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1.
AJNR Am J Neuroradiol ; 43(4): 568-574, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35301225

RESUMO

BACKGROUND: The efficacy of combined aspiration catheter and stent retriever compared with stent retriever alone for the treatment of large-vessel occlusion acute ischemic stroke is unclear. PURPOSE: Our aim was to conduct a systematic literature review and meta-analysis on several metrics of efficacy comparing aspiration catheter and stent retriever with stent retriever alone. DATA SOURCES: MEDLINE and the Cochrane Library Databases were searched. Randomized controlled trials and case-control and cohort studies were included. STUDY SELECTION: Ten comparative studies were included detailing a combined 1495 patients with aspiration catheter and stent retriever and 1864 with stent retrievers alone. DATA ANALYSIS: Data on first pass effect (TICI 2b/2c/3 after first pass), final successful reperfusion (modified TICI ≥2b), and 90-day functional independence (mRS ≤ 2) were collected. Meta-analysis was performed using a random-effects model. DATA SYNTHESIS: There was a pooled composite first pass effect of 40.8% (611/1495) versus 32.6% (608/1864) for aspiration catheter and stent retriever and stent retriever alone, respectively (P < .0001). Similarly, on a meta-analysis, aspiration catheter and stent retriever were associated with a higher first pass effect compared with stent retriever alone (OR = 1.63; 95% CI, 1.20-2.21; P = .002; I2 = 72%). There was no significant difference in composite rates of successful reperfusion between aspiration catheter and stent retriever (72.8%, 867/1190) and stent retriever alone (70.8%, 931/1314) (P = .27) or on meta-analysis (OR = 1.31; CI, 0.81-2.12; P = .27; I2 = 82%). No difference was found between aspiration catheter and stent retriever and stent retriever alone on 90-day functional independence (OR = 1.02; 95% CI, 0.77-1.36; P = .88; I2 = 40%). LIMITATIONS: This study is limited by high interstudy heterogeneity. CONCLUSIONS: On meta-analysis, aspiration catheter and stent retriever are associated with a superior first pass effect compared with stent retriever alone, but they are not associated with statistically different final reperfusion or functional independence.


Assuntos
Arteriopatias Oclusivas , Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Arteriopatias Oclusivas/complicações , Isquemia Encefálica/complicações , Isquemia Encefálica/cirurgia , Catéteres , Humanos , Estudos Retrospectivos , Stents , Acidente Vascular Cerebral/complicações , Trombectomia , Resultado do Tratamento
2.
J Pediatr Urol ; 15(5): 442-447, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31085139

RESUMO

BACKGROUND: Spinal anesthesia (SA) is an established anesthetic technique for short outpatient pediatric urological cases. To avoid general anesthesia (GA) and expand regional anesthetics to longer and more complex pediatric surgeries, the authors began a program using a combined spinal/caudal catheter (SCC) technique. STUDY DESIGN: The authors retrospectively reviewed the charts of all patients scheduled for surgery under SCC between December 2016 and April 2018 and recorded age, gender, diagnosis, procedure, conversion to GA/airway intervention, operative time, neuraxial and intravenous medications administered, complications, and outcomes. The SCC technique typically involved an initial intrathecal injection of 0.5% isobaric bupivacaine followed by placement of a caudal epidural catheter. At the discretion of the anesthesiologist, patients received 0.5 mg per kilogram of oral midazolam approximately 30 min prior to entering the operating room. One hour after the intrathecal injection, 3% chloroprocaine was administered via the caudal catheter to prolong the duration of surgical block. Intra-operative management included either continuous infusion or bolus dosing of dexmedetomidine, as needed, for patient comfort and to optimize surgical conditions. Prior to removal of caudal catheter in the post-anesthesia care unit, a supplemental bolus dose of local anesthesia was given through the catheter to provide prolonged post-operative analgesia. RESULTS: Overall, 23 children underwent attempted SCC. SA was unsuccessful in three patients, and surgery was performed under GA. The remaining 20 children all had successful SCC placement. There were 11 girls and nine boys, with a mean age of 16.5 months (3.3-43.8). Surgeries performed under SCC included seven ureteral reimplantations, two ureterocele excisions/reimplantations, two megaureter repairs, four first-stage hypospadias repairs, one distal hypospadias repair, one second-stage hypospadias repair, two feminizing genitoplasties, and one open pyeloplasty. Average length of surgery was 109 min (range 63-172 min). Pre-operative midazolam was given in 13/20 (65%). All SCC patients were spontaneously breathing room air during the operation, and there were no airway interventions. Only one SCC patient received opioids intra-operatively. There were no intra-operative or perioperative complications. DISCUSSION: This pilot study shows that the technique of SCC allows one to do more complex urologic surgery under regional anesthesia than what would be possible under pure SA alone. The main limitations of the study include the relatively small number of patients and the small median length of the operative procedures. As a proof of concept, however, this does show that complex genital surgery bladder level procedures such as ureteral reimplantation can be performed under regional anesthesia. CONCLUSION: SCC allows for more complex surgeries to be performed exclusively under regional anesthesia, thus obviating the need for airway intervention, minimizing or eliminating the use of opioids, and thus avoiding known and potential risks associated with GA. The latter is of particular importance given current concerns regarding hypothetical neurocognitive effects of GA on children aged below 3 years.


