; 337: 107-116, 2016 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-27623393

RESUMO

Sleep deprivation (SD) upsurges intracellular levels of adenosine, impairs adult neuronal cell proliferation (NCP) and cognition while caffeine, a non-selective adenosine A1 receptor (A1R) antagonist improves cognition and adult NCP during SD. We examined the selective antagonistic effects of adenosine A1R using 8-cyclopentyl-1,3-dimethylxanthine (8-CPT) on impairment of spatial reference memory and adult NCP during 48h SD. Adult male Sprague Dawley rats were sleep deprived for 48h, using an automatic cage vibrating stimulus based on animal activity. Spatial reference memory was tested as a measure of cognitive performance employing Morris Water Maze. Rats were given 8-CPT dissolved in 50% dimethyl sulfoxide (DMSO), twice daily (10mg/kg, i.p.) along with 5-bromo-2-deoxyuridine (BrdU) (50mg/kg/day, i.p.). The rats treated with 8-CPT showed significantly short mean latency and path-length to reach the platform compared to the SD rats. Consistent with these findings, 8-CPT-treated group was found to have significantly increased the number of BrdU, Ki-67 and doublecortin (DCX) positive cells. However, no significant difference was seen in NeuN expression in the Dentate Gyrus (DG). Brain-derived neurotropic factor (BDNF) expression in the DG and CA1 region was observed to decrease significantly after SD and be rescued by 8-CPT treatment. Furthermore, latency to reach platform showed a negative correlation with number of BrdU, DCX type-1 cells and BDNF expression in DG. Thus, it may be concluded that treatment with 8-CPT, an adenosine A1R antagonist during SD mitigates SD induced decline in spatial reference memory and adult NCP possibly via up regulation of BDNF levels in DG and CA1 regions.


Assuntos
Antagonistas do Receptor A1 de Adenosina/farmacologia , Hipocampo/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Receptor A1 de Adenosina/metabolismo , Privação do Sono/metabolismo , Memória Espacial/efeitos dos fármacos , Envelhecimento , Animais , Cafeína/farmacologia , Proteína Duplacortina , Hipocampo/metabolismo , Masculino , Ratos Sprague-Dawley , Memória Espacial/fisiologia
5.
Biometals ; 28(1): 175-85, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25511110

RESUMO

The hypoxic preconditioning of mammalian cells has been shown to have beneficial effects against hypoxic injuries. However, very little information is available on the comparative analysis of immunological responses to hypoxic and hypoxia mimetic exposure. Therefore, in the present study, mouse peritoneal macrophages and splenocytes were subjected to hypoxia exposure (0.5 % O2) and hypoxia mimetic Cobalt chloride (CoCl2) treatment to evaluate their effect on immune response and delineate the underlying signaling mechanisms. The results obtained indicated that super oxide generation increased while TLR4 expression and cell surface markers like CD25, CD40 and CD69 were suppressed in both the treatments as compared to normoxia. Cobalt chloride treatment increased NF-κB expression, nitric oxide (NO) and iNOS expression, cytokines TNF-α and IL-6 as compared to hypoxia exposure. Our study showed that CoCl2 stabilizes HIF-1α to create hypoxia like conditions but it mainly influences the inflammatory response via NF-κB signaling pathway by skewing the production of proinflammatory molecules like TNF-α, IL-6 and NO.


Assuntos
Hipóxia Celular/fisiologia , Cobalto/farmacologia , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Antígenos CD40/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Interleucina-6/metabolismo , Lectinas Tipo C/metabolismo , Camundongos , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
6.
Mater Sci Eng C Mater Biol Appl ; 46: 62-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25491960

