Helicobacter pylori (H. pylori) has been proposed as the foremost risk factor for the development of gastric cancer. We found that H. pylori express the enzyme glucose-6-phosphate dehydrogenase ...(HpG6PD), which participates in glucose metabolism via the pentose phosphate pathway. Thus, we hypothesized that if the biochemical and physicochemical characteristics of HpG6PD contrast with the host G6PD (human G6PD, HsG6PD), HpG6PD becomes a potential target for novel drugs against H. pylori. In this work, we characterized the biochemical properties of the HpG6PD from the H.pylori strain 29CaP and expressed the active recombinant protein, to analyze its steady-state kinetics, thermostability, and biophysical aspects. In addition, we analyzed the HpG6PD in silico structural properties to compare them with those of the HsG6PD. The optimal pH for enzyme activity was 7.5, with a T1/2 of 46.6 °C, at an optimum stability temperature of 37 °C. The apparent Km values calculated for G6P and NADP+ were 75.0 and 12.8 µM, respectively. G6P does not protect HpG6PD from trypsin digestion, but NADP+ does protect the enzyme from trypsin and guanidine hydrochloride (Gdn-HCl). The biochemical characterization of HpG6PD contributes to knowledge regarding H. pylori metabolism and opens up the possibility of using this enzyme as a potential target for specific and efficient treatment against this pathogen; structural alignment indicates that the three-dimensional (3D) homodimer model of the G6PD protein from H. pylori is different from the 3D G6PD of Homo sapiens.
PAL5 (GDI) is an endophytic bacterium with potential biotechnological applications in industry and agronomy. The recent description of its complete genome and its principal metabolic enzymes suggests ...that glucose metabolism is accomplished through the pentose phosphate pathway (PPP); however, the enzymes participating in this pathway have not yet been characterized in detail. The objective of the present work was to clone, purify, and biochemically and physicochemically characterize glucose-6-phosphate dehydrogenase (G6PD) from GDI. The gene was cloned and expressed as a tagged protein in
.
to be purified by affinity chromatography. The native state of the G6PD protein in the solution was found to be a tetramer with optimal activity at pH 8.8 and a temperature between 37 and 50 °C. The apparent
values for G6P and nicotinamide adenine dinucleotide phosphate (NADP
) were 63 and 7.2 μM, respectively. Finally, from the amino acid sequence a three-dimensional (3D) model was obtained, which allowed the arrangement of the amino acids involved in the catalytic activity, which are conserved (RIDHYLGKE, GxGGDLT, and EKPxG) with those of other species, to be identified. This characterization of the enzyme could help to identify new environmental conditions for the knowledge of the plant-microorganism interactions and a better use of GDI in new technological applications.
The aim of this study was to define a protocol for evaluating university gardens as innovative practice in Education for Sustainability and to apply it to a Latin-American study case, that of the ...Agroecological Garden in the Faculty of Biology at the Veracruzana University (Mexico). A comparative evaluation was conducted between two different moments (December 2018 and January 2021) based on sustainability indicators that were adapted from the SAEMETH-G methodology, using three levels of increasing complexity. These levels were the selection of sustainability dimensions, the individuation of the components, and the selection of the appropriate indicators. At the beginning of 2021, the selected Agroecological Garden showed high sustainability, with an accumulated score of 84.04 out of a total of 100 points, with the agro-environmental dimension being the best positioned (93.74), followed by the socio-educational (91.99) and the economic-administrative (66.4) domains. A significant robustness at the socio-environmental level was evidenced. However, it is necessary to address the substantial deficiencies evidenced at the economic-administrative level, especially in relation to financing and institutionalization, in order to make this innovative didactic resource sustainable and thus contribute to education for sustainability among university students.
Haemophilus influenzae is a commensal organism found in the upper respiratory tract of humans. When H. influenzae becomes a pathogen, these bacteria can move out of their commensal niche and cause ...multiple respiratory tract diseases such as otitis media, sinusitis, conjunctivitis and bronchitis in children, and chronic obstructive pulmonary disease in adults. However, H. influenzae is currently considered a non-flagellate bacterium.
