Cissus sicyoides (princess vine) in the long-term treatment of streptozotocin-diabetic rats

Leaf decoctions of Cissus sicyoides (princess vine) are taken widely as a popular remedy for diabetes mellitus in Brazil, where its common name is 'vegetal insulin'. However, there have been practically no attempts so far to determine scientifically whether it has antidiabetic effects and we decided to administer leaf decoctions, over extended periods, to normal and streptozotocin-diabetic rats, and investigate the effects of this treatment on the physiological and metabolic parameters that are altered in diabetic animals. The experimental model adopted was shown to be appropriate by running a parallel treatment with insulin, which led to expected improvements in several abnormal parameter values. The decoction treatment significantly reduced the intake of both food and fluid and the volume of urine excreted, as well as the levels of blood glucose, urinary glucose and urinary urea, in comparison with controls. Lipid metabolism was not affected by the treatment; nor was the level of hepatic glycogen in diabetic animals, which indicated that the mechanism responsible for the improvement in carbohydrate metabolism, observed in animals treated with the decoction, could not involve inhibition of glycogenolysis and/or stimulation of glycogenesis. The fact that normal animals treated with C. sicyoides exhibited no changes in any of the measured parameters suggests that its mode of action in diabetic animals does not resemble those of sulphonylurea or insulin. It may, however, act in a similar way to biguanide, via inhibition of gluconeogenesis.

Long-term effects of insulin therapy, islet transplantation, and pancreas transplantation in the prevention of glomerular changes in kidneys of alloxan-induced diabetic rats

Groups of inbred alloxan-induced diabetic rats were treated with insulin (I), islets (IT), or pancreas transplantation (PT). Nondiabetic (N) and untreated diabetic (D) control groups were concurrently included. Each group was divided into five subgroups of 10 rats and killed after follow-up of 1, 3, 6, 9, and 12 months. Clinical and laboratory parameters were recorded, and kidney ultrastructural and morphometric analyses performed in each 12-month subgroup, namely glomerular basement membrane (GM) thickening, podocyte number, and number/extension of slit diaphragms (S). Rats from the I group showed poor metabolic control of diabetes compared with N group control rats. However, successfully transplanted rats (IT and PT) had complete restoration to normal levels for all metabolic parameters. GM thickening was significantly higher in diabetic compared with control rats. In contrast, the numbers of podocytes and slits as well as slit extensions were significantly decreased. Insulin therapy did not prevent any alterations upon comparison of diabetic vs control rats. Despite good metabolic control in IT rats, the degree of kidney lesion control never compared with that achieved in PT rats. In this group all glomerular changes were similar to the age-dependent lesions observed in control rats. We conclude that either IT or PT may be a good option for diabetes treatment, although pancreas transplantation seems to be the most effective treatment to control chronic complications.

Long-term effect of carbodiimide on dentin matrix and resin-dentin bonds

Objectives: To characterize the interaction of 1-Ethyl-3-[3-dimethylaminopropyl] carbodiimide Hydrochloride (EDC) with dentin matrix and its effect on the resin-dentin bond. Methods: Changes to the stiffness of demineralized dentin fragments treated with EDC/N-hydroxysuccinimide (NHS) in different solutions were evaluated at different time points. The resistance against enzymatic degradation was indirectly evaluated by ultimate tensile strength (UTS) test of demineralized dentin treated or not with EDC/NHS and subjected to collagenase digestion. Short- and long-term evaluations of the strength of resin-dentin interfaces treated with EDC/NHS for 1 h were performed using microtensile bond strength (mu TBS) test. All data (MPa) were individually analyzed using ANOVA and Tukey HSD tests (alpha = 0.05). Results: The different exposure times significantly increased the stiffness of dentin (p < 0.0001, control-5.15 and EDC/NHS-29.50), while no differences were observed among the different solutions of EDC/NHS (p = 0.063). Collagenase challenge did not affect the UTS values of EDC/NHS group (6.08) (p > 0.05), while complete degradation was observed for the control group (p = 0.0008, control-20.84 and EDC/NHS-43.15). EDC/NHS treatment did not significantly increase resin-dentin mu TBS, but the values remained stable after 12 months water storage (p < 0.05). Conclusions: Biomimetic use of EDC/NHS to induce exogenous collagen cross-links resulted in increased mechanical properties and stability of dentin matrix and dentin-resin interfaces. (C) 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 94B: 250-255, 2010.

Long-term effects of developmental exposure to di-n-butyl-phthalate (DBP) on rat prostate: Proliferative and inflammatory disorders and a possible role of androgens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Long-term inhibition of 5-alpha reductase and aromatase changes the cellular and extracellular compartments in gerbil ventral prostate at different postnatal ages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Long term evaluation of morphometric and ultrastructural changes of testes of alloxan-induced diabetic rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The role of exercise on long-term effects of alloxan administered in neonatal rats