RESUMO

Cell proliferation, cell morphology and protein adsorption on near ß-type Ti-13Zr-13Nb (TZN) alloy and Ti-13Zr-13Nb-0.5B (TZNB) composite have been investigated and compared to evaluate the effect of boron addition which has been added to the Ti alloy to improve their poor tribological properties by forming in situ TiB precipitates. MG63 cell proliferation on substrates with different chemistry but the same topography was compared. The MTT assay test showed that the cell viability on the TZN alloy was higher than the boron containing TZNB composite after 36 h of incubation and the difference was pronounced after 7 days. However, both the materials showed substantially higher cell attachment than the control (polystyrene). For the same period of incubation in fetal bovine serum (FBS), the amount of protein adsorbed on the surface of boron free TZN samples was higher than that in the case of boron containing TZNB composite. The presence of boron in the TZN alloy influenced protein adsorption and cell response and they are lower in TZNB than in TZN as a result of the associated difference in chemical characteristics.


Assuntos
Materiais Biocompatíveis/farmacologia , Boro/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Titânio/química , Adsorção , Materiais Biocompatíveis/química , Boro/química , Linhagem Celular Tumoral , Humanos , Proteínas/metabolismo , Propriedades de Superfície
7.
Indian J Med Res ; 140(4): 520-3, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25488446

RESUMO

BACKGROUND & OBJECTIVES: Immune activation and inflammation play critical roles in the stressful environmental conditions like high altitude, extreme cold, etc. Human leukocyte antigen-G (HLA-G) is a non classical major histocompatiblity complex class I (MHC class- I) protein, upregulated in the context of transplantation, malignancy and inflammation. We hypothesized serum HLA-G as a possible stress biomarker and studied levels of soluble form of HLA-G (sHLA-G) in Indian Antarctic expeditioners. METHODS: sHLA-G ELISA was performed in the serum of summer (n=27) and winter (n=22) Indian Antarctic expeditioners. The summer expeditioners were evaluated at three different time points, i.e. before leaving India, after one month ship borne journey, and after staying one month at Indian research base, Maitri in Antarctica, while winter expeditioners were evaluated at five different time points, i.e. before leaving India, and in the month of March, May, August and November at Antarctica. RESULTS: o0 ne month ship borne journey did not cause any significant change in the sHLA-G level as compared to the baseline level of the summer expeditioners. sHLA-G levels were not changed significantly in the months of March, May, August and November as compared to the baseline level of the winter expeditioners. INTERPRETATION & CONCLUSIONS: Our results indicated that the extreme conditions of Antarctica did not cause any significant change in the sHLA-G level in both summer and winter expeditioners.


Assuntos
Biomarcadores/sangue , Antígenos HLA/sangue , Antígenos HLA-G/sangue , Estresse Fisiológico , Adulto , Regiões Antárticas , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Estações do Ano
8.
Int Immunopharmacol ; 20(1): 89-94, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24594274

RESUMO

Endotoxins from infectious organisms lead to sepsis, a systemic inflammatory response, and a major cause of death. Numerous studies have shown the potential role of plants and plant-derived compounds in the suppression of LPS induced endotoxemia in vivo. In the present study, we have identified a plant namely Seabuckthorn (Hippophae rhamnoides L.) as a potent agent for the treatment of endotoxemia. The objective of the study was to investigate the influence of Supercritical Extract of Seabuckthorn Leaves (SCE200ET) and its active component Isorhamnetin (IR) on the LPS induced endotoxemia in Balb/c mice by measuring the level of nitric oxide (NO), TNF-α and IL-6. Expression of COX-2 and iNOS was measured to understand the involvement of various pathways in the mechanism of action of SCE200ET and IR. The results indicated that SCE200ET and IR inhibited LPS induced NO production by peritoneal macrophages. Cytokines mediated effector functions were influenced by the reduction of IL-6 and TNF-α production and CD40 expression was also markedly diminished in the extract or IR treated groups. In addition, the anti-inflammatory properties were further characterized by decreased expression of COX-2 and iNOS proteins. Fractionation and phytochemical analysis of the extract by RP-HPLC led to identification of isorhamnetin, as bioactive component. Thus, SCE200ET extract and its active component Isorhamnetin could be potential therapeutic agents for the treatment of endotoxin induced sepsis.


