Morphological Changes of the Endometrial Epithelium in the Bitch during Metoestrus and Anoestrus

Although cyclic changes of the endometrium in dogs involving both stromal and glandular compartments have been described, the fate of the surface epithelium after progressive growth and secretion is still unclear. In the present study, uteri of 43 healthy bitches in metoestrus and anoestrus were examined macroscopically and histologically. Tissue biopsies were taken from three different locations (cranial and middle parts of uterine horns and bifurcation). The stage of the oestrous cycle was determined by evaluation of progesterone and oestradiol levels in plasma hormone and was also confirmed clinically. Crypts formed in the luteal phase were covered with a columnar epithelium which gradually underwent fatty degeneration. In addition, the stromal part of the crypts disappeared and finally, in early anoestrus, epithelial sheaths desquamated and shed off into the uterine lumen. The surface epithelium was replaced by new cuboidal cells proliferating and migrating from the glandular openings. These findings were confirmed by oil red O staining and immunohistochemical detection of proliferation with Ki‐67 marker.     

The reproductive performance of dairy cows with anovulatory anoestrus that were injected with either gonadotrophin-releasing hormone or oestradiol benzoate as part of a re-treatment process after insemination

This experiment compared the reproductive performance of synchronised anoestrous dairy cows that were treated initially with a combination of progesterone and oestradiol benzoate and then with either gonadotrophin-releasing hormone (GnRH) or oestradiol benzoate to resynchronise returns to service. It was hypothesised that injecting anoestrous dairy cows with GnRH 12-15 days after insemination and coinciding with the time of insertion of a controlled intravaginal progesterone-releasing (CIDR) device would increase conception rates to the preceding 1st insemination compared with oestradiol benzoate treated cows; both GnRH and oestradiol benzoate would resynchronising the returns to service of those cows that did not conceive to the preceding insemination. Groups of cows in 11 herds were presented for a veterinary examination after they had not been seen in oestrus postpartum. Those cows diagnosed with anovulatory anoestrus (n = 1112) by manual rectal palpation and/or ultrasonography were enrolled in the trial. Each enrolled cow was injected with 2 mg oestradiol benzoate i.m. on Day -10, (where Day 0 was the 1st day of the planned insemination) concurrently with vaginal insertion of a CIDR device. The device inserted was withdrawn on Day -2 and then each cow injected i.m. with 1 mg of oestradiol benzoate on Day -1 unless it was in oestrus. Observation for oestrus preceded each insemination. Every cow that had been inseminated on Days -1,0,1 or 2 was presented for treatment for resynchrony on Day 14 (n = 891). They were divided into 2 groups; those with an even number were each injected i.m. with 250 microg of a GnRH agonist (Treatment group n = 477); each of the cows with an odd number injected i.m. with 1 mg of oestradiol benzoate (control group, n = 414). Each GnRH or oestradiol benzoate injection preceded reinsertion of a CIDR device previously inserted from Days -10 to -2. It was withdrawn on Day 22, 24 hours before injecting 1 mg oestradiol benzoate. Cows observed in oestrus were submitted for a 2nd insemination. Every enrolled cow still present in the herd was pregnancy tested by palpation of uterine contents per rectum about 6 weeks later and again at the end of a herd's seasonal breeding programme. The alternative use of GnRH instead of oestradiol benzoate did not affect the percentage of cows conceiving within 3 days of the mating start date (MSD) (35.6 % vs 35.3 %, P = 0.90), resubmission rates for a 2nd insemination among cows not pregnant to the 1st insemination (81.6 % vs 83.5 %, P = 0.41), 6-week pregnancy rate (59.3 % vs 60.6 %, P = 0.65), 21-weekpregnancy rate (86.6 vs 85.0, P = 0.36), mean interval from MSD to conception (32.5 +/- 1.8 days vs 29.9 +/- 1.8 days, P = 0.26) or conception rate of cows reinseminated by Day 28 (43.3 % vs 38.8 %, P = 0.39). When GnRH was compared with oestradiol benzoate, it did not increase conception rates to the 1st service; it was as effective as oestradiol benzoate in synchronising returns to service in previously treated anoestrous cows that did not conceive to the 1st service. Its use affected neither conception rates to the preceding 1st inseminations nor to the following 2nd inseminations.     

