Fig 9 - uploaded by Anthony Whyte
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Coronal CT scan of a pig head. The mastoid air cell system (straight arrow) is seen to lie medial to the temporomandibular joint and inferior to the tympanic cavity (curved arrow).
Source publication
This study was undertaken to develop a functional model of otitis media with effusion (OME) in the pig (Susscrofa), with the purpose of investigating the origin of lymphocytes populating the middle ear during the course of an inflammatory process. The relevance of the model to the human condition of OME is to a large extent dependent on the anatomi...
Context in source publication
Context 1
... contrast to the human, the air cell system of the pig was found lying inferiorly rather than posteriorly to the tympanic cavity (Fig. 9). There was no aditus ad antrum or antrum seen in any of the pigs examined. The floor of the tympanic cavity was cribiform in appearance and the air cells were positioned inferior to this, lying within the plexiform bone of the tympanic bulla (Fig. 1). A variable number of interconnecting air cells were found within the tympanic bulla. ...
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Citations
... We found that 16/18 pigs showed 1 or more ruptured ear drums, despite the substantially reduced total pressure achieved and the slowed recompression rate as the cycles progressed. Unfortunately, we are still unable to conclude whether the rupture is occurring during decompression or recompression, but it seems that the ear drums of pigs are particularly susceptible to barotrauma, since these pressure changes (and the normal LAPS cycle) would not cause ear drum rupture in humans, and when damage does occur, it is usually related to recompression (Mirza and Richardson, 2005;Pracy et al 1998;Richmond et al 1989). We also note that the use of cadavers rather than live pigs may have affected the results due to lack of muscle tone affecting the tension and therefore function of the Eustachian tube, compromising the ability of the ear to equalise. ...
Defra Science and Research Projects - Final Report MH0154
Pigs are commonly rendered unconscious (stunned) with carbon dioxide gas before slaughter, but this practice gives rise to important welfare concerns because it induces breathlessness and above certain concentrations, pain. Induction of unconsciousness by hypoxia (lack of oxygen) is considered to be more humane, and experiments indicate that pigs do not find it aversive. However, achieving this sort of stun with inert gases such as argon and nitrogen is technically problematic and is considered to be too expensive for commercial use. Low Atmospheric Pressure Stunning (LAPS) is a possible alternative, whereby animals are rendered unconscious by gradually reducing air pressure and therefore oxygen availability to achieve a progressive hypoxia. This is called hypobaric hypoxia and is equivalent to rapidly ascending to high altitude, which is reported as not unpleasant or painful to humans. LAPS has been developed for commercial use to stun poultry and it has been shown to be as humane as immersion in inert gases. The aim of this project is to systematically investigate the feasibility of developing LAPS as a humane, reliable and efficient method of stunning for commercial pigs. Initially, we will conduct experiments to determine suitable and effective decompression rates for pigs, aiming to achieve a commercially feasible cycle time, while attempting to minimise welfare compromise. If effective curves are identified, extensive behavioural and physiological welfare assessments during LAPS will then be carried out. We will determine the time to loss of consciousness during LAPS and specifically look for signs of pain, anxiety and aversion to the process. The responses of pigs undergoing LAPS will be compared to pigs exposed to carbon dioxide in the same way as current commercial practice, to evaluate if LAPS is demonstrably more humane. Pathological assessments will also be conducted to check for signs of organ damage. For LAPS to be an economically feasible alternative to current practice there should be no compromise to meat quality and little impact on current slaughter line productivity (i.e. throughput rates). Therefore meat quality parameters will be measured and an economic feasibility analysis conducted to assess commercial viability. Encouragingly, the nature of LAPS systems would allow group stunning and minimal stressful handling similar to that currently used. It may be that LAPS is not a suitable method for the stunning of pigs, either because it is associated with unexpected and/or unavoidable welfare costs or because it cannot be achieved humanely in a cycle time that is suitable for application to commercial slaughter – in anticipation of this, we have built into our project key decision points where our steering group, including stakeholders and funders, will carefully consider if the work should continue.
