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1.
Neurol India ; 65(5): 1001-1005, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28879885

RESUMO

BACKGROUND: Guillain-Barré syndrome (GBS) and its subtypes are associated with distinct anti-ganglioside antibodies. Hence, we aimed to determine the frequency of anti-ganglioside antibodies and its correlation with clinical features, electrophysiological patterns, and outcome in patients with GBS. MATERIAL AND METHODS: The data regarding clinical features, electrophysiological patterns, and outcome at 6 months were collected and analyzed from the case records of patients diagnosed with GBS during 2008-2013 at a tertiary care hospital in south India. RESULTS: A total of 204 patients with GBS were studied, and 73 patients (mean age: 37.6 ± 17.5 years) who underwent anti-ganglioside antibody testing were analyzed. Male-to-female ratio was 2.5:1. IgG anti-ganglioside antibodies were positive in 41/73 patients. The most common IgG anti-ganglioside antibody observed in the acute demyelinating variant was anti-GT1b (n = 13; 17.8%), and, those in the acute axonal variant were anti-GM1, anti-GM2, anti-GD1b, and anti-GT1b antibodies (n = 9;12.3% each). Three patients died and 5 patients were unable to walk independently at the end of 6 months. CONCLUSIONS: The frequency of anti-ganglioside antibodies in our cohort with GBS was 56%, with IgG anti-GT1b antibody being the most common. The anti-ganglioside antibodies were significantly positive in acute motor axonal neuropathy (AMAN) subtype of GBS. The presence of anti-ganglioside antibodies was not found to be of significant use in predicting the outcome. Although it was observed that the absence, and not the presence, of anti-ganglioside antibodies was associated with antecedent infection, dysautonomia, and requirement of ventilator support, the overall disease severity was not antibody dependant.


Assuntos
Autoanticorpos/imunologia , Autoantígenos/imunologia , Gangliosídeos/imunologia , Síndrome de Guillain-Barré/imunologia , Síndrome de Guillain-Barré/fisiopatologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
2.
Indian J Med Res ; 143(6): 793-797, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27748304

RESUMO

BACKGROUND & OBJECTIVES: Ingestion of Cleistanthus collinus causes hypokalemia and cardiac arrhythmias leading to mortality in most cases. We undertook this retrospective study to evaluate the clinical presentation and predictors of outcome in critically ill patients admitted with C. collinus poisoning. METHODS: The case records of 56 patients admitted to the medical intensive care unit (MICU) of a tertiary care teaching hospital in south India (2000-2014) with C. collinus poisoning were retrospectively analysed. RESULTS: The mean age of patients was 36.7±13.3 yr; there were 30 males. Salient clinical manifestations included hypokalemia (58%), neutrophilic leucocytosis (48.2%), acute kidney injury (AKI) (42.9%), acute respiratory failure requiring mechanical ventilation (AcRFMv) (32.1%), shock (21.4%); cardiac arrhythmias and neuromuscular weakness (19.6% each); 21 patients (37.5%) had adverse outcome. Longer time-lapsed from consumption to reaching emergency room [median (interquartile range)] (hours) [49 (22-97) vs. 28 (7-56), p =0.0380 ]; higher acute physiology and chronic health evaluation II (APACHE II) score at presentation [14 (8.25-14.75) vs. 2 (0-6) P<0.001]; and presence of the following [odds ratio (95% confidence intervals)] at initial presentation: shock [37.40 (4.29-325.98), P=0.001]; AcRFMv [26.67 (5.86-121.39), P<0.001]; elevated alanine aminotransferase [5.71 (1.30-25.03), p0 =0.021]; metabolic acidosis [5.48 (1.68-17.89), P=0.005]; acute kidney injury (AKI) [5 (1.55-16.06), P=0.007]; hyponatremia [4.67 (1.25-17.44), P=0.022]; and neutrophilic leucocytosis [3.80 (1.02-14.21), P=0.047] predicted death. A significant (P<0.001) increasing trend in mortality was observed with increasing International Program on Chemical Safety Poisoning Severity Score (IPCS-CSS) grade. INTERPRETATION & CONCLUSIONS: C. collinus is a lethal poison associated with high mortality for which there is no specific antidote. Careful search and meticulous monitoring of the predictors of death and initiating appropriate corrective measures can be life saving.


