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.

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

ABSTRACT 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.

Simple and low cost tridimensional model of the cerebral hemisphere / Modelo tridimensional básico y de bajo costo del hemisferio cerebral

Handmade anatomy models may be a complementary useful tool to dissection and prosection, since the student interacts with the body structure in a three-dimensional way. In this study homemade dough (biscuit) was used to create a brain model. Two anatomy trainees from the medical school of the Universidade Federal Fluminense (Niteroi Brazil) were challenged to model the gross anatomy of the lateral aspect of the brain. They prepared and handled homemade dough to produce a simple and low cost model of the cerebral hemisphere. Styrofoam balls fixed by pins were used to create a framework, and dough rolls were modeled in order to create the brain sulci and gyri. At the end, the model closely resembled three-dimensional features of the human brain. Also, brain lobes were easily identified, as well as some major gyri and sulci, such as the central and lateral sulci and the precentral and postcentral gyri. In conclusion, the three-dimensional spatial characteristics, the clear identification of sulci and gyri and the brain lobes, make this model a good tool for students who only require basic anatomy in their curriculum.

Los modelos de anatomía elaborados a mano pueden ser una herramienta útil y complementaria a la disección y la prosección, debido a que el alumno interactúa con la estructura del cuerpo de manera tridimensional. En este estudio se utilizó una masa casera (bizcocho) para crear un modelo cerebral. Dos estudiantes de anatomía de la Facultad de Medicina de la Universidade Federal Fluminense (Niteroi, Brasil) fueron desafiados a modelar la anatomía macroscópica de la cara lateral del cerebro. Prepararon y manejaron masa casera para producir un modelo simple y de bajo costo del hemisferio cerebral. Bolas de espuma de poliestireno fijado por alfileres se utilizaron para crear un marco, y los rollos de masa fueron modelados con el fin de crear los surcos cerebrales y giros. Al final, el modelo resultó ser muy semejante a las características tridimensionales del cerebro humano. Además, los lóbulos cerebrales fueron fácilmente identificados, así como algunos giros y surcos mayores, tales como el surco central y lateral y el giro precentral y postcentral. En conclusión, las características espaciales tridimensionales, la identificación clara de los surcos y giros y los lóbulos cerebrales, hacen de este modelo una buena herramienta para los estudiantes que sólo requieren anatomía básica en su plan de estudios.

The relationship between renal warm ischemia time and glomerular loss. An experimental study in a pig model

Abstract Purpose: To investigate the glomerular number after different warm ischemia times. Methods: Thirty two pigs were assigned into four groups. Three groups (G10, G20, and G30) were treated with 10, 20, and 30 minutes of left renal warm ischemia. The sham group underwent the same surgery without renal ischemia. The animals were euthanized after 3 weeks, and the kidneys were collected. Right kidneys were used as controls. The kidney weight, volume, cortical-medullar ratio, glomerular volumetric density, volume-weighted mean glomerular volume, and the total number of glomeruli per kidney were obtained. Serum creatinine levels were assessed pre and postoperatively. Results: Serum creatinine levels did not differ among the groups. All parameters were similar for the sham, G10, and G20 groups upon comparison of the right and left organs. The G30 group pigs' left kidneys had lower weight, volume, and cortical-medullar ratio and 24.6% less glomeruli compared to the right kidney. A negative correlation was found between warm ischemia time and glomerular number. Conclusions: About one quarter of glomeruli was lost after 30 minutes of renal warm ischemia. No glomeruli loss was detected before 20 minutes of warm ischemia. However, progressive glomerular loss was associated with increasing warm ischemia time.

Glomerular loss after arteriovenous and arterial clamping for renal warm ischemia in a swine model

ABSTRACT PURPOSE: To evaluate the glomerular loss after arteriovenous or arterial warm ischemia in a swine model. METHODS: Twenty four pigs were divided into Group Sham (submitted to all surgical steps except the renal ischemia), Group AV (submitted to 30 minutes of warm ischemia by arteriovenous clamping of left kidney vessels), and Group A (submitted to 30 minutes of ischemia by arterial clamping). Right kidneys were used as controls. Weigh, volume, cortical volume, glomerular volumetric density (Vv[Glom]), volume-weighted glomerular volume (VWGV), and the total number of glomeruli were measured for each organ. RESULTS: Group AV showed a 24.5% reduction in its left kidney Vv[Glom] and a 25.4% reduction in the VWGV, when compared to the right kidney. Reductions were also observed when compared to kidneys of sham group. There was a reduction of 19.2% in the total number of glomeruli in AV kidneys. No difference was observed in any parameters analyzed on the left kidneys from group A. CONCLUSIONS: Renal warm ischemia of 30 minutes by arterial clamping did not caused significant glomerular damage, but arteriovenous clamping caused significant glomerular loss in a swine model. Clamping only the renal artery should be considered to minimize renal injury after partial nephrectomies.

Pneumoperitoneum induces morphological alterations in the rat testicle

PURPOSE:To investigate the seminiferous tubule histological morphology after an 8 mmHg pneumoperitoneum in the rat model. METHODS: Fourteen rats were divided into two groups: a Sham group submitted to anesthesia and a pneumoperitoneum (Pp) group submitted to abdominal insufflation at 8 mmHg during three hours, followed by desuflation. All rats were killed after six weeks, testicles were collected and evaluated for the tubule diameter, germinative epithelium height and Johnsen´s score. Means were compared by using the Student's-t-test. RESULTS:The seminiferous tubule diameter was diminished by 11.3% in the group submitted to pneumoperitoneum (p<0.05). No significant difference was found among the groups when analyzing the epithelium height and Johnsen´s score. CONCLUSION:In the rat model, the seminiferous tubules present structural alterations when subjected to pneumoperitoneum of 8 mmHg during three hours.

Sinusoidal Constriction and Vascular Hypertrophy in the Diabetes-Induced Rabbit Penis

Objective To assess the morphological changes of penile vascular structures and the corpus cavernosum area in alloxan-induced diabetic rabbits. Materials and Methods Twenty male rabbits (2 months old) were divided into two groups with 10 rabbits each, the control group (CG) and the diabetic group (DG). The animals from DG received an intravenous injection of alloxan (100mg/kg) to induce the diabetes. Ten weeks after the induction of diabetes, all animals were euthanized. Two fragments of the penile shaft were harvested and samples were processed and paraffin embedded. Sections (5µm) were cut and stained for histological and immunohistochemical markers. Results Nuclear protrusion toward the lumen, and cytoplasmic vacuolization were observed in the tunica intima of the dorsal artery of the penis in DG. The thicknesses of the tunica media increased significantly in DG (p = 0.0350). It was also observed a significant increase in the area of the tunica media (p = 0.0179). There was no significant change in smooth muscle cell density in the tunica media of the dorsal artery of the penis (p = 0.0855). The collagen fiber pattern of the tunica adventitia of the dorsal artery of the penis was different between the control and diabetic groups. There was a significant decrease in the area occupied by the cavernous sinuses in DG (p = 0.0013). Conclusion Alloxan-induced diabetes mellitus in rabbits promotes important changes in penile vascular structures, thereby decreasing blood supply and affecting penile hemodynamics, leading to erectile dysfunction. .