Metabolic and hematologic consequences of colectomy associated to hepatectomy in rats

To investigate the influence of partial colectomy associated with hepatectomy on the biodistribution of the 99mTc-phytate, on metabolic parameters, as well as labeling and morphology of red blood cells. METHODS: Wistar rats were distributed into three groups (each with six), nominated as colectomy, colectomy+hepatectomy and sham. In the 30th postoperative day all rats were injected with 99mTc-phytate 0.1mL i.v. (radioactivity 0.66 MBq). After 15 minutes, liver sample was harvested and weighed. Percentage radioactivity per gram of tissue (%ATI/g) was determined using an automatic gammacounter. Serum AST, ALT, alkaline phosphatase and red blood cells labeling were determined. RESULTS: The liver %ATI/g and red blood cells labeling were lower in colectomy and colectomy+hepatectomy rats than in sham rats (p <0.05), and no difference was detected comparing the colectomy and colectomy+hepatectomy groups. Red blood cells morphology did not differ among groups. Serum levels of AST, ALT and alkaline fosfatase were significantly higher in colectomy+hepatectomy than in colectomy rats (p<0.001). CONCLUSION: Hepatectomy associated with colectomy lowered the uptake of radiopharmaceutical in liver and in red blood cells in rats, coinciding with changes in liver enzymatic activity.

Desenvolvimento de nanosistemas farmacêuticos para terapia gênica

Gene therapy is one of the major challenges of the post-genomic research and it is based on the transfer of genetic material into a cell, tissue or organ in order to cure or improve the patient s clinical status. In general, gene therapy consists in the insertion of functional genes aiming substitute, complement or inhibit defective genes. The achievement of a foreigner DNA expression into a population of cells requires its transfer to the target. Therefore, a key issue is to create systems, vectors, able to transfer and protect the DNA until it reaches the target. The disadvantages related to the use of viral vectors have encouraged efforts to develop emulsions as non-viral vectors. In fact, they are easy to produce, present suitable stability and enable transfection. The aim of this work was to evaluate two different non-viral vectors, cationic liposomes and nanoemulsions, and the possibility of their use in gene therapy. For the two systems, cationic lipids and helper lipids were used. Nanoemulsions were prepared using sonication method and were composed of Captex® 355; Tween® 80; Spam® 80; cationic lipid, Stearylamine (SA) or 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP) and water (Milli-Q®). These systems were characterized by average droplet size, Polidispersion Index (PI) and Zeta Potential. The stability of the systems; as well as the DNA compaction capacity; their cytotoxicity and the cytotoxicity of the isolated components; and their transfection capacity; were also evaluated. Liposomes were made by hydration film method and were composed of DOTAP; 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), containing or not Rhodaminephosphatidylethanolamine (PE- Rhodamine) and the conjugate Hyaluronic Acid DOPE (HA-DOPE). These systems were also characterized as nanoemulsions. Stability of the systems and the influence of time, size of plasmid and presence or absence of endotoxin in the formation of lipoplexes were also analyzed. Besides, the ophthalmic biodistribution of PE-Rhodamine containing liposomes was studied after intravitreal injection. The obtained results show that these systems are promising non-viral vector for further utilization in gene therapy and that this field seems to be very important in the clinical practice in this century. However, from the possibility to the practice, there is still a long way

Comparação de efeitos dos extratos de Hypericum perforatum (Hipérico) e de Mentha crispa (Hortelã) em diferentes modelos experiemtais

