Histological and ultrastructural studies on the coronary artery of adult domestic dog (Canis familiaris)

The objective of this work was to study the histological structure of the dog's coronary artery by light and transmission electron microscope (TEM). The coronary artery consisted of three tunics: tunica intima, tunica media and tunica adventitia. The tunica intima consisted of endothelium rested directly on internal elastic lamina without the subendothelial connective tissue layer. The tunica media were composed of smooth muscle fibres interspersed with few elastic and collagen fibres. The tunica adventitia consisted of collagen and elastic fibres intermingled with fibroblast cells; it had vasa vasorum and nervi vasorum. Some histomorphometric measurements were performed and compared statistically. The ultrastructural study showed that the endothelial cells were communicated through complex junctions and characterised by filiform cytoplasmic processes passed through the opening of the underlying internal elastic membrane. The smooth muscle fibres of tunica media communicated with each other through cytoplasmic processes. The tunica adventitia showed minute non-myelinated nerve. This work revealed that the dog's coronary arteries are typical muscular arteries, which show little structural variations from that of other mammals.     

Essential oil variation among and within six Achillea species transferred from different ecological regions in Iran to the field conditions

The compositions of essential oils of 19 accessions belonging to six different Achillea species, transferred from the natural habitats in 10 provinces of Iran to the field conditions, were assessed. The relationship between the leaf areas of selected accessions with their essential oil content was also investigated. Essential oil yield of dried plants obtained by hydro-distillation ranged from 0.1 to 2.7% in leaves. Results indicated a significant variation in oil composition among and within species. Total of 94 compounds were identified in 19 accessions belonging to the six species of A. millefolium, A. filipendulina, A. tenuifolia, A. santolina, A. biebersteinii and A. eriophora. The major constituents of the leaves in the tested genotypes were determined as germacrene-D, bicyclogermacrene, camphor, borneol, 1,8-cineole, spathulenol and bornyl acetate. According to the major compounds, four chemotypes were defined as: (I) spathulenol (1.64–34.31%) + camphor (0.2–15.61%) (7 accessions); (II₁) germacrene-D (18.78–23.93%) + borneol (7.93–8.26%) + bornyl acetate (11.56–14.66%) (5 accessions); (II₂) germacrene-D (13.28–36.28%) + bicyclogermacrene (5.93–8.4%) + 1,8-cineole (15.26–19.41%) + camphor (14.95–23.32%) (2 accessions); (III) borneol + camphor (52.04–63.27) (2 accessions); (IV) germacrene-D (45.86–69.64%) (3 accessions). The relationships of chemotypes with soil type and climatic conditions of collected regions were assessed, as probable reasons of high variations in essential oil components, and discussed.     

Influence of different sources and levels of dietary protein and lipid on the growth,feed efficiency,muscle composition and fatty acid profile of Snakehead Channa striatus (Bloch, 1793) fingerling

Nine isoenergetic (18.5 kJ g⁻¹) diets were formulated, in a 3 × 3 factorial design, by varying three levels of dietary protein (350, 400 and 450 g kg⁻¹) at each of three levels of dietary lipid (65, 90 and 115 g kg⁻¹) accordingly. Each diet was hand fed two times daily for 8 weeks to triplicate homogenous groups of eight fish (average weight 3.34 ± 0.02 g) per tank connected to a recirculation system. Results showed that the feed efficiency and growth performance significantly (P<0.05) increased with increasing protein level at the two lower lipid levels (65 and 90 g kg⁻¹), respectively, as indicated by indices such as %weight gain, specific growth rate, protein efficiency ratio, feed conversion ratio and feed intake, but did not at the highest lipid level (115 g kg⁻¹). The muscle polyunsaturated fatty acids (PUFA) content declined with increasing dietary protein level at the lipid levels producing the highest growth, suggesting that the utilization of PUFA influences growth. Whereas the muscle monounsaturated fatty acids level was generally lower than the dietary levels in all the treatments tested, indicating preferential catabolism for energy, the muscle saturated fatty acids level was comparatively higher than in the diets, indicating selective deposition. Docosa hexaenoic acid (22:6n3, DHA), which was very low in the diet and in the initial fish, was higher in the muscle of some of the treatments, indicating the ability of Channa striatus to desaturate and elongate short‐chain PUFA to long‐chain HUFA, due to the availability of dietary 18:3n3 and 20:5n3 (the precursors for DHA biosynthesis). It could be concluded, based on the results of this trial, that a diet formulated to contain 65 g kg⁻¹ lipid and 450 g kg⁻¹ protein, with a gross energy of 18.5 kJ g⁻¹ and a dietary n3/n6 PUFA ratio of about 0.1, is sufficient to promote good feed efficiency and growth performance in C. striatus fingerling.     

