Enzymatic Procedure Research Articles

Simple and rapid formic acid sample treatment for the isolation of HgSe nanoparticles from animal tissues

The present work explores for the first time the potential of formic acid on the extraction of tiemannite (HgSe) nanoparticles from seabird tissues, in particular giant petrels. Mercury (Hg) is considered one of the top ten chemicals of major public health concern. However, the fate and metabolic pathways of Hg in living organisms remain unknown. Methylmercury (MeHg), largely produced by microbial activity in the aquatic ecosystems is biomagnified in the trophic web. HgSe is considered the end-product of MeHg demethylation in biota and an increasing number of studies focuses on the characterization of this solid compound to understand its biomineralization. In this study, a conventional enzymatic treatment is compared with a simpler and environmentally friendly extraction by using formic acid (5 mL of = 50 % formic acid) as exclusive reagent. The analyses by spICP-MS of the resulting extracts from a variety of seabird biological tissues (liver, kidneys, brain, muscle) reveal comparable results by both extraction approaches in terms of nanoparticles stability and extraction efficiency. Therefore, the results included in this work demonstrate the good performance of employing organic acid as simple, cost effective and green procedure to extract HgSe nanoparticles from animal tissues. Moreover, an alternative consisting of a classical enzymatic procedure but with ultrasonic assistance reducing the extraction time from 12 h to 2 min is also described for the first time. The sample processing methodologies developed, combined with spICP-MS, have emerged as powerful tools for the rapid screening and quantification of HgSe nanoparticles in animal tissues. Finally, this combination allowed us to identify the possible occurrence of Cd particles and As particles associated with HgSe NPs in seabirds.

Efficacy of Adipose-Derived Mesenchymal Stem Cells and Stromal Vascular Fraction Alone and Combined to Biomaterials in Tendinopathy or Tendon Injury: Systematic Review of Current Concepts

Background and Objectives: Tendon injury and tendinopathy are among the most frequent musculoskeletal diseases and represent a challenging issue for surgeons as well as a great socio-economic global burden. Despite the current treatments available, either surgical or conservative, the tendon healing process is often suboptimal and impaired. This is due to the inherent scarce ability of tendon tissue to repair and return itself to the original structure. Recently, Adipose-derived mesenchymal stem cells (ADSC) and stromal vascular fraction (SVF) have gained a central interest in the scientific community, demonstrating their effectiveness in treatments of acute and chronic tendon disorders in animals and humans. Either enzymatic or mechanical procedures to obtain ADSC and SVF have been described and used in current clinical practice. However, no unified protocols and processes have been established. Materials and Methods: This systematic review aims at providing a comprehensive update of the literature on the clinical application of ADSC enzymatically or mechanically processed to obtain SVF, alone and in association with biomaterials in the local treatment of tendinopathy and tendon injury in vivo, in animal models and humans. The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: Thirty-two articles met our inclusion criteria, with a total of 18 studies in animals, 10 studies in humans and 4 studies concerning the application of biomaterials in vivo in animals. The review of the literature suggests that ADSC/SVF therapy can represent a promising alternative in tendonregenerative medicine for the enhancement of tendon healing. Conclusions: Nevertheless, further investigations and randomized control trials are needed to improve the knowledge, standardize the procedures and extend the consensus on their use for such applications.

ISOLATION, MODIFICATION AND UTILIZATION OF STARCH FROM GREEN BANANA PEEL AS A FRUIT WASTE

–Green Banana peels obtained from the production of banana chips are still used. Because it is only used as animal feed, it is relatively inexpensive. The pharmaceutical business, as well as a number of food and non-food companies, can all greatly benefit from research into the potential benefits of using banana peel as a source of starch. Starch was extracted from the banana peel using alkaline, sedimentation, centrifugation and enzymatic procedures. Physical, chemical and enzymatic methods were utilized to modify the native starch. Measurements were made of the native and modified starches’ yield and functional characteristics. The centrifugation method produced the highest starch yield, at 22.6% on a dry basis, followed by the enzymatic, alkaline, and sedimentation methods. The ability to bind water is greater than the ability to bind oil. Alkaline has a higher water solubility index, while sedimentation has a lower one. Following the alteration process, the amylose content increased, which reduced the gelling ability. Enzymatic modification decreased the amylose content and increase in water solubility. WBC and OBC increased in physical and chemical modification but decreased in enzymatic method. Banana peel substantial source of starch for the food and pharmaceutical industries.

