Estudio Anatómico Comparado de las Arterias de la Base del Encéfalo del Pudú pudu (Molina, 1782) y del Bovino

A comparison using the corrosion method was made between Pudú pudu (Molina, 1782) ventral brain arteries and those of the cow. The Pudú's Rete mirabile epidurale rostrale (Nomina Anatomica Veterinaria, 1994) is ventrally formed by branches of the A. maxillaris, and caudally formed by the A. vertebralis. The Hypophysis is surrounded by the Rete mirabile rostrale. The lateral parts are rostrally joined to that gland by a thin vascular bridge and caudally by thick arteries. The Pudú's Circulus arteriosus cerebri is asymmetrical, that is, on the right side the A. cerebri rostralis ends in the A. cerebri media. The left-side A. cerebri rostralis irrigates every rostral portion of the encephalon. In the cow, practically the same arteries come out of the Circulus arteriosus cerebri, which is not asymmetrical. The A. cerebri caudalis comes first out of the A. communicans caudalis and then the branches for the Pons, and finally the A. cerebelli rostralis. In this species, there are arterial blocks that are not present in Pudú.     

Evolución morfológica en el epitelio seminífero del Cerdo en diferentes edades (Sus scrofa de la raza Landrace)*

The morphological development of the seminiferous epithelium in the pig at different ages ( Sus scrofa , Landrace breed)
In the Pig, Landrace breed, were observed, at different ages, among 15 to 210–220 days, the morphological patterns of the seminiferous epithelium that lines "cordonal" tubules at 15 to 30 days of postnatal and "luminal" tubules at 120 to 210–220 days of age. Although some morphological events of cellular differentiation were observed at 120 days, and the spermatogenesis process apparently could be observed at 180–190 days, really the overall characteristics of the cellular differentiation in the seminiferous epithelium, with the presence of luminal spermatozoa, were observed at 210–220 days of age. This last stage is considered as the puberal age.     

Cronología de Osificación Postnatal de las Articulaciones del Hombro y Codo en el Gato Siamés (Felts catus L.)

Chronology of the postnatal ossification of the shoulder and cubit joints of the Siam cat (Felts catus L.) A study was done by radiological techniques to show the chronology of ossification of the shoulder and cubit joints in the Siam cat, from birth up to the 25th week of postnatal development. For this experiment we used 40 little cats (19 males and 21 females) belonging to 11 litters subjected to different controls: pattern race, healthy, feeding, growing up and radioactivity. The time of the appearance and the evolution of the ossification centers is determined as well as the phenomenon of fusion during this time. The postnatal ossification from both joints of the Siam cat is compared with that of the common cat.     

Observaciones en el punto de unión neuroectodermo-ectodermo no neural en embriones de pollo en neurulación tratados con citocalasina B ≪in ovo≫

Observations in the point of union of the neuroectoderm with the nonneural ectoderm in chick embryos after treatment "in ovo" with cytochalasin B during neurulation
Treatment of "in ovo" chick embryos with cytochalasin B during neurulation resulted in the failure of formation of the neural folds, producing an alteration in the point of union of the neuroectoderm with the nonneural ectoderm in its final development. This alteration consisted in the appearance of folding and superposition of both epithelia in this zone. The results support a possible role of the apical microfilaments in neuroectoderm and nonneural ectoderm in the process of neurulation.     

Involución de Germenes Dentarios en la Oveja (Ovis aries)

In this study we examined some histologic and histochemical characteristics of the embryonic sheep dental epithelium in early odontogenesis. During the first trimester of development, a short-lived dental lamina was observed. Apparently in the sheep, the interactions between epithelial and ectomesenchymal cells required for tooth normal morphogenesis are altered.     

Cronología de Osificación Postnatal del Autópodo Torócico en el Gato Siamés (Felis catus L.)*

Chronology of the postnatal ossification of the Thoracic autopodo in the Siam cat (Felis catus L.) A study was done by radiological techniques to show the chronology of ossification of the thoracic autopodo of the Siam cat from birth up to the 25th week of postnatal development. For this experiment we used 40 little cats (19 males and 21 females) belonging to 11 litters subjected to different controls: pattern race, healthy, feeding, grow up and radioactivity. The time of the appearance and evolution of the centres that form the basipodo, metapodo and acropodo of the thoracic limb is determined. Likewise it is analized the phenomenon of fusion during that time to define the main ossification sequence in the carpo. The aspects of the postnatal ossification of the thoracic autopodo in the Siam cat are compared with the literature of differents authors about the common cat.     

Correlación Anatomo-radiológica de la Cabeza en la Cabra de Raza Canaria (Capra hircus L.)