Lack of LH response to oestradiol treatment in cows with cystic ovarian disease and effect of progesterone treatment or manual rupture.

The luteinising hormone (LH) surge in response to 1 mg oestradiol benzoate intramuscular injection was studied on 67 occasions in 45 cows with cystic ovarian disease 20 to 150 days post partum. Cows diagnosed as having luteal cysts were given 500 micrograms cloprostenol intramuscularly 24 hours before oestradiol, to induce luteolysis. Oestradiol benzoate was also given to eight post partum acyclic and eight cyclic cows and in all these cases a control LH response was characterised for comparison. Eight of 17 cows with luteal cysts (47 per cent), and 10 of 21 cows with follicular cysts (48 per cent), released LH in response to oestradiol. Some cows with cysts were given one of two treatments. Seven cows with follicular cysts were treated with a progesterone-releasing device (PRID) for seven days: all responded to a second oestradiol treatment given 24 hours after removal of the PRID. Luteal cysts in three cows and follicular cysts in nine cows were ruptured manually: only one cow (a luteal case) responded to the second oestradiol treatment given 24 hours after manual rupture. In eight cows initially diagnosed with luteal cysts, cloprostenol was not given and plasma progesterone concentration at the time of oestradiol treatment was high (over 0.9 ng ml-1): none released LH in response to oestradiol. As manual rupture did not improve the LH response to oestradiol, it is concluded that the defective LH response to oestradiol in cows with cystic ovarian disease was not influenced in the short-term by cyst fluid contents.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of oestrus synchronisation programmes in dairy cattle using oestradiol benzoate, short-acting progesterone and cloprostenol, or buserelin and cloprostenol

AIM: To evaluate the efficacy of a programme using oestradiol benzoate, progesterone and the prostaglandin-F2 (PG) analogue, cloprostenol, to synchronise oestrus and ovulation in dairy cows, compared with a programme using a gonadotropinreleasing hormone (GnRH) agonist, buserelin, and cloprostenol. METHODS: Twenty non-lactating dairy cows, at random stages of the oestrus cycle, were randomly assigned to 1 of 2 treatments. In Treatment 1 ( OPPG; n=10), cows were injected with 2 mg oestradiol benzoate intramuscularly (IM) plus 200 mg progesterone subcutaneously (SC) on Day 0, followed by 500 microg cloprostenol IM on Day 9 and 1 mg oestradiol benzoate on Day 10. In Treatment 2 (GPG; n=10), cows were injected with 10 microg buserelin IM on Day 0, 500 microg cloprostenol IM on Day 7 and 10 microg buserelin on Day 9. The ovaries of all cows were examined by ultrasonography, using an 8 MHz probe, from 5 days before the initial treatment until ovulation. Cows were observed for oestrus 3 times daily for 7 days after cloprostenol treatment. Blood samples were collected daily for determination of progesterone, and 6-hourly for 36 h after the second oestradiol or buserelin injection for the determination of follicle stimulating hormone (FSH) and luteinising hormone (LH) concentrations. RESULTS: The percentage of cows observed in oestrus was higher in the OPPG group than in the GPG group (100% vs 55.6%, p=0.018). Treatment with either short-acting progesterone plus oestradiol benzoate or buserelin was followed by atresia or ovulation of the dominant follicle. Emergence of a new follicular wave occurred earlier (p>0.001) in the GPG group (2.2+/-0.2 days) than in the OPPG group (3.6+/-0.2 days). There was no significant difference between treatment groups in the variation of time of follicular wave emergence or size of the largest follicles at either the time of initial treatment (10.8+/-1.4 mm vs 11.1+/-0.8 mm), cloprostenol treatment (13.8+/-0.7 mm vs 14.0+/-1.3 mm) or of ovulation (15.4+/-0.7 mm vs 17.6+/-1.1 mm; p=0.10). The LH surge occurred sooner after the second injection of buserelin (4.0+/-1.0 h) than after the second injection of oestradiol benzoate (22.8+/-1.2 h; p>0.001). The interval between the second injection of oestradiol benzoate or buserelin and ovulation did not differ significantly between treatment groups (1.7+/-0.3 days vs 1.6+/-0.2 days; p=0.69). CONCLUSIONS: The use of short-term progesterone treatment, combined with oestradiol benzoate for follicular wave synchronisation, and cloprostenol to cause lysis of residual luteal tissue, is a promising alternative to established methods of oestrus synchronisation in cows.     