In this study, 90 clinical isolates of H. influenzae strains (typeable and non-typeable) showed different degrees of the swarm-motility phenotype in vitro.Keys findings. One of these strains, NTHi BUAP96, showed the highest motility rate and its flagella were revealed using transmission electron microscopy and Ryu staining. Moreover, the flagellar genes fliC and flgH exhibited high homology with those of Actinobacillus pleuropneumoniae, Escherichia coli and Shigella flexneri. Furthermore, Western blot analysis, using anti-flagellin heterologous antibodies from E. coli, demonstrated cross-reaction with a protein present in NTHi BUAP96.
This study provides, for the first time, information on flagellar expression in H. influenzae, representing an important finding related to its evolution and pathogenic potential.
is an important pathogen that can form biofilms on food contact surfaces (FCS) in the dairy industry, posing a serious food safety, and quality concern. Biofilm is a complex system, influenced by ...nutritional-related factors that regulate the synthesis of the components of the biofilm matrix. This study determines the prevalence of biofilm-associated genes and evaluates the development under different growth conditions and compositions of biofilms produced by
.
Biofilms were developed in TSB, TSBG, TSBNaCl, and TSBGNaCl on stainless-steel (SS), with enumeration at 24 and 192 h visualized by epifluorescence and scanning electron microscopy (SEM). The composition of biofilms was determined using enzymatic and chemical treatments and confocal laser scanning microscopy (CLSM).
A total of 84
(SA1-SA84) strains were collected from 293 dairy industry FCS (FCS-stainless steel
= 183 and FCS-polypropylene
= 110) for this study. The isolates harbored the genes
(66%),
(53%),
(52%),
(38%),
(20%), and
(9.5%). 99. In particular, the biofilm formed by
-positive
onto SS showed a high cell density in all culture media at 192 h in comparison with the biofilms formed at 24 h (
< 0.05). Epifluorescence microscopy and SEM revealed the metabolically active cells and the different stages of biofilm formation. CLSM analysis detected extracellular polymeric of
biofilms on SS, such as eDNA, proteins, and polysaccharides. Finally, the level of detachment on being treated with DNase I (44.7%) and NaIO 4(42.4%) was greater in the biofilms developed in TSB compared to culture medium supplemented with NaCl at 24 h; however, there was no significant difference when the culture medium was supplemented with glucose. In addition, after treatment with proteinase K, there was a lower level of biomass detachment (17.7%) of the biofilm developed in TSBNaCl (
< 0.05 at 24 h) compared to that in TSB, TSBG, and TSBGNaCl (33.6, 36.9, and 37.8%, respectively). These results represent a deep insight into the composition of
biofilms present in the dairy industry, which promotes the development of more efficient composition-specific disinfection strategies.
Abstract Rice (Oryza sativa L) is an important source of essential elements but also can contain high As concentrations, which may be consumed and causes health effects. This work aimed to contribute ...to the lack of information quantifying the total arsenic (tAs) in 31 domestic rice (white rice, n=19; brown rice, n=7; parboiled rice, n=5) of different brands purchased in Peruvian markets. The tAs content was conducted by ICP-MS. The tAs concentration was compared to the maximum limits prescribed by regulatory agencies. Dietary intake (DI), dietary exposure (DE), and margin of exposure (MOE) were estimated. tAs concentration in white, brown and parboiled rice were 0.292 ± 0.106 mg/kg, 0.401 ± 0.081 mg/kg, 0.229 ± 0.03 mg/kg, respectively. Arsenic concentration in white rice exceeded limits recommended by FAO/WHO (0.20 mg kg-1), and European legislation (0.25 mg kg-1), but no Mercosul limits (0.3 mg kg-1). The DE showed that, on average, Peruvians consume 5.60 μg As kg-1 BW weekly. The MOE value was higher than 1 at the mean dietary exposure level. Our findings suggest that the health risk from dietary arsenic exposure is low for the Peruvian population. However, more studies are needed to reduce dietary arsenic exposure in Peru.
