Observations on the Fine Structure of the Liver in the Camel (Camelus dromedarius)

The structure of macroscopically inconspicuous livers in 23 adult camels (Camelus dromedarius) was studied by light and transmission electron microscopy. A well-developed connective tissue characterizes the camel liver. Thick trabeculae divide the liver parenchyma into lobules. Portal tracts and central veins are surrounded by a variable amount of fibrous tissue. In the perisinusoidal space (DISSE), collagen fibres form a dense three-dimensional network around the sinusoids. A mild to moderate fatty infiltration is present in hepatocytes of all animals. In the epithelial cells of the bile ducts, small to medium sized lipid inclusions are a common feature. The ultrastructure of hepatocytes in the camel liver corresponds to that of other domestic mammalian species. The endothelial cells lining the sinusoids show a multiple fenestration and are surrounded by a discontinuous basal lamina. Fat-storing cells are numerous and contain lipid droplets varying in size, number and electron density from one cell to another.     

Retinol Values in the Plasma of the Arabian Camel (Camelus dromedarius) and the Influence of Aflatoxicosis

The normal values are reported of the concentration of vitamin A (retinol) in the plasma of 44 male and female adult camels (Camelus dromedarius) in the United Arab Emirates. The concentrations of the vitamin in the plasma of eight camels of both sexes afflicted with aflatoxicosis were also determined. The mean concentration (±SD) of the vitamin in healthy camels was 460.1±49.3 ng/L. Sex had no significant effect on the concentration of the vitamin. Camels with aflatoxicosis had a mean concentration of retinol in the plasma of 243.4±32.3 ng/L. The concentrations of aflatoxins in the liver and ruminal contents of these animals were 18.2±1.3 and 243.4 g/kg, respectively.     

Ultrastructure of Camel (Camelus dromedarius) Spermatozoa

Spermatozoa collected from the caudae epididymidis of six camels were examined by phase contrast, scanning electron and transmission electron microscopy. A comparison of the morphology of the camel spermatozoa with that of other domestic animals is presented.     

Computed tomographic and radiographic morphology of the pastern and coffin joints of One-Humped Camel (Camelus dromedarius)

The objective of the current study was to describe the structures of the pastern and coffin joints in dromedary camel using x-ray, bone and soft tissue windows computed tomography (CT) and three-dimensional volume rendering (3DVR) of CT imaging. 3DVR of CT was obtained at the slight flexed dorsal view, plantar view, dorsolateral view and lateral view which explained all the surfaces and structures of the digit bony parts even the parts of the articular surface. The processed images of 3DVR of CT showed different patterns of the cortical, cancellous, subchondral bones and medullary cavity of the bones of the digits. The present study showed clearly all the hard and soft tissues in the pastern and coffin joints of the camel in CT images; however, the plantar ligaments of the pastern joint and ligaments of the navicular cartilage identified on CT images. The CT soft tissue window visualized the joint cavity and their pouches and tendon sheath of the flexor tendons better than the bone window CT. The radiographic, CT and 3D images could be used as a normal reference for the interpretation of some clinical diseases in the pastern and coffin joints of the camel.     

Some Endotoxin-induced Clinical and Biochemical Changes in Plasma of Camels (Camelus dromedarius)

Intravenous administration of endotoxin, prepared from E. coli serotype O55:B5, at a dose of 0.1 microg/kg body weight to calves and adult camels induced fever and increased haematocrit, triiodothyronine and cortisol values. The endotoxin-treated animals showed significantly decreased (p < 0.05) total protein, urea, glucose and creatinine. A significant increase was seen in the activity of aspartate aminotransaminase and creatine kinase. These results demonstrate high sensitivity of camels to endotoxin.     

