Effect of Glucose on Endo-xylanase and β-xylosidase Production by Fungi Isolated in Indonesia

Xylanases are widely produced by fungi, and the production of polysaccharide-degrading enzymes, in general, are usually subjected to carbon catabolite repression. In this work, the ability of several Indonesian indigenous fungi to produce endo-xylanase and β-xylosidase and their responses to glucose as a repressor were determined. Ten fungi were grown in a liquid medium supplemented with glucose as the repressor (0, 1%, 3%, and 5%), and the endo-xylanase and β-xylosidase productions were assayed. Aspergillus aculeatus FIG1 and A. oryzae KKB4 produced 3.85 and 0.70 U/mL of endo-xylanase, respectively, compared with other strains (0.22 U/mL or less). Trichoderma asperellum PK1J2, T. virens MLT2J2, A. aculeatus FIG1, T. asperellum MLT5J1, A. oryzae KKB4, and T. asperellum MLT3J2 produced 0.021–0.065 U/mL of β-xylosidase, whereas the other strains produced 0.013 U/mL or less of β-xylosidase. Adding 1% glucose to the growth medium can partially repress endo-xylanase production in A. aculeatus FIG1, T. asperellum PK1J2, and T. virens MLT4J1 and completely repress other strains. By adding 1% glucose, strains FIG1, PK1J2, and MLT4J1 suffered almost complete repression of β-xylosidase production, although such strains exhibited partial repression of endo-xylanase production. β-Xylosidase produced by the other strains showed complete repression by adding 1% glucose, except for A. aculeatus FIG1, A. tamarii FNCC 6151, and T. asperellum MLT1J1, which showed partial repression. Therefore, adding 3% glucose to the growth medium can result in complete repression of endo-xylanase and β-xylosidase productions in all strains examined.

Environmentally Friendly Extraction of Antioxidants from Elettaria cardamomum seeds with Glucose-Citric Acid-Based Natural Deep Eutectic Solvent

Elettaria cardamomum belongs to the Zingiberaceae family. It contains components (phenolic compounds, alkaloids, terpenoids) it has antioxidant, anti-inflammatory and antimicrobial effects. The purpose of this study is to research the effect of glucose-citric acid based natural deep eutectic solvent (NADES) on the antioxidant activity of Elettaria cardamomum. In this study, glucose-citric acid was used as a NADES and methanol-water was used as a conventional solvent. The radical scavenging activities, phenolic compound and tannin amounts of the extracts obtained as a result of extraction with two different solvents were found. Antioxidant activities of extracts prepared with natural deep eutectic solvent were found to be higher. It has been shown that NADES, which are less harmful on the health and environment, have low toxicity and are environmentally friendly, can be used in extraction instead of traditional solvents such as hexane, benzene, and methanol.

Effects of osmolality and solutes on the morphology of red blood cells according to three-dimensional refractive index tomography

Phosphate-buffered saline (PBS) and Alsever’s solution (AS) are frequently used as media in blood-related studies, while 0.9% normal saline (NS) is frequently used in transfusion medicine. Despite the frequent use, the effects of these solutions on the shape and volume of red blood cells (RBCs) have not been reported. We collected blood samples from five healthy adults and used three-dimensional refractive index tomography to investigate the changes in the morphology of RBCs caused by changes in osmolality and solutes at the single-cell level. After diluting 2 μL of RBCs 200-fold with each solution (PBS, AS, and 0.9% NS), 40 randomly selected RBCs were microscopically observed. RBC shape was measured considering sphericity, which is a dimensionless quantity ranging from 0 (flat) to 1 (spherical). RBCs in plasma or AS showed a biconcave shape with a small sphericity, whereas those in 0.9% NS or PBS showed a spherical shape with a large sphericity. Moreover, we confirmed that sodium chloride alone could not elicit the biconcave shape of RBCs, which could be maintained only in the presence of an osmotic pressure-maintaining substance, such as glucose or mannitol. Although 0.9% NS solution is one of the most commonly used fluids in hematology and transfusion medicine, RBCs in 0.9% NS or PBS are not biconcave. Therefore, as the debate on the use of NS continues, future clinical studies or applications should consider the effect of glucose or mannitol on the shape of RBCs.

