Higher Animal Survival Research Articles

Ethanolic extract of Euphorbia royleana Boiss. reduces metastasis of breast cancer cells and inhibits tumor progression in vivo.

Metastasis is the most devastating attribute of breast cancer (BC) that leads to high mortality. It is a complex process of tumor cell migration, invasion, and angiogenesis. In this study, we evaluated the effect of ERA on BC metastasis and BC progression in vivo. The transwell invasion/migration and wound healing assays showed that ERA treatment significantly reduced the invasion and migration of BC cell lines. The expression of mesenchymal (E-cadherin and N-cadherin), matrix metalloproteinases (MMP2, MMP9), and stemness markers (Oct3) were down-regulated by ERA. Furthermore, ERA down-regulated angiogenic chemokines (CXCL1/2/3, CXCL5, and CXCL12) expression in the highly metastatic MDA-MB-231 cell line. The clonogenic survival of BC cells was also reduced by ERA treatment. Strikingly, ERA prevented DMBA-induced tumor growth in Swiss albino mice as depicted by a high animal survival rate (84%) in the ERA group and histopathological analysis. Conclusively, this study revealed that ERA possesses anti-metastatic potential and also reduces the growth of BC in vivo. Moreover, the GC-MS data revealed the presence of biologically active compounds (Lupeol, Phytol, phytosterol) and some rare (9, 19-Cyclolanost) phyto metabolites in ERA extract. However, further studies are suggestive to identify and isolate the therapeutic agents from ERA to combat BC and metastasis.

Towards a more sustainable feed for New Zealand farmed abalone: Inclusion of insect meal and grape pomace as alternative ingredients

Abalone, locally called pāua, is a valuable export product in New Zealand, contributing between NZD $50-60 million annually towards the country’s export economy [1]. Generally, one of the most significant bottlenecks of land-based abalone aquaculture is the high cost of the feed, which can be up to 50% of the production cost [2]. The high price has been attributed to fish meal, which is a key ingredient used in aquaculture feeds due to its excellent amino acid profile and palatability. However, fish meal use has been questioned due to the utilisation of wild fish to feed farmed fish and the exacerbation of overfishing marine resources [3]. Alternative ingredients, such as insects and winery waste products, are potential candidates as protein replacements due to their suitable nutritional profile and more sustainable production. This study aims to 1) develop and characterise alternative formulated feed for pāua (Haliotis iris) using insect meal and grape pomace and 2) evaluate the nutritional and growth alterations in juvenile pāua receiving different formulated feeds for 6 months. Proximate analysis is used to identify nutritional variations in body and faecal matter, and liquid/gas chromatography–mass spectrometry (LC/GC–MS) analyses are utilised to characterise amino acid and fatty acid profiles in tissue samples. Results show a high animal survival rate of 95% and increased seawater stability of experimental diets compared to a commercial feed. Nutritional analyses show no significant variations in animal tissues in terms of protein proportions and amino acid profiles, but differences were found in the lipid proportions and fatty acid profiles. This research will present the evidence to support the potential use of insect meal and grape marc as fishmeal replacements in abalone feeds, leading to a more sustainable aquaculture.

Fitness of the pestiferous small rodent Mastomys natalensis in an agroecosystem in Mayuge district, Lake Victoria Crescent, Uganda

Abstract A 2.5-year study was conducted to understand the fitness of Mastomys natalensis in an agroecosystem in relationship with environmental predictors. The study was conducted in Mayuge district, in the Lake Victoria Crescent zone in Eastern Uganda. Fitness was measured in terms of survival, maturation and capture probability and estimated using multi-event capture-recapture models. Survival rates were higher after high rainfall in the previous month and increased with increasing population density of the animals. Maturation rate, on the other hand, showed no significant association with any predictor variables, while capture probability was significantly associated with sex of the animals, with higher capture probability for males. The results demonstrate that the fitness of M. natalensis in an agroecosystem is dependent on rainfall, sex and current population density. The aforementioned results were associated with increasing vegetation which provides cover for animal nesting and abundant food for the animals during rainfall periods and thus increased survival, high mobility in males in search for mates thus exposing animals to high chances of being captured and increased prey saturation at high population density resulting in high animal survival. These results have important implications for the timing of management strategies, i.e. control efforts should be enforced during the rainfall seasons to prevent high population buildup in the succeeding seasons.

Chronic toxicity of silver nanoparticles to Daphnia magna under different feeding conditions

Despite substantial information on the acute toxicity of silver nanoparticles (AgNP) to aquatic organisms, little is known about their potential chronic effects and the applicability of current test guidelines for testing nanomaterials. The purpose of this study was to study the influence of food availability on toxicity. This was done through a series of Daphnia magna 21-day reproduction tests (OECD 211) using 30nm citric acid stabilized AgNP aimed at studying the influence of food abundance on the reproductive toxicity of AgNP in D. magna. The experiments were carried out as static renewal tests with exposure concentrations from 10 to 50μgAg/L, and test animals were fed green algae Pseudokirchneriella subcapitata in low and high food treatments. The endpoints recorded were survival, growth of parent animals and number of live neonates produced. Detrimental effects of AgNP on survival, growth and reproduction were observed in concentrations higher than 10μgAg/L, whereas the animals exposed to 10μgAg/L had larger body length and produced more offspring than controls at both food treatments. High food treatment resulted in higher animal survival, growth and reproduction compared to result found for low food treatment.

