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1.
Ann Oncol ; 31(4): 507-516, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32139298

RESUMO

BACKGROUND: Osimertinib is a potent, third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). The multi-arm phase Ib TATTON study (NCT02143466) was designed to assess the safety and tolerability of osimertinib in combination with other targeted therapies: selumetinib (MEK1/2 inhibitor), savolitinib (MET-TKI), or durvalumab [anti-programmed cell death ligand 1 (anti-PD-L1) monoclonal antibody]. PATIENTS AND METHODS: Patients with advanced EGFR-mutant non-small-cell lung cancer and disease progression on a prior EGFR-TKI were enrolled and allocated to dose-escalating cohorts combining osimertinib 80 mg orally (p.o.) once a day with selumetinib (25-75 mg p.o. twice a day; continuous or intermittent), savolitinib (600-800 mg p.o. once a day), or durvalumab (3-10 mg/kg intravenous every 2 weeks). RESULTS: At data cut-off (28 February 2018), 77 patients were enrolled and received osimertinib plus selumetinib (n = 36), savolitinib (n = 18), or durvalumab (n = 23). Most common adverse events (any grade), occurring in ≥20% of patients across dose groups, were: selumetinib arm-diarrhea (75%), rash (58%), nausea (47%); savolitinib arm-nausea (67%), rash (56%), vomiting (50%); durvalumab arm-rash (48%), vomiting (43%), diarrhea (39%). Dose-limiting toxicities were reported in the selumetinib 25 mg (n = 1), 50 mg (n = 1), and 75 mg (n = 4) continuous-dose groups, savolitinib 600 mg (n = 1) and 800 mg dose groups (n = 2), and durvalumab 10 mg/kg (n = 1) dose group. The objective response rate was 42% (95% confidence interval 26% to 59%), 44% (22% to 69%), and 43% (23% to 66%) in the selumetinib, savolitinib, and durvalumab arms, respectively. CONCLUSION: Our results demonstrate the feasibility of combining osimertinib 80 mg with selumetinib or savolitinib at identified tolerable, active doses. A combination of osimertinib with durvalumab was not feasible due to increased reporting of interstitial lung disease. Osimertinib-based combination therapies represent a compelling approach now being further investigated. CLINICAL TRIALS NUMBER: NCT02143466.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Acrilamidas , Compostos de Anilina/uso terapêutico , Anticorpos Monoclonais/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Benzimidazóis , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Mutação , Inibidores de Proteínas Quinases/efeitos adversos , Pirazinas , Triazinas
2.
RSC Adv ; 8(21): 11357-11366, 2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35542769

RESUMO

The vibrational spectrum ω i of a re-optimized neutral gold cluster Au58 has been calculated using a numerical finite-difference approach and the density-functional tight-binding (DFTB) method. We have exactly predicted the vibrational frequency ranging from 3.88 through to 304.49 cm-1 which depends on the size and the arrangement of the atoms in the nanoparticle morphology of the cluster at ΔE = 0. Our investigation has revealed that the vibrational spectrum is strongly influenced by size and structure. It is well known that gold atomic clusters can have planar or hollow cage-like structures due to their relativistic effect. However, in our study, by first principles calculations on a Au58 cluster we have proposed that gold clusters of medium size can form a shell-like structure (skeleton/helmet), this is demonstrated by the remarkable robustness of a double shell structure with a hollow inner shell of about ten atoms. Finally, the structure symmetry (C 1) is confirmed through the cluster size, vibrational spectroscopy, and by studying the effect of temperature on a neutral gold cluster for the first time.

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 132: 110-20, 2014 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-24858352

RESUMO

Quantum mechanical calculations of energies, geometries and vibrational wave numbers of 3-chloro-2,4,5,6-tetrafluoropyridine and 4-bromo-2,3,5,6-tetrafluoropyridine have been performed by DFT level of theory using B3LYP/6-31+G(d) and B3LYP/6-311++G(d,p) as basis sets. The optimized geometrical parameters obtained by B3LYP method show good agreement with experimental data. The difference between the observed and scaled wave number values of most of the fundamentals is very small. A detailed interpretation of the FT-IR and FT-Raman spectra of 3-chloro-2,4,5,6-tetrafluoropyridine and 4-bromo-2,3,5,6-tetrafluoropyridine were also reported. Molecular stability and bond strength were investigated by applying the natural bond orbital analysis (NBO). The calculated HOMO and LUMO energies show that charge transfer occurs in the molecules. Information about the size, shape, charge density distribution, and site of chemical reactivity of the molecules has been obtained by mapping electron density isosurface with electrostatic potential (ESP). Thermodynamic properties (heat capacity, entropy and enthalpy and Gibb's free energy) of the title compounds at different temperatures were calculated.