The effect of GnRH or oestradiol injected at pro-oestrus on luteal function and follicular dynamics of the subsequent oestrous cycle in non-lactating cycling Holstein cows

Oestrous synchronization involves synchronization of ovarian follicular turnover, new wave emergence, and finally induction of ovulation. The final step can be synchronized by the parenteral administration of either GnRH or oestradiol benzoate. This study investigated corpus luteum and follicular emergence after ovulation had been induced by the administration of either GnRH or oestradiol benzoate. The injection of oestradiol benzoate may have delayed the emergence of the first follicular wave subsequent to the induced ovulation; administration of oestradiol benzoate or GnRH lowered the progesterone rise so that the maximum dioestrous concentration of progesterone on Day 9 was lower when cows were treated during pro-oestrus compared to the spontaneously ovulating controls. One implication of findings from the present study is that induction of ovulation with either oestradiol benzoate or GnRH, administered 24 or 36 h after withdrawal of the CIDR device, respectively, may lower fertility. Future studies must identify the timing of administration relative to the time of CIDR device withdrawal and the optimum concentration of oestradiol benzoate or GnRH that would not have untoward effects on the development of the corpus lutea, particularly within the first week of dioestrus.     

Light and electron microscopic study of the thoracic respiratory air sacs of the fowl

There are conflicting reports in the existing literature on the nature of the epithelial lining and the content of the supporting connective tissue of the respiratory air sacs of birds. The present study describes the light and electron microscopic structure of the thoracic air sacs of the fowl. A simple squamous epithelium lined the greater part of the thoracic air sacs. The squamous cells characteristically contained vesicles filled with lamellar or myelinoid material. Localized areas of cuboidal to columnar ciliated epithelium were randomly distributed and often associated with underlying blood vessels. Isolated ciliated cells first appeared on squamous or low cuboidal cells and increased in frequency as the cells became taller. Occasional basal and goblet cells were seen between the ciliated columnar cells. A fibrous connective tissue stroma supported the epithelium. Fine elastic fibres were particularly prevalent immediately below the epithelium. Isolated smooth muscle myocytes were present in the connective tissue stroma. A sheet of smooth muscle extended some distance into the membrane from the attachment of the latter to the body wall. Numerous small blood vessels, lymphatics and occasional nerve bundles were observed in the stroma.     

Light and electron microscopical observations on the terminal airways and alveoli of the lung of the SA (Cape) fur seal Arctocephalus pusillus

During activities of the Sea Fisheries Research Institute at Kleinzee, lung samples from six South African fur seals were collected. The terminal airways showed pseudostratified ciliated columnar epithelium with numerous goblet cells and occasional brush cells. Smooth muscle, cartilage and submucosal glands were also present. The epithelium changed over a short distance, in the smaller airways, through pseudostratified columnar non-ciliated to simple cuboidal epithelium with no goblet cells. The columnar non-ciliated cells contained secretory granules, which appeared to be serous. No Clara cells were found. Cartilage and muscle were present throughout, up to the origin of the alveolar ducts, but the glands disappeared together with the goblet cells. Alveoli were lined by types one and two alveolar epithelial cells, with subepithelial capillaries. They were divided by an alveolar septum with a well developed alveolar knob. This knob contained elastic fibres and fibroblasts, but not the smooth muscle cells which are present in terrestrial mammals and in Phocidae.     

Exfoliative vaginal cytology during the oestrous cycle of the cow, after ovariectomy, and after exogenous progesterone and oestradiol-17 beta

Vaginal exfoliative cytology was studied in five normal cyclical Friesian cows over 10 oestrous cycles each. Oestrus was assessed by the use of KaMaR heat mount detectors, whilst progesterone concentrations were measured in the peripheral blood using radioimmunoassay. Apart from oestrus, the exfoliative cytology was not consistent in appearance and did not appear to be influenced directly by the changes in endogenous ovarian steroid hormones. Four of the cows were subsequently ovariectomized and the vaginal exfoliative cytology monitored before and after the administration of 2 g of progesterone in a slow release vehicle and, following a rest period, after the administration of 12.5 mg oestradiol benzoate in oil. Peripheral progesterone and oestradiol-17 beta concentrations were measured in the peripheral plasma. Although the total number of epithelial cells increased after both hormone treatments no specific changes were observed.     

