Peripheral levels of vascular endothelial growth factor (VEGF) are higher in gonadotropin stimulated as compared to natural ovarian cycles

Licht, Peter B.; Neuwinger, J.; Fischer, O.; Siebzehnrübl, E.; Wildt, L.

doi:10.1055/s-2001-17402

Cited by 17 publications

(19 citation statements)

References 19 publications

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“…Although tissue analysis clearly demonstrated involvement of VEGF, PD‐ECGF, and TSP‐1 in various steps of the menstrual cycle, there is substantial controversy about the cyclicity of angiogenic factors in serum or plasma samples from premenopausal women. No cyclic variation of circulating VEGF has been detected to date in plasma samples 36, 42, 43. Similarly, we could not demonstrate a significant difference in VEGF, PD‐ECGF, or TSP‐1 concentrations in plasma samples taken during the proliferative versus secretory phase of the female reproductive cycle.…”

Section: Discussioncontrasting

confidence: 85%

Modification of phenol–formaldehyde resol resins by lignin, starch, and urea

Turunen

Alvila

Pakkanen

et al. 2003

J of Applied Polymer Sci

111

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Lignin-based chemicals, starch, and urea were used as modifiers for phenol-formaldehyde resol resins. The effects of the addition stage of the modifiers used in the synthesis of the resins and the type of modification reagent on the structures of the resins and their molar masses and reactivities were investigated. The modifications with corn starch and lignin promoted condensation; this was verified by increased molar masses and high ratios of methylene bridges to the sum of free ortho and para aromatic groups with respect to the corresponding reference resin without a modification reagent. The later the modifier was added to the resin condensation mixture, the more methylene bridges were formed with respect to the amounts of free ortho and para aromatic groups. In addition, when urea or wheat starch was added in the later condensation stage, the final condensation also reached high stages. The modifications with lignosulfonate and starch, as well as the early addition of urea, enhanced p-pЈ bridge structures. The lowest condensation stage and, therefore, the highest reactivity were found when wheat starch was added with the starting reagents. The curing heat of the wheat-starch-modified resins decreased according to the deferred addition point of starch.

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Section: Discussioncontrasting

confidence: 85%

Modification of phenol–formaldehyde resol resins by lignin, starch, and urea

Turunen

Alvila

Pakkanen

et al. 2003

J of Applied Polymer Sci

111

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“…Those factors, and possibly others, may act in concert with estrogen to promote increase in CBF during the luteal phase. We did not measure the levels of those nonsteroidal factors in the present study; however, it is known that there is a correlation between the serum level of VEGF and relaxin and the number of oocytes/corpora lutea and steroidal hormones during natural or stimulated cycles (1,17,18).…”

Section: Discussionmentioning

confidence: 99%

“…Vascular endothelial growth factor (VEGF) is known to be secreted from the ovaries, and its levels are increased during controlled ovarian stimulation (18). VEGF was reported to increase local CBF in a rat model (38).…”