A radiologic and tomographic study was made of the cranioencephalic topography of canary goats of medium weight and size. In a first step, the exocranialis references corresponding to an axis designed at the level of the meatus acusticus externus and parallel to the basicranial axis were anatomically and radiologically defined. Conventional stereotaxic techniques were then used to reach the standard position of the head in order to obtain macroscopical cross sections at different levels perpendicular to the base of the cranium. In a second step, a tomographic study was made to confirm the design of the axis.     

InducciÓn Experimental á Malformaciones por Instilacion de Etanol en Huevos Embrionados de Polio (Gallus gallus)

The teratogenic effect of alcohol on chick embryos has been confirmed by many investigators. However, how this occurs is unknown. The aim of this study was to establish a teratogenic pattern of alcohol effects, on the first stages of development in avians. Fertilized eggs were infused through the air space of the shell on day 0, with ethanol in concentrations of 20%, 40% and 60%. The control group was infused with 0.1 ml of NaCl at 0.9%. At a second stage, the eggs were treated on the 4th day of incubation, using the same method. In both groups the eggs were removed on the 11th day of incubation. The teratological manifestations that appeared more frequently were evisceration, haemorrhagic embryos, oedema, cranial deformities, lack of eyes, and umbilical hernia, showing every embryo a clear reduction in size and body weight.     

Mecanismos de Desarrollo de la Cúpula en los Conductos Semicirculares de las Aves: I. Secreción Celular

A study of the crista ampullaris of the vestibular apparatus was carried out in chicken embryos. The study group included embryos between stages 24 and 39 of Hamburger-Hamilton. This study elucidates the relationship of the cupula with respect to the epithelium of the crista ampullaris. With electron microscopic examination, the rough endoplasmic reticulum of the crista epithelial sustentacular cells at developmental stage of 31 H-H, demonstrated dilatations containing secretory material. Vesicles, with adhering ribosomes appear to be formed from these dilatations. At later stages of development, the vesicular material took on the characteristics of the fibrillary material composing the cupula. In some cells, secretory vesicles are seen near the apical border of these cells, where they apparently secrete vesicular contents into the endolymphatic space, contributing to the formation of the cupula.     

Paracooperia horaki n. sp. (Nematoda: Trichostrongylidae) from the nyala Tragelaphus angasi Gray, 1849

A new species of Paracooperia Travassos, 1935 was found in small numbers in the small intestines of 36 out of 68 nyala Tragelaphus angasi Gray 1849 in the Mkuzi, Ndumu and Umfolozi Game Reserves, Natal. The worms, for which the name Paracooperia horaki is proposed, can be differentiated from the closely related Paracooperia devossi Boomker & Kingsley, 1984 by the absence of ridges on 1 of the branches of the spicules, the slightly longer branches of the tips of the dorsal ray and the large hemispheric knobs on the ends of the spicules. Furthermore, the branch of the spicules that bears the hook-like process is about two thirds the length of the spicule in P. devossi and almost the entire length of the spicule in P. horaki. The ovigerous females of P. horaki have 2 or 3 expanded ridges in front of the vulva that form vulvar flaps. The females without eggs resemble those of P. devossi and have only a single vulvar flap.     

Etude en microscopie optique des poils (Pili) dela faune pyrénéene sauvage en vue de leur détermination

This study presents certain data on the hairs of forty species of pyrenean mammals in order to recognize them in the faeces of wild carnivores. Six orders have been considered, in which there are 37 wild species and 3 domestic ones. Samples were taken from the skin of Regio dorsocostalis, on adult animals, and examined by optic microscopy. Different kinds of hairs and their constitutive parts were measured and observed, and a classification established in accordance with previous works. New Nomina Anatomica are proposed. Specific diagnosis of hairs is more or less easy according to the group to which they belong.     

Consideraciones Anatomofuncionales de una Aponeurosis Radiocarpiana Caudal en Tigre, Leon y Gato Domestico (Panthera tigris, Panthera leo y Felis catus)

This study describes a strong aponeurosis on the caudal surface of the antebrachium, between the Mm. Flexoris and the M. pronator quadratus. This aponeurosis has not been experimentally validated. By dissection and macroscopic examination of formaldehyde-prepared material, and experimental surgical tran-section of the structure in F. catus, the aponeurosis is described and its functional capacity is determined. The origin of the aponeurosis is the Facies caudalis, Margo medialis of the Radius and distal Ulna and inserts on the Crista transversa of the Radius and the Ligg. radiocarpeum palmare and ulno-carpeum palmare, and a strong Pars radialis. Its disposition is similar to that of the supernumerary M. anterior radialis brevis in humans. Surgical transection of the aponeurosis in F. catus resulted in hyperextension of the Manus and a decrease in the Carpus in its weight-bearing ability. These findings indicate the anatomico-functional importance of the aponeurosis in providing support to the claws.