Publications by authors named "TRELLES J"

Article Synopsis
  • The study aimed to investigate whether there is a link between SARS-CoV-2 serologic status and the risk of preeclampsia in immunologically naive pregnant patients.
  • Researchers conducted a retrospective study involving 440 pregnant patients and found that being seropositive for SARS-CoV-2 antibodies did not correlate with higher rates of preeclampsia.
  • The main factor associated with developing preeclampsia was a previous history of preeclampsia, highlighting the need for further research on infection timing and preeclampsia risk.
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School violence is a global public health epidemic, with students with disabilities at a significantly greater risk than their non-disabled peers. Students with disabilities are more vulnerable to school violence from peers, teachers, and school staff due to stereotypes and prejudice. Teachers are pivotal in preventing violence and intervening, but literature on the role that teachers play in responding to disability-based violence is limited.

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Article Synopsis
  • Several immobilization strategies for Gluconobacter oxydans NBRC 14819 (Gox) were tested for converting crude glycerol to dihydroxyacetone (DHA), using materials like agar, agarose, and polyacrylamide.
  • Agar-immobilized Gox proved to be the most effective, achieving 50 g/L glycerol conversion to DHA solely in water and allowing for reutilization over eight cycles, producing significantly more DHA than free cell batches.
  • The study highlights the efficiency of immobilized biocatalysts, demonstrating high productivity in a water-based environment, which could reduce downstream processing costs.
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Nowadays, enzyme-mediated processes offer an eco-friendly and efficient alternative to the traditional multistep and environmentally harmful chemical processes. Herein we report the enzymatic synthesis of cladribine by a novel 2'-deoxyribosyltransferase (NDT)-based combined biocatalyst. To this end, NDT (NDT) was successfully immobilized through a two-step immobilization methodology, including a covalent immobilization onto glutaraldehyde-activated biomimetic silica nanoparticles followed by biocatalyst entrapment in calcium alginate.

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A novel IDA-LaNDT derivative was able to reach the highest productivity in the biosynthesis of a well-known antitumoral agent called decitabine. However, the combination of two simple and inexpensive techniques such as ionic absorption and gel entrapment with the incorporation of a bionanocomposite such as bentonite significantly improved the stability of this biocatalyst. These modifications allowed the enhancement of storage stability (for at least 18 months), reusability (400 h of successive batches without significant loss of its initial activity), and thermal and solvent stability with respect to the non-entrapped derivative.

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Cladribine (2-chloro-2'-deoxy-β-d-adenosine) is a 2'-deoxyadenosine analogue, approved by the FDA for the treatment of hairy cell leukemia and more recently has been proved for therapeutic against many autoimmune diseases as multiple sclerosis. The biosynthesis of this compound using Thermomonospora alba CECT 3324 as biocatalyst is herein reported. This thermophilic microorganism was successfully entrapped in polyacrylamide gel supplemented with nanoclays such as bentonite.

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In the present study, a novel extracellular laccase isolated from ATCC 10149 was entrapped in a bionanocomposite matrix consisting of copper alginate (Cu-alginate) supplemented with the nanoclay bentonite. After optimization, this nanobiocatalyst was able to degrade up to 90% of Remazol Brilliant Blue R (RBBR) without the addition of redox mediators and retained 70% of its initial activity for at least 1440 h, equivalent to more than 288 uses. The incorporation of nanoclay allowed alginate beads to be used in alkaline pH and strengthened its mechanical properties.

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A stable biocatalyst with magnetic properties based on immobilized Lactobacillus animalis ATCC 35,046 to obtain 2-chloroadenine-2'-deoxyriboside, known as cladribine, is reported for the first time. This nucleoside analogue is an antitumor agent used in the treatment of a wide variety of types of leukemia. In this study, an eco-compatible and alternative bioprocess to obtain cladribine was developed.

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Microbial whole cells are efficient, ecological, and low-cost catalysts that have been successfully applied in the pharmaceutical, environmental, and alimentary industries, among others.Microorganism immobilization is a good way to carry out the bioprocess under preparative conditions. The main advantages of this methodology lie in their high operational stability, easy upstream separation, and bioprocess scale-up feasibility.

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Cladribine is a nucleoside analogue widely used in the pharmaceutical industry for the treatment of several neoplasms, including hairy-cell leukemia among others. This compound has also shown efficacy in the treatment of autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. In this work, a green bioprocess for cladribine biosynthesis using immobilized Arthrobacter oxydans was developed.

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Background: Nucleoside analogue (NAs) derivatives comprise a large family of pharmaceuticals clinically used as antitumoral and antiviral compounds. Originally, the production of NAs involved chemical synthesis, but a greener bioproduction alternative exists and involves the use of enzymes that catalyze transglycosylation reactions between modified purinic or pyrimidinic bases and sugars. To be considered as an option for industrial application, it is vital to immobilize these biocatalysts.

