Is Mechanically Induced Cystic Endometrial Hyperplasia (CEH) a Suitable Model for Study of Spontaneously Occurring CEH in the Uterus of the Bitch?

Cystic endometrial hyperplasia (CEH) was experimentally reproduced by the intraluminal insertion of a silk wire in the uterus of metestral bitches to obtain a model for the study of spontaneously occurring CEH in the bitch. This mechanically reproduced CEH corresponded histologically very well to spontaneously occurring CEH. With respect to sex hormone receptor expressions, however, there was no similarity. In the mechanically induced CEH, progesterone receptor expression was reduced in the epithelial cells (surface epithelium and endometrial glands) and slightly increased in the stromal fibroblasts and myometrium as compared with the normal metestrus uterus. The oestrogen receptor expression in mechanically induced CEH was reduced in the epithelial cells (surface epithelium and endometrial glands) and more or less unchanged in the stromal fibroblast and myometrium as compared with the normal metestrus uterus. This is in contrast to the increased sex hormone receptor expressions in all uterine cell types, observed in spontaneously occurring CEH. The mechanically induced CEH model corresponds immunohistochemically more to early placentation and to pyometra in the bitch. Thus this experimental CEH model is not suitable for pathogenic studies of spontaneously occurring CEH in the bitch.     

Pseudo-placentational Endometrial Cysts in a Bitch

Cystic alterations of the canine endometrium compromise reproduction and fertility of the bitch and may lead to life-threatening diseases, such as pyometra. Even without clinical evidence, reduction of the uterine lumen by cysts implicates disturbances during migration, nidation and development of the embryo. Several studies point to the high variability of morphology of uterine endometrial cysts but they lack detailed analyses of alterations. In the present study, immunohistochemistry was used to investigate the expression of steroid hormone receptors (oestrogen, progesterone), proliferation activity, inflammation and infection in the cystic affected tissue regions in contrast to the normal endometrium. Oestrogen receptor expression showed a high density of receptors throughout the surface epithelial cells, crypt epithelial cells, glandular epithelial cells and stromal cells of the normal endometrium as well as the cystic affected regions. Proliferation in the cysts was verified in the middle and basal cells of the crypts. Neither in the endometrium nor in the cysts inflammatory processes or evidence of infection could be detected. Furthermore, lectin histochemistry and electron microscopic methods showed that lectin binding patterns and cell morphology of internal epithelial lining and surface epithelium of the cysts can be used to characterize and distinguish different types of cystic alterations. Analogies between epithelial cells of the glandular chambers of the canine placenta and the cystic cellular morphology, steroid hormone receptor distribution as well as lectin binding patterns of the endometrial cysts, as observed in this study, suggest to introduce the term 'pseudo-placentational endometrial cysts'.     

犬正常发情期与患子宫蓄脓的子宫和卵巢组织结构及乳铁蛋白表达的对比

本研究旨在探明犬子宫和卵巢在正常发情期与患子宫蓄脓时，其组织结构及乳铁蛋白（lactoferrin，LF）表达的变化特征。应用Masson’s、VVG、PAS组织化学染色方法观察乏情期、发情期、患子宫蓄脓时犬子宫及卵巢的组织结构特点，用免疫组织化学SP法观察LF的分布特征。结果显示，正常发情期犬：乏情期、发情期子宫内膜肌层厚度比分别为0.762 0、0.924 3；乏情期子宫固有层中胶原纤维含量大于发情期，发情期卵巢中胶原纤维含量大于乏情期；子宫血管层及卵巢血管内弹性膜清晰完整；子宫腺在乏情期时浅层管腔小，深层较大、腺管上皮为单层柱状上皮、上皮细胞及管腔内PAS阳性反应较强，发情期子宫腺管腔变大、腺管上皮为单层立方上皮、上皮细胞及管腔内有PAS阳性反应；子宫黏膜上皮在乏情期和发情期均为单层柱状上皮，但胞核位置不同，乏情期胞核位于中央，发情期胞核位于顶部。患子宫蓄脓犬：子宫内膜肌层厚度比为1.615 0；子宫固有层和卵巢中胶原纤维含量少于正常发情期；子宫腺管腔大，且形状不规则，管腔内有炎性细胞浸润，腺管上皮为单层立方上皮，有淋巴细胞位于基膜，上皮细胞及管腔内PAS阳性反应较弱；子宫血管层及卵巢血管内弹性膜较正常发情期变薄，且有断裂现象；子宫黏膜上皮为单层柱状上皮，胞核位于基底。LF在乏情期子宫腺上皮和卵巢中的表达水平高于发情期，而在子宫黏膜上皮中发情期的表达水平高于乏情期。患子宫蓄脓时犬子宫和卵巢中LF的表达水平均较低。综上表明，犬正常发情期与患子宫蓄脓时的子宫和卵巢组织结构特点显著不同，LF的表达水平也存在差异。     