Several clinic evaluations have been possible with radiobiocomplexes labeled with technetium-99m (99mTc). Some natural and synthetic drugs are capable of to interfere on the labeling of blood constituents with 99mTc, as well as on the biodistribution of radiobiocomplexes. Authors have also reported about the toxicity of several natural products. The aim of this study was to compare the effects of the Mentha crispa (hortelã) and of the Hypericum perforatum (hipérico) in different experimental models. On the labeling of red blood cells (RBC) and plasma and cellular proteins with 99mTc, both extracts were capable of to decrease the radioactivity percentage on the cellular compartment and on the fixation on plasma and cellular proteins. On the morphometry of the RBC, only the hortelã was capable to alter the shape and the perimeter/area ratio of the RBC. On the biodistribution of the radiobiocomplex sodium pertechnetate (Na99mTcO4), the hortelã increased the Na99mTcO4 distribution in the kidney, spleen, liver and thyroid, meanwhile the hipérico decreased the Na99mTcO4 distribution in the bone, stomach, lungs and thyroid, and increased the Na99mTcO4 distribution in the pancreas. On the bacterial cultures survival, the hipérico was capable of to protect the bacteria against the stannous chloride (SnCl2) effect. The hipérico did not alter the topology of plasmidial DNA and did not protect the plasmidial DNA against the SnCl2 action. Probably, the effects presented by both extracts could be due to chemical compounds of the extracts that could alter the morphology of the RBC and the plasma membrane ions transport, and/or by phytocomplexes that could be formed with different effects dependent on the biological system considered

Estudo de efeitos de um extrato de Arctium lappa (Bardana) na marcação dos constituintes sangüíneos com Tecnécio-99m, na biodisponibilidade do radiofármaco pertecnatato de sódio e na morfologia de hemácias de ratos Wistar

Radionuclides have been used in Nuclear Medicine for diagnostic and treatment. In basic research, cellular and molecular structures are labeled with technetium-99m (99mTc) and used as radiobiocomplexes. Some natural or synthetic drugs are capable to alter the labeling of blood constituents with 99mTc, as well as in the biodistribution of radiobiocomplexes. Arctium lappa (Bardana) has been used to treat inflammatory processes. The aim of this work was to evaluate the effects of an extract of Bardana on the labeling of blood constituents with 99mTc, on the morphology of red blood cells, on the perimeter/area ratio of red blood cells and on the biodistribution of radiophamaceutical sodium pertechnetate in Wistar rats. Extract of Bardana was capable to alter the labeling of cellular compartment with 99mTc. Plasma and cellular proteins did not present alteration on the percentage of radioactivity (%ATI). Extract of Bardana was also capable to alter the morphology and the perimeter/area ratio of red blood cells. On the biodistribution of sodium pertechnetate in animals treated with the extract of Bardana, it was observed a small and significant uptake in liver, tooth and tongue, and a high and a significant uptake in stomach, lung and testis (p<0.05). In conclusion, these findings could be justified due to the effects of some chemical compounds in the Bardana extract. This study was a multidisciplinary experimental research. It was developed with the contribution of the different Departments and Services of the Hospital Universitário Pedro Ernesto of the Universidade Estadual do Rio de Janeiro

Estudo de efeitos de um extrato aquoso de farinha de casca de maracujá (Passiflora edulis f. flavicarpa) na marcação de constituintes sangüíneos com Tecnécio 99m, na morfometria das hemácias e na biodisponibilidade do radiofármaco Pertecnetato de Sódio em ratos Wistar

Blood constituents labelled with technetium-99m (99mTc) has been used with radiobiocomplexes in several procedures in nuclear medicine. Some natural and sintetic drugs are capable to interfere on the labeling of blood constituents with 99mTc, on the morphology of red blood cells (RBC) and on the biodistribution of radiobiocomplexes. The aim of this study was evaluate the effect of an extract of Passiflora edulis f. flavicarpa on the labeling of blood constituints with 99mTc, on the morphology of RBC and on the biodistribution of the radiopharmaceutical sodium perthecnetate in Wistar rats. On the in vitro studies the Passiflora edulis f. flavicarpa decreased significantly (p<0.05) the %ATI on plasma proteins and on the in vitro morhology of RBC, the passion fruit peel flour altered the shape and the perimeter/área ratio. On the in vivo estudies the extract did not altered the %ATI in blood constituents, and did not altered the shape of RBC. Although, on the biodistribution of the radiobiocomplex sodium perthecnetate (Na99mTcO4) this extract decreased significantly (p<0.05) the uptake in duodenum, spleen, pâncreas and blood, and increased the uptake in stomach. It can be suggested that the effects presented by this extract could be a result of some substances contained in this extract that could alter the binding of 99mTc to plasma proteins, the morphology of RBC and the biodistribution of the radiobiocomplex sodium perthecnetate. This study was multidisciplinary experimental research. It was developed with the contribution of different Departments and Services of the Hospital Universitário Pedro Ernesto of the Universidade Estadual do Rio de Janeiro