Assuntos
Modelos Moleculares , Piridinas/química , Teoria Quântica , Análise Espectral Raman , Vibração , Conformação Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Termodinâmica
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 124: 451-69, 2014 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-24508884

RESUMO

The FT-IR and FT-Raman spectra of 4-tert-butyl-3-methoxy-2,6-dinitrotoluene (musk ambrette) have been recorded in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. The total energy calculations of musk ambrette were tried for the possible conformers. The molecular structure, geometry optimization, vibrational frequencies were obtained by the density functional theory (DFT) using B3LYP and LSDA method with 6-311G(d,p) basis set for the most stable conformer "C1". The complete assignments were performed on the basis of the potential energy distribution (PED) of the vibrational modes, calculated and the scaled values were compared with experimental FT-IR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The stability of the molecule arising from hyper conjugate interactions and the charge delocalization has been analyzed using bond orbital (NBO) analysis. The HOMO and LUMO energy gap reveals that the energy gap reflects the chemical activity of the molecule. The dipole moment (µ), polarizability (α), anisotropy polarizability (Δα) and first hyperpolarizability (ßtot) of the molecule have been reported. The thermodynamic functions (heat capacity, entropy and enthalpy) were obtained for the range of temperature 100-1000 K. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecule has been obtained by mapping electron density isosurface with molecular electrostatic potential (MEP).


Assuntos
Dinitrobenzenos/química , Elétrons , Modelos Moleculares , Conformação Molecular , Vibração , Dureza , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Eletricidade Estática , Termodinâmica
5.
J Hand Surg Eur Vol ; 38(7): 780-7, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23599279

RESUMO

The aim of this study was to measure inter- and intra-observer agreement on the radiographic classification of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist. Radiographs of 41 patients with SLAC wrist and 47 patients with SNAC wrist were graded on two separate occasions by four orthopaedic consultants specializing in hand and wrist surgery. Inter-observer agreement was evaluated using the multi-rater kappa value. Landis and Koch criteria were used to assess the level of agreement. Intra-observer agreement was tested by re-grading the radiographs after an interval of 2 to 4 weeks and calculating the weighted kappa value. For SLAC wrist, the inter-observer agreement was moderate (kappa value = 0.59) and intra-observer agreement substantial (kappa value = 0.65). For SNAC wrist, the inter-observer agreement was slight (kappa value = 0.20) and intra-observer agreement was fair (kappa value = 0.29). Radiographic classification of SLAC wrist has moderate reliability and reproducibility, whereas classification of SNAC wrist has limited reliability.


Assuntos
Osso Semilunar/diagnóstico por imagem , Osteoartrite/classificação , Osteoartrite/diagnóstico por imagem , Osso Escafoide/diagnóstico por imagem , Articulação do Punho/diagnóstico por imagem , Adulto , Feminino , Humanos , Osso Semilunar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Osteoartrite/fisiopatologia , Radiografia , Reprodutibilidade dos Testes , Osso Escafoide/fisiopatologia , Articulação do Punho/fisiopatologia
6.
J Food Sci ; 76(1): E158-64, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21535668