Assuntos
Anestesia Caudal , Raquianestesia , Procedimentos Cirúrgicos Urológicos , Anestesia Caudal/instrumentação , Anestesia Caudal/métodos , Anestesia por Condução/métodos , Raquianestesia/instrumentação , Raquianestesia/métodos , Catéteres , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Projetos Piloto , Estudos Retrospectivos
3.
Biotechnol Appl Biochem ; 61(4): 459-65, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24712720

RESUMO

Arylacetonitrile-hydrolyzing nitrilase (E.C. 3.5.5.5) of Alcaligenes sp. MTCC 10675 has been purified by up to 46-fold to homogeneity and 32% yield using ammonium sulfate fractionation, Sephacryl S-300 gel permeation, and anion exchange chromatography. The molecular weight of the native enzyme was estimated to be 520 ± 60 kDa. The subunit has a molecular weight of 60 ± 14 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature of the purified enzyme were 6.5 and 50 °C, respectively. The purified arylacetonitrilase has a half-life of 3 H 20 Min at its optimum temperature. The value for Vmax, Km , kcat , and ki of enzyme for mandelonitrile as a substrate was 50 ± 05 µmol/Min/mg, 13 ± 02 mM, 26 ± 03 Sec(-) , and 32.4 ± 03 mM, respectively. Alcaligenes sp. MTCC 10675 arylacetonitrilase amino acid sequence has variations from other reported arylacetonitrilase, namely, A11G, N21H, D149N, S170T, P171R, S179A, Q180N, and S191A, and it has a high thermal stability and catalytic rate as compared with the already purified arylacetonitrilase.


Assuntos
Alcaligenes/enzimologia , Hidroliases/isolamento & purificação , Hidroliases/metabolismo , Biocatálise , Estabilidade Enzimática , Hidroliases/química , Concentração de Íons de Hidrogênio , Peso Molecular , Temperatura
4.
Appl Microbiol Biotechnol ; 98(1): 83-94, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24104468

RESUMO

Alcaligenes sp. MTCC 10675 has been isolated from soil sample using enrichment method and has nitrilase catalytic system which is highly specific for the hydrolysis of arylaliphatic nitriles. Optimization of culture conditions using response surface methodology and inducer-mediated approach enhanced arylacetonitrilase production significantly (2.4-fold). Isobutyronitrile acted as an effective inducer for the induction of arylacetonitrilase, and it is highly specific for arylacetonitriles (phenyl acetonitrile and mandelonitrile). Arylacetonitrilase has no effect on its relative velocity (V r) up to 20 mM substrate (mandelonitrile) concentration and at 30 mM mandelonitrile, 23.4 % degree of inhibition (I d) was recorded. Half life of arylacetonitrilase of Alcaligenes sp. MTCC 10675 was 27.5 h at 25 °C. Hg(2+), Ag(+), Pb(3+), and Co(2+) were strong inhibitor of arylacetonitrilase activity which resulted into 100 %, 91 %, 84 %, and 83 % inhibition, respectively. Polar protic solvent (dichloromethane, dimethylsulphooxide, and n-butanol) reduce arylacetonitrilase activity up to 80-94 % at 10 % concentration. Alcaligenes sp. MTCC 10675 has higher biocatalytic activity, i.e., 3.9 gg(-1) dcw, which is highest in comparison to till reported organism. Arylacetonitrilase-mediated hydrolysis of racemic mandelonitrile resulted into R-(-) mandelic acid with 99.0 % enantiomeric excess (e.e.).


