Metabolic and ultrastructural renal changes in adult Wistar rats fed by a cafeteria diet

PURPOSE

To evaluate, by quantitative and qualitative methods, the glomerular ultrastructure in Wistar rats fed a cafeteria diet.

METHODS

Male Wistar rats were divided into two groups at 21 days of age: control (C, n = 10) and cafeteria diet (CAF, n = 8). The animals were followed up until 5 months of age, followed by euthanasia. The blood, kidneys, and fat deposits--epididymal, retroperitoneal, and subcutaneous--were extracted and analyzed. Data were analyzed by Student's t test, and p < 0.05 was considered statistically significant.

RESULTS

The cafeteria diet promoted glucose intolerance, hyperglycemia (p < 0.0001), and deposition of retroperitoneal fat (p < 0.005). Scanning electron microscopy revealed that the length of the foot process was similar in both groups. The quantitative analyses by transmission electron microscopy revealed that the cafeteria diet reduced the thickness of the glomerular basement membrane (p < 0.05).

CONCLUSIONS

The intake of lipids and simple carbohydrates were found to be associated with alteration in the glomerular ultrastructure. However, more studies are needed to evaluate not only the effects of high-protein and high-fat diets on components of the glomerular filtration barrier, but also renal physiology.

Effects of chronic restraint stress in the prostate of prepubertal and adult rats

PURPOSE

To investigate the effects of chronic stress in the prostate of prepubertal and adult rats.

METHODS

Thirty-two male rats were assigned into four groups depending on the type of treatment (control or stressed) and the age at which stress was initiated (prepubertal or adult). Restraint stress stimuli were applied for six weeks. Stressed prepubertal and adult rats evaluated immediately after the last stress stimuli were named SP and SA groups, respectively. Age-matched rats were used as control groups (CP and CA). At the end of the experiment, the rats were euthanized, and prostate morphological parameters were evaluated and statistically compared.

RESULTS

Application of stress stimuli to the SP group resulted in reduced body weight, but no prostate morphological modification was noted. The SA group showed reduced testosterone level and prostatic epithelium surface density, in comparison to CA group. Further, the prostatic lumen surface density was increased in adult stressed animals, in comparison to adult controls.

CONCLUSIONS

The stress stimuli promoted changes in hormonal and morphological parameters in the prostate of adult stressed rats. Prepubertal stressed animals did not presented modifications of prostate morphology.

What is the effect of Tribulus terrestris on testicular morphology and sperm production? An experimental study in the rat model

The objective of this study was to investigate whether treatment with Tribulus terrestris (Tt) has any impact on the testicular morphology and function in a rodent model. Twenty male rats were divided into a control group and a group receiving 100 mg kg-1 body weight of Tt supplementation. After 40 days of experiment, the animals were submitted to euthanasia; epididymal tail spermatozoa were collected; and spermatozoa concentration, motility, and viability were analyzed. In addition, testicles were collected and processed for histomorphometrical analyses. Data were compared using the Student's t-test and considered significant when P < 0.05. Spermatozoa concentration, motility, and viability showed no difference between the groups. Further, testicular weight and volume, seminiferous tubule diameter, tunica propria surface density, seminiferous epithelium surface density, and intertubular compartment surface density were statistically similar between the groups. However, seminiferous epithelium height and tubular lumen surface density were augmented in animals treated with Tt. Treatment with Tt does not cause a major impact on testicular morphology, promoting only subtle modifications. No difference on spermatozoa parameters was observed.

Histomorphometric comparison of the corpus cavernosum of rats submitted to euthanasia with ketamine and xylazine or isoflurane

PURPOSE

To compare the penile histoarchitecture of rats euthanized with isoflurane or with ketamine and xylazine.

METHODS

Fourteen male rats were divided into two groups: ISO, with animals euthanized with isoflurane; and K+X, with animals euthanized with ketamine (150 mg/kg) associated with xylazine (15 mg/kg). Immediately after the death, the penises were dissected, fixed in a 4% buffered formalin solution, and processed for histomorphometric analysis. The surface densities (Sv) of the corpus cavernosum structures (connective tissue, smooth muscle, sinusoidal space, and elastic fibers) were evaluated using Image J software. The distribution of collagen types I and III was qualitatively assessed. Statistical analyses were performed using the Student's t test for data comparison, considering it statistically significant when p < 0.05.

