Biomedical subjects

J Camón

Publications and source records attributed to J Camón.

11 recordsLinked to original sources

PubMed2001

Confocal scanning laser microscopy examination of bovine vaginal fluid at oestrus.

This article reports the study of the structural elements of bovine vaginal fluid at oestrus using a confocal scanning laser microscope (CSLM) to examine samples collected from 10 lactating cows at the time of insemination. The filamentous glycoproteins, which form the structural component of vaginal fluid, were stained with fluorophore acridine orange for 10 min. This microscopy technique permits visualization of a network of non-oriented filaments of different thickness in a three-dimensional array. This arrangement was repeated throughout the sample and was common to all samples. Interfilament spaces varied in width between cows and ranged from 1 to 20 microns. The present results provide a new, non-aggressive technique for the study of biological samples that show hydrogel-like behaviour. Due to its simplicity, the CSLM technique proposed offers the advantages of (1) providing realistic images of vaginal fluid structure, free from artifacts arising from sample preparation, and (2) the possibility of observing specimens shortly after collection. CSLM proved to be a useful tool for the examination of vaginal fluid and may also serve as a good control for artifacts associated with scanning electron microscopy procedures.

Animals↗

PubMed1997

A scanning electron microscope study of the structural component of the bovine vaginal fluid at oestrus.

The ultrastructure of the vaginal fluid of cows at oestrus was analysed by scanning electron microscopy. Samples of vaginal fluid were collected from 7 normally cycling and healthy cows, 3 to 4 years of age, in oestrus. Evaluation of the patterns of crystallization was used as a previous assessment of the quality of the samples. SEM images revealed a structure made up of non-oriented filaments constituting a network with a three-dimensional arrangement. These filaments were of different diameters and ranged between 50 and 400 nm. Mesh size, defined as the minimum distance measurement between strands, ranged between 2 to 8 microns.

Animals↗

PubMed1995

Persistent truncus arteriosus in a diprosopic newborn calf.

A newborn diprosopic female calf had a partially duplicated head with two faces each exhibiting a mouth, a snout, an anomalous incomplete mandible, two eyes and a lateral ear. A single ear with two small auditory canals was present on the midline between the two medial eyes. A type 1 persistent truncus arteriosus and hypoplasia of the thoracic portion of thymus were the most outstanding extracranial defects. In the heart, a persistent foramen secundum and a large patent foramen ovale allowed communication between the right and left atria. In the right ventricle, the small conus arteriosus was separated in part from the inflow tract by an anomalous 'septomarginal muscular septum'. An interventricular septal defect was also present. A large undivided truncus arteriosus, exhibiting a tricuspid truncal valve at its origin, arose for the most part from the conus arteriosus of the right ventricle. The truncus gave rise to the brachiocephalic trunk, the aortic arch, a small pulmonary trunk, from which the left and right pulmonary arteries emerged, and two coronary arteries. The etiology and pathogenetic mechanisms implicated in the appearance of persistent truncus arteriosus are reviewed. It is suggested that a deficit or insufficiency in the cranial neural crest may play a role in the pathogenetic mechanisms leading to the production of persistent truncus arteriosus and related defects in cephalic duplications.

Animals↗

PubMed1994

Development in vitro of rabbit embryos after freezing by two-step or ultra-rapid cooling methods.

The effects of rapid freezing by two-step and ultra-rapid cooling methods on 2-cell, 8 to 16-cell, compacted morula and early blastocyst stages of rabbit embryos were examined. Dimethylsulfoxide (DMSO, 3.5 mol/l) combined with sucrose (0.25 mol/l) was used as the freezing medium. The embryos were loaded into plastic straws with the freezing medium, held during 2.5 min and then were directly plunged into liquid nitrogen (ultra-rapid cooling) or after a time from 30 to 45 min held at -27 degrees C (two-step cooling). After rapid thawing embryo development was evaluated by in vitro developmental capacity shown by the embryos and was compared to control. All studied embryonic stages developed in vitro after two-step and ultra-rapid cooling procedures. However, higher developmental rates were obtained when the two-step cooling method was used. Using the two-step cooling method, best results were obtained at compacted morula and blastocyst stages, and no significant differences were shown when compared with control embryos at blastocyst stage. All embryonic stages to which the ultra-rapid cooling method was applied showed lower developmental rates than control. The results show that a high proportion of rabbit embryos can develop in vitro after freezing by two-step cooling method.

Animals↗

PubMed1992

Morphology of a dicephalic cat.

A detailed anatomical study of a dicephalic iniodymic monosomic cat in conjunction with the morphogenetical implications of the observed anomalies is presented. The animal exhibited two heads joined at the level of an anomalous medial exoccipital bone. Two brains and two foramina magna were present. The vertebral column was single but the cranial cervical vertebrae (C2 to C5) had doubled bodies. Cervical rachischisis with myeloschisis were associated defects. Two nasopharyngeal and oropharyngeal cavities converged caudally into a single laryngopharynx. The esophagus, larynx and trachea were single. Duplication of the tongue and hyoid apparatus was present. Palatoschisis affected both oral cavities. Hypoplasia of the anatomical structures in the medial aspects of both heads was observed. Microphthalmia was also observed in both medial eyes. Comparative aspects of the morphology, causative agents, and mechanisms and anomalous morphogenesis of anterior duplications are reviewed and discussed.

Abnormalities, Multiple↗

PubMed1991

Vascular anatomy of a dicephalic cat.