Assuntos
Alcaligenes/enzimologia , Aminoidrolases/metabolismo , Ácidos Mandélicos/metabolismo , Acetonitrilas/metabolismo , Alcaligenes/química , Alcaligenes/isolamento & purificação , Aminoidrolases/química , Inibidores Enzimáticos/metabolismo , Estabilidade Enzimática , Regulação Enzimológica da Expressão Gênica , Concentração de Íons de Hidrogênio , Cinética , Metais/metabolismo , Nitrilas/metabolismo , Microbiologia do Solo , Temperatura , Ativação Transcricional
5.
3 Biotech ; 4(4): 375-381, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28324474

RESUMO

Alcaligenes sp. MTCC 10674 has a bienzymatic system for the hydrolysis of nitriles. The nitrile hydratase and amidase have been purified simultaneously to homogeneity using a combination of (NH)4SO4 precipitation, ion exchange chromatography and gel permeation chromatography. Nitrile hydratase and amidase have molecular weight of 47 and 114 kDa, respectively and exist as heterodimer. Optimum temperatures for maximum activity of nitrile hydratase and amidase were 15 °C (2.4 U/mg protein) and 45 °C (2.3 U/mg protein), respectively. Nitrile hydratase showed maximum 7.8 U/mg protein at 50 mM acrylonitrile and amidase has 9.2 U/mg protein at 25 mM propionamide. Nitrile hydratase has Vmax 10 µmol/min/mg and Km 40 mM, while amidase has Vmax 12.5 µmol/min/mg and Km 45.5 mM, respectively. Heavy metal ions Hg2+, Ag+, Pb2+ and Cu2+ were strong inhibitors of nitrile hydratase and amidase activity.

6.
Bioprocess Biosyst Eng ; 36(5): 613-25, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22945851

RESUMO

Alcaligenes sp. MTCC 10674 was isolated as acetone cyanohydrin hydrolyzing bacterium from soil of orchid gardens of Himachal Pradesh. Acetone cyanohydrin hydrolyzing activity of this organism comprised nitrile hydratase and amidase activities. It exhibited higher substrate specificity towards aliphatic hydroxynitrile (acetone cyanohydrin) in comparison to arylaliphatic hydroxynitrile. Isobutyronitrile (40 mM) acted as a carbon source as well as inducer for growth of Alcaligenes sp. MTCC 10674 and expression of acetone cyanohydrin hydrolyzing activity. Optimization of culture condition using response surface methodology increased acetone cyanohydrin hydrolyzing activity by 1.3-fold, while inducer mediation approach increased the activity by 1.2-fold. The half life of this enzyme was 25 h at 15 °C. V max and K m value for acetone cyanohydrin hydrolyzing enzyme was 0.71 µmol mg(-1) min(-1) and 14.3 mM, when acetone cyanohydrin was used as substrate. Acetone cyanohydrin hydrolyzing enzyme encountered product inhibition and IC50 and K i value were calculated to be 28 and 10.2 mM, respectively, when product α-hydroxyisobutyric acid was added in the reaction. Under optimized reaction conditions at 40 ml fed batch scale, 3 mg dcw ml (-) resting cells of Alcaligenes sp. MTCC 10674 fully converted 0.33 M acetone cyanohydrin into α-hydroxyisobutyric acid (1.02 g) in 6 h 40 min. The characterization of acetone cyanohydrins hydrolyzing activity revealed that it comprises bienzymatic nitrile hydrolyzing system, i.e. nitrile hydratase and amidase for the production of α-hydroxyisobutyric acid from acetone cyanohydrin and maximum 70 % yield is being reported for the first time.


