This study was developed aiming to evaluate the effects of maternal feed-restriction on development of gastrointestinal tract (GIT) of bovine fetus at different gestational stages. Feed-restricted cows were fed 1.2 times the maintenance level while the control group was fed ad libitum. Pregnant cows were slaughtered at 136, 189, 239, and 269 days of gestation and gastrointestinal tracts of the fetuses were evaluated. No effects of maternal nutrition on body weight (P ¼ 0.17) and body length (P ¼0.13) of the fetuses were observed. No major effects of feed restriction on GIT mass of the fetuses were observed (P ¼ 0.51). However, the weight of small intestine per unit of body weight was 11.24% greater (P ¼0.04) in fetuses from restricted dams. Additionally, the length of small intestine and its villi were 12.93% and 16.44% respectively greater (P o .001) in fetuses from restricted dams compared to those from non-restricted dams. These data indicates that maternal feed-restriction does not affect the development of most of fetal gastrointestinal parts besides small intestine which in turn increases its surface area as a response of maternal feed restriction.

The development degree of mammals at birth is markedly variable especially between placental and non-placental species. In marsupial mammals the organogenesis is completed during a period called external gestation, when the young animal remains at the maternal pouch being breastfed for, on average 90 days. This study reported the relevant morphological features found in the pancreas of the Brazilian opossum Didelphis aurita, a marsupial mammal, during its intramarsupial development. Newborns and young opossums removed from the pouch were divided into groups according to their average body length. The animals with few hours of intramarsupial life had visibly immature pancreas, due to the presence of early arrangement of endocrine and exocrine components. There was an only very large pancreatic duct, and blood vessels full of nucleated erythrocytes. In the individuals who were in the second third of intramarsupial development, the exocrine components were arranged in developing acini and endocrine cells were found arranged in early islets. The presence of connective tissue and the division of the organ into lobes became more evident at this stage. In the last third of the external gestation, we found better structured acini with relatively small lumens. The islets were well-organized, and the presence of connective tissue around them was the most evident. Morphometric analyses showed considerable variations in the proportion of pancreatic structural components between the stages of intramarsupial development, indicating that marsupial pancreas undergoes morphological modifications and grows during the period of external gestation.

The ingestion of considerable amounts of water or food contaminated with nickel can be very toxic. The present work was conducted aiming to evaluate the effects of nickel exposures on ascending colon of adult Wistar male rats at hystometric level. We used 12 animals that were divided in a control (ingested uncontaminated water) and a nickel-contaminated (i.e., 25 mg de nickel/L of water) groups. Nickel chloride was offered in declorinated water and the experiment had a 56 days exposure period. A portion of the ascending colon was removed of the animals and subjected to hystological labelling processes using blue toluidin (for general hystometric description), Alcian Blue (AB, for acid mucins) and periodic acid-Schiff (PAS) technique (for neutral mucins). The potential differences between groups were desgined by applying the Whitney test and t test (p < 0.05). The crypts were smaller for the nickel-contaminated group, even though these organism exhibited broader and higher crypts. Nickel-contaminated animals exhibited a smaller amount of calyceform cells with AB and PAS positive reactions as well as a less mucus quantities when compared with nickel-uncontaminated animals. Such reductions on the amount of calyceform cells with AB and PAS positive reactions may be related wiht the shallower crypts, which possibly reduced the synthesis and secretion of mucins, compromissing the functional aspects (e.g., lubrification and intestinal mucosa protection) of the nickel-contaminated large intestines. Interestingly, the wider and higher crypts and higher epithelium collumn on the nickel-contaminated animals may represent a relevant trade-off for the intestinal mucosa protection.

The high incidence of melanoma has received significant attention. Despite advances in early detection and standard treatment options, new strategies that improve therapy with reduced side effects are highly desirable. Several studies have demonstrated the efficiency of doxorubicin (Dox) to treat melanoma, however, side effects limit its clinical use. Drug delivery systems, especially nanostructured ones, are a useful approach to enhance antitumor activity and reduce the toxicity of drugs. Here, we report the use of calcium phosphate nanoparticles functionalized with Dox and hyaluronic acid (N-Dox) to enhance Dox antiproliferative activity. The effects were accessed in A-375 melanoma cells, in which N-Dox significantly decreased IC50 over 48 hours (0.142 ± 0.07) compared to the free drug (0.44 ± 0.25). Treatment triggered DNA damage, increased nuclear area, and senescent phenotype. Furthermore, it did not form colonies after 14 days of incubation preceded by short exposure treatment. These preliminary results indicate that N-Dox hold promise for melanoma treatment, reducing the minimum effective dose and perhaps a reduction in the cost of treatment.

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