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Cytochrome C was purified from camel skeletal muscles using ammonium sulphate fractionation and gel filtration on Sephadex G25 and Sephecryl S200 columns. The preparations were pure by SDS-PAGE criteria, with molecular weight of 12,300 Dalton. The electrophoretic mobility of camel cytochrome C was the same as that of the horse heart. The spectral characteristics of the isolated cytochrome C were also investigated.
Carnitine (CA) plays an important role in the metabolism of fatty acids. Its presence is considerable in tissues that utilize fatty acids as an important source of energy, such as the heart and the skeletal muscle. The presence of free, short-chain acyl and long-chain acyl carnitine was shown for the first time in various tissues of the camel eye. The ratio of acyl carnitine (AC) to free carnitine (FC) was high in aqueous humor, indicating a predominance of AC, while it was low in vitreous humor, indicating a higher concentration of FC. The highest concentration of total carnitine (TC) was observed in the retina, followed by the cornea, while the lowest was found in lens nucleus. Among various forms, FC concentration was the highest in the cornea while it was the lowest in the lens cortex. In the cornea and retina, the proportion of short-chain acylcarnitines (SC) was two-fold when compared to long-chain acylcarnitines (LC), while in the lens it was the same. The ratio of AC to FC in the retina was high, indicating a predominance of AC, while in lens it was low, indicating a higher concentration of FC. In contrast, L-CA in the cornea was present equally between the free and the esterified forms. The quantitative differences in the distribution of L-CA in various tissues of the camel eye reflect that it may be involved in providing a source of readily available energy.
Folding stabilities of camelized human antibody VH domains were studied through the determination of their melting points in thermodenaturation experiments. The melting point of a VH domain originating from a synthetic library of human VHs, which had been optimized for the use as small recognition units through the mimicking of camelid antibody heavy chains occurring naturally without light chain, was 56.6 degrees C compared with 71.2 degrees C of the original human VH. Its stability was improved (melting point 61.6 degrees C) through three mutations to mimic camelid VHs even further: Va137 was replaced by phenylalanine and two cysteines were introduced at position 33 and 100b. The resulting VH folded properly and formed a second intradomain disulphide between the extra cysteines. The new mutations were then built constitutively into a phage-display VH library, from which antigen-specific VHs were selected. Two were analysed for stability with melting points of 72.6 and 75.3 degrees C. Thus secondary camelization enabled the isolation of VHs with improved folding stabilities exceeding even that of the original human VH. This indicates an effect on folding stability for some mutations specific in the light chain lacking camelid heavy chains.
Rates of oxygen consumption and respiratory water loss were studied in camels that were exposed to desert heat and water deprivation. We found that changes in body temperature are accompanied by considerable changes in respiratory water loss. Body temperature fluctuations are greatest in dehydrated camels (up to 7 degrees C), and in these the respiratory water loss might vary from abut 0.06 to 1.2 g/min. The respiratory frequency varied from about 4 to 28 min-1, while the metabolic rate varied less than twofold. The lowest values for respiratory water loss can be explained by the exhalation of air at temperatures far below body temperature, and, in addition, removal of water vapour from the exhaled air, resulting in exhalation of air at less than 100% relative humidity.
The pharmacokinetics of tobramycin were determined in six healthy camels (Camelus dromedarius) following the intravenous (i.v.) and intramuscular (i.m.) administration of single doses of tobramycin sulphate (40 mg/ml). The half-life to tobramycin was 189 +/- 21 min and the mean residence time was 254 +/- 26 min. The apparent volume of distribution (area method) was 245 +/- 21 ml/kg, while volume of the central compartment of the two-compartment pharmacokinetic model was 110 +/- 12 ml/kg. The clearance (systemic) of tobramycin was 0.90 +/- 0.10 ml/min/kg. Values of the pharmacokinetic parameters suggest that glomerular filtration rate is lower in camels than in other ruminant species, horses, dogs and cats. Following i.m. administration of the dose (1.0 mg/kg), the drug was rapidly absorbed with peak serum concentration of 3.32 +/- 0.59 micrograms/ml at 20-30 min; the absorption half-life was 3.9 +/- 0.9 min. The systemic availability of tobramycin was 90.7 +/- 14.4%. The apparent half-life was 201 +/- 40 min, which was not significantly longer than the half-life following i.v. administration of the drug. Based on the pharmacokinetic values obtained in this study, a dosing rate of 2.5 mg/kg administered by i.m. injection at 12-h intervals can be recommended. This dosage regimen should achieve an average steady state serum concentration of 4 micrograms/ml with peak serum concentration approaching, but not exceeding, 10 micrograms/ml.
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 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.