Assuntos
Alcaligenes/enzimologia , Amidoidrolases/biossíntese , Proteínas de Bactérias/biossíntese , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Hidroliases/biossíntese , Hidroxibutiratos/metabolismo , Nitrilas/farmacologia , Alcaligenes/crescimento & desenvolvimento , Alcaligenes/isolamento & purificação , Microbiologia do Solo
7.
3 Biotech ; 3(3): 247-254, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28324375

RESUMO

A number of traditional fermented products are prepared and consumed in Himachal and the types of traditional fermented products of Himachal are unique and different from other areas. Bhatooru is an indigenous leavened bread or roti and constitutes the staple diet of rural population of Himachal. The microbiological analysis of the inoculums (malera) revealed that it composed of a consortium of microorganisms. Population of Lactobacillus, Leuconostoc and Saccharomyces cerevisiae increased from 4.77 to 8.0 log cfu/g of dry matter in 10 h of fermentation. The amount of total proteins increased from 13.6 to 18.4 % (w/w). The total sugars during fermentation decreased from 74.1 to 50.1 % (w/w) on dry weight basis. However, the reducing sugar level of the fermenting samples increased significantly from 7.8 to 16.5 mg/g dry matter in the first 4 h and thereafter, it gradually decreased to 10.0 mg/g dry matter. Similarly starch content decreased from 70.2 to 48.3 % (w/w) on dry weight basis by 10 h of fermentation. In fermented samples protease activity increased from 0.48 U/g dry matter to 11.5 U/g in 6 h and then decreased to 3.21 U/g on dry weight basis at 10 h. Amylase activity initially increased from 65.0 to 79.4 U to 6 h and then declined to 69.9 U/g of dry matter. Fermentation in bhatooru significantly enhanced the B vitamin levels especially thiamine, riboflavin and nicotinic acid and essential amino acids viz methionine, phenylalanine, threonine, lysine and leucine.

8.
Appl Biochem Biotechnol ; 168(3): 465-86, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22833401

RESUMO

The NHase encoding gene of mutant 4D was isolated by PCR amplification. The NHase gene of mutant 4D was successfully cloned and expressed in Escherichia coli by using Ek/LIC Duet cloning kits (Novagen). For the active expression of the NHase gene, the co-expression of small cobalt transporter gene (P-protein gene) has also been co-expressed with NHase gene E. coli. The nucleotide sequence of this NHase gene revealed high homology with the H-NHase of Rhodococcus rhodochrous J1. The recombinant E. coli cells showed higher NHase activity (5.9 U/mg dcw) as compared to the wild (4.1 U/mg dcw) whereas it is less than the mutant strain (8.4 U/mg dcw). Addition of cobalt ion in Luria-Bertani medium is needed up to a very small concentration (0.4 mM) for NHase activity. The recombinant E. coli exhibited maximum NHase activity at 6 h of incubation and was purified with a yield of 56 % with specific activity of 37.1 U/mg protein.


Assuntos
Proteínas de Bactérias/genética , Clonagem Molecular , Escherichia coli/genética , Hidroliases/genética , Rhodococcus/enzimologia , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Sequência de Bases , Escherichia coli/metabolismo , Expressão Gênica , Hidroliases/química , Hidroliases/metabolismo , Dados de Sequência Molecular , Rhodococcus/genética , Alinhamento de Sequência
9.
Folia Microbiol (Praha) ; 55(5): 442-6, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20941578

RESUMO

The nitrile hydratase (NHase) of Rhodococcus rhodochrous PA-34 catalyzed the conversion of acrylonitrile to acrylamide. The resting cells (having NHase activity) (8 %; 1 mL corresponds to 22 mg dry cell mass, DCM) were immobilized in polyacrylamide gel containing 12.5 % acrylamide, 0.6 % bisacrylamide, 0.2 % diammonium persulfate and 0.4 % TEMED. The polyacrylamide entrapped cells (1.12 mg DCM/mL) completely converted acrylonitrile in 3 h at 10 °C, using 0.1 mol/L potassium phosphate buffer. In a partitioned fed batch reactor, 432 g/L acrylamide was accumulated after 1 d. The polyacrylamide discs were recycled up to 3×; 405, 210 and 170 g/L acrylamide was produced in 1st, 2nd and 3rd recycling reactions. In four cycles, a total of 1217 g acrylamide was produced by recycling the same mass of entrapped cells.


