Search Results (5)

Mammalian spermatozoa undergo a series of physiological and biochemical changes in the oviduct that lead them to acquire the ability to fertilize eggs. During their transit in the oviduct, spermatozoa face a series of environmental changes that can affect sperm viability. A series of ion channels and transporters, as well as the sperm cytoskeleton, allow spermatozoa to remain viable and functional. Cl⁻ channels such as TMEM16A (calcium-activated chloride channel), CFTR (cystic fibrosis transmembrane conductance regulator), and ClC3 (chloride voltage-gated channel 3) are some of the ion transporters involved in maintaining cellular homeostasis. They are expressed in mammalian spermatozoa and are associated with capacitation, acrosomal reaction, and motility. However, little is known about their role in maintaining sperm volume. Therefore, this study aimed to determine the mechanism through which TMEM16A maintains sperm volume during capacitation. The effects of TMEM16A were compared to those of CFTR and ClC3. Spermatozoa were capacitated in the presence of specific TMEM16A, CFTR, and ClC3 inhibitors, and the results showed that only TMEM16A inhibition increased acrosomal volume, leading to changes within the acrosome. Similarly, only TMEM16A inhibition prevented actin polymerization during capacitation. Further analysis showed that TMEM16A inhibition also prevented ERK1/2 and RhoA activation. On the other hand, TMEM16A and CFTR inhibition affected both capacitation and spontaneous acrosomal reaction, whereas ClC3 inhibition only affected the spontaneous acrosomal reaction. In conclusion, during capacitation, TMEM16A activity regulates acrosomal structure through actin polymerization and by regulating ERK1/2 and RhoA activities. Full article

The purpose of this review is to present reasons for pregnancy loss in dogs. Termination of pregnancy can occur at any stage of gestation, sometimes even before pregnancy is diagnosed. If embryonic death occurs before day 35 of gestation, the embryo is absorbed. Fetal death in the second half of gestation leads to abortion or fetal emphysema, maceration, or mummification. Abnormal embryonic development, competition between placental sites, or genetic abnormalities of the embryo(s) can lead to termination of pregnancy. Maternal factors that alter ovarian function or the environment in the oviducts and uterus, such as cystic endometrial hyperplasia or inflammation, can lead to pregnancy loss. Abnormalities of the placenta, uterine torsion, metrocoele, environmental stress, and malnutrition can have detrimental effects on fetal development. Several drugs or medications can also have embryotoxic/teratogenic effect. Endocrinological disorders such as hypoluteodism, gestational diabetes, and hypothyroidism can be reasons for pregnancy failure. Several bacteria, protozoa, and viruses can cause pregnancy loss in dogs. Etiological diagnoses of pregnancy loss in dogs are challenging as the exact causes are not always obvious; so, a multi-faceted approach is required. Full article

Background: Adenomatoid tumor (AT) is a rare benign neoplasm of mesothelial origin, which mainly occurs in the male and female genital tracts. The most common site for AT occurrence in women is the uterus, which makes the presentation in the fallopian tube(s) a rarity with an incidence of approximately 0.5%. The reported extragenital sites include serosal surfaces, adrenal glands, and visceral organs, are even less common. Macroscopically, ATs present as white-grayish or yellowish irregular yet circumscribed firm nodules, often containing cystic components. Owing to a vast array of histomorphological growth patterns, ATs tend to mimic malignancy and trigger overresection. Such clinical situations have been described by several studies for the ovaries, uterus, and fallopian tubes, underlining the importance of differential diagnosis in order to avoid superfluous treatment. Methods: Herein, we report a presentation of an AT at the oviductal lumen, detected incidentally during prophylactic bilateral salpingo-oophorectomy in a 67-year-old patient with a BRCA1 mutation. Results: Immunohistochemical staining revealed a positive expression for calretinin, WT1, and cytokeratin 7, and negative expression for both PAX8 and CD34, thus confirming the diagnosis of AT and excluding tubal malignancy. Conclusions: This report, with a concise review of the global literature on tubal AT, brings attention to the solitary and asymptomatic nature of the tumor. With a clear diagnosis, no surgical radicality is necessary. Full article

Infectious bronchitis virus (IBV) is an avian coronavirus that causes respiratory disease but can affect the reproductive tract of laying-type chickens. If infection occurs in pullets, false layer syndrome, which is characterized by the development of large, fluid-filled cystic oviducts, can occur. Recently, IBV strain DMV/1639 has been detected in parts of Canada and the U.S., where false layer syndrome has occurred, though it is not clear if IBV is the sole cause or if age at infection is an influencing variable. Our study investigates the role and timing of IBV infection on the development of false layer syndrome, using the IBV types DMV/1639 and Massachusetts (Mass). Six groups of 120 SPF chickens were challenged at either three, seven, or fourteen days of age, using either DMV/1639 or Mass IBV. Cystic oviducts were seen in all the challenged groups, and the pullets challenged at 14 days of age had fewer cystic oviducts than pullets challenged at 3 or 7 days of age. The highest percentage of severe histology lesion scores were seen in the 3-day challenge groups. The data collected in this experiment confirm that IBV DMV/1639 causes cystic oviducts and indicate that age at infection plays a role in the pathogenesis of false layer syndrome. Full article

Infectious bronchitis virus (IBV) infection causes significant economic losses to various sectors of the poultry industry worldwide. Over the past few years, the incidence of false layer syndrome in Eastern Canadian layer flocks has been associated with the increased prevalence of the IBV Delmarva (DMV)/1639 strain. In this study, 1-day-old specific-pathogen-free (SPF) hens were infected with the Canadian DMV/1639 strain and observed until 16 weeks of age in order to determine if the IBV DMV/1639 strain is causing false layer syndrome. Early after infection, the virus showed a wide tissue distribution with characteristic gross and histopathological lesions in the respiratory tract and kidney. Around 60–70% of the infected hens demonstrated continuous cloacal viral shedding until the end of the experiment (at 16 weeks) which was associated with high IBV genome loads detected in the cecal tonsils. The experiment confirmed the field observations that the Canadian DMV/1639 strain is highly pathogenic to the female reproductive tract causing marked cystic lesions in the oviduct. Moreover, significant histopathological damage was observed in the ovary. Our study provides a detailed description of the pathological consequences of the IBV DMV/1639 strain circulating in an important poultry production sector. Full article