Treatment of suckling beef cattle with a progestagen sponge and oestradiol benzoate or equine chorionic gonadotrophin

The ovarian responses of anoestrus beef cows to a combined treatment with medroxy-progesterone acetate (MAP) sponges and oestradiol benzoate or equine chorionic gonadotrophin (eCG) were evaluated. Forty-five suckling Hereford cows were allocated to three equal groups. Group 1 received a MAP sponge for seven days plus an injection of 2 mg oestradiol benzoate when the sponge was inserted (day 0) and 1 mg when the sponge was withdrawn; group 2 received identical treatment until day 7, when a dose of 400 iu of eCG was administered, and group 3 were left untreated as control animals. From day 0 to day 11 the cows' ovaries were examined daily by transrectal ultrasonography, and their oestrous behaviour was observed from 24 hours to 96 hours after the sponge was removed. Data from cows that had a corpus luteum present before the sponge was withdrawn were not used in subsequent analyses; there were four in group 1, five in group 2 and four in group 3. In 19 of the 21 cows in groups 1 and 2 a new follicular wave was observed to emerge at a mean (sd) interval of 3.9 (0.3) days after the insertion of the sponge, whereas in group 3 it occurred in all 11 cows after 3.4 (0.6) days. Only the six cows that had a follicle of 9 mm or larger in diameter ovulated (P < or = 0.001). Nine of the 11 cows in group 1 came into oestrus, compared with two of the 10 in group 2 and none of the control cows (P < or = 0.001). Ovulation was observed in four, two and none of the cows in groups 1, 2 and 3, respectively.     

Light and scanning electron microscopic studies of the nasal turbinates of the horse

The nasal turbinates of 5 young horses were studied by light and scanning electron-microscopy. Stratified cuboidal epithelium lined the rostral part of the dorsal and ventral nasal turbinates of the vestibular region. The polyangular microvillus cells of this region were separated by linear depressions. The mid and caudal parts of the dorsal and ventral nasal turbinates and the rostral part of the ethmoturbinates were lined by pseudostratified columnar ciliated respiratory epithelium. Numerous cilia with dilated blebs on the ciliated cells concealed adjacent non-ciliated supporting cells and goblet cells. The olfactory zone consisting of the olfactory vesicle and a dense network of olfactory cilia localized to the caudal part of the ethmoturbinates. The three regions were delineated from each other by transitional zones.     

Light and electron microscopic study of the thyroid gland of the camel (Camelus dromedarius)

The thyroid gland of sexually immature dromedary camels was studied using both light and electron microscopy. The thyroid gland contained follicles of different sizes in both summer and winter. However, most of the follicles were large in summer and small in winter. The large follicles were lined by very low cuboidal or semi-squamous follicular cells whereas the small ones were lined by high cuboidal or low columnar follicular cells. Electron microscopy showed that the very low cuboidal follicular cells were poor in organelles and were considered hypoactive. High cuboidal follicular cells on the other hand, were rich in organelles that included mitochondria, cisternae of rough endoplasmic reticulum, secretory vesicles, colloid droplets, heterosomes and autophagic vacuoles; they were considered to be very active. The possible role played by these organelles is synthesis of thyroglobulin and liberation of tri- and tetraiodothyronine is discussed. A few degenerate follicular cells were infrequently encountered in the camel thyroid. Parafollicular (C) cells were not seen in this study either with light or electron microscopy.     