... Pigs have considerable physiological and anatomical similarities with humans, leading to the increasing importance of porcine-specific reproductive biotechnology in human regenerative medicine (Pracy et al., 1998;Swindle et al., 2012). Despite the similarities, however, porcine ovarian follicle research remains underdeveloped and no culture system has been established. ...
This study aimed to develop a novel culture system for porcine ovarian follicles that yields developmentally competent oocytes. We mechanically isolated ovarian follicles of various sizes 325–500 mm and treated them with ovine follicle stimulating hormone OFSH at different concentrations 0–400 mIU. Follicle diameter, antrum formation and cumulus oocyte complex COC recovery rate were significantly higher p andlt; 0.05 under the 0 and 50 mIU OFSH treatments compared with the remaining concentrations 100, 200 and 400 mIU. Additionally, follicles cultured for 3 and 4 d differed significantly p andlt; 0.05 in follicle diameter, antrum formation rate and COC recovery from those cultured for 5 and 6 d. Follicle characteristics did not differ across diameter: those at 250–300, 301–400 and 401–500 mm in vitro had antrum formation rates of 90%, 92% and 90%, along with COC recovery of 78%, 82% and 85%, respectively. Furthermore, nuclear maturation percentages for oocytes that experienced germinal vesicle breakdown (GVBD) were 10%, 13% and 14%, depending on the size of the originating follicle (250–300, 301–400 and 401–500 mm). Nuclear maturation for metaphase II (MII) oocytes derived from follicles of those three sizes were 1%, 2% and 1%, respectively. After 3 d of culture, the 250–300 mm group differed significantly from other size groups in follicle diameter and COC recovery. This study provides insight into establishing effective protocols of ovarian follicle culture, thus improving efforts to preserve large-mammal fertility.
... However, the small sizes of the middle ear, ET, and nasal cavity have limited the application of small animal experimental models of ET. Pracy reported that the pig ET and middle ear are very similar to those in humans, being approximately the same size and following a more or less identical development course in both species (Pracy et al., 1998). Recently, a sheep cadaver model has been used successfully for endoscopic implantation of a stent from the pharyngeal orifice (Miller et al., 2014), indicating that large animal models would be more suitable for ET studies than the small animals mentioned above. ...
... As reported by Pracy, the gross anatomy of the middle ear of the pig is very similar to that of humans, although there are a number of minor differences that are anatomically important (Pracy et al., 1998). The two main differences related to our research were in the mastoid and handle of malleus. ...
... During removal of the osseous external auditory canal and tympanic membrane, we were able to retain the ossicular chain, chorda tympani nerve, and facial nerve in all cases (Fig. 1A). Interestingly, the handle of malleus had a different orientation to that in humans: that is, it was inclined downward, medially, and anteriorly in pigs, in contrast to downward, medially, and slightly posteriorly in humans (Pracy et al., 1998). Therefore, in all structures of the middle ear cavity in the miniature pig, the handle of malleus serves as a reliable landmark for locating the tympanic orifice (Fig. 1B). ...
This study was performed to investigate whether miniature pigs are a suitable animal model for studies of the Eustachian tube (ET). Sixteen Chinese experimental miniature pigs were used in this investigation. Ten animals were used for anatomical and morphometric analyses to obtain qualitative and quantitative information regarding the ET. Three animals were used for histological analysis to determine the fine structure of ET cross‐sections. Three animals were used to investigate the feasibility of balloon dilation of the Eustachian tube (BDET). The anatomical study indicated that the pharyngeal orifice and tympanic orifice of the miniature pig ET are located at the posterior end of the nasal lateral wall and anterior wall of the middle ear cavity, respectively. The cartilaginous tube was seen to pass through the whole length of the ET, the length of the cartilaginous part of the ET and the diameter of the isthmus were similar between humans and miniature pigs. The inclination of the ET in miniature pigs was larger than that in humans. The gross histology seemed to be slightly different between miniature pig and human, but the fine structures were essentially the same in both species. BDET experiments verified that the miniature pig model is suitable as a model for clinical operations. The miniature pig ET corresponds very well to that of humans. In addition, the miniature pig ET is suitable as a model for clinical operations. Therefore, the miniature pig is a valid animal model for ET study. Anat Rec, 302:1024–1038, 2019. © 2019 Wiley Periodicals, Inc.