Mouse Corneal Epithelial and Stromal Cell Isolation and Culture.

Corneal epithelium and stroma are the major cellular structures for ocular protection and vision accuracy; they play important roles in corneal wound healing and inflammation under pathological conditions. Unlike human, murine corneal and stromal fibroblast cells are difficult to isolate for cell culture. In our laboratory, we successfully used an ex vivo culture procedure and an enzymatic procedure to isolate, purify, and culture mouse corneal epithelial and stromal fibroblast cells. Key features • Primary cell culture models of a disease are critical for cellular and molecular mechanism studies. • Corneal tissues with the limbus contain stem cells to generate both epithelial and stromal cells. • An ex vivo corneal culture provides a constant generation of primary corneal cells for multiple passages. • The isolated cells are validated by the corneal epithelial cell markers Krt12 and Cdh1 and the stromal fibroblast marker Vim.

Comparative Accuracy of In Vitro Rumen Fermentation and Enzymatic Methodologies for Determination of Undigested Neutral Detergent Fiber in Forages and Development of Predictive Equations Using NIRS

Undigested neutral detergent fiber (uNDF) is becoming more widely recognized as an important fiber fraction in forage quality assessment because it explains a portion of NDF that is inaccessible to digestion in the ruminant digestive system and is, thus, important in modeling the digestion kinetics of the potentially degradable component of NDF. In experiment 1, uNDF was determined in several forage species in order to compare the accuracy of two reference methods: (1) a long-term in vitro ruminal fermentation (240 h) using an Ankom DaisyII incubator and (2) a multi-step enzymatic method without ruminal fluid. The objective of experiment 2 was to construct predictive equations for uNDF estimation using acid detergent lignin (ADL) and near-infrared reflectance spectroscopy (NIRS) in a pool (n = 264) of alfalfa hay, timothy hay, and tall fescue straw, using the most accurate reference method selected in experiment 1. Partial least squares regression analysis was used to calibrate the reference values against NIRS spectra. Several indicators were used to assess the performance of validation results, including standard error of cross-validation (SECrV), coefficient of determination of cross-validation (R2CrV), and ratio percentage deviation (RPD). The findings of experiment 1 suggested that, relative to the in vitro ruminal methodology, the enzymatic approach overestimated uNDF concentration of forages. Repeatability coefficient was also greater when uNDF was determined using the in vitro versus enzymatic procedure, potentially disqualifying the enzymatic method for the uNDF analysis in forages. In experiment 2, a poor relationship was established between ADL and uNDF (R2 < 0.60), suggesting the inadequacy of ADL parameter to represent the uNDF pool size in these forages. The best predictive equation using NIRS was obtained for alfalfa hay (R2CrV = 0.92; SECrV = 1.16; RPD = 3.57), using the in vitro fermentation as a reference method. The predictive equations were moderately accurate for timothy hay (R2CrV = 0.80; SECrV = 1.31; RPD = 2.08) and tall fescue straw (R2CrV = 0.79; SECrV = 1.38; RPD = 2.18). Our findings suggested the inadequacy of the enzymatic procedure in accurately determining uNDF concentration of forages as compared with the in vitro rumen fermentation protocol. Although the NIRS equations developed using the alfalfa hay dataset were more accurate than that of timothy hay and tall fescue straw, the validation results verified applicability of the equations as a fast screening tool for qualitative prediction of uNDF in these forages, which is important in commercial settings.

Assessing the Formation of Purine Lesions in Mitochondrial DNA of Cockayne Syndrome Cells.

