Ultrastructure of the tubular glands in the isthmus region of the oviduct in laying and natural moulting commercial egg‐type chickens

The study investigated the ultrastructural characteristics of tubular gland and duct cells, as well as luminal gland cells in the isthmus region of the oviduct of laying and natural moulting hens. Tubular glands in laying birds were composed of type 1 and 2 cells. Based on the preponderance of each cell type, in relation to the location of a developing egg in the oviduct of the domestic fowl, these gland cells may represent different functional states of the same cell. The findings of the study on natural moulting birds suggest that autophagy is a process confined to the early stages of degeneration, while necrosis occurs in the terminal stages.     

Progesterone and oestrogen receptor immunoreactivity in the vagina of the immature ostrich,Struthio camelus

1. The presence of sperm storage tubules in the cranial, middle and caudal regions of the vagina in the immature ostrich was studied. In addition, progesterone and oestrogen receptor immunoreactivity in these regions was investigated. 2. Sperm storage tubules were observed only in birds with active ovaries. Progesterone receptor immunoreactivity was more intense in birds with active ovaries, whilst immunostaining for the oestrogen receptor was absent in birds with both active and inactive ovaries. 3. These results suggest that steroid hormones produced by the active ovary mediate the activation of the progesterone receptor.     

An immunohistochemical study of the distribution of intermediate filaments in the ovary of the emu (Dromaius novaehollandiae)

The immunohistochemical localization of the intermediate filaments desmin, vimentin and smooth muscle actin (SMA) in the ovary of the emu was described in the present study. The cortical region of the ovary contained developing and atretic primordial, pre-vitellogenic and vitellogenic follicles. Vimentin immunostaining was demonstrated in the granulosa cell layer of primordial, pre-vitellogenic and vitellogenic developing and atretic follicles. An interesting finding of the present study was the localization of SMA in fibroblasts located in the theca externa of late vitellogenic follicles. The presence of SMA in these fibroblasts suggests that they possess characteristics of smooth muscle cells.     

Comparative histomorphological and ultrastructural study of the luminal epithelium of the isthmus in laying and moulting domestic fowls (Gallus domesticus)

This study describes ciliated, nonciliated and mitochondrial luminal epithelial cells of the isthmus in laying and moulting domestic fowls using histological and ultrastructural techniques. The ciliated cells were nonsecretory, while numerous electron‐dense secretory granules were present in the nonciliated cells of laying birds. Mitochondrial cells, occurring in two morphologically distinct forms, constituted the third type of epithelial cell present in the isthmus. The SEM study showed that the luminal epithelium was dominated by ciliated cells, the cilia of which partially obscured adjacent nonciliated cells. The involution of the luminal epithelium in moulting birds occurred via autophagy, apoptosis and necrosis. Autophagic inclusions, which included autophagosomes and autolysosomes, were present in the early degenerative phases of ciliated, nonciliated and mitochondrial cells. Nonciliated cells underwent degeneration via apoptosis, which was characterized by nuclear and cytoplasmic condensation. Apoptotic and necrotic ciliated cells were evident during the intermediate and advanced stages of regression. The presence of apoptotic cell death was confirmed using the TUNEL assay. Loss of cilia via the formation of cilia packets was observed using TEM and SEM. Necrotic cell death occurred in mitochondrial cells during the intermediate and late stages of degeneration. In conclusion, the findings of the study on isthmus involution in moulting birds suggest that autophagy is a process confined to the early stages of degeneration, while apoptosis and/or necrosis occur in the terminal stages of regression.     

Immunoreactivities to protein gene product 9.5, neurofilament protein and neuron specific enolase in nerves in the oviduct of the sexually immature ostrich, Struthio camelus

The present study investigated the distribution of nerves in the oviduct of the sexually immature ostrich. The presence of protein gene product 9.5, neurofilament protein and neuron specific enolase nerve fibres were demonstrated in the infundibulum, magnum, isthmus, shell gland and vagina. Nerve fibres containing protein gene product 9.5, neuron specific enolase and neurofilament protein were particularly numerous in the tunica muscularis and intermuscular connective tissue areas of the shell gland and vagina. The presence of a large number of nerves in these oviductal regions is probably important in the coordination of muscle contraction. An interesting finding of the study was the presence of protein gene product 9.5 and neuron specific enolase immunopositive nerve fibres in the walls of blood vessels. It is likely that these nerves are autonomicin nature and play a role in the regulation of blood flow. This study has shown the presence of an extensive neural network in the oviduct of the ostrich. In addition, the results of the investigation have shown that the neuronal markers protein gene product 9.5, neurofilament protein and neuron specific enolase can be used to demonstate nerve fibres in the ostrich.     