Role of progestin-induced mammary-derived growth hormone in the pathogenesis of cystic endometrial hyperplasia in the bitch

Endogenous progesterone and synthetic progestins may induce hypersecretion of growth hormone (GH) of mammary origin, hyperplastic ductular changes in the mammary gland, and the development of cystic endometrial hyperplasia (CEH) in dogs. It was investigated whether progestin-induced mammary GH plays a role in the pathogenesis of CEH in the bitch. During 1 year, bitches with surgically excised mammary glands and healthy control bitches received medroxyprogesterone acetate (MPA). Before and after MPA treatment, uterine and mammary tissues were collected for histological, immunohistochemical, and RT-PCR examination. After MPA administration, the mammary tissue in the control dogs had differentiated into lobulo-alveolar structures and CEH was present in all uteri of both dog groups. In the MPA-exposed mammary tissue of the control dogs, GH could only be demonstrated immunohistochemically in proliferating epithelium. After treatment with MPA the dogs of both groups had immunohistochemically demonstrable GH in the cytoplasm of hyperplastic glandular uterine epithelial cells. RT-PCR analysis of the mammary gland tissue after MPA administration demonstrated a significant higher GH gene, and lower GHR gene expression than before treatment. In the uterus, the expression of the gene encoding for GH was significantly increased in the mastectomized dogs, whereas in the control dogs the expression of the gene encoding for insulin-like growth factor-I had significantly increased with MPA administration. MPA treatment significantly down regulated PR gene expression in the uterus in both dog groups. These results indicate that progestin-induced GH of mammary origin is not an essential component in the development of CEH in the bitch.     

Oestrogen and progesterone receptors in the uterine wall of bitches with cystic endometrial hyperplasia/pyometra

Fresh samples of uterine wall and peripheral plasma were obtained from 13 bitches of different breeds when they were treated for cystic endometrial hyperplasia/pyometra by ovariohysterectomy. The plasma samples were assayed for progesterone and 17beta-oestradiol, and the tissue samples were examined histopathologically and for the presence of oestrogen and progesterone receptors by an immunocytochemical method. The immunoreactivity was scored semiquantitatively, taking into account both the intensity and distribution of the specific staining of the receptors, by using a simplified scoring system. The scores for both oestrogen and progesterone receptors in the glandular epithelium were much lower, and in the endometrial stroma a mean (sd) score for oestrogen receptors was 46.0 (44.7) compared with 0 in comparable endometrial tissues from normal bitches at the same stage of the oestrous cycle.     

The immunohistochemical evaluation of estrogen receptor-alpha and progesterone receptors of normal, hyperplastic, and neoplastic endometrium in 88 pet rabbits