The Effect of Glucose and Poloxamer 188 on Red-Blood-Cell Aggregation

Glucose metabolism disorders contribute to the development of various diseases. Numerous studies show that these disorders not only change the normal values of biochemical parameters but also affect the mechanical properties of blood. To show the influence of glucose and poloxamer 188 (P188) on the mechanical properties of a red-blood-cell (RBC) suspension, we studied the aggregation of the cells. To show the mechanisms of the mechanical properties of blood, we studied the effects of glucose and poloxamer 188 (P188) on red-blood-cell aggregation. We used a model in which cells were suspended in a dextran 70 solution at a concentration of 2 g/dL with glucose and P188 at concentrations of 0–3 g/dL and 0–3 mg/mL, respectively. RBC aggregation was determined using an aggregometer, and measurements were performed every 4 min for 1 h. Such a procedure enabled the incubation of RBCs in solution. The aggregation index determined from the obtained syllectograms was used as a measure of aggregation. Both the presence of glucose and that of P188 increased the aggregation index with the incubation time until saturation was reached. The time needed for the saturation of the aggregation index increased with increasing glucose and P188 concentrations. As the concentrations of these components increased, the joint effect of glucose and P188 increased the weakening of RBC aggregation. The mechanisms of the observed changes in RBC aggregation in glucose and P188 solutions are discussed.

Prognostic value of glucose fluctuation in patients undergoing thrombolysis or thrombectomy due to acute ischemic stroke

Background Hyperglycemia during acute ischemic stroke is associated with worse outcomes, and this glucose altitude may persist in the initial days. In this study, we investigate the effect of glucose fluctuations in the first 4 days in patients diagnosed with acute ischemic stroke and who underwent ivr-tPA ± interventional thrombectomy or only interventional thrombectomy on stroke prognosis. Study was designed bicentered retrospective case series. Patients older than 18 years were included and those suitable for acute treatment, treatment indications, contraindications, and treatment management of hyperglycemia were selected according to the 2018 American Stroke Association guidelines. The effect of fasting glucose values of patients in the first 4 days on admission and 24th hour NIHSS scores, duration of hospitalization, disability, mortality, and prognosis were analyzed. We aimed to demostred the effect of the first 4-day glucose values measured in patients treated in a stroke center on clinical prospect. Results One hundred and seventy-six patients were included in the study. Group 1 included 30 (17%) patients with severe clinical condition (NIHSS at admission ≥ 16), and Group 2 comprised 146 (83%) patients with moderate and mild clinical condition (NIHSS at admission < 16). The glucose values of Groups 1 and 2 were found as follows: day 1 (admission): 178.7 ± 10.3 mg/dl and 138.3 ± 54.9 mg/dl, day 2: 197.7 ± 99.8 mg/dl and 137.6 ± 51.8 mg/dl, day 3: 186.1 ± 97.6 mg/dl and 127.5 ± 50.0 mg/dl, and day 4: 169.2 ± 85.0 mg/dl and 126.7 ± 49.3 mg/dl (p < 0.05). Mortality risk of patients with glucose ≥ 200 mg/dl was 43.5% on day 1 (p > 0.05), 57.1% on day 2, 68.4% on day 3, and 76.5% on day 4 (p < 0.05). Conclusions The glucose level of patients in severe clinical condition peaked on the second day and that 4 days of resilient severe hyperglycemia is a negative risk factor for sequela and mortality.

Microarray Analysis of Breast Cancer Gene Expression Profiling in Response to 2-Deoxyglucose, Metformin, and Glucose Starvation

