Furosemide to lower antenatal severe hypertension: a randomized placebo-controlled trial.

BACKGROUND: Hypertensive disorders of pregnancy are a leading cause of perinatal morbidity, and timely treatment of severely elevated blood pressure is recommended to prevent serious sequelae. In acute hypertension marked by increased blood volume, it is unknown whether diuretics used as an adjunct to antihypertensive medications lead to more effective blood pressure control. OBJECTIVE: This study aimed to evaluate whether the addition of intravenous furosemide to first-line antihypertensive agents reduces systolic blood pressure in acute-onset, severe antenatal hypertension with wide (≥60 mm Hg) pulse pressure. STUDY DESIGN: In this double-blinded randomized trial, participants received 40 mg of intravenous furosemide or placebo in addition to a first-line antihypertensive agent. The primary outcome was mean systolic blood pressure during the first hour after intervention. Secondary outcomes included corresponding diastolic blood pressure; systolic blood pressure, diastolic blood pressure, and pulse pressure at 2 hours after intervention; total reduction from qualifying blood pressure; duration of blood pressure control; need for additional antihypertensive doses within 1 hour; and electrolytes and urine output. A sample size of 35 participants per group was planned to detect a 15-mm Hg difference in blood pressure. RESULTS: Between January 2021 and March 2022, 65 individuals were randomized: 33 to furosemide and 32 to placebo. Baseline characteristics were similar between the groups. There was no difference in the primary outcome of mean 1-hour systolic blood pressure (147 [14.8] vs 152 [13.8] mm Hg; P=.200). We found a reduction in 2-hour systolic blood pressure (139 [18.5] vs 154 [18.4] mm Hg; P=.007) and a decrease in 2-hour pulse pressure (55 [12.5] vs 67 [15.1]; P=.003) in the furosemide group. Subgroup analysis according to hypertension type showed a significant reduction in 2-hour systolic blood pressure and 2-hour pulse pressure among patients with new-onset hypertension, but not among those with preexisting hypertension. Urine output was greater in the furosemide group, with no difference in electrolytes and creatinine before and after intervention. CONCLUSION: Intravenous furosemide in conjunction with a first-line antihypertensive agent did not significantly reduce systolic blood pressure in the first hour after administration. However, both systolic blood pressure and pulse pressure at 2 hours were decreased in the furosemide group. These findings suggest that a 1-time dose of intravenous furosemide is a reasonable adjunct to achieve blood pressure control, particularly in patients in whom increased volume is suspected.

Adherence to Mediterranean diet impacts gastrointestinal microbial diversity throughout pregnancy.

BACKGROUND: Consumption of a diet with high adherence to a Mediterranean diet pattern (MDP) has been associated with a favorable gastrointestinal tract (GIT) microbiome. A healthy GIT microbiome in pregnancy, as defined by increased alpha diversity, is associated with lower chance of adverse perinatal outcomes. This study aimed to evaluate the impact of adherence to an MDP on GIT microbial diversity longitudinally throughout pregnancy. METHODS: Adherence to MDP was scored by the Alternate Mediterranean (aMED) Diet Quality Score, after being applied to a validated Food Frequency Questionnaire. Association of aMED Scores with GIT alpha diversity profiles were compared linearly and across time using a linear mixed model, including covariates of age, body mass index (BMI), ethnicity, and parity. RESULTS: Forty-one participants of Filipino, Japanese, Native Hawaiian, and Non-Hispanic White descent provided dietary information and microbiome samples during each trimester of pregnancy. Alpha diversity profiles changed over gestation, with decreased microbial diversity in the third trimester. aMED scores positively correlated with Chao1 Index and Observed Species Number (r = 0.244, p = 0.017, and r = 0.233, p = 0.023, respectively). The strongest association was detected in the third trimester (Chao 1: r = 0.43, p = 0.020, Observed Species Number: r = 0.41, p = 0.026). Participants with higher aMED scores had higher relative abundance of Acidaminoacaeae at the family level (p = 0.0169), as well as higher abundance of several species known to increase production of short chain fatty acids within the GIT. CONCLUSIONS: Adherence to MDP pattern is associated with increased maternal GIT microbial diversity, and promotes the abundance of bacteria that produce short chain fatty acids. Increased consumption of fruits, vegetables and legumes with low red meat consumption were key components driving this association. The effect of nutrition however, was less of an effect than pregnancy itself. Further studies are needed to determine if adherence to a Mediterranean diet translates not only into microbial health, but also into reduced risk of adverse pregnancy outcomes.