Mitochondrial (mt) DNA and nuclear (n) DNA have known structures and roles in cells; however, they are rarely compared under specific conditions such as oxidative or degenerative environments that can create damage to the DNA base moieties. Six purine lesions were ascertained in the mtDNA of wild type (wt) CSA (CS3BE-wtCSA) and wtCSB (CS1AN-wtCSB) cells and defective counterparts CS3BE and CS1AN in comparison with the corresponding total (t) DNA (t = n + mt). In particular, the four 5',8-cyclopurine (cPu) and the two 8-oxo-purine (8-oxo-Pu) lesions were accurately quantified by LC-MS/MS analysis using isotopomeric internal standards after an enzymatic digestion procedure. The 8-oxo-Pu levels were found to be in the range of 25-50 lesions/107 nucleotides in both the mtDNA and tDNA. The four cPu were undetectable in the mtDNA both in defective cells and in the wt counterparts (CSA and CSB), contrary to their detection in tDNA, indicating a nonappearance of hydroxyl radical (HO•) reactivity within the mtDNA. In order to assess the HO• reactivity towards purine nucleobases in the two genetic materials, we performed γ-radiolysis experiments coupled with the 8-oxo-Pu and cPu quantifications on isolated mtDNA and tDNA from wtCSB cells. In the latter experiments, all six purine lesions were detected in both of the DNA, showing a higher resistance to HO• attack in the case of mtDNA compared with tDNA, likely due to their different DNA helical topology influencing the relative abundance of the lesions.

Simple and efficient enzymatic procedure for p-coumaric acid synthesis: Complete bioconversion and biocatalyst recycling under alkaline condition

p-Coumaric acid (para-hydroxycinnamic acid, p-HCA), as a kind of natural active substance from plant cell walls, is widely used in medicine, food, and cosmetics with its antioxidant, anticancer, and other properties. Biological production of p-HCA can be achieved via one-step deamination of the L-tyrosine by tyrosine ammonia-lyase (TAL). Here, a new highly active TAL (Fc-TAL) from Flavobacterium columnare was identified via gene mining and heterologous expression. The purified Fc-TAL completely converts 22 mM L-tyrosine to p-HCA under alkaline condition (pH 9.5–10.0) at 55 °C. To increase enzymatic recyclability and reduce the bioproduction cost, Fc-TAL was immobilized on a silica nanospheres through silica-binding peptides (SiBP2) at pH 10. In comparison to free enzyme, the immobilized TALSiBP2 exhibited higher stability, over 50% activity was retained even after 10 consecutive catalytic cycles. Further experiments revealed that an aliquot of immobilized enzyme (about 200 mg TAL) can transform 20 g L-tyrosine into17.8 g p-HCA with 96% yields and 98% purity through 5 consecutive reaction cycles. Our studies not only provided a strategy for enzyme immobilization in alkaline condition, but also developed a green process for p-coumaric acid biosynthesis with the highest conversion rate and yield reported to date.

Information decay and enzymatic information recovery for DNA data storage

Synthetic DNA has been proposed as a storage medium for digital information due to its high theoretical storage density and anticipated long storage horizons. However, under all ambient storage conditions, DNA undergoes a slow chemical decay process resulting in nicked (broken) DNA strands, and the information stored in these strands is no longer readable. In this work we design an enzymatic repair procedure, which is applicable to the DNA pool prior to readout and can partially reverse the damage. Through a chemical understanding of the decay process, an overhang at the 3’ end of the damaged site is identified as obstructive to repair via the base excision-repair (BER) mechanism. The obstruction can be removed via the enzyme apurinic/apyrimidinic endonuclease I (APE1), thereby enabling repair of hydrolytically damaged DNA via Bst polymerase and Taq ligase. Simulations of damage and repair reveal the benefit of the enzymatic repair step for DNA data storage, especially when data is stored in DNA at high storage densities (=low physical redundancy) and for long time durations.