Ultramicroscopical Study on Thyrocalcitonin Cells in the Camel (Camelus dromedarius)

Thyrocalcitonin cells (C cells) were predominantly demonstrated in the ultimobranchial (UB) structures of the thyroid gland of one‐humped camels. The UB population was observed as clear cells, either singly distributed or as groups of cells between the component cellular elements lining the UB structures. They displayed various shapes: oval, pear‐like, rounded, cubical, columnar and or ellipsoid. Those populating the cell nests or solid cellular masses were almost polygonal or ovoid in shape. The cytoplasm contained well‐developed golgi complexes, several mitochondria and characteristically presented rounded or oval membrane‐bound electron dense granules of different sizes. The latter granules were irregularly distributed within the cytoplasm especially at the vascular pole. The nucleus of C cells was relatively large, indented, occupying a more or less central position in the cytoplasm. It presented various chromatin contents; the heterochromatin variety was predominantly demonstrated at the marginal zone. However, the euchromatin occupied a more central position within the nucleus.     

The Coronary Arteries of the Dromedary Camel (Camelus dromedarius)

The pattern of distribution of the coronary arteries of the camel was studied by combining dissection and vinyl acetate casts. The results showed that in the camel the right coronary artery supplies the interventricular subsinuosal artery, characteristic of a right coronary pattern. The septal branch that supplied the interventricular septum originated from the paraconal interventricular artery. A muscular bridge was observed crossing each of the paraconal and subsinuosal interventricular arteries in the middle third of the longitudinal grooves.     

Coronary arterial anatomy of the one-humped camel (Camelus dromedarius)

The detailed coronary arterial anatomy of seven camels was studied and compared with that of horses and cattle. In camels, there is a bilateral coronary supply, the right coronary artery being the larger. The left coronary artery follows the same pattern as that in horses. The ramus collateralis proximalis in camels separates off some distance away from the origin of the ramus interventricularis paraconalis, as in horses, whereas it separates off very quickly in cattle. The ramus collateralis distalis has two branches in camels, whereas the left distal ventriculi ramus does not branch. The ramus angularis is also absent but the left distal atrii ramus is present.Abbreviations LCR left ramus circumflexus - RCR right circumflexus ramus - RIS ramus interventricularis subsinosus - RIVP ramus interventricularis paraconalis     

Sedative and analgesic effects of romifidine in camels (Camelus dromedarius)

ObjectiveTo evaluate the clinical effectiveness and the sedative and analgesic effects of intravenous (IV) romifidine in camels.Study designRandomized prospective study.AnimalsEighteen healthy adult Dromedary camels.MethodsRomifidine was administered IV to camels (n = 6) at three different doses (40, 80 or 120 μg kg^?1). Time of onset, degree and duration of sedation and analgesia were recorded immediately after drug administration. Heart rate, respiratory rate, ruminal contractions, muscle relaxation, response to auditory and tactile stimulation, distance between ears, distance from lower lip to the ground, and degree of ataxia were also recorded pre-administration and at 5, 15, 30, 45, 60, 90, 120 and 180 minutes post-administration. Plasma glucose, blood urea nitrogen and creatinine were measured.ResultsRomifidine produced dose dependent sedation and analgesia. Significant decreases in heart rate (p < 0.001), ruminal contractions (p < 0.05), distance from lower lip to the ground (p < 0.001), response to auditory and tactile stimuli (p < 0.01), and significant increases in the degree of ataxia (p < 0.01), distance between the ear tips (p < 0.001) and blood glucose (p < 0.01) concentration were recorded after administration of romifidine until recovery. However, no significant changes in rectal temperature and respiratory rate were recorded.Conclusions and clinical relevanceIntravenous administration of romifidine at three different doses appeared to be an effective sedative and analgesic agent for camels. Bradycardia, ruminal atony, and hyperglycemia were the most important adverse effects after IV administration of romifidine. The IV administration of romifidine at a dose rate of 120 μg kg^?1 caused profound sedation and analgesia. Romifidine could be used for chemical restraint for a variety of diagnostic and minor surgical procedures in camels.     