Section: Discussionmentioning

confidence: 99%

Cerebral blood flow is increased during controlled ovarian stimulation

Nevo¹,

Soustiel²,

Thaler³

2007

American Journal of Physiology-Heart and Circulatory Physiology

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Estrogen appears to enhance cerebral blood flow (CBF). An association between CBF and physiologically altered hormonal levels due to menstrual cycle, menopause, or exogenous manipulations such as ovariectomy or hormone replacement therapy has been demonstrated. The purpose of this study was to determine the association between ovarian stimulation and CBF in vivo by measuring blood flow in the internal carotid artery (ICA) after pituitary suppression and during controlled ovarian stimulation in women undergoing in vitro fertilization treatment cycles. ICA volume flows were measured by angle-independent dual-beam ultrasound Doppler in 12 women undergoing controlled ovarian stimulation. Measurements were performed after pituitary/ovarian suppression, in the late follicular phase, and at midluteal phase. Blood flow in the ICA increased by 22.2% and 32% in the late follicular and midluteal phases compared with the respective values obtained during ovarian suppression (P Ͻ 0.0005 and P Ͻ 0.0001, respectively). There was a significant correlation between increments in estrogen levels and increments in CBF when the late follicular phase was compared with the ovarian suppression period (r ϭ 0.8, P Ͻ 0.001). Mean blood flow velocity significantly increased (by 15.7% and 16.9%, respectively) and cerebral vascular resistance significantly decreased (by 17.6% and 26.5%) during the late follicular and midluteal phases compared with respective measures during ovarian suppression. There was a significant correlation between an increase in estrogen levels and a decrease in cerebral vascular resistance when the late follicular phase was compared with the ovarian suppression period (r ϭ Ϫ0.6, P Ͻ 0.05). These changes imply sex hormone-associated intracranial vasodilation leading to increased CBF during controlled ovarian stimulation.estrogen; progesterone; angle-independent Doppler; in vitro fertilization RECENT REPORTS HAVE SUGGESTED that the cerebral circulation may be affected by hormonal status. Increased cerebral blood flow (CBF) velocities were observed in the presence of high levels of estradiol (3,25). Progesterone was shown to increase peripheral blood flow in pigs (24) and to have neuroprotective properties in male rats (12). However, there is little information regarding the effect of estrogen and progesterone on CBF in human subjects.During controlled ovarian stimulation that is utilized for in vitro fertilization (IVF) treatment cycles, there is a significant increase in serum estradiol levels during the hyperstimulated follicular phase and the luteal phase (13). The source of estrogen during an IVF cycle is the hyperstimulated follicles in the follicular phase and the corpora lutea during the luteal phase. Progesterone levels start to increase after the induction of final oocyte maturation by human chorionic gonadotropin (hCG), and supraphysiological levels are encountered during the luteal phase (11). Progesterone is secreted during the luteal phase from multiple corpora lutea that develop after trigger of oocyte ma...

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“…That said, although no tubal ectopic pregnancy had a serum VEGF !5 pg/ml, the overall values were widely spread over a range from 11.1 to 1056 pg/ml (Mueller et al 2004). Although serum VEGF concentrations are increased after ovarian stimulation in an IVF cycle (Licht et al 2001), they are still higher in tubal ectopic pregnancy than intrauterine pregnancy in this cohort of women (Fasouliotis et al 2004). Using an increased cut-off of 700 pg/ml, serum VEGF was able to distinguish a normal intrauterine pregnancy from a tubal ectopic pregnancy with a PPV of 70% and an abnormal intrauterine pregnancy from a tubal ectopic pregnancy with a PPV of 88% (Fasouliotis et al 2004).…”

Section: Vascular Endothelial Growth Factormentioning

confidence: 99%

Serum biomarkers of tubal ectopic pregnancy: current candidates and future possibilities

Cartwright¹,

Duncan²,

Critchley³

et al. 2009

Reproduction

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Ectopic pregnancy remains a considerable cause of maternal morbidity and mortality worldwide. Currently, it is diagnosed using a combination of transvaginal ultrasound and serial serum b-human chorionic gonadotrophin levels. Diagnosis is often delayed and these tests are time-consuming and costly, both psychologically to the patient and financially to health services. The development of a biomarker that can differentiate a tubal ectopic from an intrauterine implantation is therefore important. In the pre-genomic era, a one-by-one scientific approach has revealed over 20 candidate biomarkers that could be used as a test to diagnose ectopic pregnancy although at present their clinical utility is very limited. These biomarkers cluster into themes: markers of abnormal embryo/trophoblast growth, markers of abnormal corpus luteum function, markers of a growing pregnancy in the Fallopian tube, markers of inflammation and peritoneal irritation, and uterine markers of normal implantation. It is likely that this thematic approach will facilitate the identification of newer biomarkers using microarray technology and inform the development of investigative paradigms using multiple markers at the time of presentation.

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Peripheral levels of vascular endothelial growth factor (VEGF) are higher in gonadotropin stimulated as compared to natural ovarian cycles

Cited by 17 publications

References 19 publications

Modification of phenol–formaldehyde resol resins by lignin, starch, and urea

Modification of phenol–formaldehyde resol resins by lignin, starch, and urea

Cerebral blood flow is increased during controlled ovarian stimulation

Serum biomarkers of tubal ectopic pregnancy: current candidates and future possibilities

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