... We need to find a suitable animal model which is commonly available and anatomically closely resembles human being [3,4]. Some authors have given detailed anatomy of individual species like pig [5], sheep [6,7] and primate [4]. Bergin et al. [3] compared the temporal bone and ear anatomy of large group of experimental lab animals, with the intention of using them as models for live surgery. ...
The study was undertaken to compare the micro ear anatomy of three commonly available animal models which are expected to have similar anatomy to human and to find out suitable model among them as an alternative for human cadaver temporal bone dissection. This is an observational study of comparison of micro ear anatomy of the three animal models with human. Decapitated heads of cattle, pig and sheep were collected from slaughter houses, soft tissues along with brain were removed and preserved in commercially available formalin preservative. CT scan was taken for the three specimens and 3D reconstructions were done. Each specimen was subjected to micro dissection and the anatomical features were studied and compared with human. Among the three animal models sheep is found to be an ideal model for a beginner because of ease of exposure of bone, very thin cortical bone, and no cellularity, good exposure of all the middle ear structures and similar interrelations of middle ear structures with human. Pig may not be an ideal model because of abundant fatty soft tissues, thick periosteum very narrow space occupied by the middle ear, difficulty in accessing cellularity small fragile ossicular chain and overhanging facial nerve.
... Most of the lastly performed works spot a light on the clinical significant of the middle ear and studded it in practically applied form, Somnerauer et al. (2012) in equine. The donkey has been the chosen one for the present research as experimental animal, many authors tried to apply that among the domestic animals, Lavinsky & Goycoolea (1997) a &b in sheep, Pracy et al. (1998) in pig, Seibel et al. (2006) in sheep, Seibel et al. (2006 in human and sheep, Zirkle et al. (2007) andGurr et al. (2009) in pig. Mean while others compared the middle ear of animals to human Hoffstetter (2011) in human in pig. ...
... While König and Liebich (2014) in domestic mammals has the opinion that the middle ear consisted of tympanic cavity, auditory ossicles and auditory tube, the former comprised the epitympanicum, mesotympanicum and hypotympanicum. On the other hand, Pracy et al. (1998) in pig classified the middle ear into Eustachian tube, tympanic cavity and air cell system within the tympanic bulla. Regarding the proceeding recorded system, the present results pointed out that the gate of entrance to the tympanic air cells was referred to the mastoid antrum which was the part of the mesotympanicum. ...
... Concerning the bony anatomical relations of the middle ear in the current study revealed that it resembles a biconvex lens with dorsomedial and ventrolateral faces. A result which was in contrast to that cited by Pracy et al. (1998) in pig which declared that it was look's like a biconcaved lens with six walls; roof, anterior, posterior, lateral, medial and floor. In this respect, Ragab & Osman (1987) in buffalo reported dorsal, ventral, lateral and medial walls. ...
The middle ear is an irregular cavity composed of three ossicles, malleus, incus, stape,
which transmit sound waves to the inner ear and converted into mechanical energy. Due to the importance of the middle ear in voice transmissions this study was established. In this research, in order to investigate morphologically, the details of sus scrofa Atilla middle ear ossicles, 5 matured male animals skulls were used. After anatomical examination of different parts of the temporal bone and removing the bones, the middle ear bones were exposed, in addition to examine the shape, dimensions and details of each bone were measured using an ocular micrometer. Finally, data were evaluated and analyzed using the Sigma Statt statistics software. In sus scrofa Atilla, temporal bone, similar to other animals, consisted of three parts: squamous, tympanic and petrous part. The length of the outer ear canal to the tympanic membrane is 37±0.14 mm. Thetympanic membrane is circular in animal and the diameter of the tympanic membrane is about 12.5±0.21 mm. The tympanic membrane has also Beige color. In the boar, the number of middle ear ossicles was three, including Malleus, Incus and Stapes. Morphometric results showed that the Malleus ossicle had a head, neck, handle and three distinct process including anterior, muscular and lateral process. Incus ossicle consists of a body, two long and short crura and has two articular surfaces. A short or posterior crura attaches to the posterior wall of the body and the long crura are connected to the stape ossicle.
