Morphometric analysis of rat parameters during an animal model of colorectal cancer

Colorectal cancer is one of the leading causes of death by cancer worldwide. Animal models have been used in experimental research to find new solutions for old biomedical questions. This research aimed to make a contribution to characterize the rat model of colorectal cancer. Twelve male Wistar rats obtained from Charles River were randomly divided into two groups: control group and induced group. All ethical issues were considered, following the guidelines of the Portuguese Direção Geral de Alimentação e Veterinária (approval number 010535). Animals from induced group received a weekly intraperitoneal injection of N, N’-Dimethylhydrazine (DMH), for seven consecutive weeks. All rats were monitored for signs of distress, weight loss, and food and water consumption. Abdominal ultrasound examinations were performed before the first DMH administration and the animals’ sacrifice. Thirteen weeks later, all surviving animals were sacrificed, organs and blood were collected. Animals from control group showed a higher mean body weight. The mean relative weight of soleus was lower in induced animals when compared to the control animals (p<0.005), which may suggest the development of anorexia. Although there were no significant differences in colon’s weight, induced animals had shorter colon. The microhematocrit was not different between groups. The ultrasound examination showed a high vascularized abdominal mass in induced animals. Some induced animals had a swollen abdomen which difficult the ultrasound examination. The animals showed little changes in their biological parameters, suggesting that the disease was at an early stage. Histological analysis of animals’ organs will provide a better perception of the colorectal cancer induction

Crossing boundaries with action research: A multinational study of school-family-community collaboration

When it began in 1990 with funds from the US Department of Education, the Center on Families, Communities, Schools, and Children's Learning established an International Network of Scholars as a forum of researchers around the world who were studying various aspects of the topic. The Center sponsored an informal journal, Unidad, and International Roundtables in the USA and Europe to promote exchange of ideas and research plans. Out of these exchanges, the idea for a multinational action research project grew. The multinational study, which began in 1992 and involved more than 40 researchers in eight projects in five countries (Australia, Chile, The Czech Republic, Portugal, and Spain), is based on the conceptual framework of the Center which views the inter-institutional connections of the school, family, and community as a set of overlapping spheres of influence on children's learning and …info:eu-repo/semantics/publishedVersio

Pulegone and Eugenol Oral Supplementation in Laboratory Animals: Results from Acute and Chronic Studies

Essential oils are natural compounds used by humans for scientific purposes due to their wide range of properties. Eugenol is mostly present in clove oil, while pulegone is the main constituent of pennyroyal oil. To guarantee the safe use of eugenol and pulegone for both humans and animals, this study addressed, for the first time, the effects of these compounds, at low doses (chronic toxicity) and high doses (acute toxicity), in laboratory animals. Thirty-five FVB/n female mice were randomly assigned to seven groups (n = 5): group I (control, non-additive diet); group II (2.6 mg of eugenol + 2.6 mg of pulegone); group III (5.2 mg of eugenol + 5.2 mg of pulegone); group IV (7.8 mg of eugenol + 7.8 mg of pulegone); group V (7.8 mg of eugenol); group VI (7.8 mg of pulegone); and group VII (1000 mg of eugenol + 1000 mg of pulegone). The compounds were administered in the food. Groups I to VI were integrated into the chronic toxicity study, lasting 28 days, and group VII was used in the acute toxicity study, lasting 7 days. Animals were monitored to assess their general welfare. Water and food intake, as well as body weight, were recorded. On the 29th day, all animals were euthanized by an overdose of ketamine and xylazine, and a complete necropsy was performed. Blood samples were collected directly from the heart for microhematocrit and serum analysis, as well as for comet assay. Organs were collected, weighed, and fixed in formaldehyde for further histological analysis and enzymatic assay. Eugenol and pulegone induced behavioral changes in the animals, namely in the posture, hair appearance and grooming, and in mental status. These compounds also caused a decrease in the animals' body weight, as well as in the food and water consumption. A mortality rate of 20% was registered in the acute toxicity group. Both compounds modulated the serum levels of triglycerides and alanine aminotransferase. Eugenol and pulegone induced genetic damage in all animals. Eugenol increased the activity of the CAT enzyme. Both compounds increased the GR enzyme at the highest dose. Moreover, pulegone administered as a single compound increased the activity of the GST enzyme. Histopathological analysis revealed inflammatory infiltrates in the lungs of groups II, III, and IV. The results suggest that eugenol and pulegone may exert beneficial or harmful effects, depending on the dose, and if applied alone or in combination

