The structure and function of the cervix during pregnancy

Nott, James P.; Bonney, Elizabeth A.; Pickering, James D.; Simpson, Nigel

doi:10.1016/j.tria.2016.02.001

Cited by 61 publications

(66 citation statements)

References 45 publications

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“…The sphincter-like effect of the collagenous and muscular fibers at the internal os has its greatest strength during the luteal phase of ovulation and relaxes up to 2 days prior to menstruation. 21 Our results showed that the greatest speeds at the internal os were obtained during the secretory phase of the endometrium, corresponding to the luteal ovarian phase. Further research could incorporate SWS obtained during the first few days of menstruation, when the internal os should be at its softest.…”

Section: Discussionmentioning

confidence: 56%

“…In the nongravid state the uterine cervix measures approximately 25 mm in length and 20 to 25 mm in total width, equating to an approximately 10mm width of collagenous and smooth muscle tissue around the central canal. 21 Histologic evidence shows that the cervical canal is surrounded by a layer of longitudinal smooth muscle fibers adjacent to the canal. Wrapping circumferentially around the longitudinal layer is a layer of smooth muscle and collagenous cells (Figure 3).…”

Section: Shear Wave Region Of Interest Placementmentioning

confidence: 99%

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Shear Wave Elastography on the Uterine Cervix: Technical Development for the Transvaginal Approach

O'Hara

Zelesco

Sun

2018

J of Ultrasound Medicine

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Section: Discussionmentioning

confidence: 56%

Section: Shear Wave Region Of Interest Placementmentioning

confidence: 99%

Shear Wave Elastography on the Uterine Cervix: Technical Development for the Transvaginal Approach

O'Hara

Zelesco

Sun

2018

J of Ultrasound Medicine

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“…The greater abundances of these bacteria in the vagina may be due to the anatomy of the cow's reproductive tract but some mechanism likely reduces their presence in the uterus (Songer, 1996;Singh et al, 2008). Mechanisms may include a physical barrier provided by the cervix (Singer and Jordan, 2009;Nott et al, 2016); competition with other microbes more suited to the environment (Recine et al, 2016); antagonistic environment created by mutualistic microbes in coordination with the host (Klebanoff et al, 1991;Boskey et al, 2001;Kaewsrichan et al, 2006); or simply a constant introduction of these bacteria in the vagina from feces, providing constant opportunities for colonization.…”

Section: Discussionmentioning

confidence: 99%

112 Vaginal and uterine bacterial communities in postpartum lactating cows

Clemmons¹,

Dantas²,

Franco³

et al. 2017

Journal of Animal Science

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Reproductive inefficiency in cattle has major impacts on overall productivity of cattle operations, increasing cost of production, and impacting the sustainability of the cattle enterprise. Decreased reproductive success and associated disease states have been correlated with the presence of specific microbes and microbial community profiles, yet details of the relationship between microbial communities and host physiology are not well known. The present study profiles and compares the microbial communities in the bovine uterus and vagina using 16S rRNA sequencing of the V1-V3 hypervariable region at the time of artificial insemination. Significant differences (p < 0.05) between the vaginal and uterine communities were observed at the level of α-diversity metrics, including Chao1, Shannon's Diversity Index, and observed OTU. Greater clustering of vaginal OTU was apparent in principal coordinate analysis compared to uterine OTU, despite greater diversity in the vaginal community in both weighted and unweighted UniFrac distance matrices (p < 0.05). There was a significantly greater relative abundance of unassigned taxa in the uterus (p = 0.008), otherwise there were few differences between the overall community profiles. Both vaginal and uterine communities were dominated by Firmicutes, although the relative abundance of rRNA sequences corresponding to species in this phylum was significantly (p = 0.007) lower in the uterine community. Additional differences were observed at the genus level, specifically in abundances within Clostridium (p = 0.009), Anaerofustis (p = 0.018), Atopobium (p = 0.035), Oscillospira (p = 0.035), 5-7N15 (p = 0.035), Mycoplasma (p = 0.035), Odoribacter (p = 0.042), and within the families Clostridiaceae (p = 0.006), Alcaligenaceae (p = 0.021), and Ruminococcaceae (p = 0.021). Overall, the comparison revealed differences and commonalities among bovine reproductive organs, which may be influenced by host physiology. The increased abundance of unassigned taxa found in the uterus may play a significant biological role in the reproductive status of the animal. The study represents an initial dataset for comparing bacterial communities prior to establishment of pregnancy.

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“…Throughout gestation, the cervix has to be closed and rigid to protect and hold the fetus inside the uterus, while at term and during labor, it must be dilated and soften to help the newborn's passage. This transformation is supported by cervical ripening (Nott et al, 2016). Collagen, elastin, macromolecular components, and smooth muscle, which constitute the cervix, are altered by a complex biologic mechanism in cervical remodeling; however, the full process has not yet been fully clarified.…”

Section: Introductionmentioning

confidence: 99%

α-Tocopherol Potentiates the Cervical Resistance Decreasing Effects of COX Inhibitors in Pregnant Rats: The Putative Role of Cyclooxygenase-2 Inhibition

Kothencz

Hajagos-Tóth

Szűcs

et al. 2018

J Pharmacol Exp Ther

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Vitamin E and their analogs as antioxidant and lipid-soluble compounds can have diverse effects on the physiologic processes. By binding to receptors and enzymes, they may modify the action of drugs. It has been proved that a-tocopherol succinate modifies the effects of b 2 agonist terbutaline and cyclooxygenase (COX) inhibitors on rat trachea and myometrium. Our aim was to investigate how a-tocopherol and COX inhibitors may influence cervical resistance in rats. The cervical resistance of nonpregnant and 22 day-pregnant Sprague-Dawley rats was determined in an isolated organ bath in vitro. a-Tocopherol-succinate (10 2 7 M) was used, whereas the COX-nonselective diclofenac (10 2 6 M), the COX-2-selective rofecoxib (10 26 M), and the COX-1-selective SC-560 (10 26 M) were applied as inhibitors. The COX activities of the cervices were measured by enzyme immunoassay. The modifying effect of single doses of COX inhibitors and tocopherol on the onset of labor was investigated in vivo. The cervical resistance of nonpregnant samples was not changed by either a-tocopherol or COX inhibitors. On pregnant cervices, tocopherol, diclofenac, or rofecoxib pretreatment decreased cervical resistance that was further reduced by COX inhibitors after pretreatment with tocopherol. a-Tocopherol elicited a significant COX-2 enzyme inhibition in cervical samples from pregnant rats. By coadministration of tocopherol and rofecoxib, the parturition was initiated earlier than in the other groups. It is supposed that COXs play a significant role not only in cervical ripening, but also in the contraction of the cervical smooth muscle a few hours before parturition. This latter action may be developed by COX-2-liberated prostaglandins.

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The structure and function of the cervix during pregnancy

Cited by 61 publications

References 45 publications

Shear Wave Elastography on the Uterine Cervix: Technical Development for the Transvaginal Approach

Shear Wave Elastography on the Uterine Cervix: Technical Development for the Transvaginal Approach

112 Vaginal and uterine bacterial communities in postpartum lactating cows

α-Tocopherol Potentiates the Cervical Resistance Decreasing Effects of COX Inhibitors in Pregnant Rats: The Putative Role of Cyclooxygenase-2 Inhibition

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