Assuntos
Acrilamida/metabolismo , Resinas Acrílicas , Acrilonitrila/metabolismo , Células Imobilizadas/metabolismo , Rhodococcus/metabolismo , Proteínas de Bactérias/metabolismo , Biotecnologia/métodos , Hidroliases/metabolismo , Rhodococcus/enzimologia , Rhodococcus/crescimento & desenvolvimento
10.
Biodegradation ; 21(5): 761-70, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20204468

RESUMO

The soil actinobacteria Rhodococcus rhodochrous PA-34, Rhodococcus sp. NDB 1165 and Nocardia globerula NHB-2 grown in the presence of isobutyronitrile exhibited nitrilase activities towards benzonitrile (approx. 1.1-1.9 U mg(-1) dry cell weight). The resting cell suspensions eliminated benzonitrile and the benzonitrile analogues chloroxynil (3,5-dichloro-4-hydroxybenzonitrile), bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) and ioxynil (3,5-diiodo-4-hydroxybenzonitrile) (0.5 mM each) from reaction mixtures at 30 degrees C and pH 8.0. The products were isolated and identified as the corresponding substituted benzoic acids. The reaction rates decreased in the order benzonitrile >> chloroxynil > bromoxynil > ioxynil in all strains. Depending on the strain, 92-100, 70-90 and 30-51% of chloroxynil, bromoxynil and ioxynil, respectively, was hydrolyzed after 5 h. After a 20-h incubation, almost full conversion of chloroxynil and bromoxynil was observed in all strains, while only about 60% of the added ioxynil was converted into carboxylic acid. The product of ioxynil was not metabolized any further, and those of the other two herbicides very slowly. None of the nitrilase-producing strains hydrolyzed dichlobenil (2,6-dichlorobenzonitrile). 3,5-Dibromo-4-hydroxybenzoic acid exhibited less inhibitory effect than bromoxynil both on luminescent bacteria and germinating seeds of Lactuca sativa. 3,5-Diiodo-4-hydroxybenzoic acid only exhibited lower toxicity than ioxynil in the latter test.


Assuntos
Actinobacteria/metabolismo , Herbicidas/metabolismo , Herbicidas/toxicidade , Nitrilas/metabolismo , Nitrilas/toxicidade , Microbiologia do Solo , Actinobacteria/efeitos dos fármacos , Actinobacteria/enzimologia , Amidas/metabolismo , Amidoidrolases/metabolismo , Aminoidrolases/metabolismo , Biodegradação Ambiental/efeitos dos fármacos , Biotransformação/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Hidrólise/efeitos dos fármacos , Lactuca/efeitos dos fármacos , Lactuca/crescimento & desenvolvimento , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Testes de Toxicidade Aguda
11.
J Food Sci Technol ; 47(4): 458-60, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23572671

RESUMO

A solid state fermentation process was tried for the production of citric acid from apple pomace left after juice extraction using Aspergillus niger van. Tieghem MTCC 281 spores as inoculum (36.8 × 10(4) spores/100 g of pomace). The yield of citric acid was optimized by varying the amount of methanol (1-5% v/w), temperature (25-35°C) and time of incubation (1-7 days) for fermentation process. Optimum yield of citric acid (4.6 g/100 g of pomace) was recorded with 4% (v/w) methanol after 5 days of incubation at 30°C.

12.
Indian J Microbiol ; 49(3): 237-42, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23100776

RESUMO

A propionitrile-induced nitrile hydratase (NHase), a promising biocatalyst for synthesis of organic amides has been purified from cell-free extract of Rhodococcus rhodochrous PA-34. About 11-fold purification of NHase was achieved with 52% yield. The SDS-PAGE of the purified enzyme revealed that it consisted of two subunits of 25.04 kD and 30.6 kD. However, the molecular weight of holoenzyme was speculated to be 86 kD by native-PAGE. This NHase exhibited maximum activity at pH 8.0 and temperature 40°C. Half-life was 2 h at 40°C and 0.5 h at 50°C. The Km and Vmax were 167 mM and 250 µmole/min/mg using 25 mM 3-cyanopyridine as substrate. AgNO(3), Pb(CH(3)COO)(2) and HgCl(2) inhibited the NHase to extent of 89-100%.

13.
Acta Microbiol Immunol Hung ; 54(1): 79-88, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17523394

RESUMO

The free and agar immobilized cells of Nocardia globerula NHB-2 having nitrilase (EC 3.5.5.1) activity were used to catalyse the transformation of benzonitrile to benzoic acid. The whole cells of N. globerula NHB-2 were immobilized in agar which exhibited maximum conversion of benzonitrile to benzoic acid in 0.1 M potassium phosphate buffer pH 7.5 (free cells) 8.0 (immobilized cells), temperature 40 degrees C, cells 2 mg dcm ml(-1) reaction mixture and benzonitrile (4% v/v) in 4 h (free cells). The effect of temperature on the stability of nitrilase was studied and cells retained 100% activity at 30 degrees C and lost 50% activity at 40 degrees C. In a fed batch mode of reaction 108 and 84 gl(-1) benzoic acid was produced using free and agar entrapped cells (2 g dcm). The agar immobilized cells were recycled up to three times and 80, 62, 20 gl(-1) benzoic acid was again produced respectively in each of three cycles and a total 244 g benzoic acid was produced by recycling the same mass of immobilized biocatalyst.