Efeito de extratos vegetais na parasitemia do Trypanosoma cruzi e na biodistribuição do pertecnetato de sódio (Na99mTcO4)

Artemisia vulgaris (AV) is an antihelmintic and antimalarial drug; Aloe vera(babosa) acts as antidiabetic, laxative and anti-inflammatory; Benznidazole (BZ) is a trypanocidal of Trypanosoma cruzi (TC). Technetium-99m (99mTc) has been used in nuclear medicine to obtain diagnostic images. This study evaluated the plant effects in TC parasitemia and in the biodistribution of 99mTc in mice. Twenty mice were infected by TC. At the peak of parasitemia, 5 mice received babosa; 5 received AV and 5 received BZ. The parasitemia was determined in 0, 2, 4 and 6 h of drugs administration. Five infected mice without drugs, 5 mice without TC and the group treated with AV, received 99mTc. The radioactivity was calculated. Infected mice that received babosa reduced significantly (p<0.05) the parasitemia. The percentage of activity (%ATI) decreased significantly in the AV group. These results indicate that babosa possibly is an anti-TC drug and AV reduces the %ATI probably due to its biological effects

Biodistribuição do pertecnetato de sódio após cirurgia do Switch Duodenal

The biliopancretic diversion with duodenal switch is one of the mixing techniques used in the treatment of morbid obesity. The duodenal switch reduces the stomach capacity and leaves only 50-100 cm of small intestine for nutrition and absorption. The surgery produces hormonal, structural and biochemical changes, which can influence on the result of scintigraphic examinations in operated patients. With the objective of evaluate the postoperative biodistribution of sodium pertechnetate (Na99mTcO4) in brain, thyroid, heart, lung, liver, spleen, kidney, stomach, duodenum, pancreas, small intestine, bladder, muscle and bone of Wistar rats. The rats were randomly allocated into 3 groups of 7 rats each: the duodenal switch group (DS), the control group (C) and the sham group (S). They were operated under anesthesia and aseptic technique. In the tenth postoperative day, 0.1mL of sodium pertechnetate was injected via orbital plexus. After 30 min the animals were killed with overdose of anesthetic and samples of liver, spleen, pancreas, stomach, duodenum, small intestine, thyroid, lung, heart, kidney, bladder, muscle, bone and brain were harvested, washed with saline and weighed. The detention of radioactivity was made using the automatic Gamma Counter Wizard, PerkinElmer and the percentage of activity per gram of tissue (%ATI/g) was calculated. There was no early or late mortality in either rats groups. The values of percent radioactivity per gram of tissue (%ATI/g), showed no significant difference in liver, stomach, small bowel, duodenum, kidney, heart, bladder, bone and brain, when compared the DS rats with sham and controls rats. A postoperative significant increase in mean %ATI/g levels was observed in spleen, pancreas and muscle in group DS rats, as compared to group S and C rats (p<0.05). In the lung there was an increase and in thyroid a decrease in mean %ATI/g of DS rats, when compared to sham rats (p>0.05). In conclusion, the biliopancreatic diversion with duodenal switch in rats modified the biodistribution of sodium pertechnetate in thyroid, lung, pancreas, spleen and muscle. The study had the participation of the departments and laboratories researches, as Nucleus of Experimental Surgery, Department of Surgery, Laboratory of Radiobiology, Department of Pathology and Service of Nuclear Medicine, certifying the character of a multidisciplinary research

Biodistribuição do pertecnetato de sódio (Na99mTcO4) em ratos submetidos à ressecção extensa de intestino delgado

