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1.
Appl Opt ; 57(23): 6808-6816, 2018 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-30129630

RESUMO

Two-step selective photoionization of lithium isotopes is carried out in a hollow cathode (HC) discharge lamp using a nitrogen-laser-pumped homemade tunable dye laser (∼0.2 cm-1, 7 ns, 640-680 nm). The HC lamp is developed in-house and used as a lithium ion source as well as a detector. The dark space region of HC discharge is illuminated by a dye laser exciting pulse followed by an ionizing radiation from the nitrogen laser. The high electric field (∼kV/cm) present in HC dark space is exploited for fast charge collection, produced by the simultaneous interaction of exciting and ionizing laser beams with sputtered lithium atoms, enabling the detection of photoionization signal. Photoionization signals with a high signal-to-noise ratio are obtained without using any amplifier. Effects of the ionizing laser pulse energy and the precise tuning of the dye laser on lithium photoionization signal, across 670.780 nm (S1/22→P1/2,3/22) transition, are studied. The fine structure of lithium is clearly identified, and its two isotopes (Li7,6) are fairly resolved in the measured photoionization spectrum. Using a saturation technique, the photoionization cross section and the number density of lithium atoms for the Li7 (P3/22) excited level are also measured as 18.5±2.4 Mb, N0∼1.7×109 (atoms/cm3). The results obtained infer that HC-lamp-based photoionization is an easier and cost-effective way of selective photoionization of lithium atoms, and it can be applied for other elements also.

2.
Appl Opt ; 56(6): 1579-1584, 2017 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-28234362

RESUMO

We report Doppler-free spectroscopy of neutral europium carried out using the saturation absorption technique. In the present experiment, Eu/Ne hollow cathode discharge is used as an atomic vapor source of europium. The Eu transition 4f76s2(S87/2°)→4f76s6p(P89/2) at 601.815 nm and 4f75d6s(aD1013/2°)→4f75d6p(zD811/2) at 580.027 nm are investigated. The frequency separation between the adjacent hyperfine transitions as well as hyperfine structure (HFS) constants are calculated from the obtained experimental spectra. The HFS constant obtained for the state 4f76s6p(P89/2) are A151=664.8 MHz; B151=293.5 MHz, and for state 4f75d6p(zD811/2), the values are A151=7.6 MHz; B151=-60 MHz. These obtained values are in good agreement with the results reported in the literature using laser induced atomic beam fluorescence technique.

3.
Acta Endocrinol (Buchar) ; 13(1): 126-128, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-31149161

RESUMO

OBJECTIVE: Gestational diabetes mellitus (GDM) increases the foetal morbidity and mortality and there is also risk of development of type II diabetes for the mother. In pregnancy iron supplementations are given to all the females in India. Data are not available on the relationship between serum ferritin and GDM in Indian populations. MATERIAL & METHODS: Case control study was done on 90 women (30 GDM patients approx 28 weeks of gestation and 60 control subjects without GDM) referred to the tertiary care hospital at New Delhi. Ferritin was analysed by ELISA kit. They were analyzed for the correlation of ferritin with blood glucose in GDM patients. RESULTS: On comparison with blood glucose the levels of ferritin were statistically significantly high in GDM cases as compared to controls (p value 0.008). There was a negative correlation of ferritin with blood glucose level (r value -0.039, p value 0.794). DISCUSSION: Pregnancy is an equivalent of an inflammatory state and the high levels of ferritin can help in determining the need of iron supplementation given in pregnant females. Women who had high serum ferritin had the greatest risk of GDM. CONCLUSION: This study suggests a possible link between elevated serum ferritin and low-grade inflammation. Further studies in larger populations are required to establish this study.

