Extended reality visualization of medical museum specimens: Online presentation of conjoined twins curated by Dr. Jacob Henle between 1844-1852.

Background: The purpose of this study is to characterize a full-term conjoined twins' cadaver curated by Dr. Jacob Henle sometime between 1844 and 1852 and demonstrate digital distribution of an old and rare medical museum specimen using an extended reality (XR) model workflow. Methods: The cadaver (Preparation 296) is in the Department of Anatomy and Cell Biology at the University of Heidelberg. An XR display workflow comprises image capture, segmentation, and visualization using CT/MR scans derived from the cadaver. Online radiology presentation to medical students focuses on diagnostic characteristics of anatomical systems depicted with XR models. Results: Developmental defects in Preparation 296 include duplicated supradiaphragmatic structures and abnormal osteological features. Subdiaphragmatically, the gut is continuous on the right, but terminates at the distal esophagus on the left. One large liver occupies the abdomen with one spleen located on the left side. Observations suggest duplication of the primitive streak and separate notochords rostrally. Duplication occurs near the yolk sac and involves midgut formation while secondary midline fusion of the upper extremities and ribs likely results from the proximity of the embryos during development. Medical students access the model with device agnostic software during the curricular topic "Human Body Plan" that includes embryology concepts covering mechanisms of twinning. Conclusions: The workflow enables ease-of-access XR visualizations of an old and rare museum specimen. This study also demonstrates digital distribution and utilization of XR models applicable to embryology education.

Toxicity evaluation of Louisiana nearshore marsh sediments following the Deepwater Horizon oil spill.

A crucial step towards understanding potential impacts of the Deepwater Horizon oil spill to marsh ecosystems was to quantitatively determine the toxicity of oil remaining in the sediment. The objective of this study was to assess the potential injury to benthic species using standardized toxicity bioassays. Sediments were collected from locations with differing degrees of oiling based on previous assessments. Less than 13% of the 315 toxicity tests resulted in toxicity to amphipods, mysid shrimp, or sea urchins. There was no relationship among toxicity test results, oiling category or measured total polycyclic aromatic hydrocarbons (PAHs). Equilibrium partitioning sediment benchmarks and additive toxic units (ESBTUs) were applied as an additional line of evidence to evaluate the potential adverse effects based on PAH concentrations in field sediments. The ∑ESBTUs based on 34 PAHs at the 64 nearshore sampling locations were <1, indicating PAHs in sediments were unlikely to cause adverse impacts.

Improvements in biometric health measures among individuals with intellectual disabilities: A controlled evaluation of the Fit 5 program.

BACKGROUND: Individuals with intellectual disabilities (ID) have poorer health statuses compared to the general population. Actions are needed to address health disparities and promote healthy lifestyles among individuals with ID. Moreover, studies that consider program settings for this population are needed. OBJECTIVE: The Special Olympics health program, Fit 5, was evaluated to assess effectiveness in improving health measures for individuals with ID. The settings of programs' implementation were also considered. METHODS: Four Special Olympics basketball teams participated as an intervention group, and three teams as a control group, in a study of the Fit 5 program that was implemented during, and as part of, a regular 8-week basketball season. Resting heart rate (RHR) and blood pressure, and height and weight to calculate Body Mass Index (BMI), were measured before and after the program. Differences in pre- and post-measures were compared between the two groups with paired samples t-tests and ANCOVA. RESULTS: Participants in the intervention group had significantly greater improvements in resting systolic and diastolic blood pressures (p = 0.02 and 0.03, respectively) and RHR (p = 0.003). BMI increased for both groups; however, the increase in the intervention group was significantly less (p = 0.006). The Special Olympics setting was considered familiar and supportive and effectively reached individuals with ID. CONCLUSION: The Fit 5 program positively impacts RHR and blood pressure, and could help reduce extents of BMI increases, in individuals with ID when implemented in a common setting. Further investigation of the impact of Fit 5 and similar programs in additional settings is warranted.