Učinci ekstrakta Cytinus hypocistis (L.) L. u životinjskom modelu neoplazije inducirane papiloma virusom

Infections with certain types of papillomavirus, such as the human papillomavirus 16 (HPV16), are associated with the development of preneoplastic lesions and cancers of the anogenital, and head and neck regions. Cytinus hypocistis (L.) L. extracts are composed of substances presenting antiproliferative, antioxidant, anti-inflammatory and antibacterial properties, which might be promising as new therapeutic compounds. This study analysed the influence of topical application of an extract obtained from C. hypocistis (CH) on K14-HPV16 and FVB/n mice to evaluate its therapeutic and toxicological properties. To achieve the study goals, 30 female mice, 33–37 weeks old, were divided into six groups (n=5/group): I (HPV+CH3.1); II (HPV+CH6.2); III (HPV+CH12.4); IV (FVB/n+CH12.4); V (HPV+control) and VI (FVB/n+-control). CH was applied topically to both ears for 28 days. After this period, all animals were sacrificed for samples collection. Skin lesions were classified histologically. Toxicological parameters included haematological and biochemical blood markers, and hepatic oxidative stress analysis. Transgenic animals showed a decrease in mean body weight regardless of the concentration of extract applied. The extract had no influence on physiological parameters, organ weight, or biochemical and oxidative stress parameters. Histology demonstrated the presence of proliferative epithelial lesions in the skin and oral mucosa of K14-HPV16 mice, with no association with the application of this extract. Overall, the application of CH extract had no influence on the skin lesions and was well tolerated by the animals in these concentrations.Infekcije određenim vrstama papiloma virusa, poput humanog papiloma virusa 16 (HPV16), povezane su s razvojem preneoplastičnih lezija i karcinoma anogenitalnog područja i područja glave i vrata. Ekstrakti Cytinus hypocistis (CH) sadrže tvari koje pokazuju antiproliferativna, antioksidativna, protuupalna i antibakterijska svojstva te bi stoga mogle predstavljati nove, obećavajuće terapijske spojeve. Cilj je ovog rada bio analizirati utjecaj topikalne primjene ekstrakta dobivenog iz C. hypocistis (L.) L. na K14-HPV16 i FVB/n miševima za procjenu njegovih terapijskih i toksikoloških svojstava. Za postizanje ciljeva istraživanja, trideset ženki miševa starosti 33-37 tjedana podijeljeno je u šest skupina (n=5/ skupini): I (HPV+CH3,1); II (HPV+CH6,2); III (HPV+CH12,4); IV (FVB/n+CH12,4); V (HPV+kontrola) i VI (FVB/n+kontrola). CH je tijekom 28 dana topikalno primijenjen na oba uha. Nakon tog razdoblja sve životinje su žrtvovane u svrhu prikupljanja rezulata. Lezije kože su histološki klasificirane. Toksikološki parametri uključivali su hematološke i biokemijske markere krvi te analizu oksidativnog stresa jetre. Transgenične životinje pokazale su smanjenje srednje tjelesne mase, bez obzira na primijenjenu koncentraciju ekstrakta. Ekstrakt nije utjecao na fiziološke parametre, masu organa ili parametre biokemijskog i oksidativnog stresa. Histološki je dokazana prisutnost proliferativnih epitelnih lezija na koži i oralnoj sluznici K14-HPV16 miševa, bez povezanosti s primjenom ovog ekstrakta. Općenito, primjena CH ekstrakta nije utjecala na lezije kože te su ga životinje dobro podnosile u primijenjenim koncentracijama