Tetrandrine suppresses tumor growth and angiogenesis of gliomas in rats

Tetrandrine, a bisbenzylisoquinoline alkaloid, has antitumor effects against some cancers, but its effects on gliomas are unknown. In this study, we investigated the effects of tetrandrine on the growth and angiogenesis of rat RT-2 gliomas. We treated RT-2 glioma cells with tetrandrine and then measured cytotoxicity, apoptosis and expression of vascular endothelial growth factor (VEGF). We also examined the cytotoxic effect of tetrandrine on the ECV304 human umbilical vein endothelial cells and the effects of tetrandrine on the in vivo angiogenesis. Tumor size and animal survival were followed in tetrandrine-treated rats with subcutaneous or intracerebral gliomas. Expression of CD31 in tetrandrine-treated gliomas was followed to study its effect on glioma-induced angiogenesis. Tetrandrine had cytotoxic effects and induced apoptosis of glioma cells in a concentration- and time-dependent manner. Tetrandrine also inhibited the expression of VEGF in glioma cells, induced cytotoxicity effect on the ECV304 cells and suppressed the in vivo angiogenesis. Tetrandrine (150 mg/kg/day) had significant antitumor effects on subcutaneous tumors and led to slower tumor growth rate, longer animal survival time and higher animal survival (p < 0.05). Tetrandrine also affected intracerebral tumors and prolonged animal survival (p < 0.05) without affecting survival rate. Immunohistochemical analyses showed that the subcutaneous gliomas from tetrandrine-treated rats had fewer microvessel densities than control rats (p = 0.01). The results demonstrate that tetrandrine is cytotoxic to RT-2 glioma cells, has antitumor effects on subcutaneous and intracerebral gliomas, and inhibits angiogenesis in subcutaneous gliomas. Tetrandrine has potential as a treatment for gliomas.

Antiarrhythmic activity of a membrane-protecting agent Sal’magin in rats with aconitine-induced arrhythmias

Antiarrhythmic activity of a membrane-protecting agent Sal'magin was studied in rats with aconitine-induced cardiac arrhythmias. The test preparation was more potent than amiodaron in producing the antiarrhythmic effect in rats with Na(+)-induced cardiac arrhythmias. The absence of side effects, low toxicity, and high animal survival rate under experimental conditions suggest that Sal'magin holds much promise as an antiarrhythmic drug in clinical practice.

Dendritic cell:CD4+ T cells interactions following injury.

A number of laboratory and clinical studies have shown that extensive thermal injury induces a state of immune suppression, and that predisposes the injured host to critical morbidity and mortality. The principal outcome of such immune suppression is an increased susceptibility of injured host to opportunistic pathogens causing high risk of death. Both clinical and laboratory studies have shown that immune suppression with burns is characterized by monocyte/macrophage hyperactivity and/or depressed adaptive cell-mediated immunity associated with T lymphocyte functional deficit, viz., decreased IL-2 production and proliferation. Our studies showed that CD4+T cell apoptosis in burn or sepsis rats, although higher than in sham rats, was less than 50% of that in rats with the combined burn-plus-sepsis injury. Also, the CD4+ T cell responsiveness, assessed by IL-2 production and proliferation, in the burn or sepsis animals, though significantly less than in the sham group, was less than that in the burn-plus-sepsis group. The differences in the T cell deficits after the individual burn or sepsis injuries and the combined injury condition seemed well correlated with differences in mortality in these injured animal groups. From these observations, it seemed reasonable to hypothesize that T cell incompetence with burn or sepsis alone was mostly reversible which allowed for an eventual restoration of T cell homeostasis and competence compatible with high animal survival. On the other hand, the exacerbation of animal mortality with burn-plus-sepsis seemed related to a sustained loss of immune-competence and a critical deletion of antigen triggered T cells. (Supported by NIH MBRS SCORE Grant No. 3 S06 GM008043-34S1 project#6, and NSF MRI DBI-0520869)

The activation of ribonucleotide reductase in animal organs as the cellular response against the treatment with DNA-damaging factors and the influence of radioprotectors on this effect

Cellular requirements for deoxyribonucleotide (dNTP) pools during DNA synthesis are related to ensuring of the accuracy of DNA copying during replication and repair. This paper covers some problems on the reactions of dNTP synthesis system in organs of animals against the treatment with DNA-damaging agents. Ribonucleoside diphosphate reductase (NDPR) is the key enzyme for the synthesis of dNTP, since it catalyses the reductive conversion of ribonucleotides to deoxyribonucleotides. The results obtained show that the rapid and transient increase in NDPR activity in animal organs occurs as cellular response against the treatment with DNA-damaging agents (SOS-type activation). We have also found the intensive radioprotector-stimulated activation of deoxyribonucleotide synthesis as well as DNA and protein synthesis in mice organs within 3 days after the administration of two radioprotectors, indralin and indometaphen, that provide the high animal survival. Our studies suggest that these effects are the most important steps in the protective mechanism of the radioprotectors and are responsible for the high animal survival.