Pi Class Research Articles

Pi Class – A Revolutionary Step Forward in Hybrid Class Management System

The COVID-19 pandemic has caused widespread disruptions globally, resulting in a state of health emergency with numerous deaths reported and an overall implementation of quarantine and isolation. Strict lockdowns have been implemented to curb the spread of the virus, requiring social distancing and limiting physical interactions. These measures had far-reaching impacts on all aspects of life, including education. Education was one of the most affected sectors, with difficulty delivering quality education in schools, colleges, and universities. It was hard to provide quality education, a basic need of humanity. In this research paper, we propose an adequate solution to overcome the difficulties of maintaining educational quality during and after the COVID-19 pandemic and its multiple variants. The proposed solution is a hybrid model for an autonomous lecture recording system that facilitates students to attend physical classes and attend lectures virtually. The solution proposed is a cost-effective and convenient way for students to access lectures. The application involves hardware and software components that record and preserve lectures' audio and visual aspects. The system will allow lectures to be delivered directly to the students' devices. The major modules of the project include Python scripting, model training, UI/UX design, and app development.

Transmitted Antiretroviral Drug Resistance to Integrase Strand Transfer Inhibitors Class in São Paulo Metropolitan Area, Brazil.

A newer integrase strand transfer inhibitor (INSTI) cabotegravir was recently approved for both therapy and prophylaxis and can play an essential role in the fight against AIDS. It shares similar resistance profile to dolutegravir, the cornerstone of Brazilian antiretroviral (ARV) treatment, with about 600 thousand people living with HIV in Brazil currently on regimens that contain this INSTI. Health services in the São Paulo metropolitan area are responsible for a large proportion of ARV dispensation in the country. Estimating transmitted drug resistance mutation (TDRM) in the area before cabotegravir introduction may provide a useful baseline information. Partial HIV-1 pol gene was sequenced (Sanger) from 192 newly diagnosed individuals from São Paulo and nearby cities (2020 to March 2023) at integrase, with 85 also at protease/reverse transcriptase regions. Retrotranscribed plasma RNA, amplified with nested PCR, was edited (Recall or Sequencher) and analyzed at Rega and Stanford db. Surveillance drug resistance mutations (SDRM) to INSTI class was detected in three cases (1.6%; 95% CI: 0.5%-5%), two E138K and one R263K, with 7.8% (95% CI: 5%-13%) with resistance mutations (major or accessory). SDRM for nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and PI classes were identified in 7 (8.2% CI: 95% 4%-16%) cases. Subtype B predominated (69%), followed by subtype C (16%), now the second most prevalent infection in this area. Among 131 patients treated for over 6 months, 92% were virally suppressed below 200 copies/mL, with low TCD4 counts independently associated to failure. SDRM to INSTI class is rare in the area. Intermediate rates of transmitted resistance to other ARV classes are comparable to previous estimates. Viral suppression rates may depend on TCD4 counts, another negative impact of late diagnosis in care that deserves more attention.

Study on lipid and fatty acid composition of \(\textit{Thelenota ananas}\) collected from Bai Dong Island, Ha Long Bay, Vietnam

The paper studies the lipid and fatty acid composition of the sea cucumber Thelenota ananas collected on Bai Dong Island, Ha Long Bay, Vietnam. The total lipid content of dry sample weight was relatively high (11.89%). The triacylglycerol TG has the highest concentration in total lipids with a ratio of up to 66.73%; the PL and PI classes do not have a significant difference with the proportions of 13.44 and 11.65% in total lipids. Two classes of sterol ST, hydrocarbon-wax HW and free fatty acid FFA account for a small proportion. The two main classes of phospholipids are PC and PE, with a ratio of 47.10% and 33.29% of total phospholipids. There are 36 fatty acids identified, of which total saturated fatty acids (SFA) account for 41.61%; Monounsaturated fatty acids (MUFA) account for 32.15%, and polyunsaturated fatty acids (PUFA) account for 25.63%; the main fatty acids are stearic acid (18:0) accounting for 13.15% of the total fatty acids; 16:1n-9 accounts for 14.87%, and 20:5n-3 EPA fatty acids account for 15.3% of the total fatty acids. Among the fatty acids, n-9 (omega 9) accounts for the highest proportion with 25.16%; n-3 fatty acids (omega 3) account for 18.43%; n-6 (omega 6), n-7 (omega 7) fatty acids account for 5.8 and 6.5%, respectively. In this study, the n3/n6 ratio of the sea cucumber sample Thelenota ananas was 3.18%, consistent with the evaluation standards of the World Health Organization (WHO) of n3/n6 ratio ≥ 0.1%. It is classified as a good foodstuff for human health; therefore, it can be considered a source of food that can be used to serve community health care needs.