The present study was designed to analyse the effects of aerobic exercise on the metabolic effects of alloxan. Male Wistar newborn rats (2 days old) received alloxan (200 mg (kg body weight)(-1)) intraperitoneally (A rats). Vehicle-injected rats were used as controls (C rats). At 28 days old, some of the A rats were subjected to swimming for 1 h day(-1), 5 day week(-1) (AT rats). At 28, 60 and 90 days old the animals were subjected to glucose (GTTo) and insulin (ITTsc) tolerance tests. All the animals were then killed by decapitation for blood and tissue evaluations. on the 60th day, there was a reduction in blood glucose level during the GTTo (mmol l(-1) (90 min)(-1)) in the AT rats (7640.7+/-694.0) with respect to C (7057.5+/-776.9) and A (8555.6+/-1096.7) rats. However on the 90th day, AT rats showed higher glucose levels (8004.6+/-267.9) when compared to the other groups (C, 7305.5+/-871.2; A, 7088.8+/-536.9). The serum free fatty acid (FFA) concentration (muEq l(-1)) was higher in the alloxan-treated animals (A, 231.1+/-58.5; AT, 169.8+/-20.1) than in controls (C, 101.4+/-22.4). In conclusion, although the high blood glucose level is transitory in the A animals, some blood and tissue alterations remain and can be harmful to the maintenance of homeostasis. Physical exercise counteracted only partially these alterations. Furthermore, training worsened glucose tolerance at the 90th day, suggesting that exercise intensity should be adjusted to the diabetic condition.

Gluconeogenesis and glucose replacement rate during long-term fasting of Japanese quails

Gluconeogenic activity and kinetic parameters of glucose metabolism were estimated during the different phases of prolonged food deprivation in quails. Gluconeogenic activity, estimated from the rate of increase of incorporation of (HCO3-)-C-14 into circulating glucose, was significantly higher in fasted quails than in fed birds, whatever the period of food deprivation. However, gluconeogenic activity during phase II, although higher than in the fed state, was significantly lower than in quails fasted for 2 days (phase I) or in those on the final (phase III) period of starvation. Gluconeogenic activity did not differ significantly in birds from phases I and III. Rates of glucose replacement, estimated with [6-H-3]-glucose, were very high (20.5 mg . kg(-1). min(-1)) in fed quails and were markedly reduced (to about 42% of fed values) by fasting, no difference being observed between quails fasted for 2 and 5 days. Because of the poor condition of the birds, glucose replacement rates could not be measured during phase III. The present data are the first to provide direct evidence for the changes in gluconeogenesis which occur during prolonged food deprivation.

Long-term accumulation of uranium in bones of Wistar rats as a function of intake dosages

Groups of Wistar rats were fed with ration doped with uranyl nitrate at concentration A ranging from 0.5 to 100 ppm, starting after the weaning period and lasting until the postpuberty period when the animals were sacrificed. Uranium in the ashes of bones was determined by neutron activation analysis. It was found that the uranium concentration in the bones. as a function of A, exhibits a change in its slope at similar to20 ppm-a probable consequence of the malfunctioning of kidneys. The uranium transfer coefficient was obtained and an analytical expression was fitted into the data. thus allowing extrapolation down to low doses. Internal and localized doses were calculated. Absorbed doses exceeded the critical dose. even for the lowest uranium dosage.

THE LONG-TERM EVOLUTION OF IMMUNE DEPOSITS IN PASSIVE HEYMANN NEPHRITIS

1. To study the long term course of passive Heymann nephritis (PHN), 42 adult male Wistar rats were injected with rabbit anti-FX1A serum (PHN group) and 42 rats received normal rabbit serum (control group). Two animals from each group were sacrificed 2 weeks after the inoculation and 10 animals each from the control and PHN groups were sacrificed 4, 13, 25 and 53 weeks later.2. The PHN group exhibited a significant elevation in 20-h proteinuria which lasted from the first week (control group, 9.19 +/- 0.87; PHN group, 25.3 +/- 2.66) to the 25th week (control group, 22.6 +/- 2.15; PHN group, 66.7 +/- 10.4) except for week 17. From week 29 to week 53 there was no statistical difference between the 2 groups.3. Light microscopy showed no difference between the kidneys of PHN and control rats. Immunofluorescence microscopy in PHN rats showed granular deposition of autologous and heterologous IgG on the glomerular basement membrane (GBM), whose intensity and pattern did not change during 53 weeks of observation.4. When examined by electron microscopy the glomeruli of PHN rats showed: a) electron-dense deposits which were initially subepithelial and homogeneous and later intramembranous, granular and often surrounded by an electron-transparent halo; b) focal thickening of the GBM at the sites of intramembranous deposits; c) effacement of podocytes located close to the deposits; d) penetration of the podocytes into the GBM associated with the deposits; e) presence of osmiophilic granules in the cytoplasm of the podocyte located inside the GBM similar to the granules of the deposits next to them. The association of the penetration of the podocytes into the GBM with the deposits and the presence of the osmiophilic granules inside the foot process have not been described previously in PHN.5. The results suggest that the podocytes play a role in the clearing of intramembranous deposits in PHN.

Selection of radio transmitter and attachment method for post-release monitoring of captive-bred reintroduced Red-billed Curassow Crax blumenbachii, Brazil

Long-term monitoring of reintroduced individuals is a central component of many endangered species reintroduction programs. Radio-telemetry techniques are rarely used to monitor reintroduced captive-bred Cracids and few data exist regarding possible adverse effects of radio-tagging Cracids. In this study, we identify an appropriate radio transmitter design and develop a suitable attachment method that minimizes anthropogenic influence and enables long-term, post-release monitoring (2-3 years) of reintroduced captive-bred Red-billed Curassows in the Brazilian Atlantic Rainforest. We also review studies about the effects of different VHF radio transmitter models on survival, reproduction, behavior, and physiology of Galliformes.