Background: Breast cancer (BC) is the most frequently diagnosed cancer in women. Altering glucose metabolism and its effects on cancer progression and treatment resistance is an emerging interest in BC research. For instance, combining chemotherapy with glucose-lowering drugs (2-deoxyglucose (2-DG), metformin) or glucose starvation (GS) has shown better outcomes than with chemotherapy alone. However, the genes and molecular mechanisms that govern the action of these glucose deprivation conditions have not been fully elucidated. Here, we compared the effect of glucose deprivation (2-DG, metformin, GS) on MDA-MB-231 and MCF-7 BC cell lines using microarray analysis to establish a database of differentially expressed genes and enrichment pathways, in order to investigate the beneficial effect of glucose-lowering treatments on the vulnerability of BC cells.Methods: MDA-MB-231 and MCF-7 cells were treated with 20 mM metformin or 4 mM 2-DG for 48 hours. GS was performed by gradually decreasing the concentration of glucose in the culture medium to 0 g/L with fetal bovine serum over 1 week. Expression profiling was carried out using Affymetrix Human Clariom S microarrays. Differentially expressed genes were obtained from the Transcriptome Analysis Console and enriched using DAVID and R packages.Results: Our results showed that MDA-MB-231 cells were more responsive to glucose deprivation than MCF-7 cells. Endoplasmic reticulum stress response and cell cycle inhibition were detected after all three glucose deprivations in MDA-MB-231 cells and only under the metformin and GS conditions in MCF-7 cells. Induction of apoptosis and inhibition of DNA replication were observed with all three treatments in MDA-MB-231 cells and metformin-treated MCF-7 cells. Upregulation of cellular response to reactive oxygen species and inhibition of DNA repair mechanisms resulted after metformin and GS administration in MDA-MB-231 cell lines and metformin-treated MCF-7 cells. Autophagy was induced after 2-DG treatment in MDA-MB-231 cells and after metformin in MCF-7 cells. Finally, enhanced cell-cell adhesion and inhibition of DNA methylation and cholesterol biosynthesis were observed with GS only in MDA-MB-231 cells. Conclusion: GS had the greatest effect on breast cancer cells compared to 2-DG and metformin. Our results suggest that the combination of metformin and GS should weaken both cell lines and makes them more vulnerable to conventional chemotherapy.

Co-metabolic Effect of Glucose on Methane Production and Phenanthrene Removal in an Enriched Phenanthrene-Degrading Consortium Under Methanogenesis

Anaerobic digestion is used to treat diverse waste classes, and polycyclic aromatic hydrocarbons (PAHs) are a class of refractory compounds that common in wastes treated using anaerobic digestion. In this study, a microbial consortium with the ability to degrade phenanthrene under methanogenesis was enriched from paddy soil to investigate the cometabolic effect of glucose on methane (CH4) production and phenanthrene (a representative PAH) degradation under methanogenic conditions. The addition of glucose enhanced the CH4 production rate (from 0.37 to 2.25mg⋅L−1⋅d−1) but had no influence on the degradation rate of phenanthrene. Moreover, glucose addition significantly decreased the microbial α-diversity (from 2.59 to 1.30) of the enriched consortium but showed no significant effect on the microbial community (R2=0.39, p=0.10), archaeal community (R2=0.48, p=0.10), or functional profile (R2=0.48, p=0.10). The relative abundance of genes involved in the degradation of aromatic compounds showed a decreasing tendency with the addition of glucose, whereas that of genes related to CH4 synthesis was not affected. Additionally, the abundance of genes related to the acetate pathway was the highest among the four types of CH4 synthesis pathways detected in the enriched consortium, which averagely accounted for 48.24% of the total CH4 synthesis pathway, indicating that the acetate pathway is dominant in this phenanthrene-degrading system during methanogenesis. Our results reveal that achieving an ideal effect is diffcult via co-metabolism in a single-stage digestion system of PAH under methanogenesis; thus, other anaerobic systems with higher PAH removal efficiency should be combined with methanogenic digestion, assembling a multistage pattern to enhance the PAH removal rate and CH4 production in anaerobic digestion.

The clinical effect of glucose meter selection upon the detection of neonatal hypoglycemia

Neonatal hypoglycemia is a common, transitional metabolic state that may lead to poor neurodevelopmental outcomes if unrecognized or managed inadequately. Given its frequency of presentation and immense clinical significance, a myriad of clinical practice guidelines have been published outlining appropriate screening, diagnosis, and treatment principles—many endorsing the use of glucose point-of-care testing (POCT). Unfortunately, the well-intended ‘march’ toward POCT, with bedside glucose meters as screening devices in the NICU, has resulted in unintended consequences with critical implications: a lack of international traceability to the ‘gold’ standard glucose method by POCT devices, under-recognition of POCT limitations, and a reliance upon a technology primarily driven to detect hyperglycemia in the adult population as opposed to neonatal hypoglycemia. As providers continue to advocate for improved POCT, there must be robust communication between providers and the clinical laboratory in the selection, standardization, and interpretation of glucose POCT to ensure optimal neonatal glucose detection.