Sedentary Time and Cumulative Risk of Preserved and Reduced Ejection Fraction Heart Failure: From the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: This study examined the relationship between self-reported sedentary time (ST) and the cumulative risk of heart failure with preserved ejection fraction (HFpEF) and reduced ejection fraction (HFrEF) in a diverse cohort of U.S. adults 45-84 years of age. METHODS AND RESULTS: Using data from the Multi-Ethnic Study of Atherosclerosis (MESA), we identified 6,814 subjects, all free of baseline cardiovascular disease. Cox regression was used to calculate the hazard ratios (HR) associated with risk of HFpEF and HFrEF. Weekly ST was dichotomized based on the 75th percentile (1890 min/wk). During ∼11.2 years of follow-up there were 178 first incident HF diagnoses: 74 HFpEF and 69 HFrEF. Baseline ST >1890 min/wk was significantly associated with an increased risk of HFpEF (HR 1.87, 95% confidence interval [CI] 1.13-3.09, P = .01), but not of HFrEF. The relationship with HFpEF remained significant in fully adjusted models including physical activity and waist circumference (HR 2.16, 95% CI 1.23-3.78, P < .01). In addition, every 60-minute increase in weekly ST was associated with a 3% increased risk of HFpEF (HR 1.03, 95% CI 1.01-1.05, P < .01). CONCLUSIONS: Sedentary time >1890 min/wk (∼4.5 h/d) is a significant predictor of HFpEF, independently from physical activity and adiposity.

Mode of physical activity participation by body mass index: 2015 behavioural risk factor surveillance system.

Body mass index (BMI) continues to be used as a marker of health due its strong correlation with adiposity and health. Physical activity (PA) has been shown to be favourably associated with a desirable BMI. Few studies have examined mode of PA participation across BMI indices with a mutually exclusive underweight BMI range. The purpose of this study was to examine the relationship between modes of PA and BMI. Data from the 2015 Behavioral Risk Factor Surveillance System was analysed. Underweight, overweight, and obese BMI categories possessed 35, 20, and 46% lower odds of meeting current PA guidelines. The obese BMI group was found to have lower odds of meeting the aerobic only and strength only guidelines. Underweight, overweight, and obese groups possessed 63, 18, and 76% greater odds of meeting neither PA guideline, respectively.

Upper-Extremity Explosive Resistance Training With Older Adults Can Be Regulated Using the Rating of Perceived Exertion.

Row Lazzarini, BR, Dropp, M, and Lloyd, W. Upper-extremity explosive resistance training with older adults can be regulated using the rating of perceived exertion. J Strength Cond Res 31(3): 831-836, 2017-Explosive resistance training (ERT) improves muscle strength and power in older adults. Previous work has determined that the Borg rating of perceived exertion (RPE) scale can be used to regulate ERT loads for older adults on the leg press exercise. The purpose of this study was to assess the relationship between the Borg RPE scale and ERT loads relative to the 1 repetition maximum (%1RM) in older adults during the chest press exercise. Healthy seniors (n = 10 men, mean [SD] age 75.8 [7.9]; n = 10 women, age 73.0 [6.3]) took part in 2 sessions on nonconsecutive days. During the first session, subjects reported their RPE during multiple ERT repetitions on the chest press for 7 loads across the spectrum of "light" to "heavy", ranging from 20 to 105% body weight. The loads, concealed from the participants, were presented in randomized order. During the second session, a 1RM strength test was conducted. Each load experienced on the first visit was calculated as %1RM. Rating of perceived exertion was averaged across subjects for each 5% range of 1RM from 35% 1RM to 110% 1RM. Regression analysis was used to determine if RPE predicts %1RM during chest press ERT. Rating of perceived exertion predicted the %1RM corresponding with chest press ERT loads (R = 97.6%, SEE 3.6, p < 0.001). Loads that would elicit both strength and power gains (70-90% 1RM) corresponded with an RPE of 14-17. As previously demonstrated with the leg press, ERT loads can be regulated for older adults during the chest press using RPE, allowing ERT to be conducted without maximal strength testing. This approach may increase the adoption of this training method for a broader spectrum of seniors.