RESUMO

Microfiltration (MF) membranes with pore sizes of 200 and 450 nm and ultrafiltration (UF) membranes with molecular weight cut off of 50, 100, and 500 kDa were assessed for their ability to eliminate nonprotein substances from okara protein extract in a laboratory cross-flow membrane system. Both MF and UF improved the protein content of okara extract to a similar extent from approximately 68% to approximately 81% owing to the presence of protein in the feed leading to the formation of dynamic layer controlling the performance rather than the actual pore size of membranes. Although normalized flux in MF-450 (117 LMH/MPa) was close to UF-500 (118 LMH/MPa), the latter was selected based on higher average flux (47 LMH) offering the advantage of reduced processing time. Membrane processing of soy extract improved the protein content from 62% to 85% much closer to the target value. However, the final protein content in okara (approximately 80%) did not reach the target value (90%) owing to the greater presence of soluble fibers that were retained by the membrane. Solubility curve of membrane okara protein concentrate (MOPC) showed lower solubility than soy protein concentrate and a commercial isolate in the entire pH range. However, water absorption and fat-binding capacities of MOPC were either superior or comparable while emulsifying properties were in accordance with its solubility. The results of this study showed that okara protein concentrate (80%) could be produced using membrane technology without loss of any true proteins, thus offering value addition to okara, hitherto underutilized. Practical Application: Okara, a byproduct obtained during processing soybean for soymilk, is either underutilized or unutilized in spite of the fact that its protein quality is as good as that of soy milk and tofu. Membrane-processed protein products have been shown to possess superior functional properties compared to conventionally produced protein products. However, the potential of membrane technology has not been exploited for the recovery of okara protein. Our study showed that protein content of okara extract could be improved from approximately 68% to approximately 81% without losing any true proteins in the process.


Assuntos
Tecnologia de Alimentos , Proteínas de Vegetais Comestíveis/química , Proteínas de Vegetais Comestíveis/isolamento & purificação , Proteínas de Soja/química , Proteínas de Soja/isolamento & purificação , Algoritmos , Emulsificantes/análise , Emulsificantes/química , Emulsificantes/economia , Emulsificantes/isolamento & purificação , Emulsões , Filtração , Indústria de Processamento de Alimentos/economia , Concentração de Íons de Hidrogênio , Resíduos Industriais/análise , Resíduos Industriais/economia , Peso Molecular , Óleos de Plantas/análise , Proteínas de Vegetais Comestíveis/economia , Proteínas de Vegetais Comestíveis/metabolismo , Sementes/química , Solubilidade , Proteínas de Soja/economia , Proteínas de Soja/metabolismo , Glycine max/química , Fatores de Tempo , Inibidores da Tripsina/metabolismo , Ultrafiltração , Água/análise
7.
J Indian Med Assoc ; 109(7): 497, 499, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22315844

RESUMO

A 23-year-old male presented with fever of 5 days duration. His peripheral smear was positive for Plasmodium vivax. He was treated for malaria and responded. During investigation with USG it was found that he had absent left kidney. An abdominal contrast enhanced CT scan revealed ectopic kidney and spleen in the left hemithorax. This was a rare case of ectopic thoracic kidney and spleen.


Assuntos
Coristoma/diagnóstico por imagem , Rim , Baço , Doenças Torácicas/diagnóstico por imagem , Humanos , Masculino , Tomografia Computadorizada por Raios X , Adulto Jovem
8.
J Food Sci Technol ; 47(1): 34-41, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23572598

RESUMO

Cereals and millets generally hydrate at a moderate rate and their hydration behaviour differs in native and in processed state. The study was on the hydration of paddy, milled rice, parboiled rice, wheat, millets and equilibrium moisture content (EMC) on soaking at room temperature. Paddy hydrated very slowly, hydration rate was slow in brown rice but fast in milled rice and highest in waxy rice. In most of the rice varieties, maximum absorption occurred at the end of 30 min. In wheat hydration rate was slow and its EMC was highest (43%). Maize grits of big size hydrated slowly compared to small grits. In coarse cereals EMC varied from 28 to 38%. Foxtail millet hydration was slow whereas that of finger millet was fast. The data were tested on the Peleg's equation, which gave a reasonable fit to experimental data. Peleg's constants k1 and k2 were calculated for the above grains and their hydration behaviour has been predicted. The model fitted very well to milled rice hydration data where the coefficient of variance ranged from 0.9982 to 0.9995. With exception in some millet the hydration data fitted well with the Peleg's equation. Generalized equations have been formulated for prediction of moisture content of cereals and millets.

9.
J Food Sci Technol ; 47(1): 42-6, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23572599

RESUMO

Hydration behaviour of legumes with and without seed coat in split form at room temperature (28°C) was studied. Equilibrium moisture content (EMC) on soaking at room temperature of these legumes with seed coat varied from 53 to 65% (wb). Soybean hydrated fast while horse gram, black gram and green gram hydrated very slowly. Legumes in split form hydrated fast and completed their hydration in 3 h. EMC at room temperature varied from 52 to 58%. Peleg's equation could be fitted to the hydration of all legumes except green gram and horse gram. Coefficient of correlation for legume and splits (dhal) varied from 0.96 to 0.99, thus proving the validity of Peleg's equation. EMC of masur dhal fitted perfectly to the Peleg's equation. EMC predicted from average k1 and k2 values remained almost same in legume splits.