Early Start Peritoneal Dialysis: Technique Survival in Long-Term Follow-Up

Background/Aims: Peritoneal dialysis (PD) has gained interest over the last decade as a viable option for early start dialysis. It is still unknown if shorter break-in periods and less time for proper patient evaluation and training could influence technique survival in comparison to planned-start PD. Methods: A prospective and observational study that compared technique survival in a cohort of patients who started either early or planned PD. Early start PD was defined as break-in period from 3 to 14 days with no previous nephrologist follow-up or patient training. Results: A total of 154 patients were included (40 as early start PD), followed by a median time of 381 days. Comparing early vs. planned-start PD, groups were similar concerning age 56 (40; 70) vs. 48 (32; 63) years, p=0.071, body mass index (BMI) 23.3 ± 4.2 vs. 23.8 ± 4.0 kg/m2, p=0.567 and male gender (60 vs. 48%, p=0.201), respectively. Comparing early vs. planned-start groups, there were no differences regarding PD dropout for peritonitis (7.5 vs. 11.4%, p=0.764), catheter dysfunction (12.5 vs. 17.5%, p=0.619) and patient burnout (0 vs. 4.4%, p=0.328), respectively. Less patients in early start group quit PD for peritoneal membrane failure in comparison to planned-start group (2.5 vs. 16.7%, p=0.026). In multivariate cox-regression analysis, the only factors independently associated with technique failure were BMI&#x3e; 25 kg/m² (p=0.033) and Diabetes Mellitus (p=0.013), whereas no differences regarding early vs. planned-PD start were observed (p=0.184). Conclusion: Despite the adverse scenario for initiating dialysis, early start PD had similar outcomes in comparison to planned-start PD in long-term follow-up

Study of thermal degradation of PLGA, PLGA nanospheres and PLGA/Maghemite superparamagnetic nanospheres

Poly(glycolide-co-lactide) (PLGA) nanospheres containing magnetic materials have been extensively studied because of its biomedical applications. Therefore, it is very important to know thermal properties of these materials in addition to other physical properties. Thermal degradation activation energy (Eα) of PLGA nanospheres with maghemite entrapment (PLGA-Mag), PLGA nanospheres (hollow spheres) (PLGA-H) obtained by an emulsion method and unprocessed PLGA (PLGA-R) were calculated by isoconversional Vyazovkin method based on data of TG analysis in order to evaluate modifications in thermal behavior caused by nanospheres obtainment process or by maghemite entrapment. Both hydrodynamic diameter in the range of 200-250 nm and polydispersity index lower than 0.3 are considered satisfactory. Thermal degradation of PLGA-R begins at higher temperatures than those of PLGA-H and PLGA-Mag, but processed samples presented increase in thermal stability, which was greater before processing by emulsion and in the presence of the magnetic materials. PLGA-Mag presents superparamagnetic behavior at room temperature

Optimization of maghemite-loaded PLGA nanospheres for biomedical applications

Magnetic nanoparticles have been proposed as interesting tools for biomedical purposes. One of their promising utilization is the MRI in which magnetic substances like maghemite are used in a nanometric size and encapsulated within locally biodegradable nanoparticles. In this work, maghemite has been obtained by a modified sol-gel method and encapsulated in polymer-based nanospheres. The nanospheres have been prepared by single emulsion evaporation method. The different parameters influencing the size, polydispersity index and zeta potential surface of nanospheres were investigated. The size of nanospheres was found to increase as the concentration of PLGA increases, but lower sizes were obtained for 3 min of sonication time and surfactant concentration of 1%. Zeta potential response of magnetic nanospheres towards pH variation was similar to that of maghemite-free nanospheres confirming the encapsulation of maghemite within PLGA nanospheres. The maghemite entrapment efficiency and maghemite content for nanospheres are 12% and 0.59% w/w respectively