4.
Appl Opt ; 54(4): 595-602, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25967764

RESUMO

Laser-assisted Penning ionization (LAPI) is detected in a Ne/Eu hollow cathode (HC) discharge lamp using the pulsed optogalvanic (OG) method. In the Ne/Eu discharge, doubly ionized europium excited energy levels Eu[4f(7)(P(7/2,5/2)6)] lie within the thermal limit (∼kT) from the laser-excited neon's energy level [2p(5)(P3/202)3p or 2p(8) (in Paschen notation)] lying at 149,848 cm(-1). Therefore, Penning ionization (PI) of europium atoms likely to occur into its highly excited ionic states is investigated. To probe the PI of europium, the temporal profiles of its counterpart neon OG signal are studied as a function of discharge current for the transitions (1s(4)→2p(8)) and (1s(2)→2p(2)), corresponding to 650.65 and 659.89 nm wavelengths, respectively. It is observed that PI of europium alters the overall discharge characteristics significantly and, hence, modifies the temporal profile of the OG signals accordingly. The quasi-resonant ionizing energy transfer collisions between laser-excited Ne 2p(8) atoms and electronically excited europium P(9/2)10 atoms are used to explain the LAPI mechanism. Such LAPI studies carried out in HC discharge could be useful for the discharge of a metal-vapor laser with appropriate Penning mixtures.

5.
Appl Opt ; 53(19): 4320-6, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25089996

RESUMO

The optogalvanic (OG) effect has been observed in a Eu/Ne hollow cathode discharge lamp using pulsed laser irradiation. An OG spectrum is recorded in dye laser wavelength region 574­602 nm using a boxcar-averager. In total 41 atomic lines are observed. Of these, 38 lines are assigned to neon transitions. Two lines observed corresponding to wavelengths 576.519 and 601.815 nm are assigned to europium transitions; (4f 7 6s 2 , S 8 7/2 →4f 7 6s6p , zP 6 7/2 ) and (4f 7 6s 2 , S 8 7/2 →4f 7 6s6p , zP 8 9/2 ), respectively, and the remaining line at 582.475 nm could not be assigned. The effect of the discharge current on europium as well as neon OG signals is also studied. At moderate discharge current values, an extra positive peak is observed in neon OG signal for the transition (1s 5 →2p 2 ) at 588.189 nm, which is explained by Penning-ionization process using the quasi-resonant energy transfer interactions between excited neon and europium atoms lying in 2p 2 and D 10 9/2 states, respectively.

6.
Appl Opt ; 52(18): 4404-11, 2013 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-23842186

RESUMO

Laser-induced optogalvanic (OG) signal oscillations detected in miniature neon glow discharge plasma are investigated using a discharge equivalent-circuit model. The damped oscillations in OG signal are generated when a pulsed dye laser is tuned to a specific neon transition (1s5→2p2) at 588.2 nm under the discharge conditions where dynamic resistance changes its sign. Penning ionization via quasi-resonant energy transfer collisions between neon gas atoms in metastable state and sputtered electrode atoms in ground state is discussed to explain the negative differential resistance properties of discharge plasma that are attributed to oscillations in the OG signal. The experimentally observed results are simulated by analyzing the behavior of an equivalent discharge-OG circuit. Good agreement between theoretically calculated and experimental results is observed. It is found that discharge plasma is more sensitive and less stable in close vicinity to dynamic resistance sign inversion, which can be useful for weak-optical-transition OG detection.

7.
SAR QSAR Environ Res ; 34(6): 501-521, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37462112

RESUMO

Gastric cancer (GC) is the fifth most prevalent form of cancer worldwide. CagA - positive Helicobacter pylori infects more than 60% of the human population. Moreover, chronic infection of CagA-positive H. pylori can directly affect GC incidence. In the current study, we have repurposed FDA-approved antibiotics that are viable alternatives to current regimens and can potentially be used as combination therapy against the CagA of H. pylori. The 100 FDA-approved gram negative antibiotics were screened against CagA protein using the AutoDock 4.2 tool. Further, top nine compounds were selected based on higher binding affinity with CagA. The trajectory analysis of MD simulations reflected that binding of these drugs with CagA stabilizes the system. Nonetheless, atomic density map and principal component analysis also support the notion of stable binding of antibiotics to the protein. The residues ASP96, GLN100, PRO184, and THR185 of compound cefpiramide, doxycycline, delafloxacin, metacycline, oxytetracycline, and ertapenem were involved in the binding with CagA protein. These residues are crucial for the CagA that aids in entry or pathogenesis of the bacterium. The screened FDA-approved antibiotics have a potential druggability to inhibit CagA and reduce the progression of H. pylori borne diseases.