10.
Phys Rev Lett ; 98(7): 076101, 2007 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-17359037

RESUMO

On the basis of first-principles calculations of clusters and one dimensional infinitely long subnanowires of the binary systems, we find that alkali-noble metal alloy wires show better linearity and stability than either pure alkali metal or noble metal wires. The enhanced alternating charge buildup on atoms by charge transfer helps the atoms line up straight. The cesium doped gold wires showing significant charge transfer from cesium to gold can be stabilized as linear or circular monoatomic chains.

11.
J Hum Genet ; 51(11): 998-1005, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16969583

RESUMO

The ethnic variation in the GGN and CAG microsatellites of the androgen receptor (AR) gene suggests their role in the substantial racial difference in prostate cancer risk. Hence, we performed a case-control study to assess whether GGN repeats independently or in combination with CAG repeats were associated with prostate cancer risk in South Indian men. The repeat lengths of the AR gene determined by Gene scan analysis, revealed that men with GGN repeats 21 repeats (OR 0.91 at 95% CI-0.52-1.58). However, when CAG repeats of our earlier study was combined with the GGN repeat data, the cases exhibited significantly higher frequency of the haplotypes CAG 21(OR-6.9 at 95%CI-2.85-17.01, P < 0.001) compared to the controls. No significant association was observed between GGN repeats and prostate-specific antigen levels and the age at diagnosis. Although a trend of short GGN repeats length in high-grade was observed, it was not significant (P = 0.09). Overall, our data reveals that specific GGN/CAG haplotypes (CAG 21) of AR gene increase the risk of prostate cancer and thus could serve as susceptibility marker for prostate cancer in South Indian men.


Assuntos
Predisposição Genética para Doença , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/genética , Idoso , Estudos de Casos e Controles , Variação Genética , Haplótipos , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Risco , Expansão das Repetições de Trinucleotídeos
12.
Asian Pac J Cancer Prev ; 6(3): 309-14, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16235991

RESUMO

Inter-individual differences in cancer susceptibility may be mediated in part through polymorphic variability in the bioactivation and detoxification of carcinogens. The glutathione S-transferases (GSTs), which are active in detoxification of wide variety of carcinogens, have been consistently implicated as cancer susceptibility genes in this context. We here assessed the association of GSTM1 and GSTP1 polymorphisms with susceptibility to prostate cancer in a case-control study of 75 patients and 100 age-matched controls in a South Indian population. The GSTM1 null polymorphism was detected by PCR and the GSTP1 Ile105Val polymorphism by PCR-RFLP using peripheral blood DNA. There was no significant link between the null genotype of GSTM1 and risk of prostate cancer (OR-1.79; 95% CI-0.78-4.11; P-0.18). However, the GSTP1 Ile/Val genotype was significantly associated with a decreased risk for prostate cancer (OR-0.36; 95% CI-0.18-0.73; P<0.001). Analysis of the variant GSTM1 and GSTP1 genotypes in combination did not reveal any significant difference between cases and controls, even with a stratified analysis tumor grades. Thus our study indicates that the GSTP1 Ile/Val genotype may decrease risk of prostate cancer in the South Indian population.


Assuntos
Predisposição Genética para Doença , Glutationa S-Transferase pi/genética , Glutationa Transferase/genética , Polimorfismo Genético , Neoplasias da Próstata/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Genótipo , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Neoplasias da Próstata/etiologia , Fatores de Risco
13.
J Assoc Physicians India ; 49: 692-6, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11573553

RESUMO

Two hundred and sixty seven patients of uncomplicated P. falciparum malaria completed study in a multicentric phase III clinical trial of Arteether. Arteether was given intramuscularly in a dose of 150 mg daily for three consecutive days. Each patient was followed upto 28 days of alpha, beta arteether therapy. The cure rate was 97% with fever clearance time between 1-7 days (24-168 hours) and parasite clearance time between 1-3 days (24-72 hours). Parasite reappearance rate was found to be 3% and reported at only three of the centres. Following the treatment no adverse effect was observed on haematological, biochemical and vital clinical parameters.