Immunohistochemical Localization of the Progesterone and Oestrogen α Receptors in the Uterine Horns of the African Giant Rat (Cricetomys gambianus)

The present study investigated the immunolocalization of the progesterone and oestrogen α receptors in the uterine horns of the African giant rat during the oestrous cycle. The progesterone and oestrogen α receptors were demonstrated in various cellular constituents of the endometrium, myometrium and perimetrium. The intensity of progesterone and oestrogen α receptor immunostaining in the endometrial and myometrial layers of the uterine horns varied during the oestrous cycle. The intensity of oestrogen α receptor immunoreactivity in the luminal epithelium was high during pro‐oestrus, oestrus and dioestrus. Progesterone and oestrogen α receptor immunoreactivity in the endometrial epithelia was absent during metoestrus. Moderate to strong immunostaining for the progesterone and oestrogen α receptors was demonstrated in the myometrial smooth muscle cells during pro‐oestrus, oestrus and dioestrus. The intensity of progesterone and oestrogen α receptor immunostaining in the myometrial smooth muscle cells was low during metoestrus. Stromal cells in the perimetrium consistently expressed progesterone and oestrogen α receptor immunoreactivity throughout the oestrous cycle. The findings of the study indicate that in the giant rat the immunolocalization of the progesterone and oestrogen α receptors, in endometrial and myometrial regions of the uterine horns, varies during the oestrous cycle.     

An ultrastructural characterization of the ooplasm in ovarian follicles of the immature ostrich (Struthio camelus)

Primordial, pre-vitellogenic and vitellogenic follicles were present in the ovary of the immature ostrich. The oocytes of these follicles were composed of a nucleus surrounded by ooplasm. Central, intermediate and cortical regions formed the ooplasm. The organelles present in these ooplasmic regions varied depending on the stage of follicular development. In primordial and small pre-vitellogenic (100-150 microm in diameter) follicles the central region of the ooplasm was dominated by an accumulation of organelles, which formed Balbiani's vitelline body. In contrast, the central region in vitellogenic follicles was filled with numerous large yolk spheres, many of which contained lining bodies. Numerous lipid droplets interspersed with mitochondria and small yolk spheres formed the intermediate ooplasmic region in primordial and small pre-vitellogenic follicles. In large pre-vitellogenic (150-400 microm in diameter) and vitellogenic follicles the intermediate region contained a greater density of mitochondria and small yolk spheres. Small yolk spheres were observed in the cortical region of pre-vitellogenic follicles. An interesting feature of the cortical region in vitellogenic follicles was the frequent occurrence of Golgi complexes. The results of the study indicate that although the ovarian follicles in the immature ostrich are not ovulated, the components and composition of the ooplasm are similar to those observed in the mature follicles of other avian species.     

An immunohistochemical study of ovarian innervation in the emu (Dromaius novaehollandiae)

The present study investigated the distribution of nerves in the ovary of the emu. The neuronal markers, protein gene product 9.5, neurofilament protein and neuron specific enolase demonstrated the constituents of the extrinsic and intrinsic ovarian neural systems. The extrinsic neural system was composed of ganglia in the ovarian stalk, as well as nerve bundles, which were distributed throughout the ovary. Isolated neuronal cell bodies, in the medulla and cortex, formed the intrinsic neural system. An interesting finding of the study was the presence of nerve bundles, circumscribed by lymphocytes, in the ovarian stalk. The findings of the study indicate that the distribution of nerve fibres and neuronal cell bodies in the emu ovary is similar, but not identical to that of the domestic fowl and ostrich.     

Foot-and-mouth disease: detection of antibodies in cattle sera by blocking ELISA.

A blocking ELISA was developed for the detection of antibodies to foot-and-mouth disease virus SAT1, SAT2 and SAT3 and for the quantification of antibodies on a single dilution of serum. The avidin-biotin system was used. The test was compared with the liquid-phase ELISA executed at the World Reference Laboratory for foot-and-mouth disease. It was found to have favourable logistics and combined high specificity with high sensitivity. The quantitative test using a single dilution of serum was resource saving and proved to be a reliable and precise method for the assessment of antibody levels.     

Seroprevalence of brucellosis and its associated risk factors in cattle from smallholder dairy farms in Zimbabwe

A cross-sectional study was conducted to investigate seroprevalence of brucellosis and the associated risk factors in cattle from smallholder dairy farms in Gokwe, Marirangwe, Mushagashe, Nharira, Rusitu and Wedza areas of Zimbabwe. A total of 1,440 cattle from 203 herds were tested serially for Brucella antibodies using Rose Bengal test and the competitive ELISA. Weighted seroprevalence estimates were calculated and risk factors in individual cattle investigated using logistic regression analysis. The overall individual animal brucellosis seroprevalence was low, with mean of 5.6% (95% confidence interval (CI), 4.4%, 6.8%). Gokwe had the highest individual (12.6%; 95% CI, 3.9%, 21.4%) and herd-level (40.0%; 95% CI, 22.1%, 58.0%), while Wedza had the lowest individual (2.3%; 95% CI, 0%, 5.3%) and herd-level (8.0%; 95% CI, 0.0%, 18.9%) brucellosis seroprevalence, respectively. In individual cattle, the area of origin, age and history of abortion were independently associated with brucellosis seroprevalence. While the seroprevalence was independent of sex, it decreased with increasing age. Cattle 2–4 years old had higher odds (odds ratio (OR) = 3.2; 95% CI, 1.1%, 9.1%) of being seropositive compared to those >7 years. Cows with a history of abortion were more likely to be seropositive (OR = 7.9; 95% CI, 3.1, 20.1) than controls. In conclusion, the area-to-area variation of brucellosis may be linked to ecological factors and differences in management practices. The implementation of stamping out policy, bleeding and testing animals before movement and promoting the use self-contained units are likely to significantly reduce the public health risks associated with Brucella infections in cattle.