The Stape ossicle has a footplate and three anterior, posterior, and muscular process which anterior process is shorter than posterior. In the present study, the components of the middle ear in the boar was investigated. It was determined that the number of middle ear ossicles in the boar was similar to pigs, and the only difference was the size of the ossicles processes.
PURPOSE:
Initial study of the pig`s temporal bone anatomy in order to enable a new experimental model in ear surgery.
METHODS:
Dissection of five temporal bones of Sus scrofa pigs obtained from UNIFESP - Surgical Skills Laboratory, removed with hole saw to avoid any injury and stored in formaldehyde 10% for better conservation. The microdissection in all five temporal bone had the following steps: inspection of the outer part, external canal and tympanic membrane microscopy, mastoidectomy, removal of external ear canal and tympanic membrane, inspection of ossicular chain and middle ear.
RESULTS:
Anatomically it is located at the same position than in humans. Some landmarks usually found in humans are missing. The tympanic membrane of the pig showed to be very similar to the human, separating the external and the middle ear. The middle ear`s appearance is very similar than in humans. The ossicular chain is almost exactly the same, as well as the facial nerve, showing the same relationship with the lateral semicircular canal.
CONCLUSION:
The temporal bone of the pigs can be used as an alternative for training in ear surgery, especially due the facility to find it and its similarity with temporal bone of the humans.
Objective
The nasal mucosa is equipped with abundant lymphatic tissues, serving as the first line of defense against invasion by microorganisms. In this study, we characterized the features of the nasal mucosa of Bama minipigs (Sus scrofa domestica) via histological analysis.
Methods
Five cross sections (I, II, III, IV, and V) were obtained from the distal end of the nasal cavity toward the pharynx (along the cavity axis) and examined. Specifically, CD3⁺ T cells, immunoglobulin A (IgA)⁺ cells, and M cells were detected by immunohistochemistry, while dendritic cells (DCs) were detected by immunofluorescence. The distribution of goblet cells was determined by periodic acid-Schiff (PAS) staining.
Results
The nasal cavity of Bama minipigs can be divided into three parts: the regio vestibularis (I, II), regio respiratoria (III, IV), and regio olfactoria (V). Lymphoid tissue was present at random locations in the nasal cavity. Abundant lymphoid tissue was located in the roof of the nasopharyngeal meatus and was continuous with the lymphoid tissue of the pharynx. The distribution of CD3⁺ T cells, IgA⁺ cells, M cells, and DCs increased distally in the nasal cavity.
Conclusions
The present work comprises a histological study of the nasal cavity of Bama minipigs, and will be beneficial for understanding the mechanisms of immunity in these animals after nasal vaccination.
Background
Pigs with SCID can be a useful model in regenerative medicine, xenotransplantation, and cancer cell transplantation studies. Utilizing genome editing technologies such as CRISPR/Cas9 system allows us to generate genetically engineered pigs at a higher efficiency. In this study, we report generation and phenotypic characterization of IL2RG knockout female pigs produced through combination of CRISPR/Cas9 system and SCNT. As expected, pigs lacking IL2RG presented SCID phenotype. Methods
First, specific CRISPR/Cas9 systems targeting IL2RG were introduced into developing pig embryos then the embryos were transferred into surrogates. A total of six fetuses were obtained from the embryo transfer and fetal fibroblast cell lines were established. Then IL2RG knockout female cells carrying biallelic genetic modification were used as donor cells for SCNT, followed by embryo transfer. ResultsThree live cloned female piglets carrying biallelic mutations in IL2RG were produced. All cloned piglets completely lacked thymus and they had a significantly reduced level of mature T, B and NK cells in their blood and spleen. Conclusions
Here, we generated IL2RG knockout female pigs showing phenotypic characterization of SCID. This IL2RG knockout female pigs will be a promising model for biomedical and translational research.