Assuntos
Proteínas de Bactérias , Neoplasias Gástricas , Humanos , Antibacterianos/farmacologia , Antígenos de Bactérias/química , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/química , Simulação de Dinâmica Molecular , Proteínas Oncogênicas/metabolismo , Relação Quantitativa Estrutura-Atividade , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia
8.
J Dairy Sci ; 95(4): 1921-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22459839

RESUMO

Surveillance of antimicrobial use and resistance is needed to manage antimicrobial resistance in bacteria. In this study, data were collected on antimicrobial use and resistance in Staphylococcus aureus (n=562), isolated from intramammary infections and (sub)clinical mastitis cases on 89 dairy farms in 4 regions of Canada [Alberta, Ontario, Québec, and the Maritime Provinces (Prince Edward Island, Nova Scotia, and New Brunswick)]. Dairy producers were asked to deposit empty drug containers into specially provided receptacles, and antimicrobial drug use rate was calculated to quantify antimicrobial use. Minimum inhibitory concentrations were determined using the Sensititer bovine mastitis plate system (TREK Diagnostic Systems Inc., Cleveland, OH), containing antimicrobials commonly used for mastitis treatment and control. Multivariable logistic regression models were built to determine herd-level risk factors of penicillin, ampicillin, pirlimycin, penicillin-novobiocin combination, tetracycline and sulfadimethoxine resistance in Staph. aureus isolates. Intramammary administration of the penicillin-novobiocin combination for dry cow therapy was associated with penicillin and ampicillin resistance [odds ratio (OR): 2.17 and 3.10, respectively]. Systemic administration of penicillin was associated with penicillin resistance (OR: 1.63). Intramammary administration of pirlimycin for lactating cow mastitis treatment was associated with pirlimycin resistance as well (OR: 2.07). Average herd parity was associated with ampicillin and tetracycline resistance (OR: 3.88 and 0.02, respectively). Average herd size was also associated with tetracycline resistance (OR: 1.02). Dairy herds in the Maritime region had higher odds of penicillin and lower odds of ampicillin resistance than dairy herds in Québec (OR: 2.18 and 0.19, respectively). Alberta dairy herds had lower odds of ampicillin and sulfadimethoxine resistance than dairy herds in Québec (OR: 0.04 and 0.08, respectively). Ontario dairy herds had lower odds of tetracycline and sulfadimethoxine resistance than dairy herds in Québec (OR: 0.05 and 0.33, respectively). Herd-level use of certain antimicrobials administered for mastitis treatment and control, such as intramammary penicillin and pirlimycin as well as systemically administered penicillin and florfenicol, was positively associated with antimicrobial resistance in bovine mastitis pathogens in the field conditions. Differences in antimicrobial resistance outcomes across 4 regions of Canada were observed.


Assuntos
Antibacterianos/administração & dosagem , Indústria de Laticínios/métodos , Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Resistência a Ampicilina , Análise de Variância , Animais , Canadá , Bovinos , Clindamicina/análogos & derivados , Feminino , Testes de Sensibilidade Microbiana/veterinária , Leite/citologia , Leite/microbiologia , Resistência às Penicilinas , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/isolamento & purificação , Resistência a Tetraciclina
9.
J Dairy Sci ; 95(8): 4319-32, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22818446

RESUMO

Monitoring of antimicrobial resistance (AMR) in bacteria has clinical and public health significance. The present study determined prevalence of AMR in common mastitis pathogens Staphylococcus aureus, including methicillin-resistant Staph. aureus (MRSA; n=1,810), Escherichia coli (n=394), and Klebsiella species (n=139), including extended-spectrum ß-lactamase (ESBL)-producing E. coli and Klebsiella species, isolated from milk samples on 89 dairy farms in 6 Canadian provinces. Minimum inhibitory concentrations (MIC) were determined using the Sensititer bovine mastitis plate (Trek Diagnostic Systems Inc., Cleveland, OH) and a National Antimicrobial Resistance Monitoring System gram-negative panel containing antimicrobials commonly used for mastitis treatment and control. Denim blue chromogenic agar and real-time PCR were used to screen and confirm MRSA, respectively. Resistance proportion estimates ranged from 0% for cephalothin and oxacillin to 8.8% for penicillin in Staph. aureus isolates, and 15% of the resistant Staph. aureus isolates were multidrug resistant. One MRSA isolate was confirmed (prevalence: 0.05%). Resistance proportion estimates ranged from 0% for ceftriaxone and ciprofloxacin to 14.8% for tetracycline in E. coli, and 0% for amikacin, ceftiofur, ciprofloxacin, and nalidixic acid to 18.6% for tetracycline in Klebsiella species isolates. Further, 62.8 and 55% of the resistant E. coli and Klebsiella species isolates were multidrug resistant, respectively. Resistance to >5 and >2 antimicrobials was most common in E. coli and Klebsiella species isolates, respectively, and no ESBL producers were found. Prevalence of AMR in bovine mastitis pathogens was low. Most gram-negative udder pathogens were multidrug resistant; MRSA was rarely found, and ESBL E. coli and Klebsiella species isolates were absent in Canadian milk samples.