Chemical Modification of Ginsenoside on Cell Viability and Cytokine Secretion.

BACKGROUND: Rb1 is a ginsenoside steroid glycoside found exclusively in the plant Panax ginseng. In an earlier report, we showed that Rb1 increased cell proliferation and reduced VEGF (vascular endothelial growth factor) secretion by human retinal pigment epithelial (ARPE19) cells. OBJECTIVE: In the present study, we hypothesized that chemical modification of Rb1 changes the level of VEGF secretion by ARPE19 cells. METHOD: Three derivatives of Rb1 were chemically synthesized by hydrogenation (Rb1-H2), acetylation (Rb1-Acyl), and epoxidation (Rb1-Epoxy). Structural modifications were confirmed by 1H Nuclear Magnetic Resonance (NMR) spectra and Mass Spectrometry (MS). To test the biological activity, chemically modified compounds were added to cell culture media and incubated for 72 hours at a concentration of 250 nM at 37°C. Conditioned media were collected and cells were harvested/ counted after treatment. Viable cell numbers were determined by the trypan blue dye exclusion method and VEGF levels by Enzyme-Linked Immunosorbent Assays (ELISA). RESULTS: Consistent with the prior report, results of the present study show Rb1 increased cell proliferation and decreased VEGF secretion. Similar to Rb1's effect on cell proliferation, treatment with Rb1-H2, Rb1-Acyl and Rb1-Epoxy resulted in an increase in cell numbers. In contrast to Rb1- induced decrease in VEGF secretion, treatment with Rb1-H2, Rb-Acyl and Rb1-Epoxy resulted in increased VEGF levels. CONCLUSION: Chemical modifications of the ginsenoside Rb1 significantly affect the biological activity of VEGF secretion by ARPE19 cells. Additional SAR (Structure Activity Relationship) experiments will be conducted to study the detailed mechanisms by which how specific modifications of Rb1 functional groups alter biological activities.

Effect of Glucose on Retinal Endothelial Cell Viability and VEGF Secretion.

Previous studies have shown that in diabetic patients, there is an increase of retinal capillaries associated with the development of diabetic retinopathy in the eye. The objective of current study is to investigate the effect of glucose on retinal endothelial cell viability and VEGF secretion. 20,000 cells per well were treated without glucose or with 5.5mM (euglycemic), 18.5mM and 30mM (hyperglycemic) glucose for 24 hours. Viable cells were counted using Trypan blue dye exclusion method. ELISA was used to measure VEGF secretion from cells into the cell medium. The number of viable cells incubated with 5.5mM glucose (physiological control) increased by 53.7% after 24 hours. In comparison, cells treated with 18.5mM glucose decreased by 2.8% while cells treated with 30mM glucose decreased by 20% after 24 hours of incubation. Cells without glucose treatment (0mM control) decreased by 33.3%. In contrast to the decrease of viable cell numbers after treatment with high glucose, there is an increase in VEGF secretion (pg/mL) to the cell medium with increase in glucose concentration from 5.5mM to 0, 18.5, and 30mM. The amount of VEGF secreted per cell also increased with increasing glucose concentrations. Our results show that viability of retinal endothelial cells and VEGF release are highly responsive to changes in glucose concentration. Such glucose-induced changes in retinal endothelial cells may negatively impact the integrity of the microvasculature in the diabetic retina leading to angiogenesis and microaneursyms.

Oxidative Stress Induces Senescence in Cultured RPE Cells.