The expression of estrogen receptor-alpha (ER) and progesterone receptor (PR) in normal, hyperplastic, and neoplastic endometrium in rabbits was evaluated by immunohistochemistry. The tissues evaluated were 27 normal uteri, 19 cases with endometrial hyperplasia, and 42 adenocarcinomas. Sixteen of 27 cases of normal uteri (59.3%) and 13 out of 19 hyperplasias (68.4%) stained positive with both ER-alpha and PR. Adenocarcinomas were further subdivided into 26 papillary and 16 tubular/solid adenocarcinomas. Papillary adenocarcinoma infiltrated the myometrium late in the disease and caused attenuation of the myometrium. In contrast, tubular/solid adenocarcinoma invaded into the deep myometrium early in the disease without thinning of the myometrium. Twenty-one cases out of 26 (80.8%) cases of papillary adenocarcinoma were both ER-alpha and PR negative, whereas 15 out of 16 (93.8%) of the tubular/solid adenocarcinomas were positive for ER-alpha, PR, or both. The total immunoreactive scores of ER-alpha, PR, and mode of myometrial invasion were significantly different between histopathologic types. This suggests that there may be 2 different developmental pathways for uterine adenocarcinomas in the rabbit.     

Ultrasonography and Cystic Hyperplasia–Pyometra Complex in the Bitch

Cystic endometrial hyperplasia-pyometra complex is the most frequent and important endometrial disorder encountered in bitches. The pathogenesis of the disease is related to the activity of progesterone [Feldman and Nelson, Canine and Feline Endocrinology and Reproduction (1996) W.B. Saunders, Philadelphia]. Cystic endometrial hyperplasia (CEH) is an abnormal response of the bitch's uterus to ovarian hormones [De Bosschere et al. Theriogenology (2001) 55, 1509]. CEH is considered by many authors to be an exaggerated response of the uterus to chronic progestational stimulation during the luteal phase of the oestrous cycle, causing an abnormal accumulation of fluid within the endometrial glands and uterine lumen (De Bosschere et al. 2001). The resulting lesions of pyometra are due to the interaction between bacteria and hormones. The aim of this study was to evaluate if transabdominal uterine ultrasonography can be a useful and reliable diagnostic method to confirm Dow's [Veterinary Record (1958) 70, 1102] and De Bosschere's histopathological classification of CEH-pyometra complex. The study was carried out on 45 bitches with pyometra, 10 purebreds and 35 crossbreeds, 1-15 years old, 20% of which had whelped at least once. None of these animals had received exogenous oestrogen or progesterone treatment. On admission the 45 animals were in the luteal phase of the oestrus cycle. Clinical signs, blood parameters, uterine ultrasonography, bacterial swabs and uterine histopathological results were recorded. Results suggest that ultrasonographic examination is a useful and reliable tool for the diagnosis of cystic endometrial hyperplasia.     

Molecular studies on oestrogen α and progesterone receptors and histomorphometric analysis of canine uteri following aglepristone treatment

Aglepristone, a competitive progesterone antagonist, is successfully used in various progesterone-dependent conditions. This study investigated uterine histomorphometric analysis, and expressions of the oestrogen α receptor (ERα) and progesterone receptor (PR) in uteri of bitches following the single dose of aglepristone treatment. Twelve client-owned healthy diestrous bitches were used in the study. The single dose of aglepristone (Alizine^®, 10 mg/kg) was injected subcutaneously 5 days before ovariohysterectomy in the treatment group (n = 6); bitches without treatment served as a control group (n = 6). Uteri were collected for histomorphometric analysis, ERα and PR gene, and protein expressions studies. The mRNA expressions of ERα and PR were determined by RT-qPCR. Immunohistochemical analysis was used to evaluate the ERα and PR protein expressions using an H-score in five parts of the uterus. The results demonstrated glandular epithelium height significantly decreased (p < .05) and ERα mRNA increased (p < .01) in treated dogs. Of the treated bitches, lower expression levels of ERα were observed in the luminal epithelium, crypt and glandular epithelium, with higher expression in the endometrial stroma and myometrium (p < .05); however, PR expression decreased in the luminal epithelium, crypt and glandular epithelium (p < .01). In conclusion, reduction of the uterine glandular epithelium and ERα mRNA upregulation together with changes in ERα and PR expressions were observed in the treated bitches. However, changes in uterine ERα and PR expressions in the treated bitches depended on tissue layers. The treatment had no effect on serum oestradiol and progesterone levels.     

Severe hematometra in a dog with cystic endometrial hyperplasia/pyometra complex.