Assuntos
Anti-Infecciosos/farmacologia , Escherichia coli/efeitos dos fármacos , Klebsiella/efeitos dos fármacos , Mastite Bovina/microbiologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Animais , Anti-Infecciosos/uso terapêutico , Canadá/epidemiologia , Bovinos , Distribuição de Qui-Quadrado , Farmacorresistência Bacteriana Múltipla , Escherichia coli/isolamento & purificação , Feminino , Klebsiella/isolamento & purificação , Mastite Bovina/tratamento farmacológico , Mastite Bovina/epidemiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana/veterinária , Leite/microbiologia , Prevalência
10.
J Dairy Sci ; 95(3): 1209-21, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22365205

RESUMO

Antimicrobial use (AMU) data are critical for formulating policies for containing antimicrobial resistance. The present study determined AMU on Canadian dairy farms and characterized variation in AMU based on herd-level factors such as milk production, somatic cell count, herd size, geographic region and housing type. Drug use data were collected on 89 dairy herds in 4 regions of Canada, Alberta, Ontario, Québec, and the Maritime provinces (Prince Edward Island, New Brunswick, and Nova Scotia) for an average of 540 d per herd. Dairy producers and farm personnel were asked to deposit empty drug containers into specially provided receptacles. Antimicrobial use was measured as antimicrobial drug use rate (ADUR), with the unit being number of animal defined-daily doses (ADD)/1,000 cow-days. Antimicrobial drug use rates were determined at farm, region, and national level. Combined ADUR of all antimicrobial classes was 14.35 ADD/1,000 cow-days nationally. National level ADUR of the 6 most commonly used antimicrobial drug classes, cephalosporins, penicillins, penicillin combinations, tetracyclines, trimethoprim-sulfonamide combinations, and lincosamides were 3.05, 2.56, 2.20, 1.83, 0.87, and 0.84 ADD/1,000 cow-days, respectively. Dairy herds in Ontario were higher users of third-generation cephalosporins (ceftiofur) than in Québec. Alberta dairy herds were higher users of tetracyclines in comparison to Maritimes. Antimicrobial drug use rate was higher via systemic route as compared with intramammary and other routes of administration (topical, oral, and intrauterine). The ADUR of antimicrobials used intramammarily was higher for clinical mastitis treatment than dry cow therapy. For dry cow therapy, penicillin ADUR was greater than ADUR of first-generation cephalosporins. For clinical mastitis treatment, ADUR of intramammary penicillin combinations was greater than ADUR of cephapirin. Herd-level milk production was positively associated with overall ADUR, ADUR of systemically administered ceftiofur, cephapirin administered for dry cow therapy, and pirlimycin administered for clinical mastitis treatment. Herd size and ADUR of systemically administered ceftiofur were also positively associated. In conclusion, ß-lactams were most commonly used on Canadian dairy farms. Among antimicrobials of very high importance in human medicine, the use of fluoroquinolones was rare, whereas third-generation cephalosporins and penicillin combinations containing colistin were used very frequently on Canadian dairy farms.


Assuntos
Anti-Infecciosos/uso terapêutico , Indústria de Laticínios/métodos , Animais , Anti-Infecciosos/administração & dosagem , Canadá , Bovinos , Cefalosporinas/uso terapêutico , Indústria de Laticínios/estatística & dados numéricos , Feminino , Penicilinas/uso terapêutico , Tetraciclina/uso terapêutico
11.
J Clin Microbiol ; 49(4): 1568-77, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21270215

