Reproductive tract biology: Of mice and men.

The study of male and female reproductive tract development requires expertise in two separate disciplines, developmental biology and endocrinology. For ease of experimentation and economy, the mouse has been used extensively as a model for human development and pathogenesis, and for the most part similarities in developmental processes and hormone action provide ample justification for the relevance of mouse models for human reproductive tract development. Indeed, there are many examples describing the phenotype of human genetic disorders that have a reasonably comparable phenotype in mice, attesting to the congruence between mouse and human development. However, anatomic, developmental and endocrinologic differences exist between mice and humans that (1) must be appreciated and (2) considered with caution when extrapolating information between all animal models and humans. It is critical that the investigator be aware of both the similarities and differences in organogenesis and hormone action within male and female reproductive tracts so as to focus on those features of mouse models with clear relevance to human development/pathology. This review, written by a team with extensive expertise in the anatomy, developmental biology and endocrinology of both mouse and human urogenital tracts, focusses upon the significant human/mouse differences, and when appropriate voices a cautionary note regarding extrapolation of mouse models for understanding development of human male and female reproductive tracts

Effect of Ethanol Extract of Chayote on the Activity of Glutathione Peroxide and Blood Sugar in Mice with Hyperglycemia

BACKGROUND: Streptozotocin (STZ) causes hyperglycemia in guinea pig through oxidative stress mechanism that damages pancreatic cells. Ethanol extract of chayote (Sechium edule Jacq. Swartz), locally called as “Ekstrak Etanol Buah Labu Siam” (EEBLS), was hypothesized to decrease oxidative stress. Glutathione peroxidase (GPx) is the general name of an enzyme family with peroxidase activity whose main biological role is to protect the organism from oxidative damage. This study aimed to determine the effect of EEBLS on decreasing blood sugar level and increasing the activity of GPx enzyme. SUBJECT AND METHODS: This was a randomized controlled trial with before and after intervention outcome variable measurement. The study subjects were white male mice (Mus musculus L.) with DD Webster strain randomized into 4 groups: (1) Negative control group (normal); (2) Positive control group with STZ 60 mg/kgBW; (3) Experimental group I with STZ 60 mg/kgBW and EEBLS of 100 mg/kgBW; and (4) Expe-rimental group II with STZ 60 mg/kgBW and EEBLS of 200 mg/kgBW. The addition of STZ 60 mg/kgBW was intended to increase blood sugar level. RESULTS: Blood sugar level (mg/dL) on the 28th day in the negative control group was (mean=127.67; SD=12.93), positive control group (mean=184.29; SD=21.24), experimental group I (145.33; SD=11.13), and experimental group II (mean=133.50; SD=38.19). EEBLS decreased blood sugar and it was statistically significant (p=0.001). The activity of GPx on the 28th day in the negative control group was (mean=420.05; SD=78.95), positive control group (mean=425.98; SD=22.50), experimental group I (mean=427.57; SD=73.82), and experimental group II (mean=418.46; SD=54.90). EEBLS did not increase the activity of GPx; the change in GPx was not statistically significant (p=0.992). CONCLUSION: Ethanol extract of chayote (Sechium edule Jacq. Swartz) administered either in 100 mg/kgBW or 200 mg/kgBW decrease blood glucose level in mice, but does not increase the activity of glutathione peroxidase. Keywords: blood glucose, glutathione peroxidase, ethanol extract of chayot

Effect of Ethanol Extract of Chayote (Sechiumedule.Jacq.Swartz) on the Activity of Glutathione Peroxide (GPx) in House Mice (Musmusculus L) Strain DD Webster Hyperglycemia Induced by Streptozotocin (STZ)

Background: Streptozotocin can cause hyperglycemia in Guinea pig through the mechanism of oxidative stress which damages pancreatic b cells. Ethanol extract of chayote can decrease oxidative stress. This study aimed to determine the effect of Ethanol Extract of Chayote ((EEBLS) Ekstrak Etanol Buah Labu Siam) on decreasing blood sugar content and increasing the activity of glutathione peroxide enzyme. Research Method: This was an experimental study. The samples were using random sampling technique. The control group was using male white mice (Musmusculus L.) Strain DD Webster which randomized into four groups: negative control group, positive control group, group which got EEBLS of 100 mg/kgBB, and group which got EEBLS of 200 mg/kgBB.Research Result: The result of the research showed that there was significant decrease in blood sugar, compared with the control group. There was insignificant decrease in the activity of glutathione peroxide enzyme, compared with the control group.Conclusion: The conclusion of the research was that EEBLS of 200 mg/kgBB decreased blood sugar content of mice significantly, but there was no significant change in the activity of glutathione peroxide enzyme when EEBLS was given to the mice. Keywords: streptozotocin, oxidative stress, antioxidant, flavonoidCorrespondence: Jekson Martiar Siahaan. Biomedical Science, Faculty of Medicine, North Sumatera University.Indonesian Journal of Medicine (2016), 1(1): 44-49https://doi.org/10.26911/theijmed.2016.01.01.0

A Matter of Priorities: Effects of Increased Opportunities for Extracurricular and Non-Traditional Learning Experiences on Student Time Management and Attitudes

Many schools are emphasizing non-traditional and extracurricular learning experiences for undergraduate engineering students. These include activities such as incorporating servicelearning projects into the classroom, involving students in design competitions (e.g., solar car, formula car races), and promoting involvement in traditional campus organizations. Often this emphasis is in response to changes in ABET requirements, desires of future employers, and needs to improve student retention. What are the effects of emphasizing these sorts of activities on student attitudes and time management decisions? We examine the influences on students\u27 priorities for allocating their time and their perceptions of the relative importance of available activities, especially traditional coursework. We present data relating key personality and motivational factors to patterns of student social involvement, organizational commitment, academic performance, and work habits and attitudes. Implications for educators and potential cost-benefit trade-offs for particular student subpopulations are also presented