An 18-month-old, intact female German shepherd dog was presented for evaluation of severe, frank hemorrhage from the vulva. A complete blood count, serum biochemical analysis, and urinalysis supported acute hemorrhage. Abdominal radiographs were unremarkable. Abdominal ultrasound demonstrated that the uterine body and cranial vaginal lumen were fluid-filled and contained hyperechoic, polypoid masses that were suspected to be blood clots. Exploratory laparotomy revealed a mildly enlarged uterus with a diffuse, cystic endometrium; significant amounts of blood and blood clots within the lumen; and several focal accumulations of yellow fluid presumed to be a purulent exudate. Histopathology confirmed severe, cystic, endometrial hyperplasia and pyometra complex.     

Use of a low dose prostaglandin F2 alpha in bitches

The dosage of Prostaglandin F2 alpha used until the present (100, 250 and 1000 micrograms/kg bw), in order to treat pyometra in the bitch, was accompanied with side effects such as salivation, vomiting and diarrhea. In the present work, the efficiency of low dose Prostaglandin (20 micrograms/kg bw) was examined in two different groups of patients: Group 1: Included 9 bitches pregnant for a period of 5-7 weeks duration. Initially the bitches were treated 3 or 4 times per day with Prostaglandin F2 alpha. In these cases abortion took place within 4 to 11 days. Group 2: 12 dogs, suffering from pyometra, were treated 3 times per day with PGF2 alpha for 8 days. In 9 dogs the pyometra resolved and the bitches came in estrus 2-5 months after treatment. 7 bitches have been mated and 6 of these gave birth to healthy litters. During a follow-up period of at least 10 months there has not been a reoccurrence of pyometra. In 3 out of the 12 dogs the uteri were still enlarged after 8 days of treatment. These bitches underwent ovariohysterectomy and a cystic hyperplasia of the endometrium was diagnosed histologically. The low dose (20 micrograms/kg BW) Prostaglandin F2 alpha induced in all dogs the expulsion of the uterine contents. Side effects during the treatment were not observed.     

Measurement of C‐reactive protein and Prostaglandin F2α Metabolite Concentrations in Differentiation of Canine Pyometra and Cystic Endometrial Hyperplasia/Mucometra

Canine pyometra is a dioestrus period disease in which systemic inflammatory response syndrome (SIRS) is a common outcome due to the response of the body to the bacterial infection. The purpose of this study was i) to differentiate canine pyometra and cystic endometrial hyperplasia (CEH)/mucometra by measuring serum C‐reactive protein (CRP) and prostaglandin F_2α metabolite (PGFM) concentrations in blood and ii) to compare serum concentrations of CRP and PGFM in bitches with a pathological uterus (pyometra or CEH/mucometra) to concentrations in bitches with a healthy uterus. Mean CRP concentrations were found significantly higher (p < 0.001) in dogs with pyometra compared to those with CEH/mucometra or healthy uterus. However, no statistical difference could be detected between the groups for mean PGFM concentrations. Mean white blood cell count (WBC), alkaline phosphatase (ALP) and total protein concentrations were found significantly higher (p < 0.001) in dogs with pyometra. Escherichia coli was the most frequently isolated microorganism from dogs with pyometra (64.3%). Edwardsiella spp. was detected in a single case of pyometra for the first time. In conclusion, our results demonstrate that serum CRP concentrations were increased in dogs with pyometra and thus we conclude that serum CRP concentration but not PGFM might be useful as a marker to differentiate a case of CEH/mucometra from pyometra in female dogs. To the authors' knowledge, this is the first report in which Edwardsiella spp. has been isolated in the canine uterus.     

Uterine neoplasia in 13 cats.