The aim of this research is to determine whether oxidative stress induces cellular senescence in human retinal pigment epithelial cells. Cultured ARPE19 cells were subjected to different concentrations of hydrogen peroxide to induce oxidative stress. Cells were seeded into 24-well plates with hydrogen peroxide added to cell medium and incubated at 37°C + 5% CO2 for a 90-minute period [at 0, 300, 400 and 800 micromolar (MCM) hydrogen peroxide]. The number of viable ARPE19 cells were recorded using the Trypan Blue Dye Exclusion Method and cell senescence was measured by positive staining for senescence-associated beta-galactosidase (SA-beta-Gal) protein. Without hydrogen peroxide treatment, the number of viable ARPE19 cells increased significantly from 50,000 cells/well to 197,000 within 72 hours. Treatment with hydrogen peroxide reduced this level of cell proliferation significantly (to 52,167 cells at 400 MCM; to 49,263 cells at 800 MCM). Meanwhile, cells with a high level of positive senescence-indicator SA-Beta-Gal-positive staining was induced by hydrogen peroxide treatment (from a baseline level of 12% to 80% at 400 MCM and at 800 MCM). Our data suggests that oxidative stress from hydrogen peroxide treatment inhibited ARPE19 cell proliferation and induced cellular senescence.

Treadmill walking is not equivalent to overground walking for the study of walking smoothness and rhythmicity in older adults.

Treadmills are appealing for gait studies, but some gait mechanics are disrupted during treadmill walking. The purpose of this study was to examine the effects of speed and treadmill walking on walking smoothness and rhythmicity of 40 men and women between the ages of 70-96 years. Gait smoothness was examined during overground (OG) and treadmill (TM) walking by calculating the harmonic ratio from linear accelerations measured at the level of the lumbar spine. Rhythmicity was quantified as the stride time standard deviation. TM walking was performed at two speeds: a speed matching the natural OG walk speed (TM-OG), and a preferred TM speed (PTM). A dual-task OG condition (OG-DT) was evaluated to determine if TM walking posed a similar cognitive challenge. Statistical analysis included a one-way Analysis of Variance with Bonferroni corrected post hoc comparisons and the Wilcoxon signed rank test for non-normally distributed variables. Average PTM speed was slower than OG. Compared to OG, those who could reach the TM-OG speed (74.3% of sample) exhibited improved ML smoothness and rhythmicity, and the slower PTM caused worsened vertical and AP smoothness, but did not affect rhythmicity. PTM disrupted smoothness and rhythmicity differently than the OG-DT condition, likely due to reduced speed. The use of treadmills for gait smoothness and rhythmicity studies in older adults is problematic; some participants will not achieve OG speed during TM walking, walking at the TM-OG speed artificially improves rhythmicity and ML smoothness, and walking at the slower PTM speed worsens vertical and AP gait smoothness.

An Evaluation of Select Test Variables Potentially Affecting Acute Oil Toxicity.

In the wake of the Deepwater Horizon incident (2010) in the Gulf of Mexico, an abundance of research studies have been performed, but the methodologies used have varied making comparisons and replication difficult. In this study, acute toxicity tests with mysids and inland silversides were performed to examine the effect of different variables on test results. The toxicity test variables evaluated in this study included (1) open versus closed static test chambers, (2) natural versus artificial diluent, (3) aerated versus nonaerated test solution, and (4) low versus medium energy water-accommodated (WAF) mixing energies. The use of tests using natural or artificial diluent showed no difference in either toxicity test or analytical chemistry results. Based on median lethal concentrations (LC50) of WAFs of unweathered oil (MASS), mysid tests performed in closed chambers were approximately 41 % lower than LC50 values from open-chamber studies, possibly a result of the presence of low-molecular weight volatile aromatics (i.e., naphthalenes). This research also showed that using a medium-energy WAF (with a 20­25 % vortex) increases the number of chemical components compared with low-energy WAF, thus affecting the composition of the exposure media and increasing toxicity. The comparison of toxic units as a measure of the potential toxicity of fresh and weathered oils showed that weathered oils (e.g., Juniper, CTC) are less toxic than the unweathered MASS oil. In the event of future oil spills, these variables should be considered to ensure that data regarding the potential toxicity and environmental risk are of good quality and reproducible.