Assuntos
Injúria Renal Aguda/fisiopatologia , Arritmias Cardíacas/fisiopatologia , Euphorbiaceae/toxicidade , Hipopotassemia/fisiopatologia , Intoxicação por Plantas/fisiopatologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Índia , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Centros de Atenção Terciária
3.
Opt Express ; 22(10): 12238-47, 2014 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-24921342

RESUMO

An insulator-metal-insulator plasmonic interconnect using TiN, a CMOS-compatible material, is proposed and investigated experimentally at the telecommunication wavelength of 1.55 µm. The TiN waveguide was shown to obtain propagation losses less than 0.8 dB/mm with a mode size of 9.8 µm on sapphire, which agree well with theoretical predictions. A theoretical analysis of a solid-state structure using Si(3)N(4) superstrates and ultra-thin metal strips shows that propagation losses less than 0.3 dB/mm with a mode size of 9 µm are attainable. This work illustrates the potential of TiN as a realistic plasmonic material for practical solid-state, integrated nano-optic and hybrid photonic devices.

4.
Ann R Coll Surg Engl ; 105(3): 247-251, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35175143

RESUMO

INTRODUCTION: Reconstruction of a surgical defect is an important part of the management of oral cancers. Microvascular free flap construction provides better functional and cosmetic outcomes. METHODS: Between 2014 and 2020, some 524 patients underwent microvascular reconstruction. Comorbidity variables were scored using the Charlson Comorbidity Index (CCI). Complications were recorded using Clavien-Dindo criteria. RESULTS: Eighty-three (15.84%), 339 (64.69%) and 102 (19.47%) patients underwent free radial forearm flap, free anterolateral thigh flap and free fibula osteocutaneous flap (FFOCF), respectively. Clavien-Dindo complications of grade III and above were seen in 39 (7.44%) patients. Total flap loss was seen in 18 patients and of these, 16 were salvaged using alternative free flaps or pedicled flaps. On univariate analysis, overall and major complication rates were higher in FFOCF (p=0.171). Major complications significantly more common in patients with a CCI score >4 (p=0.001). Patients aged >65 years had higher rates of complications (p=0.03). CONCLUSION: Microvascular free tissue transfer is a reliable, safe and gold standard modality in surgical reconstruction and can be replicated in non-institutional settings.


Assuntos
Retalhos de Tecido Biológico , Neoplasias Bucais , Humanos , Neoplasias Bucais/cirurgia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Coxa da Perna/cirurgia , Extremidade Inferior
5.
Opt Express ; 20(7): 8100-16, 2012 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-22453481

RESUMO

We directly demonstrate an improvement in the radiative decay rate of dye molecules near multilayer hyperbolic metamaterials (HMMs). Our comprehensive study shows a radiative decay rate for rhodamine 800 (Rh800) that is several times higher due to the use of HMM samples as compared to dielectric substrates. This is also the first experimental demonstration that multilayer hyperbolic metamaterials provide an increase in the radiative decay rate relative to those from either thin or thick gold films.


Assuntos
Corantes/química , Manufaturas , Meia-Vida , Cinética
6.
J Ind Microbiol Biotechnol ; 39(1): 93-8, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21691794

RESUMO

The thermoalkalophilic Bacillus halodurans JB 99 cells known for production of novel thermostable alkaline keratinolytic protease were immobilized in calcium alginate matrix. Batch and repeated batch cultivation using calcium alginate immobilized cells were studied for alkaline protease production in submerged fermentation. Immobilized cells with 2.5% alginate and 350 beads/flask of initial cell loading showed enhanced production of alkaline protease by 23.2% (5,275 ± 39.4 U/ml) as compared to free cells (4,280 ± 35.4 U/ml) after 24 h. In the semicontinuous mode of cultivation, immobilized cells under optimized conditions produced an appreciable level of alkaline protease in up to nine cycles and reached a maximal value of 5,975 U/ml after the seventh cycle. The enzyme produced from immobilized cells efficiently degraded chicken feathers in the presence of a reducing agent which can help the poultry industry in the management of keratin-rich waste and obtaining value-added products.