双峰驼跖趾关节解剖结构

采用大体解剖学方法,研究了成年双峰驼的８个跖趾关节,并与马、牛、羊、猪、犬等动物的对等器官进行了比较。结果发现,双峰驼跖趾关节的形态结构有以下显著特征：（１）跖骨远端关节面后部有矢状嵴,近趾节骨近端关节面后部有与之相对应的矢状沟,这种结构与跖行动物和趾行动物相类似;（２）籽骨上没有对应近趾节骨近端的关节面;（３）籽骨间韧带只连接同一趾上的２个籽骨,与牛的将２趾的４个近籽骨连在一起的结构不同;（４）轴侧侧副韧带不像牛的那样与对侧的同名韧带共同起始于跖骨远端滑车间切迹,而是分别起始于此切迹的轴侧韧带窝及韧带结节;（５）轴侧侧副韧带仅为１层,而远轴侧侧副韧带分为２层;（６）籽骨直韧带、趾间趾节骨籽骨韧带及趾间近韧带均缺如。     

Uterine Activity after Induction of Hypocalcaemia in the Ovariectomized Camel (Camelus Dromedarius)

Al-Eknah, M.M., Homeida, A.M., Dafalla, E.A., Galil, A.K.A. and Al-Tahir, A.Y., 1997. Uterine activity after induction of hypocalcaemia in the ovariectomized camel (Camelus dromedarius). Veterinary Research Communications, 21 (1), 45-50.Bilateral ovariectomy was performed in three parous, non-pregnant camels. Intrauterine and intra-abdominal pressure changes were recorded using balloon-tipped catheters. Uterine contractions were induced and maintained in the ovariectomized camels by daily intramuscular injections of 5 mg oestradiol benzoate throughout the experimental period. The frequency of uterine contractions varied from 6 to 9 per minute, whereas the amplitude varied from 2 to 3 kPa in all the animals. Inducing hypocalcaemia to a level of 0.5 mmol/L by Na2EDTA reduced the amplitude of the contractions to below 1 kPa (p<0.001). The frequency of the contractions was not affected.     

The Arterial Supply of the Cubital Joint in the Bactrian Camel (Camelus bactrianus)

The arterial supply of the six cubital joints from bactrian camels was studied. There were 15 arterial branches supplying the joint. The branches that arose from the transverse cubital artery were the medial anterior, superior anterior, lateral anterior, middle anterior, inferior anterior, superior lateral, middle lateral, inferior lateral, superior posterior and superior lateral posterior cubital branches. The branches originating from the collateral ulnar artery were the medial, middle posterior, inferior posterior, medial posterior and inferior lateral posterior cubital branches. These arteries united with each other around the cubital joint.     

Prenatal Development of the Eye Tunics in the Dromedary Camel (Camelus dromedarius)

Studies of ocular development in the dromedary camel (Camelus dromedarius) have not been reported previously. The aim of the present investigation was therefore to document the major landmarks and the time course in the prenatal development of the eye tunics in dromedary camel and its accommodation with the surrounding hard environment of the desert. Serial histological sections of dromedary camel embryos and foetuses were used. Age estimation was made on the basis of gestational size, crown vertebral‐rump length (CVRL), which ranged 1.2–110 cm. The eye of the dromedary camel developed in a similar manner to that of the human and domestic animals eyes; the principal differences were in the time of occurrence of certain developmental events, pigmented peripheral cornea near the limbus, a remarkably thickened Descemet's membrane and pigmentation in the corneo‐scleral junction, which represent an adaptive modification in relation to a severe environment.     