RESULTS

Regarding the Sv of connective tissue, smooth muscle and sinusoidal space, there were no differences between animals in both groups. On the other hand, the animals euthanized with the association of ketamine and xylazine showed the Sv of elastic fibers 24.8% higher in relation to animals euthanized with isoflurane.

CONCLUSIONS

The euthanasia method affected one of the morphological parameters of the rat penises. The choice of euthanasia method must be standardized to reduce bias and to obtain reliable and reproducible results.

Does treatment with dutasteride or finasteride has impact on renal morphology? Experimental study

PURPOSE

To investigate whether renal modifications occur following treatment with dutasteride or finasteride.

METHODS

Twenty-four male rats were divided into three groups: control (that received distilled water), dutasteride (0.5 mg/kg/day), and finasteride (5 mg/kg/day) groups. All administrations were given by gavage for 40 consecutive days. After inducing euthanasia, blood was collected for urea and creatinine analyses, and both the kidneys were collected for stereological analyses of kidney morphology.

RESULTS

Serum urea and creatinine levels were increased in both the finasteride and the dutasteride groups compared with those in the control group. In addition, kidney weight, kidney volume, cortical volume, glomerular volumetric density, and mean glomerular volume were reduced in both treatment groups. Finally, the number of glomeruli per kidney was reduced by 26.8% in the finasteride group and by 51.6% in the dutasteride group compared with that in the control group.

CONCLUSIONS

The 5-ARIs finasteride and dutasteride promoted morphological and functional damages in rat kidneys. In addition, rats in the dutasteride group showed more severe renal modifications than those in the finasteride group.

Effects of nandrolone decanoate on femur morphology. Experimental study

PURPOSE

To evaluate the immediate and late effects of nandrolone on femur morphology of rats.

METHODS

Twenty-eight animals with 20 weeks of age were divided into four groups: C28, control animals that were euthanized eight weeks after the experiment started; C40, control animals euthanized 20 weeks after the experiment started; T28, treated animals receiving nandrolone during eight weeks and euthanized immediately after the treatment period; and T40, animals treated during eight weeks and euthanized 12 weeks after the end of the treatment. Treated animals received nandrolone decanoate during eight weeks and control groups received peanut oil by intramuscular injection. After euthanasia, femurs were removed, dissected, weighted and measured by digital pachymeter.

RESULTS

The T40 group presented an increase on distal epiphysis diameter when compared to C40 group. There was no difference between treated and control groups in relation to body and femur absolute weight, relative weight and length of femur. There was also no difference in relation to diameter of proximal epiphysis and diameter of diaphysis among the groups.

CONCLUSIONS

Nandrolone decanoate does not produce significant effect on femur, exception on its distal extremity at late period. The effects of such drug may depend on the time after administration.

Quercetin as a nephroprotector after warm ischemia: histomorphometric evaluation in a rodent model

Purpose:

To quantitatively evaluate the possible long-term protective effects of quercetin during renal warm ischemia.

Materials and Methods:

Male rats were allocated into 4 groups: sham (S), sham quercetin (SQ), ischemia (I), and ischemia quercetin (IQ). Groups SQ and IQ received quercetin (50mg/kg) before and after surgery. Groups I and IQ had their left renal vessels clamped for 60 minutes. All animals were euthanized four weeks after the procedure, and serum urea and creatinine levels were measured. Renal weight and volume, cortex-non-cortex area ratio (C-NC), cortical volume (CV), glomerular volumetric density (Vv[glom]), volume-weighted glomerular volume (VWGV) and number of glomeruli per kidney (N[glom]) were evaluated by stereological methods. Results were considered statistically significant when p <0.05.