Separation of Microplastic Particles from Sewage Sludge Extracts Using Magnetic Seeded Filtration

Microplastic particles (MP) are efficiently retained in wastewater treatment plants and enriched in sewage sludge. For monitoring MP contents in wastewater systems, sewage sludge is thus well suited, but also requires an isolation of MP from the sludge matrix, as other sewage sludge components may interfere with the MP identification and quantification. Although organic matter in sludge samples can be removed through acid and enzymatic digestion procedures, cellulose - mainly from toilet paper - remains in the digests, due to its high chemical resistivity and similar density to MP. We apply the separation concept of magnetic seeded filtration to isolate MP through selective hetero-agglomeration with magnetic seed particles. MP and cellulose differ in their hydrophobic properties and we investigate to what extent these differences can be exploited to selectively form MP-magnetite hetero-agglomerates in the presence of cellulose. These hetero-agglomerates are subsequently separated using a magnet. Five MP types (Polyethylene terephthalate (PET), polypropylene (PP), low density polyethylene (LDPE), polyvinyl chloride (PVC) and polystyrene (PS)) and cellulose particles were mixed in different combinations with both hydrophilic and hydrophobic (silanized) magnetite particles. PET, PP, LDPE and PS only poorly agglomerated with pristine (hydrophilic) magnetite, but efficiently formed hetero-agglomerates with hydrophobic magnetite and were successfully removed from suspensions (80−100%). PVC agglomerated more efficiently with pristine than with hydrophobic magnetite and cellulose only agglomerated to a limited extent with either hydrophilic or hydrophobic magnetite, resulting in a high process selectivity. Results from experiments conducted at different ionic strengths and with hydrophilic and hydrophobic magnetite suggests that the agglomeration process was dominated by hydrophobic interactions. Enzymatic and oxidative treatment of the MP only marginally affected the separation efficiencies and (treated) MP spiked to sewage sludge extracts were successfully recovered using magnetic seeded filtration.

Preliminary Single-Center Experience of Bromelain-Based Eschar Removal in Children with Mixed Deep Dermal and Full Thickness Burns.

Introduction: Early eschar removal is the standard management of burns. The goal is to remove all of the necrotic tissue and render the wound suitable for healing or skin grafting. The enzymatic debridement of burn wounds allows for minimally invasive removal of burn eschar. The aim of the study was to describe and compare the demographic characteristics, surgical treatment and outcomes of patients treated with Nexobrid® with patients who had standard surgical excision. Material and Methods: A retrospective review was conducted on children who underwent enzymatic debridement. The study group was compared with children treated with the standard of care (SoC). Results: Twelve children (mean age 8 years, range 3 to 15 years) with mixed deep dermal and full thickness burn wounds were treated with Nexobrid®. The mean size of the burns was 29% TBSA. The median percentage TBSA debrided using Nexobrid® was 15% (range 2–27%). In a clinical assessment, enzymatic debridement was effective in removing dead tissue in a single application. No adverse reaction to Nexobrid® and serious complications after enzymatic procedure were recorded in the study group. The estimated relative risk of the need for reconstructive procedures decreases 3.5 times for the study group (RR 3.5, 95%CI 0.9–13.5, p = 0.089). Conclusion: The bromelain-based enzymatic method offers a good and safe debridement option to improve the treatment and life quality of children with severe burns. The main outcome of interest was the number of reconstructive procedures due to scar contractures, which was reduced in the group treated enzymatically compared to the SoC-treated children.

Rapid, high-yield enzymatic synthesis of n.c.a. 6-[18F]fluorodopamine (6-[18F]FDA) for in vivo application

6-[18F]Fluorodopamine (6-[18F]FDA) proved valuable as a diagnostic tool for neuroendocrine and rare tumors, such as ganglioneuromas and pheochromocytomas, however, clinical application is still limited. So far, its radiosyntheses were impeded by the formation of side-products, low molar activity, multi-step reactions and the use of challenging precursors. Here, we describe a detailed enzymatic procedure for fast, simple and high yield synthesis of no carrier added 6-[18F]FDA from 6-[18F]FDOPA with high radiochemical yield of ~69 % and >95 % purity as determined by radio-HPLC and -TLC. The product formulation was stable and suitable for in vivo application.