Endosperm Development in Maize and Related to Photosynthate Supply

Maize ( Zea mays , L. Sweet Corn) plants were given shaded, partially shaded and control light treatments during 10 days or 20 days periods around the time of pollination. Glucose, sucrose, starch and dry matter (DM) contents were measured at intervals in composite samples of pericarp/nucellus (PN), and in endosperms taken from developing kernels. Total kernel DM per ear at maturity was higher in the partially shaded treatment than control and shaded treatments due to higher kernel set in apical regions of ears. In PN at 11 days after pollination (DAP), DM and sucrose contents were slightly greater in partially shaded than control and shaded plants. Glucose contents were substantially greater than controls in PN of partially shaded plants and were less than control in shaded plants. In endosperms from apical kernels at 5 to 10 DAP (during cell division), DM, glucose and sucrose contents were substantially less in shaded than control and partially shaded plants, sucrose contents were greater in endosperms of partially shaded than control plants. Sugar contents in endosperms from basal kernels were nearly the same in the three light treatments. At 10 DAP, apical and basal endosperms in shaded plants had fewer nuclei than those of the other light treatments. The light treatments appeared to effect apical kernel growth by influencing the extent of cell division.     

African horse sickness: An overview

A short overview of African horse sickness disease was given. Results were described of a research project that was carried out in Egypt cooperatively between Egyptian and American scientists. The virus was isolated from the blood of street dogs and camels from southern Egypt close to the Sudan border. Camel tick Hyaloma dromadarrii and dog tick Rhipicephalus sanguineus sanguineus harbored and transmitted the virus. Optimal reaction times were determined for agar diffusion precipitin and direct fluorescent antibody tests. Complement fixation and agar precipitin diffusion do not differentiate virus serotypes. Formalin, acetylethyleneimine, and binary ethyleneimine respectively inactivated the virus. Inactive preparation with adjuvant are promising vaccines. The virus was inactivated by irradiation. Plant antiviral extracts were investigated. Latent AHS virus in dogs was activated, producing viremia incident to the dogs being bitten by Culicoides. An antimoulting insecticide was more effective on early developmental stages of Culicoides pipiens.     

Effects of Dietary Thyme (Thymus vulgaris) and Fish Oil on Semen Quality of Miniature Caspian Horse

Thyme (Thymus vulgaris) is a subshrub from the lamiaceae family with plants that are rich in essential oils and antioxidative phenolic substances. The aim of the study was to investigate the effect of dietary thyme and fish oil supplementation on the semen characteristics of miniature Caspian horse. Sixteen stallions were randomly allocated into four groups and received four different diets: unsupplemented control diet, supplemented with fish oil at 2.5% dry matter intake (DMI), supplemented with fish oil (2.5% DMI), and thyme (0.02% DMI), and supplemented with thyme (0.02% DMI). All experimental diets were formulated according to National Research Council (1998). Semen was collected at 0, 30, 60, and 90 days. The semen samples were cooled and preserved at 5°C. Cooled diluted semen samples were evaluated in vitro by microscopic assessments of chilled sperm motility, acrosomal and other abnormalities (head, midpieces, and tail), viability (evaluated by Eosin–nigrosin), and plasma membrane integrity (evaluated by hypo osmolarity swelling test), and the level of malondialdehyde (MDA) was determined during cool storage 0, 24, and 48 hours after collection. The results showed that total and progressive sperm motility and plasma membrane integrity and functionality in all groups were significantly decreased with increasing storage time. On the other hand, the level of MDA in all groups was significantly increased with increasing storage time. Also, the results showed that most sperm quality parameters in this study were significantly higher in fish oil–thyme and fish oil group compared with thyme and control groups after 24 and 48 hours of storage at 5°C. We concluded that dietary supplementation of fish oil and thyme can improve sperm quality in miniature Caspian stallions during storage in cool condition via increasing total and progressive motility and plasma membrane integrity and functionality. More advances in vitro evaluations and artificial insemination are required to reveal the exact effects of thyme on miniature Caspian stallion sperm quality and its fertilizing ability.     