Structure of the Carotid Sinus of the Dromedary Camel (Camelus dromedarius)

The morphology of the terminal segment of the common carotid artery of the camel was studied. It was found that this artery terminated by giving off a patent internal carotid artery and continuing as the external carotid artery. A presumptive carotid sinus was present at the region of origin of the internal carotid. Similar to that of other mammals, the carotid sinus of the camel was characterized by a comparatively thin vascular wall rich in elastic fibres. With the electron microscope, free (non-encapsulated) afferent endings, efferent endings, encapsulated axons and bundles of unmyelinated and myelinated nerve fibres were found in the wall of the presumptive carotid sinus. The free afferent endings closely resembled baroreceptor endings of the carotid sinus of other mammalian species in their mitochondrial content and the presence of abnormal organelles such as lamellar bodies, vesicular mitochondria and dense bodies. They were regarded as slowly adapting baroreceptors. The presumptive efferent endings were considered adrenergic whereas the encapsulated axons were thought to be the proximal parts of encapsulated sensory nerve endings.     

The Arterial Supply of the Metacarpophalangeal Joint in the Bactrian Camel (Camelus bactrianus)

The arterial supply of the six metacarpophalangeal joints was studied in Bactrian camels. The arterial branches supplying the metacarpophalangeal joints were derived from the metacarpal distal perforating, medial and lateral branches of the palmar metacarpal artery III, medial and lateral branches of the palmar common digital artery III and the abaxial palmar proper digital arteries III and IV. These arterial branches were the proximal dorsoaxial distal metacarpal, distal dorsoaxial distal metacarpal, abaxial distal metacarpal, palmar distal metacarpal, interosseous distal metacarpal, dorsoaxial proximal proximal phalangeal, palmoaxial proximal proximal phalangeal, palmoabaxial proximal proximal phalangeal and dorsoabaxial proximal proximal phalangeal branches. They linked with each other around the metacarpophalangeal joint.     

The Arterial Supply of the Carpal Joint in the Bactrian Camel (Camelus Bactrianus)

The arterial supply of the six carpal joints was studied in Bactrian camels. The arterial branches supplying the carpal joints were the proximal medial dorsal, middle medial dorsal, distal medial dorsal, proximal lateral dorsal, distal lateral dorsal, proximal medial palmar, distal medial palmar, lateral palmar, proximal palmar and dorsal palmar carpi and the dorsal interosseous antebrachium branches. Some small unnamed branches supplied the diverticulum and the antebrachiocarpal joint capsule. All these arteries arose from the lateral and medial branches of the radial artery.     

Specialised Vascular Structures in the Pododerma of the Camel Footpad (Camelus dromedarius)

Transversal, horizontal and sagittal sections of the brain were stained by the ancient but efficient Mulligan method, a procedure that establishes a clear macroscopic difference between the white and grey substances. Different structures of each section were studied and most of the details were identified and named according to the NAV. All sections were projected onto the whole brain. By means of this easy and basic procedure the students increase their understanding of (1) the size and/or the form and/or the topography of several prominent structures of the brain, (2) the general distribution of the substancia alba and grisea, and they begin to understand the complexity of the brain.     

The Arterial Supply to the Eye of the Bactrian Camel (Camelus bactrianus)

The arterial supply to the eye of the bactrian camel (Camelus bactrianus) was studied by gross dissection. The supply came from the external ophthalmic, external ethmoidal and malar and maxillary tubercular arteries, ophthalmic rete mirabile, and the rostral epidural rete mirabile. The external ophthalmic artery gave rise to branches to supply the dorsal oblique muscle, lacrimal gland, superior and inferior eyelids, and the lateral angle of the eye, and to take part in the formation of the rostral epidural rete and the ophthalmic rete mirabile. The external ethmoidal artery detached off some branches to supply the ventral and medial dorsal rectus oblique muscles, the conjunctiva of the superior eyelid and the fat body of the orbit. The branches of the malar artery supplied the inferior, superior and third eyelids, ventral oblique muscle, and the medial angle of the eye. The ophthalmic rete mirabile gave off many branches to supply the rectus muscles of the eye, dorsal oblique and retractor oculi muscles, levator muscle of the superior eyelid, and the choroid.