Initial evaluation of a mobile SARS-CoV-2 RT-LAMP testing strategy.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) control in the United States remains hampered, in part, by testing limitations. We evaluated a simple, outdoor, mobile, colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay workflow where self-collected saliva is tested for SARS-CoV-2 RNA. From July 16 to November 19, 2020, 4,704 surveillance samples were collected from volunteers and tested for SARS-CoV-2 at 5 sites. A total of 21 samples tested positive for SARS-CoV-2 by RT-LAMP; 12 were confirmed positive by subsequent quantitative reverse-transcription polymerase chain reaction (qRT-PCR) testing, while 8 were negative for SARS-CoV-2 RNA, and 1 could not be confirmed because the donor did not consent to further molecular testing. We estimated the RT-LAMP assay's false-negative rate from July 16 to September 17, 2020 by pooling residual heat-inactivated saliva that was unambiguously negative by RT-LAMP into groups of 6 or less and testing for SARS-CoV-2 RNA by qRT-PCR. We observed a 98.8% concordance between the RT-LAMP and qRT-PCR assays, with only 5 of 421 RT-LAMP negative pools (2,493 samples) testing positive in the more sensitive qRT-PCR assay. Overall, we demonstrate a rapid testing method that can be implemented outside the traditional laboratory setting by individuals with basic molecular biology skills and can effectively identify asymptomatic individuals who would not typically meet the criteria for symptom-based testing modalities.

Initial Evaluation of a Mobile SARS-CoV-2 RT-LAMP Testing Strategy.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) control in the United States remains hampered, in part, by testing limitations. We evaluated a simple, outdoor, mobile, colorimetric reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay workflow where self-collected saliva is tested for SARS-CoV-2 RNA. From July 16, 2020, to November 19, 2020, surveillance samples (n = 4704) were collected from volunteers and tested for SARS-CoV-2 at 5 sites. Twenty-one samples tested positive for SARS-CoV-2 by RT-LAMP; 12 were confirmed positive by subsequent quantitative reverse-transcription polymerase chain reaction (qRT-PCR) testing, whereas 8 tested negative for SARS-CoV-2 RNA, and 1 could not be confirmed because the donor did not consent to further molecular testing. We estimated the false-negative rate of the RT-LAMP assay only from July 16, 2020, to September 17, 2020 by pooling residual heat-inactivated saliva that was unambiguously negative by RT-LAMP into groups of 6 or fewer and testing for SARS-CoV-2 RNA by qRT-PCR. We observed a 98.8% concordance between the RT-LAMP and qRT-PCR assays, with only 5 of 421 RT-LAMP-negative pools (2493 total samples) testing positive in the more-sensitive qRT-PCR assay. Overall, we demonstrate a rapid testing method that can be implemented outside the traditional laboratory setting by individuals with basic molecular biology skills and that can effectively identify asymptomatic individuals who would not typically meet the criteria for symptom-based testing modalities.

Initial evaluation of a mobile SARS-CoV-2 RT-LAMP testing strategy

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) control in the United States remains hampered, in part, by testing limitations. We evaluated a simple, outdoor, mobile, colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay workflow where self-collected saliva is tested for SARS-CoV-2 RNA. From July 16 to November 19, 2020, 4,704 surveillance samples were collected from volunteers and tested for SARS-CoV-2 at 5 sites. A total of 21 samples tested positive for SARS-CoV-2 by RT-LAMP; 12 were confirmed positive by subsequent quantitative reverse-transcription polymerase chain reaction (qRT-PCR) testing, while 8 were negative for SARS-CoV-2 RNA, and 1 could not be confirmed because the donor did not consent to further molecular testing. We estimated the RT-LAMP assays false-negative rate from July 16 to September 17, 2020 by pooling residual heat-inactivated saliva that was unambiguously negative by RT-LAMP into groups of 6 or less and testing for SARS-CoV-2 RNA by qRT-PCR. We observed a 98.8% concordance between the RT-LAMP and qRT-PCR assays, with only 5 of 421 RT-LAMP negative pools (2,493 samples) testing positive in the more sensitive qRT-PCR assay. Overall, we demonstrate a rapid testing method that can be implemented outside the traditional laboratory setting by individuals with basic molecular biology skills and can effectively identify asymptomatic individuals who would not typically meet the criteria for symptom-based testing modalities.