Assuntos
Ácido Benzoico/metabolismo , Nitrilas/metabolismo , Nocardia/metabolismo , Ágar , Aminoidrolases/metabolismo , Biotransformação , Células Imobilizadas , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Temperatura
14.
Appl Microbiol Biotechnol ; 74(3): 535-9, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17216468

RESUMO

Butyramide is an important chemical commodity, which is used for the synthesis of hydroxamic acids and electrorheological fluids and for the preparation of beta-amodoorganotin compounds. The nitrile hydratase (Nhase) of Rhodococcus rhodochrous PA-34 catalyzed the conversion of butyronitrile to butyramide. The maximum Nhase activity [18 U/mg dry cell weight (dcw)] of whole cells of R. rhodochrous PA-34 was observed at pH 7.0 with 10% (v/v) butyronitrile and 1 mg cells (dcw)/ml reaction mixture at 10 degrees C. The cells of R. rhodochrous PA-34 retained almost 50% activity when incubated for 1 h in the presence of 85% (v/v) butyronitrile. A yield of 597 g of butyramide (6.8 M) was obtained using 60% (v/v) butyronitrile, 1 g cells (dry weight) in a 1-l batch reaction at 10 degrees C for 6 h.


Assuntos
Amidas/metabolismo , Nitrilas/metabolismo , Rhodococcus/metabolismo , Biotransformação , Hidroliases/análise , Concentração de Íons de Hidrogênio , Temperatura , Fatores de Tempo
15.
Indian J Microbiol ; 47(1): 34-41, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23100637

RESUMO

The nitrile hydratase (NHase, EC 3.5.5.1) activity of Rhodococcus rhodochrous PA-34 was explored for the conversion of 3-cyanopyridine to nicotinamide. The NHase activity (∼18 U/mg dry cell weight, dcw) was observed in 0.1 M phosphate buffer, pH 8.0 containing 1M 3-cyanopyridine as substrate, and 0.75 mg of resting cells (dry cell weight) per ml reaction mixture at 40°C. However, 25°C was more suitable for prolonged batch reaction at high substrate (3-cyanopyridine) concentration. In a batch reaction (1 liter), 7M 3-cyanopyridine (729 g) was completely converted to nicotinamide (855 g) in 12h at 25°C using 9.0 g resting cells (dry cell weight) of R. rhodochrous PA-34.

16.
Indian J Exp Biol ; 44(3): 240-5, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16538864

RESUMO

Nocardia globerula NHB-2 exhibited an intracellular acetonitrile hydrolysing activity (AHA) when cultivated in nutrient broth supplemented with glucose (10.0 g/l) and yeast extract (1.0 g/l), at pH 8.0, 30 degrees C for 21 hr. Maximum AHA was recorded in the culture containing 0.1 M of sodium phosphate buffer, (pH 8.8) at 45 degrees C for 15 min with 600 micromol of acetonitrile and resting cells of N. globerula NHB-2 equivalent to 1.0 ml culture broth. This activity was stable up to 40 degrees C and was completely inactivated at or above 60 degrees C. About five-fold increase in AHA was observed after optimization of culture and reaction conditions. Under the optimized conditions, this organism hydrolyzed various nitriles and amides such as propionitrile, benzonitrile. acetamide, and acrylamide to corresponding acids. This nitrile/amide hydrolysing activity of N. globerula NHB-2 has potential applications in enzymatic synthesis of organic acids and bioremediation of nitriles and amides contaminated soil and water system.