Results:

Serum urea levels in group I increased by 10.4% in relation to group S, but no differences were observed among the other groups. The C-NC of group I was lower than those of all other groups, and group IQ had similar results to sham groups. The Vv[glom] and N[glom] of group I were lower than those of group S (33.7% and 28.3%, respectively) and group IQ had no significant difference compared to the S group.

Conclusions:

Quercetin was effective as a nephroprotective agent in preventing the glomerular loss observed when the kidney was subjected to warm ischemia. This suggests that this flavonoid may be used preventively in kidney surgery, when warm ischemia is necessary, such as partial nephrectomy.

Evaluation of the effects of chronic stress applied from the prepubertal to the adult stages or only during adulthood on penile morphology in rats

The present study aimed to evaluate the effects of chronic stress from the prepubertal to the adult stages or during adulthood on penile morphology in rats. The animals were immobilized in a cylinder for 2 h daily for a total of six weeks to simulate stress. Ten rats were exposed to stress stimulus beginning from the prepubertal age, while nine rats were exposed to stress stimulus only during adulthood. Animals were killed at 24 h after the last stress session for short-term evaluation (SP-S and SA-S), while other age-matched rats were sacrificed at 6 weeks after the last stress session for long-term evaluation (SP-L and SA-L). Age-matched animals were used as controls (CP-S, CA-S, CP-L and CA-L). After treatment, serum testosterone levels and areas of cavernosum structures were evaluated. We observed no changes in serum testosterone levels after stress treatment. Results revealed that the area of the corpus cavernosum without the tunica albuginea in animals in the SA-S group was 16% lower than that in the CA-S group. The smooth muscle was 31% lower in the SP-L group than in the SP-S group and 42% lower in the SA-S group than in the CA-S group. The elastic fiber system was 48% lower in the SP-L group than in the CP-L group and 59% lower in the SA-S group than in the CA-S group. Chronic stress promoted morphological changes in the rat penis and was significantly more pronounced when the stress occurred throughout the adulthood. Chronically applied single stress stimulus caused greater damage to the penis when induced directly during adulthood than when introduced before puberty to adulthood and could be associated with erectile dysfunction.

Immediate and Late Effects of Stress on Kidneys of Prepubertal and Adult Rats

BACKGROUND/AIMS

Stress had been related to physiological and morphological alterations in different organs, however kidney morphology and function after stress conditions are not well-known. To evaluate the effects of chronic stress on renal morphology in prepubertal and adult rats, and to investigate if the effects of induced stress remain stable or worsen following removal of the stress stimuli.

METHODS

Forty prepubertal rats (4 weeks old) and thirty six adult rats (10 weeks old) were used. Each age group was divided a into control group and a stressed group. Stressed animals were restrained in rigid tubes 2 hours per day for 6 weeks. Animals were euthanized 24 hours after the last stress stimulus for immediate evaluation (50% of the groups), and 6 weeks after the last stress stimulus for late evaluation (50% of the groups). Kidney weight and volume, cortical-medullar ratio, glomerular volumetric density, volume-weighted glomerular volume, and number of glomeruli per kidney were evaluated using the Image J software.

RESULTS

Prepubertal stressed animals showed reduced kidney weight and volume, and increased cortical-medullar ratio in comparison to its control group when evaluated immediately. Furthermore, stressed prepubertal and adult animals evaluated immediately had reduced glomerular volumetric density. Most importantly, all stressed groups exhibited reduced number of glomeruli per kidney. Other analyzed parameters did not difeer significantly the groups.

CONCLUSION

Chronic stress induced before and after puberty led to irreversible glomerular loss, however, renal impairment was interrupted by removal of the stress stimuli.

Volume and Shape Assessment of Renal Radiofrequency Ablation Lesion

OBJECTIVE

To evaluate the microscopic characteristics and quantify the volume of a radiofrequency ablation (RFA) lesion.

METHODS

Ten male pigs were submitted to laparoscopic RFA. An RFA needle was introduced in the lower pole of the left kidney to create a lesion expected to be a sphere of 2.0 cm diameter. The animals were followed up for 21 days. Kidneys were weighed and the volume was assessed using Scherle's method. Cavalieri's principle was used to assess the RFA volume, and sphericity was calculated to assess RFA lesion. One sample t test was used to compare RFA volume with the volume of a sphere of 2.0 cm diameter, and sphericity to hypothetical values of a sphere and an icosahedron. Fragments of RFA region were histologically evaluated.