Light and electron microscope studies on the nasopharynx and nasopharyngeal tonsil of the horse

Light and electron microscope studies were conducted on the nasopharynx and the nasopharyngeal tonsil of 15 young horses. The nasopharynx and nasopharyngeal tonsil was lined with pseudostratified columnar ciliated epithelium and goblet cells. The lymphoepithelium of the nasopharyngeal tonsil was folded forming crypts, the mucosa of which was modified into follicle associated epithelium characterized by stratified cuboidal epithelium, loss of cilia, absence of goblet cells and infiltration of lymphocytes. The lamina propria mucosae of the nasopharyngeal tonsil contained well-developed lymphoid tissue and clusters of seromucus acini. Scanning electron-microscopy revealed a dense mat of cilia covering the nasopharynx and nasopharyngeal tonsil. The follicle-associated epithelium consisted of different populations of microvillus cells in addition to M cells with very short microvilli and a few squamous and intermediate cells. Microvillus cells in the deeper part of the FAE had larger microvilli and their cytoplasm contained a dense population of mitochondria, smooth and rough endoplasmic reticulum, Golgi complexes and lysosomes. The flat surfaced M cell had a more electron-dense cytoplasm and contained small supranuclear vacuoles in addition to the organelles seen in microvillus cells.     

Effect of oestrous resynchronization on the reproductive efficiency of zebu cows

The aim of this study was to develop a resynchronization strategy before the return of oestrus in cows diagnosed as not pregnant after fixed‐time artificial insemination (TAI). A total of 839 cows, approximately 45 days post‐partum, were synchronized using TAI. On day 0, intravaginal progesterone‐releasing devices were inserted and 2 mg of oestradiol benzoate was administered. Eight days later (D8), the progesterone‐releasing devices were removed and oestradiol cypionate (0.5 mg, eCG [300 IU]) and prostaglandin (7.5 mg) were administered. All cows were inseminated between 48 and 56 hr after device removal (D10). Thirty days after TAI, cows that were not diagnosed as pregnant by ultrasound were immediately resynchronized and again inseminated at a fixed time. The hormonal protocol used in the first and second rounds of TAI was the same. The pregnancy rate after the first TAI was 52%, and after the second TAI, it was 49%. The increase in the total pregnancy rate (synchronization + second oestrous synchronization) compared to a single synchronization was 23.5%. In conclusion, resynchronization of oestrus and ovulation in zebu cows that had previously undergone TAI protocols is effective in increasing the reproductive efficiency.     

Ultrastructural features of the uterus in the sexually immature ostrich (Struthio camelus) during periods of ovarian inactivity and activity

The ultrastructure of the surface epithelium and tubular glands of the uterus in the immature ostrich is described. In ostriches with inactive ovaries the uterus is lined by a non-ciliated simple columnar epithelium, with basally located heterochromatic nuclei. Scanning electron microscopy revealed that these non-ciliated cells have a dense microvillous cover. A simple columnar to pseudostratified columnar epithelium, comprised of non-ciliated and ciliated cells, lines the uterus in birds with active ovaries. The ciliated cells possess a wide luminal region, which contains a nucleus and various organelles. An accumulation of secretory granules was observed in the apical regions of the non-ciliated cells, as well as in a few ciliated cells. In addition to non-ciliated and ciliated cells, a cell type with rarefied cytoplasm was also identified. These cells appear to correspond to calcium secreting cells identified in other avian species. The results of this study indicate that, although uterine differentiation is present in immature ostriches with active ovaries, the production of secretory product appears to occur mainly in non-ciliated epithelial cells.     

产后奶牛子宫内膜的扫描电镜观察

应用扫描电镜观察了 5头奶牛产后不同时期子宫内膜的变化。结果发现 ,分娩后早期 ,奶牛子宫内膜部分破损 ,与破损部位相邻的细胞在产后 1周内相继脱落 ;未破损内膜上皮细胞表面的纤毛和微绒毛形状不整、数量减少。产后2周 ,基底细胞开始生长 ,至产后 4 5 d时生长完成 ;产后 4周 ,内膜破损区域缩小 ,上皮细胞表面纤毛和微绒毛形状规则、数量增加 ;产后 4 5 d,偶见上皮细胞缺失 ;至产后 6 0 d,子宫内膜上皮细胞完整、排列有序、被覆纤毛和微绒毛。上述结果表明 ,奶牛子宫内膜在分娩后 6 0 d内完成修复。     

Histochemical and surface ultrastructural characteristics of the nasal cavity of laughing dove