Assuntos
Anti-Inflamatórios/farmacologia , Endotoxemia/imunologia , Hippophae , Extratos Vegetais/farmacologia , Quercetina/análogos & derivados , Animais , Anti-Inflamatórios/uso terapêutico , Antígenos CD40/imunologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ciclo-Oxigenase 2/imunologia , Endotoxemia/tratamento farmacológico , Feminino , Interleucina-6/imunologia , Lipopolissacarídeos , Macrófagos Peritoneais/imunologia , Camundongos Endogâmicos BALB C , Óxido Nítrico/imunologia , Óxido Nítrico Sintase Tipo II/imunologia , Fitoterapia , Extratos Vegetais/uso terapêutico , Folhas de Planta , Quercetina/farmacologia , Quercetina/uso terapêutico , Baço/citologia , Fator de Necrose Tumoral alfa/imunologia
9.
Arch Virol ; 159(8): 1975-86, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24590566

RESUMO

Recognition of virus infection by retinoic acid-inducible gene (RIG) I and melanoma differentiation-associated protein (MDA) 5, which are RNA helicases, and interferon-stimulated gene (ISG) 15 activates cascades of signal transduction pathways leading to production of type I interferons and proinflammatory cytokines that orchestrate the elimination of the viruses. However, it has been demonstrated that RNA-helicase-mediated innate immunity plays an essential role in defending the host from infection. In our efforts to identify plant-derived antivirals that selectively enhance ISG- and RNA-helicase-mediated antiviral immune responses, we identified a plant, rhodiola, that significantly promoted ISG, RIG-I and MDA 5 gene expression and an antiviral immune response against dengue virus (DENV) infection. Rhodiola induced interferon (IFN) ß and other cytokines, including IL-1ß, TNF-α, IL-6 and IL-8, in infected cells. It was also found that rhodiola upregulated phosphorylated eIF-2α, PKR and NF-kB in infected cells. In addition, the number of NK cells was also increased by rhodiola treatment in dengue-virus-infected human PBMCs. Treatment with a crude extract of rhodiola (RAE) resulted in effects in the 20 % range, which is similar to the magnitude of the same effects observed in DENV infections. Taken together, our results imply that rhodiola induces pharmacological modulation of RIG-I, MDA 5 and ISG signal transduction pathways in favor of the induction of a beneficial antiviral immune response against dengue virus, which can be a novel therapeutic strategy for management of infection.


Assuntos
Citocinas/genética , RNA Helicases DEAD-box/genética , Vírus da Dengue/efeitos dos fármacos , Dengue/imunologia , Extratos Vegetais/farmacologia , Rhodiola/química , Ubiquitinas/genética , Replicação Viral/efeitos dos fármacos , Antivirais/farmacologia , Citocinas/imunologia , Proteína DEAD-box 58 , RNA Helicases DEAD-box/imunologia , Dengue/tratamento farmacológico , Dengue/genética , Dengue/virologia , Vírus da Dengue/fisiologia , Humanos , Imunidade Inata/efeitos dos fármacos , Helicase IFIH1 Induzida por Interferon , Monócitos/imunologia , Monócitos/virologia , Receptores Imunológicos , Rizoma/química , Ubiquitinas/imunologia , Regulação para Cima/efeitos dos fármacos
10.
J Mech Behav Biomed Mater ; 10: 1-12, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22520414

RESUMO

The effect of heat treatment on the mechanical properties of Ti-35Nb-5.7Ta-7.2Zr (TNZT) and Ti-35Nb-5.7Ta-7.2Zr-0.5B (TNZTB) alloys has been investigated. In the case of TNZT alloy, the presence of ω phase in the matrix has a greater effect on strength and hardness than the presence of secondary α precipitates. The TNZTB alloy shows higher hardness and tensile strength than the TNZT alloy due to the formation of hard TiB precipitates in the matrix of the former. However, the boron free alloy offers higher ductility than the boron containing alloy. Presence of TiB precipitates in the matrix increases the strength of the TNZTB alloy when ω precipitates are present in the matrix. However, the boride precipitates have no substantial influence on the strength of the TNZTB alloy when ω phase in the matrix is replaced by the α phase. The elastic modulus of the TNZT samples shows a very small variation with different heat treatment conditions. The TNZT alloy samples containing ß and ω phases show higher elastic modulus than the samples containing ß and α phases. The elastic modulus of the TNZTB alloy is higher than that of the TNZT alloy due to the formation of high modulus TiB particles in the matrix. Both the alloys show better cell adhesion and spreading than the control material (polystyrene). However, the boron free Ti-alloy shows better cell attachment than the boron containing Ti-alloy.