Assuntos
Acetonitrilas/metabolismo , Nocardia/metabolismo , Catálise , Meios de Cultura , Concentração de Íons de Hidrogênio , Hidrólise , Íons/química , Metais/química , Metais/farmacologia , Nocardia/efeitos dos fármacos , Especificidade por Substrato , Temperatura , Fatores de Tempo
17.
Indian J Exp Biol ; 42(5): 515-21, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15233479

RESUMO

A thermostable extracellular protease of Bacillus sp. APR-4 was purified by size-exclusion and ion-exchange chromatographic methods and its properties were studied. The purified enzyme had a specific activity of 21,000 U/mg of protein and gave single band on SDS/PAGE with a molecular mass of 16.9 KDa. This protease had an optimal pH of 9 and exhibited its highest activity at 60 degrees C. The enzyme activity was inhibited by EDTA, suggesting the presence of metal residue at the active site. Ca2+ (5 mM) had stabilising effect on the activity of protease, but Cu2+ (5 mM) had inhibitory effect. The enzyme exhibited highest specificity towards casein (1%) and had a Km of 26.3 mg/ml and a Vmax of 47.6 U/mg with casein as a substrate. The stability of this enzyme was evaluated in the presence of some organic solvents and the enzyme was stable in methanol, petroleum ether and ethanol. Detergents (Wheel, Farishta) had stimulatory effect on the activity of this enzyme.


Assuntos
Bacillus/enzimologia , Endopeptidases/isolamento & purificação , Alcanos/química , Sítios de Ligação , Cálcio/química , Cálcio/metabolismo , Caseínas/química , Cromatografia em Gel , Cromatografia por Troca Iônica , Detergentes/farmacologia , Eletroforese em Gel de Poliacrilamida , Endopeptidases/química , Etanol/química , Concentração de Íons de Hidrogênio , Cinética , Magnésio/metabolismo , Metanol/química , Proteínas/química , Solventes/química , Especificidade por Substrato , Temperatura
18.
Boll Chim Farm ; 134(1): 9-15, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7734126

RESUMO

3-[Mercapto]-n-propanoxy/methyl-ethanoxy branched chain in 5,6-Diphenyl- 1,2,4-triazine were condensed with O-phenylene diamine or O- aminophenol or o-aminothiophenol. The carboxylic groups of the synthesized compounds were cyclised to yield imidazoles, oxazoles and thiazoles. They were screened for their anti-inflammatory response in albino rats against carrageenin induced paw oedema. The active compounds were also evaluated for their ED50 value in albino rats and analgesic activity in albino mice. The compounds exhibited significant anti-inflammatory activity also showed marked protection against aconitine induced writhing response. The potent compounds showed high LD50 values.


Assuntos
Anti-Inflamatórios não Esteroides/síntese química , Triazinas/síntese química , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/toxicidade , Isomerismo , Camundongos , Ratos , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/patologia , Triazinas/farmacologia , Triazinas/toxicidade
19.
Boll Chim Farm ; 133(8): 521-6, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7826587

RESUMO

2-Mercapto-6-phenyl-1,3,4-thiadiazole-(3,2-a)-s-triazine-5,7-dithione (1) was converted to 2-[3-carboxyl-2-methyl-1-mercapto]-6-phenyl-1,3,4-thiadiazole-(3,2-a)-s- triazine-5,6 dithione (2) and 2-thioethanoic acid-6-phenyl-1,3,4-thiadiazole-(3, 2-a)-s-triazine-5,7-dithione (4). This on reaction with o-phenylenediamine/ethylenediamine/o-aminophenol/o-aminothiophenol and polyphosphoric acid yielded compounds 3 (a-d) and 5 (a-d). The compounds 1,2,4,3 (a-d) and 5 (a-d) were evaluated for their anti-inflammatory activity against carrageenan induced paw oedema. The compounds found potent were further tested for their antiwrithmogenic activity in albino mice. Two compounds (2,3c) exhibited significant anti-inflammatory activity, also showed protection against aconitine induced writhing response, with high approximate LD50 values.


Assuntos
Anti-Inflamatórios não Esteroides/síntese química , Tiadiazóis/síntese química , Triazinas/síntese química , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/toxicidade , Carragenina , Edema/induzido quimicamente , Edema/prevenção & controle , Camundongos , Ratos
20.
World J Microbiol Biotechnol ; 10(1): 116-7, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24420900

RESUMO

The co-culture of cellulolytic moulds and yeasts on apple pomace in solid-state fermentation (SSF) and liquid-state fermentation (LSF) increased the protein content of apple pomace. The co-culture of Candida utilis and Aspergillus niger was the best among several combinations and increased the protein content of dried and pectin-extracted apple pomace to 20% and 17%, respectively, under SSF conditions.

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