RESULTS

Three animals developed postoperative complications and were excluded from the analyses. There was no difference in the mean weight and volume between right and left kidneys following RFA. The mean total volume of RFA injury was 3.44 cm³. There was no difference in the RFA volume in comparison with hypothetical volumes of a sphere and an icosahedron of 2.0 cm diameter. Sphericity of the RFA injury was not similar with a sphere; however, it was similar to an icosahedron. Histology revealed areas of coagulation necrosis, fibrosis, and inflammatory mononuclear infiltration. Areas with normal tissue were also observed.

CONCLUSION

The volume of injury caused by RFA was as expected and its shape was comparable with an icosahedron. Microscopic evaluation revealed areas of normal-appearing tissue.

Nutritional supplementation with arginine protects radiation-induced effects. An experimental study

PURPOSE:

To investigate the protective effect of L-arginine on the prostate (nonneoplasic) of rats with radiation-induced injury.

METHODS:

Twenty-nine Wistar rats, male adult, allocated into three groups: Control group (C) was not exposed to irradiation (n=10); Radiated group (R) had undergone pelvic irradiation (n=10); Supplemented and radiated group (R+S) had undergone pelvic irradiation plus L-arginine supplementation (n=9). The animals were observed for signs of toxicity. After euthanization, the prostate was dissected under magnification and stained by hematoxylin and eosin to study acinar structures and stained with Picrosirius red for collagen analysis.

RESULTS:

After radiation exposure, all animals presented diarrhea, but supplementation with L-arginine reduced this effect. The weight gain in the R+S group was significantly higher than in the C and R groups. In the R+S group the collagen density and the prostate acinar area was similar to the R and C groups. Epithelial height was significantly reduced in group R compared with group C (p<0.0001). When comparing the group R+S with R, a statistical difference was observed to be present (p<0.0001).

CONCLUSIONS:

Pelvic radiation promotes systemic effects and some structural modifications in the ventral prostate of rats. These modifications can be prevented by oral supplementation with L-arginine.

Glomerular Loss After Renal Radiofrequency Ablation Are Comparable to 30 Minutes of Warm Ischemia

PURPOSE

To compare, with stereological methods, the glomerular loss in kidneys submitted to radiofrequency ablation (RFA) or warm ischemia.

MATERIALS AND METHODS

Twenty-six male pigs were divided into three groups. Eight animals were allocated in the sham group, which was submitted to laparoscopic dissection of the left renal hilum, without renal ischemia. Eight animals were allocated in the ischemia group, which had the left renal hilum clamped for 30 minutes under laparoscopic access. Ten animals were submitted to RFA of the left kidney lower pole, under laparoscopic visualization. Animals were euthanized 21 days after surgery, when kidneys were collected. Fragments of the upper pole of the left kidney were processed for morphometric analysis. Right kidney was used as self-controls for each animal. Glomerular volumetric density (Vv[glom]); volume-weighted glomerular volume (VWGV); and glomerular density were quantified by stereological methods and compared by Student's t-test and one-way-analysis of variance with Dunnett's post-test.

RESULTS

Three animals in the RFA group developed postoperative complications (Urinoma/Hydronephrosis) and were excluded from the analysis. No difference was found among the kidneys submitted to RFA and warm ischemia for all parameters. However, these kidneys showed lower Vv[glom] and glomerular density when compared to its self-controls (right kidneys), and when compared to sham-operated animals (p < 0.05). No difference was observed in regards to VWGV among the groups.

CONCLUSION

RFA in pigs determines a significant reduction of glomerular density in the remaining parenchyma. This alteration was comparable to that observed in kidneys submitted to 30 minutes of warm ischemia.

Morphometric study of the corpus cavernosum after anabolic androgenic steroid administration in pubertal and adult rats

PURPOSE

To evaluate the penile morphological modifications of pubertal and adult rats chronically treated with supra-physiological doses of anabolic androgenic steroids.