RESUMO

Determining the accuracy and precision of a measuring instrument is pertinent in antimicrobial susceptibility testing. This study was conducted to predict the diagnostic accuracy of the Sensititre MIC mastitis panel (Sensititre) and agar disk diffusion (ADD) method with reference to the manual broth microdilution test method for antimicrobial resistance profiling of Escherichia coli (n = 156), Staphylococcus aureus (n = 154), streptococcal (n = 116), and enterococcal (n = 31) bovine clinical mastitis isolates. The activities of ampicillin, ceftiofur, cephalothin, erythromycin, oxacillin, penicillin, the penicillin-novobiocin combination, pirlimycin, and tetracycline were tested against the isolates. Diagnostic accuracy was determined by estimating the area under the receiver operating characteristic curve; intertest essential and categorical agreements were determined as well. Sensititre and the ADD method demonstrated moderate to highly accurate (71 to 99%) and moderate to perfect (71 to 100%) predictive accuracies for 74 and 76% of the isolate-antimicrobial MIC combinations, respectively. However, the diagnostic accuracy was low for S. aureus-ceftiofur/oxacillin combinations and other streptococcus-ampicillin combinations by either testing method. Essential agreement between Sensititre automatic MIC readings and MIC readings obtained by the broth microdilution test method was 87%. Essential agreement between Sensititre automatic and manual MIC reading methods was 97%. Furthermore, the ADD test method and Sensititre MIC method exhibited 92 and 91% categorical agreement (sensitive, intermediate, resistant) of results, respectively, compared with the reference method. However, both methods demonstrated lower agreement for E. coli-ampicillin/cephalothin combinations than for Gram-positive isolates. In conclusion, the Sensititre and ADD methods had moderate to high diagnostic accuracy and very good essential and categorical agreement for most udder pathogen-antimicrobial combinations and can be readily employed in veterinary diagnostic laboratories.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Animais , Bactérias/isolamento & purificação , Bovinos , Feminino , Testes de Sensibilidade Microbiana/métodos
12.
Transfusion ; 50(7 Pt 2): 1625-9, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21175475

RESUMO

BACKGROUND: Prior studies have noted that donor retention may be negatively impacted by the total time it takes to complete the blood donation process. STUDY DESIGN AND METHODS: To gain a comprehensive understanding of the blood donation process and examine opportunities for operational improvements, an educational partnership established between a blood bank and a university designed and implemented a donor-driven data collection strategy. RESULTS: A large amount of real-time, comprehensive, donor-reported data was collected as donors navigated the process, which has enabled a thorough analysis of the process and its potential improvements. CONCLUSION: In this paper, we describe the design and implementation efforts, examine the challenges in operationalizing a donor-driven data collection approach, and present insights and recommendations for its application in similar settings.


Assuntos
Doadores de Sangue , Coleta de Dados/métodos , Humanos
14.
Nat Prod Res ; 22(3): 269-74, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18266159

RESUMO

In order to scientifically appraise some of the folkloric uses of Solanum khasianum Clarke (Solanaceae), the present study was undertaken to examine the anti-inflammatory and anthelmintic properties of the berries of ethanol extract. Anti-inflammatory activity was tested in carrageenan induced rat hind paw edema method at three dose level of 200, 300, and 400 mg kg(-1) respectively, Diclofenac sodium (100 mg kg(-1)) was used as the reference standard. The anti-inflammatory activity of the extract was compared with standard and control. The anthelmintic activity of the extract was tested on tape worm, liver fluke, thread worm, and hook worm using two different concentrations, 100 and 200 mg mL(-1) respectively. Time taken for the inhibition of motility was noted and compared with the standard drug, Piperazine citrate 15 mg mL. The plant extract significantly (p < 0.01) reduced the inflammation of the rats when compared to the control group. Also, the ethanol extract of the plant paralyzed the worms followed by death, which was comparable with that of the standard. This study supports the folk claim.


