The aim of this study was to describe and illustrate the morphology of the stomach, liver, intestine, and their vasculature to support the planning of surgical therapeutic methods in abdominal cavity. On adult Wistar rats corrosion casts were prepared from the arterial system and Duracryl Dental and PUR SP were used as a casting medium and was performed macroscopic anatomical dissection of the stomach, liver, and intestine was performed. The rat stomach was a large, semilunar shaped sac with composite lining. On the stomach was very marked fundus, which formed a blind sac (saccus cecus). The rat liver was divided into six lobes, but without gall bladder. Intestine of the rat was simple, but cecum had a shape as a stomach. The following variations were observed in the origin of the cranial mesenteric artery. On the corrosion cast specimens we noticed the presence of the anastomosis between middle colic artery (a. colica media) and left colic artery (a. colica sinistra). We investigated the second anastomosis between middle colic artery and left colic artery. The results of this study reveal that the functional anatomical relationship between the rat stomach, liver and intestine is important for the development of surgical research in human and veterinary medicine.

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Objectives Recently, it has been confirmed, that excess fluid and waste products from the brain are drained into the cerebrospinal fluid (CSF) and afterwards cleared via the olfactory route and/or lymphatic vessels in the brain dura and corresponding extracranial lymphatic structures. Therefore, the aim of present study was to monitor time-dependent uptake of Evans blue (EB) tracer from subarachnoid space into the meningeal lymphatic vessels and extracranial lymph nodes in rats during 3 hours-12 days. Methods EB was injected into the cisterna magna of anesthetized rats and after required survival, plasma, brain dura matter and corresponding lymph nodes (cervical, thoracic and lumbar) were dissected and processed for lymphatic vessels analyses using immunofluorescence and immunohistochemistry. Furthermore, we have used sensitive ultra-high-performance liquid chromatography (UHPLC) method for the determination of EB concentrations in selected samples. Results Using a combination of imaging methods, we have detected two different types of the vascular structures in the brain dura and in deep cervical lymph nodes. The blood vessels, which were RECA-1 + positive and the lymphatic-like vessels, expressing bright intense red fluorescence of EB tracer. Subsequently, using UHPLC with UV detection, we have quantified the EB concentration in positive structures by 3 hours up to 12 days after tracer delivery. A significant increase of EB concentration was detected in deep cervical lymph nodes already at 3 hours with a peak at 1 day that decreased to about one-tenth of its peak value by 12 days. Similar pattern was detected in brain dura. On the contrary, the brain tissue and plasma were almost negative for EB tracer during all tested time periods. Conclusion Our results demonstrate the dynamic changes of EB in meningeal lymphatic vessels and in deep cervical lymph nodes, thus recapitulating the downstream outflow of intracisternally injected tracer during 3 hours-12 days via dura mater lymphatic vessels towards corresponding extracranial draining system, particularly the deep cervical lymph nodes.

BackgroundThe laboratory rat is one of the most popular experimental models for the experimental surgery of the liver. The objective of this study was to investigate the morphometric parameters, physiological data, differences in configuration of liver lobes, biliary system, and vasculature (arteries, veins, and lymphatic vessels) of the liver in laboratory rats. In addition, this study supports the anatomic literature and identified similarities and differences with human and other mammals.Material/MethodsForty laboratory rats were dissected to prepare corrosion casts of vascular system specimens (n=20), determine the lymph vessels and lymph nodes (n=10), and for macroscopic anatomical dissection (n=10) of the rat liver. The results are listed in percentages. The anatomical nomenclature of the liver morphology, its arteries, veins, lymph nodes, and lymphatic vessels are in accordance with Nomina Anatomica Veterinaria.ResultsWe found many variations in origin, direction, and division of the arterial, venous, and lymphatic systems in rat livers, and found differences in morphometric parameters compared to results reported by other authors. The portal vein was formed by 4 tributaries in 23%, by 3 branches in 64%, and by 2 tributaries in 13%. The liver lymph was drained to the 2 different lymph nodes. The nomenclature and morphological characteristics of the rat liver vary among authors.ConclusionsOur results may be useful for the planing of experimental surgery and for cooperation with other investigation methods to help fight liver diseases in human populations.

Canine cognitive dysfunction syndrome (CCDS) is a progressive neurodegenerative disorder in senior dogs that is mainly associated with decreased ability to learn and respond to stimuli. It is commonly under-diagnosed because behavioral changes are often attributed to the natural process of aging. In the present study, we used for the first time a comprehensive approach enabling early diagnosis of canine patients with mild cognitive disorders (MiCI). We included CAnine DEmentia Scale (CADES) questionnaires, biochemical parameters, and biomarkers in blood serum, and correlated them with post-mortem histopathological changes. The CADES questionnaires enabled us to identify MiCI dogs developing changes mainly in domains corresponding to social interaction and spatial orientation, which seems to be crucial for delineating early cognitive disorders. Biochemical analyses in these dogs showed slightly elevated liver enzyme parameters (AST and ALT) and significantly decreased sodium and chloride levels in blood serum. Furthermore, we describe for the first time a significant increase of neurofilament light chain (NFL) in blood serum of MiCI dogs, compared to normal aging seniors and young controls, but no changes in TAU protein and amyloid-β (Aβ42) peptide levels. In canine brains with cognitive impairment, amyloid plaques of mainly diffuse and dense types were detected. Furthermore, activated microglia with amoeboid body and dystrophic processes occurred, in some cases with spheroidal and bulbous swellings. On the other hand, no TAU pathology or neurofibrillary tangles were detected. These results suggest that a combination of CADES questionnaire mainly with CNS injury biomarker (NFL) and with biochemical parameters (ALT, AST, Na, and Cl) in blood serum may predict CCDS in senior dogs.