The Heart of the Killer Whale: Description of a Plastinated Specimen and Review of the Available Literature

Simple Summary

The killer whale (Orcinus orca, Linnaeus, 1958) is an odontocete and is the largest member of the family Delphinidae. Free-ranging animals are capable of considerable physical efforts, either as acute bursts or sustained speeds during foraging, diving or protracted long-distance migrations. In this article, the morphology of a plastinated heart of a killer whale and functional adaptations of the gross anatomy in the context of a variety of physiologic demands is evaluated. The four chambers, their content, respective openings and communicating passages are defined based on a specimen used for plastination and thus available for extended and detailed anatomic studies.

Abstract

The killer whale (Orcinus orca, Linnaeus, 1958) is the largest extant delphinid. Despite its worldwide distribution in the wild and in dolphinariums, its anatomy remains relatively poorly described. In the present study, we describe the detailed morphology of a plastinated killer whale heart. The gross description of the arteries and veins reaching the organ and its coronary vessels are reported. Additional endoscopy and CT (computed tomography) scanning were performed to provide extensive measurements of its parts. In many aspects, the killer whale heart conformed to other delphinid heart descriptions, including position, relative size and shape and specific features such as extensive papillary muscles, trabecular endocardium and trabecula septomarginalis. These characteristics are representative of the delphinid family, suggesting that its functions and capacities are similar to that of other, smaller, dolphins and help understand the conditions in which these predators exert their remarkable physical performance necessary for their survival.

Effect of the manipulation of the duodenal papilla during double balloon enteroscopy

AIM: To determine the hypothesis that inflating the balloons in the duodenal papilla determines changes in the biochemical markers of pancreatitis.

METHODS: Four groups of pigs were used: Group papilla (GP), the overtube’s balloon was inflated in the area of the papilla; GP + double balloon enteroscopy (GP + DBE), the overtube’s balloon was kept inflated in the area of the papilla for 20 min before a DBE; Group DBE (GDBE), DBE was carried out after insuring the balloon’s inflation far from the pancreatic papilla; and Group control (GC). Serum concentrations of amylase, lipase and C-reactive protein (CRP) were evaluated. Pancreases were processed for histopathology examination.

RESULTS: Main changes occurred 24 h after the procedure compared with baseline levels. Amylase levels increased significantly in GP (59.2% higher) and were moderately higher in groups GP + DBE and GDBE (22.7% and 20%, respectively). Lipase increased in GP and GP + DBE, whereas it hardly changed in GDBE and in GC. CRP increased significantly in GP, GP + DBE and GDBE, while no changes were reported for GC. No statistically significant difference between groups GP and GP + DBE was found for the histopathological findings, except for vacuolization and necrosis of the pancreatic parenchyma that was higher in GP than in GP + DBE.

CONCLUSION: The manipulation of the duodenal papilla by the inflated overtube’s balloon during DBE causes pancreatic structural damage and increased biochemical markers associated with pancreatitis.

Effect of double-balloon enteroscopy on pancreas: an experimental porcine model

AIM

To evaluate the effect of double-balloon enteroscopy (DBE) on pancreas histology and levels of pancreatic enzymes.

METHODS

Conventional upper gastrointestinal endoscopy was performed on five control pigs. Oral DBE was performed with an EN-450T5 enteroscope on 20 pigs. Two experimental groups (10 pigs each) were defined according to DBE duration: 90 min for Group 1 and 140 min for group 2. During oral insertion, the balloons were not inflated in the descending part of the duodenum to avoid the minor duodenal papilla. Serum amylase, lipase and C-reactive protein (CRP) levels were monitored before the procedure and repeated every 30 min until the exploration was finished, as well as 24 h and 7 d after. After the procedure and for a total of 7 d, the pigs were observed twice a day for signs of decreased activity, irritability, vomiting or anorexia. Gross and microscopic examination of the pancreas was performed on day 7.

RESULTS

All animals tolerated DBE without clinical manifestations of acute pancreatitis. Experimental groups had higher levels of enzymes than the control group at 24 h. Throughout the exploration, the amylase levels increased significantly above the baseline 24 h after DBE, although the increase was not statistically significant and did not reach 20% of the baseline. An increase in lipase and CRP was observed at 24 h after the procedure, although by day 7, all enzymatic levels had returned to baseline. No differences between groups 1 and 2 were found for any enzyme and sampling site during and after the procedure. Similarly, no correlation between insertion depth and enzyme levels was observed. Direct in situ and post-removal inspection of the pancreas did not show any evidence of fluid collection, abscesses or hemorrhage. Histological examination of the pancreas from groups 1 and 2 revealed the existence of focal areas (0.14-0.26 mm2) of ischemic necrosis in 47.4% of the animals. In the pigs with damaged pancreas, the left lobe (tail) was always affected. However, this only happened in 83.3% of the samples from the right lobe (head) and in 33.3% of the samples from the body of the pancreas. Significant differences were found between the left lobe (tail) and the body for the percentage of affected pancreas. Both the size of the lesions and the percentage of affected pancreas were higher in the left pancreatic lobe (tail). The presence of the lesions was not related to the exploration length.

CONCLUSION

The increase in pancreatic enzymes after DBE could be related to focal points of pancreatic ischemic necrosis due to mechanical stress.

Evaluation of wedged arterial injection as a new technique for delivery of experimental therapeutic substances into the porcine pancreas

OBJECTIVES

To prospectively evaluate the technical feasibility and efficacy of wedged arterial injection (WAI) as a potential route for experimental selective therapy to the pancreas of healthy pigs.

MATERIALS AND METHODS

Selective angiographies were completed in ten pigs under general anaesthesia. By superselective angiography, the catheter was inserted and wedged into the major pancreatic artery, blocking the blood flow. In order to evaluate the efficacy of the WAI method, a DNA-specific fluorescent dye (Hoechst 33258) was used.

RESULTS

Histological study revealed a uniform distribution of the fluorescent dye within the nuclei of the endocrine and exocrine pancreatic cells. Pancreatic and liver enzymes as well as histopathology of the pancreas were normal.

CONCLUSION

WAI is a highly effective minimally invasive methodology to target the porcine pancreas. The findings suggest that WAI may contribute to developing preclinical assays of pancreas gene or cell-transfer therapies in swine model.

How useful is plastination in learning anatomy?

In recent years plastination has begun to revolutionize the way in which human and veterinary gross anatomy can be presented to students. The study reported here assessed the efficacy of plastinated organs as teaching resources in an innovative anatomy teaching/learning system. The main objective was to evaluate whether the use of plastinated organs improves the quality of teaching and learning of anatomy. For this purpose, we used an interdepartmental approach involving the departments of Veterinary Anatomy, Human Anatomy, Veterinary Surgery, and Education Development and Research Methods. The knowledge base of control and experimental student groups was examined before and after use of the fixed or plastinated resources, respectively, to gather information evaluating the effectiveness of these teaching resources. Significant differences (p < 0.001) between control and experimental groups of Human and Veterinary Anatomy were observed in the post-test results. The Veterinary Surgery students had the most positive opinion of the use of plastinated specimens. Using these data, we were able to quantitatively characterize the use of plastinated specimens as anatomy teaching resources. This analysis showed that all the plastinated resources available were heavily used and deemed useful by students. Although the properties of plastinated specimens accommodate student needs at various levels, traditional material should be used in conjunction with plastinated resources.