Can platform use patterns be an indicator of HIV-related risk and sub-group heterogeneity among men who have sex with men in Singapore: a latent class analysis.

Low-level HIV epidemic settings like Singapore face the challenge of reaching men at-risk who have less contact with programmes. We investigated patterns of meeting platform use by men seeking male sexual partners (MSM) as potential marker of risk to differentiate sub-groups for interventions. Latent Class Analysis (LCA) was applied to a survey sample of MSM recruited from bars/clubs, saunas and a smartphone application, using purposive sampling. The best-fit LCA model which identified homogeneous sub-groups with similar patterns of meeting platform was factored in multivariable regression to identify associations with risk behaviors on the pathway to HIV infection. Overall 1,141 MSM were recruited from bars/clubs (n = 426), saunas (n = 531), and online (n = 184). Five patterns emerged, reflecting salient platform use characteristics: Sauna-centric (SC; n = 413), App-centric (AC; n = 276), Multiple-platforms (MP; n = 123), Platform-inactive (PI; n = 257), and "Do not hook up" (DNH; n = 72) classes. Men in the SC and MP classes had high probabilities of using saunas to meet partners; SC were older and less likely to have disclosed their sexual orientation. The MP class had high probabilities of connecting across all platforms in addition to saunas and more likely to have disclosed their sexual orientation, than the PI class. Men in the SC and MP classes had twice the odds of reporting multiple sex partners (aORSC = 2.1; 95%CI: 1.33.2; aORMP = 2.2; 95%CI: 1.14.6). Single/non-partnered MSM and those using alcohol/drugs during sex had 1.7 (95%CI: 1.22.5) and 3.2 (95%CI: 2.05.1) the odds respectively, of reporting multiple sex partners. The SC and MP classes had higher odds of engaging in group sex while MSM using alcohol/drugs during sex had twice the odds of reporting group sex. Alcohol/drugs and group sex were independently associated with condomless sex (as was lower education). Group sex, alcohol/drugs during sex, disclosure of sexual orientation or being Singaporean/permanent resident were associated with recent testing for HIV. The five distinct risk profiles identified can help tailor differentiated HIV interventions-combined with field knowledge and other prevention-to expand HIV self-testing, Pre-Exposure Prophylaxis and other services (e.g., Mpox vaccination) to sub-groups at risk.

Unified Supersymmetric Description of Shape-Invariant Potentials within and beyond the Natanzon Class

The transformations of supersymmetric quantum mechanics are discussed within a formalism that employs a six-parameter function, from which the superpotential and the supersymmetric partner potentials V−(x) and V+(x) are constructed in a general form. By specific choice of the parameters, V−(x) and V+(x) are matched with the general form of PI class potentials and their rationally extended versions. The choice of the parameters also determines which of the four possible SUSY transformations Ti, i=1,…4 is in effect. After this general discussion, the formulae are specified to the three members of this potential class, the Scarf I, Scarf II and generalized Pöschl–Teller potentials. Due to the different domains of definition and their consequences on the boundary conditions, the results turn out to be rather diverse for the three potentials, while the mathematical formalism and the network of the potentials interconnected by the SUSYQM transformations still remains common to a large extent. The general framework allows a unified and consistent interpretation of earlier isolated findings. It also helps to connect the results to further potential classes and to place them into a more general context within the zoo of exactly solvable potentials.