METHODS

Forty-eight male Wistar rats were distributed into four groups: two control groups, 105- and 65-day-old (C105 and C65, respectively) injected with peanut oil (vehicle); and two treated groups, 105- and 65-day-old (T105 and T65, respectively) injected with nandrolone decanoate at a dose of 10 mg Kg-1 of body weight. The rats were injected once a week for eight weeks. The rats were then killed and their penises were processed for histomorphometric analyses. The mean of each parameter was statistically compared.

RESULTS

A corpus cavernosum reduction of 12.5% and 10.9% was observed in the T105 and T65 groups, respectively, when compared with their respective control groups. The cavernosum smooth muscle surface density diminished by 5.6% and 12.9% in the T65 and T105 groups, respectively, when compared with their controls. In contrast, the sinusoidal space increased by 17% in the T105 group and decreased by 9.6% in the T65 group.

CONCLUSION

The use of supra-physiological doses of AAS promotes structural changes in the rat penis, by altering the proportions of corpus cavernosum tissues, in both pubertal and adult treated animals.

Laparoscopic correction of experimentally induced diaphragmatic rupture in dogs

PURPOSE

To describe the dog as a model for studying laparoscopic correction of experimental diaphragmatic ruptures.

METHODS

Five male dogs were used in this study. Under laparoscopic approach, a defect of 7 cm was created on the left ventral insertion of the diaphragm. Fourteen days after this procedure, the abdomen was explored using laparoscopic access and the diaphragmatic defect was corrected with intracorporeal suture. The dislocated organs, surgical time, and suturing time were recorded. Analgesia and clinical condition were monitored during the postoperative period.

RESULTS

All animals recovered well from the diaphragmatic rupture creation. After 14 days, abdominal organs (liver, spleen, omentum and/or intestine) were found inside the thoracic cavity in all animals. It was possible to reposition the organs and suture the defect by laparoscopic access in three animals. These animals showed excellent postoperative recovery. It was not possible to reposition the liver safely when it was friable.

CONCLUSIONS

Laparoscopic creation of diaphragmatic rupture in dogs is feasible. Dogs are a good model for training and studying the correction of experimentally created diaphragmatic rupture by the laparoscopic approach. A friable liver is a complicating factor that should be taken into account. Animals submitted to laparoscopic correction showed excellent postoperative recovery.

Experimental infection with the Toxoplasma gondii ME-49 strain in the Brazilian BR-1 mini pig is a suitable animal model for human toxoplasmosis

Toxoplasma gondii causes toxoplasmosis, a worldwide disease. Experimentation with pigs is necessary for the development of new therapeutic approaches to human diseases. BR-1 mini pigs were intramuscularly infected with T. gondii with tachyzoites (RH strain) or orally infected with cysts (ME-49 strain). Haematology and serum biochemistry were analysed and buffy coat cells were inoculated in mice to determine tachyzoite circulation. No alterations were observed in erythrocyte and platelet values; however, band neutrophils increased seven days after infection with ME-49. Serology of the mice inoculated with pig blood leucocytes revealed circulating ME-49 or RH strain tachyzoites in the pigs' peripheral blood at two and seven or nine days post-infection. The tachyzoites were also directly observed in blood smears from the infected pigs outside and inside leucocytes for longer periods. Alanine-aminotransferase was high at days 21 and 32 in the RH infected pigs. After 90 days, the pigs were euthanised and their tissue samples were processed and inoculated into mice. The mice serology revealed the presence of parasites in the hearts, ileums and mesenteric lymph nodes of the pigs. Additionally, cysts in the mice were only observed after pig heart tissue inoculation. The infected pigs presented similar human outcomes with relatively low pathogenicity and the BR-1 mini pig model infected with ME-49 is suitable to monitor experimental toxoplasmosis.

SCIENTIFIC LEADERS FOR THE FUTURE: PRIMARY AND SECONDARY EDUCATION

OBJECTIVE

To present a high school insertion pilot project in post graduate programs (PPG) and discuss the mechanisms for the formation of leaders in science.