Assuntos
Alginatos , Bacillus/enzimologia , Proteínas de Bactérias/biossíntese , Endopeptidases/biossíntese , Animais , Proteínas de Bactérias/metabolismo , Células Imobilizadas/enzimologia , Endopeptidases/metabolismo , Estabilidade Enzimática , Plumas/metabolismo , Fermentação , Ácido Glucurônico , Ácidos Hexurônicos , Temperatura
7.
Food Chem ; 396: 133737, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-35870241

RESUMO

The drastic increase in the utilization and conversion of biomass has been an effect of sustainability and circular economy in the food processing sector. Rice bran wax (RBW), an intermediate by-product of rice bran oil refining industries, has been one of the underutilized waste materials. The FT-IR analysis showed that RBW contains many similar compounds to that of beeswax (BW) and carnauba wax (CW). The DSC thermographs showed melting and crystallization temperatures of RBW as 78.55 and 73.43 °C, respectively, lesser than CW and more than BW. The peak profiling of XRD diffractographs has shown full-width at half-maximum of CW and RBW as 0.61 and 0.45, respectively, indicating distortion in crystal formation. The sequential extracts of RBW in hexane, dichloromethane, and ethylacetate have shown antimicrobial activity against E. coli and S. typhi. The research provides a baseline for extraction and separation of specialty compounds from RBW for by-product utilization.


Assuntos
Escherichia coli , Oryza , Oryza/química , Compostos Fitoquímicos , Óleo de Farelo de Arroz/química , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Clin Transl Oncol ; 22(1): 37-49, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31006835

RESUMO

PURPOSE: Breast cancer is a leading cause of cancer mortality in developed countries. We performed a meta-analysis of randomized clinical trials to investigate the effect of metformin on biomarkers associated with breast cancer outcomes and to explore the dose-response relationship. METHODS: A systematic search was performed from onset of the database to January 2019 in MEDLINE/PubMed, SCOPUS, and Cochrane library to identify randomized clinical trials investigating the impact of metformin on insulin, glucose, CRP, leptin, body mass indices (BMI), cholesterol, Ki-67, and Homeostatic Model Assessment for Insulin-Resistance (HOMA-IR). Effect sizes were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI) using a random-effects models. RESULTS: Nine studies providing 1,363 participants were included in the meta-analysis. Pooled results showed a significant reduction in insulin (WMD: - 0.99 U/ml, 95% CI - 1.66, - 0.33), glucose (WMD: - 1.78 ml/dl, 95% CI - 2.96, - 0.60), CRP (WMD: - 0.60 mg/l, 95% CI - 0.88, - 0.33), HOMA-IR (WMD: - 0.45, 95% CI - 0.77, - 0.11), leptin (WMD: - 2.44 ng/ml, 95% CI - 3.28, - 1.61), BMI (WMD: - 0.55 kg/m2, 95% CI - 1.00, - 0.11), and Ki-67 (WMD: - 4.06, 95% CI - 7.59, - 0.54). Results of the subgroup analyses showed that insulin, glucose, and BMI decreased more significantly when the duration of administering metformin intervention was above 4 weeks. We did not observe non-linear changes in the dose-response relationship between metformin and biomarkers as outcomes. CONCLUSIONS: Breast cancer patients receiving metformin as treatment for diabetes showed significant reduction in levels of insulin, fasting glucose, CRP, HOMA, leptin, BMI, and Ki-67.