Thirteen uterine tumors were diagnosed in 13 cats and accounted for 0.29% of all feline neoplasms received during a 9.6-year period. Age at diagnosis ranged from 3 to 16 years; median 9 years. Six were Domestic Shorthair cats, and 7 were purebred cats of 5 different breeds. Eight adenocarcinomas and 1 mixed Müllerian tumor (adenosarcoma) comprised the endometrial tumors. Myometrial tumors included 3 leiomyomas and 1 leiomyosarcoma. One of the adenocarcinomas developed in the uterine stump of an ovariohysterectomized cat; the other cats were sexually intact. Concurrent mammary adenocarcinoma was diagnosed in 1 cat with uterine adenocarcinoma and in another with uterine leiomyoma. Tumors were discovered during elective ovariohysterectomy in 2 cats, but at least 3 others had experienced reproductive problems (infertility or pyometra). Five cats presented for abdominal or pelvic masses. Endometrial adenocarcinomas were positive immunohistochemically for cytokeratins and negative for smooth muscle actin (SMA): 1 of 6 cats was positive for vimentin and 4 of 8 were positive for estrogen receptor-alpha (ER alpha). Adenosarcoma stromal cells were positive for vimentin and ER alpha but negative for cytokeratins and SMA. Smooth muscle tumors were positive for vimentin and SMA and negative for cytokeratins. Leiomyomas, but not the leiomyosarcomas, were positive for ER alpha. Adenocarcinomas in 4 cats had metastasized by the time of ovariohysterectomy. Two other cats were euthanized 5 months after ovariohysterectomy; at least one of these cats had developed an abdominal mass that was not examined histologically. Only 2 cats with endometrial adenocarcinoma had disease-free intervals longer than 5 months after surgery. Metastasis was not detected in any mesenchymal tumor; however, these cats were either euthanized on discovery of the tumor or the tumor was first detected at necropsy.     

Lectin‐binding Sites on the Normal and Pathologic Uterus of Sows

The lectin‐binding pattern was compared in the normal and pathological uterus of sows during the ovarian cycle. The following biotinylated lectins were used: Con A, DBA, SBA, PNA, RCA‐I, UEA‐I and WGA. Glycoconjugate labelling showed differences between phases of ovarian cycle and presence of morphologic lesions. Cystic endometrial hyperplasia increased the RCA‐I reaction in the apical region of the glandular epithelium. There was higher intensity of labelling of WGA in the glandular epithelium in uteri with endometritis. In addition, increased Con A binding in the glandular epithelium and mild reduction of UEA‐I reactivity in the glycocalyx of the glandular epithelium were detected in the cases of endometritis. The results of this study show that morphologic alterations modify the sugar pattern in the porcine uterus. These modifications in glycoconjugates may be one of the reasons for decreased fertility in sows.     

C-reactive protein in the differentiation of pyometra from cystic endometrial hyperplasia/mucometra in dogs

Hematological parameters, plasma C-reactive protein (CRP), and tumor necrosis factor alpha were analyzed in 64 dogs with a presumptive diagnosis of pyometra. Final diagnosis (i.e., pyometra or cystic endometrial hyperplasia [CEH]) was determined by histopathology. As a single test, the percentage of band neutrophils had the highest sensitivity in the prediction of pyometra (sensitivity, 94%). The combination of percentage of bands and CRP had the highest sensitivity (97.7%; specificity, 75%) in predicting the presence of pyometra. The most common clinical signs noted in the study were vaginal discharge, polyuria, polydipsia, lethargy, and gastrointestinal signs. A combination of three or more of these clinical signs was significantly associated with pyometra.     

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.     

犬子宫内膜炎的新分类：从解剖学和组织病理学角度分析

本研究旨在通过优化对犬子宫内膜炎的分类,提高其在临床上的诊断率,为进一步探讨犬子宫内膜炎的标准分类提供一定的理论依据。对40只母犬进行卵巢子宫摘除术,通过观察患犬有无临床症状、子宫内膜结构在组织学上有无囊性扩张、内膜与肌层厚度(Endo/Myo)比值、基质成分和炎性细胞浸润情况,将犬子宫内膜炎进行更深入的分类。结果表明,可将子宫内膜炎在组织病理学上大致分为两组,临床症状组和无临床症状组,临床症状组又可分为无炎症类、轻度炎性浸润类、重度炎性浸润类(增生)和重度炎性浸润类(萎缩)四类,无临床症状组包括健康类和内膜囊性增生类(CEH)。本研究为制定犬子宫内膜炎的标准分类提供了一种较客观的判定方法。     

