Immunoexpression of proliferating cell nuclear antigen (PCNA) in spleen of splenectomized rats with preservation of inferior pole, submitted to hyperbaric oxygenation

Effects of inferior splenic lobe pole fixation and gastrosplenic peritoneal membrane section on the vitality of the remanent of subtotal splenectomy in rats

PURPOSE

To investigate the vitality of the spleen lower pole after subtotal splenectomy with suture to the stomach and after posterior peritoneal gastro-splenic membrane section, using macro and microscopic evaluations.

METHODS

Sixty Wistar rats were used in this study and were randomly distributed in the three groups: Group 1: (n=20), subtotal splenectomy with lower pole preservation, Group 2: (n=20) subtotal splenectomy with lower pole preservation and suture to the stomach, Group 3: subtotal splenectomy with lower pole preservation and posterior peritoneal gastrosplenic ligament section. The animals were sacrificed 45 days after the surgery and the spleen lower poles were removed for macroscopic and microscopic examination.

RESULTS

All animals in this series survived. No macroscopic differences were encountered between the groups. Microscopic evaluation observed statistic difference concerning fibrosis between group 1 and 3 (p ≤ 0.05), but the analysis for necrosis and inflammation presented no differences.

CONCLUSION

Vitality of the spleen lower pole after subtotal splenectomy is minimally modified when it is fixed to the stomach or when the posterior peritoneal gastrosplenic ligament is resected.

Effect of total splenectomy in the lipid profile in mice

PURPOSE

To analyze total splenectomy effect on the lipid profile - total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), very-low-density lipoprotein cholesterol (VLDL) and triglycerides levels, in Balb/c mice.

METHODS

Thirty Balb/c male mice, one (1) month old and average weight 26.2g ± 4.0 were used in the experiment. They were distributed into three groups of 10 animals each: a control group (non-operated), a simulation group (spleen manipulation) and the splenectomy group. The animals were subjected to blood sampling to measure plasma lipid levels, at three different times: before surgery, days 30 and 75 of the experiment.

RESULTS

Increased total cholesterol and LDL were observed in the control group from the start to end of the experiment. The simulation group showed increased rates of VLDL and triglycerides at the 30th and 75th days. Splenectomized animals showed no significant change.

CONCLUSION

Total splenectomy did not induce increased plasma lipids levels of in Balb/c mice.

Micronucleus test in peripheral blood of rats treated with hyperbaric oxygen after subtotal splenectomy preserving the lower pole

PURPOSE

To assess the mutagenic potential of the oxygen inhalation therapy (HBO), by means of the micronucleus test, performed in peripheral blood of rats that underwent subtotal splenectomy with lower pole preservation (ESTPI), after HBO sessions or simulations.

METHODS

Eighteen male Wistar rats, were distributed into three groups of six animals: group 1 - submitted to ESTPI and HBO sessions; group 2 - submitted to ESTPI and HBO simulations; group 3 - underwent cyclophosphamide administration. In groups 1 and 2, blood samples from the animals' tails were collected before surgery (T0) and immediately after the 13th HBO session or simulation (T1). In group 3, tail blood samples were collected from animals before (T0) and 24 hours after (T1) cyclophosphamide (CP) delivery. The number of micronucleated normochromatic erythrocytes (MNNCE) was determined by blind counting 2000 normochromatic erythrocytes (NCE) per animal.

RESULTS

Micronuclei average after CP delivery in group 3 was higher than before its use, thus confirming the mutagenic activity of this drug (p=0.01). In groups 1 and 2, no significant difference in the average of Micronuclei was observed when comparing it to blood samples before and after the 13th HBO session or simulation.

CONCLUSION

The treatment protocol used in this study did not induce Micronucleus formation in animals submitted to ESTPI and HBO treatment or simulation.

NaCl pretreatment attenuates H.pylori-induced DNA damage and exacerbates proliferation of gastric epithelial cells (GES-1)

Background

Both H. pylori infection and high salt (NaCl) diet are risks of gastric cancer, however, the interaction pattern of the two is not very clear. Our objective was to investigate the effects of NaCl-pretreated H. pylori on DNA damage and proliferation of gastric epithelial cell (GES-1).

Methods

GES-1 cells were co-cultured with H.pylori or NaCl-pretreated H. pylori (with 30% NaCl) for 24 h. The morphological changes of all cells were observed by inverted phase contrast microscopy and transmission electron microscopy. Oxidative DNA damage was examined by immunofluorescence. Alterations in mitochondrial membrane potential and apoptosis rate were detected by flow cytometry and western blot, and expression of Ki-67, PCNA and P21 were evaluated using the immunocytochemical staining.

Results

GES-1 cells co-cultured with NaCl-pretreated H.pylori exhibited morphological changes and oxidative DNA damage. Although no significant disruption of the mitochondrial membrane potential (ΔΨm) and apoptotic rate were observed compared with control groups, there were significant decreased in Bax and Caspase3 proteins and increased in Bcl-2 protein in GES-1 cells infected with H. pylori³⁰ when compared with GES-1 cells cultured with H. pylori. In addition, we found a proliferative effect on GES-1 cells with an increased expression of Ki-67 and PCNA as well as a decreased p21 expression, through which the cells may acquire the potential for malignant transformation.

Conclusion

NaCl-pretreated H. pylori possessed the ability to cause cell injury and promote proliferation in gastric epithelial cells.