LESSONS LEARNED AND NEXT STEPS FOR BUILDING KNOWLEDGE ABOUT TRIBAL MATERNAL, INFANT, AND EARLY CHILDHOOD HOME VISITING.

Authors in this Special Issue of the Infant Mental Health Journal shared the work of the first three cohorts of Tribal Maternal, Infant, and Early Childhood Home Visiting (MIECHV) grantees funded by the Administration for Children and Families. Since 2010, Tribal MIECHV grantees have served families and children prenatally to kindergarten entry in American Indian and Alaska Native (AI/AN) communities across the lower 48 United States and Alaska. Articles highlighted challenges and opportunities that arose as grantees adapted, enhanced, implemented, and evaluated their home-visiting models. This article summarizes nine lessons learned across the articles in this Special Issue. Lessons learned address the importance of strengths-based approaches, relationship-building, tribal community stakeholder involvement, capacity-building, alignment of resources and expectations, tribal values, adaptation to increase cultural and contextual attunement, indigenous ways of knowing, community voice, and sustainability. Next steps in Tribal MIECHV are discussed in light of these lessons learned.

Investigating Mechanisms of Stillbirth in the Setting of Prenatal Substance Use.

INTRODUCTION: Intrauterine fetal demise affects between 0.4-0.8% of pregnancies worldwide. This significant adverse pregnancy outcome continues to be poorly understood. In utero exposure to substances increases the risk of stillbirth to varying degrees according to the type of substance and degree of exposure. The aim of this qualitative narrative review is to investigate common biologic relationships between stillbirth and maternal substance use. METHODS: A PubMed literature search was conducted to query the most commonly used substances and biologic mechanisms of stillbirth. Search terms included "stillbirth," "intrauterine fetal demise," "placenta," "cocaine," "tobacco," "alcohol," "methamphetamines," "opioids/ opiates," and "cannabis." RESULTS: There are very few studies identifying a direct link between substance use and stillbirth. Several studies demonstrate associations with placental lesions of insufficiency including poor invasion, vasoconstriction, and sequestration of toxic substances that inhibit nutrient transport. Restricted fetal growth is the most common finding in pregnancies complicated by all types of substance use. DISCUSSION: More research is needed to understand the biologic mechanisms of stillbirth. Such knowledge will be foundational to understanding how to prevent and treat the adverse effects of substances during pregnancy.

Urine Protein/Creatinine Ratios during Labor: A Prospective Observational Study.

PURPOSE: To evaluate the utility of urine protein/creatinine ratio (uPCR) measurements among healthy parturients at term we performed a prospective cohort study at a community teaching hospital. METHODS: Serial urine samples were collected. Ninety-three women contributed 284 urine samples. uPCRs were determined. Multiple imputation and paired sampled analysis was performed when appropriate. RESULTS: Two-thirds (63/93) of women had at least one measured uPCR ≥ 0.3. One-third (31/93) had a uPCR ≥ 0.3 at admission, including 39.1% (9/23) of women not in labor. Median (IQR) uPCRs increased during labor and after delivery: latent phase/no labor, 0.15 (0.06-0.32); active phase, 0.29 (0.10-0.58); early postpartum, 0.45 (0.18-1.36) (all p < 0.04). Median uPCRs were significantly < 0.3 in the latent phase and significantly > 0.3 in the immediate postpartum period (p < 0.01). Women who labored before cesarean delivery had the highest early postpartum uPCRs: median (IQR) 1.16 (0.39-1.80). A negative urine dipstick protein result did not exclude uPCR ≥ 0.3. uPCRs were similar when compared by method of urine collection. CONCLUSION: uPCR ≥ 0.3 is common among healthy women with uncomplicated pregnancies at term. uPCR increases during labor and is not a reliable measure of pathologic proteinuria at term or during the peripartum period.

Trust development: testing a new model in undergraduate roommate relationships.

Interpersonal trust is a vital component of social relationships. In this study the roles of parental attachment, perceived similarity of trustee to self, and social exchange processes in trust development were investigated longitudinally with randomly assigned, same-sex undergraduate roommates during emerging adulthood. A total of 214 first-year students completed weekly self-report measures during the first 5 weeks of the fall semester. Perceived similarity measured the second week and social exchange with roommates across the 5 weeks predicted participants' trust in their roommate, with social exchange mediating the relation between perceived similarity and trust. Results highlight interrelations of social exchange and trust in established relationships.

Cyclin-mediated G1 arrest by celecoxib differs in low-versus high-grade bladder cancer.