Assuntos
Ligas/química , Materiais Biocompatíveis/química , Compostos de Boro/química , Temperatura Alta , Fenômenos Mecânicos , Titânio/química , Materiais Biocompatíveis/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Módulo de Elasticidade , Dureza , Humanos , Resistência à Tração
11.
J Food Sci ; 77(2): C156-61, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22225422

RESUMO

The aim of this study was to evaluate the in vitro antioxidant potential of hydro-ethanolic extract of a novel phytococktail comprising of sea buckthorn, apricot, and Rhodiola (SAR) from trans-Himalaya. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) activity of the extract increased in a dose-dependent manner (upto 0.1 mg/mL), and was found to be about 38% of that of ascorbic acid at 0.1 mg/mL. The hydro-ethanolic extract of SAR also scavenged the ABTS(.+) radical generated by ABTS/potassium persulfate (PPS) system and was found to be about 62% of that of ascorbic acid at 0.1 mg/ mL. The total antioxidant power of the extract was determined by ferric reducing antioxidant power (FRAP) assay. Total phenolic content was found to be 1.28016 × 10(-3) mol gallic acid equivalent (GAE)/g extract. Total flavonoid and flavonol contents were estimated to be 2.5970 × 10(-4) mol and 4.87 × 10(-4) mol quercetin equivalent/g extract, respectively. The hydro-ethanolic extract of this phytococktail indicated presence of essential phytoconstituents of polyphenols, flavonoids, flavonols, and ascorbic acid, which contributed significantly to its antioxidant capacity. The combination of the 3 plants may well support their use in traditional medicine to combat oxidative stress and high-altitude sickness.


Assuntos
Antioxidantes/farmacologia , Frutas/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Ácido Ascórbico/metabolismo , Benzotiazóis/metabolismo , Etanol/química , Ácido Gálico/metabolismo , Hippophae/química , Prunus/química , Rhodiola/química , Ácidos Sulfônicos/metabolismo
12.
Immunopharmacol Immunotoxicol ; 34(3): 513-8, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22239552

RESUMO

In the present study, we have evaluated the anti-cellular and immunomodulatory potential of aqueous extract of Rhodiola imbricata rhizome (RAE). Rhodiola extract inhibited the proliferation of human T cell lymphoma cell line EL-4 and erythroleukemic cell line HL-60. Furthermore, treatment of human peripheral blood mononuclear cells (hPBMCs) with lipopolysaccharide (LPS) and RAE suppressed regulated upon activation, normal T cell expressed and secreted (RANTES) production. However, number of TNF-α spots was increased in RAE treated hPBMCs. The reverse transcriptase polymerase chain reaction (RT-PCR) analysis of RAE treated rat splenocytes confirmed the up regulation of TLR-4 mRNA expression. Therefore, the present study concludes that RAE has potent immune boosting activity which might be useful in immunocompromised individuals.