This study aimed to elucidate development of the areola in the early dromedary placenta in comparison with that of the pig and mare. Placental tissues from 25 pregnant camels were obtained from Cairo abattoir and prepared for light, scanning and transmission electron microscopy by routine methods. Vascular casts were made by injection of 4 : 1 liquid plastic mixture of mercox and methylmethacrylate. Areolar formation was first observed at 4.5 cm curved-crown-rump CVR length, while by 5-9 cm CVR length, the endometrial surface was uneven and studded with numerous uterine gland openings, where corresponding foetal areolae were barely detectable and the foetal areolar cells were of variable appearance and covered with long microvilli. At 10-13 cm CVR length the uterine gland openings developed irregular folds and the maternal areolar cells showed numerous apical blebs. At 14-29 cm CVR length the foetal areolae showed a great increase in height at the expense of their width. At 30-34 cm (CVR) length the maternal areolae appeared discoid and sharply demarcated from the surrounding inter-areolar tissues and the foetal areolae were rounded to irregular in shape with well-developed areolar rims. The vascular casts showed a widely meshed capillary network on the maternal areola, connecting with the pre- and post-capillary vessels, whereas the foetal side showed a relatively dense capillary meshwork. These studies indicate that the areola in the placenta of the one-humped camel is of the regular type like in the pig, and is poorly vascularized.
Ultrastructure of the camel's endometrium in normal and diseased conditions, was studied using the electron microscope. The samples were obtained from 6 normal uteri and 10 uteri with inflammatory lesions. Three ovaries of the latter 10 uteri showed ovarian cysts. All the animals were non-pregnant. No cyclic changes were taken in consideration because the camel is an induced ovulator animal. The surface and the glandular epithelium of the normal uteri consisted of one layer of tall columnar cells, resting on an undulating membrane. The free borders of cells showed microvilli, motile cilia and zeiotic blebs. Desmosomes and gap junctions were seen as means of connections between the neighboring cells. The nuclei were large, oval and situated in the lower half of the cells. Two types of mitochondria were seen. One type was small, rounded and dilated, and the other was large and elongated. Many lipid droplets and scanty glycogen granules were common findings in the normal cells. Granulated bodies similar to those described in the epithelium of the human uterus and containing acid phosphatase were found. Many other cytoplasmic organelles and granules were seen. The endometrial stroma consisted mainly of stromal cells of irregular shape, and collagen fibres. The collagen fibres were present in amounts larger than many other species. In the diseased uteri, the changes in the epithelium consisted mainly of hyperplasia of the cells and marked increase of all cytoplasmic inclusions and vacuoles. There was also marked increase in the number of the crossing lymphocytes through the epithelial layer. The collagen fibres of the stroma increased in amount and the stromal cells became similar in shape to the fibroblasts. A large number of mast cells as well as other types of inflammatory cells infiltrated the stroma. Non-specific bacterial infections were detected on bacteriological examination of the inflamed uteri. Neither bacteria nor other microbial agents could be seen ultrastructurally. In an uterus associated with ovarian cysts, the microvilli of its epithelium showed marked changes in their shape and length.
NAGase activity (NAGase) and serum albumin concentrations were determined in milk from 101 traditionally managed camels in the Sudan. NAGase, a lysosomal enzyme released from damaged epithelial cells as well as other somatic cells in milk, was recorded for quarter milk samples from camels (n = 353) using the fluoroscan method. NAGase activity in major pathogen-infected quarters was significantly (P < 0.05) higher than in minor pathogen-infected and non-infected quarters. Means for minor pathogen-infected quarters were also significantly higher than non-infected quarters. Concentrations of serum albumin, resulting from increased vascular permeability, in quarter milk samples (n = 320) were measured by the radial immunodiffusion test. Serum albumin content in milk was not affected by infection status of the quarter. There were, however, large variations in serum albumin levels and, to a lesser extent, NAGase values between samples in both infected and non-infected quarters. NAGase was more effective in predicting bacteriological status of the quarter than serum albumin.
The oxidative burst activity of phagocytic cells isolated from camel blood and mammary glands was studied using a chemiluminescence (Cl) assay. The polymorphonuclear leucocytes (PMNL) isolated from camel blood mounted a luminol-dependent Cl response upon stimulation with opsonized zymosan or opsonized Staphylococcus aureus. These responses showed an overall similarity to those described in other mammalian species. The leucocytes isolated from the mammary glands mounted Cl responses similar to those observed with blood PMNL but to a lower magnitude. Like the Cl responses of blood cells, the Cl responses induced by mammary gland leucocytes were associated with degranulation and the release of lysosomal enzymes such as myeloperoxidase (MPO).