The arterial and venous systems of the neck and heads of a dicephalic iniodymic monosomic cat are described. In the arterial system, an anomalous lingual branch of the right external carotid formed a large subhyoid arch, extending to the midline between both heads, giving off branches supplying the medial aspect of both heads and terminating in two medial internal carotid arteries each for the right or left head. This vessel was considered as an anomalous supernumerary common carotid artery. In the venous system, each lingual branch of linguofacial veins united and formed an anomalous venous arch. It received rostrally a long midline vein running between both heads and connecting with the medial internal jugular system. This vein received tributaries from the left and right heads and was considered as a supernumerary jugular vein. From these observations, and those of others in the literature, it can tentatively be suggested that, in congenital cephalic duplications in domestic mammals, the arterial blood supply for the medial aspect of both heads tends to come from the lingual branch of the external carotid artery, with an unexplained prevailing contribution of the right external carotid system. Two different venous patterns have been observed. In animal especies exhibiting a hyoid venous arch, such as carnivores, a midline supernumerary external jugular vein draining at the anomalous junction between lingual veins of both heads is formed, whilst in animals lacking a constant hyoid venous arch, such as ruminants, an asymmetrical supernumerary external jugular vein draining into the right "normal" external jugular vein has been repeatedly described.

Animals↗

PubMed1990

Diprosopia in a cat.

A diprosopic cat is described. In the head, two snouts, three eyes and two pinnae were present. The mandible was single and immobile because labial skin of both upper lips and single lower lip was partly fused. Superimposition of upper and lower dental arches was impossible and the mouths remained permanently open. Two incomplete oral cavities were present and the two tongues were joined at their base. The brain was duplicated in part. In the cranium only occipital and temporal bones were normal, the basisphenoid was bifurcated and the remaining bones were duplicated. Embryological mechanisms are discussed.

Animals↗

PubMed1990

Associated multiple congenital malformations in domestic animals. Contribution of four cases.

The incidence and significance of the appearance of various associated congenital malformations in a single individual have received poor attention in veterinary medicine. In this article, the malformations exhibited by four animals pertaining to three different animal species are described, and the possible reasons for the association of these anomalies are discussed from the viewpoint of the comparative medicine. All four animals showed two or three malformations constituting unrecognized teratological syndromes, so-called one-of-a-kind syndromes, which have not previously been described, at least in these particular animal species. A pig was affected by a series of craniofacial anomalies consisting in a first arch syndrome together with an occipito-parietal meningocele. Another member of the porcine species showed holoprosencephaly with cyclopia, various defects in the left forelimb and an extensive omphalocele. A dicephalic cat with cervical rachischisis and myeloschisis and a dog exhibiting spina bifida, curled tail and atresia ani are also described.

Abnormalities, Multiple↗

PubMed1990

Ultrastructural aspects of the production of extracellular matrix components by the chick embryonic notochord in vitro.

The morphology of extracellular matrix (ECM) components and of the cell organelles, particularly the Golgi complex and its derived structures, implicated in the production of ECM in the chick embryonic notochord have been studied by transmission electron microscopy. Isolated notochordal fragments were cultured in suspension in liquid medium. Native striated collagen fibrils with a period of 540 A were observed in the perinotochordal sheath. Fine granular and filamentous materials suggestive of proteoglycans have been observed in intercellular spaces and under the basal lamina of the notochordal sheath. Golgi mature vesicles with structures resembling the previously described segment-long-spacing (SLS)-like aggregates and secretory vesicles probably containing proteoglycans or condensed collagen precursors have also been observed.

Animals↗

PubMed1985

Presence of cilia in the chick embryonic notochord.

Cilia have been observed in cells of the chick embryonic notochord in different developmental stages. The ciliated notochordal cells were present both at the center and at the periphery of the organ. A well outlined central cavity in the notochord was not observed.

Animals↗

PubMedDate not supplied

A structural study of the bovine vaginal fluid at estrus.

The present study describes the structural components of the bovine vaginal fluid at estrus by scanning electron microscopy (SEM) following critical point- and freeze-drying preparation procedures. Confocal scanning laser microscopy (CLSM) was also used to evaluate the structural integrity of samples, and a control sample was assessed by adding sperm to the vaginal fluid. Samples were collected from 10 cows at the time of artificial insemination, prepared for SEM by using critical point- and freeze-drying procedures, gold coated, and observed by SEM. Mesh size and filament thickness were measured with an image analyzer. Of the 10 samples processed, 4 were considered altered following critical point drying. Compaction and lack of filaments were observed in these samples. A small area of one sample showed a honey comb-like structure when freeze drying was used. Nonoriented filaments with different thicknesses and with a network-like structure were observed throughout the remainder of the samples. Filaments throughout all samples were also observed by CSLM. After critical point drying, the mesh area ranged from 0.8 to 101.4 microns 2; the minor axis from 0.7 to 10.8 microns; and filament thickness from 40 to 442 nm. Using freeze drying, the mesh area ranged from 0.9 to 493.8 microns 2; the minor axis from 0.7 to 27.5 microns; and filament thickness from 40 to 800 nm. When samples were freeze dried, mesh values were similar to the interstrand channels observed by CSLM. In sperm-vaginal fluid samples, following critical point- or freeze-drying procedures, spermatozoa were oriented randomly in the vaginal fluid and did not seem to alter filamentous structure. Our data suggest that the freeze-drying procedure better preserves the true structural dimensions of the vaginal fluid. Furthermore, the filamentous structure of the vaginal fluid does not appear to impede sperm transport.

Animals↗