Ten apparently healthy, adult laughing doves were used to document detailed histological, histochemical and surface ultrastructural features of the nasal cavity and to investigate the structure‐function relationship of the nasal cavity in this species. We observed that the nasal cavity of the laughing dove was composed of three main regions: nasal vestibule, respiratory and olfactory. Each region presented a characteristic epithelial lining. The epithelium varied along the nasal vestibule from keratinized stratified squamous rostrally to non‐keratinized stratified squamous in the middle and stratified cuboidal in the caudal region of the nasal vestibule. The respiratory region was lined with pseudostratified columnar epithelium and was initially devoid of both goblet cells and cilia, but cilia then appeared and increased gradually in number close to the olfactory region. The caudal part of the respiratory region presented a stratified cuboidal epithelium. Strong alcianophilic, intra‐epithelial mucous glands were identified, starting at the caudal region of the nasal vestibule and extended into the respiratory region. The olfactory region was lined with a pseudostratified epithelium that consisted of three different cell types: olfactory, support cells and basal cells. In conclusion, the current investigation presents new information concerning the histological, histochemical and ultrastructural features of the laughing dove's nasal cavity. Furthermore, the findings of this study may prove to be a valuable contribution to the avian histology and pathology literature.     

Prenatal development of adenohypophyseal cell types, ovary, and uterus of dromedary camel

The somatotrophic and thyrotrophic cells were originally developed in the adenohypophysis from undifferentiated chromophobic cells at the foetal age of 4-8 weeks. The follicle-stimulating hormone cells appeared at a foetal age of 24-28 weeks. Prolactin and luteinizing hormone cells were first seen at of foetal age levels of 32-36 and 40 weeks. The germinal epithelium of flattened and cuboidal cells in the ovary was changed to cubical and columnar types, 24-28 weeks of foetal age. The sex cords appeared at 8-12 weeks of foetal age. The primary and secondary follicles were observed at 8-12 and 20-24 weeks of foetal age, respectively. Follicular cavity was noticed at 32-36 weeks, while large follicles encapsulated by follicular sheath were seen in the 40th week of foetal age. Some ovarian follicles degenerated during or after their development. Surface epithelium in the uterus changed from cubical to columnar type at 8-12 weeks of foetal age. The endometrium was clearly distinguished from the myometrium at 16-20 weeks of foetal age. The uterine glands appeared at 16-20 weeks as short and straight tubular glands, and they began to branch in the 40th week of foetal age.     

The role of the vaginal smear in the detection of metoestrus and anoestrus in the bitch

The vaginal smear was studied in relation to the rest of the genital tract during metoestrus and anoestrus in the bitch. The smear of progressive metoestrus contained superficial, large intermediate, small intermediate and parabasal cells. Cytolysis was absent and WBCs were abundant. In regressive metoestrus, there was a shift towards more basal type cells. Also, cuboidal and columnar cells became common and cytolysis was present. In anoestrus, parabasal and small intermediate cells, in addition to cuboidal and columnar, were the dominant cell types in the smear. Cytolysis was now marked and WBCs were absent or scarce.     

Histology,histochemistry and ultrastructure of the nasopharyngeal tonsil of the buffalo (Bubalus bubalis)

The light microscopic appearance and ultrastructure of the nasopharyngeal tonsil (tonsilla pharyngea), collected from 12 adult buffaloes of local mixed breed, were explored for the distribution of different types of epithelia, lymphoid tissue and high endothelial venules. The tonsillar mucosa was lined by pseudostratified columnar ciliated epithelium having goblet cells. The respiratory epithelium associated with the underlying lymphoid tissue formed the lymphoepithelium. The epithelium was further modified into follicle‐associated epithelium (FAE) characterized by reduced epithelial height, presence of a few dome‐shaped cuboidal cells equivalent of the M‐cells and absence of goblet and ciliated cells. The lymphoid tissue was distributed in the form of isolated lymphoid cells, diffuse lymphoid tissue and lymphoid follicles, mainly distributed within the propria‐submucosa along with the sero‐mucous glandular tissue. The goblet cells of the respiratory epithelium and the acinar cells contained different mucopolysaccharides. Scanning electron microscopy of the surface mucosa demonstrated a dense mat of cilia, island‐like arrangement of microvillus cells, M‐cells and a few brush‐like cells. The transmission electron microscopy revealed the different cell organelles of the respiratory epithelium and the FAE. Lymphocyte migration via the high endothelial venules in the propria‐submucosa was also observed.