Assuntos
Biomarcadores/sangue , Neoplasias da Mama/sangue , Neoplasias da Mama/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Neoplasias da Mama/patologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Resistência à Insulina , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto
10.
Electromyogr Clin Neurophysiol ; 48(3-4): 169-80, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18551837

RESUMO

Surface electromyogram (sEMG) has numerous applications. It has been widely used in various biosignal and neuro rehabilitation applications. There is an urgent need for establishing a simple yet robust system that can be used to identify subtle complex hand actions and gestures for control of prosthesis and other computer assisted devices. Earlier work to identify the hand actions and gestures based on sEMG suffers from limitation that these are suitable for gross actions where there is only one prime-mover muscle involved and not suitable for small subtle and complex muscle contraction. This paper presents the hand gesture identification using sEMG decomposed using semi-blind independent component analysis combined with neural network based classifier. The aim was to provide reliable and natural control for rehabilitation and human computer interaction applications. We have proposed a model based approach where the hand muscle anatomy is known. The system was tested on 5 subjects and with experiments repeated on different days. The system was compared with raw sEMG as used by other researchers. The system is able to classify the different hand actions 100%. In comparison, the classification of the traditional ICA and raw sEMG for the same experiments and similar features was a poor 65% and 60% respectively. This research demonstrates that sEMG can be decomposed to the individual muscle activities using semi-blind ICA. The muscle activity after decomposition can be used to accurately identify small and subtle hand actions and gestures. Finally the ICA source separation was validated with mixing matrix analysis.


Assuntos
Inteligência Artificial , Membros Artificiais , Eletromiografia/estatística & dados numéricos , Gestos , Mãos/inervação , Redes Neurais de Computação , Reconhecimento Automatizado de Padrão , Processamento de Sinais Assistido por Computador , Interface Usuário-Computador , Potenciais de Ação/fisiologia , Adulto , Feminino , Mãos/fisiologia , Humanos , Contração Isométrica/fisiologia , Masculino , Neurônios Motores/fisiologia , Músculo Esquelético/inervação , Análise de Componente Principal
11.
Int J Yoga ; 11(1): 53-58, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29343931

RESUMO

CONTEXT: Different types of breathing exercises have varied effects on cardiovascular parameters and the stress levels in an individual. AIM: The aim of this study was to assess the effect of a modified form of isolated alternate nostril, slow breathing exercise on perceived stress, and cardiovascular parameters in young, male volunteers. SETTINGS AND DESIGN: This was a randomized control study carried out at Advanced Centre for Yoga Therapy Education and Research, Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry in 2014. SUBJECTS AND METHODS: Hundred healthy male volunteers were randomized into control group, n = 50 and slow breathing group (study), n = 50. Slow breathing exercise training was given to study group for 30 min a day, 5 times/week for 12 weeks, under the supervision of certified yoga trainers. Perceived Stress Scale (PSS) using Cohen's questionnaire, anthropometric parameters such as body mass index (BMI), waist-hip ratio (WHR), and cardiovascular parameters such as heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were recorded at baseline and after 12 weeks. The control group did not receive any intervention. Slow breathing exercise training was provided for the study group. During the study period, one volunteer opted out of the study group due to personal reasons. RESULTS: HR, SBP, DBP, and PSS decreased significantly (P < 0.05) in the study group following 12 weeks slow breathing exercise training, while no significant change (P > 0.05) was observed in BMI and WHR. There was no significant change in the control group. CONCLUSION: Twelve weeks of modified slow breathing exercise reduced perceived stress and improved the cardiovascular parameters. The above results indicate that our modified slow breathing exercise is effective in reducing stress and improving the cardiovascular parameters.