Immunodeficiency in canine demodectic mange. I. Experimental production of lesions using antilymphocyte serum

Two experiments were conducted to further clarify the importance of cell-mediated immunity in cases of canine demodectic mange. Pups obtained from pregnant pedigreed beagle bitches were exposed to mites (Demodex canis Leydig, 1859) and then injected with rabbit anticanine lymphocyte serum (ALS). Littermates received either mites alone, ALS alone, or were retained as negative controls. Squamous lesions of demodicosis developed in all pups receiving both ALS and mites as well as in two pups receiving only mites. No lesions were observed in any of the remaining pups. A marked decline in the number of peripheral lymphocytes developed in pups receiving ALS. These cells returned to normal numbers 3 weeks after treatment was discontinued. The squamous lesions on affected pups continued to coalesce until generalized demodicosis became established. Spontaneous resolution of mite-infested areas was never observed and pustular lesions did not develop.It was concluded that the cellular immune system of the dog, functioning as a defense mechanism against the establishment and proliferation of D. canis, is of paramount importance in preventing the development of demodectic mange.     

Immunodeficiency in canine demodectic mange. II. Skin reactions to phytohemagglutinin and concanavalin A

The T-lymphocyte mitogens phytohemagglutinin (PHA) and concanavalin A (Con A) were used as skin test agents to assess the cellular immune competence of dogs with demodectic mange. The intradermal injection of either mitogen into the abdomen of dogs produced a local erythematous and indurated papule characteristic of a delayed hypersensitive response. The mean diameter of the reaction at 24 and 48 following injection was significantly smaller in eight demodectic dogs than in eight dogs free from mite infestation (P < 0.05). This suppressed response suggested that dogs with demodicosis may have a hypoactive cellular immune system rendering them less capable of combating invading demodicids.The intradermal injection of PHA and Con A also produced an immediate wheal reaction. The mean diameter of the wheal after 15 min was significantly larger in demodectic dogs than in the control animals (P < 0.05). A possible reason for this difference and a potential mechanism for the reaction are discussed.     

Early pregnancy diagnosis by means of ultrasonography as a method of improving reproductive efficiency in goats

Eighteen cyclic Shiba goats were used in this study. Estrus was synchronized with a single injection of 125 microg of a synthetic analogue of prostaglandin F(2)alpha (PGF(2)alpha) after detection of at least one corpus luteum by B-mode ultrasonography. Blood samples were collected from each animal on days 0, 7 and 21 post-mating for progesterone assay. Animals in estrus were either allowed to be mated by fertile bucks twice during estrus (group I; n=12) or not at all (group II; n=6). Ultrasonographic examinations were performed transrectally or transabdominally using a real-time B-mode scanner equipped with a 7.5 or 5 MHz transducer. All animals exhibited estrus 56.0 +/- 2.7 h after injection of PGF2alpha. The results show that the accuracy of the progesterone assay in diagnosing pregnancy on day 21 after mating was 80% for pregnancy and 100% for non-pregnancy, retrospectively. Ultrasonographic examinations showed that gestational sac and embryos heartbeats were detected on days 20.2 +/- 0.6 and 24.3 +/- 0.7 of gestation, respectively. Placentomes were detected on day 35.4 +/- 1.0 of gestation as small nodules (0.7 +/- 0.2 cm in size). At two months pregnancy, skeletal structures like skull, thorax and long bones were clear. Biparietal diameter of the skull and length of long bones could be used as an estimate of gestational age. The accuracy of detection of fetal number using real-time B-mode ultrasonography was 91.7% on day 60 of gestation. In conclusion, progesterone assay at day 21 post-mating (cut-off value, 1 ng/ml) can be used for pregnancy diagnosis in goats. However, B-mode transrectal ultrasonography was more efficient due to detection of embryo and confirmation of its viability by heartbeats. In addition, fetal number and gestational age could be determined only by ultrasonography.     

Perineuronal Nets in the Central Nervous System

The remnant of ultimobranchial (UB) body in the thyroid gland of adult buffalo was studied. This remnant appeared in the form of irregular and elongated follicles of various size and shape with folded lumen. These structures occupied a peripheral location beneath the capsule, as well as being embedded mostly in the vascular connective tissue of the thyroid. Calcitonin cells were predominantly localized in the UB follicles. Scanning electron microscopy revealed that surface of most UB follicular cells was almost flat and polyhedral or hexagonal in shape. Other follicles possessed cells with dome shaped apical surface demarcated by a shallow intercellular depression. The luminal surface of the follicular cell lining was studded with microvilli that appeared with various density and length and were numerous at the cellular borders. Interestingly, most of UB follicular cells were provided with single cilium, projecting over the cell surface. Notably some UB follicles presented various stages of apocrine activities.