Quantitative lipidomics in green robusta coffees from the Brazilian Amazon by LC-HRMS

Lipids play an important role in coffee bean development and impact the coffee brew quality. The lipid fraction of raw coffee beans is mainly composed of triacylglycerols (TG) and other minor constituents, such as diterpenes, sterols, phospholipids (PL), and βN-alkanoyl-5-hydroxytryptamides (Cn-5HT). Despite these classes of compounds having been previously characterized by lipidomics, this approach was limited to semi-quantitative analysis. In this work, we developed a multiclass quantitative approach using liquid chromatography-high resolution mass spectrometry to quantify lipids in raw robusta coffees from different producers of the Brazilian Amazon region. The quantitative method for LPC, PC, PI, PG, DG, TG, and Cn-5HT classes was successfully developed and validated. The total lipid content in the robusta coffees ranged from 17.13 to 29.03 g 100 g−1 for TG, 1.44 2.10 g 100 g−1 for DG, 0.27–0.53 g 100 g−1 for PC, 0.34–0.36 g 100 g−1 for FI, 0.10–0.19 g 100 g−1 for Cn-5HT, and 0.01 g 100 g−1 for LPC. In addition, individual components from the Cn-5HT class were analyzed. PC, PI, TG, DG, and Cn-5HTs were relevant factors in discriminating the coffee samples according to their origin. Therefore, these results can help to further understand how the lipid composition of coffee beans is related to the place of harvest and the development of origin certificates of Amazon robusta coffees.

Human oocytes image classification method based on deep neural networks

BackgroundThe effectiveness of in vitro fertilization depends on the assessment and selection of oocytes and embryos with the highest developmental potential. One of the tasks in the ICSI (intracytoplasmic sperm injection) procedure is the classification of oocytes according to the stages of their meiotic maturity. Oocytes classification traditionally is done manually during their observation under the light microscope. The paper is part of the bigger task, the development of the system for optimal oocyte and embryos selection. In the hereby work, we present the method for the automatic classification of oocytes based on their images, that employs DNN algorithms.ResultsFor the purpose of oocyte class determination, two structures based on deep neural networks were applied. DeepLabV3Plus was responsible for the analysis of oocyte images in order to extract specific regions of oocyte images. Then extracted components were transferred to the network, inspired by the SqueezeNet architecture, for the purpose of oocyte type classification. The structure of this network was refined by a genetic algorithm in order to improve generalization abilities as well as reduce the network’s FLOPs thus minimizing inference time. As a result, overline{Acc} at the level of 0.964 was obtained at the level of the validation set and 0.957 at the level of the test set. Generated neural networks as well as code that allows running the processing pipe were made publicly available.ConclusionsIn this paper, the complete pipeline was proposed that is able to automatically classify human oocytes into three classes MI, MII, and PI based on the oocytes’ microscopic image.

Molecular species of some glycerophospholipid classes of soft coral \(\textit{Sinularia leptoclados}\) collected in Nha Trang, Khanh Hoa

In the soft coral Sinularia leptoclados, 30 molecular species belonged to 4 glycerophospholipid classes, including 8 ethanolamine glycerophospholipid (PE), 13 choline glycerophospholipid (PC), 3 serine glycerophospholipid (PS) and 6 inositol glycerophospholipid (PI) molecular species were identified. PE 18:1e/20:4, PC 18:0e/20:4, PS 18:0e/24:5 and PI 18:0/24:5 are the most abundant species with value of 69.94%, 45.57%, 68.55% and 68.18%, respectively. The PE, PC, and PS classes are reported to contain alkylacylphospholipid; meanwhile, a considerable level of diacylphospholipid is found in PI. A large portion of C20:4n polyunsaturated fatty acid was found in PE and PC; meanwhile, C16, C18, C22, and C24 fatty acids were reported at a minor level. The most dominant polyunsaturated fatty acid in PI and PS is tetracosapolyenoic C24. In the presence of fatty acids specific for the biosynthesis of zooxanthellae18:4n and 22:6n, PC is the most influenced class by the lipid composition of symbiotic microalgae. The PC 16:0e/18:4 and PC 18:1e/22:6 molecular species with recorded content of 1.69% and 8.05% are the evidence for lipid transportation from zooxanthellae to host corals. The PE, PS, and PI classes exhibit the lipid composition of the host coral; also, they are less affected by zooxanthellae lipids.