12.
Ann Indian Acad Neurol ; 21(3): 209-213, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30258264

RESUMO

AIM: Limited data regarding stroke subtypes exist from South Asian countries. The aim of the study was to determine the pattern of ischemic stroke subtypes and their associated risk factors, in a 10-year long hospital-based registry in the South Indian city of Hyderabad. MATERIALS AND METHODS: The Hyderabad stroke registry systematically collected clinical, radiological, and laboratory data of fully investigated consecutive stroke patients and studied pattern of ischemic stroke subtypes and their risk factor association. RESULTS: The cohort comprised of 2642 patients: 2072 (78.4%) were ischemic and 570 (21.6%) were hemorrhagic strokes. In the ischemic stroke cohort, the mean age was 54.1 years and 1622 (78.3%) were men. The most common ischemic stroke subtype was large artery atherosclerosis (LAA) comprising 37.6% (n = 779), followed by small vessel occlusion comprising 19.9% (n = 413) and cardioembolism 11% (n = 228). Stroke of other determined etiologies constituted 4.2% (n = 86) and stroke of undetermined etiology was observed in 27.3%. Among patients with LAA, 610 (78.3%) patients had intracranial and 169 (21.7%) had extracranial disease as the underlying mechanism. Risk factor profile demonstrated that hyperlipidemia was significantly associated with LAA and ischemic heart disease with cardioembolic strokes. CONCLUSIONS: The study reveals a distinct pattern of ischemic stroke subtypes in the Indian context that has overlapping features of registries from West and East Asian countries. Both large artery and small vessel diseases are substantially represented with a predominance of intracranial atherosclerosis. The study results have significant implications for developing preventive and management strategies for stroke care and research in India.

13.
Biomed Pharmacother ; 91: 436-445, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28475922

RESUMO

Breast cancer is one of the most frequently diagnosed cancer in woman. Triple-negative breast cancer (TNBC) is most aggressive form of breast cancer. There is a growing interest in the use of natural products in combinational chemotherapy to improve the effectiveness in combating proliferation of cancer cells. Here, we hypothesized that coralyne in combination with paclitaxel may exhibit synergistic effect on inhibition of proliferation, migration and induction of apoptosis in MCF-7 and MDA-MB-231 breast cancer cell lines. MTT and BrdU incorporation assays were performed to study the effect of drugs alone and in combination on cell cytotoxicity and proliferation of the breast cancer cell lines, respectively. Adhesion and wound healing assays were performed to study the cell and extracellular matrix interactions. In addition, expression of proliferation marker ki-67 and apoptotic markers Bax and Bcl-2 was determined to study the effect of coralyne in combination with paclitaxel by reverse transcriptase PCR and confirmed by Western blot. The results indicated the synergism between coralyne and paclitaxel on proliferation and migration of breast cancer cell lines. This study also showed that combinational drug treatment decreased the expression of ki-67 and there was an increase in pro apoptotic factor Bax with decreased in expression of anti-apoptotic factor Bcl-2 in breast cancer cell lines with negligible effect on normal breast cell line. Overall, our data described the promising therapeutic potential of coralyne in combination with paclitaxel in treating breast cancer at lower effective dose.


Assuntos
Alcaloides de Berberina/farmacologia , Neoplasias da Mama/patologia , Movimento Celular/efeitos dos fármacos , Paclitaxel/farmacologia , Alcaloides de Berberina/química , Adesão Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Interações Medicamentosas , Sinergismo Farmacológico , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Células MCF-7 , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Paclitaxel/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
14.
Electromyogr Clin Neurophysiol ; 46(5): 295-309, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17059103