BIGH3 protein and macrophages in retinal endothelial cell apoptosis.

Diabetes is a pandemic disease with a higher occurrence in minority populations. The molecular mechanism to initiate diabetes-associated retinal angiogenesis remains largely unknown. We propose an inflammatory pathway of diabetic retinopathy in which macrophages in the diabetic eye provide TGFß to retinal endothelial cells (REC) in the retinal microvasculature. In response to TGFß, REC synthesize and secrete a pro-apoptotic BIGH3 (TGFß-Induced Gene Human Clone 3) protein, which acts in an autocrine loop to induce REC apoptosis. Rhesus monkey retinal endothelial cells (RhREC) were treated with dMCM (cell media of macrophages treated with high glucose and LDL) and assayed for apoptosis (TUNEL), BIGH3 mRNA (qPCR), and protein (Western blots) expressions. Cells were also treated with ΤGFß1 and 2 for BIGH3 mRNA and protein expression. Inhibition assays were carried out using antibodies for TGFß1 and for BIGH3 to block apoptosis and mRNA expression. BIGH3 in cultured RhREC cells were identified by immunohistochemistry (IHC). Distribution of BIGH3 and macrophages in the diabetic mouse retina was examined with IHC. RhRECs treated with dMCM or TGFß showed a significant increase in apoptosis and BIGH3 protein expression. Recombinant BIGH3 added to RhREC culture medium led to a dose-dependent increase in apoptosis. Antibodies (Ab) directed against BIGH3 and TGFß, as well as TGFß receptor blocker resulted in a significant reduction in apoptosis induced by either dMCM, TGFß or BIGH3. IHC showed that cultured RhREC constitutively expressed BIGH3. Macrophage and BIGH3 protein were co-localized to the inner retina of the diabetic mouse eye. Our results support a novel inflammatory pathway for diabetic retinopathy. This pathway is initiated by TGFß released from macrophages, which promotes synthesis and release of BIGH3 protein by REC and REC apoptosis.

Interphotoreceptor retinoid-binding protein (IRBP) promotes retinol uptake and release by rat Müller cells (rMC-1) in vitro: implications for the cone visual cycle.

PURPOSE: Interphotoreceptor retinoid-binding protein's (IRBP) role in facilitating the exchange of retinoids between rod and cone photoreceptors, RPE, and Müller cells in the visual cycle remains a mystery. Interphotoreceptor retinoid-binding protein's ability to bind the pericellular matrix of the cone outer segment and Müller cell villi suggests a function in all-trans and 11-cis retinol targeted trafficking in the cone visual cycle. We hypothesize that IRBP facilitates delivery and uptake of all-trans retinol to and release of 11-cis retinol from rat Müller cells (rMC-1). METHODS: Rat Müller cells were incubated with all-trans retinol and BSA or bovine IRBP (bIRBP). Retinoids in the cell homogenates and conditioned media were analyzed by high performance liquid chromatography (HPLC). RESULTS: Cells incubated with 10 µM retinol and BSA had 2100 pmol of all-trans retinol per milligram homogenate protein compared with 3450 pmol when retinol was delivered by bIRBP; these cells also had 450 pmol all-trans retinyl ester per milligram when retinol was delivered by BSA compared with 270 pmol when retinol was delivered by bIRBP. Conditioned media from cells incubated with retinol delivered by BSA did not contain11-cis retinol. However, cells with retinol delivered by bIRBP released 130 pmol/mL of 11-cis retinol into the cell media. Incubation with 5.0 mM deferoxamine (an iron chelator) reduced IRBP-dependent 11-cis retinol retrieval by 60%. CONCLUSIONS: Promoting Müller cell uptake of all-trans retinol and release of 11-cis retinol is a previously unrecognized function of IRBP that may be critical to cone function and integrity.

Improving tobacco-free advocacy on college campuses: a novel strategy to aid in the understanding of student perceptions about policy proposals.