Production of Bioethanol from Bunches of Palm Oil Using Purification Equipment with Bioethanol Traps

Due to the rising demand for motor vehicle fuel, Indonesia's requirement for fossil fuels rises by an average of 10% annually. The supply of fossil energy, which serves as the primary raw material for generating fuel oil, is negatively correlated with the demand for fuel (BBM). Fresh Fruit Bunches (FFB), Empty Fruit Bunches (EFB), and fiber were the types of oil palm bunches employed in this investigation. EFB and fiber are industrial by products that are currently being used inefficiently and frequently pollute the environment. This trash is still only very minimally processed; it is still stored, burned in the incinerator, used as mulch on oil palm fields, and composted. 51.2 percent cellulose and 16.30 percent lignin are both present in EFB. Lignin makes up 20.0 percent of fiber, whereas cellulose makes up 57.0 percent. Through chemical and enzymatic procedures, this cellulose content may be exploited as a source of reducing sugars. FFB is used as a benchmark to evaluate how effectively the prototype tool works. Different kinds of high-quality bioethanol are produced from each raw source. Different kinds of high-quality bioethanol are produced from each raw source. Fresh Fruit Bunches (FFB), which have a refractive index of 1.35676 and a volume of 2,192 ml, are the best quality of bioethanol made from raw materials. The findings demonstrated that varied volumes and refractive indices were produced depending on how raw materials were treated. The quality generated improves with increased treatment volume. Alkaline delignification was followed by acid delignification to get the optimum grade. Empty Fruit Bunch (EFB) material, which had a refractive index of 1.34376, 2,105 ml of bioethanol, and a 68.15 percent ethanol concentration. This study is unique in that it includes a bioethanol trap to quicken the conversion of steam into liquid bioethanol. Condensation is completed in 15–20 minutes less time thanks to the bioethanol trap.

Automated-Mechanical Procedure Compared to Gentle Enzymatic Tissue Dissociation in Cell Function Studies.

The first step to obtain a cellular suspension from tissues is the disaggregation procedure. The cell suspension method has to provide a representative sample of the different cellular subpopulations and to maximize the number of viable functional cells. Here, we analyzed specific cell functions in cell suspensions from several rat tissues obtained by two different methods, automated–mechanical and enzymatic disaggregation. Flow cytometric, confocal, and ultrastructural (TEM) analyses were applied to the spleen, testis, liver and other tissues. Samples were treated by an enzymatic trypsin solution or processed by the Medimachine II (MMII). The automated–mechanical and enzymatic disaggregation procedures have shown to work similarly in some tissues, which displayed comparable amounts of apoptotic/necrotic cells. However, cells obtained by the enzyme-free Medimachine II protocols show a better preservation lysosome and mitochondria labeling, whereas the enzymatic gentle dissociation appears to constantly induce a lower amount of intracellular ROS; nevertheless, lightly increased ROS can be recognized as a complimentary signal to promote cell survival. Therefore, MMII represents a simple, fast, and standardized method for tissue processing, which allows to minimize bias arising from the operator’s ability. Our study points out technical issues to be adopted for specific organs and tissues to obtain functional cells.

CORRELATION ENTRE LES PARAMETRES IMPEDANCEMETRIQUES ET LE PROFIL LIPIDIQUE CHEZ DES PATIENTS DIABETIQUES DE TYPE 2

In type 2 diabetes, abnormalities of lipid metabolism and tissue distribution are common and associated with an increased risk of cardiovascular disease. The aim of this work was to study the relationship between the impedancemetric parameters and the lipid profile in a population of type 2 diabetics followed in the Endocrinology Department MED VI of Marrakech. Body fat was assessed using a body composition analyzer. Serum triglyceride, total cholesterol and low and high density lipoprotein cholesterol levels (LDL-c and HDL-c) were determined by standard enzymatic procedures. Relationships between age, impedancemetric parameters with several metabolic elements including serum lipid levels and HBA1c were analyzed in both sexes separately. The correlation of the lipid profile was higher with body fat compared to the Body Mass Index(BMI): LDL-C r = 0.32 vs 0.26, HDL-C r = -0.46 vs -0.43, total cholesterol r = 0.15 vs r = 0.08. To sum up, in light of our study, compared to BMI, body fat measured by impedancemetry more accurately reflects the lipid profile in type 2 diabetics.