RESUMO

Surface electromyogram (SEMG) has numerous applications, but the presence of artefacts and noise, especially at low level of muscle activity make the recordings unreliable. Spectral and temporal overlap can make the removal of artefacts and noise, or separation of relevant signals from other bioelectric signals extremely difficult. Individual muscles may be considered as independent at the local level and this makes an argument for separating the signals using independent component analysis (ICA). In the recent past, due to the easy availability of ICA tools, numbers of researchers have attempted to use ICA for this application. This paper reports research conducted to evaluate the use of ICA for the separation of muscle activity and removal of the artefacts from SEMG. It discusses some of the conditions that could affect the reliability of the separation and evaluates issues related to the properties of the signals and number of sources. The paper also identifies the lack of suitable measure of quality of separation for bioelectric signals and it recommends and tests a more robust measure of separation. The paper also reports tests using Zibulevsky's technique of temporal plotting to identify number of independent sources in SEMG recordings. The theoretical analysis and experimental results demonstrate that ICA is suitable for SEMG signals. The results identify the unsuitability of ICA when the number of sources is greater than the number of recording channels. The results also demonstrate the limitations of such applications due to the inability of the system to identify the correct order and magnitude of the signals. The paper determines the suitability of the use of error measure using simulated mixing matrix and the estimated unmixing matrix as a means identifying the quality of separation of the output. The work demonstrates that even at extremely low level of muscle contraction, and with filtering using wavelets and band pass filters, it is not possible to get the data sparse enough to identify number of independent sources using Zibulevs.ky's technique.


Assuntos
Artefatos , Eletromiografia , Músculo Esquelético/fisiologia , Processamento de Sinais Assistido por Computador , Algoritmos , Humanos , Distribuição Normal , Análise de Componente Principal
15.
Int Sch Res Notices ; 2016: 9458627, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28116350

RESUMO

Embedded systems are extensively used in home automation systems, small office systems, vehicle communication systems, and health service systems. The services provided by these systems are available on the Internet and these services need to be protected. Security features like IP filtering, UDP protection, or TCP protection need to be implemented depending on the specific application used by the device. Every device on the Internet must have network interface. This paper proposes the design of the embedded Secured Ethernet Interface System to protect the service available on the Internet against the SYN flood attack. In this experimental study, Secured Ethernet Interface System is customized to protect the web service against the SYN flood attack. Secured Ethernet Interface System is implemented on ALTERA Stratix IV FPGA as a system on chip and uses the modified SYN flood attack protection method. The experimental results using Secured Ethernet Interface System indicate increase in number of genuine clients getting service from the server, considerable improvement in the data transfer rate, and better response time during the SYN flood attack.

16.
Cardiovasc Res ; 39(3): 571-9, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9861299

RESUMO

OBJECTIVES: We examined the effects of chronic type A endothelin receptor (ETA) blockade in a dog model of pacing-induced cardiomyopathy. METHODS: Eight dogs received an ETA antagonist, LU 135252 (50 mg/kg orally daily) and nine dogs received a matching placebo starting at day three of pacing and continued for the remainder of the three weeks of pacing. RESULTS: In the placebo group, the mean pulmonary artery pressure and left ventricular end diastolic pressure increased from 16 +/- 3 and 8 +/- 2 mmHg, respectively, at baseline to 40 +/- 11 and 34 +/- 7 mmHg, respectively, at two weeks (both p < 0.001 versus baseline). Cardiac output declined from 3.5 +/- 0.7 to 1.9 +/- 0.6 l/min (p < 0.001). In the treatment group, LU 135252 attenuated the increase in mean pulmonary artery and left ventricular end diastolic pressure (16 +/- 3 and 9 +/- 1 mmHg at baseline to 29 +/- 3 and 27 +/- 3 mmHg, respectively, at two weeks (p < 0.001), and the decline in cardiac output (3.2 +/- 0.3 to 2.6 +/- 0.8 l/min, p < 0.01; p < 0.05 versus placebo for the three parameters). Systemic and pulmonary vascular resistance increased only in the placebo group. Left ventricular end-diastolic volume increased to a similar degree. However, LU 135252 attenuated the increase in plasma norepinephrine level (placebo, 1.2 +/- 0.5 to 3.7 +/- 1.9 pmol/l; treatment, 0.8 +/- 0.3 to 2.4 +/- 0.6 pmol/l; both p < 0.001 versus baseline; p < 0.05 versus placebo). CONCLUSION: Our results suggest that endothelin-1 plays a role in the hemodynamic perturbations in canine pacing-induced cardiomyopathy. The favourable hemodynamic effects without concomitant aggravation of neurohormonal activation suggests that ETA receptor blockade may be beneficial in the treatment of heart failure.