BACKGROUND: Celecoxib and other non-steroidal anti-inflammatory drugs (NSAIDs) are being evaluated in the prevention of bladder and other cancers. Here we investigate molecular effects of celecoxib independent of cyclooxygenase (COX)-2 expression levels in urothelial carcinoma of the bladder. MATERIALS AND METHODS: Low-grade RT-4 and high-grade UM-UC-3 bladder cancer cells were treated with 0-50 muM celecoxib. Growth, cell cycle and apoptosis were measured by crystal violet elution and flow cytometry. Western analysis was performed for COX-2, Rb, cyclin B1/D1, and phospho-cyclin B1/D1. COX-2 induction was achieved with phorbol ester. RESULTS: Celecoxib inhibited growth of RT-4 and UM-UC-3, with G(1) cell cycle arrest and altered cyclin B1/D1 expression in RT-4, whereas Rb up-regulation occurred in UM-UC-3. Apoptosis occurred in both cell lines. CONCLUSION: Celecoxib induces G(1) cell cycle arrest in low- and high-grade bladder cancer by different pathways. This heterogeneous molecular response supports combination approaches to prevention and treatment.

Chromosomal abnormality at 6p25.1-25.3 identifies a susceptibility locus for hypothalamic hamartoma associated with epilepsy.

The pathogenesis of hypothalamic hamartoma (HH) associated with epilepsy is unknown. We have identified an individual with HH and refractory epilepsy exhibiting subtle dysmorphic features. High-resolution karyotype identified a duplication of the terminal end of 6p (6p25.1-25.3), confirmed by fluorescent in situ-hybridization (FISH). Copy number analysis with high-density (250K) single nucleotide polymorphism (SNP) genotyping microarrays characterized the abnormality as a series of amplified regions between 1.4 Mb and 10.2 Mb, with a small tandem deletion from 8.8 Mb to 9.7 Mb. There are 38 RefSeq genes within the duplicated regions, and no known coding sequences within the deletion. This unique patient helps identify 6p25.1-25.3 as a possible susceptibility locus for sporadic HH.

Genome-wide SNP arrays as a diagnostic tool: clinical description, genetic mapping, and molecular characterization of Salla disease in an Old Order Mennonite population.

An Old Order Mennonite child was evaluated for gross motor delay, truncal ataxia, and slow linear growth. The diagnostic evaluation, which included sub-specialty consultations, neuroimaging, and metabolic testing, was long, costly, and did not yield a diagnosis. Recognition of a similarly affected second cousin prompted a genome-wide homozygosity mapping study using high-density single nucleotide polymorphism (SNP) arrays. SNP genotypes from two affected individuals and their parents were used to localize the disease locus to a 14.9 Mb region on chromosome 6. This region contained 55 genes, including SLC17A5, the gene encoding the lysosomal N-acetylneuraminic acid transport protein. Direct sequencing of SLC17A5 in the proband revealed homozygosity for the 115C --> T (R39C) sequence variant, the common cause of Salla disease in Finland. Three additional affected Mennonite individuals, ages 8 months to 50 years, were subsequently identified by directed molecular genetic testing. This small-scale mapping study was rapid, inexpensive, and analytically simple. In families with shared genetic heritage, genome-wide SNP arrays with relatively high marker density allow disease gene mapping studies to be incorporated into routine diagnostic evaluations.

Lung epithelial cells release ATP during ozone exposure: signaling for cell survival.

The common air pollutant ozone causes acute toxicity to human airways. In primary and transformed epithelial cells from all levels of human or rat airways, ozone levels relevant to air pollution (50-200 ppb) increased extracellular [ATP] within 7-30 min. A human bronchial epithelial cell line (16HBE14o(-)) that forms electrically resistant polarized monolayers had up to 10-fold greater apical than basolateral surface extracellular [ATP] within 7 min of ozone exposure. Increased extracellular [ATP] appeared due to ATP secretion or release because (1) inhibition of ectonucleotidase (cell surface enzyme(s) which degrade ATP) by ozone did not occur until >120 min of ozone exposure and (2) brefeldin A, a secretory inhibitor, eliminated elevation of extracellular [ATP] without affecting intracellular ATP. Extracellular ATP protected against ozone toxicity in a P2Y receptor-dependent manner as (1) removal of ATP and adenosine by apyrase and adenosine deaminase, respectively, potentiated ozone toxicity, (2) extracellular supplementation with ATP, a poorly hydrolyzable ATP analog ATPgammaS, or UTP inhibited apoptotic and necrotic ozone-mediated cell death, and (3) ATP-mediated protection was eliminated by P2 and P2Y receptor inhibitors suramin and Cibacron blue (reactive blue 2), respectively. The decline in glucose uptake caused by prolonged ozone exposure was prevented by supplemental extracellular ATP, an effect blocked by suramin. Further, Akt and ERK phosphorylation resulted from exposure to supplemental extracellular ATP. Thus, extracellularly released ATP signals to prevent ozone-induced death and supplementation with ATP or its analogs can augment protection, at least in part via Akt and /or ERK signaling pathways and their metabolic effects.

