Conformation and anatomical relations of the liver of llama (Lama glama).

Morphological studies of the liver of the llama are structural supportive to the clinical practice, surgery and specific diagnostic techniques. The aims of this study were first to determine the location of the organ and the direction of its major axis to project it to the abdominal wall, identifying visible and palpable bony references. Secondly, to characterize and determine anatomical relations of the surfaces, borders and angles of the llama liver, as well as, of its lobulation. Twenty adult llamas of both sexes and two foetuses of 6.5- and 7-month-old were used. Llama liver is a post-diaphragmatic organ located in the cranial abdominal region, in the right hypochondrium, in relationship with the last six ribs. Dorsally, it can exceeds the last (twelfth) rib. Its major axis presents a cranio-ventral bent. Its shape is irregularly triangular. It presents two surfaces (parietal and visceral), three borders (cranial, caudal and ventral) and three angles (dorsal, cranial and caudal).

Conducto hepatopancreático de la llama / Hepatopancreatic duct of llama

La estructura de las vísceras y glándulas anexas del aparato digestivo de los camélidos sudamericanos, muestran diferencias morfológicas con relación a otros rumiantes. Los estudios macroscópicos realizados, nos permitieron observar que en los camélidos sudamericanos la ampolla duodenal y el conducto hepatopancreático (CHP) presentan características particulares que le confieren una marcada diferencia con los bovinos domésticos, al presentar una desembocadura común de ambos conductos. Los estudios se realizaron mediante técnicas histológicas de rutina y por medio de histoquímica de lectinas. El conducto biliar se une al pancreático a unos 3 cm del duodeno, formando el CHP que desemboca sobre el duodeno en el pliegue duodenal, bien visible, con dirección caudal a favor del tránsito intestinal, recorriendo 2 cm por dentro de la mucosa intestinal. Presenta un orificio terminal en forma de bisel, ubicado a unos 40 cm del píloro. No se observa conducto pancreático accesorio. El CHP se halla tapizado por epitelio cilíndroco simple, sin células caliciformes. Sobre el pliegue duodenal se observa mayor desarrollo glandular, aumentando su espesor. El epitelio cilíndrico es más alto, más acidófilo y se invagina formando glándulas rodeadas de tejido conectivo. Las glándulas son tubulares con células acidófilas y basófilas, ricas en mucopolisacáridos. Para caracterizar los glicoconjugados, se utilizó una batería de siete lectinas (con A, UEA-1, SBA, DBA, PNA, RCA-1, WGA). En las células epiteliales de la mucosa, los glucoconjugados más destacados presentes son la N-acetilglucosamina y N-acetilgalactosamina dado que dieron marcada reactividad con las lectinas WGA y SBA. La N-acetilglucosamina y N-acetilgalactosamina son aminoazúcares que suelen encontrarse como carbohidratos estructurales. En las glándulas de la mucosa del CHP se observó que las células presentan N-acetilgalactosamina y en menor proporción N-glucosamina

Evaluation of the intraperitoneal route for the transfusion of erythrocytes using rats and dogs

Se evaluó la transfusión intraperitoneal en ratas y perros con vía alternativa para la reposición de sangre. Se inyectaron eritrocitos marcados con 59Fe a 5 perros en un volumen equivalente al 50% de la masa eritrocitaria teórica de los animales. Otros 3 perros y 12 ratas fueron inyectados con volúmenes de eritrocitos proporcionales al 9% del volumen globular de los animales. La máxima incorporación de eritrocitos a la circulación sanguínea de las ratas fue de 96ñ7% a las 48h. El T 1/2 de sobrevida de las células fue de 29 días. La máxima actividad promedio en todos los perros fue de 91.2ñ6% a las 96 h post-transfusión. Se verificó destrucción al azar de los eritrocitos y el tiempo medio de sobrevida se estimó en 66 días. La transfusión se efectuó en unos 15 segundos en las ratas y entre 2 y 4 minutos en los perros. En la necropsia se observaron reacciones serosas mínimas. El procedimiento es recomendable por su rapidez, seguridad y sencillez

Evaluation of the intraperitoneal route for the transfusion of erythrocytes using rats and dogs.

The intraperitoneal transfusion of red cells in rats and dogs was evaluated as an alternative route for blood restoration. Erythrocytes labeled with 59Fe, equivalent to about 50% of the estimated total red cell volume, were injected in the abdominal cavity of 5 dogs. Three other dogs and 12 rats were injected with a volume proportional to the 9%. The maximal incorporation of tagged red cells in the circulation of the rats was of 96 +/- 7% at 48 h. One half of the erythrocytes disappeared from the circulation 29 days later. Computing data from all dogs, the mean highest value, 91.2 +/- 6%, was reached at 96 h and although random destruction of the cells occurred, the estimated T1/2 of survival was about 66 days. The injection was completed in about 15 seconds in the rats and in 2 to 4 minutes in the dogs. At the necropsy only minor serosal reactions were observed in the peritoneal cavity of the animals. Intraperitoneal transfusion can be recommended as a rapid, safe and efficient procedure for blood supply.

Alignment and intracytoplasmic disintegration of synaptic vesicles in the brain cortex.

Perfusion fixation with highly concentrated aldehydes suggests that the synaptic vesicles undergo disintegration within the presynaptic ending upon touching the presynaptic membrane rather than being released by exocytosis into the intersynaptic cleft. Three factors have been explored in order to inquire further into the possible significance of the findings: (a) fixative concentration; (b) physiological activity; (c) cell depolarization. The transformation of the vesicles into amorphous, electron-dense material was observed in all experiments in all synapses, including those fixed with the lowest concentration of aldehydes. Besides, after acute ischemia and perfusion of excitatory and depolarizing pharmacological agents, the synaptic vesicles were seen to conflue upon the intersynaptic cleft in well-aligned rows. It was also found that the vesicles flow post mortem towards the intersynaptic cleft with absolute specificity.

Synaptic vesicle relationships with the presynaptic membrane as shown by a new method of fast chemical fixation.

Brief vascular perfusion of the rat brain with a mixture of concentrated aldehydes completely insolubilized the brain protein in less than 30 s and yielded excellent ultrastructural preservation. Abundant synaptic vesicles closely and specifically attached to the presynaptic membrane were constantly detected. These vesicles appeared to undergo progressive transformation into amorphous, electron-dense material. No evidence of vesicle exocytosis was detected in the brains perfused in vivo but fixations performed 1 h after death showed abundant exocytotic-like images. The results suggest that the vesicles may not be exocytotically released to the intersynaptic cleft but disintegrate intracytoplasmically in the immediate vicinity of the presynaptic membrane.