Microbial transglutaminase-mediated formation of erythropoietin-polyester conjugates

Erythropoietin (EPO) is a glycoprotein hormone that has been used to treat anemia in patients with chronic kidney disease and in cancer patients who are receiving chemotherapy. Here, we investigated the accessibility of the glutamine (Gln, Q) residues of recombinant human erythropoietin (rHuEPO) towards a thermoresistant variant microbial transglutaminase (mTGase), TG16 with the aim of developing novel rHuEPO conjugates that may potentially enhance its biological efficacy. As a model bioconjugation, we studied the reactivity of rHuEPO towards TG16 with a low molar mass amine group containing substrate, monodansyl cadaverine (MDC). The reactions were carried out at a Tm of 54.3 °C, the transition temperature of rHuEPO. Characterization by SDS-PAGE and mass spectrometry confirmed the conjugates formation. Then, we examined the conjugation of rHuEPO with a biodegradable and biocompatible polyester, poly(D-sorbitol adipate) (PDSA). To achieve this, PDSA was enzymatically synthesized using lipase B from Candida antartica (CAL-B), chemically modified with side chains having free primary amine (NH2) groups that can be acyl acceptor substrate of TG16, thoroughly characterized by 1H NMR spectroscopy, and then applied for the TG16-mediated conjugation reaction with rHuEPO. rHuEPO conjugates generated by this approach were identified by SDS-PAGE proving that the amine-grafted PDSA is accepted as a substrate for TG16. The successful conjugation was further verified by the detection of high molar mass fluorescent bands after labelling of amine-grafted PDSA with rhodamine B-isothiocyanate. Overall, this enzymatic procedure is considered as an effective approach to prepare biodegradable rHuEPO-polymer conjugates even in the presence of N- and O-glycans.

Relationship of Blood Groups to the Incidence of Hyperuricemia and Hyperglycemia

Several experiments have been carried out to estimate the relationship between blood grouping types and the occurrence of diabetes, but not hyperuricemia. The effects of the potential correlation between the ABO blood groups and the incidence of these cases have been recorded in this study. The aim of this study is to see whether there is a connection between ABO blood groups and the occurrence of hyperuricemia and hyperglycemia among samples of Iraqi patients. This research was carried out in Educational Laboratories/Medical City (Baghdad Governorate). The research was carried out of the ABO blood with age range (40-70) years, ABO blood group was performed by the sliding method, while uric acid and glucose blood levels were measured by utilizing an enzymatic procedure. There are significant differences in the levels of uric acid between blood groups (A and AB) and blood groups (A and O), while the levels of serum glucose were highly significant between blood groups (B and AB) and blood groups (AB and O). It is concluded that blood groups type AB could be the most vulnerable to the occurrence of hyperuricemia and hyperglycemia. However, further investigations with consideration to Rhesus factor Rh are required.

Enzymatic pre-treatment of grape seeds for an oil with higher antioxidant activity

The paper investigates the effect of the enzymatic pre-treatment of grape seeds from six Romanian cultivars on the oil extracted. The grape seeds of some white and red Romanian grape varieties were separated from winery waste, washed, dried and ground, with the oil then obtained by extraction with petroleum ether. The extraction was performed directly or after a preliminary treatment with a commercial pectin lyase. The enzymatic procedure applied was more cost effective compared to other treatments previously described in which a cocktail of enzymes was used. The quantity of the extracted oil was measured in both types of processing, with an increase being observed for pre-treated samples. The fatty acid profiles (FAPs) of the oils resulted for the treated and untreated seeds were determined. No change in the composition was noticed. The reductive power of these oils was also investigated. Compared to the untreated samples for the same variety, the enzyme pre-treatment resulted in a superior antioxidant capacity.