Interleukin-1 receptor antagonist attenuates airway hyperresponsiveness following exposure to ozone.

The role of an interleukin (IL)-1 receptor antagonist (IL-1Ra) on the development of airway hyperresponsiveness (AHR) and airway inflammation following acute O(3) exposure in mice was investigated. Exposure of C57/BL6 mice to O(3) at a concentration of 2.0 ppm or filtered air for 3 h resulted in increases in airway responsiveness to inhaled methacholine (MCh) 8 and 16 h after the exposure, and an increase in neutrophils in the bronchoalveolar lavage (BAL) fluid. IL-1beta expression, assessed by gene microarray, was increased 2-fold 4 h after O(3) exposure, and returned to baseline levels by 24 h. Levels of IL-1beta in lung homogenates were also increased 8 h after O(3) exposure. Administration of (human) IL-1Ra before and after O(3) exposure prevented development of AHR and decreased BAL fluid neutrophilia. Increases in chemokine levels in lung homogenates, tumor necrosis factor-alpha, MIP-2, and keratinocyte chemoattractant following O(3) exposure were prevented by IL-1Ra. Inhalation of dexamethasone, an inhibitor of IL-1 production, blocked the development of AHR, BAL fluid neutrophilia, and decreased levels of IL-1 following O(3) exposure. In summary, acute exposure to O(3) induces AHR, neutrophilic inflammation, epithelial damage, and IL-1. An IL-1Ra effectively prevents the development of altered airway function, inflammation, and structural damage.

Complement activation is critical to airway hyperresponsiveness after acute ozone exposure.

Ozone (O3) can induce airway hyperresponsiveness (AHR) and neutrophilic inflammation. We evaluated the role of complement in development of AHR and inflammation after acute O3 exposure in mice. Mice were exposed to O3 at 2 ppm for 3 hours, and airway responsiveness to methacholine was measured 8 hours after O3 exposure. Complement was depleted or inhibited by intraperitoneal injection of cobra venom factor (CVF) or complement receptor-related gene y (Crry)-Ig, a potent C3 convertase inhibitor; neutrophils were depleted using an antineutrophil monoclonal antibody. CVF attenuated the development of AHR by O3. Administration of Crry-Ig also prevented the development of AHR. Bronchoalveolar lavage (BAL) fluid neutrophilia after O3 exposure was significantly decreased by administration of either CVF or Crry-Ig. Increased BAL fluid total protein after O3 exposure was lowered by depletion or inhibition of complement. In contrast to the effects of complement inhibition or depletion, depletion of BAL neutrophil counts by more than 90% with the monoclonal antibody did not affect the development of AHR after O3 exposure. These data indicated that activation of the complement system follows acute O3 exposure and is important to the development of AHR and airway neutrophilia. However, this neutrophil response does not appear necessary for the development of AHR.

Hyperoxia-induced DNA damage causes decreased DNA methylation in human lung epithelial-like A549 cells.

The effect of hyperoxia on levels of DNA damage and global DNA methylation was examined in lung epithelial-like A549 cells. DNA damage was assessed by the single-cell gel electrophoresis (comet assay) and DNA methylation status by the cytosine extension assays. Cells exposed to ionizing radiation (0, 1, 2, 4, or 8 Gy) showed increasing rates of percentage of DNA in the tail and tail length with increasing radiation dose. When cells were exposed to room air (normoxia) for 1 day and 95% O2 (hyperoxia) for 1, 2, 3, 4, and 5 days, data indicated that hyperoxia caused time-dependent increases in levels of (a) single strand breaks, (b) double strand breaks, and (c) 8-oxoguanine. Decreased DNA methylation also was observed at day 5 of hyperoxic exposure, suggesting that hyperoxia-induced DNA damage can influence patterns of DNA methylation in a lung-derived cell line.

An automated system for exposure of cultured cells and other materials to ozone.