Assuntos
Antagonistas dos Receptores de Endotelina , Insuficiência Cardíaca/tratamento farmacológico , Fenilpropionatos/administração & dosagem , Pirimidinas/administração & dosagem , Administração Oral , Animais , Fator Natriurético Atrial/sangue , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Estimulação Cardíaca Artificial , Cães , Ecocardiografia , Endotelina-1/farmacologia , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Masculino , Norepinefrina/sangue , Fenilpropionatos/uso terapêutico , Pirimidinas/uso terapêutico , Distribuição Aleatória , Receptor de Endotelina A , Resistência Vascular/efeitos dos fármacos , Remodelação Ventricular/efeitos dos fármacos
17.
Free Radic Biol Med ; 35(5): 475-84, 2003 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-12927597

RESUMO

To understand the relative importance of phenolic O-H and the CH-H hydrogen on the antioxidant activity and the free radical reactions of Curcumin, (1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione), biochemical, physicochemical, and density functional theory (DFT) studies were carried out with curcumin and dimethoxy curcumin (1,7-bis[3, 4-dimethoxy phenyl]-1,6-heptadiene-3,5-dione). The antioxidant activity of these compounds was tested by following radiation-induced lipid peroxidation in rat liver microsomes, and the results suggested that at equal concentration, the efficiency to inhibit lipid peroxidation is changed from 82% with curcumin to 24% with dimethoxy curcumin. Kinetics of reaction of (2,2'-diphenyl-1-picrylhydrazyl) DPPH, a stable hydrogen abstracting free radical was tested with these two compounds using stopped-flow spectrometer and steady state spectrophotometer. The bimolecular rate constant for curcumin was found to be approximately 1800 times greater than that for the dimethoxy derivative. Cyclic voltammetry studies of these two systems indicated two closely lying oxidation peaks at 0.84 and 1.0 V vs. SCE for curcumin, while only one peak at 1.0 V vs. SCE was observed for dimethoxy curcumin. Pulse radiolysis induced one-electron oxidation of curcumin and dimethoxy curcumin was studied at neutral pH using (*)N(3) radicals. This reaction with curcumin produced phenoxyl radicals absorbing at 500 nm, while in the case of dimethoxy curcumin a very weak signal in the UV region was observed. These results suggest that, although the energetics to remove hydrogen from both phenolic OH and the CH(2) group of the beta-diketo structure are very close, the phenolic OH is essential for both antioxidant activity and free radical kinetics. This is further confirmed by DFT calculations where it is shown that the -OH hydrogen is more labile for abstraction compared to the -CH(2) hydrogen in curcumin. Based on various experimental and theoretical results it is definitely concluded that the phenolic OH plays a major role in the activity of curcumin.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Curcumina/farmacologia , Radicais Livres/metabolismo , Hidrogênio/metabolismo , Hidróxidos/metabolismo , Metano/análogos & derivados , Animais , Radioisótopos de Cobalto , Curcumina/análogos & derivados , Raios gama , Hidrocarbonetos , Cinética , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos da radiação , Masculino , Metano/química , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Microssomos Hepáticos/efeitos da radiação , Oxirredução , Fenóis/química , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico
18.
BMC Genet ; 5: 1, 2004 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-14715088

RESUMO

BACKGROUND: The genus Morus, known as mulberry, is a dioecious and cross-pollinating plant that is the sole food for the domesticated silkworm, Bombyx mori. Traditional methods using morphological traits for classification are largely unsuccessful in establishing the diversity and relationships among different mulberry species because of environmental influence on traits of interest. As a more robust alternative, PCR based marker assays including RAPD and ISSR were employed to study the genetic diversity and interrelationships among twelve domesticated and three wild mulberry species. RESULTS: RAPD analysis using 19 random primers generated 128 discrete markers ranging from 500-3000 bp in size. One-hundred-nineteen of these were polymorphic (92%), with an average of 6.26 markers per primer. Among these were a few putative species-specific amplification products which could be useful for germplasm classification and introgression studies. The ISSR analysis employed six anchored primers, 4 of which generated 93 polymorphic markers with an average of 23.25 markers per primer. Cluster analysis of RAPD and ISSR data using the WINBOOT package to calculate the Dice coefficient resulted into two clusters, one comprising polyploid wild species and the other with domesticated (mostly diploid) species. CONCLUSION: These results suggest that RAPD and ISSR markers are useful for mulberry genetic diversity analysis and germplasm characterization, and that putative species-specific markers may be obtained which can be converted to SCARs after further studies.