Assuntos
Antimaláricos/uso terapêutico , Artemisininas , Malária Falciparum/tratamento farmacológico , Sesquiterpenos/uso terapêutico , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
14.
Rapid Commun Mass Spectrom ; 15(12): 915-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11400196

RESUMO

Gatifloxacin is an advanced-generation, 8-methoxyfluoroquinolone that is active against a broad spectrum of pathogens, including antiobiotic resistant Streptococcus pneumoniae. Development of a rapid, sensitive and selective method for the determination of gatifloxacin in human plasma is essential for understanding the pharmacokinetics of the drug when administered orally or intravenously. Solid phase extraction (SPE) using Oasis HLB was used to extract gatifloxacin and the internal standard ciprofloxacin from plasma. A method based on liquid chromatography/electrospray tandem mass spectrometry (LC/ESI-MS/MS) was developed and validated to quantitate gatifloxacin in human plasma. The precursor and major product ions of the analyte were monitored on a triple quadrupole mass spectrometer with positive ion electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. Mechanisms for the formation of collision-induced dissociation products of gatifloxacin are proposed. Linear calibration curves were generated from 10--1000 ng/mL with coefficients of determination greater than 0.99. The interday and intraday precision (%RSD) was less than 6.0% and accuracy (%error) was less than 5.4% for gatifloxacin. The limit of detection (LOD) for the method was 500 pg/mL based on a signal-to-noise ratio of 3.


Assuntos
Anti-Infecciosos/sangue , Cromatografia Líquida de Alta Pressão/métodos , Fluoroquinolonas , Espectrometria de Massas por Ionização por Electrospray/métodos , Ciprofloxacina/sangue , Gatifloxacina , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fatores de Tempo
15.
J Assoc Physicians India ; 49: 372-4, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11291981

RESUMO

Mucormycosis is the name for invasive fungal infection caused by mucorales. The disease is uncommon and produces serious and rapidly fatal infection in patients with serious pre-existing illness. The classical presentation of rhinocerebral mucormycosis is involvement of nasal mucosa with invasion of paranasal sinuses and orbit. We report a case of mucormycosis in an otherwise healthy female who had developed acute renal failure following gastroenteritis.


Assuntos
Injúria Renal Aguda/complicações , Infecções do Sistema Nervoso Central/etiologia , Mucormicose/etiologia , Nariz/patologia , Adulto , Antibacterianos/uso terapêutico , Evolução Fatal , Feminino , Gastroenterite/complicações , Humanos , Imunocompetência , Mucormicose/diagnóstico , Mucormicose/tratamento farmacológico
16.
J Assoc Physicians India ; 49: 1155-60, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11996434

RESUMO

OBJECTIVE: To evaluate efficacy of alpha;beta arteether in patients of P. falciparum malaria presenting with complications was undertaken in a multicentric clinical trial. METHOD: Each patient who consented to undergo clinical trial with parenteral Arteether was treated with a fixed dose schedule of Arteether given intramuscularly in a dose of 150 mg once a day on three consecutive days. Every patient was followed upto 28 days with clinical, haematological and parasitological monitoring every day upto one week and thereafter at 14, 21 and 28 days. The response was assessed in terms of fever clearance time, parasite clearance time, cure rate and parasite reappearance rate. RESULTS: A total of 211 patients of P. falciparum malaria were included in the study from four centres (Bhilai, Guwahati, Jamshedpur and Rourkela). Results of this study showed that fever clearance time ranged between 24-168 hours, parasite clearance time ranged between 24-120 hours and overall mortality ranged between 4-8.5%. Out of 211, only 14 patients expired during the study, of these, 10 patients expired within first two days i.e. before completing the three day schedule of arteether therapy. Tolerability to arteether injection was good in all these patients and no untoward effects were experienced or reported during the study. Overall cure rate observed in these studies was 93%. CONCLUSION: This study shows a rapid parasite and fever clearance in patients of complicated P. falciparum malaria.