Implications of Glutathione-S-transferases in Mitogen-activated protein kinase pathway: Risk associated with anticancer drug resistance

Anticancer drug resistance is a perilous glitch to accomplish alleviation of disease in patients with cancer. The setback of drug resistance in chemotherapy is a weighty snag of present time. Hassle of carcinoma has ability to develop resistance that arises due to certain alterations in drug targets. In the course of anticancer administrations, development of targeted therapies anticipates a new arena to subdue the drug resistance. Exalted levels of certain glutathione transferase isozymes have been identified with malign transformations as well as with anticancer drug resistance. Glutathione-S-transferases are a large group of phase-II detoxification enzymes which catalyse the conjugation of reduced glutathione to a broad range of exogenous as well as endogenous compounds. The enzymes of this family are divided into two distinct subgroups namely: cytosolic enzymes and membrane bound microsomal enzymes. Human cytosolic glutathione-S-transferases are extremely polymorphic in nature and exist in many forms such as mu, pi, alpha, theta, omega and zeta. Among these enzymes, mu and pi classes take part in regulation of mitogen-activated protein kinase pathway in directing cellular responses with apoptosis signal-regulating kinase and c-Jun Nterminal kinase 1 protein interactions. In normal condition, these two protein are mainly activated in response to cellular stress. The implications of glutathione S-transferase in development of anticancer drug resistance have been observed in two distinct ways. The first way is through direct detoxification mechanism while the second way deals with the action of glutathione S-transferase (mu and pi forms) as inhibitor to mitogen-activated protein kinase pathway.

Alexander Munn

An immunohistochemical study of glutathione S-transferase (GST) expression in hepatocellular carcinoma and cholangiocarcinoma is described. Unlike most animal models of hepatic malignancy pi class GST was not consistently overexpressed in...

Evaluation of Phenolic Content Diversity along with Antioxidant/Pro-Oxidant, Glutathione Transferase Inhibition, and Cytotoxic Potential of Selected Commonly Used Plants.

The function of antioxidant polyphenols has been demonstrated for their ability to protect against a variety of diseases. However, some antioxidants have been shown to be pro-oxidant. Some of the important antioxidant enzymes are glutathione transferases (GST), which are involved in maintaining redox homeostasis. GST class Pi (GSTP1-1) hyper-activation is a feature that is found in cancer. This work aims to demonstrate the relationship between the phytochemicals of 18 plants and their ability to act as antioxidant/pro-oxidant agents, as well as their effects on the activity of GSTP1-1 and their cellular toxicity. Tamarindus indica, Cinnamomum verum, and Alpinia galanga extracts had high phytochemical contents, moderate heavy metal levels, and antioxidant/pro-oxidant activities. Among the main plant components identified using high-performance liquid chromatography, only chlorogenic acid, catechin, and quercetin can function as antioxidants and pro-oxidants. Hibiscus sabdariffa, C. verum, A. galanga, T. indica, Gossypium arboreum, and Punica granatum were among the plant extracts examined that inhibited the activity of the purified recombinant GSTP1-1, with the inhibition constant values ranging from 0.48 to 1.67 mg of gallic acid equivalent/g. The level of cytotoxicity was also studied to determine the effects of these extracts on human Caucasian breast cancer. The findings revealed that plants with high phenol content had an antioxidant/pro-oxidant capacity as well as inhibition of the activity of GST. However, the cytotoxic effect was not associated with all of the extracts, which indicates that polyphenols interact with other components that may influence their observed behavior.

Groundwater quality evaluation for domestic and irrigation purposes for the Nwanedi Agricultural Community, Limpopo Province, South Africa

In addition to quantity of water supply for various water uses, water quality is also of concern. The current state of the water quality is not known; neither is its suitability for domestic and agricultural uses. The current study investigated the suitability of the groundwater resource for domestic and agricultural uses in Nwanedi agricultural community. Water samples were collected from the existing boreholes following procedure for standard water sampling. Physicochemical parameters (pH, TDS, EC), anions (Cl−, SO42−, HCO3, and NO3--N), cations (Mg, Ca, K, and Na), and HCO3 were analysed successively. The assay results were used to generate the agricultural water quality parameters (Sodium Adsorption Ratio, Magnesium Adsorption Ratio, Permeability Index, Residual Sodium Carbonates, Sodium percentage, Kelly's Ration and Chloride Index). Also, the communality test was conducted to investigate the suitability of the data for factor analysis and the loading of different parameters on the resultant factors. The assay results indicated that the water quality in the area is relatively fresh and adequate for domestic consumption, although there are infrequent excessive levels of nitrates ranging between 0.52–135.54 mg/l. Similarly, the groundwater was found to be ideal for irrigation (SAR 0.07–0.94 meq/l, MAR 26–48 meq/l, PI (92.5%) Class 1, PI 13–111 meq/l, RSC < −1, and CI = Class 1). The communalities which are the index of the measure of efficiency indicated that all the parameters except K were suitable for FA assessment. The hydrochemical composition is controlled by natural and anthropogenic processes such as on-sight sanitation, agricultural leachates, and domestic effluents. Future comparative studies on how groundwater quality is influenced by climate conditions (dry and wet season) should be conducted in this area.

