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Nathan J Hoeldtke

Publications and source records attributed to Nathan J Hoeldtke.

8 recordsLinked to original sources
PubMed2006

17-Hydroxyprogesterone caproate reverses induced vasoconstriction of the fetoplacental arteries by the thromboxane mimetic U46619.

OBJECTIVE: This study was undertaken to determine whether 17-hydroxyprogesterone caproate (17P) has a vasoactive effect on fetoplacental vasculature. STUDY DESIGN: Two cotyledons were obtained from each of 5 placentas. Baseline perfusion was established with Hanks-based solution. One cotyledon from each pair was then infused with perfusate to which U46619 a thromboxane sympathomimetic had been added. After 30 minutes, a dose of 17P was then administered to each cotyledon. Finally, a vasoconstricting dose of angiotensin II was administered to each cotyledon. Perfusion pressures were recorded throughout. Statistical analysis of pressure change for a single cotyledon was performed by using a paired t test. Statistical analysis of mean perfusion pressure difference between U46619 exposed and nonexposed cotyledons was analyzed by using a students t test. RESULTS: 17P did not significantly alter the perfusion pressure of the control cotyledon. (30.6 +/- 8.3 mm Hg vs 30.1 +/- 7.8 mm Hg P = .48). 17P administration significantly lowered the perfusion pressure of the U46619 preconstricted vessels in comparison with preadministration. (60.1 +/- 13 mm Hg vs 27.3 +/- 7.1 mm Hg P = .03). Both groups of cotyledons responded with vasoconstriction to angiotension II with no difference in response between groups (38.3 +/- 12 mm Hg vs 45.8 +/- 8.2 mm Hg P = .63). CONCLUSION: 17P reverses induced vasoconstriction by U46619 in fetoplacental arteries.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2005

Progesterone modulation of inflammatory cytokine production in a fetoplacental artery explant model.

OBJECTIVE: The purpose of this study was to determine if progesterone has an effect on fetoplacental artery production of inflammatory cytokines. STUDY DESIGN: Chorionic plate arteries were dissected from 5 placentas obtained from normal pregnancies after delivery at term. Arteries were incubated in Dulbecco's modified Eagle's medium (DMEM) alone, DMEM and lipopolysaccharide (LPS), DMEM with progesterone (P4), and DMEM with P4 and LPS. Samples of the tissue culture media were collected and evaluated for interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-10 (IL-10) by immunoassay. RESULTS: There was a significant decrease in the production of IL-6 in P4-exposed fetoplacental arteries after LPS stimulation (P < .001). IL-10 and TNF-alpha levels were similar in control and treatment groups after LPS exposure. CONCLUSION: Pretreating fetoplacental arteries with P4 significantly decreased the production of IL-6 after LPS stimulation without altering the production of TNF-alpha or IL-10.

Adult↗
PubMed2003

The effects of a cyclo-oxygenase II inhibitor on placental artery production of thromboxane and prostacyclin.

OBJECTIVE: The study was undertaken to determine the effects of a cyclo-oxygenase II inhibitor on fetoplacental artery production of prostacyclin and thromboxane A(2). STUDY DESIGN: Eight placentas were obtained from normal parturients at delivery and four chorionic plate arteries were dissected from each placenta. Arteries were incubated in media alone, media plus angiotensin II (1x10(-10) mol), media plus rofecoxib (300 ng/mL), or media plus angiotensin II and rofecoxib. Serial samples were assayed for metabolites of thromboxane B(2) and prostacyclin by enzyme-linked immunosorbent assay. Results were compared by analysis of variance, and P<.05 was considered significant. RESULTS: At 24 hours, 6-keto-prostaglandin F(1alpha) levels in the rofecoxib group (1.74+/-1.39 ng/mg tissue, P<.01) and the rofecoxib plus angiotensin II group (2.15+/-1.85 ng/mg tissue, P<.01) were significantly lower than levels in the control group (4.25+/-2.03 ng/mg tissue). Thromboxane B(2) levels were lower in the angiotensin II group (0.65+/-0.33 ng/mg tissue) than the control group (1.22+/-0.70 ng/mg tissue, P<.05). CONCLUSION: Cyclo-oxygenase II inhibition decreases the production of prostacyclin in fetoplacental arteries and alters the normal ratio of thromboxane A(2) to prostacyclin.

Angiotensin II↗
PubMed2003

Fetoplacental vascular tone is modified by magnesium sulfate in the preeclamptic ex vivo human placental cotyledon.

OBJECTIVE: The purpose of this study was to evaluate fetoplacental vascular tone and response to a vasoconstrictor in placentas of preeclamptic and normotensive pregnancies with and without the presence of magnesium sulfate. STUDY DESIGN: Two cotyledons from each placenta were selected from preeclamptic (n=8) and normotensive (n=7) pregnancies. In one cotyledon from each pair, the maternal circuit was perfused with magnesium sulfate. The fetal arteries were injected sequentially with angiotensin II (10(-10)mol and 10(-11.5) mol). Perfusion pressures and response to angiotensin II were compared, with regard to preeclampsia and exposure to magnesium sulfate. RESULTS: Perfusion pressure was higher in preeclamptic placentas, compared with normotensive placentas (30.4 mm Hg vs 24.4 mm Hg, P=.02). There was a decrease in perfusion pressure with exposure to magnesium sulfate in preeclamptic placentas (22.5 mm Hg, P<.01), but not in normotensive placentas. Fetoplacental vascular response to angiotensin II was not affected by preeclampsia or magnesium sulfate. CONCLUSION: In placentas from preeclamptic pregnancies there is increased fetoplacental perfusion pressure, which decreases with exposure to sulfate.

Angiotensin II↗
PubMed2003

Perinatal hospice. Comprehensive care for the family of the fetus with a lethal condition.

OBJECTIVE: To describe our experience in providing a program of structured interdisciplinary care for the families of fetuses prenatally diagnosed with a lethal congenital anomaly. STUDY DESIGN: We developed a comprehensive "perinatal hospice" program for the supportive care of families with fetuses known to have a lethal condition. Upon prenatal diagnosis of a lethal fetal condition, parents were presented with the option of elective pregnancy termination versus a multi-disciplinary program of ongoing supportive care until the time of spontaneous labor or until delivery was required for obstetric indications. We evaluated patient use of this new service and the natural history of pregnancies managed in this fashion. RESULTS: The population consisted of 33 patients carrying a fetus with a clearly delineated lethal anomaly. Twenty-eight (85%) chose to participate in the perinatal hospice program. Of these, 11/28 (39%) had an intrauterine fetal death and 17/28 (61%) delivered a live-born infant. Among the live-born infants were 12 vaginal deliveries, 4 preterm and 8 at term. Obstetric indications or maternal request resulted in cesarean delivery for 5/28 (18%), 4 preterm and 1 at term, all live born. All live-born infants died within 20 minutes to 2 months. There were no maternal complications. CONCLUSION: The availability of a structured program providing ongoing, comprehensive, multidisciplinary, supportive perinatal care offers a tangible and safe alternative to early elective pregnancy termination for patients carrying a fetus with a lethal congenital condition.

Adult↗