Assuntos
Antimaláricos/efeitos adversos , Antimaláricos/uso terapêutico , Artemisininas , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Sesquiterpenos/efeitos adversos , Sesquiterpenos/uso terapêutico , Adolescente , Adulto , Animais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
17.
J Chromatogr B Biomed Sci Appl ; 748(1): 157-66, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11092595

RESUMO

Nitric oxide (NO) is synthesized from L-arginine (ARG) catalyzed by the enzyme nitric oxide synthase (NOS) and is important in the regulation of vascular tone, neurotransmission and host defense. N,N-Dimethyl L-arginine (asymmetric dimethylarginine, ADMA) and N-monomethyl L-arginine (MMA) are endogenous inhibitors of NOS. N,N'-Dimethyl L-arginine (symmetric dimethylarginine, SDMA), the inactive enantiomer of ADMA is also known to be present endogenously. A simple, sensitive and fast LC-MS-MS method was developed to extract and quantitate ADMA, SDMA, MMA and ARG from human plasma. 13C6-ARG was used as the internal standard for the assay. Protein precipitation using acetonitrile gave good recoveries of all the compounds from plasma. The compounds were separated by HPLC in less than 15 min using a silica column. The limits of detection for this method were found to be approximately 1 ng/ml for ARG, ADMA and SDMA and 2.5 ng/ml for MMA. The total LC-MS-MS analysis time is less than 15 min making this the fastest and most specific method reported to date. The use of an isocratic liquid chromatographic separation makes this method optimal for high sample throughput. The inter- and intra-day precision (% RSD) and accuracy (% error) for this assay were less than 15%. The average concentrations of ARG, ADMA, SDMA and MMA in plasma from 20 human subjects were found to be 10.9+/-4.1 microg/ml, 25.1+/-9.4 ng/ml, 33.2+/-13.1 ng/ml and 19.6+/-3.8 ng/ml, respectively.


Assuntos
Arginina/sangue , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Humanos , Metilação , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
Rapid Commun Mass Spectrom ; 14(3): 168-72, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10637423

RESUMO

Development of a rapid, sensitive and selective method for the determination of antimigraine drugs from human serum is essential for understanding the pharmacokinetics of these drugs when administered concurrently. Solid phase extraction (SPE) using Oasis HLB was used to extract the drugs (sumatriptan, naratriptan, zolmitriptan and rizatriptan) and the internal standard bufotenine from serum. A method based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed and validated to simultaneously quantitate these antimigraine drugs from human serum. The precursor and major product ions of the analytes were monitored on a triple quadrupole mass spectrometer with positive ion electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. The base peak in all the analytes is formed by alpha cleavage associated with protonation of the secondary amine. Mechanisms for the formation of the collision-induced dissociation products of these antimigraine compounds are proposed. Linear calibration curves were generated from 1-100 ng/mL with all coefficients of determination greater than 0.99. The inter- and intraday precision (%RSD) were less than 9.3% and accuracy (%error) was less than 9.8% for all components. The limits of detection (LOD) for the method were 250 pg/mL for sumatriptan and 100 pg/mL for the remaining analytes based on a signal-to-noise ratio of 3.


Assuntos
Cromatografia Líquida de Alta Pressão , Indóis/sangue , Espectrometria de Massas/métodos , Transtornos de Enxaqueca/tratamento farmacológico , Oxazóis/sangue , Oxazolidinonas , Piperidinas/sangue , Agonistas do Receptor de Serotonina/sangue , Sumatriptana/sangue , Triazóis/sangue , Vasoconstritores/sangue , Bufotenina/sangue , Bufotenina/química , Humanos , Indóis/química , Transtornos de Enxaqueca/sangue , Estrutura Molecular , Oxazóis/química , Piperidinas/química , Sensibilidade e Especificidade , Agonistas do Receptor de Serotonina/química , Sumatriptana/química , Triazóis/química , Triptaminas , Vasoconstritores/química
19.
J Laryngol Otol ; 113(4): 355-7, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10474673

RESUMO

Two cases of bilateral moderate to severe sensorineural hearing loss due to oral administration of metronidazole are reported. There has been only one case report of deafness following metronidazole therapy in the world literature. The hearing loss recovered gradually in a period of four to six weeks following withdrawal of drug and oral steroid therapy. The possible mechanism of ototoxicity is discussed. Awareness by the treating physician of ototoxicity due to any drug is stressed.


Assuntos
Anti-Infecciosos/efeitos adversos , Perda Auditiva Neurossensorial/induzido quimicamente , Metronidazol/efeitos adversos , Zumbido/induzido quimicamente , Adolescente , Adulto , Audiometria de Tons Puros , Feminino , Glucocorticoides/uso terapêutico , Perda Auditiva Neurossensorial/tratamento farmacológico , Humanos , Masculino , Prednisolona/uso terapêutico , Zumbido/tratamento farmacológico
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