Uloga biomarkera redoks homeostaze u nastanku i progresiji svetloćelijskog karcinoma bubrežnog parenhima

The clear cell renal cell carcinoma (ccRCC) is the most frequent and the most aggresive subtype of renal cell carcinoma usually detected at an already advanced stage. It might even be observed as a metabolic disease since complex molecular changes and disturbed redox homeostasis are its hallmark. As certain changes are characteristic for tumorigenesis, while some other for metastatic disease, the identification of metabolic modifications could also point out the stage of tumor progression. Hypoxia inducible factor, as a factor regulating transcription of genes encoding glycolytic enzymes, as well as controlling lipid accumulation, has a particular place in ccRCC development. Additionaly, disturbed redox homeostasis induces the Keap1/Nrf2 pathway which further modulates the synthesis of phase-II detoxifying metabolism enzymes. The upregulation of glutathione transferases, Pi class especially, inhibits kinase-dependent apoptosis that is essential in tumor progression. Furthermore, hydrogen peroxide (H2O2) acts as a signaling molecule conveying redox signals, while superoxide dismutase, as well as glutathione peroxidase are enzymes involved in its production and degradation. Hence, the activity of these enzymes impacts hydrogen peroxide levels and consequentially the ability of ccRCC cells to evade negative effect of reactive oxygen species.

Arsenic and Protein Expression: It might help to know the mechanism of As toxicity

Arsenic and Protein Expression: It might help to know the mechanism of As toxicity

Online Node- and Edge-Deletion Problems with Advice

In online edge- and node-deletion problems the input arrives node by node and an algorithm has to delete nodes or edges in order to keep the input graph in a given graph class Pi at all times. We consider only hereditary properties Pi , for which optimal online algorithms exist and which can be characterized by a set of forbidden subgraphs {{mathcal{F}}} and analyze the advice complexity of getting an optimal solution. We give almost tight bounds on the Delayed Connected{{mathcal{F}}}-Node-Deletion Problem, where all graphs of the family {mathcal{F}} have to be connected and almost tight lower and upper bounds for the DelayedH-Node-Deletion Problem, where there is one forbidden induced subgraph H that may be connected or not. For the DelayedH-Node-Deletion Problem the advice complexity is basically an easy function of the size of the biggest component in H. Additionally, we give tight bounds on the Delayed Connected{mathcal{F}}-Edge-Deletion Problem, where we have an arbitrary number of forbidden connected graphs. For the latter result we present an algorithm that computes the advice complexity directly from {mathcal{F}}. We give a separate analysis for the Delayed ConnectedH-Edge-Deletion Problem, which is less general but admits a bound that is easier to compute.

Regulation of transgelin and GST-pi proteins in the tissues of hamsters exposed to sodium arsenite

Regulation of transgelin and GST-pi proteins in the tissues of hamsters exposed to sodium arsenite

Does and duration of exposure time dependent regulation of proteins in the urinary bladder of hamsters exposed to sodium arsenite

Does and duration of exposure time dependent regulation of proteins in the urinary bladder of hamsters exposed to sodium arsenite

An increase in O-GlcNAcylation of Sp1 down-regulates the gene expression of pi class glutathione S-transferase in diabetic mice

Oxidative stress is a key factor contributing to the development of diabetes complications. Glutathione S-transferases (GSTs) protect against products of oxidative stress by conjugating glutathione to electrophilic substrates, producing compounds that are generally less reactive and more soluble. The expression and activity of GSTs during diabetes have been extensively studied, but little is known about regulation mechanisms of Pi-class GST (GSTP). The aim of the present study was to evaluate how GSTP is regulated in a Streptozotocin (STZ)-induced murine diabetes model. GST activity and GSTP expression were determined in adult male mice diabetized with STZ. Specificity protein 1 (Sp1) expression and O-glycosylation, as well as the role of AP-1 members Jun and Fos in the regulation of GSTP expression, were also assessed. The results showed that GST total activity and GSTP mRNA and protein levels were decreased in the diabetic liver, and returned to normal values after insulin administration. The insulin-mimetic drug vanadate was also able to restore GST activity, but failed to recover GSTP mRNA/protein levels. In diabetic animals, O-glycosylated Sp1 levels were increased, whereas, in insulin-treated animals, glycosylation values were similar to those of controls. After vanadate administration, Sp1 expression levels and glycosylation were lower than those of controls. Our results suggest that hyperglycemia could lead to the observed increase in Sp1 O-glycosylation, which would, in turn, lead to a decrease in the expression of Sp1-dependent GSTP in the liver of diabetic mice.