OBJECTIVE: Tobacco-control policy proposals are usually met with opposition on college campuses. Research to understand students' viewpoints about health-related policy proposals and messaging strategies, however, does not exist. This study investigated students' perceptions about a smoke-free policy proposal to help understand their positions of support and opposition and to inform the development of effective messaging strategies. PARTICIPANTS: In January 2012, 1,266 undergraduate students from a midwestern university completed an online questionnaire about smoke-free campus policies. METHODS: Responses were coded and analyzed using Linguistic Inquiry and Word Count software and chi-square, independent-samples t tests, and binary logistic models. RESULTS: Most students who supported a smoke-free policy considered environmental or aesthetic conditions, whereas most opponents used personal freedom frames of thought. Supporters viewed smoking policies in personal terms, and opponents suggested means-ends policy reasoning. CONCLUSIONS: Taken together, points of reference and emotions about proposed policies provided insight about participants' perspectives to help inform effective policy advocacy efforts.

The characterization of living bacterial colonies using nanospray desorption electrospray ionization mass spectrometry.

Nanospray desorption electrospray ionization (nano-DESI) coupled with high-resolution mass spectrometry (MS) and tandem mass spectrometry (MS/MS) enable detailed molecular characterization of living bacterial colonies directly from nutrient agar. The ability to detect molecular signatures of living microbial communities is important for investigating metabolic exchange between species without affecting the viability of the colonies. We describe the protocol for bacterial growth, sample preparation, ambient profiling, and data analysis of microbial communities using nano-DESI MS.

Improving parenting skills for families of young children in pediatric settings: a randomized clinical trial.

IMPORTANCE: Disruptive behavior disorders, such as attention-deficient/hyperactivity disorder and oppositional defiant disorder, are common and stable throughout childhood. These disorders cause long-term morbidity but benefit from early intervention. While symptoms are often evident before preschool, few children receive appropriate treatment during this period. Group parent training, such as the Incredible Years program, has been shown to be effective in improving parenting strategies and reducing children's disruptive behaviors. Because they already monitor young children's behavior and development, primary care pediatricians are in a good position to intervene early when indicated. OBJECTIVE: To investigate the feasibility and effectiveness of parent-training groups delivered to parents of toddlers in pediatric primary care settings. DESIGN, SETTING, AND PARTICIPANTS: This randomized clinical trial was conducted at 11 diverse pediatric practices in the Greater Boston area. A total of 273 parents of children between 2 and 4 years old who acknowledged disruptive behaviors on a 20-item checklist were included. INTERVENTION: A 10-week Incredible Years parent-training group co-led by a research clinician and a pediatric staff member. MAIN OUTCOMES AND MEASURES: Self-reports and structured videotaped observations of parent and child behaviors conducted prior to, immediately after, and 12 months after the intervention. RESULTS: A total of 150 parents were randomly assigned to the intervention or the waiting-list group. An additional 123 parents were assigned to receive intervention without a randomly selected comparison group. Compared with the waiting-list group, greater improvement was observed in both intervention groups (P < .05). No differences were observed between the randomized and the nonrandomized intervention groups. CONCLUSIONS AND RELEVANCE: Self-reports and structured observations provided evidence of improvements in parenting practices and child disruptive behaviors that were attributable to participation in the Incredible Years groups. This study demonstrated the feasibility and effectiveness of parent-training groups conducted in pediatric office settings to reduce disruptive behavior in toddlers. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00402857.

Development of a Standard Reference Material for metabolomics research.

The National Institute of Standards and Technology (NIST), in collaboration with the National Institutes of Health (NIH), has developed a Standard Reference Material (SRM) to support technology development in metabolomics research. SRM 1950 Metabolites in Human Plasma is intended to have metabolite concentrations that are representative of those found in adult human plasma. The plasma used in the preparation of SRM 1950 was collected from both male and female donors, and donor ethnicity targets were selected based upon the ethnic makeup of the U.S. population. Metabolomics research is diverse in terms of both instrumentation and scientific goals. This SRM was designed to apply broadly to the field, not toward specific applications. Therefore, concentrations of approximately 100 analytes, including amino acids, fatty acids, trace elements, vitamins, hormones, selenoproteins, clinical markers, and perfluorinated compounds (PFCs), were determined. Value assignment measurements were performed by NIST and the Centers for Disease Control and Prevention (CDC). SRM 1950 is the first reference material developed specifically for metabolomics research.