Assuntos
Anti-Helmínticos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Extratos Vegetais/farmacologia , Solanum/química , Anti-Helmínticos/química , Anti-Inflamatórios não Esteroides/química , Frutas/química , Medicina Tradicional , Extratos Vegetais/química
15.
Rev Sci Instrum ; 88(9): 093101, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28964210

RESUMO

Development of a demountable and see-through hollow cathode (HC) discharge lamp suitable for optogalvanic (OG) spectroscopy is described. The design of the HC lamp is simple, compact, and inexpensive. Lithium, investigated rarely by the OG method, is selected for cathode material as its isotopes are important for nuclear industry. The HC lamp is characterized electrically and optically for discharge oscillations free OG effect. Strong OG signals of lithium as well as neon (as buffer gas) are produced precisely upon copper vapor laser pumped tunable dye laser irradiation. The HC lamp is capable of generating a clean OG resonance spectrum in the available dye laser wavelength scanning range (627.5-676 nm) obtained with 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran dye. About 28 resonant OG lines are explicitly observed. Majority of them have been identified using j-l coupling scheme and assigned to the well-known neon transitions. One line that corresponds to wavelength near about 670.80 nm is assigned to lithium and resolved for its fine (2S1/2 → 2P1/2, 3/2) transitions. These OG transitions allow 0.33 cm-1 accuracy and can be used to supplement the OG transition data available from other sources to calibrate the wavelength of a scanning dye laser with precision at atomic levels.

16.
J Colloid Interface Sci ; 296(1): 59-63, 2006 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-16168429

RESUMO

Batch studies were conducted to investigate the kinetics and isotherms of Cu(II) biosorption on the biomass of green alga Spirogyra species. It is observed that the biosorption capacity of the biomass strongly depends on pH and algal dose. The maximum biosorption capacity of 133.3 mg Cu(II)/g of dry weight of biomass was observed at an optimum pH of 5 in 120 min with an algal dose of 20 g/L. Desorption studies were conducted with 133.3 mg/g of Cu(II) loaded biomass using different desorption agents including HCl, EDTA, H2SO4, NaCl, and H2O. The maximum desorption of 95.3% was obtained with HCl in 15 min. The results indicate that with the advantages of high metal biosorption capacity and satisfactory recovery of Cu(II), Spirogyra can be used as an efficient and economic biosorbent material for the removal and recovery of toxic heavy metals from polluted water.


Assuntos
Clorófitas/química , Cobre/farmacocinética , Poluentes Químicos da Água/farmacocinética , Adsorção , Biodegradação Ambiental , Biomassa , Concentração de Íons de Hidrogênio , Soluções/química , Termodinâmica , Água/química
17.
Cell Signal ; 11(8): 603-10, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10433521

RESUMO

The Ras-GRF exchange factor can activate Ras-dependent responses following the activation of heterotrimeric G-protein and calcium signalling. In stable lines of NIH-3T3 fibroblasts that express Ras-GRF, the agonist lysophosphatidic acid (LPA) increases the phosphorylation state and activity of Ras-GRF. The stimulation of Ras-GRF can be demonstrated in vitro, in an assay using recombinant Ras substrate, and in situ, by a selective increase in the ability of LPA to stimulate mitogen-activated protein (MAP) kinase. The increase in Ras-GRF phosphorylation state, which occurs on serine residues, and the increase in exchange factor activity are blocked by pretreatment with pertussis toxin. Activation of Ras-GRF by LPA can also be inhibited by chelation of intracellular calcium and treatment of the Ras-GRF with protein phosphatase 1 (PP1), supporting a model in which Ras-GRF serves to integrate signals from multiple transduction pathways.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Lisofosfolipídeos/metabolismo , Células 3T3 , Animais , Sinalização do Cálcio , Proteínas de Ciclo Celular/genética , Expressão Gênica , Lisofosfolipídeos/farmacologia , Camundongos , ras-GRF1
18.
J Colloid Interface Sci ; 288(1): 55-60, 2005 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-15927561

RESUMO

Arsenic is a toxic element and may be found in natural waters as well as in industrial waters. Leaching of arsenic from industrial wastewater into groundwater may cause significant contamination, which requires proper treatment before its use as drinking water. The present study describes removal of arsenic(III) on iron oxide-coated sand in batch studies conducted as a function of pH, time, initial arsenic concentration, and adsorbent dosage. The results were compared with those for uncoated sand. The adsorption data fitted well in the Langmuir model at different initial concentration of As(III) at 20 g/l fixed adsorbent dose. Maximum adsorption of As(III) for coated sand is found to be much higher (28.57 microg/g) than that for uncoated sand (5.63 microg/g) at pH 7.5 in 2 h. The maximum As(III) removal efficiency achieved is 99% for coated sand at an adsorbent dose of 20 g/l with initial As(III) concentration of 100 microg/l in batch studies. Column studies have also been carried out with 400 microg/l arsenic (pH 7.5) by varying the contact time, filtration rate, and bed depth. Results of column studies demonstrated that at a filtration rate of 4 ml/min the maximum removal of As(III) observed was 94% for coated sand in a contact time of 2 h. The results observed in batch and column studies indicate that iron oxide-coated sand is a suitable adsorbent for reducing As(III) concentration to the limit (50 microg/l) recommended by Indian Standards for Drinking Water.