Massive resection of the small intestine results in short bowel syndrome with anti-absorptive effect and repercussions on the metabolism. Morphologic and functional evaluation may be necessary in order to control wrapped organs. Scintigraphy an examination with little invading and no biologic damage can be used. The purpose were to assess the biodistribution of sodium pertecnetate in organs of rats subjected to massive resection of the small intestine, the intestinal adaptation of the remnant intestinal mucosa and weight curve evaluation in the postoperative period. Twenty-one Wistar rats were randomly allocated into three groups (n = 7). The operated group named short bowel (SB) after anesthetized was subjected to massive resection of the small intestine; the control group (C), and sham group (SHAM). On the 30th postoperative day, 0.l mL of sodium pertechnetate was injected into the venous orbital plexus. After 30 minutes, the rats were killed with an overdose of anesthetic, and fragments of the liver, spleen, pancreas, stomach, duodenum, small intestine, thyroid, lung, heart, kidney, bladder, muscle, femur and brain were harvested. The percentage of radioactivity per gram of tissue (%ATI/g) was determined using Gama Counter WizardTM 1470, PerkinElmer to all samples. Biopsies of 3 cm remaining jejunum were removed to histological analyses. Analysis of variance (ANOVA) and the Tukey test for multiple comparisons were used, considering p<0.05 as significant. The study had the participation of some departments and laboratories, as Nucleus of Experimental Surgery, Department of Surgery, Laboratory of Radiobiology, Department of Pathology and Service of Nuclear Medicine, certifying the character of a multidisciplinary research. The results were no significant differences in %ATI/g of the sodium pertechnetate in the organs of the groups studied (p>0.05). An increase in the weight of the SB rats was observed after the second postoperative week. The jejunal mucosal thickness of the SB rats was significantly greater than that of C and sham rats (p<0.05. The biodistribution of sodium pertechnetate was not affected by massive intestinal resection in rats. An adaptive response by the intestinal mucosa probably contributed to the reversion of weight loss and the biodistribution of sodium pertechnetate was not affected by the surgery

Consequências da colectomia associada à hepatectomia no metabolismo hepático e na forma e função de hemácias em ratos

This study investigated the influence of partial colectomy associated with hepatectomy on the biodistribution of the 99mTc-phytate, on metabolic parameters, as well as labeling and morphology of red blood cells. Wistar rats were distributed into three groups (each with 6), nominated as colectomy, colectomy+hepatectomy and sham. In the 30th postoperative day all rats were injected with 99mTc-phytate 0.1mL i.v. (radioactivity 0.66 MBq). After 15 minutes, liver sample was harvested and weighed. Percentage radioactivity per gram of tissue (%ATI/g) was determined using an automatic gamma-counter. Serum AST, ALT, alkaline phosphatase and red blood cells labeling were determined. The liver %ATI/g and red blood cells labeling were lower in colectomy and colectomy+hepatectomy rats than in sham rats (p <0.05), and no difference was detected comparing the colectomy and colectomy+hepatectomy groups. Red blood cells morphology did not differ among groups. Serum levels of AST, ALT and alkaline fosfatase were significantly higher in colectomy+hepatectomy than in colectomy rats (p<0.001). Hepatectomy associated with colectomy lowered the uptake of radiopharmaceutical in liver and in red blood cells in rats, coinciding with changes in liver enzymatic activity