Seasonal availability and sensitivity of two field-collected mayflies for the development of a standardized toxicity test.

Ecologically relevant toxicity tests may provide the best protection of sensitive aquatic fauna, but without established culturing or test methodology for such organisms, results may be unreliable and difficult to repeat. Further, field-collected organisms may not be feasible for routine testing purposes, as often required for permitted discharges. This study examined the feasibility of testing two field-collected mayflies, Isonychia bicolor and Maccaffertium spp., over a 1-year period. Seasonal comparisons of availability indicated I. bicolor and Maccaffertium spp. were most abundant during the winter months, resulting in 31 and 49 % of total organisms collected in 2009, while summer was the most difficult time to collect either species. Initial testing in January 2009 resulted in the highest no observable effect concentration (NOEC) values for survivorship (8 g NaCl for I. bicolor and 4 and 8 g NaCl/L for Maccaffertium spp.) when tested at 9 °C. Subsequent tests conducted at 20-23 °C resulted in 7-day NOEC values substantially lower (mean = 1.44 and 1.59 g NaCl/L). Geometric means of exuviae indicated a dose-dependent response for I. bicolor exposed to NaCl, while no dose-dependent response was observed for Maccaffertium spp. with average number of molts varying from 4.93 in the 0.5 g NaCl/L concentration to 3.80 for control organisms followed by 2.24 (1 g NaCl/L). Averages again increased to 3.09 in the 2 g NaCl/L concentration, but declined in the highest concentrations (4-10 g NaCl/L). Based on the results of this feasibility study, field-collected mayflies appear to be too unpredictable in test responses, and therefore, such tests would be unreliable as stand-alone indicators of effluent toxicity.

Estrogen-induced retinal endothelial cell proliferation: possible involvement of pigment epithelium-derived factor and phosphoinositide 3-kinase/mitogen-activated protein kinase pathways.

PURPOSE: Diabetic retinopathy is a leading cause of blindness due to a progressive damage of the retina by neovascularization and other related ocular complications. However, the molecular mechanism underlying the development of diabetic retinopathy is not well understood. An increase in estrogen levels during puberty is associated with an accelerated development of diabetic retinopathy. Previously, we have introduced 17ß-estradiol (E2) to rhesus retinal capillary endothelial cells (RhRECs) in culture and observed a dose- and time-dependent increase in the number of viable cells. The purpose of this present study was to investigate the molecular signaling pathway associated with this estrogen-induced proliferation of RhRECs. METHODS: Estrogen receptor (ER) ER(α) and ER(ß) mRNA expression, and protein synthesis were measured at 0, 3, 6, and 12 h using nested polymerase chain reaction and Western blots. Phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathway inhibitors were introduced into culture media to study their effects on E2-induced cell proliferation and pigment epithelium-derived factor (PEDF) synthesis. The levels of PEDF in the conditioned media were measured by enzyme-linked immunosorbent assay. RESULTS: Exogenous E2 induced a significant increase in the expression of ER(ß) along with an increase in the number of viable RhRECs. Cotreatment of E2 with PI3K and MAPK inhibitors significantly reduced the E2-induced effect on cell proliferation and PEDF production in a dose-dependent manner. CONCLUSION: Results from the present study suggest that an E2-induced increase in the proliferation of RhRECs may be mediated by the action of ER(ß.) Both PI3K and MAPK signaling pathways are involved in this E2-induced cell proliferation, which may follow changes in PEDF levels controlled by these pathways. Further studies will provide additional details on the interaction between these pathways to control changes in PEDF levels and cell proliferation.