Haliotis cracherodii is the only abalone species listed as critically endangered (IUCN Red List) and protected under the Endangered Species Act (ESA) since 2009. The population started decreasing in ...the mid-1980s throughout its biogeographical range due to the “withering syndrome” disease. The objective of this study was to evaluate the thermoregulation of the black abalone, establishing its preferred temperature, locomotion displacement, and critical thermal maximum (CTMax). The preferred temperature (PT) was 13.8 °C. The theoretical temperature for optimal growth of the black abalone was 14.3 °C. The locomotion displacement in the gradient had an interval of 137 to 83 cm h–1. CTMax was evaluated, the first abalone detached from the substrate at a temperature of 25.4 °C and the last one at 31 °C; CTMax of 50% was calculated at 29.7 °C. These data will allow us to maintain and condition the black abalone in captivity with the final goal of producing seed for the restoration of disease-impacted populations on the Baja California Peninsula. ENSO events may also affect the survival of black abalone. We extrapolated the Thermal Safety Margin (TSM) = (28.8 – 18.31 °C) = 10.49 °C in weak ENSOs, but in stronger ENSO the TSM value diminishes to 3.17 °C suggesting that black abalone may be vulnerable to climate change.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
the stability of total parenteral nutrition admixtures for neonates (TPNAn) has been questioned in relation to the interaction between calcium and fish oil emulsions.
the aim of this study was to ...check the stability (particle size < 1 µm) of different individualized TPNAn prepared with fish-oil emulsion and containing calcium at concentrations ranging from 10 to 20 mmol/L.
admixtures analyzed: twelve different formulations with SMOFlipid® 20 % (conserved for 24 h and for 96 h), three formulations with Lipoplus® 20 % (conserved for 96 h) and three formulations with SMOFlipid® 20 % with Multi-12K1® Pediatric (conserved for 96 h). Two bags were compounded for each formulation and conservation period. Measurements on each admixture bag: particle standardized diameter by laser diffraction technique and pH by a calibrated pH-meter. Data analysis with mixed linear regression models.
maximum particle size was < 0.8 µm for all investigated admixtures. Lipid concentration of 5 g/L and sodium and potassium concentration of 100 mmol/L slightly increased the proportion of particles > 0.6 µm. Ninety six hours storage also increased the percentage of particles > 0.6 µm (+0.143 ± 0.07; p = 0.038) but did not influence other parameters. No association with calcium composition was observed. Amino acid content was inversely correlated with pH (-0.83; p < 0.0001).
the studied individualized parenteral nutrition admixtures for newborns that contain fish oil emulsions and meet cation requirements are stable for at least 96 hours.
Tryptophan hydroxylase-type 2 (Tph2) is the first rate-limiting step in the biosynthesis of serotonin (5-HT) in the brain. The ophthalmic administration (Op-Ad) is a non-invasive method that allows ...delivering genetic vehicles through the eye and reaches the brain. Here, the murine
Tph2
gene was cloned in a non-viral vector (pIRES-hrGFP-1a), generating pIRES-hrGFP-1a-Tph2, plus the FLAG-tag. Recombinant Tph2-FLAG was detected and tested in vitro and in vivo
,
where 25 μg of pIRES-hrGFP-1a-Tph2-FLAG was Op-Ad to mice. The construct was capable of expressing and producing the recombinant Tph2-FLAG in vitro and in vivo
.
The in vivo assays showed that the construct efficiently crossed the Hemato-Ocular Barrier and the Blood–Brain Barrier, reached brain cells, passed the optical nerves, and transcribed mRNA-Tph2-FLAG in different brain areas. The recombinant Tph2-FLAG was observed in amygdala and brainstem, mainly in raphe dorsal and medial. Relative
Tph2
expression of threefold over basal level was recorded three days after Op-Ad. These results demonstrated that pIRES-hrGFP-Tph2-FLAG, administrated through the eyes was capable of reaching the brain, transcribing, and translating
Tph2
. In conclusion, this study showed the feasibility of delivering therapeutic genes, such as the
Tph2,
the first enzyme, rate-limiting step in the 5-HT biosynthesis.
Objective. To validate hemoglobin (Hb) concentration in venous blood (VB) using the HemoCue 201+ in a subsample of children and women from the Mexican National Health and Nutrition Survey 2022. ...Materials and methods. Prior to field work 50 HemoCue 201+ devices were verified using venous blood. During the field work 57 children (aged 1-11) and 62 women (aged 12-49) donated 3 mL of VB each. Hb was measured in each device of HemoCue 201+ and in a hematologic autoanalyzer for the validation. Results. No significant bias was found in most of the devices. An adjustment criterion was used for 22 devices. Hb mean difference results were -0.049±0.578 g/dL in children and -0.098±0.628 g/dL in women. Conclusions. The HemoCue 201+ is a valid tool for estimating Hb concentration to produce reliable estimates of anemia prevalence when using venous blood.
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