The ileum as a determinant organ of the functional liver cell mass in rats

PURPOSE: To evaluate if the ileum resection changes the functioning liver cell mass, the hepatic metabolism and the biodistribution of radiopharmaceutical in rats. METHODS: Twelve Wistar rats weighing 285g±34g were randomly divided into the ileum resection group (n = 6) and sham group rats (n = 6). After 30 days, they were anesthetized and 0.1mL of 99m-Tc-phytate(0.66MBq) was injected via femoral vein. After 30 minutes, blood samples were collected for red blood cells radioactive labeling and serum ALT, AST and gammaGT. Liver samples were used for 99m-Tc-phytatepercentage of radioactivity/gram of tissue and histopathology. Student’s t test was used with significance 0.05. RESULTS: There was a higher uptake of 99m-Tc-phytate in the liver of sham rats, compared to the ileum resection group (p<0.05). GammaGT, ALT and AST were increased in ileum resection rats compared to sham (p<0.05). The he patocytes count was significantly lower in ileum resection group than in sham (p<0.05). Liver: body mass ratio was lower in experimental animals than in sham group (p<0.05). CONCLUSION: These data support that the ileum has important role in liver function and liver mass regulation, and they have potential clinical implications regarding the pathogenesis of liver injury following lower bowel resection.

Metabolic and hematologic consequences of colectomy associated to hepatectomy in rats

To investigate the influence of partial colectomy associated with hepatectomy on the biodistribution of the 99mTc-phytate, on metabolic parameters, as well as labeling and morphology of red blood cells. METHODS: Wistar rats were distributed into three groups (each with six), nominated as colectomy, colectomy+hepatectomy and sham. In the 30th postoperative day all rats were injected with 99mTc-phytate 0.1mL i.v. (radioactivity 0.66 MBq). After 15 minutes, liver sample was harvested and weighed. Percentage radioactivity per gram of tissue (%ATI/g) was determined using an automatic gammacounter. Serum AST, ALT, alkaline phosphatase and red blood cells labeling were determined. RESULTS: The liver %ATI/g and red blood cells labeling were lower in colectomy and colectomy+hepatectomy rats than in sham rats (p <0.05), and no difference was detected comparing the colectomy and colectomy+hepatectomy groups. Red blood cells morphology did not differ among groups. Serum levels of AST, ALT and alkaline fosfatase were significantly higher in colectomy+hepatectomy than in colectomy rats (p<0.001). CONCLUSION: Hepatectomy associated with colectomy lowered the uptake of radiopharmaceutical in liver and in red blood cells in rats, coinciding with changes in liver enzymatic activity.

Desenvolvimento de nanosistemas farmacêuticos para terapia gênica

Gene therapy is one of the major challenges of the post-genomic research and it is based on the transfer of genetic material into a cell, tissue or organ in order to cure or improve the patient s clinical status. In general, gene therapy consists in the insertion of functional genes aiming substitute, complement or inhibit defective genes. The achievement of a foreigner DNA expression into a population of cells requires its transfer to the target. Therefore, a key issue is to create systems, vectors, able to transfer and protect the DNA until it reaches the target. The disadvantages related to the use of viral vectors have encouraged efforts to develop emulsions as non-viral vectors. In fact, they are easy to produce, present suitable stability and enable transfection. The aim of this work was to evaluate two different non-viral vectors, cationic liposomes and nanoemulsions, and the possibility of their use in gene therapy. For the two systems, cationic lipids and helper lipids were used. Nanoemulsions were prepared using sonication method and were composed of Captex® 355; Tween® 80; Spam® 80; cationic lipid, Stearylamine (SA) or 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP) and water (Milli-Q®). These systems were characterized by average droplet size, Polidispersion Index (PI) and Zeta Potential. The stability of the systems; as well as the DNA compaction capacity; their cytotoxicity and the cytotoxicity of the isolated components; and their transfection capacity; were also evaluated. Liposomes were made by hydration film method and were composed of DOTAP; 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), containing or not Rhodaminephosphatidylethanolamine (PE- Rhodamine) and the conjugate Hyaluronic Acid DOPE (HA-DOPE). These systems were also characterized as nanoemulsions. Stability of the systems and the influence of time, size of plasmid and presence or absence of endotoxin in the formation of lipoplexes were also analyzed. Besides, the ophthalmic biodistribution of PE-Rhodamine containing liposomes was studied after intravitreal injection. The obtained results show that these systems are promising non-viral vector for further utilization in gene therapy and that this field seems to be very important in the clinical practice in this century. However, from the possibility to the practice, there is still a long way