In this study we examined the superior colliculus of the midbrain of the one-humped (dromedary) camel, Camelus dromedarius, using Nissl staining and anti-neuronal-specific nuclear protein (NeuN) immunohistochemistry for total neuronal population as well as for the enkephalins, somatostatin (SOM) and substance P (SP). It was found that, unlike in most mammals, the superior colliculus is much larger than the inferior colliculus. The superior colliculus is concerned with visual reflexes and the co-ordination of head, neck and eye movements, which are certainly of importance to this animal with large eyes, head and neck, and apparently good vision. The basic neuronal architecture and lamination of the superior colliculus are similar to that in other mammals. However, we describe for the first time an unusually large content of neurons in the superior colliculus with strong immunoreactivity for met-enkephalin, an endogenous opioid. We classified the majority of these neurons as small (perimeters of 40-50 microm), and localized diffusely throughout the superficial grey and stratum opticum. In addition, large pyramidal-like neurons with perimeters of 100 microm and above were present in the intermediate grey layer. Large unipolar cells were located immediately dorsal to the deep grey layer. By contrast, small neurons (perimeters of 40-50 microm) immunopositive to SOM and SP were located exclusively in the superficial grey layer. We propose that this system may be associated with a pain-inhibiting pathway that has been described from the periaqueductal grey matter, juxtaposing the deep layers of the superior colliculus, to the lower brainstem and spinal cord. Such pain inhibition could be important in relation to the camel's life in the harsh environment of its native deserts, often living in very high temperatures with no shade and a diet consisting largely of thorny branches.
Recently attention has been focused on the investigation of new and effective routes for drug administration in order to avoid their side effects in the human body. Red blood cells (RBCs) exhibit many advantages, i.e., they are naturally occurring, biodegradable, and non-immunogenic. Their use as drug carriers has many potential applications, including slow drug delivery to the body tissue and drug targeting to a specific site. In this work, the fluorescent exogenous agent sodium fluorescein (uranin) was used as the probe for the encapsulation of the RBCs. The encapsulation process was applied in two different mammalian RBCs: camel and bovine. The results indicate that the encapsulation efficiency of bovine RBCs was 34.0 +/- 3.0% with an RBC recovery rate of approximately 75% whereas that of camel RBCs was only 8.0 +/- 2.0% with a cell recovery rate of approximately 47%. These differences demonstrate the dependency of the encapsulation process on the type of mammalian source of the RBCs.
Saudi Arabian camels (Camelus dromedarius) are infected with three species of Eimeria: E. dromedarii (28.4%), E. rajasthani (22.2%), and E. cameli (19.2%); 41.6% of the animals examined were positive. The highest prevalence of infection was reported in the western region of the country. Mixed infection with two Eimeria species is most common; E. dromedarii was most frequently and generally the most predominant species. Eimeria dromedarii and E. rajasthani are described for the first time from Saudi Arabian camels.
Effects of storage at room temperature (23-25 degrees C) and refrigeration (4-5 degrees C) on various biochemical constituents of camel serum were investigated. Albumin, globulin, calcium, phosphorus, cholesterol, aspartate aminotransferase (AST), alkaline phosphatase (AP) and gamma glutamyltransferase (GGT) did not change over 9 days when stored at 4-5 degree C. At 4-5 degree C, creatinine, iron and glucose in camel sera remained stable for 6 days; total protein for 7 days; and blood urea nitrogen for 8 days. Decreased activities in creatine kinase (CK), lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) were apparent after 1, 6, and 7 days, respectively. At room temperature, total protein, albumin, globulin, calcium and phosphorus were stable throughout the 9 days. Changes in glucose and iron occurred after 3 days. Stability at room temperature for LDH was 1 day; AST, 3 days; GGT and ALT, 6 days; and AP, 8 days. CK activity had already declined by 4 hours and by 9 days, only 34% activity remained.
Young camels were inoculated intradermally with either camelpox or smallpox virus and the courses of infection, including serological response, were compared. Camelpox virus was highly infectious; generalized disease resulted which was transmitted naturally to contact animals. Smallpox virus produced only transient lesions at the inoculation site and a less marked serological response. Nevertheless, the camels inoculated with smallpox virus subsequently resisted a severe challenge with camelpox virus, and the possibility that limited replication of smallpox virus took place is discussed. The differences demonstrated between the behavior of the vituses is discussed in the light of their otherwise close relationship and the limited information available about camelpox infections in man.
Clinical and pathological findings from instances of ataxia in a group of wildebeeste (Connochaetes taurinus), two llamas (Llama glama) and one Arabian camel (Camelus dromedarius) are presented. Clinically, all the affected animals showed a non-febrile, progressive ataxia. Neuropathologically, Wallerian degeneration was diffuse in the spinal cord of the camel and llamas but was focal in the wildebeeste. Degeneration was present in the cervical dorsal roots in the wildebeeste and in the ventral nerve roots at all levels of the cord in the llamas. Peripheral nerve were affected in all the species. The possible roles of copper deficiency and plant poisons in the aetiology of the condition are discussed.
A technique for needle liver biopsy in camels was developed. Xylazine, 15 mg/100 kg intravenously, was used for sedation and analgesia. A 1.2 mm X 7 cm Menghini needle was introduced anteroventrally through the ninth right intercostal space, 1 cm caudal to the ninth rib and 2 cm dorsal to the costal cartilage. The needle was directed toward the contralateral olecranon with the camel in sternal recumbency. A core of liver tissue between 1 and 2 cm long was obtained from 99 of 120 attempts in 23 animals. There were no adverse effects from the procedure and histological preservation of the tissue was excellent.