绵羊妊娠识别、建立和维持的信号系统

妊娠的建立和维持归因于胚体的信号和黄体对孕酮的产生,在反刍动物,胚体滋养层分泌的激素抑制子宫内膜产生前列腺素PGF2α。在发情周期的绵羊,孕酮下调子宫内膜腔上皮和子宫腺上皮孕酮受体基因的表达,并伴随着上皮雌激素受体和催产素受体的增加。在催产素的作用下,子宫开始分泌溶黄体作用的前列腺素F2α。在妊娠绵羊,孕体滋养层产生的干扰素可作用于子宫内膜而直接抑制雌激素受体基因和催产素受体基因的转录。孕酮、干扰素、胎盘催乳素和生殖激素共同组成了一个"作用网络"来调节子宫的功能分化和子宫腺的形态发生,从而维持绵羊妊娠。本文综述了绵羊妊娠识别、建立和维持的信号系统。     

犬子宫蓄脓的病因及诊治

犬子宫蓄脓是临床上常见的产科疾病,主要发生在犬发情后期,根据临床症状可将其分为开放型子宫蓄脓和闭锁型子宫蓄脓。犬子宫蓄脓是在子宫内膜囊性增生、孕酮浓度增加、雌激素浓度降低和细菌感染等因素作用下子宫发生的炎性病变。作者对犬子宫蓄脓的病因、诊断及治疗进行了综述。     

Immunohistochemical Expression of Cyclooxygenase‐2 (COX‐2) in Feline Endometrial Adenocarcinoma and in Normal and Hyperplastic Endometria

Cyclooxygenase‐2 (COX‐2) is overexpressed in several human and animal neoplasms, including the human endometrial carcinoma. It has been suggested as a prognostic marker and a potential therapeutic target. This study aimed to (i) clarify histological aspects of feline endometrial adenocarcinomas (FEA) of the papillary serous type and (ii) characterize COX‐2 immunohistochemical expression in normal, hyperplastic and neoplastic endometrium in this species. Archived paraffin‐embedded tissue samples of 33 FEA, eight cystic endometrial hyperplasias (CEHs) and 21 samples of normal, healthy endometrium in the follicular (FS; n = 10) and luteal (LS; n = 11) stages were evaluated. Histological evaluation of haematoxylin and eosin‐stained sections of the FEA revealed a papillary proliferation of neoplastic cells of serous type, accompanied by clear and multinucleated cells. Other architectural arrangements mainly included solid and tubular growth. Randomly distributed areas of necrosis within the tumours were commonly observed. Invasion of the myometrium, of the serosa and of the vascular and/or lymphatic vessels was not constant features. The mean number of mitoses was higher in FEA compared to non‐neoplastic endometrium. COX‐2 scores were lower in FEA (p = 0.003) and CEH (p = 0.05) when compared to normal epithelium (NE). The loss of the membrane apical reinforcement in epithelial cells was observed in FEA samples, which was accompanied by the dislocation of COX‐2 labelling into the cytoplasm and the perinuclear area; in contrast, in epithelial cells in the healthy and hyperplastic endometria, the immunoreaction showed the characteristic pattern of apical membrane reinforcement, suggestive of the membrane polarization. COX‐2 epithelial scores were higher in the FS than in the LS. No differences were found in stromal COX‐2 expression between normal, CEH and FEA groups, but it was higher in the LS than in the FS. In summary, loss of COX‐2 compartmentalization in neoplastic epithelial cells might be one of the molecular events underlying endometrial carcinogenesis.     

Scanning electron microscopy of pathologic changes in the epithelial surfaces of the uterus and uterine tubes of cows

Genital tracts from 15 cows with catarrhal and purulent inflammation of the uterus and uterine tubes, cystic hyperplasia of the endometrium, or hydrosalpinx were evaluated by the use of scanning electron microscopy to determine epithelial changes associated with these conditions. Uterine epithelium was revealed to be easily damaged, even in the course of mild inflammation, whereas epithelium of the uterine tube was more resistant.