METHODS

This study presents a review and pilot project. Bibliographic search occurred in sites of CAPES, MEC, SciELO and library of virtual books from January/ 2014 to February/2015. The pilot is in PPG-Medicine III Translational Surgery/UNIFESP and Pathophysiology and Surgical Sciences / UERJ. The junior undergraduate students (ICj) came from public school and develop scientific activities: scientific meetings, graduation and inclusion in research projects. The evaluation will occur at the end of one year, with the results essays, reports and participation in scientific events.

RESULTS

In Brazil, one of the main challenges of education is the high average years of study. The PNPG (2011-2020) shows the insertion of basic education in all PPG. In the Pathophysiology and Surgical Sciences/UERJ there are currently 11 high school students who have followed the scientific meetings and are being prepared for the inclusion in research projects. There was 30% of absence, owing to the high school hours. This result and the experience allow creating future alternatives to enhance the integration project.

CONCLUSION

The leadership in science is formed from a complex relationship between basic education and investment in research. PPG-Medicine III courses follow the vanguard with initiatives focused on scientific and technological development. Thus, projects involving basic education students represent promoter model and environment leaders.

OBJETIVO

Apresentar um projeto piloto de inserção do ensino médio em programas de pós-graduação (PPG) e discutir os mecanismos para a formação de líderes em ciência.

MÉTODOS

Realizou-se um estudo de revisão e apresentação de piloto. A busca bibliográfica ocorreu nos sites da CAPES, MEC, Scielo e biblioteca de livros virtuais, de janeiro/2014 a fevereiro/2015. O piloto ocorre nos PPG-Medicina III em Cirurgia Translacional/UNIFESP e Fisiopatologia e Ciências Cirúrgicas/UERJ. Os alunos de iniciação científica júnior (ICj) são oriundos de escola pública e desenvolvem atividades científicas: participação em reuniões científicas, graduação e inserção nos projetos de pesquisa. A avaliação ocorrerá ao final de um ano, com redações dos resultados, relatórios e participações em eventos científicos.

RESULTADOS

No Brasil, um dos principais desafios da educação é a alta média de anos de estudo. O PNPG (2011-2020) apresenta a inserção da educação básica em todos os PPG. Na Fisiopatologia e Ciências Cirúrgicas/UERJ há atualmente 11 alunos do ensino médio, que já acompanharam as reuniões científicas e preparam-se para a inserção em projetos de pesquisa. Houve 30% de desistência, devido à alta carga horária escolar. Esse resultado e a experiência vivenciada permite criar alternativas futuras para aprimorar o projeto de inserção.

CONCLUSÃO

A liderança em ciências é formada a partir de uma complexa relação entre educação básica e investimentos na pesquisa. Cursos de PPG-Medicina III seguem na vanguarda com iniciativas focadas no desenvolvimento científico e tecnológico. Assim, projetos envolvendo alunos da educação básica representam modelo e ambiente promotor de líderes.

Effects of immobilization stress on kidneys of Wistar male rats: a morphometrical and stereological analysis

This paper verifies the morphological changes induced by immobilization stress on the kidney of rats by using stereological methods. Fifteen 4-week-old Wistar male rats were randomly assigned to control (n = 7) and stressed (n = 8) groups. Stress stimuli were performed over 5 weeks by immobilization of the rats for 2 h daily in a rigid opaque plastic cylinder that restrained their movements. Increases in the adrenal mass index (p < 0.05) and decreases in serum testosterone levels (p < 0.05) demonstrated the efficacy of the stressor stimuli. Stressed rats presented diminished body weight gain when compared to controls (p < 0.05). The mean values of kidney weight, kidney volume, kidney volume index and glomerular volume density were significantly lower in the stressed group (p < 0.05); nevertheless, no significant difference was found in the cortical/medullar ratio or in the volume-weighted mean glomerular volume. The number of glomeruli per kidney was 45% lower in the stressed group (p < 0.0001), but no change in serum creatinine levels was found. However, the morphological alterations may have serious implications predisposing individuals to renal disease and hypertension in adult life.