Effectiveness of stratospheric solar-radiation management as a function of climate sensitivity

If implementation of proposals to engineer the climate through solar-radiation management (SRM) ever occurs, it is likely to be contingent on climate sensitivity. However, modelling studies examining the effectiveness of SRM as a strategy to offset anthropogenic climate change have used only the standard parameterizations of atmosphere–ocean general circulation models that yield climate sensitivities close to the Coupled Model Intercomparison Project mean. Here, we use a perturbed-physics ensemble modelling experiment to examine how the response of the climate to SRM implemented in the stratosphere (SRM-S) varies under different greenhouse-gas climate sensitivities. When SRM-S is used to compensate for rising atmospheric concentrations of greenhouse gases, its effectiveness in stabilizing regional climates diminishes with increasing climate sensitivity. However, the potential of SRM-S to slow down unmitigated climate change, even regionally, increases with climate sensitivity. On average, in variants of the model with higher sensitivity, SRM-S reduces regional rates of temperature change by more than 90% and rates of precipitation change by more than 50%.Engineering and Applied Science

Radiobiological restrictions and tolerance doses of repeated single-fraction hdr-irradiation of intersecting small liver volumes for recurrent hepatic metastases

<p>Abstract</p> <p>Background</p> <p>To assess radiobiological restrictions and tolerance doses as well as other toxic effects derived from repeated applications of single-fraction high dose rate irradiation of small liver volumes in clinical practice.</p> <p>Methods</p> <p>Twenty patients with liver metastases were treated repeatedly (2 - 4 times) at identical or intersecting locations by CT-guided interstitial brachytherapy with varying time intervals. Magnetic resonance imaging using the hepatocyte selective contrast media Gd-BOPTA was performed before and after treatment to determine the volume of hepatocyte function loss (called pseudolesion), and the last acquired MRI data set was merged with the dose distributions of all administered brachytherapies. We calculated the BED (biologically equivalent dose for a single dose d = 2 Gy) for different α/β values (2, 3, 10, 20, 100) based on the linear-quadratic model and estimated the tolerance dose for liver parenchyma D₉₀as the BED exposing 90% of the pseudolesion in MRI.</p> <p>Results</p> <p>The tolerance doses D₉₀after repeated brachytherapy sessions were found between 22 - 24 Gy and proved only slightly dependent on α/β in the clinically relevant range of α/β = 2 - 10 Gy. Variance analysis showed a significant dependency of D₉₀with respect to the intervals between the first irradiation and the MRI control (p < 0.05), and to the number of interventions. In addition, we observed a significant inverse correlation (p = 0.037) between D₉₀and the pseudolesion's volume. No symptoms of liver dysfunction or other toxic effects such as abscess formation occurred during the follow-up time, neither acute nor on the long-term.</p> <p>Conclusions</p> <p>Inactivation of liver parenchyma occurs at a BED of approx. 22 - 24 Gy corresponding to a single dose of ~10 Gy (α/β ~ 5 Gy). This tolerance dose is consistent with the large potential to treat oligotopic and/or recurrent liver metastases by CT-guided HDR brachytherapy without radiation-induced liver disease (RILD). Repeated small volume irradiation may be applied safely within the limits of this study.</p

A risk-based framework for assessing the effectiveness of stratospheric aerosol geoengineering

Open Access journalCopyright: © 2014 Ferraro et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Geoengineering by stratospheric aerosol injection has been proposed as a policy response to warming from human emissions of greenhouse gases, but it may produce unequal regional impacts. We present a simple, intuitive risk-based framework for classifying these impacts according to whether geoengineering increases or decreases the risk of substantial climate change, with further classification by the level of existing risk from climate change from increasing carbon dioxide concentrations. This framework is applied to two climate model simulations of geoengineering counterbalancing the surface warming produced by a quadrupling of carbon dioxide concentrations, with one using a layer of sulphate aerosol in the lower stratosphere, and the other a reduction in total solar irradiance. The solar dimming model simulation shows less regional inequality of impacts compared with the aerosol geoengineering simulation. In the solar dimming simulation, 10% of the Earth's surface area, containing 10% of its population and 11% of its gross domestic product, experiences greater risk of substantial precipitation changes under geoengineering than under enhanced carbon dioxide concentrations. In the aerosol geoengineering simulation the increased risk of substantial precipitation change is experienced by 42% of Earth's surface area, containing 36% of its population and 60% of its gross domestic product.Natural Environment Research Council (NERC

Applications of Microbiome Analyses in Alternative Poultry Broiler Production Systems

While most of the focus on poultry microbiome research has been directed toward conventional poultry production, there is increasing interest in characterizing microbial populations originating from alternative or non-conventional poultry production. This is in part due to the growing general popularity in locally produced foods and more specifically the attractiveness of free-range or pasture raised poultry. Most of the focus of microbiome characterization in pasture flock birds has been on live bird production, primarily on the gastrointestinal tract. Interest in environmental impacts on production responses and management strategies have been key factors for comparative microbiome studies. This has important ramifications since these birds are not only raised under different conditions, but the grower cycle can be longer and in some cases slower growing breeds used. The impact of different feed additives is also of interest with some microbiome-based studies having examined the effect of feeding these additives to birds grown under pasture flock conditions. In the future, microbiome research approaches offer unique opportunities to develop better live bird management strategies and design optimal feed additive approaches for pasture flock poultry production systems