19.
Cardiovasc Res ; 23(12): 1001-6, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2559806

RESUMO

Fentanyl, a mu selective opioid agonist in wide clinical use, raises the ventricular fibrillation threshold in the normal canine myocardium. We have previously shown that this effect is amplified by haemorrhagic stress. In order to determine if mu receptor activation is antifibrillatory during acute myocardial ischaemia, we compared the effects of two mu selective agents, fentanyl and buprenorphine, in open chest chloralose anaesthetised dogs. Each drug was administered intravenously in two doses 1 h apart (fentanyl 30 micrograms.kg-1.dose; buprenorphine 0.3 mg.kg-1.dose). Ventricular fibrillation threshold was measured during right ventricular pacing using the single stimulus technique. The threshold was determined before and during a 10 min left anterior descending coronary artery occlusion. Prior to fentanyl administration, ventricular fibrillation threshold decreased from a control value of 19(SEM 2) mA to 12(1) mA during coronary artery occlusion. After the first dose of this drug an attenuation in the ischaemia induced fall in fibrillation threshold from 23(4) mA to 15(2) mA was observed. After the second dose of fentanyl the decline in fibrillation threshold was significantly blunted at 22(4) mA during control and 18(3) mA during occlusion, p less than 0.05 compared to no drug. In an additional series of experiments atropine sulphate abolished the antifibrillatory action of fentanyl, indicating that vagal efferent activation is responsible for the protective effect of the drug during acute myocardial ischaemia. This is in contrast with its mode of action during haemorrhage, when it enhances vagal afferent inhibition of sympathetic tone, and atropine pretreatment is without effect.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Buprenorfina/farmacologia , Doença das Coronárias/fisiopatologia , Fentanila/farmacologia , Sistema de Condução Cardíaco/efeitos dos fármacos , Receptores Opioides/efeitos dos fármacos , Fibrilação Ventricular/fisiopatologia , Animais , Cães , Sistema de Condução Cardíaco/fisiopatologia , Receptores Opioides mu
20.
Indian J Pharm Sci ; 77(6): 687-93, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26997696

RESUMO

Adverse drug reactions associated with the use of anticancer drugs are a worldwide problem and cannot be ignored. Adverse drug reactions can range from nausea, vomiting or any other mild reaction to severe myelosuppression. The study was planned to observe the suspected adverse drug reactions of cancer chemotherapy in patients aged >18 years having cancer attending Postgraduate Institute of Medical Education and Research, Chandigarh. During the study period, 101 patients of breast cancer and 73 patients of lung cancer were screened for occurrence of adverse drug reactions during their treatment with chemotherapy. About 87.36% patients experienced adverse drug reactions, 90.09% and 83.56% of breast and lung cancer patients experienced at least one adverse drug reaction respectively. In breast cancer patients, 41.58% patients were prescribed fluorouracil+doxorubicin+cyclophosphamide while paclitaxel was prescribed to 22.77% patients. Alopecia (54.94%), nail discolouration (43.96%), dysgeusia (38.46%), anorexia (30.77%), nausea (29.67%), and neuropathy (29.67%) were found to be very common in breast cancer patients treated with single/combined regimen. In lung cancer group of patients, cisplatin with docetaxel, cisplatin with pemetrexed and cisplatin with irinotecan were prescribed to 30.14, 24.65 and 17.81% patients, respectively. Dysgeusia (40.98%), diarrhoea (39.34%), anorexia (32.77%) and constipation (31.15%) and alopecia (31.15%) were commonly observed adverse drug reactions having lung cancer patients. Causality assessments using World Health Organization causality assessment scale showed that observed adverse drug reactions were of probable (64.67%) and possible (35.33%) categories. Alopecia, dysgeusia, anorexia, constipation diarrhoea, nausea, nail discoloration were more prevalent amongst the cancer patients undergoing chemotherapy.

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