Characterization of Dog Glutathione Transferase P1-1, an Enzyme Relevant to Veterinary Medicine.

Glutathione transferases (GSTs) form a family of detoxication enzymes instrumental in the inactivation and elimination of electrophilic mutagenic and carcinogenic compounds. The Pi class GST P1-1 is present in most tissues and is commonly overexpressed in neoplastic cells. GST P1-1 in the dog, Canis lupus familiaris, has merits as a marker for tumors and as a target for enzyme-activated prodrugs. We produced the canine enzyme CluGST P1-1 by heterologous bacterial expression and verified its cross-reactivity with antihuman-GST P1-1 antibodies. The catalytic activity with alternative substrates of biological significance was determined, and the most active substrate found was benzyl isothiocyanate. Among established GST inhibitors, Cibacron Blue showed positive cooperativity with an IC50 value of 43 nM. Dog GST P1-1 catalyzes activation of the prodrug Telcyta, but the activity is significantly lower than that of the human homolog.

Exposure of Rats to Multiple Oral Doses of Dichloroacetate Results in Upregulation of Hepatic Glutathione Transferases and NAD(P)H Dehydrogenase [Quinone] 1.

Dichloroacetate (DCA) is an investigational drug that is used in the treatment of various congenital and acquired disorders of energy metabolism. Although DCA is generally well tolerated, some patients experience peripheral neuropathy, a side effect more common in adults than children. Repetitive DCA dosing causes downregulation of its metabolizing enzyme, glutathione transferase zeta 1 (GSTZ1), which is also critical in the detoxification of maleylacetoacetate and maleylacetone. GSTZ1 (-/-) knockout mice show upregulation of glutathione transferases (GSTs) and antioxidant enzymes as well as an increase in the ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH), suggesting GSTZ1 deficiency causes oxidative stress. We hypothesized that DCA-mediated depletion of GSTZ1 causes oxidative stress and used the rat to examine induction of GSTs and antioxidant enzymes after repeated DCA exposure. We determined the expression of alpha, mu, pi, and omega class GSTs, NAD(P)H dehydrogenase [quinone] 1 (NQO1), gamma-glutamylcysteine ligase complex (GCLC), and glutathione synthetase (GSS). GSH and GSSG levels were measured by liquid chromatography-tandem mass spectrometry. Enzyme activity was measured in hepatic cytosol using 1-chloro-2,4-dinitrobenzene, 1,2-dichloro-4-nitrobenzene, and 2,6-dichloroindophenol as substrates. In comparison with acetate-treated controls, DCA dosing increased the relative expression of GSTA1/A2 irrespective of rodent age, whereas only adults displayed higher levels of GSTM1 and GSTO1. NQO1 expression and activity were higher in juveniles after DCA dosing. GSH concentrations were increased by DCA in adults, but the GSH:GSSG ratio was not changed. Levels of GCLC and GSS were higher and lower, respectively, in adults treated with DCA. We conclude that DCA-mediated depletion of GSTZ1 causes oxidative stress and promotes the induction of antioxidant enzymes that may vary between age groups. SIGNIFICANCE STATEMENT: Treatment with the investigational drug, dichloroacetate (DCA), results in loss of glutathione transferase zeta 1 (GSTZ1) and subsequent increases in body burden of the electrophilic tyrosine metabolites, maleylacetoacetate and maleylacetone. Loss of GSTZ1 in genetically modified mice is associated with induction of glutathione transferases and alteration of the ratio of oxidized to reduced glutathione. Therefore, we determined whether pharmacological depletion of GSTZ1 through repeat administration of DCA produced similar changes in the liver, which could affect responses to other drugs and toxicants.