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Enzyme immobilization using hydrogels is a low-cost and effective system for the degradation of bulk pectin derived from orange industry residues. Polygalacturonases obtained from four different bacterial strains of genus were immobilized in alginate gel and assayed for pectin hydrolysis. The enzyme from ATCC 10897 proved to be superior and more stable within the alginate matrix.

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Shiga toxin (Stx)-producing Escherichia coli (STEC) infections are implicated in the development of the life-threatening hemolytic-uremic syndrome (HUS). Despite the magnitude of the social and economic problems caused by HUS, no licensed vaccine or effective therapy is currently available for human use. Prevention of STEC infections continues being the most important measure to reduce HUS incidence.

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Ribavirin is a synthetic guanosine analogue with a broad-spectrum of antiviral activity. It is clinically effective against several viruses, such as respiratory syncytial virus, several hemorrhagic fever viruses and HCV when combined with pegylated interferon-α. Phosphopentomutase (PPM) catalyzes the transfer of intramolecular phosphate (from C1 to C5) on ribose, and is involved in pentose phosphate pathway and in purine metabolism.

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Derivatized-agarose supports are suitable for enzyme immobilization by different methods, taking advantage of different physical, chemical and biological conditions of the protein and the support. In this study, agarose particles were modified with MANAE, PEI and glyoxyl groups and evaluated to stabilize polygalacturonase from Streptomyces halstedii ATCC 10897. A new immobilized biocatalyst was developed using glyoxyl-agarose as support; it exhibited high performance in degrading polygalacturonic acid and releasing oligogalacturonides.

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Ribavirin is an antiviral compound widely used in Hepatitis C Virus therapy. Biotransformation of this nucleoside analogue using ATCC 12407 as biocatalyst is herein reported. Reaction parameters such as microorganism amounts, substrate ratio and temperature were optimized reaching conversion yields of 86%.

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Microbial whole cells are efficient, ecological, and low-cost catalysts that have been successfully applied in the pharmaceutical, environmental, and alimentary industries, among others. Microorganism immobilization is a good way to carry out the bioprocess under preparative conditions. The main advantages of this methodology lie in their high operational stability, easy upstream separation and bioprocess scale-up feasibility.

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This work describes the application of thermophilic microorganisms for obtaining 6-halogenated purine nucleosides. Biosynthesis of 6-chloropurine-2'-deoxyriboside and 6-chloropurine riboside was achieved by Geobacillus stearothermophilus CECT 43 with a conversion of 90% and 68%, respectively. Furthermore, the selected microorganism was satisfactorily stabilized by immobilization in an agarose matrix.

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An efficient and green bioprocess to obtain 2,6-diaminopurine nucleosides using thermophilic bacteria is herein reported. Geobacillus stearothermophilus CECT 43 showed a conversion rate of 90 and 83% at 2 h to obtain 2,6-diaminopurine-2'-deoxyriboside and 2,6-diaminopurine riboside, respectively. The selected biocatalyst was successfully stabilized in an agarose matrix and used to produce up to 23.

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Article Synopsis
  • This study presents a green bioprocess for producing 5-halogenated pyrimidine nucleosides from thymidine using whole cells.
  • Free and immobilized Aeromonas salmonicida demonstrated high conversion rates for synthesizing 5-fluoro-2'-deoxyuridine (floxuridine).
  • The immobilized cells showed stability for over 4 months and could be reused at least 30 times, making them efficient for pharmaceutical applications, particularly as antitumoral agents.
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Different supports, such as alginate, agar, agarose, and polyacrylamide, were used to immobilize Escherichia coli BL 21 by entrapment techniques. The transglycosylation reaction involved in the synthesis of adenosine from uridine and adenine was chosen as a model system to study the characteristics of these biocatalysts. Whole cells immobilized on agarose proved to be optimal and could be used up to 30 times without significant loss of activity.

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Enzymatic hydrolysis of acetylated nucleosides using microbial whole cells has been carried out for the first time. Unlike Candida antarctica B lipase-catalysed alcoholysis, none of the tested microorganisms displayed a common deacetylation profile. Depending on the substrate and the biocatalyst used, 5'-selective deprotection or mixtures of mono O-acetylated products were obtained.

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Modified nucleosides can be prepared by microbial transglycosylation from cheaper nucleoside precursors using free or immobilised whole cells. An efficient screening method to find transglycosylation activity in microorganisms was developed for the synthesis of 6-modified purine nucleosides, such as 6-chloro-, 6-methoxy-, 6-iodo- and 6-mercaptopurine ribonucleoside. Out of 100 microorganisms screened, Bacillus stearothermophilus ATCC 12980 was the best for this purpose.

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This study evaluated endometrial histology in women using the once-a-month injectable contraceptive Cyclofem for one year or more. The study received IRB approval. Seventeen Cyclofem users accepted to be submitted to an endometrial biopsy.

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