Ozone, a highly reactive oxidant gas, is a major constituent of urban air pollution. Studies of the toxic effects of ozone on cultured cells and other materials are most appropriately conducted under conditions of humidity, temperature, and ozone concentration similar to those in which those materials are naturally exposed. An automated system designed for exposure of cultured cells and other materials to environmentally relevant levels of ozone under nearly physiological conditions is described. Although based on time-proven manually controlled systems, this system is automated using computer programming and hardware that allow unattended operations for extended time periods while maintaining tight control over ozone levels, humidity, and temperature. Experiments were conducted to ensure that the distribution of ozone within the exposure chambers was homogeneous. In addition, experiments were performed to ensure that changes in media volume within the tissue culture plates were minimal, in order to prevent either desiccation of the cultured cells or dilution of the cell culture media. A rocker system is described that allows the tissue culture plates within each exposure vessel to be rocked from end to end to promote mixing of both the gas phase and the liquid phase on each side of the cell culture insert membrane. Since automation of the system allows unattended operation of the system for extended periods, safety systems are described that prevent exposure of investigators to elevated levels of ozone under a variety of system failure conditions.

Hypoxia protects human lung microvascular endothelial and epithelial-like cells against oxygen toxicity: role of phosphatidylinositol 3-kinase.

Hypoxic preconditioning is protective against oxidant-related damage in various organs, such as the heart. We previously showed that rats exposed to hypoxia also exhibit resistance to lethal pulmonary oxygen toxicity. The underlying mechanism and whether similar preconditioning is applicable to cellular models is unknown. In the present study, it was found that hypoxic pre-exposure induces a significant protective effect against hyperoxia-induced cell death in human lung microvascular endothelial cells (HLMVECs) and epithelial type II-like A549 cells. This effect of hypoxia is mediated by the phosphatidylinositol 3-kinase (PI3-K) signaling pathway because the presence of the PI3-K inhibitors, LY294002 and wortmannin, during pre-exposure to hypoxia completely blocks subsequent protection. Further, the hypoxia-dependent protection from hyperoxia was found to be associated with a 2-fold increase in PI3-K activity in hypoxia. Transient overexpression of a catalytically active class IA PI3-K p110alpha isoform also enhanced survival of A549 cells 2-fold compared with the empty vector control. These results indicate that hypoxia-induced activation of PI3-K is an important event in the acquisition of resistance against subsequent hyperoxic toxicity.

"Active" and "passive" learning of three-dimensional object structure within an immersive virtual reality environment.

We used a fully immersive virtual reality environment to study whether actively interacting with objects would effect subsequent recognition, when compared with passively observing the same objects. We found that when participants learned object structure by actively rotating the objects, the objects were recognized faster during a subsequent recognition task than when object structure was learned through passive observation. We also found that participants focused their study time during active exploration on a limited number of object views, while ignoring other views. Overall, our results suggest that allowing active exploration of an object during initial learning can facilitate recognition of that object, perhaps owing to the control that the participant has over the object views upon which they can focus. The virtual reality environment is ideal for studying such processes, allowing realistic interaction with objects while maintaining experimenter control.

Elevated expression of hexokinase II protects human lung epithelial-like A549 cells against oxidative injury.

Increased glucose utilization and hexokinase (HK)-II expression are adaptive features of lung cells exposed to hypoxia or hyperoxia. HK-II is the most regulated isoform of HK. Whether its overexpression could be protective against oxidative stress was explored in human lung epithelial-like (A549) cells. HK-II was overexpressed in A549 cells in a tetracycline-repressible retroviral vector system. Elevated expression of HK-II was confirmed by Western blot and activity measurements. Cell death caused by exposure to hyperoxia was decreased in HK-II-overexpressing cells. This effect was reversed when HK-II expression was suppressed with doxycycline. A similar protective effect was observed in HK-II-overexpressing cells after treatment with 1 mM hydrogen peroxide for 48 h. At baseline, fluorescence microscopy showed that overexpressed HK-II was localized to mitochondria. Electron microscopic studies showed that hyperoxia-exposed HK-II overexpressors had better-preserved and quantitatively smaller mitochondria than those in which the HK-II expression was suppressed or in the nontransduced A549 cells. Mitochondrial membrane potential was increased in HK-II-overexpressing cells exposed to hyperoxia compared with the nontransduced control cells under similar conditions. The present study demonstrates that HK-II protects human lung epithelial-like A549 cells against oxidative insults by protecting the mitochondria.