Assuntos
Leucócitos Mononucleares/metabolismo , Extratos Vegetais/farmacologia , Rizoma/química , Rhodiola/química , Animais , Quimiocina CCL5/biossíntese , Quimiocina CCL5/imunologia , Células HL-60 , Humanos , Leucócitos Mononucleares/imunologia , Lipopolissacarídeos/farmacologia , Masculino , Extratos Vegetais/química , RNA Mensageiro/biossíntese , RNA Mensageiro/imunologia , Ratos , Ratos Sprague-Dawley , Receptor 4 Toll-Like/biossíntese , Receptor 4 Toll-Like/imunologia , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/imunologia
13.
Respir Physiol Neurobiol ; 178(2): 329-36, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21787887

RESUMO

To investigate whether there is a change in airway rapidly adapting receptor (RAR) activity during high altitude exposure, rabbits were placed in a high altitude simulation chamber (barometric pressure, 429 mm Hg). With 12 h exposure, when there was pulmonary congestion, an increase in basal RAR activity was observed. With 36 h exposure, when there was alveolar edema, there was a further increase in basal RAR activity. In these backgrounds, there was an increase in the sensitivity of the RARs to substance P (SP). To assess whether there was an increase in lung SP level, neutral endopeptidase activity was determined which showed a decrease in low barometric pressure exposed groups. It is concluded that along with the SP released, pulmonary congestion and edema produced, respectively by different durations of low barometric pressure exposure cause a progressive increase in RAR activity which may account for the respiratory symptoms reported in climbers who are unacclimatized.


Assuntos
Adaptação Fisiológica/fisiologia , Doença da Altitude/metabolismo , Pressão Atmosférica , Receptores Pulmonares de Alongamento/metabolismo , Substância P/fisiologia , Doença da Altitude/patologia , Animais , Neprilisina/biossíntese , Receptores Pulmonares de Alongamento/fisiologia , Coelhos , Células Receptoras Sensoriais/enzimologia , Células Receptoras Sensoriais/metabolismo , Substância P/metabolismo
14.
Neuroscience ; 161(2): 501-14, 2009 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-19318118

RESUMO

Exposure to hypobaric hypoxia, a condition involving decreased availability of oxygen is known to be associated with oxidative stress, neurodegeneration and memory impairment. The multifactorial response of the brain and the complex signaling pathways involved therewith limits the therapeutic efficacy of several antioxidants in ameliorating hypobaric hypoxia-induced memory impairment. The present study was therefore aimed at investigating the potential of acetyl-l-carnitine (ALCAR), a known antioxidant that has been reported to augment neurotrophin-mediated survival mechanisms, in ameliorating hypoxia-induced neurodegeneration and memory impairment. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor involved in the cellular defense mechanism against oxidative stress related to brain injury and neurological disorders. The study was designed to understand the mechanisms involving Nrf2 stabilization following exposure to hypobaric hypoxia. The results displayed reference memory impairment in Sprague-Dawley rats exposed to hypobaric hypoxia (7620 m) for 14 consecutive days which however improved on administration of ALCAR during hypoxic exposure. The study also revealed Nrf2 regulated augmented antioxidant response on administration of ALCAR which was through a novel tyrosine kinase A (TrkA) receptor-mediated mechanism. A decrease in free radical generation, lipid peroxidation and protein oxidation was also observed along with a concomitant increase in thioredoxin and reduced glutathione levels on administration of ALCAR during exposure to hypobaric hypoxia. The present study therefore reveals the therapeutic potential of ALCAR under conditions of hypobaric hypoxia and elucidates a novel mechanism of action of the drug.


Assuntos
Acetilcarnitina/farmacologia , Altitude , Antioxidantes/farmacologia , Hipóxia/prevenção & controle , Memória/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Acetilcarnitina/uso terapêutico , Animais , Antioxidantes/uso terapêutico , Espaço Extracelular/metabolismo , Hipocampo/patologia , Hipóxia/patologia , Hipóxia/fisiopatologia , Masculino , Aprendizagem em Labirinto , Neurônios/metabolismo , Neurônios/patologia , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/fisiologia , Fosforilação , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Receptor trkA/biossíntese , Tiorredoxinas/biossíntese
15.
Physiol Behav ; 92(4): 643-50, 2007 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-17602713