Metabolic adaptation to the chronic loss of Ca2+ signaling induced by KO of IP3 receptors or the mitochondrial Ca2+ uniporter

Calcium signaling is essential for regulating many biological processes. Endoplasmic reticulum inositol trisphosphate receptors (IP3Rs) and the mitochondrial Ca2+ uniporter (MCU) are key proteins that regulate intracellular Ca2+ concentration. Mitochondrial Ca2+ accumulation activates Ca2+-sensitive dehydrogenases of the tricarboxylic acid (TCA) cycle that maintain the biosynthetic and bioenergetic needs of both normal and cancer cells. However, the interplay between calcium signaling and metabolism is not well understood. In this study, we used human cancer cell lines (HEK293 and HeLa) with stable KOs of all three IP3R isoforms (triple KO [TKO]) or MCU to examine metabolic and bioenergetic responses to the chronic loss of cytosolic and/or mitochondrial Ca2+ signaling. Our results show that TKO cells (exhibiting total loss of Ca2+ signaling) are viable, displaying a lower proliferation and oxygen consumption rate, with no significant changes in ATP levels, even when made to rely solely on the TCA cycle for energy production. MCU KO cells also maintained normal ATP levels but showed increased proliferation, oxygen consumption, and metabolism of both glucose and glutamine. However, MCU KO cells were unable to maintain ATP levels and died when relying solely on the TCA cycle for energy. We conclude that constitutive Ca2+ signaling is dispensable for the bioenergetic needs of both IP3R TKO and MCU KO human cancer cells, likely because of adequate basal glycolytic and TCA cycle flux. However, in MCU KO cells, the higher energy expenditure associated with increased proliferation and oxygen consumption makes these cells more prone to bioenergetic failure under conditions of metabolic stress.

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues.

Sugar-modified nucleosides have gained considerable attention in the scientific community, either for use as molecular probes or as therapeutic agents. When the methylene group of the ribose ring is replaced with a sulfur atom at the 3’-position, these compounds have proved to be structurally potent nucleoside analogues, and the best example is BCH-189. The majority of methods traditionally involves the chemical modification of nucleoside structures. It requires the creation of artificial sugars, which is accompanied by coupling nucleobases via N-glycosylation. However, over the last three decades, efforts were made for the synthesis of 1,3-oxathiolane nucleosides by selective N-glycosylation of carbohydrate precursors at C-1, and this approach has emerged as a strong alternative that allows simple modification. This review aims to provide a comprehensive overview on the reported methods in the literature to access 1,3-oxathiolane nucleosides. The first focus of this review is the construction of the 1,3-oxathiolane ring from different starting materials. The second focus involves the coupling of the 1,3-oxathiolane ring with different nucleobases in a way that only one isomer is produced in a stereoselective manner via N-glycosylation. An emphasis has been placed on the C–N-glycosidic bond constructed during the formation of the nucleoside analogue. The third focus is on the separation of enantiomers of 1,3-oxathiolane nucleosides via resolution methods. The chemical as well as enzymatic procedures are reviewed and segregated in this review for effective synthesis of 1,3-oxathiolane nucleoside analogues.

Radular Morphology of Thiarid from Raja Ampat

Radula in gastropods is considered as a constant and conservative character that can be used in classification and phylogenetic at certain taxa level. However, character of radula is also ecophenotypic, so that the morphology of the radula can also indicates intraspecific variations that able to detect differences among species. The insights of the radular morphology specific to Thiaridae is important for classifying species within this family. Through an enzymatic procedure using the proteinase-K, five radula of Thiarid from Raja Ampat were extracted. The results of research on radula showed that the five species studied had the taeniglossan radula type. The band of the radula is 1.8 - 4.8 mm long and consists of marginal teeth, lateral teeth, and rachidian. The radula formula is 2/1/R/1/2 with a 3-4/1/3-4 rachidian pattern and a 2-3/1/2-3 lateral teeth pattern. The mesocone shape of the rachidian and lateral teeth varies between rounded and pointed.