Assuntos
Marcadores Genéticos/genética , Variação Genética , Morus/genética , DNA de Plantas/genética , DNA de Plantas/metabolismo , Eletroforese em Gel de Ágar , Morus/classificação , Reação em Cadeia da Polimerase , Técnica de Amplificação ao Acaso de DNA Polimórfico , Sequências Repetitivas de Ácido Nucleico/genética , Especificidade da Espécie
19.
Peptides ; 15(7): 1255-9, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7854978

RESUMO

We investigated the use of two HPLC injectors, one reserved for standards and the other for blanks or biological samples, to minimize shadowing in the measurement of angiotensin II (ANGII). HPLC carryover of standard ANGII to blank with a one-injector and a two-injector system were 47.0 +/- 5.0 and 2.4 +/- 0.5 fmol/ml, respectively, a 19.6-fold reduction. Measured normal canine left ventricular myocardium ANGII level by the two-injector HPLC-RIA system was 22.3 +/- 2.4 fmol/g, with a signal-to-noise ratio of 11.7, an improved signal-to-noise ratio of 29.3 fold vs. the one injector. This innovation reduced the incidence of false-positive ANGII results, and thus can be applied to other compounds that exhibit HPLC-derived shadowing.


Assuntos
Angiotensina II/análise , Cromatografia Líquida de Alta Pressão/métodos , Angiotensina II/isolamento & purificação , Angiotensina II/normas , Angiotensinas/isolamento & purificação , Animais , Cromatografia Líquida de Alta Pressão/normas , Cães , Masculino , Miocárdio/química , Padrões de Referência
20.
Phytochemistry ; 63(1): 97-104, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12657303

RESUMO

Four aqueous extracts from different parts of medicinal plants used in Ayurveda (an ancient Indian Medicine) viz., Momardica charantia Linn (AP1), Glycyrrhiza glabra (AP2), Acacia catechu (AP3), and Terminalia chebula (AP4) were examined for their potential as antioxidants. The antioxidant activity of these extracts was tested by studying the inhibition of radiation induced lipid peroxidation in rat liver microsomes at different doses in the range of 100-600 Gy as estimated by thiobarbituric acid reactive substances (TBARS). Of all these extracts, AP4 showed maximum inhibition in the TBARS formation and hence is considered the best antioxidant among these four extracts. The extracts were found to restore antioxidant enzyme superoxide dismutase (SOD) from the radiation induced damage. The antioxidant capacities were also evaluated in terms of ascorbate equivalents by different methods such as cyclic voltammetry, decay of ABTS(.-) radical by pulse radiolysis and decrease in the absorbance of DPPH radicals. The results were found to be in agreement with the lipid peroxidation data and AP4 showed maximum value of ascorbate equivalents. Therefore AP4, with high antioxidant activity, is considered as the best among these four extracts.


Assuntos
Antioxidantes/análise , Antioxidantes/farmacologia , Ayurveda , Plantas Medicinais/química , Animais , Ácido Ascórbico/química , Compostos de Bifenilo , Relação Dose-Resposta a Droga , Eletroquímica/métodos , Radicais Livres/química , Radicais Livres/metabolismo , Raios gama , Concentração Inibidora 50 , Cinética , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos da radiação , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/efeitos da radiação , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos da radiação , Picratos/química , Extratos Vegetais/farmacologia , Radiólise de Impulso/métodos , Ratos , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
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