RESUMO

Exposure to high altitude (HA), especially extreme altitude, is associated with impairment of cognitive functions including memory and increased oxidative stress. However, the underlying mechanisms involved are not well understood. It is hypothesized that HA induced oxidative stress may be one of the factors underlying hypoxia induced memory impairment. The aim of the present study was to investigate the effect of hypobaric hypoxia (HH) on spatial working and reference memory functions, oxidative stress markers in rats and effect of supplementation of N-acetyl cysteine (NAC). The rats were divided into four groups. Group I served as normoxic (n=6), Group II served as hypoxic (n=6), Group III as hypoxia group treated with NAC (n=6) and Group IV served as normoxic group treated with NAC (n=6). Group II & III were exposed to HH for 3 days equivalent to 6100 m and received oral NAC supplementation (750 mg/kg) daily. Rats from all the groups were trained in Morris Water Maze (MWM) task for 8 consecutive days. Spatial working and reference memory were tested immediately after the termination of HH and then the rats were sacrificed for estimation of oxidative stress markers in hippocampus. Rats displayed significant deficits in spatial working memory, and increased oxidative stress along with decrease in antioxidant status on hypoxic exposure. Supplementation with NAC in hypoxia-exposed group improved spatial memory performance, and decreased oxidative stress. These findings indicate that hypoxic exposure is associated with increased oxidative stress, which may have caused memory deficit in rats exposed to simulated HA.


Assuntos
Acetilcisteína/farmacologia , Doença da Altitude/tratamento farmacológico , Aprendizagem em Labirinto/efeitos dos fármacos , Memória de Curto Prazo/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Acetilcisteína/metabolismo , Doença da Altitude/metabolismo , Doença da Altitude/fisiopatologia , Análise de Variância , Animais , Pressão Atmosférica , Suplementos Nutricionais , Radicais Livres/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipóxia/tratamento farmacológico , Hipóxia/metabolismo , Masculino , Aprendizagem em Labirinto/fisiologia , Memória de Curto Prazo/fisiologia , Fármacos Neuroprotetores/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Consumo de Oxigênio , Ratos , Ratos Sprague-Dawley , Percepção Espacial/efeitos dos fármacos , Percepção Espacial/fisiologia
16.
Brain Res ; 1046(1-2): 97-104, 2005 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-15919066

RESUMO

Hippocampus has received a considerable attention in the recent past due to its role in a number of important functions such as learning and memory. The effect of hypoxia on neuronal cell injury especially on hippocampal cells is not well known. The aim of the present study was to characterize the biochemical changes in primary cultured hippocampal neurons during hypoxic exposure and the protective effect of N-acetyl cysteine on hypoxia-induced cytotoxicity. The hippocampal culture grown in 24-well plates was exposed to hypoxia for 3 h in a dessicator in 95% N(2), 5% CO(2) atmosphere at 37 degrees C. Later, the cells were allowed to recover for 1 h under normoxia. It was observed that there is an appreciable increase in cytotoxicity in cells exposed to hypoxia. Further, there was a significant decrease in mitochondrial membrane potential and appreciable increase in reactive oxygen species and single-strand DNA breaks in cells exposed to hypoxia compared to control. There is a significant fall in glutathione peroxidase, glutathione reductase, reduced glutathione levels, and nitric oxide in the cells exposed to hypoxia. Significant elevation in the intracellular calcium level in the cells on exposure to hypoxia was observed. Supplementation with NAC (50 microM) resulted in a significant cytoprotection, fall in ROS generation, and higher antioxidant levels similar to that of control cells. NAC also inhibited DNA strand breaks induced by hypoxia. The study indicates that NAC has significant neuroprotective activity during hypoxia in primary hippocampal culture.


Assuntos
Acetilcisteína/farmacologia , Hipocampo/metabolismo , Hipóxia/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/fisiologia , Animais , Antioxidantes/metabolismo , Morte Celular/fisiologia , Células Cultivadas , Fragmentação do DNA/fisiologia , Radicais Livres/metabolismo , Hipocampo/citologia , Hipóxia/tratamento farmacológico , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
17.
Bioorg Med Chem Lett ; 11(24): 3143-6, 2001 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-11720861

RESUMO

2-Methoxystypandrone, a naphthoquinone, was isolated from a Chinese herb Polygonum cuspidatum by bioassay guided fractionation using HRV 3C-protease assay. It showed an IC(50) value of 4.6 microM and is moderately selective. A new 10-step, total synthesis of 2-methoxystypandrone was accomplished in 45% overall yield using a Diels-Alder approach. Several analogues of this compound were prepared. Isolation, synthesis and HRV 3C-protease structure-activity relationships of these compounds have been described.


Assuntos
Naftoquinonas/síntese química , Naftoquinonas/isolamento & purificação , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , Proteínas Virais/antagonistas & inibidores , Proteases Virais 3C , Cisteína Endopeptidases , Naftoquinonas/química , Inibidores de Proteases/química , Relação Estrutura-Atividade
18.
J Chem Inf Comput Sci ; 41(5): 1395-406, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11604041

RESUMO

Similarity searches based on chemical descriptors have proven extremely useful in aiding large-scale drug screening. Typically an investigator starts with a "probe", a drug-like molecule with an interesting biological activity, and searches a database to find similar compounds. In some projects, however, the only known actives are peptides, and the investigator needs to identify drug-like actives. 3D similarity methods are able to help in this endeavor but suffer from the necessity of having to specify the active conformation of the probe, something that is not always possible at the beginning of a project. Also, 3D methods are slow and are complicated by the need to generate low-energy conformations. In contrast, topological methods are relatively rapid and do not depend on conformation. However, unmodified topological similarity methods, given a peptide probe, will preferentially select other peptides from a database. In this paper we show some simple protocols that, if used with a standard topological similarity search method, are sufficient to select nonpeptide actives given a peptide probe. We demonstrate these protocols by using 10 peptide-like probes to select appropriate nonpeptide actives from the MDDR database.


Assuntos
Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Peptídeos/química , Simulação por Computador , Bases de Dados de Proteínas , Avaliação Pré-Clínica de Medicamentos/estatística & dados numéricos , Estrutura Molecular
19.
J Biol Chem ; 276(48): 45207-16, 2001 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-11487585

RESUMO

B cell linker protein (BLNK) is a SLP-76-related adaptor protein essential for signal transduction from the BCR. To identify components of BLNK-associated signaling pathways, we performed a phosphorylation-dependent yeast two-hybrid analysis using BLNK probes. Here we report that the serine/threonine kinase hematopoietic progenitor kinase 1 (HPK1), which is activated upon antigen-receptor stimulation and which has been implicated in the regulation of MAP kinase pathways, interacts physically and functionally with BLNK in B cells and with SLP-76 in T cells. This interaction requires Tyr(379) of HPK1 and the Src homology 2 (SH2) domain of BLNK/SLP-76. Via homology modeling, we defined a consensus binding site within ligands for SLP family SH2 domains. We further demonstrate that the SH2 domain of SLP-76 participates in the regulation of AP-1 and NFAT activation in response to T cell receptor (TCR) stimulation and that HPK1 inhibits AP-1 activation in a manner partially dependent on its interaction with SLP-76. Our data are consistent with a model in which full activation of HPK1 requires its own phosphorylation on tyrosine and subsequent interaction with adaptors of the SLP family, providing a mechanistic basis for the integration of this kinase into antigen receptor signaling cascades.


Assuntos
Proteínas de Transporte/metabolismo , Linfócitos/metabolismo , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Sítios de Ligação , Linhagem Celular , DNA Complementar/metabolismo , Bases de Dados como Assunto , Ativação Enzimática , Humanos , Immunoblotting , Células Jurkat , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Mutação , Testes de Precipitina , Ligação Proteica , Estrutura Terciária de Proteína , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Linfócitos T/metabolismo , Fator de Transcrição AP-1/metabolismo , Técnicas do Sistema de Duplo-Híbrido , Regulação para Cima , Domínios de Homologia de src
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